[PATCH 5.4 109/168] dm writecache: verify watermark during resume

Greg Kroah-Hartman
2020-03-10T12:53:35Z

From: Mikulas Patocka <mpatocka@redhat.com>

commit 41c526c5af46d4c4dab7f72c99000b7fac0b9702 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/md/dm-writecache.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -625,6 +625,12 @@ static void writecache_add_to_freelist(s
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)
{
struct wc_entry *e;
@@ -646,8 +652,8 @@ static struct wc_entry *writecache_pop_f
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;
}
@@ -961,6 +967,8 @@ erase_this:
writecache_commit_flushed(wc, false);
}

+ writecache_verify_watermark(wc);
+
wc_unlock(wc);
}