From: Dave Chinner dchinner@redhat.com
[ Upstream commit dc04db2aa7c9307e740d6d0e173085301c173b1a ]
To catch the obvious graph cycle problem and hence potential endless looping.
Signed-off-by: Dave Chinner dchinner@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Dave Chinner david@fromorbit.com Signed-off-by: Leah Rumancik leah.rumancik@gmail.com Acked-by: Darrick J. Wong djwong@kernel.org --- fs/xfs/libxfs/xfs_btree.c | 140 ++++++++++++++++++++++++++++---------- 1 file changed, 105 insertions(+), 35 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c index 298395481713..5bec048343b0 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -51,6 +51,52 @@ xfs_btree_magic( return magic; }
+static xfs_failaddr_t +xfs_btree_check_lblock_siblings( + struct xfs_mount *mp, + struct xfs_btree_cur *cur, + int level, + xfs_fsblock_t fsb, + xfs_fsblock_t sibling) +{ + if (sibling == NULLFSBLOCK) + return NULL; + if (sibling == fsb) + return __this_address; + if (level >= 0) { + if (!xfs_btree_check_lptr(cur, sibling, level + 1)) + return __this_address; + } else { + if (!xfs_verify_fsbno(mp, sibling)) + return __this_address; + } + + return NULL; +} + +static xfs_failaddr_t +xfs_btree_check_sblock_siblings( + struct xfs_mount *mp, + struct xfs_btree_cur *cur, + int level, + xfs_agnumber_t agno, + xfs_agblock_t agbno, + xfs_agblock_t sibling) +{ + if (sibling == NULLAGBLOCK) + return NULL; + if (sibling == agbno) + return __this_address; + if (level >= 0) { + if (!xfs_btree_check_sptr(cur, sibling, level + 1)) + return __this_address; + } else { + if (!xfs_verify_agbno(mp, agno, sibling)) + return __this_address; + } + return NULL; +} + /* * Check a long btree block header. Return the address of the failing check, * or NULL if everything is ok. @@ -65,6 +111,8 @@ __xfs_btree_check_lblock( struct xfs_mount *mp = cur->bc_mp; xfs_btnum_t btnum = cur->bc_btnum; int crc = xfs_has_crc(mp); + xfs_failaddr_t fa; + xfs_fsblock_t fsb = NULLFSBLOCK;
if (crc) { if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid)) @@ -83,16 +131,16 @@ __xfs_btree_check_lblock( if (be16_to_cpu(block->bb_numrecs) > cur->bc_ops->get_maxrecs(cur, level)) return __this_address; - if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) && - !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_leftsib), - level + 1)) - return __this_address; - if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) && - !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_rightsib), - level + 1)) - return __this_address;
- return NULL; + if (bp) + fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp)); + + fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb, + be64_to_cpu(block->bb_u.l.bb_leftsib)); + if (!fa) + fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb, + be64_to_cpu(block->bb_u.l.bb_rightsib)); + return fa; }
/* Check a long btree block header. */ @@ -130,6 +178,9 @@ __xfs_btree_check_sblock( struct xfs_mount *mp = cur->bc_mp; xfs_btnum_t btnum = cur->bc_btnum; int crc = xfs_has_crc(mp); + xfs_failaddr_t fa; + xfs_agblock_t agbno = NULLAGBLOCK; + xfs_agnumber_t agno = NULLAGNUMBER;
if (crc) { if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid)) @@ -146,16 +197,18 @@ __xfs_btree_check_sblock( if (be16_to_cpu(block->bb_numrecs) > cur->bc_ops->get_maxrecs(cur, level)) return __this_address; - if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) && - !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_leftsib), - level + 1)) - return __this_address; - if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) && - !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_rightsib), - level + 1)) - return __this_address;
- return NULL; + if (bp) { + agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp)); + agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp)); + } + + fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno, agbno, + be32_to_cpu(block->bb_u.s.bb_leftsib)); + if (!fa) + fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno, + agbno, be32_to_cpu(block->bb_u.s.bb_rightsib)); + return fa; }
/* Check a short btree block header. */ @@ -4265,6 +4318,21 @@ xfs_btree_visit_block( if (xfs_btree_ptr_is_null(cur, &rptr)) return -ENOENT;
+ /* + * We only visit blocks once in this walk, so we have to avoid the + * internal xfs_btree_lookup_get_block() optimisation where it will + * return the same block without checking if the right sibling points + * back to us and creates a cyclic reference in the btree. + */ + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { + if (be64_to_cpu(rptr.l) == XFS_DADDR_TO_FSB(cur->bc_mp, + xfs_buf_daddr(bp))) + return -EFSCORRUPTED; + } else { + if (be32_to_cpu(rptr.s) == xfs_daddr_to_agbno(cur->bc_mp, + xfs_buf_daddr(bp))) + return -EFSCORRUPTED; + } return xfs_btree_lookup_get_block(cur, level, &rptr, &block); }
@@ -4439,20 +4507,21 @@ xfs_btree_lblock_verify( { struct xfs_mount *mp = bp->b_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); + xfs_fsblock_t fsb; + xfs_failaddr_t fa;
/* numrecs verification */ if (be16_to_cpu(block->bb_numrecs) > max_recs) return __this_address;
/* sibling pointer verification */ - if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) && - !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_leftsib))) - return __this_address; - if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) && - !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_rightsib))) - return __this_address; - - return NULL; + fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp)); + fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb, + be64_to_cpu(block->bb_u.l.bb_leftsib)); + if (!fa) + fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb, + be64_to_cpu(block->bb_u.l.bb_rightsib)); + return fa; }
/** @@ -4493,7 +4562,9 @@ xfs_btree_sblock_verify( { struct xfs_mount *mp = bp->b_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); - xfs_agblock_t agno; + xfs_agnumber_t agno; + xfs_agblock_t agbno; + xfs_failaddr_t fa;
/* numrecs verification */ if (be16_to_cpu(block->bb_numrecs) > max_recs) @@ -4501,14 +4572,13 @@ xfs_btree_sblock_verify(
/* sibling pointer verification */ agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp)); - if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) && - !xfs_verify_agbno(mp, agno, be32_to_cpu(block->bb_u.s.bb_leftsib))) - return __this_address; - if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) && - !xfs_verify_agbno(mp, agno, be32_to_cpu(block->bb_u.s.bb_rightsib))) - return __this_address; - - return NULL; + agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp)); + fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno, + be32_to_cpu(block->bb_u.s.bb_leftsib)); + if (!fa) + fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno, + be32_to_cpu(block->bb_u.s.bb_rightsib)); + return fa; }
/*