1 files changed, 31 insertions, 11 deletions

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 9ac8aa8dc38c..e7aa82faa3d5 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -1376,17 +1376,6 @@ xlog_find_tail(
         *tail_blk = BLOCK_LSN(be64_to_cpu(rhead->h_tail_lsn));
 
         /*
-         * Trim the head block back to skip over torn records. We can have
-         * multiple log I/Os in flight at any time, so we assume CRC failures
-         * back through the previous several records are torn writes and skip
-         * them.
-         */
-        error = xlog_verify_head(log, head_blk, tail_blk, bp, &rhead_blk,
-                                 &rhead, &wrapped);
-        if (error)
-                goto done;
-
-        /*
          * Set the log state based on the current head record.
          */
         xlog_set_state(log, *head_blk, rhead, rhead_blk, wrapped);
@@ -1402,6 +1391,37 @@ xlog_find_tail(
                 goto done;
 
         /*
+         * Verify the log head if the log is not clean (e.g., we have anything
+         * but an unmount record at the head). This uses CRC verification to
+         * detect and trim torn writes. If discovered, CRC failures are
+         * considered torn writes and the log head is trimmed accordingly.
+         *
+         * Note that we can only run CRC verification when the log is dirty
+         * because there's no guarantee that the log data behind an unmount
+         * record is compatible with the current architecture.
+         */
+        if (!clean) {
+                xfs_daddr_t     orig_head = *head_blk;
+
+                error = xlog_verify_head(log, head_blk, tail_blk, bp,
+                                         &rhead_blk, &rhead, &wrapped);
+                if (error)
+                        goto done;
+
+                /* update in-core state again if the head changed */
+                if (*head_blk != orig_head) {
+                        xlog_set_state(log, *head_blk, rhead, rhead_blk,
+                                       wrapped);
+                        tail_lsn = atomic64_read(&log->l_tail_lsn);
+                        error = xlog_check_unmount_rec(log, head_blk, tail_blk,
+                                                       rhead, rhead_blk, bp,
+                                                       &clean);
+                        if (error)
+                                goto done;
+                }
+        }
+
+        /*
          * Note that the unmount was clean. If the unmount was not clean, we
          * need to know this to rebuild the superblock counters from the perag
          * headers if we have a filesystem using non-persistent counters.