From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 7F3017F50 for ; Tue, 3 Dec 2013 15:29:52 -0600 (CST) Received: from whiskey.americas.sgi.com (whiskey.americas.sgi.com [128.162.233.19]) by relay3.corp.sgi.com (Postfix) with ESMTP id 0656CAC002 for ; Tue, 3 Dec 2013 13:29:51 -0800 (PST) Date: Tue, 3 Dec 2013 15:29:51 -0600 From: Ben Myers Subject: [PATCH] xfs: reinstate the iolock in xfs_readdir Message-ID: <20131203212951.GP1935@sgi.com> MIME-Version: 1.0 Content-Disposition: inline List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Although it was removed in commit 051e7cd44ab8, ilock needs to be taken in xfs_readdir because we might have to read the extent list in from disk. This keeps other threads from reading from or writing to the extent list while it is being read in and is still in a transitional state. This has been associated with "Access to block zero" messages on directories with large numbers of extents resulting from excessive filesytem fragmentation, as well as extent list corruption. Unfortunately no test case at this point. Signed-off-by: Ben Myers --- fs/xfs/xfs_dir2_readdir.c | 4 ++++ 1 file changed, 4 insertions(+) Index: b/fs/xfs/xfs_dir2_readdir.c =================================================================== --- a/fs/xfs/xfs_dir2_readdir.c 2013-12-02 17:40:38.895185673 -0600 +++ b/fs/xfs/xfs_dir2_readdir.c 2013-12-02 17:40:49.025225554 -0600 @@ -674,6 +674,7 @@ xfs_readdir( { int rval; /* return value */ int v; /* type-checking value */ + uint lock_mode; trace_xfs_readdir(dp); @@ -683,6 +684,7 @@ xfs_readdir( ASSERT(S_ISDIR(dp->i_d.di_mode)); XFS_STATS_INC(xs_dir_getdents); + lock_mode = xfs_ilock_map_shared(dp); if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) rval = xfs_dir2_sf_getdents(dp, ctx); else if ((rval = xfs_dir2_isblock(NULL, dp, &v))) @@ -691,5 +693,7 @@ xfs_readdir( rval = xfs_dir2_block_getdents(dp, ctx); else rval = xfs_dir2_leaf_getdents(dp, ctx, bufsize); + xfs_iunlock_map_shared(dp, lock_mode); + return rval; } _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs