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> |
Andrew Morton | 250297e | 2013-04-29 15:06:12 -0700 | [diff] [blame] | 28 | #include <linux/ramfs.h> |
Hugh Dickins | caefba1 | 2009-04-13 14:40:12 -0700 | [diff] [blame] | 29 | #include <linux/pagemap.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 30 | #include <linux/file.h> |
| 31 | #include <linux/mm.h> |
Paul Gortmaker | b95f1b31 | 2011-10-16 02:01:52 -0400 | [diff] [blame] | 32 | #include <linux/export.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 33 | #include <linux/swap.h> |
Kent Overstreet | a27bb33 | 2013-05-07 16:19:08 -0700 | [diff] [blame] | 34 | #include <linux/aio.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 35 | |
| 36 | static struct vfsmount *shm_mnt; |
| 37 | |
| 38 | #ifdef CONFIG_SHMEM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | /* |
| 40 | * This virtual memory filesystem is heavily based on the ramfs. It |
| 41 | * extends ramfs by the ability to use swap and honor resource limits |
| 42 | * which makes it a completely usable filesystem. |
| 43 | */ |
| 44 | |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 45 | #include <linux/xattr.h> |
Christoph Hellwig | a569425 | 2007-07-17 04:04:28 -0700 | [diff] [blame] | 46 | #include <linux/exportfs.h> |
Christoph Hellwig | 1c7c474 | 2009-11-03 16:44:44 +0100 | [diff] [blame] | 47 | #include <linux/posix_acl.h> |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 48 | #include <linux/generic_acl.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | #include <linux/mman.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | #include <linux/string.h> |
| 51 | #include <linux/slab.h> |
| 52 | #include <linux/backing-dev.h> |
| 53 | #include <linux/shmem_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | #include <linux/blkdev.h> |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 56 | #include <linux/pagevec.h> |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 57 | #include <linux/percpu_counter.h> |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 58 | #include <linux/falloc.h> |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 59 | #include <linux/splice.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | #include <linux/security.h> |
| 61 | #include <linux/swapops.h> |
| 62 | #include <linux/mempolicy.h> |
| 63 | #include <linux/namei.h> |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 64 | #include <linux/ctype.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 65 | #include <linux/migrate.h> |
Christoph Lameter | c1f60a5 | 2006-09-25 23:31:11 -0700 | [diff] [blame] | 66 | #include <linux/highmem.h> |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 67 | #include <linux/seq_file.h> |
Mimi Zohar | 9256292 | 2008-10-07 14:00:12 -0400 | [diff] [blame] | 68 | #include <linux/magic.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 69 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | #include <asm/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | #include <asm/pgtable.h> |
| 72 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | #define BLOCKS_PER_PAGE (PAGE_CACHE_SIZE/512) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | #define VM_ACCT(size) (PAGE_CACHE_ALIGN(size) >> PAGE_SHIFT) |
| 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | /* Pretend that each entry is of this size in directory's i_size */ |
| 77 | #define BOGO_DIRENT_SIZE 20 |
| 78 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 79 | /* Symlink up to this size is kmalloc'ed instead of using a swappable page */ |
| 80 | #define SHORT_SYMLINK_LEN 128 |
| 81 | |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 82 | /* |
| 83 | * shmem_fallocate and shmem_writepage communicate via inode->i_private |
| 84 | * (with i_mutex making sure that it has only one user at a time): |
| 85 | * we would prefer not to enlarge the shmem inode just for that. |
| 86 | */ |
| 87 | struct shmem_falloc { |
| 88 | pgoff_t start; /* start of range currently being fallocated */ |
| 89 | pgoff_t next; /* the next page offset to be fallocated */ |
| 90 | pgoff_t nr_falloced; /* how many new pages have been fallocated */ |
| 91 | pgoff_t nr_unswapped; /* how often writepage refused to swap out */ |
| 92 | }; |
| 93 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 94 | /* Flag allocation requirements to shmem_getpage */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | enum sgp_type { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | SGP_READ, /* don't exceed i_size, don't allocate page */ |
| 97 | SGP_CACHE, /* don't exceed i_size, may allocate page */ |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 98 | SGP_DIRTY, /* like SGP_CACHE, but set new page dirty */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 99 | SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */ |
| 100 | SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | }; |
| 102 | |
Andrew Morton | b76db73 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 103 | #ifdef CONFIG_TMPFS |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 104 | static unsigned long shmem_default_max_blocks(void) |
| 105 | { |
| 106 | return totalram_pages / 2; |
| 107 | } |
| 108 | |
| 109 | static unsigned long shmem_default_max_inodes(void) |
| 110 | { |
| 111 | return min(totalram_pages - totalhigh_pages, totalram_pages / 2); |
| 112 | } |
Andrew Morton | b76db73 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 113 | #endif |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 114 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 115 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp); |
| 116 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 117 | struct shmem_inode_info *info, pgoff_t index); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 118 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
| 119 | struct page **pagep, enum sgp_type sgp, gfp_t gfp, int *fault_type); |
| 120 | |
| 121 | static inline int shmem_getpage(struct inode *inode, pgoff_t index, |
| 122 | struct page **pagep, enum sgp_type sgp, int *fault_type) |
| 123 | { |
| 124 | return shmem_getpage_gfp(inode, index, pagep, sgp, |
| 125 | mapping_gfp_mask(inode->i_mapping), fault_type); |
| 126 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb) |
| 129 | { |
| 130 | return sb->s_fs_info; |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * shmem_file_setup pre-accounts the whole fixed size of a VM object, |
| 135 | * for shared memory and for shared anonymous (/dev/zero) mappings |
| 136 | * (unless MAP_NORESERVE and sysctl_overcommit_memory <= 1), |
| 137 | * consistent with the pre-accounting of private mappings ... |
| 138 | */ |
| 139 | static inline int shmem_acct_size(unsigned long flags, loff_t size) |
| 140 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 141 | return (flags & VM_NORESERVE) ? |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 142 | 0 : security_vm_enough_memory_mm(current->mm, VM_ACCT(size)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | } |
| 144 | |
| 145 | static inline void shmem_unacct_size(unsigned long flags, loff_t size) |
| 146 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 147 | if (!(flags & VM_NORESERVE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | vm_unacct_memory(VM_ACCT(size)); |
| 149 | } |
| 150 | |
| 151 | /* |
| 152 | * ... whereas tmpfs objects are accounted incrementally as |
| 153 | * pages are allocated, in order to allow huge sparse files. |
| 154 | * shmem_getpage reports shmem_acct_block failure as -ENOSPC not -ENOMEM, |
| 155 | * so that a failure on a sparse tmpfs mapping will give SIGBUS not OOM. |
| 156 | */ |
| 157 | static inline int shmem_acct_block(unsigned long flags) |
| 158 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 159 | return (flags & VM_NORESERVE) ? |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 160 | 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] | 161 | } |
| 162 | |
| 163 | static inline void shmem_unacct_blocks(unsigned long flags, long pages) |
| 164 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 165 | if (flags & VM_NORESERVE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | vm_unacct_memory(pages * VM_ACCT(PAGE_CACHE_SIZE)); |
| 167 | } |
| 168 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 169 | static const struct super_operations shmem_ops; |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 170 | static const struct address_space_operations shmem_aops; |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 171 | static const struct file_operations shmem_file_operations; |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 172 | static const struct inode_operations shmem_inode_operations; |
| 173 | static const struct inode_operations shmem_dir_inode_operations; |
| 174 | static const struct inode_operations shmem_special_inode_operations; |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 175 | static const struct vm_operations_struct shmem_vm_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | |
Ravikiran G Thirumalai | 6c231b7 | 2005-09-06 15:17:45 -0700 | [diff] [blame] | 177 | static struct backing_dev_info shmem_backing_dev_info __read_mostly = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | .ra_pages = 0, /* No readahead */ |
Rik van Riel | 4f98a2f | 2008-10-18 20:26:32 -0700 | [diff] [blame] | 179 | .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | }; |
| 181 | |
| 182 | static LIST_HEAD(shmem_swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 183 | static DEFINE_MUTEX(shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 185 | static int shmem_reserve_inode(struct super_block *sb) |
| 186 | { |
| 187 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 188 | if (sbinfo->max_inodes) { |
| 189 | spin_lock(&sbinfo->stat_lock); |
| 190 | if (!sbinfo->free_inodes) { |
| 191 | spin_unlock(&sbinfo->stat_lock); |
| 192 | return -ENOSPC; |
| 193 | } |
| 194 | sbinfo->free_inodes--; |
| 195 | spin_unlock(&sbinfo->stat_lock); |
| 196 | } |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | static void shmem_free_inode(struct super_block *sb) |
| 201 | { |
| 202 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 203 | if (sbinfo->max_inodes) { |
| 204 | spin_lock(&sbinfo->stat_lock); |
| 205 | sbinfo->free_inodes++; |
| 206 | spin_unlock(&sbinfo->stat_lock); |
| 207 | } |
| 208 | } |
| 209 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 210 | /** |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 211 | * shmem_recalc_inode - recalculate the block usage of an inode |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | * @inode: inode to recalc |
| 213 | * |
| 214 | * We have to calculate the free blocks since the mm can drop |
| 215 | * undirtied hole pages behind our back. |
| 216 | * |
| 217 | * But normally info->alloced == inode->i_mapping->nrpages + info->swapped |
| 218 | * So mm freed is info->alloced - (inode->i_mapping->nrpages + info->swapped) |
| 219 | * |
| 220 | * It has to be called with the spinlock held. |
| 221 | */ |
| 222 | static void shmem_recalc_inode(struct inode *inode) |
| 223 | { |
| 224 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 225 | long freed; |
| 226 | |
| 227 | freed = info->alloced - info->swapped - inode->i_mapping->nrpages; |
| 228 | if (freed > 0) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 229 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 230 | if (sbinfo->max_blocks) |
| 231 | percpu_counter_add(&sbinfo->used_blocks, -freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | info->alloced -= freed; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 233 | inode->i_blocks -= freed * BLOCKS_PER_PAGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | shmem_unacct_blocks(info->flags, freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | } |
| 236 | } |
| 237 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 238 | /* |
| 239 | * Replace item expected in radix tree by a new item, while holding tree lock. |
| 240 | */ |
| 241 | static int shmem_radix_tree_replace(struct address_space *mapping, |
| 242 | pgoff_t index, void *expected, void *replacement) |
| 243 | { |
| 244 | void **pslot; |
| 245 | void *item = NULL; |
| 246 | |
| 247 | VM_BUG_ON(!expected); |
| 248 | pslot = radix_tree_lookup_slot(&mapping->page_tree, index); |
| 249 | if (pslot) |
| 250 | item = radix_tree_deref_slot_protected(pslot, |
| 251 | &mapping->tree_lock); |
| 252 | if (item != expected) |
| 253 | return -ENOENT; |
| 254 | if (replacement) |
| 255 | radix_tree_replace_slot(pslot, replacement); |
| 256 | else |
| 257 | radix_tree_delete(&mapping->page_tree, index); |
| 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | /* |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 262 | * Sometimes, before we decide whether to proceed or to fail, we must check |
| 263 | * that an entry was not already brought back from swap by a racing thread. |
| 264 | * |
| 265 | * Checking page is not enough: by the time a SwapCache page is locked, it |
| 266 | * might be reused, and again be SwapCache, using the same swap as before. |
| 267 | */ |
| 268 | static bool shmem_confirm_swap(struct address_space *mapping, |
| 269 | pgoff_t index, swp_entry_t swap) |
| 270 | { |
| 271 | void *item; |
| 272 | |
| 273 | rcu_read_lock(); |
| 274 | item = radix_tree_lookup(&mapping->page_tree, index); |
| 275 | rcu_read_unlock(); |
| 276 | return item == swp_to_radix_entry(swap); |
| 277 | } |
| 278 | |
| 279 | /* |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 280 | * Like add_to_page_cache_locked, but error if expected item has gone. |
| 281 | */ |
| 282 | static int shmem_add_to_page_cache(struct page *page, |
| 283 | struct address_space *mapping, |
| 284 | pgoff_t index, gfp_t gfp, void *expected) |
| 285 | { |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 286 | int error; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 287 | |
| 288 | VM_BUG_ON(!PageLocked(page)); |
| 289 | VM_BUG_ON(!PageSwapBacked(page)); |
| 290 | |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 291 | page_cache_get(page); |
| 292 | page->mapping = mapping; |
| 293 | page->index = index; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 294 | |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 295 | spin_lock_irq(&mapping->tree_lock); |
| 296 | if (!expected) |
| 297 | error = radix_tree_insert(&mapping->page_tree, index, page); |
| 298 | else |
| 299 | error = shmem_radix_tree_replace(mapping, index, expected, |
| 300 | page); |
| 301 | if (!error) { |
| 302 | mapping->nrpages++; |
| 303 | __inc_zone_page_state(page, NR_FILE_PAGES); |
| 304 | __inc_zone_page_state(page, NR_SHMEM); |
| 305 | spin_unlock_irq(&mapping->tree_lock); |
| 306 | } else { |
| 307 | page->mapping = NULL; |
| 308 | spin_unlock_irq(&mapping->tree_lock); |
| 309 | page_cache_release(page); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 310 | } |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 311 | return error; |
| 312 | } |
| 313 | |
| 314 | /* |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 315 | * Like delete_from_page_cache, but substitutes swap for page. |
| 316 | */ |
| 317 | static void shmem_delete_from_page_cache(struct page *page, void *radswap) |
| 318 | { |
| 319 | struct address_space *mapping = page->mapping; |
| 320 | int error; |
| 321 | |
| 322 | spin_lock_irq(&mapping->tree_lock); |
| 323 | error = shmem_radix_tree_replace(mapping, page->index, page, radswap); |
| 324 | page->mapping = NULL; |
| 325 | mapping->nrpages--; |
| 326 | __dec_zone_page_state(page, NR_FILE_PAGES); |
| 327 | __dec_zone_page_state(page, NR_SHMEM); |
| 328 | spin_unlock_irq(&mapping->tree_lock); |
| 329 | page_cache_release(page); |
| 330 | BUG_ON(error); |
| 331 | } |
| 332 | |
| 333 | /* |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 334 | * Like find_get_pages, but collecting swap entries as well as pages. |
| 335 | */ |
| 336 | static unsigned shmem_find_get_pages_and_swap(struct address_space *mapping, |
| 337 | pgoff_t start, unsigned int nr_pages, |
| 338 | struct page **pages, pgoff_t *indices) |
| 339 | { |
Johannes Weiner | 860f275 | 2013-02-22 16:35:17 -0800 | [diff] [blame] | 340 | void **slot; |
| 341 | unsigned int ret = 0; |
| 342 | struct radix_tree_iter iter; |
| 343 | |
| 344 | if (!nr_pages) |
| 345 | return 0; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 346 | |
| 347 | rcu_read_lock(); |
| 348 | restart: |
Johannes Weiner | 860f275 | 2013-02-22 16:35:17 -0800 | [diff] [blame] | 349 | radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 350 | struct page *page; |
| 351 | repeat: |
Johannes Weiner | 860f275 | 2013-02-22 16:35:17 -0800 | [diff] [blame] | 352 | page = radix_tree_deref_slot(slot); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 353 | if (unlikely(!page)) |
| 354 | continue; |
| 355 | if (radix_tree_exception(page)) { |
Hugh Dickins | 8079b1c | 2011-08-03 16:21:28 -0700 | [diff] [blame] | 356 | if (radix_tree_deref_retry(page)) |
| 357 | goto restart; |
| 358 | /* |
| 359 | * Otherwise, we must be storing a swap entry |
| 360 | * here as an exceptional entry: so return it |
| 361 | * without attempting to raise page count. |
| 362 | */ |
| 363 | goto export; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 364 | } |
| 365 | if (!page_cache_get_speculative(page)) |
| 366 | goto repeat; |
| 367 | |
| 368 | /* Has the page moved? */ |
Johannes Weiner | 860f275 | 2013-02-22 16:35:17 -0800 | [diff] [blame] | 369 | if (unlikely(page != *slot)) { |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 370 | page_cache_release(page); |
| 371 | goto repeat; |
| 372 | } |
| 373 | export: |
Johannes Weiner | 860f275 | 2013-02-22 16:35:17 -0800 | [diff] [blame] | 374 | indices[ret] = iter.index; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 375 | pages[ret] = page; |
Johannes Weiner | 860f275 | 2013-02-22 16:35:17 -0800 | [diff] [blame] | 376 | if (++ret == nr_pages) |
| 377 | break; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 378 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 379 | rcu_read_unlock(); |
| 380 | return ret; |
| 381 | } |
| 382 | |
| 383 | /* |
| 384 | * Remove swap entry from radix tree, free the swap and its page cache. |
| 385 | */ |
| 386 | static int shmem_free_swap(struct address_space *mapping, |
| 387 | pgoff_t index, void *radswap) |
| 388 | { |
| 389 | int error; |
| 390 | |
| 391 | spin_lock_irq(&mapping->tree_lock); |
| 392 | error = shmem_radix_tree_replace(mapping, index, radswap, NULL); |
| 393 | spin_unlock_irq(&mapping->tree_lock); |
| 394 | if (!error) |
| 395 | free_swap_and_cache(radix_to_swp_entry(radswap)); |
| 396 | return error; |
| 397 | } |
| 398 | |
| 399 | /* |
| 400 | * Pagevec may contain swap entries, so shuffle up pages before releasing. |
| 401 | */ |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 402 | static void shmem_deswap_pagevec(struct pagevec *pvec) |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 403 | { |
| 404 | int i, j; |
| 405 | |
| 406 | for (i = 0, j = 0; i < pagevec_count(pvec); i++) { |
| 407 | struct page *page = pvec->pages[i]; |
| 408 | if (!radix_tree_exceptional_entry(page)) |
| 409 | pvec->pages[j++] = page; |
| 410 | } |
| 411 | pvec->nr = j; |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 412 | } |
| 413 | |
| 414 | /* |
| 415 | * SysV IPC SHM_UNLOCK restore Unevictable pages to their evictable lists. |
| 416 | */ |
