Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Resizable virtual memory filesystem for Linux. |
| 3 | * |
| 4 | * Copyright (C) 2000 Linus Torvalds. |
| 5 | * 2000 Transmeta Corp. |
| 6 | * 2000-2001 Christoph Rohland |
| 7 | * 2000-2001 SAP AG |
| 8 | * 2002 Red Hat Inc. |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 9 | * Copyright (C) 2002-2011 Hugh Dickins. |
| 10 | * Copyright (C) 2011 Google Inc. |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 11 | * Copyright (C) 2002-2005 VERITAS Software Corporation. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * Copyright (C) 2004 Andi Kleen, SuSE Labs |
| 13 | * |
| 14 | * Extended attribute support for tmpfs: |
| 15 | * Copyright (c) 2004, Luke Kenneth Casson Leighton <lkcl@lkcl.net> |
| 16 | * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> |
| 17 | * |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 18 | * tiny-shmem: |
| 19 | * Copyright (c) 2004, 2008 Matt Mackall <mpm@selenic.com> |
| 20 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | * This file is released under the GPL. |
| 22 | */ |
| 23 | |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 24 | #include <linux/fs.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/vfs.h> |
| 27 | #include <linux/mount.h> |
Hugh Dickins | caefba1 | 2009-04-13 14:40:12 -0700 | [diff] [blame] | 28 | #include <linux/pagemap.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 29 | #include <linux/file.h> |
| 30 | #include <linux/mm.h> |
Paul Gortmaker | b95f1b31 | 2011-10-16 02:01:52 -0400 | [diff] [blame] | 31 | #include <linux/export.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 32 | #include <linux/swap.h> |
| 33 | |
| 34 | static struct vfsmount *shm_mnt; |
| 35 | |
| 36 | #ifdef CONFIG_SHMEM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | /* |
| 38 | * This virtual memory filesystem is heavily based on the ramfs. It |
| 39 | * extends ramfs by the ability to use swap and honor resource limits |
| 40 | * which makes it a completely usable filesystem. |
| 41 | */ |
| 42 | |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 43 | #include <linux/xattr.h> |
Christoph Hellwig | a569425 | 2007-07-17 04:04:28 -0700 | [diff] [blame] | 44 | #include <linux/exportfs.h> |
Christoph Hellwig | 1c7c474 | 2009-11-03 16:44:44 +0100 | [diff] [blame] | 45 | #include <linux/posix_acl.h> |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 46 | #include <linux/generic_acl.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | #include <linux/mman.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | #include <linux/string.h> |
| 49 | #include <linux/slab.h> |
| 50 | #include <linux/backing-dev.h> |
| 51 | #include <linux/shmem_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | #include <linux/blkdev.h> |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 54 | #include <linux/pagevec.h> |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 55 | #include <linux/percpu_counter.h> |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 56 | #include <linux/falloc.h> |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 57 | #include <linux/splice.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | #include <linux/security.h> |
| 59 | #include <linux/swapops.h> |
| 60 | #include <linux/mempolicy.h> |
| 61 | #include <linux/namei.h> |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 62 | #include <linux/ctype.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 63 | #include <linux/migrate.h> |
Christoph Lameter | c1f60a5 | 2006-09-25 23:31:11 -0700 | [diff] [blame] | 64 | #include <linux/highmem.h> |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 65 | #include <linux/seq_file.h> |
Mimi Zohar | 9256292 | 2008-10-07 14:00:12 -0400 | [diff] [blame] | 66 | #include <linux/magic.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 67 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | #include <asm/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | #include <asm/pgtable.h> |
| 70 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | #define BLOCKS_PER_PAGE (PAGE_CACHE_SIZE/512) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | #define VM_ACCT(size) (PAGE_CACHE_ALIGN(size) >> PAGE_SHIFT) |
| 73 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | /* Pretend that each entry is of this size in directory's i_size */ |
| 75 | #define BOGO_DIRENT_SIZE 20 |
| 76 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 77 | /* Symlink up to this size is kmalloc'ed instead of using a swappable page */ |
| 78 | #define SHORT_SYMLINK_LEN 128 |
| 79 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 80 | struct shmem_xattr { |
| 81 | struct list_head list; /* anchored by shmem_inode_info->xattr_list */ |
| 82 | char *name; /* xattr name */ |
| 83 | size_t size; |
| 84 | char value[0]; |
| 85 | }; |
| 86 | |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 87 | /* |
| 88 | * shmem_fallocate and shmem_writepage communicate via inode->i_private |
| 89 | * (with i_mutex making sure that it has only one user at a time): |
| 90 | * we would prefer not to enlarge the shmem inode just for that. |
| 91 | */ |
| 92 | struct shmem_falloc { |
| 93 | pgoff_t start; /* start of range currently being fallocated */ |
| 94 | pgoff_t next; /* the next page offset to be fallocated */ |
| 95 | pgoff_t nr_falloced; /* how many new pages have been fallocated */ |
| 96 | pgoff_t nr_unswapped; /* how often writepage refused to swap out */ |
| 97 | }; |
| 98 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 99 | /* Flag allocation requirements to shmem_getpage */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | enum sgp_type { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | SGP_READ, /* don't exceed i_size, don't allocate page */ |
| 102 | SGP_CACHE, /* don't exceed i_size, may allocate page */ |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 103 | SGP_DIRTY, /* like SGP_CACHE, but set new page dirty */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 104 | SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */ |
| 105 | SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | }; |
| 107 | |
Andrew Morton | b76db73 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 108 | #ifdef CONFIG_TMPFS |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 109 | static unsigned long shmem_default_max_blocks(void) |
| 110 | { |
| 111 | return totalram_pages / 2; |
| 112 | } |
| 113 | |
| 114 | static unsigned long shmem_default_max_inodes(void) |
| 115 | { |
| 116 | return min(totalram_pages - totalhigh_pages, totalram_pages / 2); |
| 117 | } |
Andrew Morton | b76db73 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 118 | #endif |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 119 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 120 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp); |
| 121 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 122 | struct shmem_inode_info *info, pgoff_t index); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 123 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
| 124 | struct page **pagep, enum sgp_type sgp, gfp_t gfp, int *fault_type); |
| 125 | |
| 126 | static inline int shmem_getpage(struct inode *inode, pgoff_t index, |
| 127 | struct page **pagep, enum sgp_type sgp, int *fault_type) |
| 128 | { |
| 129 | return shmem_getpage_gfp(inode, index, pagep, sgp, |
| 130 | mapping_gfp_mask(inode->i_mapping), fault_type); |
| 131 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb) |
| 134 | { |
| 135 | return sb->s_fs_info; |
| 136 | } |
| 137 | |
| 138 | /* |
| 139 | * shmem_file_setup pre-accounts the whole fixed size of a VM object, |
| 140 | * for shared memory and for shared anonymous (/dev/zero) mappings |
| 141 | * (unless MAP_NORESERVE and sysctl_overcommit_memory <= 1), |
| 142 | * consistent with the pre-accounting of private mappings ... |
| 143 | */ |
| 144 | static inline int shmem_acct_size(unsigned long flags, loff_t size) |
| 145 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 146 | return (flags & VM_NORESERVE) ? |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 147 | 0 : security_vm_enough_memory_mm(current->mm, VM_ACCT(size)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | } |
| 149 | |
| 150 | static inline void shmem_unacct_size(unsigned long flags, loff_t size) |
| 151 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 152 | if (!(flags & VM_NORESERVE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | vm_unacct_memory(VM_ACCT(size)); |
| 154 | } |
| 155 | |
| 156 | /* |
| 157 | * ... whereas tmpfs objects are accounted incrementally as |
| 158 | * pages are allocated, in order to allow huge sparse files. |
| 159 | * shmem_getpage reports shmem_acct_block failure as -ENOSPC not -ENOMEM, |
| 160 | * so that a failure on a sparse tmpfs mapping will give SIGBUS not OOM. |
| 161 | */ |
| 162 | static inline int shmem_acct_block(unsigned long flags) |
| 163 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 164 | return (flags & VM_NORESERVE) ? |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 165 | security_vm_enough_memory_mm(current->mm, VM_ACCT(PAGE_CACHE_SIZE)) : 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | } |
| 167 | |
| 168 | static inline void shmem_unacct_blocks(unsigned long flags, long pages) |
| 169 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 170 | if (flags & VM_NORESERVE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | vm_unacct_memory(pages * VM_ACCT(PAGE_CACHE_SIZE)); |
| 172 | } |
| 173 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 174 | static const struct super_operations shmem_ops; |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 175 | static const struct address_space_operations shmem_aops; |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 176 | static const struct file_operations shmem_file_operations; |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 177 | static const struct inode_operations shmem_inode_operations; |
| 178 | static const struct inode_operations shmem_dir_inode_operations; |
| 179 | static const struct inode_operations shmem_special_inode_operations; |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 180 | static const struct vm_operations_struct shmem_vm_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | |
Ravikiran G Thirumalai | 6c231b7 | 2005-09-06 15:17:45 -0700 | [diff] [blame] | 182 | static struct backing_dev_info shmem_backing_dev_info __read_mostly = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | .ra_pages = 0, /* No readahead */ |
Rik van Riel | 4f98a2f | 2008-10-18 20:26:32 -0700 | [diff] [blame] | 184 | .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | }; |
| 186 | |
| 187 | static LIST_HEAD(shmem_swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 188 | static DEFINE_MUTEX(shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 190 | static int shmem_reserve_inode(struct super_block *sb) |
| 191 | { |
| 192 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 193 | if (sbinfo->max_inodes) { |
| 194 | spin_lock(&sbinfo->stat_lock); |
| 195 | if (!sbinfo->free_inodes) { |
| 196 | spin_unlock(&sbinfo->stat_lock); |
| 197 | return -ENOSPC; |
| 198 | } |
| 199 | sbinfo->free_inodes--; |
| 200 | spin_unlock(&sbinfo->stat_lock); |
| 201 | } |
| 202 | return 0; |
| 203 | } |
| 204 | |
| 205 | static void shmem_free_inode(struct super_block *sb) |
| 206 | { |
| 207 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 208 | if (sbinfo->max_inodes) { |
| 209 | spin_lock(&sbinfo->stat_lock); |
| 210 | sbinfo->free_inodes++; |
| 211 | spin_unlock(&sbinfo->stat_lock); |
| 212 | } |
| 213 | } |
| 214 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 215 | /** |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 216 | * shmem_recalc_inode - recalculate the block usage of an inode |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | * @inode: inode to recalc |
| 218 | * |
| 219 | * We have to calculate the free blocks since the mm can drop |
| 220 | * undirtied hole pages behind our back. |
| 221 | * |
| 222 | * But normally info->alloced == inode->i_mapping->nrpages + info->swapped |
| 223 | * So mm freed is info->alloced - (inode->i_mapping->nrpages + info->swapped) |
| 224 | * |
| 225 | * It has to be called with the spinlock held. |
| 226 | */ |
| 227 | static void shmem_recalc_inode(struct inode *inode) |
| 228 | { |
| 229 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 230 | long freed; |
| 231 | |
| 232 | freed = info->alloced - info->swapped - inode->i_mapping->nrpages; |
| 233 | if (freed > 0) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 234 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 235 | if (sbinfo->max_blocks) |
| 236 | percpu_counter_add(&sbinfo->used_blocks, -freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | info->alloced -= freed; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 238 | inode->i_blocks -= freed * BLOCKS_PER_PAGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | shmem_unacct_blocks(info->flags, freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | } |
| 241 | } |
| 242 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 243 | /* |
| 244 | * Replace item expected in radix tree by a new item, while holding tree lock. |
| 245 | */ |
| 246 | static int shmem_radix_tree_replace(struct address_space *mapping, |
| 247 | pgoff_t index, void *expected, void *replacement) |
| 248 | { |
| 249 | void **pslot; |
| 250 | void *item = NULL; |
| 251 | |
| 252 | VM_BUG_ON(!expected); |
| 253 | pslot = radix_tree_lookup_slot(&mapping->page_tree, index); |
| 254 | if (pslot) |
| 255 | item = radix_tree_deref_slot_protected(pslot, |
| 256 | &mapping->tree_lock); |
| 257 | if (item != expected) |
| 258 | return -ENOENT; |
| 259 | if (replacement) |
| 260 | radix_tree_replace_slot(pslot, replacement); |
| 261 | else |
| 262 | radix_tree_delete(&mapping->page_tree, index); |
| 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | /* |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 267 | * Sometimes, before we decide whether to proceed or to fail, we must check |
| 268 | * that an entry was not already brought back from swap by a racing thread. |
| 269 | * |
| 270 | * Checking page is not enough: by the time a SwapCache page is locked, it |
| 271 | * might be reused, and again be SwapCache, using the same swap as before. |
| 272 | */ |
| 273 | static bool shmem_confirm_swap(struct address_space *mapping, |
| 274 | pgoff_t index, swp_entry_t swap) |
| 275 | { |
| 276 | void *item; |
| 277 | |
| 278 | rcu_read_lock(); |
| 279 | item = radix_tree_lookup(&mapping->page_tree, index); |
| 280 | rcu_read_unlock(); |
| 281 | return item == swp_to_radix_entry(swap); |
| 282 | } |
| 283 | |
| 284 | /* |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 285 | * Like add_to_page_cache_locked, but error if expected item has gone. |
| 286 | */ |
| 287 | static int shmem_add_to_page_cache(struct page *page, |
| 288 | struct address_space *mapping, |
| 289 | pgoff_t index, gfp_t gfp, void *expected) |
| 290 | { |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 291 | int error; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 292 | |
| 293 | VM_BUG_ON(!PageLocked(page)); |
| 294 | VM_BUG_ON(!PageSwapBacked(page)); |
| 295 | |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 296 | page_cache_get(page); |
| 297 | page->mapping = mapping; |
| 298 | page->index = index; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 299 | |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 300 | spin_lock_irq(&mapping->tree_lock); |
| 301 | if (!expected) |
| 302 | error = radix_tree_insert(&mapping->page_tree, index, page); |
| 303 | else |
| 304 | error = shmem_radix_tree_replace(mapping, index, expected, |
| 305 | page); |
| 306 | if (!error) { |
| 307 | mapping->nrpages++; |
| 308 | __inc_zone_page_state(page, NR_FILE_PAGES); |
| 309 | __inc_zone_page_state(page, NR_SHMEM); |
| 310 | spin_unlock_irq(&mapping->tree_lock); |
| 311 | } else { |
| 312 | page->mapping = NULL; |
| 313 | spin_unlock_irq(&mapping->tree_lock); |
| 314 | page_cache_release(page); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 315 | } |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 316 | return error; |
| 317 | } |
| 318 | |
| 319 | /* |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 320 | * Like delete_from_page_cache, but substitutes swap for page. |
| 321 | */ |
| 322 | static void shmem_delete_from_page_cache(struct page *page, void *radswap) |
| 323 | { |
| 324 | struct address_space *mapping = page->mapping; |
| 325 | int error; |
| 326 | |
| 327 | spin_lock_irq(&mapping->tree_lock); |
| 328 | error = shmem_radix_tree_replace(mapping, page->index, page, radswap); |
| 329 | page->mapping = NULL; |
| 330 | mapping->nrpages--; |
| 331 | __dec_zone_page_state(page, NR_FILE_PAGES); |
| 332 | __dec_zone_page_state(page, NR_SHMEM); |
| 333 | spin_unlock_irq(&mapping->tree_lock); |
| 334 | page_cache_release(page); |
| 335 | BUG_ON(error); |
| 336 | } |
| 337 | |
| 338 | /* |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 339 | * Like find_get_pages, but collecting swap entries as well as pages. |
| 340 | */ |
| 341 | static unsigned shmem_find_get_pages_and_swap(struct address_space *mapping, |
| 342 | pgoff_t start, unsigned int nr_pages, |
| 343 | struct page **pages, pgoff_t *indices) |
| 344 | { |
| 345 | unsigned int i; |
| 346 | unsigned int ret; |
| 347 | unsigned int nr_found; |
| 348 | |
| 349 | rcu_read_lock(); |
| 350 | restart: |
| 351 | nr_found = radix_tree_gang_lookup_slot(&mapping->page_tree, |
| 352 | (void ***)pages, indices, start, nr_pages); |
| 353 | ret = 0; |
| 354 | for (i = 0; i < nr_found; i++) { |
| 355 | struct page *page; |
| 356 | repeat: |
| 357 | page = radix_tree_deref_slot((void **)pages[i]); |
| 358 | if (unlikely(!page)) |
| 359 | continue; |
| 360 | if (radix_tree_exception(page)) { |
Hugh Dickins | 8079b1c | 2011-08-03 16:21:28 -0700 | [diff] [blame] | 361 | if (radix_tree_deref_retry(page)) |
| 362 | goto restart; |
| 363 | /* |
| 364 | * Otherwise, we must be storing a swap entry |
| 365 | * here as an exceptional entry: so return it |
| 366 | * without attempting to raise page count. |
| 367 | */ |
| 368 | goto export; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 369 | } |
| 370 | if (!page_cache_get_speculative(page)) |
| 371 | goto repeat; |
| 372 | |
| 373 | /* Has the page moved? */ |
| 374 | if (unlikely(page != *((void **)pages[i]))) { |
| 375 | page_cache_release(page); |
| 376 | goto repeat; |
| 377 | } |
| 378 | export: |
| 379 | indices[ret] = indices[i]; |
| 380 | pages[ret] = page; |
| 381 | ret++; |
| 382 | } |
| 383 | if (unlikely(!ret && nr_found)) |
| 384 | goto restart; |
| 385 | rcu_read_unlock(); |
| 386 | return ret; |
| 387 | } |
| 388 | |
| 389 | /* |
| 390 | * Remove swap entry from radix tree, free the swap and its page cache. |
| 391 | */ |
| 392 | static int shmem_free_swap(struct address_space *mapping, |
