2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
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
7 * published by the Free Software Foundation.
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.
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
20 #include "xfs_types.h"
24 #include "xfs_trans.h"
28 #include "xfs_dmapi.h"
29 #include "xfs_mount.h"
30 #include "xfs_bmap_btree.h"
31 #include "xfs_alloc_btree.h"
32 #include "xfs_ialloc_btree.h"
33 #include "xfs_dir2_sf.h"
34 #include "xfs_attr_sf.h"
35 #include "xfs_dinode.h"
36 #include "xfs_inode.h"
37 #include "xfs_btree.h"
38 #include "xfs_ialloc.h"
39 #include "xfs_quota.h"
40 #include "xfs_utils.h"
43 * Look up an inode by number in the given file system.
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
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.
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
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.
77 struct inode *old_inode;
81 unsigned long first_index, mask;
85 /* the radix tree exists only in inode capable AGs */
86 if (XFS_INO_TO_AGNO(mp, ino) >= mp->m_maxagi)
89 /* get the perag structure and ensure that it's inode capable */
90 pag = xfs_get_perag(mp, ino);
91 if (!pag->pagi_inodeok)
93 ASSERT(pag->pag_ici_init);
94 agino = XFS_INO_TO_AGINO(mp, ino);
97 read_lock(&pag->pag_ici_lock);
98 ip = radix_tree_lookup(&pag->pag_ici_root, agino);
102 * If INEW is set this inode is being set up
103 * we need to pause and try again.
105 if (xfs_iflags_test(ip, XFS_INEW)) {
106 read_unlock(&pag->pag_ici_lock);
108 XFS_STATS_INC(xs_ig_frecycle);
113 old_inode = ip->i_vnode;
114 if (old_inode == NULL) {
116 * If IRECLAIM is set this inode is
117 * on its way out of the system,
118 * we need to pause and try again.
120 if (xfs_iflags_test(ip, XFS_IRECLAIM)) {
121 read_unlock(&pag->pag_ici_lock);
123 XFS_STATS_INC(xs_ig_frecycle);
127 ASSERT(xfs_iflags_test(ip, XFS_IRECLAIMABLE));
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.
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);
142 xfs_itrace_exit_tag(ip, "xfs_iget.alloc");
144 XFS_STATS_INC(xs_ig_found);
145 xfs_iflags_clear(ip, XFS_IRECLAIMABLE);
146 read_unlock(&pag->pag_ici_lock);
149 list_del_init(&ip->i_reclaim);
150 XFS_MOUNT_IUNLOCK(mp);
154 } else if (inode != old_inode) {
155 /* The inode is being torn down, pause and
158 if (old_inode->i_state & (I_FREEING | I_CLEAR)) {
159 read_unlock(&pag->pag_ici_lock);
161 XFS_STATS_INC(xs_ig_frecycle);
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?
170 "xfs_iget_core: ambiguous vns: vp/0x%p, invp/0x%p",
177 read_unlock(&pag->pag_ici_lock);
178 XFS_STATS_INC(xs_ig_found);
181 if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) {
182 xfs_put_perag(mp, pag);
187 xfs_ilock(ip, lock_flags);
189 xfs_iflags_clear(ip, XFS_ISTALE);
190 xfs_itrace_exit_tag(ip, "xfs_iget.found");
197 read_unlock(&pag->pag_ici_lock);
198 XFS_STATS_INC(xs_ig_missed);
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.
204 error = xfs_iread(mp, tp, ino, &ip, bno,
205 (flags & XFS_IGET_BULKSTAT) ? XFS_IMAP_BULKSTAT : 0);
207 xfs_put_perag(mp, pag);
211 xfs_itrace_exit_tag(ip, "xfs_iget.alloc");
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");
222 xfs_ilock(ip, lock_flags);
224 if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) {
226 xfs_put_perag(mp, pag);
231 * Preload the radix tree so we can insert safely under the
234 if (radix_tree_preload(GFP_KERNEL)) {
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);
243 * insert the new inode
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();
251 XFS_STATS_INC(xs_ig_dup);
256 * These values _must_ be set before releasing the radix tree lock!
