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_btree.h"
34 #include "xfs_dir2_sf.h"
35 #include "xfs_attr_sf.h"
36 #include "xfs_inode.h"
37 #include "xfs_dinode.h"
38 #include "xfs_error.h"
39 #include "xfs_mru_cache.h"
40 #include "xfs_filestream.h"
41 #include "xfs_vnodeops.h"
42 #include "xfs_utils.h"
43 #include "xfs_buf_item.h"
44 #include "xfs_inode_item.h"
46 #include "xfs_quota.h"
47 #include "xfs_trace.h"
49 #include <linux/kthread.h>
50 #include <linux/freezer.h>
56 struct xfs_perag *pag,
57 uint32_t *first_index,
64 * use a gang lookup to find the next inode in the tree
65 * as the tree is sparse and a gang lookup walks to find
66 * the number of objects requested.
68 if (tag == XFS_ICI_NO_TAG) {
69 nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
70 (void **)&ip, *first_index, 1);
72 nr_found = radix_tree_gang_lookup_tag(&pag->pag_ici_root,
73 (void **)&ip, *first_index, 1, tag);
79 * Update the index for the next lookup. Catch overflows
80 * into the next AG range which can occur if we have inodes
81 * in the last block of the AG and we are currently
82 * pointing to the last inode.
84 *first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
85 if (*first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
93 struct xfs_perag *pag,
94 int (*execute)(struct xfs_inode *ip,
95 struct xfs_perag *pag, int flags),
101 uint32_t first_index;
113 write_lock(&pag->pag_ici_lock);
115 read_lock(&pag->pag_ici_lock);
116 ip = xfs_inode_ag_lookup(mp, pag, &first_index, tag);
119 write_unlock(&pag->pag_ici_lock);
121 read_unlock(&pag->pag_ici_lock);
125 /* execute releases pag->pag_ici_lock */
126 error = execute(ip, pag, flags);
127 if (error == EAGAIN) {
134 /* bail out if the filesystem is corrupted. */
135 if (error == EFSCORRUPTED)
138 } while ((*nr_to_scan)--);
148 * Select the next per-ag structure to iterate during the walk. The reclaim
149 * walk is optimised only to walk AGs with reclaimable inodes in them.
151 static struct xfs_perag *
152 xfs_inode_ag_iter_next_pag(
153 struct xfs_mount *mp,
154 xfs_agnumber_t *first,
157 struct xfs_perag *pag = NULL;
159 if (tag == XFS_ICI_RECLAIM_TAG) {
163 spin_lock(&mp->m_perag_lock);
164 found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
165 (void **)&pag, *first, 1, tag);
167 spin_unlock(&mp->m_perag_lock);
170 *first = pag->pag_agno + 1;
171 /* open coded pag reference increment */
172 ref = atomic_inc_return(&pag->pag_ref);
173 spin_unlock(&mp->m_perag_lock);
174 trace_xfs_perag_get_reclaim(mp, pag->pag_agno, ref, _RET_IP_);
176 pag = xfs_perag_get(mp, *first);
183 xfs_inode_ag_iterator(
184 struct xfs_mount *mp,
185 int (*execute)(struct xfs_inode *ip,
186 struct xfs_perag *pag, int flags),
192 struct xfs_perag *pag;
198 nr = nr_to_scan ? *nr_to_scan : INT_MAX;
200 while ((pag = xfs_inode_ag_iter_next_pag(mp, &ag, tag))) {
201 error = xfs_inode_ag_walk(mp, pag, execute, flags, tag,
206 if (error == EFSCORRUPTED)
214 return XFS_ERROR(last_error);
217 /* must be called with pag_ici_lock held and releases it */
219 xfs_sync_inode_valid(
220 struct xfs_inode *ip,
221 struct xfs_perag *pag)
223 struct inode *inode = VFS_I(ip);
224 int error = EFSCORRUPTED;
226 /* nothing to sync during shutdown */
227 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
230 /* avoid new or reclaimable inodes. Leave for reclaim code to flush */
232 if (xfs_iflags_test(ip, XFS_INEW | XFS_IRECLAIMABLE | XFS_IRECLAIM))
235 /* If we can't grab the inode, it must on it's way to reclaim. */
239 if (is_bad_inode(inode)) {
247 read_unlock(&pag->pag_ici_lock);
253 struct xfs_inode *ip,
254 struct xfs_perag *pag,
257 struct inode *inode = VFS_I(ip);
258 struct address_space *mapping = inode->i_mapping;
261 error = xfs_sync_inode_valid(ip, pag);
265 if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
268 if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
269 if (flags & SYNC_TRYLOCK)
271 xfs_ilock(ip, XFS_IOLOCK_SHARED);
274 error = xfs_flush_pages(ip, 0, -1, (flags & SYNC_WAIT) ?