| 393 | pgoff_t index, void *radswap) |
| 394 | { |
| 395 | int error; |
| 396 | |
| 397 | spin_lock_irq(&mapping->tree_lock); |
| 398 | error = shmem_radix_tree_replace(mapping, index, radswap, NULL); |
| 399 | spin_unlock_irq(&mapping->tree_lock); |
| 400 | if (!error) |
| 401 | free_swap_and_cache(radix_to_swp_entry(radswap)); |
| 402 | return error; |
| 403 | } |
| 404 | |
| 405 | /* |
| 406 | * Pagevec may contain swap entries, so shuffle up pages before releasing. |
| 407 | */ |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 408 | static void shmem_deswap_pagevec(struct pagevec *pvec) |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 409 | { |
| 410 | int i, j; |
| 411 | |
| 412 | for (i = 0, j = 0; i < pagevec_count(pvec); i++) { |
| 413 | struct page *page = pvec->pages[i]; |
| 414 | if (!radix_tree_exceptional_entry(page)) |
| 415 | pvec->pages[j++] = page; |
| 416 | } |
| 417 | pvec->nr = j; |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 418 | } |
| 419 | |
| 420 | /* |
| 421 | * SysV IPC SHM_UNLOCK restore Unevictable pages to their evictable lists. |
| 422 | */ |
| 423 | void shmem_unlock_mapping(struct address_space *mapping) |
| 424 | { |
| 425 | struct pagevec pvec; |
| 426 | pgoff_t indices[PAGEVEC_SIZE]; |
| 427 | pgoff_t index = 0; |
| 428 | |
| 429 | pagevec_init(&pvec, 0); |
| 430 | /* |
| 431 | * Minor point, but we might as well stop if someone else SHM_LOCKs it. |
| 432 | */ |
| 433 | while (!mapping_unevictable(mapping)) { |
| 434 | /* |
| 435 | * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it |
| 436 | * has finished, if it hits a row of PAGEVEC_SIZE swap entries. |
| 437 | */ |
| 438 | pvec.nr = shmem_find_get_pages_and_swap(mapping, index, |
| 439 | PAGEVEC_SIZE, pvec.pages, indices); |
| 440 | if (!pvec.nr) |
| 441 | break; |
| 442 | index = indices[pvec.nr - 1] + 1; |
| 443 | shmem_deswap_pagevec(&pvec); |
| 444 | check_move_unevictable_pages(pvec.pages, pvec.nr); |
| 445 | pagevec_release(&pvec); |
| 446 | cond_resched(); |
| 447 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 448 | } |
| 449 | |
| 450 | /* |
| 451 | * Remove range of pages and swap entries from radix tree, and free them. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 452 | * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 453 | */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 454 | static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, |
| 455 | bool unfalloc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | { |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 457 | struct address_space *mapping = inode->i_mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | struct shmem_inode_info *info = SHMEM_I(inode); |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 459 | pgoff_t start = (lstart + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 460 | pgoff_t end = (lend + 1) >> PAGE_CACHE_SHIFT; |
| 461 | unsigned int partial_start = lstart & (PAGE_CACHE_SIZE - 1); |
| 462 | unsigned int partial_end = (lend + 1) & (PAGE_CACHE_SIZE - 1); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 463 | struct pagevec pvec; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 464 | pgoff_t indices[PAGEVEC_SIZE]; |
| 465 | long nr_swaps_freed = 0; |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 466 | pgoff_t index; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 467 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 469 | if (lend == -1) |
| 470 | end = -1; /* unsigned, so actually very big */ |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 471 | |
| 472 | pagevec_init(&pvec, 0); |
| 473 | index = start; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 474 | while (index < end) { |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 475 | pvec.nr = shmem_find_get_pages_and_swap(mapping, index, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 476 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 477 | pvec.pages, indices); |
| 478 | if (!pvec.nr) |
| 479 | break; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 480 | mem_cgroup_uncharge_start(); |
| 481 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 482 | struct page *page = pvec.pages[i]; |
| 483 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 484 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 485 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 486 | break; |
| 487 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 488 | if (radix_tree_exceptional_entry(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 489 | if (unfalloc) |
| 490 | continue; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 491 | nr_swaps_freed += !shmem_free_swap(mapping, |
| 492 | index, page); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 493 | continue; |
| 494 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 495 | |
| 496 | if (!trylock_page(page)) |
| 497 | continue; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 498 | if (!unfalloc || !PageUptodate(page)) { |
| 499 | if (page->mapping == mapping) { |
| 500 | VM_BUG_ON(PageWriteback(page)); |
| 501 | truncate_inode_page(mapping, page); |
| 502 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 503 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 504 | unlock_page(page); |
| 505 | } |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 506 | shmem_deswap_pagevec(&pvec); |
| 507 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 508 | mem_cgroup_uncharge_end(); |
| 509 | cond_resched(); |
| 510 | index++; |
| 511 | } |
| 512 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 513 | if (partial_start) { |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 514 | struct page *page = NULL; |
| 515 | shmem_getpage(inode, start - 1, &page, SGP_READ, NULL); |
| 516 | if (page) { |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 517 | unsigned int top = PAGE_CACHE_SIZE; |
| 518 | if (start > end) { |
| 519 | top = partial_end; |
| 520 | partial_end = 0; |
| 521 | } |
| 522 | zero_user_segment(page, partial_start, top); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 523 | set_page_dirty(page); |
| 524 | unlock_page(page); |
| 525 | page_cache_release(page); |
| 526 | } |
| 527 | } |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 528 | if (partial_end) { |
| 529 | struct page *page = NULL; |
| 530 | shmem_getpage(inode, end, &page, SGP_READ, NULL); |
| 531 | if (page) { |
| 532 | zero_user_segment(page, 0, partial_end); |
| 533 | set_page_dirty(page); |
| 534 | unlock_page(page); |
| 535 | page_cache_release(page); |
| 536 | } |
| 537 | } |
| 538 | if (start >= end) |
| 539 | return; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 540 | |
| 541 | index = start; |
| 542 | for ( ; ; ) { |
| 543 | cond_resched(); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 544 | pvec.nr = shmem_find_get_pages_and_swap(mapping, index, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 545 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 546 | pvec.pages, indices); |
| 547 | if (!pvec.nr) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 548 | if (index == start || unfalloc) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 549 | break; |
| 550 | index = start; |
| 551 | continue; |
| 552 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 553 | if ((index == start || unfalloc) && indices[0] >= end) { |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 554 | shmem_deswap_pagevec(&pvec); |
| 555 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 556 | break; |
| 557 | } |
| 558 | mem_cgroup_uncharge_start(); |
| 559 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 560 | struct page *page = pvec.pages[i]; |
| 561 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 562 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 563 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 564 | break; |
| 565 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 566 | if (radix_tree_exceptional_entry(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 567 | if (unfalloc) |
| 568 | continue; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 569 | nr_swaps_freed += !shmem_free_swap(mapping, |
| 570 | index, page); |
| 571 | continue; |
| 572 | } |
| 573 | |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 574 | lock_page(page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 575 | if (!unfalloc || !PageUptodate(page)) { |
| 576 | if (page->mapping == mapping) { |
| 577 | VM_BUG_ON(PageWriteback(page)); |
| 578 | truncate_inode_page(mapping, page); |
| 579 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 580 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 581 | unlock_page(page); |
| 582 | } |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 583 | shmem_deswap_pagevec(&pvec); |
| 584 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 585 | mem_cgroup_uncharge_end(); |
| 586 | index++; |
| 587 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 588 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 589 | spin_lock(&info->lock); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 590 | info->swapped -= nr_swaps_freed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | shmem_recalc_inode(inode); |
| 592 | spin_unlock(&info->lock); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 593 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 595 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) |
| 596 | { |
| 597 | shmem_undo_range(inode, lstart, lend, false); |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 598 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 600 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 602 | static int shmem_setattr(struct dentry *dentry, struct iattr *attr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | { |
| 604 | struct inode *inode = dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 605 | int error; |
| 606 | |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 607 | error = inode_change_ok(inode, attr); |
| 608 | if (error) |
| 609 | return error; |
| 610 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 611 | if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { |
| 612 | loff_t oldsize = inode->i_size; |
| 613 | loff_t newsize = attr->ia_size; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 614 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 615 | if (newsize != oldsize) { |
| 616 | i_size_write(inode, newsize); |
| 617 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
| 618 | } |
| 619 | if (newsize < oldsize) { |
| 620 | loff_t holebegin = round_up(newsize, PAGE_SIZE); |
| 621 | unmap_mapping_range(inode->i_mapping, holebegin, 0, 1); |
| 622 | shmem_truncate_range(inode, newsize, (loff_t)-1); |
| 623 | /* unmap again to remove racily COWed private pages */ |
| 624 | unmap_mapping_range(inode->i_mapping, holebegin, 0, 1); |
| 625 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | } |
| 627 | |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 628 | setattr_copy(inode, attr); |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 629 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 630 | if (attr->ia_valid & ATTR_MODE) |
Christoph Hellwig | 1c7c474 | 2009-11-03 16:44:44 +0100 | [diff] [blame] | 631 | error = generic_acl_chmod(inode); |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 632 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | return error; |
| 634 | } |
| 635 | |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 636 | static void shmem_evict_inode(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | struct shmem_inode_info *info = SHMEM_I(inode); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 639 | struct shmem_xattr *xattr, *nxattr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 641 | if (inode->i_mapping->a_ops == &shmem_aops) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | shmem_unacct_size(info->flags, inode->i_size); |
| 643 | inode->i_size = 0; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 644 | shmem_truncate_range(inode, 0, (loff_t)-1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | if (!list_empty(&info->swaplist)) { |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 646 | mutex_lock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 648 | mutex_unlock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 649 | } |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 650 | } else |
| 651 | kfree(info->symlink); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 652 | |
| 653 | list_for_each_entry_safe(xattr, nxattr, &info->xattr_list, list) { |
| 654 | kfree(xattr->name); |
| 655 | kfree(xattr); |
| 656 | } |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 657 | BUG_ON(inode->i_blocks); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 658 | shmem_free_inode(inode->i_sb); |
Jan Kara | dbd5768 | 2012-05-03 14:48:02 +0200 | [diff] [blame] | 659 | clear_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | } |
| 661 | |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 662 | /* |
| 663 | * If swap found in inode, free it and move page from swapcache to filecache. |
| 664 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 665 | static int shmem_unuse_inode(struct shmem_inode_info *info, |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 666 | swp_entry_t swap, struct page **pagep) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | { |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 668 | struct address_space *mapping = info->vfs_inode.i_mapping; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 669 | void *radswap; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 670 | pgoff_t index; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 671 | gfp_t gfp; |
| 672 | int error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 674 | radswap = swp_to_radix_entry(swap); |
Hugh Dickins | e504f3f | 2011-08-03 16:21:27 -0700 | [diff] [blame] | 675 | index = radix_tree_locate_item(&mapping->page_tree, radswap); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 676 | if (index == -1) |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 677 | return 0; |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 678 | |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 679 | /* |
| 680 | * Move _head_ to start search for next from here. |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 681 | * But be careful: shmem_evict_inode checks list_empty without taking |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 682 | * mutex, and there's an instant in list_move_tail when info->swaplist |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 683 | * would appear empty, if it were the only one on shmem_swaplist. |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 684 | */ |
| 685 | if (shmem_swaplist.next != &info->swaplist) |
| 686 | list_move_tail(&shmem_swaplist, &info->swaplist); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 687 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 688 | gfp = mapping_gfp_mask(mapping); |
| 689 | if (shmem_should_replace_page(*pagep, gfp)) { |
| 690 | mutex_unlock(&shmem_swaplist_mutex); |
| 691 | error = shmem_replace_page(pagep, gfp, info, index); |
| 692 | mutex_lock(&shmem_swaplist_mutex); |
| 693 | /* |
| 694 | * We needed to drop mutex to make that restrictive page |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 695 | * allocation, but the inode might have been freed while we |
| 696 | * dropped it: although a racing shmem_evict_inode() cannot |
| 697 | * complete without emptying the radix_tree, our page lock |
| 698 | * on this swapcache page is not enough to prevent that - |
| 699 | * free_swap_and_cache() of our swap entry will only |
| 700 | * trylock_page(), removing swap from radix_tree whatever. |
| 701 | * |
| 702 | * We must not proceed to shmem_add_to_page_cache() if the |
| 703 | * inode has been freed, but of course we cannot rely on |
| 704 | * inode or mapping or info to check that. However, we can |
| 705 | * safely check if our swap entry is still in use (and here |
| 706 | * it can't have got reused for another page): if it's still |
| 707 | * in use, then the inode cannot have been freed yet, and we |
| 708 | * can safely proceed (if it's no longer in use, that tells |
| 709 | * nothing about the inode, but we don't need to unuse swap). |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 710 | */ |
| 711 | if (!page_swapcount(*pagep)) |
| 712 | error = -ENOENT; |
| 713 | } |
| 714 | |
KAMEZAWA Hiroyuki | d13d144 | 2009-01-07 18:07:56 -0800 | [diff] [blame] | 715 | /* |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 716 | * We rely on shmem_swaplist_mutex, not only to protect the swaplist, |
| 717 | * but also to hold up shmem_evict_inode(): so inode cannot be freed |
| 718 | * beneath us (pagelock doesn't help until the page is in pagecache). |
KAMEZAWA Hiroyuki | d13d144 | 2009-01-07 18:07:56 -0800 | [diff] [blame] | 719 | */ |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 720 | if (!error) |
| 721 | error = shmem_add_to_page_cache(*pagep, mapping, index, |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 722 | GFP_NOWAIT, radswap); |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 723 | if (error != -ENOMEM) { |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 724 | /* |
| 725 | * Truncation and eviction use free_swap_and_cache(), which |
| 726 | * only does trylock page: if we raced, best clean up here. |
| 727 | */ |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 728 | delete_from_swap_cache(*pagep); |
| 729 | set_page_dirty(*pagep); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 730 | if (!error) { |
| 731 | spin_lock(&info->lock); |
| 732 | info->swapped--; |
| 733 | spin_unlock(&info->lock); |
| 734 | swap_free(swap); |
| 735 | } |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 736 | error = 1; /* not an error, but entry was found */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | } |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 738 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | } |
| 740 | |
| 741 | /* |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 742 | * Search through swapped inodes to find and replace swap by page. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 744 | int shmem_unuse(swp_entry_t swap, struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 746 | struct list_head *this, *next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | struct shmem_inode_info *info; |
| 748 | int found = 0; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 749 | int error = 0; |
| 750 | |
| 751 | /* |
| 752 | * There's a faint possibility that swap page was replaced before |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 753 | * caller locked it: caller will come back later with the right page. |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 754 | */ |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 755 | if (unlikely(!PageSwapCache(page) || page_private(page) != swap.val)) |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 756 | goto out; |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 757 | |
