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" |
a844f451 | 21 | #include "xfs_bit.h" |
1da177e4 | 22 | #include "xfs_log.h" |
a844f451 | 23 | #include "xfs_inum.h" |
1da177e4 LT |
24 | #include "xfs_trans.h" |
25 | #include "xfs_sb.h" | |
26 | #include "xfs_ag.h" | |
1da177e4 LT |
27 | #include "xfs_dir2.h" |
28 | #include "xfs_dmapi.h" | |
29 | #include "xfs_mount.h" | |
1da177e4 | 30 | #include "xfs_bmap_btree.h" |
a844f451 | 31 | #include "xfs_alloc_btree.h" |
1da177e4 | 32 | #include "xfs_ialloc_btree.h" |
1da177e4 | 33 | #include "xfs_dir2_sf.h" |
a844f451 | 34 | #include "xfs_attr_sf.h" |
1da177e4 LT |
35 | #include "xfs_dinode.h" |
36 | #include "xfs_inode.h" | |
a844f451 NS |
37 | #include "xfs_btree.h" |
38 | #include "xfs_ialloc.h" | |
1da177e4 LT |
39 | #include "xfs_quota.h" |
40 | #include "xfs_utils.h" | |
1da177e4 | 41 | |
1da177e4 LT |
42 | /* |
43 | * Look up an inode by number in the given file system. | |
da353b0d DC |
44 | * The inode is looked up in the cache held in each AG. |
45 | * If the inode is found in the cache, attach it to the provided | |
46 | * vnode. | |
1da177e4 | 47 | * |
da353b0d DC |
48 | * If it is not in core, read it in from the file system's device, |
49 | * add it to the cache and attach the provided vnode. | |
1da177e4 LT |
50 | * |
51 | * The inode is locked according to the value of the lock_flags parameter. | |
52 | * This flag parameter indicates how and if the inode's IO lock and inode lock | |
53 | * should be taken. | |
54 | * | |
55 | * mp -- the mount point structure for the current file system. It points | |
56 | * to the inode hash table. | |
57 | * tp -- a pointer to the current transaction if there is one. This is | |
58 | * simply passed through to the xfs_iread() call. | |
59 | * ino -- the number of the inode desired. This is the unique identifier | |
60 | * within the file system for the inode being requested. | |
61 | * lock_flags -- flags indicating how to lock the inode. See the comment | |
62 | * for xfs_ilock() for a list of valid values. | |
63 | * bno -- the block number starting the buffer containing the inode, | |
64 | * if known (as by bulkstat), else 0. | |
65 | */ | |
66 | STATIC int | |
67 | xfs_iget_core( | |
10090be2 | 68 | struct inode *inode, |
1da177e4 LT |
69 | xfs_mount_t *mp, |
70 | xfs_trans_t *tp, | |
71 | xfs_ino_t ino, | |
72 | uint flags, | |
73 | uint lock_flags, | |
74 | xfs_inode_t **ipp, | |
75 | xfs_daddr_t bno) | |
76 | { | |
10090be2 | 77 | struct inode *old_inode; |
1da177e4 LT |
78 | xfs_inode_t *ip; |
79 | xfs_inode_t *iq; | |
1da177e4 | 80 | int error; |
da353b0d DC |
81 | unsigned long first_index, mask; |
82 | xfs_perag_t *pag; | |
83 | xfs_agino_t agino; | |
84 | ||
85 | /* the radix tree exists only in inode capable AGs */ | |
86 | if (XFS_INO_TO_AGNO(mp, ino) >= mp->m_maxagi) | |
87 | return EINVAL; | |
88 | ||
89 | /* get the perag structure and ensure that it's inode capable */ | |
90 | pag = xfs_get_perag(mp, ino); | |
91 | if (!pag->pagi_inodeok) | |
92 | return EINVAL; | |
93 | ASSERT(pag->pag_ici_init); | |
94 | agino = XFS_INO_TO_AGINO(mp, ino); | |
1da177e4 LT |
95 | |
96 | again: | |
da353b0d DC |
97 | read_lock(&pag->pag_ici_lock); |
98 | ip = radix_tree_lookup(&pag->pag_ici_root, agino); | |
99 | ||
100 | if (ip != NULL) { | |
101 | /* | |
102 | * If INEW is set this inode is being set up | |
103 | * we need to pause and try again. | |
104 | */ | |
105 | if (xfs_iflags_test(ip, XFS_INEW)) { | |
106 | read_unlock(&pag->pag_ici_lock); | |
107 | delay(1); | |
108 | XFS_STATS_INC(xs_ig_frecycle); | |
109 | ||
