Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
7b718769 NS |
2 | * Copyright (c) 2000-2005 Silicon Graphics, Inc. |
3 | * All Rights Reserved. | |
1da177e4 | 4 | * |
7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 | 13 | * |
7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 17 | */ |
1da177e4 | 18 | #include "xfs.h" |
a844f451 | 19 | #include "xfs_fs.h" |
1da177e4 | 20 | #include "xfs_types.h" |
ef14f0c1 | 21 | #include "xfs_acl.h" |
a844f451 | 22 | #include "xfs_bit.h" |
1da177e4 | 23 | #include "xfs_log.h" |
a844f451 | 24 | #include "xfs_inum.h" |
1da177e4 LT |
25 | #include "xfs_trans.h" |
26 | #include "xfs_sb.h" | |
27 | #include "xfs_ag.h" | |
1da177e4 | 28 | #include "xfs_mount.h" |
1da177e4 | 29 | #include "xfs_bmap_btree.h" |
a844f451 | 30 | #include "xfs_alloc_btree.h" |
1da177e4 | 31 | #include "xfs_ialloc_btree.h" |
1da177e4 LT |
32 | #include "xfs_dinode.h" |
33 | #include "xfs_inode.h" | |
a844f451 NS |
34 | #include "xfs_btree.h" |
35 | #include "xfs_ialloc.h" | |
1da177e4 LT |
36 | #include "xfs_quota.h" |
37 | #include "xfs_utils.h" | |
783a2f65 DC |
38 | #include "xfs_trans_priv.h" |
39 | #include "xfs_inode_item.h" | |
24f211ba | 40 | #include "xfs_bmap.h" |
0b1b213f | 41 | #include "xfs_trace.h" |
24f211ba CH |
42 | |
43 | ||
dcfcf205 DC |
44 | /* |
45 | * Define xfs inode iolock lockdep classes. We need to ensure that all active | |
46 | * inodes are considered the same for lockdep purposes, including inodes that | |
47 | * are recycled through the XFS_IRECLAIMABLE state. This is the the only way to | |
48 | * guarantee the locks are considered the same when there are multiple lock | |
49 | * initialisation siteѕ. Also, define a reclaimable inode class so it is | |
50 | * obvious in lockdep reports which class the report is against. | |
51 | */ | |
52 | static struct lock_class_key xfs_iolock_active; | |
53 | struct lock_class_key xfs_iolock_reclaimable; | |
54 | ||
24f211ba CH |
55 | /* |
56 | * Allocate and initialise an xfs_inode. | |
57 | */ | |
58 | STATIC struct xfs_inode * | |
59 | xfs_inode_alloc( | |
60 | struct xfs_mount *mp, | |
61 | xfs_ino_t ino) | |
62 | { | |
63 | struct xfs_inode *ip; | |
64 | ||
65 | /* | |
66 | * if this didn't occur in transactions, we could use | |
67 | * KM_MAYFAIL and return NULL here on ENOMEM. Set the | |
68 | * code up to do this anyway. | |
69 | */ | |
70 | ip = kmem_zone_alloc(xfs_inode_zone, KM_SLEEP); | |
71 | if (!ip) | |
72 | return NULL; | |
54e34621 CH |
73 | if (inode_init_always(mp->m_super, VFS_I(ip))) { |
74 | kmem_zone_free(xfs_inode_zone, ip); | |
75 | return NULL; | |
76 | } | |
24f211ba | 77 | |
24f211ba CH |
78 | ASSERT(atomic_read(&ip->i_pincount) == 0); |
79 | ASSERT(!spin_is_locked(&ip->i_flags_lock)); | |
474fce06 | 80 | ASSERT(!xfs_isiflocked(ip)); |
1a3e8f3d | 81 | ASSERT(ip->i_ino == 0); |
033da48f CH |
82 | |
83 | mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino); | |
dcfcf205 DC |
84 | lockdep_set_class_and_name(&ip->i_iolock.mr_lock, |
85 | &xfs_iolock_active, "xfs_iolock_active"); | |
24f211ba | 86 | |
24f211ba CH |
87 | /* initialise the xfs inode */ |
88 | ip->i_ino = ino; | |
89 | ip->i_mount = mp; | |
90 | memset(&ip->i_imap, 0, sizeof(struct xfs_imap)); | |
91 | ip->i_afp = NULL; | |
92 | memset(&ip->i_df, 0, sizeof(xfs_ifork_t)); | |
93 | ip->i_flags = 0; | |
94 | ip->i_update_core = 0; | |
24f211ba CH |
95 | ip->i_delayed_blks = 0; |
96 | memset(&ip->i_d, 0, sizeof(xfs_icdinode_t)); | |
24f211ba | 97 | |
24f211ba CH |
98 | return ip; |
99 | } | |
