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Diffstat (limited to 'fs/xfs/linux-2.6/xfs_sync.c')
-rw-r--r--fs/xfs/linux-2.6/xfs_sync.c1045
1 files changed, 0 insertions, 1045 deletions
diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
deleted file mode 100644
index e22f0057d21..00000000000
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ /dev/null
@@ -1,1045 +0,0 @@
-/*
- * Copyright (c) 2000-2005 Silicon Graphics, Inc.
- * All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- */
-#include "xfs.h"
-#include "xfs_fs.h"
-#include "xfs_types.h"
-#include "xfs_bit.h"
-#include "xfs_log.h"
-#include "xfs_inum.h"
-#include "xfs_trans.h"
-#include "xfs_sb.h"
-#include "xfs_ag.h"
-#include "xfs_mount.h"
-#include "xfs_bmap_btree.h"
-#include "xfs_inode.h"
-#include "xfs_dinode.h"
-#include "xfs_error.h"
-#include "xfs_filestream.h"
-#include "xfs_vnodeops.h"
-#include "xfs_inode_item.h"
-#include "xfs_quota.h"
-#include "xfs_trace.h"
-#include "xfs_fsops.h"
-
-#include <linux/kthread.h>
-#include <linux/freezer.h>
-
-/*
- * The inode lookup is done in batches to keep the amount of lock traffic and
- * radix tree lookups to a minimum. The batch size is a trade off between
- * lookup reduction and stack usage. This is in the reclaim path, so we can't
- * be too greedy.
- */
-#define XFS_LOOKUP_BATCH 32
-
-STATIC int
-xfs_inode_ag_walk_grab(
- struct xfs_inode *ip)
-{
- struct inode *inode = VFS_I(ip);
-
- ASSERT(rcu_read_lock_held());
-
- /*
- * check for stale RCU freed inode
- *
- * If the inode has been reallocated, it doesn't matter if it's not in
- * the AG we are walking - we are walking for writeback, so if it
- * passes all the "valid inode" checks and is dirty, then we'll write
- * it back anyway. If it has been reallocated and still being
- * initialised, the XFS_INEW check below will catch it.
- */
- spin_lock(&ip->i_flags_lock);
- if (!ip->i_ino)
- goto out_unlock_noent;
-
- /* avoid new or reclaimable inodes. Leave for reclaim code to flush */
- if (__xfs_iflags_test(ip, XFS_INEW | XFS_IRECLAIMABLE | XFS_IRECLAIM))
- goto out_unlock_noent;
- spin_unlock(&ip->i_flags_lock);
-
- /* nothing to sync during shutdown */
- if (XFS_FORCED_SHUTDOWN(ip->i_mount))
- return EFSCORRUPTED;
-
- /* If we can't grab the inode, it must on it's way to reclaim. */
- if (!igrab(inode))
- return ENOENT;
-
- if (is_bad_inode(inode)) {
- IRELE(ip);
- return ENOENT;
- }
-
- /* inode is valid */
- return 0;
-
-out_unlock_noent:
- spin_unlock(&ip->i_flags_lock);
- return ENOENT;
-}
-
-STATIC int
-xfs_inode_ag_walk(
- struct xfs_mount *mp,
- struct xfs_perag *pag,
- int (*execute)(struct xfs_inode *ip,
- struct xfs_perag *pag, int flags),
- int flags)
-{
- uint32_t first_index;
- int last_error = 0;
- int skipped;
- int done;
- int nr_found;
-
-restart:
- done = 0;
- skipped = 0;
- first_index = 0;
- nr_found = 0;
- do {
- struct xfs_inode *batch[XFS_LOOKUP_BATCH];
- int error = 0;
- int i;
-
- rcu_read_lock();
- nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
- (void **)batch, first_index,
- XFS_LOOKUP_BATCH);
- if (!nr_found) {
- rcu_read_unlock();
- break;
- }
-
- /*
- * Grab the inodes before we drop the lock. if we found
- * nothing, nr == 0 and the loop will be skipped.
- */
- for (i = 0; i < nr_found; i++) {
- struct xfs_inode *ip = batch[i];
-
- if (done || xfs_inode_ag_walk_grab(ip))
- batch[i] = NULL;
-
- /*
- * Update the index for the next lookup. Catch
- * overflows into the next AG range which can occur if
- * we have inodes in the last block of the AG and we
- * are currently pointing to the last inode.
- *
- * Because we may see inodes that are from the wrong AG
- * due to RCU freeing and reallocation, only update the
- * index if it lies in this AG. It was a race that lead
- * us to see this inode, so another lookup from the
- * same index will not find it again.
- */
- if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
- continue;
- first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
- if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
- done = 1;
- }
-
- /* unlock now we've grabbed the inodes. */
- rcu_read_unlock();
-
- for (i = 0; i < nr_found; i++) {
- if (!batch[i])
- continue;
- error = execute(batch[i], pag, flags);
- IRELE(batch[i]);
- if (error == EAGAIN) {
- skipped++;
- continue;
- }
- if (error && last_error != EFSCORRUPTED)
- last_error = error;
- }
-
- /* bail out if the filesystem is corrupted. */
- if (error == EFSCORRUPTED)
- break;
-
- } while (nr_found && !done);
-
- if (skipped) {
- delay(1);
- goto restart;
- }
- return last_error;
-}
-
-int
-xfs_inode_ag_iterator(
- struct xfs_mount *mp,
- int (*execute)(struct xfs_inode *ip,
- struct xfs_perag *pag, int flags),
- int flags)
-{
- struct xfs_perag *pag;
- int error = 0;
- int last_error = 0;
- xfs_agnumber_t ag;
-
- ag = 0;
- while ((pag = xfs_perag_get(mp, ag))) {
- ag = pag->pag_agno + 1;
- error = xfs_inode_ag_walk(mp, pag, execute, flags);
- xfs_perag_put(pag);
- if (error) {
- last_error = error;
- if (error == EFSCORRUPTED)
- break;
- }
- }
- return XFS_ERROR(last_error);
-}
-
-STATIC int
-xfs_sync_inode_data(
- struct xfs_inode *ip,
- struct xfs_perag *pag,
- int flags)
-{
- struct inode *inode = VFS_I(ip);
- struct address_space *mapping = inode->i_mapping;
- int error = 0;
-
- if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
- goto out_wait;
-
- if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
- if (flags & SYNC_TRYLOCK)
- goto out_wait;
- xfs_ilock(ip, XFS_IOLOCK_SHARED);
- }
-
- error = xfs_flush_pages(ip, 0, -1, (flags & SYNC_WAIT) ?
- 0 : XBF_ASYNC, FI_NONE);
- xfs_iunlock(ip, XFS_IOLOCK_SHARED);
-
- out_wait:
- if (flags & SYNC_WAIT)
- xfs_ioend_wait(ip);
- return error;
-}
-
-STATIC int
-xfs_sync_inode_attr(
- struct xfs_inode *ip,
- struct xfs_perag *pag,
- int flags)
-{
- int error = 0;
-
- xfs_ilock(ip, XFS_ILOCK_SHARED);
- if (xfs_inode_clean(ip))
- goto out_unlock;
- if (!xfs_iflock_nowait(ip)) {
- if (!(flags & SYNC_WAIT))
- goto out_unlock;
- xfs_iflock(ip);
- }
-
- if (xfs_inode_clean(ip)) {
- xfs_ifunlock(ip);
- goto out_unlock;
- }
-
- error = xfs_iflush(ip, flags);
-
- out_unlock:
- xfs_iunlock(ip, XFS_ILOCK_SHARED);
- return error;
-}
-
-/*
- * Write out pagecache data for the whole filesystem.
- */
-STATIC int
-xfs_sync_data(
- struct xfs_mount *mp,
- int flags)
-{
- int error;
-
- ASSERT((flags & ~(SYNC_TRYLOCK|SYNC_WAIT)) == 0);
-
- error = xfs_inode_ag_iterator(mp, xfs_sync_inode_data, flags);
- if (error)
- return XFS_ERROR(error);
-
- xfs_log_force(mp, (flags & SYNC_WAIT) ? XFS_LOG_SYNC : 0);
- return 0;
-}
-
-/*
- * Write out inode metadata (attributes) for the whole filesystem.