258 ip->i_udquot = ip->i_gdquot = NULL;
259 xfs_iflags_set(ip, XFS_INEW);
261 write_unlock(&pag->pag_ici_lock);
262 radix_tree_preload_end();
265 * Link ip to its mount and thread it on the mount's inode list.
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;
280 XFS_MOUNT_IUNLOCK(mp);
281 xfs_put_perag(mp, pag);
284 ASSERT(ip->i_df.if_ext_max ==
285 XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t));
287 xfs_iflags_set(ip, XFS_IMODIFIED);
291 * Set up the Linux with the Linux inode.
294 inode->i_private = ip;
297 * If we have a real type for an on-disk inode, we can set ops(&unlock)
298 * now. If it's a new inode being created, xfs_ialloc will handle it.
300 if (ip->i_d.di_mode != 0)
307 * The 'normal' internal xfs_iget, if needed it will
308 * 'allocate', or 'get', the vnode.
324 XFS_STATS_INC(xs_ig_attempts);
327 inode = iget_locked(mp->m_super, ino);
329 /* If we got no inode we are out of memory */
332 if (inode->i_state & I_NEW) {
333 XFS_STATS_INC(vn_active);
334 XFS_STATS_INC(vn_alloc);
336 error = xfs_iget_core(inode, mp, tp, ino, flags,
337 lock_flags, ipp, bno);
339 make_bad_inode(inode);
340 if (inode->i_state & I_NEW)
341 unlock_new_inode(inode);
348 * If the inode is not fully constructed due to
349 * filehandle mismatches wait for the inode to go
350 * away and try again.
352 * iget_locked will call __wait_on_freeing_inode
353 * to wait for the inode to go away.
355 if (is_bad_inode(inode)) {
369 xfs_ilock(ip, lock_flags);
370 XFS_STATS_INC(xs_ig_found);
376 * Look for the inode corresponding to the given ino in the hash table.
377 * If it is there and its i_transp pointer matches tp, return it.
378 * Otherwise, return NULL.
381 xfs_inode_incore(xfs_mount_t *mp,
388 pag = xfs_get_perag(mp, ino);
389 read_lock(&pag->pag_ici_lock);
390 ip = radix_tree_lookup(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ino));
391 read_unlock(&pag->pag_ici_lock);
392 xfs_put_perag(mp, pag);
394 /* the returned inode must match the transaction */
395 if (ip && (ip->i_transp != tp))
401 * Decrement reference count of an inode structure and unlock it.
403 * ip -- the inode being released
404 * lock_flags -- this parameter indicates the inode's locks to be
405 * to be released. See the comment on xfs_iunlock() for a list
409 xfs_iput(xfs_inode_t *ip,
412 xfs_itrace_entry(ip);
413 xfs_iunlock(ip, lock_flags);
418 * Special iput for brand-new inodes that are still locked
425 struct inode *inode = VFS_I(ip);
427 xfs_itrace_entry(ip);
429 if ((ip->i_d.di_mode == 0)) {
430 ASSERT(!xfs_iflags_test(ip, XFS_IRECLAIMABLE));
431 make_bad_inode(inode);
433 if (inode->i_state & I_NEW)
434 unlock_new_inode(inode);
436 xfs_iunlock(ip, lock_flags);
442 * This routine embodies the part of the reclaim code that pulls
443 * the inode from the inode hash table and the mount structure's
445 * This should only be called from xfs_reclaim().
448 xfs_ireclaim(xfs_inode_t *ip)
451 * Remove from old hash list and mount list.
453 XFS_STATS_INC(xs_ig_reclaims);
458 * Here we do a spurious inode lock in order to coordinate with
459 * xfs_sync(). This is because xfs_sync() references the inodes
460 * in the mount list without taking references on the corresponding
461 * vnodes. We make that OK here by ensuring that we wait until
462 * the inode is unlocked in xfs_sync() before we go ahead and
463 * free it. We get both the regular lock and the io lock because
464 * the xfs_sync() code may need to drop the regular one but will
465 * still hold the io lock.
467 xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
470 * Release dquots (and their references) if any. An inode may escape
471 * xfs_inactive and get here via vn_alloc->vn_reclaim path.