1da177e4 | 100 | |
fa0d7e3d NP |
101 | STATIC void |
102 | xfs_inode_free_callback( | |
103 | struct rcu_head *head) | |
104 | { | |
105 | struct inode *inode = container_of(head, struct inode, i_rcu); | |
106 | struct xfs_inode *ip = XFS_I(inode); | |
107 | ||
fa0d7e3d NP |
108 | kmem_zone_free(xfs_inode_zone, ip); |
109 | } | |
110 | ||
2f11feab | 111 | void |
b36ec042 CH |
112 | xfs_inode_free( |
113 | struct xfs_inode *ip) | |
114 | { | |
115 | switch (ip->i_d.di_mode & S_IFMT) { | |
116 | case S_IFREG: | |
117 | case S_IFDIR: | |
118 | case S_IFLNK: | |
119 | xfs_idestroy_fork(ip, XFS_DATA_FORK); | |
120 | break; | |
121 | } | |
122 | ||
123 | if (ip->i_afp) | |
124 | xfs_idestroy_fork(ip, XFS_ATTR_FORK); | |
125 | ||
b36ec042 CH |
126 | if (ip->i_itemp) { |
127 | /* | |
128 | * Only if we are shutting down the fs will we see an | |
129 | * inode still in the AIL. If it is there, we should remove | |
130 | * it to prevent a use-after-free from occurring. | |
131 | */ | |
132 | xfs_log_item_t *lip = &ip->i_itemp->ili_item; | |
133 | struct xfs_ail *ailp = lip->li_ailp; | |
134 | ||
135 | ASSERT(((lip->li_flags & XFS_LI_IN_AIL) == 0) || | |
136 | XFS_FORCED_SHUTDOWN(ip->i_mount)); | |
137 | if (lip->li_flags & XFS_LI_IN_AIL) { | |
138 | spin_lock(&ailp->xa_lock); | |
139 | if (lip->li_flags & XFS_LI_IN_AIL) | |
140 | xfs_trans_ail_delete(ailp, lip); | |
141 | else | |
142 | spin_unlock(&ailp->xa_lock); | |
143 | } | |
144 | xfs_inode_item_destroy(ip); | |
145 | ip->i_itemp = NULL; | |
146 | } | |
147 | ||
148 | /* asserts to verify all state is correct here */ | |
b36ec042 CH |
149 | ASSERT(atomic_read(&ip->i_pincount) == 0); |
150 | ASSERT(!spin_is_locked(&ip->i_flags_lock)); | |
474fce06 | 151 | ASSERT(!xfs_isiflocked(ip)); |
b36ec042 | 152 | |
1a3e8f3d DC |
153 | /* |
154 | * Because we use RCU freeing we need to ensure the inode always | |
155 | * appears to be reclaimed with an invalid inode number when in the | |
156 | * free state. The ip->i_flags_lock provides the barrier against lookup | |
157 | * races. | |
158 | */ | |
159 | spin_lock(&ip->i_flags_lock); | |
160 | ip->i_flags = XFS_IRECLAIM; | |
161 | ip->i_ino = 0; | |
162 | spin_unlock(&ip->i_flags_lock); | |
92f1c008 AE |
163 | |
164 | call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback); | |
b36ec042 CH |
165 | } |
166 | ||
1da177e4 | 167 | /* |
6441e549 | 168 | * Check the validity of the inode we just found it the cache |
1da177e4 | 169 | */ |
6441e549 DC |
170 | static int |
171 | xfs_iget_cache_hit( | |
6441e549 DC |
172 | struct xfs_perag *pag, |
173 | struct xfs_inode *ip, | |
1a3e8f3d | 174 | xfs_ino_t ino, |
6441e549 | 175 | int flags, |
1a3e8f3d | 176 | int lock_flags) __releases(RCU) |
1da177e4 | 177 | { |
bc990f5c | 178 | struct inode *inode = VFS_I(ip); |
6441e549 | 179 | struct xfs_mount *mp = ip->i_mount; |
bc990f5c CH |
180 | int error; |
181 | ||
1a3e8f3d DC |
182 | /* |
183 | * check for re-use of an inode within an RCU grace period due to the | |
184 | * radix tree nodes not being updated yet. We monitor for this by | |
185 | * setting the inode number to zero before freeing the inode structure. | |
186 | * If the inode has been reallocated and set up, then the inode number | |
187 | * will not match, so check for that, too. | |
188 | */ | |
bc990f5c | 189 | spin_lock(&ip->i_flags_lock); |
1a3e8f3d DC |
190 | if (ip->i_ino != ino) { |
191 | trace_xfs_iget_skip(ip); | |
192 | XFS_STATS_INC(xs_ig_frecycle); | |
193 | error = EAGAIN; | |
194 | goto out_error; | |
195 | } | |
196 | ||