- */
-STATIC int
-xfs_sync_attr(
- struct xfs_mount *mp,
- int flags)
-{
- ASSERT((flags & ~SYNC_WAIT) == 0);
-
- return xfs_inode_ag_iterator(mp, xfs_sync_inode_attr, flags);
-}
-
-STATIC int
-xfs_sync_fsdata(
- struct xfs_mount *mp)
-{
- struct xfs_buf *bp;
-
- /*
- * If the buffer is pinned then push on the log so we won't get stuck
- * waiting in the write for someone, maybe ourselves, to flush the log.
- *
- * Even though we just pushed the log above, we did not have the
- * superblock buffer locked at that point so it can become pinned in
- * between there and here.
- */
- bp = xfs_getsb(mp, 0);
- if (XFS_BUF_ISPINNED(bp))
- xfs_log_force(mp, 0);
-
- return xfs_bwrite(mp, bp);
-}
-
-/*
- * When remounting a filesystem read-only or freezing the filesystem, we have
- * two phases to execute. This first phase is syncing the data before we
- * quiesce the filesystem, and the second is flushing all the inodes out after
- * we've waited for all the transactions created by the first phase to
- * complete. The second phase ensures that the inodes are written to their
- * location on disk rather than just existing in transactions in the log. This
- * means after a quiesce there is no log replay required to write the inodes to
- * disk (this is the main difference between a sync and a quiesce).
- */
-/*
- * First stage of freeze - no writers will make progress now we are here,
- * so we flush delwri and delalloc buffers here, then wait for all I/O to
- * complete. Data is frozen at that point. Metadata is not frozen,
- * transactions can still occur here so don't bother flushing the buftarg
- * because it'll just get dirty again.
- */
-int
-xfs_quiesce_data(
- struct xfs_mount *mp)
-{
- int error, error2 = 0;
-
- /* push non-blocking */
- xfs_sync_data(mp, 0);
- xfs_qm_sync(mp, SYNC_TRYLOCK);
-
- /* push and block till complete */
- xfs_sync_data(mp, SYNC_WAIT);
- xfs_qm_sync(mp, SYNC_WAIT);
-
- /* write superblock and hoover up shutdown errors */
- error = xfs_sync_fsdata(mp);
-
- /* make sure all delwri buffers are written out */
- xfs_flush_buftarg(mp->m_ddev_targp, 1);
-
- /* mark the log as covered if needed */
- if (xfs_log_need_covered(mp))
- error2 = xfs_fs_log_dummy(mp);
-
- /* flush data-only devices */
- if (mp->m_rtdev_targp)
- XFS_bflush(mp->m_rtdev_targp);
-
- return error ? error : error2;
-}
-
-STATIC void
-xfs_quiesce_fs(
- struct xfs_mount *mp)
-{
- int count = 0, pincount;
-
- xfs_reclaim_inodes(mp, 0);
- xfs_flush_buftarg(mp->m_ddev_targp, 0);
-
- /*
- * This loop must run at least twice. The first instance of the loop
- * will flush most meta data but that will generate more meta data
- * (typically directory updates). Which then must be flushed and
- * logged before we can write the unmount record. We also so sync
- * reclaim of inodes to catch any that the above delwri flush skipped.
- */
- do {
- xfs_reclaim_inodes(mp, SYNC_WAIT);
- xfs_sync_attr(mp, SYNC_WAIT);
- pincount = xfs_flush_buftarg(mp->m_ddev_targp, 1);
- if (!pincount) {
- delay(50);
- count++;
- }
- } while (count < 2);
-}
-
-/*
- * Second stage of a quiesce. The data is already synced, now we have to take
- * care of the metadata. New transactions are already blocked, so we need to
- * wait for any remaining transactions to drain out before proceding.
- */
-void
-xfs_quiesce_attr(
- struct xfs_mount *mp)
-{
- int error = 0;
-
- /* wait for all modifications to complete */
- while (atomic_read(&mp->m_active_trans) > 0)
- delay(100);
-
- /* flush inodes and push all remaining buffers out to disk */
- xfs_quiesce_fs(mp);
-
- /*
- * Just warn here till VFS can correctly support
- * read-only remount without racing.