| 758 | /* |
| 759 | * Charge page using GFP_KERNEL while we can wait, before taking |
| 760 | * the shmem_swaplist_mutex which might hold up shmem_writepage(). |
| 761 | * Charged back to the user (not to caller) when swap account is used. |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 762 | */ |
| 763 | error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL); |
| 764 | if (error) |
| 765 | goto out; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 766 | /* No radix_tree_preload: swap entry keeps a place for page in tree */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 768 | mutex_lock(&shmem_swaplist_mutex); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 769 | list_for_each_safe(this, next, &shmem_swaplist) { |
| 770 | info = list_entry(this, struct shmem_inode_info, swaplist); |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 771 | if (info->swapped) |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 772 | found = shmem_unuse_inode(info, swap, &page); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 773 | else |
| 774 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 775 | cond_resched(); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 776 | if (found) |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 777 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | } |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 779 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 780 | |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 781 | if (found < 0) |
| 782 | error = found; |
| 783 | out: |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 784 | unlock_page(page); |
| 785 | page_cache_release(page); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 786 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | } |
| 788 | |
| 789 | /* |
| 790 | * Move the page from the page cache to the swap cache. |
| 791 | */ |
| 792 | static int shmem_writepage(struct page *page, struct writeback_control *wbc) |
| 793 | { |
| 794 | struct shmem_inode_info *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | struct address_space *mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | struct inode *inode; |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 797 | swp_entry_t swap; |
| 798 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | |
| 800 | BUG_ON(!PageLocked(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | mapping = page->mapping; |
| 802 | index = page->index; |
| 803 | inode = mapping->host; |
| 804 | info = SHMEM_I(inode); |
| 805 | if (info->flags & VM_LOCKED) |
| 806 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 807 | if (!total_swap_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | goto redirty; |
| 809 | |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 810 | /* |
| 811 | * shmem_backing_dev_info's capabilities prevent regular writeback or |
| 812 | * sync from ever calling shmem_writepage; but a stacking filesystem |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 813 | * might use ->writepage of its underlying filesystem, in which case |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 814 | * tmpfs should write out to swap only in response to memory pressure, |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 815 | * and not for the writeback threads or sync. |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 816 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 817 | if (!wbc->for_reclaim) { |
| 818 | WARN_ON_ONCE(1); /* Still happens? Tell us about it! */ |
| 819 | goto redirty; |
| 820 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 821 | |
| 822 | /* |
| 823 | * This is somewhat ridiculous, but without plumbing a SWAP_MAP_FALLOC |
| 824 | * value into swapfile.c, the only way we can correctly account for a |
| 825 | * fallocated page arriving here is now to initialize it and write it. |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 826 | * |
| 827 | * That's okay for a page already fallocated earlier, but if we have |
| 828 | * not yet completed the fallocation, then (a) we want to keep track |
| 829 | * of this page in case we have to undo it, and (b) it may not be a |
| 830 | * good idea to continue anyway, once we're pushing into swap. So |
| 831 | * reactivate the page, and let shmem_fallocate() quit when too many. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 832 | */ |
| 833 | if (!PageUptodate(page)) { |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 834 | if (inode->i_private) { |
| 835 | struct shmem_falloc *shmem_falloc; |
| 836 | spin_lock(&inode->i_lock); |
| 837 | shmem_falloc = inode->i_private; |
| 838 | if (shmem_falloc && |
| 839 | index >= shmem_falloc->start && |
| 840 | index < shmem_falloc->next) |
| 841 | shmem_falloc->nr_unswapped++; |
| 842 | else |
| 843 | shmem_falloc = NULL; |
| 844 | spin_unlock(&inode->i_lock); |
| 845 | if (shmem_falloc) |
| 846 | goto redirty; |
| 847 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 848 | clear_highpage(page); |
| 849 | flush_dcache_page(page); |
| 850 | SetPageUptodate(page); |
| 851 | } |
| 852 | |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 853 | swap = get_swap_page(); |
| 854 | if (!swap.val) |
| 855 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 856 | |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 857 | /* |
| 858 | * Add inode to shmem_unuse()'s list of swapped-out inodes, |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 859 | * if it's not already there. Do it now before the page is |
| 860 | * moved to swap cache, when its pagelock no longer protects |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 861 | * the inode from eviction. But don't unlock the mutex until |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 862 | * we've incremented swapped, because shmem_unuse_inode() will |
| 863 | * prune a !swapped inode from the swaplist under this mutex. |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 864 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 865 | mutex_lock(&shmem_swaplist_mutex); |
| 866 | if (list_empty(&info->swaplist)) |
| 867 | list_add_tail(&info->swaplist, &shmem_swaplist); |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 868 | |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 869 | if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) { |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 870 | swap_shmem_alloc(swap); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 871 | shmem_delete_from_page_cache(page, swp_to_radix_entry(swap)); |
| 872 | |
| 873 | spin_lock(&info->lock); |
| 874 | info->swapped++; |
| 875 | shmem_recalc_inode(inode); |
Hugh Dickins | 826267c | 2011-05-28 13:14:09 -0700 | [diff] [blame] | 876 | spin_unlock(&info->lock); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 877 | |
| 878 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 879 | BUG_ON(page_mapped(page)); |
Hugh Dickins | 9fab561 | 2009-03-31 15:23:33 -0700 | [diff] [blame] | 880 | swap_writepage(page, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | return 0; |
| 882 | } |
| 883 | |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 884 | mutex_unlock(&shmem_swaplist_mutex); |
KAMEZAWA Hiroyuki | cb4b86b | 2009-06-16 15:32:52 -0700 | [diff] [blame] | 885 | swapcache_free(swap, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 886 | redirty: |
| 887 | set_page_dirty(page); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 888 | if (wbc->for_reclaim) |
| 889 | return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */ |
| 890 | unlock_page(page); |
| 891 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 892 | } |
| 893 | |
| 894 | #ifdef CONFIG_NUMA |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 895 | #ifdef CONFIG_TMPFS |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 896 | static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 897 | { |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 898 | char buffer[64]; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 899 | |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 900 | if (!mpol || mpol->mode == MPOL_DEFAULT) |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 901 | return; /* show nothing */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 902 | |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 903 | mpol_to_str(buffer, sizeof(buffer), mpol, 1); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 904 | |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 905 | seq_printf(seq, ",mpol=%s", buffer); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 906 | } |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 907 | |
| 908 | static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 909 | { |
| 910 | struct mempolicy *mpol = NULL; |
| 911 | if (sbinfo->mpol) { |
| 912 | spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */ |
| 913 | mpol = sbinfo->mpol; |
| 914 | mpol_get(mpol); |
| 915 | spin_unlock(&sbinfo->stat_lock); |
| 916 | } |
| 917 | return mpol; |
| 918 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 919 | #endif /* CONFIG_TMPFS */ |
| 920 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 921 | static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, |
| 922 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | { |
Lee Schermerhorn | 52cd3b0 | 2008-04-28 02:13:16 -0700 | [diff] [blame] | 924 | struct mempolicy mpol, *spol; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 925 | struct vm_area_struct pvma; |
| 926 | |
Lee Schermerhorn | 52cd3b0 | 2008-04-28 02:13:16 -0700 | [diff] [blame] | 927 | spol = mpol_cond_copy(&mpol, |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 928 | mpol_shared_policy_lookup(&info->policy, index)); |
Lee Schermerhorn | 52cd3b0 | 2008-04-28 02:13:16 -0700 | [diff] [blame] | 929 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 930 | /* Create a pseudo vma that just contains the policy */ |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 931 | pvma.vm_start = 0; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 932 | pvma.vm_pgoff = index; |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 933 | pvma.vm_ops = NULL; |
Lee Schermerhorn | 52cd3b0 | 2008-04-28 02:13:16 -0700 | [diff] [blame] | 934 | pvma.vm_policy = spol; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 935 | return swapin_readahead(swap, gfp, &pvma, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 936 | } |
| 937 | |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 938 | static struct page *shmem_alloc_page(gfp_t gfp, |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 939 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 940 | { |
| 941 | struct vm_area_struct pvma; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 942 | |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 943 | /* Create a pseudo vma that just contains the policy */ |
| 944 | pvma.vm_start = 0; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 945 | pvma.vm_pgoff = index; |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 946 | pvma.vm_ops = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 947 | pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index); |
Lee Schermerhorn | 52cd3b0 | 2008-04-28 02:13:16 -0700 | [diff] [blame] | 948 | |
| 949 | /* |
| 950 | * alloc_page_vma() will drop the shared policy reference |
| 951 | */ |
| 952 | return alloc_page_vma(gfp, &pvma, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 953 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 954 | #else /* !CONFIG_NUMA */ |
| 955 | #ifdef CONFIG_TMPFS |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 956 | static inline void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 957 | { |
| 958 | } |
| 959 | #endif /* CONFIG_TMPFS */ |
| 960 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 961 | static inline struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, |
| 962 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 964 | return swapin_readahead(swap, gfp, NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 965 | } |
| 966 | |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 967 | static inline struct page *shmem_alloc_page(gfp_t gfp, |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 968 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 969 | { |
Hugh Dickins | e84e2e1 | 2007-11-28 18:55:10 +0000 | [diff] [blame] | 970 | return alloc_page(gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 972 | #endif /* CONFIG_NUMA */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 973 | |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 974 | #if !defined(CONFIG_NUMA) || !defined(CONFIG_TMPFS) |
| 975 | static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 976 | { |
| 977 | return NULL; |
| 978 | } |
| 979 | #endif |
| 980 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 981 | /* |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 982 | * When a page is moved from swapcache to shmem filecache (either by the |
| 983 | * usual swapin of shmem_getpage_gfp(), or by the less common swapoff of |
| 984 | * shmem_unuse_inode()), it may have been read in earlier from swap, in |
| 985 | * ignorance of the mapping it belongs to. If that mapping has special |
| 986 | * constraints (like the gma500 GEM driver, which requires RAM below 4GB), |
| 987 | * we may need to copy to a suitable page before moving to filecache. |
| 988 | * |
| 989 | * In a future release, this may well be extended to respect cpuset and |
| 990 | * NUMA mempolicy, and applied also to anonymous pages in do_swap_page(); |
| 991 | * but for now it is a simple matter of zone. |
| 992 | */ |
| 993 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp) |
| 994 | { |
| 995 | return page_zonenum(page) > gfp_zone(gfp); |
| 996 | } |
| 997 | |
| 998 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 999 | struct shmem_inode_info *info, pgoff_t index) |
| 1000 | { |
| 1001 | struct page *oldpage, *newpage; |
| 1002 | struct address_space *swap_mapping; |
| 1003 | pgoff_t swap_index; |
| 1004 | int error; |
| 1005 | |
| 1006 | oldpage = *pagep; |
| 1007 | swap_index = page_private(oldpage); |
| 1008 | swap_mapping = page_mapping(oldpage); |
| 1009 | |
| 1010 | /* |
| 1011 | * We have arrived here because our zones are constrained, so don't |
| 1012 | * limit chance of success by further cpuset and node constraints. |
| 1013 | */ |
| 1014 | gfp &= ~GFP_CONSTRAINT_MASK; |
| 1015 | newpage = shmem_alloc_page(gfp, info, index); |
| 1016 | if (!newpage) |
| 1017 | return -ENOMEM; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1018 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1019 | page_cache_get(newpage); |
| 1020 | copy_highpage(newpage, oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1021 | flush_dcache_page(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1022 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1023 | __set_page_locked(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1024 | SetPageUptodate(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1025 | SetPageSwapBacked(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1026 | set_page_private(newpage, swap_index); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1027 | SetPageSwapCache(newpage); |
| 1028 | |
| 1029 | /* |
| 1030 | * Our caller will very soon move newpage out of swapcache, but it's |
| 1031 | * a nice clean interface for us to replace oldpage by newpage there. |
| 1032 | */ |
| 1033 | spin_lock_irq(&swap_mapping->tree_lock); |
| 1034 | error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage, |
| 1035 | newpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1036 | if (!error) { |
| 1037 | __inc_zone_page_state(newpage, NR_FILE_PAGES); |
| 1038 | __dec_zone_page_state(oldpage, NR_FILE_PAGES); |
| 1039 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1040 | spin_unlock_irq(&swap_mapping->tree_lock); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1041 | |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1042 | if (unlikely(error)) { |
| 1043 | /* |
| 1044 | * Is this possible? I think not, now that our callers check |
| 1045 | * both PageSwapCache and page_private after getting page lock; |
| 1046 | * but be defensive. Reverse old to newpage for clear and free. |
| 1047 | */ |
| 1048 | oldpage = newpage; |
| 1049 | } else { |
| 1050 | mem_cgroup_replace_page_cache(oldpage, newpage); |
| 1051 | lru_cache_add_anon(newpage); |
| 1052 | *pagep = newpage; |
| 1053 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1054 | |
| 1055 | ClearPageSwapCache(oldpage); |
| 1056 | set_page_private(oldpage, 0); |
| 1057 | |
| 1058 | unlock_page(oldpage); |
| 1059 | page_cache_release(oldpage); |
| 1060 | page_cache_release(oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1061 | return error; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1062 | } |
| 1063 | |
| 1064 | /* |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1065 | * shmem_getpage_gfp - find page in cache, or get from swap, or allocate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1066 | * |
| 1067 | * If we allocate a new one we do not mark it dirty. That's up to the |
| 1068 | * vm. If we swap it in we mark it dirty since we also free the swap |
| 1069 | * entry since a page cannot live in both the swap and page cache |
| 1070 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1071 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1072 | struct page **pagep, enum sgp_type sgp, gfp_t gfp, int *fault_type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1073 | { |
| 1074 | struct address_space *mapping = inode->i_mapping; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1075 | struct shmem_inode_info *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | struct shmem_sb_info *sbinfo; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1077 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1078 | swp_entry_t swap; |
| 1079 | int error; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1080 | int once = 0; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1081 | int alloced = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1083 | if (index > (MAX_LFS_FILESIZE >> PAGE_CACHE_SHIFT)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1084 | return -EFBIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | repeat: |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1086 | swap.val = 0; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1087 | page = find_lock_page(mapping, index); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1088 | if (radix_tree_exceptional_entry(page)) { |
| 1089 | swap = radix_to_swp_entry(page); |
| 1090 | page = NULL; |
| 1091 | } |
| 1092 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1093 | if (sgp != SGP_WRITE && sgp != SGP_FALLOC && |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1094 | ((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) { |