| 417 | void shmem_unlock_mapping(struct address_space *mapping) |
| 418 | { |
| 419 | struct pagevec pvec; |
| 420 | pgoff_t indices[PAGEVEC_SIZE]; |
| 421 | pgoff_t index = 0; |
| 422 | |
| 423 | pagevec_init(&pvec, 0); |
| 424 | /* |
| 425 | * Minor point, but we might as well stop if someone else SHM_LOCKs it. |
| 426 | */ |
| 427 | while (!mapping_unevictable(mapping)) { |
| 428 | /* |
| 429 | * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it |
| 430 | * has finished, if it hits a row of PAGEVEC_SIZE swap entries. |
| 431 | */ |
| 432 | pvec.nr = shmem_find_get_pages_and_swap(mapping, index, |
| 433 | PAGEVEC_SIZE, pvec.pages, indices); |
| 434 | if (!pvec.nr) |
| 435 | break; |
| 436 | index = indices[pvec.nr - 1] + 1; |
| 437 | shmem_deswap_pagevec(&pvec); |
| 438 | check_move_unevictable_pages(pvec.pages, pvec.nr); |
| 439 | pagevec_release(&pvec); |
| 440 | cond_resched(); |
| 441 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 442 | } |
| 443 | |
| 444 | /* |
| 445 | * 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] | 446 | * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 447 | */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 448 | static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, |
| 449 | bool unfalloc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | { |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 451 | struct address_space *mapping = inode->i_mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | struct shmem_inode_info *info = SHMEM_I(inode); |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 453 | pgoff_t start = (lstart + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 454 | pgoff_t end = (lend + 1) >> PAGE_CACHE_SHIFT; |
| 455 | unsigned int partial_start = lstart & (PAGE_CACHE_SIZE - 1); |
| 456 | unsigned int partial_end = (lend + 1) & (PAGE_CACHE_SIZE - 1); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 457 | struct pagevec pvec; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 458 | pgoff_t indices[PAGEVEC_SIZE]; |
| 459 | long nr_swaps_freed = 0; |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 460 | pgoff_t index; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 461 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 463 | if (lend == -1) |
| 464 | end = -1; /* unsigned, so actually very big */ |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 465 | |
| 466 | pagevec_init(&pvec, 0); |
| 467 | index = start; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 468 | while (index < end) { |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 469 | pvec.nr = shmem_find_get_pages_and_swap(mapping, index, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 470 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 471 | pvec.pages, indices); |
| 472 | if (!pvec.nr) |
| 473 | break; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 474 | mem_cgroup_uncharge_start(); |
| 475 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 476 | struct page *page = pvec.pages[i]; |
| 477 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 478 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 479 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 480 | break; |
| 481 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 482 | if (radix_tree_exceptional_entry(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 483 | if (unfalloc) |
| 484 | continue; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 485 | nr_swaps_freed += !shmem_free_swap(mapping, |
| 486 | index, page); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 487 | continue; |
| 488 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 489 | |
| 490 | if (!trylock_page(page)) |
| 491 | continue; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 492 | if (!unfalloc || !PageUptodate(page)) { |
| 493 | if (page->mapping == mapping) { |
| 494 | VM_BUG_ON(PageWriteback(page)); |
| 495 | truncate_inode_page(mapping, page); |
| 496 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 497 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 498 | unlock_page(page); |
| 499 | } |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 500 | shmem_deswap_pagevec(&pvec); |
| 501 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 502 | mem_cgroup_uncharge_end(); |
| 503 | cond_resched(); |
| 504 | index++; |
| 505 | } |
| 506 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 507 | if (partial_start) { |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 508 | struct page *page = NULL; |
| 509 | shmem_getpage(inode, start - 1, &page, SGP_READ, NULL); |
| 510 | if (page) { |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 511 | unsigned int top = PAGE_CACHE_SIZE; |
| 512 | if (start > end) { |
| 513 | top = partial_end; |
| 514 | partial_end = 0; |
| 515 | } |
| 516 | zero_user_segment(page, partial_start, top); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 517 | set_page_dirty(page); |
| 518 | unlock_page(page); |
| 519 | page_cache_release(page); |
| 520 | } |
| 521 | } |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 522 | if (partial_end) { |
| 523 | struct page *page = NULL; |
| 524 | shmem_getpage(inode, end, &page, SGP_READ, NULL); |
| 525 | if (page) { |
| 526 | zero_user_segment(page, 0, partial_end); |
| 527 | set_page_dirty(page); |
| 528 | unlock_page(page); |
| 529 | page_cache_release(page); |
| 530 | } |
| 531 | } |
| 532 | if (start >= end) |
| 533 | return; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 534 | |
| 535 | index = start; |
| 536 | for ( ; ; ) { |
| 537 | cond_resched(); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 538 | pvec.nr = shmem_find_get_pages_and_swap(mapping, index, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 539 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 540 | pvec.pages, indices); |
| 541 | if (!pvec.nr) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 542 | if (index == start || unfalloc) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 543 | break; |
| 544 | index = start; |
| 545 | continue; |
| 546 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 547 | if ((index == start || unfalloc) && indices[0] >= end) { |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 548 | shmem_deswap_pagevec(&pvec); |
| 549 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 550 | break; |
| 551 | } |
| 552 | mem_cgroup_uncharge_start(); |
| 553 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 554 | struct page *page = pvec.pages[i]; |
| 555 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 556 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 557 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 558 | break; |
| 559 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 560 | if (radix_tree_exceptional_entry(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 561 | if (unfalloc) |
| 562 | continue; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 563 | nr_swaps_freed += !shmem_free_swap(mapping, |
| 564 | index, page); |
| 565 | continue; |
| 566 | } |
| 567 | |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 568 | lock_page(page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 569 | if (!unfalloc || !PageUptodate(page)) { |
| 570 | if (page->mapping == mapping) { |
| 571 | VM_BUG_ON(PageWriteback(page)); |
| 572 | truncate_inode_page(mapping, page); |
| 573 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 574 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 575 | unlock_page(page); |
| 576 | } |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 577 | shmem_deswap_pagevec(&pvec); |
| 578 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 579 | mem_cgroup_uncharge_end(); |
| 580 | index++; |
| 581 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 582 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | spin_lock(&info->lock); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 584 | info->swapped -= nr_swaps_freed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | shmem_recalc_inode(inode); |
| 586 | spin_unlock(&info->lock); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 587 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 589 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) |
| 590 | { |
| 591 | shmem_undo_range(inode, lstart, lend, false); |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 592 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 594 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 595 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 596 | static int shmem_setattr(struct dentry *dentry, struct iattr *attr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | { |
| 598 | struct inode *inode = dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | int error; |
| 600 | |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 601 | error = inode_change_ok(inode, attr); |
| 602 | if (error) |
| 603 | return error; |
| 604 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 605 | if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { |
| 606 | loff_t oldsize = inode->i_size; |
| 607 | loff_t newsize = attr->ia_size; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 608 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 609 | if (newsize != oldsize) { |
| 610 | i_size_write(inode, newsize); |
| 611 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
| 612 | } |
| 613 | if (newsize < oldsize) { |
| 614 | loff_t holebegin = round_up(newsize, PAGE_SIZE); |
| 615 | unmap_mapping_range(inode->i_mapping, holebegin, 0, 1); |
| 616 | shmem_truncate_range(inode, newsize, (loff_t)-1); |
| 617 | /* unmap again to remove racily COWed private pages */ |
| 618 | unmap_mapping_range(inode->i_mapping, holebegin, 0, 1); |
| 619 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | } |
| 621 | |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 622 | setattr_copy(inode, attr); |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 623 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Christoph Hellwig | db78b87 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 624 | if (attr->ia_valid & ATTR_MODE) |
Christoph Hellwig | 1c7c474 | 2009-11-03 16:44:44 +0100 | [diff] [blame] | 625 | error = generic_acl_chmod(inode); |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 626 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | return error; |
| 628 | } |
| 629 | |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 630 | static void shmem_evict_inode(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 633 | |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 634 | if (inode->i_mapping->a_ops == &shmem_aops) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | shmem_unacct_size(info->flags, inode->i_size); |
| 636 | inode->i_size = 0; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 637 | shmem_truncate_range(inode, 0, (loff_t)-1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | if (!list_empty(&info->swaplist)) { |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 639 | mutex_lock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 641 | mutex_unlock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | } |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 643 | } else |
| 644 | kfree(info->symlink); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 645 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 646 | simple_xattrs_free(&info->xattrs); |
Hugh Dickins | 0f3c42f | 2012-11-16 14:15:04 -0800 | [diff] [blame] | 647 | WARN_ON(inode->i_blocks); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 648 | shmem_free_inode(inode->i_sb); |
Jan Kara | dbd5768 | 2012-05-03 14:48:02 +0200 | [diff] [blame] | 649 | clear_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | } |
| 651 | |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 652 | /* |
| 653 | * If swap found in inode, free it and move page from swapcache to filecache. |
| 654 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 655 | static int shmem_unuse_inode(struct shmem_inode_info *info, |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 656 | swp_entry_t swap, struct page **pagep) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | { |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 658 | struct address_space *mapping = info->vfs_inode.i_mapping; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 659 | void *radswap; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 660 | pgoff_t index; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 661 | gfp_t gfp; |
| 662 | int error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 664 | radswap = swp_to_radix_entry(swap); |
Hugh Dickins | e504f3f | 2011-08-03 16:21:27 -0700 | [diff] [blame] | 665 | index = radix_tree_locate_item(&mapping->page_tree, radswap); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 666 | if (index == -1) |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 667 | return 0; |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 668 | |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 669 | /* |
| 670 | * Move _head_ to start search for next from here. |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 671 | * But be careful: shmem_evict_inode checks list_empty without taking |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 672 | * 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] | 673 | * would appear empty, if it were the only one on shmem_swaplist. |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 674 | */ |
| 675 | if (shmem_swaplist.next != &info->swaplist) |
| 676 | list_move_tail(&shmem_swaplist, &info->swaplist); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 677 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 678 | gfp = mapping_gfp_mask(mapping); |
| 679 | if (shmem_should_replace_page(*pagep, gfp)) { |
| 680 | mutex_unlock(&shmem_swaplist_mutex); |
| 681 | error = shmem_replace_page(pagep, gfp, info, index); |
| 682 | mutex_lock(&shmem_swaplist_mutex); |
| 683 | /* |
| 684 | * We needed to drop mutex to make that restrictive page |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 685 | * allocation, but the inode might have been freed while we |
| 686 | * dropped it: although a racing shmem_evict_inode() cannot |
| 687 | * complete without emptying the radix_tree, our page lock |
| 688 | * on this swapcache page is not enough to prevent that - |
| 689 | * free_swap_and_cache() of our swap entry will only |
| 690 | * trylock_page(), removing swap from radix_tree whatever. |
| 691 | * |
| 692 | * We must not proceed to shmem_add_to_page_cache() if the |
| 693 | * inode has been freed, but of course we cannot rely on |
| 694 | * inode or mapping or info to check that. However, we can |
| 695 | * safely check if our swap entry is still in use (and here |
| 696 | * it can't have got reused for another page): if it's still |
| 697 | * in use, then the inode cannot have been freed yet, and we |
| 698 | * can safely proceed (if it's no longer in use, that tells |
| 699 | * nothing about the inode, but we don't need to unuse swap). |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 700 | */ |
| 701 | if (!page_swapcount(*pagep)) |
| 702 | error = -ENOENT; |
| 703 | } |
| 704 | |
KAMEZAWA Hiroyuki | d13d144 | 2009-01-07 18:07:56 -0800 | [diff] [blame] | 705 | /* |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 706 | * We rely on shmem_swaplist_mutex, not only to protect the swaplist, |
| 707 | * but also to hold up shmem_evict_inode(): so inode cannot be freed |
| 708 | * beneath us (pagelock doesn't help until the page is in pagecache). |
KAMEZAWA Hiroyuki | d13d144 | 2009-01-07 18:07:56 -0800 | [diff] [blame] | 709 | */ |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 710 | if (!error) |
| 711 | error = shmem_add_to_page_cache(*pagep, mapping, index, |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 712 | GFP_NOWAIT, radswap); |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 713 | if (error != -ENOMEM) { |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 714 | /* |
| 715 | * Truncation and eviction use free_swap_and_cache(), which |
| 716 | * only does trylock page: if we raced, best clean up here. |
| 717 | */ |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 718 | delete_from_swap_cache(*pagep); |
| 719 | set_page_dirty(*pagep); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 720 | if (!error) { |
| 721 | spin_lock(&info->lock); |
| 722 | info->swapped--; |
| 723 | spin_unlock(&info->lock); |
| 724 | swap_free(swap); |
| 725 | } |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 726 | error = 1; /* not an error, but entry was found */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 727 | } |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 728 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 729 | } |
| 730 | |
| 731 | /* |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 732 | * Search through swapped inodes to find and replace swap by page. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 734 | int shmem_unuse(swp_entry_t swap, struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 736 | struct list_head *this, *next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | struct shmem_inode_info *info; |
| 738 | int found = 0; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 739 | int error = 0; |
| 740 | |
| 741 | /* |
| 742 | * There's a faint possibility that swap page was replaced before |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 743 | * caller locked it: caller will come back later with the right page. |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 744 | */ |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 745 | if (unlikely(!PageSwapCache(page) || page_private(page) != swap.val)) |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 746 | goto out; |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 747 | |
| 748 | /* |
| 749 | * Charge page using GFP_KERNEL while we can wait, before taking |
| 750 | * the shmem_swaplist_mutex which might hold up shmem_writepage(). |
| 751 | * 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] | 752 | */ |
| 753 | error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL); |
| 754 | if (error) |
| 755 | goto out; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 756 | /* 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] | 757 | |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 758 | mutex_lock(&shmem_swaplist_mutex); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 759 | list_for_each_safe(this, next, &shmem_swaplist) { |
| 760 | info = list_entry(this, struct shmem_inode_info, swaplist); |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 761 | if (info->swapped) |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 762 | found = shmem_unuse_inode(info, swap, &page); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 763 | else |
| 764 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 765 | cond_resched(); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 766 | if (found) |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 767 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | } |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 769 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 770 | |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 771 | if (found < 0) |
| 772 | error = found; |
| 773 | out: |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 774 | unlock_page(page); |
