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 | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 9 | * Copyright (C) 2002-2005 Hugh Dickins. |
| 10 | * Copyright (C) 2002-2005 VERITAS Software Corporation. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | * Copyright (C) 2004 Andi Kleen, SuSE Labs |
| 12 | * |
| 13 | * Extended attribute support for tmpfs: |
| 14 | * Copyright (c) 2004, Luke Kenneth Casson Leighton <lkcl@lkcl.net> |
| 15 | * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> |
| 16 | * |
| 17 | * This file is released under the GPL. |
| 18 | */ |
| 19 | |
| 20 | /* |
| 21 | * This virtual memory filesystem is heavily based on the ramfs. It |
| 22 | * extends ramfs by the ability to use swap and honor resource limits |
| 23 | * which makes it a completely usable filesystem. |
| 24 | */ |
| 25 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <linux/module.h> |
| 27 | #include <linux/init.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | #include <linux/fs.h> |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 29 | #include <linux/xattr.h> |
Christoph Hellwig | a569425 | 2007-07-17 04:04:28 -0700 | [diff] [blame] | 30 | #include <linux/exportfs.h> |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 31 | #include <linux/generic_acl.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <linux/mm.h> |
| 33 | #include <linux/mman.h> |
| 34 | #include <linux/file.h> |
| 35 | #include <linux/swap.h> |
| 36 | #include <linux/pagemap.h> |
| 37 | #include <linux/string.h> |
| 38 | #include <linux/slab.h> |
| 39 | #include <linux/backing-dev.h> |
| 40 | #include <linux/shmem_fs.h> |
| 41 | #include <linux/mount.h> |
| 42 | #include <linux/writeback.h> |
| 43 | #include <linux/vfs.h> |
| 44 | #include <linux/blkdev.h> |
| 45 | #include <linux/security.h> |
| 46 | #include <linux/swapops.h> |
| 47 | #include <linux/mempolicy.h> |
| 48 | #include <linux/namei.h> |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 49 | #include <linux/ctype.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 50 | #include <linux/migrate.h> |
Christoph Lameter | c1f60a5 | 2006-09-25 23:31:11 -0700 | [diff] [blame] | 51 | #include <linux/highmem.h> |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 52 | #include <linux/seq_file.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 53 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | #include <asm/uaccess.h> |
| 55 | #include <asm/div64.h> |
| 56 | #include <asm/pgtable.h> |
| 57 | |
| 58 | /* This magic number is used in glibc for posix shared memory */ |
| 59 | #define TMPFS_MAGIC 0x01021994 |
| 60 | |
| 61 | #define ENTRIES_PER_PAGE (PAGE_CACHE_SIZE/sizeof(unsigned long)) |
| 62 | #define ENTRIES_PER_PAGEPAGE (ENTRIES_PER_PAGE*ENTRIES_PER_PAGE) |
| 63 | #define BLOCKS_PER_PAGE (PAGE_CACHE_SIZE/512) |
| 64 | |
| 65 | #define SHMEM_MAX_INDEX (SHMEM_NR_DIRECT + (ENTRIES_PER_PAGEPAGE/2) * (ENTRIES_PER_PAGE+1)) |
| 66 | #define SHMEM_MAX_BYTES ((unsigned long long)SHMEM_MAX_INDEX << PAGE_CACHE_SHIFT) |
| 67 | |
| 68 | #define VM_ACCT(size) (PAGE_CACHE_ALIGN(size) >> PAGE_SHIFT) |
| 69 | |
| 70 | /* info->flags needs VM_flags to handle pagein/truncate races efficiently */ |
| 71 | #define SHMEM_PAGEIN VM_READ |
| 72 | #define SHMEM_TRUNCATE VM_WRITE |
| 73 | |
| 74 | /* Definition to limit shmem_truncate's steps between cond_rescheds */ |
| 75 | #define LATENCY_LIMIT 64 |
| 76 | |
| 77 | /* Pretend that each entry is of this size in directory's i_size */ |
| 78 | #define BOGO_DIRENT_SIZE 20 |
| 79 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | /* Flag allocation requirements to shmem_getpage and shmem_swp_alloc */ |
| 81 | enum sgp_type { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | SGP_READ, /* don't exceed i_size, don't allocate page */ |
| 83 | SGP_CACHE, /* don't exceed i_size, may allocate page */ |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 84 | SGP_DIRTY, /* like SGP_CACHE, but set new page dirty */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | SGP_WRITE, /* may exceed i_size, may allocate page */ |
| 86 | }; |
| 87 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 88 | static unsigned long shmem_default_max_blocks(void) |
| 89 | { |
| 90 | return totalram_pages / 2; |
| 91 | } |
| 92 | |
| 93 | static unsigned long shmem_default_max_inodes(void) |
| 94 | { |
| 95 | return min(totalram_pages - totalhigh_pages, totalram_pages / 2); |
| 96 | } |
| 97 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | static int shmem_getpage(struct inode *inode, unsigned long idx, |
| 99 | struct page **pagep, enum sgp_type sgp, int *type); |
| 100 | |
Al Viro | 6daa0e2 | 2005-10-21 03:18:50 -0400 | [diff] [blame] | 101 | static inline struct page *shmem_dir_alloc(gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | { |
| 103 | /* |
| 104 | * The above definition of ENTRIES_PER_PAGE, and the use of |
| 105 | * BLOCKS_PER_PAGE on indirect pages, assume PAGE_CACHE_SIZE: |
| 106 | * might be reconsidered if it ever diverges from PAGE_SIZE. |
Mel Gorman | 769848c | 2007-07-17 04:03:05 -0700 | [diff] [blame] | 107 | * |
Mel Gorman | e12ba74 | 2007-10-16 01:25:52 -0700 | [diff] [blame] | 108 | * Mobility flags are masked out as swap vectors cannot move |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | */ |
Mel Gorman | e12ba74 | 2007-10-16 01:25:52 -0700 | [diff] [blame] | 110 | return alloc_pages((gfp_mask & ~GFP_MOVABLE_MASK) | __GFP_ZERO, |
Mel Gorman | 769848c | 2007-07-17 04:03:05 -0700 | [diff] [blame] | 111 | PAGE_CACHE_SHIFT-PAGE_SHIFT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | } |
| 113 | |
| 114 | static inline void shmem_dir_free(struct page *page) |
| 115 | { |
| 116 | __free_pages(page, PAGE_CACHE_SHIFT-PAGE_SHIFT); |
| 117 | } |
| 118 | |
| 119 | static struct page **shmem_dir_map(struct page *page) |
| 120 | { |
| 121 | return (struct page **)kmap_atomic(page, KM_USER0); |
| 122 | } |
| 123 | |
| 124 | static inline void shmem_dir_unmap(struct page **dir) |
| 125 | { |
| 126 | kunmap_atomic(dir, KM_USER0); |
| 127 | } |
| 128 | |
| 129 | static swp_entry_t *shmem_swp_map(struct page *page) |
| 130 | { |
| 131 | return (swp_entry_t *)kmap_atomic(page, KM_USER1); |
| 132 | } |
| 133 | |
| 134 | static inline void shmem_swp_balance_unmap(void) |
| 135 | { |
| 136 | /* |
| 137 | * When passing a pointer to an i_direct entry, to code which |
| 138 | * also handles indirect entries and so will shmem_swp_unmap, |
| 139 | * we must arrange for the preempt count to remain in balance. |
| 140 | * What kmap_atomic of a lowmem page does depends on config |
| 141 | * and architecture, so pretend to kmap_atomic some lowmem page. |
| 142 | */ |
| 143 | (void) kmap_atomic(ZERO_PAGE(0), KM_USER1); |
| 144 | } |
| 145 | |
| 146 | static inline void shmem_swp_unmap(swp_entry_t *entry) |
| 147 | { |
| 148 | kunmap_atomic(entry, KM_USER1); |
| 149 | } |
| 150 | |
| 151 | static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb) |
| 152 | { |
| 153 | return sb->s_fs_info; |
| 154 | } |
| 155 | |
| 156 | /* |
| 157 | * shmem_file_setup pre-accounts the whole fixed size of a VM object, |
| 158 | * for shared memory and for shared anonymous (/dev/zero) mappings |
| 159 | * (unless MAP_NORESERVE and sysctl_overcommit_memory <= 1), |
| 160 | * consistent with the pre-accounting of private mappings ... |
| 161 | */ |
| 162 | static inline int shmem_acct_size(unsigned long flags, loff_t size) |
| 163 | { |
| 164 | return (flags & VM_ACCOUNT)? |
| 165 | security_vm_enough_memory(VM_ACCT(size)): 0; |
| 166 | } |
| 167 | |
| 168 | static inline void shmem_unacct_size(unsigned long flags, loff_t size) |
| 169 | { |
| 170 | if (flags & VM_ACCOUNT) |
| 171 | vm_unacct_memory(VM_ACCT(size)); |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * ... whereas tmpfs objects are accounted incrementally as |
| 176 | * pages are allocated, in order to allow huge sparse files. |
| 177 | * shmem_getpage reports shmem_acct_block failure as -ENOSPC not -ENOMEM, |
| 178 | * so that a failure on a sparse tmpfs mapping will give SIGBUS not OOM. |
| 179 | */ |
| 180 | static inline int shmem_acct_block(unsigned long flags) |
| 181 | { |
| 182 | return (flags & VM_ACCOUNT)? |
| 183 | 0: security_vm_enough_memory(VM_ACCT(PAGE_CACHE_SIZE)); |
| 184 | } |
| 185 | |
| 186 | static inline void shmem_unacct_blocks(unsigned long flags, long pages) |
| 187 | { |
| 188 | if (!(flags & VM_ACCOUNT)) |
| 189 | vm_unacct_memory(pages * VM_ACCT(PAGE_CACHE_SIZE)); |
| 190 | } |
| 191 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 192 | static const struct super_operations shmem_ops; |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 193 | static const struct address_space_operations shmem_aops; |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 194 | static const struct file_operations shmem_file_operations; |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 195 | static const struct inode_operations shmem_inode_operations; |
| 196 | static const struct inode_operations shmem_dir_inode_operations; |
| 197 | static const struct inode_operations shmem_special_inode_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | static struct vm_operations_struct shmem_vm_ops; |
| 199 | |
Ravikiran G Thirumalai | 6c231b7 | 2005-09-06 15:17:45 -0700 | [diff] [blame] | 200 | static struct backing_dev_info shmem_backing_dev_info __read_mostly = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | .ra_pages = 0, /* No readahead */ |
| 202 | .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, |
| 203 | .unplug_io_fn = default_unplug_io_fn, |
| 204 | }; |
| 205 | |
| 206 | static LIST_HEAD(shmem_swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 207 | static DEFINE_MUTEX(shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | |
| 209 | static void shmem_free_blocks(struct inode *inode, long pages) |
| 210 | { |
| 211 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 212 | if (sbinfo->max_blocks) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | spin_lock(&sbinfo->stat_lock); |
| 214 | sbinfo->free_blocks += pages; |
| 215 | inode->i_blocks -= pages*BLOCKS_PER_PAGE; |
| 216 | spin_unlock(&sbinfo->stat_lock); |
| 217 | } |
| 218 | } |
| 219 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 220 | static int shmem_reserve_inode(struct super_block *sb) |
| 221 | { |
| 222 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 223 | if (sbinfo->max_inodes) { |
| 224 | spin_lock(&sbinfo->stat_lock); |
| 225 | if (!sbinfo->free_inodes) { |
| 226 | spin_unlock(&sbinfo->stat_lock); |
| 227 | return -ENOSPC; |
| 228 | } |
| 229 | sbinfo->free_inodes--; |
| 230 | spin_unlock(&sbinfo->stat_lock); |
| 231 | } |
| 232 | return 0; |
| 233 | } |
| 234 | |
| 235 | static void shmem_free_inode(struct super_block *sb) |
| 236 | { |
| 237 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 238 | if (sbinfo->max_inodes) { |
| 239 | spin_lock(&sbinfo->stat_lock); |
| 240 | sbinfo->free_inodes++; |
| 241 | spin_unlock(&sbinfo->stat_lock); |
| 242 | } |
| 243 | } |
| 244 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | /* |
| 246 | * shmem_recalc_inode - recalculate the size of an inode |
| 247 | * |
| 248 | * @inode: inode to recalc |
| 249 | * |
| 250 | * We have to calculate the free blocks since the mm can drop |
| 251 | * undirtied hole pages behind our back. |
| 252 | * |
| 253 | * But normally info->alloced == inode->i_mapping->nrpages + info->swapped |
| 254 | * So mm freed is info->alloced - (inode->i_mapping->nrpages + info->swapped) |
| 255 | * |
| 256 | * It has to be called with the spinlock held. |
| 257 | */ |
| 258 | static void shmem_recalc_inode(struct inode *inode) |
| 259 | { |
| 260 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 261 | long freed; |
| 262 | |
| 263 | freed = info->alloced - info->swapped - inode->i_mapping->nrpages; |
| 264 | if (freed > 0) { |
| 265 | info->alloced -= freed; |
| 266 | shmem_unacct_blocks(info->flags, freed); |
| 267 | shmem_free_blocks(inode, freed); |
| 268 | } |
| 269 | } |
| 270 | |
| 271 | /* |
| 272 | * shmem_swp_entry - find the swap vector position in the info structure |
| 273 | * |
| 274 | * @info: info structure for the inode |
| 275 | * @index: index of the page to find |
| 276 | * @page: optional page to add to the structure. Has to be preset to |
| 277 | * all zeros |
| 278 | * |
| 279 | * If there is no space allocated yet it will return NULL when |
| 280 | * page is NULL, else it will use the page for the needed block, |
| 281 | * setting it to NULL on return to indicate that it has been used. |
| 282 | * |
| 283 | * The swap vector is organized the following way: |
| 284 | * |
| 285 | * There are SHMEM_NR_DIRECT entries directly stored in the |
| 286 | * shmem_inode_info structure. So small files do not need an addional |
| 287 | * allocation. |
| 288 | * |
| 289 | * For pages with index > SHMEM_NR_DIRECT there is the pointer |
| 290 | * i_indirect which points to a page which holds in the first half |
| 291 | * doubly indirect blocks, in the second half triple indirect blocks: |
| 292 | * |
| 293 | * For an artificial ENTRIES_PER_PAGE = 4 this would lead to the |
| 294 | * following layout (for SHMEM_NR_DIRECT == 16): |
| 295 | * |
| 296 | * i_indirect -> dir --> 16-19 |
| 297 | * | +-> 20-23 |
| 298 | * | |
| 299 | * +-->dir2 --> 24-27 |
| 300 | * | +-> 28-31 |
| 301 | * | +-> 32-35 |
| 302 | * | +-> 36-39 |
| 303 | * | |
| 304 | * +-->dir3 --> 40-43 |
| 305 | * +-> 44-47 |
| 306 | * +-> 48-51 |
| 307 | * +-> 52-55 |
| 308 | */ |
| 309 | static swp_entry_t *shmem_swp_entry(struct shmem_inode_info *info, unsigned long index, struct page **page) |
| 310 | { |
| 311 | unsigned long offset; |
| 312 | struct page **dir; |
| 313 | struct page *subdir; |
| 314 | |
| 315 | if (index < SHMEM_NR_DIRECT) { |
| 316 | shmem_swp_balance_unmap(); |
| 317 | return info->i_direct+index; |
| 318 | } |
| 319 | if (!info->i_indirect) { |
| 320 | if (page) { |
| 321 | info->i_indirect = *page; |
| 322 | *page = NULL; |
| 323 | } |
| 324 | return NULL; /* need another page */ |
| 325 | } |
| 326 | |
| 327 | index -= SHMEM_NR_DIRECT; |
| 328 | offset = index % ENTRIES_PER_PAGE; |
| 329 | index /= ENTRIES_PER_PAGE; |
| 330 | dir = shmem_dir_map(info->i_indirect); |
| 331 | |
| 332 | if (index >= ENTRIES_PER_PAGE/2) { |
| 333 | index -= ENTRIES_PER_PAGE/2; |
| 334 | dir += ENTRIES_PER_PAGE/2 + index/ENTRIES_PER_PAGE; |
| 335 | index %= ENTRIES_PER_PAGE; |
| 336 | subdir = *dir; |
| 337 | if (!subdir) { |
| 338 | if (page) { |
| 339 | *dir = *page; |
| 340 | *page = NULL; |
| 341 | } |
| 342 | shmem_dir_unmap(dir); |
| 343 | return NULL; /* need another page */ |
| 344 | } |
| 345 | shmem_dir_unmap(dir); |
| 346 | dir = shmem_dir_map(subdir); |
| 347 | } |
| 348 | |
| 349 | dir += index; |
| 350 | subdir = *dir; |
