[PATCH] knfsd: Convert sunrpc_cache to use krefs

.. it makes some of the code nicer.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

8 files changed, 72 insertions, 84 deletions

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index abd68965822f..cc811a1094cb 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -57,18 +57,17 @@ static int		exp_verify_string(char *cp, int max);
 #define EXPKEY_HASHMASK         (EXPKEY_HASHMAX -1)
 static struct cache_head *expkey_table[EXPKEY_HASHMAX];
 
-void expkey_put(struct cache_head *item, struct cache_detail *cd)
+void expkey_put(struct kref *ref)
 {
-        if (cache_put(item, cd)) {
-                struct svc_expkey *key = container_of(item, struct svc_expkey, h);
-                if (test_bit(CACHE_VALID, &item->flags) &&
-                    !test_bit(CACHE_NEGATIVE, &item->flags)) {
-                        dput(key->ek_dentry);
-                        mntput(key->ek_mnt);
-                }
-                auth_domain_put(key->ek_client);
-                kfree(key);
+        struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
+
+        if (test_bit(CACHE_VALID, &key->h.flags) &&
+            !test_bit(CACHE_NEGATIVE, &key->h.flags)) {
+                dput(key->ek_dentry);
+                mntput(key->ek_mnt);
         }
+        auth_domain_put(key->ek_client);
+        kfree(key);
 }
 
 static void expkey_request(struct cache_detail *cd,
@@ -158,7 +157,7 @@ static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
                 set_bit(CACHE_NEGATIVE, &key.h.flags);
                 ek = svc_expkey_update(&key, ek);
                 if (ek)
-                        expkey_put(&ek->h, &svc_expkey_cache);
+                        cache_put(&ek->h, &svc_expkey_cache);
                 else err = -ENOMEM;
         } else {
                 struct nameidata nd;
@@ -172,7 +171,7 @@ static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
                 
                 ek = svc_expkey_update(&key, ek);
                 if (ek)
-                        expkey_put(&ek->h, &svc_expkey_cache);
+                        cache_put(&ek->h, &svc_expkey_cache);
                 else
                         err = -ENOMEM;
                 path_release(&nd);
@@ -318,15 +317,13 @@ svc_expkey_update(struct svc_expkey *new, struct svc_expkey *old)
 
 static struct cache_head *export_table[EXPORT_HASHMAX];
 
-void svc_export_put(struct cache_head *item, struct cache_detail *cd)
+static void svc_export_put(struct kref *ref)
 {
-        if (cache_put(item, cd)) {
-                struct svc_export *exp = container_of(item, struct svc_export, h);
-                dput(exp->ex_dentry);
-                mntput(exp->ex_mnt);
-                auth_domain_put(exp->ex_client);
-                kfree(exp);
-        }
+        struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
+        dput(exp->ex_dentry);
+        mntput(exp->ex_mnt);
+        auth_domain_put(exp->ex_client);
+        kfree(exp);
 }
 
 static void svc_export_request(struct cache_detail *cd,
@@ -633,7 +630,7 @@ static int exp_set_key(svc_client *clp, int fsid_type, u32 *fsidv,
         if (ek)
                 ek = svc_expkey_update(&key,ek);
         if (ek) {
-                expkey_put(&ek->h, &svc_expkey_cache);
+                cache_put(&ek->h, &svc_expkey_cache);
                 return 0;
         }
         return -ENOMEM;
@@ -762,7 +759,7 @@ static void exp_fsid_unhash(struct svc_export *exp)
         ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid);
         if (ek && !IS_ERR(ek)) {
                 ek->h.expiry_time = get_seconds()-1;
-                expkey_put(&ek->h, &svc_expkey_cache);
+                cache_put(&ek->h, &svc_expkey_cache);
         }
         svc_expkey_cache.nextcheck = get_seconds();
 }
@@ -800,7 +797,7 @@ static void exp_unhash(struct svc_export *exp)
         ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);
         if (ek && !IS_ERR(ek)) {
                 ek->h.expiry_time = get_seconds()-1;
-                expkey_put(&ek->h, &svc_expkey_cache);
+                cache_put(&ek->h, &svc_expkey_cache);
         }
         svc_expkey_cache.nextcheck = get_seconds();
 }
@@ -902,7 +899,7 @@ finish:
         if (exp)
                 exp_put(exp);
         if (fsid_key && !IS_ERR(fsid_key))
-                expkey_put(&fsid_key->h, &svc_expkey_cache);
+                cache_put(&fsid_key->h, &svc_expkey_cache);
         if (clp)
                 auth_domain_put(clp);
         path_release(&nd);
@@ -1030,7 +1027,7 @@ exp_find(struct auth_domain *clp, int fsid_type, u32 *fsidv,
                 return ERR_PTR(PTR_ERR(ek));
 