110 | goto again; | |
111 | } | |
1da177e4 | 112 | |
10090be2 CH |
113 | old_inode = ip->i_vnode; |
114 | if (old_inode == NULL) { | |
1da177e4 | 115 | /* |
da353b0d DC |
116 | * If IRECLAIM is set this inode is |
117 | * on its way out of the system, | |
1da177e4 LT |
118 | * we need to pause and try again. |
119 | */ | |
da353b0d DC |
120 | if (xfs_iflags_test(ip, XFS_IRECLAIM)) { |
121 | read_unlock(&pag->pag_ici_lock); | |
1da177e4 LT |
122 | delay(1); |
123 | XFS_STATS_INC(xs_ig_frecycle); | |
124 | ||
125 | goto again; | |
126 | } | |
da353b0d | 127 | ASSERT(xfs_iflags_test(ip, XFS_IRECLAIMABLE)); |
1da177e4 | 128 | |
da353b0d DC |
129 | /* |
130 | * If lookup is racing with unlink, then we | |
131 | * should return an error immediately so we | |
132 | * don't remove it from the reclaim list and | |
133 | * potentially leak the inode. | |
134 | */ | |
135 | if ((ip->i_d.di_mode == 0) && | |
136 | !(flags & XFS_IGET_CREATE)) { | |
137 | read_unlock(&pag->pag_ici_lock); | |
138 | xfs_put_perag(mp, pag); | |
139 | return ENOENT; | |
140 | } | |
1da177e4 | 141 | |
15947f2d | 142 | xfs_itrace_exit_tag(ip, "xfs_iget.alloc"); |
1da177e4 | 143 | |
da353b0d | 144 | XFS_STATS_INC(xs_ig_found); |
da353b0d DC |
145 | xfs_iflags_clear(ip, XFS_IRECLAIMABLE); |
146 | read_unlock(&pag->pag_ici_lock); | |
1da177e4 | 147 | |
da353b0d DC |
148 | XFS_MOUNT_ILOCK(mp); |
149 | list_del_init(&ip->i_reclaim); | |
150 | XFS_MOUNT_IUNLOCK(mp); | |
1da177e4 | 151 | |
da353b0d | 152 | goto finish_inode; |
1da177e4 | 153 | |
10090be2 | 154 | } else if (inode != old_inode) { |
da353b0d DC |
155 | /* The inode is being torn down, pause and |
156 | * try again. | |
71bce256 | 157 | */ |
10090be2 | 158 | if (old_inode->i_state & (I_FREEING | I_CLEAR)) { |
da353b0d DC |
159 | read_unlock(&pag->pag_ici_lock); |
160 | delay(1); | |
161 | XFS_STATS_INC(xs_ig_frecycle); | |
1da177e4 | 162 | |
da353b0d | 163 | goto again; |
1da177e4 | 164 | } |
da353b0d DC |
165 | /* Chances are the other vnode (the one in the inode) is being torn |
166 | * down right now, and we landed on top of it. Question is, what do | |
167 | * we do? Unhook the old inode and hook up the new one? | |
168 | */ | |
169 | cmn_err(CE_PANIC, | |
170 | "xfs_iget_core: ambiguous vns: vp/0x%p, invp/0x%p", | |
10090be2 | 171 | old_inode, inode); |
da353b0d | 172 | } |
745b1f47 | 173 | |
da353b0d DC |
174 | /* |
175 | * Inode cache hit | |
176 | */ | |
177 | read_unlock(&pag->pag_ici_lock); | |
178 | XFS_STATS_INC(xs_ig_found); | |
1da177e4 | 179 | |
da353b0d | 180 | finish_inode: |
613d7043 CH |
181 | if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) { |
182 | xfs_put_perag(mp, pag); | |
183 | return ENOENT; | |
1da177e4 | 184 | } |
da353b0d DC |
185 | |
186 | if (lock_flags != 0) | |
187 | xfs_ilock(ip, lock_flags); | |
188 | ||
189 | xfs_iflags_clear(ip, XFS_ISTALE); | |
15947f2d | 190 | xfs_itrace_exit_tag(ip, "xfs_iget.found"); |
da353b0d | 191 | goto return_ip; |
1da177e4 LT |
192 | } |
193 | ||
194 | /* | |
da353b0d | 195 | * Inode cache miss |
1da177e4 | 196 | */ |
da353b0d | 197 | read_unlock(&pag->pag_ici_lock); |
1da177e4 LT |
198 | XFS_STATS_INC(xs_ig_missed); |
199 | ||
1da177e4 LT |
200 | /* |
201 | * Read the disk inode attributes into a new inode structure and get | |
202 | * a new vnode for it. This should also initialize i_ino and i_mount. | |
203 | */ | |
745b1f47 NS |
204 | error = xfs_iread(mp, tp, ino, &ip, bno, |
205 | (flags & XFS_IGET_BULKSTAT) ? XFS_IMAP_BULKSTAT : 0); | |
da353b0d DC |
206 | if (error) { |
207 | xfs_put_perag(mp, pag); | |
1da177e4 | 208 | return error; |
