Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/mm/swapfile.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
| 5 | * Swap reorganised 29.12.95, Stephen Tweedie |
| 6 | */ |
| 7 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | #include <linux/mm.h> |
Ingo Molnar | 6e84f31 | 2017-02-08 18:51:29 +0100 | [diff] [blame] | 9 | #include <linux/sched/mm.h> |
Ingo Molnar | 2993002 | 2017-02-08 18:51:36 +0100 | [diff] [blame] | 10 | #include <linux/sched/task.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/hugetlb.h> |
| 12 | #include <linux/mman.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/kernel_stat.h> |
| 15 | #include <linux/swap.h> |
| 16 | #include <linux/vmalloc.h> |
| 17 | #include <linux/pagemap.h> |
| 18 | #include <linux/namei.h> |
Hugh Dickins | 072441e | 2011-06-27 16:18:02 -0700 | [diff] [blame] | 19 | #include <linux/shmem_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/blkdev.h> |
Hugh Dickins | 20137a4 | 2009-01-06 14:39:54 -0800 | [diff] [blame] | 21 | #include <linux/random.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/writeback.h> |
| 23 | #include <linux/proc_fs.h> |
| 24 | #include <linux/seq_file.h> |
| 25 | #include <linux/init.h> |
Hugh Dickins | 5ad6468 | 2009-12-14 17:59:24 -0800 | [diff] [blame] | 26 | #include <linux/ksm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <linux/rmap.h> |
| 28 | #include <linux/security.h> |
| 29 | #include <linux/backing-dev.h> |
Ingo Molnar | fc0abb1 | 2006-01-18 17:42:33 -0800 | [diff] [blame] | 30 | #include <linux/mutex.h> |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 31 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <linux/syscalls.h> |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 33 | #include <linux/memcontrol.h> |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 34 | #include <linux/poll.h> |
David Rientjes | 72788c3 | 2011-05-24 17:11:40 -0700 | [diff] [blame] | 35 | #include <linux/oom.h> |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 36 | #include <linux/frontswap.h> |
| 37 | #include <linux/swapfile.h> |
Mel Gorman | f981c59 | 2012-07-31 16:44:47 -0700 | [diff] [blame] | 38 | #include <linux/export.h> |
Tim Chen | 67afa38 | 2017-02-22 15:45:39 -0800 | [diff] [blame] | 39 | #include <linux/swap_slots.h> |
Huang Ying | 155b5f8 | 2017-07-06 15:40:31 -0700 | [diff] [blame] | 40 | #include <linux/sort.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
| 42 | #include <asm/pgtable.h> |
| 43 | #include <asm/tlbflush.h> |
| 44 | #include <linux/swapops.h> |
Johannes Weiner | 5d1ea48 | 2014-12-10 15:44:55 -0800 | [diff] [blame] | 45 | #include <linux/swap_cgroup.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 47 | static bool swap_count_continued(struct swap_info_struct *, pgoff_t, |
| 48 | unsigned char); |
| 49 | static void free_swap_count_continuations(struct swap_info_struct *); |
Lee Schermerhorn | d4906e1 | 2009-12-14 17:58:49 -0800 | [diff] [blame] | 50 | static sector_t map_swap_entry(swp_entry_t, struct block_device**); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 51 | |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 52 | DEFINE_SPINLOCK(swap_lock); |
Adrian Bunk | 7c363b8 | 2008-07-25 19:46:24 -0700 | [diff] [blame] | 53 | static unsigned int nr_swapfiles; |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 54 | atomic_long_t nr_swap_pages; |
Chris Wilson | fb0fec5 | 2015-12-04 15:58:53 +0000 | [diff] [blame] | 55 | /* |
| 56 | * Some modules use swappable objects and may try to swap them out under |
| 57 | * memory pressure (via the shrinker). Before doing so, they may wish to |
| 58 | * check to see if any swap space is available. |
| 59 | */ |
| 60 | EXPORT_SYMBOL_GPL(nr_swap_pages); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 61 | /* protected with swap_lock. reading in vm_swap_full() doesn't need lock */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | long total_swap_pages; |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 63 | static int least_priority = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | static const char Bad_file[] = "Bad swap file entry "; |
| 66 | static const char Unused_file[] = "Unused swap file entry "; |
| 67 | static const char Bad_offset[] = "Bad swap offset entry "; |
| 68 | static const char Unused_offset[] = "Unused swap offset entry "; |
| 69 | |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 70 | /* |
| 71 | * all active swap_info_structs |
| 72 | * protected with swap_lock, and ordered by priority. |
| 73 | */ |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 74 | PLIST_HEAD(swap_active_head); |
| 75 | |
| 76 | /* |
| 77 | * all available (active, not full) swap_info_structs |
| 78 | * protected with swap_avail_lock, ordered by priority. |
| 79 | * This is used by get_swap_page() instead of swap_active_head |
| 80 | * because swap_active_head includes all swap_info_structs, |
| 81 | * but get_swap_page() doesn't need to look at full ones. |
| 82 | * This uses its own lock instead of swap_lock because when a |
| 83 | * swap_info_struct changes between not-full/full, it needs to |
| 84 | * add/remove itself to/from this list, but the swap_info_struct->lock |
| 85 | * is held and the locking order requires swap_lock to be taken |
| 86 | * before any swap_info_struct->lock. |
| 87 | */ |
Colin Ian King | bfc6b1c | 2018-04-10 16:29:55 -0700 | [diff] [blame] | 88 | static struct plist_head *swap_avail_heads; |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 89 | static DEFINE_SPINLOCK(swap_avail_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 91 | struct swap_info_struct *swap_info[MAX_SWAPFILES]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | |
Ingo Molnar | fc0abb1 | 2006-01-18 17:42:33 -0800 | [diff] [blame] | 93 | static DEFINE_MUTEX(swapon_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 95 | static DECLARE_WAIT_QUEUE_HEAD(proc_poll_wait); |
| 96 | /* Activity counter to indicate that a swapon or swapoff has occurred */ |
| 97 | static atomic_t proc_poll_event = ATOMIC_INIT(0); |
| 98 | |
Huang Ying | 81a0298 | 2017-09-06 16:24:43 -0700 | [diff] [blame] | 99 | atomic_t nr_rotate_swap = ATOMIC_INIT(0); |
| 100 | |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 101 | static struct swap_info_struct *swap_type_to_swap_info(int type) |
| 102 | { |
| 103 | if (type >= READ_ONCE(nr_swapfiles)) |
| 104 | return NULL; |
| 105 | |
| 106 | smp_rmb(); /* Pairs with smp_wmb in alloc_swap_info. */ |
| 107 | return READ_ONCE(swap_info[type]); |
| 108 | } |
| 109 | |
Hugh Dickins | 8d69aae | 2009-12-14 17:58:45 -0800 | [diff] [blame] | 110 | static inline unsigned char swap_count(unsigned char ent) |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 111 | { |
Daniel Jordan | 955c97f | 2018-06-14 15:26:21 -0700 | [diff] [blame] | 112 | return ent & ~SWAP_HAS_CACHE; /* may include COUNT_CONTINUED flag */ |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 113 | } |
| 114 | |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 115 | /* returns 1 if swap entry is freed */ |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 116 | static int |
| 117 | __try_to_reclaim_swap(struct swap_info_struct *si, unsigned long offset) |
| 118 | { |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 119 | swp_entry_t entry = swp_entry(si->type, offset); |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 120 | struct page *page; |
| 121 | int ret = 0; |
| 122 | |
Huang Ying | f6ab1f7 | 2016-10-07 17:00:21 -0700 | [diff] [blame] | 123 | page = find_get_page(swap_address_space(entry), swp_offset(entry)); |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 124 | if (!page) |
| 125 | return 0; |
| 126 | /* |
| 127 | * This function is called from scan_swap_map() and it's called |
| 128 | * by vmscan.c at reclaiming pages. So, we hold a lock on a page, here. |
| 129 | * We have to use trylock for avoiding deadlock. This is a special |
| 130 | * case and you should use try_to_free_swap() with explicit lock_page() |
| 131 | * in usual operations. |
| 132 | */ |
| 133 | if (trylock_page(page)) { |
| 134 | ret = try_to_free_swap(page); |
| 135 | unlock_page(page); |
| 136 | } |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 137 | put_page(page); |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 138 | return ret; |
| 139 | } |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 140 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | /* |
Hugh Dickins | 6a6ba83 | 2009-01-06 14:39:51 -0800 | [diff] [blame] | 142 | * swapon tell device that all the old swap contents can be discarded, |
| 143 | * to allow the swap device to optimize its wear-levelling. |
| 144 | */ |
| 145 | static int discard_swap(struct swap_info_struct *si) |
| 146 | { |
| 147 | struct swap_extent *se; |
Hugh Dickins | 9625a5f | 2009-12-14 17:58:42 -0800 | [diff] [blame] | 148 | sector_t start_block; |
| 149 | sector_t nr_blocks; |
Hugh Dickins | 6a6ba83 | 2009-01-06 14:39:51 -0800 | [diff] [blame] | 150 | int err = 0; |
| 151 | |
Hugh Dickins | 9625a5f | 2009-12-14 17:58:42 -0800 | [diff] [blame] | 152 | /* Do not discard the swap header page! */ |
| 153 | se = &si->first_swap_extent; |
| 154 | start_block = (se->start_block + 1) << (PAGE_SHIFT - 9); |
| 155 | nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9); |
| 156 | if (nr_blocks) { |
| 157 | err = blkdev_issue_discard(si->bdev, start_block, |
Christoph Hellwig | dd3932e | 2010-09-16 20:51:46 +0200 | [diff] [blame] | 158 | nr_blocks, GFP_KERNEL, 0); |
Hugh Dickins | 9625a5f | 2009-12-14 17:58:42 -0800 | [diff] [blame] | 159 | if (err) |
| 160 | return err; |
| 161 | cond_resched(); |
| 162 | } |
Hugh Dickins | 6a6ba83 | 2009-01-06 14:39:51 -0800 | [diff] [blame] | 163 | |
Hugh Dickins | 9625a5f | 2009-12-14 17:58:42 -0800 | [diff] [blame] | 164 | list_for_each_entry(se, &si->first_swap_extent.list, list) { |
| 165 | start_block = se->start_block << (PAGE_SHIFT - 9); |
| 166 | nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9); |
Hugh Dickins | 6a6ba83 | 2009-01-06 14:39:51 -0800 | [diff] [blame] | 167 | |
| 168 | err = blkdev_issue_discard(si->bdev, start_block, |
Christoph Hellwig | dd3932e | 2010-09-16 20:51:46 +0200 | [diff] [blame] | 169 | nr_blocks, GFP_KERNEL, 0); |
Hugh Dickins | 6a6ba83 | 2009-01-06 14:39:51 -0800 | [diff] [blame] | 170 | if (err) |
| 171 | break; |
| 172 | |
| 173 | cond_resched(); |
| 174 | } |
| 175 | return err; /* That will often be -EOPNOTSUPP */ |
| 176 | } |
| 177 | |
Hugh Dickins | 7992fde | 2009-01-06 14:39:53 -0800 | [diff] [blame] | 178 | /* |
| 179 | * swap allocation tell device that a cluster of swap can now be discarded, |
| 180 | * to allow the swap device to optimize its wear-levelling. |
| 181 | */ |
| 182 | static void discard_swap_cluster(struct swap_info_struct *si, |
| 183 | pgoff_t start_page, pgoff_t nr_pages) |
| 184 | { |
| 185 | struct swap_extent *se = si->curr_swap_extent; |
| 186 | int found_extent = 0; |
| 187 | |
| 188 | while (nr_pages) { |
Hugh Dickins | 7992fde | 2009-01-06 14:39:53 -0800 | [diff] [blame] | 189 | if (se->start_page <= start_page && |
| 190 | start_page < se->start_page + se->nr_pages) { |
| 191 | pgoff_t offset = start_page - se->start_page; |
| 192 | sector_t start_block = se->start_block + offset; |
Hugh Dickins | 858a2990 | 2009-01-06 14:39:56 -0800 | [diff] [blame] | 193 | sector_t nr_blocks = se->nr_pages - offset; |
Hugh Dickins | 7992fde | 2009-01-06 14:39:53 -0800 | [diff] [blame] | 194 | |
| 195 | if (nr_blocks > nr_pages) |
| 196 | nr_blocks = nr_pages; |
| 197 | start_page += nr_blocks; |
| 198 | nr_pages -= nr_blocks; |
| 199 | |
| 200 | if (!found_extent++) |
| 201 | si->curr_swap_extent = se; |
| 202 | |
| 203 | start_block <<= PAGE_SHIFT - 9; |
| 204 | nr_blocks <<= PAGE_SHIFT - 9; |
| 205 | if (blkdev_issue_discard(si->bdev, start_block, |
Christoph Hellwig | dd3932e | 2010-09-16 20:51:46 +0200 | [diff] [blame] | 206 | nr_blocks, GFP_NOIO, 0)) |
Hugh Dickins | 7992fde | 2009-01-06 14:39:53 -0800 | [diff] [blame] | 207 | break; |
| 208 | } |
| 209 | |
Geliang Tang | a8ae499 | 2016-01-14 15:20:45 -0800 | [diff] [blame] | 210 | se = list_next_entry(se, list); |
Hugh Dickins | 7992fde | 2009-01-06 14:39:53 -0800 | [diff] [blame] | 211 | } |
| 212 | } |
| 213 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 214 | #ifdef CONFIG_THP_SWAP |
| 215 | #define SWAPFILE_CLUSTER HPAGE_PMD_NR |
Huang Ying | a448f2d | 2018-08-21 21:52:17 -0700 | [diff] [blame] | 216 | |
| 217 | #define swap_entry_size(size) (size) |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 218 | #else |
Hugh Dickins | 048c27f | 2005-09-03 15:54:40 -0700 | [diff] [blame] | 219 | #define SWAPFILE_CLUSTER 256 |
Huang Ying | a448f2d | 2018-08-21 21:52:17 -0700 | [diff] [blame] | 220 | |
| 221 | /* |
| 222 | * Define swap_entry_size() as constant to let compiler to optimize |
| 223 | * out some code if !CONFIG_THP_SWAP |
| 224 | */ |
| 225 | #define swap_entry_size(size) 1 |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 226 | #endif |
Hugh Dickins | 048c27f | 2005-09-03 15:54:40 -0700 | [diff] [blame] | 227 | #define LATENCY_LIMIT 256 |
| 228 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 229 | static inline void cluster_set_flag(struct swap_cluster_info *info, |
| 230 | unsigned int flag) |
| 231 | { |
| 232 | info->flags = flag; |
| 233 | } |
| 234 | |
| 235 | static inline unsigned int cluster_count(struct swap_cluster_info *info) |
| 236 | { |
| 237 | return info->data; |
| 238 | } |
| 239 | |
| 240 | static inline void cluster_set_count(struct swap_cluster_info *info, |
| 241 | unsigned int c) |
| 242 | { |
| 243 | info->data = c; |
| 244 | } |
| 245 | |
| 246 | static inline void cluster_set_count_flag(struct swap_cluster_info *info, |
| 247 | unsigned int c, unsigned int f) |
| 248 | { |
| 249 | info->flags = f; |
| 250 | info->data = c; |
| 251 | } |
| 252 | |
| 253 | static inline unsigned int cluster_next(struct swap_cluster_info *info) |
| 254 | { |
| 255 | return info->data; |
| 256 | } |
| 257 | |
| 258 | static inline void cluster_set_next(struct swap_cluster_info *info, |
| 259 | unsigned int n) |
| 260 | { |
| 261 | info->data = n; |
| 262 | } |
| 263 | |
| 264 | static inline void cluster_set_next_flag(struct swap_cluster_info *info, |
| 265 | unsigned int n, unsigned int f) |
| 266 | { |
| 267 | info->flags = f; |
| 268 | info->data = n; |
| 269 | } |
| 270 | |
| 271 | static inline bool cluster_is_free(struct swap_cluster_info *info) |
| 272 | { |
| 273 | return info->flags & CLUSTER_FLAG_FREE; |
| 274 | } |
| 275 | |
| 276 | static inline bool cluster_is_null(struct swap_cluster_info *info) |
| 277 | { |
| 278 | return info->flags & CLUSTER_FLAG_NEXT_NULL; |
| 279 | } |
| 280 | |
| 281 | static inline void cluster_set_null(struct swap_cluster_info *info) |
| 282 | { |
| 283 | info->flags = CLUSTER_FLAG_NEXT_NULL; |
| 284 | info->data = 0; |
| 285 | } |
| 286 | |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 287 | static inline bool cluster_is_huge(struct swap_cluster_info *info) |
| 288 | { |
Huang Ying | 33ee011 | 2018-08-21 21:52:13 -0700 | [diff] [blame] | 289 | if (IS_ENABLED(CONFIG_THP_SWAP)) |
| 290 | return info->flags & CLUSTER_FLAG_HUGE; |
| 291 | return false; |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 292 | } |
| 293 | |
| 294 | static inline void cluster_clear_huge(struct swap_cluster_info *info) |
| 295 | { |
| 296 | info->flags &= ~CLUSTER_FLAG_HUGE; |
| 297 | } |
| 298 | |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 299 | static inline struct swap_cluster_info *lock_cluster(struct swap_info_struct *si, |
| 300 | unsigned long offset) |
| 301 | { |
| 302 | struct swap_cluster_info *ci; |
| 303 | |
| 304 | ci = si->cluster_info; |
| 305 | if (ci) { |
| 306 | ci += offset / SWAPFILE_CLUSTER; |
| 307 | spin_lock(&ci->lock); |
| 308 | } |
| 309 | return ci; |
| 310 | } |
| 311 | |
| 312 | static inline void unlock_cluster(struct swap_cluster_info *ci) |
| 313 | { |
| 314 | if (ci) |
| 315 | spin_unlock(&ci->lock); |
| 316 | } |
| 317 | |
Huang Ying | 59d98bf | 2018-08-21 21:52:01 -0700 | [diff] [blame] | 318 | /* |
| 319 | * Determine the locking method in use for this device. Return |
| 320 | * swap_cluster_info if SSD-style cluster-based locking is in place. |
| 321 | */ |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 322 | static inline struct swap_cluster_info *lock_cluster_or_swap_info( |
Huang Ying | 59d98bf | 2018-08-21 21:52:01 -0700 | [diff] [blame] | 323 | struct swap_info_struct *si, unsigned long offset) |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 324 | { |
| 325 | struct swap_cluster_info *ci; |
| 326 | |
Huang Ying | 59d98bf | 2018-08-21 21:52:01 -0700 | [diff] [blame] | 327 | /* Try to use fine-grained SSD-style locking if available: */ |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 328 | ci = lock_cluster(si, offset); |
Huang Ying | 59d98bf | 2018-08-21 21:52:01 -0700 | [diff] [blame] | 329 | /* Otherwise, fall back to traditional, coarse locking: */ |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 330 | if (!ci) |
| 331 | spin_lock(&si->lock); |
| 332 | |
| 333 | return ci; |
| 334 | } |
| 335 | |
| 336 | static inline void unlock_cluster_or_swap_info(struct swap_info_struct *si, |
| 337 | struct swap_cluster_info *ci) |
| 338 | { |
| 339 | if (ci) |
| 340 | unlock_cluster(ci); |
| 341 | else |
| 342 | spin_unlock(&si->lock); |
| 343 | } |
| 344 | |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 345 | static inline bool cluster_list_empty(struct swap_cluster_list *list) |
| 346 | { |
| 347 | return cluster_is_null(&list->head); |
| 348 | } |
| 349 | |
| 350 | static inline unsigned int cluster_list_first(struct swap_cluster_list *list) |
| 351 | { |
| 352 | return cluster_next(&list->head); |
| 353 | } |
| 354 | |
| 355 | static void cluster_list_init(struct swap_cluster_list *list) |
| 356 | { |
| 357 | cluster_set_null(&list->head); |
| 358 | cluster_set_null(&list->tail); |
| 359 | } |
| 360 | |
| 361 | static void cluster_list_add_tail(struct swap_cluster_list *list, |
| 362 | struct swap_cluster_info *ci, |
| 363 | unsigned int idx) |
| 364 | { |
| 365 | if (cluster_list_empty(list)) { |
| 366 | cluster_set_next_flag(&list->head, idx, 0); |
| 367 | cluster_set_next_flag(&list->tail, idx, 0); |
| 368 | } else { |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 369 | struct swap_cluster_info *ci_tail; |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 370 | unsigned int tail = cluster_next(&list->tail); |
| 371 | |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 372 | /* |
| 373 | * Nested cluster lock, but both cluster locks are |
| 374 | * only acquired when we held swap_info_struct->lock |
| 375 | */ |
| 376 | ci_tail = ci + tail; |
| 377 | spin_lock_nested(&ci_tail->lock, SINGLE_DEPTH_NESTING); |
| 378 | cluster_set_next(ci_tail, idx); |
Huang Ying | 0ef017d | 2017-05-03 14:54:36 -0700 | [diff] [blame] | 379 | spin_unlock(&ci_tail->lock); |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 380 | cluster_set_next_flag(&list->tail, idx, 0); |
| 381 | } |
| 382 | } |
| 383 | |
| 384 | static unsigned int cluster_list_del_first(struct swap_cluster_list *list, |
| 385 | struct swap_cluster_info *ci) |
| 386 | { |
| 387 | unsigned int idx; |
| 388 | |
| 389 | idx = cluster_next(&list->head); |
| 390 | if (cluster_next(&list->tail) == idx) { |
| 391 | cluster_set_null(&list->head); |
| 392 | cluster_set_null(&list->tail); |
| 393 | } else |
| 394 | cluster_set_next_flag(&list->head, |
| 395 | cluster_next(&ci[idx]), 0); |
| 396 | |
| 397 | return idx; |
| 398 | } |
| 399 | |
Shaohua Li | 815c2c5 | 2013-09-11 14:20:30 -0700 | [diff] [blame] | 400 | /* Add a cluster to discard list and schedule it to do discard */ |
| 401 | static void swap_cluster_schedule_discard(struct swap_info_struct *si, |
| 402 | unsigned int idx) |
| 403 | { |
| 404 | /* |
| 405 | * If scan_swap_map() can't find a free cluster, it will check |
| 406 | * si->swap_map directly. To make sure the discarding cluster isn't |
| 407 | * taken by scan_swap_map(), mark the swap entries bad (occupied). It |
| 408 | * will be cleared after discard |
| 409 | */ |
| 410 | memset(si->swap_map + idx * SWAPFILE_CLUSTER, |
| 411 | SWAP_MAP_BAD, SWAPFILE_CLUSTER); |
| 412 | |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 413 | cluster_list_add_tail(&si->discard_clusters, si->cluster_info, idx); |
Shaohua Li | 815c2c5 | 2013-09-11 14:20:30 -0700 | [diff] [blame] | 414 | |
| 415 | schedule_work(&si->discard_work); |
| 416 | } |
| 417 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 418 | static void __free_cluster(struct swap_info_struct *si, unsigned long idx) |
| 419 | { |
| 420 | struct swap_cluster_info *ci = si->cluster_info; |
| 421 | |
| 422 | cluster_set_flag(ci + idx, CLUSTER_FLAG_FREE); |
| 423 | cluster_list_add_tail(&si->free_clusters, ci, idx); |
| 424 | } |
| 425 | |
Shaohua Li | 815c2c5 | 2013-09-11 14:20:30 -0700 | [diff] [blame] | 426 | /* |
| 427 | * Doing discard actually. After a cluster discard is finished, the cluster |
| 428 | * will be added to free cluster list. caller should hold si->lock. |
| 429 | */ |
| 430 | static void swap_do_scheduled_discard(struct swap_info_struct *si) |
| 431 | { |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 432 | struct swap_cluster_info *info, *ci; |
Shaohua Li | 815c2c5 | 2013-09-11 14:20:30 -0700 | [diff] [blame] | 433 | unsigned int idx; |
| 434 | |
| 435 | info = si->cluster_info; |
| 436 | |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 437 | while (!cluster_list_empty(&si->discard_clusters)) { |
| 438 | idx = cluster_list_del_first(&si->discard_clusters, info); |
Shaohua Li | 815c2c5 | 2013-09-11 14:20:30 -0700 | [diff] [blame] | 439 | spin_unlock(&si->lock); |
| 440 | |
| 441 | discard_swap_cluster(si, idx * SWAPFILE_CLUSTER, |
| 442 | SWAPFILE_CLUSTER); |
| 443 | |
| 444 | spin_lock(&si->lock); |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 445 | ci = lock_cluster(si, idx * SWAPFILE_CLUSTER); |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 446 | __free_cluster(si, idx); |
Shaohua Li | 815c2c5 | 2013-09-11 14:20:30 -0700 | [diff] [blame] | 447 | memset(si->swap_map + idx * SWAPFILE_CLUSTER, |
| 448 | 0, SWAPFILE_CLUSTER); |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 449 | unlock_cluster(ci); |
Shaohua Li | 815c2c5 | 2013-09-11 14:20:30 -0700 | [diff] [blame] | 450 | } |
| 451 | } |
| 452 | |
| 453 | static void swap_discard_work(struct work_struct *work) |
| 454 | { |
| 455 | struct swap_info_struct *si; |
| 456 | |
| 457 | si = container_of(work, struct swap_info_struct, discard_work); |
| 458 | |
| 459 | spin_lock(&si->lock); |
| 460 | swap_do_scheduled_discard(si); |
| 461 | spin_unlock(&si->lock); |
| 462 | } |
| 463 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 464 | static void alloc_cluster(struct swap_info_struct *si, unsigned long idx) |
| 465 | { |
| 466 | struct swap_cluster_info *ci = si->cluster_info; |
| 467 | |
| 468 | VM_BUG_ON(cluster_list_first(&si->free_clusters) != idx); |
| 469 | cluster_list_del_first(&si->free_clusters, ci); |
| 470 | cluster_set_count_flag(ci + idx, 0, 0); |
| 471 | } |
| 472 | |
| 473 | static void free_cluster(struct swap_info_struct *si, unsigned long idx) |
| 474 | { |
| 475 | struct swap_cluster_info *ci = si->cluster_info + idx; |
| 476 | |
| 477 | VM_BUG_ON(cluster_count(ci) != 0); |
| 478 | /* |
| 479 | * If the swap is discardable, prepare discard the cluster |
| 480 | * instead of free it immediately. The cluster will be freed |
| 481 | * after discard. |
| 482 | */ |
| 483 | if ((si->flags & (SWP_WRITEOK | SWP_PAGE_DISCARD)) == |
| 484 | (SWP_WRITEOK | SWP_PAGE_DISCARD)) { |
| 485 | swap_cluster_schedule_discard(si, idx); |
| 486 | return; |
| 487 | } |
| 488 | |
| 489 | __free_cluster(si, idx); |
| 490 | } |
| 491 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 492 | /* |
| 493 | * The cluster corresponding to page_nr will be used. The cluster will be |
| 494 | * removed from free cluster list and its usage counter will be increased. |
| 495 | */ |
| 496 | static void inc_cluster_info_page(struct swap_info_struct *p, |
| 497 | struct swap_cluster_info *cluster_info, unsigned long page_nr) |
| 498 | { |
| 499 | unsigned long idx = page_nr / SWAPFILE_CLUSTER; |
| 500 | |
| 501 | if (!cluster_info) |
| 502 | return; |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 503 | if (cluster_is_free(&cluster_info[idx])) |
| 504 | alloc_cluster(p, idx); |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 505 | |
| 506 | VM_BUG_ON(cluster_count(&cluster_info[idx]) >= SWAPFILE_CLUSTER); |
| 507 | cluster_set_count(&cluster_info[idx], |
| 508 | cluster_count(&cluster_info[idx]) + 1); |
| 509 | } |
| 510 | |
| 511 | /* |
| 512 | * The cluster corresponding to page_nr decreases one usage. If the usage |
| 513 | * counter becomes 0, which means no page in the cluster is in using, we can |
| 514 | * optionally discard the cluster and add it to free cluster list. |
| 515 | */ |
| 516 | static void dec_cluster_info_page(struct swap_info_struct *p, |
| 517 | struct swap_cluster_info *cluster_info, unsigned long page_nr) |
| 518 | { |
| 519 | unsigned long idx = page_nr / SWAPFILE_CLUSTER; |
| 520 | |
| 521 | if (!cluster_info) |
| 522 | return; |
| 523 | |
| 524 | VM_BUG_ON(cluster_count(&cluster_info[idx]) == 0); |
| 525 | cluster_set_count(&cluster_info[idx], |
| 526 | cluster_count(&cluster_info[idx]) - 1); |
| 527 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 528 | if (cluster_count(&cluster_info[idx]) == 0) |
| 529 | free_cluster(p, idx); |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 530 | } |
| 531 | |
| 532 | /* |
| 533 | * It's possible scan_swap_map() uses a free cluster in the middle of free |
| 534 | * cluster list. Avoiding such abuse to avoid list corruption. |
| 535 | */ |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 536 | static bool |
| 537 | scan_swap_map_ssd_cluster_conflict(struct swap_info_struct *si, |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 538 | unsigned long offset) |
| 539 | { |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 540 | struct percpu_cluster *percpu_cluster; |
| 541 | bool conflict; |
| 542 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 543 | offset /= SWAPFILE_CLUSTER; |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 544 | conflict = !cluster_list_empty(&si->free_clusters) && |
