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"
23 #include "xfs_trans.h"
24 #include "xfs_trans_priv.h"
27 #include "xfs_mount.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_inode.h"
30 #include "xfs_dinode.h"
31 #include "xfs_error.h"
32 #include "xfs_filestream.h"
33 #include "xfs_vnodeops.h"
34 #include "xfs_inode_item.h"
35 #include "xfs_quota.h"
36 #include "xfs_trace.h"
37 #include "xfs_fsops.h"
39 #include <linux/kthread.h>
40 #include <linux/freezer.h>
42 struct workqueue_struct *xfs_syncd_wq; /* sync workqueue */
45 * The inode lookup is done in batches to keep the amount of lock traffic and
46 * radix tree lookups to a minimum. The batch size is a trade off between
47 * lookup reduction and stack usage. This is in the reclaim path, so we can't
50 #define XFS_LOOKUP_BATCH 32
53 xfs_inode_ag_walk_grab(
56 struct inode *inode = VFS_I(ip);
58 ASSERT(rcu_read_lock_held());
61 * check for stale RCU freed inode
63 * If the inode has been reallocated, it doesn't matter if it's not in
64 * the AG we are walking - we are walking for writeback, so if it
65 * passes all the "valid inode" checks and is dirty, then we'll write
66 * it back anyway. If it has been reallocated and still being
67 * initialised, the XFS_INEW check below will catch it.
69 spin_lock(&ip->i_flags_lock);
71 goto out_unlock_noent;
73 /* avoid new or reclaimable inodes. Leave for reclaim code to flush */
74 if (__xfs_iflags_test(ip, XFS_INEW | XFS_IRECLAIMABLE | XFS_IRECLAIM))
75 goto out_unlock_noent;
76 spin_unlock(&ip->i_flags_lock);
78 /* nothing to sync during shutdown */
79 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
82 /* If we can't grab the inode, it must on it's way to reclaim. */
86 if (is_bad_inode(inode)) {
95 spin_unlock(&ip->i_flags_lock);
101 struct xfs_mount *mp,
102 struct xfs_perag *pag,
103 int (*execute)(struct xfs_inode *ip,
104 struct xfs_perag *pag, int flags),
107 uint32_t first_index;
119 struct xfs_inode *batch[XFS_LOOKUP_BATCH];
124 nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
125 (void **)batch, first_index,
133 * Grab the inodes before we drop the lock. if we found
134 * nothing, nr == 0 and the loop will be skipped.
136 for (i = 0; i < nr_found; i++) {
137 struct xfs_inode *ip = batch[i];
139 if (done || xfs_inode_ag_walk_grab(ip))
143 * Update the index for the next lookup. Catch
144 * overflows into the next AG range which can occur if
145 * we have inodes in the last block of the AG and we
146 * are currently pointing to the last inode.
148 * Because we may see inodes that are from the wrong AG
149 * due to RCU freeing and reallocation, only update the
150 * index if it lies in this AG. It was a race that lead
151 * us to see this inode, so another lookup from the
152 * same index will not find it again.
154 if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
156 first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
157 if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
161 /* unlock now we've grabbed the inodes. */
164 for (i = 0; i < nr_found; i++) {
167 error = execute(batch[i], pag, flags);
169 if (error == EAGAIN) {
173 if (error && last_error != EFSCORRUPTED)
177 /* bail out if the filesystem is corrupted. */
178 if (error == EFSCORRUPTED)
183 } while (nr_found && !done);
193 xfs_inode_ag_iterator(
194 struct xfs_mount *mp,
195 int (*execute)(struct xfs_inode *ip,
196 struct xfs_perag *pag, int flags),
199 struct xfs_perag *pag;
205 while ((pag = xfs_perag_get(mp, ag))) {
206 ag = pag->pag_agno + 1;
207 error = xfs_inode_ag_walk(mp, pag, execute, flags);
211 if (error == EFSCORRUPTED)
215 return XFS_ERROR(last_error);
220 struct xfs_inode *ip,
221 struct xfs_perag *pag,
224 struct inode *inode = VFS_I(ip);
225 struct address_space *mapping = inode->i_mapping;
228 if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
231 if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
232 if (flags & SYNC_TRYLOCK)
234 xfs_ilock(ip, XFS_IOLOCK_SHARED);
237 error = xfs_flush_pages(ip, 0, -1, (flags & SYNC_WAIT) ?