da353b0d | 209 | } |
1da177e4 | 210 | |
15947f2d | 211 | xfs_itrace_exit_tag(ip, "xfs_iget.alloc"); |
1da177e4 | 212 | |
10090be2 CH |
213 | |
214 | mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER, | |
215 | "xfsino", ip->i_ino); | |
216 | mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino); | |
217 | init_waitqueue_head(&ip->i_ipin_wait); | |
218 | atomic_set(&ip->i_pincount, 0); | |
219 | initnsema(&ip->i_flock, 1, "xfsfino"); | |
220 | ||
745b1f47 | 221 | if (lock_flags) |
1da177e4 | 222 | xfs_ilock(ip, lock_flags); |
745b1f47 NS |
223 | |
224 | if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) { | |
1da177e4 | 225 | xfs_idestroy(ip); |
da353b0d | 226 | xfs_put_perag(mp, pag); |
1da177e4 LT |
227 | return ENOENT; |
228 | } | |
229 | ||
230 | /* | |
bad55843 DC |
231 | * Preload the radix tree so we can insert safely under the |
232 | * write spinlock. | |
1da177e4 | 233 | */ |
da353b0d | 234 | if (radix_tree_preload(GFP_KERNEL)) { |
72772a3b | 235 | xfs_idestroy(ip); |
da353b0d DC |
236 | delay(1); |
237 | goto again; | |
238 | } | |
239 | mask = ~(((XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog)) - 1); | |
240 | first_index = agino & mask; | |
241 | write_lock(&pag->pag_ici_lock); | |
da353b0d DC |
242 | /* |
243 | * insert the new inode | |
244 | */ | |
245 | error = radix_tree_insert(&pag->pag_ici_root, agino, ip); | |
246 | if (unlikely(error)) { | |
247 | BUG_ON(error != -EEXIST); | |
248 | write_unlock(&pag->pag_ici_lock); | |
249 | radix_tree_preload_end(); | |
250 | xfs_idestroy(ip); | |
251 | XFS_STATS_INC(xs_ig_dup); | |
252 | goto again; | |
1da177e4 LT |
253 | } |
254 | ||
255 | /* | |
bad55843 | 256 | * These values _must_ be set before releasing the radix tree lock! |
1da177e4 | 257 | */ |
1da177e4 | 258 | ip->i_udquot = ip->i_gdquot = NULL; |
7a18c386 | 259 | xfs_iflags_set(ip, XFS_INEW); |
1da177e4 | 260 | |
da353b0d DC |
261 | write_unlock(&pag->pag_ici_lock); |
262 | radix_tree_preload_end(); | |
1da177e4 LT |
263 | |
264 | /* | |
265 | * Link ip to its mount and thread it on the mount's inode list. | |
266 | */ | |
267 | XFS_MOUNT_ILOCK(mp); | |
268 | if ((iq = mp->m_inodes)) { | |
269 | ASSERT(iq->i_mprev->i_mnext == iq); | |
270 | ip->i_mprev = iq->i_mprev; | |
271 | iq->i_mprev->i_mnext = ip; | |
272 | iq->i_mprev = ip; | |
273 | ip->i_mnext = iq; | |
274 | } else { | |
275 | ip->i_mnext = ip; | |
276 | ip->i_mprev = ip; | |
277 | } | |
278 | mp->m_inodes = ip; | |
279 | ||
280 | XFS_MOUNT_IUNLOCK(mp); | |
da353b0d | 281 | xfs_put_perag(mp, pag); |
1da177e4 LT |
282 | |
283 | return_ip: | |
284 | ASSERT(ip->i_df.if_ext_max == | |
285 | XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t)); | |
286 | ||
b3aea4ed | 287 | xfs_iflags_set(ip, XFS_IMODIFIED); |
1da177e4 LT |
288 | *ipp = ip; |
289 | ||
290 | /* | |
291 | * If we have a real type for an on-disk inode, we can set ops(&unlock) | |
292 | * now. If it's a new inode being created, xfs_ialloc will handle it. | |
293 | */ | |
10090be2 | 294 | xfs_initialize_vnode(mp, inode, ip); |
1da177e4 LT |
295 | return 0; |
296 | } | |
297 | ||
298 | ||
299 | /* | |
300 | * The 'normal' internal xfs_iget, if needed it will | |
301 | * 'allocate', or 'get', the vnode. | |
302 | */ | |
303 | int | |
304 | xfs_iget( | |
305 | xfs_mount_t *mp, | |
306 | xfs_trans_t *tp, | |
307 | xfs_ino_t ino, | |
308 | uint flags, | |
309 | uint lock_flags, | |
310 | xfs_inode_t **ipp, | |
311 | xfs_daddr_t bno) | |
312 | { | |
313 | struct inode *inode; | |
10090be2 | 314 | xfs_inode_t *ip; |
1da177e4 LT |
315 | int error; |
316 | ||
1da177e4 LT |
