Blame view
fs/super.c
34.6 KB
1da177e4c Linux-2.6.12-rc2 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 |
/* * linux/fs/super.c * * Copyright (C) 1991, 1992 Linus Torvalds * * super.c contains code to handle: - mount structures * - super-block tables * - filesystem drivers list * - mount system call * - umount system call * - ustat system call * * GK 2/5/95 - Changed to support mounting the root fs via NFS * * Added kerneld support: Jacques Gelinas and Bjorn Ekwall * Added change_root: Werner Almesberger & Hans Lermen, Feb '96 * Added options to /proc/mounts: |
96de0e252 Convert files to ... |
18 |
* Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996. |
1da177e4c Linux-2.6.12-rc2 |
19 20 21 |
* Added devfs support: Richard Gooch <rgooch@atnf.csiro.au>, 13-JAN-1998 * Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000 */ |
630d9c472 fs: reduce the us... |
22 |
#include <linux/export.h> |
1da177e4c Linux-2.6.12-rc2 |
23 |
#include <linux/slab.h> |
1da177e4c Linux-2.6.12-rc2 |
24 25 |
#include <linux/acct.h> #include <linux/blkdev.h> |
1da177e4c Linux-2.6.12-rc2 |
26 27 |
#include <linux/mount.h> #include <linux/security.h> |
1da177e4c Linux-2.6.12-rc2 |
28 29 |
#include <linux/writeback.h> /* for the emergency remount stuff */ #include <linux/idr.h> |
353ab6e97 [PATCH] sem2mutex... |
30 |
#include <linux/mutex.h> |
5477d0fac fs: fs/super.c ne... |
31 |
#include <linux/backing-dev.h> |
ceb5bdc2d fs: dcache per-bu... |
32 |
#include <linux/rculist_bl.h> |
c515e1fd3 mm/fs: add hooks ... |
33 |
#include <linux/cleancache.h> |
404015308 security: trim se... |
34 |
#include <linux/fsnotify.h> |
5accdf82b fs: Improve files... |
35 |
#include <linux/lockdep.h> |
6d59e7f58 [PATCH] move a bu... |
36 |
#include "internal.h" |
1da177e4c Linux-2.6.12-rc2 |
37 |
|
1da177e4c Linux-2.6.12-rc2 |
38 39 |
LIST_HEAD(super_blocks); DEFINE_SPINLOCK(sb_lock); |
5accdf82b fs: Improve files... |
40 41 42 43 44 |
static char *sb_writers_name[SB_FREEZE_LEVELS] = { "sb_writers", "sb_pagefaults", "sb_internal", }; |
b0d40c92a superblock: intro... |
45 46 47 48 49 50 51 |
/* * One thing we have to be careful of with a per-sb shrinker is that we don't * drop the last active reference to the superblock from within the shrinker. * If that happens we could trigger unregistering the shrinker from within the * shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we * take a passive reference to the superblock to avoid this from occurring. */ |
0a234c6dc shrinker: convert... |
52 53 |
static unsigned long super_cache_scan(struct shrinker *shrink, struct shrink_control *sc) |
b0d40c92a superblock: intro... |
54 55 |
{ struct super_block *sb; |
0a234c6dc shrinker: convert... |
56 57 58 59 60 |
long fs_objects = 0; long total_objects; long freed = 0; long dentries; long inodes; |
b0d40c92a superblock: intro... |
61 62 63 64 65 66 67 |
sb = container_of(shrink, struct super_block, s_shrink); /* * Deadlock avoidance. We may hold various FS locks, and we don't want * to recurse into the FS that called us in clear_inode() and friends.. */ |
0a234c6dc shrinker: convert... |
68 69 |
if (!(sc->gfp_mask & __GFP_FS)) return SHRINK_STOP; |
b0d40c92a superblock: intro... |
70 71 |
if (!grab_super_passive(sb)) |
0a234c6dc shrinker: convert... |
72 |
return SHRINK_STOP; |
b0d40c92a superblock: intro... |
73 |
|
d04079039 prune_super(): sb... |
74 |
if (sb->s_op->nr_cached_objects) |
9b17c6238 fs: convert inode... |
75 |
fs_objects = sb->s_op->nr_cached_objects(sb, sc->nid); |
0e1fdafd9 superblock: add f... |
76 |
|
9b17c6238 fs: convert inode... |
77 78 |
inodes = list_lru_count_node(&sb->s_inode_lru, sc->nid); dentries = list_lru_count_node(&sb->s_dentry_lru, sc->nid); |
f60415675 dcache: convert t... |
79 |
total_objects = dentries + inodes + fs_objects + 1; |
0e1fdafd9 superblock: add f... |
80 |
|
0a234c6dc shrinker: convert... |
81 |
/* proportion the scan between the caches */ |
f60415675 dcache: convert t... |
82 |
dentries = mult_frac(sc->nr_to_scan, dentries, total_objects); |
bc3b14cb2 inode: convert in... |
83 |
inodes = mult_frac(sc->nr_to_scan, inodes, total_objects); |
b0d40c92a superblock: intro... |
84 |
|
0a234c6dc shrinker: convert... |
85 86 87 88 |
/* * prune the dcache first as the icache is pinned by it, then * prune the icache, followed by the filesystem specific caches */ |
9b17c6238 fs: convert inode... |
89 90 |
freed = prune_dcache_sb(sb, dentries, sc->nid); freed += prune_icache_sb(sb, inodes, sc->nid); |
0a234c6dc shrinker: convert... |
91 92 93 94 |
if (fs_objects) { fs_objects = mult_frac(sc->nr_to_scan, fs_objects, total_objects); |
9b17c6238 fs: convert inode... |
95 96 |
freed += sb->s_op->free_cached_objects(sb, fs_objects, sc->nid); |
b0d40c92a superblock: intro... |
97 |
} |
0a234c6dc shrinker: convert... |
98 99 100 101 102 103 104 105 106 107 108 |
drop_super(sb); return freed; } static unsigned long super_cache_count(struct shrinker *shrink, struct shrink_control *sc) { struct super_block *sb; long total_objects = 0; sb = container_of(shrink, struct super_block, s_shrink); |
d23da150a fs/superblock: av... |
109 110 111 112 113 114 115 116 |
/* * Don't call grab_super_passive as it is a potential * scalability bottleneck. The counts could get updated * between super_cache_count and super_cache_scan anyway. * Call to super_cache_count with shrinker_rwsem held * ensures the safety of call to list_lru_count_node() and * s_op->nr_cached_objects(). */ |
0a234c6dc shrinker: convert... |
117 |
if (sb->s_op && sb->s_op->nr_cached_objects) |
9b17c6238 fs: convert inode... |
118 119 |
total_objects = sb->s_op->nr_cached_objects(sb, sc->nid); |
0a234c6dc shrinker: convert... |
120 |
|
9b17c6238 fs: convert inode... |
121 122 123 124 |
total_objects += list_lru_count_node(&sb->s_dentry_lru, sc->nid); total_objects += list_lru_count_node(&sb->s_inode_lru, sc->nid); |
0a234c6dc shrinker: convert... |
125 |
|
55f841ce9 super: fix calcul... |
126 |
total_objects = vfs_pressure_ratio(total_objects); |
0e1fdafd9 superblock: add f... |
127 |
return total_objects; |
b0d40c92a superblock: intro... |
128 |
} |
7eb5e8826 uninline destroy_... |
129 130 131 132 133 134 135 |
/** * destroy_super - frees a superblock * @s: superblock to free * * Frees a superblock. */ static void destroy_super(struct super_block *s) |
5accdf82b fs: Improve files... |
136 137 |
{ int i; |
7eb5e8826 uninline destroy_... |
138 139 |
list_lru_destroy(&s->s_dentry_lru); list_lru_destroy(&s->s_inode_lru); |
5accdf82b fs: Improve files... |
140 141 |
for (i = 0; i < SB_FREEZE_LEVELS; i++) percpu_counter_destroy(&s->s_writers.counter[i]); |
7eb5e8826 uninline destroy_... |
142 143 144 145 |
security_sb_free(s); WARN_ON(!list_empty(&s->s_mounts)); kfree(s->s_subtype); kfree(s->s_options); |
e2fec7c35 make freeing supe... |
146 |
kfree_rcu(s, rcu); |
5accdf82b fs: Improve files... |
147 |
} |
1da177e4c Linux-2.6.12-rc2 |
148 149 |
/** * alloc_super - create new superblock |
fe2bbc483 [PATCH] add missi... |
150 |
* @type: filesystem type superblock should belong to |
9249e17fe VFS: Pass mount f... |
151 |
* @flags: the mount flags |