275 0 : XBF_ASYNC, FI_NONE);
276 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
279 if (flags & SYNC_WAIT)
287 struct xfs_inode *ip,
288 struct xfs_perag *pag,
293 error = xfs_sync_inode_valid(ip, pag);
297 xfs_ilock(ip, XFS_ILOCK_SHARED);
298 if (xfs_inode_clean(ip))
300 if (!xfs_iflock_nowait(ip)) {
301 if (!(flags & SYNC_WAIT))
306 if (xfs_inode_clean(ip)) {
311 error = xfs_iflush(ip, flags);
314 xfs_iunlock(ip, XFS_ILOCK_SHARED);
320 * Write out pagecache data for the whole filesystem.
324 struct xfs_mount *mp,
329 ASSERT((flags & ~(SYNC_TRYLOCK|SYNC_WAIT)) == 0);
331 error = xfs_inode_ag_iterator(mp, xfs_sync_inode_data, flags,
332 XFS_ICI_NO_TAG, 0, NULL);
334 return XFS_ERROR(error);
336 xfs_log_force(mp, (flags & SYNC_WAIT) ? XFS_LOG_SYNC : 0);
341 * Write out inode metadata (attributes) for the whole filesystem.
345 struct xfs_mount *mp,
348 ASSERT((flags & ~SYNC_WAIT) == 0);
350 return xfs_inode_ag_iterator(mp, xfs_sync_inode_attr, flags,
351 XFS_ICI_NO_TAG, 0, NULL);
355 xfs_commit_dummy_trans(
356 struct xfs_mount *mp,
359 struct xfs_inode *ip = mp->m_rootip;
360 struct xfs_trans *tp;
364 * Put a dummy transaction in the log to tell recovery
365 * that all others are OK.
367 tp = xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);
368 error = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0);
370 xfs_trans_cancel(tp, 0);
374 xfs_ilock(ip, XFS_ILOCK_EXCL);
376 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
377 xfs_trans_ihold(tp, ip);
378 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
379 error = xfs_trans_commit(tp, 0);
380 xfs_iunlock(ip, XFS_ILOCK_EXCL);
382 /* the log force ensures this transaction is pushed to disk */
383 xfs_log_force(mp, (flags & SYNC_WAIT) ? XFS_LOG_SYNC : 0);
389 struct xfs_mount *mp)
394 * If the buffer is pinned then push on the log so we won't get stuck
395 * waiting in the write for someone, maybe ourselves, to flush the log.
397 * Even though we just pushed the log above, we did not have the
398 * superblock buffer locked at that point so it can become pinned in
399 * between there and here.
401 bp = xfs_getsb(mp, 0);
402 if (XFS_BUF_ISPINNED(bp))
403 xfs_log_force(mp, 0);
405 return xfs_bwrite(mp, bp);
409 * When remounting a filesystem read-only or freezing the filesystem, we have
410 * two phases to execute. This first phase is syncing the data before we
411 * quiesce the filesystem, and the second is flushing all the inodes out after
412 * we've waited for all the transactions created by the first phase to
413 * complete. The second phase ensures that the inodes are written to their
414 * location on disk rather than just existing in transactions in the log. This
415 * means after a quiesce there is no log replay required to write the inodes to
416 * disk (this is the main difference between a sync and a quiesce).
