[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>

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 @@ exp_export(struct nfsctl_export *nxp)
 	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);
 }
 

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;
 }
 

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;

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)

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);

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 @@ svcauth_gss_accept(struct svc_rqst *rqstp, u32 *authp)
 	ret = SVC_DROP;
 out:
 	if (rsci)
-		rsc_put(&rsci->h, &rsc_cache);
+		cache_put(&rsci->h, &rsc_cache);
 	return ret;
 }
 
@@ -1168,7 +1164,7 @@ svcauth_gss_release(struct svc_rqst *rqstp)
 		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;