1da177e4c Linux-2.6.12-rc2 |
152 153 154 155 |
* * Allocates and initializes a new &struct super_block. alloc_super() * returns a pointer new superblock or %NULL if allocation had failed. */ |
9249e17fe VFS: Pass mount f... |
156 |
static struct super_block *alloc_super(struct file_system_type *type, int flags) |
1da177e4c Linux-2.6.12-rc2 |
157 |
{ |
11b0b5abb [PATCH] use kzall... |
158 |
struct super_block *s = kzalloc(sizeof(struct super_block), GFP_USER); |
b87221de6 const: mark remai... |
159 |
static const struct super_operations default_op; |
7eb5e8826 uninline destroy_... |
160 161 162 163 |
int i; if (!s) return NULL; |
1da177e4c Linux-2.6.12-rc2 |
164 |
|
b5bd856a0 fs/super.c: fix W... |
165 |
INIT_LIST_HEAD(&s->s_mounts); |
7eb5e8826 uninline destroy_... |
166 167 |
if (security_sb_alloc(s)) goto fail; |
7b7a8665e direct-io: Implem... |
168 |
|
7eb5e8826 uninline destroy_... |
169 170 171 172 173 |
for (i = 0; i < SB_FREEZE_LEVELS; i++) { if (percpu_counter_init(&s->s_writers.counter[i], 0) < 0) goto fail; lockdep_init_map(&s->s_writers.lock_map[i], sb_writers_name[i], &type->s_writers_key[i], 0); |
1da177e4c Linux-2.6.12-rc2 |
174 |
} |
7eb5e8826 uninline destroy_... |
175 176 177 178 179 180 181 182 183 184 185 186 |
init_waitqueue_head(&s->s_writers.wait); init_waitqueue_head(&s->s_writers.wait_unfrozen); s->s_flags = flags; s->s_bdi = &default_backing_dev_info; INIT_HLIST_NODE(&s->s_instances); INIT_HLIST_BL_HEAD(&s->s_anon); INIT_LIST_HEAD(&s->s_inodes); if (list_lru_init(&s->s_dentry_lru)) goto fail; if (list_lru_init(&s->s_inode_lru)) goto fail; |
7eb5e8826 uninline destroy_... |
187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 |
init_rwsem(&s->s_umount); lockdep_set_class(&s->s_umount, &type->s_umount_key); /* * sget() can have s_umount recursion. * * When it cannot find a suitable sb, it allocates a new * one (this one), and tries again to find a suitable old * one. * * In case that succeeds, it will acquire the s_umount * lock of the old one. Since these are clearly distrinct * locks, and this object isn't exposed yet, there's no * risk of deadlocks. * * Annotate this by putting this lock in a different * subclass. */ down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING); s->s_count = 1; atomic_set(&s->s_active, 1); mutex_init(&s->s_vfs_rename_mutex); lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key); mutex_init(&s->s_dquot.dqio_mutex); mutex_init(&s->s_dquot.dqonoff_mutex); init_rwsem(&s->s_dquot.dqptr_sem); s->s_maxbytes = MAX_NON_LFS; s->s_op = &default_op; s->s_time_gran = 1000000000; s->cleancache_poolid = -1; s->s_shrink.seeks = DEFAULT_SEEKS; s->s_shrink.scan_objects = super_cache_scan; s->s_shrink.count_objects = super_cache_count; s->s_shrink.batch = 1024; s->s_shrink.flags = SHRINKER_NUMA_AWARE; |
1da177e4c Linux-2.6.12-rc2 |
222 |
return s; |
5ca302c8e list_lru: dynamic... |
223 |
|
7eb5e8826 uninline destroy_... |
224 225 226 |
fail: destroy_super(s); return NULL; |
1da177e4c Linux-2.6.12-rc2 |
227 228 229 230 231 |
} /* Superblock refcounting */ /* |
35cf7ba0b Bury __put_super_... |
232 |
* Drop a superblock's refcount. The caller must hold sb_lock. |
1da177e4c Linux-2.6.12-rc2 |
233 |
*/ |
f47ec3f28 trim fs/internal.h |
234 |
static void __put_super(struct super_block *sb) |
1da177e4c Linux-2.6.12-rc2 |
235 |
{ |
1da177e4c Linux-2.6.12-rc2 |
236 |
if (!--sb->s_count) { |
551de6f34 Leave superblocks... |
237 |
list_del_init(&sb->s_list); |
1da177e4c Linux-2.6.12-rc2 |
238 |
destroy_super(sb); |
1da177e4c Linux-2.6.12-rc2 |
239 |
} |
1da177e4c Linux-2.6.12-rc2 |
240 241 242 243 244 245 246 247 248 |
} /** * put_super - drop a temporary reference to superblock * @sb: superblock in question * * Drops a temporary reference, frees superblock if there's no * references left. */ |
f47ec3f28 trim fs/internal.h |
249 |
static void put_super(struct super_block *sb) |
1da177e4c Linux-2.6.12-rc2 |
250 251 252 253 254 255 256 257 |
{ spin_lock(&sb_lock); __put_super(sb); spin_unlock(&sb_lock); } /** |
1712ac8fd Saner locking aro... |
258 |
* deactivate_locked_super - drop an active reference to superblock |
1da177e4c Linux-2.6.12-rc2 |
259 260 |
* @s: superblock to deactivate * |
1712ac8fd Saner locking aro... |
261 262 |
* Drops an active reference to superblock, converting it into a temprory * one if there is no other active references left. In that case we |
1da177e4c Linux-2.6.12-rc2 |
263 264 |
* tell fs driver to shut it down and drop the temporary reference we * had just acquired. |
1712ac8fd Saner locking aro... |
265 266 |
* * Caller holds exclusive lock on superblock; that lock is released. |
1da177e4c Linux-2.6.12-rc2 |
267 |
*/ |
1712ac8fd Saner locking aro... |
268 |
void deactivate_locked_super(struct super_block *s) |
1da177e4c Linux-2.6.12-rc2 |
269 270 |
{ struct file_system_type *fs = s->s_type; |
b20bd1a5e get rid of S_BIAS |
271 |
if (atomic_dec_and_test(&s->s_active)) { |
3167760f8 mm: cleancache: s... |
272 |
cleancache_invalidate_fs(s); |
b0d40c92a superblock: intro... |
273 |
unregister_shrinker(&s->s_shrink); |
28f2cd4f6 fs/superblock: un... |
274 |
fs->kill_sb(s); |
f5e1dd345 super: fix for de... |
275 |
|
1da177e4c Linux-2.6.12-rc2 |
276 277 |
put_filesystem(fs); put_super(s); |
1712ac8fd Saner locking aro... |
278 279 |
} else { up_write(&s->s_umount); |
1da177e4c Linux-2.6.12-rc2 |
280 281 |
} } |
1712ac8fd Saner locking aro... |
282 |
EXPORT_SYMBOL(deactivate_locked_super); |
1da177e4c Linux-2.6.12-rc2 |
283 284 |
/** |
1712ac8fd Saner locking aro... |
285 |
* deactivate_super - drop an active reference to superblock |
74dbbdd7f New helper: deact... |
286 287 |
* @s: superblock to deactivate * |
1712ac8fd Saner locking aro... |
288 289 290 |
* Variant of deactivate_locked_super(), except that superblock is *not* * locked by caller. If we are going to drop the final active reference, * lock will be acquired prior to that. |
74dbbdd7f New helper: deact... |
291 |
*/ |
1712ac8fd Saner locking aro... |
292 |
void deactivate_super(struct super_block *s) |
74dbbdd7f New helper: deact... |
293 |
{ |
1712ac8fd Saner locking aro... |
294 295 296 |
if (!atomic_add_unless(&s->s_active, -1, 1)) { down_write(&s->s_umount); deactivate_locked_super(s); |
74dbbdd7f New helper: deact... |
297 298 |
} } |
1712ac8fd Saner locking aro... |
299 |
EXPORT_SYMBOL(deactivate_super); |
74dbbdd7f New helper: deact... |
300 301 |
/** |
1da177e4c Linux-2.6.12-rc2 |
302 303 304 305 306 307 308 309 |
* grab_super - acquire an active reference * @s: reference we are trying to make active * * Tries to acquire an active reference. grab_super() is used when we * had just found a superblock in super_blocks or fs_type->fs_supers * and want to turn it into a full-blown active reference. grab_super() * is called with sb_lock held and drops it. Returns 1 in case of * success, 0 if we had failed (superblock contents was already dead or |
acfec9a5a livelock avoidanc... |
310 311 312 |
* dying when grab_super() had been called). Note that this is only * called for superblocks not in rundown mode (== ones still on ->fs_supers * of their type), so increment of ->s_count is OK here. |