419 * First stage of freeze - no writers will make progress now we are here,
420 * so we flush delwri and delalloc buffers here, then wait for all I/O to
421 * complete. Data is frozen at that point. Metadata is not frozen,
422 * transactions can still occur here so don't bother flushing the buftarg
423 * because it'll just get dirty again.
427 struct xfs_mount *mp)
429 int error, error2 = 0;
431 /* push non-blocking */
432 xfs_sync_data(mp, 0);
433 xfs_qm_sync(mp, SYNC_TRYLOCK);
435 /* push and block till complete */
436 xfs_sync_data(mp, SYNC_WAIT);
437 xfs_qm_sync(mp, SYNC_WAIT);
439 /* write superblock and hoover up shutdown errors */
440 error = xfs_sync_fsdata(mp);
442 /* make sure all delwri buffers are written out */
443 xfs_flush_buftarg(mp->m_ddev_targp, 1);
445 /* mark the log as covered if needed */
446 if (xfs_log_need_covered(mp))
447 error2 = xfs_commit_dummy_trans(mp, SYNC_WAIT);
449 /* flush data-only devices */
450 if (mp->m_rtdev_targp)
451 XFS_bflush(mp->m_rtdev_targp);
453 return error ? error : error2;
458 struct xfs_mount *mp)
460 int count = 0, pincount;
462 xfs_reclaim_inodes(mp, 0);
463 xfs_flush_buftarg(mp->m_ddev_targp, 0);
466 * This loop must run at least twice. The first instance of the loop
467 * will flush most meta data but that will generate more meta data
468 * (typically directory updates). Which then must be flushed and
469 * logged before we can write the unmount record. We also so sync
470 * reclaim of inodes to catch any that the above delwri flush skipped.
473 xfs_reclaim_inodes(mp, SYNC_WAIT);
474 xfs_sync_attr(mp, SYNC_WAIT);
475 pincount = xfs_flush_buftarg(mp->m_ddev_targp, 1);
484 * Second stage of a quiesce. The data is already synced, now we have to take
485 * care of the metadata. New transactions are already blocked, so we need to
486 * wait for any remaining transactions to drain out before proceding.
490 struct xfs_mount *mp)
494 /* wait for all modifications to complete */
495 while (atomic_read(&mp->m_active_trans) > 0)
498 /* flush inodes and push all remaining buffers out to disk */
502 * Just warn here till VFS can correctly support
503 * read-only remount without racing.
505 WARN_ON(atomic_read(&mp->m_active_trans) != 0);
507 /* Push the superblock and write an unmount record */
508 error = xfs_log_sbcount(mp, 1);
510 xfs_fs_cmn_err(CE_WARN, mp,
511 "xfs_attr_quiesce: failed to log sb changes. "
512 "Frozen image may not be consistent.");
513 xfs_log_unmount_write(mp);
514 xfs_unmountfs_writesb(mp);
518 * Enqueue a work item to be picked up by the vfs xfssyncd thread.
519 * Doing this has two advantages:
520 * - It saves on stack space, which is tight in certain situations
521 * - It can be used (with care) as a mechanism to avoid deadlocks.
522 * Flushing while allocating in a full filesystem requires both.
