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1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11 *
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like. Any license provided herein, whether implied or
15 * otherwise, applies only to this software file. Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write the Free Software Foundation, Inc., 59
21 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22 *
23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24 * Mountain View, CA 94043, or:
25 *
26 * http://www.sgi.com
27 *
28 * For further information regarding this notice, see:
29 *
30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31 */
32
33#include "xfs.h"
34
35#include "xfs_macros.h"
36#include "xfs_types.h"
37#include "xfs_inum.h"
38#include "xfs_log.h"
39#include "xfs_trans.h"
40#include "xfs_sb.h"
41#include "xfs_ag.h"
42#include "xfs_dir.h"
43#include "xfs_dir2.h"
44#include "xfs_dmapi.h"
45#include "xfs_mount.h"
46#include "xfs_alloc_btree.h"
47#include "xfs_bmap_btree.h"
48#include "xfs_ialloc_btree.h"
49#include "xfs_btree.h"
50#include "xfs_ialloc.h"
51#include "xfs_attr_sf.h"
52#include "xfs_dir_sf.h"
53#include "xfs_dir2_sf.h"
54#include "xfs_dinode.h"
55#include "xfs_inode.h"
56#include "xfs_quota.h"
57#include "xfs_utils.h"
58#include "xfs_bit.h"
59
60/*
61 * Initialize the inode hash table for the newly mounted file system.
62 * Choose an initial table size based on user specified value, else
63 * use a simple algorithm using the maximum number of inodes as an
64 * indicator for table size, and clamp it between one and some large
65 * number of pages.
66 */
67void
68xfs_ihash_init(xfs_mount_t *mp)
69{
70 __uint64_t icount;
71 uint i, flags = KM_SLEEP | KM_MAYFAIL;
72
73 if (!mp->m_ihsize) {
74 icount = mp->m_maxicount ? mp->m_maxicount :
75 (mp->m_sb.sb_dblocks << mp->m_sb.sb_inopblog);
76 mp->m_ihsize = 1 << max_t(uint, 8,
77 (xfs_highbit64(icount) + 1) / 2);
78 mp->m_ihsize = min_t(uint, mp->m_ihsize,
79 (64 * NBPP) / sizeof(xfs_ihash_t));
80 }
81
82 while (!(mp->m_ihash = (xfs_ihash_t *)kmem_zalloc(mp->m_ihsize *
83 sizeof(xfs_ihash_t), flags))) {
84 if ((mp->m_ihsize >>= 1) <= NBPP)
85 flags = KM_SLEEP;
86 }
87 for (i = 0; i < mp->m_ihsize; i++) {
88 rwlock_init(&(mp->m_ihash[i].ih_lock));
89 }
90}
91
92/*
93 * Free up structures allocated by xfs_ihash_init, at unmount time.
94 */
95void
96xfs_ihash_free(xfs_mount_t *mp)
97{
98 kmem_free(mp->m_ihash, mp->m_ihsize*sizeof(xfs_ihash_t));
99 mp->m_ihash = NULL;
100}
101
102/*
103 * Initialize the inode cluster hash table for the newly mounted file system.
104 * Its size is derived from the ihash table size.
105 */
106void
107xfs_chash_init(xfs_mount_t *mp)
108{
109 uint i;
110
111 mp->m_chsize = max_t(uint, 1, mp->m_ihsize /
112 (XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog));
113 mp->m_chsize = min_t(uint, mp->m_chsize, mp->m_ihsize);
114 mp->m_chash = (xfs_chash_t *)kmem_zalloc(mp->m_chsize
115 * sizeof(xfs_chash_t),
116 KM_SLEEP);
117 for (i = 0; i < mp->m_chsize; i++) {
118 spinlock_init(&mp->m_chash[i].ch_lock,"xfshash");
119 }
120}
121
122/*
123 * Free up structures allocated by xfs_chash_init, at unmount time.
124 */
125void
126xfs_chash_free(xfs_mount_t *mp)
127{
128 int i;
129
130 for (i = 0; i < mp->m_chsize; i++) {
131 spinlock_destroy(&mp->m_chash[i].ch_lock);
132 }
133
134 kmem_free(mp->m_chash, mp->m_chsize*sizeof(xfs_chash_t));
135 mp->m_chash = NULL;
136}
137
138/*
139 * Look up an inode by number in the given file system.