| 351 | if (!subdir) { |
| 352 | if (!page || !(subdir = *page)) { |
| 353 | shmem_dir_unmap(dir); |
| 354 | return NULL; /* need a page */ |
| 355 | } |
| 356 | *dir = subdir; |
| 357 | *page = NULL; |
| 358 | } |
| 359 | shmem_dir_unmap(dir); |
| 360 | return shmem_swp_map(subdir) + offset; |
| 361 | } |
| 362 | |
| 363 | static void shmem_swp_set(struct shmem_inode_info *info, swp_entry_t *entry, unsigned long value) |
| 364 | { |
| 365 | long incdec = value? 1: -1; |
| 366 | |
| 367 | entry->val = value; |
| 368 | info->swapped += incdec; |
Hugh Dickins | 4c21e2f | 2005-10-29 18:16:40 -0700 | [diff] [blame] | 369 | if ((unsigned long)(entry - info->i_direct) >= SHMEM_NR_DIRECT) { |
| 370 | struct page *page = kmap_atomic_to_page(entry); |
| 371 | set_page_private(page, page_private(page) + incdec); |
| 372 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | } |
| 374 | |
| 375 | /* |
| 376 | * shmem_swp_alloc - get the position of the swap entry for the page. |
| 377 | * If it does not exist allocate the entry. |
| 378 | * |
| 379 | * @info: info structure for the inode |
| 380 | * @index: index of the page to find |
| 381 | * @sgp: check and recheck i_size? skip allocation? |
| 382 | */ |
| 383 | static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long index, enum sgp_type sgp) |
| 384 | { |
| 385 | struct inode *inode = &info->vfs_inode; |
| 386 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 387 | struct page *page = NULL; |
| 388 | swp_entry_t *entry; |
| 389 | |
| 390 | if (sgp != SGP_WRITE && |
| 391 | ((loff_t) index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) |
| 392 | return ERR_PTR(-EINVAL); |
| 393 | |
| 394 | while (!(entry = shmem_swp_entry(info, index, &page))) { |
| 395 | if (sgp == SGP_READ) |
| 396 | return shmem_swp_map(ZERO_PAGE(0)); |
| 397 | /* |
| 398 | * Test free_blocks against 1 not 0, since we have 1 data |
| 399 | * page (and perhaps indirect index pages) yet to allocate: |
| 400 | * a waste to allocate index if we cannot allocate data. |
| 401 | */ |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 402 | if (sbinfo->max_blocks) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | spin_lock(&sbinfo->stat_lock); |
| 404 | if (sbinfo->free_blocks <= 1) { |
| 405 | spin_unlock(&sbinfo->stat_lock); |
| 406 | return ERR_PTR(-ENOSPC); |
| 407 | } |
| 408 | sbinfo->free_blocks--; |
| 409 | inode->i_blocks += BLOCKS_PER_PAGE; |
| 410 | spin_unlock(&sbinfo->stat_lock); |
| 411 | } |
| 412 | |
| 413 | spin_unlock(&info->lock); |
Mel Gorman | 769848c | 2007-07-17 04:03:05 -0700 | [diff] [blame] | 414 | page = shmem_dir_alloc(mapping_gfp_mask(inode->i_mapping)); |
Hugh Dickins | 4c21e2f | 2005-10-29 18:16:40 -0700 | [diff] [blame] | 415 | if (page) |
| 416 | set_page_private(page, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | spin_lock(&info->lock); |
| 418 | |
| 419 | if (!page) { |
| 420 | shmem_free_blocks(inode, 1); |
| 421 | return ERR_PTR(-ENOMEM); |
| 422 | } |
| 423 | if (sgp != SGP_WRITE && |
| 424 | ((loff_t) index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) { |
| 425 | entry = ERR_PTR(-EINVAL); |
| 426 | break; |
| 427 | } |
| 428 | if (info->next_index <= index) |
| 429 | info->next_index = index + 1; |
| 430 | } |
| 431 | if (page) { |
| 432 | /* another task gave its page, or truncated the file */ |
| 433 | shmem_free_blocks(inode, 1); |
| 434 | shmem_dir_free(page); |
| 435 | } |
| 436 | if (info->next_index <= index && !IS_ERR(entry)) |
| 437 | info->next_index = index + 1; |
| 438 | return entry; |
| 439 | } |
| 440 | |
| 441 | /* |
| 442 | * shmem_free_swp - free some swap entries in a directory |
| 443 | * |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 444 | * @dir: pointer to the directory |
| 445 | * @edir: pointer after last entry of the directory |
| 446 | * @punch_lock: pointer to spinlock when needed for the holepunch case |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | */ |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 448 | static int shmem_free_swp(swp_entry_t *dir, swp_entry_t *edir, |
| 449 | spinlock_t *punch_lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | { |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 451 | spinlock_t *punch_unlock = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | swp_entry_t *ptr; |
| 453 | int freed = 0; |
| 454 | |
| 455 | for (ptr = dir; ptr < edir; ptr++) { |
| 456 | if (ptr->val) { |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 457 | if (unlikely(punch_lock)) { |
| 458 | punch_unlock = punch_lock; |
| 459 | punch_lock = NULL; |
| 460 | spin_lock(punch_unlock); |
| 461 | if (!ptr->val) |
| 462 | continue; |
| 463 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | free_swap_and_cache(*ptr); |
| 465 | *ptr = (swp_entry_t){0}; |
| 466 | freed++; |
| 467 | } |
| 468 | } |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 469 | if (punch_unlock) |
| 470 | spin_unlock(punch_unlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | return freed; |
| 472 | } |
| 473 | |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 474 | static int shmem_map_and_free_swp(struct page *subdir, int offset, |
| 475 | int limit, struct page ***dir, spinlock_t *punch_lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | { |
| 477 | swp_entry_t *ptr; |
| 478 | int freed = 0; |
| 479 | |
| 480 | ptr = shmem_swp_map(subdir); |
| 481 | for (; offset < limit; offset += LATENCY_LIMIT) { |
| 482 | int size = limit - offset; |
| 483 | if (size > LATENCY_LIMIT) |
| 484 | size = LATENCY_LIMIT; |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 485 | freed += shmem_free_swp(ptr+offset, ptr+offset+size, |
| 486 | punch_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | if (need_resched()) { |
| 488 | shmem_swp_unmap(ptr); |
| 489 | if (*dir) { |
| 490 | shmem_dir_unmap(*dir); |
| 491 | *dir = NULL; |
| 492 | } |
| 493 | cond_resched(); |
| 494 | ptr = shmem_swp_map(subdir); |
| 495 | } |
| 496 | } |
| 497 | shmem_swp_unmap(ptr); |
| 498 | return freed; |
| 499 | } |
| 500 | |
| 501 | static void shmem_free_pages(struct list_head *next) |
| 502 | { |
| 503 | struct page *page; |
| 504 | int freed = 0; |
| 505 | |
| 506 | do { |
| 507 | page = container_of(next, struct page, lru); |
| 508 | next = next->next; |
| 509 | shmem_dir_free(page); |
| 510 | freed++; |
| 511 | if (freed >= LATENCY_LIMIT) { |
| 512 | cond_resched(); |
| 513 | freed = 0; |
| 514 | } |
| 515 | } while (next); |
| 516 | } |
| 517 | |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 518 | static void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | { |
| 520 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 521 | unsigned long idx; |
| 522 | unsigned long size; |
| 523 | unsigned long limit; |
| 524 | unsigned long stage; |
| 525 | unsigned long diroff; |
| 526 | struct page **dir; |
| 527 | struct page *topdir; |
| 528 | struct page *middir; |
| 529 | struct page *subdir; |
| 530 | swp_entry_t *ptr; |
| 531 | LIST_HEAD(pages_to_free); |
| 532 | long nr_pages_to_free = 0; |
| 533 | long nr_swaps_freed = 0; |
| 534 | int offset; |
| 535 | int freed; |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 536 | int punch_hole; |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 537 | spinlock_t *needs_lock; |
| 538 | spinlock_t *punch_lock; |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 539 | unsigned long upper_limit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 540 | |
| 541 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 542 | idx = (start + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | if (idx >= info->next_index) |
| 544 | return; |
| 545 | |
| 546 | spin_lock(&info->lock); |
| 547 | info->flags |= SHMEM_TRUNCATE; |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 548 | if (likely(end == (loff_t) -1)) { |
| 549 | limit = info->next_index; |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 550 | upper_limit = SHMEM_MAX_INDEX; |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 551 | info->next_index = idx; |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 552 | needs_lock = NULL; |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 553 | punch_hole = 0; |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 554 | } else { |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 555 | if (end + 1 >= inode->i_size) { /* we may free a little more */ |
| 556 | limit = (inode->i_size + PAGE_CACHE_SIZE - 1) >> |
| 557 | PAGE_CACHE_SHIFT; |
| 558 | upper_limit = SHMEM_MAX_INDEX; |
| 559 | } else { |
| 560 | limit = (end + 1) >> PAGE_CACHE_SHIFT; |
| 561 | upper_limit = limit; |
| 562 | } |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 563 | needs_lock = &info->lock; |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 564 | punch_hole = 1; |
| 565 | } |
| 566 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | topdir = info->i_indirect; |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 568 | if (topdir && idx <= SHMEM_NR_DIRECT && !punch_hole) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | info->i_indirect = NULL; |
| 570 | nr_pages_to_free++; |
| 571 | list_add(&topdir->lru, &pages_to_free); |
| 572 | } |
| 573 | spin_unlock(&info->lock); |
| 574 | |
| 575 | if (info->swapped && idx < SHMEM_NR_DIRECT) { |
| 576 | ptr = info->i_direct; |
| 577 | size = limit; |
| 578 | if (size > SHMEM_NR_DIRECT) |
| 579 | size = SHMEM_NR_DIRECT; |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 580 | nr_swaps_freed = shmem_free_swp(ptr+idx, ptr+size, needs_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | } |
Badari Pulavarty | 92a3d03 | 2006-12-22 01:06:23 -0800 | [diff] [blame] | 582 | |
| 583 | /* |
| 584 | * If there are no indirect blocks or we are punching a hole |
| 585 | * below indirect blocks, nothing to be done. |
| 586 | */ |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 587 | if (!topdir || limit <= SHMEM_NR_DIRECT) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | goto done2; |
| 589 | |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 590 | /* |
| 591 | * The truncation case has already dropped info->lock, and we're safe |
| 592 | * because i_size and next_index have already been lowered, preventing |
| 593 | * access beyond. But in the punch_hole case, we still need to take |
| 594 | * the lock when updating the swap directory, because there might be |
| 595 | * racing accesses by shmem_getpage(SGP_CACHE), shmem_unuse_inode or |
| 596 | * shmem_writepage. However, whenever we find we can remove a whole |
| 597 | * directory page (not at the misaligned start or end of the range), |
| 598 | * we first NULLify its pointer in the level above, and then have no |
| 599 | * need to take the lock when updating its contents: needs_lock and |
| 600 | * punch_lock (either pointing to info->lock or NULL) manage this. |
| 601 | */ |
| 602 | |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 603 | upper_limit -= SHMEM_NR_DIRECT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 604 | limit -= SHMEM_NR_DIRECT; |
| 605 | idx = (idx > SHMEM_NR_DIRECT)? (idx - SHMEM_NR_DIRECT): 0; |
| 606 | offset = idx % ENTRIES_PER_PAGE; |
| 607 | idx -= offset; |
| 608 | |
| 609 | dir = shmem_dir_map(topdir); |
| 610 | stage = ENTRIES_PER_PAGEPAGE/2; |
| 611 | if (idx < ENTRIES_PER_PAGEPAGE/2) { |
| 612 | middir = topdir; |
| 613 | diroff = idx/ENTRIES_PER_PAGE; |
| 614 | } else { |
| 615 | dir += ENTRIES_PER_PAGE/2; |
| 616 | dir += (idx - ENTRIES_PER_PAGEPAGE/2)/ENTRIES_PER_PAGEPAGE; |
| 617 | while (stage <= idx) |
| 618 | stage += ENTRIES_PER_PAGEPAGE; |
| 619 | middir = *dir; |
| 620 | if (*dir) { |
| 621 | diroff = ((idx - ENTRIES_PER_PAGEPAGE/2) % |
| 622 | ENTRIES_PER_PAGEPAGE) / ENTRIES_PER_PAGE; |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 623 | if (!diroff && !offset && upper_limit >= stage) { |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 624 | if (needs_lock) { |
| 625 | spin_lock(needs_lock); |
| 626 | *dir = NULL; |
| 627 | spin_unlock(needs_lock); |
| 628 | needs_lock = NULL; |
| 629 | } else |
| 630 | *dir = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | nr_pages_to_free++; |
| 632 | list_add(&middir->lru, &pages_to_free); |
| 633 | } |
| 634 | shmem_dir_unmap(dir); |
| 635 | dir = shmem_dir_map(middir); |
| 636 | } else { |
| 637 | diroff = 0; |
| 638 | offset = 0; |
| 639 | idx = stage; |
| 640 | } |
| 641 | } |
| 642 | |
| 643 | for (; idx < limit; idx += ENTRIES_PER_PAGE, diroff++) { |
| 644 | if (unlikely(idx == stage)) { |
| 645 | shmem_dir_unmap(dir); |
| 646 | dir = shmem_dir_map(topdir) + |
| 647 | ENTRIES_PER_PAGE/2 + idx/ENTRIES_PER_PAGEPAGE; |
| 648 | while (!*dir) { |
| 649 | dir++; |
| 650 | idx += ENTRIES_PER_PAGEPAGE; |
| 651 | if (idx >= limit) |
| 652 | goto done1; |
| 653 | } |
| 654 | stage = idx + ENTRIES_PER_PAGEPAGE; |
| 655 | middir = *dir; |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 656 | if (punch_hole) |
| 657 | needs_lock = &info->lock; |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 658 | if (upper_limit >= stage) { |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 659 | if (needs_lock) { |
| 660 | spin_lock(needs_lock); |
| 661 | *dir = NULL; |
| 662 | spin_unlock(needs_lock); |
| 663 | needs_lock = NULL; |
| 664 | } else |
| 665 | *dir = NULL; |
Hugh Dickins | a2646d1 | 2007-03-29 01:20:35 -0700 | [diff] [blame] | 666 | nr_pages_to_free++; |
| 667 | list_add(&middir->lru, &pages_to_free); |
| 668 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | shmem_dir_unmap(dir); |
| 670 | cond_resched(); |
| 671 | dir = shmem_dir_map(middir); |
| 672 | diroff = 0; |
| 673 | } |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 674 | punch_lock = needs_lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | subdir = dir[diroff]; |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 676 | if (subdir && !offset && upper_limit-idx >= ENTRIES_PER_PAGE) { |
| 677 | if (needs_lock) { |
| 678 | spin_lock(needs_lock); |
| 679 | dir[diroff] = NULL; |
| 680 | spin_unlock(needs_lock); |
| 681 | punch_lock = NULL; |
| 682 | } else |
| 683 | dir[diroff] = NULL; |
| 684 | nr_pages_to_free++; |
| 685 | list_add(&subdir->lru, &pages_to_free); |
| 686 | } |
| 687 | if (subdir && page_private(subdir) /* has swap entries */) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 688 | size = limit - idx; |
| 689 | if (size > ENTRIES_PER_PAGE) |
| 690 | size = ENTRIES_PER_PAGE; |
| 691 | freed = shmem_map_and_free_swp(subdir, |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 692 | offset, size, &dir, punch_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | if (!dir) |
| 694 | dir = shmem_dir_map(middir); |
| 695 | nr_swaps_freed += freed; |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 696 | if (offset || punch_lock) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | spin_lock(&info->lock); |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 698 | set_page_private(subdir, |
