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>

3 files changed, 28 insertions, 9 deletions

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index d29b70a..cbbc594 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 ef22179..996bd88 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 2b95597..4aba926 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();