From f71401617acd8fccb2461dcd03d8868f8c87c07b Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Tue, 20 Dec 2016 22:38:01 -0600 Subject: [PATCH] xfs_repair: junk leaf attribute if count == 0 We have recently seen a case where, during log replay, the attr3 leaf verifier reported corruption when encountering a leaf attribute with a count of 0 in the header. We chalked this up to a transient state when a shortform leaf was created, the attribute didn't fit, and we promoted the (empty) attribute to the larger leaf form. I've recently been given a metadump of unknown provenance which actually contains a leaf attribute with count 0 on disk. This causes the verifier to fire every time xfs_repair is run: Metadata corruption detected at xfs_attr3_leaf block 0x480988/0x1000 If this 0-count state is detected, we should just junk the leaf, same as we would do if the count was too high. With this change, we now remedy the problem: Metadata corruption detected at xfs_attr3_leaf block 0x480988/0x1000 bad attribute count 0 in attr block 0, inode 12587828 problem with attribute contents in inode 12587828 clearing inode 12587828 attributes correcting nblocks for inode 12587828, was 2 - counted 1 Signed-off-by: Eric Sandeen Reviewed-by: Brian Foster Signed-off-by: Eric Sandeen --- repair/attr_repair.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/repair/attr_repair.c b/repair/attr_repair.c index 40cb5f7f7..b855a1018 100644 --- a/repair/attr_repair.c +++ b/repair/attr_repair.c @@ -593,7 +593,8 @@ process_leaf_attr_block( stop = xfs_attr3_leaf_hdr_size(leaf); /* does the count look sorta valid? */ - if (leafhdr.count * sizeof(xfs_attr_leaf_entry_t) + stop > + if (!leafhdr.count || + leafhdr.count * sizeof(xfs_attr_leaf_entry_t) + stop > mp->m_sb.sb_blocksize) { do_warn( _("bad attribute count %d in attr block %u, inode %" PRIu64 "\n"), -- 2.47.2