[PATCH v2 1/8] nfsd: always move DRC entries to the end of LRU list when updating timestamp

Jeff Layton
2013-02-04T13:18:15Z

...otherwise, we end up with the list ordering wrong. Currently, it's
not a problem since we skip RC_INPROG entries, but keeping the ordering
strict will be necessary for a later patch that adds a cache cleaner.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
fs/nfsd/nfscache.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index b89e7c8..9d80dfa 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -129,6 +129,7 @@ void nfsd_reply_cache_shutdown(void)
static void
lru_put_end(struct svc_cacherep *rp)
{
+ rp->c_timestamp = jiffies;
list_move_tail(&rp->c_lru, &lru_head);
}

@@ -245,9 +246,9 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
rpc_set_port((struct sockaddr *)&rp->c_addr, rpc_get_port(svc_addr(rqstp)));
rp->c_prot = proto;
rp->c_vers = vers;
- rp->c_timestamp = jiffies;

hash_refile(rp);
+ lru_put_end(rp);

/* release any buffer */
if (rp->c_type == RC_REPLBUFF) {
@@ -262,7 +263,6 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
found_entry:
/* We found a matching entry which is either in progress or done. */
age = jiffies - rp->c_timestamp;
- rp->c_timestamp = jiffies;
lru_put_end(rp);

rtn = RC_DROPIT;
@@ -354,7 +354,6 @@ nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
rp->c_secure = rqstp->rq_secure;
rp->c_type = cachetype;
rp->c_state = RC_DONE;
- rp->c_timestamp = jiffies;
spin_unlock(&cache_lock);
return;
}
--
1.7.11.7