[PATCH 06/11] xfs_repair: check v5 filesystem attr block header sanity

Darrick J. Wong
2015-08-26T00:33:03Z

Check the v5 fields (uuid, blocknr, owner) of attribute blocks for
obvious errors while scanning xattr blocks. If the ownership info
is incorrect, kill the block.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
repair/attr_repair.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)

diff --git a/repair/attr_repair.c b/repair/attr_repair.c
index c2b7c3a..8d03161 100644
--- a/repair/attr_repair.c
+++ b/repair/attr_repair.c
@@ -1508,6 +1508,44 @@ process_node_attr(
return (process_leaf_attr_level(mp, &da_cursor));
}

+/* check v5 metadata */
+static int
+__check_attr_header(
+ struct xfs_mount *mp,
+ struct xfs_buf *bp,
+ xfs_ino_t ino)
+{
+ struct xfs_da3_blkinfo *info = bp->b_addr;
+
+ if (info->hdr.magic != cpu_to_be16(XFS_ATTR3_LEAF_MAGIC) &&
+ info->hdr.magic != cpu_to_be16(XFS_DA3_NODE_MAGIC))
+ return 0;
+
+ /* verify owner */
+ if (be64_to_cpu(info->owner) != ino) {
+ do_warn(
+_("expected owner inode %" PRIu64 ", got %llu, attr block %" PRIu64 "\n"),
+ ino, be64_to_cpu(info->owner), bp->b_bn);
+ return 1;
+ }
+ /* verify block number */
+ if (be64_to_cpu(info->blkno) != bp->b_bn) {
+ do_warn(
+_("expected block %" PRIu64 ", got %llu, inode %" PRIu64 "attr block\n"),
+ bp->b_bn, be64_to_cpu(info->blkno), ino);
+ return 1;
+ }
+ /* verify uuid */
+ if (platform_uuid_compare(&info->uuid, &mp->m_sb.sb_meta_uuid) != 0) {
+ do_warn(
+_("wrong FS UUID, inode %" PRIu64 " attr block %" PRIu64 "\n"),
+ ino, bp->b_bn);
+ return 1;
+ }
+
+ return 0;
+}
+
/*
* Start processing for a leaf or fuller btree.
* A leaf directory is one where the attribute fork is too big for
@@ -1564,6 +1602,13 @@ process_longform_attr(
if (bp->b_error == -EFSBADCRC)
(*repair)++;

+ /* is this block sane? */
+ if (__check_attr_header(mp, bp, ino)) {
+ *repair = 0;
+ libxfs_putbuf(bp);
+ return 1;
+ }
+
/* verify leaf block */
leaf = (xfs_attr_leafblock_t *)XFS_BUF_PTR(bp);
xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);