| 545 | offset != cluster_list_first(&si->free_clusters) && |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 546 | cluster_is_free(&si->cluster_info[offset]); |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 547 | |
| 548 | if (!conflict) |
| 549 | return false; |
| 550 | |
| 551 | percpu_cluster = this_cpu_ptr(si->percpu_cluster); |
| 552 | cluster_set_null(&percpu_cluster->index); |
| 553 | return true; |
| 554 | } |
| 555 | |
| 556 | /* |
| 557 | * Try to get a swap entry from current cpu's swap entry pool (a cluster). This |
| 558 | * might involve allocating a new cluster for current CPU too. |
| 559 | */ |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 560 | static bool scan_swap_map_try_ssd_cluster(struct swap_info_struct *si, |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 561 | unsigned long *offset, unsigned long *scan_base) |
| 562 | { |
| 563 | struct percpu_cluster *cluster; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 564 | struct swap_cluster_info *ci; |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 565 | bool found_free; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 566 | unsigned long tmp, max; |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 567 | |
| 568 | new_cluster: |
| 569 | cluster = this_cpu_ptr(si->percpu_cluster); |
| 570 | if (cluster_is_null(&cluster->index)) { |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 571 | if (!cluster_list_empty(&si->free_clusters)) { |
| 572 | cluster->index = si->free_clusters.head; |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 573 | cluster->next = cluster_next(&cluster->index) * |
| 574 | SWAPFILE_CLUSTER; |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 575 | } else if (!cluster_list_empty(&si->discard_clusters)) { |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 576 | /* |
| 577 | * we don't have free cluster but have some clusters in |
| 578 | * discarding, do discard now and reclaim them |
| 579 | */ |
| 580 | swap_do_scheduled_discard(si); |
| 581 | *scan_base = *offset = si->cluster_next; |
| 582 | goto new_cluster; |
| 583 | } else |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 584 | return false; |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 585 | } |
| 586 | |
| 587 | found_free = false; |
| 588 | |
| 589 | /* |
| 590 | * Other CPUs can use our cluster if they can't find a free cluster, |
| 591 | * check if there is still free entry in the cluster |
| 592 | */ |
| 593 | tmp = cluster->next; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 594 | max = min_t(unsigned long, si->max, |
| 595 | (cluster_next(&cluster->index) + 1) * SWAPFILE_CLUSTER); |
| 596 | if (tmp >= max) { |
| 597 | cluster_set_null(&cluster->index); |
| 598 | goto new_cluster; |
| 599 | } |
| 600 | ci = lock_cluster(si, tmp); |
| 601 | while (tmp < max) { |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 602 | if (!si->swap_map[tmp]) { |
| 603 | found_free = true; |
| 604 | break; |
| 605 | } |
| 606 | tmp++; |
| 607 | } |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 608 | unlock_cluster(ci); |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 609 | if (!found_free) { |
| 610 | cluster_set_null(&cluster->index); |
| 611 | goto new_cluster; |
| 612 | } |
| 613 | cluster->next = tmp + 1; |
| 614 | *offset = tmp; |
| 615 | *scan_base = tmp; |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 616 | return found_free; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 617 | } |
| 618 | |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 619 | static void __del_from_avail_list(struct swap_info_struct *p) |
| 620 | { |
| 621 | int nid; |
| 622 | |
| 623 | for_each_node(nid) |
| 624 | plist_del(&p->avail_lists[nid], &swap_avail_heads[nid]); |
| 625 | } |
| 626 | |
| 627 | static void del_from_avail_list(struct swap_info_struct *p) |
| 628 | { |
| 629 | spin_lock(&swap_avail_lock); |
| 630 | __del_from_avail_list(p); |
| 631 | spin_unlock(&swap_avail_lock); |
| 632 | } |
| 633 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 634 | static void swap_range_alloc(struct swap_info_struct *si, unsigned long offset, |
| 635 | unsigned int nr_entries) |
| 636 | { |
| 637 | unsigned int end = offset + nr_entries - 1; |
| 638 | |
| 639 | if (offset == si->lowest_bit) |
| 640 | si->lowest_bit += nr_entries; |
| 641 | if (end == si->highest_bit) |
| 642 | si->highest_bit -= nr_entries; |
| 643 | si->inuse_pages += nr_entries; |
| 644 | if (si->inuse_pages == si->pages) { |
| 645 | si->lowest_bit = si->max; |
| 646 | si->highest_bit = 0; |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 647 | del_from_avail_list(si); |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 648 | } |
| 649 | } |
| 650 | |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 651 | static void add_to_avail_list(struct swap_info_struct *p) |
| 652 | { |
| 653 | int nid; |
| 654 | |
| 655 | spin_lock(&swap_avail_lock); |
| 656 | for_each_node(nid) { |
| 657 | WARN_ON(!plist_node_empty(&p->avail_lists[nid])); |
| 658 | plist_add(&p->avail_lists[nid], &swap_avail_heads[nid]); |
| 659 | } |
| 660 | spin_unlock(&swap_avail_lock); |
| 661 | } |
| 662 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 663 | static void swap_range_free(struct swap_info_struct *si, unsigned long offset, |
| 664 | unsigned int nr_entries) |
| 665 | { |
| 666 | unsigned long end = offset + nr_entries - 1; |
| 667 | void (*swap_slot_free_notify)(struct block_device *, unsigned long); |
| 668 | |
| 669 | if (offset < si->lowest_bit) |
| 670 | si->lowest_bit = offset; |
| 671 | if (end > si->highest_bit) { |
| 672 | bool was_full = !si->highest_bit; |
| 673 | |
| 674 | si->highest_bit = end; |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 675 | if (was_full && (si->flags & SWP_WRITEOK)) |
| 676 | add_to_avail_list(si); |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 677 | } |
| 678 | atomic_long_add(nr_entries, &nr_swap_pages); |
| 679 | si->inuse_pages -= nr_entries; |
| 680 | if (si->flags & SWP_BLKDEV) |
| 681 | swap_slot_free_notify = |
| 682 | si->bdev->bd_disk->fops->swap_slot_free_notify; |
| 683 | else |
| 684 | swap_slot_free_notify = NULL; |
| 685 | while (offset <= end) { |
| 686 | frontswap_invalidate_page(si->type, offset); |
| 687 | if (swap_slot_free_notify) |
| 688 | swap_slot_free_notify(si->bdev, offset); |
| 689 | offset++; |
| 690 | } |
| 691 | } |
| 692 | |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 693 | static int scan_swap_map_slots(struct swap_info_struct *si, |
| 694 | unsigned char usage, int nr, |
| 695 | swp_entry_t slots[]) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | { |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 697 | struct swap_cluster_info *ci; |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 698 | unsigned long offset; |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 699 | unsigned long scan_base; |
Hugh Dickins | 7992fde | 2009-01-06 14:39:53 -0800 | [diff] [blame] | 700 | unsigned long last_in_cluster = 0; |
Hugh Dickins | 048c27f | 2005-09-03 15:54:40 -0700 | [diff] [blame] | 701 | int latency_ration = LATENCY_LIMIT; |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 702 | int n_ret = 0; |
| 703 | |
| 704 | if (nr > SWAP_BATCH) |
| 705 | nr = SWAP_BATCH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | |
Hugh Dickins | 886bb7e | 2009-01-06 14:39:48 -0800 | [diff] [blame] | 707 | /* |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 708 | * We try to cluster swap pages by allocating them sequentially |
| 709 | * in swap. Once we've allocated SWAPFILE_CLUSTER pages this |
| 710 | * way, however, we resort to first-free allocation, starting |
| 711 | * a new cluster. This prevents us from scattering swap pages |
| 712 | * all over the entire swap partition, so that we reduce |
| 713 | * overall disk seek times between swap pages. -- sct |
| 714 | * But we do now try to find an empty cluster. -Andrea |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 715 | * And we let swap pages go all over an SSD partition. Hugh |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 716 | */ |
| 717 | |
Hugh Dickins | 52b7efdb | 2005-09-03 15:54:39 -0700 | [diff] [blame] | 718 | si->flags += SWP_SCANNING; |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 719 | scan_base = offset = si->cluster_next; |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 720 | |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 721 | /* SSD algorithm */ |
| 722 | if (si->cluster_info) { |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 723 | if (scan_swap_map_try_ssd_cluster(si, &offset, &scan_base)) |
| 724 | goto checks; |
| 725 | else |
| 726 | goto scan; |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 727 | } |
| 728 | |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 729 | if (unlikely(!si->cluster_nr--)) { |
| 730 | if (si->pages - si->inuse_pages < SWAPFILE_CLUSTER) { |
| 731 | si->cluster_nr = SWAPFILE_CLUSTER - 1; |
| 732 | goto checks; |
| 733 | } |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 734 | |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 735 | spin_unlock(&si->lock); |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 736 | |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 737 | /* |
| 738 | * If seek is expensive, start searching for new cluster from |
| 739 | * start of partition, to minimize the span of allocated swap. |
Chen Yucong | 50088c4 | 2014-06-04 16:10:57 -0700 | [diff] [blame] | 740 | * If seek is cheap, that is the SWP_SOLIDSTATE si->cluster_info |
| 741 | * case, just handled by scan_swap_map_try_ssd_cluster() above. |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 742 | */ |
Chen Yucong | 50088c4 | 2014-06-04 16:10:57 -0700 | [diff] [blame] | 743 | scan_base = offset = si->lowest_bit; |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 744 | last_in_cluster = offset + SWAPFILE_CLUSTER - 1; |
| 745 | |
| 746 | /* Locate the first empty (unaligned) cluster */ |
| 747 | for (; last_in_cluster <= si->highest_bit; offset++) { |
| 748 | if (si->swap_map[offset]) |
| 749 | last_in_cluster = offset + SWAPFILE_CLUSTER; |
| 750 | else if (offset == last_in_cluster) { |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 751 | spin_lock(&si->lock); |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 752 | offset -= SWAPFILE_CLUSTER - 1; |
| 753 | si->cluster_next = offset; |
| 754 | si->cluster_nr = SWAPFILE_CLUSTER - 1; |
| 755 | goto checks; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | } |
Hugh Dickins | 048c27f | 2005-09-03 15:54:40 -0700 | [diff] [blame] | 757 | if (unlikely(--latency_ration < 0)) { |
| 758 | cond_resched(); |
| 759 | latency_ration = LATENCY_LIMIT; |
| 760 | } |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 761 | } |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 762 | |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 763 | offset = scan_base; |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 764 | spin_lock(&si->lock); |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 765 | si->cluster_nr = SWAPFILE_CLUSTER - 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | } |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 767 | |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 768 | checks: |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 769 | if (si->cluster_info) { |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 770 | while (scan_swap_map_ssd_cluster_conflict(si, offset)) { |
| 771 | /* take a break if we already got some slots */ |
| 772 | if (n_ret) |
| 773 | goto done; |
| 774 | if (!scan_swap_map_try_ssd_cluster(si, &offset, |
| 775 | &scan_base)) |
| 776 | goto scan; |
| 777 | } |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 778 | } |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 779 | if (!(si->flags & SWP_WRITEOK)) |
Hugh Dickins | 52b7efdb | 2005-09-03 15:54:39 -0700 | [diff] [blame] | 780 | goto no_page; |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 781 | if (!si->highest_bit) |
| 782 | goto no_page; |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 783 | if (offset > si->highest_bit) |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 784 | scan_base = offset = si->lowest_bit; |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 785 | |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 786 | ci = lock_cluster(si, offset); |
Hugh Dickins | b73d7fc | 2010-09-09 16:38:09 -0700 | [diff] [blame] | 787 | /* reuse swap entry of cache-only swap if not busy. */ |
| 788 | if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 789 | int swap_was_freed; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 790 | unlock_cluster(ci); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 791 | spin_unlock(&si->lock); |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 792 | swap_was_freed = __try_to_reclaim_swap(si, offset); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 793 | spin_lock(&si->lock); |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 794 | /* entry was freed successfully, try to use this again */ |
| 795 | if (swap_was_freed) |
| 796 | goto checks; |
| 797 | goto scan; /* check next one */ |
| 798 | } |
| 799 | |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 800 | if (si->swap_map[offset]) { |
| 801 | unlock_cluster(ci); |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 802 | if (!n_ret) |
| 803 | goto scan; |
| 804 | else |
| 805 | goto done; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 806 | } |
Huang Ying | 2872bb2 | 2017-05-03 14:54:39 -0700 | [diff] [blame] | 807 | si->swap_map[offset] = usage; |
| 808 | inc_cluster_info_page(si, si->cluster_info, offset); |
| 809 | unlock_cluster(ci); |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 810 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 811 | swap_range_alloc(si, offset, 1); |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 812 | si->cluster_next = offset + 1; |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 813 | slots[n_ret++] = swp_entry(si->type, offset); |
Hugh Dickins | 7992fde | 2009-01-06 14:39:53 -0800 | [diff] [blame] | 814 | |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 815 | /* got enough slots or reach max slots? */ |
| 816 | if ((n_ret == nr) || (offset >= si->highest_bit)) |
| 817 | goto done; |
| 818 | |
| 819 | /* search for next available slot */ |
| 820 | |
| 821 | /* time to take a break? */ |
| 822 | if (unlikely(--latency_ration < 0)) { |
| 823 | if (n_ret) |
| 824 | goto done; |
| 825 | spin_unlock(&si->lock); |
| 826 | cond_resched(); |
| 827 | spin_lock(&si->lock); |
| 828 | latency_ration = LATENCY_LIMIT; |
| 829 | } |
| 830 | |
| 831 | /* try to get more slots in cluster */ |
| 832 | if (si->cluster_info) { |
| 833 | if (scan_swap_map_try_ssd_cluster(si, &offset, &scan_base)) |
| 834 | goto checks; |
| 835 | else |
| 836 | goto done; |
| 837 | } |
| 838 | /* non-ssd case */ |
| 839 | ++offset; |
| 840 | |
| 841 | /* non-ssd case, still more slots in cluster? */ |
| 842 | if (si->cluster_nr && !si->swap_map[offset]) { |
| 843 | --si->cluster_nr; |
| 844 | goto checks; |
| 845 | } |
| 846 | |
| 847 | done: |
| 848 | si->flags -= SWP_SCANNING; |
| 849 | return n_ret; |
Hugh Dickins | ebebbbe | 2009-01-06 14:39:50 -0800 | [diff] [blame] | 850 | |
| 851 | scan: |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 852 | spin_unlock(&si->lock); |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 853 | while (++offset <= si->highest_bit) { |
Hugh Dickins | 52b7efdb | 2005-09-03 15:54:39 -0700 | [diff] [blame] | 854 | if (!si->swap_map[offset]) { |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 855 | spin_lock(&si->lock); |
Hugh Dickins | 52b7efdb | 2005-09-03 15:54:39 -0700 | [diff] [blame] | 856 | goto checks; |
| 857 | } |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 858 | if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 859 | spin_lock(&si->lock); |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 860 | goto checks; |
| 861 | } |
Hugh Dickins | 048c27f | 2005-09-03 15:54:40 -0700 | [diff] [blame] | 862 | if (unlikely(--latency_ration < 0)) { |
| 863 | cond_resched(); |
| 864 | latency_ration = LATENCY_LIMIT; |
| 865 | } |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 866 | } |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 867 | offset = si->lowest_bit; |
Jamie Liu | a599806 | 2014-01-23 15:53:40 -0800 | [diff] [blame] | 868 | while (offset < scan_base) { |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 869 | if (!si->swap_map[offset]) { |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 870 | spin_lock(&si->lock); |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 871 | goto checks; |
| 872 | } |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 873 | if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 874 | spin_lock(&si->lock); |
KAMEZAWA Hiroyuki | c9e4441 | 2009-06-16 15:32:54 -0700 | [diff] [blame] | 875 | goto checks; |
| 876 | } |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 877 | if (unlikely(--latency_ration < 0)) { |
| 878 | cond_resched(); |
| 879 | latency_ration = LATENCY_LIMIT; |
| 880 | } |
Jamie Liu | a599806 | 2014-01-23 15:53:40 -0800 | [diff] [blame] | 881 | offset++; |
Hugh Dickins | c60aa17 | 2009-01-06 14:39:55 -0800 | [diff] [blame] | 882 | } |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 883 | spin_lock(&si->lock); |
Hugh Dickins | 7dfad41 | 2005-09-03 15:54:38 -0700 | [diff] [blame] | 884 | |
| 885 | no_page: |
Hugh Dickins | 52b7efdb | 2005-09-03 15:54:39 -0700 | [diff] [blame] | 886 | si->flags -= SWP_SCANNING; |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 887 | return n_ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | } |
| 889 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 890 | static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot) |
| 891 | { |
| 892 | unsigned long idx; |
| 893 | struct swap_cluster_info *ci; |
| 894 | unsigned long offset, i; |
| 895 | unsigned char *map; |
| 896 | |
Huang Ying | fe5266d | 2018-08-21 21:52:05 -0700 | [diff] [blame] | 897 | /* |
| 898 | * Should not even be attempting cluster allocations when huge |
| 899 | * page swap is disabled. Warn and fail the allocation. |
| 900 | */ |
| 901 | if (!IS_ENABLED(CONFIG_THP_SWAP)) { |
| 902 | VM_WARN_ON_ONCE(1); |
| 903 | return 0; |
| 904 | } |
| 905 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 906 | if (cluster_list_empty(&si->free_clusters)) |
| 907 | return 0; |
| 908 | |
| 909 | idx = cluster_list_first(&si->free_clusters); |
| 910 | offset = idx * SWAPFILE_CLUSTER; |
| 911 | ci = lock_cluster(si, offset); |
| 912 | alloc_cluster(si, idx); |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 913 | cluster_set_count_flag(ci, SWAPFILE_CLUSTER, CLUSTER_FLAG_HUGE); |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 914 | |
| 915 | map = si->swap_map + offset; |
| 916 | for (i = 0; i < SWAPFILE_CLUSTER; i++) |
| 917 | map[i] = SWAP_HAS_CACHE; |
| 918 | unlock_cluster(ci); |
| 919 | swap_range_alloc(si, offset, SWAPFILE_CLUSTER); |
| 920 | *slot = swp_entry(si->type, offset); |
| 921 | |
| 922 | return 1; |
| 923 | } |
| 924 | |
| 925 | static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx) |
| 926 | { |
| 927 | unsigned long offset = idx * SWAPFILE_CLUSTER; |
| 928 | struct swap_cluster_info *ci; |
| 929 | |
| 930 | ci = lock_cluster(si, offset); |
| 931 | cluster_set_count_flag(ci, 0, 0); |
| 932 | free_cluster(si, idx); |
| 933 | unlock_cluster(ci); |
| 934 | swap_range_free(si, offset, SWAPFILE_CLUSTER); |
| 935 | } |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 936 | |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 937 | static unsigned long scan_swap_map(struct swap_info_struct *si, |
| 938 | unsigned char usage) |
| 939 | { |
| 940 | swp_entry_t entry; |
| 941 | int n_ret; |
| 942 | |
| 943 | n_ret = scan_swap_map_slots(si, usage, 1, &entry); |
| 944 | |
| 945 | if (n_ret) |
| 946 | return swp_offset(entry); |
| 947 | else |
| 948 | return 0; |
| 949 | |
| 950 | } |
| 951 | |
Huang Ying | 5d5e8f1 | 2018-08-21 21:52:20 -0700 | [diff] [blame] | 952 | int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 953 | { |
Huang Ying | 5d5e8f1 | 2018-08-21 21:52:20 -0700 | [diff] [blame] | 954 | unsigned long size = swap_entry_size(entry_size); |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 955 | struct swap_info_struct *si, *next; |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 956 | long avail_pgs; |
| 957 | int n_ret = 0; |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 958 | int node; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 959 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 960 | /* Only single cluster request supported */ |
Huang Ying | 5d5e8f1 | 2018-08-21 21:52:20 -0700 | [diff] [blame] | 961 | WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER); |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 962 | |
Huang Ying | 5d5e8f1 | 2018-08-21 21:52:20 -0700 | [diff] [blame] | 963 | avail_pgs = atomic_long_read(&nr_swap_pages) / size; |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 964 | if (avail_pgs <= 0) |
Hugh Dickins | fb4f88d | 2005-09-03 15:54:37 -0700 | [diff] [blame] | 965 | goto noswap; |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 966 | |
| 967 | if (n_goal > SWAP_BATCH) |
| 968 | n_goal = SWAP_BATCH; |
| 969 | |
| 970 | if (n_goal > avail_pgs) |
| 971 | n_goal = avail_pgs; |
| 972 | |
Huang Ying | 5d5e8f1 | 2018-08-21 21:52:20 -0700 | [diff] [blame] | 973 | atomic_long_sub(n_goal * size, &nr_swap_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 975 | spin_lock(&swap_avail_lock); |
| 976 | |
| 977 | start_over: |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 978 | node = numa_node_id(); |
| 979 | plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) { |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 980 | /* requeue si to after same-priority siblings */ |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 981 | plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]); |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 982 | spin_unlock(&swap_avail_lock); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 983 | spin_lock(&si->lock); |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 984 | if (!si->highest_bit || !(si->flags & SWP_WRITEOK)) { |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 985 | spin_lock(&swap_avail_lock); |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 986 | if (plist_node_empty(&si->avail_lists[node])) { |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 987 | spin_unlock(&si->lock); |
| 988 | goto nextsi; |
| 989 | } |
| 990 | WARN(!si->highest_bit, |
| 991 | "swap_info %d in list but !highest_bit\n", |
| 992 | si->type); |
| 993 | WARN(!(si->flags & SWP_WRITEOK), |
| 994 | "swap_info %d in list but !SWP_WRITEOK\n", |
| 995 | si->type); |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 996 | __del_from_avail_list(si); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 997 | spin_unlock(&si->lock); |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 998 | goto nextsi; |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 999 | } |
Huang Ying | 5d5e8f1 | 2018-08-21 21:52:20 -0700 | [diff] [blame] | 1000 | if (size == SWAPFILE_CLUSTER) { |
Gao Xiang | f3e8ed3 | 2020-09-25 21:19:01 -0700 | [diff] [blame] | 1001 | if (si->flags & SWP_BLKDEV) |
Huang Ying | f0eea18 | 2017-09-06 16:22:23 -0700 | [diff] [blame] | 1002 | n_ret = swap_alloc_cluster(si, swp_entries); |
| 1003 | } else |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 1004 | n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE, |
| 1005 | n_goal, swp_entries); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 1006 | spin_unlock(&si->lock); |
Huang Ying | 5d5e8f1 | 2018-08-21 21:52:20 -0700 | [diff] [blame] | 1007 | if (n_ret || size == SWAPFILE_CLUSTER) |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 1008 | goto check_out; |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 1009 | pr_debug("scan_swap_map of si %d failed to find offset\n", |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 1010 | si->type); |
| 1011 | |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 1012 | spin_lock(&swap_avail_lock); |
| 1013 | nextsi: |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 1014 | /* |
| 1015 | * if we got here, it's likely that si was almost full before, |
| 1016 | * and since scan_swap_map() can drop the si->lock, multiple |
| 1017 | * callers probably all tried to get a page from the same si |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 1018 | * and it filled up before we could get one; or, the si filled |
| 1019 | * up between us dropping swap_avail_lock and taking si->lock. |
| 1020 | * Since we dropped the swap_avail_lock, the swap_avail_head |
| 1021 | * list may have been modified; so if next is still in the |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 1022 | * swap_avail_head list then try it, otherwise start over |
| 1023 | * if we have not gotten any slots. |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 1024 | */ |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 1025 | if (plist_node_empty(&next->avail_lists[node])) |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 1026 | goto start_over; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1027 | } |
Hugh Dickins | fb4f88d | 2005-09-03 15:54:37 -0700 | [diff] [blame] | 1028 | |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 1029 | spin_unlock(&swap_avail_lock); |
| 1030 | |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 1031 | check_out: |
| 1032 | if (n_ret < n_goal) |
Huang Ying | 5d5e8f1 | 2018-08-21 21:52:20 -0700 | [diff] [blame] | 1033 | atomic_long_add((long)(n_goal - n_ret) * size, |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 1034 | &nr_swap_pages); |
Hugh Dickins | fb4f88d | 2005-09-03 15:54:37 -0700 | [diff] [blame] | 1035 | noswap: |
Tim Chen | 36005ba | 2017-02-22 15:45:33 -0800 | [diff] [blame] | 1036 | return n_ret; |
| 1037 | } |
| 1038 | |
Seth Jennings | 2de1a7e | 2013-11-12 15:07:46 -0800 | [diff] [blame] | 1039 | /* The only caller of this function is now suspend routine */ |
Hugh Dickins | 910321e | 2010-09-09 16:38:07 -0700 | [diff] [blame] | 1040 | swp_entry_t get_swap_page_of_type(int type) |
