diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_sync.c')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_sync.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c index 6c10f1d..594cd82 100644 --- a/fs/xfs/linux-2.6/xfs_sync.c +++ b/fs/xfs/linux-2.6/xfs_sync.c @@ -761,8 +761,10 @@ xfs_reclaim_inode( struct xfs_perag *pag, int sync_mode) { - int error = 0; + int error; +restart: + error = 0; xfs_ilock(ip, XFS_ILOCK_EXCL); if (!xfs_iflock_nowait(ip)) { if (!(sync_mode & SYNC_WAIT)) @@ -788,9 +790,31 @@ xfs_reclaim_inode( if (xfs_inode_clean(ip)) goto reclaim; - /* Now we have an inode that needs flushing */ - error = xfs_iflush(ip, sync_mode); + /* + * Now we have an inode that needs flushing. + * + * We do a nonblocking flush here even if we are doing a SYNC_WAIT + * reclaim as we can deadlock with inode cluster removal. + * 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 will 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 on a SYNC_WAIT flush, + * 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, SYNC_TRYLOCK | sync_mode); if (sync_mode & SYNC_WAIT) { + if (error == EAGAIN) { + xfs_iunlock(ip, XFS_ILOCK_EXCL); + /* backoff longer than in xfs_ifree_cluster */ + delay(2); + goto restart; + } xfs_iflock(ip); goto reclaim; } |