ext4/jbd2: Avoid WARN() messages when failing to write to the superblock

This fixes some very common warnings reported by kerneloops.org

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 25 insertions, 2 deletions

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 81186a29742e..01c3901c3a07 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1255,6 +1255,22 @@ void jbd2_journal_update_superblock(journal_t *journal, int wait)
                 goto out;
         }
 
+        if (buffer_write_io_error(bh)) {
+                /*
+                 * Oh, dear.  A previous attempt to write the journal
+                 * superblock failed.  This could happen because the
+                 * USB device was yanked out.  Or it could happen to
+                 * be a transient write error and maybe the block will
+                 * be remapped.  Nothing we can do but to retry the
+                 * write and hope for the best.
+                 */
+                printk(KERN_ERR "JBD2: previous I/O error detected "
+                       "for journal superblock update for %s.\n",
+                       journal->j_devname);
+                clear_buffer_write_io_error(bh);
+                set_buffer_uptodate(bh);
+        }
+
         spin_lock(&journal->j_state_lock);
         jbd_debug(1,"JBD: updating superblock (start %ld, seq %d, errno %d)\n",
                   journal->j_tail, journal->j_tail_sequence, journal->j_errno);
@@ -1266,9 +1282,16 @@ void jbd2_journal_update_superblock(journal_t *journal, int wait)
 
         BUFFER_TRACE(bh, "marking dirty");
         mark_buffer_dirty(bh);
-        if (wait)
+        if (wait) {
                 sync_dirty_buffer(bh);
-        else
+                if (buffer_write_io_error(bh)) {
+                        printk(KERN_ERR "JBD2: I/O error detected "
+                               "when updating journal superblock for %s.\n",
+                               journal->j_devname);
+                        clear_buffer_write_io_error(bh);
+                        set_buffer_uptodate(bh);
+                }
+        } else
                 ll_rw_block(SWRITE, 1, &bh);
 
 out: