NFSD: Add nfsd_file_lru_dispose_list() helper

Refactor the invariant part of nfsd_file_lru_walk_list() into a
separate helper function.

Reviewed-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 27611aca16a4cd7fb9e6954990c6af96363cb739..af22d9e34db5f10a530c860e156ea880fe1fdc94 100644 (file)
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -451,11 +451,31 @@ out_skip:
        return LRU_SKIP;
 }
 
+/*
+ * Unhash items on @dispose immediately, then queue them on the
+ * disposal workqueue to finish releasing them in the background.
+ *
+ * cel: Note that between the time list_lru_shrink_walk runs and
+ * now, these items are in the hash table but marked unhashed.
+ * Why release these outside of lru_cb ? There's no lock ordering
+ * problem since lru_cb currently takes no lock.
+ */
+static void nfsd_file_gc_dispose_list(struct list_head *dispose)
+{
+       struct nfsd_file *nf;
+
+       list_for_each_entry(nf, dispose, nf_lru) {
+               spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
+               nfsd_file_do_unhash(nf);
+               spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
+       }
+       nfsd_file_dispose_list_delayed(dispose);
+}
+
 static unsigned long
 nfsd_file_lru_walk_list(struct shrink_control *sc)
 {
        LIST_HEAD(head);
-       struct nfsd_file *nf;
        unsigned long ret;
 
        if (sc)
@@ -465,12 +485,7 @@ nfsd_file_lru_walk_list(struct shrink_control *sc)
                ret = list_lru_walk(&nfsd_file_lru,
                                nfsd_file_lru_cb,
                                &head, LONG_MAX);
-       list_for_each_entry(nf, &head, nf_lru) {
-               spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
-               nfsd_file_do_unhash(nf);
-               spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
-       }
-       nfsd_file_dispose_list_delayed(&head);
+       nfsd_file_gc_dispose_list(&head);
        return ret;
 }