238 0 : XBF_ASYNC, FI_NONE);
239 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
244 * Write out pagecache data for the whole filesystem.
248 struct xfs_mount *mp,
253 ASSERT((flags & ~(SYNC_TRYLOCK|SYNC_WAIT)) == 0);
255 error = xfs_inode_ag_iterator(mp, xfs_sync_inode_data, flags);
257 return XFS_ERROR(error);
259 xfs_log_force(mp, (flags & SYNC_WAIT) ? XFS_LOG_SYNC : 0);
265 struct xfs_mount *mp)
271 * If the buffer is pinned then push on the log so we won't get stuck
272 * waiting in the write for someone, maybe ourselves, to flush the log.
274 * Even though we just pushed the log above, we did not have the
275 * superblock buffer locked at that point so it can become pinned in
276 * between there and here.
278 bp = xfs_getsb(mp, 0);
279 if (xfs_buf_ispinned(bp))
280 xfs_log_force(mp, 0);
281 error = xfs_bwrite(bp);
287 * When remounting a filesystem read-only or freezing the filesystem, we have
288 * two phases to execute. This first phase is syncing the data before we
289 * quiesce the filesystem, and the second is flushing all the inodes out after
290 * we've waited for all the transactions created by the first phase to
291 * complete. The second phase ensures that the inodes are written to their
292 * location on disk rather than just existing in transactions in the log. This
293 * means after a quiesce there is no log replay required to write the inodes to
294 * disk (this is the main difference between a sync and a quiesce).
297 * First stage of freeze - no writers will make progress now we are here,
298 * so we flush delwri and delalloc buffers here, then wait for all I/O to
299 * complete. Data is frozen at that point. Metadata is not frozen,
300 * transactions can still occur here so don't bother emptying the AIL
301 * because it'll just get dirty again.
305 struct xfs_mount *mp)
307 int error, error2 = 0;
309 /* force out the log */
310 xfs_log_force(mp, XFS_LOG_SYNC);
312 /* write superblock and hoover up shutdown errors */
313 error = xfs_sync_fsdata(mp);
315 /* mark the log as covered if needed */
316 if (xfs_log_need_covered(mp))
317 error2 = xfs_fs_log_dummy(mp);
319 return error ? error : error2;
323 * Second stage of a quiesce. The data is already synced, now we have to take
324 * care of the metadata. New transactions are already blocked, so we need to
325 * wait for any remaining transactions to drain out before proceeding.
329 struct xfs_mount *mp)
333 /* wait for all modifications to complete */
334 while (atomic_read(&mp->m_active_trans) > 0)
337 /* reclaim inodes to do any IO before the freeze completes */
338 xfs_reclaim_inodes(mp, 0);
339 xfs_reclaim_inodes(mp, SYNC_WAIT);
341 /* flush all pending changes from the AIL */
342 xfs_ail_push_all_sync(mp->m_ail);
345 * Just warn here till VFS can correctly support
346 * read-only remount without racing.
348 WARN_ON(atomic_read(&mp->m_active_trans) != 0);
350 /* Push the superblock and write an unmount record */
351 error = xfs_log_sbcount(mp);
353 xfs_warn(mp, "xfs_attr_quiesce: failed to log sb changes. "
354 "Frozen image may not be consistent.");
355 xfs_log_unmount_write(mp);
358 * At this point we might have modified the superblock again and thus
359 * added an item to the AIL, thus flush it again.
