From: Ben Myers Date: Fri, 6 Dec 2013 20:30:11 +0000 (-0800) Subject: xfs: reinstate the ilock in xfs_readdir X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=40194ecc6d78327d98e66de3213db96ca0a31e6f;p=deliverable%2Flinux.git xfs: reinstate the ilock in xfs_readdir 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 Reviewed-by: Dave Chinner --- diff --git a/fs/xfs/xfs_dir2_readdir.c b/fs/xfs/xfs_dir2_readdir.c index c4e50c6ed584..aead369e1c30 100644 --- a/fs/xfs/xfs_dir2_readdir.c +++ b/fs/xfs/xfs_dir2_readdir.c @@ -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_data_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(dp, lock_mode); + return rval; }