From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2130.oracle.com ([156.151.31.86]:53936 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726800AbeJEHoA (ORCPT ); Fri, 5 Oct 2018 03:44:00 -0400 Subject: [PATCH 1/3] xfs: xrep_findroot_block should reject root blocks with siblings From: "Darrick J. Wong" Date: Thu, 04 Oct 2018 17:47:44 -0700 Message-ID: <153870046473.29695.7280792997309785336.stgit@magnolia> In-Reply-To: <153870045847.29695.10286947858219936840.stgit@magnolia> References: <153870045847.29695.10286947858219936840.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: david@fromorbit.com, darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org, Brian Foster From: Darrick J. Wong In xrep_findroot_block, if we find a candidate root block with sibling pointers or sibling blocks on the same tree level, we should not return that block as a tree root because root blocks cannot have siblings. Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster --- fs/xfs/scrub/repair.c | 61 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 48 insertions(+), 13 deletions(-) diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c index 9f08dd9bf1d5..63786341ac2a 100644 --- a/fs/xfs/scrub/repair.c +++ b/fs/xfs/scrub/repair.c @@ -692,12 +692,13 @@ xrep_findroot_block( struct xrep_find_ag_btree *fab, uint64_t owner, xfs_agblock_t agbno, - bool *found_it) + bool *done_with_block) { struct xfs_mount *mp = ri->sc->mp; struct xfs_buf *bp; struct xfs_btree_block *btblock; xfs_daddr_t daddr; + int block_level; int error; daddr = XFS_AGB_TO_DADDR(mp, ri->sc->sa.agno, agbno); @@ -735,18 +736,52 @@ xrep_findroot_block( goto out; bp->b_ops = fab->buf_ops; - /* Ignore this block if it's lower in the tree than we've seen. */ - if (fab->root != NULLAGBLOCK && - xfs_btree_get_level(btblock) < fab->height) - goto out; - /* Make sure we pass the verifiers. */ bp->b_ops->verify_read(bp); if (bp->b_error) goto out; - fab->root = agbno; - fab->height = xfs_btree_get_level(btblock) + 1; - *found_it = true; + + /* + * This block passes the magic/uuid and verifier tests for this btree + * type. We don't need the caller to try the other tree types. + */ + *done_with_block = true; + + /* + * Compare this btree block's level to the height of the current + * candidate root block. + * + * If the level matches the root we found previously, throw away both + * blocks because there can't be two candidate roots. + * + * If level is lower in the tree than the root we found previously, + * ignore this block. + */ + block_level = xfs_btree_get_level(btblock); + if (block_level + 1 == fab->height) { + fab->root = NULLAGBLOCK; + goto out; + } else if (block_level < fab->height) { + goto out; + } + + /* + * This is the highest block in the tree that we've found so far. + * Update the btree height to reflect what we've learned from this + * block. + */ + fab->height = block_level + 1; + + /* + * If this block doesn't have sibling pointers, then it's the new root + * block candidate. Otherwise, the root will be found farther up the + * tree. + */ + if (btblock->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) && + btblock->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK)) + fab->root = agbno; + else + fab->root = NULLAGBLOCK; trace_xrep_findroot_block(mp, ri->sc->sa.agno, agbno, be32_to_cpu(btblock->bb_magic), fab->height - 1); @@ -768,7 +803,7 @@ xrep_findroot_rmap( struct xrep_findroot *ri = priv; struct xrep_find_ag_btree *fab; xfs_agblock_t b; - bool found_it; + bool done; int error = 0; /* Ignore anything that isn't AG metadata. */ @@ -777,16 +812,16 @@ xrep_findroot_rmap( /* Otherwise scan each block + btree type. */ for (b = 0; b < rec->rm_blockcount; b++) { - found_it = false; + done = false; for (fab = ri->btree_info; fab->buf_ops; fab++) { if (rec->rm_owner != fab->rmap_owner) continue; error = xrep_findroot_block(ri, fab, rec->rm_owner, rec->rm_startblock + b, - &found_it); + &done); if (error) return error; - if (found_it) + if (done) break; } }