         exp = exp_get_by_name(clp, ek->ek_mnt, ek->ek_dentry, reqp);
-        expkey_put(&ek->h, &svc_expkey_cache);
+        cache_put(&ek->h, &svc_expkey_cache);
 
         if (!exp || IS_ERR(exp))
                 return ERR_PTR(PTR_ERR(exp));
@@ -1068,7 +1065,7 @@ exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp,
         else
                 rv = fh_compose(fhp, exp,
                                 fsid_key->ek_dentry, NULL);
-        expkey_put(&fsid_key->h, &svc_expkey_cache);
+        cache_put(&fsid_key->h, &svc_expkey_cache);
         return rv;
 }
 
@@ -1187,7 +1184,7 @@ static int e_show(struct seq_file *m, void *p)
         cache_get(&exp->h);
         if (cache_check(&svc_export_cache, &exp->h, NULL))
                 return 0;
-        if (cache_put(&exp->h, &svc_export_cache)) BUG();
+        cache_put(&exp->h, &svc_export_cache);
         return svc_export_show(m, &svc_export_cache, cp);
 }
 
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index 75cfbb68b205..4b6aa60dfceb 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -96,12 +96,10 @@ ent_init(struct cache_head *cnew, struct cache_head *citm)
 }
 
 static void
-ent_put(struct cache_head *ch, struct cache_detail *cd)
+ent_put(struct kref *ref)
 {
-        if (cache_put(ch, cd)) {
-                struct ent *map = container_of(ch, struct ent, h);
-                kfree(map);
-        }
+        struct ent *map = container_of(ref, struct ent, h.ref);
+        kfree(map);
 }
 
 static struct cache_head *
@@ -270,7 +268,7 @@ idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
         if (res == NULL)
                 goto out;
 
-        ent_put(&res->h, &idtoname_cache);
+        cache_put(&res->h, &idtoname_cache);
 
         error = 0;
 out:
@@ -433,7 +431,7 @@ nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
         if (res == NULL)
                 goto out;
 
-        ent_put(&res->h, &nametoid_cache);
+        cache_put(&res->h, &nametoid_cache);
         error = 0;
 out:
         kfree(buf1);
@@ -562,7 +560,7 @@ do_idmap_lookup_nowait(struct ent *(*lookup_fn)(struct ent *),
                 goto out_put;
         return 0;
 out_put:
-        ent_put(&(*item)->h, detail);
+        cache_put(&(*item)->h, detail);
 out_err:
         *item = NULL;
         return ret;
@@ -613,7 +611,7 @@ idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen
         if (ret)
                 return ret;
         *id = item->id;
-        ent_put(&item->h, &nametoid_cache);
+        cache_put(&item->h, &nametoid_cache);
         return 0;
 }
 
@@ -635,7 +633,7 @@ idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
         ret = strlen(item->name);
         BUG_ON(ret > IDMAP_NAMESZ);
         memcpy(name, item->name, ret);
-        ent_put(&item->h, &idtoname_cache);
+        cache_put(&item->h, &idtoname_cache);
         return ret;
 }
 
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 7a3e397b4ed3..3f2ec2e6d06c 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -506,7 +506,7 @@ fh_put(struct svc_fh *fhp)
                 nfsd_nr_put++;
         }
         if (exp) {
-                svc_export_put(&exp->h, &svc_export_cache);
+                cache_put(&exp->h, &svc_export_cache);
                 fhp->fh_export = NULL;
         }
         return;
diff --git a/include/linux/nfsd/export.h b/include/linux/nfsd/export.h
index d52e0b7ad37b..a6c08a47b25c 100644
--- a/include/linux/nfsd/export.h
+++ b/include/linux/nfsd/export.h
@@ -102,13 +102,11 @@ int			exp_rootfh(struct auth_domain *,
 int                     exp_pseudoroot(struct auth_domain *, struct svc_fh *fhp, struct cache_req *creq);
 int                     nfserrno(int errno);
 
-extern void expkey_put(struct cache_head *item, struct cache_detail *cd);
-extern void svc_export_put(struct cache_head *item, struct cache_detail *cd);
 extern struct cache_detail svc_export_cache, svc_expkey_cache;
 
 static inline void exp_put(struct svc_export *exp)
 {
-        svc_export_put(&exp->h, &svc_export_cache);
+        cache_put(&exp->h, &svc_export_cache);
 }
 
 static inline void exp_get(struct svc_export *exp)
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index a37fead1873b..ad3f5cbdb770 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -50,7 +50,7 @@ struct cache_head {
         time_t          last_refresh;   /* If CACHE_PENDING, this is when upcall 
                                          * was sent, else this is when update was received
                                          */
-        atomic_t        refcnt;
+        struct kref     ref;
         unsigned long   flags;
 };
 #define CACHE_VALID     0       /* Entry contains valid data */
@@ -68,8 +68,7 @@ struct cache_detail {
         atomic_t                inuse; /* active user-space update or lookup */
 