317 | XFS_STATS_INC(xs_ig_attempts); |
318 | ||
ba403ab4 | 319 | retry: |
b267ce99 | 320 | inode = iget_locked(mp->m_super, ino); |
10090be2 CH |
321 | if (!inode) |
322 | /* If we got no inode we are out of memory */ | |
323 | return ENOMEM; | |
324 | ||
325 | if (inode->i_state & I_NEW) { | |
326 | XFS_STATS_INC(vn_active); | |
327 | XFS_STATS_INC(vn_alloc); | |
328 | ||
329 | error = xfs_iget_core(inode, mp, tp, ino, flags, | |
330 | lock_flags, ipp, bno); | |
331 | if (error) { | |
332 | make_bad_inode(inode); | |
333 | if (inode->i_state & I_NEW) | |
334 | unlock_new_inode(inode); | |
335 | iput(inode); | |
1da177e4 | 336 | } |
10090be2 CH |
337 | return error; |
338 | } | |
1da177e4 | 339 | |
10090be2 CH |
340 | /* |
341 | * If the inode is not fully constructed due to | |
342 | * filehandle mismatches wait for the inode to go | |
343 | * away and try again. | |
344 | * | |
345 | * iget_locked will call __wait_on_freeing_inode | |
346 | * to wait for the inode to go away. | |
347 | */ | |
348 | if (is_bad_inode(inode)) { | |
349 | iput(inode); | |
350 | delay(1); | |
351 | goto retry; | |
352 | } | |
1da177e4 | 353 | |
10090be2 CH |
354 | ip = XFS_I(inode); |
355 | if (!ip) { | |
356 | iput(inode); | |
357 | delay(1); | |
358 | goto retry; | |
359 | } | |
360 | ||
361 | if (lock_flags != 0) | |
362 | xfs_ilock(ip, lock_flags); | |
363 | XFS_STATS_INC(xs_ig_found); | |
364 | *ipp = ip; | |
365 | return 0; | |
1da177e4 LT |
366 | } |
367 | ||
368 | /* | |
369 | * Look for the inode corresponding to the given ino in the hash table. | |
370 | * If it is there and its i_transp pointer matches tp, return it. | |
371 | * Otherwise, return NULL. | |
372 | */ | |
373 | xfs_inode_t * | |
374 | xfs_inode_incore(xfs_mount_t *mp, | |
375 | xfs_ino_t ino, | |
376 | xfs_trans_t *tp) | |
377 | { | |
1da177e4 | 378 | xfs_inode_t *ip; |
da353b0d DC |
379 | xfs_perag_t *pag; |
380 | ||
381 | pag = xfs_get_perag(mp, ino); | |
382 | read_lock(&pag->pag_ici_lock); | |
383 | ip = radix_tree_lookup(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ino)); | |
384 | read_unlock(&pag->pag_ici_lock); | |
385 | xfs_put_perag(mp, pag); | |
386 | ||
387 | /* the returned inode must match the transaction */ | |
388 | if (ip && (ip->i_transp != tp)) | |
389 | return NULL; | |
390 | return ip; | |
1da177e4 LT |
391 | } |
392 | ||
393 | /* | |
394 | * Decrement reference count of an inode structure and unlock it. | |
395 | * | |
396 | * ip -- the inode being released | |
397 | * lock_flags -- this parameter indicates the inode's locks to be | |
398 | * to be released. See the comment on xfs_iunlock() for a list | |
399 | * of valid values. | |
400 | */ | |
401 | void | |
402 | xfs_iput(xfs_inode_t *ip, | |
403 | uint lock_flags) | |
404 | { | |
cf441eeb | 405 | xfs_itrace_entry(ip); |
1da177e4 | 406 | xfs_iunlock(ip, lock_flags); |
10090be2 | 407 | IRELE(ip); |
1da177e4 LT |
408 | } |
409 | ||
410 | /* | |
411 | * Special iput for brand-new inodes that are still locked | |
412 | */ | |
413 | void | |
414 | xfs_iput_new(xfs_inode_t *ip, | |
415 | uint lock_flags) | |
416 | { | |
10090be2 | 417 | struct inode *inode = ip->i_vnode; |
1da177e4 | 418 | |
cf441eeb | 419 | xfs_itrace_entry(ip); |
1da177e4 LT |
420 | |
421 | if ((ip->i_d.di_mode == 0)) { | |
7a18c386 | 422 | ASSERT(!xfs_iflags_test(ip, XFS_IRECLAIMABLE)); |
10090be2 | 423 | make_bad_inode(inode); |
1da177e4 LT |
424 | } |
425 | if (inode->i_state & I_NEW) | |
426 | unlock_new_inode(inode); | |
427 | if (lock_flags) | |
428 | xfs_iunlock(ip, lock_flags); | |
10090be2 | 429 | IRELE(ip); |
1da177e4 LT |
430 | } |