- */
- WARN_ON(atomic_read(&mp->m_active_trans) != 0);
-
- /* Push the superblock and write an unmount record */
- error = xfs_log_sbcount(mp, 1);
- if (error)
- xfs_fs_cmn_err(CE_WARN, mp,
- "xfs_attr_quiesce: failed to log sb changes. "
- "Frozen image may not be consistent.");
- xfs_log_unmount_write(mp);
- xfs_unmountfs_writesb(mp);
-}
-
-/*
- * Enqueue a work item to be picked up by the vfs xfssyncd thread.
- * Doing this has two advantages:
- * - It saves on stack space, which is tight in certain situations
- * - It can be used (with care) as a mechanism to avoid deadlocks.
- * Flushing while allocating in a full filesystem requires both.
- */
-STATIC void
-xfs_syncd_queue_work(
- struct xfs_mount *mp,
- void *data,
- void (*syncer)(struct xfs_mount *, void *),
- struct completion *completion)
-{
- struct xfs_sync_work *work;
-
- work = kmem_alloc(sizeof(struct xfs_sync_work), KM_SLEEP);
- INIT_LIST_HEAD(&work->w_list);
- work->w_syncer = syncer;
- work->w_data = data;
- work->w_mount = mp;
- work->w_completion = completion;
- spin_lock(&mp->m_sync_lock);
- list_add_tail(&work->w_list, &mp->m_sync_list);
- spin_unlock(&mp->m_sync_lock);
- wake_up_process(mp->m_sync_task);
-}
-
-/*
- * Flush delayed allocate data, attempting to free up reserved space
- * from existing allocations. At this point a new allocation attempt
- * has failed with ENOSPC and we are in the process of scratching our
- * heads, looking about for more room...
- */
-STATIC void
-xfs_flush_inodes_work(
- struct xfs_mount *mp,
- void *arg)
-{
- struct inode *inode = arg;
- xfs_sync_data(mp, SYNC_TRYLOCK);
- xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT);
- iput(inode);
-}
-
-void
-xfs_flush_inodes(
- xfs_inode_t *ip)
-{
- struct inode *inode = VFS_I(ip);
- DECLARE_COMPLETION_ONSTACK(completion);
-
- igrab(inode);
- xfs_syncd_queue_work(ip->i_mount, inode, xfs_flush_inodes_work, &completion);
- wait_for_completion(&completion);
- xfs_log_force(ip->i_mount, XFS_LOG_SYNC);
-}
-
-/*
- * Every sync period we need to unpin all items, reclaim inodes and sync
- * disk quotas. We might need to cover the log to indicate that the
- * filesystem is idle and not frozen.
- */
-STATIC void
-xfs_sync_worker(
- struct xfs_mount *mp,
- void *unused)
-{
- int error;
-
- if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
- /* dgc: errors ignored here */
- if (mp->m_super->s_frozen == SB_UNFROZEN &&
- xfs_log_need_covered(mp))
- error = xfs_fs_log_dummy(mp);
- else
- xfs_log_force(mp, 0);
- xfs_reclaim_inodes(mp, 0);
- error = xfs_qm_sync(mp, SYNC_TRYLOCK);
- }
- mp->m_sync_seq++;
- wake_up(&mp->m_wait_single_sync_task);
-}
-
-STATIC int
-xfssyncd(
- void *arg)
-{
- struct xfs_mount *mp = arg;
- long timeleft;
- xfs_sync_work_t *work, *n;
- LIST_HEAD (tmp);
-
- set_freezable();
- timeleft = xfs_syncd_centisecs * msecs_to_jiffies(10);
- for (;;) {
- if (list_empty(&mp->m_sync_list))
- timeleft = schedule_timeout_interruptible(timeleft);
- /* swsusp */
- try_to_freeze();
- if (kthread_should_stop() && list_empty(&mp->m_sync_list))
- break;
-
- spin_lock(&mp->m_sync_lock);
- /*
- * We can get woken by laptop mode, to do a sync -
- * that's the (only!) case where the list would be
- * empty with time remaining.