473 XFS_QM_DQDETACH(ip->i_mount, ip);
476 * Pull our behavior descriptor from the vnode chain.
479 ip->i_vnode->i_private = NULL;
484 * Free all memory associated with the inode.
486 xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
491 * This routine removes an about-to-be-destroyed inode from
492 * all of the lists in which it is located with the exception
493 * of the behavior chain.
499 xfs_mount_t *mp = ip->i_mount;
500 xfs_perag_t *pag = xfs_get_perag(mp, ip->i_ino);
503 write_lock(&pag->pag_ici_lock);
504 radix_tree_delete(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino));
505 write_unlock(&pag->pag_ici_lock);
506 xfs_put_perag(mp, pag);
509 * Remove from mount's inode list.
512 ASSERT((ip->i_mnext != NULL) && (ip->i_mprev != NULL));
514 iq->i_mprev = ip->i_mprev;
515 ip->i_mprev->i_mnext = iq;
518 * Fix up the head pointer if it points to the inode being deleted.
520 if (mp->m_inodes == ip) {
528 /* Deal with the deleted inodes list */
529 list_del_init(&ip->i_reclaim);
532 XFS_MOUNT_IUNLOCK(mp);
536 * This is a wrapper routine around the xfs_ilock() routine
537 * used to centralize some grungy code. It is used in places
538 * that wish to lock the inode solely for reading the extents.
539 * The reason these places can't just call xfs_ilock(SHARED)
540 * is that the inode lock also guards to bringing in of the
541 * extents from disk for a file in b-tree format. If the inode
542 * is in b-tree format, then we need to lock the inode exclusively
543 * until the extents are read in. Locking it exclusively all
544 * the time would limit our parallelism unnecessarily, though.
545 * What we do instead is check to see if the extents have been
546 * read in yet, and only lock the inode exclusively if they
549 * The function returns a value which should be given to the
550 * corresponding xfs_iunlock_map_shared(). This value is
551 * the mode in which the lock was actually taken.
554 xfs_ilock_map_shared(
559 if ((ip->i_d.di_format == XFS_DINODE_FMT_BTREE) &&
560 ((ip->i_df.if_flags & XFS_IFEXTENTS) == 0)) {
561 lock_mode = XFS_ILOCK_EXCL;
563 lock_mode = XFS_ILOCK_SHARED;
566 xfs_ilock(ip, lock_mode);
572 * This is simply the unlock routine to go with xfs_ilock_map_shared().
573 * All it does is call xfs_iunlock() with the given lock_mode.
576 xfs_iunlock_map_shared(
578 unsigned int lock_mode)
580 xfs_iunlock(ip, lock_mode);
584 * The xfs inode contains 2 locks: a multi-reader lock called the
585 * i_iolock and a multi-reader lock called the i_lock. This routine
586 * allows either or both of the locks to be obtained.
588 * The 2 locks should always be ordered so that the IO lock is
589 * obtained first in order to prevent deadlock.
591 * ip -- the inode being locked
592 * lock_flags -- this parameter indicates the inode's locks
593 * to be locked. It can be:
598 * XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED,
599 * XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL,
600 * XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED,
601 * XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL
609 * You can't set both SHARED and EXCL for the same lock,
610 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
611 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
613 ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
614 (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
615 ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
616 (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
617 ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
619 if (lock_flags & XFS_IOLOCK_EXCL)
620 mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
621 else if (lock_flags & XFS_IOLOCK_SHARED)
622 mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
624 if (lock_flags & XFS_ILOCK_EXCL)
625 mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
626 else if (lock_flags & XFS_ILOCK_SHARED)
627 mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
629 xfs_ilock_trace(ip, 1, lock_flags, (inst_t *)__return_address);
633 * This is just like xfs_ilock(), except that the caller
634 * is guaranteed not to sleep. It returns 1 if it gets
635 * the requested locks and 0 otherwise. If the IO lock is
636 * obtained but the inode lock cannot be, then the IO lock
637 * is dropped before returning.