| 775 | page_cache_release(page); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 776 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | } |
| 778 | |
| 779 | /* |
| 780 | * Move the page from the page cache to the swap cache. |
| 781 | */ |
| 782 | static int shmem_writepage(struct page *page, struct writeback_control *wbc) |
| 783 | { |
| 784 | struct shmem_inode_info *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 785 | struct address_space *mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | struct inode *inode; |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 787 | swp_entry_t swap; |
| 788 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 789 | |
| 790 | BUG_ON(!PageLocked(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | mapping = page->mapping; |
| 792 | index = page->index; |
| 793 | inode = mapping->host; |
| 794 | info = SHMEM_I(inode); |
| 795 | if (info->flags & VM_LOCKED) |
| 796 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 797 | if (!total_swap_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | goto redirty; |
| 799 | |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 800 | /* |
| 801 | * shmem_backing_dev_info's capabilities prevent regular writeback or |
| 802 | * sync from ever calling shmem_writepage; but a stacking filesystem |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 803 | * might use ->writepage of its underlying filesystem, in which case |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 804 | * tmpfs should write out to swap only in response to memory pressure, |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 805 | * and not for the writeback threads or sync. |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 806 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 807 | if (!wbc->for_reclaim) { |
| 808 | WARN_ON_ONCE(1); /* Still happens? Tell us about it! */ |
| 809 | goto redirty; |
| 810 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 811 | |
| 812 | /* |
| 813 | * This is somewhat ridiculous, but without plumbing a SWAP_MAP_FALLOC |
| 814 | * value into swapfile.c, the only way we can correctly account for a |
| 815 | * fallocated page arriving here is now to initialize it and write it. |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 816 | * |
| 817 | * That's okay for a page already fallocated earlier, but if we have |
| 818 | * not yet completed the fallocation, then (a) we want to keep track |
| 819 | * of this page in case we have to undo it, and (b) it may not be a |
| 820 | * good idea to continue anyway, once we're pushing into swap. So |
| 821 | * reactivate the page, and let shmem_fallocate() quit when too many. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 822 | */ |
| 823 | if (!PageUptodate(page)) { |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 824 | if (inode->i_private) { |
| 825 | struct shmem_falloc *shmem_falloc; |
| 826 | spin_lock(&inode->i_lock); |
| 827 | shmem_falloc = inode->i_private; |
| 828 | if (shmem_falloc && |
| 829 | index >= shmem_falloc->start && |
| 830 | index < shmem_falloc->next) |
| 831 | shmem_falloc->nr_unswapped++; |
| 832 | else |
| 833 | shmem_falloc = NULL; |
| 834 | spin_unlock(&inode->i_lock); |
| 835 | if (shmem_falloc) |
| 836 | goto redirty; |
| 837 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 838 | clear_highpage(page); |
| 839 | flush_dcache_page(page); |
| 840 | SetPageUptodate(page); |
| 841 | } |
| 842 | |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 843 | swap = get_swap_page(); |
| 844 | if (!swap.val) |
| 845 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 846 | |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 847 | /* |
| 848 | * Add inode to shmem_unuse()'s list of swapped-out inodes, |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 849 | * if it's not already there. Do it now before the page is |
| 850 | * moved to swap cache, when its pagelock no longer protects |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 851 | * the inode from eviction. But don't unlock the mutex until |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 852 | * we've incremented swapped, because shmem_unuse_inode() will |
| 853 | * prune a !swapped inode from the swaplist under this mutex. |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 854 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 855 | mutex_lock(&shmem_swaplist_mutex); |
| 856 | if (list_empty(&info->swaplist)) |
| 857 | list_add_tail(&info->swaplist, &shmem_swaplist); |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 858 | |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 859 | if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) { |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 860 | swap_shmem_alloc(swap); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 861 | shmem_delete_from_page_cache(page, swp_to_radix_entry(swap)); |
| 862 | |
| 863 | spin_lock(&info->lock); |
| 864 | info->swapped++; |
| 865 | shmem_recalc_inode(inode); |
Hugh Dickins | 826267c | 2011-05-28 13:14:09 -0700 | [diff] [blame] | 866 | spin_unlock(&info->lock); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 867 | |
| 868 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 869 | BUG_ON(page_mapped(page)); |
Hugh Dickins | 9fab561 | 2009-03-31 15:23:33 -0700 | [diff] [blame] | 870 | swap_writepage(page, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | return 0; |
| 872 | } |
| 873 | |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 874 | mutex_unlock(&shmem_swaplist_mutex); |
KAMEZAWA Hiroyuki | cb4b86b | 2009-06-16 15:32:52 -0700 | [diff] [blame] | 875 | swapcache_free(swap, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | redirty: |
| 877 | set_page_dirty(page); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 878 | if (wbc->for_reclaim) |
| 879 | return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */ |
| 880 | unlock_page(page); |
| 881 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | } |
| 883 | |
| 884 | #ifdef CONFIG_NUMA |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 885 | #ifdef CONFIG_TMPFS |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 886 | 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] | 887 | { |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 888 | char buffer[64]; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 889 | |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 890 | if (!mpol || mpol->mode == MPOL_DEFAULT) |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 891 | return; /* show nothing */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 892 | |
Hugh Dickins | a7a88b2 | 2013-01-02 02:04:23 -0800 | [diff] [blame] | 893 | mpol_to_str(buffer, sizeof(buffer), mpol); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 894 | |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 895 | seq_printf(seq, ",mpol=%s", buffer); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 896 | } |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 897 | |
| 898 | static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 899 | { |
| 900 | struct mempolicy *mpol = NULL; |
| 901 | if (sbinfo->mpol) { |
| 902 | spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */ |
| 903 | mpol = sbinfo->mpol; |
| 904 | mpol_get(mpol); |
| 905 | spin_unlock(&sbinfo->stat_lock); |
| 906 | } |
| 907 | return mpol; |
| 908 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 909 | #endif /* CONFIG_TMPFS */ |
| 910 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 911 | static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, |
| 912 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 913 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 914 | struct vm_area_struct pvma; |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 915 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 916 | |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 917 | /* Create a pseudo vma that just contains the policy */ |
| 918 | pvma.vm_start = 0; |
Nathan Zimmer | 09c231c | 2012-07-31 16:46:17 -0700 | [diff] [blame] | 919 | /* Bias interleave by inode number to distribute better across nodes */ |
| 920 | pvma.vm_pgoff = index + info->vfs_inode.i_ino; |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 921 | pvma.vm_ops = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 922 | pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index); |
Lee Schermerhorn | 52cd3b0 | 2008-04-28 02:13:16 -0700 | [diff] [blame] | 923 | |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 924 | page = swapin_readahead(swap, gfp, &pvma, 0); |
| 925 | |
| 926 | /* Drop reference taken by mpol_shared_policy_lookup() */ |
| 927 | mpol_cond_put(pvma.vm_policy); |
| 928 | |
| 929 | return page; |
| 930 | } |
| 931 | |
| 932 | static struct page *shmem_alloc_page(gfp_t gfp, |
| 933 | struct shmem_inode_info *info, pgoff_t index) |
| 934 | { |
| 935 | struct vm_area_struct pvma; |
| 936 | struct page *page; |
| 937 | |
| 938 | /* Create a pseudo vma that just contains the policy */ |
| 939 | pvma.vm_start = 0; |
| 940 | /* Bias interleave by inode number to distribute better across nodes */ |
| 941 | pvma.vm_pgoff = index + info->vfs_inode.i_ino; |
| 942 | pvma.vm_ops = NULL; |
| 943 | pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index); |
| 944 | |
| 945 | page = alloc_page_vma(gfp, &pvma, 0); |
| 946 | |
| 947 | /* Drop reference taken by mpol_shared_policy_lookup() */ |
| 948 | mpol_cond_put(pvma.vm_policy); |
| 949 | |
| 950 | return page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 951 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 952 | #else /* !CONFIG_NUMA */ |
| 953 | #ifdef CONFIG_TMPFS |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 954 | 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] | 955 | { |
| 956 | } |
| 957 | #endif /* CONFIG_TMPFS */ |
| 958 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 959 | static inline struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, |
| 960 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 961 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 962 | return swapin_readahead(swap, gfp, NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | } |
| 964 | |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 965 | static inline struct page *shmem_alloc_page(gfp_t gfp, |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 966 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 967 | { |
Hugh Dickins | e84e2e1 | 2007-11-28 18:55:10 +0000 | [diff] [blame] | 968 | return alloc_page(gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 969 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 970 | #endif /* CONFIG_NUMA */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 972 | #if !defined(CONFIG_NUMA) || !defined(CONFIG_TMPFS) |
| 973 | static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 974 | { |
| 975 | return NULL; |
| 976 | } |
| 977 | #endif |
| 978 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | /* |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 980 | * When a page is moved from swapcache to shmem filecache (either by the |
| 981 | * usual swapin of shmem_getpage_gfp(), or by the less common swapoff of |
| 982 | * shmem_unuse_inode()), it may have been read in earlier from swap, in |
| 983 | * ignorance of the mapping it belongs to. If that mapping has special |
| 984 | * constraints (like the gma500 GEM driver, which requires RAM below 4GB), |
| 985 | * we may need to copy to a suitable page before moving to filecache. |
| 986 | * |
| 987 | * In a future release, this may well be extended to respect cpuset and |
| 988 | * NUMA mempolicy, and applied also to anonymous pages in do_swap_page(); |
| 989 | * but for now it is a simple matter of zone. |
| 990 | */ |
| 991 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp) |
| 992 | { |
| 993 | return page_zonenum(page) > gfp_zone(gfp); |
| 994 | } |
| 995 | |
| 996 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 997 | struct shmem_inode_info *info, pgoff_t index) |
| 998 | { |
| 999 | struct page *oldpage, *newpage; |
| 1000 | struct address_space *swap_mapping; |
| 1001 | pgoff_t swap_index; |
| 1002 | int error; |
| 1003 | |
| 1004 | oldpage = *pagep; |
| 1005 | swap_index = page_private(oldpage); |
| 1006 | swap_mapping = page_mapping(oldpage); |
| 1007 | |
| 1008 | /* |
| 1009 | * We have arrived here because our zones are constrained, so don't |
| 1010 | * limit chance of success by further cpuset and node constraints. |
| 1011 | */ |
| 1012 | gfp &= ~GFP_CONSTRAINT_MASK; |
| 1013 | newpage = shmem_alloc_page(gfp, info, index); |
| 1014 | if (!newpage) |
| 1015 | return -ENOMEM; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1016 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1017 | page_cache_get(newpage); |
| 1018 | copy_highpage(newpage, oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1019 | flush_dcache_page(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1020 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1021 | __set_page_locked(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1022 | SetPageUptodate(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1023 | SetPageSwapBacked(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1024 | set_page_private(newpage, swap_index); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1025 | SetPageSwapCache(newpage); |
| 1026 | |
| 1027 | /* |
| 1028 | * Our caller will very soon move newpage out of swapcache, but it's |
| 1029 | * a nice clean interface for us to replace oldpage by newpage there. |
| 1030 | */ |
| 1031 | spin_lock_irq(&swap_mapping->tree_lock); |
| 1032 | error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage, |
| 1033 | newpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1034 | if (!error) { |
| 1035 | __inc_zone_page_state(newpage, NR_FILE_PAGES); |
| 1036 | __dec_zone_page_state(oldpage, NR_FILE_PAGES); |
| 1037 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1038 | spin_unlock_irq(&swap_mapping->tree_lock); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1039 | |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1040 | if (unlikely(error)) { |
| 1041 | /* |
| 1042 | * Is this possible? I think not, now that our callers check |
| 1043 | * both PageSwapCache and page_private after getting page lock; |
| 1044 | * but be defensive. Reverse old to newpage for clear and free. |
| 1045 | */ |
| 1046 | oldpage = newpage; |
| 1047 | } else { |
| 1048 | mem_cgroup_replace_page_cache(oldpage, newpage); |
| 1049 | lru_cache_add_anon(newpage); |
| 1050 | *pagep = newpage; |
| 1051 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1052 | |
| 1053 | ClearPageSwapCache(oldpage); |
| 1054 | set_page_private(oldpage, 0); |
| 1055 | |
| 1056 | unlock_page(oldpage); |
| 1057 | page_cache_release(oldpage); |
| 1058 | page_cache_release(oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1059 | return error; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1060 | } |
| 1061 | |
| 1062 | /* |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1063 | * 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] | 1064 | * |
| 1065 | * If we allocate a new one we do not mark it dirty. That's up to the |
| 1066 | * vm. If we swap it in we mark it dirty since we also free the swap |
| 1067 | * entry since a page cannot live in both the swap and page cache |
| 1068 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1069 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1070 | 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] | 1071 | { |
| 1072 | struct address_space *mapping = inode->i_mapping; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1073 | struct shmem_inode_info *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | struct shmem_sb_info *sbinfo; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1075 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | swp_entry_t swap; |
| 1077 | int error; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1078 | int once = 0; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1079 | int alloced = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1080 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1081 | if (index > (MAX_LFS_FILESIZE >> PAGE_CACHE_SHIFT)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | return -EFBIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1083 | repeat: |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1084 | swap.val = 0; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1085 | page = find_lock_page(mapping, index); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1086 | if (radix_tree_exceptional_entry(page)) { |
| 1087 | swap = radix_to_swp_entry(page); |
| 1088 | page = NULL; |
| 1089 | } |
| 1090 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1091 | if (sgp != SGP_WRITE && sgp != SGP_FALLOC && |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1092 | ((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) { |
| 1093 | error = -EINVAL; |
| 1094 | goto failed; |
| 1095 | } |
| 1096 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1097 | /* fallocated page? */ |
| 1098 | if (page && !PageUptodate(page)) { |
| 1099 | if (sgp != SGP_READ) |
| 1100 | goto clear; |
| 1101 | unlock_page(page); |
| 1102 | page_cache_release(page); |
| 1103 | page = NULL; |
| 1104 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1105 | if (page || (sgp == SGP_READ && !swap.val)) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1106 | *pagep = page; |
| 1107 | return 0; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1108 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1109 | |
| 1110 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1111 | * Fast cache lookup did not find it: |
| 1112 | * bring it back from swap or allocate. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1113 | */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1114 | info = SHMEM_I(inode); |
| 1115 | sbinfo = SHMEM_SB(inode->i_sb); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1116 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1117 | if (swap.val) { |
| 1118 | /* Look it up and read it in.. */ |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1119 | page = lookup_swap_cache(swap); |
| 1120 | if (!page) { |
Ying Han | 456f998 | 2011-05-26 16:25:38 -0700 | [diff] [blame] | 1121 | /* here we actually do the io */ |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1122 | if (fault_type) |
| 1123 | *fault_type |= VM_FAULT_MAJOR; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1124 | page = shmem_swapin(swap, gfp, info, index); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1125 | if (!page) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1126 | error = -ENOMEM; |
| 1127 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1128 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1129 | } |
| 1130 | |
| 1131 | /* We have to do this with page locked to prevent races */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1132 | lock_page(page); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1133 | if (!PageSwapCache(page) || page_private(page) != swap.val || |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1134 | !shmem_confirm_swap(mapping, index, swap)) { |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1135 | error = -EEXIST; /* try again */ |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1136 | goto unlock; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1137 | } |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1138 | if (!PageUptodate(page)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1139 | error = -EIO; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1140 | goto failed; |