| 699 | page_private(subdir) - freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | spin_unlock(&info->lock); |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 701 | } else |
| 702 | BUG_ON(page_private(subdir) != freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | } |
Hugh Dickins | 1ae7000 | 2007-03-29 01:20:36 -0700 | [diff] [blame] | 704 | offset = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | } |
| 706 | done1: |
| 707 | shmem_dir_unmap(dir); |
| 708 | done2: |
| 709 | if (inode->i_mapping->nrpages && (info->flags & SHMEM_PAGEIN)) { |
| 710 | /* |
| 711 | * Call truncate_inode_pages again: racing shmem_unuse_inode |
| 712 | * may have swizzled a page in from swap since vmtruncate or |
| 713 | * generic_delete_inode did it, before we lowered next_index. |
| 714 | * Also, though shmem_getpage checks i_size before adding to |
| 715 | * cache, no recheck after: so fix the narrow window there too. |
Hugh Dickins | 16a1001 | 2007-03-29 01:20:37 -0700 | [diff] [blame] | 716 | * |
| 717 | * Recalling truncate_inode_pages_range and unmap_mapping_range |
| 718 | * every time for punch_hole (which never got a chance to clear |
| 719 | * SHMEM_PAGEIN at the start of vmtruncate_range) is expensive, |
| 720 | * yet hardly ever necessary: try to optimize them out later. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | */ |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 722 | truncate_inode_pages_range(inode->i_mapping, start, end); |
Hugh Dickins | 16a1001 | 2007-03-29 01:20:37 -0700 | [diff] [blame] | 723 | if (punch_hole) |
| 724 | unmap_mapping_range(inode->i_mapping, start, |
| 725 | end - start, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | } |
| 727 | |
| 728 | spin_lock(&info->lock); |
| 729 | info->flags &= ~SHMEM_TRUNCATE; |
| 730 | info->swapped -= nr_swaps_freed; |
| 731 | if (nr_pages_to_free) |
| 732 | shmem_free_blocks(inode, nr_pages_to_free); |
| 733 | shmem_recalc_inode(inode); |
| 734 | spin_unlock(&info->lock); |
| 735 | |
| 736 | /* |
| 737 | * Empty swap vector directory pages to be freed? |
| 738 | */ |
| 739 | if (!list_empty(&pages_to_free)) { |
| 740 | pages_to_free.prev->next = NULL; |
| 741 | shmem_free_pages(pages_to_free.next); |
| 742 | } |
| 743 | } |
| 744 | |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 745 | static void shmem_truncate(struct inode *inode) |
| 746 | { |
| 747 | shmem_truncate_range(inode, inode->i_size, (loff_t)-1); |
| 748 | } |
| 749 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 750 | static int shmem_notify_change(struct dentry *dentry, struct iattr *attr) |
| 751 | { |
| 752 | struct inode *inode = dentry->d_inode; |
| 753 | struct page *page = NULL; |
| 754 | int error; |
| 755 | |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 756 | if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | if (attr->ia_size < inode->i_size) { |
| 758 | /* |
| 759 | * If truncating down to a partial page, then |
| 760 | * if that page is already allocated, hold it |
| 761 | * in memory until the truncation is over, so |
| 762 | * truncate_partial_page cannnot miss it were |
| 763 | * it assigned to swap. |
| 764 | */ |
| 765 | if (attr->ia_size & (PAGE_CACHE_SIZE-1)) { |
| 766 | (void) shmem_getpage(inode, |
| 767 | attr->ia_size>>PAGE_CACHE_SHIFT, |
| 768 | &page, SGP_READ, NULL); |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 769 | if (page) |
| 770 | unlock_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | } |
| 772 | /* |
| 773 | * Reset SHMEM_PAGEIN flag so that shmem_truncate can |
| 774 | * detect if any pages might have been added to cache |
| 775 | * after truncate_inode_pages. But we needn't bother |
| 776 | * if it's being fully truncated to zero-length: the |
| 777 | * nrpages check is efficient enough in that case. |
| 778 | */ |
| 779 | if (attr->ia_size) { |
| 780 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 781 | spin_lock(&info->lock); |
| 782 | info->flags &= ~SHMEM_PAGEIN; |
| 783 | spin_unlock(&info->lock); |
| 784 | } |
| 785 | } |
| 786 | } |
| 787 | |
| 788 | error = inode_change_ok(inode, attr); |
| 789 | if (!error) |
| 790 | error = inode_setattr(inode, attr); |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 791 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 792 | if (!error && (attr->ia_valid & ATTR_MODE)) |
| 793 | error = generic_acl_chmod(inode, &shmem_acl_ops); |
| 794 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | if (page) |
| 796 | page_cache_release(page); |
| 797 | return error; |
| 798 | } |
| 799 | |
| 800 | static void shmem_delete_inode(struct inode *inode) |
| 801 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 802 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 803 | |
| 804 | if (inode->i_op->truncate == shmem_truncate) { |
Mark Fasheh | fef2665 | 2005-09-09 13:01:31 -0700 | [diff] [blame] | 805 | truncate_inode_pages(inode->i_mapping, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | shmem_unacct_size(info->flags, inode->i_size); |
| 807 | inode->i_size = 0; |
| 808 | shmem_truncate(inode); |
| 809 | if (!list_empty(&info->swaplist)) { |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 810 | mutex_lock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 812 | mutex_unlock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | } |
| 814 | } |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 815 | BUG_ON(inode->i_blocks); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 816 | shmem_free_inode(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 817 | clear_inode(inode); |
| 818 | } |
| 819 | |
| 820 | static inline int shmem_find_swp(swp_entry_t entry, swp_entry_t *dir, swp_entry_t *edir) |
| 821 | { |
| 822 | swp_entry_t *ptr; |
| 823 | |
| 824 | for (ptr = dir; ptr < edir; ptr++) { |
| 825 | if (ptr->val == entry.val) |
| 826 | return ptr - dir; |
| 827 | } |
| 828 | return -1; |
| 829 | } |
| 830 | |
| 831 | static int shmem_unuse_inode(struct shmem_inode_info *info, swp_entry_t entry, struct page *page) |
| 832 | { |
| 833 | struct inode *inode; |
| 834 | unsigned long idx; |
| 835 | unsigned long size; |
| 836 | unsigned long limit; |
| 837 | unsigned long stage; |
| 838 | struct page **dir; |
| 839 | struct page *subdir; |
| 840 | swp_entry_t *ptr; |
| 841 | int offset; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 842 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 843 | |
| 844 | idx = 0; |
| 845 | ptr = info->i_direct; |
| 846 | spin_lock(&info->lock); |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 847 | if (!info->swapped) { |
| 848 | list_del_init(&info->swaplist); |
| 849 | goto lost2; |
| 850 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | limit = info->next_index; |
| 852 | size = limit; |
| 853 | if (size > SHMEM_NR_DIRECT) |
| 854 | size = SHMEM_NR_DIRECT; |
| 855 | offset = shmem_find_swp(entry, ptr, ptr+size); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 856 | if (offset >= 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | goto found; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | if (!info->i_indirect) |
| 859 | goto lost2; |
| 860 | |
| 861 | dir = shmem_dir_map(info->i_indirect); |
| 862 | stage = SHMEM_NR_DIRECT + ENTRIES_PER_PAGEPAGE/2; |
| 863 | |
| 864 | for (idx = SHMEM_NR_DIRECT; idx < limit; idx += ENTRIES_PER_PAGE, dir++) { |
| 865 | if (unlikely(idx == stage)) { |
| 866 | shmem_dir_unmap(dir-1); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 867 | if (cond_resched_lock(&info->lock)) { |
| 868 | /* check it has not been truncated */ |
| 869 | if (limit > info->next_index) { |
| 870 | limit = info->next_index; |
| 871 | if (idx >= limit) |
| 872 | goto lost2; |
| 873 | } |
| 874 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 875 | dir = shmem_dir_map(info->i_indirect) + |
| 876 | ENTRIES_PER_PAGE/2 + idx/ENTRIES_PER_PAGEPAGE; |
| 877 | while (!*dir) { |
| 878 | dir++; |
| 879 | idx += ENTRIES_PER_PAGEPAGE; |
| 880 | if (idx >= limit) |
| 881 | goto lost1; |
| 882 | } |
| 883 | stage = idx + ENTRIES_PER_PAGEPAGE; |
| 884 | subdir = *dir; |
| 885 | shmem_dir_unmap(dir); |
| 886 | dir = shmem_dir_map(subdir); |
| 887 | } |
| 888 | subdir = *dir; |
Hugh Dickins | 4c21e2f | 2005-10-29 18:16:40 -0700 | [diff] [blame] | 889 | if (subdir && page_private(subdir)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 890 | ptr = shmem_swp_map(subdir); |
| 891 | size = limit - idx; |
| 892 | if (size > ENTRIES_PER_PAGE) |
| 893 | size = ENTRIES_PER_PAGE; |
| 894 | offset = shmem_find_swp(entry, ptr, ptr+size); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 895 | shmem_swp_unmap(ptr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 896 | if (offset >= 0) { |
| 897 | shmem_dir_unmap(dir); |
| 898 | goto found; |
| 899 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 900 | } |
| 901 | } |
| 902 | lost1: |
| 903 | shmem_dir_unmap(dir-1); |
| 904 | lost2: |
| 905 | spin_unlock(&info->lock); |
| 906 | return 0; |
| 907 | found: |
| 908 | idx += offset; |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 909 | inode = igrab(&info->vfs_inode); |
| 910 | spin_unlock(&info->lock); |
| 911 | |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 912 | /* |
| 913 | * Move _head_ to start search for next from here. |
| 914 | * But be careful: shmem_delete_inode checks list_empty without taking |
| 915 | * mutex, and there's an instant in list_move_tail when info->swaplist |
| 916 | * would appear empty, if it were the only one on shmem_swaplist. We |
| 917 | * could avoid doing it if inode NULL; or use this minor optimization. |
| 918 | */ |
| 919 | if (shmem_swaplist.next != &info->swaplist) |
| 920 | list_move_tail(&shmem_swaplist, &info->swaplist); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 921 | mutex_unlock(&shmem_swaplist_mutex); |
| 922 | |
| 923 | error = 1; |
| 924 | if (!inode) |
| 925 | goto out; |
Hugh Dickins | 8236955 | 2008-02-07 00:14:22 -0800 | [diff] [blame] | 926 | /* Precharge page while we can wait, compensate afterwards */ |
| 927 | error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL); |
Hugh Dickins | b409f9f | 2008-02-04 22:28:54 -0800 | [diff] [blame] | 928 | if (error) |
| 929 | goto out; |
Hugh Dickins | 8236955 | 2008-02-07 00:14:22 -0800 | [diff] [blame] | 930 | error = radix_tree_preload(GFP_KERNEL); |
| 931 | if (error) |
| 932 | goto uncharge; |
Hugh Dickins | b409f9f | 2008-02-04 22:28:54 -0800 | [diff] [blame] | 933 | error = 1; |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 934 | |
| 935 | spin_lock(&info->lock); |
| 936 | ptr = shmem_swp_entry(info, idx, NULL); |
| 937 | if (ptr && ptr->val == entry.val) |
| 938 | error = add_to_page_cache(page, inode->i_mapping, |
Hugh Dickins | b409f9f | 2008-02-04 22:28:54 -0800 | [diff] [blame] | 939 | idx, GFP_NOWAIT); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 940 | if (error == -EEXIST) { |
| 941 | struct page *filepage = find_get_page(inode->i_mapping, idx); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 942 | error = 1; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 943 | if (filepage) { |
| 944 | /* |
| 945 | * There might be a more uptodate page coming down |
| 946 | * from a stacked writepage: forget our swappage if so. |
| 947 | */ |
| 948 | if (PageUptodate(filepage)) |
| 949 | error = 0; |
| 950 | page_cache_release(filepage); |
| 951 | } |
| 952 | } |
| 953 | if (!error) { |
Hugh Dickins | 73b1262 | 2008-02-04 22:28:50 -0800 | [diff] [blame] | 954 | delete_from_swap_cache(page); |
| 955 | set_page_dirty(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 956 | info->flags |= SHMEM_PAGEIN; |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 957 | shmem_swp_set(info, ptr, 0); |
| 958 | swap_free(entry); |
| 959 | error = 1; /* not an error, but entry was found */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 960 | } |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 961 | if (ptr) |
| 962 | shmem_swp_unmap(ptr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | spin_unlock(&info->lock); |
Hugh Dickins | b409f9f | 2008-02-04 22:28:54 -0800 | [diff] [blame] | 964 | radix_tree_preload_end(); |
Hugh Dickins | 8236955 | 2008-02-07 00:14:22 -0800 | [diff] [blame] | 965 | uncharge: |
| 966 | mem_cgroup_uncharge_page(page); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 967 | out: |
| 968 | unlock_page(page); |
| 969 | page_cache_release(page); |
| 970 | iput(inode); /* allows for NULL */ |
| 971 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 972 | } |
| 973 | |
| 974 | /* |
| 975 | * shmem_unuse() search for an eventually swapped out shmem page. |
| 976 | */ |
| 977 | int shmem_unuse(swp_entry_t entry, struct page *page) |
| 978 | { |
| 979 | struct list_head *p, *next; |
| 980 | struct shmem_inode_info *info; |
| 981 | int found = 0; |
| 982 | |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 983 | mutex_lock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | list_for_each_safe(p, next, &shmem_swaplist) { |
| 985 | info = list_entry(p, struct shmem_inode_info, swaplist); |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 986 | found = shmem_unuse_inode(info, entry, page); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 987 | cond_resched(); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 988 | if (found) |
| 989 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 990 | } |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 991 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 992 | out: return found; /* 0 or 1 or -ENOMEM */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 993 | } |
| 994 | |
| 995 | /* |
| 996 | * Move the page from the page cache to the swap cache. |
| 997 | */ |
| 998 | static int shmem_writepage(struct page *page, struct writeback_control *wbc) |
| 999 | { |
| 1000 | struct shmem_inode_info *info; |
| 1001 | swp_entry_t *entry, swap; |
| 1002 | struct address_space *mapping; |
| 1003 | unsigned long index; |
| 1004 | struct inode *inode; |
| 1005 | |
| 1006 | BUG_ON(!PageLocked(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1007 | mapping = page->mapping; |
| 1008 | index = page->index; |
| 1009 | inode = mapping->host; |
| 1010 | info = SHMEM_I(inode); |
| 1011 | if (info->flags & VM_LOCKED) |
| 1012 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1013 | if (!total_swap_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | goto redirty; |
| 1015 | |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1016 | /* |
| 1017 | * shmem_backing_dev_info's capabilities prevent regular writeback or |
| 1018 | * sync from ever calling shmem_writepage; but a stacking filesystem |
