diff options
author | Dave Chinner <dchinner@redhat.com> | 2012-10-08 21:56:09 +1100 |
---|---|---|
committer | Ben Myers <bpm@sgi.com> | 2012-10-17 13:40:09 -0500 |
commit | 6d8b79cfca39399ef9115fb65dde85993455c9a3 (patch) | |
tree | c4702e765ee5b3d10f496c42148e317d7ee98ed8 /fs/xfs/xfs_sync.c | |
parent | c75921a72a7c4bb73a5e09a697a672722e5543f1 (diff) | |
download | linux-6d8b79cfca39399ef9115fb65dde85993455c9a3.tar.bz2 |
xfs: rename xfs_sync.[ch] to xfs_icache.[ch]
xfs_sync.c now only contains inode reclaim functions and inode cache
iteration functions. It is not related to sync operations anymore.
Rename to xfs_icache.c to reflect it's contents and prepare for
consolidation with the other inode cache file that exists
(xfs_iget.c).
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_sync.c')
-rw-r--r-- | fs/xfs/xfs_sync.c | 714 |
1 files changed, 0 insertions, 714 deletions
diff --git a/fs/xfs/xfs_sync.c b/fs/xfs/xfs_sync.c deleted file mode 100644 index 7b630288bab5..000000000000 --- a/fs/xfs/xfs_sync.c +++ /dev/null @@ -1,714 +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_log.h" -#include "xfs_log_priv.h" -#include "xfs_inum.h" -#include "xfs_trans.h" -#include "xfs_trans_priv.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; - - cond_resched(); - - } 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); -} - -/* - * Queue a new inode reclaim pass if there are reclaimable inodes and there - * isn't a reclaim pass already in progress. By default it runs every 5s based - * on the xfs periodic sync default of 30s. Perhaps this should have it's own - * tunable, but that can be done if this method proves to be ineffective or too - * aggressive. - */ -static void -xfs_reclaim_work_queue( - struct xfs_mount *mp) -{ - - rcu_read_lock(); - if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) { - queue_delayed_work(mp->m_reclaim_workqueue, &mp->m_reclaim_work, - msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10)); - } - rcu_read_unlock(); -} - -/* - * This is a fast pass over the inode cache to try to get reclaim moving on as - * many inodes as possible in a short period of time. It kicks itself every few - * seconds, as well as being kicked by the inode cache shrinker when memory - * goes low. It scans as quickly as possible avoiding locked inodes or those - * already being flushed, and once done schedules a future pass. - */ -void -xfs_reclaim_worker( - struct work_struct *work) -{ - struct xfs_mount *mp = container_of(to_delayed_work(work), - struct xfs_mount, m_reclaim_work); - - xfs_reclaim_inodes(mp, SYNC_TRYLOCK); - xfs_reclaim_work_queue(mp); -} - -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); - - /* schedule periodic background inode reclaim */ - xfs_reclaim_work_queue(ip->i_mount); - - 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; - - /* - * If we are asked for non-blocking operation, do unlocked checks to - * see if the inode already is being flushed or in reclaim to avoid - * lock traffic. - */ - if ((flags & SYNC_TRYLOCK) && - __xfs_iflags_test(ip, XFS_IFLOCK | 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. The following - * table lists the inode states and the reclaim actions necessary: - * - * 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, async - requeue - * dirty, sync 0 reclaim - * - * (*) dgc: I don't think the clean, pinned state is possible but it gets - * handled anyway given the order of checks implemented. - * - * 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. - * - * Note that because the inode is flushed delayed write by AIL pushing, 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 the AIL first before trying to reclaim inodes to - * minimise the amount of time spent waiting. For background relaim, we only - * bother to reclaim clean inodes anyway. - * - * Hence the order of actions after gaining the locks should be: - * bad => reclaim - * shutdown => unpin and reclaim - * pinned, async => requeue - * pinned, sync => unpin - * stale => reclaim - * clean => reclaim - * dirty, async => requeue - * dirty, sync => flush, wait and reclaim - */ -STATIC int -xfs_reclaim_inode( - struct xfs_inode *ip, - struct xfs_perag *pag, - int sync_mode) -{ - struct xfs_buf *bp = NULL; - int error; - -restart: - 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); - xfs_iflush_abort(ip, false); - goto reclaim; - } - if (xfs_ipincount(ip)) { - if (!(sync_mode & SYNC_WAIT)) - goto out_ifunlock; - xfs_iunpin_wait(ip); - } - if (xfs_iflags_test(ip, XFS_ISTALE)) - goto reclaim; - if (xfs_inode_clean(ip)) - goto reclaim; - - /* - * Never flush out dirty data during non-blocking reclaim, as it would - * just contend with AIL pushing trying to do the same job. - */ - if (!(sync_mode & SYNC_WAIT)) - goto out_ifunlock; - - /* - * Now we have an inode that needs flushing. - * - * Note that xfs_iflush will never block on the inode buffer lock, as - * xfs_ifree_cluster() can lock the inode buffer before it locks the - * ip->i_lock, and we are doing the exact opposite here. As a result, - * doing a blocking xfs_imap_to_bp() to get the cluster buffer would - * result in an ABBA deadlock with xfs_ifree_cluster(). - * - * As xfs_ifree_cluser() must gather all inodes that are active in the - * cache to mark them stale, if we hit this case we don't actually want - * to do IO here - we want the inode marked stale so we can simply - * reclaim it. Hence if we get an EAGAIN error here, just unlock the - * inode, back off and try again. Hopefully the next pass through will - * see the stale flag set on the inode. - */ - error = xfs_iflush(ip, &bp); - if (error == EAGAIN) { - xfs_iunlock(ip, XFS_ILOCK_EXCL); - /* backoff longer than in xfs_ifree_cluster */ - delay(2); - goto restart; - } - - if (!error) { - error = xfs_bwrite(bp); - xfs_buf_relse(bp); - } - - xfs_iflock(ip); -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. - */ - xfs_ilock(ip, XFS_ILOCK_EXCL); - xfs_qm_dqdetach(ip); - xfs_iunlock(ip, XFS_ILOCK_EXCL); - - xfs_inode_free(ip); - return error; - -out_ifunlock: - xfs_ifunlock(ip); -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 the reclaim work 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; -} - -/* - * 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) { - done = 1; - 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; - - cond_resched(); - - } 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 (skipped && (flags & SYNC_WAIT) && *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); -} - -/* - * Scan a certain number of inodes for reclaim. - * - * When called we make sure that there is a background (fast) inode reclaim in - * progress, while we will throttle the speed of reclaim via doing synchronous - * reclaim of inodes. That means if we come across dirty inodes, we wait for - * them to be cleaned, which we hope will not be very long due to the - * background walker having already kicked the IO off on those dirty inodes. - */ -void -xfs_reclaim_inodes_nr( - struct xfs_mount *mp, - int nr_to_scan) -{ - /* kick background reclaimer and push the AIL */ - xfs_reclaim_work_queue(mp); - xfs_ail_push_all(mp->m_ail); - - xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan); -} - -/* - * Return the number of reclaimable inodes in the filesystem for - * the shrinker to determine how much to reclaim. - */ -int -xfs_reclaim_inodes_count( - struct xfs_mount *mp) -{ - struct xfs_perag *pag; - xfs_agnumber_t ag = 0; - int reclaimable = 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; -} - |