639 * ip -- the inode being locked
640 * lock_flags -- this parameter indicates the inode's locks to be
641 * to be locked. See the comment for xfs_ilock() for a list
650 * You can't set both SHARED and EXCL for the same lock,
651 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
652 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
654 ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
655 (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
656 ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
657 (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
658 ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
660 if (lock_flags & XFS_IOLOCK_EXCL) {
661 if (!mrtryupdate(&ip->i_iolock))
663 } else if (lock_flags & XFS_IOLOCK_SHARED) {
664 if (!mrtryaccess(&ip->i_iolock))
667 if (lock_flags & XFS_ILOCK_EXCL) {
668 if (!mrtryupdate(&ip->i_lock))
669 goto out_undo_iolock;
670 } else if (lock_flags & XFS_ILOCK_SHARED) {
671 if (!mrtryaccess(&ip->i_lock))
672 goto out_undo_iolock;
674 xfs_ilock_trace(ip, 2, lock_flags, (inst_t *)__return_address);
678 if (lock_flags & XFS_IOLOCK_EXCL)
679 mrunlock_excl(&ip->i_iolock);
680 else if (lock_flags & XFS_IOLOCK_SHARED)
681 mrunlock_shared(&ip->i_iolock);
687 * xfs_iunlock() is used to drop the inode locks acquired with
688 * xfs_ilock() and xfs_ilock_nowait(). The caller must pass
689 * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
690 * that we know which locks to drop.
692 * ip -- the inode being unlocked
693 * lock_flags -- this parameter indicates the inode's locks to be
694 * to be unlocked. See the comment for xfs_ilock() for a list
695 * of valid values for this parameter.
704 * You can't set both SHARED and EXCL for the same lock,
705 * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
706 * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
708 ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
709 (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
710 ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
711 (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
712 ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_IUNLOCK_NONOTIFY |
713 XFS_LOCK_DEP_MASK)) == 0);
714 ASSERT(lock_flags != 0);
716 if (lock_flags & XFS_IOLOCK_EXCL)
717 mrunlock_excl(&ip->i_iolock);
718 else if (lock_flags & XFS_IOLOCK_SHARED)
719 mrunlock_shared(&ip->i_iolock);
721 if (lock_flags & XFS_ILOCK_EXCL)
722 mrunlock_excl(&ip->i_lock);
723 else if (lock_flags & XFS_ILOCK_SHARED)
724 mrunlock_shared(&ip->i_lock);
726 if ((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) &&
727 !(lock_flags & XFS_IUNLOCK_NONOTIFY) && ip->i_itemp) {
729 * Let the AIL know that this item has been unlocked in case
730 * it is in the AIL and anyone is waiting on it. Don't do
731 * this if the caller has asked us not to.
733 xfs_trans_unlocked_item(ip->i_mount,
734 (xfs_log_item_t*)(ip->i_itemp));
736 xfs_ilock_trace(ip, 3, lock_flags, (inst_t *)__return_address);
740 * give up write locks. the i/o lock cannot be held nested
741 * if it is being demoted.
748 ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL));
749 ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
751 if (lock_flags & XFS_ILOCK_EXCL)
752 mrdemote(&ip->i_lock);
753 if (lock_flags & XFS_IOLOCK_EXCL)
754 mrdemote(&ip->i_iolock);
759 * Debug-only routine, without additional rw_semaphore APIs, we can
760 * now only answer requests regarding whether we hold the lock for write
761 * (reader state is outside our visibility, we only track writer state).
763 * Note: this means !xfs_isilocked would give false positives, so don't do that.
770 if ((lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) ==
772 if (!ip->i_lock.mr_writer)
776 if ((lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) ==
778 if (!ip->i_iolock.mr_writer)
787 * The following three routines simply manage the i_flock
788 * semaphore embedded in the inode. This semaphore synchronizes
789 * processes attempting to flush the in-core inode back to disk.
792 xfs_iflock(xfs_inode_t *ip)
794 psema(&(ip->i_flock), PINOD|PLTWAIT);
798 xfs_iflock_nowait(xfs_inode_t *ip)
800 return (cpsema(&(ip->i_flock)));
804 xfs_ifunlock(xfs_inode_t *ip)
806 ASSERT(issemalocked(&(ip->i_flock)));
807 vsema(&(ip->i_flock));