| 1019 | * may use the ->writepage of its underlying filesystem, in which case |
| 1020 | * tmpfs should write out to swap only in response to memory pressure, |
| 1021 | * and not for pdflush or sync. However, in those cases, we do still |
| 1022 | * want to check if there's a redundant swappage to be discarded. |
| 1023 | */ |
| 1024 | if (wbc->for_reclaim) |
| 1025 | swap = get_swap_page(); |
| 1026 | else |
| 1027 | swap.val = 0; |
| 1028 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1029 | spin_lock(&info->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | if (index >= info->next_index) { |
| 1031 | BUG_ON(!(info->flags & SHMEM_TRUNCATE)); |
| 1032 | goto unlock; |
| 1033 | } |
| 1034 | entry = shmem_swp_entry(info, index, NULL); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1035 | if (entry->val) { |
| 1036 | /* |
| 1037 | * The more uptodate page coming down from a stacked |
| 1038 | * writepage should replace our old swappage. |
| 1039 | */ |
| 1040 | free_swap_and_cache(*entry); |
| 1041 | shmem_swp_set(info, entry, 0); |
| 1042 | } |
| 1043 | shmem_recalc_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1044 | |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1045 | if (swap.val && add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) { |
Hugh Dickins | 73b1262 | 2008-02-04 22:28:50 -0800 | [diff] [blame] | 1046 | remove_from_page_cache(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1047 | shmem_swp_set(info, entry, swap.val); |
| 1048 | shmem_swp_unmap(entry); |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 1049 | if (list_empty(&info->swaplist)) |
| 1050 | inode = igrab(inode); |
| 1051 | else |
| 1052 | inode = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1053 | spin_unlock(&info->lock); |
Hugh Dickins | 73b1262 | 2008-02-04 22:28:50 -0800 | [diff] [blame] | 1054 | swap_duplicate(swap); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1055 | BUG_ON(page_mapped(page)); |
Hugh Dickins | 73b1262 | 2008-02-04 22:28:50 -0800 | [diff] [blame] | 1056 | page_cache_release(page); /* pagecache ref */ |
| 1057 | set_page_dirty(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1058 | unlock_page(page); |
Hugh Dickins | 1b1b32f | 2008-02-04 22:28:55 -0800 | [diff] [blame] | 1059 | if (inode) { |
| 1060 | mutex_lock(&shmem_swaplist_mutex); |
| 1061 | /* move instead of add in case we're racing */ |
| 1062 | list_move_tail(&info->swaplist, &shmem_swaplist); |
| 1063 | mutex_unlock(&shmem_swaplist_mutex); |
| 1064 | iput(inode); |
| 1065 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1066 | return 0; |
| 1067 | } |
| 1068 | |
| 1069 | shmem_swp_unmap(entry); |
| 1070 | unlock: |
| 1071 | spin_unlock(&info->lock); |
| 1072 | swap_free(swap); |
| 1073 | redirty: |
| 1074 | set_page_dirty(page); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1075 | if (wbc->for_reclaim) |
| 1076 | return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */ |
| 1077 | unlock_page(page); |
| 1078 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1079 | } |
| 1080 | |
| 1081 | #ifdef CONFIG_NUMA |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 1082 | #ifdef CONFIG_TMPFS |
| 1083 | static int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes) |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 1084 | { |
| 1085 | char *nodelist = strchr(value, ':'); |
| 1086 | int err = 1; |
| 1087 | |
| 1088 | if (nodelist) { |
| 1089 | /* NUL-terminate policy string */ |
| 1090 | *nodelist++ = '\0'; |
| 1091 | if (nodelist_parse(nodelist, *policy_nodes)) |
| 1092 | goto out; |
Lee Schermerhorn | 37b07e4 | 2007-10-16 01:25:39 -0700 | [diff] [blame] | 1093 | if (!nodes_subset(*policy_nodes, node_states[N_HIGH_MEMORY])) |
Hugh Dickins | a210906 | 2007-06-08 13:46:46 -0700 | [diff] [blame] | 1094 | goto out; |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 1095 | } |
| 1096 | if (!strcmp(value, "default")) { |
| 1097 | *policy = MPOL_DEFAULT; |
| 1098 | /* Don't allow a nodelist */ |
| 1099 | if (!nodelist) |
| 1100 | err = 0; |
| 1101 | } else if (!strcmp(value, "prefer")) { |
| 1102 | *policy = MPOL_PREFERRED; |
| 1103 | /* Insist on a nodelist of one node only */ |
| 1104 | if (nodelist) { |
| 1105 | char *rest = nodelist; |
| 1106 | while (isdigit(*rest)) |
| 1107 | rest++; |
| 1108 | if (!*rest) |
| 1109 | err = 0; |
| 1110 | } |
| 1111 | } else if (!strcmp(value, "bind")) { |
| 1112 | *policy = MPOL_BIND; |
| 1113 | /* Insist on a nodelist */ |
| 1114 | if (nodelist) |
| 1115 | err = 0; |
| 1116 | } else if (!strcmp(value, "interleave")) { |
| 1117 | *policy = MPOL_INTERLEAVE; |
Lee Schermerhorn | 37b07e4 | 2007-10-16 01:25:39 -0700 | [diff] [blame] | 1118 | /* |
| 1119 | * Default to online nodes with memory if no nodelist |
| 1120 | */ |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 1121 | if (!nodelist) |
Lee Schermerhorn | 37b07e4 | 2007-10-16 01:25:39 -0700 | [diff] [blame] | 1122 | *policy_nodes = node_states[N_HIGH_MEMORY]; |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 1123 | err = 0; |
| 1124 | } |
| 1125 | out: |
| 1126 | /* Restore string for error message */ |
| 1127 | if (nodelist) |
| 1128 | *--nodelist = ':'; |
| 1129 | return err; |
| 1130 | } |
| 1131 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 1132 | static void shmem_show_mpol(struct seq_file *seq, int policy, |
| 1133 | const nodemask_t policy_nodes) |
| 1134 | { |
| 1135 | char *policy_string; |
| 1136 | |
| 1137 | switch (policy) { |
| 1138 | case MPOL_PREFERRED: |
| 1139 | policy_string = "prefer"; |
| 1140 | break; |
| 1141 | case MPOL_BIND: |
| 1142 | policy_string = "bind"; |
| 1143 | break; |
| 1144 | case MPOL_INTERLEAVE: |
| 1145 | policy_string = "interleave"; |
| 1146 | break; |
| 1147 | default: |
| 1148 | /* MPOL_DEFAULT */ |
| 1149 | return; |
| 1150 | } |
| 1151 | |
| 1152 | seq_printf(seq, ",mpol=%s", policy_string); |
| 1153 | |
| 1154 | if (policy != MPOL_INTERLEAVE || |
| 1155 | !nodes_equal(policy_nodes, node_states[N_HIGH_MEMORY])) { |
| 1156 | char buffer[64]; |
| 1157 | int len; |
| 1158 | |
| 1159 | len = nodelist_scnprintf(buffer, sizeof(buffer), policy_nodes); |
| 1160 | if (len < sizeof(buffer)) |
| 1161 | seq_printf(seq, ":%s", buffer); |
| 1162 | else |
| 1163 | seq_printf(seq, ":?"); |
| 1164 | } |
| 1165 | } |
| 1166 | #endif /* CONFIG_TMPFS */ |
| 1167 | |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1168 | static struct page *shmem_swapin(swp_entry_t entry, gfp_t gfp, |
| 1169 | struct shmem_inode_info *info, unsigned long idx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1170 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1171 | struct vm_area_struct pvma; |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 1172 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1173 | |
| 1174 | /* Create a pseudo vma that just contains the policy */ |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 1175 | pvma.vm_start = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | pvma.vm_pgoff = idx; |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 1177 | pvma.vm_ops = NULL; |
| 1178 | pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx); |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1179 | page = swapin_readahead(entry, gfp, &pvma, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1180 | mpol_free(pvma.vm_policy); |
| 1181 | return page; |
| 1182 | } |
| 1183 | |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1184 | static struct page *shmem_alloc_page(gfp_t gfp, |
| 1185 | struct shmem_inode_info *info, unsigned long idx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1186 | { |
| 1187 | struct vm_area_struct pvma; |
| 1188 | struct page *page; |
| 1189 | |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 1190 | /* Create a pseudo vma that just contains the policy */ |
| 1191 | pvma.vm_start = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1192 | pvma.vm_pgoff = idx; |
Hugh Dickins | c4cc6d0 | 2008-02-04 22:28:40 -0800 | [diff] [blame] | 1193 | pvma.vm_ops = NULL; |
| 1194 | pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx); |
Hugh Dickins | e84e2e1 | 2007-11-28 18:55:10 +0000 | [diff] [blame] | 1195 | page = alloc_page_vma(gfp, &pvma, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | mpol_free(pvma.vm_policy); |
| 1197 | return page; |
| 1198 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 1199 | #else /* !CONFIG_NUMA */ |
| 1200 | #ifdef CONFIG_TMPFS |
Lee Schermerhorn | 37b07e4 | 2007-10-16 01:25:39 -0700 | [diff] [blame] | 1201 | static inline int shmem_parse_mpol(char *value, int *policy, |
| 1202 | nodemask_t *policy_nodes) |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 1203 | { |
| 1204 | return 1; |
| 1205 | } |
| 1206 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 1207 | static inline void shmem_show_mpol(struct seq_file *seq, int policy, |
| 1208 | const nodemask_t policy_nodes) |
| 1209 | { |
| 1210 | } |
| 1211 | #endif /* CONFIG_TMPFS */ |
| 1212 | |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1213 | static inline struct page *shmem_swapin(swp_entry_t entry, gfp_t gfp, |
| 1214 | struct shmem_inode_info *info, unsigned long idx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1215 | { |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1216 | return swapin_readahead(entry, gfp, NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1217 | } |
| 1218 | |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1219 | static inline struct page *shmem_alloc_page(gfp_t gfp, |
| 1220 | struct shmem_inode_info *info, unsigned long idx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1221 | { |
Hugh Dickins | e84e2e1 | 2007-11-28 18:55:10 +0000 | [diff] [blame] | 1222 | return alloc_page(gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1223 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 1224 | #endif /* CONFIG_NUMA */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1225 | |
| 1226 | /* |
| 1227 | * shmem_getpage - either get the page from swap or allocate a new one |
| 1228 | * |
| 1229 | * If we allocate a new one we do not mark it dirty. That's up to the |
| 1230 | * vm. If we swap it in we mark it dirty since we also free the swap |
| 1231 | * entry since a page cannot live in both the swap and page cache |
| 1232 | */ |
| 1233 | static int shmem_getpage(struct inode *inode, unsigned long idx, |
| 1234 | struct page **pagep, enum sgp_type sgp, int *type) |
| 1235 | { |
| 1236 | struct address_space *mapping = inode->i_mapping; |
| 1237 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 1238 | struct shmem_sb_info *sbinfo; |
| 1239 | struct page *filepage = *pagep; |
| 1240 | struct page *swappage; |
| 1241 | swp_entry_t *entry; |
| 1242 | swp_entry_t swap; |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1243 | gfp_t gfp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | int error; |
| 1245 | |
| 1246 | if (idx >= SHMEM_MAX_INDEX) |
| 1247 | return -EFBIG; |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 1248 | |
| 1249 | if (type) |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1250 | *type = 0; |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 1251 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1252 | /* |
| 1253 | * Normally, filepage is NULL on entry, and either found |
| 1254 | * uptodate immediately, or allocated and zeroed, or read |
| 1255 | * in under swappage, which is then assigned to filepage. |
Hugh Dickins | 5402b97 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1256 | * But shmem_readpage (required for splice) passes in a locked |
Hugh Dickins | ae97641 | 2007-06-04 10:00:39 +0200 | [diff] [blame] | 1257 | * filepage, which may be found not uptodate by other callers |
| 1258 | * too, and may need to be copied from the swappage read in. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | */ |
| 1260 | repeat: |
| 1261 | if (!filepage) |
| 1262 | filepage = find_lock_page(mapping, idx); |
| 1263 | if (filepage && PageUptodate(filepage)) |
| 1264 | goto done; |
| 1265 | error = 0; |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1266 | gfp = mapping_gfp_mask(mapping); |
Hugh Dickins | b409f9f | 2008-02-04 22:28:54 -0800 | [diff] [blame] | 1267 | if (!filepage) { |
| 1268 | /* |
| 1269 | * Try to preload while we can wait, to not make a habit of |
| 1270 | * draining atomic reserves; but don't latch on to this cpu. |
| 1271 | */ |
| 1272 | error = radix_tree_preload(gfp & ~__GFP_HIGHMEM); |
| 1273 | if (error) |
| 1274 | goto failed; |
| 1275 | radix_tree_preload_end(); |
| 1276 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1277 | |
| 1278 | spin_lock(&info->lock); |
| 1279 | shmem_recalc_inode(inode); |
| 1280 | entry = shmem_swp_alloc(info, idx, sgp); |
| 1281 | if (IS_ERR(entry)) { |
| 1282 | spin_unlock(&info->lock); |
| 1283 | error = PTR_ERR(entry); |
| 1284 | goto failed; |
| 1285 | } |
| 1286 | swap = *entry; |
| 1287 | |
| 1288 | if (swap.val) { |
| 1289 | /* Look it up and read it in.. */ |
| 1290 | swappage = lookup_swap_cache(swap); |
| 1291 | if (!swappage) { |
| 1292 | shmem_swp_unmap(entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1293 | /* here we actually do the io */ |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1294 | if (type && !(*type & VM_FAULT_MAJOR)) { |
Christoph Lameter | f8891e5 | 2006-06-30 01:55:45 -0700 | [diff] [blame] | 1295 | __count_vm_event(PGMAJFAULT); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1296 | *type |= VM_FAULT_MAJOR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1297 | } |
Christoph Lameter | f8891e5 | 2006-06-30 01:55:45 -0700 | [diff] [blame] | 1298 | spin_unlock(&info->lock); |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1299 | swappage = shmem_swapin(swap, gfp, info, idx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1300 | if (!swappage) { |
| 1301 | spin_lock(&info->lock); |
| 1302 | entry = shmem_swp_alloc(info, idx, sgp); |
| 1303 | if (IS_ERR(entry)) |
| 1304 | error = PTR_ERR(entry); |
| 1305 | else { |
| 1306 | if (entry->val == swap.val) |
| 1307 | error = -ENOMEM; |
| 1308 | shmem_swp_unmap(entry); |
| 1309 | } |
| 1310 | spin_unlock(&info->lock); |
| 1311 | if (error) |
| 1312 | goto failed; |
| 1313 | goto repeat; |
| 1314 | } |
| 1315 | wait_on_page_locked(swappage); |
| 1316 | page_cache_release(swappage); |
| 1317 | goto repeat; |
| 1318 | } |
| 1319 | |
| 1320 | /* We have to do this with page locked to prevent races */ |
| 1321 | if (TestSetPageLocked(swappage)) { |
| 1322 | shmem_swp_unmap(entry); |
| 1323 | spin_unlock(&info->lock); |
| 1324 | wait_on_page_locked(swappage); |
| 1325 | page_cache_release(swappage); |
| 1326 | goto repeat; |
| 1327 | } |
| 1328 | if (PageWriteback(swappage)) { |
| 1329 | shmem_swp_unmap(entry); |
| 1330 | spin_unlock(&info->lock); |
| 1331 | wait_on_page_writeback(swappage); |