| 1041 | { |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 1042 | struct swap_info_struct *si = swap_type_to_swap_info(type); |
Hugh Dickins | 910321e | 2010-09-09 16:38:07 -0700 | [diff] [blame] | 1043 | pgoff_t offset; |
| 1044 | |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 1045 | if (!si) |
| 1046 | goto fail; |
| 1047 | |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 1048 | spin_lock(&si->lock); |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 1049 | if (si->flags & SWP_WRITEOK) { |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 1050 | atomic_long_dec(&nr_swap_pages); |
Hugh Dickins | 910321e | 2010-09-09 16:38:07 -0700 | [diff] [blame] | 1051 | /* This is called for allocating swap entry, not cache */ |
| 1052 | offset = scan_swap_map(si, 1); |
| 1053 | if (offset) { |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 1054 | spin_unlock(&si->lock); |
Hugh Dickins | 910321e | 2010-09-09 16:38:07 -0700 | [diff] [blame] | 1055 | return swp_entry(type, offset); |
| 1056 | } |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 1057 | atomic_long_inc(&nr_swap_pages); |
Hugh Dickins | 910321e | 2010-09-09 16:38:07 -0700 | [diff] [blame] | 1058 | } |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 1059 | spin_unlock(&si->lock); |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 1060 | fail: |
Hugh Dickins | 910321e | 2010-09-09 16:38:07 -0700 | [diff] [blame] | 1061 | return (swp_entry_t) {0}; |
| 1062 | } |
| 1063 | |
Tim Chen | e8c26ab | 2017-02-22 15:45:29 -0800 | [diff] [blame] | 1064 | static struct swap_info_struct *__swap_info_get(swp_entry_t entry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | { |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 1066 | struct swap_info_struct *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1067 | unsigned long offset, type; |
| 1068 | |
| 1069 | if (!entry.val) |
| 1070 | goto out; |
| 1071 | type = swp_type(entry); |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 1072 | p = swap_type_to_swap_info(type); |
| 1073 | if (!p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | goto bad_nofile; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1075 | if (!(p->flags & SWP_USED)) |
| 1076 | goto bad_device; |
| 1077 | offset = swp_offset(entry); |
| 1078 | if (offset >= p->max) |
| 1079 | goto bad_offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1080 | return p; |
| 1081 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | bad_offset: |
Huang, Ying | 6a991fc | 2017-02-22 15:45:19 -0800 | [diff] [blame] | 1083 | pr_err("swap_info_get: %s%08lx\n", Bad_offset, entry.val); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1084 | goto out; |
| 1085 | bad_device: |
Huang, Ying | 6a991fc | 2017-02-22 15:45:19 -0800 | [diff] [blame] | 1086 | pr_err("swap_info_get: %s%08lx\n", Unused_file, entry.val); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1087 | goto out; |
| 1088 | bad_nofile: |
Huang, Ying | 6a991fc | 2017-02-22 15:45:19 -0800 | [diff] [blame] | 1089 | pr_err("swap_info_get: %s%08lx\n", Bad_file, entry.val); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1090 | out: |
| 1091 | return NULL; |
Hugh Dickins | 886bb7e | 2009-01-06 14:39:48 -0800 | [diff] [blame] | 1092 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | |
Tim Chen | e8c26ab | 2017-02-22 15:45:29 -0800 | [diff] [blame] | 1094 | static struct swap_info_struct *_swap_info_get(swp_entry_t entry) |
| 1095 | { |
| 1096 | struct swap_info_struct *p; |
| 1097 | |
| 1098 | p = __swap_info_get(entry); |
| 1099 | if (!p) |
| 1100 | goto out; |
| 1101 | if (!p->swap_map[swp_offset(entry)]) |
| 1102 | goto bad_free; |
| 1103 | return p; |
| 1104 | |
| 1105 | bad_free: |
| 1106 | pr_err("swap_info_get: %s%08lx\n", Unused_offset, entry.val); |
| 1107 | goto out; |
| 1108 | out: |
| 1109 | return NULL; |
| 1110 | } |
| 1111 | |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1112 | static struct swap_info_struct *swap_info_get(swp_entry_t entry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1113 | { |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1114 | struct swap_info_struct *p; |
| 1115 | |
| 1116 | p = _swap_info_get(entry); |
| 1117 | if (p) |
| 1118 | spin_lock(&p->lock); |
| 1119 | return p; |
| 1120 | } |
| 1121 | |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1122 | static struct swap_info_struct *swap_info_get_cont(swp_entry_t entry, |
| 1123 | struct swap_info_struct *q) |
| 1124 | { |
| 1125 | struct swap_info_struct *p; |
| 1126 | |
| 1127 | p = _swap_info_get(entry); |
| 1128 | |
| 1129 | if (p != q) { |
| 1130 | if (q != NULL) |
| 1131 | spin_unlock(&q->lock); |
| 1132 | if (p != NULL) |
| 1133 | spin_lock(&p->lock); |
| 1134 | } |
| 1135 | return p; |
| 1136 | } |
| 1137 | |
Huang Ying | b32d5f3 | 2018-08-21 21:52:24 -0700 | [diff] [blame] | 1138 | static unsigned char __swap_entry_free_locked(struct swap_info_struct *p, |
| 1139 | unsigned long offset, |
| 1140 | unsigned char usage) |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1141 | { |
Hugh Dickins | 8d69aae | 2009-12-14 17:58:45 -0800 | [diff] [blame] | 1142 | unsigned char count; |
| 1143 | unsigned char has_cache; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1144 | |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 1145 | count = p->swap_map[offset]; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1146 | |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 1147 | has_cache = count & SWAP_HAS_CACHE; |
| 1148 | count &= ~SWAP_HAS_CACHE; |
| 1149 | |
| 1150 | if (usage == SWAP_HAS_CACHE) { |
| 1151 | VM_BUG_ON(!has_cache); |
| 1152 | has_cache = 0; |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 1153 | } else if (count == SWAP_MAP_SHMEM) { |
| 1154 | /* |
| 1155 | * Or we could insist on shmem.c using a special |
| 1156 | * swap_shmem_free() and free_shmem_swap_and_cache()... |
| 1157 | */ |
| 1158 | count = 0; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 1159 | } else if ((count & ~COUNT_CONTINUED) <= SWAP_MAP_MAX) { |
| 1160 | if (count == COUNT_CONTINUED) { |
| 1161 | if (swap_count_continued(p, offset, count)) |
| 1162 | count = SWAP_MAP_MAX | COUNT_CONTINUED; |
| 1163 | else |
| 1164 | count = SWAP_MAP_MAX; |
| 1165 | } else |
| 1166 | count--; |
| 1167 | } |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 1168 | |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 1169 | usage = count | has_cache; |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1170 | p->swap_map[offset] = usage ? : SWAP_HAS_CACHE; |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 1171 | |
Huang Ying | b32d5f3 | 2018-08-21 21:52:24 -0700 | [diff] [blame] | 1172 | return usage; |
| 1173 | } |
| 1174 | |
| 1175 | static unsigned char __swap_entry_free(struct swap_info_struct *p, |
| 1176 | swp_entry_t entry, unsigned char usage) |
| 1177 | { |
| 1178 | struct swap_cluster_info *ci; |
| 1179 | unsigned long offset = swp_offset(entry); |
| 1180 | |
| 1181 | ci = lock_cluster_or_swap_info(p, offset); |
| 1182 | usage = __swap_entry_free_locked(p, offset, usage); |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1183 | unlock_cluster_or_swap_info(p, ci); |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1184 | |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 1185 | return usage; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1186 | } |
| 1187 | |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1188 | static void swap_entry_free(struct swap_info_struct *p, swp_entry_t entry) |
| 1189 | { |
| 1190 | struct swap_cluster_info *ci; |
| 1191 | unsigned long offset = swp_offset(entry); |
| 1192 | unsigned char count; |
| 1193 | |
| 1194 | ci = lock_cluster(p, offset); |
| 1195 | count = p->swap_map[offset]; |
| 1196 | VM_BUG_ON(count != SWAP_HAS_CACHE); |
| 1197 | p->swap_map[offset] = 0; |
| 1198 | dec_cluster_info_page(p, p->cluster_info, offset); |
| 1199 | unlock_cluster(ci); |
| 1200 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 1201 | mem_cgroup_uncharge_swap(entry, 1); |
| 1202 | swap_range_free(p, offset, 1); |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1203 | } |
| 1204 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | /* |
Seth Jennings | 2de1a7e | 2013-11-12 15:07:46 -0800 | [diff] [blame] | 1206 | * Caller has made sure that the swap device corresponding to entry |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1207 | * is still around or has not been recycled. |
| 1208 | */ |
| 1209 | void swap_free(swp_entry_t entry) |
| 1210 | { |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 1211 | struct swap_info_struct *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1212 | |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1213 | p = _swap_info_get(entry); |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1214 | if (p) { |
| 1215 | if (!__swap_entry_free(p, entry, 1)) |
Tim Chen | 67afa38 | 2017-02-22 15:45:39 -0800 | [diff] [blame] | 1216 | free_swap_slot(entry); |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1217 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1218 | } |
| 1219 | |
| 1220 | /* |
KAMEZAWA Hiroyuki | cb4b86b | 2009-06-16 15:32:52 -0700 | [diff] [blame] | 1221 | * Called after dropping swapcache to decrease refcnt to swap entries. |
| 1222 | */ |
Huang Ying | a448f2d | 2018-08-21 21:52:17 -0700 | [diff] [blame] | 1223 | void put_swap_page(struct page *page, swp_entry_t entry) |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 1224 | { |
| 1225 | unsigned long offset = swp_offset(entry); |
| 1226 | unsigned long idx = offset / SWAPFILE_CLUSTER; |
| 1227 | struct swap_cluster_info *ci; |
| 1228 | struct swap_info_struct *si; |
| 1229 | unsigned char *map; |
Huang Ying | a3aea83 | 2017-09-06 16:22:12 -0700 | [diff] [blame] | 1230 | unsigned int i, free_entries = 0; |
| 1231 | unsigned char val; |
Huang Ying | a448f2d | 2018-08-21 21:52:17 -0700 | [diff] [blame] | 1232 | int size = swap_entry_size(hpage_nr_pages(page)); |
Huang Ying | fe5266d | 2018-08-21 21:52:05 -0700 | [diff] [blame] | 1233 | |
Huang Ying | a3aea83 | 2017-09-06 16:22:12 -0700 | [diff] [blame] | 1234 | si = _swap_info_get(entry); |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 1235 | if (!si) |
| 1236 | return; |
| 1237 | |
Huang Ying | c2343d2 | 2018-08-21 21:52:29 -0700 | [diff] [blame] | 1238 | ci = lock_cluster_or_swap_info(si, offset); |
Huang Ying | a448f2d | 2018-08-21 21:52:17 -0700 | [diff] [blame] | 1239 | if (size == SWAPFILE_CLUSTER) { |
Huang Ying | a448f2d | 2018-08-21 21:52:17 -0700 | [diff] [blame] | 1240 | VM_BUG_ON(!cluster_is_huge(ci)); |
| 1241 | map = si->swap_map + offset; |
| 1242 | for (i = 0; i < SWAPFILE_CLUSTER; i++) { |
| 1243 | val = map[i]; |
| 1244 | VM_BUG_ON(!(val & SWAP_HAS_CACHE)); |
| 1245 | if (val == SWAP_HAS_CACHE) |
| 1246 | free_entries++; |
| 1247 | } |
Huang Ying | a448f2d | 2018-08-21 21:52:17 -0700 | [diff] [blame] | 1248 | cluster_clear_huge(ci); |
Huang Ying | a448f2d | 2018-08-21 21:52:17 -0700 | [diff] [blame] | 1249 | if (free_entries == SWAPFILE_CLUSTER) { |
Huang Ying | c2343d2 | 2018-08-21 21:52:29 -0700 | [diff] [blame] | 1250 | unlock_cluster_or_swap_info(si, ci); |
Huang Ying | a448f2d | 2018-08-21 21:52:17 -0700 | [diff] [blame] | 1251 | spin_lock(&si->lock); |
| 1252 | ci = lock_cluster(si, offset); |
| 1253 | memset(map, 0, SWAPFILE_CLUSTER); |
| 1254 | unlock_cluster(ci); |
| 1255 | mem_cgroup_uncharge_swap(entry, SWAPFILE_CLUSTER); |
| 1256 | swap_free_cluster(si, idx); |
| 1257 | spin_unlock(&si->lock); |
| 1258 | return; |
| 1259 | } |
| 1260 | } |
Huang Ying | c2343d2 | 2018-08-21 21:52:29 -0700 | [diff] [blame] | 1261 | for (i = 0; i < size; i++, entry.val++) { |
| 1262 | if (!__swap_entry_free_locked(si, offset + i, SWAP_HAS_CACHE)) { |
| 1263 | unlock_cluster_or_swap_info(si, ci); |
| 1264 | free_swap_slot(entry); |
| 1265 | if (i == size - 1) |
| 1266 | return; |
| 1267 | lock_cluster_or_swap_info(si, offset); |
Huang Ying | a3aea83 | 2017-09-06 16:22:12 -0700 | [diff] [blame] | 1268 | } |
| 1269 | } |
Huang Ying | c2343d2 | 2018-08-21 21:52:29 -0700 | [diff] [blame] | 1270 | unlock_cluster_or_swap_info(si, ci); |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 1271 | } |
Huang Ying | 5980768 | 2017-09-06 16:22:34 -0700 | [diff] [blame] | 1272 | |
Huang Ying | fe5266d | 2018-08-21 21:52:05 -0700 | [diff] [blame] | 1273 | #ifdef CONFIG_THP_SWAP |
Huang Ying | 5980768 | 2017-09-06 16:22:34 -0700 | [diff] [blame] | 1274 | int split_swap_cluster(swp_entry_t entry) |
| 1275 | { |
| 1276 | struct swap_info_struct *si; |
| 1277 | struct swap_cluster_info *ci; |
| 1278 | unsigned long offset = swp_offset(entry); |
| 1279 | |
| 1280 | si = _swap_info_get(entry); |
| 1281 | if (!si) |
| 1282 | return -EBUSY; |
| 1283 | ci = lock_cluster(si, offset); |
| 1284 | cluster_clear_huge(ci); |
| 1285 | unlock_cluster(ci); |
| 1286 | return 0; |
| 1287 | } |
Huang Ying | fe5266d | 2018-08-21 21:52:05 -0700 | [diff] [blame] | 1288 | #endif |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 1289 | |
Huang Ying | 155b5f8 | 2017-07-06 15:40:31 -0700 | [diff] [blame] | 1290 | static int swp_entry_cmp(const void *ent1, const void *ent2) |
| 1291 | { |
| 1292 | const swp_entry_t *e1 = ent1, *e2 = ent2; |
| 1293 | |
| 1294 | return (int)swp_type(*e1) - (int)swp_type(*e2); |
| 1295 | } |
| 1296 | |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1297 | void swapcache_free_entries(swp_entry_t *entries, int n) |
| 1298 | { |
| 1299 | struct swap_info_struct *p, *prev; |
| 1300 | int i; |
| 1301 | |
| 1302 | if (n <= 0) |
| 1303 | return; |
| 1304 | |
| 1305 | prev = NULL; |
| 1306 | p = NULL; |
Huang Ying | 155b5f8 | 2017-07-06 15:40:31 -0700 | [diff] [blame] | 1307 | |
| 1308 | /* |
| 1309 | * Sort swap entries by swap device, so each lock is only taken once. |
| 1310 | * nr_swapfiles isn't absolutely correct, but the overhead of sort() is |
| 1311 | * so low that it isn't necessary to optimize further. |
| 1312 | */ |
| 1313 | if (nr_swapfiles > 1) |
| 1314 | sort(entries, n, sizeof(entries[0]), swp_entry_cmp, NULL); |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1315 | for (i = 0; i < n; ++i) { |
| 1316 | p = swap_info_get_cont(entries[i], prev); |
| 1317 | if (p) |
| 1318 | swap_entry_free(p, entries[i]); |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1319 | prev = p; |
| 1320 | } |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1321 | if (p) |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1322 | spin_unlock(&p->lock); |
KAMEZAWA Hiroyuki | cb4b86b | 2009-06-16 15:32:52 -0700 | [diff] [blame] | 1323 | } |
| 1324 | |
| 1325 | /* |
Hugh Dickins | c475a8a | 2005-06-21 17:15:12 -0700 | [diff] [blame] | 1326 | * How many references to page are currently swapped out? |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 1327 | * This does not give an exact answer when swap count is continued, |
| 1328 | * but does include the high COUNT_CONTINUED flag to allow for that. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | */ |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1330 | int page_swapcount(struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1331 | { |
Hugh Dickins | c475a8a | 2005-06-21 17:15:12 -0700 | [diff] [blame] | 1332 | int count = 0; |
| 1333 | struct swap_info_struct *p; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1334 | struct swap_cluster_info *ci; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1335 | swp_entry_t entry; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1336 | unsigned long offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | |
Hugh Dickins | 4c21e2f | 2005-10-29 18:16:40 -0700 | [diff] [blame] | 1338 | entry.val = page_private(page); |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1339 | p = _swap_info_get(entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1340 | if (p) { |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1341 | offset = swp_offset(entry); |
| 1342 | ci = lock_cluster_or_swap_info(p, offset); |
| 1343 | count = swap_count(p->swap_map[offset]); |
| 1344 | unlock_cluster_or_swap_info(p, ci); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1345 | } |
Hugh Dickins | c475a8a | 2005-06-21 17:15:12 -0700 | [diff] [blame] | 1346 | return count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1347 | } |
| 1348 | |
Minchan Kim | aa8d22a | 2017-11-15 17:33:11 -0800 | [diff] [blame] | 1349 | int __swap_count(struct swap_info_struct *si, swp_entry_t entry) |
| 1350 | { |
| 1351 | pgoff_t offset = swp_offset(entry); |
| 1352 | |
| 1353 | return swap_count(si->swap_map[offset]); |
| 1354 | } |
| 1355 | |
Huang Ying | 322b8afe | 2017-05-03 14:52:49 -0700 | [diff] [blame] | 1356 | static int swap_swapcount(struct swap_info_struct *si, swp_entry_t entry) |
| 1357 | { |
| 1358 | int count = 0; |
| 1359 | pgoff_t offset = swp_offset(entry); |
| 1360 | struct swap_cluster_info *ci; |
| 1361 | |
| 1362 | ci = lock_cluster_or_swap_info(si, offset); |
| 1363 | count = swap_count(si->swap_map[offset]); |
| 1364 | unlock_cluster_or_swap_info(si, ci); |
| 1365 | return count; |
| 1366 | } |
| 1367 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1368 | /* |
Minchan Kim | 8334b96 | 2015-09-08 15:00:24 -0700 | [diff] [blame] | 1369 | * How many references to @entry are currently swapped out? |
Tim Chen | e8c26ab | 2017-02-22 15:45:29 -0800 | [diff] [blame] | 1370 | * This does not give an exact answer when swap count is continued, |
| 1371 | * but does include the high COUNT_CONTINUED flag to allow for that. |
| 1372 | */ |
| 1373 | int __swp_swapcount(swp_entry_t entry) |
| 1374 | { |
| 1375 | int count = 0; |
Tim Chen | e8c26ab | 2017-02-22 15:45:29 -0800 | [diff] [blame] | 1376 | struct swap_info_struct *si; |
Tim Chen | e8c26ab | 2017-02-22 15:45:29 -0800 | [diff] [blame] | 1377 | |
| 1378 | si = __swap_info_get(entry); |
Huang Ying | 322b8afe | 2017-05-03 14:52:49 -0700 | [diff] [blame] | 1379 | if (si) |
| 1380 | count = swap_swapcount(si, entry); |
Tim Chen | e8c26ab | 2017-02-22 15:45:29 -0800 | [diff] [blame] | 1381 | return count; |
| 1382 | } |
| 1383 | |
| 1384 | /* |
| 1385 | * How many references to @entry are currently swapped out? |
Minchan Kim | 8334b96 | 2015-09-08 15:00:24 -0700 | [diff] [blame] | 1386 | * This considers COUNT_CONTINUED so it returns exact answer. |
| 1387 | */ |
| 1388 | int swp_swapcount(swp_entry_t entry) |
| 1389 | { |
| 1390 | int count, tmp_count, n; |
| 1391 | struct swap_info_struct *p; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1392 | struct swap_cluster_info *ci; |
Minchan Kim | 8334b96 | 2015-09-08 15:00:24 -0700 | [diff] [blame] | 1393 | struct page *page; |
| 1394 | pgoff_t offset; |
| 1395 | unsigned char *map; |
| 1396 | |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1397 | p = _swap_info_get(entry); |
Minchan Kim | 8334b96 | 2015-09-08 15:00:24 -0700 | [diff] [blame] | 1398 | if (!p) |
| 1399 | return 0; |
| 1400 | |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1401 | offset = swp_offset(entry); |
| 1402 | |
| 1403 | ci = lock_cluster_or_swap_info(p, offset); |
| 1404 | |
| 1405 | count = swap_count(p->swap_map[offset]); |
Minchan Kim | 8334b96 | 2015-09-08 15:00:24 -0700 | [diff] [blame] | 1406 | if (!(count & COUNT_CONTINUED)) |
| 1407 | goto out; |
| 1408 | |
| 1409 | count &= ~COUNT_CONTINUED; |
| 1410 | n = SWAP_MAP_MAX + 1; |
| 1411 | |
Minchan Kim | 8334b96 | 2015-09-08 15:00:24 -0700 | [diff] [blame] | 1412 | page = vmalloc_to_page(p->swap_map + offset); |
| 1413 | offset &= ~PAGE_MASK; |
| 1414 | VM_BUG_ON(page_private(page) != SWP_CONTINUED); |
| 1415 | |
| 1416 | do { |
Geliang Tang | a8ae499 | 2016-01-14 15:20:45 -0800 | [diff] [blame] | 1417 | page = list_next_entry(page, lru); |
Minchan Kim | 8334b96 | 2015-09-08 15:00:24 -0700 | [diff] [blame] | 1418 | map = kmap_atomic(page); |
| 1419 | tmp_count = map[offset]; |
| 1420 | kunmap_atomic(map); |
| 1421 | |
| 1422 | count += (tmp_count & ~COUNT_CONTINUED) * n; |
| 1423 | n *= (SWAP_CONT_MAX + 1); |
| 1424 | } while (tmp_count & COUNT_CONTINUED); |
| 1425 | out: |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 1426 | unlock_cluster_or_swap_info(p, ci); |
Minchan Kim | 8334b96 | 2015-09-08 15:00:24 -0700 | [diff] [blame] | 1427 | return count; |
| 1428 | } |
| 1429 | |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 1430 | static bool swap_page_trans_huge_swapped(struct swap_info_struct *si, |
| 1431 | swp_entry_t entry) |
| 1432 | { |
| 1433 | struct swap_cluster_info *ci; |
| 1434 | unsigned char *map = si->swap_map; |
| 1435 | unsigned long roffset = swp_offset(entry); |
| 1436 | unsigned long offset = round_down(roffset, SWAPFILE_CLUSTER); |
| 1437 | int i; |
| 1438 | bool ret = false; |
| 1439 | |
| 1440 | ci = lock_cluster_or_swap_info(si, offset); |
| 1441 | if (!ci || !cluster_is_huge(ci)) { |
Huang Ying | afa4711 | 2018-08-21 21:52:09 -0700 | [diff] [blame] | 1442 | if (swap_count(map[roffset])) |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 1443 | ret = true; |
| 1444 | goto unlock_out; |
| 1445 | } |
| 1446 | for (i = 0; i < SWAPFILE_CLUSTER; i++) { |
Huang Ying | afa4711 | 2018-08-21 21:52:09 -0700 | [diff] [blame] | 1447 | if (swap_count(map[offset + i])) { |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 1448 | ret = true; |
| 1449 | break; |
| 1450 | } |
| 1451 | } |
| 1452 | unlock_out: |
| 1453 | unlock_cluster_or_swap_info(si, ci); |
| 1454 | return ret; |
| 1455 | } |
| 1456 | |
| 1457 | static bool page_swapped(struct page *page) |
| 1458 | { |
| 1459 | swp_entry_t entry; |
| 1460 | struct swap_info_struct *si; |
| 1461 | |
Huang Ying | fe5266d | 2018-08-21 21:52:05 -0700 | [diff] [blame] | 1462 | if (!IS_ENABLED(CONFIG_THP_SWAP) || likely(!PageTransCompound(page))) |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 1463 | return page_swapcount(page) != 0; |
| 1464 | |
| 1465 | page = compound_head(page); |
| 1466 | entry.val = page_private(page); |
| 1467 | si = _swap_info_get(entry); |
| 1468 | if (si) |
| 1469 | return swap_page_trans_huge_swapped(si, entry); |
| 1470 | return false; |
| 1471 | } |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1472 | |
| 1473 | static int page_trans_huge_map_swapcount(struct page *page, int *total_mapcount, |
| 1474 | int *total_swapcount) |
| 1475 | { |
| 1476 | int i, map_swapcount, _total_mapcount, _total_swapcount; |
| 1477 | unsigned long offset = 0; |
| 1478 | struct swap_info_struct *si; |
| 1479 | struct swap_cluster_info *ci = NULL; |
| 1480 | unsigned char *map = NULL; |
| 1481 | int mapcount, swapcount = 0; |
| 1482 | |
| 1483 | /* hugetlbfs shouldn't call it */ |
| 1484 | VM_BUG_ON_PAGE(PageHuge(page), page); |
| 1485 | |
Huang Ying | fe5266d | 2018-08-21 21:52:05 -0700 | [diff] [blame] | 1486 | if (!IS_ENABLED(CONFIG_THP_SWAP) || likely(!PageTransCompound(page))) { |
| 1487 | mapcount = page_trans_huge_mapcount(page, total_mapcount); |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1488 | if (PageSwapCache(page)) |
| 1489 | swapcount = page_swapcount(page); |
| 1490 | if (total_swapcount) |
| 1491 | *total_swapcount = swapcount; |
| 1492 | return mapcount + swapcount; |
| 1493 | } |
| 1494 | |
| 1495 | page = compound_head(page); |
| 1496 | |
| 1497 | _total_mapcount = _total_swapcount = map_swapcount = 0; |
| 1498 | if (PageSwapCache(page)) { |
| 1499 | swp_entry_t entry; |
| 1500 | |
| 1501 | entry.val = page_private(page); |
| 1502 | si = _swap_info_get(entry); |
| 1503 | if (si) { |
| 1504 | map = si->swap_map; |
| 1505 | offset = swp_offset(entry); |
| 1506 | } |
| 1507 | } |
| 1508 | if (map) |
| 1509 | ci = lock_cluster(si, offset); |
| 1510 | for (i = 0; i < HPAGE_PMD_NR; i++) { |
| 1511 | mapcount = atomic_read(&page[i]._mapcount) + 1; |
| 1512 | _total_mapcount += mapcount; |
| 1513 | if (map) { |
| 1514 | swapcount = swap_count(map[offset + i]); |
| 1515 | _total_swapcount += swapcount; |
| 1516 | } |
| 1517 | map_swapcount = max(map_swapcount, mapcount + swapcount); |
| 1518 | } |
| 1519 | unlock_cluster(ci); |
| 1520 | if (PageDoubleMap(page)) { |
| 1521 | map_swapcount -= 1; |
| 1522 | _total_mapcount -= HPAGE_PMD_NR; |
| 1523 | } |
| 1524 | mapcount = compound_mapcount(page); |
| 1525 | map_swapcount += mapcount; |
| 1526 | _total_mapcount += mapcount; |
| 1527 | if (total_mapcount) |
| 1528 | *total_mapcount = _total_mapcount; |
| 1529 | if (total_swapcount) |
| 1530 | *total_swapcount = _total_swapcount; |
| 1531 | |
| 1532 | return map_swapcount; |
| 1533 | } |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 1534 | |
Minchan Kim | 8334b96 | 2015-09-08 15:00:24 -0700 | [diff] [blame] | 1535 | /* |
Hugh Dickins | 7b1fe59 | 2009-01-06 14:39:34 -0800 | [diff] [blame] | 1536 | * We can write to an anon page without COW if there are no other references |
| 1537 | * to it. And as a side-effect, free up its swap: because the old content |
| 1538 | * on disk will never be read, and seeking back there to write new content |
| 1539 | * later would only waste time away from clustering. |
Andrea Arcangeli | 6d0a07e | 2016-05-12 15:42:25 -0700 | [diff] [blame] | 1540 | * |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1541 | * NOTE: total_map_swapcount should not be relied upon by the caller if |
Andrea Arcangeli | 6d0a07e | 2016-05-12 15:42:25 -0700 | [diff] [blame] | 1542 | * reuse_swap_page() returns false, but it may be always overwritten |
| 1543 | * (see the other implementation for CONFIG_SWAP=n). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1544 | */ |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1545 | bool reuse_swap_page(struct page *page, int *total_map_swapcount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1546 | { |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1547 | int count, total_mapcount, total_swapcount; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1548 | |
Sasha Levin | 309381fea | 2014-01-23 15:52:54 -0800 | [diff] [blame] | 1549 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
Hugh Dickins | 5ad6468 | 2009-12-14 17:59:24 -0800 | [diff] [blame] | 1550 | if (unlikely(PageKsm(page))) |
Andrea Arcangeli | 6d0a07e | 2016-05-12 15:42:25 -0700 | [diff] [blame] | 1551 | return false; |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1552 | count = page_trans_huge_map_swapcount(page, &total_mapcount, |
| 1553 | &total_swapcount); |
| 1554 | if (total_map_swapcount) |
| 1555 | *total_map_swapcount = total_mapcount + total_swapcount; |
| 1556 | if (count == 1 && PageSwapCache(page) && |