da353b0d | 197 | |
6441e549 | 198 | /* |
bc990f5c CH |
199 | * If we are racing with another cache hit that is currently |
200 | * instantiating this inode or currently recycling it out of | |
201 | * reclaimabe state, wait for the initialisation to complete | |
202 | * before continuing. | |
203 | * | |
204 | * XXX(hch): eventually we should do something equivalent to | |
205 | * wait_on_inode to wait for these flags to be cleared | |
206 | * instead of polling for it. | |
6441e549 | 207 | */ |
bc990f5c | 208 | if (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) { |
0b1b213f | 209 | trace_xfs_iget_skip(ip); |
6441e549 | 210 | XFS_STATS_INC(xs_ig_frecycle); |
bc990f5c | 211 | error = EAGAIN; |
6441e549 DC |
212 | goto out_error; |
213 | } | |
da353b0d | 214 | |
bc990f5c CH |
215 | /* |
216 | * If lookup is racing with unlink return an error immediately. | |
217 | */ | |
218 | if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) { | |
219 | error = ENOENT; | |
220 | goto out_error; | |
221 | } | |
bf904248 | 222 | |
bc990f5c CH |
223 | /* |
224 | * If IRECLAIMABLE is set, we've torn down the VFS inode already. | |
225 | * Need to carefully get it back into useable state. | |
226 | */ | |
227 | if (ip->i_flags & XFS_IRECLAIMABLE) { | |
0b1b213f | 228 | trace_xfs_iget_reclaim(ip); |
da353b0d | 229 | |
6441e549 | 230 | /* |
f1f724e4 CH |
231 | * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode |
232 | * from stomping over us while we recycle the inode. We can't | |
233 | * clear the radix tree reclaimable tag yet as it requires | |
234 | * pag_ici_lock to be held exclusive. | |
6441e549 | 235 | */ |
f1f724e4 | 236 | ip->i_flags |= XFS_IRECLAIM; |
bc990f5c CH |
237 | |
238 | spin_unlock(&ip->i_flags_lock); | |
1a3e8f3d | 239 | rcu_read_unlock(); |
bc990f5c CH |
240 | |
241 | error = -inode_init_always(mp->m_super, inode); | |
242 | if (error) { | |
243 | /* | |
244 | * Re-initializing the inode failed, and we are in deep | |
245 | * trouble. Try to re-add it to the reclaim list. | |
246 | */ | |
1a3e8f3d | 247 | rcu_read_lock(); |
bc990f5c CH |
248 | spin_lock(&ip->i_flags_lock); |
249 | ||
778e24bb DC |
250 | ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM); |
251 | ASSERT(ip->i_flags & XFS_IRECLAIMABLE); | |
d2e078c3 | 252 | trace_xfs_iget_reclaim_fail(ip); |
6441e549 | 253 | goto out_error; |
da353b0d | 254 | } |
f1f724e4 | 255 | |
1a427ab0 | 256 | spin_lock(&pag->pag_ici_lock); |
f1f724e4 | 257 | spin_lock(&ip->i_flags_lock); |
778e24bb DC |
258 | |
259 | /* | |
260 | * Clear the per-lifetime state in the inode as we are now | |
261 | * effectively a new inode and need to return to the initial | |
262 | * state before reuse occurs. | |
263 | */ | |
264 | ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS; | |
f1f724e4 CH |
265 | ip->i_flags |= XFS_INEW; |
266 | __xfs_inode_clear_reclaim_tag(mp, pag, ip); | |
eaff8079 | 267 | inode->i_state = I_NEW; |
dcfcf205 DC |
268 | |
269 | ASSERT(!rwsem_is_locked(&ip->i_iolock.mr_lock)); | |
270 | mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino); | |
271 | lockdep_set_class_and_name(&ip->i_iolock.mr_lock, | |
272 | &xfs_iolock_active, "xfs_iolock_active"); | |
273 | ||
f1f724e4 | 274 | spin_unlock(&ip->i_flags_lock); |
1a427ab0 | 275 | spin_unlock(&pag->pag_ici_lock); |
bc990f5c | 276 | } else { |
bf904248 | 277 | /* If the VFS inode is being torn down, pause and try again. */ |
bc990f5c | 278 | if (!igrab(inode)) { |
d2e078c3 | 279 | trace_xfs_iget_skip(ip); |
bc990f5c CH |
280 | error = EAGAIN; |
