Commit d1a0774d authored by Jeff Layton's avatar Jeff Layton Committed by J. Bruce Fields
Browse files

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: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 25e6b8b0

fs/nfsd/cache.h

+3 −0
Original line number Diff line number Diff line
@@ -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 *);

fs/nfsd/nfscache.c

+8 −1
Original line number Diff line number Diff line
@@ -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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