140 * The inode is looked up in the hash table for the file system
141 * represented by the mount point parameter mp. Each bucket of
142 * the hash table is guarded by an individual semaphore.
143 *
144 * If the inode is found in the hash table, its corresponding vnode
145 * is obtained with a call to vn_get(). This call takes care of
146 * coordination with the reclamation of the inode and vnode. Note
147 * that the vmap structure is filled in while holding the hash lock.
148 * This gives us the state of the inode/vnode when we found it and
149 * is used for coordination in vn_get().
150 *
151 * If it is not in core, read it in from the file system's device and
152 * add the inode into the hash table.
153 *
154 * The inode is locked according to the value of the lock_flags parameter.
155 * This flag parameter indicates how and if the inode's IO lock and inode lock
156 * should be taken.
157 *
158 * mp -- the mount point structure for the current file system. It points
159 * to the inode hash table.
160 * tp -- a pointer to the current transaction if there is one. This is
161 * simply passed through to the xfs_iread() call.
162 * ino -- the number of the inode desired. This is the unique identifier
163 * within the file system for the inode being requested.
164 * lock_flags -- flags indicating how to lock the inode. See the comment
165 * for xfs_ilock() for a list of valid values.
166 * bno -- the block number starting the buffer containing the inode,
167 * if known (as by bulkstat), else 0.
168 */
169STATIC int
170xfs_iget_core(
171 vnode_t *vp,
172 xfs_mount_t *mp,
173 xfs_trans_t *tp,
174 xfs_ino_t ino,
175 uint flags,
176 uint lock_flags,
177 xfs_inode_t **ipp,
178 xfs_daddr_t bno)
179{
180 xfs_ihash_t *ih;
181 xfs_inode_t *ip;
182 xfs_inode_t *iq;
183 vnode_t *inode_vp;
184 ulong version;
185 int error;
186 /* REFERENCED */
187 xfs_chash_t *ch;
188 xfs_chashlist_t *chl, *chlnew;
189 SPLDECL(s);
190
191
192 ih = XFS_IHASH(mp, ino);
193
194again:
195 read_lock(&ih->ih_lock);
196
197 for (ip = ih->ih_next; ip != NULL; ip = ip->i_next) {
198 if (ip->i_ino == ino) {
199 /*
200 * If INEW is set this inode is being set up
201 * we need to pause and try again.
202 */
203 if (ip->i_flags & XFS_INEW) {
204 read_unlock(&ih->ih_lock);
205 delay(1);
206 XFS_STATS_INC(xs_ig_frecycle);
207
208 goto again;
209 }
210
211 inode_vp = XFS_ITOV_NULL(ip);
212 if (inode_vp == NULL) {
213 /*
214 * If IRECLAIM is set this inode is
215 * on its way out of the system,
216 * we need to pause and try again.
217 */
218 if (ip->i_flags & XFS_IRECLAIM) {
219 read_unlock(&ih->ih_lock);
220 delay(1);
221 XFS_STATS_INC(xs_ig_frecycle);
222
223 goto again;
224 }
225
226 vn_trace_exit(vp, "xfs_iget.alloc",
227 (inst_t *)__return_address);
228
229 XFS_STATS_INC(xs_ig_found);
230
231 ip->i_flags &= ~XFS_IRECLAIMABLE;
232 read_unlock(&ih->ih_lock);
233
234 XFS_MOUNT_ILOCK(mp);
235 list_del_init(&ip->i_reclaim);
236 XFS_MOUNT_IUNLOCK(mp);
237
238 goto finish_inode;
239
240 } else if (vp != inode_vp) {
241 struct inode *inode = LINVFS_GET_IP(inode_vp);
242
243 /* The inode is being torn down, pause and
244 * try again.
245 */
246 if (inode->i_state & (I_FREEING | I_CLEAR)) {
247 read_unlock(&ih->ih_lock);
248 delay(1);
249 XFS_STATS_INC(xs_ig_frecycle);
250
251 goto again;
252 }
253/* Chances are the other vnode (the one in the inode) is being torn
254 * down right now, and we landed on top of it. Question is, what do
255 * we do? Unhook the old inode and hook up the new one?
