[PATCH v6 4/4] nfsd: fix up the filecache laundrette scheduling

[Jeff Layton <jlayton@kernel.org>]

We don't really care whether there are hashed entries when it comes to
scheduling the laundrette. They might all be non-gc entries, after all.
We only want to schedule it if there are entries on the LRU.

Switch to using list_lru_count, and move the check into
nfsd_file_gc_worker. The other callsite in nfsd_file_put doesn't need to
count entries, since it only schedules the laundrette after adding an
entry to the LRU.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfsd/filecache.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index d8f9430d29e4..29b216b1d15c 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -211,12 +211,9 @@ static const struct rhashtable_params nfsd_file_rhash_params = {
 static void
 nfsd_file_schedule_laundrette(void)
 {
-	if ((atomic_read(&nfsd_file_rhash_tbl.nelems) == 0) ||
-	    test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags) == 0)
-		return;
-
-	queue_delayed_work(system_wq, &nfsd_filecache_laundrette,
-			NFSD_LAUNDRETTE_DELAY);
+	if (test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags))
+		queue_delayed_work(system_wq, &nfsd_filecache_laundrette,
+				   NFSD_LAUNDRETTE_DELAY);
 }
 
 static void
@@ -671,7 +668,8 @@ static void
 nfsd_file_gc_worker(struct work_struct *work)
 {
 	nfsd_file_gc();
-	nfsd_file_schedule_laundrette();
+	if (list_lru_count(&nfsd_file_lru))
+		nfsd_file_schedule_laundrette();
 }
 
 static unsigned long
-- 
2.38.1