| 1095 | error = -EINVAL; |
| 1096 | goto failed; |
| 1097 | } |
| 1098 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1099 | /* fallocated page? */ |
| 1100 | if (page && !PageUptodate(page)) { |
| 1101 | if (sgp != SGP_READ) |
| 1102 | goto clear; |
| 1103 | unlock_page(page); |
| 1104 | page_cache_release(page); |
| 1105 | page = NULL; |
| 1106 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1107 | if (page || (sgp == SGP_READ && !swap.val)) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1108 | *pagep = page; |
| 1109 | return 0; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1110 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1111 | |
| 1112 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1113 | * Fast cache lookup did not find it: |
| 1114 | * bring it back from swap or allocate. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1115 | */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1116 | info = SHMEM_I(inode); |
| 1117 | sbinfo = SHMEM_SB(inode->i_sb); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1118 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1119 | if (swap.val) { |
| 1120 | /* Look it up and read it in.. */ |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1121 | page = lookup_swap_cache(swap); |
| 1122 | if (!page) { |
Ying Han | 456f998 | 2011-05-26 16:25:38 -0700 | [diff] [blame] | 1123 | /* here we actually do the io */ |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1124 | if (fault_type) |
| 1125 | *fault_type |= VM_FAULT_MAJOR; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1126 | page = shmem_swapin(swap, gfp, info, index); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1127 | if (!page) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1128 | error = -ENOMEM; |
| 1129 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1131 | } |
| 1132 | |
| 1133 | /* We have to do this with page locked to prevent races */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1134 | lock_page(page); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1135 | if (!PageSwapCache(page) || page_private(page) != swap.val || |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1136 | !shmem_confirm_swap(mapping, index, swap)) { |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1137 | error = -EEXIST; /* try again */ |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1138 | goto unlock; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1139 | } |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1140 | if (!PageUptodate(page)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1141 | error = -EIO; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1142 | goto failed; |
| 1143 | } |
| 1144 | wait_on_page_writeback(page); |
| 1145 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1146 | if (shmem_should_replace_page(page, gfp)) { |
| 1147 | error = shmem_replace_page(&page, gfp, info, index); |
| 1148 | if (error) |
| 1149 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | } |
| 1151 | |
Hugh Dickins | aa3b189 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1152 | error = mem_cgroup_cache_charge(page, current->mm, |
| 1153 | gfp & GFP_RECLAIM_MASK); |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1154 | if (!error) { |
Hugh Dickins | aa3b189 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1155 | error = shmem_add_to_page_cache(page, mapping, index, |
| 1156 | gfp, swp_to_radix_entry(swap)); |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1157 | /* We already confirmed swap, and make no allocation */ |
| 1158 | VM_BUG_ON(error); |
| 1159 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1160 | if (error) |
| 1161 | goto failed; |
| 1162 | |
| 1163 | spin_lock(&info->lock); |
| 1164 | info->swapped--; |
| 1165 | shmem_recalc_inode(inode); |
| 1166 | spin_unlock(&info->lock); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1167 | |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1168 | delete_from_swap_cache(page); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1169 | set_page_dirty(page); |
| 1170 | swap_free(swap); |
| 1171 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1172 | } else { |
| 1173 | if (shmem_acct_block(info->flags)) { |
| 1174 | error = -ENOSPC; |
| 1175 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | } |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1177 | if (sbinfo->max_blocks) { |
Hugh Dickins | fc5da22 | 2011-04-14 15:22:07 -0700 | [diff] [blame] | 1178 | if (percpu_counter_compare(&sbinfo->used_blocks, |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1179 | sbinfo->max_blocks) >= 0) { |
| 1180 | error = -ENOSPC; |
| 1181 | goto unacct; |
| 1182 | } |
Tim Chen | 7e49629 | 2010-08-09 17:19:05 -0700 | [diff] [blame] | 1183 | percpu_counter_inc(&sbinfo->used_blocks); |
Hugh Dickins | 59a16ea | 2011-05-11 15:13:38 -0700 | [diff] [blame] | 1184 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1185 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1186 | page = shmem_alloc_page(gfp, info, index); |
| 1187 | if (!page) { |
| 1188 | error = -ENOMEM; |
| 1189 | goto decused; |
| 1190 | } |
| 1191 | |
| 1192 | SetPageSwapBacked(page); |
| 1193 | __set_page_locked(page); |
Hugh Dickins | aa3b189 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1194 | error = mem_cgroup_cache_charge(page, current->mm, |
| 1195 | gfp & GFP_RECLAIM_MASK); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1196 | if (error) |
| 1197 | goto decused; |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 1198 | error = radix_tree_preload(gfp & GFP_RECLAIM_MASK); |
| 1199 | if (!error) { |
| 1200 | error = shmem_add_to_page_cache(page, mapping, index, |
| 1201 | gfp, NULL); |
| 1202 | radix_tree_preload_end(); |
| 1203 | } |
| 1204 | if (error) { |
| 1205 | mem_cgroup_uncharge_cache_page(page); |
| 1206 | goto decused; |
| 1207 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1208 | lru_cache_add_anon(page); |
| 1209 | |
| 1210 | spin_lock(&info->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1211 | info->alloced++; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1212 | inode->i_blocks += BLOCKS_PER_PAGE; |
| 1213 | shmem_recalc_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1214 | spin_unlock(&info->lock); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1215 | alloced = true; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1216 | |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1217 | /* |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1218 | * Let SGP_FALLOC use the SGP_WRITE optimization on a new page. |
| 1219 | */ |
| 1220 | if (sgp == SGP_FALLOC) |
| 1221 | sgp = SGP_WRITE; |
| 1222 | clear: |
| 1223 | /* |
| 1224 | * Let SGP_WRITE caller clear ends if write does not fill page; |
| 1225 | * but SGP_FALLOC on a page fallocated earlier must initialize |
| 1226 | * it now, lest undo on failure cancel our earlier guarantee. |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1227 | */ |
| 1228 | if (sgp != SGP_WRITE) { |
| 1229 | clear_highpage(page); |
| 1230 | flush_dcache_page(page); |
| 1231 | SetPageUptodate(page); |
| 1232 | } |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1233 | if (sgp == SGP_DIRTY) |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1234 | set_page_dirty(page); |
Hugh Dickins | 59a16ea | 2011-05-11 15:13:38 -0700 | [diff] [blame] | 1235 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1236 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1237 | /* Perhaps the file has been truncated since we checked */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1238 | if (sgp != SGP_WRITE && sgp != SGP_FALLOC && |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1239 | ((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) { |
| 1240 | error = -EINVAL; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1241 | if (alloced) |
| 1242 | goto trunc; |
| 1243 | else |
| 1244 | goto failed; |
Shaohua Li | ff36b801 | 2010-08-09 17:19:06 -0700 | [diff] [blame] | 1245 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1246 | *pagep = page; |
| 1247 | return 0; |
Nick Piggin | d00806b | 2007-07-19 01:46:57 -0700 | [diff] [blame] | 1248 | |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1249 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1250 | * Error recovery. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1251 | */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1252 | trunc: |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1253 | info = SHMEM_I(inode); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1254 | ClearPageDirty(page); |
| 1255 | delete_from_page_cache(page); |
| 1256 | spin_lock(&info->lock); |
| 1257 | info->alloced--; |
| 1258 | inode->i_blocks -= BLOCKS_PER_PAGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | spin_unlock(&info->lock); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1260 | decused: |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1261 | sbinfo = SHMEM_SB(inode->i_sb); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1262 | if (sbinfo->max_blocks) |
| 1263 | percpu_counter_add(&sbinfo->used_blocks, -1); |
| 1264 | unacct: |
| 1265 | shmem_unacct_blocks(info->flags, 1); |
| 1266 | failed: |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1267 | if (swap.val && error != -EINVAL && |
| 1268 | !shmem_confirm_swap(mapping, index, swap)) |
| 1269 | error = -EEXIST; |
| 1270 | unlock: |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1271 | if (page) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1272 | unlock_page(page); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1273 | page_cache_release(page); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1274 | } |
| 1275 | if (error == -ENOSPC && !once++) { |
| 1276 | info = SHMEM_I(inode); |
| 1277 | spin_lock(&info->lock); |
| 1278 | shmem_recalc_inode(inode); |
| 1279 | spin_unlock(&info->lock); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1280 | goto repeat; |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1281 | } |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1282 | if (error == -EEXIST) /* from above or from radix_tree_insert */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1283 | goto repeat; |
| 1284 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1285 | } |
| 1286 | |
| 1287 | static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 1288 | { |
| 1289 | struct inode *inode = vma->vm_file->f_path.dentry->d_inode; |
| 1290 | int error; |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1291 | int ret = VM_FAULT_LOCKED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1292 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1293 | error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret); |
| 1294 | if (error) |
| 1295 | return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1296 | |
Ying Han | 456f998 | 2011-05-26 16:25:38 -0700 | [diff] [blame] | 1297 | if (ret & VM_FAULT_MAJOR) { |
| 1298 | count_vm_event(PGMAJFAULT); |
| 1299 | mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); |
| 1300 | } |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1301 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1302 | } |
| 1303 | |
| 1304 | #ifdef CONFIG_NUMA |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1305 | static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1306 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1307 | struct inode *inode = vma->vm_file->f_path.dentry->d_inode; |
| 1308 | return mpol_set_shared_policy(&SHMEM_I(inode)->policy, vma, mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1309 | } |
| 1310 | |
Adrian Bunk | d8dc74f | 2007-10-16 01:26:26 -0700 | [diff] [blame] | 1311 | static struct mempolicy *shmem_get_policy(struct vm_area_struct *vma, |
| 1312 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1313 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1314 | struct inode *inode = vma->vm_file->f_path.dentry->d_inode; |
| 1315 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1316 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1317 | index = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
| 1318 | return mpol_shared_policy_lookup(&SHMEM_I(inode)->policy, index); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1319 | } |
| 1320 | #endif |
| 1321 | |
| 1322 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 1323 | { |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1324 | struct inode *inode = file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1325 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 1326 | int retval = -ENOMEM; |
| 1327 | |
| 1328 | spin_lock(&info->lock); |
| 1329 | if (lock && !(info->flags & VM_LOCKED)) { |
| 1330 | if (!user_shm_lock(inode->i_size, user)) |
| 1331 | goto out_nomem; |
| 1332 | info->flags |= VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 1333 | mapping_set_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1334 | } |
| 1335 | if (!lock && (info->flags & VM_LOCKED) && user) { |
| 1336 | user_shm_unlock(inode->i_size, user); |
| 1337 | info->flags &= ~VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 1338 | mapping_clear_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1339 | } |
| 1340 | retval = 0; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 1341 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1342 | out_nomem: |
| 1343 | spin_unlock(&info->lock); |
| 1344 | return retval; |
| 1345 | } |
| 1346 | |
Adrian Bunk | 9b83a6a | 2007-02-28 20:11:03 -0800 | [diff] [blame] | 1347 | static int shmem_mmap(struct file *file, struct vm_area_struct *vma) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1348 | { |
| 1349 | file_accessed(file); |
| 1350 | vma->vm_ops = &shmem_vm_ops; |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1351 | vma->vm_flags |= VM_CAN_NONLINEAR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1352 | return 0; |
| 1353 | } |
| 1354 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 1355 | static struct inode *shmem_get_inode(struct super_block *sb, const struct inode *dir, |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 1356 | umode_t mode, dev_t dev, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1357 | { |
| 1358 | struct inode *inode; |
| 1359 | struct shmem_inode_info *info; |
| 1360 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 1361 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1362 | if (shmem_reserve_inode(sb)) |
| 1363 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1364 | |
| 1365 | inode = new_inode(sb); |
| 1366 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 1367 | inode->i_ino = get_next_ino(); |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 1368 | inode_init_owner(inode, dir, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1369 | inode->i_blocks = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1370 | inode->i_mapping->backing_dev_info = &shmem_backing_dev_info; |
| 1371 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 1372 | inode->i_generation = get_seconds(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | info = SHMEM_I(inode); |
| 1374 | memset(info, 0, (char *)inode - (char *)info); |
| 1375 | spin_lock_init(&info->lock); |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 1376 | info->flags = flags & VM_NORESERVE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1377 | INIT_LIST_HEAD(&info->swaplist); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 1378 | INIT_LIST_HEAD(&info->xattr_list); |
Al Viro | 72c0490 | 2009-06-24 16:58:48 -0400 | [diff] [blame] | 1379 | cache_no_acl(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1380 | |
| 1381 | switch (mode & S_IFMT) { |
| 1382 | default: |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 1383 | inode->i_op = &shmem_special_inode_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1384 | init_special_inode(inode, mode, dev); |
| 1385 | break; |
| 1386 | case S_IFREG: |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 1387 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1388 | inode->i_op = &shmem_inode_operations; |
| 1389 | inode->i_fop = &shmem_file_operations; |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1390 | mpol_shared_policy_init(&info->policy, |
| 1391 | shmem_get_sbmpol(sbinfo)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1392 | break; |
| 1393 | case S_IFDIR: |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1394 | inc_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1395 | /* Some things misbehave if size == 0 on a directory */ |
| 1396 | inode->i_size = 2 * BOGO_DIRENT_SIZE; |
| 1397 | inode->i_op = &shmem_dir_inode_operations; |
| 1398 | inode->i_fop = &simple_dir_operations; |
| 1399 | break; |
| 1400 | case S_IFLNK: |
| 1401 | /* |
| 1402 | * Must not load anything in the rbtree, |
| 1403 | * mpol_free_shared_policy will not be called. |
| 1404 | */ |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1405 | mpol_shared_policy_init(&info->policy, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1406 | break; |
| 1407 | } |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1408 | } else |
| 1409 | shmem_free_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1410 | return inode; |
| 1411 | } |
| 1412 | |
| 1413 | #ifdef CONFIG_TMPFS |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 1414 | static const struct inode_operations shmem_symlink_inode_operations; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 1415 | static const struct inode_operations shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1416 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 1417 | #ifdef CONFIG_TMPFS_XATTR |
| 1418 | static int shmem_initxattrs(struct inode *, const struct xattr *, void *); |
| 1419 | #else |
| 1420 | #define shmem_initxattrs NULL |
| 1421 | #endif |
| 1422 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1423 | static int |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1424 | shmem_write_begin(struct file *file, struct address_space *mapping, |
| 1425 | loff_t pos, unsigned len, unsigned flags, |
| 1426 | struct page **pagep, void **fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1427 | { |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1428 | struct inode *inode = mapping->host; |
| 1429 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1430 | return shmem_getpage(inode, index, pagep, SGP_WRITE, NULL); |
| 1431 | } |
| 1432 | |
| 1433 | static int |
| 1434 | shmem_write_end(struct file *file, struct address_space *mapping, |
| 1435 | loff_t pos, unsigned len, unsigned copied, |
| 1436 | struct page *page, void *fsdata) |
| 1437 | { |
| 1438 | struct inode *inode = mapping->host; |
| 1439 | |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1440 | if (pos + copied > inode->i_size) |
| 1441 | i_size_write(inode, pos + copied); |
| 1442 | |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1443 | if (!PageUptodate(page)) { |