| 1557 | (likely(!PageTransCompound(page)) || |
| 1558 | /* The remaining swap count will be freed soon */ |
| 1559 | total_swapcount == page_swapcount(page))) { |
Minchan Kim | f057142 | 2017-01-10 16:58:15 -0800 | [diff] [blame] | 1560 | if (!PageWriteback(page)) { |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1561 | page = compound_head(page); |
Hugh Dickins | 7b1fe59 | 2009-01-06 14:39:34 -0800 | [diff] [blame] | 1562 | delete_from_swap_cache(page); |
| 1563 | SetPageDirty(page); |
Minchan Kim | f057142 | 2017-01-10 16:58:15 -0800 | [diff] [blame] | 1564 | } else { |
| 1565 | swp_entry_t entry; |
| 1566 | struct swap_info_struct *p; |
| 1567 | |
| 1568 | entry.val = page_private(page); |
| 1569 | p = swap_info_get(entry); |
| 1570 | if (p->flags & SWP_STABLE_WRITES) { |
| 1571 | spin_unlock(&p->lock); |
| 1572 | return false; |
| 1573 | } |
| 1574 | spin_unlock(&p->lock); |
Hugh Dickins | 7b1fe59 | 2009-01-06 14:39:34 -0800 | [diff] [blame] | 1575 | } |
| 1576 | } |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1577 | |
Hugh Dickins | 5ad6468 | 2009-12-14 17:59:24 -0800 | [diff] [blame] | 1578 | return count <= 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1579 | } |
| 1580 | |
| 1581 | /* |
Hugh Dickins | a2c43ee | 2009-01-06 14:39:36 -0800 | [diff] [blame] | 1582 | * If swap is getting full, or if there are no more mappings of this page, |
| 1583 | * then try_to_free_swap is called to free its swap space. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1584 | */ |
Hugh Dickins | a2c43ee | 2009-01-06 14:39:36 -0800 | [diff] [blame] | 1585 | int try_to_free_swap(struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1586 | { |
Sasha Levin | 309381fea | 2014-01-23 15:52:54 -0800 | [diff] [blame] | 1587 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1588 | |
| 1589 | if (!PageSwapCache(page)) |
| 1590 | return 0; |
| 1591 | if (PageWriteback(page)) |
| 1592 | return 0; |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 1593 | if (page_swapped(page)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1594 | return 0; |
| 1595 | |
Hugh Dickins | b73d7fc | 2010-09-09 16:38:09 -0700 | [diff] [blame] | 1596 | /* |
| 1597 | * Once hibernation has begun to create its image of memory, |
| 1598 | * there's a danger that one of the calls to try_to_free_swap() |
| 1599 | * - most probably a call from __try_to_reclaim_swap() while |
| 1600 | * hibernation is allocating its own swap pages for the image, |
| 1601 | * but conceivably even a call from memory reclaim - will free |
| 1602 | * the swap from a page which has already been recorded in the |
| 1603 | * image as a clean swapcache page, and then reuse its swap for |
| 1604 | * another page of the image. On waking from hibernation, the |
| 1605 | * original page might be freed under memory pressure, then |
| 1606 | * later read back in from swap, now with the wrong data. |
| 1607 | * |
Seth Jennings | 2de1a7e | 2013-11-12 15:07:46 -0800 | [diff] [blame] | 1608 | * Hibernation suspends storage while it is writing the image |
Mel Gorman | f90ac39 | 2012-01-10 15:07:15 -0800 | [diff] [blame] | 1609 | * to disk so check that here. |
Hugh Dickins | b73d7fc | 2010-09-09 16:38:09 -0700 | [diff] [blame] | 1610 | */ |
Mel Gorman | f90ac39 | 2012-01-10 15:07:15 -0800 | [diff] [blame] | 1611 | if (pm_suspended_storage()) |
Hugh Dickins | b73d7fc | 2010-09-09 16:38:09 -0700 | [diff] [blame] | 1612 | return 0; |
| 1613 | |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 1614 | page = compound_head(page); |
Hugh Dickins | a2c43ee | 2009-01-06 14:39:36 -0800 | [diff] [blame] | 1615 | delete_from_swap_cache(page); |
| 1616 | SetPageDirty(page); |
| 1617 | return 1; |
Rik van Riel | 68a22394 | 2008-10-18 20:26:23 -0700 | [diff] [blame] | 1618 | } |
| 1619 | |
| 1620 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1621 | * Free the swap entry like above, but also try to |
| 1622 | * free the page cache entry if it is the last user. |
| 1623 | */ |
Hugh Dickins | 2509ef2 | 2009-01-06 14:40:10 -0800 | [diff] [blame] | 1624 | int free_swap_and_cache(swp_entry_t entry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1625 | { |
Hugh Dickins | 2509ef2 | 2009-01-06 14:40:10 -0800 | [diff] [blame] | 1626 | struct swap_info_struct *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1627 | struct page *page = NULL; |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1628 | unsigned char count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1629 | |
Andi Kleen | a7420aa | 2009-09-16 11:50:05 +0200 | [diff] [blame] | 1630 | if (non_swap_entry(entry)) |
Hugh Dickins | 2509ef2 | 2009-01-06 14:40:10 -0800 | [diff] [blame] | 1631 | return 1; |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 1632 | |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1633 | p = _swap_info_get(entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1634 | if (p) { |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1635 | count = __swap_entry_free(p, entry, 1); |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 1636 | if (count == SWAP_HAS_CACHE && |
| 1637 | !swap_page_trans_huge_swapped(p, entry)) { |
Shaohua Li | 33806f0 | 2013-02-22 16:34:37 -0800 | [diff] [blame] | 1638 | page = find_get_page(swap_address_space(entry), |
Huang Ying | f6ab1f7 | 2016-10-07 17:00:21 -0700 | [diff] [blame] | 1639 | swp_offset(entry)); |
Nick Piggin | 8413ac9 | 2008-10-18 20:26:59 -0700 | [diff] [blame] | 1640 | if (page && !trylock_page(page)) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1641 | put_page(page); |
Nick Piggin | 93fac70 | 2006-03-31 02:29:56 -0800 | [diff] [blame] | 1642 | page = NULL; |
| 1643 | } |
Tim Chen | 7c00baf | 2017-02-22 15:45:36 -0800 | [diff] [blame] | 1644 | } else if (!count) |
Tim Chen | 67afa38 | 2017-02-22 15:45:39 -0800 | [diff] [blame] | 1645 | free_swap_slot(entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1646 | } |
| 1647 | if (page) { |
Hugh Dickins | a2c43ee | 2009-01-06 14:39:36 -0800 | [diff] [blame] | 1648 | /* |
| 1649 | * Not mapped elsewhere, or swap space full? Free it! |
| 1650 | * Also recheck PageSwapCache now page is locked (above). |
| 1651 | */ |
Nick Piggin | 93fac70 | 2006-03-31 02:29:56 -0800 | [diff] [blame] | 1652 | if (PageSwapCache(page) && !PageWriteback(page) && |
Huang Ying | 322b8afe | 2017-05-03 14:52:49 -0700 | [diff] [blame] | 1653 | (!page_mapped(page) || mem_cgroup_swap_full(page)) && |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 1654 | !swap_page_trans_huge_swapped(p, entry)) { |
| 1655 | page = compound_head(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1656 | delete_from_swap_cache(page); |
| 1657 | SetPageDirty(page); |
| 1658 | } |
| 1659 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1660 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1661 | } |
Hugh Dickins | 2509ef2 | 2009-01-06 14:40:10 -0800 | [diff] [blame] | 1662 | return p != NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1663 | } |
| 1664 | |
Rafael J. Wysocki | b0cb1a1 | 2007-07-29 23:24:36 +0200 | [diff] [blame] | 1665 | #ifdef CONFIG_HIBERNATION |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1666 | /* |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1667 | * Find the swap type that corresponds to given device (if any). |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1668 | * |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1669 | * @offset - number of the PAGE_SIZE-sized block of the device, starting |
| 1670 | * from 0, in which the swap header is expected to be located. |
| 1671 | * |
| 1672 | * This is needed for the suspend to disk (aka swsusp). |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1673 | */ |
Rafael J. Wysocki | 7bf2368 | 2007-01-05 16:36:28 -0800 | [diff] [blame] | 1674 | int swap_type_of(dev_t device, sector_t offset, struct block_device **bdev_p) |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1675 | { |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1676 | struct block_device *bdev = NULL; |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 1677 | int type; |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1678 | |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1679 | if (device) |
| 1680 | bdev = bdget(device); |
| 1681 | |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1682 | spin_lock(&swap_lock); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 1683 | for (type = 0; type < nr_swapfiles; type++) { |
| 1684 | struct swap_info_struct *sis = swap_info[type]; |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1685 | |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1686 | if (!(sis->flags & SWP_WRITEOK)) |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1687 | continue; |
Rafael J. Wysocki | b6b5bce | 2006-08-27 01:23:25 -0700 | [diff] [blame] | 1688 | |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1689 | if (!bdev) { |
Rafael J. Wysocki | 7bf2368 | 2007-01-05 16:36:28 -0800 | [diff] [blame] | 1690 | if (bdev_p) |
Alan Jenkins | dddac6a | 2009-07-29 21:07:55 +0200 | [diff] [blame] | 1691 | *bdev_p = bdgrab(sis->bdev); |
Rafael J. Wysocki | 7bf2368 | 2007-01-05 16:36:28 -0800 | [diff] [blame] | 1692 | |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 1693 | spin_unlock(&swap_lock); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 1694 | return type; |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 1695 | } |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1696 | if (bdev == sis->bdev) { |
Hugh Dickins | 9625a5f | 2009-12-14 17:58:42 -0800 | [diff] [blame] | 1697 | struct swap_extent *se = &sis->first_swap_extent; |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1698 | |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1699 | if (se->start_block == offset) { |
Rafael J. Wysocki | 7bf2368 | 2007-01-05 16:36:28 -0800 | [diff] [blame] | 1700 | if (bdev_p) |
Alan Jenkins | dddac6a | 2009-07-29 21:07:55 +0200 | [diff] [blame] | 1701 | *bdev_p = bdgrab(sis->bdev); |
Rafael J. Wysocki | 7bf2368 | 2007-01-05 16:36:28 -0800 | [diff] [blame] | 1702 | |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1703 | spin_unlock(&swap_lock); |
| 1704 | bdput(bdev); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 1705 | return type; |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1706 | } |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1707 | } |
| 1708 | } |
| 1709 | spin_unlock(&swap_lock); |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 1710 | if (bdev) |
| 1711 | bdput(bdev); |
| 1712 | |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1713 | return -ENODEV; |
| 1714 | } |
| 1715 | |
| 1716 | /* |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 1717 | * Get the (PAGE_SIZE) block corresponding to given offset on the swapdev |
| 1718 | * corresponding to given index in swap_info (swap type). |
| 1719 | */ |
| 1720 | sector_t swapdev_block(int type, pgoff_t offset) |
| 1721 | { |
| 1722 | struct block_device *bdev; |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 1723 | struct swap_info_struct *si = swap_type_to_swap_info(type); |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 1724 | |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 1725 | if (!si || !(si->flags & SWP_WRITEOK)) |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 1726 | return 0; |
Lee Schermerhorn | d4906e1 | 2009-12-14 17:58:49 -0800 | [diff] [blame] | 1727 | return map_swap_entry(swp_entry(type, offset), &bdev); |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 1728 | } |
| 1729 | |
| 1730 | /* |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1731 | * Return either the total number of swap pages of given type, or the number |
| 1732 | * of free pages of that type (depending on @free) |
| 1733 | * |
| 1734 | * This is needed for software suspend |
| 1735 | */ |
| 1736 | unsigned int count_swap_pages(int type, int free) |
| 1737 | { |
| 1738 | unsigned int n = 0; |
| 1739 | |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 1740 | spin_lock(&swap_lock); |
| 1741 | if ((unsigned int)type < nr_swapfiles) { |
| 1742 | struct swap_info_struct *sis = swap_info[type]; |
| 1743 | |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 1744 | spin_lock(&sis->lock); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 1745 | if (sis->flags & SWP_WRITEOK) { |
| 1746 | n = sis->pages; |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1747 | if (free) |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 1748 | n -= sis->inuse_pages; |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1749 | } |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 1750 | spin_unlock(&sis->lock); |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1751 | } |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 1752 | spin_unlock(&swap_lock); |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1753 | return n; |
| 1754 | } |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 1755 | #endif /* CONFIG_HIBERNATION */ |
Rafael J. Wysocki | f577eb3 | 2006-03-23 02:59:59 -0800 | [diff] [blame] | 1756 | |
Hugh Dickins | 9f8bdb3 | 2016-01-15 16:57:34 -0800 | [diff] [blame] | 1757 | static inline int pte_same_as_swp(pte_t pte, pte_t swp_pte) |
Cyrill Gorcunov | 179ef71 | 2013-08-13 16:00:49 -0700 | [diff] [blame] | 1758 | { |
Hugh Dickins | 9f8bdb3 | 2016-01-15 16:57:34 -0800 | [diff] [blame] | 1759 | return pte_same(pte_swp_clear_soft_dirty(pte), swp_pte); |
Cyrill Gorcunov | 179ef71 | 2013-08-13 16:00:49 -0700 | [diff] [blame] | 1760 | } |
| 1761 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1762 | /* |
Hugh Dickins | 72866f6 | 2005-10-29 18:15:55 -0700 | [diff] [blame] | 1763 | * No need to decide whether this PTE shares the swap entry with others, |
| 1764 | * just let do_wp_page work it out if a write is requested later - to |
| 1765 | * force COW, vm_page_prot omits write permission from any private vma. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1766 | */ |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1767 | static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1768 | unsigned long addr, swp_entry_t entry, struct page *page) |
| 1769 | { |
Hugh Dickins | 9e16b7f | 2013-02-22 16:36:09 -0800 | [diff] [blame] | 1770 | struct page *swapcache; |
Johannes Weiner | 72835c8 | 2012-01-12 17:18:32 -0800 | [diff] [blame] | 1771 | struct mem_cgroup *memcg; |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1772 | spinlock_t *ptl; |
| 1773 | pte_t *pte; |
| 1774 | int ret = 1; |
| 1775 | |
Hugh Dickins | 9e16b7f | 2013-02-22 16:36:09 -0800 | [diff] [blame] | 1776 | swapcache = page; |
| 1777 | page = ksm_might_need_to_copy(page, vma, addr); |
| 1778 | if (unlikely(!page)) |
| 1779 | return -ENOMEM; |
| 1780 | |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1781 | if (mem_cgroup_try_charge(page, vma->vm_mm, GFP_KERNEL, |
| 1782 | &memcg, false)) { |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1783 | ret = -ENOMEM; |
KAMEZAWA Hiroyuki | 85d9fc8 | 2009-01-29 14:25:13 -0800 | [diff] [blame] | 1784 | goto out_nolock; |
| 1785 | } |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1786 | |
| 1787 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
Hugh Dickins | 9f8bdb3 | 2016-01-15 16:57:34 -0800 | [diff] [blame] | 1788 | if (unlikely(!pte_same_as_swp(*pte, swp_entry_to_pte(entry)))) { |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1789 | mem_cgroup_cancel_charge(page, memcg, false); |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1790 | ret = 0; |
| 1791 | goto out; |
| 1792 | } |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1793 | |
KAMEZAWA Hiroyuki | b084d43 | 2010-03-05 13:41:42 -0800 | [diff] [blame] | 1794 | dec_mm_counter(vma->vm_mm, MM_SWAPENTS); |
KAMEZAWA Hiroyuki | d559db0 | 2010-03-05 13:41:39 -0800 | [diff] [blame] | 1795 | inc_mm_counter(vma->vm_mm, MM_ANONPAGES); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1796 | get_page(page); |
| 1797 | set_pte_at(vma->vm_mm, addr, pte, |
| 1798 | pte_mkold(mk_pte(page, vma->vm_page_prot))); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1799 | if (page == swapcache) { |
Kirill A. Shutemov | d281ee6 | 2016-01-15 16:52:16 -0800 | [diff] [blame] | 1800 | page_add_anon_rmap(page, vma, addr, false); |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1801 | mem_cgroup_commit_charge(page, memcg, true, false); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1802 | } else { /* ksm created a completely new copy */ |
Kirill A. Shutemov | d281ee6 | 2016-01-15 16:52:16 -0800 | [diff] [blame] | 1803 | page_add_new_anon_rmap(page, vma, addr, false); |
Kirill A. Shutemov | f627c2f | 2016-01-15 16:52:20 -0800 | [diff] [blame] | 1804 | mem_cgroup_commit_charge(page, memcg, false, false); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 1805 | lru_cache_add_active_or_unevictable(page, vma); |
| 1806 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1807 | swap_free(entry); |
| 1808 | /* |
| 1809 | * Move the page to the active list so it is not |
| 1810 | * immediately swapped out again after swapon. |
| 1811 | */ |
| 1812 | activate_page(page); |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1813 | out: |
| 1814 | pte_unmap_unlock(pte, ptl); |
KAMEZAWA Hiroyuki | 85d9fc8 | 2009-01-29 14:25:13 -0800 | [diff] [blame] | 1815 | out_nolock: |
Hugh Dickins | 9e16b7f | 2013-02-22 16:36:09 -0800 | [diff] [blame] | 1816 | if (page != swapcache) { |
| 1817 | unlock_page(page); |
| 1818 | put_page(page); |
| 1819 | } |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1820 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1821 | } |
| 1822 | |
| 1823 | static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd, |
| 1824 | unsigned long addr, unsigned long end, |
| 1825 | swp_entry_t entry, struct page *page) |
| 1826 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1827 | pte_t swp_pte = swp_entry_to_pte(entry); |
Hugh Dickins | 705e87c | 2005-10-29 18:16:27 -0700 | [diff] [blame] | 1828 | pte_t *pte; |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1829 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1830 | |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1831 | /* |
| 1832 | * We don't actually need pte lock while scanning for swp_pte: since |
| 1833 | * we hold page lock and mmap_sem, swp_pte cannot be inserted into the |
| 1834 | * page table while we're scanning; though it could get zapped, and on |
| 1835 | * some architectures (e.g. x86_32 with PAE) we might catch a glimpse |
| 1836 | * of unmatched parts which look like swp_pte, so unuse_pte must |
| 1837 | * recheck under pte lock. Scanning without pte lock lets it be |
Seth Jennings | 2de1a7e | 2013-11-12 15:07:46 -0800 | [diff] [blame] | 1838 | * preemptable whenever CONFIG_PREEMPT but not CONFIG_HIGHPTE. |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1839 | */ |
| 1840 | pte = pte_offset_map(pmd, addr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1841 | do { |
| 1842 | /* |
| 1843 | * swapoff spends a _lot_ of time in this loop! |
| 1844 | * Test inline before going to call unuse_pte. |
| 1845 | */ |
Hugh Dickins | 9f8bdb3 | 2016-01-15 16:57:34 -0800 | [diff] [blame] | 1846 | if (unlikely(pte_same_as_swp(*pte, swp_pte))) { |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1847 | pte_unmap(pte); |
| 1848 | ret = unuse_pte(vma, pmd, addr, entry, page); |
| 1849 | if (ret) |
| 1850 | goto out; |
| 1851 | pte = pte_offset_map(pmd, addr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1852 | } |
| 1853 | } while (pte++, addr += PAGE_SIZE, addr != end); |
Hugh Dickins | 044d66c | 2008-02-07 00:14:04 -0800 | [diff] [blame] | 1854 | pte_unmap(pte - 1); |
| 1855 | out: |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1856 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1857 | } |
| 1858 | |
| 1859 | static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud, |
| 1860 | unsigned long addr, unsigned long end, |
| 1861 | swp_entry_t entry, struct page *page) |
| 1862 | { |
| 1863 | pmd_t *pmd; |
| 1864 | unsigned long next; |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1865 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1866 | |
| 1867 | pmd = pmd_offset(pud, addr); |
| 1868 | do { |
Hugh Dickins | dc644a0 | 2016-12-12 16:44:44 -0800 | [diff] [blame] | 1869 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1870 | next = pmd_addr_end(addr, end); |
Andrea Arcangeli | 1a5a990 | 2012-03-21 16:33:42 -0700 | [diff] [blame] | 1871 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1872 | continue; |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1873 | ret = unuse_pte_range(vma, pmd, addr, next, entry, page); |
| 1874 | if (ret) |
| 1875 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1876 | } while (pmd++, addr = next, addr != end); |
| 1877 | return 0; |
| 1878 | } |
| 1879 | |
Kirill A. Shutemov | c2febaf | 2017-03-09 17:24:07 +0300 | [diff] [blame] | 1880 | static inline int unuse_pud_range(struct vm_area_struct *vma, p4d_t *p4d, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1881 | unsigned long addr, unsigned long end, |
| 1882 | swp_entry_t entry, struct page *page) |
| 1883 | { |
| 1884 | pud_t *pud; |
| 1885 | unsigned long next; |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1886 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1887 | |
Kirill A. Shutemov | c2febaf | 2017-03-09 17:24:07 +0300 | [diff] [blame] | 1888 | pud = pud_offset(p4d, addr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1889 | do { |
| 1890 | next = pud_addr_end(addr, end); |
| 1891 | if (pud_none_or_clear_bad(pud)) |
| 1892 | continue; |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1893 | ret = unuse_pmd_range(vma, pud, addr, next, entry, page); |
| 1894 | if (ret) |
| 1895 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1896 | } while (pud++, addr = next, addr != end); |
| 1897 | return 0; |
| 1898 | } |
| 1899 | |
Kirill A. Shutemov | c2febaf | 2017-03-09 17:24:07 +0300 | [diff] [blame] | 1900 | static inline int unuse_p4d_range(struct vm_area_struct *vma, pgd_t *pgd, |
| 1901 | unsigned long addr, unsigned long end, |
| 1902 | swp_entry_t entry, struct page *page) |
| 1903 | { |
| 1904 | p4d_t *p4d; |
| 1905 | unsigned long next; |
| 1906 | int ret; |
| 1907 | |
| 1908 | p4d = p4d_offset(pgd, addr); |
| 1909 | do { |
| 1910 | next = p4d_addr_end(addr, end); |
| 1911 | if (p4d_none_or_clear_bad(p4d)) |
| 1912 | continue; |
| 1913 | ret = unuse_pud_range(vma, p4d, addr, next, entry, page); |
| 1914 | if (ret) |
| 1915 | return ret; |
| 1916 | } while (p4d++, addr = next, addr != end); |
| 1917 | return 0; |
| 1918 | } |
| 1919 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1920 | static int unuse_vma(struct vm_area_struct *vma, |
| 1921 | swp_entry_t entry, struct page *page) |
| 1922 | { |
| 1923 | pgd_t *pgd; |
| 1924 | unsigned long addr, end, next; |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1925 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1926 | |
Hugh Dickins | 3ca7b3c | 2009-12-14 17:58:57 -0800 | [diff] [blame] | 1927 | if (page_anon_vma(page)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1928 | addr = page_address_in_vma(page, vma); |
| 1929 | if (addr == -EFAULT) |
| 1930 | return 0; |
| 1931 | else |
| 1932 | end = addr + PAGE_SIZE; |
| 1933 | } else { |
| 1934 | addr = vma->vm_start; |
| 1935 | end = vma->vm_end; |
| 1936 | } |
| 1937 | |
| 1938 | pgd = pgd_offset(vma->vm_mm, addr); |
| 1939 | do { |
| 1940 | next = pgd_addr_end(addr, end); |
| 1941 | if (pgd_none_or_clear_bad(pgd)) |
| 1942 | continue; |
Kirill A. Shutemov | c2febaf | 2017-03-09 17:24:07 +0300 | [diff] [blame] | 1943 | ret = unuse_p4d_range(vma, pgd, addr, next, entry, page); |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1944 | if (ret) |
| 1945 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1946 | } while (pgd++, addr = next, addr != end); |
| 1947 | return 0; |
| 1948 | } |
| 1949 | |
| 1950 | static int unuse_mm(struct mm_struct *mm, |
| 1951 | swp_entry_t entry, struct page *page) |
| 1952 | { |
| 1953 | struct vm_area_struct *vma; |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1954 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1955 | |
| 1956 | if (!down_read_trylock(&mm->mmap_sem)) { |
| 1957 | /* |
Fernando Luis Vazquez Cao | 7d03431 | 2008-07-29 22:33:41 -0700 | [diff] [blame] | 1958 | * Activate page so shrink_inactive_list is unlikely to unmap |
| 1959 | * its ptes while lock is dropped, so swapoff can make progress. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1960 | */ |
Hugh Dickins | c475a8a | 2005-06-21 17:15:12 -0700 | [diff] [blame] | 1961 | activate_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1962 | unlock_page(page); |
| 1963 | down_read(&mm->mmap_sem); |
| 1964 | lock_page(page); |
| 1965 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1966 | for (vma = mm->mmap; vma; vma = vma->vm_next) { |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1967 | if (vma->anon_vma && (ret = unuse_vma(vma, entry, page))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1968 | break; |
Hugh Dickins | dc644a0 | 2016-12-12 16:44:44 -0800 | [diff] [blame] | 1969 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1970 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1971 | up_read(&mm->mmap_sem); |
Balbir Singh | 8a9f3cc | 2008-02-07 00:13:53 -0800 | [diff] [blame] | 1972 | return (ret < 0)? ret: 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1973 | } |
| 1974 | |
| 1975 | /* |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 1976 | * Scan swap_map (or frontswap_map if frontswap parameter is true) |
| 1977 | * from current position to next entry still in use. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1978 | * Recycle to start on reaching the end, returning 0 when empty. |
| 1979 | */ |
Hugh Dickins | 6eb396d | 2005-09-03 15:54:35 -0700 | [diff] [blame] | 1980 | static unsigned int find_next_to_unuse(struct swap_info_struct *si, |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 1981 | unsigned int prev, bool frontswap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1982 | { |
Hugh Dickins | 6eb396d | 2005-09-03 15:54:35 -0700 | [diff] [blame] | 1983 | unsigned int max = si->max; |
| 1984 | unsigned int i = prev; |
Hugh Dickins | 8d69aae | 2009-12-14 17:58:45 -0800 | [diff] [blame] | 1985 | unsigned char count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1986 | |