281 | goto out_error; | |
282 | } | |
1da177e4 | 283 | |
bc990f5c CH |
284 | /* We've got a live one. */ |
285 | spin_unlock(&ip->i_flags_lock); | |
1a3e8f3d | 286 | rcu_read_unlock(); |
d2e078c3 | 287 | trace_xfs_iget_hit(ip); |
6441e549 | 288 | } |
da353b0d | 289 | |
6441e549 DC |
290 | if (lock_flags != 0) |
291 | xfs_ilock(ip, lock_flags); | |
da353b0d | 292 | |
6441e549 | 293 | xfs_iflags_clear(ip, XFS_ISTALE); |
6441e549 | 294 | XFS_STATS_INC(xs_ig_found); |
0b1b213f | 295 | |
6441e549 | 296 | return 0; |
1da177e4 | 297 | |
6441e549 | 298 | out_error: |
bc990f5c | 299 | spin_unlock(&ip->i_flags_lock); |
1a3e8f3d | 300 | rcu_read_unlock(); |
6441e549 DC |
301 | return error; |
302 | } | |
303 | ||
304 | ||
305 | static int | |
306 | xfs_iget_cache_miss( | |
307 | struct xfs_mount *mp, | |
308 | struct xfs_perag *pag, | |
309 | xfs_trans_t *tp, | |
310 | xfs_ino_t ino, | |
311 | struct xfs_inode **ipp, | |
6441e549 | 312 | int flags, |
0c3dc2b0 | 313 | int lock_flags) |
6441e549 DC |
314 | { |
315 | struct xfs_inode *ip; | |
316 | int error; | |
6441e549 | 317 | xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino); |
1da177e4 | 318 | |
24f211ba CH |
319 | ip = xfs_inode_alloc(mp, ino); |
320 | if (!ip) | |
321 | return ENOMEM; | |
322 | ||
7b6259e7 | 323 | error = xfs_iread(mp, tp, ip, flags); |
6441e549 | 324 | if (error) |
24f211ba | 325 | goto out_destroy; |
1da177e4 | 326 | |
d2e078c3 | 327 | trace_xfs_iget_miss(ip); |
1da177e4 | 328 | |
745b1f47 | 329 | if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) { |
6441e549 DC |
330 | error = ENOENT; |
331 | goto out_destroy; | |
1da177e4 LT |
332 | } |
333 | ||
334 | /* | |
bad55843 | 335 | * Preload the radix tree so we can insert safely under the |
56e73ec4 DC |
336 | * write spinlock. Note that we cannot sleep inside the preload |
337 | * region. | |
1da177e4 | 338 | */ |
da353b0d | 339 | if (radix_tree_preload(GFP_KERNEL)) { |
6441e549 | 340 | error = EAGAIN; |
ed93ec39 CH |
341 | goto out_destroy; |
342 | } | |
343 | ||
344 | /* | |
345 | * Because the inode hasn't been added to the radix-tree yet it can't | |
346 | * be found by another thread, so we can do the non-sleeping lock here. | |
347 | */ | |
348 | if (lock_flags) { | |
349 | if (!xfs_ilock_nowait(ip, lock_flags)) | |
350 | BUG(); | |
da353b0d | 351 | } |
f338f903 | 352 | |
1a427ab0 | 353 | spin_lock(&pag->pag_ici_lock); |
6441e549 DC |
354 | |
355 | /* insert the new inode */ | |
da353b0d DC |
356 | error = radix_tree_insert(&pag->pag_ici_root, agino, ip); |
357 | if (unlikely(error)) { | |
6441e549 | 358 | WARN_ON(error != -EEXIST); |
da353b0d | 359 | XFS_STATS_INC(xs_ig_dup); |
6441e549 | 360 | error = EAGAIN; |
56e73ec4 | 361 | goto out_preload_end; |
1da177e4 LT |
362 | } |
363 | ||
6441e549 | 364 | /* These values _must_ be set before releasing the radix tree lock! */ |
1da177e4 | 365 | ip->i_udquot = ip->i_gdquot = NULL; |
7a18c386 | 366 | xfs_iflags_set(ip, XFS_INEW); |
1da177e4 | 367 | |
1a427ab0 | 368 | spin_unlock(&pag->pag_ici_lock); |
da353b0d | 369 | radix_tree_preload_end(); |
0b1b213f | 370 | |
6441e549 DC |
371 | *ipp = ip; |
372 | return 0; | |
373 | ||
56e73ec4 | 374 | out_preload_end: |
1a427ab0 | 375 | spin_unlock(&pag->pag_ici_lock); |
6441e549 | 376 | radix_tree_preload_end(); |
56e73ec4 DC |
377 | if (lock_flags) |
378 | xfs_iunlock(ip, lock_flags); | |
6441e549 | 379 | out_destroy: |
b36ec042 CH |
380 | __destroy_inode(VFS_I(ip)); |
381 | xfs_inode_free(ip); | |
6441e549 DC |
382 | return error; |
383 | } | |
384 | ||
385 | /* | |