| 1141 | } |
| 1142 | wait_on_page_writeback(page); |
| 1143 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1144 | if (shmem_should_replace_page(page, gfp)) { |
| 1145 | error = shmem_replace_page(&page, gfp, info, index); |
| 1146 | if (error) |
| 1147 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1148 | } |
| 1149 | |
Hugh Dickins | aa3b189 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1150 | error = mem_cgroup_cache_charge(page, current->mm, |
| 1151 | gfp & GFP_RECLAIM_MASK); |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1152 | if (!error) { |
Hugh Dickins | aa3b189 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1153 | error = shmem_add_to_page_cache(page, mapping, index, |
| 1154 | gfp, swp_to_radix_entry(swap)); |
Hugh Dickins | 215c02b | 2012-11-16 14:15:03 -0800 | [diff] [blame] | 1155 | /* |
| 1156 | * We already confirmed swap under page lock, and make |
| 1157 | * no memory allocation here, so usually no possibility |
| 1158 | * of error; but free_swap_and_cache() only trylocks a |
| 1159 | * page, so it is just possible that the entry has been |
| 1160 | * truncated or holepunched since swap was confirmed. |
| 1161 | * shmem_undo_range() will have done some of the |
| 1162 | * unaccounting, now delete_from_swap_cache() will do |
| 1163 | * the rest (including mem_cgroup_uncharge_swapcache). |
| 1164 | * Reset swap.val? No, leave it so "failed" goes back to |
| 1165 | * "repeat": reading a hole and writing should succeed. |
| 1166 | */ |
| 1167 | if (error) |
| 1168 | delete_from_swap_cache(page); |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1169 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1170 | if (error) |
| 1171 | goto failed; |
| 1172 | |
| 1173 | spin_lock(&info->lock); |
| 1174 | info->swapped--; |
| 1175 | shmem_recalc_inode(inode); |
| 1176 | spin_unlock(&info->lock); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1177 | |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1178 | delete_from_swap_cache(page); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1179 | set_page_dirty(page); |
| 1180 | swap_free(swap); |
| 1181 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1182 | } else { |
| 1183 | if (shmem_acct_block(info->flags)) { |
| 1184 | error = -ENOSPC; |
| 1185 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1186 | } |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1187 | if (sbinfo->max_blocks) { |
Hugh Dickins | fc5da22 | 2011-04-14 15:22:07 -0700 | [diff] [blame] | 1188 | if (percpu_counter_compare(&sbinfo->used_blocks, |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1189 | sbinfo->max_blocks) >= 0) { |
| 1190 | error = -ENOSPC; |
| 1191 | goto unacct; |
| 1192 | } |
Tim Chen | 7e49629 | 2010-08-09 17:19:05 -0700 | [diff] [blame] | 1193 | percpu_counter_inc(&sbinfo->used_blocks); |
Hugh Dickins | 59a16ea | 2011-05-11 15:13:38 -0700 | [diff] [blame] | 1194 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1195 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1196 | page = shmem_alloc_page(gfp, info, index); |
| 1197 | if (!page) { |
| 1198 | error = -ENOMEM; |
| 1199 | goto decused; |
| 1200 | } |
| 1201 | |
| 1202 | SetPageSwapBacked(page); |
| 1203 | __set_page_locked(page); |
Hugh Dickins | aa3b189 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1204 | error = mem_cgroup_cache_charge(page, current->mm, |
| 1205 | gfp & GFP_RECLAIM_MASK); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1206 | if (error) |
| 1207 | goto decused; |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 1208 | error = radix_tree_preload(gfp & GFP_RECLAIM_MASK); |
| 1209 | if (!error) { |
| 1210 | error = shmem_add_to_page_cache(page, mapping, index, |
| 1211 | gfp, NULL); |
| 1212 | radix_tree_preload_end(); |
| 1213 | } |
| 1214 | if (error) { |
| 1215 | mem_cgroup_uncharge_cache_page(page); |
| 1216 | goto decused; |
| 1217 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1218 | lru_cache_add_anon(page); |
| 1219 | |
| 1220 | spin_lock(&info->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1221 | info->alloced++; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1222 | inode->i_blocks += BLOCKS_PER_PAGE; |
| 1223 | shmem_recalc_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | spin_unlock(&info->lock); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1225 | alloced = true; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1226 | |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1227 | /* |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1228 | * Let SGP_FALLOC use the SGP_WRITE optimization on a new page. |
| 1229 | */ |
| 1230 | if (sgp == SGP_FALLOC) |
| 1231 | sgp = SGP_WRITE; |
| 1232 | clear: |
| 1233 | /* |
| 1234 | * Let SGP_WRITE caller clear ends if write does not fill page; |
| 1235 | * but SGP_FALLOC on a page fallocated earlier must initialize |
| 1236 | * it now, lest undo on failure cancel our earlier guarantee. |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1237 | */ |
| 1238 | if (sgp != SGP_WRITE) { |
| 1239 | clear_highpage(page); |
| 1240 | flush_dcache_page(page); |
| 1241 | SetPageUptodate(page); |
| 1242 | } |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1243 | if (sgp == SGP_DIRTY) |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1244 | set_page_dirty(page); |
Hugh Dickins | 59a16ea | 2011-05-11 15:13:38 -0700 | [diff] [blame] | 1245 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1246 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1247 | /* Perhaps the file has been truncated since we checked */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1248 | if (sgp != SGP_WRITE && sgp != SGP_FALLOC && |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1249 | ((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) { |
| 1250 | error = -EINVAL; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1251 | if (alloced) |
| 1252 | goto trunc; |
| 1253 | else |
| 1254 | goto failed; |
Shaohua Li | ff36b801 | 2010-08-09 17:19:06 -0700 | [diff] [blame] | 1255 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1256 | *pagep = page; |
| 1257 | return 0; |
Nick Piggin | d00806b | 2007-07-19 01:46:57 -0700 | [diff] [blame] | 1258 | |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1259 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1260 | * Error recovery. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1261 | */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1262 | trunc: |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1263 | info = SHMEM_I(inode); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1264 | ClearPageDirty(page); |
| 1265 | delete_from_page_cache(page); |
| 1266 | spin_lock(&info->lock); |
| 1267 | info->alloced--; |
| 1268 | inode->i_blocks -= BLOCKS_PER_PAGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1269 | spin_unlock(&info->lock); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1270 | decused: |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1271 | sbinfo = SHMEM_SB(inode->i_sb); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1272 | if (sbinfo->max_blocks) |
| 1273 | percpu_counter_add(&sbinfo->used_blocks, -1); |
| 1274 | unacct: |
| 1275 | shmem_unacct_blocks(info->flags, 1); |
| 1276 | failed: |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1277 | if (swap.val && error != -EINVAL && |
| 1278 | !shmem_confirm_swap(mapping, index, swap)) |
| 1279 | error = -EEXIST; |
| 1280 | unlock: |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1281 | if (page) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1282 | unlock_page(page); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1283 | page_cache_release(page); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1284 | } |
| 1285 | if (error == -ENOSPC && !once++) { |
| 1286 | info = SHMEM_I(inode); |
| 1287 | spin_lock(&info->lock); |
| 1288 | shmem_recalc_inode(inode); |
| 1289 | spin_unlock(&info->lock); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1290 | goto repeat; |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1291 | } |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 1292 | if (error == -EEXIST) /* from above or from radix_tree_insert */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1293 | goto repeat; |
| 1294 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | } |
| 1296 | |
| 1297 | static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 1298 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1299 | struct inode *inode = file_inode(vma->vm_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1300 | int error; |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1301 | int ret = VM_FAULT_LOCKED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1302 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret); |
| 1304 | if (error) |
| 1305 | return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1306 | |
Ying Han | 456f998 | 2011-05-26 16:25:38 -0700 | [diff] [blame] | 1307 | if (ret & VM_FAULT_MAJOR) { |
| 1308 | count_vm_event(PGMAJFAULT); |
| 1309 | mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); |
| 1310 | } |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1311 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1312 | } |
| 1313 | |
| 1314 | #ifdef CONFIG_NUMA |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1315 | 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] | 1316 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1317 | struct inode *inode = file_inode(vma->vm_file); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1318 | return mpol_set_shared_policy(&SHMEM_I(inode)->policy, vma, mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1319 | } |
| 1320 | |
Adrian Bunk | d8dc74f | 2007-10-16 01:26:26 -0700 | [diff] [blame] | 1321 | static struct mempolicy *shmem_get_policy(struct vm_area_struct *vma, |
| 1322 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1323 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1324 | struct inode *inode = file_inode(vma->vm_file); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1325 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1326 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1327 | index = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
| 1328 | return mpol_shared_policy_lookup(&SHMEM_I(inode)->policy, index); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | } |
| 1330 | #endif |
| 1331 | |
| 1332 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 1333 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1334 | struct inode *inode = file_inode(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1335 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 1336 | int retval = -ENOMEM; |
| 1337 | |
| 1338 | spin_lock(&info->lock); |
| 1339 | if (lock && !(info->flags & VM_LOCKED)) { |
| 1340 | if (!user_shm_lock(inode->i_size, user)) |
| 1341 | goto out_nomem; |
| 1342 | info->flags |= VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 1343 | mapping_set_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1344 | } |
| 1345 | if (!lock && (info->flags & VM_LOCKED) && user) { |
| 1346 | user_shm_unlock(inode->i_size, user); |
| 1347 | info->flags &= ~VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 1348 | mapping_clear_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1349 | } |
| 1350 | retval = 0; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 1351 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1352 | out_nomem: |
| 1353 | spin_unlock(&info->lock); |
| 1354 | return retval; |
| 1355 | } |
| 1356 | |
Adrian Bunk | 9b83a6a | 2007-02-28 20:11:03 -0800 | [diff] [blame] | 1357 | static int shmem_mmap(struct file *file, struct vm_area_struct *vma) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1358 | { |
| 1359 | file_accessed(file); |
| 1360 | vma->vm_ops = &shmem_vm_ops; |
| 1361 | return 0; |
| 1362 | } |
| 1363 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 1364 | 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] | 1365 | umode_t mode, dev_t dev, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1366 | { |
| 1367 | struct inode *inode; |
| 1368 | struct shmem_inode_info *info; |
| 1369 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 1370 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1371 | if (shmem_reserve_inode(sb)) |
| 1372 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | |
| 1374 | inode = new_inode(sb); |
| 1375 | if (inode) { |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 1376 | inode->i_ino = get_next_ino(); |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 1377 | inode_init_owner(inode, dir, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1378 | inode->i_blocks = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1379 | inode->i_mapping->backing_dev_info = &shmem_backing_dev_info; |
| 1380 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 1381 | inode->i_generation = get_seconds(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1382 | info = SHMEM_I(inode); |
| 1383 | memset(info, 0, (char *)inode - (char *)info); |
| 1384 | spin_lock_init(&info->lock); |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 1385 | info->flags = flags & VM_NORESERVE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1386 | INIT_LIST_HEAD(&info->swaplist); |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 1387 | simple_xattrs_init(&info->xattrs); |
Al Viro | 72c0490 | 2009-06-24 16:58:48 -0400 | [diff] [blame] | 1388 | cache_no_acl(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1389 | |
| 1390 | switch (mode & S_IFMT) { |
| 1391 | default: |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 1392 | inode->i_op = &shmem_special_inode_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1393 | init_special_inode(inode, mode, dev); |
| 1394 | break; |
| 1395 | case S_IFREG: |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 1396 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1397 | inode->i_op = &shmem_inode_operations; |
| 1398 | inode->i_fop = &shmem_file_operations; |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1399 | mpol_shared_policy_init(&info->policy, |
| 1400 | shmem_get_sbmpol(sbinfo)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1401 | break; |
| 1402 | case S_IFDIR: |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1403 | inc_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1404 | /* Some things misbehave if size == 0 on a directory */ |
| 1405 | inode->i_size = 2 * BOGO_DIRENT_SIZE; |
| 1406 | inode->i_op = &shmem_dir_inode_operations; |
| 1407 | inode->i_fop = &simple_dir_operations; |
| 1408 | break; |
| 1409 | case S_IFLNK: |
| 1410 | /* |
| 1411 | * Must not load anything in the rbtree, |
| 1412 | * mpol_free_shared_policy will not be called. |
| 1413 | */ |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1414 | mpol_shared_policy_init(&info->policy, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1415 | break; |
| 1416 | } |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1417 | } else |
| 1418 | shmem_free_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1419 | return inode; |
| 1420 | } |
| 1421 | |
| 1422 | #ifdef CONFIG_TMPFS |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 1423 | static const struct inode_operations shmem_symlink_inode_operations; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 1424 | static const struct inode_operations shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1425 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 1426 | #ifdef CONFIG_TMPFS_XATTR |
| 1427 | static int shmem_initxattrs(struct inode *, const struct xattr *, void *); |
| 1428 | #else |
| 1429 | #define shmem_initxattrs NULL |
| 1430 | #endif |
| 1431 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1432 | static int |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1433 | shmem_write_begin(struct file *file, struct address_space *mapping, |
| 1434 | loff_t pos, unsigned len, unsigned flags, |
| 1435 | struct page **pagep, void **fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1436 | { |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1437 | struct inode *inode = mapping->host; |
| 1438 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1439 | return shmem_getpage(inode, index, pagep, SGP_WRITE, NULL); |
| 1440 | } |
| 1441 | |
| 1442 | static int |
| 1443 | shmem_write_end(struct file *file, struct address_space *mapping, |
| 1444 | loff_t pos, unsigned len, unsigned copied, |
| 1445 | struct page *page, void *fsdata) |
| 1446 | { |
| 1447 | struct inode *inode = mapping->host; |
| 1448 | |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1449 | if (pos + copied > inode->i_size) |
| 1450 | i_size_write(inode, pos + copied); |
| 1451 | |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1452 | if (!PageUptodate(page)) { |
| 1453 | if (copied < PAGE_CACHE_SIZE) { |
| 1454 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
| 1455 | zero_user_segments(page, 0, from, |
| 1456 | from + copied, PAGE_CACHE_SIZE); |
| 1457 | } |
| 1458 | SetPageUptodate(page); |
| 1459 | } |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1460 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 1461 | unlock_page(page); |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1462 | page_cache_release(page); |
| 1463 | |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1464 | return copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | } |
| 1466 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1467 | static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor) |
| 1468 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1469 | struct inode *inode = file_inode(filp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | struct address_space *mapping = inode->i_mapping; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1471 | pgoff_t index; |
| 1472 | unsigned long offset; |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1473 | enum sgp_type sgp = SGP_READ; |
| 1474 | |
| 1475 | /* |
| 1476 | * Might this read be for a stacking filesystem? Then when reading |
| 1477 | * holes of a sparse file, we actually need to allocate those pages, |
| 1478 | * and even mark them dirty, so it cannot exceed the max_blocks limit. |
| 1479 | */ |
| 1480 | if (segment_eq(get_fs(), KERNEL_DS)) |
| 1481 | sgp = SGP_DIRTY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1482 | |
| 1483 | index = *ppos >> PAGE_CACHE_SHIFT; |
| 1484 | offset = *ppos & ~PAGE_CACHE_MASK; |
| 1485 | |
| 1486 | for (;;) { |
| 1487 | struct page *page = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1488 | pgoff_t end_index; |
| 1489 | unsigned long nr, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1490 | loff_t i_size = i_size_read(inode); |
| 1491 | |
| 1492 | end_index = i_size >> PAGE_CACHE_SHIFT; |
| 1493 | if (index > end_index) |
| 1494 | break; |
| 1495 | if (index == end_index) { |
| 1496 | nr = i_size & ~PAGE_CACHE_MASK; |
| 1497 | if (nr <= offset) |
| 1498 | break; |
| 1499 | } |