         char                    *name;
-        void                    (*cache_put)(struct cache_head *,
-                                             struct cache_detail*);
+        void                    (*cache_put)(struct kref *);
 
         void                    (*cache_request)(struct cache_detail *cd,
                                                  struct cache_head *h,
@@ -151,17 +150,17 @@ extern void cache_clean_deferred(void *owner);
 
 static inline struct cache_head  *cache_get(struct cache_head *h)
 {
-        atomic_inc(&h->refcnt);
+        kref_get(&h->ref);
         return h;
 }
 
 
-static inline int cache_put(struct cache_head *h, struct cache_detail *cd)
+static inline void cache_put(struct cache_head *h, struct cache_detail *cd)
 {
-        if (atomic_read(&h->refcnt) <= 2 &&
+        if (atomic_read(&h->ref.refcount) <= 2 &&
             h->expiry_time < cd->nextcheck)
                 cd->nextcheck = h->expiry_time;
-        return atomic_dec_and_test(&h->refcnt);
+        kref_put(&h->ref, cd->cache_put);
 }
 
 extern void cache_init(struct cache_head *h);
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 380152603d1e..4d7eb9e704da 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -89,13 +89,11 @@ static void rsi_free(struct rsi *rsii)
         kfree(rsii->out_token.data);
 }
 
-static void rsi_put(struct cache_head *item, struct cache_detail *cd)
+static void rsi_put(struct kref *ref)
 {
-        struct rsi *rsii = container_of(item, struct rsi, h);
-        if (cache_put(item, cd)) {
-                rsi_free(rsii);
-                kfree(rsii);
-        }
+        struct rsi *rsii = container_of(ref, struct rsi, h.ref);
+        rsi_free(rsii);
+        kfree(rsii);
 }
 
 static inline int rsi_hash(struct rsi *item)
@@ -267,7 +265,7 @@ static int rsi_parse(struct cache_detail *cd,
 out:
         rsi_free(&rsii);
         if (rsip)
-                rsi_put(&rsip->h, &rsi_cache);
+                cache_put(&rsip->h, &rsi_cache);
         else
                 status = -ENOMEM;
         return status;
@@ -357,14 +355,12 @@ static void rsc_free(struct rsc *rsci)
                 put_group_info(rsci->cred.cr_group_info);
 }
 
-static void rsc_put(struct cache_head *item, struct cache_detail *cd)
+static void rsc_put(struct kref *ref)
 {
-        struct rsc *rsci = container_of(item, struct rsc, h);
+        struct rsc *rsci = container_of(ref, struct rsc, h.ref);
 
-        if (cache_put(item, cd)) {
-                rsc_free(rsci);
-                kfree(rsci);
-        }
+        rsc_free(rsci);
+        kfree(rsci);
 }
 
 static inline int
@@ -509,7 +505,7 @@ static int rsc_parse(struct cache_detail *cd,
 out:
         rsc_free(&rsci);
         if (rscp)
-                rsc_put(&rscp->h, &rsc_cache);
+                cache_put(&rscp->h, &rsc_cache);
         else
                 status = -ENOMEM;
         return status;
@@ -1076,7 +1072,7 @@ drop:
         ret = SVC_DROP;
 out:
         if (rsci)
-                rsc_put(&rsci->h, &rsc_cache);
+                cache_put(&rsci->h, &rsc_cache);
         return ret;
 }
 
@@ -1168,7 +1164,7 @@ out_err:
                 put_group_info(rqstp->rq_cred.cr_group_info);
         rqstp->rq_cred.cr_group_info = NULL;
         if (gsd->rsci)
-                rsc_put(&gsd->rsci->h, &rsc_cache);
+                cache_put(&gsd->rsci->h, &rsc_cache);
         gsd->rsci = NULL;
 