525 xfs_syncd_queue_work(
526 struct xfs_mount *mp,
528 void (*syncer)(struct xfs_mount *, void *),
529 struct completion *completion)
531 struct xfs_sync_work *work;
533 work = kmem_alloc(sizeof(struct xfs_sync_work), KM_SLEEP);
534 INIT_LIST_HEAD(&work->w_list);
535 work->w_syncer = syncer;
538 work->w_completion = completion;
539 spin_lock(&mp->m_sync_lock);
540 list_add_tail(&work->w_list, &mp->m_sync_list);
541 spin_unlock(&mp->m_sync_lock);
542 wake_up_process(mp->m_sync_task);
546 * Flush delayed allocate data, attempting to free up reserved space
547 * from existing allocations. At this point a new allocation attempt
548 * has failed with ENOSPC and we are in the process of scratching our
549 * heads, looking about for more room...
552 xfs_flush_inodes_work(
553 struct xfs_mount *mp,
556 struct inode *inode = arg;
557 xfs_sync_data(mp, SYNC_TRYLOCK);
558 xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT);
566 struct inode *inode = VFS_I(ip);
567 DECLARE_COMPLETION_ONSTACK(completion);
570 xfs_syncd_queue_work(ip->i_mount, inode, xfs_flush_inodes_work, &completion);
571 wait_for_completion(&completion);
572 xfs_log_force(ip->i_mount, XFS_LOG_SYNC);
576 * Every sync period we need to unpin all items, reclaim inodes and sync
577 * disk quotas. We might need to cover the log to indicate that the
578 * filesystem is idle.
582 struct xfs_mount *mp,
587 if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
588 xfs_log_force(mp, 0);
589 xfs_reclaim_inodes(mp, 0);
590 /* dgc: errors ignored here */
591 error = xfs_qm_sync(mp, SYNC_TRYLOCK);
592 if (xfs_log_need_covered(mp))
593 error = xfs_commit_dummy_trans(mp, 0);
596 wake_up(&mp->m_wait_single_sync_task);
603 struct xfs_mount *mp = arg;
605 xfs_sync_work_t *work, *n;
609 timeleft = xfs_syncd_centisecs * msecs_to_jiffies(10);
611 if (list_empty(&mp->m_sync_list))
612 timeleft = schedule_timeout_interruptible(timeleft);
615 if (kthread_should_stop() && list_empty(&mp->m_sync_list))
618 spin_lock(&mp->m_sync_lock);
620 * We can get woken by laptop mode, to do a sync -
621 * that's the (only!) case where the list would be
622 * empty with time remaining.
624 if (!timeleft || list_empty(&mp->m_sync_list)) {
626 timeleft = xfs_syncd_centisecs *
627 msecs_to_jiffies(10);
628 INIT_LIST_HEAD(&mp->m_sync_work.w_list);
629 list_add_tail(&mp->m_sync_work.w_list,
632 list_splice_init(&mp->m_sync_list, &tmp);
633 spin_unlock(&mp->m_sync_lock);
635 list_for_each_entry_safe(work, n, &tmp, w_list) {
636 (*work->w_syncer)(mp, work->w_data);
637 list_del(&work->w_list);
638 if (work == &mp->m_sync_work)
640 if (work->w_completion)
641 complete(work->w_completion);
651 struct xfs_mount *mp)
653 mp->m_sync_work.w_syncer = xfs_sync_worker;
654 mp->m_sync_work.w_mount = mp;
655 mp->m_sync_work.w_completion = NULL;
656 mp->m_sync_task = kthread_run(xfssyncd, mp, "xfssyncd/%s", mp->m_fsname);
657 if (IS_ERR(mp->m_sync_task))
658 return -PTR_ERR(mp->m_sync_task);
664 struct xfs_mount *mp)
666 kthread_stop(mp->m_sync_task);
670 __xfs_inode_set_reclaim_tag(
671 struct xfs_perag *pag,
672 struct xfs_inode *ip)
674 radix_tree_tag_set(&pag->pag_ici_root,
675 XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino),
676 XFS_ICI_RECLAIM_TAG);
678 if (!pag->pag_ici_reclaimable) {
679 /* propagate the reclaim tag up into the perag radix tree */
680 spin_lock(&ip->i_mount->m_perag_lock);
681 radix_tree_tag_set(&ip->i_mount->m_perag_tree,
682 XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
683 XFS_ICI_RECLAIM_TAG);
684 spin_unlock(&ip->i_mount->m_perag_lock);
685 trace_xfs_perag_set_reclaim(ip->i_mount, pag->pag_agno,
688 pag->pag_ici_reclaimable++;
692 * We set the inode flag atomically with the radix tree tag.