- */
- if (!timeleft || list_empty(&mp->m_sync_list)) {
- if (!timeleft)
- timeleft = xfs_syncd_centisecs *
- msecs_to_jiffies(10);
- INIT_LIST_HEAD(&mp->m_sync_work.w_list);
- list_add_tail(&mp->m_sync_work.w_list,
- &mp->m_sync_list);
- }
- list_splice_init(&mp->m_sync_list, &tmp);
- spin_unlock(&mp->m_sync_lock);
-
- list_for_each_entry_safe(work, n, &tmp, w_list) {
- (*work->w_syncer)(mp, work->w_data);
- list_del(&work->w_list);
- if (work == &mp->m_sync_work)
- continue;
- if (work->w_completion)
- complete(work->w_completion);
- kmem_free(work);
- }
- }
-
- return 0;
-}
-
-int
-xfs_syncd_init(
- struct xfs_mount *mp)
-{
- mp->m_sync_work.w_syncer = xfs_sync_worker;
- mp->m_sync_work.w_mount = mp;
- mp->m_sync_work.w_completion = NULL;
- mp->m_sync_task = kthread_run(xfssyncd, mp, "xfssyncd/%s", mp->m_fsname);
- if (IS_ERR(mp->m_sync_task))
- return -PTR_ERR(mp->m_sync_task);
- return 0;
-}
-
-void
-xfs_syncd_stop(
- struct xfs_mount *mp)
-{
- kthread_stop(mp->m_sync_task);
-}
-
-void
-__xfs_inode_set_reclaim_tag(
- struct xfs_perag *pag,
- struct xfs_inode *ip)
-{
- radix_tree_tag_set(&pag->pag_ici_root,
- XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino),
- XFS_ICI_RECLAIM_TAG);
-
- if (!pag->pag_ici_reclaimable) {
- /* propagate the reclaim tag up into the perag radix tree */
- spin_lock(&ip->i_mount->m_perag_lock);
- radix_tree_tag_set(&ip->i_mount->m_perag_tree,
- XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
- XFS_ICI_RECLAIM_TAG);
- spin_unlock(&ip->i_mount->m_perag_lock);
- trace_xfs_perag_set_reclaim(ip->i_mount, pag->pag_agno,
- -1, _RET_IP_);
- }
- pag->pag_ici_reclaimable++;
-}
-
-/*
- * We set the inode flag atomically with the radix tree tag.
- * Once we get tag lookups on the radix tree, this inode flag
- * can go away.
- */
-void
-xfs_inode_set_reclaim_tag(
- xfs_inode_t *ip)
-{
- struct xfs_mount *mp = ip->i_mount;
- struct xfs_perag *pag;
-
- pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
- spin_lock(&pag->pag_ici_lock);
- spin_lock(&ip->i_flags_lock);
- __xfs_inode_set_reclaim_tag(pag, ip);
- __xfs_iflags_set(ip, XFS_IRECLAIMABLE);
- spin_unlock(&ip->i_flags_lock);
- spin_unlock(&pag->pag_ici_lock);
- xfs_perag_put(pag);
-}
-
-STATIC void
-__xfs_inode_clear_reclaim(
- xfs_perag_t *pag,
- xfs_inode_t *ip)
-{
- pag->pag_ici_reclaimable--;
- if (!pag->pag_ici_reclaimable) {
- /* clear the reclaim tag from the perag radix tree */
- spin_lock(&ip->i_mount->m_perag_lock);
- radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
- XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
- XFS_ICI_RECLAIM_TAG);
- spin_unlock(&ip->i_mount->m_perag_lock);
- trace_xfs_perag_clear_reclaim(ip->i_mount, pag->pag_agno,
- -1, _RET_IP_);
- }
-}
-
-void
-__xfs_inode_clear_reclaim_tag(
- xfs_mount_t *mp,
- xfs_perag_t *pag,
- xfs_inode_t *ip)
-{
- radix_tree_tag_clear(&pag->pag_ici_root,
- XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG);
- __xfs_inode_clear_reclaim(pag, ip);
-}
-
-/*
- * Grab the inode for reclaim exclusively.
- * Return 0 if we grabbed it, non-zero otherwise.