361 xfs_ail_push_all_sync(mp->m_ail);
364 * The superblock buffer is uncached and xfsaild_push() will lock and
365 * set the XBF_ASYNC flag on the buffer. We cannot do xfs_buf_iowait()
366 * here but a lock on the superblock buffer will block until iodone()
369 xfs_buf_lock(mp->m_sb_bp);
370 xfs_buf_unlock(mp->m_sb_bp);
374 xfs_syncd_queue_sync(
375 struct xfs_mount *mp)
377 queue_delayed_work(xfs_syncd_wq, &mp->m_sync_work,
378 msecs_to_jiffies(xfs_syncd_centisecs * 10));
382 * Every sync period we need to unpin all items, reclaim inodes and sync
383 * disk quotas. We might need to cover the log to indicate that the
384 * filesystem is idle and not frozen.
388 struct work_struct *work)
390 struct xfs_mount *mp = container_of(to_delayed_work(work),
391 struct xfs_mount, m_sync_work);
395 * We shouldn't write/force the log if we are in the mount/unmount
396 * process or on a read only filesystem. The workqueue still needs to be
397 * active in both cases, however, because it is used for inode reclaim
398 * during these times. Use the MS_ACTIVE flag to avoid doing anything
399 * during mount. Doing work during unmount is avoided by calling
400 * cancel_delayed_work_sync on this work queue before tearing down
401 * the ail and the log in xfs_log_unmount.
403 if (!(mp->m_super->s_flags & MS_ACTIVE) &&
404 !(mp->m_flags & XFS_MOUNT_RDONLY)) {
405 /* dgc: errors ignored here */
406 if (mp->m_super->s_writers.frozen == SB_UNFROZEN &&
407 xfs_log_need_covered(mp))
408 error = xfs_fs_log_dummy(mp);
410 xfs_log_force(mp, 0);
412 /* start pushing all the metadata that is currently
414 xfs_ail_push_all(mp->m_ail);
417 /* queue us up again */
418 xfs_syncd_queue_sync(mp);
422 * Queue a new inode reclaim pass if there are reclaimable inodes and there
423 * isn't a reclaim pass already in progress. By default it runs every 5s based
424 * on the xfs syncd work default of 30s. Perhaps this should have it's own
425 * tunable, but that can be done if this method proves to be ineffective or too
429 xfs_syncd_queue_reclaim(
430 struct xfs_mount *mp)
434 if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
435 queue_delayed_work(xfs_syncd_wq, &mp->m_reclaim_work,
436 msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10));
442 * This is a fast pass over the inode cache to try to get reclaim moving on as
443 * many inodes as possible in a short period of time. It kicks itself every few
444 * seconds, as well as being kicked by the inode cache shrinker when memory
445 * goes low. It scans as quickly as possible avoiding locked inodes or those
446 * already being flushed, and once done schedules a future pass.
450 struct work_struct *work)
452 struct xfs_mount *mp = container_of(to_delayed_work(work),
453 struct xfs_mount, m_reclaim_work);
455 xfs_reclaim_inodes(mp, SYNC_TRYLOCK);
456 xfs_syncd_queue_reclaim(mp);
460 * Flush delayed allocate data, attempting to free up reserved space
461 * from existing allocations. At this point a new allocation attempt
462 * has failed with ENOSPC and we are in the process of scratching our
463 * heads, looking about for more room.
465 * Queue a new data flush if there isn't one already in progress and
466 * wait for completion of the flush. This means that we only ever have one
467 * inode flush in progress no matter how many ENOSPC events are occurring and
468 * so will prevent the system from bogging down due to every concurrent
469 * ENOSPC event scanning all the active inodes in the system for writeback.
473 struct xfs_inode *ip)
475 struct xfs_mount *mp = ip->i_mount;
477 queue_work(xfs_syncd_wq, &mp->m_flush_work);
478 flush_work(&mp->m_flush_work);
483 struct work_struct *work)
485 struct xfs_mount *mp = container_of(work,
486 struct xfs_mount, m_flush_work);
488 xfs_sync_data(mp, SYNC_TRYLOCK);
489 xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT);
493 __xfs_inode_set_reclaim_tag(
494 struct xfs_perag *pag,
495 struct xfs_inode *ip)
497 radix_tree_tag_set(&pag->pag_ici_root,
498 XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino),
499 XFS_ICI_RECLAIM_TAG);
501 if (!pag->pag_ici_reclaimable) {
502 /* propagate the reclaim tag up into the perag radix tree */
503 spin_lock(&ip->i_mount->m_perag_lock);
504 radix_tree_tag_set(&ip->i_mount->m_perag_tree,
505 XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
506 XFS_ICI_RECLAIM_TAG);
507 spin_unlock(&ip->i_mount->m_perag_lock);
509 /* schedule periodic background inode reclaim */
510 xfs_syncd_queue_reclaim(ip->i_mount);
512 trace_xfs_perag_set_reclaim(ip->i_mount, pag->pag_agno,
515 pag->pag_ici_reclaimable++;
519 * We set the inode flag atomically with the radix tree tag.