386 | * Look up an inode by number in the given file system. | |
387 | * The inode is looked up in the cache held in each AG. | |
bf904248 DC |
388 | * If the inode is found in the cache, initialise the vfs inode |
389 | * if necessary. | |
6441e549 DC |
390 | * |
391 | * If it is not in core, read it in from the file system's device, | |
bf904248 | 392 | * add it to the cache and initialise the vfs inode. |
6441e549 DC |
393 | * |
394 | * The inode is locked according to the value of the lock_flags parameter. | |
395 | * This flag parameter indicates how and if the inode's IO lock and inode lock | |
396 | * should be taken. | |
397 | * | |
398 | * mp -- the mount point structure for the current file system. It points | |
399 | * to the inode hash table. | |
400 | * tp -- a pointer to the current transaction if there is one. This is | |
401 | * simply passed through to the xfs_iread() call. | |
402 | * ino -- the number of the inode desired. This is the unique identifier | |
403 | * within the file system for the inode being requested. | |
404 | * lock_flags -- flags indicating how to lock the inode. See the comment | |
405 | * for xfs_ilock() for a list of valid values. | |
6441e549 | 406 | */ |
bf904248 DC |
407 | int |
408 | xfs_iget( | |
6441e549 DC |
409 | xfs_mount_t *mp, |
410 | xfs_trans_t *tp, | |
411 | xfs_ino_t ino, | |
412 | uint flags, | |
413 | uint lock_flags, | |
7b6259e7 | 414 | xfs_inode_t **ipp) |
6441e549 DC |
415 | { |
416 | xfs_inode_t *ip; | |
417 | int error; | |
418 | xfs_perag_t *pag; | |
419 | xfs_agino_t agino; | |
420 | ||
d276734d | 421 | /* reject inode numbers outside existing AGs */ |
1a3e8f3d | 422 | if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount) |
6441e549 DC |
423 | return EINVAL; |
424 | ||
425 | /* get the perag structure and ensure that it's inode capable */ | |
5017e97d | 426 | pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino)); |
6441e549 DC |
427 | agino = XFS_INO_TO_AGINO(mp, ino); |
428 | ||
429 | again: | |
430 | error = 0; | |
1a3e8f3d | 431 | rcu_read_lock(); |
6441e549 DC |
432 | ip = radix_tree_lookup(&pag->pag_ici_root, agino); |
433 | ||
434 | if (ip) { | |
1a3e8f3d | 435 | error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags); |
6441e549 DC |
436 | if (error) |
437 | goto out_error_or_again; | |
438 | } else { | |
1a3e8f3d | 439 | rcu_read_unlock(); |
6441e549 DC |
440 | XFS_STATS_INC(xs_ig_missed); |
441 | ||
7b6259e7 | 442 | error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip, |
6441e549 DC |
443 | flags, lock_flags); |
444 | if (error) | |
445 | goto out_error_or_again; | |
446 | } | |
5017e97d | 447 | xfs_perag_put(pag); |
1da177e4 | 448 | |
1da177e4 LT |
449 | *ipp = ip; |
450 | ||
451 | /* | |
452 | * If we have a real type for an on-disk inode, we can set ops(&unlock) | |
453 | * now. If it's a new inode being created, xfs_ialloc will handle it. | |
454 | */ | |
bf904248 | 455 | if (xfs_iflags_test(ip, XFS_INEW) && ip->i_d.di_mode != 0) |
41be8bed | 456 | xfs_setup_inode(ip); |
1da177e4 | 457 | return 0; |
6441e549 DC |
458 | |
459 | out_error_or_again: | |
460 | if (error == EAGAIN) { | |
461 | delay(1); | |
462 | goto again; | |
463 | } | |
5017e97d | 464 | xfs_perag_put(pag); |
6441e549 | 465 | return error; |
1da177e4 LT |
466 | } |
467 | ||
1da177e4 LT |
468 | /* |
469 | * This is a wrapper routine around the xfs_ilock() routine | |
470 | * used to centralize some grungy code. It is used in places | |
471 | * that wish to lock the inode solely for reading the extents. | |
