dm log: use flush callback fn

Call the flush callback from the log.

If flush failed, we have no alternative but to mark the whole log as dirty.
Also we set the variable flush_failed to prevent any bits ever being marked as
clean again.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 666a80e3602e07dcb8c312fd4d2081b707de11f1..315e36a96b6f47e46592b5d9578cd218aa01e9d9 100644 (file)
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -677,13 +677,26 @@ static int core_flush(struct dm_dirty_log *log)
 
 static int disk_flush(struct dm_dirty_log *log)
 {
-       int r;
-       struct log_c *lc = (struct log_c *) log->context;
+       int r, i;
+       struct log_c *lc = log->context;
 
        /* only write if the log has changed */
        if (!lc->touched_cleaned && !lc->touched_dirtied)
                return 0;
 
+       if (lc->touched_cleaned && log->flush_callback_fn &&
+           log->flush_callback_fn(lc->ti)) {
+               /*
+                * At this point it is impossible to determine which
+                * regions are clean and which are dirty (without
+                * re-reading the log off disk). So mark all of them
+                * dirty.
+                */
+               lc->flush_failed = 1;
+               for (i = 0; i < lc->region_count; i++)
+                       log_clear_bit(lc, lc->clean_bits, i);
+       }
+
        r = rw_header(lc, WRITE);
        if (r)
                fail_log_device(lc);