693 * Once we get tag lookups on the radix tree, this inode flag
697 xfs_inode_set_reclaim_tag(
700 struct xfs_mount *mp = ip->i_mount;
701 struct xfs_perag *pag;
703 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
704 write_lock(&pag->pag_ici_lock);
705 spin_lock(&ip->i_flags_lock);
706 __xfs_inode_set_reclaim_tag(pag, ip);
707 __xfs_iflags_set(ip, XFS_IRECLAIMABLE);
708 spin_unlock(&ip->i_flags_lock);
709 write_unlock(&pag->pag_ici_lock);
714 __xfs_inode_clear_reclaim_tag(
719 radix_tree_tag_clear(&pag->pag_ici_root,
720 XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG);
721 pag->pag_ici_reclaimable--;
722 if (!pag->pag_ici_reclaimable) {
723 /* clear the reclaim tag from the perag radix tree */
724 spin_lock(&ip->i_mount->m_perag_lock);
725 radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
726 XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
727 XFS_ICI_RECLAIM_TAG);
728 spin_unlock(&ip->i_mount->m_perag_lock);
729 trace_xfs_perag_clear_reclaim(ip->i_mount, pag->pag_agno,
735 * Inodes in different states need to be treated differently, and the return
736 * value of xfs_iflush is not sufficient to get this right. The following table
737 * lists the inode states and the reclaim actions necessary for non-blocking
741 * inode state iflush ret required action
742 * --------------- ---------- ---------------
744 * shutdown EIO unpin and reclaim
745 * clean, unpinned 0 reclaim
746 * stale, unpinned 0 reclaim
747 * clean, pinned(*) 0 requeue
748 * stale, pinned EAGAIN requeue
749 * dirty, delwri ok 0 requeue
750 * dirty, delwri blocked EAGAIN requeue
751 * dirty, sync flush 0 reclaim
753 * (*) dgc: I don't think the clean, pinned state is possible but it gets
754 * handled anyway given the order of checks implemented.
756 * As can be seen from the table, the return value of xfs_iflush() is not
757 * sufficient to correctly decide the reclaim action here. The checks in
758 * xfs_iflush() might look like duplicates, but they are not.
760 * Also, because we get the flush lock first, we know that any inode that has
761 * been flushed delwri has had the flush completed by the time we check that
762 * the inode is clean. The clean inode check needs to be done before flushing
763 * the inode delwri otherwise we would loop forever requeuing clean inodes as
764 * we cannot tell apart a successful delwri flush and a clean inode from the
765 * return value of xfs_iflush().
767 * Note that because the inode is flushed delayed write by background
768 * writeback, the flush lock may already be held here and waiting on it can
769 * result in very long latencies. Hence for sync reclaims, where we wait on the
770 * flush lock, the caller should push out delayed write inodes first before
771 * trying to reclaim them to minimise the amount of time spent waiting. For
772 * background relaim, we just requeue the inode for the next pass.
774 * Hence the order of actions after gaining the locks should be:
776 * shutdown => unpin and reclaim
777 * pinned, delwri => requeue
778 * pinned, sync => unpin
781 * dirty, delwri => flush and requeue
782 * dirty, sync => flush, wait and reclaim
786 struct xfs_inode *ip,
787 struct xfs_perag *pag,
793 * The radix tree lock here protects a thread in xfs_iget from racing
794 * with us starting reclaim on the inode. Once we have the
795 * XFS_IRECLAIM flag set it will not touch us.
