[v2,02/31] NFSD: Report filecache LRU size

Commit Message

Chuck Lever June 28, 2022, 6:05 p.m. UTC

Surface the NFSD filecache's LRU list length to help field
troubleshooters monitor filecache issues.

Signed-off-by: Chuck Lever <[e-mail]>
---
 fs/nfsd/filecache.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Patch

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 9cb2d590c036..a0234d194ec1 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -1068,7 +1068,7 @@  nfsd_file_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 static int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
 {
 	unsigned int i, count = 0, longest = 0;
-	unsigned long hits = 0;
+	unsigned long lru = 0, hits = 0;
 
 	/*
 	 * No need for spinlocks here since we're not terribly interested in
@@ -1081,6 +1081,7 @@  static int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
 			count += nfsd_file_hashtbl[i].nfb_count;
 			longest = max(longest, nfsd_file_hashtbl[i].nfb_count);
 		}
+		lru = list_lru_count(&nfsd_file_lru);
 	}
 	mutex_unlock(&nfsd_mutex);
 
@@ -1089,6 +1090,7 @@  static int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
 
 	seq_printf(m, "total entries: %u\n", count);
 	seq_printf(m, "longest chain: %u\n", longest);
+	seq_printf(m, "lru entries:   %lu\n", lru);
 	seq_printf(m, "cache hits:    %lu\n", hits);
 	return 0;
 }