- */
-STATIC int
-xfs_reclaim_inode_grab(
- struct xfs_inode *ip,
- int flags)
-{
- ASSERT(rcu_read_lock_held());
-
- /* quick check for stale RCU freed inode */
- if (!ip->i_ino)
- return 1;
-
- /*
- * do some unlocked checks first to avoid unnecessary lock traffic.
- * The first is a flush lock check, the second is a already in reclaim
- * check. Only do these checks if we are not going to block on locks.
- */
- if ((flags & SYNC_TRYLOCK) &&
- (!ip->i_flush.done || __xfs_iflags_test(ip, XFS_IRECLAIM))) {
- return 1;
- }
-
- /*
- * The radix tree lock here protects a thread in xfs_iget from racing
- * with us starting reclaim on the inode. Once we have the
- * XFS_IRECLAIM flag set it will not touch us.
- *
- * Due to RCU lookup, we may find inodes that have been freed and only
- * have XFS_IRECLAIM set. Indeed, we may see reallocated inodes that
- * aren't candidates for reclaim at all, so we must check the
- * XFS_IRECLAIMABLE is set first before proceeding to reclaim.
- */
- spin_lock(&ip->i_flags_lock);
- if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) ||
- __xfs_iflags_test(ip, XFS_IRECLAIM)) {
- /* not a reclaim candidate. */
- spin_unlock(&ip->i_flags_lock);
- return 1;
- }
- __xfs_iflags_set(ip, XFS_IRECLAIM);
- spin_unlock(&ip->i_flags_lock);
- return 0;
-}
-
-/*
- * Inodes in different states need to be treated differently, and the return
- * value of xfs_iflush is not sufficient to get this right. The following table
- * lists the inode states and the reclaim actions necessary for non-blocking
- * reclaim:
- *
- *
- * inode state iflush ret required action
- * --------------- ---------- ---------------
- * bad - reclaim
- * shutdown EIO unpin and reclaim
- * clean, unpinned 0 reclaim
- * stale, unpinned 0 reclaim
- * clean, pinned(*) 0 requeue
- * stale, pinned EAGAIN requeue
- * dirty, delwri ok 0 requeue
- * dirty, delwri blocked EAGAIN requeue
- * dirty, sync flush 0 reclaim
- *
- * (*) dgc: I don't think the clean, pinned state is possible but it gets
- * handled anyway given the order of checks implemented.
- *
- * As can be seen from the table, the return value of xfs_iflush() is not
- * sufficient to correctly decide the reclaim action here. The checks in
- * xfs_iflush() might look like duplicates, but they are not.
- *
- * Also, because we get the flush lock first, we know that any inode that has
- * been flushed delwri has had the flush completed by the time we check that
- * the inode is clean. The clean inode check needs to be done before flushing
- * the inode delwri otherwise we would loop forever requeuing clean inodes as
- * we cannot tell apart a successful delwri flush and a clean inode from the
- * return value of xfs_iflush().
- *
- * Note that because the inode is flushed delayed write by background
- * writeback, the flush lock may already be held here and waiting on it can
- * result in very long latencies. Hence for sync reclaims, where we wait on the
- * flush lock, the caller should push out delayed write inodes first before
- * trying to reclaim them to minimise the amount of time spent waiting. For
- * background relaim, we just requeue the inode for the next pass.
