[PATCH v2] xfs_repair: handling a block with bad crc, bad uuid, and bad magic number needs fixing

[bodonnel@redhat.com]

From: Bill O'Donnell <bodonnel@redhat.com>

In certain cases, if a block is so messed up that crc, uuid and magic
number are all bad, we need to not only detect in phase3 but fix it
properly in phase6. In the current code, the mechanism doesn't work
in that it only pays attention to one of the parameters.

Note: in this case, the nlink inode link count drops to 1, but
re-running xfs_repair fixes it back to 2. This is a side effect that
should probably be handled in update_inode_nlinks() with separate patch.
Regardless, running xfs_repair twice fixes the issue. Also, this patch
fixes the issue with v5, but not v4 xfs.

Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>

v2: remove superfluous wantmagic logic

---
 repair/phase6.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/repair/phase6.c b/repair/phase6.c
index 4064a84b2450..9cffbb1f4510 100644
--- a/repair/phase6.c
+++ b/repair/phase6.c
@@ -2364,7 +2364,6 @@ longform_dir2_entry_check(
 	     da_bno = (xfs_dablk_t)next_da_bno) {
 		const struct xfs_buf_ops *ops;
 		int			 error;
-		struct xfs_dir2_data_hdr *d;
 
 		next_da_bno = da_bno + mp->m_dir_geo->fsbcount - 1;
 		if (bmap_next_offset(ip, &next_da_bno)) {
@@ -2404,9 +2403,7 @@ longform_dir2_entry_check(
 		}
 
 		/* check v5 metadata */
-		d = bp->b_addr;
-		if (be32_to_cpu(d->magic) == XFS_DIR3_BLOCK_MAGIC ||
-		    be32_to_cpu(d->magic) == XFS_DIR3_DATA_MAGIC) {
+		if (xfs_has_crc(mp)) {
 			error = check_dir3_header(mp, bp, ino);
 			if (error) {
 				fixit++;
-- 
2.48.1