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-rw-r--r--fs/nfsd/nfscache.c29
1 files changed, 19 insertions, 10 deletions
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 5bfc2ac60d54..6f0aa4989c61 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -29,15 +29,24 @@
29 */ 29 */
30#define CACHESIZE 1024 30#define CACHESIZE 1024
31#define HASHSIZE 64 31#define HASHSIZE 64
32#define REQHASH(xid) (((((__force __u32)xid) >> 24) ^ ((__force __u32)xid)) & (HASHSIZE-1))
33 32
34static struct hlist_head * hash_list; 33static struct hlist_head * cache_hash;
35static struct list_head lru_head; 34static struct list_head lru_head;
36static int cache_disabled = 1; 35static int cache_disabled = 1;
37 36
37/*
38 * Calculate the hash index from an XID.
39 */
40static inline u32 request_hash(u32 xid)
41{
42 u32 h = xid;
43 h ^= (xid >> 24);
44 return h & (HASHSIZE-1);
45}
46
38static int nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec); 47static int nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
39 48
40/* 49/*
41 * locking for the reply cache: 50 * locking for the reply cache:
42 * A cache entry is "single use" if c_state == RC_INPROG 51 * A cache entry is "single use" if c_state == RC_INPROG
43 * Otherwise, it when accessing _prev or _next, the lock must be held. 52 * Otherwise, it when accessing _prev or _next, the lock must be held.
@@ -62,8 +71,8 @@ int nfsd_reply_cache_init(void)
62 i--; 71 i--;
63 } 72 }
64 73
65 hash_list = kcalloc (HASHSIZE, sizeof(struct hlist_head), GFP_KERNEL); 74 cache_hash = kcalloc (HASHSIZE, sizeof(struct hlist_head), GFP_KERNEL);
66 if (!hash_list) 75 if (!cache_hash)
67 goto out_nomem; 76 goto out_nomem;
68 77
69 cache_disabled = 0; 78 cache_disabled = 0;
@@ -88,8 +97,8 @@ void nfsd_reply_cache_shutdown(void)
88 97
89 cache_disabled = 1; 98 cache_disabled = 1;
90 99
91 kfree (hash_list); 100 kfree (cache_hash);
92 hash_list = NULL; 101 cache_hash = NULL;
93} 102}
94 103
95/* 104/*
@@ -108,7 +117,7 @@ static void
108hash_refile(struct svc_cacherep *rp) 117hash_refile(struct svc_cacherep *rp)
109{ 118{
110 hlist_del_init(&rp->c_hash); 119 hlist_del_init(&rp->c_hash);
111 hlist_add_head(&rp->c_hash, hash_list + REQHASH(rp->c_xid)); 120 hlist_add_head(&rp->c_hash, cache_hash + request_hash(rp->c_xid));
112} 121}
113 122
114/* 123/*
@@ -138,7 +147,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp, int type)
138 spin_lock(&cache_lock); 147 spin_lock(&cache_lock);
139 rtn = RC_DOIT; 148 rtn = RC_DOIT;
140 149
141 rh = &hash_list[REQHASH(xid)]; 150 rh = &cache_hash[request_hash(xid)];
142 hlist_for_each_entry(rp, hn, rh, c_hash) { 151 hlist_for_each_entry(rp, hn, rh, c_hash) {
143 if (rp->c_state != RC_UNUSED && 152 if (rp->c_state != RC_UNUSED &&
144 xid == rp->c_xid && proc == rp->c_proc && 153 xid == rp->c_xid && proc == rp->c_proc &&
@@ -264,7 +273,7 @@ nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
264 273
265 len = resv->iov_len - ((char*)statp - (char*)resv->iov_base); 274 len = resv->iov_len - ((char*)statp - (char*)resv->iov_base);
266 len >>= 2; 275 len >>= 2;
267 276
268 /* Don't cache excessive amounts of data and XDR failures */ 277 /* Don't cache excessive amounts of data and XDR failures */
269 if (!statp || len > (256 >> 2)) { 278 if (!statp || len > (256 >> 2)) {
270 rp->c_state = RC_UNUSED; 279 rp->c_state = RC_UNUSED;