| 1500 | |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1501 | desc->error = shmem_getpage(inode, index, &page, sgp, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1502 | if (desc->error) { |
| 1503 | if (desc->error == -EINVAL) |
| 1504 | desc->error = 0; |
| 1505 | break; |
| 1506 | } |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1507 | if (page) |
| 1508 | unlock_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1509 | |
| 1510 | /* |
| 1511 | * We must evaluate after, since reads (unlike writes) |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1512 | * are called without i_mutex protection against truncate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1513 | */ |
| 1514 | nr = PAGE_CACHE_SIZE; |
| 1515 | i_size = i_size_read(inode); |
| 1516 | end_index = i_size >> PAGE_CACHE_SHIFT; |
| 1517 | if (index == end_index) { |
| 1518 | nr = i_size & ~PAGE_CACHE_MASK; |
| 1519 | if (nr <= offset) { |
| 1520 | if (page) |
| 1521 | page_cache_release(page); |
| 1522 | break; |
| 1523 | } |
| 1524 | } |
| 1525 | nr -= offset; |
| 1526 | |
| 1527 | if (page) { |
| 1528 | /* |
| 1529 | * If users can be writing to this page using arbitrary |
| 1530 | * virtual addresses, take care about potential aliasing |
| 1531 | * before reading the page on the kernel side. |
| 1532 | */ |
| 1533 | if (mapping_writably_mapped(mapping)) |
| 1534 | flush_dcache_page(page); |
| 1535 | /* |
| 1536 | * Mark the page accessed if we read the beginning. |
| 1537 | */ |
| 1538 | if (!offset) |
| 1539 | mark_page_accessed(page); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 1540 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1541 | page = ZERO_PAGE(0); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 1542 | page_cache_get(page); |
| 1543 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1544 | |
| 1545 | /* |
| 1546 | * Ok, we have the page, and it's up-to-date, so |
| 1547 | * now we can copy it to user space... |
| 1548 | * |
| 1549 | * The actor routine returns how many bytes were actually used.. |
| 1550 | * NOTE! This may not be the same as how much of a user buffer |
| 1551 | * we filled up (we may be padding etc), so we can only update |
| 1552 | * "pos" here (the actor routine has to update the user buffer |
| 1553 | * pointers and the remaining count). |
| 1554 | */ |
| 1555 | ret = actor(desc, page, offset, nr); |
| 1556 | offset += ret; |
| 1557 | index += offset >> PAGE_CACHE_SHIFT; |
| 1558 | offset &= ~PAGE_CACHE_MASK; |
| 1559 | |
| 1560 | page_cache_release(page); |
| 1561 | if (ret != nr || !desc->count) |
| 1562 | break; |
| 1563 | |
| 1564 | cond_resched(); |
| 1565 | } |
| 1566 | |
| 1567 | *ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset; |
| 1568 | file_accessed(filp); |
| 1569 | } |
| 1570 | |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1571 | static ssize_t shmem_file_aio_read(struct kiocb *iocb, |
| 1572 | const struct iovec *iov, unsigned long nr_segs, loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1573 | { |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1574 | struct file *filp = iocb->ki_filp; |
| 1575 | ssize_t retval; |
| 1576 | unsigned long seg; |
| 1577 | size_t count; |
| 1578 | loff_t *ppos = &iocb->ki_pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1579 | |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1580 | retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); |
| 1581 | if (retval) |
| 1582 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1583 | |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1584 | for (seg = 0; seg < nr_segs; seg++) { |
| 1585 | read_descriptor_t desc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1586 | |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 1587 | desc.written = 0; |
| 1588 | desc.arg.buf = iov[seg].iov_base; |
| 1589 | desc.count = iov[seg].iov_len; |
| 1590 | if (desc.count == 0) |
| 1591 | continue; |
| 1592 | desc.error = 0; |
| 1593 | do_shmem_file_read(filp, ppos, &desc, file_read_actor); |
| 1594 | retval += desc.written; |
| 1595 | if (desc.error) { |
| 1596 | retval = retval ?: desc.error; |
| 1597 | break; |
| 1598 | } |
| 1599 | if (desc.count > 0) |
| 1600 | break; |
| 1601 | } |
| 1602 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1603 | } |
| 1604 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1605 | static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, |
| 1606 | struct pipe_inode_info *pipe, size_t len, |
| 1607 | unsigned int flags) |
| 1608 | { |
| 1609 | struct address_space *mapping = in->f_mapping; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1610 | struct inode *inode = mapping->host; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1611 | unsigned int loff, nr_pages, req_pages; |
| 1612 | struct page *pages[PIPE_DEF_BUFFERS]; |
| 1613 | struct partial_page partial[PIPE_DEF_BUFFERS]; |
| 1614 | struct page *page; |
| 1615 | pgoff_t index, end_index; |
| 1616 | loff_t isize, left; |
| 1617 | int error, page_nr; |
| 1618 | struct splice_pipe_desc spd = { |
| 1619 | .pages = pages, |
| 1620 | .partial = partial, |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 1621 | .nr_pages_max = PIPE_DEF_BUFFERS, |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1622 | .flags = flags, |
| 1623 | .ops = &page_cache_pipe_buf_ops, |
| 1624 | .spd_release = spd_release_page, |
| 1625 | }; |
| 1626 | |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1627 | isize = i_size_read(inode); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1628 | if (unlikely(*ppos >= isize)) |
| 1629 | return 0; |
| 1630 | |
| 1631 | left = isize - *ppos; |
| 1632 | if (unlikely(left < len)) |
| 1633 | len = left; |
| 1634 | |
| 1635 | if (splice_grow_spd(pipe, &spd)) |
| 1636 | return -ENOMEM; |
| 1637 | |
| 1638 | index = *ppos >> PAGE_CACHE_SHIFT; |
| 1639 | loff = *ppos & ~PAGE_CACHE_MASK; |
| 1640 | req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| 1641 | nr_pages = min(req_pages, pipe->buffers); |
| 1642 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1643 | spd.nr_pages = find_get_pages_contig(mapping, index, |
| 1644 | nr_pages, spd.pages); |
| 1645 | index += spd.nr_pages; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1646 | error = 0; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1647 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1648 | while (spd.nr_pages < nr_pages) { |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1649 | error = shmem_getpage(inode, index, &page, SGP_CACHE, NULL); |
| 1650 | if (error) |
| 1651 | break; |
| 1652 | unlock_page(page); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1653 | spd.pages[spd.nr_pages++] = page; |
| 1654 | index++; |
| 1655 | } |
| 1656 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1657 | index = *ppos >> PAGE_CACHE_SHIFT; |
| 1658 | nr_pages = spd.nr_pages; |
| 1659 | spd.nr_pages = 0; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1660 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1661 | for (page_nr = 0; page_nr < nr_pages; page_nr++) { |
| 1662 | unsigned int this_len; |
| 1663 | |
| 1664 | if (!len) |
| 1665 | break; |
| 1666 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1667 | this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff); |
| 1668 | page = spd.pages[page_nr]; |
| 1669 | |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1670 | if (!PageUptodate(page) || page->mapping != mapping) { |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1671 | error = shmem_getpage(inode, index, &page, |
| 1672 | SGP_CACHE, NULL); |
| 1673 | if (error) |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1674 | break; |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1675 | unlock_page(page); |
| 1676 | page_cache_release(spd.pages[page_nr]); |
| 1677 | spd.pages[page_nr] = page; |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1678 | } |
Hugh Dickins | 71f0e07 | 2011-07-25 17:12:33 -0700 | [diff] [blame] | 1679 | |
| 1680 | isize = i_size_read(inode); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1681 | end_index = (isize - 1) >> PAGE_CACHE_SHIFT; |
| 1682 | if (unlikely(!isize || index > end_index)) |
| 1683 | break; |
| 1684 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1685 | if (end_index == index) { |
| 1686 | unsigned int plen; |
| 1687 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1688 | plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1; |
| 1689 | if (plen <= loff) |
| 1690 | break; |
| 1691 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1692 | this_len = min(this_len, plen - loff); |
| 1693 | len = this_len; |
| 1694 | } |
| 1695 | |
| 1696 | spd.partial[page_nr].offset = loff; |
| 1697 | spd.partial[page_nr].len = this_len; |
| 1698 | len -= this_len; |
| 1699 | loff = 0; |
| 1700 | spd.nr_pages++; |
| 1701 | index++; |
| 1702 | } |
| 1703 | |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1704 | while (page_nr < nr_pages) |
| 1705 | page_cache_release(spd.pages[page_nr++]); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1706 | |
| 1707 | if (spd.nr_pages) |
| 1708 | error = splice_to_pipe(pipe, &spd); |
| 1709 | |
Eric Dumazet | 047fe36 | 2012-06-12 15:24:40 +0200 | [diff] [blame] | 1710 | splice_shrink_spd(&spd); |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 1711 | |
| 1712 | if (error > 0) { |
| 1713 | *ppos += error; |
| 1714 | file_accessed(in); |
| 1715 | } |
| 1716 | return error; |
| 1717 | } |
| 1718 | |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1719 | /* |
| 1720 | * llseek SEEK_DATA or SEEK_HOLE through the radix_tree. |
| 1721 | */ |
| 1722 | static pgoff_t shmem_seek_hole_data(struct address_space *mapping, |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1723 | pgoff_t index, pgoff_t end, int whence) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1724 | { |
| 1725 | struct page *page; |
| 1726 | struct pagevec pvec; |
| 1727 | pgoff_t indices[PAGEVEC_SIZE]; |
| 1728 | bool done = false; |
| 1729 | int i; |
| 1730 | |
| 1731 | pagevec_init(&pvec, 0); |
| 1732 | pvec.nr = 1; /* start small: we may be there already */ |
| 1733 | while (!done) { |
| 1734 | pvec.nr = shmem_find_get_pages_and_swap(mapping, index, |
| 1735 | pvec.nr, pvec.pages, indices); |
| 1736 | if (!pvec.nr) { |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1737 | if (whence == SEEK_DATA) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1738 | index = end; |
| 1739 | break; |
| 1740 | } |
| 1741 | for (i = 0; i < pvec.nr; i++, index++) { |
| 1742 | if (index < indices[i]) { |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1743 | if (whence == SEEK_HOLE) { |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1744 | done = true; |
| 1745 | break; |
| 1746 | } |
| 1747 | index = indices[i]; |
| 1748 | } |
| 1749 | page = pvec.pages[i]; |
| 1750 | if (page && !radix_tree_exceptional_entry(page)) { |
| 1751 | if (!PageUptodate(page)) |
| 1752 | page = NULL; |
| 1753 | } |
| 1754 | if (index >= end || |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1755 | (page && whence == SEEK_DATA) || |
| 1756 | (!page && whence == SEEK_HOLE)) { |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1757 | done = true; |
| 1758 | break; |
| 1759 | } |
| 1760 | } |
| 1761 | shmem_deswap_pagevec(&pvec); |
| 1762 | pagevec_release(&pvec); |
| 1763 | pvec.nr = PAGEVEC_SIZE; |
| 1764 | cond_resched(); |
| 1765 | } |
| 1766 | return index; |
| 1767 | } |
| 1768 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1769 | static loff_t shmem_file_llseek(struct file *file, loff_t offset, int whence) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1770 | { |
| 1771 | struct address_space *mapping = file->f_mapping; |
| 1772 | struct inode *inode = mapping->host; |
| 1773 | pgoff_t start, end; |
| 1774 | loff_t new_offset; |
| 1775 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1776 | if (whence != SEEK_DATA && whence != SEEK_HOLE) |
| 1777 | return generic_file_llseek_size(file, offset, whence, |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1778 | MAX_LFS_FILESIZE, i_size_read(inode)); |
| 1779 | mutex_lock(&inode->i_mutex); |
| 1780 | /* We're holding i_mutex so we can access i_size directly */ |
| 1781 | |
| 1782 | if (offset < 0) |
| 1783 | offset = -EINVAL; |
| 1784 | else if (offset >= inode->i_size) |
| 1785 | offset = -ENXIO; |
| 1786 | else { |
| 1787 | start = offset >> PAGE_CACHE_SHIFT; |
| 1788 | end = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1789 | new_offset = shmem_seek_hole_data(mapping, start, end, whence); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1790 | new_offset <<= PAGE_CACHE_SHIFT; |
| 1791 | if (new_offset > offset) { |
| 1792 | if (new_offset < inode->i_size) |
| 1793 | offset = new_offset; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 1794 | else if (whence == SEEK_DATA) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1795 | offset = -ENXIO; |
| 1796 | else |
| 1797 | offset = inode->i_size; |
| 1798 | } |
| 1799 | } |
| 1800 | |
Hugh Dickins | 387aae6 | 2013-08-04 11:30:25 -0700 | [diff] [blame] | 1801 | if (offset >= 0) |
| 1802 | offset = vfs_setpos(file, offset, MAX_LFS_FILESIZE); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 1803 | mutex_unlock(&inode->i_mutex); |
| 1804 | return offset; |
| 1805 | } |
| 1806 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 1807 | static long shmem_fallocate(struct file *file, int mode, loff_t offset, |
| 1808 | loff_t len) |
| 1809 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1810 | struct inode *inode = file_inode(file); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1811 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1812 | struct shmem_falloc shmem_falloc; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1813 | pgoff_t start, index, end; |
| 1814 | int error; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 1815 | |
| 1816 | mutex_lock(&inode->i_mutex); |
| 1817 | |
| 1818 | if (mode & FALLOC_FL_PUNCH_HOLE) { |
| 1819 | struct address_space *mapping = file->f_mapping; |
| 1820 | loff_t unmap_start = round_up(offset, PAGE_SIZE); |
| 1821 | loff_t unmap_end = round_down(offset + len, PAGE_SIZE) - 1; |
| 1822 | |
| 1823 | if ((u64)unmap_end > (u64)unmap_start) |
| 1824 | unmap_mapping_range(mapping, unmap_start, |
| 1825 | 1 + unmap_end - unmap_start, 0); |
| 1826 | shmem_truncate_range(inode, offset, offset + len - 1); |
| 1827 | /* No need to unmap again: hole-punching leaves COWed pages */ |
| 1828 | error = 0; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1829 | goto out; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 1830 | } |
| 1831 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1832 | /* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */ |
| 1833 | error = inode_newsize_ok(inode, offset + len); |
| 1834 | if (error) |
| 1835 | goto out; |
| 1836 | |
| 1837 | start = offset >> PAGE_CACHE_SHIFT; |
| 1838 | end = (offset + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| 1839 | /* Try to avoid a swapstorm if len is impossible to satisfy */ |
| 1840 | if (sbinfo->max_blocks && end - start > sbinfo->max_blocks) { |
| 1841 | error = -ENOSPC; |
| 1842 | goto out; |
| 1843 | } |
| 1844 | |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1845 | shmem_falloc.start = start; |
| 1846 | shmem_falloc.next = start; |
| 1847 | shmem_falloc.nr_falloced = 0; |
| 1848 | shmem_falloc.nr_unswapped = 0; |
| 1849 | spin_lock(&inode->i_lock); |
| 1850 | inode->i_private = &shmem_falloc; |
| 1851 | spin_unlock(&inode->i_lock); |
| 1852 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1853 | for (index = start; index < end; index++) { |
| 1854 | struct page *page; |
| 1855 | |
| 1856 | /* |
| 1857 | * Good, the fallocate(2) manpage permits EINTR: we may have |
| 1858 | * been interrupted because we are using up too much memory. |
| 1859 | */ |
| 1860 | if (signal_pending(current)) |
| 1861 | error = -EINTR; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1862 | else if (shmem_falloc.nr_unswapped > shmem_falloc.nr_falloced) |
| 1863 | error = -ENOMEM; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1864 | else |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1865 | error = shmem_getpage(inode, index, &page, SGP_FALLOC, |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1866 | NULL); |
| 1867 | if (error) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1868 | /* Remove the !PageUptodate pages we added */ |
| 1869 | shmem_undo_range(inode, |
| 1870 | (loff_t)start << PAGE_CACHE_SHIFT, |
| 1871 | (loff_t)index << PAGE_CACHE_SHIFT, true); |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1872 | goto undone; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1873 | } |
| 1874 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1875 | /* |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1876 | * Inform shmem_writepage() how far we have reached. |
| 1877 | * No need for lock or barrier: we have the page lock. |
| 1878 | */ |
| 1879 | shmem_falloc.next++; |
| 1880 | if (!PageUptodate(page)) |
| 1881 | shmem_falloc.nr_falloced++; |
| 1882 | |
| 1883 | /* |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1884 | * If !PageUptodate, leave it that way so that freeable pages |
| 1885 | * can be recognized if we need to rollback on error later. |
| 1886 | * But set_page_dirty so that memory pressure will swap rather |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1887 | * than free the pages we are allocating (and SGP_CACHE pages |
| 1888 | * might still be clean: we now need to mark those dirty too). |
| 1889 | */ |
| 1890 | set_page_dirty(page); |
| 1891 | unlock_page(page); |
| 1892 | page_cache_release(page); |
| 1893 | cond_resched(); |
| 1894 | } |
| 1895 | |
| 1896 | if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) |
| 1897 | i_size_write(inode, offset + len); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1898 | inode->i_ctime = CURRENT_TIME; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1899 | undone: |
| 1900 | spin_lock(&inode->i_lock); |
| 1901 | inode->i_private = NULL; |
| 1902 | spin_unlock(&inode->i_lock); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 1903 | out: |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 1904 | mutex_unlock(&inode->i_mutex); |
| 1905 | return error; |
| 1906 | } |
| 1907 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 1908 | static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1909 | { |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 1910 | struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1911 | |
| 1912 | buf->f_type = TMPFS_MAGIC; |
| 1913 | buf->f_bsize = PAGE_CACHE_SIZE; |
| 1914 | buf->f_namelen = NAME_MAX; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1915 | if (sbinfo->max_blocks) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1916 | buf->f_blocks = sbinfo->max_blocks; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1917 | buf->f_bavail = |
| 1918 | buf->f_bfree = sbinfo->max_blocks - |
| 1919 | percpu_counter_sum(&sbinfo->used_blocks); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1920 | } |
| 1921 | if (sbinfo->max_inodes) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1922 | buf->f_files = sbinfo->max_inodes; |
| 1923 | buf->f_ffree = sbinfo->free_inodes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1924 | } |
| 1925 | /* else leave those fields 0 like simple_statfs */ |
| 1926 | return 0; |
| 1927 | } |
| 1928 | |
| 1929 | /* |
| 1930 | * File creation. Allocate an inode, and we're done.. |
