diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfsd/nfscache.c | 94 |
1 files changed, 44 insertions, 50 deletions
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index cef4686f87ef..527ce4c65765 100644 --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -121,7 +121,7 @@ nfsd_cache_hash(__be32 xid) } static struct svc_cacherep * -nfsd_reply_cache_alloc(void) +nfsd_reply_cache_alloc(struct svc_rqst *rqstp, __wsum csum) { struct svc_cacherep *rp; @@ -130,6 +130,16 @@ nfsd_reply_cache_alloc(void) rp->c_state = RC_UNUSED; rp->c_type = RC_NOCACHE; INIT_LIST_HEAD(&rp->c_lru); + + rp->c_xid = rqstp->rq_xid; + rp->c_proc = rqstp->rq_proc; + memset(&rp->c_addr, 0, sizeof(rp->c_addr)); + rpc_copy_addr((struct sockaddr *)&rp->c_addr, svc_addr(rqstp)); + rpc_set_port((struct sockaddr *)&rp->c_addr, rpc_get_port(svc_addr(rqstp))); + rp->c_prot = rqstp->rq_prot; + rp->c_vers = rqstp->rq_vers; + rp->c_len = rqstp->rq_arg.len; + rp->c_csum = csum; } return rp; } @@ -141,9 +151,11 @@ nfsd_reply_cache_free_locked(struct svc_cacherep *rp) drc_mem_usage -= rp->c_replvec.iov_len; kfree(rp->c_replvec.iov_base); } - list_del(&rp->c_lru); - atomic_dec(&num_drc_entries); - drc_mem_usage -= sizeof(*rp); + if (rp->c_state != RC_UNUSED) { + list_del(&rp->c_lru); + atomic_dec(&num_drc_entries); + drc_mem_usage -= sizeof(*rp); + } kmem_cache_free(drc_slab, rp); } @@ -319,24 +331,23 @@ nfsd_cache_csum(struct svc_rqst *rqstp) } static bool -nfsd_cache_match(struct svc_rqst *rqstp, __wsum csum, struct svc_cacherep *rp) +nfsd_cache_match(const struct svc_cacherep *key, const struct svc_cacherep *rp) { /* Check RPC XID first */ - if (rqstp->rq_xid != rp->c_xid) + if (key->c_xid != rp->c_xid) return false; /* compare checksum of NFS data */ - if (csum != rp->c_csum) { + if (key->c_csum != rp->c_csum) { ++payload_misses; return false; } /* Other discriminators */ - if (rqstp->rq_proc != rp->c_proc || - rqstp->rq_prot != rp->c_prot || - rqstp->rq_vers != rp->c_vers || - rqstp->rq_arg.len != rp->c_len || - !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)) + if (key->c_proc != rp->c_proc || + key->c_prot != rp->c_prot || + key->c_vers != rp->c_vers || + key->c_len != rp->c_len || + memcmp(&key->c_addr, &rp->c_addr, sizeof(key->c_addr)) != 0) return false; return true; @@ -345,19 +356,18 @@ nfsd_cache_match(struct svc_rqst *rqstp, __wsum csum, struct svc_cacherep *rp) /* * Search the request hash for an entry that matches the given rqstp. * Must be called with cache_lock held. Returns the found entry or - * NULL on failure. + * inserts an empty key on failure. */ static struct svc_cacherep * -nfsd_cache_search(struct nfsd_drc_bucket *b, struct svc_rqst *rqstp, - __wsum csum) +nfsd_cache_insert(struct nfsd_drc_bucket *b, struct svc_cacherep *key) { - struct svc_cacherep *rp, *ret = NULL; + struct svc_cacherep *rp, *ret = key; struct list_head *rh = &b->lru_head; unsigned int entries = 0; list_for_each_entry(rp, rh, c_lru) { ++entries; - if (nfsd_cache_match(rqstp, csum, rp)) { + if (nfsd_cache_match(key, rp)) { ret = rp; break; } @@ -374,6 +384,7 @@ nfsd_cache_search(struct nfsd_drc_bucket *b, struct svc_rqst *rqstp, atomic_read(&num_drc_entries)); } + lru_put_end(b, ret); return ret; } @@ -389,9 +400,6 @@ nfsd_cache_lookup(struct svc_rqst *rqstp) { struct svc_cacherep *rp, *found; __be32 xid = rqstp->rq_xid; - u32 proto = rqstp->rq_prot, - vers = rqstp->rq_vers, - proc = rqstp->rq_proc; __wsum csum; u32 hash = nfsd_cache_hash(xid); struct nfsd_drc_bucket *b = &drc_hashtbl[hash]; @@ -410,52 +418,38 @@ nfsd_cache_lookup(struct svc_rqst *rqstp) * Since the common case is a cache miss followed by an insert, * preallocate an entry. */ - rp = nfsd_reply_cache_alloc(); - spin_lock(&b->cache_lock); - if (likely(rp)) { - atomic_inc(&num_drc_entries); - drc_mem_usage += sizeof(*rp); + rp = nfsd_reply_cache_alloc(rqstp, csum); + if (!rp) { + dprintk("nfsd: unable to allocate DRC entry!\n"); + return rtn; } - /* go ahead and prune the cache */ - prune_bucket(b); - - found = nfsd_cache_search(b, rqstp, csum); - if (found) { - if (likely(rp)) - nfsd_reply_cache_free_locked(rp); + spin_lock(&b->cache_lock); + found = nfsd_cache_insert(b, rp); + if (found != rp) { + nfsd_reply_cache_free_locked(rp); rp = found; goto found_entry; } - if (!rp) { - dprintk("nfsd: unable to allocate DRC entry!\n"); - goto out; - } - nfsdstats.rcmisses++; rqstp->rq_cacherep = rp; rp->c_state = RC_INPROG; - rp->c_xid = xid; - rp->c_proc = proc; - rpc_copy_addr((struct sockaddr *)&rp->c_addr, svc_addr(rqstp)); - rpc_set_port((struct sockaddr *)&rp->c_addr, rpc_get_port(svc_addr(rqstp))); - rp->c_prot = proto; - rp->c_vers = vers; - rp->c_len = rqstp->rq_arg.len; - rp->c_csum = csum; - lru_put_end(b, rp); + atomic_inc(&num_drc_entries); + drc_mem_usage += sizeof(*rp); + + /* go ahead and prune the cache */ + prune_bucket(b); out: spin_unlock(&b->cache_lock); return rtn; found_entry: - nfsdstats.rchits++; /* We found a matching entry which is either in progress or done. */ - lru_put_end(b, rp); - + nfsdstats.rchits++; rtn = RC_DROPIT; + /* Request being processed */ if (rp->c_state == RC_INPROG) goto out; |