| 1332 | unlock_page(swappage); |
| 1333 | page_cache_release(swappage); |
| 1334 | goto repeat; |
| 1335 | } |
| 1336 | if (!PageUptodate(swappage)) { |
| 1337 | shmem_swp_unmap(entry); |
| 1338 | spin_unlock(&info->lock); |
| 1339 | unlock_page(swappage); |
| 1340 | page_cache_release(swappage); |
| 1341 | error = -EIO; |
| 1342 | goto failed; |
| 1343 | } |
| 1344 | |
| 1345 | if (filepage) { |
| 1346 | shmem_swp_set(info, entry, 0); |
| 1347 | shmem_swp_unmap(entry); |
| 1348 | delete_from_swap_cache(swappage); |
| 1349 | spin_unlock(&info->lock); |
| 1350 | copy_highpage(filepage, swappage); |
| 1351 | unlock_page(swappage); |
| 1352 | page_cache_release(swappage); |
| 1353 | flush_dcache_page(filepage); |
| 1354 | SetPageUptodate(filepage); |
| 1355 | set_page_dirty(filepage); |
| 1356 | swap_free(swap); |
Hugh Dickins | 73b1262 | 2008-02-04 22:28:50 -0800 | [diff] [blame] | 1357 | } else if (!(error = add_to_page_cache( |
Hugh Dickins | b409f9f | 2008-02-04 22:28:54 -0800 | [diff] [blame] | 1358 | swappage, mapping, idx, GFP_NOWAIT))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1359 | info->flags |= SHMEM_PAGEIN; |
| 1360 | shmem_swp_set(info, entry, 0); |
| 1361 | shmem_swp_unmap(entry); |
Hugh Dickins | 73b1262 | 2008-02-04 22:28:50 -0800 | [diff] [blame] | 1362 | delete_from_swap_cache(swappage); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1363 | spin_unlock(&info->lock); |
| 1364 | filepage = swappage; |
Hugh Dickins | 73b1262 | 2008-02-04 22:28:50 -0800 | [diff] [blame] | 1365 | set_page_dirty(filepage); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1366 | swap_free(swap); |
| 1367 | } else { |
| 1368 | shmem_swp_unmap(entry); |
| 1369 | spin_unlock(&info->lock); |
| 1370 | unlock_page(swappage); |
| 1371 | page_cache_release(swappage); |
Hugh Dickins | 8236955 | 2008-02-07 00:14:22 -0800 | [diff] [blame] | 1372 | if (error == -ENOMEM) { |
| 1373 | /* allow reclaim from this memory cgroup */ |
| 1374 | error = mem_cgroup_cache_charge(NULL, |
| 1375 | current->mm, gfp & ~__GFP_HIGHMEM); |
| 1376 | if (error) |
| 1377 | goto failed; |
| 1378 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1379 | goto repeat; |
| 1380 | } |
| 1381 | } else if (sgp == SGP_READ && !filepage) { |
| 1382 | shmem_swp_unmap(entry); |
| 1383 | filepage = find_get_page(mapping, idx); |
| 1384 | if (filepage && |
| 1385 | (!PageUptodate(filepage) || TestSetPageLocked(filepage))) { |
| 1386 | spin_unlock(&info->lock); |
| 1387 | wait_on_page_locked(filepage); |
| 1388 | page_cache_release(filepage); |
| 1389 | filepage = NULL; |
| 1390 | goto repeat; |
| 1391 | } |
| 1392 | spin_unlock(&info->lock); |
| 1393 | } else { |
| 1394 | shmem_swp_unmap(entry); |
| 1395 | sbinfo = SHMEM_SB(inode->i_sb); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1396 | if (sbinfo->max_blocks) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1397 | spin_lock(&sbinfo->stat_lock); |
| 1398 | if (sbinfo->free_blocks == 0 || |
| 1399 | shmem_acct_block(info->flags)) { |
| 1400 | spin_unlock(&sbinfo->stat_lock); |
| 1401 | spin_unlock(&info->lock); |
| 1402 | error = -ENOSPC; |
| 1403 | goto failed; |
| 1404 | } |
| 1405 | sbinfo->free_blocks--; |
| 1406 | inode->i_blocks += BLOCKS_PER_PAGE; |
| 1407 | spin_unlock(&sbinfo->stat_lock); |
| 1408 | } else if (shmem_acct_block(info->flags)) { |
| 1409 | spin_unlock(&info->lock); |
| 1410 | error = -ENOSPC; |
| 1411 | goto failed; |
| 1412 | } |
| 1413 | |
| 1414 | if (!filepage) { |
| 1415 | spin_unlock(&info->lock); |
Hugh Dickins | 02098fe | 2008-02-04 22:28:42 -0800 | [diff] [blame] | 1416 | filepage = shmem_alloc_page(gfp, info, idx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1417 | if (!filepage) { |
| 1418 | shmem_unacct_blocks(info->flags, 1); |
| 1419 | shmem_free_blocks(inode, 1); |
| 1420 | error = -ENOMEM; |
| 1421 | goto failed; |
| 1422 | } |
| 1423 | |
Hugh Dickins | 8236955 | 2008-02-07 00:14:22 -0800 | [diff] [blame] | 1424 | /* Precharge page while we can wait, compensate after */ |
| 1425 | error = mem_cgroup_cache_charge(filepage, current->mm, |
| 1426 | gfp & ~__GFP_HIGHMEM); |
| 1427 | if (error) { |
| 1428 | page_cache_release(filepage); |
| 1429 | shmem_unacct_blocks(info->flags, 1); |
| 1430 | shmem_free_blocks(inode, 1); |
| 1431 | filepage = NULL; |
| 1432 | goto failed; |
| 1433 | } |
| 1434 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1435 | spin_lock(&info->lock); |
| 1436 | entry = shmem_swp_alloc(info, idx, sgp); |
| 1437 | if (IS_ERR(entry)) |
| 1438 | error = PTR_ERR(entry); |
| 1439 | else { |
| 1440 | swap = *entry; |
| 1441 | shmem_swp_unmap(entry); |
| 1442 | } |
| 1443 | if (error || swap.val || 0 != add_to_page_cache_lru( |
Hugh Dickins | b409f9f | 2008-02-04 22:28:54 -0800 | [diff] [blame] | 1444 | filepage, mapping, idx, GFP_NOWAIT)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1445 | spin_unlock(&info->lock); |
Hugh Dickins | 8236955 | 2008-02-07 00:14:22 -0800 | [diff] [blame] | 1446 | mem_cgroup_uncharge_page(filepage); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1447 | page_cache_release(filepage); |
| 1448 | shmem_unacct_blocks(info->flags, 1); |
| 1449 | shmem_free_blocks(inode, 1); |
| 1450 | filepage = NULL; |
| 1451 | if (error) |
| 1452 | goto failed; |
| 1453 | goto repeat; |
| 1454 | } |
Hugh Dickins | 8236955 | 2008-02-07 00:14:22 -0800 | [diff] [blame] | 1455 | mem_cgroup_uncharge_page(filepage); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1456 | info->flags |= SHMEM_PAGEIN; |
| 1457 | } |
| 1458 | |
| 1459 | info->alloced++; |
| 1460 | spin_unlock(&info->lock); |
Hugh Dickins | e84e2e1 | 2007-11-28 18:55:10 +0000 | [diff] [blame] | 1461 | clear_highpage(filepage); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1462 | flush_dcache_page(filepage); |
| 1463 | SetPageUptodate(filepage); |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1464 | if (sgp == SGP_DIRTY) |
| 1465 | set_page_dirty(filepage); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1466 | } |
| 1467 | done: |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1468 | *pagep = filepage; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1469 | return 0; |
| 1470 | |
| 1471 | failed: |
| 1472 | if (*pagep != filepage) { |
| 1473 | unlock_page(filepage); |
| 1474 | page_cache_release(filepage); |
| 1475 | } |
| 1476 | return error; |
| 1477 | } |
| 1478 | |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1479 | static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1480 | { |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1481 | struct inode *inode = vma->vm_file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1482 | int error; |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1483 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1484 | |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1485 | if (((loff_t)vmf->pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode)) |
| 1486 | return VM_FAULT_SIGBUS; |
Nick Piggin | d00806b | 2007-07-19 01:46:57 -0700 | [diff] [blame] | 1487 | |
Hugh Dickins | 27d54b3 | 2008-02-04 22:28:43 -0800 | [diff] [blame] | 1488 | error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret); |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1489 | if (error) |
| 1490 | return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1491 | |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1492 | mark_page_accessed(vmf->page); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1493 | return ret | VM_FAULT_LOCKED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | } |
| 1495 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1496 | #ifdef CONFIG_NUMA |
Adrian Bunk | d8dc74f | 2007-10-16 01:26:26 -0700 | [diff] [blame] | 1497 | static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1498 | { |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1499 | struct inode *i = vma->vm_file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1500 | return mpol_set_shared_policy(&SHMEM_I(i)->policy, vma, new); |
| 1501 | } |
| 1502 | |
Adrian Bunk | d8dc74f | 2007-10-16 01:26:26 -0700 | [diff] [blame] | 1503 | static struct mempolicy *shmem_get_policy(struct vm_area_struct *vma, |
| 1504 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1505 | { |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1506 | struct inode *i = vma->vm_file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1507 | unsigned long idx; |
| 1508 | |
| 1509 | idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
| 1510 | return mpol_shared_policy_lookup(&SHMEM_I(i)->policy, idx); |
| 1511 | } |
| 1512 | #endif |
| 1513 | |
| 1514 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 1515 | { |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1516 | struct inode *inode = file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1517 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 1518 | int retval = -ENOMEM; |
| 1519 | |
| 1520 | spin_lock(&info->lock); |
| 1521 | if (lock && !(info->flags & VM_LOCKED)) { |
| 1522 | if (!user_shm_lock(inode->i_size, user)) |
| 1523 | goto out_nomem; |
| 1524 | info->flags |= VM_LOCKED; |
| 1525 | } |
| 1526 | if (!lock && (info->flags & VM_LOCKED) && user) { |
| 1527 | user_shm_unlock(inode->i_size, user); |
| 1528 | info->flags &= ~VM_LOCKED; |
| 1529 | } |
| 1530 | retval = 0; |
| 1531 | out_nomem: |
| 1532 | spin_unlock(&info->lock); |
| 1533 | return retval; |
| 1534 | } |
| 1535 | |
Adrian Bunk | 9b83a6a | 2007-02-28 20:11:03 -0800 | [diff] [blame] | 1536 | static int shmem_mmap(struct file *file, struct vm_area_struct *vma) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1537 | { |
| 1538 | file_accessed(file); |
| 1539 | vma->vm_ops = &shmem_vm_ops; |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1540 | vma->vm_flags |= VM_CAN_NONLINEAR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1541 | return 0; |
| 1542 | } |
| 1543 | |
| 1544 | static struct inode * |
| 1545 | shmem_get_inode(struct super_block *sb, int mode, dev_t dev) |
| 1546 | { |
| 1547 | struct inode *inode; |
| 1548 | struct shmem_inode_info *info; |
| 1549 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 1550 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1551 | if (shmem_reserve_inode(sb)) |
| 1552 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1553 | |
| 1554 | inode = new_inode(sb); |
| 1555 | if (inode) { |
| 1556 | inode->i_mode = mode; |
| 1557 | inode->i_uid = current->fsuid; |
| 1558 | inode->i_gid = current->fsgid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1559 | inode->i_blocks = 0; |
| 1560 | inode->i_mapping->a_ops = &shmem_aops; |
| 1561 | inode->i_mapping->backing_dev_info = &shmem_backing_dev_info; |
| 1562 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 1563 | inode->i_generation = get_seconds(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1564 | info = SHMEM_I(inode); |
| 1565 | memset(info, 0, (char *)inode - (char *)info); |
| 1566 | spin_lock_init(&info->lock); |
| 1567 | INIT_LIST_HEAD(&info->swaplist); |
| 1568 | |
| 1569 | switch (mode & S_IFMT) { |
| 1570 | default: |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 1571 | inode->i_op = &shmem_special_inode_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1572 | init_special_inode(inode, mode, dev); |
| 1573 | break; |
| 1574 | case S_IFREG: |
| 1575 | inode->i_op = &shmem_inode_operations; |
| 1576 | inode->i_fop = &shmem_file_operations; |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 1577 | mpol_shared_policy_init(&info->policy, sbinfo->policy, |
| 1578 | &sbinfo->policy_nodes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1579 | break; |
| 1580 | case S_IFDIR: |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1581 | inc_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1582 | /* Some things misbehave if size == 0 on a directory */ |
| 1583 | inode->i_size = 2 * BOGO_DIRENT_SIZE; |
| 1584 | inode->i_op = &shmem_dir_inode_operations; |
| 1585 | inode->i_fop = &simple_dir_operations; |
| 1586 | break; |
| 1587 | case S_IFLNK: |
| 1588 | /* |
| 1589 | * Must not load anything in the rbtree, |
| 1590 | * mpol_free_shared_policy will not be called. |
| 1591 | */ |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 1592 | mpol_shared_policy_init(&info->policy, MPOL_DEFAULT, |
| 1593 | NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1594 | break; |
| 1595 | } |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1596 | } else |
| 1597 | shmem_free_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1598 | return inode; |
| 1599 | } |
| 1600 | |
| 1601 | #ifdef CONFIG_TMPFS |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 1602 | static const struct inode_operations shmem_symlink_inode_operations; |
| 1603 | static const struct inode_operations shmem_symlink_inline_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1604 | |
| 1605 | /* |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1606 | * Normally tmpfs avoids the use of shmem_readpage and shmem_write_begin; |
Hugh Dickins | ae97641 | 2007-06-04 10:00:39 +0200 | [diff] [blame] | 1607 | * but providing them allows a tmpfs file to be used for splice, sendfile, and |
| 1608 | * below the loop driver, in the generic fashion that many filesystems support. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1609 | */ |
Hugh Dickins | ae97641 | 2007-06-04 10:00:39 +0200 | [diff] [blame] | 1610 | static int shmem_readpage(struct file *file, struct page *page) |
| 1611 | { |
| 1612 | struct inode *inode = page->mapping->host; |
| 1613 | int error = shmem_getpage(inode, page->index, &page, SGP_CACHE, NULL); |
| 1614 | unlock_page(page); |
| 1615 | return error; |
| 1616 | } |
| 1617 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1618 | static int |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1619 | shmem_write_begin(struct file *file, struct address_space *mapping, |
| 1620 | loff_t pos, unsigned len, unsigned flags, |
| 1621 | struct page **pagep, void **fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1622 | { |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1623 | struct inode *inode = mapping->host; |
| 1624 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
| 1625 | *pagep = NULL; |
| 1626 | return shmem_getpage(inode, index, pagep, SGP_WRITE, NULL); |
| 1627 | } |
| 1628 | |
| 1629 | static int |
| 1630 | shmem_write_end(struct file *file, struct address_space *mapping, |
| 1631 | loff_t pos, unsigned len, unsigned copied, |
| 1632 | struct page *page, void *fsdata) |
| 1633 | { |
| 1634 | struct inode *inode = mapping->host; |
| 1635 | |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1636 | if (pos + copied > inode->i_size) |
| 1637 | i_size_write(inode, pos + copied); |
| 1638 | |
| 1639 | unlock_page(page); |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1640 | set_page_dirty(page); |
