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authorJeff Layton <jlayton@redhat.com>2013-01-28 14:41:13 -0500
committerJ. Bruce Fields <bfields@redhat.com>2013-02-04 09:16:23 -0500
commitd1a0774de6cb908f5ba7806d09aaf86bb03fa182 (patch)
treebe9d6cc9f4bd3ce0c7f3da6665ced8f91e752258
parent25e6b8b0e1a247747db5275b1b6b362f5acf2245 (diff)
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op-kernel-dev-d1a0774de6cb908f5ba7806d09aaf86bb03fa182.tar.gz
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>
-rw-r--r--fs/nfsd/cache.h3
-rw-r--r--fs/nfsd/nfscache.c9
2 files changed, 11 insertions, 1 deletions
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 @@ enum {
*/
#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 @@ hash_refile(struct svc_cacherep *rp)
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 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
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++;
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