- *
- * Hence the order of actions after gaining the locks should be:
- * bad => reclaim
- * shutdown => unpin and reclaim
- * pinned, delwri => requeue
- * pinned, sync => unpin
- * stale => reclaim
- * clean => reclaim
- * dirty, delwri => flush and requeue
- * dirty, sync => flush, wait and reclaim
- */
-STATIC int
-xfs_reclaim_inode(
- struct xfs_inode *ip,
- struct xfs_perag *pag,
- int sync_mode)
-{
- int error = 0;
-
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- if (!xfs_iflock_nowait(ip)) {
- if (!(sync_mode & SYNC_WAIT))
- goto out;
- xfs_iflock(ip);
- }
-
- if (is_bad_inode(VFS_I(ip)))
- goto reclaim;
- if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
- xfs_iunpin_wait(ip);
- goto reclaim;
- }
- if (xfs_ipincount(ip)) {
- if (!(sync_mode & SYNC_WAIT)) {
- xfs_ifunlock(ip);
- goto out;
- }
- xfs_iunpin_wait(ip);
- }
- if (xfs_iflags_test(ip, XFS_ISTALE))
- goto reclaim;
- if (xfs_inode_clean(ip))
- goto reclaim;
-
- /* Now we have an inode that needs flushing */
- error = xfs_iflush(ip, sync_mode);
- if (sync_mode & SYNC_WAIT) {
- xfs_iflock(ip);
- goto reclaim;
- }
-
- /*
- * When we have to flush an inode but don't have SYNC_WAIT set, we
- * flush the inode out using a delwri buffer and wait for the next
- * call into reclaim to find it in a clean state instead of waiting for
- * it now. We also don't return errors here - if the error is transient
- * then the next reclaim pass will flush the inode, and if the error
- * is permanent then the next sync reclaim will reclaim the inode and
- * pass on the error.
- */
- if (error && error != EAGAIN && !XFS_FORCED_SHUTDOWN(ip->i_mount)) {
- xfs_fs_cmn_err(CE_WARN, ip->i_mount,
- "inode 0x%llx background reclaim flush failed with %d",
- (long long)ip->i_ino, error);
- }
-out:
- xfs_iflags_clear(ip, XFS_IRECLAIM);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- /*
- * We could return EAGAIN here to make reclaim rescan the inode tree in
- * a short while. However, this just burns CPU time scanning the tree
- * waiting for IO to complete and xfssyncd never goes back to the idle
- * state. Instead, return 0 to let the next scheduled background reclaim
- * attempt to reclaim the inode again.
- */
- return 0;
-
-reclaim:
- xfs_ifunlock(ip);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
-
- XFS_STATS_INC(xs_ig_reclaims);
- /*
- * Remove the inode from the per-AG radix tree.
- *
- * Because radix_tree_delete won't complain even if the item was never
- * added to the tree assert that it's been there before to catch
- * problems with the inode life time early on.
- */
- spin_lock(&pag->pag_ici_lock);
- if (!radix_tree_delete(&pag->pag_ici_root,
- XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino)))
- ASSERT(0);
- __xfs_inode_clear_reclaim(pag, ip);
- spin_unlock(&pag->pag_ici_lock);
-
- /*
- * Here we do an (almost) spurious inode lock in order to coordinate
- * with inode cache radix tree lookups. This is because the lookup
- * can reference the inodes in the cache without taking references.
- *
- * We make that OK here by ensuring that we wait until the inode is
- * unlocked after the lookup before we go ahead and free it. We get
- * both the ilock and the iolock because the code may need to drop the
- * ilock one but will still hold the iolock.
- */
- xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
- xfs_qm_dqdetach(ip);
- xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
-
- xfs_inode_free(ip);
- return error;
-
-}
-
-/*
- * Walk the AGs and reclaim the inodes in them. Even if the filesystem is
- * corrupted, we still want to try to reclaim all the inodes. If we don't,
- * then a shut down during filesystem unmount reclaim walk leak all the
- * unreclaimed inodes.
- */
-int
-xfs_reclaim_inodes_ag(
- struct xfs_mount *mp,
- int flags,
- int *nr_to_scan)
-{
- struct xfs_perag *pag;
- int error = 0;
- int last_error = 0;
- xfs_agnumber_t ag;
- int trylock = flags & SYNC_TRYLOCK;
- int skipped;
-
-restart:
- ag = 0;
- skipped = 0;
- while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
- unsigned long first_index = 0;
- int done = 0;
- int nr_found = 0;
-
- ag = pag->pag_agno + 1;
-
- if (trylock) {
- if (!mutex_trylock(&pag->pag_ici_reclaim_lock)) {
- skipped++;
- xfs_perag_put(pag);
- continue;
- }
- first_index = pag->pag_ici_reclaim_cursor;
- } else
- mutex_lock(&pag->pag_ici_reclaim_lock);
-
- do {
- struct xfs_inode *batch[XFS_LOOKUP_BATCH];
- int i;
-
- rcu_read_lock();
- nr_found = radix_tree_gang_lookup_tag(
- &pag->pag_ici_root,
- (void **)batch, first_index,
- XFS_LOOKUP_BATCH,
- XFS_ICI_RECLAIM_TAG);
- if (!nr_found) {
- rcu_read_unlock();
- break;
- }
-
- /*
- * Grab the inodes before we drop the lock. if we found
- * nothing, nr == 0 and the loop will be skipped.