256 */
257 cmn_err(CE_PANIC,
258 "xfs_iget_core: ambiguous vns: vp/0x%p, invp/0x%p",
259 inode_vp, vp);
260 }
261
262 read_unlock(&ih->ih_lock);
263
264 XFS_STATS_INC(xs_ig_found);
265
266finish_inode:
267 if (ip->i_d.di_mode == 0) {
268 if (!(flags & IGET_CREATE))
269 return ENOENT;
270 xfs_iocore_inode_reinit(ip);
271 }
272
273 if (lock_flags != 0)
274 xfs_ilock(ip, lock_flags);
275
276 ip->i_flags &= ~XFS_ISTALE;
277
278 vn_trace_exit(vp, "xfs_iget.found",
279 (inst_t *)__return_address);
280 goto return_ip;
281 }
282 }
283
284 /*
285 * Inode cache miss: save the hash chain version stamp and unlock
286 * the chain, so we don't deadlock in vn_alloc.
287 */
288 XFS_STATS_INC(xs_ig_missed);
289
290 version = ih->ih_version;
291
292 read_unlock(&ih->ih_lock);
293
294 /*
295 * Read the disk inode attributes into a new inode structure and get
296 * a new vnode for it. This should also initialize i_ino and i_mount.
297 */
298 error = xfs_iread(mp, tp, ino, &ip, bno);
299 if (error) {
300 return error;
301 }
302
303 vn_trace_exit(vp, "xfs_iget.alloc", (inst_t *)__return_address);
304
305 xfs_inode_lock_init(ip, vp);
306 xfs_iocore_inode_init(ip);
307
308 if (lock_flags != 0) {
309 xfs_ilock(ip, lock_flags);
310 }
311
312 if ((ip->i_d.di_mode == 0) && !(flags & IGET_CREATE)) {
313 xfs_idestroy(ip);
314 return ENOENT;
315 }
316
317 /*
318 * Put ip on its hash chain, unless someone else hashed a duplicate
319 * after we released the hash lock.
320 */
321 write_lock(&ih->ih_lock);
322
323 if (ih->ih_version != version) {
324 for (iq = ih->ih_next; iq != NULL; iq = iq->i_next) {
325 if (iq->i_ino == ino) {
326 write_unlock(&ih->ih_lock);
327 xfs_idestroy(ip);
328
329 XFS_STATS_INC(xs_ig_dup);
330 goto again;
331 }
332 }
333 }
334
335 /*
336 * These values _must_ be set before releasing ihlock!
337 */
338 ip->i_hash = ih;
339 if ((iq = ih->ih_next)) {
340 iq->i_prevp = &ip->i_next;
341 }
342 ip->i_next = iq;
343 ip->i_prevp = &ih->ih_next;
344 ih->ih_next = ip;
345 ip->i_udquot = ip->i_gdquot = NULL;
346 ih->ih_version++;
347 ip->i_flags |= XFS_INEW;
348
349 write_unlock(&ih->ih_lock);
350
351 /*
352 * put ip on its cluster's hash chain
353 */
354 ASSERT(ip->i_chash == NULL && ip->i_cprev == NULL &&
355 ip->i_cnext == NULL);
356
357 chlnew = NULL;
358 ch = XFS_CHASH(mp, ip->i_blkno);
359 chlredo:
360 s = mutex_spinlock(&ch->ch_lock);
361 for (chl = ch->ch_list; chl != NULL; chl = chl->chl_next) {
362 if (chl->chl_blkno == ip->i_blkno) {
363
364 /* insert this inode into the doubly-linked list
365 * where chl points */
366 if ((iq = chl->chl_ip)) {
367 ip->i_cprev = iq->i_cprev;
368 iq->i_cprev->i_cnext = ip;
369 iq->i_cprev = ip;
370 ip->i_cnext = iq;
371 } else {
372 ip->i_cnext = ip;
373 ip->i_cprev = ip;
374 }
375 chl->chl_ip = ip;
376 ip->i_chash = chl;
377 break;
378 }
379 }
380
381 /* no hash list found for this block; add a new hash list */
382 if (chl == NULL) {
383 if (chlnew == NULL) {
384 mutex_spinunlock(&ch->ch_lock, s);
385 ASSERT(xfs_chashlist_zone != NULL);
386 chlnew = (xfs_chashlist_t *)
387 kmem_zone_alloc(xfs_chashlist_zone,
388 KM_SLEEP);
389 ASSERT(chlnew != NULL);
390 goto chlredo;
391 } else {
392 ip->i_cnext = ip;
393 ip->i_cprev = ip;
394 ip->i_chash = chlnew;
395 chlnew->chl_ip = ip;
396 chlnew->chl_blkno = ip->i_blkno;
397 chlnew->chl_next = ch->ch_list;
398 ch->ch_list = chlnew;
399 chlnew = NULL;
400 }
401 } else {
402 if (chlnew != NULL) {
403 kmem_zone_free(xfs_chashlist_zone, chlnew);
404 }
405 }
406
407 mutex_spinunlock(&ch->ch_lock, s);
408
409
410 /*
411 * Link ip to its mount and thread it on the mount's inode list.