1da177e4c Linux-2.6.12-rc2 |
313 |
*/ |
9c4dbee79 [PATCH] fs: add l... |
314 |
static int grab_super(struct super_block *s) __releases(sb_lock) |
1da177e4c Linux-2.6.12-rc2 |
315 316 317 318 |
{ s->s_count++; spin_unlock(&sb_lock); down_write(&s->s_umount); |
acfec9a5a livelock avoidanc... |
319 320 321 322 |
if ((s->s_flags & MS_BORN) && atomic_inc_not_zero(&s->s_active)) { put_super(s); return 1; } |
1da177e4c Linux-2.6.12-rc2 |
323 324 |
up_write(&s->s_umount); put_super(s); |
1da177e4c Linux-2.6.12-rc2 |
325 326 |
return 0; } |
cf9a2ae8d [PATCH] BLOCK: Mo... |
327 |
/* |
12ad3ab66 superblock: move ... |
328 |
* grab_super_passive - acquire a passive reference |
331cbdeed writeback: Fix so... |
329 |
* @sb: reference we are trying to grab |
12ad3ab66 superblock: move ... |
330 331 332 333 334 335 336 337 338 339 340 341 |
* * Tries to acquire a passive reference. This is used in places where we * cannot take an active reference but we need to ensure that the * superblock does not go away while we are working on it. It returns * false if a reference was not gained, and returns true with the s_umount * lock held in read mode if a reference is gained. On successful return, * the caller must drop the s_umount lock and the passive reference when * done. */ bool grab_super_passive(struct super_block *sb) { spin_lock(&sb_lock); |
a5166169f vfs: convert fs_s... |
342 |
if (hlist_unhashed(&sb->s_instances)) { |
12ad3ab66 superblock: move ... |
343 344 345 346 347 348 349 350 |
spin_unlock(&sb_lock); return false; } sb->s_count++; spin_unlock(&sb_lock); if (down_read_trylock(&sb->s_umount)) { |
dabe0dc19 vfs: fix the rest... |
351 |
if (sb->s_root && (sb->s_flags & MS_BORN)) |
12ad3ab66 superblock: move ... |
352 353 354 355 356 357 358 |
return true; up_read(&sb->s_umount); } put_super(sb); return false; } |
1da177e4c Linux-2.6.12-rc2 |
359 360 361 362 363 364 365 366 367 |
/** * generic_shutdown_super - common helper for ->kill_sb() * @sb: superblock to kill * * generic_shutdown_super() does all fs-independent work on superblock * shutdown. Typical ->kill_sb() should pick all fs-specific objects * that need destruction out of superblock, call generic_shutdown_super() * and release aforementioned objects. Note: dentries and inodes _are_ * taken care of and do not need specific handling. |
c636ebdb1 [PATCH] VFS: Dest... |
368 369 370 371 |
* * Upon calling this function, the filesystem may no longer alter or * rearrange the set of dentries belonging to this super_block, nor may it * change the attachments of dentries to inodes. |
1da177e4c Linux-2.6.12-rc2 |
372 373 374 |
*/ void generic_shutdown_super(struct super_block *sb) { |
ee9b6d61a [PATCH] Mark stru... |
375 |
const struct super_operations *sop = sb->s_op; |
1da177e4c Linux-2.6.12-rc2 |
376 |
|
c636ebdb1 [PATCH] VFS: Dest... |
377 378 |
if (sb->s_root) { shrink_dcache_for_umount(sb); |
60b0680fa vfs: Rename fsync... |
379 |
sync_filesystem(sb); |
1da177e4c Linux-2.6.12-rc2 |
380 |
sb->s_flags &= ~MS_ACTIVE; |
efaee1920 async: make the f... |
381 |
|
63997e98a split invalidate_... |
382 383 384 |
fsnotify_unmount_inodes(&sb->s_inodes); evict_inodes(sb); |
1da177e4c Linux-2.6.12-rc2 |
385 |
|
7b7a8665e direct-io: Implem... |
386 387 388 389 |
if (sb->s_dio_done_wq) { destroy_workqueue(sb->s_dio_done_wq); sb->s_dio_done_wq = NULL; } |
1da177e4c Linux-2.6.12-rc2 |
390 391 |
if (sop->put_super) sop->put_super(sb); |
63997e98a split invalidate_... |
392 |
if (!list_empty(&sb->s_inodes)) { |
7b4fe29e0 [PATCH] More info... |
393 394 395 396 |
printk("VFS: Busy inodes after unmount of %s. " "Self-destruct in 5 seconds. Have a nice day... ", sb->s_id); |
1da177e4c Linux-2.6.12-rc2 |
397 |
} |
1da177e4c Linux-2.6.12-rc2 |
398 399 400 |
} spin_lock(&sb_lock); /* should be initialized for __put_super_and_need_restart() */ |
a5166169f vfs: convert fs_s... |
401 |
hlist_del_init(&sb->s_instances); |
1da177e4c Linux-2.6.12-rc2 |
402 403 404 405 406 407 408 409 410 411 412 |
spin_unlock(&sb_lock); up_write(&sb->s_umount); } EXPORT_SYMBOL(generic_shutdown_super); /** * sget - find or create a superblock * @type: filesystem type superblock should belong to * @test: comparison callback * @set: setup callback |
9249e17fe VFS: Pass mount f... |
413 |
* @flags: mount flags |
1da177e4c Linux-2.6.12-rc2 |
414 415 416 417 418 |
* @data: argument to each of them */ struct super_block *sget(struct file_system_type *type, int (*test)(struct super_block *,void *), int (*set)(struct super_block *,void *), |
9249e17fe VFS: Pass mount f... |
419 |
int flags, |
1da177e4c Linux-2.6.12-rc2 |
420 421 422 |
void *data) { struct super_block *s = NULL; |
d47301271 fs/super.c: use l... |
423 |
struct super_block *old; |
1da177e4c Linux-2.6.12-rc2 |
424 425 426 427 |
int err; retry: spin_lock(&sb_lock); |
d47301271 fs/super.c: use l... |
428 |
if (test) { |
b67bfe0d4 hlist: drop the n... |
429 |
hlist_for_each_entry(old, &type->fs_supers, s_instances) { |
d47301271 fs/super.c: use l... |
430 431 432 433 |
if (!test(old, data)) continue; if (!grab_super(old)) goto retry; |
a3cfbb53b vfs: add missing ... |
434 435 |
if (s) { up_write(&s->s_umount); |
d47301271 fs/super.c: use l... |
436 |
destroy_super(s); |
7a4dec538 Fix sget() race w... |
437 |
s = NULL; |
a3cfbb53b vfs: add missing ... |
438 |
} |
d47301271 fs/super.c: use l... |
439 440 |
return old; } |
1da177e4c Linux-2.6.12-rc2 |
441 442 443 |
} if (!s) { spin_unlock(&sb_lock); |
9249e17fe VFS: Pass mount f... |
444 |
s = alloc_super(type, flags); |
1da177e4c Linux-2.6.12-rc2 |
445 446 447 448 449 450 451 452 |
if (!s) return ERR_PTR(-ENOMEM); goto retry; } err = set(s, data); if (err) { spin_unlock(&sb_lock); |
a3cfbb53b vfs: add missing ... |
453 |
up_write(&s->s_umount); |
1da177e4c Linux-2.6.12-rc2 |
454 455 456 457 458 459 |
destroy_super(s); return ERR_PTR(err); } s->s_type = type; strlcpy(s->s_id, type->name, sizeof(s->s_id)); list_add_tail(&s->s_list, &super_blocks); |
a5166169f vfs: convert fs_s... |
460 |
hlist_add_head(&s->s_instances, &type->fs_supers); |
1da177e4c Linux-2.6.12-rc2 |
461 462 |
spin_unlock(&sb_lock); get_filesystem(type); |
b0d40c92a superblock: intro... |
463 |
register_shrinker(&s->s_shrink); |
1da177e4c Linux-2.6.12-rc2 |
464 465 466 467 468 469 470 471 472 473 474 475 |
return s; } EXPORT_SYMBOL(sget); void drop_super(struct super_block *sb) { up_read(&sb->s_umount); put_super(sb); } EXPORT_SYMBOL(drop_super); |
e50047533 cleanup sync_supers |
476 |
/** |
01a05b337 new helper: itera... |
477 478 479 480 481 482 483 484 485 |
* iterate_supers - call function for all active superblocks * @f: function to call * @arg: argument to pass to it * * Scans the superblock list and calls given function, passing it * locked superblock and given argument. */ void iterate_supers(void (*f)(struct super_block *, void *), void *arg) { |
dca332528 no need for list_... |
486 |
struct super_block *sb, *p = NULL; |
01a05b337 new helper: itera... |
487 488 |
spin_lock(&sb_lock); |
dca332528 no need for list_... |
489 |
list_for_each_entry(sb, &super_blocks, s_list) { |
