diff options
Diffstat (limited to 'fs/nfsd/nfscache.c')
| -rw-r--r-- | fs/nfsd/nfscache.c | 33 |
1 files changed, 21 insertions, 12 deletions
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index 5bfc2ac60d54..4638635c5d87 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; |