520 * Once we get tag lookups on the radix tree, this inode flag
524 xfs_inode_set_reclaim_tag(
527 struct xfs_mount *mp = ip->i_mount;
528 struct xfs_perag *pag;
530 pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
531 spin_lock(&pag->pag_ici_lock);
532 spin_lock(&ip->i_flags_lock);
533 __xfs_inode_set_reclaim_tag(pag, ip);
534 __xfs_iflags_set(ip, XFS_IRECLAIMABLE);
535 spin_unlock(&ip->i_flags_lock);
536 spin_unlock(&pag->pag_ici_lock);
541 __xfs_inode_clear_reclaim(
545 pag->pag_ici_reclaimable--;
546 if (!pag->pag_ici_reclaimable) {
547 /* clear the reclaim tag from the perag radix tree */
548 spin_lock(&ip->i_mount->m_perag_lock);
549 radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
550 XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
551 XFS_ICI_RECLAIM_TAG);
552 spin_unlock(&ip->i_mount->m_perag_lock);
553 trace_xfs_perag_clear_reclaim(ip->i_mount, pag->pag_agno,
559 __xfs_inode_clear_reclaim_tag(
564 radix_tree_tag_clear(&pag->pag_ici_root,
565 XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG);
566 __xfs_inode_clear_reclaim(pag, ip);
570 * Grab the inode for reclaim exclusively.
571 * Return 0 if we grabbed it, non-zero otherwise.
574 xfs_reclaim_inode_grab(
575 struct xfs_inode *ip,
578 ASSERT(rcu_read_lock_held());
580 /* quick check for stale RCU freed inode */
585 * If we are asked for non-blocking operation, do unlocked checks to
586 * see if the inode already is being flushed or in reclaim to avoid
589 if ((flags & SYNC_TRYLOCK) &&
590 __xfs_iflags_test(ip, XFS_IFLOCK | XFS_IRECLAIM))
594 * The radix tree lock here protects a thread in xfs_iget from racing
595 * with us starting reclaim on the inode. Once we have the
596 * XFS_IRECLAIM flag set it will not touch us.
598 * Due to RCU lookup, we may find inodes that have been freed and only
599 * have XFS_IRECLAIM set. Indeed, we may see reallocated inodes that
600 * aren't candidates for reclaim at all, so we must check the
601 * XFS_IRECLAIMABLE is set first before proceeding to reclaim.
603 spin_lock(&ip->i_flags_lock);
604 if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) ||
605 __xfs_iflags_test(ip, XFS_IRECLAIM)) {
606 /* not a reclaim candidate. */
607 spin_unlock(&ip->i_flags_lock);
610 __xfs_iflags_set(ip, XFS_IRECLAIM);
611 spin_unlock(&ip->i_flags_lock);
616 * Inodes in different states need to be treated differently. The following
617 * table lists the inode states and the reclaim actions necessary:
619 * inode state iflush ret required action
620 * --------------- ---------- ---------------
622 * shutdown EIO unpin and reclaim
623 * clean, unpinned 0 reclaim
624 * stale, unpinned 0 reclaim
625 * clean, pinned(*) 0 requeue
626 * stale, pinned EAGAIN requeue
627 * dirty, async - requeue
628 * dirty, sync 0 reclaim
630 * (*) dgc: I don't think the clean, pinned state is possible but it gets
631 * handled anyway given the order of checks implemented.