a5166169f vfs: convert fs_s... |
490 |
if (hlist_unhashed(&sb->s_instances)) |
01a05b337 new helper: itera... |
491 492 493 494 495 |
continue; sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); |
dabe0dc19 vfs: fix the rest... |
496 |
if (sb->s_root && (sb->s_flags & MS_BORN)) |
01a05b337 new helper: itera... |
497 498 499 500 |
f(sb, arg); up_read(&sb->s_umount); spin_lock(&sb_lock); |
dca332528 no need for list_... |
501 502 503 |
if (p) __put_super(p); p = sb; |
01a05b337 new helper: itera... |
504 |
} |
dca332528 no need for list_... |
505 506 |
if (p) __put_super(p); |
01a05b337 new helper: itera... |
507 508 509 510 |
spin_unlock(&sb_lock); } /** |
43e15cdbe new helper: itera... |
511 512 513 514 515 516 517 518 519 520 521 522 523 524 |
* iterate_supers_type - call function for superblocks of given type * @type: fs type * @f: function to call * @arg: argument to pass to it * * Scans the superblock list and calls given function, passing it * locked superblock and given argument. */ void iterate_supers_type(struct file_system_type *type, void (*f)(struct super_block *, void *), void *arg) { struct super_block *sb, *p = NULL; spin_lock(&sb_lock); |
b67bfe0d4 hlist: drop the n... |
525 |
hlist_for_each_entry(sb, &type->fs_supers, s_instances) { |
43e15cdbe new helper: itera... |
526 527 528 529 |
sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); |
dabe0dc19 vfs: fix the rest... |
530 |
if (sb->s_root && (sb->s_flags & MS_BORN)) |
43e15cdbe new helper: itera... |
531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 |
f(sb, arg); up_read(&sb->s_umount); spin_lock(&sb_lock); if (p) __put_super(p); p = sb; } if (p) __put_super(p); spin_unlock(&sb_lock); } EXPORT_SYMBOL(iterate_supers_type); /** |
1da177e4c Linux-2.6.12-rc2 |
547 548 549 550 551 552 |
* get_super - get the superblock of a device * @bdev: device to get the superblock for * * Scans the superblock list and finds the superblock of the file system * mounted on the device given. %NULL is returned if no match is found. */ |
df40c01a9 In get_super() an... |
553 |
struct super_block *get_super(struct block_device *bdev) |
1da177e4c Linux-2.6.12-rc2 |
554 |
{ |
618f06362 [PATCH] O(1) sb l... |
555 |
struct super_block *sb; |
1da177e4c Linux-2.6.12-rc2 |
556 557 |
if (!bdev) return NULL; |
618f06362 [PATCH] O(1) sb l... |
558 |
|
1da177e4c Linux-2.6.12-rc2 |
559 |
spin_lock(&sb_lock); |
618f06362 [PATCH] O(1) sb l... |
560 561 |
rescan: list_for_each_entry(sb, &super_blocks, s_list) { |
a5166169f vfs: convert fs_s... |
562 |
if (hlist_unhashed(&sb->s_instances)) |
551de6f34 Leave superblocks... |
563 |
continue; |
618f06362 [PATCH] O(1) sb l... |
564 565 |
if (sb->s_bdev == bdev) { sb->s_count++; |
1da177e4c Linux-2.6.12-rc2 |
566 |
spin_unlock(&sb_lock); |
618f06362 [PATCH] O(1) sb l... |
567 |
down_read(&sb->s_umount); |
df40c01a9 In get_super() an... |
568 |
/* still alive? */ |
dabe0dc19 vfs: fix the rest... |
569 |
if (sb->s_root && (sb->s_flags & MS_BORN)) |
618f06362 [PATCH] O(1) sb l... |
570 571 |
return sb; up_read(&sb->s_umount); |
df40c01a9 In get_super() an... |
572 |
/* nope, got unmounted */ |
618f06362 [PATCH] O(1) sb l... |
573 |
spin_lock(&sb_lock); |
df40c01a9 In get_super() an... |
574 575 |
__put_super(sb); goto rescan; |
1da177e4c Linux-2.6.12-rc2 |
576 577 578 579 580 581 582 |
} } spin_unlock(&sb_lock); return NULL; } EXPORT_SYMBOL(get_super); |
4504230a7 freeze_bdev: grab... |
583 584 |
/** |
6b6dc836a vfs: Provide func... |
585 586 587 588 589 590 591 592 593 594 595 596 |
* get_super_thawed - get thawed superblock of a device * @bdev: device to get the superblock for * * Scans the superblock list and finds the superblock of the file system * mounted on the device. The superblock is returned once it is thawed * (or immediately if it was not frozen). %NULL is returned if no match * is found. */ struct super_block *get_super_thawed(struct block_device *bdev) { while (1) { struct super_block *s = get_super(bdev); |
5accdf82b fs: Improve files... |
597 |
if (!s || s->s_writers.frozen == SB_UNFROZEN) |
6b6dc836a vfs: Provide func... |
598 599 |
return s; up_read(&s->s_umount); |
5accdf82b fs: Improve files... |
600 601 |
wait_event(s->s_writers.wait_unfrozen, s->s_writers.frozen == SB_UNFROZEN); |
6b6dc836a vfs: Provide func... |
602 603 604 605 606 607 |
put_super(s); } } EXPORT_SYMBOL(get_super_thawed); /** |
4504230a7 freeze_bdev: grab... |
608 609 610 611 612 |
* get_active_super - get an active reference to the superblock of a device * @bdev: device to get the superblock for * * Scans the superblock list and finds the superblock of the file system * mounted on the device given. Returns the superblock with an active |
d3f214730 Move grabbing s_u... |
613 |
* reference or %NULL if none was found. |
4504230a7 freeze_bdev: grab... |
614 615 616 617 618 619 620 |
*/ struct super_block *get_active_super(struct block_device *bdev) { struct super_block *sb; if (!bdev) return NULL; |
1494583de fix get_active_su... |
621 |
restart: |
4504230a7 freeze_bdev: grab... |
622 623 |
spin_lock(&sb_lock); list_for_each_entry(sb, &super_blocks, s_list) { |
a5166169f vfs: convert fs_s... |
624 |
if (hlist_unhashed(&sb->s_instances)) |
551de6f34 Leave superblocks... |
625 |
continue; |
1494583de fix get_active_su... |
626 |
if (sb->s_bdev == bdev) { |
acfec9a5a livelock avoidanc... |
627 |
if (!grab_super(sb)) |
1494583de fix get_active_su... |
628 |
goto restart; |
acfec9a5a livelock avoidanc... |
629 630 |
up_write(&sb->s_umount); return sb; |
1494583de fix get_active_su... |
631 |
} |
4504230a7 freeze_bdev: grab... |
632 633 634 635 |
} spin_unlock(&sb_lock); return NULL; } |
1da177e4c Linux-2.6.12-rc2 |
636 |
|
df40c01a9 In get_super() an... |
637 |
struct super_block *user_get_super(dev_t dev) |
1da177e4c Linux-2.6.12-rc2 |
638 |
{ |
618f06362 [PATCH] O(1) sb l... |
639 |
struct super_block *sb; |
1da177e4c Linux-2.6.12-rc2 |
640 |
|
1da177e4c Linux-2.6.12-rc2 |
641 |
spin_lock(&sb_lock); |
618f06362 [PATCH] O(1) sb l... |
642 643 |
rescan: list_for_each_entry(sb, &super_blocks, s_list) { |
a5166169f vfs: convert fs_s... |
644 |
if (hlist_unhashed(&sb->s_instances)) |
551de6f34 Leave superblocks... |
645 |
continue; |
618f06362 [PATCH] O(1) sb l... |
646 647 |
if (sb->s_dev == dev) { sb->s_count++; |
1da177e4c Linux-2.6.12-rc2 |
648 |
spin_unlock(&sb_lock); |
618f06362 [PATCH] O(1) sb l... |
649 |
down_read(&sb->s_umount); |
df40c01a9 In get_super() an... |
650 |
/* still alive? */ |
dabe0dc19 vfs: fix the rest... |
651 |
if (sb->s_root && (sb->s_flags & MS_BORN)) |
618f06362 [PATCH] O(1) sb l... |
652 653 |
return sb; up_read(&sb->s_umount); |
df40c01a9 In get_super() an... |
654 |
/* nope, got unmounted */ |
618f06362 [PATCH] O(1) sb l... |
655 |
spin_lock(&sb_lock); |
df40c01a9 In get_super() an... |
656 657 |
__put_super(sb); goto rescan; |
1da177e4c Linux-2.6.12-rc2 |
658 659 660 661 662 |
} } spin_unlock(&sb_lock); return NULL; } |
1da177e4c Linux-2.6.12-rc2 |
663 |
/** |
1da177e4c Linux-2.6.12-rc2 |
664 665 666 667 668 669 670 671 672 673 674 |