431 | ||
432 | ||
433 | /* | |
434 | * This routine embodies the part of the reclaim code that pulls | |
435 | * the inode from the inode hash table and the mount structure's | |
436 | * inode list. | |
437 | * This should only be called from xfs_reclaim(). | |
438 | */ | |
439 | void | |
440 | xfs_ireclaim(xfs_inode_t *ip) | |
441 | { | |
1da177e4 LT |
442 | /* |
443 | * Remove from old hash list and mount list. | |
444 | */ | |
445 | XFS_STATS_INC(xs_ig_reclaims); | |
446 | ||
447 | xfs_iextract(ip); | |
448 | ||
449 | /* | |
450 | * Here we do a spurious inode lock in order to coordinate with | |
451 | * xfs_sync(). This is because xfs_sync() references the inodes | |
452 | * in the mount list without taking references on the corresponding | |
453 | * vnodes. We make that OK here by ensuring that we wait until | |
454 | * the inode is unlocked in xfs_sync() before we go ahead and | |
455 | * free it. We get both the regular lock and the io lock because | |
456 | * the xfs_sync() code may need to drop the regular one but will | |
457 | * still hold the io lock. | |
458 | */ | |
459 | xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); | |
460 | ||
461 | /* | |
462 | * Release dquots (and their references) if any. An inode may escape | |
463 | * xfs_inactive and get here via vn_alloc->vn_reclaim path. | |
464 | */ | |
465 | XFS_QM_DQDETACH(ip->i_mount, ip); | |
466 | ||
467 | /* | |
468 | * Pull our behavior descriptor from the vnode chain. | |
469 | */ | |
10090be2 CH |
470 | if (ip->i_vnode) { |
471 | ip->i_vnode->i_private = NULL; | |
739bfb2a | 472 | ip->i_vnode = NULL; |
1da177e4 LT |
473 | } |
474 | ||
475 | /* | |
476 | * Free all memory associated with the inode. | |
477 | */ | |
439b8434 | 478 | xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); |
1da177e4 LT |
479 | xfs_idestroy(ip); |
480 | } | |
481 | ||
482 | /* | |
483 | * This routine removes an about-to-be-destroyed inode from | |
484 | * all of the lists in which it is located with the exception | |
485 | * of the behavior chain. | |
486 | */ | |
487 | void | |
488 | xfs_iextract( | |
489 | xfs_inode_t *ip) | |
490 | { | |
da353b0d DC |
491 | xfs_mount_t *mp = ip->i_mount; |
492 | xfs_perag_t *pag = xfs_get_perag(mp, ip->i_ino); | |
1da177e4 | 493 | xfs_inode_t *iq; |
da353b0d DC |
494 | |
495 | write_lock(&pag->pag_ici_lock); | |
496 | radix_tree_delete(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino)); | |
497 | write_unlock(&pag->pag_ici_lock); | |
498 | xfs_put_perag(mp, pag); | |
1da177e4 | 499 | |
1da177e4 LT |
500 | /* |
501 | * Remove from mount's inode list. | |
502 | */ | |
503 | XFS_MOUNT_ILOCK(mp); | |
504 | ASSERT((ip->i_mnext != NULL) && (ip->i_mprev != NULL)); | |
505 | iq = ip->i_mnext; | |
506 | iq->i_mprev = ip->i_mprev; | |
507 | ip->i_mprev->i_mnext = iq; | |
508 | ||
509 | /* | |
510 | * Fix up the head pointer if it points to the inode being deleted. | |
511 | */ | |
512 | if (mp->m_inodes == ip) { | |
513 | if (ip == iq) { | |
514 | mp->m_inodes = NULL; | |
515 | } else { | |
516 | mp->m_inodes = iq; | |
517 | } | |
518 | } | |
519 | ||
520 | /* Deal with the deleted inodes list */ | |
521 | list_del_init(&ip->i_reclaim); | |
522 | ||
523 | mp->m_ireclaims++; | |
524 | XFS_MOUNT_IUNLOCK(mp); | |
525 | } | |
526 | ||
527 | /* | |
528 | * This is a wrapper routine around the xfs_ilock() routine | |
529 | * used to centralize some grungy code. It is used in places | |
530 | * that wish to lock the inode solely for reading the extents. | |
531 | * The reason these places can't just call xfs_ilock(SHARED) | |