| 1641 | page_cache_release(page); |
| 1642 | |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 1643 | return copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1644 | } |
| 1645 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1646 | static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor) |
| 1647 | { |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 1648 | struct inode *inode = filp->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1649 | struct address_space *mapping = inode->i_mapping; |
| 1650 | unsigned long index, offset; |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1651 | enum sgp_type sgp = SGP_READ; |
| 1652 | |
| 1653 | /* |
| 1654 | * Might this read be for a stacking filesystem? Then when reading |
| 1655 | * holes of a sparse file, we actually need to allocate those pages, |
| 1656 | * and even mark them dirty, so it cannot exceed the max_blocks limit. |
| 1657 | */ |
| 1658 | if (segment_eq(get_fs(), KERNEL_DS)) |
| 1659 | sgp = SGP_DIRTY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1660 | |
| 1661 | index = *ppos >> PAGE_CACHE_SHIFT; |
| 1662 | offset = *ppos & ~PAGE_CACHE_MASK; |
| 1663 | |
| 1664 | for (;;) { |
| 1665 | struct page *page = NULL; |
| 1666 | unsigned long end_index, nr, ret; |
| 1667 | loff_t i_size = i_size_read(inode); |
| 1668 | |
| 1669 | end_index = i_size >> PAGE_CACHE_SHIFT; |
| 1670 | if (index > end_index) |
| 1671 | break; |
| 1672 | if (index == end_index) { |
| 1673 | nr = i_size & ~PAGE_CACHE_MASK; |
| 1674 | if (nr <= offset) |
| 1675 | break; |
| 1676 | } |
| 1677 | |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1678 | desc->error = shmem_getpage(inode, index, &page, sgp, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1679 | if (desc->error) { |
| 1680 | if (desc->error == -EINVAL) |
| 1681 | desc->error = 0; |
| 1682 | break; |
| 1683 | } |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1684 | if (page) |
| 1685 | unlock_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1686 | |
| 1687 | /* |
| 1688 | * We must evaluate after, since reads (unlike writes) |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1689 | * are called without i_mutex protection against truncate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1690 | */ |
| 1691 | nr = PAGE_CACHE_SIZE; |
| 1692 | i_size = i_size_read(inode); |
| 1693 | end_index = i_size >> PAGE_CACHE_SHIFT; |
| 1694 | if (index == end_index) { |
| 1695 | nr = i_size & ~PAGE_CACHE_MASK; |
| 1696 | if (nr <= offset) { |
| 1697 | if (page) |
| 1698 | page_cache_release(page); |
| 1699 | break; |
| 1700 | } |
| 1701 | } |
| 1702 | nr -= offset; |
| 1703 | |
| 1704 | if (page) { |
| 1705 | /* |
| 1706 | * If users can be writing to this page using arbitrary |
| 1707 | * virtual addresses, take care about potential aliasing |
| 1708 | * before reading the page on the kernel side. |
| 1709 | */ |
| 1710 | if (mapping_writably_mapped(mapping)) |
| 1711 | flush_dcache_page(page); |
| 1712 | /* |
| 1713 | * Mark the page accessed if we read the beginning. |
| 1714 | */ |
| 1715 | if (!offset) |
| 1716 | mark_page_accessed(page); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 1717 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1718 | page = ZERO_PAGE(0); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 1719 | page_cache_get(page); |
| 1720 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1721 | |
| 1722 | /* |
| 1723 | * Ok, we have the page, and it's up-to-date, so |
| 1724 | * now we can copy it to user space... |
| 1725 | * |
| 1726 | * The actor routine returns how many bytes were actually used.. |
| 1727 | * NOTE! This may not be the same as how much of a user buffer |
| 1728 | * we filled up (we may be padding etc), so we can only update |
| 1729 | * "pos" here (the actor routine has to update the user buffer |
| 1730 | * pointers and the remaining count). |
| 1731 | */ |
| 1732 | ret = actor(desc, page, offset, nr); |
| 1733 | offset += ret; |
| 1734 | index += offset >> PAGE_CACHE_SHIFT; |
| 1735 | offset &= ~PAGE_CACHE_MASK; |
| 1736 | |
| 1737 | page_cache_release(page); |
| 1738 | if (ret != nr || !desc->count) |
| 1739 | break; |
| 1740 | |
| 1741 | cond_resched(); |
| 1742 | } |
| 1743 | |
| 1744 | *ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset; |
| 1745 | file_accessed(filp); |
| 1746 | } |
| 1747 | |
| 1748 | static ssize_t shmem_file_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) |
| 1749 | { |
| 1750 | read_descriptor_t desc; |
| 1751 | |
| 1752 | if ((ssize_t) count < 0) |
| 1753 | return -EINVAL; |
| 1754 | if (!access_ok(VERIFY_WRITE, buf, count)) |
| 1755 | return -EFAULT; |
| 1756 | if (!count) |
| 1757 | return 0; |
| 1758 | |
| 1759 | desc.written = 0; |
| 1760 | desc.count = count; |
| 1761 | desc.arg.buf = buf; |
| 1762 | desc.error = 0; |
| 1763 | |
| 1764 | do_shmem_file_read(filp, ppos, &desc, file_read_actor); |
| 1765 | if (desc.written) |
| 1766 | return desc.written; |
| 1767 | return desc.error; |
| 1768 | } |
| 1769 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 1770 | static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1771 | { |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 1772 | struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1773 | |
| 1774 | buf->f_type = TMPFS_MAGIC; |
| 1775 | buf->f_bsize = PAGE_CACHE_SIZE; |
| 1776 | buf->f_namelen = NAME_MAX; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1777 | spin_lock(&sbinfo->stat_lock); |
| 1778 | if (sbinfo->max_blocks) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1779 | buf->f_blocks = sbinfo->max_blocks; |
| 1780 | buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1781 | } |
| 1782 | if (sbinfo->max_inodes) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1783 | buf->f_files = sbinfo->max_inodes; |
| 1784 | buf->f_ffree = sbinfo->free_inodes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1785 | } |
| 1786 | /* else leave those fields 0 like simple_statfs */ |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 1787 | spin_unlock(&sbinfo->stat_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1788 | return 0; |
| 1789 | } |
| 1790 | |
| 1791 | /* |
| 1792 | * File creation. Allocate an inode, and we're done.. |
| 1793 | */ |
| 1794 | static int |
| 1795 | shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) |
| 1796 | { |
| 1797 | struct inode *inode = shmem_get_inode(dir->i_sb, mode, dev); |
| 1798 | int error = -ENOSPC; |
| 1799 | |
| 1800 | if (inode) { |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 1801 | error = security_inode_init_security(inode, dir, NULL, NULL, |
| 1802 | NULL); |
| 1803 | if (error) { |
| 1804 | if (error != -EOPNOTSUPP) { |
| 1805 | iput(inode); |
| 1806 | return error; |
| 1807 | } |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 1808 | } |
| 1809 | error = shmem_acl_init(inode, dir); |
| 1810 | if (error) { |
| 1811 | iput(inode); |
| 1812 | return error; |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 1813 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1814 | if (dir->i_mode & S_ISGID) { |
| 1815 | inode->i_gid = dir->i_gid; |
| 1816 | if (S_ISDIR(mode)) |
| 1817 | inode->i_mode |= S_ISGID; |
| 1818 | } |
| 1819 | dir->i_size += BOGO_DIRENT_SIZE; |
| 1820 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| 1821 | d_instantiate(dentry, inode); |
| 1822 | dget(dentry); /* Extra count - pin the dentry in core */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1823 | } |
| 1824 | return error; |
| 1825 | } |
| 1826 | |
| 1827 | static int shmem_mkdir(struct inode *dir, struct dentry *dentry, int mode) |
| 1828 | { |
| 1829 | int error; |
| 1830 | |
| 1831 | if ((error = shmem_mknod(dir, dentry, mode | S_IFDIR, 0))) |
| 1832 | return error; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1833 | inc_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1834 | return 0; |
| 1835 | } |
| 1836 | |
| 1837 | static int shmem_create(struct inode *dir, struct dentry *dentry, int mode, |
| 1838 | struct nameidata *nd) |
| 1839 | { |
| 1840 | return shmem_mknod(dir, dentry, mode | S_IFREG, 0); |
| 1841 | } |
| 1842 | |
| 1843 | /* |
| 1844 | * Link a file.. |
| 1845 | */ |
| 1846 | static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
| 1847 | { |
| 1848 | struct inode *inode = old_dentry->d_inode; |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1849 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1850 | |
| 1851 | /* |
| 1852 | * No ordinary (disk based) filesystem counts links as inodes; |
| 1853 | * but each new link needs a new dentry, pinning lowmem, and |
| 1854 | * tmpfs dentries cannot be pruned until they are unlinked. |
| 1855 | */ |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1856 | ret = shmem_reserve_inode(inode->i_sb); |
| 1857 | if (ret) |
| 1858 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1859 | |
| 1860 | dir->i_size += BOGO_DIRENT_SIZE; |
| 1861 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1862 | inc_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1863 | atomic_inc(&inode->i_count); /* New dentry reference */ |
| 1864 | dget(dentry); /* Extra pinning count for the created dentry */ |
| 1865 | d_instantiate(dentry, inode); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1866 | out: |
| 1867 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1868 | } |
| 1869 | |
| 1870 | static int shmem_unlink(struct inode *dir, struct dentry *dentry) |
| 1871 | { |
| 1872 | struct inode *inode = dentry->d_inode; |
| 1873 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1874 | if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) |
| 1875 | shmem_free_inode(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1876 | |
| 1877 | dir->i_size -= BOGO_DIRENT_SIZE; |
| 1878 | inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 1879 | drop_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1880 | dput(dentry); /* Undo the count from "create" - this does all the work */ |
| 1881 | return 0; |
| 1882 | } |
| 1883 | |
| 1884 | static int shmem_rmdir(struct inode *dir, struct dentry *dentry) |
| 1885 | { |
| 1886 | if (!simple_empty(dentry)) |
| 1887 | return -ENOTEMPTY; |
| 1888 | |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 1889 | drop_nlink(dentry->d_inode); |
| 1890 | drop_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1891 | return shmem_unlink(dir, dentry); |
| 1892 | } |
| 1893 | |
| 1894 | /* |
| 1895 | * The VFS layer already does all the dentry stuff for rename, |
| 1896 | * we just have to decrement the usage count for the target if |
| 1897 | * it exists so that the VFS layer correctly free's it when it |
| 1898 | * gets overwritten. |
| 1899 | */ |
| 1900 | static int shmem_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) |
| 1901 | { |
| 1902 | struct inode *inode = old_dentry->d_inode; |
| 1903 | int they_are_dirs = S_ISDIR(inode->i_mode); |
| 1904 | |
| 1905 | if (!simple_empty(new_dentry)) |
| 1906 | return -ENOTEMPTY; |
| 1907 | |
| 1908 | if (new_dentry->d_inode) { |
| 1909 | (void) shmem_unlink(new_dir, new_dentry); |
| 1910 | if (they_are_dirs) |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 1911 | drop_nlink(old_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1912 | } else if (they_are_dirs) { |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 1913 | drop_nlink(old_dir); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 1914 | inc_nlink(new_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1915 | } |
| 1916 | |
| 1917 | old_dir->i_size -= BOGO_DIRENT_SIZE; |
| 1918 | new_dir->i_size += BOGO_DIRENT_SIZE; |
| 1919 | old_dir->i_ctime = old_dir->i_mtime = |
| 1920 | new_dir->i_ctime = new_dir->i_mtime = |
| 1921 | inode->i_ctime = CURRENT_TIME; |
| 1922 | return 0; |
| 1923 | } |
| 1924 | |
| 1925 | static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *symname) |
| 1926 | { |
| 1927 | int error; |
| 1928 | int len; |
| 1929 | struct inode *inode; |
| 1930 | struct page *page = NULL; |
| 1931 | char *kaddr; |
| 1932 | struct shmem_inode_info *info; |
| 1933 | |
| 1934 | len = strlen(symname) + 1; |
| 1935 | if (len > PAGE_CACHE_SIZE) |
| 1936 | return -ENAMETOOLONG; |
| 1937 | |
| 1938 | inode = shmem_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0); |
| 1939 | if (!inode) |
| 1940 | return -ENOSPC; |
| 1941 | |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 1942 | error = security_inode_init_security(inode, dir, NULL, NULL, |
| 1943 | NULL); |
| 1944 | if (error) { |
| 1945 | if (error != -EOPNOTSUPP) { |
| 1946 | iput(inode); |
| 1947 | return error; |
| 1948 | } |
| 1949 | error = 0; |
| 1950 | } |
| 1951 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1952 | info = SHMEM_I(inode); |
| 1953 | inode->i_size = len-1; |
| 1954 | if (len <= (char *)inode - (char *)info) { |
| 1955 | /* do it inline */ |
| 1956 | memcpy(info, symname, len); |
| 1957 | inode->i_op = &shmem_symlink_inline_operations; |
| 1958 | } else { |
| 1959 | error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL); |
| 1960 | if (error) { |
| 1961 | iput(inode); |
| 1962 | return error; |
| 1963 | } |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1964 | unlock_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1965 | inode->i_op = &shmem_symlink_inode_operations; |
| 1966 | kaddr = kmap_atomic(page, KM_USER0); |
| 1967 | memcpy(kaddr, symname, len); |
| 1968 | kunmap_atomic(kaddr, KM_USER0); |
| 1969 | set_page_dirty(page); |
| 1970 | page_cache_release(page); |
| 1971 | } |
| 1972 | if (dir->i_mode & S_ISGID) |
| 1973 | inode->i_gid = dir->i_gid; |
| 1974 | dir->i_size += BOGO_DIRENT_SIZE; |
| 1975 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| 1976 | d_instantiate(dentry, inode); |
| 1977 | dget(dentry); |
| 1978 | return 0; |
| 1979 | } |
| 1980 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 1981 | static void *shmem_follow_link_inline(struct dentry *dentry, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1982 | { |
| 1983 | nd_set_link(nd, (char *)SHMEM_I(dentry->d_inode)); |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 1984 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1985 | } |
| 1986 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 1987 | static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1988 | { |
| 1989 | struct page *page = NULL; |
| 1990 | int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL); |
| 1991 | nd_set_link(nd, res ? ERR_PTR(res) : kmap(page)); |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 1992 | if (page) |
| 1993 | unlock_page(page); |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 1994 | return page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1995 | } |
