nfsd: clean up and clarify the cache expiration code
Add a preprocessor constant for the expiry time of cache entries, and
move the test for an expired entry into a function. Note that the current
code does not test for RC_INPROG. It just assumes that it won't take more
than 2 minutes to fill out an in-progress entry.
I'm not sure how valid that assumption is though, so let's just ensure
that we never consider an RC_INPROG entry to be expired.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/cache.h b/fs/nfsd/cache.h
index f8c6df8..9c7232b 100644
--- a/fs/nfsd/cache.h
+++ b/fs/nfsd/cache.h
@@ -70,6 +70,9 @@
*/
#define RC_DELAY (HZ/5)
+/* Cache entries expire after this time period */
+#define RC_EXPIRE (120 * HZ)
+
int nfsd_reply_cache_init(void);
void nfsd_reply_cache_shutdown(void);
int nfsd_cache_lookup(struct svc_rqst *);
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 2cdc4be..634b856 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -142,6 +142,13 @@
hlist_add_head(&rp->c_hash, cache_hash + request_hash(rp->c_xid));
}
+static inline bool
+nfsd_cache_entry_expired(struct svc_cacherep *rp)
+{
+ return rp->c_state != RC_INPROG &&
+ time_after(jiffies, rp->c_timestamp + RC_EXPIRE);
+}
+
/*
* Try to find an entry matching the current call in the cache. When none
* is found, we grab the oldest unlocked entry off the LRU list.
@@ -175,7 +182,7 @@
if (rp->c_state != RC_UNUSED &&
xid == rp->c_xid && proc == rp->c_proc &&
proto == rp->c_prot && vers == rp->c_vers &&
- time_before(jiffies, rp->c_timestamp + 120*HZ) &&
+ !nfsd_cache_entry_expired(rp) &&
rpc_cmp_addr(svc_addr(rqstp), (struct sockaddr *)&rp->c_addr) &&
rpc_get_port(svc_addr(rqstp)) == rpc_get_port((struct sockaddr *)&rp->c_addr)) {
nfsdstats.rchits++;