532 | * is that the inode lock also guards to bringing in of the | |
533 | * extents from disk for a file in b-tree format. If the inode | |
534 | * is in b-tree format, then we need to lock the inode exclusively | |
535 | * until the extents are read in. Locking it exclusively all | |
536 | * the time would limit our parallelism unnecessarily, though. | |
537 | * What we do instead is check to see if the extents have been | |
538 | * read in yet, and only lock the inode exclusively if they | |
539 | * have not. | |
540 | * | |
541 | * The function returns a value which should be given to the | |
542 | * corresponding xfs_iunlock_map_shared(). This value is | |
543 | * the mode in which the lock was actually taken. | |
544 | */ | |
545 | uint | |
546 | xfs_ilock_map_shared( | |
547 | xfs_inode_t *ip) | |
548 | { | |
549 | uint lock_mode; | |
550 | ||
551 | if ((ip->i_d.di_format == XFS_DINODE_FMT_BTREE) && | |
552 | ((ip->i_df.if_flags & XFS_IFEXTENTS) == 0)) { | |
553 | lock_mode = XFS_ILOCK_EXCL; | |
554 | } else { | |
555 | lock_mode = XFS_ILOCK_SHARED; | |
556 | } | |
557 | ||
558 | xfs_ilock(ip, lock_mode); | |
559 | ||
560 | return lock_mode; | |
561 | } | |
562 | ||
563 | /* | |
564 | * This is simply the unlock routine to go with xfs_ilock_map_shared(). | |
565 | * All it does is call xfs_iunlock() with the given lock_mode. | |
566 | */ | |
567 | void | |
568 | xfs_iunlock_map_shared( | |
569 | xfs_inode_t *ip, | |
570 | unsigned int lock_mode) | |
571 | { | |
572 | xfs_iunlock(ip, lock_mode); | |
573 | } | |
574 | ||
575 | /* | |
576 | * The xfs inode contains 2 locks: a multi-reader lock called the | |
577 | * i_iolock and a multi-reader lock called the i_lock. This routine | |
578 | * allows either or both of the locks to be obtained. | |
579 | * | |
580 | * The 2 locks should always be ordered so that the IO lock is | |
581 | * obtained first in order to prevent deadlock. | |
582 | * | |
583 | * ip -- the inode being locked | |
584 | * lock_flags -- this parameter indicates the inode's locks | |
585 | * to be locked. It can be: | |
586 | * XFS_IOLOCK_SHARED, | |
587 | * XFS_IOLOCK_EXCL, | |
588 | * XFS_ILOCK_SHARED, | |
589 | * XFS_ILOCK_EXCL, | |
590 | * XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED, | |
591 | * XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL, | |
592 | * XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED, | |
593 | * XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL | |
594 | */ | |
595 | void | |
579aa9ca CH |
596 | xfs_ilock( |
597 | xfs_inode_t *ip, | |
598 | uint lock_flags) | |
1da177e4 LT |
599 | { |
600 | /* | |
601 | * You can't set both SHARED and EXCL for the same lock, | |
602 | * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED, | |
603 | * and XFS_ILOCK_EXCL are valid values to set in lock_flags. | |
604 | */ | |
605 | ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != | |
606 | (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); | |
607 | ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != | |
608 | (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); | |
f7c66ce3 | 609 | ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0); |
1da177e4 | 610 | |
579aa9ca | 611 | if (lock_flags & XFS_IOLOCK_EXCL) |
f7c66ce3 | 612 | mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags)); |
579aa9ca | 613 | else if (lock_flags & XFS_IOLOCK_SHARED) |
f7c66ce3 | 614 | mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags)); |
579aa9ca CH |
615 | |
616 | if (lock_flags & XFS_ILOCK_EXCL) | |
f7c66ce3 | 617 | mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); |