412 */
413 XFS_MOUNT_ILOCK(mp);
414 if ((iq = mp->m_inodes)) {
415 ASSERT(iq->i_mprev->i_mnext == iq);
416 ip->i_mprev = iq->i_mprev;
417 iq->i_mprev->i_mnext = ip;
418 iq->i_mprev = ip;
419 ip->i_mnext = iq;
420 } else {
421 ip->i_mnext = ip;
422 ip->i_mprev = ip;
423 }
424 mp->m_inodes = ip;
425
426 XFS_MOUNT_IUNLOCK(mp);
427
428 return_ip:
429 ASSERT(ip->i_df.if_ext_max ==
430 XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t));
431
432 ASSERT(((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) != 0) ==
433 ((ip->i_iocore.io_flags & XFS_IOCORE_RT) != 0));
434
435 *ipp = ip;
436
437 /*
438 * If we have a real type for an on-disk inode, we can set ops(&unlock)
439 * now. If it's a new inode being created, xfs_ialloc will handle it.
440 */
441 VFS_INIT_VNODE(XFS_MTOVFS(mp), vp, XFS_ITOBHV(ip), 1);
442
443 return 0;
444}
445
446
447/*
448 * The 'normal' internal xfs_iget, if needed it will
449 * 'allocate', or 'get', the vnode.
450 */
451int
452xfs_iget(
453 xfs_mount_t *mp,
454 xfs_trans_t *tp,
455 xfs_ino_t ino,
456 uint flags,
457 uint lock_flags,
458 xfs_inode_t **ipp,
459 xfs_daddr_t bno)
460{
461 struct inode *inode;
462 vnode_t *vp = NULL;
463 int error;
464
465retry:
466 XFS_STATS_INC(xs_ig_attempts);
467
468 if ((inode = iget_locked(XFS_MTOVFS(mp)->vfs_super, ino))) {
469 bhv_desc_t *bdp;
470 xfs_inode_t *ip;
471 int newnode;
472
473 vp = LINVFS_GET_VP(inode);
474 if (inode->i_state & I_NEW) {
475inode_allocate:
476 vn_initialize(inode);
477 error = xfs_iget_core(vp, mp, tp, ino, flags,
478 lock_flags, ipp, bno);
479 if (error) {
480 vn_mark_bad(vp);
481 if (inode->i_state & I_NEW)
482 unlock_new_inode(inode);
483 iput(inode);
484 }
485 } else {
486 /* These are true if the inode is in inactive or
487 * reclaim. The linux inode is about to go away,
488 * wait for that path to finish, and try again.
489 */
490 if (vp->v_flag & (VINACT | VRECLM)) {
491 vn_wait(vp);
492 iput(inode);
493 goto retry;
494 }
495
496 if (is_bad_inode(inode)) {
497 iput(inode);
498 return EIO;
499 }
500
501 bdp = vn_bhv_lookup(VN_BHV_HEAD(vp), &xfs_vnodeops);
502 if (bdp == NULL) {
503 XFS_STATS_INC(xs_ig_dup);
504 goto inode_allocate;
505 }
506 ip = XFS_BHVTOI(bdp);
507 if (lock_flags != 0)
508 xfs_ilock(ip, lock_flags);
509 newnode = (ip->i_d.di_mode == 0);
510 if (newnode)
511 xfs_iocore_inode_reinit(ip);
512 XFS_STATS_INC(xs_ig_found);
513 *ipp = ip;
514 error = 0;
515 }
516 } else
517 error = ENOMEM; /* If we got no inode we are out of memory */
518
519 return error;
520}
521
522/*
523 * Do the setup for the various locks within the incore inode.