472 | * The reason these places can't just call xfs_ilock(SHARED) | |
473 | * is that the inode lock also guards to bringing in of the | |
474 | * extents from disk for a file in b-tree format. If the inode | |
475 | * is in b-tree format, then we need to lock the inode exclusively | |
476 | * until the extents are read in. Locking it exclusively all | |
477 | * the time would limit our parallelism unnecessarily, though. | |
478 | * What we do instead is check to see if the extents have been | |
479 | * read in yet, and only lock the inode exclusively if they | |
480 | * have not. | |
481 | * | |
482 | * The function returns a value which should be given to the | |
483 | * corresponding xfs_iunlock_map_shared(). This value is | |
484 | * the mode in which the lock was actually taken. | |
485 | */ | |
486 | uint | |
487 | xfs_ilock_map_shared( | |
488 | xfs_inode_t *ip) | |
489 | { | |
490 | uint lock_mode; | |
491 | ||
492 | if ((ip->i_d.di_format == XFS_DINODE_FMT_BTREE) && | |
493 | ((ip->i_df.if_flags & XFS_IFEXTENTS) == 0)) { | |
494 | lock_mode = XFS_ILOCK_EXCL; | |
495 | } else { | |
496 | lock_mode = XFS_ILOCK_SHARED; | |
497 | } | |
498 | ||
499 | xfs_ilock(ip, lock_mode); | |
500 | ||
501 | return lock_mode; | |
502 | } | |
503 | ||
504 | /* | |
505 | * This is simply the unlock routine to go with xfs_ilock_map_shared(). | |
506 | * All it does is call xfs_iunlock() with the given lock_mode. | |
507 | */ | |
508 | void | |
509 | xfs_iunlock_map_shared( | |
510 | xfs_inode_t *ip, | |
511 | unsigned int lock_mode) | |
512 | { | |
513 | xfs_iunlock(ip, lock_mode); | |
514 | } | |
515 | ||
516 | /* | |
517 | * The xfs inode contains 2 locks: a multi-reader lock called the | |
518 | * i_iolock and a multi-reader lock called the i_lock. This routine | |
519 | * allows either or both of the locks to be obtained. | |
520 | * | |
521 | * The 2 locks should always be ordered so that the IO lock is | |
522 | * obtained first in order to prevent deadlock. | |
523 | * | |
524 | * ip -- the inode being locked | |
525 | * lock_flags -- this parameter indicates the inode's locks | |
526 | * to be locked. It can be: | |
527 | * XFS_IOLOCK_SHARED, | |
528 | * XFS_IOLOCK_EXCL, | |
529 | * XFS_ILOCK_SHARED, | |
530 | * XFS_ILOCK_EXCL, | |
531 | * XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED, | |
532 | * XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL, | |
533 | * XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED, | |
534 | * XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL | |
535 | */ | |
536 | void | |
579aa9ca CH |
537 | xfs_ilock( |
538 | xfs_inode_t *ip, | |
539 | uint lock_flags) | |
1da177e4 LT |
540 | { |
541 | /* | |
542 | * You can't set both SHARED and EXCL for the same lock, | |
543 | * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED, | |
544 | * and XFS_ILOCK_EXCL are valid values to set in lock_flags. | |
545 | */ | |
546 | ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != | |
547 | (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); | |
548 | ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != | |
549 | (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); | |
f7c66ce3 | 550 | ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0); |
1da177e4 | 551 | |
579aa9ca | 552 | if (lock_flags & XFS_IOLOCK_EXCL) |
f7c66ce3 | 553 | mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags)); |
579aa9ca | 554 | else if (lock_flags & XFS_IOLOCK_SHARED) |
f7c66ce3 | 555 | mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags)); |
