[PATCH v2 01/16] xfs_repair: fix missing dir buffer corruption checks

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Darrick J. Wong <darrick.wong@oracle.com>

The da_read_buf() function operates in "salvage" mode, which means that
if the verifiers fail, it will return a buffer with b_error set.  The
callers of da_read_buf, however, do not adequately check for verifier
errors, which means that repair can fail to flag a corrupt filesystem.

Fix the callers to do this properly.  The dabtree block walker and the
dabtree path checker functions to complain any time the da node / leafn
verifiers fail.  Fix the directory block walking functions to complain
about EFSCORRUPTED, since they already dealt with EFSBADCRC.

Found by running xfs/496 against lhdr.stale = middlebit.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
v2: check for corruption before checking magics; expand corruption
checks to other da_read_buf callers
---
 repair/da_util.c |   25 ++++++++++++++++---------
 repair/dir2.c    |   21 +++++++++++++++++++++
 2 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/repair/da_util.c b/repair/da_util.c
index 5061880f..7239c2e2 100644
--- a/repair/da_util.c
+++ b/repair/da_util.c
@@ -134,6 +134,15 @@ _("can't read %s block %u for inode %" PRIu64 "\n"),
 			goto error_out;
 		}
 
+		/* corrupt leafn/node; rebuild the dir. */
+		if (bp->b_error == -EFSBADCRC || bp->b_error == -EFSCORRUPTED) {
+			do_warn(
+_("corrupt %s tree block %u for inode %" PRIu64 "\n"),
+				FORKNAME(whichfork), bno, da_cursor->ino);
+			libxfs_buf_relse(bp);
+			goto error_out;
+		}
+
 		node = bp->b_addr;
 		libxfs_da3_node_hdr_from_disk(mp, &nodehdr, node);
 
@@ -160,15 +169,6 @@ _("bad %s magic number 0x%x in inode %" PRIu64 " bno = %u\n"),
 			goto error_out;
 		}
 
-		/* corrupt node; rebuild the dir. */
-		if (bp->b_error == -EFSBADCRC || bp->b_error == -EFSCORRUPTED) {
-			libxfs_buf_relse(bp);
-			do_warn(
-_("corrupt %s tree block %u for inode %" PRIu64 "\n"),
-				FORKNAME(whichfork), bno, da_cursor->ino);
-			goto error_out;
-		}
-
 		if (nodehdr.count > geo->node_ents) {
 			do_warn(
 _("bad %s record count in inode %" PRIu64 ", count = %d, max = %d\n"),
@@ -562,6 +562,13 @@ _("can't read %s block %u for inode %" PRIu64 "\n"),
 				FORKNAME(whichfork), dabno, cursor->ino);
 			return 1;
 		}
+		if (bp->b_error == -EFSCORRUPTED || bp->b_error == -EFSBADCRC) {
+			do_warn(
+_("corrupt %s tree block %u for inode %" PRIu64 "\n"),
+				FORKNAME(whichfork), dabno, cursor->ino);
+			libxfs_buf_relse(bp);
+			return 1;
+		}
 
 		newnode = bp->b_addr;
 		libxfs_da3_node_hdr_from_disk(mp, &nodehdr, newnode);
diff --git a/repair/dir2.c b/repair/dir2.c
index cbbce601..b374bc7b 100644
--- a/repair/dir2.c
+++ b/repair/dir2.c
@@ -983,6 +983,13 @@ _("can't read block %u for directory inode %" PRIu64 "\n"),
 			mp->m_dir_geo->datablk, ino);
 		return 1;
 	}
+	if (bp->b_error == -EFSCORRUPTED) {
+		do_warn(
+_("corrupt directory block %u for inode %" PRIu64 "\n"),
+			mp->m_dir_geo->datablk, ino);
+		libxfs_buf_relse(bp);
+		return 1;
+	}
 	/*
 	 * Verify the block
 	 */
@@ -1122,6 +1129,13 @@ _("can't read file block %u for directory inode %" PRIu64 "\n"),
 				da_bno, ino);
 			goto error_out;
 		}
+		if (bp->b_error == -EFSCORRUPTED) {
+			do_warn(
+_("corrupt directory leafn block %u for inode %" PRIu64 "\n"),
+				da_bno, ino);
+			libxfs_buf_relse(bp);
+			goto error_out;
+		}
 		leaf = bp->b_addr;
 		libxfs_dir2_leaf_hdr_from_disk(mp, &leafhdr, leaf);
 		/*
@@ -1324,6 +1338,13 @@ _("can't read block %" PRIu64 " for directory inode %" PRIu64 "\n"),
 				dbno, ino);
 			continue;
 		}
+		if (bp->b_error == -EFSCORRUPTED) {
+			do_warn(
+_("corrupt directory data block %lu for inode %" PRIu64 "\n"),
+				dbno, ino);
+			libxfs_buf_relse(bp);
+			continue;
+		}
 		data = bp->b_addr;
 		if (!(be32_to_cpu(data->magic) == XFS_DIR2_DATA_MAGIC ||
 		      be32_to_cpu(data->magic) == XFS_DIR3_DATA_MAGIC))