| 1996 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 1997 | 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] | 1998 | { |
| 1999 | if (!IS_ERR(nd_get_link(nd))) { |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2000 | struct page *page = cookie; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2001 | kunmap(page); |
| 2002 | mark_page_accessed(page); |
| 2003 | page_cache_release(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2004 | } |
| 2005 | } |
| 2006 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2007 | static const struct inode_operations shmem_symlink_inline_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2008 | .readlink = generic_readlink, |
| 2009 | .follow_link = shmem_follow_link_inline, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2010 | }; |
| 2011 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2012 | static const struct inode_operations shmem_symlink_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2013 | .truncate = shmem_truncate, |
| 2014 | .readlink = generic_readlink, |
| 2015 | .follow_link = shmem_follow_link, |
| 2016 | .put_link = shmem_put_link, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2017 | }; |
| 2018 | |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2019 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 2020 | /** |
| 2021 | * Superblocks without xattr inode operations will get security.* xattr |
| 2022 | * support from the VFS "for free". As soon as we have any other xattrs |
| 2023 | * like ACLs, we also need to implement the security.* handlers at |
| 2024 | * filesystem level, though. |
| 2025 | */ |
| 2026 | |
| 2027 | static size_t shmem_xattr_security_list(struct inode *inode, char *list, |
| 2028 | size_t list_len, const char *name, |
| 2029 | size_t name_len) |
| 2030 | { |
| 2031 | return security_inode_listsecurity(inode, list, list_len); |
| 2032 | } |
| 2033 | |
| 2034 | static int shmem_xattr_security_get(struct inode *inode, const char *name, |
| 2035 | void *buffer, size_t size) |
| 2036 | { |
| 2037 | if (strcmp(name, "") == 0) |
| 2038 | return -EINVAL; |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 2039 | return xattr_getsecurity(inode, name, buffer, size); |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2040 | } |
| 2041 | |
| 2042 | static int shmem_xattr_security_set(struct inode *inode, const char *name, |
| 2043 | const void *value, size_t size, int flags) |
| 2044 | { |
| 2045 | if (strcmp(name, "") == 0) |
| 2046 | return -EINVAL; |
| 2047 | return security_inode_setsecurity(inode, name, value, size, flags); |
| 2048 | } |
| 2049 | |
Adrian Bunk | 1f370a2 | 2006-12-06 20:38:21 -0800 | [diff] [blame] | 2050 | static struct xattr_handler shmem_xattr_security_handler = { |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2051 | .prefix = XATTR_SECURITY_PREFIX, |
| 2052 | .list = shmem_xattr_security_list, |
| 2053 | .get = shmem_xattr_security_get, |
| 2054 | .set = shmem_xattr_security_set, |
| 2055 | }; |
| 2056 | |
| 2057 | static struct xattr_handler *shmem_xattr_handlers[] = { |
| 2058 | &shmem_xattr_acl_access_handler, |
| 2059 | &shmem_xattr_acl_default_handler, |
| 2060 | &shmem_xattr_security_handler, |
| 2061 | NULL |
| 2062 | }; |
| 2063 | #endif |
| 2064 | |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2065 | static struct dentry *shmem_get_parent(struct dentry *child) |
| 2066 | { |
| 2067 | return ERR_PTR(-ESTALE); |
| 2068 | } |
| 2069 | |
| 2070 | static int shmem_match(struct inode *ino, void *vfh) |
| 2071 | { |
| 2072 | __u32 *fh = vfh; |
| 2073 | __u64 inum = fh[2]; |
| 2074 | inum = (inum << 32) | fh[1]; |
| 2075 | return ino->i_ino == inum && fh[0] == ino->i_generation; |
| 2076 | } |
| 2077 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2078 | static struct dentry *shmem_fh_to_dentry(struct super_block *sb, |
| 2079 | struct fid *fid, int fh_len, int fh_type) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2080 | { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2081 | struct inode *inode; |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2082 | struct dentry *dentry = NULL; |
| 2083 | u64 inum = fid->raw[2]; |
| 2084 | inum = (inum << 32) | fid->raw[1]; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2085 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2086 | if (fh_len < 3) |
| 2087 | return NULL; |
| 2088 | |
| 2089 | inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), |
| 2090 | shmem_match, fid->raw); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2091 | if (inode) { |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2092 | dentry = d_find_alias(inode); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2093 | iput(inode); |
| 2094 | } |
| 2095 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2096 | return dentry; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2097 | } |
| 2098 | |
| 2099 | static int shmem_encode_fh(struct dentry *dentry, __u32 *fh, int *len, |
| 2100 | int connectable) |
| 2101 | { |
| 2102 | struct inode *inode = dentry->d_inode; |
| 2103 | |
| 2104 | if (*len < 3) |
| 2105 | return 255; |
| 2106 | |
| 2107 | if (hlist_unhashed(&inode->i_hash)) { |
| 2108 | /* Unfortunately insert_inode_hash is not idempotent, |
| 2109 | * so as we hash inodes here rather than at creation |
| 2110 | * time, we need a lock to ensure we only try |
| 2111 | * to do it once |
| 2112 | */ |
| 2113 | static DEFINE_SPINLOCK(lock); |
| 2114 | spin_lock(&lock); |
| 2115 | if (hlist_unhashed(&inode->i_hash)) |
| 2116 | __insert_inode_hash(inode, |
| 2117 | inode->i_ino + inode->i_generation); |
| 2118 | spin_unlock(&lock); |
| 2119 | } |
| 2120 | |
| 2121 | fh[0] = inode->i_generation; |
| 2122 | fh[1] = inode->i_ino; |
| 2123 | fh[2] = ((__u64)inode->i_ino) >> 32; |
| 2124 | |
| 2125 | *len = 3; |
| 2126 | return 1; |
| 2127 | } |
| 2128 | |
Christoph Hellwig | 3965516 | 2007-10-21 16:42:17 -0700 | [diff] [blame] | 2129 | static const struct export_operations shmem_export_ops = { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2130 | .get_parent = shmem_get_parent, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2131 | .encode_fh = shmem_encode_fh, |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 2132 | .fh_to_dentry = shmem_fh_to_dentry, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2133 | }; |
| 2134 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2135 | static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo, |
| 2136 | bool remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2137 | { |
| 2138 | char *this_char, *value, *rest; |
| 2139 | |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 2140 | while (options != NULL) { |
| 2141 | this_char = options; |
| 2142 | for (;;) { |
| 2143 | /* |
| 2144 | * NUL-terminate this option: unfortunately, |
| 2145 | * mount options form a comma-separated list, |
| 2146 | * but mpol's nodelist may also contain commas. |
| 2147 | */ |
| 2148 | options = strchr(options, ','); |
| 2149 | if (options == NULL) |
| 2150 | break; |
| 2151 | options++; |
| 2152 | if (!isdigit(*options)) { |
| 2153 | options[-1] = '\0'; |
| 2154 | break; |
| 2155 | } |
| 2156 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2157 | if (!*this_char) |
| 2158 | continue; |
| 2159 | if ((value = strchr(this_char,'=')) != NULL) { |
| 2160 | *value++ = 0; |
| 2161 | } else { |
| 2162 | printk(KERN_ERR |
| 2163 | "tmpfs: No value for mount option '%s'\n", |
| 2164 | this_char); |
| 2165 | return 1; |
| 2166 | } |
| 2167 | |
| 2168 | if (!strcmp(this_char,"size")) { |
| 2169 | unsigned long long size; |
| 2170 | size = memparse(value,&rest); |
| 2171 | if (*rest == '%') { |
| 2172 | size <<= PAGE_SHIFT; |
| 2173 | size *= totalram_pages; |
| 2174 | do_div(size, 100); |
| 2175 | rest++; |
| 2176 | } |
| 2177 | if (*rest) |
| 2178 | goto bad_val; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2179 | sbinfo->max_blocks = |
| 2180 | DIV_ROUND_UP(size, PAGE_CACHE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2181 | } else if (!strcmp(this_char,"nr_blocks")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2182 | sbinfo->max_blocks = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2183 | if (*rest) |
| 2184 | goto bad_val; |
| 2185 | } else if (!strcmp(this_char,"nr_inodes")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2186 | sbinfo->max_inodes = memparse(value, &rest); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2187 | if (*rest) |
| 2188 | goto bad_val; |
| 2189 | } else if (!strcmp(this_char,"mode")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2190 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2191 | continue; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2192 | sbinfo->mode = simple_strtoul(value, &rest, 8) & 07777; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2193 | if (*rest) |
| 2194 | goto bad_val; |
| 2195 | } else if (!strcmp(this_char,"uid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2196 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2197 | continue; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2198 | sbinfo->uid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2199 | if (*rest) |
| 2200 | goto bad_val; |
| 2201 | } else if (!strcmp(this_char,"gid")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2202 | if (remount) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2203 | continue; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2204 | sbinfo->gid = simple_strtoul(value, &rest, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2205 | if (*rest) |
| 2206 | goto bad_val; |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 2207 | } else if (!strcmp(this_char,"mpol")) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2208 | if (shmem_parse_mpol(value, &sbinfo->policy, |
| 2209 | &sbinfo->policy_nodes)) |
Robin Holt | 7339ff8 | 2006-01-14 13:20:48 -0800 | [diff] [blame] | 2210 | goto bad_val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2211 | } else { |
| 2212 | printk(KERN_ERR "tmpfs: Bad mount option %s\n", |
| 2213 | this_char); |
| 2214 | return 1; |
| 2215 | } |
| 2216 | } |
| 2217 | return 0; |
| 2218 | |
| 2219 | bad_val: |
| 2220 | printk(KERN_ERR "tmpfs: Bad value '%s' for mount option '%s'\n", |
| 2221 | value, this_char); |
| 2222 | return 1; |
| 2223 | |
| 2224 | } |
| 2225 | |
| 2226 | static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) |
| 2227 | { |
| 2228 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2229 | struct shmem_sb_info config = *sbinfo; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2230 | unsigned long blocks; |
| 2231 | unsigned long inodes; |
| 2232 | int error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2233 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2234 | if (shmem_parse_options(data, &config, true)) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2235 | return error; |
| 2236 | |
| 2237 | spin_lock(&sbinfo->stat_lock); |
| 2238 | blocks = sbinfo->max_blocks - sbinfo->free_blocks; |
| 2239 | inodes = sbinfo->max_inodes - sbinfo->free_inodes; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2240 | if (config.max_blocks < blocks) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2241 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2242 | if (config.max_inodes < inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2243 | goto out; |
| 2244 | /* |
| 2245 | * Those tests also disallow limited->unlimited while any are in |
| 2246 | * use, so i_blocks will always be zero when max_blocks is zero; |
| 2247 | * but we must separately disallow unlimited->limited, because |
| 2248 | * in that case we have no record of how much is already in use. |
| 2249 | */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2250 | if (config.max_blocks && !sbinfo->max_blocks) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2251 | goto out; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2252 | if (config.max_inodes && !sbinfo->max_inodes) |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2253 | goto out; |
| 2254 | |
| 2255 | error = 0; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2256 | sbinfo->max_blocks = config.max_blocks; |
| 2257 | sbinfo->free_blocks = config.max_blocks - blocks; |
| 2258 | sbinfo->max_inodes = config.max_inodes; |
| 2259 | sbinfo->free_inodes = config.max_inodes - inodes; |
| 2260 | sbinfo->policy = config.policy; |
| 2261 | sbinfo->policy_nodes = config.policy_nodes; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2262 | out: |
| 2263 | spin_unlock(&sbinfo->stat_lock); |
| 2264 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2265 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2266 | |
| 2267 | static int shmem_show_options(struct seq_file *seq, struct vfsmount *vfs) |
| 2268 | { |
| 2269 | struct shmem_sb_info *sbinfo = SHMEM_SB(vfs->mnt_sb); |
| 2270 | |
| 2271 | if (sbinfo->max_blocks != shmem_default_max_blocks()) |
| 2272 | seq_printf(seq, ",size=%luk", |
| 2273 | sbinfo->max_blocks << (PAGE_CACHE_SHIFT - 10)); |
| 2274 | if (sbinfo->max_inodes != shmem_default_max_inodes()) |
| 2275 | seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes); |
| 2276 | if (sbinfo->mode != (S_IRWXUGO | S_ISVTX)) |
| 2277 | seq_printf(seq, ",mode=%03o", sbinfo->mode); |
| 2278 | if (sbinfo->uid != 0) |
| 2279 | seq_printf(seq, ",uid=%u", sbinfo->uid); |
| 2280 | if (sbinfo->gid != 0) |
| 2281 | seq_printf(seq, ",gid=%u", sbinfo->gid); |
| 2282 | shmem_show_mpol(seq, sbinfo->policy, sbinfo->policy_nodes); |
| 2283 | return 0; |
| 2284 | } |
| 2285 | #endif /* CONFIG_TMPFS */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2286 | |
| 2287 | static void shmem_put_super(struct super_block *sb) |
| 2288 | { |
| 2289 | kfree(sb->s_fs_info); |
| 2290 | sb->s_fs_info = NULL; |
| 2291 | } |
| 2292 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2293 | static int shmem_fill_super(struct super_block *sb, |
| 2294 | void *data, int silent) |
| 2295 | { |
| 2296 | struct inode *inode; |
| 2297 | struct dentry *root; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2298 | struct shmem_sb_info *sbinfo; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2299 | int err = -ENOMEM; |
| 2300 | |
| 2301 | /* Round up to L1_CACHE_BYTES to resist false sharing */ |
| 2302 | sbinfo = kmalloc(max((int)sizeof(struct shmem_sb_info), |
| 2303 | L1_CACHE_BYTES), GFP_KERNEL); |
| 2304 | if (!sbinfo) |
| 2305 | return -ENOMEM; |
| 2306 | |
| 2307 | sbinfo->max_blocks = 0; |
| 2308 | sbinfo->max_inodes = 0; |
| 2309 | sbinfo->mode = S_IRWXUGO | S_ISVTX; |
| 2310 | sbinfo->uid = current->fsuid; |
| 2311 | sbinfo->gid = current->fsgid; |
| 2312 | sbinfo->policy = MPOL_DEFAULT; |
| 2313 | sbinfo->policy_nodes = node_states[N_HIGH_MEMORY]; |