579aa9ca CH |
556 | |
557 | if (lock_flags & XFS_ILOCK_EXCL) | |
f7c66ce3 | 558 | mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); |
579aa9ca | 559 | else if (lock_flags & XFS_ILOCK_SHARED) |
f7c66ce3 | 560 | mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); |
579aa9ca | 561 | |
0b1b213f | 562 | trace_xfs_ilock(ip, lock_flags, _RET_IP_); |
1da177e4 LT |
563 | } |
564 | ||
565 | /* | |
566 | * This is just like xfs_ilock(), except that the caller | |
567 | * is guaranteed not to sleep. It returns 1 if it gets | |
568 | * the requested locks and 0 otherwise. If the IO lock is | |
569 | * obtained but the inode lock cannot be, then the IO lock | |
570 | * is dropped before returning. | |
571 | * | |
572 | * ip -- the inode being locked | |
573 | * lock_flags -- this parameter indicates the inode's locks to be | |
574 | * to be locked. See the comment for xfs_ilock() for a list | |
575 | * of valid values. | |
1da177e4 LT |
576 | */ |
577 | int | |
579aa9ca CH |
578 | xfs_ilock_nowait( |
579 | xfs_inode_t *ip, | |
580 | uint lock_flags) | |
1da177e4 | 581 | { |
1da177e4 LT |
582 | /* |
583 | * You can't set both SHARED and EXCL for the same lock, | |
584 | * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED, | |
585 | * and XFS_ILOCK_EXCL are valid values to set in lock_flags. | |
586 | */ | |
587 | ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != | |
588 | (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); | |
589 | ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != | |
590 | (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); | |
f7c66ce3 | 591 | ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0); |
1da177e4 | 592 | |
1da177e4 | 593 | if (lock_flags & XFS_IOLOCK_EXCL) { |
579aa9ca CH |
594 | if (!mrtryupdate(&ip->i_iolock)) |
595 | goto out; | |
1da177e4 | 596 | } else if (lock_flags & XFS_IOLOCK_SHARED) { |
579aa9ca CH |
597 | if (!mrtryaccess(&ip->i_iolock)) |
598 | goto out; | |
1da177e4 LT |
599 | } |
600 | if (lock_flags & XFS_ILOCK_EXCL) { | |
579aa9ca CH |
601 | if (!mrtryupdate(&ip->i_lock)) |
602 | goto out_undo_iolock; | |
1da177e4 | 603 | } else if (lock_flags & XFS_ILOCK_SHARED) { |
579aa9ca CH |
604 | if (!mrtryaccess(&ip->i_lock)) |
605 | goto out_undo_iolock; | |
1da177e4 | 606 | } |
0b1b213f | 607 | trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_); |
1da177e4 | 608 | return 1; |
579aa9ca CH |
609 | |
610 | out_undo_iolock: | |
611 | if (lock_flags & XFS_IOLOCK_EXCL) | |
612 | mrunlock_excl(&ip->i_iolock); | |
613 | else if (lock_flags & XFS_IOLOCK_SHARED) | |
614 | mrunlock_shared(&ip->i_iolock); | |
615 | out: | |
616 | return 0; | |
1da177e4 LT |
617 | } |
618 | ||
619 | /* | |
620 | * xfs_iunlock() is used to drop the inode locks acquired with | |
621 | * xfs_ilock() and xfs_ilock_nowait(). The caller must pass | |
622 | * in the flags given to xfs_ilock() or xfs_ilock_nowait() so | |
623 | * that we know which locks to drop. | |
624 | * | |
625 | * ip -- the inode being unlocked | |
626 | * lock_flags -- this parameter indicates the inode's locks to be | |
627 | * to be unlocked. See the comment for xfs_ilock() for a list | |
628 | * of valid values for this parameter. | |
629 | * | |
630 | */ | |
631 | void | |
579aa9ca CH |
632 | xfs_iunlock( |
633 | xfs_inode_t *ip, | |
634 | uint lock_flags) | |
1da177e4 LT |
635 | { |
636 | /* | |
637 | * You can't set both SHARED and EXCL for the same lock, | |
638 | * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED, | |