| 1444 | if (copied < PAGE_CACHE_SIZE) { |
| 1445 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
| 1446 | zero_user_segments(page, 0, from, |
| 1447 | from + copied, PAGE_CACHE_SIZE); |
| 1448 | } |
| 1449 | SetPageUptodate(page); |
| 1450 | } |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1451 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 1452 | unlock_page(page); |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1453 | page_cache_release(page); |
| 1454 | |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1455 | return copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1456 | } |
| 1457 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1458 | static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor) |
| 1459 | { |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1460 | struct inode *inode = filp->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | struct address_space *mapping = inode->i_mapping; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1462 | pgoff_t index; |
| 1463 | unsigned long offset; |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1464 | enum sgp_type sgp = SGP_READ; |
| 1465 | |
| 1466 | /* |
| 1467 | * Might this read be for a stacking filesystem? Then when reading |
| 1468 | * holes of a sparse file, we actually need to allocate those pages, |
| 1469 | * and even mark them dirty, so it cannot exceed the max_blocks limit. |
| 1470 | */ |
| 1471 | if (segment_eq(get_fs(), KERNEL_DS)) |
| 1472 | sgp = SGP_DIRTY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1473 | |
| 1474 | index = *ppos >> PAGE_CACHE_SHIFT; |
| 1475 | offset = *ppos & ~PAGE_CACHE_MASK; |
| 1476 | |
| 1477 | for (;;) { |
| 1478 | struct page *page = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1479 | pgoff_t end_index; |
| 1480 | unsigned long nr, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1481 | loff_t i_size = i_size_read(inode); |
| 1482 | |
| 1483 | end_index = i_size >> PAGE_CACHE_SHIFT; |
| 1484 | if (index > end_index) |
| 1485 | break; |
| 1486 | if (index == end_index) { |
| 1487 | nr = i_size & ~PAGE_CACHE_MASK; |
| 1488 | if (nr <= offset) |
| 1489 | break; |
| 1490 | } |
| 1491 | |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1492 | desc->error = shmem_getpage(inode, index, &page, sgp, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1493 | if (desc->error) { |
| 1494 | if (desc->error == -EINVAL) |
| 1495 | desc->error = 0; |
| 1496 | break; |
| 1497 | } |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1498 | if (page) |
| 1499 | unlock_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1500 | |
| 1501 | /* |
| 1502 | * We must evaluate after, since reads (unlike writes) |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1503 | * are called without i_mutex protection against truncate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1504 | */ |
| 1505 | nr = PAGE_CACHE_SIZE; |
| 1506 | i_size = i_size_read(inode); |
| 1507 | end_index = i_size >> PAGE_CACHE_SHIFT; |
| 1508 | if (index == end_index) { |
| 1509 | nr = i_size & ~PAGE_CACHE_MASK; |
| 1510 | if (nr <= offset) { |
| 1511 | if (page) |
| 1512 | page_cache_release(page); |
| 1513 | break; |
| 1514 | } |
| 1515 | } |
| 1516 | nr -= offset; |
| 1517 | |
| 1518 | if (page) { |
| 1519 | /* |
| 1520 | * If users can be writing to this page using arbitrary |
| 1521 | * virtual addresses, take care about potential aliasing |
| 1522 | * before reading the page on the kernel side. |
| 1523 | */ |
| 1524 | if (mapping_writably_mapped(mapping)) |
| 1525 | flush_dcache_page(page); |
| 1526 | /* |
| 1527 | * Mark the page accessed if we read the beginning. |
| 1528 | */ |
| 1529 | if (!offset) |
| 1530 | mark_page_accessed(page); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 1531 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1532 | page = ZERO_PAGE(0); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 1533 | page_cache_get(page); |
| 1534 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1535 | |
| 1536 | /* |
| 1537 | * Ok, we have the page, and it's up-to-date, so |
| 1538 | * now we can copy it to user space... |
| 1539 | * |
| 1540 | * The actor routine returns how many bytes were actually used.. |
| 1541 | * NOTE! This may not be the same as how much of a user buffer |
| 1542 | * we filled up (we may be padding etc), so we can only update |
| 1543 | * "pos" here (the actor routine has to update the user buffer |
| 1544 | * pointers and the remaining count). |
| 1545 | */ |
| 1546 | ret = actor(desc, page, offset, nr); |
| 1547 | offset += ret; |
| 1548 | index += offset >> PAGE_CACHE_SHIFT; |
| 1549 | offset &= ~PAGE_CACHE_MASK; |
| 1550 | |
| 1551 | page_cache_release(page); |
| 1552 | if (ret != nr || !desc->count) |
| 1553 | break; |
| 1554 | |
| 1555 | cond_resched(); |
| 1556 | } |
| 1557 | |
| 1558 | *ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset; |
| 1559 | file_accessed(filp); |
| 1560 | } |
| 1561 | |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1562 | static ssize_t shmem_file_aio_read(struct kiocb *iocb, |
| 1563 | const struct iovec *iov, unsigned long nr_segs, loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1564 | { |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1565 | struct file *filp = iocb->ki_filp; |
| 1566 | ssize_t retval; |
| 1567 | unsigned long seg; |
| 1568 | size_t count; |
| 1569 | loff_t *ppos = &iocb->ki_pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1570 | |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1571 | retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); |
| 1572 | if (retval) |
| 1573 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1574 | |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1575 | for (seg = 0; seg < nr_segs; seg++) { |
| 1576 | read_descriptor_t desc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1577 | |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1578 | desc.written = 0; |
| 1579 | desc.arg.buf = iov[seg].iov_base; |
| 1580 | desc.count = iov[seg].iov_len; |
| 1581 | if (desc.count == 0) |
| 1582 | continue; |
| 1583 | desc.error = 0; |
| 1584 | do_shmem_file_read(filp, ppos, &desc, file_read_actor); |
| 1585 | retval += desc.written; |
| 1586 | if (desc.error) { |
| 1587 | retval = retval ?: desc.error; |
| 1588 | break; |
| 1589 | } |
| 1590 | if (desc.count > 0) |
| 1591 | break; |
| 1592 | } |
| 1593 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1594 | } |
| 1595 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1596 | static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, |
| 1597 | struct pipe_inode_info *pipe, size_t len, |
| 1598 | unsigned int flags) |
| 1599 | { |
| 1600 | struct address_space *mapping = in->f_mapping; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1601 | struct inode *inode = mapping->host; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1602 | unsigned int loff, nr_pages, req_pages; |
| 1603 | struct page *pages[PIPE_DEF_BUFFERS]; |
| 1604 | struct partial_page partial[PIPE_DEF_BUFFERS]; |
| 1605 | struct page *page; |
| 1606 | pgoff_t index, end_index; |
| 1607 | loff_t isize, left; |
| 1608 | int error, page_nr; |
| 1609 | struct splice_pipe_desc spd = { |
| 1610 | .pages = pages, |
| 1611 | .partial = partial, |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 1612 | .nr_pages_max = PIPE_DEF_BUFFERS, |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1613 | .flags = flags, |
| 1614 | .ops = &page_cache_pipe_buf_ops, |
| 1615 | .spd_release = spd_release_page, |
| 1616 | }; |
| 1617 | |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1618 | isize = i_size_read(inode); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1619 | if (unlikely(*ppos >= isize)) |
| 1620 | return 0; |
| 1621 | |
| 1622 | left = isize - *ppos; |
| 1623 | if (unlikely(left < len)) |
| 1624 | len = left; |
| 1625 | |
| 1626 | if (splice_grow_spd(pipe, &spd)) |
| 1627 | return -ENOMEM; |
| 1628 | |
| 1629 | index = *ppos >> PAGE_CACHE_SHIFT; |
| 1630 | loff = *ppos & ~PAGE_CACHE_MASK; |
| 1631 | req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| 1632 | nr_pages = min(req_pages, pipe->buffers); |
| 1633 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1634 | spd.nr_pages = find_get_pages_contig(mapping, index, |
| 1635 | nr_pages, spd.pages); |
| 1636 | index += spd.nr_pages; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1637 | error = 0; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1638 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1639 | while (spd.nr_pages < nr_pages) { |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1640 | error = shmem_getpage(inode, index, &page, SGP_CACHE, NULL); |
| 1641 | if (error) |
| 1642 | break; |
| 1643 | unlock_page(page); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1644 | spd.pages[spd.nr_pages++] = page; |
| 1645 | index++; |
| 1646 | } |
| 1647 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1648 | index = *ppos >> PAGE_CACHE_SHIFT; |
| 1649 | nr_pages = spd.nr_pages; |
| 1650 | spd.nr_pages = 0; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1651 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1652 | for (page_nr = 0; page_nr < nr_pages; page_nr++) { |
| 1653 | unsigned int this_len; |
| 1654 | |
| 1655 | if (!len) |
| 1656 | break; |
| 1657 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1658 | this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff); |
| 1659 | page = spd.pages[page_nr]; |
| 1660 | |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1661 | if (!PageUptodate(page) || page->mapping != mapping) { |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1662 | error = shmem_getpage(inode, index, &page, |
| 1663 | SGP_CACHE, NULL); |
| 1664 | if (error) |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1665 | break; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1666 | unlock_page(page); |
| 1667 | page_cache_release(spd.pages[page_nr]); |
| 1668 | spd.pages[page_nr] = page; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1669 | } |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1670 | |
| 1671 | isize = i_size_read(inode); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1672 | end_index = (isize - 1) >> PAGE_CACHE_SHIFT; |
| 1673 | if (unlikely(!isize || index > end_index)) |
| 1674 | break; |
| 1675 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1676 | if (end_index == index) { |
| 1677 | unsigned int plen; |
| 1678 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1679 | plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1; |
| 1680 | if (plen <= loff) |
| 1681 | break; |
| 1682 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1683 | this_len = min(this_len, plen - loff); |
| 1684 | len = this_len; |
| 1685 | } |
| 1686 | |
| 1687 | spd.partial[page_nr].offset = loff; |
| 1688 | spd.partial[page_nr].len = this_len; |
| 1689 | len -= this_len; |
| 1690 | loff = 0; |
| 1691 | spd.nr_pages++; |
| 1692 | index++; |
| 1693 | } |
| 1694 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1695 | while (page_nr < nr_pages) |
| 1696 | page_cache_release(spd.pages[page_nr++]); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1697 | |
| 1698 | if (spd.nr_pages) |
| 1699 | error = splice_to_pipe(pipe, &spd); |
| 1700 | |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 1701 | splice_shrink_spd(&spd); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1702 | |
| 1703 | if (error > 0) { |
| 1704 | *ppos += error; |
| 1705 | file_accessed(in); |
| 1706 | } |
| 1707 | return error; |
| 1708 | } |
| 1709 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 1710 | static long shmem_fallocate(struct file *file, int mode, loff_t offset, |
| 1711 | loff_t len) |
| 1712 | { |
| 1713 | struct inode *inode = file->f_path.dentry->d_inode; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1714 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1715 | struct shmem_falloc shmem_falloc; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1716 | pgoff_t start, index, end; |
| 1717 | int error; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 1718 | |
| 1719 | mutex_lock(&inode->i_mutex); |
| 1720 | |
| 1721 | if (mode & FALLOC_FL_PUNCH_HOLE) { |
| 1722 | struct address_space *mapping = file->f_mapping; |
| 1723 | loff_t unmap_start = round_up(offset, PAGE_SIZE); |
| 1724 | loff_t unmap_end = round_down(offset + len, PAGE_SIZE) - 1; |
| 1725 | |
| 1726 | if ((u64)unmap_end > (u64)unmap_start) |
| 1727 | unmap_mapping_range(mapping, unmap_start, |
| 1728 | 1 + unmap_end - unmap_start, 0); |
| 1729 | shmem_truncate_range(inode, offset, offset + len - 1); |
| 1730 | /* No need to unmap again: hole-punching leaves COWed pages */ |
| 1731 | error = 0; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1732 | goto out; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 1733 | } |
| 1734 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1735 | /* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */ |
| 1736 | error = inode_newsize_ok(inode, offset + len); |
| 1737 | if (error) |
| 1738 | goto out; |
| 1739 | |
| 1740 | start = offset >> PAGE_CACHE_SHIFT; |
| 1741 | end = (offset + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| 1742 | /* Try to avoid a swapstorm if len is impossible to satisfy */ |
| 1743 | if (sbinfo->max_blocks && end - start > sbinfo->max_blocks) { |
| 1744 | error = -ENOSPC; |
| 1745 | goto out; |
| 1746 | } |
| 1747 | |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1748 | shmem_falloc.start = start; |
| 1749 | shmem_falloc.next = start; |
| 1750 | shmem_falloc.nr_falloced = 0; |
| 1751 | shmem_falloc.nr_unswapped = 0; |
| 1752 | spin_lock(&inode->i_lock); |
| 1753 | inode->i_private = &shmem_falloc; |
| 1754 | spin_unlock(&inode->i_lock); |
| 1755 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1756 | for (index = start; index < end; index++) { |
| 1757 | struct page *page; |
| 1758 | |
| 1759 | /* |
| 1760 | * Good, the fallocate(2) manpage permits EINTR: we may have |
| 1761 | * been interrupted because we are using up too much memory. |
| 1762 | */ |
| 1763 | if (signal_pending(current)) |
| 1764 | error = -EINTR; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1765 | else if (shmem_falloc.nr_unswapped > shmem_falloc.nr_falloced) |
| 1766 | error = -ENOMEM; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1767 | else |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1768 | error = shmem_getpage(inode, index, &page, SGP_FALLOC, |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1769 | NULL); |
| 1770 | if (error) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1771 | /* Remove the !PageUptodate pages we added */ |
| 1772 | shmem_undo_range(inode, |
| 1773 | (loff_t)start << PAGE_CACHE_SHIFT, |
| 1774 | (loff_t)index << PAGE_CACHE_SHIFT, true); |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1775 | goto undone; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1776 | } |
| 1777 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1778 | /* |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1779 | * Inform shmem_writepage() how far we have reached. |
| 1780 | * No need for lock or barrier: we have the page lock. |
| 1781 | */ |
| 1782 | shmem_falloc.next++; |
| 1783 | if (!PageUptodate(page)) |
| 1784 | shmem_falloc.nr_falloced++; |
| 1785 | |
| 1786 | /* |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1787 | * If !PageUptodate, leave it that way so that freeable pages |
| 1788 | * can be recognized if we need to rollback on error later. |
| 1789 | * But set_page_dirty so that memory pressure will swap rather |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1790 | * than free the pages we are allocating (and SGP_CACHE pages |
| 1791 | * might still be clean: we now need to mark those dirty too). |
| 1792 | */ |
| 1793 | set_page_dirty(page); |
| 1794 | unlock_page(page); |
| 1795 | page_cache_release(page); |
| 1796 | cond_resched(); |
| 1797 | } |
| 1798 | |
| 1799 | if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) |
| 1800 | i_size_write(inode, offset + len); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1801 | inode->i_ctime = CURRENT_TIME; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1802 | undone: |
| 1803 | spin_lock(&inode->i_lock); |
| 1804 | inode->i_private = NULL; |
| 1805 | spin_unlock(&inode->i_lock); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1806 | out: |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 1807 | mutex_unlock(&inode->i_mutex); |
| 1808 | return error; |
| 1809 | } |
| 1810 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 1811 | static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1812 | { |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 1813 | struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1814 | |
| 1815 | buf->f_type = TMPFS_MAGIC; |
| 1816 | buf->f_bsize = PAGE_CACHE_SIZE; |
| 1817 | buf->f_namelen = NAME_MAX; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1818 | if (sbinfo->max_blocks) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1819 | buf->f_blocks = sbinfo->max_blocks; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1820 | buf->f_bavail = |
| 1821 | buf->f_bfree = sbinfo->max_blocks - |
| 1822 | percpu_counter_sum(&sbinfo->used_blocks); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1823 | } |
| 1824 | if (sbinfo->max_inodes) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1825 | buf->f_files = sbinfo->max_inodes; |
| 1826 | buf->f_ffree = sbinfo->free_inodes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1827 | } |
| 1828 | /* else leave those fields 0 like simple_statfs */ |
| 1829 | return 0; |
| 1830 | } |
| 1831 | |
| 1832 | /* |
| 1833 | * File creation. Allocate an inode, and we're done.. |
| 1834 | */ |
| 1835 | static int |
Al Viro | 1a67aaf | 2011-07-26 01:52:52 -0400 | [diff] [blame] | 1836 | shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1837 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 1838 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1839 | int error = -ENOSPC; |
| 1840 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 1841 | inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1842 | if (inode) { |
Eric Paris | 2a7dba3 | 2011-02-01 11:05:39 -0500 | [diff] [blame] | 1843 | error = security_inode_init_security(inode, dir, |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 1844 | &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 1845 | shmem_initxattrs, NULL); |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 1846 | if (error) { |
| 1847 | if (error != -EOPNOTSUPP) { |
| 1848 | iput(inode); |
| 1849 | return error; |
| 1850 | } |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 1851 | } |
Christoph Hellwig | 1c7c474 | 2009-11-03 16:44:44 +0100 | [diff] [blame] | 1852 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 1853 | error = generic_acl_init(inode, dir); |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 1854 | if (error) { |
| 1855 | iput(inode); |