579aa9ca | 618 | else if (lock_flags & XFS_ILOCK_SHARED) |
f7c66ce3 | 619 | mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); |
579aa9ca | 620 | |
1da177e4 LT |
621 | xfs_ilock_trace(ip, 1, lock_flags, (inst_t *)__return_address); |
622 | } | |
623 | ||
624 | /* | |
625 | * This is just like xfs_ilock(), except that the caller | |
626 | * is guaranteed not to sleep. It returns 1 if it gets | |
627 | * the requested locks and 0 otherwise. If the IO lock is | |
628 | * obtained but the inode lock cannot be, then the IO lock | |
629 | * is dropped before returning. | |
630 | * | |
631 | * ip -- the inode being locked | |
632 | * lock_flags -- this parameter indicates the inode's locks to be | |
633 | * to be locked. See the comment for xfs_ilock() for a list | |
634 | * of valid values. | |
1da177e4 LT |
635 | */ |
636 | int | |
579aa9ca CH |
637 | xfs_ilock_nowait( |
638 | xfs_inode_t *ip, | |
639 | uint lock_flags) | |
1da177e4 | 640 | { |
1da177e4 LT |
641 | /* |
642 | * You can't set both SHARED and EXCL for the same lock, | |
643 | * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED, | |
644 | * and XFS_ILOCK_EXCL are valid values to set in lock_flags. | |
645 | */ | |
646 | ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != | |
647 | (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); | |
648 | ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != | |
649 | (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); | |
f7c66ce3 | 650 | ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0); |
1da177e4 | 651 | |
1da177e4 | 652 | if (lock_flags & XFS_IOLOCK_EXCL) { |
579aa9ca CH |
653 | if (!mrtryupdate(&ip->i_iolock)) |
654 | goto out; | |
1da177e4 | 655 | } else if (lock_flags & XFS_IOLOCK_SHARED) { |
579aa9ca CH |
656 | if (!mrtryaccess(&ip->i_iolock)) |
657 | goto out; | |
1da177e4 LT |
658 | } |
659 | if (lock_flags & XFS_ILOCK_EXCL) { | |
579aa9ca CH |
660 | if (!mrtryupdate(&ip->i_lock)) |
661 | goto out_undo_iolock; | |
1da177e4 | 662 | } else if (lock_flags & XFS_ILOCK_SHARED) { |
579aa9ca CH |
663 | if (!mrtryaccess(&ip->i_lock)) |
664 | goto out_undo_iolock; | |
1da177e4 LT |
665 | } |
666 | xfs_ilock_trace(ip, 2, lock_flags, (inst_t *)__return_address); | |
667 | return 1; | |
579aa9ca CH |
668 | |
669 | out_undo_iolock: | |
670 | if (lock_flags & XFS_IOLOCK_EXCL) | |
671 | mrunlock_excl(&ip->i_iolock); | |
672 | else if (lock_flags & XFS_IOLOCK_SHARED) | |
673 | mrunlock_shared(&ip->i_iolock); | |
674 | out: | |
675 | return 0; | |
1da177e4 LT |
676 | } |
677 | ||
678 | /* | |
679 | * xfs_iunlock() is used to drop the inode locks acquired with | |
680 | * xfs_ilock() and xfs_ilock_nowait(). The caller must pass | |
681 | * in the flags given to xfs_ilock() or xfs_ilock_nowait() so | |
682 | * that we know which locks to drop. | |
683 | * | |
684 | * ip -- the inode being unlocked | |
685 | * lock_flags -- this parameter indicates the inode's locks to be | |
686 | * to be unlocked. See the comment for xfs_ilock() for a list | |
687 | * of valid values for this parameter. | |
688 | * | |
689 | */ | |
690 | void | |
579aa9ca CH |
691 | xfs_iunlock( |
692 | xfs_inode_t *ip, | |
693 | uint lock_flags) | |
1da177e4 LT |
694 | { |
695 | /* | |
696 | * You can't set both SHARED and EXCL for the same lock, | |
697 | * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED, | |
698 | * and XFS_ILOCK_EXCL are valid values to set in lock_flags. | |
699 | */ | |
700 | ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != | |
701 | (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); | |
