nfsd: fix up the filecache laundrette scheduling

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>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 1418bc889aa0855c6affc216eff8e5d59453c74c..da7c9cb12403d1959d7f4e4865652cf9efb6dbf9 100644 (file)
--- 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
@@ -666,7 +663,8 @@ 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