dm writecache: correct uncommitted_block when discarding uncommitted entry

commit 39495b12ef1cf602e6abd350dce2ef4199906531 upstream.

When uncommitted entry has been discarded, correct wc->uncommitted_block
for getting the exact number.

Fixes: 48debafe4f2fe ("dm: add writecache target")
Cc: stable@vger.kernel.org
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 0d6ca72..64d75bb 100644 (file)
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -805,6 +805,8 @@ static void writecache_discard(struct dm_writecache *wc, sector_t start, sector_
                                writecache_wait_for_ios(wc, WRITE);
                                discarded_something = true;
                        }
+                       if (!writecache_entry_is_committed(wc, e))
+                               wc->uncommitted_blocks--;
                        writecache_free_entry(wc, e);
                }