797 spin_lock(&ip->i_flags_lock);
798 ASSERT_ALWAYS(__xfs_iflags_test(ip, XFS_IRECLAIMABLE));
799 if (__xfs_iflags_test(ip, XFS_IRECLAIM)) {
800 /* ignore as it is already under reclaim */
801 spin_unlock(&ip->i_flags_lock);
802 write_unlock(&pag->pag_ici_lock);
805 __xfs_iflags_set(ip, XFS_IRECLAIM);
806 spin_unlock(&ip->i_flags_lock);
807 write_unlock(&pag->pag_ici_lock);
809 xfs_ilock(ip, XFS_ILOCK_EXCL);
810 if (!xfs_iflock_nowait(ip)) {
811 if (!(sync_mode & SYNC_WAIT))
816 if (is_bad_inode(VFS_I(ip)))
818 if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
822 if (xfs_ipincount(ip)) {
823 if (!(sync_mode & SYNC_WAIT)) {
829 if (xfs_iflags_test(ip, XFS_ISTALE))
831 if (xfs_inode_clean(ip))
834 /* Now we have an inode that needs flushing */
835 error = xfs_iflush(ip, sync_mode);
836 if (sync_mode & SYNC_WAIT) {
842 * When we have to flush an inode but don't have SYNC_WAIT set, we
843 * flush the inode out using a delwri buffer and wait for the next
844 * call into reclaim to find it in a clean state instead of waiting for
845 * it now. We also don't return errors here - if the error is transient
846 * then the next reclaim pass will flush the inode, and if the error
847 * is permanent then the next sync reclaim will reclaim the inode and
850 if (error && error != EAGAIN && !XFS_FORCED_SHUTDOWN(ip->i_mount)) {
851 xfs_fs_cmn_err(CE_WARN, ip->i_mount,
852 "inode 0x%llx background reclaim flush failed with %d",
853 (long long)ip->i_ino, error);
856 xfs_iflags_clear(ip, XFS_IRECLAIM);
857 xfs_iunlock(ip, XFS_ILOCK_EXCL);
859 * We could return EAGAIN here to make reclaim rescan the inode tree in
860 * a short while. However, this just burns CPU time scanning the tree
861 * waiting for IO to complete and xfssyncd never goes back to the idle
862 * state. Instead, return 0 to let the next scheduled background reclaim
863 * attempt to reclaim the inode again.
869 xfs_iunlock(ip, XFS_ILOCK_EXCL);
880 return xfs_inode_ag_iterator(mp, xfs_reclaim_inode, mode,
881 XFS_ICI_RECLAIM_TAG, 1, NULL);
885 * Shrinker infrastructure.
888 xfs_reclaim_inode_shrink(
889 struct shrinker *shrink,
893 struct xfs_mount *mp;
894 struct xfs_perag *pag;
898 mp = container_of(shrink, struct xfs_mount, m_inode_shrink);
900 if (!(gfp_mask & __GFP_FS))
903 xfs_inode_ag_iterator(mp, xfs_reclaim_inode, 0,
904 XFS_ICI_RECLAIM_TAG, 1, &nr_to_scan);
905 /* if we don't exhaust the scan, don't bother coming back */
912 while ((pag = xfs_inode_ag_iter_next_pag(mp, &ag,
913 XFS_ICI_RECLAIM_TAG))) {
914 reclaimable += pag->pag_ici_reclaimable;
921 xfs_inode_shrinker_register(
922 struct xfs_mount *mp)
924 mp->m_inode_shrink.shrink = xfs_reclaim_inode_shrink;
925 mp->m_inode_shrink.seeks = DEFAULT_SEEKS;
926 register_shrinker(&mp->m_inode_shrink);
930 xfs_inode_shrinker_unregister(
931 struct xfs_mount *mp)
933 unregister_shrinker(&mp->m_inode_shrink);