| /* |
| * 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_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> |
| |
| struct workqueue_struct *xfs_syncd_wq; /* sync workqueue */ |
| |
| /* |
| * 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); |
| } |
| |
| 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)) |
| return 0; |
| |
| if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) { |
| if (flags & SYNC_TRYLOCK) |
| return 0; |
| 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); |
| 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; |
| } |
| |
| STATIC int |
| xfs_sync_fsdata( |
| struct xfs_mount *mp) |
| { |
| struct xfs_buf *bp; |
| int error; |
| |
| /* |
| * 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); |
| error = xfs_bwrite(bp); |
| xfs_buf_relse(bp); |
| return error; |
| } |
| |
| /* |
| * 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 emptying the AIL |
| * because it'll just get dirty again. |
| */ |
| int |
| xfs_quiesce_data( |
| struct xfs_mount *mp) |
| { |
| int error, error2 = 0; |
| |
| /* force out the log */ |
| xfs_log_force(mp, XFS_LOG_SYNC); |
| |
| /* write superblock and hoover up shutdown errors */ |
| error = xfs_sync_fsdata(mp); |
| |
| /* mark the log as covered if needed */ |
| if (xfs_log_need_covered(mp)) |
| error2 = xfs_fs_log_dummy(mp); |
| |
| return error ? error : error2; |
| } |
| |
| /* |
| * 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 proceeding. |
| */ |
| 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); |
| |
| /* reclaim inodes to do any IO before the freeze completes */ |
| xfs_reclaim_inodes(mp, 0); |
| xfs_reclaim_inodes(mp, SYNC_WAIT); |
| |
| /* flush all pending changes from the AIL */ |
| xfs_ail_push_all_sync(mp->m_ail); |
| |
| /* |
| * 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); |
| if (error) |
| xfs_warn(mp, "xfs_attr_quiesce: failed to log sb changes. " |
| "Frozen image may not be consistent."); |
| xfs_log_unmount_write(mp); |
| |
| /* |
| * At this point we might have modified the superblock again and thus |
| * added an item to the AIL, thus flush it again. |
| */ |
| xfs_ail_push_all_sync(mp->m_ail); |
| } |
| |
| static void |
| xfs_syncd_queue_sync( |
| struct xfs_mount *mp) |
| { |
| queue_delayed_work(xfs_syncd_wq, &mp->m_sync_work, |
| msecs_to_jiffies(xfs_syncd_centisecs * 10)); |
| } |
| |
| /* |
| * 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 work_struct *work) |
| { |
| struct xfs_mount *mp = container_of(to_delayed_work(work), |
| struct xfs_mount, m_sync_work); |
| int error; |
| |
| /* |
| * We shouldn't write/force the log if we are in the mount/unmount |
| * process or on a read only filesystem. The workqueue still needs to be |
| * active in both cases, however, because it is used for inode reclaim |
| * during these times. hence use the MS_ACTIVE flag to avoid doing |
| * anything in these periods. |
| */ |
| if (!(mp->m_super->s_flags & MS_ACTIVE) && |
| !(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); |
| |
| /* start pushing all the metadata that is currently dirty */ |
| xfs_ail_push_all(mp->m_ail); |
| } |
| |
| /* queue us up again */ |
| xfs_syncd_queue_sync(mp); |
| } |
| |
| /* |
| * 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 syncd work 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_syncd_queue_reclaim( |
| struct xfs_mount *mp) |
| { |
| |
| rcu_read_lock(); |
| if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) { |
| queue_delayed_work(xfs_syncd_wq, &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. |
| */ |
| STATIC 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_syncd_queue_reclaim(mp); |
| } |
| |
| /* |
| * 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. |
| * |
| * Queue a new data flush if there isn't one already in progress and |
| * wait for completion of the flush. This means that we only ever have one |
| * inode flush in progress no matter how many ENOSPC events are occurring and |
| * so will prevent the system from bogging down due to every concurrent |
| * ENOSPC event scanning all the active inodes in the system for writeback. |
| */ |
| void |
| xfs_flush_inodes( |
| struct xfs_inode *ip) |
| { |
| struct xfs_mount *mp = ip->i_mount; |
| |
| queue_work(xfs_syncd_wq, &mp->m_flush_work); |
| flush_work_sync(&mp->m_flush_work); |
| } |
| |
| STATIC void |
| xfs_flush_worker( |
| struct work_struct *work) |
| { |
| struct xfs_mount *mp = container_of(work, |
| struct xfs_mount, m_flush_work); |
| |
| xfs_sync_data(mp, SYNC_TRYLOCK); |
| xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT); |
| } |
| |
| int |
| xfs_syncd_init( |
| struct xfs_mount *mp) |
| { |
| INIT_WORK(&mp->m_flush_work, xfs_flush_worker); |
| INIT_DELAYED_WORK(&mp->m_sync_work, xfs_sync_worker); |
| INIT_DELAYED_WORK(&mp->m_reclaim_work, xfs_reclaim_worker); |
| |
| xfs_syncd_queue_sync(mp); |
| |
| return 0; |
| } |
| |
| void |
| xfs_syncd_stop( |
| struct xfs_mount *mp) |
| { |
| cancel_delayed_work_sync(&mp->m_sync_work); |
| cancel_delayed_work_sync(&mp->m_reclaim_work); |
| cancel_work_sync(&mp->m_flush_work); |
| } |
| |
| 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_syncd_queue_reclaim(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); |
| 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_itobp() 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 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; |
| } |
| |
| /* |
| * 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_syncd_queue_reclaim(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; |
| } |
| |