524 */
525void
526xfs_inode_lock_init(
527 xfs_inode_t *ip,
528 vnode_t *vp)
529{
530 mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER,
531 "xfsino", (long)vp->v_number);
532 mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", vp->v_number);
533 init_waitqueue_head(&ip->i_ipin_wait);
534 atomic_set(&ip->i_pincount, 0);
535 init_sema(&ip->i_flock, 1, "xfsfino", vp->v_number);
536}
537
538/*
539 * Look for the inode corresponding to the given ino in the hash table.
540 * If it is there and its i_transp pointer matches tp, return it.
541 * Otherwise, return NULL.
542 */
543xfs_inode_t *
544xfs_inode_incore(xfs_mount_t *mp,
545 xfs_ino_t ino,
546 xfs_trans_t *tp)
547{
548 xfs_ihash_t *ih;
549 xfs_inode_t *ip;
550
551 ih = XFS_IHASH(mp, ino);
552 read_lock(&ih->ih_lock);
553 for (ip = ih->ih_next; ip != NULL; ip = ip->i_next) {
554 if (ip->i_ino == ino) {
555 /*
556 * If we find it and tp matches, return it.
557 * Otherwise break from the loop and return
558 * NULL.
559 */
560 if (ip->i_transp == tp) {
561 read_unlock(&ih->ih_lock);
562 return (ip);
563 }
564 break;
565 }
566 }
567 read_unlock(&ih->ih_lock);
568 return (NULL);
569}
570
571/*
572 * Decrement reference count of an inode structure and unlock it.
573 *
574 * ip -- the inode being released
575 * lock_flags -- this parameter indicates the inode's locks to be
576 * to be released. See the comment on xfs_iunlock() for a list
577 * of valid values.
578 */
579void
580xfs_iput(xfs_inode_t *ip,
581 uint lock_flags)
582{
583 vnode_t *vp = XFS_ITOV(ip);
584
585 vn_trace_entry(vp, "xfs_iput", (inst_t *)__return_address);
586
587 xfs_iunlock(ip, lock_flags);
588
589 VN_RELE(vp);
590}
591
592/*
593 * Special iput for brand-new inodes that are still locked
594 */
595void
596xfs_iput_new(xfs_inode_t *ip,
597 uint lock_flags)
598{
599 vnode_t *vp = XFS_ITOV(ip);
600 struct inode *inode = LINVFS_GET_IP(vp);
601
602 vn_trace_entry(vp, "xfs_iput_new", (inst_t *)__return_address);
603
604 if ((ip->i_d.di_mode == 0)) {
605 ASSERT(!(ip->i_flags & XFS_IRECLAIMABLE));
606 vn_mark_bad(vp);
607 }
608 if (inode->i_state & I_NEW)
609 unlock_new_inode(inode);
610 if (lock_flags)
611 xfs_iunlock(ip, lock_flags);
612 VN_RELE(vp);
613}
614
615
616/*
617 * This routine embodies the part of the reclaim code that pulls
618 * the inode from the inode hash table and the mount structure's
619 * inode list.
620 * This should only be called from xfs_reclaim().
621 */
622void
623xfs_ireclaim(xfs_inode_t *ip)
624{
625 vnode_t *vp;
626
627 /*
628 * Remove from old hash list and mount list.
629 */
630 XFS_STATS_INC(xs_ig_reclaims);
631
632 xfs_iextract(ip);
633
634 /*
635 * Here we do a spurious inode lock in order to coordinate with
636 * xfs_sync(). This is because xfs_sync() references the inodes
637 * in the mount list without taking references on the corresponding
638 * vnodes. We make that OK here by ensuring that we wait until
639 * the inode is unlocked in xfs_sync() before we go ahead and
640 * free it. We get both the regular lock and the io lock because
641 * the xfs_sync() code may need to drop the regular one but will
642 * still hold the io lock.
643 */
644 xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
645
646 /*
647 * Release dquots (and their references) if any. An inode may escape
648 * xfs_inactive and get here via vn_alloc->vn_reclaim path.