| 1856 | return error; |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 1857 | } |
Al Viro | 718deb6 | 2009-12-16 19:35:36 -0500 | [diff] [blame] | 1858 | #else |
| 1859 | error = 0; |
Christoph Hellwig | 1c7c474 | 2009-11-03 16:44:44 +0100 | [diff] [blame] | 1860 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1861 | dir->i_size += BOGO_DIRENT_SIZE; |
| 1862 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| 1863 | d_instantiate(dentry, inode); |
| 1864 | dget(dentry); /* Extra count - pin the dentry in core */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1865 | } |
| 1866 | return error; |
| 1867 | } |
| 1868 | |
Al Viro | 18bb1db | 2011-07-26 01:41:39 -0400 | [diff] [blame] | 1869 | static int shmem_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1870 | { |
| 1871 | int error; |
| 1872 | |
| 1873 | if ((error = shmem_mknod(dir, dentry, mode | S_IFDIR, 0))) |
| 1874 | return error; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1875 | inc_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1876 | return 0; |
| 1877 | } |
| 1878 | |
Al Viro | 4acdaf2 | 2011-07-26 01:42:34 -0400 | [diff] [blame] | 1879 | static int shmem_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1880 | struct nameidata *nd) |
| 1881 | { |
| 1882 | return shmem_mknod(dir, dentry, mode | S_IFREG, 0); |
| 1883 | } |
| 1884 | |
| 1885 | /* |
| 1886 | * Link a file.. |
| 1887 | */ |
| 1888 | static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
| 1889 | { |
| 1890 | struct inode *inode = old_dentry->d_inode; |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1891 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1892 | |
| 1893 | /* |
| 1894 | * No ordinary (disk based) filesystem counts links as inodes; |
| 1895 | * but each new link needs a new dentry, pinning lowmem, and |
| 1896 | * tmpfs dentries cannot be pruned until they are unlinked. |
| 1897 | */ |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1898 | ret = shmem_reserve_inode(inode->i_sb); |
| 1899 | if (ret) |
| 1900 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1901 | |
| 1902 | dir->i_size += BOGO_DIRENT_SIZE; |
| 1903 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1904 | inc_nlink(inode); |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 1905 | ihold(inode); /* New dentry reference */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1906 | dget(dentry); /* Extra pinning count for the created dentry */ |
| 1907 | d_instantiate(dentry, inode); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1908 | out: |
| 1909 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1910 | } |
| 1911 | |
| 1912 | static int shmem_unlink(struct inode *dir, struct dentry *dentry) |
| 1913 | { |
| 1914 | struct inode *inode = dentry->d_inode; |
| 1915 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1916 | if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) |
| 1917 | shmem_free_inode(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1918 | |
| 1919 | dir->i_size -= BOGO_DIRENT_SIZE; |
| 1920 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 1921 | drop_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1922 | dput(dentry); /* Undo the count from "create" - this does all the work */ |
| 1923 | return 0; |
| 1924 | } |
| 1925 | |
| 1926 | static int shmem_rmdir(struct inode *dir, struct dentry *dentry) |
| 1927 | { |
| 1928 | if (!simple_empty(dentry)) |
| 1929 | return -ENOTEMPTY; |
| 1930 | |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 1931 | drop_nlink(dentry->d_inode); |
| 1932 | drop_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1933 | return shmem_unlink(dir, dentry); |
| 1934 | } |
| 1935 | |
| 1936 | /* |
| 1937 | * The VFS layer already does all the dentry stuff for rename, |
| 1938 | * we just have to decrement the usage count for the target if |
| 1939 | * it exists so that the VFS layer correctly free's it when it |
| 1940 | * gets overwritten. |
| 1941 | */ |
| 1942 | static int shmem_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) |
| 1943 | { |
| 1944 | struct inode *inode = old_dentry->d_inode; |
| 1945 | int they_are_dirs = S_ISDIR(inode->i_mode); |
| 1946 | |
| 1947 | if (!simple_empty(new_dentry)) |
| 1948 | return -ENOTEMPTY; |
| 1949 | |
| 1950 | if (new_dentry->d_inode) { |
| 1951 | (void) shmem_unlink(new_dir, new_dentry); |
| 1952 | if (they_are_dirs) |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 1953 | drop_nlink(old_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1954 | } else if (they_are_dirs) { |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 1955 | drop_nlink(old_dir); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1956 | inc_nlink(new_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1957 | } |
| 1958 | |
| 1959 | old_dir->i_size -= BOGO_DIRENT_SIZE; |
| 1960 | new_dir->i_size += BOGO_DIRENT_SIZE; |
| 1961 | old_dir->i_ctime = old_dir->i_mtime = |
| 1962 | new_dir->i_ctime = new_dir->i_mtime = |
| 1963 | inode->i_ctime = CURRENT_TIME; |
| 1964 | return 0; |
| 1965 | } |
| 1966 | |
| 1967 | static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *symname) |
| 1968 | { |
| 1969 | int error; |
| 1970 | int len; |
| 1971 | struct inode *inode; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1972 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1973 | char *kaddr; |
| 1974 | struct shmem_inode_info *info; |
| 1975 | |
| 1976 | len = strlen(symname) + 1; |
| 1977 | if (len > PAGE_CACHE_SIZE) |
| 1978 | return -ENAMETOOLONG; |
| 1979 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 1980 | inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1981 | if (!inode) |
| 1982 | return -ENOSPC; |
| 1983 | |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 1984 | error = security_inode_init_security(inode, dir, &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 1985 | shmem_initxattrs, NULL); |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 1986 | if (error) { |
| 1987 | if (error != -EOPNOTSUPP) { |
| 1988 | iput(inode); |
| 1989 | return error; |
| 1990 | } |
| 1991 | error = 0; |
| 1992 | } |
| 1993 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1994 | info = SHMEM_I(inode); |
| 1995 | inode->i_size = len-1; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 1996 | if (len <= SHORT_SYMLINK_LEN) { |
| 1997 | info->symlink = kmemdup(symname, len, GFP_KERNEL); |
| 1998 | if (!info->symlink) { |
| 1999 | iput(inode); |
| 2000 | return -ENOMEM; |
| 2001 | } |
| 2002 | inode->i_op = &shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2003 | } else { |
| 2004 | error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL); |
| 2005 | if (error) { |
| 2006 | iput(inode); |
| 2007 | return error; |
| 2008 | } |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 2009 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2010 | inode->i_op = &shmem_symlink_inode_operations; |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 2011 | kaddr = kmap_atomic(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2012 | memcpy(kaddr, symname, len); |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 2013 | kunmap_atomic(kaddr); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2014 | SetPageUptodate(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2015 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 2016 | unlock_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2017 | page_cache_release(page); |
| 2018 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2019 | dir->i_size += BOGO_DIRENT_SIZE; |
| 2020 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| 2021 | d_instantiate(dentry, inode); |
| 2022 | dget(dentry); |
| 2023 | return 0; |
| 2024 | } |
| 2025 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2026 | static void *shmem_follow_short_symlink(struct dentry *dentry, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2027 | { |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2028 | nd_set_link(nd, SHMEM_I(dentry->d_inode)->symlink); |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2029 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2030 | } |
| 2031 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2032 | static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2033 | { |
| 2034 | struct page *page = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2035 | int error = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL); |
| 2036 | nd_set_link(nd, error ? ERR_PTR(error) : kmap(page)); |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2037 | if (page) |
| 2038 | unlock_page(page); |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2039 | return page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2040 | } |
| 2041 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2042 | static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2043 | { |
| 2044 | if (!IS_ERR(nd_get_link(nd))) { |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2045 | struct page *page = cookie; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2046 | kunmap(page); |
| 2047 | mark_page_accessed(page); |
| 2048 | page_cache_release(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2049 | } |
| 2050 | } |
| 2051 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2052 | #ifdef CONFIG_TMPFS_XATTR |
| 2053 | /* |
| 2054 | * Superblocks without xattr inode operations may get some security.* xattr |
| 2055 | * support from the LSM "for free". As soon as we have any other xattrs |
| 2056 | * like ACLs, we also need to implement the security.* handlers at |
| 2057 | * filesystem level, though. |
| 2058 | */ |
| 2059 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2060 | /* |
| 2061 | * Allocate new xattr and copy in the value; but leave the name to callers. |
| 2062 | */ |
| 2063 | static struct shmem_xattr *shmem_xattr_alloc(const void *value, size_t size) |
| 2064 | { |
| 2065 | struct shmem_xattr *new_xattr; |
| 2066 | size_t len; |
| 2067 | |
| 2068 | /* wrap around? */ |
| 2069 | len = sizeof(*new_xattr) + size; |
| 2070 | if (len <= sizeof(*new_xattr)) |
| 2071 | return NULL; |
| 2072 | |
| 2073 | new_xattr = kmalloc(len, GFP_KERNEL); |
| 2074 | if (!new_xattr) |
| 2075 | return NULL; |
| 2076 | |
| 2077 | new_xattr->size = size; |
| 2078 | memcpy(new_xattr->value, value, size); |
| 2079 | return new_xattr; |
| 2080 | } |
| 2081 | |
| 2082 | /* |
| 2083 | * Callback for security_inode_init_security() for acquiring xattrs. |
| 2084 | */ |
| 2085 | static int shmem_initxattrs(struct inode *inode, |
| 2086 | const struct xattr *xattr_array, |
| 2087 | void *fs_info) |
| 2088 | { |
| 2089 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 2090 | const struct xattr *xattr; |
| 2091 | struct shmem_xattr *new_xattr; |
| 2092 | size_t len; |
| 2093 | |
| 2094 | for (xattr = xattr_array; xattr->name != NULL; xattr++) { |
| 2095 | new_xattr = shmem_xattr_alloc(xattr->value, xattr->value_len); |
| 2096 | if (!new_xattr) |
| 2097 | return -ENOMEM; |
| 2098 | |
| 2099 | len = strlen(xattr->name) + 1; |
| 2100 | new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len, |
| 2101 | GFP_KERNEL); |
| 2102 | if (!new_xattr->name) { |
| 2103 | kfree(new_xattr); |
| 2104 | return -ENOMEM; |
| 2105 | } |
| 2106 | |
| 2107 | memcpy(new_xattr->name, XATTR_SECURITY_PREFIX, |
| 2108 | XATTR_SECURITY_PREFIX_LEN); |
| 2109 | memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN, |
| 2110 | xattr->name, len); |
| 2111 | |
| 2112 | spin_lock(&info->lock); |
| 2113 | list_add(&new_xattr->list, &info->xattr_list); |
| 2114 | spin_unlock(&info->lock); |
| 2115 | } |
| 2116 | |
| 2117 | return 0; |
| 2118 | } |
| 2119 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2120 | static int shmem_xattr_get(struct dentry *dentry, const char *name, |
| 2121 | void *buffer, size_t size) |
| 2122 | { |
| 2123 | struct shmem_inode_info *info; |
| 2124 | struct shmem_xattr *xattr; |
| 2125 | int ret = -ENODATA; |
| 2126 | |
| 2127 | info = SHMEM_I(dentry->d_inode); |
| 2128 | |
| 2129 | spin_lock(&info->lock); |
| 2130 | list_for_each_entry(xattr, &info->xattr_list, list) { |
| 2131 | if (strcmp(name, xattr->name)) |
| 2132 | continue; |
| 2133 | |
| 2134 | ret = xattr->size; |
| 2135 | if (buffer) { |
| 2136 | if (size < xattr->size) |
| 2137 | ret = -ERANGE; |
| 2138 | else |
| 2139 | memcpy(buffer, xattr->value, xattr->size); |
| 2140 | } |
| 2141 | break; |
| 2142 | } |
| 2143 | spin_unlock(&info->lock); |
| 2144 | return ret; |
| 2145 | } |
| 2146 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2147 | static int shmem_xattr_set(struct inode *inode, const char *name, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2148 | const void *value, size_t size, int flags) |
| 2149 | { |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2150 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 2151 | struct shmem_xattr *xattr; |
| 2152 | struct shmem_xattr *new_xattr = NULL; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2153 | int err = 0; |
| 2154 | |
| 2155 | /* value == NULL means remove */ |
| 2156 | if (value) { |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2157 | new_xattr = shmem_xattr_alloc(value, size); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2158 | if (!new_xattr) |
| 2159 | return -ENOMEM; |
| 2160 | |
| 2161 | new_xattr->name = kstrdup(name, GFP_KERNEL); |
| 2162 | if (!new_xattr->name) { |
| 2163 | kfree(new_xattr); |
| 2164 | return -ENOMEM; |
| 2165 | } |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2166 | } |
| 2167 | |
| 2168 | spin_lock(&info->lock); |
| 2169 | list_for_each_entry(xattr, &info->xattr_list, list) { |
| 2170 | if (!strcmp(name, xattr->name)) { |
| 2171 | if (flags & XATTR_CREATE) { |
| 2172 | xattr = new_xattr; |
| 2173 | err = -EEXIST; |
| 2174 | } else if (new_xattr) { |
| 2175 | list_replace(&xattr->list, &new_xattr->list); |
| 2176 | } else { |
| 2177 | list_del(&xattr->list); |
| 2178 | } |
| 2179 | goto out; |
| 2180 | } |
| 2181 | } |
| 2182 | if (flags & XATTR_REPLACE) { |
| 2183 | xattr = new_xattr; |
| 2184 | err = -ENODATA; |
| 2185 | } else { |
| 2186 | list_add(&new_xattr->list, &info->xattr_list); |
| 2187 | xattr = NULL; |
| 2188 | } |
| 2189 | out: |
| 2190 | spin_unlock(&info->lock); |
| 2191 | if (xattr) |
| 2192 | kfree(xattr->name); |
| 2193 | kfree(xattr); |
| 2194 | return err; |
| 2195 | } |
| 2196 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2197 | static const struct xattr_handler *shmem_xattr_handlers[] = { |
| 2198 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 2199 | &generic_acl_access_handler, |
| 2200 | &generic_acl_default_handler, |
| 2201 | #endif |
| 2202 | NULL |
| 2203 | }; |
| 2204 | |
| 2205 | static int shmem_xattr_validate(const char *name) |
| 2206 | { |
| 2207 | struct { const char *prefix; size_t len; } arr[] = { |
| 2208 | { XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN }, |
| 2209 | { XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN } |
| 2210 | }; |
| 2211 | int i; |
| 2212 | |
| 2213 | for (i = 0; i < ARRAY_SIZE(arr); i++) { |
| 2214 | size_t preflen = arr[i].len; |
| 2215 | if (strncmp(name, arr[i].prefix, preflen) == 0) { |
| 2216 | if (!name[preflen]) |
| 2217 | return -EINVAL; |
| 2218 | return 0; |
| 2219 | } |
| 2220 | } |
| 2221 | return -EOPNOTSUPP; |
| 2222 | } |
| 2223 | |
| 2224 | static ssize_t shmem_getxattr(struct dentry *dentry, const char *name, |
| 2225 | void *buffer, size_t size) |
| 2226 | { |
| 2227 | int err; |
| 2228 | |
| 2229 | /* |
| 2230 | * If this is a request for a synthetic attribute in the system.* |
| 2231 | * namespace use the generic infrastructure to resolve a handler |
| 2232 | * for it via sb->s_xattr. |
| 2233 | */ |
| 2234 | if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) |
| 2235 | return generic_getxattr(dentry, name, buffer, size); |
| 2236 | |
| 2237 | err = shmem_xattr_validate(name); |
| 2238 | if (err) |
| 2239 | return err; |
| 2240 | |
| 2241 | return shmem_xattr_get(dentry, name, buffer, size); |
| 2242 | } |
| 2243 | |
| 2244 | static int shmem_setxattr(struct dentry *dentry, const char *name, |
| 2245 | const void *value, size_t size, int flags) |
| 2246 | { |
| 2247 | int err; |
| 2248 | |
| 2249 | /* |
| 2250 | * If this is a request for a synthetic attribute in the system.* |
| 2251 | * namespace use the generic infrastructure to resolve a handler |
| 2252 | * for it via sb->s_xattr. |
| 2253 | */ |
| 2254 | if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) |
| 2255 | return generic_setxattr(dentry, name, value, size, flags); |
| 2256 | |
| 2257 | err = shmem_xattr_validate(name); |
| 2258 | if (err) |
| 2259 | return err; |
| 2260 | |
| 2261 | if (size == 0) |
| 2262 | value = ""; /* empty EA, do not remove */ |
| 2263 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2264 | return shmem_xattr_set(dentry->d_inode, name, value, size, flags); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2265 | |
| 2266 | } |
| 2267 | |
| 2268 | static int shmem_removexattr(struct dentry *dentry, const char *name) |
| 2269 | { |
| 2270 | int err; |
| 2271 | |
| 2272 | /* |
| 2273 | * If this is a request for a synthetic attribute in the system.* |
| 2274 | * namespace use the generic infrastructure to resolve a handler |
| 2275 | * for it via sb->s_xattr. |
| 2276 | */ |
| 2277 | if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) |
| 2278 | return generic_removexattr(dentry, name); |
| 2279 | |
| 2280 | err = shmem_xattr_validate(name); |
| 2281 | if (err) |
| 2282 | return err; |
| 2283 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2284 | return shmem_xattr_set(dentry->d_inode, name, NULL, 0, XATTR_REPLACE); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2285 | } |
| 2286 | |
| 2287 | static bool xattr_is_trusted(const char *name) |
| 2288 | { |
| 2289 | return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN); |
| 2290 | } |
| 2291 | |
| 2292 | static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size) |
| 2293 | { |
| 2294 | bool trusted = capable(CAP_SYS_ADMIN); |
| 2295 | struct shmem_xattr *xattr; |
| 2296 | struct shmem_inode_info *info; |
| 2297 | size_t used = 0; |
| 2298 | |
| 2299 | info = SHMEM_I(dentry->d_inode); |
| 2300 | |
| 2301 | spin_lock(&info->lock); |
| 2302 | list_for_each_entry(xattr, &info->xattr_list, list) { |
| 2303 | size_t len; |
| 2304 | |
| 2305 | /* skip "trusted." attributes for unprivileged callers */ |
| 2306 | if (!trusted && xattr_is_trusted(xattr->name)) |
| 2307 | continue; |
| 2308 | |
| 2309 | len = strlen(xattr->name) + 1; |
| 2310 | used += len; |
| 2311 | if (buffer) { |
| 2312 | if (size < used) { |
| 2313 | used = -ERANGE; |
| 2314 | break; |
| 2315 | } |
| 2316 | memcpy(buffer, xattr->name, len); |
| 2317 | buffer += len; |
| 2318 | } |
| 2319 | } |
| 2320 | spin_unlock(&info->lock); |
| 2321 | |
| 2322 | return used; |
| 2323 | } |
| 2324 | #endif /* CONFIG_TMPFS_XATTR */ |