| 1987 | /* |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 1988 | * No need for swap_lock here: we're just looking |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1989 | * for whether an entry is in use, not modifying it; false |
| 1990 | * hits are okay, and sys_swapoff() has already prevented new |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 1991 | * allocations from this area (while holding swap_lock). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1992 | */ |
| 1993 | for (;;) { |
| 1994 | if (++i >= max) { |
| 1995 | if (!prev) { |
| 1996 | i = 0; |
| 1997 | break; |
| 1998 | } |
| 1999 | /* |
| 2000 | * No entries in use at top of swap_map, |
| 2001 | * loop back to start and recheck there. |
| 2002 | */ |
| 2003 | max = prev + 1; |
| 2004 | prev = 0; |
| 2005 | i = 1; |
| 2006 | } |
Jason Low | 4db0c3c | 2015-04-15 16:14:08 -0700 | [diff] [blame] | 2007 | count = READ_ONCE(si->swap_map[i]); |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 2008 | if (count && swap_count(count) != SWAP_MAP_BAD) |
Hugh Dickins | dc644a0 | 2016-12-12 16:44:44 -0800 | [diff] [blame] | 2009 | if (!frontswap || frontswap_test(si, i)) |
| 2010 | break; |
| 2011 | if ((i % LATENCY_LIMIT) == 0) |
| 2012 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2013 | } |
| 2014 | return i; |
| 2015 | } |
| 2016 | |
| 2017 | /* |
| 2018 | * We completely avoid races by reading each swap page in advance, |
| 2019 | * and then search for the process using it. All the necessary |
| 2020 | * page table adjustments can then be made atomically. |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 2021 | * |
| 2022 | * if the boolean frontswap is true, only unuse pages_to_unuse pages; |
| 2023 | * pages_to_unuse==0 means all pages; ignored if frontswap is false |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2024 | */ |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 2025 | int try_to_unuse(unsigned int type, bool frontswap, |
| 2026 | unsigned long pages_to_unuse) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2027 | { |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2028 | struct swap_info_struct *si = swap_info[type]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2029 | struct mm_struct *start_mm; |
Shaohua Li | edfe23d | 2013-09-11 14:20:31 -0700 | [diff] [blame] | 2030 | volatile unsigned char *swap_map; /* swap_map is accessed without |
| 2031 | * locking. Mark it as volatile |
| 2032 | * to prevent compiler doing |
| 2033 | * something odd. |
| 2034 | */ |
Hugh Dickins | 8d69aae | 2009-12-14 17:58:45 -0800 | [diff] [blame] | 2035 | unsigned char swcount; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2036 | struct page *page; |
| 2037 | swp_entry_t entry; |
Hugh Dickins | 6eb396d | 2005-09-03 15:54:35 -0700 | [diff] [blame] | 2038 | unsigned int i = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2039 | int retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2040 | |
| 2041 | /* |
| 2042 | * When searching mms for an entry, a good strategy is to |
| 2043 | * start at the first mm we freed the previous entry from |
| 2044 | * (though actually we don't notice whether we or coincidence |
| 2045 | * freed the entry). Initialize this start_mm with a hold. |
| 2046 | * |
| 2047 | * A simpler strategy would be to start at the last mm we |
| 2048 | * freed the previous entry from; but that would take less |
| 2049 | * advantage of mmlist ordering, which clusters forked mms |
| 2050 | * together, child after parent. If we race with dup_mmap(), we |
| 2051 | * prefer to resolve parent before child, lest we miss entries |
| 2052 | * duplicated after we scanned child: using last mm would invert |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 2053 | * that. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2054 | */ |
| 2055 | start_mm = &init_mm; |
Vegard Nossum | 3fce371 | 2017-02-27 14:30:10 -0800 | [diff] [blame] | 2056 | mmget(&init_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2057 | |
| 2058 | /* |
| 2059 | * Keep on scanning until all entries have gone. Usually, |
| 2060 | * one pass through swap_map is enough, but not necessarily: |
| 2061 | * there are races when an instance of an entry might be missed. |
| 2062 | */ |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 2063 | while ((i = find_next_to_unuse(si, i, frontswap)) != 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2064 | if (signal_pending(current)) { |
| 2065 | retval = -EINTR; |
| 2066 | break; |
| 2067 | } |
| 2068 | |
Hugh Dickins | 886bb7e | 2009-01-06 14:39:48 -0800 | [diff] [blame] | 2069 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2070 | * Get a page for the entry, using the existing swap |
| 2071 | * cache page if there is one. Otherwise, get a clean |
Hugh Dickins | 886bb7e | 2009-01-06 14:39:48 -0800 | [diff] [blame] | 2072 | * page and read the swap into it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2073 | */ |
| 2074 | swap_map = &si->swap_map[i]; |
| 2075 | entry = swp_entry(type, i); |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 2076 | page = read_swap_cache_async(entry, |
Shaohua Li | 2395562 | 2017-07-10 15:47:11 -0700 | [diff] [blame] | 2077 | GFP_HIGHUSER_MOVABLE, NULL, 0, false); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2078 | if (!page) { |
| 2079 | /* |
| 2080 | * Either swap_duplicate() failed because entry |
| 2081 | * has been freed independently, and will not be |
| 2082 | * reused since sys_swapoff() already disabled |
| 2083 | * allocation from here, or alloc_page() failed. |
| 2084 | */ |
Shaohua Li | edfe23d | 2013-09-11 14:20:31 -0700 | [diff] [blame] | 2085 | swcount = *swap_map; |
| 2086 | /* |
| 2087 | * We don't hold lock here, so the swap entry could be |
| 2088 | * SWAP_MAP_BAD (when the cluster is discarding). |
| 2089 | * Instead of fail out, We can just skip the swap |
| 2090 | * entry because swapoff will wait for discarding |
| 2091 | * finish anyway. |
| 2092 | */ |
| 2093 | if (!swcount || swcount == SWAP_MAP_BAD) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2094 | continue; |
| 2095 | retval = -ENOMEM; |
| 2096 | break; |
| 2097 | } |
| 2098 | |
| 2099 | /* |
| 2100 | * Don't hold on to start_mm if it looks like exiting. |
| 2101 | */ |
| 2102 | if (atomic_read(&start_mm->mm_users) == 1) { |
| 2103 | mmput(start_mm); |
| 2104 | start_mm = &init_mm; |
Vegard Nossum | 3fce371 | 2017-02-27 14:30:10 -0800 | [diff] [blame] | 2105 | mmget(&init_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2106 | } |
| 2107 | |
| 2108 | /* |
| 2109 | * Wait for and lock page. When do_swap_page races with |
| 2110 | * try_to_unuse, do_swap_page can handle the fault much |
| 2111 | * faster than try_to_unuse can locate the entry. This |
| 2112 | * apparently redundant "wait_on_page_locked" lets try_to_unuse |
| 2113 | * defer to do_swap_page in such a case - in some tests, |
| 2114 | * do_swap_page and try_to_unuse repeatedly compete. |
| 2115 | */ |
| 2116 | wait_on_page_locked(page); |
| 2117 | wait_on_page_writeback(page); |
| 2118 | lock_page(page); |
| 2119 | wait_on_page_writeback(page); |
| 2120 | |
| 2121 | /* |
| 2122 | * Remove all references to entry. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2123 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2124 | swcount = *swap_map; |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 2125 | if (swap_count(swcount) == SWAP_MAP_SHMEM) { |
| 2126 | retval = shmem_unuse(entry, page); |
| 2127 | /* page has already been unlocked and released */ |
| 2128 | if (retval < 0) |
| 2129 | break; |
| 2130 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2131 | } |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 2132 | if (swap_count(swcount) && start_mm != &init_mm) |
| 2133 | retval = unuse_mm(start_mm, entry, page); |
| 2134 | |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 2135 | if (swap_count(*swap_map)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2136 | int set_start_mm = (*swap_map >= swcount); |
| 2137 | struct list_head *p = &start_mm->mmlist; |
| 2138 | struct mm_struct *new_start_mm = start_mm; |
| 2139 | struct mm_struct *prev_mm = start_mm; |
| 2140 | struct mm_struct *mm; |
| 2141 | |
Vegard Nossum | 3fce371 | 2017-02-27 14:30:10 -0800 | [diff] [blame] | 2142 | mmget(new_start_mm); |
| 2143 | mmget(prev_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2144 | spin_lock(&mmlist_lock); |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 2145 | while (swap_count(*swap_map) && !retval && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2146 | (p = p->next) != &start_mm->mmlist) { |
| 2147 | mm = list_entry(p, struct mm_struct, mmlist); |
Vegard Nossum | 388f793 | 2017-02-27 14:30:13 -0800 | [diff] [blame] | 2148 | if (!mmget_not_zero(mm)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2149 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2150 | spin_unlock(&mmlist_lock); |
| 2151 | mmput(prev_mm); |
| 2152 | prev_mm = mm; |
| 2153 | |
| 2154 | cond_resched(); |
| 2155 | |
| 2156 | swcount = *swap_map; |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 2157 | if (!swap_count(swcount)) /* any usage ? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2158 | ; |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 2159 | else if (mm == &init_mm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2160 | set_start_mm = 1; |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 2161 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2162 | retval = unuse_mm(mm, entry, page); |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 2163 | |
Bo Liu | 32c5fc1 | 2009-11-02 16:50:33 +0000 | [diff] [blame] | 2164 | if (set_start_mm && *swap_map < swcount) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2165 | mmput(new_start_mm); |
Vegard Nossum | 3fce371 | 2017-02-27 14:30:10 -0800 | [diff] [blame] | 2166 | mmget(mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2167 | new_start_mm = mm; |
| 2168 | set_start_mm = 0; |
| 2169 | } |
| 2170 | spin_lock(&mmlist_lock); |
| 2171 | } |
| 2172 | spin_unlock(&mmlist_lock); |
| 2173 | mmput(prev_mm); |
| 2174 | mmput(start_mm); |
| 2175 | start_mm = new_start_mm; |
| 2176 | } |
| 2177 | if (retval) { |
| 2178 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2179 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2180 | break; |
| 2181 | } |
| 2182 | |
| 2183 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2184 | * If a reference remains (rare), we would like to leave |
| 2185 | * the page in the swap cache; but try_to_unmap could |
| 2186 | * then re-duplicate the entry once we drop page lock, |
| 2187 | * so we might loop indefinitely; also, that page could |
| 2188 | * not be swapped out to other storage meanwhile. So: |
| 2189 | * delete from cache even if there's another reference, |
| 2190 | * after ensuring that the data has been saved to disk - |
| 2191 | * since if the reference remains (rarer), it will be |
| 2192 | * read from disk into another page. Splitting into two |
| 2193 | * pages would be incorrect if swap supported "shared |
| 2194 | * private" pages, but they are handled by tmpfs files. |
Hugh Dickins | 5ad6468 | 2009-12-14 17:59:24 -0800 | [diff] [blame] | 2195 | * |
| 2196 | * Given how unuse_vma() targets one particular offset |
| 2197 | * in an anon_vma, once the anon_vma has been determined, |
| 2198 | * this splitting happens to be just what is needed to |
| 2199 | * handle where KSM pages have been swapped out: re-reading |
| 2200 | * is unnecessarily slow, but we can fix that later on. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2201 | */ |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 2202 | if (swap_count(*swap_map) && |
| 2203 | PageDirty(page) && PageSwapCache(page)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2204 | struct writeback_control wbc = { |
| 2205 | .sync_mode = WB_SYNC_NONE, |
| 2206 | }; |
| 2207 | |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 2208 | swap_writepage(compound_head(page), &wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2209 | lock_page(page); |
| 2210 | wait_on_page_writeback(page); |
| 2211 | } |
Hugh Dickins | 68bdc8d | 2009-01-06 14:39:37 -0800 | [diff] [blame] | 2212 | |
| 2213 | /* |
| 2214 | * It is conceivable that a racing task removed this page from |
| 2215 | * swap cache just before we acquired the page lock at the top, |
| 2216 | * or while we dropped it in unuse_mm(). The page might even |
| 2217 | * be back in swap cache on another swap area: that we must not |
| 2218 | * delete, since it may not have been written out to swap yet. |
| 2219 | */ |
| 2220 | if (PageSwapCache(page) && |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 2221 | likely(page_private(page) == entry.val) && |
Huang Ying | 8da7075 | 2018-12-28 00:39:53 -0800 | [diff] [blame] | 2222 | (!PageTransCompound(page) || |
| 2223 | !swap_page_trans_huge_swapped(si, entry))) |
Huang Ying | e070982 | 2017-09-06 16:22:16 -0700 | [diff] [blame] | 2224 | delete_from_swap_cache(compound_head(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2225 | |
| 2226 | /* |
| 2227 | * So we could skip searching mms once swap count went |
| 2228 | * to 1, we did not mark any present ptes as dirty: must |
Anderson Briglia | 2706a1b | 2007-07-15 23:38:09 -0700 | [diff] [blame] | 2229 | * mark page dirty so shrink_page_list will preserve it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2230 | */ |
| 2231 | SetPageDirty(page); |
| 2232 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2233 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2234 | |
| 2235 | /* |
| 2236 | * Make sure that we aren't completely killing |
| 2237 | * interactive performance. |
| 2238 | */ |
| 2239 | cond_resched(); |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 2240 | if (frontswap && pages_to_unuse > 0) { |
| 2241 | if (!--pages_to_unuse) |
| 2242 | break; |
| 2243 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2244 | } |
| 2245 | |
| 2246 | mmput(start_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2247 | return retval; |
| 2248 | } |
| 2249 | |
| 2250 | /* |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2251 | * After a successful try_to_unuse, if no swap is now in use, we know |
| 2252 | * we can empty the mmlist. swap_lock must be held on entry and exit. |
| 2253 | * Note that mmlist_lock nests inside swap_lock, and an mm must be |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2254 | * added to the mmlist just after page_duplicate - before would be racy. |
| 2255 | */ |
| 2256 | static void drain_mmlist(void) |
| 2257 | { |
| 2258 | struct list_head *p, *next; |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2259 | unsigned int type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2260 | |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2261 | for (type = 0; type < nr_swapfiles; type++) |
| 2262 | if (swap_info[type]->inuse_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2263 | return; |
| 2264 | spin_lock(&mmlist_lock); |
| 2265 | list_for_each_safe(p, next, &init_mm.mmlist) |
| 2266 | list_del_init(p); |
| 2267 | spin_unlock(&mmlist_lock); |
| 2268 | } |
| 2269 | |
| 2270 | /* |
| 2271 | * Use this swapdev's extent info to locate the (PAGE_SIZE) block which |
Lee Schermerhorn | d4906e1 | 2009-12-14 17:58:49 -0800 | [diff] [blame] | 2272 | * corresponds to page offset for the specified swap entry. |
| 2273 | * Note that the type of this function is sector_t, but it returns page offset |
| 2274 | * into the bdev, not sector offset. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2275 | */ |
Lee Schermerhorn | d4906e1 | 2009-12-14 17:58:49 -0800 | [diff] [blame] | 2276 | static sector_t map_swap_entry(swp_entry_t entry, struct block_device **bdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2277 | { |
Hugh Dickins | f29ad6a | 2009-12-14 17:58:40 -0800 | [diff] [blame] | 2278 | struct swap_info_struct *sis; |
| 2279 | struct swap_extent *start_se; |
| 2280 | struct swap_extent *se; |
| 2281 | pgoff_t offset; |
| 2282 | |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 2283 | sis = swp_swap_info(entry); |
Hugh Dickins | f29ad6a | 2009-12-14 17:58:40 -0800 | [diff] [blame] | 2284 | *bdev = sis->bdev; |
| 2285 | |
| 2286 | offset = swp_offset(entry); |
| 2287 | start_se = sis->curr_swap_extent; |
| 2288 | se = start_se; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2289 | |
| 2290 | for ( ; ; ) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2291 | if (se->start_page <= offset && |
| 2292 | offset < (se->start_page + se->nr_pages)) { |
| 2293 | return se->start_block + (offset - se->start_page); |
| 2294 | } |
Geliang Tang | a8ae499 | 2016-01-14 15:20:45 -0800 | [diff] [blame] | 2295 | se = list_next_entry(se, list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2296 | sis->curr_swap_extent = se; |
| 2297 | BUG_ON(se == start_se); /* It *must* be present */ |
| 2298 | } |
| 2299 | } |
| 2300 | |
| 2301 | /* |
Lee Schermerhorn | d4906e1 | 2009-12-14 17:58:49 -0800 | [diff] [blame] | 2302 | * Returns the page offset into bdev for the specified page's swap entry. |
| 2303 | */ |
| 2304 | sector_t map_swap_page(struct page *page, struct block_device **bdev) |
| 2305 | { |
| 2306 | swp_entry_t entry; |
| 2307 | entry.val = page_private(page); |
| 2308 | return map_swap_entry(entry, bdev); |
| 2309 | } |
| 2310 | |
| 2311 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2312 | * Free all of a swapdev's extent information |
| 2313 | */ |
| 2314 | static void destroy_swap_extents(struct swap_info_struct *sis) |
| 2315 | { |
Hugh Dickins | 9625a5f | 2009-12-14 17:58:42 -0800 | [diff] [blame] | 2316 | while (!list_empty(&sis->first_swap_extent.list)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2317 | struct swap_extent *se; |
| 2318 | |
Geliang Tang | a8ae499 | 2016-01-14 15:20:45 -0800 | [diff] [blame] | 2319 | se = list_first_entry(&sis->first_swap_extent.list, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2320 | struct swap_extent, list); |
| 2321 | list_del(&se->list); |
| 2322 | kfree(se); |
| 2323 | } |
Mel Gorman | 62c230b | 2012-07-31 16:44:55 -0700 | [diff] [blame] | 2324 | |
| 2325 | if (sis->flags & SWP_FILE) { |
| 2326 | struct file *swap_file = sis->swap_file; |
| 2327 | struct address_space *mapping = swap_file->f_mapping; |
| 2328 | |
| 2329 | sis->flags &= ~SWP_FILE; |
| 2330 | mapping->a_ops->swap_deactivate(swap_file); |
| 2331 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2332 | } |
| 2333 | |
| 2334 | /* |
| 2335 | * Add a block range (and the corresponding page range) into this swapdev's |
Hugh Dickins | 11d3188 | 2005-09-03 15:54:34 -0700 | [diff] [blame] | 2336 | * extent list. The extent list is kept sorted in page order. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2337 | * |
Hugh Dickins | 11d3188 | 2005-09-03 15:54:34 -0700 | [diff] [blame] | 2338 | * This function rather assumes that it is called in ascending page order. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2339 | */ |
Mel Gorman | a509bc1 | 2012-07-31 16:44:57 -0700 | [diff] [blame] | 2340 | int |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2341 | add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, |
| 2342 | unsigned long nr_pages, sector_t start_block) |
| 2343 | { |
| 2344 | struct swap_extent *se; |
| 2345 | struct swap_extent *new_se; |
| 2346 | struct list_head *lh; |
| 2347 | |
Hugh Dickins | 9625a5f | 2009-12-14 17:58:42 -0800 | [diff] [blame] | 2348 | if (start_page == 0) { |
| 2349 | se = &sis->first_swap_extent; |
| 2350 | sis->curr_swap_extent = se; |
| 2351 | se->start_page = 0; |
| 2352 | se->nr_pages = nr_pages; |
| 2353 | se->start_block = start_block; |
| 2354 | return 1; |
| 2355 | } else { |
| 2356 | lh = sis->first_swap_extent.list.prev; /* Highest extent */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2357 | se = list_entry(lh, struct swap_extent, list); |
Hugh Dickins | 11d3188 | 2005-09-03 15:54:34 -0700 | [diff] [blame] | 2358 | BUG_ON(se->start_page + se->nr_pages != start_page); |
| 2359 | if (se->start_block + se->nr_pages == start_block) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2360 | /* Merge it */ |
| 2361 | se->nr_pages += nr_pages; |
| 2362 | return 0; |
| 2363 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2364 | } |
| 2365 | |
| 2366 | /* |
| 2367 | * No merge. Insert a new extent, preserving ordering. |
| 2368 | */ |
| 2369 | new_se = kmalloc(sizeof(*se), GFP_KERNEL); |
| 2370 | if (new_se == NULL) |
| 2371 | return -ENOMEM; |
| 2372 | new_se->start_page = start_page; |
| 2373 | new_se->nr_pages = nr_pages; |
| 2374 | new_se->start_block = start_block; |
| 2375 | |
Hugh Dickins | 9625a5f | 2009-12-14 17:58:42 -0800 | [diff] [blame] | 2376 | list_add_tail(&new_se->list, &sis->first_swap_extent.list); |
Hugh Dickins | 53092a7 | 2005-09-03 15:54:34 -0700 | [diff] [blame] | 2377 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2378 | } |
| 2379 | |
| 2380 | /* |
| 2381 | * A `swap extent' is a simple thing which maps a contiguous range of pages |
| 2382 | * onto a contiguous range of disk blocks. An ordered list of swap extents |
| 2383 | * is built at swapon time and is then used at swap_writepage/swap_readpage |
| 2384 | * time for locating where on disk a page belongs. |
| 2385 | * |
| 2386 | * If the swapfile is an S_ISBLK block device, a single extent is installed. |
| 2387 | * This is done so that the main operating code can treat S_ISBLK and S_ISREG |
| 2388 | * swap files identically. |
| 2389 | * |
| 2390 | * Whether the swapdev is an S_ISREG file or an S_ISBLK blockdev, the swap |
| 2391 | * extent list operates in PAGE_SIZE disk blocks. Both S_ISREG and S_ISBLK |
| 2392 | * swapfiles are handled *identically* after swapon time. |
| 2393 | * |
| 2394 | * For S_ISREG swapfiles, setup_swap_extents() will walk all the file's blocks |
| 2395 | * and will parse them into an ordered extent list, in PAGE_SIZE chunks. If |
| 2396 | * some stray blocks are found which do not fall within the PAGE_SIZE alignment |
| 2397 | * requirements, they are simply tossed out - we will never use those blocks |
| 2398 | * for swapping. |
| 2399 | * |
Hugh Dickins | b0d9bcd | 2005-09-03 15:54:31 -0700 | [diff] [blame] | 2400 | * For S_ISREG swapfiles we set S_SWAPFILE across the life of the swapon. This |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2401 | * prevents root from shooting her foot off by ftruncating an in-use swapfile, |
| 2402 | * which will scribble on the fs. |
| 2403 | * |
| 2404 | * The amount of disk space which a single swap extent represents varies. |
| 2405 | * Typically it is in the 1-4 megabyte range. So we can have hundreds of |
| 2406 | * extents in the list. To avoid much list walking, we cache the previous |
| 2407 | * search location in `curr_swap_extent', and start new searches from there. |
| 2408 | * This is extremely effective. The average number of iterations in |
| 2409 | * map_swap_page() has been measured at about 0.3 per page. - akpm. |
| 2410 | */ |
Hugh Dickins | 53092a7 | 2005-09-03 15:54:34 -0700 | [diff] [blame] | 2411 | static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2412 | { |
Mel Gorman | 62c230b | 2012-07-31 16:44:55 -0700 | [diff] [blame] | 2413 | struct file *swap_file = sis->swap_file; |
| 2414 | struct address_space *mapping = swap_file->f_mapping; |
| 2415 | struct inode *inode = mapping->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2416 | int ret; |
| 2417 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2418 | if (S_ISBLK(inode->i_mode)) { |
| 2419 | ret = add_swap_extent(sis, 0, sis->max, 0); |
Hugh Dickins | 53092a7 | 2005-09-03 15:54:34 -0700 | [diff] [blame] | 2420 | *span = sis->pages; |
Mel Gorman | a509bc1 | 2012-07-31 16:44:57 -0700 | [diff] [blame] | 2421 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2422 | } |
| 2423 | |
Mel Gorman | 62c230b | 2012-07-31 16:44:55 -0700 | [diff] [blame] | 2424 | if (mapping->a_ops->swap_activate) { |
Mel Gorman | a509bc1 | 2012-07-31 16:44:57 -0700 | [diff] [blame] | 2425 | ret = mapping->a_ops->swap_activate(sis, swap_file, span); |
Mel Gorman | 62c230b | 2012-07-31 16:44:55 -0700 | [diff] [blame] | 2426 | if (!ret) { |
| 2427 | sis->flags |= SWP_FILE; |
| 2428 | ret = add_swap_extent(sis, 0, sis->max, 0); |
| 2429 | *span = sis->pages; |
| 2430 | } |
Mel Gorman | a509bc1 | 2012-07-31 16:44:57 -0700 | [diff] [blame] | 2431 | return ret; |
Mel Gorman | 62c230b | 2012-07-31 16:44:55 -0700 | [diff] [blame] | 2432 | } |
| 2433 | |
Mel Gorman | a509bc1 | 2012-07-31 16:44:57 -0700 | [diff] [blame] | 2434 | return generic_swapfile_activate(sis, swap_file, span); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2435 | } |
| 2436 | |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 2437 | static int swap_node(struct swap_info_struct *p) |
| 2438 | { |
| 2439 | struct block_device *bdev; |
| 2440 | |
| 2441 | if (p->bdev) |
| 2442 | bdev = p->bdev; |
| 2443 | else |
| 2444 | bdev = p->swap_file->f_inode->i_sb->s_bdev; |
| 2445 | |
| 2446 | return bdev ? bdev->bd_disk->node_id : NUMA_NO_NODE; |
| 2447 | } |
| 2448 | |
Cesar Eduardo Barros | cf0cac0 | 2012-12-11 16:01:13 -0800 | [diff] [blame] | 2449 | static void _enable_swap_info(struct swap_info_struct *p, int prio, |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 2450 | unsigned char *swap_map, |
| 2451 | struct swap_cluster_info *cluster_info) |
Cesar Eduardo Barros | 4053154 | 2011-03-22 16:33:37 -0700 | [diff] [blame] | 2452 | { |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 2453 | int i; |
| 2454 | |
Cesar Eduardo Barros | 4053154 | 2011-03-22 16:33:37 -0700 | [diff] [blame] | 2455 | if (prio >= 0) |
| 2456 | p->prio = prio; |
| 2457 | else |
| 2458 | p->prio = --least_priority; |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 2459 | /* |
| 2460 | * the plist prio is negated because plist ordering is |
| 2461 | * low-to-high, while swap ordering is high-to-low |
| 2462 | */ |
| 2463 | p->list.prio = -p->prio; |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 2464 | for_each_node(i) { |
| 2465 | if (p->prio >= 0) |
| 2466 | p->avail_lists[i].prio = -p->prio; |
| 2467 | else { |
| 2468 | if (swap_node(p) == i) |
| 2469 | p->avail_lists[i].prio = 1; |
| 2470 | else |
| 2471 | p->avail_lists[i].prio = -p->prio; |
| 2472 | } |
| 2473 | } |
Cesar Eduardo Barros | 4053154 | 2011-03-22 16:33:37 -0700 | [diff] [blame] | 2474 | p->swap_map = swap_map; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 2475 | p->cluster_info = cluster_info; |
Cesar Eduardo Barros | 4053154 | 2011-03-22 16:33:37 -0700 | [diff] [blame] | 2476 | p->flags |= SWP_WRITEOK; |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2477 | atomic_long_add(p->pages, &nr_swap_pages); |
Cesar Eduardo Barros | 4053154 | 2011-03-22 16:33:37 -0700 | [diff] [blame] | 2478 | total_swap_pages += p->pages; |
| 2479 | |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2480 | assert_spin_locked(&swap_lock); |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2481 | /* |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 2482 | * both lists are plists, and thus priority ordered. |
| 2483 | * swap_active_head needs to be priority ordered for swapoff(), |
| 2484 | * which on removal of any swap_info_struct with an auto-assigned |
| 2485 | * (i.e. negative) priority increments the auto-assigned priority |
| 2486 | * of any lower-priority swap_info_structs. |
| 2487 | * swap_avail_head needs to be priority ordered for get_swap_page(), |
| 2488 | * which allocates swap pages from the highest available priority |
| 2489 | * swap_info_struct. |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2490 | */ |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 2491 | plist_add(&p->list, &swap_active_head); |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 2492 | add_to_avail_list(p); |
Cesar Eduardo Barros | cf0cac0 | 2012-12-11 16:01:13 -0800 | [diff] [blame] | 2493 | } |
| 2494 | |
| 2495 | static void enable_swap_info(struct swap_info_struct *p, int prio, |
| 2496 | unsigned char *swap_map, |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 2497 | struct swap_cluster_info *cluster_info, |
Cesar Eduardo Barros | cf0cac0 | 2012-12-11 16:01:13 -0800 | [diff] [blame] | 2498 | unsigned long *frontswap_map) |
| 2499 | { |
Minchan Kim | 4f89849 | 2013-04-30 15:26:54 -0700 | [diff] [blame] | 2500 | frontswap_init(p->type, frontswap_map); |
Cesar Eduardo Barros | cf0cac0 | 2012-12-11 16:01:13 -0800 | [diff] [blame] | 2501 | spin_lock(&swap_lock); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2502 | spin_lock(&p->lock); |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 2503 | _enable_swap_info(p, prio, swap_map, cluster_info); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2504 | spin_unlock(&p->lock); |
Cesar Eduardo Barros | cf0cac0 | 2012-12-11 16:01:13 -0800 | [diff] [blame] | 2505 | spin_unlock(&swap_lock); |
| 2506 | } |
| 2507 | |
| 2508 | static void reinsert_swap_info(struct swap_info_struct *p) |
| 2509 | { |
| 2510 | spin_lock(&swap_lock); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2511 | spin_lock(&p->lock); |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 2512 | _enable_swap_info(p, p->prio, p->swap_map, p->cluster_info); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2513 | spin_unlock(&p->lock); |
Cesar Eduardo Barros | 4053154 | 2011-03-22 16:33:37 -0700 | [diff] [blame] | 2514 | spin_unlock(&swap_lock); |
| 2515 | } |
| 2516 | |
Tim Chen | 67afa38 | 2017-02-22 15:45:39 -0800 | [diff] [blame] | 2517 | bool has_usable_swap(void) |
| 2518 | { |
| 2519 | bool ret = true; |
| 2520 | |
| 2521 | spin_lock(&swap_lock); |
| 2522 | if (plist_head_empty(&swap_active_head)) |
| 2523 | ret = false; |
| 2524 | spin_unlock(&swap_lock); |
| 2525 | return ret; |
| 2526 | } |
| 2527 | |
Heiko Carstens | c4ea37c | 2009-01-14 14:14:28 +0100 | [diff] [blame] | 2528 | SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2529 | { |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 2530 | struct swap_info_struct *p = NULL; |
Hugh Dickins | 8d69aae | 2009-12-14 17:58:45 -0800 | [diff] [blame] | 2531 | unsigned char *swap_map; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 2532 | struct swap_cluster_info *cluster_info; |
Minchan Kim | 4f89849 | 2013-04-30 15:26:54 -0700 | [diff] [blame] | 2533 | unsigned long *frontswap_map; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2534 | struct file *swap_file, *victim; |
| 2535 | struct address_space *mapping; |
| 2536 | struct inode *inode; |
Jeff Layton | 91a27b2 | 2012-10-10 15:25:28 -0400 | [diff] [blame] | 2537 | struct filename *pathname; |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2538 | int err, found = 0; |
Krzysztof Kozlowski | 5b808a2 | 2013-10-16 13:47:06 -0700 | [diff] [blame] | 2539 | unsigned int old_block_size; |
Hugh Dickins | 886bb7e | 2009-01-06 14:39:48 -0800 | [diff] [blame] | 2540 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2541 | if (!capable(CAP_SYS_ADMIN)) |
| 2542 | return -EPERM; |
| 2543 | |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 2544 | BUG_ON(!current->mm); |
| 2545 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2546 | pathname = getname(specialfile); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2547 | if (IS_ERR(pathname)) |
Xiaotian Feng | f58b59c | 2012-11-16 14:14:55 -0800 | [diff] [blame] | 2548 | return PTR_ERR(pathname); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2549 | |
Jeff Layton | 669abf4 | 2012-10-10 16:43:10 -0400 | [diff] [blame] | 2550 | victim = file_open_name(pathname, O_RDWR|O_LARGEFILE, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2551 | err = PTR_ERR(victim); |
| 2552 | if (IS_ERR(victim)) |
| 2553 | goto out; |
| 2554 | |
| 2555 | mapping = victim->f_mapping; |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2556 | spin_lock(&swap_lock); |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 2557 | plist_for_each_entry(p, &swap_active_head, list) { |
Hugh Dickins | 22c6f8fd | 2009-01-06 14:39:48 -0800 | [diff] [blame] | 2558 | if (p->flags & SWP_WRITEOK) { |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2559 | if (p->swap_file->f_mapping == mapping) { |
| 2560 | found = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2561 | break; |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2562 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2563 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2564 | } |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2565 | if (!found) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2566 | err = -EINVAL; |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2567 | spin_unlock(&swap_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2568 | goto out_dput; |
| 2569 | } |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 2570 | if (!security_vm_enough_memory_mm(current->mm, p->pages)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2571 | vm_unacct_memory(p->pages); |
| 2572 | else { |
| 2573 | err = -ENOMEM; |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2574 | spin_unlock(&swap_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2575 | goto out_dput; |
| 2576 | } |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 2577 | del_from_avail_list(p); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2578 | spin_lock(&p->lock); |
Hugh Dickins | 78ecba0 | 2008-07-23 21:28:23 -0700 | [diff] [blame] | 2579 | if (p->prio < 0) { |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2580 | struct swap_info_struct *si = p; |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 2581 | int nid; |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2582 | |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 2583 | plist_for_each_entry_continue(si, &swap_active_head, list) { |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2584 | si->prio++; |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 2585 | si->list.prio--; |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 2586 | for_each_node(nid) { |
| 2587 | if (si->avail_lists[nid].prio != 1) |
| 2588 | si->avail_lists[nid].prio--; |
| 2589 | } |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2590 | } |
Hugh Dickins | 78ecba0 | 2008-07-23 21:28:23 -0700 | [diff] [blame] | 2591 | least_priority++; |
| 2592 | } |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 2593 | plist_del(&p->list, &swap_active_head); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2594 | atomic_long_sub(p->pages, &nr_swap_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2595 | total_swap_pages -= p->pages; |
| 2596 | p->flags &= ~SWP_WRITEOK; |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2597 | spin_unlock(&p->lock); |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2598 | spin_unlock(&swap_lock); |
Hugh Dickins | fb4f88d | 2005-09-03 15:54:37 -0700 | [diff] [blame] | 2599 | |
Tim Chen | 039939a | 2017-02-22 15:45:43 -0800 | [diff] [blame] | 2600 | disable_swap_slots_cache_lock(); |
| 2601 | |
David Rientjes | e1e12d2 | 2012-12-11 16:02:56 -0800 | [diff] [blame] | 2602 | set_current_oom_origin(); |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2603 | err = try_to_unuse(p->type, false, 0); /* force unuse all pages */ |
David Rientjes | e1e12d2 | 2012-12-11 16:02:56 -0800 | [diff] [blame] | 2604 | clear_current_oom_origin(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2605 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2606 | if (err) { |
| 2607 | /* re-insert swap space back into swap_list */ |
Cesar Eduardo Barros | cf0cac0 | 2012-12-11 16:01:13 -0800 | [diff] [blame] | 2608 | reinsert_swap_info(p); |
Tim Chen | 039939a | 2017-02-22 15:45:43 -0800 | [diff] [blame] | 2609 | reenable_swap_slots_cache_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2610 | goto out_dput; |
| 2611 | } |
Hugh Dickins | 52b7efdb | 2005-09-03 15:54:39 -0700 | [diff] [blame] | 2612 | |
Tim Chen | 039939a | 2017-02-22 15:45:43 -0800 | [diff] [blame] | 2613 | reenable_swap_slots_cache_unlock(); |
| 2614 | |
Shaohua Li | 815c2c5 | 2013-09-11 14:20:30 -0700 | [diff] [blame] | 2615 | flush_work(&p->discard_work); |
| 2616 | |
Hugh Dickins | 4cd3bb1 | 2005-09-03 15:54:33 -0700 | [diff] [blame] | 2617 | destroy_swap_extents(p); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 2618 | if (p->flags & SWP_CONTINUED) |
| 2619 | free_swap_count_continuations(p); |
| 2620 | |
Huang Ying | 81a0298 | 2017-09-06 16:24:43 -0700 | [diff] [blame] | 2621 | if (!p->bdev || !blk_queue_nonrot(bdev_get_queue(p->bdev))) |
| 2622 | atomic_dec(&nr_rotate_swap); |
| 2623 | |
Ingo Molnar | fc0abb1 | 2006-01-18 17:42:33 -0800 | [diff] [blame] | 2624 | mutex_lock(&swapon_mutex); |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2625 | spin_lock(&swap_lock); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2626 | spin_lock(&p->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2627 | drain_mmlist(); |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2628 | |
| 2629 | /* wait for anyone still in scan_swap_map */ |
| 2630 | p->highest_bit = 0; /* cuts scans short */ |
| 2631 | while (p->flags >= SWP_SCANNING) { |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2632 | spin_unlock(&p->lock); |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2633 | spin_unlock(&swap_lock); |
Nishanth Aravamudan | 13e4b57 | 2005-09-10 00:27:25 -0700 | [diff] [blame] | 2634 | schedule_timeout_uninterruptible(1); |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2635 | spin_lock(&swap_lock); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2636 | spin_lock(&p->lock); |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2637 | } |
| 2638 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2639 | swap_file = p->swap_file; |
Krzysztof Kozlowski | 5b808a2 | 2013-10-16 13:47:06 -0700 | [diff] [blame] | 2640 | old_block_size = p->old_block_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2641 | p->swap_file = NULL; |
| 2642 | p->max = 0; |
| 2643 | swap_map = p->swap_map; |
| 2644 | p->swap_map = NULL; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 2645 | cluster_info = p->cluster_info; |
| 2646 | p->cluster_info = NULL; |
Minchan Kim | 4f89849 | 2013-04-30 15:26:54 -0700 | [diff] [blame] | 2647 | frontswap_map = frontswap_map_get(p); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2648 | spin_unlock(&p->lock); |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2649 | spin_unlock(&swap_lock); |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2650 | frontswap_invalidate_area(p->type); |
Krzysztof Kozlowski | 58e97ba | 2013-11-12 15:07:47 -0800 | [diff] [blame] | 2651 | frontswap_map_set(p, NULL); |
Ingo Molnar | fc0abb1 | 2006-01-18 17:42:33 -0800 | [diff] [blame] | 2652 | mutex_unlock(&swapon_mutex); |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 2653 | free_percpu(p->percpu_cluster); |
| 2654 | p->percpu_cluster = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2655 | vfree(swap_map); |
Huang Ying | 54f180d | 2017-05-08 15:57:40 -0700 | [diff] [blame] | 2656 | kvfree(cluster_info); |
| 2657 | kvfree(frontswap_map); |
Seth Jennings | 2de1a7e | 2013-11-12 15:07:46 -0800 | [diff] [blame] | 2658 | /* Destroy swap account information */ |
Dan Streetman | adfab83 | 2014-06-04 16:09:53 -0700 | [diff] [blame] | 2659 | swap_cgroup_swapoff(p->type); |
Huang, Ying | 4b3ef9d | 2017-02-22 15:45:26 -0800 | [diff] [blame] | 2660 | exit_swap_address_space(p->type); |
KAMEZAWA Hiroyuki | 27a7faa | 2009-01-07 18:07:58 -0800 | [diff] [blame] | 2661 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2662 | inode = mapping->host; |
| 2663 | if (S_ISBLK(inode->i_mode)) { |
| 2664 | struct block_device *bdev = I_BDEV(inode); |
Krzysztof Kozlowski | 5b808a2 | 2013-10-16 13:47:06 -0700 | [diff] [blame] | 2665 | set_blocksize(bdev, old_block_size); |
Tejun Heo | e525fd8 | 2010-11-13 11:55:17 +0100 | [diff] [blame] | 2666 | blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2667 | } else { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2668 | inode_lock(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2669 | inode->i_flags &= ~S_SWAPFILE; |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2670 | inode_unlock(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2671 | } |
| 2672 | filp_close(swap_file, NULL); |
Weijie Yang | f893ab4 | 2014-02-06 12:04:23 -0800 | [diff] [blame] | 2673 | |
| 2674 | /* |
| 2675 | * Clear the SWP_USED flag after all resources are freed so that swapon |
| 2676 | * can reuse this swap_info in alloc_swap_info() safely. It is ok to |
| 2677 | * not hold p->lock after we cleared its SWP_WRITEOK. |
| 2678 | */ |
| 2679 | spin_lock(&swap_lock); |
| 2680 | p->flags = 0; |
| 2681 | spin_unlock(&swap_lock); |
| 2682 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2683 | err = 0; |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2684 | atomic_inc(&proc_poll_event); |
| 2685 | wake_up_interruptible(&proc_poll_wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2686 | |
| 2687 | out_dput: |
| 2688 | filp_close(victim, NULL); |
| 2689 | out: |
Xiaotian Feng | f58b59c | 2012-11-16 14:14:55 -0800 | [diff] [blame] | 2690 | putname(pathname); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2691 | return err; |
| 2692 | } |
| 2693 | |
| 2694 | #ifdef CONFIG_PROC_FS |
Al Viro | 9dd9574 | 2017-07-03 00:42:43 -0400 | [diff] [blame] | 2695 | static __poll_t swaps_poll(struct file *file, poll_table *wait) |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2696 | { |
Kay Sievers | f151463 | 2011-07-12 20:48:39 +0200 | [diff] [blame] | 2697 | struct seq_file *seq = file->private_data; |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2698 | |
| 2699 | poll_wait(file, &proc_poll_wait, wait); |
| 2700 | |
Kay Sievers | f151463 | 2011-07-12 20:48:39 +0200 | [diff] [blame] | 2701 | if (seq->poll_event != atomic_read(&proc_poll_event)) { |
| 2702 | seq->poll_event = atomic_read(&proc_poll_event); |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame] | 2703 | return EPOLLIN | EPOLLRDNORM | EPOLLERR | EPOLLPRI; |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2704 | } |
| 2705 | |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame] | 2706 | return EPOLLIN | EPOLLRDNORM; |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2707 | } |
| 2708 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2709 | /* iterator */ |
| 2710 | static void *swap_start(struct seq_file *swap, loff_t *pos) |
| 2711 | { |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2712 | struct swap_info_struct *si; |
| 2713 | int type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2714 | loff_t l = *pos; |
| 2715 | |
Ingo Molnar | fc0abb1 | 2006-01-18 17:42:33 -0800 | [diff] [blame] | 2716 | mutex_lock(&swapon_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2717 | |
Suleiman Souhlal | 881e4aa | 2006-12-06 20:32:28 -0800 | [diff] [blame] | 2718 | if (!l) |
| 2719 | return SEQ_START_TOKEN; |
| 2720 | |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 2721 | for (type = 0; (si = swap_type_to_swap_info(type)); type++) { |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2722 | if (!(si->flags & SWP_USED) || !si->swap_map) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2723 | continue; |
Suleiman Souhlal | 881e4aa | 2006-12-06 20:32:28 -0800 | [diff] [blame] | 2724 | if (!--l) |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2725 | return si; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2726 | } |
| 2727 | |
| 2728 | return NULL; |
| 2729 | } |
| 2730 | |
| 2731 | static void *swap_next(struct seq_file *swap, void *v, loff_t *pos) |
| 2732 | { |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2733 | struct swap_info_struct *si = v; |
| 2734 | int type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2735 | |
Suleiman Souhlal | 881e4aa | 2006-12-06 20:32:28 -0800 | [diff] [blame] | 2736 | if (v == SEQ_START_TOKEN) |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2737 | type = 0; |
| 2738 | else |
| 2739 | type = si->type + 1; |
Suleiman Souhlal | 881e4aa | 2006-12-06 20:32:28 -0800 | [diff] [blame] | 2740 | |
Vasily Averin | 52f5a09 | 2020-01-30 22:13:39 -0800 | [diff] [blame] | 2741 | ++(*pos); |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 2742 | for (; (si = swap_type_to_swap_info(type)); type++) { |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2743 | if (!(si->flags & SWP_USED) || !si->swap_map) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2744 | continue; |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2745 | return si; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2746 | } |
| 2747 | |
| 2748 | return NULL; |
| 2749 | } |
| 2750 | |
| 2751 | static void swap_stop(struct seq_file *swap, void *v) |
| 2752 | { |
Ingo Molnar | fc0abb1 | 2006-01-18 17:42:33 -0800 | [diff] [blame] | 2753 | mutex_unlock(&swapon_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2754 | } |
| 2755 | |
| 2756 | static int swap_show(struct seq_file *swap, void *v) |
| 2757 | { |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2758 | struct swap_info_struct *si = v; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2759 | struct file *file; |
| 2760 | int len; |
| 2761 | |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2762 | if (si == SEQ_START_TOKEN) { |
Suleiman Souhlal | 881e4aa | 2006-12-06 20:32:28 -0800 | [diff] [blame] | 2763 | seq_puts(swap,"Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n"); |
| 2764 | return 0; |
| 2765 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2766 | |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2767 | file = si->swap_file; |
Miklos Szeredi | 2726d56 | 2015-06-19 10:30:28 +0200 | [diff] [blame] | 2768 | len = seq_file_path(swap, file, " \t\n\\"); |
Hugh Dickins | 6eb396d | 2005-09-03 15:54:35 -0700 | [diff] [blame] | 2769 | seq_printf(swap, "%*s%s\t%u\t%u\t%d\n", |
Hugh Dickins | 886bb7e | 2009-01-06 14:39:48 -0800 | [diff] [blame] | 2770 | len < 40 ? 40 - len : 1, " ", |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2771 | S_ISBLK(file_inode(file)->i_mode) ? |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2772 | "partition" : "file\t", |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2773 | si->pages << (PAGE_SHIFT - 10), |
| 2774 | si->inuse_pages << (PAGE_SHIFT - 10), |
| 2775 | si->prio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2776 | return 0; |
| 2777 | } |
| 2778 | |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 2779 | static const struct seq_operations swaps_op = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2780 | .start = swap_start, |
| 2781 | .next = swap_next, |
| 2782 | .stop = swap_stop, |
| 2783 | .show = swap_show |
| 2784 | }; |
| 2785 | |
| 2786 | static int swaps_open(struct inode *inode, struct file *file) |
| 2787 | { |
Kay Sievers | f151463 | 2011-07-12 20:48:39 +0200 | [diff] [blame] | 2788 | struct seq_file *seq; |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2789 | int ret; |
| 2790 | |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2791 | ret = seq_open(file, &swaps_op); |
Kay Sievers | f151463 | 2011-07-12 20:48:39 +0200 | [diff] [blame] | 2792 | if (ret) |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2793 | return ret; |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2794 | |
Kay Sievers | f151463 | 2011-07-12 20:48:39 +0200 | [diff] [blame] | 2795 | seq = file->private_data; |
| 2796 | seq->poll_event = atomic_read(&proc_poll_event); |
| 2797 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2798 | } |
| 2799 | |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 2800 | static const struct file_operations proc_swaps_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2801 | .open = swaps_open, |
| 2802 | .read = seq_read, |
| 2803 | .llseek = seq_lseek, |
| 2804 | .release = seq_release, |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 2805 | .poll = swaps_poll, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2806 | }; |
| 2807 | |
| 2808 | static int __init procswaps_init(void) |
| 2809 | { |
Denis V. Lunev | 3d71f86 | 2008-04-29 01:02:13 -0700 | [diff] [blame] | 2810 | proc_create("swaps", 0, NULL, &proc_swaps_operations); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2811 | return 0; |
| 2812 | } |
| 2813 | __initcall(procswaps_init); |
| 2814 | #endif /* CONFIG_PROC_FS */ |
| 2815 | |
Jan Beulich | 1796316 | 2008-12-16 11:35:24 +0000 | [diff] [blame] | 2816 | #ifdef MAX_SWAPFILES_CHECK |
| 2817 | static int __init max_swapfiles_check(void) |
| 2818 | { |
| 2819 | MAX_SWAPFILES_CHECK(); |
| 2820 | return 0; |
| 2821 | } |
| 2822 | late_initcall(max_swapfiles_check); |
| 2823 | #endif |
| 2824 | |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 2825 | static struct swap_info_struct *alloc_swap_info(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2826 | { |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 2827 | struct swap_info_struct *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2828 | unsigned int type; |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 2829 | int i; |
Aaron Lu | b0cd52e | 2018-12-28 00:34:39 -0800 | [diff] [blame] | 2830 | int size = sizeof(*p) + nr_node_ids * sizeof(struct plist_node); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2831 | |
Aaron Lu | b0cd52e | 2018-12-28 00:34:39 -0800 | [diff] [blame] | 2832 | p = kvzalloc(size, GFP_KERNEL); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2833 | if (!p) |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 2834 | return ERR_PTR(-ENOMEM); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2835 | |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2836 | spin_lock(&swap_lock); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2837 | for (type = 0; type < nr_swapfiles; type++) { |
| 2838 | if (!(swap_info[type]->flags & SWP_USED)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2839 | break; |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2840 | } |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 2841 | if (type >= MAX_SWAPFILES) { |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2842 | spin_unlock(&swap_lock); |
Vasily Averin | 113737c | 2018-11-16 15:08:11 -0800 | [diff] [blame] | 2843 | kvfree(p); |
Cesar Eduardo Barros | 730c058 | 2011-03-22 16:33:19 -0700 | [diff] [blame] | 2844 | return ERR_PTR(-EPERM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2845 | } |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2846 | if (type >= nr_swapfiles) { |
| 2847 | p->type = type; |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 2848 | WRITE_ONCE(swap_info[type], p); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2849 | /* |
| 2850 | * Write swap_info[type] before nr_swapfiles, in case a |
| 2851 | * racing procfs swap_start() or swap_next() is reading them. |
| 2852 | * (We never shrink nr_swapfiles, we never free this entry.) |
| 2853 | */ |
| 2854 | smp_wmb(); |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 2855 | WRITE_ONCE(nr_swapfiles, nr_swapfiles + 1); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2856 | } else { |
Vasily Averin | 113737c | 2018-11-16 15:08:11 -0800 | [diff] [blame] | 2857 | kvfree(p); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2858 | p = swap_info[type]; |
| 2859 | /* |
| 2860 | * Do not memset this entry: a racing procfs swap_next() |
| 2861 | * would be relying on p->type to remain valid. |
| 2862 | */ |
| 2863 | } |
Hugh Dickins | 9625a5f | 2009-12-14 17:58:42 -0800 | [diff] [blame] | 2864 | INIT_LIST_HEAD(&p->first_swap_extent.list); |
Dan Streetman | 18ab4d4 | 2014-06-04 16:09:59 -0700 | [diff] [blame] | 2865 | plist_node_init(&p->list, 0); |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 2866 | for_each_node(i) |
| 2867 | plist_node_init(&p->avail_lists[i], 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2868 | p->flags = SWP_USED; |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 2869 | spin_unlock(&swap_lock); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 2870 | spin_lock_init(&p->lock); |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 2871 | spin_lock_init(&p->cont_lock); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 2872 | |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 2873 | return p; |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 2874 | } |
| 2875 | |
Cesar Eduardo Barros | 4d0e1e1 | 2011-03-22 16:33:26 -0700 | [diff] [blame] | 2876 | static int claim_swapfile(struct swap_info_struct *p, struct inode *inode) |
| 2877 | { |
| 2878 | int error; |
| 2879 | |
| 2880 | if (S_ISBLK(inode->i_mode)) { |
| 2881 | p->bdev = bdgrab(I_BDEV(inode)); |
| 2882 | error = blkdev_get(p->bdev, |
Hugh Dickins | 6f179af | 2015-08-17 17:34:27 -0700 | [diff] [blame] | 2883 | FMODE_READ | FMODE_WRITE | FMODE_EXCL, p); |
