knfsd: allow cache_register to return error on failure

Newer server features such as nfsv4 and gss depend on proc to work, so a
failure to initialize the proc files they need should be treated as
fatal.

Thanks to Andrew Morton for style fix and compile fix in case where
CONFIG_NFSD_V4 is undefined.

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

8 files changed, 74 insertions, 25 deletions

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index d29b70a28f2b..cbbc594ef592 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1637,13 +1637,19 @@ exp_verify_string(char *cp, int max)
 /*
  * Initialize the exports module.
  */
-void
+int
 nfsd_export_init(void)
 {
+        int rv;
         dprintk("nfsd: initializing export module.\n");
 
-        cache_register(&svc_export_cache);
-        cache_register(&svc_expkey_cache);
+        rv = cache_register(&svc_export_cache);
+        if (rv)
+                return rv;
+        rv = cache_register(&svc_expkey_cache);
+        if (rv)
+                cache_unregister(&svc_export_cache);
+        return rv;
 
 }
 
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index ef22179c49ad..996bd88b75ba 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -464,11 +464,18 @@ nametoid_update(struct ent *new, struct ent *old)
  * Exported API
  */
 
-void
+int
 nfsd_idmap_init(void)
 {
-        cache_register(&idtoname_cache);
-        cache_register(&nametoid_cache);
+        int rv;
+
+        rv = cache_register(&idtoname_cache);
+        if (rv)
+                return rv;
+        rv = cache_register(&nametoid_cache);
+        if (rv)
+                cache_unregister(&idtoname_cache);
+        return rv;
 }
 
 void
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 2b95597aa4a5..4aba92698581 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -707,9 +707,13 @@ static int __init init_nfsd(void)
         retval = nfsd_reply_cache_init();
         if (retval)
                 goto out_free_stat;
-        nfsd_export_init();     /* Exports table */
+        retval = nfsd_export_init();
+        if (retval)
+                goto out_free_cache;
         nfsd_lockd_init();      /* lockd->nfsd callbacks */
-        nfsd_idmap_init();      /* Name to ID mapping */
+        retval = nfsd_idmap_init();
+        if (retval)
+                goto out_free_lockd;
         retval = create_proc_exports_entry();
         if (retval)
                 goto out_free_idmap;
@@ -720,10 +724,12 @@ static int __init init_nfsd(void)
 out_free_all:
         remove_proc_entry("fs/nfs/exports", NULL);
         remove_proc_entry("fs/nfs", NULL);
-        nfsd_idmap_shutdown();
 out_free_idmap:
+        nfsd_idmap_shutdown();
+out_free_lockd:
         nfsd_lockd_shutdown();
         nfsd_export_shutdown();
+out_free_cache:
         nfsd_reply_cache_shutdown();
 out_free_stat:
         nfsd_stat_shutdown();
diff --git a/include/linux/nfsd/export.h b/include/linux/nfsd/export.h
index bcb7abafbca9..3a1687251367 100644
--- a/include/linux/nfsd/export.h
+++ b/include/linux/nfsd/export.h
@@ -122,7 +122,7 @@ __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp);
 /*
  * Function declarations
  */
-void                    nfsd_export_init(void);
+int                     nfsd_export_init(void);
 void                    nfsd_export_shutdown(void);
 void                    nfsd_export_flush(void);
 void                    exp_readlock(void);
diff --git a/include/linux/nfsd_idmap.h b/include/linux/nfsd_idmap.h
index e82746fcad14..d4a2ac18bd4c 100644
--- a/include/linux/nfsd_idmap.h
+++ b/include/linux/nfsd_idmap.h
@@ -44,11 +44,16 @@
 #define IDMAP_NAMESZ 128
 