| 2325 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2326 | static const struct inode_operations shmem_short_symlink_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2327 | .readlink = generic_readlink, |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2328 | .follow_link = shmem_follow_short_symlink, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2329 | #ifdef CONFIG_TMPFS_XATTR |
| 2330 | .setxattr = shmem_setxattr, |
| 2331 | .getxattr = shmem_getxattr, |
| 2332 | .listxattr = shmem_listxattr, |
| 2333 | .removexattr = shmem_removexattr, |
| 2334 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2335 | }; |
| 2336 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2337 | static const struct inode_operations shmem_symlink_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2338 | .readlink = generic_readlink, |
| 2339 | .follow_link = shmem_follow_link, |
| 2340 | .put_link = shmem_put_link, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2341 | #ifdef CONFIG_TMPFS_XATTR |
| 2342 | .setxattr = shmem_setxattr, |
| 2343 | .getxattr = shmem_getxattr, |
| 2344 | .listxattr = shmem_listxattr, |
| 2345 | .removexattr = shmem_removexattr, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2346 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2347 | }; |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2348 | |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2349 | static struct dentry *shmem_get_parent(struct dentry *child) |
| 2350 | { |
| 2351 | return ERR_PTR(-ESTALE); |
| 2352 | } |
| 2353 | |
| 2354 | static int shmem_match(struct inode *ino, void *vfh) |
| 2355 | { |
| 2356 | __u32 *fh = vfh; |
| 2357 | __u64 inum = fh[2]; |
| 2358 | inum = (inum << 32) | fh[1]; |
| 2359 | return ino->i_ino == inum && fh[0] == ino->i_generation; |
| 2360 | } |
| 2361 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2362 | static struct dentry *shmem_fh_to_dentry(struct super_block *sb, |
| 2363 | struct fid *fid, int fh_len, int fh_type) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2364 | { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2365 | struct inode *inode; |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2366 | struct dentry *dentry = NULL; |
| 2367 | u64 inum = fid->raw[2]; |
| 2368 | inum = (inum << 32) | fid->raw[1]; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2369 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2370 | if (fh_len < 3) |
| 2371 | return NULL; |
| 2372 | |
| 2373 | inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), |
| 2374 | shmem_match, fid->raw); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2375 | if (inode) { |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2376 | dentry = d_find_alias(inode); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2377 | iput(inode); |
| 2378 | } |
| 2379 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2380 | return dentry; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2381 | } |
| 2382 | |
Al Viro | b0b0382 | 2012-04-02 14:34:06 -0400 | [diff] [blame] | 2383 | static int shmem_encode_fh(struct inode *inode, __u32 *fh, int *len, |
| 2384 | struct inode *parent) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2385 | { |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 2386 | if (*len < 3) { |
| 2387 | *len = 3; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2388 | return 255; |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 2389 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2390 | |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 2391 | if (inode_unhashed(inode)) { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2392 | /* Unfortunately insert_inode_hash is not idempotent, |
| 2393 | * so as we hash inodes here rather than at creation |
| 2394 | * time, we need a lock to ensure we only try |
| 2395 | * to do it once |
| 2396 | */ |
| 2397 | static DEFINE_SPINLOCK(lock); |
| 2398 | spin_lock(&lock); |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 2399 | if (inode_unhashed(inode)) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2400 | __insert_inode_hash(inode, |
| 2401 | inode->i_ino + inode->i_generation); |
| 2402 | spin_unlock(&lock); |
| 2403 | } |
| 2404 | |
| 2405 | fh[0] = inode->i_generation; |
| 2406 | fh[1] = inode->i_ino; |
| 2407 | fh[2] = ((__u64)inode->i_ino) >> 32; |
| 2408 | |
| 2409 | *len = 3; |
| 2410 | return 1; |
| 2411 | } |
| 2412 | |
Christoph Hellwig | 3965516 | 2007-10-21 16:42:17 -0700 | [diff] [blame] | 2413 | static const struct export_operations shmem_export_ops = { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2414 | .get_parent = shmem_get_parent, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2415 | .encode_fh = shmem_encode_fh, |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2416 | .fh_to_dentry = shmem_fh_to_dentry, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2417 | }; |
| 2418 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2419 | static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo, |
| 2420 | bool remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2421 | { |
| 2422 | char *this_char, *value, *rest; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2423 | uid_t uid; |
| 2424 | gid_t gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2425 | |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 2426 | while (options != NULL) { |
| 2427 | this_char = options; |
| 2428 | for (;;) { |
| 2429 | /* |
| 2430 | * NUL-terminate this option: unfortunately, |
| 2431 | * mount options form a comma-separated list, |
| 2432 | * but mpol's nodelist may also contain commas. |
| 2433 | */ |
| 2434 | options = strchr(options, ','); |
| 2435 | if (options == NULL) |
| 2436 | break; |
| 2437 | options++; |
| 2438 | if (!isdigit(*options)) { |
| 2439 | options[-1] = '\0'; |
| 2440 | break; |
| 2441 | } |
| 2442 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2443 | if (!*this_char) |
| 2444 | continue; |
| 2445 | if ((value = strchr(this_char,'=')) != NULL) { |
| 2446 | *value++ = 0; |
| 2447 | } else { |
| 2448 | printk(KERN_ERR |
| 2449 | "tmpfs: No value for mount option '%s'\n", |
| 2450 | this_char); |
| 2451 | return 1; |
| 2452 | } |
| 2453 | |
| 2454 | if (!strcmp(this_char,"size")) { |
| 2455 | unsigned long long size; |
| 2456 | size = memparse(value,&rest); |
| 2457 | if (*rest == '%') { |
| 2458 | size <<= PAGE_SHIFT; |
| 2459 | size *= totalram_pages; |
| 2460 | do_div(size, 100); |
| 2461 | rest++; |
| 2462 | } |
| 2463 | if (*rest) |
| 2464 | goto bad_val; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2465 | sbinfo->max_blocks = |
| 2466 | DIV_ROUND_UP(size, PAGE_CACHE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2467 | } else if (!strcmp(this_char,"nr_blocks")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2468 | sbinfo->max_blocks = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2469 | if (*rest) |
| 2470 | goto bad_val; |
| 2471 | } else if (!strcmp(this_char,"nr_inodes")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2472 | sbinfo->max_inodes = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2473 | if (*rest) |
| 2474 | goto bad_val; |
| 2475 | } else if (!strcmp(this_char,"mode")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2476 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2477 | continue; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2478 | sbinfo->mode = simple_strtoul(value, &rest, 8) & 07777; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2479 | if (*rest) |
| 2480 | goto bad_val; |
| 2481 | } else if (!strcmp(this_char,"uid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2482 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2483 | continue; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2484 | uid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2485 | if (*rest) |
| 2486 | goto bad_val; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2487 | sbinfo->uid = make_kuid(current_user_ns(), uid); |
| 2488 | if (!uid_valid(sbinfo->uid)) |
| 2489 | goto bad_val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2490 | } else if (!strcmp(this_char,"gid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2491 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2492 | continue; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2493 | gid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2494 | if (*rest) |
| 2495 | goto bad_val; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2496 | sbinfo->gid = make_kgid(current_user_ns(), gid); |
| 2497 | if (!gid_valid(sbinfo->gid)) |
| 2498 | goto bad_val; |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 2499 | } else if (!strcmp(this_char,"mpol")) { |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2500 | if (mpol_parse_str(value, &sbinfo->mpol, 1)) |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 2501 | goto bad_val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2502 | } else { |
| 2503 | printk(KERN_ERR "tmpfs: Bad mount option %s\n", |
| 2504 | this_char); |
| 2505 | return 1; |
| 2506 | } |
| 2507 | } |
| 2508 | return 0; |
| 2509 | |
| 2510 | bad_val: |
| 2511 | printk(KERN_ERR "tmpfs: Bad value '%s' for mount option '%s'\n", |
| 2512 | value, this_char); |
| 2513 | return 1; |
| 2514 | |
| 2515 | } |
| 2516 | |
| 2517 | static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) |
| 2518 | { |
| 2519 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2520 | struct shmem_sb_info config = *sbinfo; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2521 | unsigned long inodes; |
| 2522 | int error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2523 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2524 | if (shmem_parse_options(data, &config, true)) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2525 | return error; |
| 2526 | |
| 2527 | spin_lock(&sbinfo->stat_lock); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2528 | inodes = sbinfo->max_inodes - sbinfo->free_inodes; |
Tim Chen | 7e49629 | 2010-08-09 17:19:05 -0700 | [diff] [blame] | 2529 | if (percpu_counter_compare(&sbinfo->used_blocks, config.max_blocks) > 0) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2530 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2531 | if (config.max_inodes < inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2532 | goto out; |
| 2533 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 2534 | * Those tests disallow limited->unlimited while any are in use; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2535 | * but we must separately disallow unlimited->limited, because |
| 2536 | * in that case we have no record of how much is already in use. |
| 2537 | */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2538 | if (config.max_blocks && !sbinfo->max_blocks) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2539 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2540 | if (config.max_inodes && !sbinfo->max_inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2541 | goto out; |
| 2542 | |
| 2543 | error = 0; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2544 | sbinfo->max_blocks = config.max_blocks; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2545 | sbinfo->max_inodes = config.max_inodes; |
| 2546 | sbinfo->free_inodes = config.max_inodes - inodes; |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2547 | |
| 2548 | mpol_put(sbinfo->mpol); |
| 2549 | sbinfo->mpol = config.mpol; /* transfers initial ref */ |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2550 | out: |
| 2551 | spin_unlock(&sbinfo->stat_lock); |
| 2552 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2553 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2554 | |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 2555 | static int shmem_show_options(struct seq_file *seq, struct dentry *root) |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2556 | { |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 2557 | struct shmem_sb_info *sbinfo = SHMEM_SB(root->d_sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2558 | |
| 2559 | if (sbinfo->max_blocks != shmem_default_max_blocks()) |
| 2560 | seq_printf(seq, ",size=%luk", |
| 2561 | sbinfo->max_blocks << (PAGE_CACHE_SHIFT - 10)); |
| 2562 | if (sbinfo->max_inodes != shmem_default_max_inodes()) |
| 2563 | seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes); |
| 2564 | if (sbinfo->mode != (S_IRWXUGO | S_ISVTX)) |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 2565 | seq_printf(seq, ",mode=%03ho", sbinfo->mode); |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2566 | if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID)) |
| 2567 | seq_printf(seq, ",uid=%u", |
| 2568 | from_kuid_munged(&init_user_ns, sbinfo->uid)); |
| 2569 | if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID)) |
| 2570 | seq_printf(seq, ",gid=%u", |
| 2571 | from_kgid_munged(&init_user_ns, sbinfo->gid)); |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2572 | shmem_show_mpol(seq, sbinfo->mpol); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2573 | return 0; |
| 2574 | } |
| 2575 | #endif /* CONFIG_TMPFS */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2576 | |
| 2577 | static void shmem_put_super(struct super_block *sb) |
| 2578 | { |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 2579 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 2580 | |
| 2581 | percpu_counter_destroy(&sbinfo->used_blocks); |
| 2582 | kfree(sbinfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2583 | sb->s_fs_info = NULL; |
| 2584 | } |
| 2585 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 2586 | int shmem_fill_super(struct super_block *sb, void *data, int silent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2587 | { |
| 2588 | struct inode *inode; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2589 | struct shmem_sb_info *sbinfo; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2590 | int err = -ENOMEM; |
| 2591 | |
| 2592 | /* Round up to L1_CACHE_BYTES to resist false sharing */ |
Pekka Enberg | 425fbf0 | 2009-09-21 17:03:50 -0700 | [diff] [blame] | 2593 | sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info), |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2594 | L1_CACHE_BYTES), GFP_KERNEL); |
| 2595 | if (!sbinfo) |
| 2596 | return -ENOMEM; |
| 2597 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2598 | sbinfo->mode = S_IRWXUGO | S_ISVTX; |
David Howells | 76aac0e | 2008-11-14 10:39:12 +1100 | [diff] [blame] | 2599 | sbinfo->uid = current_fsuid(); |
| 2600 | sbinfo->gid = current_fsgid(); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2601 | sb->s_fs_info = sbinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2602 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2603 | #ifdef CONFIG_TMPFS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2604 | /* |
| 2605 | * Per default we only allow half of the physical ram per |
| 2606 | * tmpfs instance, limiting inodes to one per page of lowmem; |
| 2607 | * but the internal instance is left unlimited. |
| 2608 | */ |
| 2609 | if (!(sb->s_flags & MS_NOUSER)) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2610 | sbinfo->max_blocks = shmem_default_max_blocks(); |
| 2611 | sbinfo->max_inodes = shmem_default_max_inodes(); |
| 2612 | if (shmem_parse_options(data, sbinfo, false)) { |
| 2613 | err = -EINVAL; |
| 2614 | goto failed; |
| 2615 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2616 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2617 | sb->s_export_op = &shmem_export_ops; |
Hugh Dickins | 2f6e38f | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 2618 | sb->s_flags |= MS_NOSEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2619 | #else |
| 2620 | sb->s_flags |= MS_NOUSER; |
| 2621 | #endif |
| 2622 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2623 | spin_lock_init(&sbinfo->stat_lock); |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 2624 | if (percpu_counter_init(&sbinfo->used_blocks, 0)) |
| 2625 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2626 | sbinfo->free_inodes = sbinfo->max_inodes; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2627 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 2628 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2629 | sb->s_blocksize = PAGE_CACHE_SIZE; |
| 2630 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 2631 | sb->s_magic = TMPFS_MAGIC; |
| 2632 | sb->s_op = &shmem_ops; |
Robin H. Johnson | cfd95a9 | 2006-06-12 21:50:25 +0100 | [diff] [blame] | 2633 | sb->s_time_gran = 1; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2634 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2635 | sb->s_xattr = shmem_xattr_handlers; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2636 | #endif |
| 2637 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2638 | sb->s_flags |= MS_POSIXACL; |
| 2639 | #endif |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2640 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2641 | inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2642 | if (!inode) |
| 2643 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2644 | inode->i_uid = sbinfo->uid; |
| 2645 | inode->i_gid = sbinfo->gid; |
Al Viro | 318ceed | 2012-02-12 22:08:01 -0500 | [diff] [blame] | 2646 | sb->s_root = d_make_root(inode); |
| 2647 | if (!sb->s_root) |
Al Viro | 48fde70 | 2012-01-08 22:15:13 -0500 | [diff] [blame] | 2648 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2649 | return 0; |
| 2650 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2651 | failed: |
| 2652 | shmem_put_super(sb); |
| 2653 | return err; |
| 2654 | } |
| 2655 | |
Pekka Enberg | fcc234f | 2006-03-22 00:08:13 -0800 | [diff] [blame] | 2656 | static struct kmem_cache *shmem_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2657 | |
| 2658 | static struct inode *shmem_alloc_inode(struct super_block *sb) |
| 2659 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2660 | struct shmem_inode_info *info; |
| 2661 | info = kmem_cache_alloc(shmem_inode_cachep, GFP_KERNEL); |
| 2662 | if (!info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2663 | return NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2664 | return &info->vfs_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2665 | } |
| 2666 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2667 | static void shmem_destroy_callback(struct rcu_head *head) |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 2668 | { |
| 2669 | struct inode *inode = container_of(head, struct inode, i_rcu); |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 2670 | kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode)); |
| 2671 | } |
| 2672 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2673 | static void shmem_destroy_inode(struct inode *inode) |
| 2674 | { |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 2675 | if (S_ISREG(inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2676 | mpol_free_shared_policy(&SHMEM_I(inode)->policy); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2677 | call_rcu(&inode->i_rcu, shmem_destroy_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2678 | } |
