diff options
| -rw-r--r-- | fs/nfsd/nfscache.c | 41 |
1 files changed, 19 insertions, 22 deletions
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index ca05f6dc3544..c61391e8e09d 100644 --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -318,55 +318,53 @@ nfsd_cache_lookup(struct svc_rqst *rqstp) __wsum csum; unsigned long age; int type = rqstp->rq_cachetype; - int rtn; + int rtn = RC_DOIT; rqstp->rq_cacherep = NULL; if (type == RC_NOCACHE) { nfsdstats.rcnocache++; - return RC_DOIT; + return rtn; } csum = nfsd_cache_csum(rqstp); + /* + * Since the common case is a cache miss followed by an insert, + * preallocate an entry. First, try to reuse the first entry on the LRU + * if it works, then go ahead and prune the LRU list. + */ spin_lock(&cache_lock); - rtn = RC_DOIT; - - rp = nfsd_cache_search(rqstp, csum); - if (rp) - goto found_entry; - - /* Try to use the first entry on the LRU */ if (!list_empty(&lru_head)) { rp = list_first_entry(&lru_head, struct svc_cacherep, c_lru); if (nfsd_cache_entry_expired(rp) || num_drc_entries >= max_drc_entries) { lru_put_end(rp); prune_cache_entries(); - goto setup_entry; + goto search_cache; } } - /* Drop the lock and allocate a new entry */ + /* No expired ones available, allocate a new one. */ spin_unlock(&cache_lock); rp = nfsd_reply_cache_alloc(); - if (!rp) { - dprintk("nfsd: unable to allocate DRC entry!\n"); - return RC_DOIT; - } spin_lock(&cache_lock); - ++num_drc_entries; + if (likely(rp)) + ++num_drc_entries; - /* - * Must search again just in case someone inserted one - * after we dropped the lock above. - */ +search_cache: found = nfsd_cache_search(rqstp, csum); if (found) { - nfsd_reply_cache_free_locked(rp); + if (likely(rp)) + nfsd_reply_cache_free_locked(rp); rp = found; goto found_entry; } + if (!rp) { + dprintk("nfsd: unable to allocate DRC entry!\n"); + goto out; + } + /* * We're keeping the one we just allocated. Are we now over the * limit? Prune one off the tip of the LRU in trade for the one we @@ -376,7 +374,6 @@ nfsd_cache_lookup(struct svc_rqst *rqstp) nfsd_reply_cache_free_locked(list_first_entry(&lru_head, struct svc_cacherep, c_lru)); -setup_entry: nfsdstats.rcmisses++; rqstp->rq_cacherep = rp; rp->c_state = RC_INPROG; |