633 * Also, because we get the flush lock first, we know that any inode that has
634 * been flushed delwri has had the flush completed by the time we check that
635 * the inode is clean.
637 * Note that because the inode is flushed delayed write by AIL pushing, the
638 * flush lock may already be held here and waiting on it can result in very
639 * long latencies. Hence for sync reclaims, where we wait on the flush lock,
640 * the caller should push the AIL first before trying to reclaim inodes to
641 * minimise the amount of time spent waiting. For background relaim, we only
642 * bother to reclaim clean inodes anyway.
644 * Hence the order of actions after gaining the locks should be:
646 * shutdown => unpin and reclaim
647 * pinned, async => requeue
648 * pinned, sync => unpin
651 * dirty, async => requeue
652 * dirty, sync => flush, wait and reclaim
656 struct xfs_inode *ip,
657 struct xfs_perag *pag,
660 struct xfs_buf *bp = NULL;
665 xfs_ilock(ip, XFS_ILOCK_EXCL);
666 if (!xfs_iflock_nowait(ip)) {
667 if (!(sync_mode & SYNC_WAIT))
672 if (is_bad_inode(VFS_I(ip)))
674 if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
676 xfs_iflush_abort(ip, false);
679 if (xfs_ipincount(ip)) {
680 if (!(sync_mode & SYNC_WAIT))
684 if (xfs_iflags_test(ip, XFS_ISTALE))
686 if (xfs_inode_clean(ip))
690 * Never flush out dirty data during non-blocking reclaim, as it would
691 * just contend with AIL pushing trying to do the same job.
693 if (!(sync_mode & SYNC_WAIT))
697 * Now we have an inode that needs flushing.
699 * Note that xfs_iflush will never block on the inode buffer lock, as
700 * xfs_ifree_cluster() can lock the inode buffer before it locks the
701 * ip->i_lock, and we are doing the exact opposite here. As a result,
702 * doing a blocking xfs_imap_to_bp() to get the cluster buffer would
703 * result in an ABBA deadlock with xfs_ifree_cluster().
705 * As xfs_ifree_cluser() must gather all inodes that are active in the
706 * cache to mark them stale, if we hit this case we don't actually want
707 * to do IO here - we want the inode marked stale so we can simply
708 * reclaim it. Hence if we get an EAGAIN error here, just unlock the
709 * inode, back off and try again. Hopefully the next pass through will
710 * see the stale flag set on the inode.
712 error = xfs_iflush(ip, &bp);
713 if (error == EAGAIN) {
714 xfs_iunlock(ip, XFS_ILOCK_EXCL);
715 /* backoff longer than in xfs_ifree_cluster */
721 error = xfs_bwrite(bp);
728 xfs_iunlock(ip, XFS_ILOCK_EXCL);
730 XFS_STATS_INC(xs_ig_reclaims);
732 * Remove the inode from the per-AG radix tree.
734 * Because radix_tree_delete won't complain even if the item was never
735 * added to the tree assert that it's been there before to catch
736 * problems with the inode life time early on.
738 spin_lock(&pag->pag_ici_lock);
739 if (!radix_tree_delete(&pag->pag_ici_root,
740 XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino)))
742 __xfs_inode_clear_reclaim(pag, ip);
743 spin_unlock(&pag->pag_ici_lock);
746 * Here we do an (almost) spurious inode lock in order to coordinate
747 * with inode cache radix tree lookups. This is because the lookup
748 * can reference the inodes in the cache without taking references.
750 * We make that OK here by ensuring that we wait until the inode is
751 * unlocked after the lookup before we go ahead and free it.
753 xfs_ilock(ip, XFS_ILOCK_EXCL);
755 xfs_iunlock(ip, XFS_ILOCK_EXCL);
763 xfs_iflags_clear(ip, XFS_IRECLAIM);
764 xfs_iunlock(ip, XFS_ILOCK_EXCL);
766 * We could return EAGAIN here to make reclaim rescan the inode tree in
767 * a short while. However, this just burns CPU time scanning the tree
768 * waiting for IO to complete and xfssyncd never goes back to the idle
769 * state. Instead, return 0 to let the next scheduled background reclaim
770 * attempt to reclaim the inode again.