702 | ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != | |
703 | (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); | |
f7c66ce3 LM |
704 | ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_IUNLOCK_NONOTIFY | |
705 | XFS_LOCK_DEP_MASK)) == 0); | |
1da177e4 LT |
706 | ASSERT(lock_flags != 0); |
707 | ||
579aa9ca CH |
708 | if (lock_flags & XFS_IOLOCK_EXCL) |
709 | mrunlock_excl(&ip->i_iolock); | |
710 | else if (lock_flags & XFS_IOLOCK_SHARED) | |
711 | mrunlock_shared(&ip->i_iolock); | |
1da177e4 | 712 | |
579aa9ca CH |
713 | if (lock_flags & XFS_ILOCK_EXCL) |
714 | mrunlock_excl(&ip->i_lock); | |
715 | else if (lock_flags & XFS_ILOCK_SHARED) | |
716 | mrunlock_shared(&ip->i_lock); | |
1da177e4 | 717 | |
579aa9ca CH |
718 | if ((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) && |
719 | !(lock_flags & XFS_IUNLOCK_NONOTIFY) && ip->i_itemp) { | |
1da177e4 LT |
720 | /* |
721 | * Let the AIL know that this item has been unlocked in case | |
722 | * it is in the AIL and anyone is waiting on it. Don't do | |
723 | * this if the caller has asked us not to. | |
724 | */ | |
579aa9ca CH |
725 | xfs_trans_unlocked_item(ip->i_mount, |
726 | (xfs_log_item_t*)(ip->i_itemp)); | |
1da177e4 LT |
727 | } |
728 | xfs_ilock_trace(ip, 3, lock_flags, (inst_t *)__return_address); | |
729 | } | |
730 | ||
731 | /* | |
732 | * give up write locks. the i/o lock cannot be held nested | |
733 | * if it is being demoted. | |
734 | */ | |
735 | void | |
579aa9ca CH |
736 | xfs_ilock_demote( |
737 | xfs_inode_t *ip, | |
738 | uint lock_flags) | |
1da177e4 LT |
739 | { |
740 | ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)); | |
741 | ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0); | |
742 | ||
579aa9ca | 743 | if (lock_flags & XFS_ILOCK_EXCL) |
1da177e4 | 744 | mrdemote(&ip->i_lock); |
579aa9ca | 745 | if (lock_flags & XFS_IOLOCK_EXCL) |
1da177e4 | 746 | mrdemote(&ip->i_iolock); |
579aa9ca CH |
747 | } |
748 | ||
749 | #ifdef DEBUG | |
750 | /* | |
751 | * Debug-only routine, without additional rw_semaphore APIs, we can | |
752 | * now only answer requests regarding whether we hold the lock for write | |
753 | * (reader state is outside our visibility, we only track writer state). | |
754 | * | |
755 | * Note: this means !xfs_isilocked would give false positives, so don't do that. | |
756 | */ | |
757 | int | |
758 | xfs_isilocked( | |
759 | xfs_inode_t *ip, | |
760 | uint lock_flags) | |
761 | { | |
762 | if ((lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) == | |
763 | XFS_ILOCK_EXCL) { | |
764 | if (!ip->i_lock.mr_writer) | |
765 | return 0; | |
1da177e4 | 766 | } |
579aa9ca CH |
767 | |
768 | if ((lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) == | |
769 | XFS_IOLOCK_EXCL) { | |
770 | if (!ip->i_iolock.mr_writer) | |
771 | return 0; | |
772 | } | |
773 | ||
774 | return 1; | |
1da177e4 | 775 | } |
579aa9ca | 776 | #endif |
1da177e4 LT |
777 | |
778 | /* | |
779 | * The following three routines simply manage the i_flock | |
780 | * semaphore embedded in the inode. This semaphore synchronizes | |
781 | * processes attempting to flush the in-core inode back to disk. | |
782 | */ | |
783 | void | |
784 | xfs_iflock(xfs_inode_t *ip) | |
785 | { | |
786 | psema(&(ip->i_flock), PINOD|PLTWAIT); | |
787 | } | |
788 | ||
789 | int | |
790 | xfs_iflock_nowait(xfs_inode_t *ip) | |
791 | { | |
792 | return (cpsema(&(ip->i_flock))); | |
793 | } | |
794 | ||
795 | void | |
796 | xfs_ifunlock(xfs_inode_t *ip) | |
797 | { | |
0d8fee32 | 798 | ASSERT(issemalocked(&(ip->i_flock))); |
1da177e4 LT |
799 | vsema(&(ip->i_flock)); |
800 | } |