| 2314 | sb->s_fs_info = sbinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2315 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2316 | #ifdef CONFIG_TMPFS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2317 | /* |
| 2318 | * Per default we only allow half of the physical ram per |
| 2319 | * tmpfs instance, limiting inodes to one per page of lowmem; |
| 2320 | * but the internal instance is left unlimited. |
| 2321 | */ |
| 2322 | if (!(sb->s_flags & MS_NOUSER)) { |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2323 | sbinfo->max_blocks = shmem_default_max_blocks(); |
| 2324 | sbinfo->max_inodes = shmem_default_max_inodes(); |
| 2325 | if (shmem_parse_options(data, sbinfo, false)) { |
| 2326 | err = -EINVAL; |
| 2327 | goto failed; |
| 2328 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2329 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 2330 | sb->s_export_op = &shmem_export_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2331 | #else |
| 2332 | sb->s_flags |= MS_NOUSER; |
| 2333 | #endif |
| 2334 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2335 | spin_lock_init(&sbinfo->stat_lock); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2336 | sbinfo->free_blocks = sbinfo->max_blocks; |
| 2337 | sbinfo->free_inodes = sbinfo->max_inodes; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2338 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2339 | sb->s_maxbytes = SHMEM_MAX_BYTES; |
| 2340 | sb->s_blocksize = PAGE_CACHE_SIZE; |
| 2341 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| 2342 | sb->s_magic = TMPFS_MAGIC; |
| 2343 | sb->s_op = &shmem_ops; |
Robin H. Johnson | cfd95a9 | 2006-06-12 21:50:25 +0100 | [diff] [blame] | 2344 | sb->s_time_gran = 1; |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2345 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 2346 | sb->s_xattr = shmem_xattr_handlers; |
| 2347 | sb->s_flags |= MS_POSIXACL; |
| 2348 | #endif |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2349 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2350 | inode = shmem_get_inode(sb, S_IFDIR | sbinfo->mode, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2351 | if (!inode) |
| 2352 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2353 | inode->i_uid = sbinfo->uid; |
| 2354 | inode->i_gid = sbinfo->gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2355 | root = d_alloc_root(inode); |
| 2356 | if (!root) |
| 2357 | goto failed_iput; |
| 2358 | sb->s_root = root; |
| 2359 | return 0; |
| 2360 | |
| 2361 | failed_iput: |
| 2362 | iput(inode); |
| 2363 | failed: |
| 2364 | shmem_put_super(sb); |
| 2365 | return err; |
| 2366 | } |
| 2367 | |
Pekka Enberg | fcc234f | 2006-03-22 00:08:13 -0800 | [diff] [blame] | 2368 | static struct kmem_cache *shmem_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2369 | |
| 2370 | static struct inode *shmem_alloc_inode(struct super_block *sb) |
| 2371 | { |
| 2372 | struct shmem_inode_info *p; |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 2373 | p = (struct shmem_inode_info *)kmem_cache_alloc(shmem_inode_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2374 | if (!p) |
| 2375 | return NULL; |
| 2376 | return &p->vfs_inode; |
| 2377 | } |
| 2378 | |
| 2379 | static void shmem_destroy_inode(struct inode *inode) |
| 2380 | { |
| 2381 | if ((inode->i_mode & S_IFMT) == S_IFREG) { |
| 2382 | /* only struct inode is valid if it's an inline symlink */ |
| 2383 | mpol_free_shared_policy(&SHMEM_I(inode)->policy); |
| 2384 | } |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2385 | shmem_acl_destroy_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2386 | kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode)); |
| 2387 | } |
| 2388 | |
Christoph Lameter | 4ba9b9d | 2007-10-16 23:25:51 -0700 | [diff] [blame] | 2389 | static void init_once(struct kmem_cache *cachep, void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2390 | { |
| 2391 | struct shmem_inode_info *p = (struct shmem_inode_info *) foo; |
| 2392 | |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 2393 | inode_init_once(&p->vfs_inode); |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2394 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 2395 | p->i_acl = NULL; |
| 2396 | p->i_default_acl = NULL; |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2397 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2398 | } |
| 2399 | |
| 2400 | static int init_inodecache(void) |
| 2401 | { |
| 2402 | shmem_inode_cachep = kmem_cache_create("shmem_inode_cache", |
| 2403 | sizeof(struct shmem_inode_info), |
Alexey Dobriyan | 040b5c6 | 2007-10-16 23:26:10 -0700 | [diff] [blame] | 2404 | 0, SLAB_PANIC, init_once); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2405 | return 0; |
| 2406 | } |
| 2407 | |
| 2408 | static void destroy_inodecache(void) |
| 2409 | { |
Alexey Dobriyan | 1a1d92c | 2006-09-27 01:49:40 -0700 | [diff] [blame] | 2410 | kmem_cache_destroy(shmem_inode_cachep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2411 | } |
| 2412 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 2413 | static const struct address_space_operations shmem_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2414 | .writepage = shmem_writepage, |
Ken Chen | 7671932 | 2007-02-10 01:43:15 -0800 | [diff] [blame] | 2415 | .set_page_dirty = __set_page_dirty_no_writeback, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2416 | #ifdef CONFIG_TMPFS |
Hugh Dickins | ae97641 | 2007-06-04 10:00:39 +0200 | [diff] [blame] | 2417 | .readpage = shmem_readpage, |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2418 | .write_begin = shmem_write_begin, |
| 2419 | .write_end = shmem_write_end, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2420 | #endif |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 2421 | .migratepage = migrate_page, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2422 | }; |
| 2423 | |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 2424 | static const struct file_operations shmem_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2425 | .mmap = shmem_mmap, |
| 2426 | #ifdef CONFIG_TMPFS |
| 2427 | .llseek = generic_file_llseek, |
| 2428 | .read = shmem_file_read, |
Hugh Dickins | 5402b97 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2429 | .write = do_sync_write, |
| 2430 | .aio_write = generic_file_aio_write, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2431 | .fsync = simple_sync_file, |
Hugh Dickins | ae97641 | 2007-06-04 10:00:39 +0200 | [diff] [blame] | 2432 | .splice_read = generic_file_splice_read, |
| 2433 | .splice_write = generic_file_splice_write, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2434 | #endif |
| 2435 | }; |
| 2436 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2437 | static const struct inode_operations shmem_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2438 | .truncate = shmem_truncate, |
| 2439 | .setattr = shmem_notify_change, |
Badari Pulavarty | f6b3ec2 | 2006-01-06 00:10:38 -0800 | [diff] [blame] | 2440 | .truncate_range = shmem_truncate_range, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2441 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 2442 | .setxattr = generic_setxattr, |
| 2443 | .getxattr = generic_getxattr, |
| 2444 | .listxattr = generic_listxattr, |
| 2445 | .removexattr = generic_removexattr, |
| 2446 | .permission = shmem_permission, |
| 2447 | #endif |
| 2448 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2449 | }; |
| 2450 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2451 | static const struct inode_operations shmem_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2452 | #ifdef CONFIG_TMPFS |
| 2453 | .create = shmem_create, |
| 2454 | .lookup = simple_lookup, |
| 2455 | .link = shmem_link, |
| 2456 | .unlink = shmem_unlink, |
| 2457 | .symlink = shmem_symlink, |
| 2458 | .mkdir = shmem_mkdir, |
| 2459 | .rmdir = shmem_rmdir, |
| 2460 | .mknod = shmem_mknod, |
| 2461 | .rename = shmem_rename, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2462 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2463 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 2464 | .setattr = shmem_notify_change, |
| 2465 | .setxattr = generic_setxattr, |
| 2466 | .getxattr = generic_getxattr, |
| 2467 | .listxattr = generic_listxattr, |
| 2468 | .removexattr = generic_removexattr, |
| 2469 | .permission = shmem_permission, |
| 2470 | #endif |
| 2471 | }; |
| 2472 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2473 | static const struct inode_operations shmem_special_inode_operations = { |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2474 | #ifdef CONFIG_TMPFS_POSIX_ACL |
| 2475 | .setattr = shmem_notify_change, |
| 2476 | .setxattr = generic_setxattr, |
| 2477 | .getxattr = generic_getxattr, |
| 2478 | .listxattr = generic_listxattr, |
| 2479 | .removexattr = generic_removexattr, |
| 2480 | .permission = shmem_permission, |
| 2481 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2482 | }; |
| 2483 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 2484 | static const struct super_operations shmem_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2485 | .alloc_inode = shmem_alloc_inode, |
| 2486 | .destroy_inode = shmem_destroy_inode, |
| 2487 | #ifdef CONFIG_TMPFS |
| 2488 | .statfs = shmem_statfs, |
| 2489 | .remount_fs = shmem_remount_fs, |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame^] | 2490 | .show_options = shmem_show_options, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2491 | #endif |
| 2492 | .delete_inode = shmem_delete_inode, |
| 2493 | .drop_inode = generic_delete_inode, |
| 2494 | .put_super = shmem_put_super, |
| 2495 | }; |
| 2496 | |
| 2497 | static struct vm_operations_struct shmem_vm_ops = { |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 2498 | .fault = shmem_fault, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2499 | #ifdef CONFIG_NUMA |
| 2500 | .set_policy = shmem_set_policy, |
| 2501 | .get_policy = shmem_get_policy, |
| 2502 | #endif |
| 2503 | }; |
| 2504 | |
| 2505 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 2506 | static int shmem_get_sb(struct file_system_type *fs_type, |
| 2507 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2508 | { |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 2509 | return get_sb_nodev(fs_type, flags, data, shmem_fill_super, mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2510 | } |
| 2511 | |
| 2512 | static struct file_system_type tmpfs_fs_type = { |
| 2513 | .owner = THIS_MODULE, |
| 2514 | .name = "tmpfs", |
| 2515 | .get_sb = shmem_get_sb, |
| 2516 | .kill_sb = kill_litter_super, |
| 2517 | }; |
| 2518 | static struct vfsmount *shm_mnt; |
| 2519 | |
| 2520 | static int __init init_tmpfs(void) |
| 2521 | { |
| 2522 | int error; |
| 2523 | |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 2524 | error = bdi_init(&shmem_backing_dev_info); |
| 2525 | if (error) |
| 2526 | goto out4; |
| 2527 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2528 | error = init_inodecache(); |
| 2529 | if (error) |
| 2530 | goto out3; |
| 2531 | |
| 2532 | error = register_filesystem(&tmpfs_fs_type); |
| 2533 | if (error) { |
| 2534 | printk(KERN_ERR "Could not register tmpfs\n"); |
| 2535 | goto out2; |
| 2536 | } |
Greg Kroah-Hartman | 95dc112 | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 2537 | |
Trond Myklebust | 1f5ce9e | 2006-06-09 09:34:16 -0400 | [diff] [blame] | 2538 | shm_mnt = vfs_kern_mount(&tmpfs_fs_type, MS_NOUSER, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2539 | tmpfs_fs_type.name, NULL); |
| 2540 | if (IS_ERR(shm_mnt)) { |
| 2541 | error = PTR_ERR(shm_mnt); |
| 2542 | printk(KERN_ERR "Could not kern_mount tmpfs\n"); |
| 2543 | goto out1; |
| 2544 | } |
| 2545 | return 0; |
| 2546 | |
| 2547 | out1: |
| 2548 | unregister_filesystem(&tmpfs_fs_type); |
| 2549 | out2: |
| 2550 | destroy_inodecache(); |
| 2551 | out3: |
Peter Zijlstra | e0bf68d | 2007-10-16 23:25:46 -0700 | [diff] [blame] | 2552 | bdi_destroy(&shmem_backing_dev_info); |
| 2553 | out4: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2554 | shm_mnt = ERR_PTR(error); |
| 2555 | return error; |
| 2556 | } |
| 2557 | module_init(init_tmpfs) |
| 2558 | |
| 2559 | /* |
| 2560 | * shmem_file_setup - get an unlinked file living in tmpfs |
| 2561 | * |
| 2562 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 2563 | * @size: size to be set for the file |
| 2564 | * |
| 2565 | */ |
| 2566 | struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags) |
| 2567 | { |
| 2568 | int error; |
| 2569 | struct file *file; |
| 2570 | struct inode *inode; |
| 2571 | struct dentry *dentry, *root; |
| 2572 | struct qstr this; |
| 2573 | |
| 2574 | if (IS_ERR(shm_mnt)) |
| 2575 | return (void *)shm_mnt; |
| 2576 | |
| 2577 | if (size < 0 || size > SHMEM_MAX_BYTES) |
| 2578 | return ERR_PTR(-EINVAL); |
| 2579 | |
| 2580 | if (shmem_acct_size(flags, size)) |
| 2581 | return ERR_PTR(-ENOMEM); |
| 2582 | |
| 2583 | error = -ENOMEM; |
| 2584 | this.name = name; |
| 2585 | this.len = strlen(name); |
| 2586 | this.hash = 0; /* will go */ |
| 2587 | root = shm_mnt->mnt_root; |
| 2588 | dentry = d_alloc(root, &this); |
| 2589 | if (!dentry) |
| 2590 | goto put_memory; |
| 2591 | |
| 2592 | error = -ENFILE; |
| 2593 | file = get_empty_filp(); |
| 2594 | if (!file) |
| 2595 | goto put_dentry; |
| 2596 | |
| 2597 | error = -ENOSPC; |
| 2598 | inode = shmem_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0); |
| 2599 | if (!inode) |
| 2600 | goto close_file; |
| 2601 | |
| 2602 | SHMEM_I(inode)->flags = flags & VM_ACCOUNT; |
| 2603 | d_instantiate(dentry, inode); |
| 2604 | inode->i_size = size; |
| 2605 | inode->i_nlink = 0; /* It is unlinked */ |
Dave Hansen | ce8d2cd | 2007-10-16 23:31:13 -0700 | [diff] [blame] | 2606 | init_file(file, shm_mnt, dentry, FMODE_WRITE | FMODE_READ, |
| 2607 | &shmem_file_operations); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2608 | return file; |
| 2609 | |
| 2610 | close_file: |
| 2611 | put_filp(file); |
| 2612 | put_dentry: |
| 2613 | dput(dentry); |
| 2614 | put_memory: |
| 2615 | shmem_unacct_size(flags, size); |
| 2616 | return ERR_PTR(error); |
| 2617 | } |
| 2618 | |
| 2619 | /* |
| 2620 | * shmem_zero_setup - setup a shared anonymous mapping |
| 2621 | * |
| 2622 | * @vma: the vma to be mmapped is prepared by do_mmap_pgoff |
| 2623 | */ |
| 2624 | int shmem_zero_setup(struct vm_area_struct *vma) |
| 2625 | { |
| 2626 | struct file *file; |
| 2627 | loff_t size = vma->vm_end - vma->vm_start; |
| 2628 | |
| 2629 | file = shmem_file_setup("dev/zero", size, vma->vm_flags); |
| 2630 | if (IS_ERR(file)) |
| 2631 | return PTR_ERR(file); |
| 2632 | |
| 2633 | if (vma->vm_file) |
| 2634 | fput(vma->vm_file); |
| 2635 | vma->vm_file = file; |
| 2636 | vma->vm_ops = &shmem_vm_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2637 | return 0; |
| 2638 | } |