[PATCH 5.1 102/122] dm cache metadata: Fix loading discard bitset

Greg Kroah-Hartman
2019-05-23T19:31:04Z

From: Nikos Tsironis <ntsironis@arrikto.com>

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>

---
drivers/md/dm-cache-metadata.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -1167,11 +1167,18 @@ static int __load_discards(struct dm_cac
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);