Cesar Eduardo Barros | 4d0e1e1 | 2011-03-22 16:33:26 -0700 | [diff] [blame] | 2884 | if (error < 0) { |
| 2885 | p->bdev = NULL; |
Hugh Dickins | 6f179af | 2015-08-17 17:34:27 -0700 | [diff] [blame] | 2886 | return error; |
Cesar Eduardo Barros | 4d0e1e1 | 2011-03-22 16:33:26 -0700 | [diff] [blame] | 2887 | } |
| 2888 | p->old_block_size = block_size(p->bdev); |
| 2889 | error = set_blocksize(p->bdev, PAGE_SIZE); |
| 2890 | if (error < 0) |
Cesar Eduardo Barros | 87ade72 | 2011-03-22 16:33:27 -0700 | [diff] [blame] | 2891 | return error; |
Cesar Eduardo Barros | 4d0e1e1 | 2011-03-22 16:33:26 -0700 | [diff] [blame] | 2892 | p->flags |= SWP_BLKDEV; |
| 2893 | } else if (S_ISREG(inode->i_mode)) { |
| 2894 | p->bdev = inode->i_sb->s_bdev; |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2895 | inode_lock(inode); |
Cesar Eduardo Barros | 87ade72 | 2011-03-22 16:33:27 -0700 | [diff] [blame] | 2896 | if (IS_SWAPFILE(inode)) |
| 2897 | return -EBUSY; |
| 2898 | } else |
| 2899 | return -EINVAL; |
Cesar Eduardo Barros | 4d0e1e1 | 2011-03-22 16:33:26 -0700 | [diff] [blame] | 2900 | |
| 2901 | return 0; |
Cesar Eduardo Barros | 4d0e1e1 | 2011-03-22 16:33:26 -0700 | [diff] [blame] | 2902 | } |
| 2903 | |
Andi Kleen | 377eeaa | 2018-06-13 15:48:28 -0700 | [diff] [blame] | 2904 | |
| 2905 | /* |
| 2906 | * Find out how many pages are allowed for a single swap device. There |
| 2907 | * are two limiting factors: |
| 2908 | * 1) the number of bits for the swap offset in the swp_entry_t type, and |
| 2909 | * 2) the number of bits in the swap pte, as defined by the different |
| 2910 | * architectures. |
| 2911 | * |
| 2912 | * In order to find the largest possible bit mask, a swap entry with |
| 2913 | * swap type 0 and swap offset ~0UL is created, encoded to a swap pte, |
| 2914 | * decoded to a swp_entry_t again, and finally the swap offset is |
| 2915 | * extracted. |
| 2916 | * |
| 2917 | * This will mask all the bits from the initial ~0UL mask that can't |
| 2918 | * be encoded in either the swp_entry_t or the architecture definition |
| 2919 | * of a swap pte. |
| 2920 | */ |
| 2921 | unsigned long generic_max_swapfile_size(void) |
| 2922 | { |
| 2923 | return swp_offset(pte_to_swp_entry( |
| 2924 | swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1; |
| 2925 | } |
| 2926 | |
| 2927 | /* Can be overridden by an architecture for additional checks. */ |
| 2928 | __weak unsigned long max_swapfile_size(void) |
| 2929 | { |
| 2930 | return generic_max_swapfile_size(); |
| 2931 | } |
| 2932 | |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2933 | static unsigned long read_swap_header(struct swap_info_struct *p, |
| 2934 | union swap_header *swap_header, |
| 2935 | struct inode *inode) |
| 2936 | { |
| 2937 | int i; |
| 2938 | unsigned long maxpages; |
| 2939 | unsigned long swapfilepages; |
Raymond Jennings | d6bbbd2 | 2013-09-11 14:20:16 -0700 | [diff] [blame] | 2940 | unsigned long last_page; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2941 | |
| 2942 | if (memcmp("SWAPSPACE2", swap_header->magic.magic, 10)) { |
Andrew Morton | 465c47f | 2013-09-11 14:20:17 -0700 | [diff] [blame] | 2943 | pr_err("Unable to find swap-space signature\n"); |
Cesar Eduardo Barros | 3871902 | 2011-03-22 16:33:30 -0700 | [diff] [blame] | 2944 | return 0; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2945 | } |
| 2946 | |
| 2947 | /* swap partition endianess hack... */ |
| 2948 | if (swab32(swap_header->info.version) == 1) { |
| 2949 | swab32s(&swap_header->info.version); |
| 2950 | swab32s(&swap_header->info.last_page); |
| 2951 | swab32s(&swap_header->info.nr_badpages); |
Jann Horn | dd111be | 2016-11-10 10:46:19 -0800 | [diff] [blame] | 2952 | if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES) |
| 2953 | return 0; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2954 | for (i = 0; i < swap_header->info.nr_badpages; i++) |
| 2955 | swab32s(&swap_header->info.badpages[i]); |
| 2956 | } |
| 2957 | /* Check the swap header's sub-version */ |
| 2958 | if (swap_header->info.version != 1) { |
Andrew Morton | 465c47f | 2013-09-11 14:20:17 -0700 | [diff] [blame] | 2959 | pr_warn("Unable to handle swap header version %d\n", |
| 2960 | swap_header->info.version); |
Cesar Eduardo Barros | 3871902 | 2011-03-22 16:33:30 -0700 | [diff] [blame] | 2961 | return 0; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2962 | } |
| 2963 | |
| 2964 | p->lowest_bit = 1; |
| 2965 | p->cluster_next = 1; |
| 2966 | p->cluster_nr = 0; |
| 2967 | |
Andi Kleen | 377eeaa | 2018-06-13 15:48:28 -0700 | [diff] [blame] | 2968 | maxpages = max_swapfile_size(); |
Raymond Jennings | d6bbbd2 | 2013-09-11 14:20:16 -0700 | [diff] [blame] | 2969 | last_page = swap_header->info.last_page; |
Tom Abraham | a06ad63 | 2018-04-10 16:29:48 -0700 | [diff] [blame] | 2970 | if (!last_page) { |
| 2971 | pr_warn("Empty swap-file\n"); |
| 2972 | return 0; |
| 2973 | } |
Raymond Jennings | d6bbbd2 | 2013-09-11 14:20:16 -0700 | [diff] [blame] | 2974 | if (last_page > maxpages) { |
Andrew Morton | 465c47f | 2013-09-11 14:20:17 -0700 | [diff] [blame] | 2975 | pr_warn("Truncating oversized swap area, only using %luk out of %luk\n", |
Raymond Jennings | d6bbbd2 | 2013-09-11 14:20:16 -0700 | [diff] [blame] | 2976 | maxpages << (PAGE_SHIFT - 10), |
| 2977 | last_page << (PAGE_SHIFT - 10)); |
| 2978 | } |
| 2979 | if (maxpages > last_page) { |
| 2980 | maxpages = last_page + 1; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2981 | /* p->max is an unsigned int: don't overflow it */ |
| 2982 | if ((unsigned int)maxpages == 0) |
| 2983 | maxpages = UINT_MAX; |
| 2984 | } |
| 2985 | p->highest_bit = maxpages - 1; |
| 2986 | |
| 2987 | if (!maxpages) |
Cesar Eduardo Barros | 3871902 | 2011-03-22 16:33:30 -0700 | [diff] [blame] | 2988 | return 0; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2989 | swapfilepages = i_size_read(inode) >> PAGE_SHIFT; |
| 2990 | if (swapfilepages && maxpages > swapfilepages) { |
Andrew Morton | 465c47f | 2013-09-11 14:20:17 -0700 | [diff] [blame] | 2991 | pr_warn("Swap area shorter than signature indicates\n"); |
Cesar Eduardo Barros | 3871902 | 2011-03-22 16:33:30 -0700 | [diff] [blame] | 2992 | return 0; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2993 | } |
| 2994 | if (swap_header->info.nr_badpages && S_ISREG(inode->i_mode)) |
Cesar Eduardo Barros | 3871902 | 2011-03-22 16:33:30 -0700 | [diff] [blame] | 2995 | return 0; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2996 | if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES) |
Cesar Eduardo Barros | 3871902 | 2011-03-22 16:33:30 -0700 | [diff] [blame] | 2997 | return 0; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 2998 | |
| 2999 | return maxpages; |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 3000 | } |
| 3001 | |
Huang, Ying | 4b3ef9d | 2017-02-22 15:45:26 -0800 | [diff] [blame] | 3002 | #define SWAP_CLUSTER_INFO_COLS \ |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3003 | DIV_ROUND_UP(L1_CACHE_BYTES, sizeof(struct swap_cluster_info)) |
Huang, Ying | 4b3ef9d | 2017-02-22 15:45:26 -0800 | [diff] [blame] | 3004 | #define SWAP_CLUSTER_SPACE_COLS \ |
| 3005 | DIV_ROUND_UP(SWAP_ADDRESS_SPACE_PAGES, SWAPFILE_CLUSTER) |
| 3006 | #define SWAP_CLUSTER_COLS \ |
| 3007 | max_t(unsigned int, SWAP_CLUSTER_INFO_COLS, SWAP_CLUSTER_SPACE_COLS) |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3008 | |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3009 | static int setup_swap_map_and_extents(struct swap_info_struct *p, |
| 3010 | union swap_header *swap_header, |
| 3011 | unsigned char *swap_map, |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3012 | struct swap_cluster_info *cluster_info, |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3013 | unsigned long maxpages, |
| 3014 | sector_t *span) |
| 3015 | { |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3016 | unsigned int j, k; |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3017 | unsigned int nr_good_pages; |
| 3018 | int nr_extents; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3019 | unsigned long nr_clusters = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER); |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3020 | unsigned long col = p->cluster_next / SWAPFILE_CLUSTER % SWAP_CLUSTER_COLS; |
| 3021 | unsigned long i, idx; |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3022 | |
| 3023 | nr_good_pages = maxpages - 1; /* omit header page */ |
| 3024 | |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 3025 | cluster_list_init(&p->free_clusters); |
| 3026 | cluster_list_init(&p->discard_clusters); |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3027 | |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3028 | for (i = 0; i < swap_header->info.nr_badpages; i++) { |
| 3029 | unsigned int page_nr = swap_header->info.badpages[i]; |
Cesar Eduardo Barros | bdb8e3f | 2011-03-22 16:33:33 -0700 | [diff] [blame] | 3030 | if (page_nr == 0 || page_nr > swap_header->info.last_page) |
| 3031 | return -EINVAL; |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3032 | if (page_nr < maxpages) { |
| 3033 | swap_map[page_nr] = SWAP_MAP_BAD; |
| 3034 | nr_good_pages--; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3035 | /* |
| 3036 | * Haven't marked the cluster free yet, no list |
| 3037 | * operation involved |
| 3038 | */ |
| 3039 | inc_cluster_info_page(p, cluster_info, page_nr); |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3040 | } |
| 3041 | } |
| 3042 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3043 | /* Haven't marked the cluster free yet, no list operation involved */ |
| 3044 | for (i = maxpages; i < round_up(maxpages, SWAPFILE_CLUSTER); i++) |
| 3045 | inc_cluster_info_page(p, cluster_info, i); |
| 3046 | |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3047 | if (nr_good_pages) { |
| 3048 | swap_map[0] = SWAP_MAP_BAD; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3049 | /* |
| 3050 | * Not mark the cluster free yet, no list |
| 3051 | * operation involved |
| 3052 | */ |
| 3053 | inc_cluster_info_page(p, cluster_info, 0); |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3054 | p->max = maxpages; |
| 3055 | p->pages = nr_good_pages; |
| 3056 | nr_extents = setup_swap_extents(p, span); |
Cesar Eduardo Barros | bdb8e3f | 2011-03-22 16:33:33 -0700 | [diff] [blame] | 3057 | if (nr_extents < 0) |
| 3058 | return nr_extents; |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3059 | nr_good_pages = p->pages; |
| 3060 | } |
| 3061 | if (!nr_good_pages) { |
Andrew Morton | 465c47f | 2013-09-11 14:20:17 -0700 | [diff] [blame] | 3062 | pr_warn("Empty swap-file\n"); |
Cesar Eduardo Barros | bdb8e3f | 2011-03-22 16:33:33 -0700 | [diff] [blame] | 3063 | return -EINVAL; |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3064 | } |
| 3065 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3066 | if (!cluster_info) |
| 3067 | return nr_extents; |
| 3068 | |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3069 | |
Huang, Ying | 4b3ef9d | 2017-02-22 15:45:26 -0800 | [diff] [blame] | 3070 | /* |
| 3071 | * Reduce false cache line sharing between cluster_info and |
| 3072 | * sharing same address space. |
| 3073 | */ |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3074 | for (k = 0; k < SWAP_CLUSTER_COLS; k++) { |
| 3075 | j = (k + col) % SWAP_CLUSTER_COLS; |
| 3076 | for (i = 0; i < DIV_ROUND_UP(nr_clusters, SWAP_CLUSTER_COLS); i++) { |
| 3077 | idx = i * SWAP_CLUSTER_COLS + j; |
| 3078 | if (idx >= nr_clusters) |
| 3079 | continue; |
| 3080 | if (cluster_count(&cluster_info[idx])) |
| 3081 | continue; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3082 | cluster_set_flag(&cluster_info[idx], CLUSTER_FLAG_FREE); |
Huang Ying | 6b53491 | 2016-10-07 16:58:42 -0700 | [diff] [blame] | 3083 | cluster_list_add_tail(&p->free_clusters, cluster_info, |
| 3084 | idx); |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3085 | } |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3086 | } |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3087 | return nr_extents; |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3088 | } |
| 3089 | |
Rafael Aquini | dcf6b7d | 2013-07-03 15:02:46 -0700 | [diff] [blame] | 3090 | /* |
| 3091 | * Helper to sys_swapon determining if a given swap |
| 3092 | * backing device queue supports DISCARD operations. |
| 3093 | */ |
| 3094 | static bool swap_discardable(struct swap_info_struct *si) |
| 3095 | { |
| 3096 | struct request_queue *q = bdev_get_queue(si->bdev); |
| 3097 | |
| 3098 | if (!q || !blk_queue_discard(q)) |
| 3099 | return false; |
| 3100 | |
| 3101 | return true; |
| 3102 | } |
| 3103 | |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3104 | SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) |
| 3105 | { |
| 3106 | struct swap_info_struct *p; |
Jeff Layton | 91a27b2 | 2012-10-10 15:25:28 -0400 | [diff] [blame] | 3107 | struct filename *name; |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3108 | struct file *swap_file = NULL; |
| 3109 | struct address_space *mapping; |
Cesar Eduardo Barros | 4053154 | 2011-03-22 16:33:37 -0700 | [diff] [blame] | 3110 | int prio; |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3111 | int error; |
| 3112 | union swap_header *swap_header; |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3113 | int nr_extents; |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3114 | sector_t span; |
| 3115 | unsigned long maxpages; |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3116 | unsigned char *swap_map = NULL; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3117 | struct swap_cluster_info *cluster_info = NULL; |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 3118 | unsigned long *frontswap_map = NULL; |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3119 | struct page *page = NULL; |
| 3120 | struct inode *inode = NULL; |
Omar Sandoval | 7cbf319 | 2018-05-25 14:47:17 -0700 | [diff] [blame] | 3121 | bool inced_nr_rotate_swap = false; |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3122 | |
Hugh Dickins | d15cab9 | 2012-03-28 14:42:42 -0700 | [diff] [blame] | 3123 | if (swap_flags & ~SWAP_FLAGS_VALID) |
| 3124 | return -EINVAL; |
| 3125 | |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3126 | if (!capable(CAP_SYS_ADMIN)) |
| 3127 | return -EPERM; |
| 3128 | |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 3129 | if (!swap_avail_heads) |
| 3130 | return -ENOMEM; |
| 3131 | |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3132 | p = alloc_swap_info(); |
Cesar Eduardo Barros | 2542e513 | 2011-03-22 16:33:18 -0700 | [diff] [blame] | 3133 | if (IS_ERR(p)) |
| 3134 | return PTR_ERR(p); |
Cesar Eduardo Barros | 53cbb24 | 2011-03-22 16:33:17 -0700 | [diff] [blame] | 3135 | |
Shaohua Li | 815c2c5 | 2013-09-11 14:20:30 -0700 | [diff] [blame] | 3136 | INIT_WORK(&p->discard_work, swap_discard_work); |
| 3137 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3138 | name = getname(specialfile); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3139 | if (IS_ERR(name)) { |
Cesar Eduardo Barros | 7de7fb6 | 2011-03-22 16:33:22 -0700 | [diff] [blame] | 3140 | error = PTR_ERR(name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3141 | name = NULL; |
Cesar Eduardo Barros | bd69010 | 2011-03-22 16:33:25 -0700 | [diff] [blame] | 3142 | goto bad_swap; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3143 | } |
Jeff Layton | 669abf4 | 2012-10-10 16:43:10 -0400 | [diff] [blame] | 3144 | swap_file = file_open_name(name, O_RDWR|O_LARGEFILE, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3145 | if (IS_ERR(swap_file)) { |
Cesar Eduardo Barros | 7de7fb6 | 2011-03-22 16:33:22 -0700 | [diff] [blame] | 3146 | error = PTR_ERR(swap_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3147 | swap_file = NULL; |
Cesar Eduardo Barros | bd69010 | 2011-03-22 16:33:25 -0700 | [diff] [blame] | 3148 | goto bad_swap; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3149 | } |
| 3150 | |
| 3151 | p->swap_file = swap_file; |
| 3152 | mapping = swap_file->f_mapping; |
Cesar Eduardo Barros | 2130781 | 2011-03-22 23:03:13 -0300 | [diff] [blame] | 3153 | inode = mapping->host; |
Hugh Dickins | 6f179af | 2015-08-17 17:34:27 -0700 | [diff] [blame] | 3154 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 3155 | /* If S_ISREG(inode->i_mode) will do inode_lock(inode); */ |
Cesar Eduardo Barros | 4d0e1e1 | 2011-03-22 16:33:26 -0700 | [diff] [blame] | 3156 | error = claim_swapfile(p, inode); |
| 3157 | if (unlikely(error)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3158 | goto bad_swap; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3159 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3160 | /* |
| 3161 | * Read the swap header. |
| 3162 | */ |
| 3163 | if (!mapping->a_ops->readpage) { |
| 3164 | error = -EINVAL; |
| 3165 | goto bad_swap; |
| 3166 | } |
Pekka Enberg | 090d2b1 | 2006-06-23 02:05:08 -0700 | [diff] [blame] | 3167 | page = read_mapping_page(mapping, 0, swap_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3168 | if (IS_ERR(page)) { |
| 3169 | error = PTR_ERR(page); |
| 3170 | goto bad_swap; |
| 3171 | } |
Hugh Dickins | 81e3397 | 2009-01-06 14:39:49 -0800 | [diff] [blame] | 3172 | swap_header = kmap(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3173 | |
Cesar Eduardo Barros | ca8bd38 | 2011-03-22 16:33:29 -0700 | [diff] [blame] | 3174 | maxpages = read_swap_header(p, swap_header, inode); |
| 3175 | if (unlikely(!maxpages)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3176 | error = -EINVAL; |
| 3177 | goto bad_swap; |
| 3178 | } |
Hugh Dickins | 886bb7e | 2009-01-06 14:39:48 -0800 | [diff] [blame] | 3179 | |
Hugh Dickins | 81e3397 | 2009-01-06 14:39:49 -0800 | [diff] [blame] | 3180 | /* OK, set up the swap map and apply the bad block list */ |
Cesar Eduardo Barros | 803d0c83 | 2011-03-22 16:33:14 -0700 | [diff] [blame] | 3181 | swap_map = vzalloc(maxpages); |
Hugh Dickins | 81e3397 | 2009-01-06 14:39:49 -0800 | [diff] [blame] | 3182 | if (!swap_map) { |
| 3183 | error = -ENOMEM; |
| 3184 | goto bad_swap; |
| 3185 | } |
Minchan Kim | f057142 | 2017-01-10 16:58:15 -0800 | [diff] [blame] | 3186 | |
| 3187 | if (bdi_cap_stable_pages_required(inode_to_bdi(inode))) |
| 3188 | p->flags |= SWP_STABLE_WRITES; |
| 3189 | |
Minchan Kim | 539a6fe | 2017-11-15 17:33:04 -0800 | [diff] [blame] | 3190 | if (bdi_cap_synchronous_io(inode_to_bdi(inode))) |
| 3191 | p->flags |= SWP_SYNCHRONOUS_IO; |
| 3192 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3193 | if (p->bdev && blk_queue_nonrot(bdev_get_queue(p->bdev))) { |
Hugh Dickins | 6f179af | 2015-08-17 17:34:27 -0700 | [diff] [blame] | 3194 | int cpu; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3195 | unsigned long ci, nr_cluster; |
Hugh Dickins | 6f179af | 2015-08-17 17:34:27 -0700 | [diff] [blame] | 3196 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3197 | p->flags |= SWP_SOLIDSTATE; |
| 3198 | /* |
| 3199 | * select a random position to start with to help wear leveling |
| 3200 | * SSD |
| 3201 | */ |
| 3202 | p->cluster_next = 1 + (prandom_u32() % p->highest_bit); |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3203 | nr_cluster = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER); |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3204 | |
Kees Cook | 778e1cd | 2018-06-12 14:04:48 -0700 | [diff] [blame] | 3205 | cluster_info = kvcalloc(nr_cluster, sizeof(*cluster_info), |
Huang Ying | 54f180d | 2017-05-08 15:57:40 -0700 | [diff] [blame] | 3206 | GFP_KERNEL); |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3207 | if (!cluster_info) { |
| 3208 | error = -ENOMEM; |
| 3209 | goto bad_swap; |
| 3210 | } |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3211 | |
| 3212 | for (ci = 0; ci < nr_cluster; ci++) |
| 3213 | spin_lock_init(&((cluster_info + ci)->lock)); |
| 3214 | |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 3215 | p->percpu_cluster = alloc_percpu(struct percpu_cluster); |
| 3216 | if (!p->percpu_cluster) { |
| 3217 | error = -ENOMEM; |
| 3218 | goto bad_swap; |
| 3219 | } |
Hugh Dickins | 6f179af | 2015-08-17 17:34:27 -0700 | [diff] [blame] | 3220 | for_each_possible_cpu(cpu) { |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 3221 | struct percpu_cluster *cluster; |
Hugh Dickins | 6f179af | 2015-08-17 17:34:27 -0700 | [diff] [blame] | 3222 | cluster = per_cpu_ptr(p->percpu_cluster, cpu); |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 3223 | cluster_set_null(&cluster->index); |
| 3224 | } |
Omar Sandoval | 7cbf319 | 2018-05-25 14:47:17 -0700 | [diff] [blame] | 3225 | } else { |
Huang Ying | 81a0298 | 2017-09-06 16:24:43 -0700 | [diff] [blame] | 3226 | atomic_inc(&nr_rotate_swap); |
Omar Sandoval | 7cbf319 | 2018-05-25 14:47:17 -0700 | [diff] [blame] | 3227 | inced_nr_rotate_swap = true; |
| 3228 | } |
Hugh Dickins | 81e3397 | 2009-01-06 14:39:49 -0800 | [diff] [blame] | 3229 | |
Cesar Eduardo Barros | 1421ef3 | 2011-03-22 16:33:31 -0700 | [diff] [blame] | 3230 | error = swap_cgroup_swapon(p->type, maxpages); |
| 3231 | if (error) |
| 3232 | goto bad_swap; |
| 3233 | |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3234 | nr_extents = setup_swap_map_and_extents(p, swap_header, swap_map, |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3235 | cluster_info, maxpages, &span); |
Cesar Eduardo Barros | 915d4d7 | 2011-03-22 16:33:32 -0700 | [diff] [blame] | 3236 | if (unlikely(nr_extents < 0)) { |
| 3237 | error = nr_extents; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3238 | goto bad_swap; |
| 3239 | } |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 3240 | /* frontswap enabled? set up bit-per-page map for frontswap */ |
Vlastimil Babka | 8ea1d2a | 2016-07-26 15:24:42 -0700 | [diff] [blame] | 3241 | if (IS_ENABLED(CONFIG_FRONTSWAP)) |
Kees Cook | 778e1cd | 2018-06-12 14:04:48 -0700 | [diff] [blame] | 3242 | frontswap_map = kvcalloc(BITS_TO_LONGS(maxpages), |
| 3243 | sizeof(long), |
Huang Ying | 54f180d | 2017-05-08 15:57:40 -0700 | [diff] [blame] | 3244 | GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3245 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3246 | if (p->bdev &&(swap_flags & SWAP_FLAG_DISCARD) && swap_discardable(p)) { |
| 3247 | /* |
| 3248 | * When discard is enabled for swap with no particular |
| 3249 | * policy flagged, we set all swap discard flags here in |
| 3250 | * order to sustain backward compatibility with older |
| 3251 | * swapon(8) releases. |
| 3252 | */ |
| 3253 | p->flags |= (SWP_DISCARDABLE | SWP_AREA_DISCARD | |
| 3254 | SWP_PAGE_DISCARD); |
Rafael Aquini | dcf6b7d | 2013-07-03 15:02:46 -0700 | [diff] [blame] | 3255 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3256 | /* |
| 3257 | * By flagging sys_swapon, a sysadmin can tell us to |
| 3258 | * either do single-time area discards only, or to just |
| 3259 | * perform discards for released swap page-clusters. |
| 3260 | * Now it's time to adjust the p->flags accordingly. |
| 3261 | */ |
| 3262 | if (swap_flags & SWAP_FLAG_DISCARD_ONCE) |
| 3263 | p->flags &= ~SWP_PAGE_DISCARD; |
| 3264 | else if (swap_flags & SWAP_FLAG_DISCARD_PAGES) |
| 3265 | p->flags &= ~SWP_AREA_DISCARD; |
Rafael Aquini | dcf6b7d | 2013-07-03 15:02:46 -0700 | [diff] [blame] | 3266 | |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3267 | /* issue a swapon-time discard if it's still required */ |
| 3268 | if (p->flags & SWP_AREA_DISCARD) { |
| 3269 | int err = discard_swap(p); |
| 3270 | if (unlikely(err)) |
| 3271 | pr_err("swapon: discard_swap(%p): %d\n", |
| 3272 | p, err); |
Rafael Aquini | dcf6b7d | 2013-07-03 15:02:46 -0700 | [diff] [blame] | 3273 | } |
Hugh Dickins | 20137a4 | 2009-01-06 14:39:54 -0800 | [diff] [blame] | 3274 | } |
Hugh Dickins | 6a6ba83 | 2009-01-06 14:39:51 -0800 | [diff] [blame] | 3275 | |
Huang, Ying | 4b3ef9d | 2017-02-22 15:45:26 -0800 | [diff] [blame] | 3276 | error = init_swap_address_space(p->type, maxpages); |
| 3277 | if (error) |
| 3278 | goto bad_swap; |
| 3279 | |
Ingo Molnar | fc0abb1 | 2006-01-18 17:42:33 -0800 | [diff] [blame] | 3280 | mutex_lock(&swapon_mutex); |
Cesar Eduardo Barros | 4053154 | 2011-03-22 16:33:37 -0700 | [diff] [blame] | 3281 | prio = -1; |
Hugh Dickins | 78ecba0 | 2008-07-23 21:28:23 -0700 | [diff] [blame] | 3282 | if (swap_flags & SWAP_FLAG_PREFER) |
Cesar Eduardo Barros | 4053154 | 2011-03-22 16:33:37 -0700 | [diff] [blame] | 3283 | prio = |
Hugh Dickins | 78ecba0 | 2008-07-23 21:28:23 -0700 | [diff] [blame] | 3284 | (swap_flags & SWAP_FLAG_PRIO_MASK) >> SWAP_FLAG_PRIO_SHIFT; |
Shaohua Li | 2a8f944 | 2013-09-11 14:20:28 -0700 | [diff] [blame] | 3285 | enable_swap_info(p, prio, swap_map, cluster_info, frontswap_map); |
Cesar Eduardo Barros | c69dbfb | 2011-03-22 16:33:35 -0700 | [diff] [blame] | 3286 | |
Joe Perches | 756a025 | 2016-03-17 14:19:47 -0700 | [diff] [blame] | 3287 | pr_info("Adding %uk swap on %s. Priority:%d extents:%d across:%lluk %s%s%s%s%s\n", |
Jeff Layton | 91a27b2 | 2012-10-10 15:25:28 -0400 | [diff] [blame] | 3288 | p->pages<<(PAGE_SHIFT-10), name->name, p->prio, |
Cesar Eduardo Barros | c69dbfb | 2011-03-22 16:33:35 -0700 | [diff] [blame] | 3289 | nr_extents, (unsigned long long)span<<(PAGE_SHIFT-10), |
| 3290 | (p->flags & SWP_SOLIDSTATE) ? "SS" : "", |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 3291 | (p->flags & SWP_DISCARDABLE) ? "D" : "", |
Rafael Aquini | dcf6b7d | 2013-07-03 15:02:46 -0700 | [diff] [blame] | 3292 | (p->flags & SWP_AREA_DISCARD) ? "s" : "", |
| 3293 | (p->flags & SWP_PAGE_DISCARD) ? "c" : "", |
Dan Magenheimer | 38b5faf | 2012-04-09 17:08:06 -0600 | [diff] [blame] | 3294 | (frontswap_map) ? "FS" : ""); |
Cesar Eduardo Barros | c69dbfb | 2011-03-22 16:33:35 -0700 | [diff] [blame] | 3295 | |
Ingo Molnar | fc0abb1 | 2006-01-18 17:42:33 -0800 | [diff] [blame] | 3296 | mutex_unlock(&swapon_mutex); |
Kay Sievers | 66d7dd5 | 2010-10-26 14:22:06 -0700 | [diff] [blame] | 3297 | atomic_inc(&proc_poll_event); |
| 3298 | wake_up_interruptible(&proc_poll_wait); |
| 3299 | |
Cesar Eduardo Barros | 9b01c35 | 2011-03-22 16:33:24 -0700 | [diff] [blame] | 3300 | if (S_ISREG(inode->i_mode)) |
| 3301 | inode->i_flags |= S_SWAPFILE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3302 | error = 0; |
| 3303 | goto out; |
| 3304 | bad_swap: |
Shaohua Li | ebc2a1a | 2013-09-11 14:20:32 -0700 | [diff] [blame] | 3305 | free_percpu(p->percpu_cluster); |
| 3306 | p->percpu_cluster = NULL; |