649 */
650 XFS_QM_DQDETACH(ip->i_mount, ip);
651
652 /*
653 * Pull our behavior descriptor from the vnode chain.
654 */
655 vp = XFS_ITOV_NULL(ip);
656 if (vp) {
657 vn_bhv_remove(VN_BHV_HEAD(vp), XFS_ITOBHV(ip));
658 }
659
660 /*
661 * Free all memory associated with the inode.
662 */
663 xfs_idestroy(ip);
664}
665
666/*
667 * This routine removes an about-to-be-destroyed inode from
668 * all of the lists in which it is located with the exception
669 * of the behavior chain.
670 */
671void
672xfs_iextract(
673 xfs_inode_t *ip)
674{
675 xfs_ihash_t *ih;
676 xfs_inode_t *iq;
677 xfs_mount_t *mp;
678 xfs_chash_t *ch;
679 xfs_chashlist_t *chl, *chm;
680 SPLDECL(s);
681
682 ih = ip->i_hash;
683 write_lock(&ih->ih_lock);
684 if ((iq = ip->i_next)) {
685 iq->i_prevp = ip->i_prevp;
686 }
687 *ip->i_prevp = iq;
688 write_unlock(&ih->ih_lock);
689
690 /*
691 * Remove from cluster hash list
692 * 1) delete the chashlist if this is the last inode on the chashlist
693 * 2) unchain from list of inodes
694 * 3) point chashlist->chl_ip to 'chl_next' if to this inode.
695 */
696 mp = ip->i_mount;
697 ch = XFS_CHASH(mp, ip->i_blkno);
698 s = mutex_spinlock(&ch->ch_lock);
699
700 if (ip->i_cnext == ip) {
701 /* Last inode on chashlist */
702 ASSERT(ip->i_cnext == ip && ip->i_cprev == ip);
703 ASSERT(ip->i_chash != NULL);
704 chm=NULL;
705 for (chl = ch->ch_list; chl != NULL; chl = chl->chl_next) {
706 if (chl->chl_blkno == ip->i_blkno) {
707 if (chm == NULL) {
708 /* first item on the list */
709 ch->ch_list = chl->chl_next;
710 } else {
711 chm->chl_next = chl->chl_next;
712 }
713 kmem_zone_free(xfs_chashlist_zone, chl);
714 break;
715 } else {
716 ASSERT(chl->chl_ip != ip);
717 chm = chl;
718 }
719 }
720 ASSERT_ALWAYS(chl != NULL);
721 } else {
722 /* delete one inode from a non-empty list */
723 iq = ip->i_cnext;
724 iq->i_cprev = ip->i_cprev;
725 ip->i_cprev->i_cnext = iq;
726 if (ip->i_chash->chl_ip == ip) {
727 ip->i_chash->chl_ip = iq;
728 }
729 ip->i_chash = __return_address;
730 ip->i_cprev = __return_address;
731 ip->i_cnext = __return_address;
732 }
733 mutex_spinunlock(&ch->ch_lock, s);
734
735 /*
736 * Remove from mount's inode list.
737 */
738 XFS_MOUNT_ILOCK(mp);
739 ASSERT((ip->i_mnext != NULL) && (ip->i_mprev != NULL));
740 iq = ip->i_mnext;
741 iq->i_mprev = ip->i_mprev;
742 ip->i_mprev->i_mnext = iq;
743
744 /*
745 * Fix up the head pointer if it points to the inode being deleted.
746 */
747 if (mp->m_inodes == ip) {
748 if (ip == iq) {
749 mp->m_inodes = NULL;
750 } else {
751 mp->m_inodes = iq;
752 }
753 }
754
755 /* Deal with the deleted inodes list */
756 list_del_init(&ip->i_reclaim);
757
758 mp->m_ireclaims++;
759 XFS_MOUNT_IUNLOCK(mp);
760}
761
762/*
763 * This is a wrapper routine around the xfs_ilock() routine
764 * used to centralize some grungy code. It is used in places
765 * that wish to lock the inode solely for reading the extents.
766 * The reason these places can't just call xfs_ilock(SHARED)
767 * is that the inode lock also guards to bringing in of the
768 * extents from disk for a file in b-tree format. If the inode
769 * is in b-tree format, then we need to lock the inode exclusively
770 * until the extents are read in. Locking it exclusively all
771 * the time would limit our parallelism unnecessarily, though.