* do_remount_sb - asks filesystem to change mount options. * @sb: superblock in question * @flags: numeric part of options * @data: the rest of options * @force: whether or not to force the change * * Alters the mount options of a mounted file system. */ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) { int retval; |
c79d967de quota: move remou... |
675 |
int remount_ro; |
4504230a7 freeze_bdev: grab... |
676 |
|
5accdf82b fs: Improve files... |
677 |
if (sb->s_writers.frozen != SB_UNFROZEN) |
4504230a7 freeze_bdev: grab... |
678 |
return -EBUSY; |
9361401eb [PATCH] BLOCK: Ma... |
679 |
#ifdef CONFIG_BLOCK |
1da177e4c Linux-2.6.12-rc2 |
680 681 |
if (!(flags & MS_RDONLY) && bdev_read_only(sb->s_bdev)) return -EACCES; |
9361401eb [PATCH] BLOCK: Ma... |
682 |
#endif |
4504230a7 freeze_bdev: grab... |
683 |
|
1da177e4c Linux-2.6.12-rc2 |
684 685 686 |
if (flags & MS_RDONLY) acct_auto_close(sb); shrink_dcache_sb(sb); |
1da177e4c Linux-2.6.12-rc2 |
687 |
|
d208bbdda fs: improve remou... |
688 |
remount_ro = (flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY); |
d208bbdda fs: improve remou... |
689 |
|
1da177e4c Linux-2.6.12-rc2 |
690 691 |
/* If we are remounting RDONLY and current sb is read/write, make sure there are no rw files opened */ |
d208bbdda fs: improve remou... |
692 |
if (remount_ro) { |
4ed5e82fe vfs: protect remo... |
693 |
if (force) { |
eee5cc270 get rid of s_file... |
694 695 |
sb->s_readonly_remount = 1; smp_wmb(); |
4ed5e82fe vfs: protect remo... |
696 697 698 699 |
} else { retval = sb_prepare_remount_readonly(sb); if (retval) return retval; |
4ed5e82fe vfs: protect remo... |
700 |
} |
1da177e4c Linux-2.6.12-rc2 |
701 702 703 |
} if (sb->s_op->remount_fs) { |
1da177e4c Linux-2.6.12-rc2 |
704 |
retval = sb->s_op->remount_fs(sb, &flags, data); |
2833eb2b4 vfs: ignore error... |
705 706 |
if (retval) { if (!force) |
4ed5e82fe vfs: protect remo... |
707 |
goto cancel_readonly; |
2833eb2b4 vfs: ignore error... |
708 709 710 711 712 |
/* If forced remount, go ahead despite any errors */ WARN(1, "forced remount of a %s fs returned %i ", sb->s_type->name, retval); } |
1da177e4c Linux-2.6.12-rc2 |
713 714 |
} sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK); |
4ed5e82fe vfs: protect remo... |
715 716 717 |
/* Needs to be ordered wrt mnt_is_readonly() */ smp_wmb(); sb->s_readonly_remount = 0; |
c79d967de quota: move remou... |
718 |
|
d208bbdda fs: improve remou... |
719 720 721 722 723 724 725 726 727 728 |
/* * Some filesystems modify their metadata via some other path than the * bdev buffer cache (eg. use a private mapping, or directories in * pagecache, etc). Also file data modifications go via their own * mappings. So If we try to mount readonly then copy the filesystem * from bdev, we could get stale data, so invalidate it to give a best * effort at coherency. */ if (remount_ro && sb->s_bdev) invalidate_bdev(sb->s_bdev); |
1da177e4c Linux-2.6.12-rc2 |
729 |
return 0; |
4ed5e82fe vfs: protect remo... |
730 731 732 733 |
cancel_readonly: sb->s_readonly_remount = 0; return retval; |
1da177e4c Linux-2.6.12-rc2 |
734 |
} |
a2a9537ac Get rid of pdflus... |
735 |
static void do_emergency_remount(struct work_struct *work) |
1da177e4c Linux-2.6.12-rc2 |
736 |
{ |
dca332528 no need for list_... |
737 |
struct super_block *sb, *p = NULL; |
1da177e4c Linux-2.6.12-rc2 |
738 739 |
spin_lock(&sb_lock); |
dca332528 no need for list_... |
740 |
list_for_each_entry(sb, &super_blocks, s_list) { |
a5166169f vfs: convert fs_s... |
741 |
if (hlist_unhashed(&sb->s_instances)) |
551de6f34 Leave superblocks... |
742 |
continue; |
1da177e4c Linux-2.6.12-rc2 |
743 744 |
sb->s_count++; spin_unlock(&sb_lock); |
443b94baa Make sure that al... |
745 |
down_write(&sb->s_umount); |
dabe0dc19 vfs: fix the rest... |
746 747 |
if (sb->s_root && sb->s_bdev && (sb->s_flags & MS_BORN) && !(sb->s_flags & MS_RDONLY)) { |
1da177e4c Linux-2.6.12-rc2 |
748 |
/* |
1da177e4c Linux-2.6.12-rc2 |
749 750 |
* What lock protects sb->s_flags?? */ |
1da177e4c Linux-2.6.12-rc2 |
751 |
do_remount_sb(sb, MS_RDONLY, NULL, 1); |
1da177e4c Linux-2.6.12-rc2 |
752 |
} |
443b94baa Make sure that al... |
753 |
up_write(&sb->s_umount); |
1da177e4c Linux-2.6.12-rc2 |
754 |
spin_lock(&sb_lock); |
dca332528 no need for list_... |
755 756 757 |
if (p) __put_super(p); p = sb; |
1da177e4c Linux-2.6.12-rc2 |
758 |
} |
dca332528 no need for list_... |
759 760 |
if (p) __put_super(p); |
1da177e4c Linux-2.6.12-rc2 |
761 |
spin_unlock(&sb_lock); |
a2a9537ac Get rid of pdflus... |
762 |
kfree(work); |
1da177e4c Linux-2.6.12-rc2 |
763 764 765 766 767 768 |
printk("Emergency Remount complete "); } void emergency_remount(void) { |
a2a9537ac Get rid of pdflus... |
769 770 771 772 773 774 775 |
struct work_struct *work; work = kmalloc(sizeof(*work), GFP_ATOMIC); if (work) { INIT_WORK(work, do_emergency_remount); schedule_work(work); } |
1da177e4c Linux-2.6.12-rc2 |
776 777 778 779 780 781 |
} /* * Unnamed block devices are dummy devices used by virtual * filesystems which don't use real block-devices. -- jrs */ |
ad76cbc63 [PATCH 2/2] anond... |
782 |
static DEFINE_IDA(unnamed_dev_ida); |
1da177e4c Linux-2.6.12-rc2 |
783 |
static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */ |
a2a4dc494 fs: Don't return ... |
784 785 786 787 |
/* Many userspace utilities consider an FSID of 0 invalid. * Always return at least 1 from get_anon_bdev. */ static int unnamed_dev_start = 1; |
1da177e4c Linux-2.6.12-rc2 |
788 |
|
0ee5dc676 btrfs: kill magic... |
789 |
int get_anon_bdev(dev_t *p) |
1da177e4c Linux-2.6.12-rc2 |
790 791 792 793 794 |
{ int dev; int error; retry: |
ad76cbc63 [PATCH 2/2] anond... |
795 |
if (ida_pre_get(&unnamed_dev_ida, GFP_ATOMIC) == 0) |
1da177e4c Linux-2.6.12-rc2 |
796 797 |
return -ENOMEM; spin_lock(&unnamed_dev_lock); |
c63e09ecc Make allocation o... |
798 |
error = ida_get_new_above(&unnamed_dev_ida, unnamed_dev_start, &dev); |
f21f62208 ... and the same ... |
799 800 |
if (!error) unnamed_dev_start = dev + 1; |
1da177e4c Linux-2.6.12-rc2 |
801 802 803 804 805 806 |
spin_unlock(&unnamed_dev_lock); if (error == -EAGAIN) /* We raced and lost with another CPU. */ goto retry; else if (error) return -EAGAIN; |
e8c8d1bc0 idr: remove MAX_I... |
807 |
if (dev == (1 << MINORBITS)) { |
1da177e4c Linux-2.6.12-rc2 |
808 |
spin_lock(&unnamed_dev_lock); |
ad76cbc63 [PATCH 2/2] anond... |
809 |
ida_remove(&unnamed_dev_ida, dev); |
f21f62208 ... and the same ... |
810 811 |
if (unnamed_dev_start > dev) unnamed_dev_start = dev; |
1da177e4c Linux-2.6.12-rc2 |
812 813 814 |
spin_unlock(&unnamed_dev_lock); return -EMFILE; } |
0ee5dc676 btrfs: kill magic... |
815 |
*p = MKDEV(0, dev & MINORMASK); |
1da177e4c Linux-2.6.12-rc2 |
816 817 |
return 0; } |
0ee5dc676 btrfs: kill magic... |
818 |
EXPORT_SYMBOL(get_anon_bdev); |
1da177e4c Linux-2.6.12-rc2 |
819 |
|
0ee5dc676 btrfs: kill magic... |
820 |
void free_anon_bdev(dev_t dev) |
1da177e4c Linux-2.6.12-rc2 |
821 |
{ |
0ee5dc676 btrfs: kill magic... |
822 |
int slot = MINOR(dev); |
1da177e4c Linux-2.6.12-rc2 |
823 |
spin_lock(&unnamed_dev_lock); |
ad76cbc63 [PATCH 2/2] anond... |
824 |
ida_remove(&unnamed_dev_ida, slot); |
