From ee58abdfcc8201f500107c7ba03f738af8b49b85 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Thu, 21 Apr 2011 09:34:26 +0000 Subject: xfs: avoid getting stuck during async inode flushes When the underlying inode buffer is locked and xfs_sync_inode_attr() is doing a non-blocking flush, xfs_iflush() can return EAGAIN. When this happens, clear the error rather than returning it to xfs_inode_ag_walk(), as returning EAGAIN will result in the AG walk delaying for a short while and trying again. This can result in background walks getting stuck on the one AG until inode buffer is unlocked by some other means. This behaviour was noticed when analysing event traces followed by code inspection and verification of the fix via further traces. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Alex Elder --- fs/xfs/linux-2.6/xfs_sync.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'fs/xfs/linux-2.6/xfs_sync.c') diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c index 3e898a48122d..cb1bb2080e44 100644 --- a/fs/xfs/linux-2.6/xfs_sync.c +++ b/fs/xfs/linux-2.6/xfs_sync.c @@ -267,6 +267,16 @@ xfs_sync_inode_attr( error = xfs_iflush(ip, flags); + /* + * We don't want to try again on non-blocking flushes that can't run + * again immediately. If an inode really must be written, then that's + * what the SYNC_WAIT flag is for. + */ + if (error == EAGAIN) { + ASSERT(!(flags & SYNC_WAIT)); + error = 0; + } + out_unlock: xfs_iunlock(ip, XFS_ILOCK_SHARED); return error; -- cgit v1.2.3-59-g8ed1b