772 * What we do instead is check to see if the extents have been
773 * read in yet, and only lock the inode exclusively if they
774 * have not.
775 *
776 * The function returns a value which should be given to the
777 * corresponding xfs_iunlock_map_shared(). This value is
778 * the mode in which the lock was actually taken.
779 */
780uint
781xfs_ilock_map_shared(
782 xfs_inode_t *ip)
783{
784 uint lock_mode;
785
786 if ((ip->i_d.di_format == XFS_DINODE_FMT_BTREE) &&
787 ((ip->i_df.if_flags & XFS_IFEXTENTS) == 0)) {
788 lock_mode = XFS_ILOCK_EXCL;
789 } else {
790 lock_mode = XFS_ILOCK_SHARED;
791 }
792
793 xfs_ilock(ip, lock_mode);
794
795 return lock_mode;
796}
797
798/*
799 * This is simply the unlock routine to go with xfs_ilock_map_shared().
800 * All it does is call xfs_iunlock() with the given lock_mode.
801 */
802void
803xfs_iunlock_map_shared(
804 xfs_inode_t *ip,
805 unsigned int lock_mode)
806{
807 xfs_iunlock(ip, lock_mode);
808}
809
810/*
811 * The xfs inode contains 2 locks: a multi-reader lock called the
812 * i_iolock and a multi-reader lock called the i_lock. This routine
813 * allows either or both of the locks to be obtained.
814 *
815 * The 2 locks should always be ordered so that the IO lock is
816 * obtained first in order to prevent deadlock.
817 *
818 * ip -- the inode being locked
819 * lock_flags -- this parameter indicates the inode's locks
820 * to be locked. It can be:
821 * XFS_IOLOCK_SHARED,
822 * XFS_IOLOCK_EXCL,
823 * XFS_ILOCK_SHARED,
824 * XFS_ILOCK_EXCL,
825 * XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED,
826 * XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL,
827 * XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED,
828 * XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL
829 */
830void
831xfs_ilock(xfs_inode_t *ip,
832 uint lock_flags)
833{
834 /*
835 * You can't set both SHARED and EXCL for the same lock,
836 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
837 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
838 */
839 ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
840 (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
841 ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
842 (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
843 ASSERT((lock_flags & ~XFS_LOCK_MASK) == 0);
844
845 if (lock_flags & XFS_IOLOCK_EXCL) {
846 mrupdate(&ip->i_iolock);
847 } else if (lock_flags & XFS_IOLOCK_SHARED) {
848 mraccess(&ip->i_iolock);
849 }
850 if (lock_flags & XFS_ILOCK_EXCL) {
851 mrupdate(&ip->i_lock);
852 } else if (lock_flags & XFS_ILOCK_SHARED) {
853 mraccess(&ip->i_lock);
854 }
855 xfs_ilock_trace(ip, 1, lock_flags, (inst_t *)__return_address);
856}
857
858/*
859 * This is just like xfs_ilock(), except that the caller
860 * is guaranteed not to sleep. It returns 1 if it gets
861 * the requested locks and 0 otherwise. If the IO lock is
862 * obtained but the inode lock cannot be, then the IO lock
863 * is dropped before returning.
864 *
865 * ip -- the inode being locked
866 * lock_flags -- this parameter indicates the inode's locks to be
867 * to be locked. See the comment for xfs_ilock() for a list
868 * of valid values.