| 2679 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2680 | static void shmem_init_inode(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2681 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2682 | struct shmem_inode_info *info = foo; |
| 2683 | inode_init_once(&info->vfs_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2684 | } |
| 2685 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2686 | static int shmem_init_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2687 | { |
| 2688 | shmem_inode_cachep = kmem_cache_create("shmem_inode_cache", |
| 2689 | sizeof(struct shmem_inode_info), |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2690 | 0, SLAB_PANIC, shmem_init_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2691 | return 0; |
| 2692 | } |
| 2693 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2694 | static void shmem_destroy_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2695 | { |
Alexey Dobriyan | 1a1d92c | 2006-09-27 01:49:40 -0700 | [diff] [blame] | 2696 | kmem_cache_destroy(shmem_inode_cachep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2697 | } |
| 2698 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 2699 | static const struct address_space_operations shmem_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2700 | .writepage = shmem_writepage, |
Ken Chen | 7671932 | 2007-02-10 01:43:15 -0800 | [diff] [blame] | 2701 | .set_page_dirty = __set_page_dirty_no_writeback, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2702 | #ifdef CONFIG_TMPFS |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2703 | .write_begin = shmem_write_begin, |
| 2704 | .write_end = shmem_write_end, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2705 | #endif |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 2706 | .migratepage = migrate_page, |
Andi Kleen | aa261f5 | 2009-09-16 11:50:16 +0200 | [diff] [blame] | 2707 | .error_remove_page = generic_error_remove_page, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2708 | }; |
| 2709 | |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 2710 | static const struct file_operations shmem_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2711 | .mmap = shmem_mmap, |
| 2712 | #ifdef CONFIG_TMPFS |
Hugh Dickins | f21f806 | 2012-07-11 14:02:45 -0700 | [diff] [blame] | 2713 | .llseek = generic_file_llseek, |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 2714 | .read = do_sync_read, |
Hugh Dickins | 5402b97 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2715 | .write = do_sync_write, |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 2716 | .aio_read = shmem_file_aio_read, |
Hugh Dickins | 5402b97 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2717 | .aio_write = generic_file_aio_write, |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 2718 | .fsync = noop_fsync, |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 2719 | .splice_read = shmem_file_splice_read, |
Hugh Dickins | ae976416 | 2007-06-04 10:00:39 +0200 | [diff] [blame] | 2720 | .splice_write = generic_file_splice_write, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2721 | .fallocate = shmem_fallocate, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2722 | #endif |
| 2723 | }; |
| 2724 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2725 | static const struct inode_operations shmem_inode_operations = { |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 2726 | .setattr = shmem_setattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2727 | #ifdef CONFIG_TMPFS_XATTR |
| 2728 | .setxattr = shmem_setxattr, |
| 2729 | .getxattr = shmem_getxattr, |
| 2730 | .listxattr = shmem_listxattr, |
| 2731 | .removexattr = shmem_removexattr, |
| 2732 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2733 | }; |
| 2734 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2735 | static const struct inode_operations shmem_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2736 | #ifdef CONFIG_TMPFS |
| 2737 | .create = shmem_create, |
| 2738 | .lookup = simple_lookup, |
| 2739 | .link = shmem_link, |
| 2740 | .unlink = shmem_unlink, |
| 2741 | .symlink = shmem_symlink, |
| 2742 | .mkdir = shmem_mkdir, |
| 2743 | .rmdir = shmem_rmdir, |
| 2744 | .mknod = shmem_mknod, |
| 2745 | .rename = shmem_rename, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2746 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2747 | #ifdef CONFIG_TMPFS_XATTR |
| 2748 | .setxattr = shmem_setxattr, |
| 2749 | .getxattr = shmem_getxattr, |
| 2750 | .listxattr = shmem_listxattr, |
| 2751 | .removexattr = shmem_removexattr, |
| 2752 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2753 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 2754 | .setattr = shmem_setattr, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2755 | #endif |
| 2756 | }; |
| 2757 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2758 | static const struct inode_operations shmem_special_inode_operations = { |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2759 | #ifdef CONFIG_TMPFS_XATTR |
| 2760 | .setxattr = shmem_setxattr, |
| 2761 | .getxattr = shmem_getxattr, |
| 2762 | .listxattr = shmem_listxattr, |
| 2763 | .removexattr = shmem_removexattr, |
| 2764 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2765 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 2766 | .setattr = shmem_setattr, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2767 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2768 | }; |
| 2769 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 2770 | static const struct super_operations shmem_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2771 | .alloc_inode = shmem_alloc_inode, |
| 2772 | .destroy_inode = shmem_destroy_inode, |
| 2773 | #ifdef CONFIG_TMPFS |
| 2774 | .statfs = shmem_statfs, |
| 2775 | .remount_fs = shmem_remount_fs, |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2776 | .show_options = shmem_show_options, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2777 | #endif |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 2778 | .evict_inode = shmem_evict_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2779 | .drop_inode = generic_delete_inode, |
| 2780 | .put_super = shmem_put_super, |
| 2781 | }; |
| 2782 | |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 2783 | static const struct vm_operations_struct shmem_vm_ops = { |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 2784 | .fault = shmem_fault, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2785 | #ifdef CONFIG_NUMA |
| 2786 | .set_policy = shmem_set_policy, |
| 2787 | .get_policy = shmem_get_policy, |
| 2788 | #endif |
| 2789 | }; |
| 2790 | |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 2791 | static struct dentry *shmem_mount(struct file_system_type *fs_type, |
| 2792 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2793 | { |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 2794 | return mount_nodev(fs_type, flags, data, shmem_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2795 | } |
| 2796 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2797 | static struct file_system_type shmem_fs_type = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2798 | .owner = THIS_MODULE, |
| 2799 | .name = "tmpfs", |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 2800 | .mount = shmem_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2801 | .kill_sb = kill_litter_super, |
| 2802 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2803 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2804 | int __init shmem_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2805 | { |
| 2806 | int error; |
| 2807 | |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 2808 | error = bdi_init(&shmem_backing_dev_info); |
| 2809 | if (error) |
| 2810 | goto out4; |
| 2811 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2812 | error = shmem_init_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2813 | if (error) |
| 2814 | goto out3; |
| 2815 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2816 | error = register_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2817 | if (error) { |
| 2818 | printk(KERN_ERR "Could not register tmpfs\n"); |
| 2819 | goto out2; |
| 2820 | } |
Greg Kroah-Hartman | 95dc112 | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 2821 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2822 | shm_mnt = vfs_kern_mount(&shmem_fs_type, MS_NOUSER, |
| 2823 | shmem_fs_type.name, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2824 | if (IS_ERR(shm_mnt)) { |
| 2825 | error = PTR_ERR(shm_mnt); |
| 2826 | printk(KERN_ERR "Could not kern_mount tmpfs\n"); |
| 2827 | goto out1; |
| 2828 | } |
| 2829 | return 0; |
| 2830 | |
| 2831 | out1: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2832 | unregister_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2833 | out2: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2834 | shmem_destroy_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2835 | out3: |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 2836 | bdi_destroy(&shmem_backing_dev_info); |
| 2837 | out4: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2838 | shm_mnt = ERR_PTR(error); |
| 2839 | return error; |
| 2840 | } |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2841 | |
| 2842 | #else /* !CONFIG_SHMEM */ |
| 2843 | |
| 2844 | /* |
| 2845 | * tiny-shmem: simple shmemfs and tmpfs using ramfs code |
| 2846 | * |
| 2847 | * This is intended for small system where the benefits of the full |
| 2848 | * shmem code (swap-backed and resource-limited) are outweighed by |
| 2849 | * their complexity. On systems without swap this code should be |
| 2850 | * effectively equivalent, but much lighter weight. |
| 2851 | */ |
| 2852 | |
| 2853 | #include <linux/ramfs.h> |
| 2854 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2855 | static struct file_system_type shmem_fs_type = { |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2856 | .name = "tmpfs", |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 2857 | .mount = ramfs_mount, |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2858 | .kill_sb = kill_litter_super, |
| 2859 | }; |
| 2860 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2861 | int __init shmem_init(void) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2862 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2863 | BUG_ON(register_filesystem(&shmem_fs_type) != 0); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2864 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2865 | shm_mnt = kern_mount(&shmem_fs_type); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2866 | BUG_ON(IS_ERR(shm_mnt)); |
| 2867 | |
| 2868 | return 0; |
| 2869 | } |
| 2870 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2871 | int shmem_unuse(swp_entry_t swap, struct page *page) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2872 | { |
| 2873 | return 0; |
| 2874 | } |
| 2875 | |
Hugh Dickins | 3f96b79 | 2009-09-21 17:03:37 -0700 | [diff] [blame] | 2876 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 2877 | { |
| 2878 | return 0; |
| 2879 | } |
| 2880 | |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 2881 | void shmem_unlock_mapping(struct address_space *mapping) |
| 2882 | { |
| 2883 | } |
| 2884 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2885 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 2886 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2887 | truncate_inode_pages_range(inode->i_mapping, lstart, lend); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 2888 | } |
| 2889 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
| 2890 | |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 2891 | #define shmem_vm_ops generic_file_vm_ops |
| 2892 | #define shmem_file_operations ramfs_file_operations |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2893 | #define shmem_get_inode(sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev) |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 2894 | #define shmem_acct_size(flags, size) 0 |
| 2895 | #define shmem_unacct_size(flags, size) do {} while (0) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2896 | |
| 2897 | #endif /* CONFIG_SHMEM */ |
| 2898 | |
| 2899 | /* common code */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2900 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 2901 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2902 | * shmem_file_setup - get an unlinked file living in tmpfs |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2903 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 2904 | * @size: size to be set for the file |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 2905 | * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2906 | */ |
Sergei Trofimovich | 168f5ac | 2009-06-16 15:33:02 -0700 | [diff] [blame] | 2907 | struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2908 | { |
| 2909 | int error; |
| 2910 | struct file *file; |
| 2911 | struct inode *inode; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2912 | struct path path; |
| 2913 | struct dentry *root; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2914 | struct qstr this; |
| 2915 | |
| 2916 | if (IS_ERR(shm_mnt)) |
| 2917 | return (void *)shm_mnt; |
| 2918 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 2919 | if (size < 0 || size > MAX_LFS_FILESIZE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2920 | return ERR_PTR(-EINVAL); |
| 2921 | |
| 2922 | if (shmem_acct_size(flags, size)) |
| 2923 | return ERR_PTR(-ENOMEM); |
| 2924 | |
| 2925 | error = -ENOMEM; |
| 2926 | this.name = name; |
| 2927 | this.len = strlen(name); |
| 2928 | this.hash = 0; /* will go */ |
| 2929 | root = shm_mnt->mnt_root; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2930 | path.dentry = d_alloc(root, &this); |
| 2931 | if (!path.dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2932 | goto put_memory; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2933 | path.mnt = mntget(shm_mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2934 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2935 | error = -ENOSPC; |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2936 | inode = shmem_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2937 | if (!inode) |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 2938 | goto put_dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2939 | |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2940 | d_instantiate(path.dentry, inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2941 | inode->i_size = size; |
Miklos Szeredi | 6d6b77f | 2011-10-28 14:13:28 +0200 | [diff] [blame] | 2942 | clear_nlink(inode); /* It is unlinked */ |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2943 | #ifndef CONFIG_MMU |
| 2944 | error = ramfs_nommu_expand_for_mapping(inode, size); |
| 2945 | if (error) |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 2946 | goto put_dentry; |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2947 | #endif |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 2948 | |
| 2949 | error = -ENFILE; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2950 | file = alloc_file(&path, FMODE_WRITE | FMODE_READ, |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 2951 | &shmem_file_operations); |
| 2952 | if (!file) |
| 2953 | goto put_dentry; |
| 2954 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2955 | return file; |
| 2956 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2957 | put_dentry: |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2958 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2959 | put_memory: |
| 2960 | shmem_unacct_size(flags, size); |
| 2961 | return ERR_PTR(error); |
| 2962 | } |
Keith Packard | 395e0dd | 2008-06-20 00:08:06 -0700 | [diff] [blame] | 2963 | EXPORT_SYMBOL_GPL(shmem_file_setup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2964 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 2965 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2966 | * shmem_zero_setup - setup a shared anonymous mapping |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2967 | * @vma: the vma to be mmapped is prepared by do_mmap_pgoff |
| 2968 | */ |
| 2969 | int shmem_zero_setup(struct vm_area_struct *vma) |
| 2970 | { |
| 2971 | struct file *file; |
| 2972 | loff_t size = vma->vm_end - vma->vm_start; |
| 2973 | |
| 2974 | file = shmem_file_setup("dev/zero", size, vma->vm_flags); |
| 2975 | if (IS_ERR(file)) |
| 2976 | return PTR_ERR(file); |
| 2977 | |
| 2978 | if (vma->vm_file) |
| 2979 | fput(vma->vm_file); |
| 2980 | vma->vm_file = file; |
| 2981 | vma->vm_ops = &shmem_vm_ops; |
Hugh Dickins | bee4c36a | 2011-03-22 16:33:43 -0700 | [diff] [blame] | 2982 | vma->vm_flags |= VM_CAN_NONLINEAR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2983 | return 0; |
| 2984 | } |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 2985 | |
| 2986 | /** |
| 2987 | * shmem_read_mapping_page_gfp - read into page cache, using specified page allocation flags. |
| 2988 | * @mapping: the page's address_space |
| 2989 | * @index: the page index |
| 2990 | * @gfp: the page allocator flags to use if allocating |
| 2991 | * |
| 2992 | * This behaves as a tmpfs "read_cache_page_gfp(mapping, index, gfp)", |
| 2993 | * with any new page allocations done using the specified allocation flags. |
| 2994 | * But read_cache_page_gfp() uses the ->readpage() method: which does not |
| 2995 | * suit tmpfs, since it may have pages in swapcache, and needs to find those |
| 2996 | * for itself; although drivers/gpu/drm i915 and ttm rely upon this support. |
| 2997 | * |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 2998 | * i915_gem_object_get_pages_gtt() mixes __GFP_NORETRY | __GFP_NOWARN in |
| 2999 | * with the mapping_gfp_mask(), to avoid OOMing the machine unnecessarily. |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3000 | */ |
| 3001 | struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, |
| 3002 | pgoff_t index, gfp_t gfp) |
| 3003 | { |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3004 | #ifdef CONFIG_SHMEM |
| 3005 | struct inode *inode = mapping->host; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3006 | struct page *page; |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3007 | int error; |
| 3008 | |
| 3009 | BUG_ON(mapping->a_ops != &shmem_aops); |
| 3010 | error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE, gfp, NULL); |
| 3011 | if (error) |
| 3012 | page = ERR_PTR(error); |
| 3013 | else |
| 3014 | unlock_page(page); |
| 3015 | return page; |
| 3016 | #else |
| 3017 | /* |
| 3018 | * The tiny !SHMEM case uses ramfs without swap |
| 3019 | */ |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3020 | return read_cache_page_gfp(mapping, index, gfp); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3021 | #endif |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3022 | } |
| 3023 | EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); |