1 files changed, 11 insertions, 2 deletions

diff --git a/fs/xfs/xfs_sb.c b/fs/xfs/xfs_sb.c
index 13c7834b0e65..b7c9aea77f8f 100644
--- a/fs/xfs/xfs_sb.c
+++ b/fs/xfs/xfs_sb.c
@@ -588,6 +588,11 @@ xfs_sb_verify(
  * single bit error could clear the feature bit and unused parts of the
  * superblock are supposed to be zero. Hence a non-null crc field indicates that
  * we've potentially lost a feature bit and we should check it anyway.
+ *
+ * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
+ * last field in V4 secondary superblocks.  So for secondary superblocks,
+ * we are more forgiving, and ignore CRC failures if the primary doesn't
+ * indicate that the fs version is V5.
  */
 static void
 xfs_sb_read_verify(
@@ -608,8 +613,12 @@ xfs_sb_read_verify(
 
                 if (!xfs_verify_cksum(bp->b_addr, be16_to_cpu(dsb->sb_sectsize),
                                       offsetof(struct xfs_sb, sb_crc))) {
-                        error = EFSCORRUPTED;
-                        goto out_error;
+                        /* Only fail bad secondaries on a known V5 filesystem */
+                        if (bp->b_bn != XFS_SB_DADDR &&
+                            xfs_sb_version_hascrc(&mp->m_sb)) {
+                                error = EFSCORRUPTED;
+                                goto out_error;
+                        }
                 }
         }
         error = xfs_sb_verify(bp, true);