869 *
870 */
871int
872xfs_ilock_nowait(xfs_inode_t *ip,
873 uint lock_flags)
874{
875 int iolocked;
876 int ilocked;
877
878 /*
879 * You can't set both SHARED and EXCL for the same lock,
880 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
881 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
882 */
883 ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
884 (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
885 ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
886 (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
887 ASSERT((lock_flags & ~XFS_LOCK_MASK) == 0);
888
889 iolocked = 0;
890 if (lock_flags & XFS_IOLOCK_EXCL) {
891 iolocked = mrtryupdate(&ip->i_iolock);
892 if (!iolocked) {
893 return 0;
894 }
895 } else if (lock_flags & XFS_IOLOCK_SHARED) {
896 iolocked = mrtryaccess(&ip->i_iolock);
897 if (!iolocked) {
898 return 0;
899 }
900 }
901 if (lock_flags & XFS_ILOCK_EXCL) {
902 ilocked = mrtryupdate(&ip->i_lock);
903 if (!ilocked) {
904 if (iolocked) {
905 mrunlock(&ip->i_iolock);
906 }
907 return 0;
908 }
909 } else if (lock_flags & XFS_ILOCK_SHARED) {
910 ilocked = mrtryaccess(&ip->i_lock);
911 if (!ilocked) {
912 if (iolocked) {
913 mrunlock(&ip->i_iolock);
914 }
915 return 0;
916 }
917 }
918 xfs_ilock_trace(ip, 2, lock_flags, (inst_t *)__return_address);
919 return 1;
920}
921
922/*
923 * xfs_iunlock() is used to drop the inode locks acquired with
924 * xfs_ilock() and xfs_ilock_nowait(). The caller must pass
925 * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
926 * that we know which locks to drop.
927 *
928 * ip -- the inode being unlocked
929 * lock_flags -- this parameter indicates the inode's locks to be
930 * to be unlocked. See the comment for xfs_ilock() for a list
931 * of valid values for this parameter.
932 *
933 */
934void
935xfs_iunlock(xfs_inode_t *ip,
936 uint lock_flags)
937{
938 /*
939 * You can't set both SHARED and EXCL for the same lock,
940 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
941 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
942 */
943 ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
944 (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
945 ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
946 (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
947 ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_IUNLOCK_NONOTIFY)) == 0);
948 ASSERT(lock_flags != 0);
949
950 if (lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) {
951 ASSERT(!(lock_flags & XFS_IOLOCK_SHARED) ||
952 (ismrlocked(&ip->i_iolock, MR_ACCESS)));
953 ASSERT(!(lock_flags & XFS_IOLOCK_EXCL) ||
954 (ismrlocked(&ip->i_iolock, MR_UPDATE)));
955 mrunlock(&ip->i_iolock);
956 }
957
958 if (lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) {
959 ASSERT(!(lock_flags & XFS_ILOCK_SHARED) ||
960 (ismrlocked(&ip->i_lock, MR_ACCESS)));
961 ASSERT(!(lock_flags & XFS_ILOCK_EXCL) ||
962 (ismrlocked(&ip->i_lock, MR_UPDATE)));
963 mrunlock(&ip->i_lock);
964
965 /*
966 * Let the AIL know that this item has been unlocked in case
967 * it is in the AIL and anyone is waiting on it. Don't do
968 * this if the caller has asked us not to.
969 */
970 if (!(lock_flags & XFS_IUNLOCK_NONOTIFY) &&
971 ip->i_itemp != NULL) {
972 xfs_trans_unlocked_item(ip->i_mount,
973 (xfs_log_item_t*)(ip->i_itemp));
974 }
975 }
976 xfs_ilock_trace(ip, 3, lock_flags, (inst_t *)__return_address);
977}
978
979/*
980 * give up write locks. the i/o lock cannot be held nested
981 * if it is being demoted.
982 */
983void
984xfs_ilock_demote(xfs_inode_t *ip,
985 uint lock_flags)
986{
987 ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL));
988 ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
989
990 if (lock_flags & XFS_ILOCK_EXCL) {
991 ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
992 mrdemote(&ip->i_lock);
993 }
994 if (lock_flags & XFS_IOLOCK_EXCL) {
995 ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE));
996 mrdemote(&ip->i_iolock);
997 }
998}
999
1000/*
1001 * The following three routines simply manage the i_flock
1002 * semaphore embedded in the inode. This semaphore synchronizes
1003 * processes attempting to flush the in-core inode back to disk.
1004 */
1005void
1006xfs_iflock(xfs_inode_t *ip)
1007{
1008 psema(&(ip->i_flock), PINOD|PLTWAIT);
1009}
1010
1011int
1012xfs_iflock_nowait(xfs_inode_t *ip)
1013{
1014 return (cpsema(&(ip->i_flock)));
1015}
1016
1017void
1018xfs_ifunlock(xfs_inode_t *ip)
1019{
1020 ASSERT(valusema(&(ip->i_flock)) <= 0);
1021 vsema(&(ip->i_flock));
1022}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-10 08:19:04 -0500