c63e09ecc Make allocation o... |
825 826 |
if (slot < unnamed_dev_start) unnamed_dev_start = slot; |
1da177e4c Linux-2.6.12-rc2 |
827 828 |
spin_unlock(&unnamed_dev_lock); } |
0ee5dc676 btrfs: kill magic... |
829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 |
EXPORT_SYMBOL(free_anon_bdev); int set_anon_super(struct super_block *s, void *data) { int error = get_anon_bdev(&s->s_dev); if (!error) s->s_bdi = &noop_backing_dev_info; return error; } EXPORT_SYMBOL(set_anon_super); void kill_anon_super(struct super_block *sb) { dev_t dev = sb->s_dev; generic_shutdown_super(sb); free_anon_bdev(dev); } |
1da177e4c Linux-2.6.12-rc2 |
847 848 |
EXPORT_SYMBOL(kill_anon_super); |
1da177e4c Linux-2.6.12-rc2 |
849 850 851 852 853 854 855 856 |
void kill_litter_super(struct super_block *sb) { if (sb->s_root) d_genocide(sb->s_root); kill_anon_super(sb); } EXPORT_SYMBOL(kill_litter_super); |
909e6d947 namespaces: move ... |
857 858 859 860 861 862 863 864 865 866 |
static int ns_test_super(struct super_block *sb, void *data) { return sb->s_fs_info == data; } static int ns_set_super(struct super_block *sb, void *data) { sb->s_fs_info = data; return set_anon_super(sb, NULL); } |
ceefda693 switch get_sb_ns(... |
867 868 |
struct dentry *mount_ns(struct file_system_type *fs_type, int flags, void *data, int (*fill_super)(struct super_block *, void *, int)) |
909e6d947 namespaces: move ... |
869 870 |
{ struct super_block *sb; |
9249e17fe VFS: Pass mount f... |
871 |
sb = sget(fs_type, ns_test_super, ns_set_super, flags, data); |
909e6d947 namespaces: move ... |
872 |
if (IS_ERR(sb)) |
ceefda693 switch get_sb_ns(... |
873 |
return ERR_CAST(sb); |
909e6d947 namespaces: move ... |
874 875 876 |
if (!sb->s_root) { int err; |
909e6d947 namespaces: move ... |
877 878 |
err = fill_super(sb, data, flags & MS_SILENT ? 1 : 0); if (err) { |
74dbbdd7f New helper: deact... |
879 |
deactivate_locked_super(sb); |
ceefda693 switch get_sb_ns(... |
880 |
return ERR_PTR(err); |
909e6d947 namespaces: move ... |
881 882 883 884 |
} sb->s_flags |= MS_ACTIVE; } |
ceefda693 switch get_sb_ns(... |
885 |
return dget(sb->s_root); |
909e6d947 namespaces: move ... |
886 |
} |
ceefda693 switch get_sb_ns(... |
887 |
EXPORT_SYMBOL(mount_ns); |
909e6d947 namespaces: move ... |
888 |
|
9361401eb [PATCH] BLOCK: Ma... |
889 |
#ifdef CONFIG_BLOCK |
1da177e4c Linux-2.6.12-rc2 |
890 891 892 893 |
static int set_bdev_super(struct super_block *s, void *data) { s->s_bdev = data; s->s_dev = s->s_bdev->bd_dev; |
32a88aa1b fs: Assign bdi in... |
894 895 896 897 898 899 |
/* * We set the bdi here to the queue backing, file systems can * overwrite this in ->fill_super() */ s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info; |
1da177e4c Linux-2.6.12-rc2 |
900 901 902 903 904 905 906 |
return 0; } static int test_bdev_super(struct super_block *s, void *data) { return (void *)s->s_bdev == data; } |
152a08366 new helper: mount... |
907 |
struct dentry *mount_bdev(struct file_system_type *fs_type, |
1da177e4c Linux-2.6.12-rc2 |
908 |
int flags, const char *dev_name, void *data, |
152a08366 new helper: mount... |
909 |
int (*fill_super)(struct super_block *, void *, int)) |
1da177e4c Linux-2.6.12-rc2 |
910 911 912 |
{ struct block_device *bdev; struct super_block *s; |
d4d776299 block: clean up b... |
913 |
fmode_t mode = FMODE_READ | FMODE_EXCL; |
1da177e4c Linux-2.6.12-rc2 |
914 |
int error = 0; |
30c40d2c0 [PATCH] propagate... |
915 916 |
if (!(flags & MS_RDONLY)) mode |= FMODE_WRITE; |
d4d776299 block: clean up b... |
917 |
bdev = blkdev_get_by_path(dev_name, mode, fs_type); |
1da177e4c Linux-2.6.12-rc2 |
918 |
if (IS_ERR(bdev)) |
152a08366 new helper: mount... |
919 |
return ERR_CAST(bdev); |
1da177e4c Linux-2.6.12-rc2 |
920 921 922 923 924 925 |
/* * once the super is inserted into the list by sget, s_umount * will protect the lockfs code from trying to start a snapshot * while we are mounting */ |
4fadd7bb2 freeze_bdev: kill... |
926 927 928 929 930 931 |
mutex_lock(&bdev->bd_fsfreeze_mutex); if (bdev->bd_fsfreeze_count > 0) { mutex_unlock(&bdev->bd_fsfreeze_mutex); error = -EBUSY; goto error_bdev; } |
9249e17fe VFS: Pass mount f... |
932 933 |
s = sget(fs_type, test_bdev_super, set_bdev_super, flags | MS_NOSEC, bdev); |
4fadd7bb2 freeze_bdev: kill... |
934 |
mutex_unlock(&bdev->bd_fsfreeze_mutex); |
1da177e4c Linux-2.6.12-rc2 |
935 |
if (IS_ERR(s)) |
454e2398b [PATCH] VFS: Perm... |
936 |
goto error_s; |
1da177e4c Linux-2.6.12-rc2 |
937 938 939 |
if (s->s_root) { if ((flags ^ s->s_flags) & MS_RDONLY) { |
74dbbdd7f New helper: deact... |
940 |
deactivate_locked_super(s); |
454e2398b [PATCH] VFS: Perm... |
941 942 |
error = -EBUSY; goto error_bdev; |
1da177e4c Linux-2.6.12-rc2 |
943 |
} |
454e2398b [PATCH] VFS: Perm... |
944 |
|
4f331f01b vfs: don't hold s... |
945 946 |
/* * s_umount nests inside bd_mutex during |
e525fd89d block: make blkde... |
947 948 949 950 |
* __invalidate_device(). blkdev_put() acquires * bd_mutex and can't be called under s_umount. Drop * s_umount temporarily. This is safe as we're * holding an active reference. |
4f331f01b vfs: don't hold s... |
951 952 |
*/ up_write(&s->s_umount); |
d4d776299 block: clean up b... |
953 |
blkdev_put(bdev, mode); |
4f331f01b vfs: don't hold s... |
954 |
down_write(&s->s_umount); |
1da177e4c Linux-2.6.12-rc2 |
955 956 |
} else { char b[BDEVNAME_SIZE]; |
30c40d2c0 [PATCH] propagate... |
957 |
s->s_mode = mode; |
1da177e4c Linux-2.6.12-rc2 |
958 |
strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); |
e78c9a004 [PATCH] fs: remov... |
959 |
sb_set_blocksize(s, block_size(bdev)); |
9b04c997b [PATCH] vfs: MS_V... |
960 |
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0); |
1da177e4c Linux-2.6.12-rc2 |
961 |
if (error) { |
74dbbdd7f New helper: deact... |
962 |
deactivate_locked_super(s); |
454e2398b [PATCH] VFS: Perm... |
963 |
goto error; |
fa675765a Revert mount/umou... |
964 |
} |
454e2398b [PATCH] VFS: Perm... |
965 966 |
s->s_flags |= MS_ACTIVE; |
87d8fe1ee add releasepage h... |
967 |
bdev->bd_super = s; |
1da177e4c Linux-2.6.12-rc2 |
968 |
} |
152a08366 new helper: mount... |
969 |
return dget(s->s_root); |
1da177e4c Linux-2.6.12-rc2 |
970 |
|
454e2398b [PATCH] VFS: Perm... |
971 972 973 |
error_s: error = PTR_ERR(s); error_bdev: |
d4d776299 block: clean up b... |
974 |
blkdev_put(bdev, mode); |
454e2398b [PATCH] VFS: Perm... |
975 |
error: |
152a08366 new helper: mount... |
976 977 978 |
return ERR_PTR(error); } EXPORT_SYMBOL(mount_bdev); |
1da177e4c Linux-2.6.12-rc2 |
979 980 981 |
void kill_block_super(struct super_block *sb) { struct block_device *bdev = sb->s_bdev; |
30c40d2c0 [PATCH] propagate... |
982 |
fmode_t mode = sb->s_mode; |
1da177e4c Linux-2.6.12-rc2 |
983 |
|
ddbaaf302 NULL noise in fs/... |
984 |
bdev->bd_super = NULL; |
1da177e4c Linux-2.6.12-rc2 |
985 986 |
generic_shutdown_super(sb); sync_blockdev(bdev); |
d4d776299 block: clean up b... |
987 |
WARN_ON_ONCE(!(mode & FMODE_EXCL)); |
e525fd89d block: make blkde... |
988 |
blkdev_put(bdev, mode | FMODE_EXCL); |
1da177e4c Linux-2.6.12-rc2 |
989 990 991 |
} EXPORT_SYMBOL(kill_block_super); |
9361401eb [PATCH] BLOCK: Ma... |
