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-rw-r--r--fs/nfsd/nfscache.c33
1 files changed, 21 insertions, 12 deletions
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 5bfc2ac..4638635 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -29,15 +29,24 @@
*/
#define CACHESIZE 1024
#define HASHSIZE 64
-#define REQHASH(xid) (((((__force __u32)xid) >> 24) ^ ((__force __u32)xid)) & (HASHSIZE-1))
-static struct hlist_head * hash_list;
+static struct hlist_head * cache_hash;
static struct list_head lru_head;
static int cache_disabled = 1;
+/*
+ * Calculate the hash index from an XID.
+ */
+static inline u32 request_hash(u32 xid)
+{
+ u32 h = xid;
+ h ^= (xid >> 24);
+ return h & (HASHSIZE-1);
+}
+
static int nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
-/*
+/*
* locking for the reply cache:
* A cache entry is "single use" if c_state == RC_INPROG
* Otherwise, it when accessing _prev or _next, the lock must be held.
@@ -62,8 +71,8 @@ int nfsd_reply_cache_init(void)
i--;
}
- hash_list = kcalloc (HASHSIZE, sizeof(struct hlist_head), GFP_KERNEL);
- if (!hash_list)
+ cache_hash = kcalloc (HASHSIZE, sizeof(struct hlist_head), GFP_KERNEL);
+ if (!cache_hash)
goto out_nomem;
cache_disabled = 0;
@@ -88,8 +97,8 @@ void nfsd_reply_cache_shutdown(void)
cache_disabled = 1;
- kfree (hash_list);
- hash_list = NULL;
+ kfree (cache_hash);
+ cache_hash = NULL;
}
/*
@@ -108,7 +117,7 @@ static void
hash_refile(struct svc_cacherep *rp)
{
hlist_del_init(&rp->c_hash);
- hlist_add_head(&rp->c_hash, hash_list + REQHASH(rp->c_xid));
+ hlist_add_head(&rp->c_hash, cache_hash + request_hash(rp->c_xid));
}
/*
@@ -138,7 +147,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp, int type)
spin_lock(&cache_lock);
rtn = RC_DOIT;
- rh = &hash_list[REQHASH(xid)];
+ rh = &cache_hash[request_hash(xid)];
hlist_for_each_entry(rp, hn, rh, c_hash) {
if (rp->c_state != RC_UNUSED &&
xid == rp->c_xid && proc == rp->c_proc &&
@@ -165,8 +174,8 @@ nfsd_cache_lookup(struct svc_rqst *rqstp, int type)
}
}
- /* This should not happen */
- if (rp == NULL) {
+ /* All entries on the LRU are in-progress. This should not happen */
+ if (&rp->c_lru == &lru_head) {
static int complaints;
printk(KERN_WARNING "nfsd: all repcache entries locked!\n");
@@ -264,7 +273,7 @@ nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
len = resv->iov_len - ((char*)statp - (char*)resv->iov_base);
len >>= 2;
-
+
/* Don't cache excessive amounts of data and XDR failures */
if (!statp || len > (256 >> 2)) {
rp->c_state = RC_UNUSED;
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