From: Darrick J. Wong Date: Wed, 12 Dec 2018 17:42:40 +0000 (-0600) Subject: xfs_repair: rebuild directory when non-root leafn blocks claim block 0 X-Git-Tag: v4.20.0-rc1~26 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3d2195e4ae45c142be8ec4600d44f23e31cf0cf2;p=thirdparty%2Fxfsprogs-dev.git xfs_repair: rebuild directory when non-root leafn blocks claim block 0 As explained in 71a6af8 Revert "xfs_repair: treat zero da btree pointers as corruption" a single root LEAFN block can exist in a directory until it grows further. This is why, normally, we skip directories with a root marked XFS_DIR2_LEAFN_MAGIC, as detected by the left-most leaf block being found at file block 0. However, if we traversed any level of a btree to get here (as indicated by da_cursor.active > 0), then a leaf block claiming block 0 indicates corruption, and we should handle it as such, and rebuild the directory. This was found by repair repeatedly rebuilding a directory containing a single leafn block (xfs/495). Fixes: 67a79e2cc932 ("xfs_repair: treat zero da btree pointers as corruption") Reported-by: Dave Chinner Signed-off-by: Darrick J. Wong [sandeen: clarify commit log, refer to revert commit] Reviewed-by: Eric Sandeen Signed-off-by: Eric Sandeen --- diff --git a/repair/dir2.c b/repair/dir2.c index ba5763ed3..e67ec590c 100644 --- a/repair/dir2.c +++ b/repair/dir2.c @@ -1243,10 +1243,21 @@ process_node_dir2( /* * Skip directories with a root marked XFS_DIR2_LEAFN_MAGIC + * + * Be careful here: If any level of the da cursor was filled out then + * the directory has a da btree containing an invalid before pointer to + * dblock 0, and we should move on to rebuilding the directory. If no + * levels in the da cursor got filled out, then we just have a single + * leafn block and we're done. */ if (bno == 0) { - release_da_cursor(mp, &da_cursor, 0); - return 0; + if (da_cursor.active > 0) { + err_release_da_cursor(mp, &da_cursor, 0); + return 1; + } else { + release_da_cursor(mp, &da_cursor, 0); + return 0; + } } else { /* * Now pass cursor and bno into leaf-block processing routine.