         return stat;
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index edcda4fd88e8..dd81e5928172 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -42,7 +42,7 @@ void cache_init(struct cache_head *h)
         time_t now = get_seconds();
         h->next = NULL;
         h->flags = 0;
-        atomic_set(&h->refcnt, 1);
+        kref_init(&h->ref);
         h->expiry_time = now + CACHE_NEW_EXPIRY;
         h->last_refresh = now;
 }
@@ -81,7 +81,7 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
                 if (detail->match(tmp, key)) {
                         cache_get(tmp);
                         write_unlock(&detail->hash_lock);
-                        detail->cache_put(new, detail);
+                        cache_put(new, detail);
                         return tmp;
                 }
         }
@@ -145,7 +145,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
         /* We need to insert a new entry */
         tmp = detail->alloc();
         if (!tmp) {
-                detail->cache_put(old, detail);
+                cache_put(old, detail);
                 return NULL;
         }
         cache_init(tmp);
@@ -165,7 +165,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
         write_unlock(&detail->hash_lock);
         cache_fresh_unlocked(tmp, detail, is_new);
         cache_fresh_unlocked(old, detail, 0);
-        detail->cache_put(old, detail);
+        cache_put(old, detail);
         return tmp;
 }
 EXPORT_SYMBOL(sunrpc_cache_update);
@@ -234,7 +234,7 @@ int cache_check(struct cache_detail *detail,
                 cache_defer_req(rqstp, h);
 
         if (rv)
-                detail->cache_put(h, detail);
+                cache_put(h, detail);
         return rv;
 }
 
@@ -431,7 +431,7 @@ static int cache_clean(void)
                         if (test_and_clear_bit(CACHE_PENDING, &ch->flags))
                                 queue_loose(current_detail, ch);
 
-                        if (atomic_read(&ch->refcnt) == 1)
+                        if (atomic_read(&ch->ref.refcount) == 1)
                                 break;
                 }
                 if (ch) {
@@ -446,7 +446,7 @@ static int cache_clean(void)
                         current_index ++;
                 spin_unlock(&cache_list_lock);
                 if (ch)
-                        d->cache_put(ch, d);
+                        cache_put(ch, d);
         } else
                 spin_unlock(&cache_list_lock);
 
@@ -723,7 +723,7 @@ cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
                     !test_bit(CACHE_PENDING, &rq->item->flags)) {
                         list_del(&rq->q.list);
                         spin_unlock(&queue_lock);
-                        cd->cache_put(rq->item, cd);
+                        cache_put(rq->item, cd);
                         kfree(rq->buf);
                         kfree(rq);
                 } else
@@ -906,7 +906,7 @@ static void queue_loose(struct cache_detail *detail, struct cache_head *ch)
                                 continue;
                         list_del(&cr->q.list);
                         spin_unlock(&queue_lock);
-                        detail->cache_put(cr->item, detail);
+                        cache_put(cr->item, detail);
                         kfree(cr->buf);
                         kfree(cr);
                         return;
@@ -1192,7 +1192,7 @@ static int c_show(struct seq_file *m, void *p)
 
         ifdebug(CACHE)
                 seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
-                           cp->expiry_time, atomic_read(&cp->refcnt), cp->flags);
+                           cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags);
         cache_get(cp);
         if (cache_check(cd, cp, NULL))
                 /* cache_check does a cache_put on failure */
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 7e38621a20b7..11020c0b7db5 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -84,15 +84,15 @@ struct ip_map {
 };
 static struct cache_head        *ip_table[IP_HASHMAX];
 
-static void ip_map_put(struct cache_head *item, struct cache_detail *cd)
+static void ip_map_put(struct kref *kref)
 {
+        struct cache_head *item = container_of(kref, struct cache_head, ref);
         struct ip_map *im = container_of(item, struct ip_map,h);
-        if (cache_put(item, cd)) {
-                if (test_bit(CACHE_VALID, &item->flags) &&
-                    !test_bit(CACHE_NEGATIVE, &item->flags))
-                        auth_domain_put(&im->m_client->h);
-                kfree(im);
-        }
+
+        if (test_bit(CACHE_VALID, &item->flags) &&
+            !test_bit(CACHE_NEGATIVE, &item->flags))
+                auth_domain_put(&im->m_client->h);
+        kfree(im);
 }
 
 #if IP_HASHBITS == 8
@@ -315,7 +315,7 @@ static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t ex
                                  hash_ip((unsigned long)ipm->m_addr.s_addr));
         if (!ch)
                 return -ENOMEM;
-        ip_map_put(ch, &ip_map_cache);
+        cache_put(ch, &ip_map_cache);
         return 0;
 }
 
@@ -369,7 +369,7 @@ struct auth_domain *auth_unix_lookup(struct in_addr addr)
                 rv = &ipm->m_client->h;
                 kref_get(&rv->ref);
         }
-        ip_map_put(&ipm->h, &ip_map_cache);
+        cache_put(&ipm->h, &ip_map_cache);
         return rv;
 }
 
@@ -403,7 +403,7 @@ svcauth_unix_set_client(struct svc_rqst *rqstp)
                 case 0:
                         rqstp->rq_client = &ipm->m_client->h;
                         kref_get(&rqstp->rq_client->ref);
-                        ip_map_put(&ipm->h, &ip_map_cache);
+                        cache_put(&ipm->h, &ip_map_cache);
                         break;
         }
         return SVC_OK;