992 |
#endif |
1da177e4c Linux-2.6.12-rc2 |
993 |
|
3c26ff6e4 convert get_sb_no... |
994 |
struct dentry *mount_nodev(struct file_system_type *fs_type, |
1da177e4c Linux-2.6.12-rc2 |
995 |
int flags, void *data, |
3c26ff6e4 convert get_sb_no... |
996 |
int (*fill_super)(struct super_block *, void *, int)) |
1da177e4c Linux-2.6.12-rc2 |
997 998 |
{ int error; |
9249e17fe VFS: Pass mount f... |
999 |
struct super_block *s = sget(fs_type, NULL, set_anon_super, flags, NULL); |
1da177e4c Linux-2.6.12-rc2 |
1000 1001 |
if (IS_ERR(s)) |
3c26ff6e4 convert get_sb_no... |
1002 |
return ERR_CAST(s); |
1da177e4c Linux-2.6.12-rc2 |
1003 |
|
9b04c997b [PATCH] vfs: MS_V... |
1004 |
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0); |
1da177e4c Linux-2.6.12-rc2 |
1005 |
if (error) { |
74dbbdd7f New helper: deact... |
1006 |
deactivate_locked_super(s); |
3c26ff6e4 convert get_sb_no... |
1007 |
return ERR_PTR(error); |
1da177e4c Linux-2.6.12-rc2 |
1008 1009 |
} s->s_flags |= MS_ACTIVE; |
3c26ff6e4 convert get_sb_no... |
1010 |
return dget(s->s_root); |
1da177e4c Linux-2.6.12-rc2 |
1011 |
} |
3c26ff6e4 convert get_sb_no... |
1012 |
EXPORT_SYMBOL(mount_nodev); |
1da177e4c Linux-2.6.12-rc2 |
1013 1014 1015 1016 |
static int compare_single(struct super_block *s, void *p) { return 1; } |
fc14f2fef convert get_sb_si... |
1017 |
struct dentry *mount_single(struct file_system_type *fs_type, |
1da177e4c Linux-2.6.12-rc2 |
1018 |
int flags, void *data, |
fc14f2fef convert get_sb_si... |
1019 |
int (*fill_super)(struct super_block *, void *, int)) |
1da177e4c Linux-2.6.12-rc2 |
1020 1021 1022 |
{ struct super_block *s; int error; |
9249e17fe VFS: Pass mount f... |
1023 |
s = sget(fs_type, compare_single, set_anon_super, flags, NULL); |
1da177e4c Linux-2.6.12-rc2 |
1024 |
if (IS_ERR(s)) |
fc14f2fef convert get_sb_si... |
1025 |
return ERR_CAST(s); |
1da177e4c Linux-2.6.12-rc2 |
1026 |
if (!s->s_root) { |
9b04c997b [PATCH] vfs: MS_V... |
1027 |
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0); |
1da177e4c Linux-2.6.12-rc2 |
1028 |
if (error) { |
74dbbdd7f New helper: deact... |
1029 |
deactivate_locked_super(s); |
fc14f2fef convert get_sb_si... |
1030 |
return ERR_PTR(error); |
1da177e4c Linux-2.6.12-rc2 |
1031 1032 |
} s->s_flags |= MS_ACTIVE; |
9329d1bea vfs: get_sb_singl... |
1033 1034 |
} else { do_remount_sb(s, flags, data, 0); |
1da177e4c Linux-2.6.12-rc2 |
1035 |
} |
fc14f2fef convert get_sb_si... |
1036 1037 1038 |
return dget(s->s_root); } EXPORT_SYMBOL(mount_single); |
9d412a43c vfs: split off vf... |
1039 1040 |
struct dentry * mount_fs(struct file_system_type *type, int flags, const char *name, void *data) |
1da177e4c Linux-2.6.12-rc2 |
1041 |
{ |
c96e41e92 beginning of tran... |
1042 |
struct dentry *root; |
9d412a43c vfs: split off vf... |
1043 |
struct super_block *sb; |
1da177e4c Linux-2.6.12-rc2 |
1044 |
char *secdata = NULL; |
9d412a43c vfs: split off vf... |
1045 |
int error = -ENOMEM; |
8089352a1 Mirror MS_KERNMOU... |
1046 |
|
e00075298 LSM/SELinux: Inte... |
1047 |
if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) { |
1da177e4c Linux-2.6.12-rc2 |
1048 |
secdata = alloc_secdata(); |
454e2398b [PATCH] VFS: Perm... |
1049 |
if (!secdata) |
9d412a43c vfs: split off vf... |
1050 |
goto out; |
1da177e4c Linux-2.6.12-rc2 |
1051 |
|
e00075298 LSM/SELinux: Inte... |
1052 |
error = security_sb_copy_data(data, secdata); |
454e2398b [PATCH] VFS: Perm... |
1053 |
if (error) |
1da177e4c Linux-2.6.12-rc2 |
1054 |
goto out_free_secdata; |
1da177e4c Linux-2.6.12-rc2 |
1055 |
} |
1a102ff92 vfs: bury ->get_sb() |
1056 1057 1058 1059 |
root = type->mount(type, flags, name, data); if (IS_ERR(root)) { error = PTR_ERR(root); goto out_free_secdata; |
c96e41e92 beginning of tran... |
1060 |
} |
9d412a43c vfs: split off vf... |
1061 1062 1063 |
sb = root->d_sb; BUG_ON(!sb); WARN_ON(!sb->s_bdi); |
6c5103890 Merge branch 'for... |
1064 |
WARN_ON(sb->s_bdi == &default_backing_dev_info); |
9d412a43c vfs: split off vf... |
1065 |
sb->s_flags |= MS_BORN; |
454e2398b [PATCH] VFS: Perm... |
1066 |
|
9d412a43c vfs: split off vf... |
1067 |
error = security_sb_kern_mount(sb, flags, secdata); |
5129a469a Catch filesystems... |
1068 1069 |
if (error) goto out_sb; |
454e2398b [PATCH] VFS: Perm... |
1070 |
|
42cb56ae2 vfs: change sb->s... |
1071 1072 1073 1074 |
/* * filesystems should never set s_maxbytes larger than MAX_LFS_FILESIZE * but s_maxbytes was an unsigned long long for many releases. Throw * this warning for a little while to try and catch filesystems that |
4358b5678 VFS: trivial: fix... |
1075 |
* violate this rule. |
42cb56ae2 vfs: change sb->s... |
1076 |
*/ |
9d412a43c vfs: split off vf... |
1077 1078 1079 |
WARN((sb->s_maxbytes < 0), "%s set sb->s_maxbytes to " "negative value (%lld) ", type->name, sb->s_maxbytes); |
42cb56ae2 vfs: change sb->s... |
1080 |
|
9d412a43c vfs: split off vf... |
1081 |
up_write(&sb->s_umount); |
8680e22f2 [PATCH] VFS: memo... |
1082 |
free_secdata(secdata); |
9d412a43c vfs: split off vf... |
1083 |
return root; |
1da177e4c Linux-2.6.12-rc2 |
1084 |
out_sb: |
9d412a43c vfs: split off vf... |
1085 1086 |
dput(root); deactivate_locked_super(sb); |
1da177e4c Linux-2.6.12-rc2 |
1087 1088 |
out_free_secdata: free_secdata(secdata); |
1da177e4c Linux-2.6.12-rc2 |
1089 |
out: |
454e2398b [PATCH] VFS: Perm... |
1090 |
return ERR_PTR(error); |
1da177e4c Linux-2.6.12-rc2 |
1091 |
} |
5accdf82b fs: Improve files... |
1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 |
/* * This is an internal function, please use sb_end_{write,pagefault,intwrite} * instead. */ void __sb_end_write(struct super_block *sb, int level) { percpu_counter_dec(&sb->s_writers.counter[level-1]); /* * Make sure s_writers are updated before we wake up waiters in * freeze_super(). */ smp_mb(); if (waitqueue_active(&sb->s_writers.wait)) wake_up(&sb->s_writers.wait); rwsem_release(&sb->s_writers.lock_map[level-1], 1, _RET_IP_); } EXPORT_SYMBOL(__sb_end_write); #ifdef CONFIG_LOCKDEP /* * We want lockdep to tell us about possible deadlocks with freezing but * it's it bit tricky to properly instrument it. Getting a freeze protection * works as getting a read lock but there are subtle problems. XFS for example * gets freeze protection on internal level twice in some cases, which is OK * only because we already hold a freeze protection also on higher level. Due * to these cases we have to tell lockdep we are doing trylock when we * already hold a freeze protection for a higher freeze level. */ static void acquire_freeze_lock(struct super_block *sb, int level, bool trylock, unsigned long ip) { int i; if (!trylock) { for (i = 0; i < level - 1; i++) if (lock_is_held(&sb->s_writers.lock_map[i])) { trylock = true; break; } } rwsem_acquire_read(&sb->s_writers.lock_map[level-1], 0, trylock, ip); } #endif /* * This is an internal function, please use sb_start_{write,pagefault,intwrite} * instead. */ int __sb_start_write(struct super_block *sb, int level, bool wait) { retry: if (unlikely(sb->s_writers.frozen >= level)) { if (!wait) return 0; wait_event(sb->s_writers.wait_unfrozen, sb->s_writers.frozen < level); } #ifdef CONFIG_LOCKDEP acquire_freeze_lock(sb, level, !wait, _RET_IP_); #endif percpu_counter_inc(&sb->s_writers.counter[level-1]); /* * Make sure counter is updated before we check for frozen. * freeze_super() first sets frozen and then checks the counter. */ smp_mb(); if (unlikely(sb->s_writers.frozen >= level)) { __sb_end_write(sb, level); goto retry; } return 1; } EXPORT_SYMBOL(__sb_start_write); /** * sb_wait_write - wait until all writers to given file system finish * @sb: the super for which we wait * @level: type of writers we wait for (normal vs page fault) * * This function waits until there are no writers of given type to given file * system. Caller of this function should make sure there can be no new writers * of type @level before calling this function. Otherwise this function can * livelock. */ static void sb_wait_write(struct super_block *sb, int level) { s64 writers; /* * We just cycle-through lockdep here so that it does not complain * about returning with lock to userspace */ rwsem_acquire(&sb->s_writers.lock_map[level-1], 0, 0, _THIS_IP_); rwsem_release(&sb->s_writers.lock_map[level-1], 1, _THIS_IP_); do { DEFINE_WAIT(wait); /* * We use a barrier in prepare_to_wait() to separate setting * of frozen and checking of the counter */ prepare_to_wait(&sb->s_writers.wait, &wait, TASK_UNINTERRUPTIBLE); writers = percpu_counter_sum(&sb->s_writers.counter[level-1]); if (writers) schedule(); finish_wait(&sb->s_writers.wait, &wait); } while (writers); } |
18e9e5104 Introduce freeze_... |
1205 |
/** |
7000d3c42 fs/super: fix ker... |
1206 1207 |
* freeze_super - lock the filesystem and force it into a consistent state * @sb: the super to lock |
18e9e5104 Introduce freeze_... |
1208 1209 1210 1211 |
* * Syncs the super to make sure the filesystem is consistent and calls the fs's * freeze_fs. Subsequent calls to this without first thawing the fs will return * -EBUSY. |
5accdf82b fs: Improve files... |
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 |
* * During this function, sb->s_writers.frozen goes through these values: * * SB_UNFROZEN: File system is normal, all writes progress as usual. * * SB_FREEZE_WRITE: The file system is in the process of being frozen. New * writes should be blocked, though page faults are still allowed. We wait for * all writes to complete and then proceed to the next stage. * * SB_FREEZE_PAGEFAULT: Freezing continues. Now also page faults are blocked * but internal fs threads can still modify the filesystem (although they * should not dirty new pages or inodes), writeback can run etc. After waiting * for all running page faults we sync the filesystem which will clean all * dirty pages and inodes (no new dirty pages or inodes can be created when * sync is running). * * SB_FREEZE_FS: The file system is frozen. Now all internal sources of fs * modification are blocked (e.g. XFS preallocation truncation on inode * reclaim). This is usually implemented by blocking new transactions for * filesystems that have them and need this additional guard. After all * internal writers are finished we call ->freeze_fs() to finish filesystem * freezing. Then we transition to SB_FREEZE_COMPLETE state. This state is * mostly auxiliary for filesystems to verify they do not modify frozen fs. * * sb->s_writers.frozen is protected by sb->s_umount. |
18e9e5104 Introduce freeze_... |
1237 1238 1239 1240 1241 1242 1243 |
*/ int freeze_super(struct super_block *sb) { int ret; atomic_inc(&sb->s_active); down_write(&sb->s_umount); |
5accdf82b fs: Improve files... |
1244 |
if (sb->s_writers.frozen != SB_UNFROZEN) { |
18e9e5104 Introduce freeze_... |
1245 1246 1247 |
deactivate_locked_super(sb); return -EBUSY; } |
dabe0dc19 vfs: fix the rest... |
1248 1249 1250 1251 |
if (!(sb->s_flags & MS_BORN)) { up_write(&sb->s_umount); return 0; /* sic - it's "nothing to do" */ } |
18e9e5104 Introduce freeze_... |
1252 |
if (sb->s_flags & MS_RDONLY) { |
5accdf82b fs: Improve files... |
1253 1254 |
/* Nothing to do really... */ sb->s_writers.frozen = SB_FREEZE_COMPLETE; |
18e9e5104 Introduce freeze_... |
1255 1256 1257 |
up_write(&sb->s_umount); return 0; } |
5accdf82b fs: Improve files... |
1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 |
/* From now on, no new normal writers can start */ sb->s_writers.frozen = SB_FREEZE_WRITE; smp_wmb(); /* Release s_umount to preserve sb_start_write -> s_umount ordering */ up_write(&sb->s_umount); sb_wait_write(sb, SB_FREEZE_WRITE); /* Now we go and block page faults... */ down_write(&sb->s_umount); sb->s_writers.frozen = SB_FREEZE_PAGEFAULT; |
18e9e5104 Introduce freeze_... |
1270 |
smp_wmb(); |
5accdf82b fs: Improve files... |
1271 1272 1273 |
sb_wait_write(sb, SB_FREEZE_PAGEFAULT); /* All writers are done so after syncing there won't be dirty data */ |
18e9e5104 Introduce freeze_... |
1274 |
sync_filesystem(sb); |
5accdf82b fs: Improve files... |
1275 1276 |
/* Now wait for internal filesystem counter */ sb->s_writers.frozen = SB_FREEZE_FS; |
18e9e5104 Introduce freeze_... |
1277 |
smp_wmb(); |
5accdf82b fs: Improve files... |
1278 |
sb_wait_write(sb, SB_FREEZE_FS); |
18e9e5104 Introduce freeze_... |
1279 |
|
18e9e5104 Introduce freeze_... |
1280 1281 1282 1283 1284 1285 |
if (sb->s_op->freeze_fs) { ret = sb->s_op->freeze_fs(sb); if (ret) { printk(KERN_ERR "VFS:Filesystem freeze failed "); |
5accdf82b fs: Improve files... |
1286 |
sb->s_writers.frozen = SB_UNFROZEN; |
e1616300a wake up s_wait_un... |
1287 |
smp_wmb(); |
5accdf82b fs: Improve files... |
1288 |
wake_up(&sb->s_writers.wait_unfrozen); |
18e9e5104 Introduce freeze_... |
1289 1290 1291 1292 |
deactivate_locked_super(sb); return ret; } } |
5accdf82b fs: Improve files... |
1293 1294 1295 1296 1297 |
/* * This is just for debugging purposes so that fs can warn if it * sees write activity when frozen is set to SB_FREEZE_COMPLETE. */ sb->s_writers.frozen = SB_FREEZE_COMPLETE; |
18e9e5104 Introduce freeze_... |
1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 |
up_write(&sb->s_umount); return 0; } EXPORT_SYMBOL(freeze_super); /** * thaw_super -- unlock filesystem * @sb: the super to thaw * * Unlocks the filesystem and marks it writeable again after freeze_super(). */ int thaw_super(struct super_block *sb) { int error; down_write(&sb->s_umount); |
5accdf82b fs: Improve files... |
1314 |
if (sb->s_writers.frozen == SB_UNFROZEN) { |
18e9e5104 Introduce freeze_... |
1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 |
up_write(&sb->s_umount); return -EINVAL; } if (sb->s_flags & MS_RDONLY) goto out; if (sb->s_op->unfreeze_fs) { error = sb->s_op->unfreeze_fs(sb); if (error) { printk(KERN_ERR "VFS:Filesystem thaw failed "); |
18e9e5104 Introduce freeze_... |
1328 1329 1330 1331 1332 1333 |
up_write(&sb->s_umount); return error; } } out: |
5accdf82b fs: Improve files... |
1334 |
sb->s_writers.frozen = SB_UNFROZEN; |
18e9e5104 Introduce freeze_... |
1335 |
smp_wmb(); |
5accdf82b fs: Improve files... |
1336 |
wake_up(&sb->s_writers.wait_unfrozen); |
18e9e5104 Introduce freeze_... |
1337 1338 1339 1340 1341 |
deactivate_locked_super(sb); return 0; } EXPORT_SYMBOL(thaw_super); |