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nfsd: Clean up drc cache in preparation for global spinlock elimination 

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Trond Myklebust 2014-08-06 13:44:20 -04:00 committed by J. Bruce Fields
parent f8d1ff47b6
commit 7142b98d9f
1 changed files with 24 additions and 21 deletions
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45
fs/nfsd/nfscache.c
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@ -27,7 +27,11 @@
*/
#define TARGET_BUCKET_SIZE 64
static struct hlist_head * cache_hash;
struct nfsd_drc_bucket {
struct hlist_head cache_hash;
};
static struct nfsd_drc_bucket *drc_hashtbl;
static struct list_head lru_head;
static struct kmem_cache *drc_slab;
@ -116,6 +120,12 @@ nfsd_hashsize(unsigned int limit)
return roundup_pow_of_two(limit / TARGET_BUCKET_SIZE);
}
static u32
nfsd_cache_hash(__be32 xid)
{
return hash_32(be32_to_cpu(xid), maskbits);
}
static struct svc_cacherep *
nfsd_reply_cache_alloc(void)
{
@ -170,8 +180,8 @@ int nfsd_reply_cache_init(void)
if (!drc_slab)
goto out_nomem;
cache_hash = kcalloc(hashsize, sizeof(struct hlist_head), GFP_KERNEL);
if (!cache_hash)
drc_hashtbl = kcalloc(hashsize, sizeof(*drc_hashtbl), GFP_KERNEL);
if (!drc_hashtbl)
goto out_nomem;
return 0;
@ -193,8 +203,8 @@ void nfsd_reply_cache_shutdown(void)
nfsd_reply_cache_free_locked(rp);
}
kfree (cache_hash);
cache_hash = NULL;
kfree (drc_hashtbl);
drc_hashtbl = NULL;
if (drc_slab) {
kmem_cache_destroy(drc_slab);
@ -218,15 +228,10 @@ lru_put_end(struct svc_cacherep *rp)
* Move a cache entry from one hash list to another
*/
static void
hash_refile(struct svc_cacherep *rp)
hash_refile(struct nfsd_drc_bucket *b, struct svc_cacherep *rp)
{
hlist_del_init(&rp->c_hash);
/*
* No point in byte swapping c_xid since we're just using it to pick
* a hash bucket.
*/
hlist_add_head(&rp->c_hash, cache_hash +
hash_32((__force u32)rp->c_xid, maskbits));
hlist_add_head(&rp->c_hash, &b->cache_hash);
}
/*
@ -355,17 +360,13 @@ nfsd_cache_match(struct svc_rqst *rqstp, __wsum csum, struct svc_cacherep *rp)
* NULL on failure.
*/
static struct svc_cacherep *
nfsd_cache_search(struct svc_rqst *rqstp, __wsum csum)
nfsd_cache_search(struct nfsd_drc_bucket *b, struct svc_rqst *rqstp,
__wsum csum)
{
struct svc_cacherep *rp, *ret = NULL;
struct hlist_head *rh;
struct hlist_head *rh = &b->cache_hash;
unsigned int entries = 0;
/*
* No point in byte swapping rq_xid since we're just using it to pick
* a hash bucket.
*/
rh = &cache_hash[hash_32((__force u32)rqstp->rq_xid, maskbits)];
hlist_for_each_entry(rp, rh, c_hash) {
++entries;
if (nfsd_cache_match(rqstp, csum, rp)) {
@ -403,6 +404,8 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
vers = rqstp->rq_vers,
proc = rqstp->rq_proc;
__wsum csum;
u32 hash = nfsd_cache_hash(xid);
struct nfsd_drc_bucket *b = &drc_hashtbl[hash];
unsigned long age;
int type = rqstp->rq_cachetype;
int rtn = RC_DOIT;
@ -429,7 +432,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
/* go ahead and prune the cache */
prune_cache_entries();
found = nfsd_cache_search(rqstp, csum);
found = nfsd_cache_search(b, rqstp, csum);
if (found) {
if (likely(rp))
nfsd_reply_cache_free_locked(rp);
@ -454,7 +457,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
rp->c_len = rqstp->rq_arg.len;
rp->c_csum = csum;
hash_refile(rp);
hash_refile(b, rp);
lru_put_end(rp);
/* release any buffer */