dm cache metadata: Fix loading discard bitset

commit e28adc3bf34e434b30e8d063df4823ba0f3e0529 upstream.

Add missing dm_bitset_cursor_next() to properly advance the bitset
cursor.

Otherwise, the discarded state of all blocks is set according to the
discarded state of the first block.

Fixes: ae4a46a1f6 ("dm cache metadata: use bitset cursor api to load discard bitset")
Cc: stable@vger.kernel.org
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 6fc9383..151aa95 100644 (file)
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -1167,11 +1167,18 @@ static int __load_discards(struct dm_cache_metadata *cmd,
                if (r)
                        return r;
 
-               for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
+               for (b = 0; ; b++) {
                        r = fn(context, cmd->discard_block_size, to_dblock(b),
                               dm_bitset_cursor_get_value(&c));
                        if (r)
                                break;
+
+                       if (b >= (from_dblock(cmd->discard_nr_blocks) - 1))
+                               break;
+
+                       r = dm_bitset_cursor_next(&c);
+                       if (r)
+                               break;
                }
 
                dm_bitset_cursor_end(&c);