776 * Walk the AGs and reclaim the inodes in them. Even if the filesystem is
777 * corrupted, we still want to try to reclaim all the inodes. If we don't,
778 * then a shut down during filesystem unmount reclaim walk leak all the
779 * unreclaimed inodes.
782 xfs_reclaim_inodes_ag(
783 struct xfs_mount *mp,
787 struct xfs_perag *pag;
791 int trylock = flags & SYNC_TRYLOCK;
797 while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
798 unsigned long first_index = 0;
802 ag = pag->pag_agno + 1;
805 if (!mutex_trylock(&pag->pag_ici_reclaim_lock)) {
810 first_index = pag->pag_ici_reclaim_cursor;
812 mutex_lock(&pag->pag_ici_reclaim_lock);
815 struct xfs_inode *batch[XFS_LOOKUP_BATCH];
819 nr_found = radix_tree_gang_lookup_tag(
821 (void **)batch, first_index,
823 XFS_ICI_RECLAIM_TAG);
831 * Grab the inodes before we drop the lock. if we found
832 * nothing, nr == 0 and the loop will be skipped.
834 for (i = 0; i < nr_found; i++) {
835 struct xfs_inode *ip = batch[i];
837 if (done || xfs_reclaim_inode_grab(ip, flags))
841 * Update the index for the next lookup. Catch
842 * overflows into the next AG range which can
843 * occur if we have inodes in the last block of
844 * the AG and we are currently pointing to the
847 * Because we may see inodes that are from the
848 * wrong AG due to RCU freeing and
849 * reallocation, only update the index if it
850 * lies in this AG. It was a race that lead us
851 * to see this inode, so another lookup from
852 * the same index will not find it again.
854 if (XFS_INO_TO_AGNO(mp, ip->i_ino) !=
857 first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
858 if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
862 /* unlock now we've grabbed the inodes. */
865 for (i = 0; i < nr_found; i++) {
868 error = xfs_reclaim_inode(batch[i], pag, flags);
869 if (error && last_error != EFSCORRUPTED)
873 *nr_to_scan -= XFS_LOOKUP_BATCH;
877 } while (nr_found && !done && *nr_to_scan > 0);
879 if (trylock && !done)
880 pag->pag_ici_reclaim_cursor = first_index;
882 pag->pag_ici_reclaim_cursor = 0;
883 mutex_unlock(&pag->pag_ici_reclaim_lock);
888 * if we skipped any AG, and we still have scan count remaining, do
889 * another pass this time using blocking reclaim semantics (i.e
890 * waiting on the reclaim locks and ignoring the reclaim cursors). This
891 * ensure that when we get more reclaimers than AGs we block rather
892 * than spin trying to execute reclaim.
894 if (skipped && (flags & SYNC_WAIT) && *nr_to_scan > 0) {
898 return XFS_ERROR(last_error);
906 int nr_to_scan = INT_MAX;
908 return xfs_reclaim_inodes_ag(mp, mode, &nr_to_scan);
912 * Scan a certain number of inodes for reclaim.
914 * When called we make sure that there is a background (fast) inode reclaim in
915 * progress, while we will throttle the speed of reclaim via doing synchronous
916 * reclaim of inodes. That means if we come across dirty inodes, we wait for
917 * them to be cleaned, which we hope will not be very long due to the
918 * background walker having already kicked the IO off on those dirty inodes.
921 xfs_reclaim_inodes_nr(
922 struct xfs_mount *mp,
925 /* kick background reclaimer and push the AIL */
926 xfs_syncd_queue_reclaim(mp);
927 xfs_ail_push_all(mp->m_ail);
929 xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan);
933 * Return the number of reclaimable inodes in the filesystem for
934 * the shrinker to determine how much to reclaim.
937 xfs_reclaim_inodes_count(
938 struct xfs_mount *mp)
940 struct xfs_perag *pag;
941 xfs_agnumber_t ag = 0;
944 while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
945 ag = pag->pag_agno + 1;
946 reclaimable += pag->pag_ici_reclaimable;