639 | * and XFS_ILOCK_EXCL are valid values to set in lock_flags. | |
640 | */ | |
641 | ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != | |
642 | (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); | |
643 | ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != | |
644 | (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); | |
f7c66ce3 LM |
645 | ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_IUNLOCK_NONOTIFY | |
646 | XFS_LOCK_DEP_MASK)) == 0); | |
1da177e4 LT |
647 | ASSERT(lock_flags != 0); |
648 | ||
579aa9ca CH |
649 | if (lock_flags & XFS_IOLOCK_EXCL) |
650 | mrunlock_excl(&ip->i_iolock); | |
651 | else if (lock_flags & XFS_IOLOCK_SHARED) | |
652 | mrunlock_shared(&ip->i_iolock); | |
1da177e4 | 653 | |
579aa9ca CH |
654 | if (lock_flags & XFS_ILOCK_EXCL) |
655 | mrunlock_excl(&ip->i_lock); | |
656 | else if (lock_flags & XFS_ILOCK_SHARED) | |
657 | mrunlock_shared(&ip->i_lock); | |
1da177e4 | 658 | |
579aa9ca CH |
659 | if ((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) && |
660 | !(lock_flags & XFS_IUNLOCK_NONOTIFY) && ip->i_itemp) { | |
1da177e4 LT |
661 | /* |
662 | * Let the AIL know that this item has been unlocked in case | |
663 | * it is in the AIL and anyone is waiting on it. Don't do | |
664 | * this if the caller has asked us not to. | |
665 | */ | |
783a2f65 | 666 | xfs_trans_unlocked_item(ip->i_itemp->ili_item.li_ailp, |
579aa9ca | 667 | (xfs_log_item_t*)(ip->i_itemp)); |
1da177e4 | 668 | } |
0b1b213f | 669 | trace_xfs_iunlock(ip, lock_flags, _RET_IP_); |
1da177e4 LT |
670 | } |
671 | ||
672 | /* | |
673 | * give up write locks. the i/o lock cannot be held nested | |
674 | * if it is being demoted. | |
675 | */ | |
676 | void | |
579aa9ca CH |
677 | xfs_ilock_demote( |
678 | xfs_inode_t *ip, | |
679 | uint lock_flags) | |
1da177e4 LT |
680 | { |
681 | ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)); | |
682 | ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0); | |
683 | ||
579aa9ca | 684 | if (lock_flags & XFS_ILOCK_EXCL) |
1da177e4 | 685 | mrdemote(&ip->i_lock); |
579aa9ca | 686 | if (lock_flags & XFS_IOLOCK_EXCL) |
1da177e4 | 687 | mrdemote(&ip->i_iolock); |
0b1b213f CH |
688 | |
689 | trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_); | |
579aa9ca CH |
690 | } |
691 | ||
692 | #ifdef DEBUG | |
579aa9ca CH |
693 | int |
694 | xfs_isilocked( | |
695 | xfs_inode_t *ip, | |
696 | uint lock_flags) | |
697 | { | |
f9369729 CH |
698 | if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) { |
699 | if (!(lock_flags & XFS_ILOCK_SHARED)) | |
700 | return !!ip->i_lock.mr_writer; | |
701 | return rwsem_is_locked(&ip->i_lock.mr_lock); | |
1da177e4 | 702 | } |
579aa9ca | 703 | |
f9369729 CH |
704 | if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) { |
705 | if (!(lock_flags & XFS_IOLOCK_SHARED)) | |
706 | return !!ip->i_iolock.mr_writer; | |
707 | return rwsem_is_locked(&ip->i_iolock.mr_lock); | |
579aa9ca CH |
708 | } |
709 | ||
f9369729 CH |
710 | ASSERT(0); |
711 | return 0; | |
1da177e4 | 712 | } |
579aa9ca | 713 | #endif |
474fce06 CH |
714 | |
715 | void | |
716 | __xfs_iflock( | |
717 | struct xfs_inode *ip) | |
718 | { | |
719 | wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IFLOCK_BIT); | |
720 | DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IFLOCK_BIT); | |
721 | ||
722 | do { | |
723 | prepare_to_wait_exclusive(wq, &wait.wait, TASK_UNINTERRUPTIBLE); | |
724 | if (xfs_isiflocked(ip)) | |
725 | io_schedule(); | |
726 | } while (!xfs_iflock_nowait(ip)); | |
727 | ||
728 | finish_wait(wq, &wait.wait); | |
729 | } |