| 1931 | */ |
| 1932 | static int |
Al Viro | 1a67aaf | 2011-07-26 01:52:52 -0400 | [diff] [blame] | 1933 | 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] | 1934 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 1935 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1936 | int error = -ENOSPC; |
| 1937 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 1938 | inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1939 | if (inode) { |
Mimi Zohar | 37ec43c | 2013-04-14 09:21:47 -0400 | [diff] [blame] | 1940 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 1941 | error = generic_acl_init(inode, dir); |
| 1942 | if (error) { |
| 1943 | iput(inode); |
| 1944 | return error; |
| 1945 | } |
| 1946 | #endif |
Eric Paris | 2a7dba3 | 2011-02-01 11:05:39 -0500 | [diff] [blame] | 1947 | error = security_inode_init_security(inode, dir, |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 1948 | &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 1949 | shmem_initxattrs, NULL); |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 1950 | if (error) { |
| 1951 | if (error != -EOPNOTSUPP) { |
| 1952 | iput(inode); |
| 1953 | return error; |
| 1954 | } |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 1955 | } |
Mimi Zohar | 37ec43c | 2013-04-14 09:21:47 -0400 | [diff] [blame] | 1956 | |
Al Viro | 718deb6 | 2009-12-16 19:35:36 -0500 | [diff] [blame] | 1957 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1958 | dir->i_size += BOGO_DIRENT_SIZE; |
| 1959 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| 1960 | d_instantiate(dentry, inode); |
| 1961 | dget(dentry); /* Extra count - pin the dentry in core */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1962 | } |
| 1963 | return error; |
| 1964 | } |
| 1965 | |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 1966 | static int |
| 1967 | shmem_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) |
| 1968 | { |
| 1969 | struct inode *inode; |
| 1970 | int error = -ENOSPC; |
| 1971 | |
| 1972 | inode = shmem_get_inode(dir->i_sb, dir, mode, 0, VM_NORESERVE); |
| 1973 | if (inode) { |
| 1974 | error = security_inode_init_security(inode, dir, |
| 1975 | NULL, |
| 1976 | shmem_initxattrs, NULL); |
| 1977 | if (error) { |
| 1978 | if (error != -EOPNOTSUPP) { |
| 1979 | iput(inode); |
| 1980 | return error; |
| 1981 | } |
| 1982 | } |
| 1983 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 1984 | error = generic_acl_init(inode, dir); |
| 1985 | if (error) { |
| 1986 | iput(inode); |
| 1987 | return error; |
| 1988 | } |
| 1989 | #else |
| 1990 | error = 0; |
| 1991 | #endif |
| 1992 | d_tmpfile(dentry, inode); |
| 1993 | } |
| 1994 | return error; |
| 1995 | } |
| 1996 | |
Al Viro | 18bb1db | 2011-07-26 01:41:39 -0400 | [diff] [blame] | 1997 | 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] | 1998 | { |
| 1999 | int error; |
| 2000 | |
| 2001 | if ((error = shmem_mknod(dir, dentry, mode | S_IFDIR, 0))) |
| 2002 | return error; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 2003 | inc_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2004 | return 0; |
| 2005 | } |
| 2006 | |
Al Viro | 4acdaf2 | 2011-07-26 01:42:34 -0400 | [diff] [blame] | 2007 | static int shmem_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
Al Viro | ebfc3b4 | 2012-06-10 18:05:36 -0400 | [diff] [blame] | 2008 | bool excl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2009 | { |
| 2010 | return shmem_mknod(dir, dentry, mode | S_IFREG, 0); |
| 2011 | } |
| 2012 | |
| 2013 | /* |
| 2014 | * Link a file.. |
| 2015 | */ |
| 2016 | static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
| 2017 | { |
| 2018 | struct inode *inode = old_dentry->d_inode; |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2019 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2020 | |
| 2021 | /* |
| 2022 | * No ordinary (disk based) filesystem counts links as inodes; |
| 2023 | * but each new link needs a new dentry, pinning lowmem, and |
| 2024 | * tmpfs dentries cannot be pruned until they are unlinked. |
| 2025 | */ |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2026 | ret = shmem_reserve_inode(inode->i_sb); |
| 2027 | if (ret) |
| 2028 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2029 | |
| 2030 | dir->i_size += BOGO_DIRENT_SIZE; |
| 2031 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 2032 | inc_nlink(inode); |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 2033 | ihold(inode); /* New dentry reference */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2034 | dget(dentry); /* Extra pinning count for the created dentry */ |
| 2035 | d_instantiate(dentry, inode); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2036 | out: |
| 2037 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2038 | } |
| 2039 | |
| 2040 | static int shmem_unlink(struct inode *dir, struct dentry *dentry) |
| 2041 | { |
| 2042 | struct inode *inode = dentry->d_inode; |
| 2043 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2044 | if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) |
| 2045 | shmem_free_inode(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2046 | |
| 2047 | dir->i_size -= BOGO_DIRENT_SIZE; |
| 2048 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 2049 | drop_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2050 | dput(dentry); /* Undo the count from "create" - this does all the work */ |
| 2051 | return 0; |
| 2052 | } |
| 2053 | |
| 2054 | static int shmem_rmdir(struct inode *dir, struct dentry *dentry) |
| 2055 | { |
| 2056 | if (!simple_empty(dentry)) |
| 2057 | return -ENOTEMPTY; |
| 2058 | |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 2059 | drop_nlink(dentry->d_inode); |
| 2060 | drop_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2061 | return shmem_unlink(dir, dentry); |
| 2062 | } |
| 2063 | |
| 2064 | /* |
| 2065 | * The VFS layer already does all the dentry stuff for rename, |
| 2066 | * we just have to decrement the usage count for the target if |
| 2067 | * it exists so that the VFS layer correctly free's it when it |
| 2068 | * gets overwritten. |
| 2069 | */ |
| 2070 | static int shmem_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) |
| 2071 | { |
| 2072 | struct inode *inode = old_dentry->d_inode; |
| 2073 | int they_are_dirs = S_ISDIR(inode->i_mode); |
| 2074 | |
| 2075 | if (!simple_empty(new_dentry)) |
| 2076 | return -ENOTEMPTY; |
| 2077 | |
| 2078 | if (new_dentry->d_inode) { |
| 2079 | (void) shmem_unlink(new_dir, new_dentry); |
| 2080 | if (they_are_dirs) |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 2081 | drop_nlink(old_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2082 | } else if (they_are_dirs) { |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 2083 | drop_nlink(old_dir); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 2084 | inc_nlink(new_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2085 | } |
| 2086 | |
| 2087 | old_dir->i_size -= BOGO_DIRENT_SIZE; |
| 2088 | new_dir->i_size += BOGO_DIRENT_SIZE; |
| 2089 | old_dir->i_ctime = old_dir->i_mtime = |
| 2090 | new_dir->i_ctime = new_dir->i_mtime = |
| 2091 | inode->i_ctime = CURRENT_TIME; |
| 2092 | return 0; |
| 2093 | } |
| 2094 | |
| 2095 | static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *symname) |
| 2096 | { |
| 2097 | int error; |
| 2098 | int len; |
| 2099 | struct inode *inode; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 2100 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2101 | char *kaddr; |
| 2102 | struct shmem_inode_info *info; |
| 2103 | |
| 2104 | len = strlen(symname) + 1; |
| 2105 | if (len > PAGE_CACHE_SIZE) |
| 2106 | return -ENAMETOOLONG; |
| 2107 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2108 | 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] | 2109 | if (!inode) |
| 2110 | return -ENOSPC; |
| 2111 | |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 2112 | error = security_inode_init_security(inode, dir, &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2113 | shmem_initxattrs, NULL); |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 2114 | if (error) { |
| 2115 | if (error != -EOPNOTSUPP) { |
| 2116 | iput(inode); |
| 2117 | return error; |
| 2118 | } |
| 2119 | error = 0; |
| 2120 | } |
| 2121 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2122 | info = SHMEM_I(inode); |
| 2123 | inode->i_size = len-1; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2124 | if (len <= SHORT_SYMLINK_LEN) { |
| 2125 | info->symlink = kmemdup(symname, len, GFP_KERNEL); |
| 2126 | if (!info->symlink) { |
| 2127 | iput(inode); |
| 2128 | return -ENOMEM; |
| 2129 | } |
| 2130 | inode->i_op = &shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2131 | } else { |
| 2132 | error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL); |
| 2133 | if (error) { |
| 2134 | iput(inode); |
| 2135 | return error; |
| 2136 | } |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 2137 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2138 | inode->i_op = &shmem_symlink_inode_operations; |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 2139 | kaddr = kmap_atomic(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2140 | memcpy(kaddr, symname, len); |
Cong Wang | 9b04c5f | 2011-11-25 23:14:39 +0800 | [diff] [blame] | 2141 | kunmap_atomic(kaddr); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2142 | SetPageUptodate(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2143 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 2144 | unlock_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2145 | page_cache_release(page); |
| 2146 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2147 | dir->i_size += BOGO_DIRENT_SIZE; |
| 2148 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| 2149 | d_instantiate(dentry, inode); |
| 2150 | dget(dentry); |
| 2151 | return 0; |
| 2152 | } |
| 2153 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2154 | static void *shmem_follow_short_symlink(struct dentry *dentry, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2155 | { |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2156 | nd_set_link(nd, SHMEM_I(dentry->d_inode)->symlink); |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2157 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2158 | } |
| 2159 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2160 | static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2161 | { |
| 2162 | struct page *page = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2163 | int error = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL); |
| 2164 | nd_set_link(nd, error ? ERR_PTR(error) : kmap(page)); |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2165 | if (page) |
| 2166 | unlock_page(page); |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2167 | return page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2168 | } |
| 2169 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2170 | 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] | 2171 | { |
| 2172 | if (!IS_ERR(nd_get_link(nd))) { |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2173 | struct page *page = cookie; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2174 | kunmap(page); |
| 2175 | mark_page_accessed(page); |
| 2176 | page_cache_release(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2177 | } |
| 2178 | } |
| 2179 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2180 | #ifdef CONFIG_TMPFS_XATTR |
| 2181 | /* |
| 2182 | * Superblocks without xattr inode operations may get some security.* xattr |
| 2183 | * support from the LSM "for free". As soon as we have any other xattrs |
| 2184 | * like ACLs, we also need to implement the security.* handlers at |
| 2185 | * filesystem level, though. |
| 2186 | */ |
| 2187 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2188 | /* |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2189 | * Callback for security_inode_init_security() for acquiring xattrs. |
| 2190 | */ |
| 2191 | static int shmem_initxattrs(struct inode *inode, |
| 2192 | const struct xattr *xattr_array, |
| 2193 | void *fs_info) |
| 2194 | { |
| 2195 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 2196 | const struct xattr *xattr; |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2197 | struct simple_xattr *new_xattr; |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2198 | size_t len; |
| 2199 | |
| 2200 | for (xattr = xattr_array; xattr->name != NULL; xattr++) { |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2201 | new_xattr = simple_xattr_alloc(xattr->value, xattr->value_len); |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2202 | if (!new_xattr) |
| 2203 | return -ENOMEM; |
| 2204 | |
| 2205 | len = strlen(xattr->name) + 1; |
| 2206 | new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len, |
| 2207 | GFP_KERNEL); |
| 2208 | if (!new_xattr->name) { |
| 2209 | kfree(new_xattr); |
| 2210 | return -ENOMEM; |
| 2211 | } |
| 2212 | |
| 2213 | memcpy(new_xattr->name, XATTR_SECURITY_PREFIX, |
| 2214 | XATTR_SECURITY_PREFIX_LEN); |
| 2215 | memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN, |
| 2216 | xattr->name, len); |
| 2217 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2218 | simple_xattr_list_add(&info->xattrs, new_xattr); |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2219 | } |
| 2220 | |
| 2221 | return 0; |
| 2222 | } |
| 2223 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2224 | static const struct xattr_handler *shmem_xattr_handlers[] = { |
| 2225 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 2226 | &generic_acl_access_handler, |
| 2227 | &generic_acl_default_handler, |
| 2228 | #endif |
| 2229 | NULL |
| 2230 | }; |
| 2231 | |
| 2232 | static int shmem_xattr_validate(const char *name) |
| 2233 | { |
| 2234 | struct { const char *prefix; size_t len; } arr[] = { |
| 2235 | { XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN }, |
| 2236 | { XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN } |
| 2237 | }; |
| 2238 | int i; |
| 2239 | |
| 2240 | for (i = 0; i < ARRAY_SIZE(arr); i++) { |
| 2241 | size_t preflen = arr[i].len; |
| 2242 | if (strncmp(name, arr[i].prefix, preflen) == 0) { |
| 2243 | if (!name[preflen]) |
| 2244 | return -EINVAL; |
| 2245 | return 0; |
| 2246 | } |
| 2247 | } |
| 2248 | return -EOPNOTSUPP; |
| 2249 | } |
| 2250 | |
| 2251 | static ssize_t shmem_getxattr(struct dentry *dentry, const char *name, |
| 2252 | void *buffer, size_t size) |
| 2253 | { |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2254 | struct shmem_inode_info *info = SHMEM_I(dentry->d_inode); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2255 | int err; |
| 2256 | |
| 2257 | /* |
| 2258 | * If this is a request for a synthetic attribute in the system.* |
| 2259 | * namespace use the generic infrastructure to resolve a handler |
| 2260 | * for it via sb->s_xattr. |
| 2261 | */ |
| 2262 | if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) |
| 2263 | return generic_getxattr(dentry, name, buffer, size); |
| 2264 | |
| 2265 | err = shmem_xattr_validate(name); |
| 2266 | if (err) |
| 2267 | return err; |
| 2268 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2269 | return simple_xattr_get(&info->xattrs, name, buffer, size); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2270 | } |
| 2271 | |
| 2272 | static int shmem_setxattr(struct dentry *dentry, const char *name, |
| 2273 | const void *value, size_t size, int flags) |
| 2274 | { |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2275 | struct shmem_inode_info *info = SHMEM_I(dentry->d_inode); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2276 | int err; |
| 2277 | |
| 2278 | /* |
| 2279 | * If this is a request for a synthetic attribute in the system.* |
| 2280 | * namespace use the generic infrastructure to resolve a handler |
| 2281 | * for it via sb->s_xattr. |
| 2282 | */ |
| 2283 | if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) |
| 2284 | return generic_setxattr(dentry, name, value, size, flags); |
| 2285 | |
| 2286 | err = shmem_xattr_validate(name); |
| 2287 | if (err) |
| 2288 | return err; |
| 2289 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2290 | return simple_xattr_set(&info->xattrs, name, value, size, flags); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2291 | } |
| 2292 | |
| 2293 | static int shmem_removexattr(struct dentry *dentry, const char *name) |
| 2294 | { |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2295 | struct shmem_inode_info *info = SHMEM_I(dentry->d_inode); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2296 | int err; |
| 2297 | |
| 2298 | /* |
| 2299 | * If this is a request for a synthetic attribute in the system.* |
| 2300 | * namespace use the generic infrastructure to resolve a handler |
| 2301 | * for it via sb->s_xattr. |
| 2302 | */ |
| 2303 | if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) |
| 2304 | return generic_removexattr(dentry, name); |
| 2305 | |
| 2306 | err = shmem_xattr_validate(name); |
| 2307 | if (err) |
| 2308 | return err; |
| 2309 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2310 | return simple_xattr_remove(&info->xattrs, name); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2311 | } |
| 2312 | |
| 2313 | static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size) |
| 2314 | { |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2315 | struct shmem_inode_info *info = SHMEM_I(dentry->d_inode); |
| 2316 | return simple_xattr_list(&info->xattrs, buffer, size); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2317 | } |
| 2318 | #endif /* CONFIG_TMPFS_XATTR */ |
| 2319 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2320 | static const struct inode_operations shmem_short_symlink_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2321 | .readlink = generic_readlink, |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2322 | .follow_link = shmem_follow_short_symlink, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2323 | #ifdef CONFIG_TMPFS_XATTR |
| 2324 | .setxattr = shmem_setxattr, |
| 2325 | .getxattr = shmem_getxattr, |
| 2326 | .listxattr = shmem_listxattr, |
| 2327 | .removexattr = shmem_removexattr, |
| 2328 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2329 | }; |
| 2330 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2331 | static const struct inode_operations shmem_symlink_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2332 | .readlink = generic_readlink, |
| 2333 | .follow_link = shmem_follow_link, |
| 2334 | .put_link = shmem_put_link, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2335 | #ifdef CONFIG_TMPFS_XATTR |
| 2336 | .setxattr = shmem_setxattr, |
| 2337 | .getxattr = shmem_getxattr, |
| 2338 | .listxattr = shmem_listxattr, |
| 2339 | .removexattr = shmem_removexattr, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2340 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2341 | }; |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2342 | |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2343 | static struct dentry *shmem_get_parent(struct dentry *child) |
| 2344 | { |
| 2345 | return ERR_PTR(-ESTALE); |
| 2346 | } |
| 2347 | |
| 2348 | static int shmem_match(struct inode *ino, void *vfh) |
| 2349 | { |
| 2350 | __u32 *fh = vfh; |
| 2351 | __u64 inum = fh[2]; |
| 2352 | inum = (inum << 32) | fh[1]; |
| 2353 | return ino->i_ino == inum && fh[0] == ino->i_generation; |
| 2354 | } |