 #ifdef CONFIG_NFSD_V4
-void nfsd_idmap_init(void);
+int nfsd_idmap_init(void);
 void nfsd_idmap_shutdown(void);
 #else
-static inline void nfsd_idmap_init(void) {};
-static inline void nfsd_idmap_shutdown(void) {};
+static inline int nfsd_idmap_init(void)
+{
+        return 0;
+}
+static inline void nfsd_idmap_shutdown(void)
+{
+}
 #endif
 
 int nfsd_map_name_to_uid(struct svc_rqst *, const char *, size_t, __u32 *);
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index b683b5ddeea9..03547d6abee5 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -169,7 +169,7 @@ extern int cache_check(struct cache_detail *detail,
 extern void cache_flush(void);
 extern void cache_purge(struct cache_detail *detail);
 #define NEVER (0x7FFFFFFF)
-extern void cache_register(struct cache_detail *cd);
+extern int cache_register(struct cache_detail *cd);
 extern void cache_unregister(struct cache_detail *cd);
 
 extern void qword_add(char **bpp, int *lp, char *str);
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index d329a12500aa..aa790bb4f7a1 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1386,10 +1386,19 @@ int
 gss_svc_init(void)
 {
         int rv = svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
-        if (rv == 0) {
-                cache_register(&rsc_cache);
-                cache_register(&rsi_cache);
-        }
+        if (rv)
+                return rv;
+        rv = cache_register(&rsc_cache);
+        if (rv)
+                goto out1;
+        rv = cache_register(&rsi_cache);
+        if (rv)
+                goto out2;
+        return 0;
+out2:
+        cache_unregister(&rsc_cache);
+out1:
+        svc_auth_unregister(RPC_AUTH_GSS);
         return rv;
 }
 
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index f41a7cc4cf62..50b1a8b441fe 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -304,20 +304,21 @@ static void remove_cache_proc_entries(struct cache_detail *cd)
         remove_proc_entry(cd->name, proc_net_rpc);
 }
 
-static void create_cache_proc_entries(struct cache_detail *cd)
+#ifdef CONFIG_PROC_FS
+static int create_cache_proc_entries(struct cache_detail *cd)
 {
         struct proc_dir_entry *p;
 
         cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc);
         if (cd->proc_ent == NULL)
-                return;
+                goto out_nomem;
         cd->proc_ent->owner = cd->owner;
         cd->channel_ent = cd->content_ent = NULL;
 
         p = create_proc_entry("flush", S_IFREG|S_IRUSR|S_IWUSR, cd->proc_ent);
         cd->flush_ent = p;
         if (p == NULL)
-                return;
+                goto out_nomem;
         p->proc_fops = &cache_flush_operations;
         p->owner = cd->owner;
         p->data = cd;
@@ -327,7 +328,7 @@ static void create_cache_proc_entries(struct cache_detail *cd)
                                       cd->proc_ent);
                 cd->channel_ent = p;
                 if (p == NULL)
-                        return;
+                        goto out_nomem;
                 p->proc_fops = &cache_file_operations;
                 p->owner = cd->owner;
                 p->data = cd;
@@ -337,16 +338,30 @@ static void create_cache_proc_entries(struct cache_detail *cd)
                                       cd->proc_ent);
                 cd->content_ent = p;
                 if (p == NULL)
-                        return;
+                        goto out_nomem;
                 p->proc_fops = &content_file_operations;
                 p->owner = cd->owner;
                 p->data = cd;
         }
+        return 0;
+out_nomem:
+        remove_cache_proc_entries(cd);
+        return -ENOMEM;
 }
+#else /* CONFIG_PROC_FS */
+static int create_cache_proc_entries(struct cache_detail *cd)
+{
+        return 0;
+}
+#endif
 
-void cache_register(struct cache_detail *cd)
+int cache_register(struct cache_detail *cd)
 {
-        create_cache_proc_entries(cd);
+        int ret;
+
+        ret = create_cache_proc_entries(cd);
+        if (ret)
+                return ret;
         rwlock_init(&cd->hash_lock);
         INIT_LIST_HEAD(&cd->queue);
         spin_lock(&cache_list_lock);
@@ -360,6 +375,7 @@ void cache_register(struct cache_detail *cd)
 
         /* start the cleaning process */
         schedule_delayed_work(&cache_cleaner, 0);
+        return 0;
 }
 
 void cache_unregister(struct cache_detail *cd)