dm writecache: verify watermark during resume

Verify the watermark upon resume - so that if the target is reloaded
with lower watermark, it will start the cleanup process immediately.

Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # 4.18+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 8d45c848cbe46ef93e904bc35d301378450e2810..d692d2a00745e44d04366f5ecc9ab2d0b767b994 100644 (file)
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -625,6 +625,12 @@ static void writecache_add_to_freelist(struct dm_writecache *wc, struct wc_entry
        wc->freelist_size++;
 }
 
+static inline void writecache_verify_watermark(struct dm_writecache *wc)
+{
+       if (unlikely(wc->freelist_size + wc->writeback_size <= wc->freelist_high_watermark))
+               queue_work(wc->writeback_wq, &wc->writeback_work);
+}
+
 static struct wc_entry *writecache_pop_from_freelist(struct dm_writecache *wc, sector_t expected_sector)
 {
        struct wc_entry *e;
@@ -650,8 +656,8 @@ static struct wc_entry *writecache_pop_from_freelist(struct dm_writecache *wc, s
                list_del(&e->lru);
        }
        wc->freelist_size--;
-       if (unlikely(wc->freelist_size + wc->writeback_size <= wc->freelist_high_watermark))
-               queue_work(wc->writeback_wq, &wc->writeback_work);
+
+       writecache_verify_watermark(wc);
 
        return e;
 }
@@ -965,6 +971,8 @@ erase_this:
                writecache_commit_flushed(wc, false);
        }
 
+       writecache_verify_watermark(wc);
+
        wc_unlock(wc);
 }