| 2355 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2356 | static struct dentry *shmem_fh_to_dentry(struct super_block *sb, |
| 2357 | struct fid *fid, int fh_len, int fh_type) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2358 | { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2359 | struct inode *inode; |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2360 | struct dentry *dentry = NULL; |
Hugh Dickins | 35c2a7f | 2012-10-07 20:32:51 -0700 | [diff] [blame] | 2361 | u64 inum; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2362 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2363 | if (fh_len < 3) |
| 2364 | return NULL; |
| 2365 | |
Hugh Dickins | 35c2a7f | 2012-10-07 20:32:51 -0700 | [diff] [blame] | 2366 | inum = fid->raw[2]; |
| 2367 | inum = (inum << 32) | fid->raw[1]; |
| 2368 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2369 | inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), |
| 2370 | shmem_match, fid->raw); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2371 | if (inode) { |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2372 | dentry = d_find_alias(inode); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2373 | iput(inode); |
| 2374 | } |
| 2375 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2376 | return dentry; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2377 | } |
| 2378 | |
Al Viro | b0b0382 | 2012-04-02 14:34:06 -0400 | [diff] [blame] | 2379 | static int shmem_encode_fh(struct inode *inode, __u32 *fh, int *len, |
| 2380 | struct inode *parent) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2381 | { |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 2382 | if (*len < 3) { |
| 2383 | *len = 3; |
Namjae Jeon | 94e07a75 | 2013-02-17 15:48:11 +0900 | [diff] [blame] | 2384 | return FILEID_INVALID; |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 2385 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2386 | |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 2387 | if (inode_unhashed(inode)) { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2388 | /* Unfortunately insert_inode_hash is not idempotent, |
| 2389 | * so as we hash inodes here rather than at creation |
| 2390 | * time, we need a lock to ensure we only try |
| 2391 | * to do it once |
| 2392 | */ |
| 2393 | static DEFINE_SPINLOCK(lock); |
| 2394 | spin_lock(&lock); |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 2395 | if (inode_unhashed(inode)) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2396 | __insert_inode_hash(inode, |
| 2397 | inode->i_ino + inode->i_generation); |
| 2398 | spin_unlock(&lock); |
| 2399 | } |
| 2400 | |
| 2401 | fh[0] = inode->i_generation; |
| 2402 | fh[1] = inode->i_ino; |
| 2403 | fh[2] = ((__u64)inode->i_ino) >> 32; |
| 2404 | |
| 2405 | *len = 3; |
| 2406 | return 1; |
| 2407 | } |
| 2408 | |
Christoph Hellwig | 3965516 | 2007-10-21 16:42:17 -0700 | [diff] [blame] | 2409 | static const struct export_operations shmem_export_ops = { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2410 | .get_parent = shmem_get_parent, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2411 | .encode_fh = shmem_encode_fh, |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2412 | .fh_to_dentry = shmem_fh_to_dentry, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2413 | }; |
| 2414 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2415 | static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo, |
| 2416 | bool remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2417 | { |
| 2418 | char *this_char, *value, *rest; |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2419 | struct mempolicy *mpol = NULL; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2420 | uid_t uid; |
| 2421 | gid_t gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2422 | |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 2423 | while (options != NULL) { |
| 2424 | this_char = options; |
| 2425 | for (;;) { |
| 2426 | /* |
| 2427 | * NUL-terminate this option: unfortunately, |
| 2428 | * mount options form a comma-separated list, |
| 2429 | * but mpol's nodelist may also contain commas. |
| 2430 | */ |
| 2431 | options = strchr(options, ','); |
| 2432 | if (options == NULL) |
| 2433 | break; |
| 2434 | options++; |
| 2435 | if (!isdigit(*options)) { |
| 2436 | options[-1] = '\0'; |
| 2437 | break; |
| 2438 | } |
| 2439 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2440 | if (!*this_char) |
| 2441 | continue; |
| 2442 | if ((value = strchr(this_char,'=')) != NULL) { |
| 2443 | *value++ = 0; |
| 2444 | } else { |
| 2445 | printk(KERN_ERR |
| 2446 | "tmpfs: No value for mount option '%s'\n", |
| 2447 | this_char); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2448 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2449 | } |
| 2450 | |
| 2451 | if (!strcmp(this_char,"size")) { |
| 2452 | unsigned long long size; |
| 2453 | size = memparse(value,&rest); |
| 2454 | if (*rest == '%') { |
| 2455 | size <<= PAGE_SHIFT; |
| 2456 | size *= totalram_pages; |
| 2457 | do_div(size, 100); |
| 2458 | rest++; |
| 2459 | } |
| 2460 | if (*rest) |
| 2461 | goto bad_val; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2462 | sbinfo->max_blocks = |
| 2463 | DIV_ROUND_UP(size, PAGE_CACHE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2464 | } else if (!strcmp(this_char,"nr_blocks")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2465 | sbinfo->max_blocks = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2466 | if (*rest) |
| 2467 | goto bad_val; |
| 2468 | } else if (!strcmp(this_char,"nr_inodes")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2469 | sbinfo->max_inodes = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2470 | if (*rest) |
| 2471 | goto bad_val; |
| 2472 | } else if (!strcmp(this_char,"mode")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2473 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2474 | continue; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2475 | sbinfo->mode = simple_strtoul(value, &rest, 8) & 07777; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2476 | if (*rest) |
| 2477 | goto bad_val; |
| 2478 | } else if (!strcmp(this_char,"uid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2479 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2480 | continue; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2481 | uid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2482 | if (*rest) |
| 2483 | goto bad_val; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2484 | sbinfo->uid = make_kuid(current_user_ns(), uid); |
| 2485 | if (!uid_valid(sbinfo->uid)) |
| 2486 | goto bad_val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2487 | } else if (!strcmp(this_char,"gid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2488 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2489 | continue; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2490 | gid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2491 | if (*rest) |
| 2492 | goto bad_val; |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2493 | sbinfo->gid = make_kgid(current_user_ns(), gid); |
| 2494 | if (!gid_valid(sbinfo->gid)) |
| 2495 | goto bad_val; |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 2496 | } else if (!strcmp(this_char,"mpol")) { |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2497 | mpol_put(mpol); |
| 2498 | mpol = NULL; |
| 2499 | if (mpol_parse_str(value, &mpol)) |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 2500 | goto bad_val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2501 | } else { |
| 2502 | printk(KERN_ERR "tmpfs: Bad mount option %s\n", |
| 2503 | this_char); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2504 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2505 | } |
| 2506 | } |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2507 | sbinfo->mpol = mpol; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2508 | return 0; |
| 2509 | |
| 2510 | bad_val: |
| 2511 | printk(KERN_ERR "tmpfs: Bad value '%s' for mount option '%s'\n", |
| 2512 | value, this_char); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2513 | error: |
| 2514 | mpol_put(mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2515 | return 1; |
| 2516 | |
| 2517 | } |
| 2518 | |
| 2519 | static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) |
| 2520 | { |
| 2521 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2522 | struct shmem_sb_info config = *sbinfo; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2523 | unsigned long inodes; |
| 2524 | int error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2525 | |
Greg Thelen | 5f00110 | 2013-02-22 16:36:01 -0800 | [diff] [blame] | 2526 | config.mpol = NULL; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2527 | if (shmem_parse_options(data, &config, true)) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2528 | return error; |
| 2529 | |
| 2530 | spin_lock(&sbinfo->stat_lock); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2531 | inodes = sbinfo->max_inodes - sbinfo->free_inodes; |
Tim Chen | 7e49629 | 2010-08-09 17:19:05 -0700 | [diff] [blame] | 2532 | if (percpu_counter_compare(&sbinfo->used_blocks, config.max_blocks) > 0) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2533 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2534 | if (config.max_inodes < inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2535 | goto out; |
| 2536 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 2537 | * Those tests disallow limited->unlimited while any are in use; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2538 | * but we must separately disallow unlimited->limited, because |
| 2539 | * in that case we have no record of how much is already in use. |
| 2540 | */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2541 | if (config.max_blocks && !sbinfo->max_blocks) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2542 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2543 | if (config.max_inodes && !sbinfo->max_inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2544 | goto out; |
| 2545 | |
| 2546 | error = 0; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2547 | sbinfo->max_blocks = config.max_blocks; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2548 | sbinfo->max_inodes = config.max_inodes; |
| 2549 | sbinfo->free_inodes = config.max_inodes - inodes; |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2550 | |
Greg Thelen | 5f00110 | 2013-02-22 16:36:01 -0800 | [diff] [blame] | 2551 | /* |
| 2552 | * Preserve previous mempolicy unless mpol remount option was specified. |
| 2553 | */ |
| 2554 | if (config.mpol) { |
| 2555 | mpol_put(sbinfo->mpol); |
| 2556 | sbinfo->mpol = config.mpol; /* transfers initial ref */ |
| 2557 | } |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2558 | out: |
| 2559 | spin_unlock(&sbinfo->stat_lock); |
| 2560 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2561 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2562 | |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 2563 | 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] | 2564 | { |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 2565 | struct shmem_sb_info *sbinfo = SHMEM_SB(root->d_sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2566 | |
| 2567 | if (sbinfo->max_blocks != shmem_default_max_blocks()) |
| 2568 | seq_printf(seq, ",size=%luk", |
| 2569 | sbinfo->max_blocks << (PAGE_CACHE_SHIFT - 10)); |
| 2570 | if (sbinfo->max_inodes != shmem_default_max_inodes()) |
| 2571 | seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes); |
| 2572 | if (sbinfo->mode != (S_IRWXUGO | S_ISVTX)) |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 2573 | seq_printf(seq, ",mode=%03ho", sbinfo->mode); |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 2574 | if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID)) |
| 2575 | seq_printf(seq, ",uid=%u", |
| 2576 | from_kuid_munged(&init_user_ns, sbinfo->uid)); |
| 2577 | if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID)) |
| 2578 | seq_printf(seq, ",gid=%u", |
| 2579 | from_kgid_munged(&init_user_ns, sbinfo->gid)); |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2580 | shmem_show_mpol(seq, sbinfo->mpol); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2581 | return 0; |
| 2582 | } |
| 2583 | #endif /* CONFIG_TMPFS */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2584 | |
| 2585 | static void shmem_put_super(struct super_block *sb) |
| 2586 | { |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 2587 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 2588 | |
| 2589 | percpu_counter_destroy(&sbinfo->used_blocks); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 2590 | mpol_put(sbinfo->mpol); |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 2591 | kfree(sbinfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2592 | sb->s_fs_info = NULL; |
| 2593 | } |
| 2594 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 2595 | int shmem_fill_super(struct super_block *sb, void *data, int silent) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2596 | { |
| 2597 | struct inode *inode; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2598 | struct shmem_sb_info *sbinfo; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2599 | int err = -ENOMEM; |
| 2600 | |
| 2601 | /* Round up to L1_CACHE_BYTES to resist false sharing */ |
Pekka Enberg | 425fbf0 | 2009-09-21 17:03:50 -0700 | [diff] [blame] | 2602 | sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info), |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2603 | L1_CACHE_BYTES), GFP_KERNEL); |
| 2604 | if (!sbinfo) |
| 2605 | return -ENOMEM; |
| 2606 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2607 | sbinfo->mode = S_IRWXUGO | S_ISVTX; |
David Howells | 76aac0e | 2008-11-14 10:39:12 +1100 | [diff] [blame] | 2608 | sbinfo->uid = current_fsuid(); |
| 2609 | sbinfo->gid = current_fsgid(); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2610 | sb->s_fs_info = sbinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2611 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2612 | #ifdef CONFIG_TMPFS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2613 | /* |
| 2614 | * Per default we only allow half of the physical ram per |
| 2615 | * tmpfs instance, limiting inodes to one per page of lowmem; |
| 2616 | * but the internal instance is left unlimited. |
| 2617 | */ |
| 2618 | if (!(sb->s_flags & MS_NOUSER)) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2619 | sbinfo->max_blocks = shmem_default_max_blocks(); |
| 2620 | sbinfo->max_inodes = shmem_default_max_inodes(); |
| 2621 | if (shmem_parse_options(data, sbinfo, false)) { |
| 2622 | err = -EINVAL; |
| 2623 | goto failed; |
| 2624 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2625 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2626 | sb->s_export_op = &shmem_export_ops; |
Hugh Dickins | 2f6e38f | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 2627 | sb->s_flags |= MS_NOSEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2628 | #else |
| 2629 | sb->s_flags |= MS_NOUSER; |
| 2630 | #endif |
| 2631 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2632 | spin_lock_init(&sbinfo->stat_lock); |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 2633 | if (percpu_counter_init(&sbinfo->used_blocks, 0)) |
| 2634 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2635 | sbinfo->free_inodes = sbinfo->max_inodes; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2636 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 2637 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2638 | sb->s_blocksize = PAGE_CACHE_SIZE; |
| 2639 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 2640 | sb->s_magic = TMPFS_MAGIC; |
| 2641 | sb->s_op = &shmem_ops; |
Robin H. Johnson | cfd95a9 | 2006-06-12 21:50:25 +0100 | [diff] [blame] | 2642 | sb->s_time_gran = 1; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2643 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2644 | sb->s_xattr = shmem_xattr_handlers; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2645 | #endif |
| 2646 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2647 | sb->s_flags |= MS_POSIXACL; |
| 2648 | #endif |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2649 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2650 | 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] | 2651 | if (!inode) |
| 2652 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2653 | inode->i_uid = sbinfo->uid; |
| 2654 | inode->i_gid = sbinfo->gid; |
Al Viro | 318ceed | 2012-02-12 22:08:01 -0500 | [diff] [blame] | 2655 | sb->s_root = d_make_root(inode); |
| 2656 | if (!sb->s_root) |
Al Viro | 48fde70 | 2012-01-08 22:15:13 -0500 | [diff] [blame] | 2657 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2658 | return 0; |
| 2659 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2660 | failed: |
| 2661 | shmem_put_super(sb); |
| 2662 | return err; |
| 2663 | } |
| 2664 | |
Pekka Enberg | fcc234f | 2006-03-22 00:08:13 -0800 | [diff] [blame] | 2665 | static struct kmem_cache *shmem_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2666 | |
| 2667 | static struct inode *shmem_alloc_inode(struct super_block *sb) |
| 2668 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2669 | struct shmem_inode_info *info; |
| 2670 | info = kmem_cache_alloc(shmem_inode_cachep, GFP_KERNEL); |
| 2671 | if (!info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2672 | return NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2673 | return &info->vfs_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2674 | } |
| 2675 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2676 | static void shmem_destroy_callback(struct rcu_head *head) |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 2677 | { |
| 2678 | struct inode *inode = container_of(head, struct inode, i_rcu); |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 2679 | kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode)); |
| 2680 | } |
| 2681 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2682 | static void shmem_destroy_inode(struct inode *inode) |
| 2683 | { |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 2684 | if (S_ISREG(inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2685 | mpol_free_shared_policy(&SHMEM_I(inode)->policy); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2686 | call_rcu(&inode->i_rcu, shmem_destroy_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2687 | } |
| 2688 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2689 | static void shmem_init_inode(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2690 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2691 | struct shmem_inode_info *info = foo; |
| 2692 | inode_init_once(&info->vfs_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2693 | } |
| 2694 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2695 | static int shmem_init_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2696 | { |
| 2697 | shmem_inode_cachep = kmem_cache_create("shmem_inode_cache", |
| 2698 | sizeof(struct shmem_inode_info), |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2699 | 0, SLAB_PANIC, shmem_init_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2700 | return 0; |
| 2701 | } |
| 2702 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2703 | static void shmem_destroy_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2704 | { |