- */
- for (i = 0; i < nr_found; i++) {
- struct xfs_inode *ip = batch[i];
-
- if (done || xfs_reclaim_inode_grab(ip, flags))
- batch[i] = NULL;
-
- /*
- * Update the index for the next lookup. Catch
- * overflows into the next AG range which can
- * occur if we have inodes in the last block of
- * the AG and we are currently pointing to the
- * last inode.
- *
- * Because we may see inodes that are from the
- * wrong AG due to RCU freeing and
- * reallocation, only update the index if it
- * lies in this AG. It was a race that lead us
- * to see this inode, so another lookup from
- * the same index will not find it again.
- */
- if (XFS_INO_TO_AGNO(mp, ip->i_ino) !=
- pag->pag_agno)
- continue;
- first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
- if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
- done = 1;
- }
-
- /* unlock now we've grabbed the inodes. */
- rcu_read_unlock();
-
- for (i = 0; i < nr_found; i++) {
- if (!batch[i])
- continue;
- error = xfs_reclaim_inode(batch[i], pag, flags);
- if (error && last_error != EFSCORRUPTED)
- last_error = error;
- }
-
- *nr_to_scan -= XFS_LOOKUP_BATCH;
-
- } while (nr_found && !done && *nr_to_scan > 0);
-
- if (trylock && !done)
- pag->pag_ici_reclaim_cursor = first_index;
- else
- pag->pag_ici_reclaim_cursor = 0;
- mutex_unlock(&pag->pag_ici_reclaim_lock);
- xfs_perag_put(pag);
- }
-
- /*
- * if we skipped any AG, and we still have scan count remaining, do
- * another pass this time using blocking reclaim semantics (i.e
- * waiting on the reclaim locks and ignoring the reclaim cursors). This
- * ensure that when we get more reclaimers than AGs we block rather
- * than spin trying to execute reclaim.
- */
- if (trylock && skipped && *nr_to_scan > 0) {
- trylock = 0;
- goto restart;
- }
- return XFS_ERROR(last_error);
-}
-
-int
-xfs_reclaim_inodes(
- xfs_mount_t *mp,
- int mode)
-{
- int nr_to_scan = INT_MAX;
-
- return xfs_reclaim_inodes_ag(mp, mode, &nr_to_scan);
-}
-
-/*
- * Shrinker infrastructure.
- */
-static int
-xfs_reclaim_inode_shrink(
- struct shrinker *shrink,
- int nr_to_scan,
- gfp_t gfp_mask)
-{
- struct xfs_mount *mp;
- struct xfs_perag *pag;
- xfs_agnumber_t ag;
- int reclaimable;
-
- mp = container_of(shrink, struct xfs_mount, m_inode_shrink);
- if (nr_to_scan) {
- if (!(gfp_mask & __GFP_FS))
- return -1;
-
- xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK, &nr_to_scan);
- /* terminate if we don't exhaust the scan */
- if (nr_to_scan > 0)
- return -1;
- }
-
- reclaimable = 0;
- ag = 0;
- while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
- ag = pag->pag_agno + 1;
- reclaimable += pag->pag_ici_reclaimable;
- xfs_perag_put(pag);
- }
- return reclaimable;
-}
-
-void
-xfs_inode_shrinker_register(
- struct xfs_mount *mp)
-{
- mp->m_inode_shrink.shrink = xfs_reclaim_inode_shrink;
- mp->m_inode_shrink.seeks = DEFAULT_SEEKS;
- register_shrinker(&mp->m_inode_shrink);
-}
-
-void
-xfs_inode_shrinker_unregister(
- struct xfs_mount *mp)
-{
- unregister_shrinker(&mp->m_inode_shrink);
-}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 01:24:58 +0000