Cesar Eduardo Barros | bd69010 | 2011-03-22 16:33:25 -0700 | [diff] [blame] | 3307 | if (inode && S_ISBLK(inode->i_mode) && p->bdev) { |
Cesar Eduardo Barros | f2090d2 | 2011-03-22 16:33:23 -0700 | [diff] [blame] | 3308 | set_blocksize(p->bdev, p->old_block_size); |
| 3309 | blkdev_put(p->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3310 | } |
Hugh Dickins | 4cd3bb1 | 2005-09-03 15:54:33 -0700 | [diff] [blame] | 3311 | destroy_swap_extents(p); |
Cesar Eduardo Barros | e8e6c2e | 2011-03-22 16:33:16 -0700 | [diff] [blame] | 3312 | swap_cgroup_swapoff(p->type); |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 3313 | spin_lock(&swap_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3314 | p->swap_file = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3315 | p->flags = 0; |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 3316 | spin_unlock(&swap_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3317 | vfree(swap_map); |
Darrick J. Wong | 8606a1a | 2017-09-08 16:13:25 -0700 | [diff] [blame] | 3318 | kvfree(cluster_info); |
David Rientjes | b6b1fd2 | 2017-09-08 16:13:29 -0700 | [diff] [blame] | 3319 | kvfree(frontswap_map); |
Omar Sandoval | 7cbf319 | 2018-05-25 14:47:17 -0700 | [diff] [blame] | 3320 | if (inced_nr_rotate_swap) |
| 3321 | atomic_dec(&nr_rotate_swap); |
Mel Gorman | 52c5056 | 2011-03-22 16:30:08 -0700 | [diff] [blame] | 3322 | if (swap_file) { |
Cesar Eduardo Barros | 2130781 | 2011-03-22 23:03:13 -0300 | [diff] [blame] | 3323 | if (inode && S_ISREG(inode->i_mode)) { |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 3324 | inode_unlock(inode); |
Cesar Eduardo Barros | 2130781 | 2011-03-22 23:03:13 -0300 | [diff] [blame] | 3325 | inode = NULL; |
| 3326 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3327 | filp_close(swap_file, NULL); |
Mel Gorman | 52c5056 | 2011-03-22 16:30:08 -0700 | [diff] [blame] | 3328 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3329 | out: |
| 3330 | if (page && !IS_ERR(page)) { |
| 3331 | kunmap(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3332 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3333 | } |
| 3334 | if (name) |
| 3335 | putname(name); |
Cesar Eduardo Barros | 9b01c35 | 2011-03-22 16:33:24 -0700 | [diff] [blame] | 3336 | if (inode && S_ISREG(inode->i_mode)) |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 3337 | inode_unlock(inode); |
Tim Chen | 039939a | 2017-02-22 15:45:43 -0800 | [diff] [blame] | 3338 | if (!error) |
| 3339 | enable_swap_slots_cache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3340 | return error; |
| 3341 | } |
| 3342 | |
| 3343 | void si_swapinfo(struct sysinfo *val) |
| 3344 | { |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 3345 | unsigned int type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3346 | unsigned long nr_to_be_unused = 0; |
| 3347 | |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 3348 | spin_lock(&swap_lock); |
Hugh Dickins | efa90a9 | 2009-12-14 17:58:41 -0800 | [diff] [blame] | 3349 | for (type = 0; type < nr_swapfiles; type++) { |
| 3350 | struct swap_info_struct *si = swap_info[type]; |
| 3351 | |
| 3352 | if ((si->flags & SWP_USED) && !(si->flags & SWP_WRITEOK)) |
| 3353 | nr_to_be_unused += si->inuse_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3354 | } |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 3355 | val->freeswap = atomic_long_read(&nr_swap_pages) + nr_to_be_unused; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3356 | val->totalswap = total_swap_pages + nr_to_be_unused; |
Hugh Dickins | 5d337b9 | 2005-09-03 15:54:41 -0700 | [diff] [blame] | 3357 | spin_unlock(&swap_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3358 | } |
| 3359 | |
| 3360 | /* |
| 3361 | * Verify that a swap entry is valid and increment its swap map count. |
| 3362 | * |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3363 | * Returns error code in following case. |
| 3364 | * - success -> 0 |
| 3365 | * - swp_entry is invalid -> EINVAL |
| 3366 | * - swp_entry is migration entry -> EINVAL |
| 3367 | * - swap-cache reference is requested but there is already one. -> EEXIST |
| 3368 | * - swap-cache reference is requested but the entry is not used. -> ENOENT |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3369 | * - swap-mapped reference requested but needs continued swap count. -> ENOMEM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3370 | */ |
Hugh Dickins | 8d69aae | 2009-12-14 17:58:45 -0800 | [diff] [blame] | 3371 | static int __swap_duplicate(swp_entry_t entry, unsigned char usage) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3372 | { |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 3373 | struct swap_info_struct *p; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3374 | struct swap_cluster_info *ci; |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 3375 | unsigned long offset; |
Hugh Dickins | 8d69aae | 2009-12-14 17:58:45 -0800 | [diff] [blame] | 3376 | unsigned char count; |
| 3377 | unsigned char has_cache; |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3378 | int err = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3379 | |
Andi Kleen | a7420aa | 2009-09-16 11:50:05 +0200 | [diff] [blame] | 3380 | if (non_swap_entry(entry)) |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3381 | goto out; |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 3382 | |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 3383 | p = swp_swap_info(entry); |
| 3384 | if (!p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3385 | goto bad_file; |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 3386 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3387 | offset = swp_offset(entry); |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3388 | if (unlikely(offset >= p->max)) |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3389 | goto out; |
| 3390 | |
| 3391 | ci = lock_cluster_or_swap_info(p, offset); |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3392 | |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3393 | count = p->swap_map[offset]; |
Shaohua Li | edfe23d | 2013-09-11 14:20:31 -0700 | [diff] [blame] | 3394 | |
| 3395 | /* |
| 3396 | * swapin_readahead() doesn't check if a swap entry is valid, so the |
| 3397 | * swap entry could be SWAP_MAP_BAD. Check here with lock held. |
| 3398 | */ |
| 3399 | if (unlikely(swap_count(count) == SWAP_MAP_BAD)) { |
| 3400 | err = -ENOENT; |
| 3401 | goto unlock_out; |
| 3402 | } |
| 3403 | |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3404 | has_cache = count & SWAP_HAS_CACHE; |
| 3405 | count &= ~SWAP_HAS_CACHE; |
| 3406 | err = 0; |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3407 | |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3408 | if (usage == SWAP_HAS_CACHE) { |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3409 | |
| 3410 | /* set SWAP_HAS_CACHE if there is no cache and entry is used */ |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3411 | if (!has_cache && count) |
| 3412 | has_cache = SWAP_HAS_CACHE; |
| 3413 | else if (has_cache) /* someone else added cache */ |
| 3414 | err = -EEXIST; |
| 3415 | else /* no users remaining */ |
| 3416 | err = -ENOENT; |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3417 | |
| 3418 | } else if (count || has_cache) { |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3419 | |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3420 | if ((count & ~COUNT_CONTINUED) < SWAP_MAP_MAX) |
| 3421 | count += usage; |
| 3422 | else if ((count & ~COUNT_CONTINUED) > SWAP_MAP_MAX) |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3423 | err = -EINVAL; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3424 | else if (swap_count_continued(p, offset, count)) |
| 3425 | count = COUNT_CONTINUED; |
| 3426 | else |
| 3427 | err = -ENOMEM; |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3428 | } else |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3429 | err = -ENOENT; /* unused swap entry */ |
| 3430 | |
| 3431 | p->swap_map[offset] = count | has_cache; |
| 3432 | |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3433 | unlock_out: |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3434 | unlock_cluster_or_swap_info(p, ci); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3435 | out: |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3436 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3437 | |
| 3438 | bad_file: |
Andrew Morton | 465c47f | 2013-09-11 14:20:17 -0700 | [diff] [blame] | 3439 | pr_err("swap_dup: %s%08lx\n", Bad_file, entry.val); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3440 | goto out; |
| 3441 | } |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3442 | |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3443 | /* |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 3444 | * Help swapoff by noting that swap entry belongs to shmem/tmpfs |
| 3445 | * (in which case its reference count is never incremented). |
| 3446 | */ |
| 3447 | void swap_shmem_alloc(swp_entry_t entry) |
| 3448 | { |
| 3449 | __swap_duplicate(entry, SWAP_MAP_SHMEM); |
| 3450 | } |
| 3451 | |
| 3452 | /* |
Hugh Dickins | 08259d5 | 2010-03-05 13:42:25 -0800 | [diff] [blame] | 3453 | * Increase reference count of swap entry by 1. |
| 3454 | * Returns 0 for success, or -ENOMEM if a swap_count_continuation is required |
| 3455 | * but could not be atomically allocated. Returns 0, just as if it succeeded, |
| 3456 | * if __swap_duplicate() fails for another reason (-EINVAL or -ENOENT), which |
| 3457 | * might occur if a page table entry has got corrupted. |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3458 | */ |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3459 | int swap_duplicate(swp_entry_t entry) |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3460 | { |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3461 | int err = 0; |
| 3462 | |
| 3463 | while (!err && __swap_duplicate(entry, 1) == -ENOMEM) |
| 3464 | err = add_swap_count_continuation(entry, GFP_ATOMIC); |
| 3465 | return err; |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3466 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3467 | |
KAMEZAWA Hiroyuki | cb4b86b | 2009-06-16 15:32:52 -0700 | [diff] [blame] | 3468 | /* |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3469 | * @entry: swap entry for which we allocate swap cache. |
| 3470 | * |
Hugh Dickins | 73c34b6 | 2009-12-14 17:58:43 -0800 | [diff] [blame] | 3471 | * Called when allocating swap cache for existing swap entry, |
KAMEZAWA Hiroyuki | 355cfa7 | 2009-06-16 15:32:53 -0700 | [diff] [blame] | 3472 | * This can return error codes. Returns 0 at success. |
| 3473 | * -EBUSY means there is a swap cache. |
| 3474 | * Note: return code is different from swap_duplicate(). |
KAMEZAWA Hiroyuki | cb4b86b | 2009-06-16 15:32:52 -0700 | [diff] [blame] | 3475 | */ |
| 3476 | int swapcache_prepare(swp_entry_t entry) |
| 3477 | { |
Hugh Dickins | 253d553 | 2009-12-14 17:58:44 -0800 | [diff] [blame] | 3478 | return __swap_duplicate(entry, SWAP_HAS_CACHE); |
KAMEZAWA Hiroyuki | cb4b86b | 2009-06-16 15:32:52 -0700 | [diff] [blame] | 3479 | } |
| 3480 | |
Minchan Kim | 0bcac06 | 2017-11-15 17:33:07 -0800 | [diff] [blame] | 3481 | struct swap_info_struct *swp_swap_info(swp_entry_t entry) |
| 3482 | { |
Daniel Jordan | ed3345a | 2019-03-05 15:48:19 -0800 | [diff] [blame] | 3483 | return swap_type_to_swap_info(swp_type(entry)); |
Minchan Kim | 0bcac06 | 2017-11-15 17:33:07 -0800 | [diff] [blame] | 3484 | } |
| 3485 | |
Mel Gorman | f981c59 | 2012-07-31 16:44:47 -0700 | [diff] [blame] | 3486 | struct swap_info_struct *page_swap_info(struct page *page) |
| 3487 | { |
Minchan Kim | 0bcac06 | 2017-11-15 17:33:07 -0800 | [diff] [blame] | 3488 | swp_entry_t entry = { .val = page_private(page) }; |
| 3489 | return swp_swap_info(entry); |
Mel Gorman | f981c59 | 2012-07-31 16:44:47 -0700 | [diff] [blame] | 3490 | } |
| 3491 | |
| 3492 | /* |
| 3493 | * out-of-line __page_file_ methods to avoid include hell. |
| 3494 | */ |
| 3495 | struct address_space *__page_file_mapping(struct page *page) |
| 3496 | { |
Mel Gorman | f981c59 | 2012-07-31 16:44:47 -0700 | [diff] [blame] | 3497 | return page_swap_info(page)->swap_file->f_mapping; |
| 3498 | } |
| 3499 | EXPORT_SYMBOL_GPL(__page_file_mapping); |
| 3500 | |
| 3501 | pgoff_t __page_file_index(struct page *page) |
| 3502 | { |
| 3503 | swp_entry_t swap = { .val = page_private(page) }; |
Mel Gorman | f981c59 | 2012-07-31 16:44:47 -0700 | [diff] [blame] | 3504 | return swp_offset(swap); |
| 3505 | } |
| 3506 | EXPORT_SYMBOL_GPL(__page_file_index); |
| 3507 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3508 | /* |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3509 | * add_swap_count_continuation - called when a swap count is duplicated |
| 3510 | * beyond SWAP_MAP_MAX, it allocates a new page and links that to the entry's |
| 3511 | * page of the original vmalloc'ed swap_map, to hold the continuation count |
| 3512 | * (for that entry and for its neighbouring PAGE_SIZE swap entries). Called |
| 3513 | * again when count is duplicated beyond SWAP_MAP_MAX * SWAP_CONT_MAX, etc. |
| 3514 | * |
| 3515 | * These continuation pages are seldom referenced: the common paths all work |
| 3516 | * on the original swap_map, only referring to a continuation page when the |
| 3517 | * low "digit" of a count is incremented or decremented through SWAP_MAP_MAX. |
| 3518 | * |
| 3519 | * add_swap_count_continuation(, GFP_ATOMIC) can be called while holding |
| 3520 | * page table locks; if it fails, add_swap_count_continuation(, GFP_KERNEL) |
| 3521 | * can be called after dropping locks. |
| 3522 | */ |
| 3523 | int add_swap_count_continuation(swp_entry_t entry, gfp_t gfp_mask) |
| 3524 | { |
| 3525 | struct swap_info_struct *si; |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3526 | struct swap_cluster_info *ci; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3527 | struct page *head; |
| 3528 | struct page *page; |
| 3529 | struct page *list_page; |
| 3530 | pgoff_t offset; |
| 3531 | unsigned char count; |
| 3532 | |
| 3533 | /* |
| 3534 | * When debugging, it's easier to use __GFP_ZERO here; but it's better |
| 3535 | * for latency not to zero a page while GFP_ATOMIC and holding locks. |
| 3536 | */ |
| 3537 | page = alloc_page(gfp_mask | __GFP_HIGHMEM); |
| 3538 | |
| 3539 | si = swap_info_get(entry); |
| 3540 | if (!si) { |
| 3541 | /* |
| 3542 | * An acceptable race has occurred since the failing |
| 3543 | * __swap_duplicate(): the swap entry has been freed, |
| 3544 | * perhaps even the whole swap_map cleared for swapoff. |
| 3545 | */ |
| 3546 | goto outer; |
| 3547 | } |
| 3548 | |
| 3549 | offset = swp_offset(entry); |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3550 | |
| 3551 | ci = lock_cluster(si, offset); |
| 3552 | |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3553 | count = si->swap_map[offset] & ~SWAP_HAS_CACHE; |
| 3554 | |
| 3555 | if ((count & ~COUNT_CONTINUED) != SWAP_MAP_MAX) { |
| 3556 | /* |
| 3557 | * The higher the swap count, the more likely it is that tasks |
| 3558 | * will race to add swap count continuation: we need to avoid |
| 3559 | * over-provisioning. |
| 3560 | */ |
| 3561 | goto out; |
| 3562 | } |
| 3563 | |
| 3564 | if (!page) { |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3565 | unlock_cluster(ci); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 3566 | spin_unlock(&si->lock); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3567 | return -ENOMEM; |
| 3568 | } |
| 3569 | |
| 3570 | /* |
| 3571 | * We are fortunate that although vmalloc_to_page uses pte_offset_map, |
Seth Jennings | 2de1a7e | 2013-11-12 15:07:46 -0800 | [diff] [blame] | 3572 | * no architecture is using highmem pages for kernel page tables: so it |
| 3573 | * will not corrupt the GFP_ATOMIC caller's atomic page table kmaps. |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3574 | */ |
| 3575 | head = vmalloc_to_page(si->swap_map + offset); |
| 3576 | offset &= ~PAGE_MASK; |
| 3577 | |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3578 | spin_lock(&si->cont_lock); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3579 | /* |
| 3580 | * Page allocation does not initialize the page's lru field, |
| 3581 | * but it does always reset its private field. |
| 3582 | */ |
| 3583 | if (!page_private(head)) { |
| 3584 | BUG_ON(count & COUNT_CONTINUED); |
| 3585 | INIT_LIST_HEAD(&head->lru); |
| 3586 | set_page_private(head, SWP_CONTINUED); |
| 3587 | si->flags |= SWP_CONTINUED; |
| 3588 | } |
| 3589 | |
| 3590 | list_for_each_entry(list_page, &head->lru, lru) { |
| 3591 | unsigned char *map; |
| 3592 | |
| 3593 | /* |
| 3594 | * If the previous map said no continuation, but we've found |
| 3595 | * a continuation page, free our allocation and use this one. |
| 3596 | */ |
| 3597 | if (!(count & COUNT_CONTINUED)) |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3598 | goto out_unlock_cont; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3599 | |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3600 | map = kmap_atomic(list_page) + offset; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3601 | count = *map; |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3602 | kunmap_atomic(map); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3603 | |
| 3604 | /* |
| 3605 | * If this continuation count now has some space in it, |
| 3606 | * free our allocation and use this one. |
| 3607 | */ |
| 3608 | if ((count & ~COUNT_CONTINUED) != SWAP_CONT_MAX) |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3609 | goto out_unlock_cont; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3610 | } |
| 3611 | |
| 3612 | list_add_tail(&page->lru, &head->lru); |
| 3613 | page = NULL; /* now it's attached, don't free it */ |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3614 | out_unlock_cont: |
| 3615 | spin_unlock(&si->cont_lock); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3616 | out: |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3617 | unlock_cluster(ci); |
Shaohua Li | ec8acf2 | 2013-02-22 16:34:38 -0800 | [diff] [blame] | 3618 | spin_unlock(&si->lock); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3619 | outer: |
| 3620 | if (page) |
| 3621 | __free_page(page); |
| 3622 | return 0; |
| 3623 | } |
| 3624 | |
| 3625 | /* |
| 3626 | * swap_count_continued - when the original swap_map count is incremented |
| 3627 | * from SWAP_MAP_MAX, check if there is already a continuation page to carry |
| 3628 | * into, carry if so, or else fail until a new continuation page is allocated; |
| 3629 | * when the original swap_map count is decremented from 0 with continuation, |
| 3630 | * borrow from the continuation and report whether it still holds more. |
Huang, Ying | 235b621 | 2017-02-22 15:45:22 -0800 | [diff] [blame] | 3631 | * Called while __swap_duplicate() or swap_entry_free() holds swap or cluster |
| 3632 | * lock. |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3633 | */ |
| 3634 | static bool swap_count_continued(struct swap_info_struct *si, |
| 3635 | pgoff_t offset, unsigned char count) |
| 3636 | { |
| 3637 | struct page *head; |
| 3638 | struct page *page; |
| 3639 | unsigned char *map; |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3640 | bool ret; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3641 | |
| 3642 | head = vmalloc_to_page(si->swap_map + offset); |
| 3643 | if (page_private(head) != SWP_CONTINUED) { |
| 3644 | BUG_ON(count & COUNT_CONTINUED); |
| 3645 | return false; /* need to add count continuation */ |
| 3646 | } |
| 3647 | |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3648 | spin_lock(&si->cont_lock); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3649 | offset &= ~PAGE_MASK; |
| 3650 | page = list_entry(head->lru.next, struct page, lru); |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3651 | map = kmap_atomic(page) + offset; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3652 | |
| 3653 | if (count == SWAP_MAP_MAX) /* initial increment from swap_map */ |
| 3654 | goto init_map; /* jump over SWAP_CONT_MAX checks */ |
| 3655 | |
| 3656 | if (count == (SWAP_MAP_MAX | COUNT_CONTINUED)) { /* incrementing */ |
| 3657 | /* |
| 3658 | * Think of how you add 1 to 999 |
| 3659 | */ |
| 3660 | while (*map == (SWAP_CONT_MAX | COUNT_CONTINUED)) { |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3661 | kunmap_atomic(map); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3662 | page = list_entry(page->lru.next, struct page, lru); |
| 3663 | BUG_ON(page == head); |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3664 | map = kmap_atomic(page) + offset; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3665 | } |
| 3666 | if (*map == SWAP_CONT_MAX) { |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3667 | kunmap_atomic(map); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3668 | page = list_entry(page->lru.next, struct page, lru); |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3669 | if (page == head) { |
| 3670 | ret = false; /* add count continuation */ |
| 3671 | goto out; |
| 3672 | } |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3673 | map = kmap_atomic(page) + offset; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3674 | init_map: *map = 0; /* we didn't zero the page */ |
| 3675 | } |
| 3676 | *map += 1; |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3677 | kunmap_atomic(map); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3678 | page = list_entry(page->lru.prev, struct page, lru); |
| 3679 | while (page != head) { |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3680 | map = kmap_atomic(page) + offset; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3681 | *map = COUNT_CONTINUED; |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3682 | kunmap_atomic(map); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3683 | page = list_entry(page->lru.prev, struct page, lru); |
| 3684 | } |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3685 | ret = true; /* incremented */ |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3686 | |
| 3687 | } else { /* decrementing */ |
| 3688 | /* |
| 3689 | * Think of how you subtract 1 from 1000 |
| 3690 | */ |
| 3691 | BUG_ON(count != COUNT_CONTINUED); |
| 3692 | while (*map == COUNT_CONTINUED) { |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3693 | kunmap_atomic(map); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3694 | page = list_entry(page->lru.next, struct page, lru); |
| 3695 | BUG_ON(page == head); |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3696 | map = kmap_atomic(page) + offset; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3697 | } |
| 3698 | BUG_ON(*map == 0); |
| 3699 | *map -= 1; |
| 3700 | if (*map == 0) |
| 3701 | count = 0; |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3702 | kunmap_atomic(map); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3703 | page = list_entry(page->lru.prev, struct page, lru); |
| 3704 | while (page != head) { |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3705 | map = kmap_atomic(page) + offset; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3706 | *map = SWAP_CONT_MAX | count; |
| 3707 | count = COUNT_CONTINUED; |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 3708 | kunmap_atomic(map); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3709 | page = list_entry(page->lru.prev, struct page, lru); |
| 3710 | } |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3711 | ret = count == COUNT_CONTINUED; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3712 | } |
Huang Ying | 2628bd6 | 2017-11-02 15:59:50 -0700 | [diff] [blame] | 3713 | out: |
| 3714 | spin_unlock(&si->cont_lock); |
| 3715 | return ret; |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3716 | } |
| 3717 | |
| 3718 | /* |
| 3719 | * free_swap_count_continuations - swapoff free all the continuation pages |
| 3720 | * appended to the swap_map, after swap_map is quiesced, before vfree'ing it. |
| 3721 | */ |
| 3722 | static void free_swap_count_continuations(struct swap_info_struct *si) |
| 3723 | { |
| 3724 | pgoff_t offset; |
| 3725 | |
| 3726 | for (offset = 0; offset < si->max; offset += PAGE_SIZE) { |
| 3727 | struct page *head; |
| 3728 | head = vmalloc_to_page(si->swap_map + offset); |
| 3729 | if (page_private(head)) { |
Geliang Tang | 0d576d2 | 2016-01-14 15:21:49 -0800 | [diff] [blame] | 3730 | struct page *page, *next; |
| 3731 | |
| 3732 | list_for_each_entry_safe(page, next, &head->lru, lru) { |
| 3733 | list_del(&page->lru); |
Hugh Dickins | 570a335b | 2009-12-14 17:58:46 -0800 | [diff] [blame] | 3734 | __free_page(page); |
| 3735 | } |
| 3736 | } |
| 3737 | } |
| 3738 | } |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 3739 | |
Tejun Heo | 2cf8558 | 2018-07-03 11:14:56 -0400 | [diff] [blame] | 3740 | #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) |
| 3741 | void mem_cgroup_throttle_swaprate(struct mem_cgroup *memcg, int node, |
| 3742 | gfp_t gfp_mask) |
| 3743 | { |
| 3744 | struct swap_info_struct *si, *next; |
| 3745 | if (!(gfp_mask & __GFP_IO) || !memcg) |
| 3746 | return; |
| 3747 | |
| 3748 | if (!blk_cgroup_congested()) |
| 3749 | return; |
| 3750 | |
| 3751 | /* |
| 3752 | * We've already scheduled a throttle, avoid taking the global swap |
| 3753 | * lock. |
| 3754 | */ |
| 3755 | if (current->throttle_queue) |
| 3756 | return; |
| 3757 | |
| 3758 | spin_lock(&swap_avail_lock); |
| 3759 | plist_for_each_entry_safe(si, next, &swap_avail_heads[node], |
| 3760 | avail_lists[node]) { |
| 3761 | if (si->bdev) { |
| 3762 | blkcg_schedule_throttle(bdev_get_queue(si->bdev), |
| 3763 | true); |
| 3764 | break; |
| 3765 | } |
| 3766 | } |
| 3767 | spin_unlock(&swap_avail_lock); |
| 3768 | } |
| 3769 | #endif |
| 3770 | |
Aaron Lu | a2468cc | 2017-09-06 16:24:57 -0700 | [diff] [blame] | 3771 | static int __init swapfile_init(void) |
| 3772 | { |
| 3773 | int nid; |
| 3774 | |
| 3775 | swap_avail_heads = kmalloc_array(nr_node_ids, sizeof(struct plist_head), |
| 3776 | GFP_KERNEL); |
| 3777 | if (!swap_avail_heads) { |
| 3778 | pr_emerg("Not enough memory for swap heads, swap is disabled\n"); |
| 3779 | return -ENOMEM; |
| 3780 | } |
| 3781 | |
| 3782 | for_each_node(nid) |
| 3783 | plist_head_init(&swap_avail_heads[nid]); |
| 3784 | |
| 3785 | return 0; |
| 3786 | } |
| 3787 | subsys_initcall(swapfile_init); |