Alexey Dobriyan | 1a1d92c | 2006-09-27 01:49:40 -0700 | [diff] [blame] | 2705 | kmem_cache_destroy(shmem_inode_cachep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2706 | } |
| 2707 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 2708 | static const struct address_space_operations shmem_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2709 | .writepage = shmem_writepage, |
Ken Chen | 7671932 | 2007-02-10 01:43:15 -0800 | [diff] [blame] | 2710 | .set_page_dirty = __set_page_dirty_no_writeback, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2711 | #ifdef CONFIG_TMPFS |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2712 | .write_begin = shmem_write_begin, |
| 2713 | .write_end = shmem_write_end, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2714 | #endif |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 2715 | .migratepage = migrate_page, |
Andi Kleen | aa261f5 | 2009-09-16 11:50:16 +0200 | [diff] [blame] | 2716 | .error_remove_page = generic_error_remove_page, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2717 | }; |
| 2718 | |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 2719 | static const struct file_operations shmem_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2720 | .mmap = shmem_mmap, |
| 2721 | #ifdef CONFIG_TMPFS |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2722 | .llseek = shmem_file_llseek, |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 2723 | .read = do_sync_read, |
Hugh Dickins | 5402b97 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2724 | .write = do_sync_write, |
Hugh Dickins | bcd78e4 | 2008-07-23 21:27:35 -0700 | [diff] [blame] | 2725 | .aio_read = shmem_file_aio_read, |
Hugh Dickins | 5402b97 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2726 | .aio_write = generic_file_aio_write, |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 2727 | .fsync = noop_fsync, |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 2728 | .splice_read = shmem_file_splice_read, |
Hugh Dickins | ae976416 | 2007-06-04 10:00:39 +0200 | [diff] [blame] | 2729 | .splice_write = generic_file_splice_write, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2730 | .fallocate = shmem_fallocate, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2731 | #endif |
| 2732 | }; |
| 2733 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2734 | static const struct inode_operations shmem_inode_operations = { |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 2735 | .setattr = shmem_setattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2736 | #ifdef CONFIG_TMPFS_XATTR |
| 2737 | .setxattr = shmem_setxattr, |
| 2738 | .getxattr = shmem_getxattr, |
| 2739 | .listxattr = shmem_listxattr, |
| 2740 | .removexattr = shmem_removexattr, |
| 2741 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2742 | }; |
| 2743 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2744 | static const struct inode_operations shmem_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2745 | #ifdef CONFIG_TMPFS |
| 2746 | .create = shmem_create, |
| 2747 | .lookup = simple_lookup, |
| 2748 | .link = shmem_link, |
| 2749 | .unlink = shmem_unlink, |
| 2750 | .symlink = shmem_symlink, |
| 2751 | .mkdir = shmem_mkdir, |
| 2752 | .rmdir = shmem_rmdir, |
| 2753 | .mknod = shmem_mknod, |
| 2754 | .rename = shmem_rename, |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 2755 | .tmpfile = shmem_tmpfile, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2756 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2757 | #ifdef CONFIG_TMPFS_XATTR |
| 2758 | .setxattr = shmem_setxattr, |
| 2759 | .getxattr = shmem_getxattr, |
| 2760 | .listxattr = shmem_listxattr, |
| 2761 | .removexattr = shmem_removexattr, |
| 2762 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2763 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 2764 | .setattr = shmem_setattr, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2765 | #endif |
| 2766 | }; |
| 2767 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2768 | static const struct inode_operations shmem_special_inode_operations = { |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 2769 | #ifdef CONFIG_TMPFS_XATTR |
| 2770 | .setxattr = shmem_setxattr, |
| 2771 | .getxattr = shmem_getxattr, |
| 2772 | .listxattr = shmem_listxattr, |
| 2773 | .removexattr = shmem_removexattr, |
| 2774 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2775 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 2776 | .setattr = shmem_setattr, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2777 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2778 | }; |
| 2779 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 2780 | static const struct super_operations shmem_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2781 | .alloc_inode = shmem_alloc_inode, |
| 2782 | .destroy_inode = shmem_destroy_inode, |
| 2783 | #ifdef CONFIG_TMPFS |
| 2784 | .statfs = shmem_statfs, |
| 2785 | .remount_fs = shmem_remount_fs, |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 2786 | .show_options = shmem_show_options, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2787 | #endif |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 2788 | .evict_inode = shmem_evict_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2789 | .drop_inode = generic_delete_inode, |
| 2790 | .put_super = shmem_put_super, |
| 2791 | }; |
| 2792 | |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 2793 | static const struct vm_operations_struct shmem_vm_ops = { |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 2794 | .fault = shmem_fault, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2795 | #ifdef CONFIG_NUMA |
| 2796 | .set_policy = shmem_set_policy, |
| 2797 | .get_policy = shmem_get_policy, |
| 2798 | #endif |
Konstantin Khlebnikov | 0b173bc | 2012-10-08 16:28:46 -0700 | [diff] [blame] | 2799 | .remap_pages = generic_file_remap_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2800 | }; |
| 2801 | |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 2802 | static struct dentry *shmem_mount(struct file_system_type *fs_type, |
| 2803 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2804 | { |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 2805 | return mount_nodev(fs_type, flags, data, shmem_fill_super); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2806 | } |
| 2807 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2808 | static struct file_system_type shmem_fs_type = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2809 | .owner = THIS_MODULE, |
| 2810 | .name = "tmpfs", |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 2811 | .mount = shmem_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2812 | .kill_sb = kill_litter_super, |
Eric W. Biederman | 2b8576c | 2013-01-25 16:32:10 -0800 | [diff] [blame] | 2813 | .fs_flags = FS_USERNS_MOUNT, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2814 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2815 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2816 | int __init shmem_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2817 | { |
| 2818 | int error; |
| 2819 | |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 2820 | error = bdi_init(&shmem_backing_dev_info); |
| 2821 | if (error) |
| 2822 | goto out4; |
| 2823 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2824 | error = shmem_init_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2825 | if (error) |
| 2826 | goto out3; |
| 2827 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2828 | error = register_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2829 | if (error) { |
| 2830 | printk(KERN_ERR "Could not register tmpfs\n"); |
| 2831 | goto out2; |
| 2832 | } |
Greg Kroah-Hartman | 95dc112 | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 2833 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2834 | shm_mnt = vfs_kern_mount(&shmem_fs_type, MS_NOUSER, |
| 2835 | shmem_fs_type.name, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2836 | if (IS_ERR(shm_mnt)) { |
| 2837 | error = PTR_ERR(shm_mnt); |
| 2838 | printk(KERN_ERR "Could not kern_mount tmpfs\n"); |
| 2839 | goto out1; |
| 2840 | } |
| 2841 | return 0; |
| 2842 | |
| 2843 | out1: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2844 | unregister_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2845 | out2: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2846 | shmem_destroy_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2847 | out3: |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 2848 | bdi_destroy(&shmem_backing_dev_info); |
| 2849 | out4: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2850 | shm_mnt = ERR_PTR(error); |
| 2851 | return error; |
| 2852 | } |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2853 | |
| 2854 | #else /* !CONFIG_SHMEM */ |
| 2855 | |
| 2856 | /* |
| 2857 | * tiny-shmem: simple shmemfs and tmpfs using ramfs code |
| 2858 | * |
| 2859 | * This is intended for small system where the benefits of the full |
| 2860 | * shmem code (swap-backed and resource-limited) are outweighed by |
| 2861 | * their complexity. On systems without swap this code should be |
| 2862 | * effectively equivalent, but much lighter weight. |
| 2863 | */ |
| 2864 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2865 | static struct file_system_type shmem_fs_type = { |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2866 | .name = "tmpfs", |
Al Viro | 3c26ff6 | 2010-07-25 11:46:36 +0400 | [diff] [blame] | 2867 | .mount = ramfs_mount, |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2868 | .kill_sb = kill_litter_super, |
Eric W. Biederman | 2b8576c | 2013-01-25 16:32:10 -0800 | [diff] [blame] | 2869 | .fs_flags = FS_USERNS_MOUNT, |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2870 | }; |
| 2871 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2872 | int __init shmem_init(void) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2873 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2874 | BUG_ON(register_filesystem(&shmem_fs_type) != 0); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2875 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2876 | shm_mnt = kern_mount(&shmem_fs_type); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2877 | BUG_ON(IS_ERR(shm_mnt)); |
| 2878 | |
| 2879 | return 0; |
| 2880 | } |
| 2881 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2882 | int shmem_unuse(swp_entry_t swap, struct page *page) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2883 | { |
| 2884 | return 0; |
| 2885 | } |
| 2886 | |
Hugh Dickins | 3f96b79 | 2009-09-21 17:03:37 -0700 | [diff] [blame] | 2887 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 2888 | { |
| 2889 | return 0; |
| 2890 | } |
| 2891 | |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 2892 | void shmem_unlock_mapping(struct address_space *mapping) |
| 2893 | { |
| 2894 | } |
| 2895 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2896 | 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] | 2897 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2898 | truncate_inode_pages_range(inode->i_mapping, lstart, lend); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 2899 | } |
| 2900 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
| 2901 | |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 2902 | #define shmem_vm_ops generic_file_vm_ops |
| 2903 | #define shmem_file_operations ramfs_file_operations |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2904 | #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] | 2905 | #define shmem_acct_size(flags, size) 0 |
| 2906 | #define shmem_unacct_size(flags, size) do {} while (0) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 2907 | |
| 2908 | #endif /* CONFIG_SHMEM */ |
| 2909 | |
| 2910 | /* common code */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2911 | |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 2912 | static struct dentry_operations anon_ops = { |
Al Viro | 118b230 | 2013-08-24 12:08:17 -0400 | [diff] [blame^] | 2913 | .d_dname = simple_dname |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 2914 | }; |
| 2915 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 2916 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2917 | * shmem_file_setup - get an unlinked file living in tmpfs |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2918 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 2919 | * @size: size to be set for the file |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 2920 | * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2921 | */ |
Sergei Trofimovich | 168f5ac | 2009-06-16 15:33:02 -0700 | [diff] [blame] | 2922 | 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] | 2923 | { |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 2924 | struct file *res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2925 | struct inode *inode; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2926 | struct path path; |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 2927 | struct super_block *sb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2928 | struct qstr this; |
| 2929 | |
| 2930 | if (IS_ERR(shm_mnt)) |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 2931 | return ERR_CAST(shm_mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2932 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 2933 | if (size < 0 || size > MAX_LFS_FILESIZE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2934 | return ERR_PTR(-EINVAL); |
| 2935 | |
| 2936 | if (shmem_acct_size(flags, size)) |
| 2937 | return ERR_PTR(-ENOMEM); |
| 2938 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 2939 | res = ERR_PTR(-ENOMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2940 | this.name = name; |
| 2941 | this.len = strlen(name); |
| 2942 | this.hash = 0; /* will go */ |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 2943 | sb = shm_mnt->mnt_sb; |
| 2944 | path.dentry = d_alloc_pseudo(sb, &this); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2945 | if (!path.dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2946 | goto put_memory; |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 2947 | d_set_d_op(path.dentry, &anon_ops); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2948 | path.mnt = mntget(shm_mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2949 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 2950 | res = ERR_PTR(-ENOSPC); |
Al Viro | 3451538 | 2013-02-14 22:38:02 -0500 | [diff] [blame] | 2951 | inode = shmem_get_inode(sb, NULL, S_IFREG | S_IRWXUGO, 0, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2952 | if (!inode) |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 2953 | goto put_dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2954 | |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2955 | d_instantiate(path.dentry, inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2956 | inode->i_size = size; |
Miklos Szeredi | 6d6b77f | 2011-10-28 14:13:28 +0200 | [diff] [blame] | 2957 | clear_nlink(inode); /* It is unlinked */ |
Al Viro | 26567cd | 2013-03-01 20:22:53 -0500 | [diff] [blame] | 2958 | res = ERR_PTR(ramfs_nommu_expand_for_mapping(inode, size)); |
| 2959 | if (IS_ERR(res)) |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 2960 | goto put_dentry; |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 2961 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 2962 | res = alloc_file(&path, FMODE_WRITE | FMODE_READ, |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 2963 | &shmem_file_operations); |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 2964 | if (IS_ERR(res)) |
Al Viro | 4b42af8 | 2009-08-05 18:25:56 +0400 | [diff] [blame] | 2965 | goto put_dentry; |
| 2966 | |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 2967 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2968 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2969 | put_dentry: |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 2970 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2971 | put_memory: |
| 2972 | shmem_unacct_size(flags, size); |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 2973 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2974 | } |
Keith Packard | 395e0dd | 2008-06-20 00:08:06 -0700 | [diff] [blame] | 2975 | EXPORT_SYMBOL_GPL(shmem_file_setup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2976 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 2977 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2978 | * shmem_zero_setup - setup a shared anonymous mapping |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2979 | * @vma: the vma to be mmapped is prepared by do_mmap_pgoff |
| 2980 | */ |
| 2981 | int shmem_zero_setup(struct vm_area_struct *vma) |
| 2982 | { |
| 2983 | struct file *file; |
| 2984 | loff_t size = vma->vm_end - vma->vm_start; |
| 2985 | |
| 2986 | file = shmem_file_setup("dev/zero", size, vma->vm_flags); |
| 2987 | if (IS_ERR(file)) |
| 2988 | return PTR_ERR(file); |
| 2989 | |
| 2990 | if (vma->vm_file) |
| 2991 | fput(vma->vm_file); |
| 2992 | vma->vm_file = file; |
| 2993 | vma->vm_ops = &shmem_vm_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2994 | return 0; |
| 2995 | } |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 2996 | |
| 2997 | /** |
| 2998 | * shmem_read_mapping_page_gfp - read into page cache, using specified page allocation flags. |
| 2999 | * @mapping: the page's address_space |
| 3000 | * @index: the page index |
| 3001 | * @gfp: the page allocator flags to use if allocating |
| 3002 | * |
| 3003 | * This behaves as a tmpfs "read_cache_page_gfp(mapping, index, gfp)", |
| 3004 | * with any new page allocations done using the specified allocation flags. |
| 3005 | * But read_cache_page_gfp() uses the ->readpage() method: which does not |
| 3006 | * suit tmpfs, since it may have pages in swapcache, and needs to find those |
| 3007 | * for itself; although drivers/gpu/drm i915 and ttm rely upon this support. |
| 3008 | * |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3009 | * i915_gem_object_get_pages_gtt() mixes __GFP_NORETRY | __GFP_NOWARN in |
| 3010 | * with the mapping_gfp_mask(), to avoid OOMing the machine unnecessarily. |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3011 | */ |
| 3012 | struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, |
| 3013 | pgoff_t index, gfp_t gfp) |
| 3014 | { |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3015 | #ifdef CONFIG_SHMEM |
| 3016 | struct inode *inode = mapping->host; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3017 | struct page *page; |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3018 | int error; |
| 3019 | |
| 3020 | BUG_ON(mapping->a_ops != &shmem_aops); |
| 3021 | error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE, gfp, NULL); |
| 3022 | if (error) |
| 3023 | page = ERR_PTR(error); |
| 3024 | else |
| 3025 | unlock_page(page); |
| 3026 | return page; |
| 3027 | #else |
| 3028 | /* |
| 3029 | * The tiny !SHMEM case uses ramfs without swap |
| 3030 | */ |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3031 | return read_cache_page_gfp(mapping, index, gfp); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3032 | #endif |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 3033 | } |
| 3034 | EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); |