[PATCH 1/3] NFS: Fall back on old idmapper if request_key() fails

[bjschuma@netapp.com]

From: Bryan Schumaker <bjschuma@netapp.com>

This patch removes the CONFIG_NFS_USE_NEW_IDMAPPER compile option.
First, the idmapper will attempt to map the id using /sbin/request-key
and nfsidmap.  If this fails (if /etc/request-key.conf is not configured
properly) then the idmapper will call the legacy code to perform the
mapping.  I left a comment stating where the legacy code begins to make
it easier for somebody to remove in the future.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
---
I tested this on both Archlinux with nfs-utils 1.2.5 and on Fedora with
nfs-utils 1.2.6-rc6.  It did what was expected in both cases.

 fs/nfs/Kconfig            |   11 ------
 fs/nfs/idmap.c            |   76 +++++++++++++++------------------------------
 fs/nfs/sysctl.c           |    2 -
 include/linux/nfs_idmap.h |   25 ---------------
 4 files changed, 25 insertions(+), 89 deletions(-)

diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index dbcd821..021d2cf 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -132,14 +132,3 @@ config NFS_USE_KERNEL_DNS
 	select DNS_RESOLVER
 	select KEYS
 	default y
-
-config NFS_USE_NEW_IDMAPPER
-	bool "Use the new idmapper upcall routine"
-	depends on NFS_V4 && KEYS
-	help
-	  Say Y here if you want NFS to use the new idmapper upcall functions.
-	  You will need /sbin/request-key (usually provided by the keyutils
-	  package).  For details, read
-	  <file:Documentation/filesystems/nfs/idmapper.txt>.
-
-	  If you are unsure, say N.
diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 2c05f19..56b1104 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -142,8 +142,6 @@ static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
 	return snprintf(buf, buflen, "%u", id);
 }
 
-#ifdef CONFIG_NFS_USE_NEW_IDMAPPER
-
 #include <linux/cred.h>
 #include <linux/sunrpc/sched.h>
 #include <linux/nfs4.h>
@@ -327,43 +325,7 @@ static int nfs_idmap_lookup_id(const char *name, size_t namelen,
 	return ret;
 }
 
-int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
-{
-	if (nfs_map_string_to_numeric(name, namelen, uid))
-		return 0;
-	return nfs_idmap_lookup_id(name, namelen, "uid", uid);
-}
-
-int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
-{
-	if (nfs_map_string_to_numeric(name, namelen, gid))
-		return 0;
-	return nfs_idmap_lookup_id(name, namelen, "gid", gid);
-}
-
-int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
-{
-	int ret = -EINVAL;
-
-	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
-		ret = nfs_idmap_lookup_name(uid, "user", buf, buflen);
-	if (ret < 0)
-		ret = nfs_map_numeric_to_string(uid, buf, buflen);
-	return ret;
-}
-int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
-{
-	int ret = -EINVAL;
-
-	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
-		ret = nfs_idmap_lookup_name(gid, "group", buf, buflen);
-	if (ret < 0)
-		ret = nfs_map_numeric_to_string(gid, buf, buflen);
-	return ret;
-}
-
-#else  /* CONFIG_NFS_USE_NEW_IDMAPPER not defined */
-
+/* idmap classic begins here */
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/init.h>
@@ -795,19 +757,27 @@ static unsigned int fnvhash32(const void *buf, size_t buflen)
 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
 {
 	struct idmap *idmap = server->nfs_client->cl_idmap;
+	int ret = -EINVAL;
 
 	if (nfs_map_string_to_numeric(name, namelen, uid))
 		return 0;
-	return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
+	ret = nfs_idmap_lookup_id(name, namelen, "uid", uid);
+	if (ret < 0)
+		ret = nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
+	return ret;
 }
 
-int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
+int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *gid)
 {
 	struct idmap *idmap = server->nfs_client->cl_idmap;
+	int ret = -EINVAL;
 
-	if (nfs_map_string_to_numeric(name, namelen, uid))
+	if (nfs_map_string_to_numeric(name, namelen, gid))
 		return 0;
-	return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
+	ret = nfs_idmap_lookup_id(name, namelen, "gid", gid);
+	if (ret < 0)
+		ret = nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, gid);
+	return ret;
 }
 
 int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
@@ -815,22 +785,26 @@ int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, s
 	struct idmap *idmap = server->nfs_client->cl_idmap;
 	int ret = -EINVAL;
 
-	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
-		ret = nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
+	if (!(server->caps & NFS_CAP_UIDGID_NOMAP)) {
+		ret = nfs_idmap_lookup_name(uid, "user", buf, buflen);
+		if (ret < 0)
+			ret = nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
+	}
 	if (ret < 0)
 		ret = nfs_map_numeric_to_string(uid, buf, buflen);
 	return ret;
 }
-int nfs_map_gid_to_group(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
+int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
 {
 	struct idmap *idmap = server->nfs_client->cl_idmap;
 	int ret = -EINVAL;
 
-	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
-		ret = nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
+	if (!(server->caps & NFS_CAP_UIDGID_NOMAP)) {
+		ret = nfs_idmap_lookup_name(gid, "group", buf, buflen);
+		if (ret < 0)
+			ret = nfs_idmap_name(idmap, &idmap->idmap_group_hash, gid, buf);
+	}
 	if (ret < 0)
-		ret = nfs_map_numeric_to_string(uid, buf, buflen);
+		ret = nfs_map_numeric_to_string(gid, buf, buflen);
 	return ret;
 }
-
-#endif /* CONFIG_NFS_USE_NEW_IDMAPPER */
diff --git a/fs/nfs/sysctl.c b/fs/nfs/sysctl.c
index 978aaeb..ad4d2e7 100644
--- a/fs/nfs/sysctl.c
+++ b/fs/nfs/sysctl.c
@@ -32,7 +32,6 @@ static ctl_table nfs_cb_sysctls[] = {
 		.extra1 = (int *)&nfs_set_port_min,
 		.extra2 = (int *)&nfs_set_port_max,
 	},
-#ifndef CONFIG_NFS_USE_NEW_IDMAPPER
 	{
 		.procname = "idmap_cache_timeout",
 		.data = &nfs_idmap_cache_timeout,
@@ -40,7 +39,6 @@ static ctl_table nfs_cb_sysctls[] = {
 		.mode = 0644,
 		.proc_handler = proc_dointvec_jiffies,
 	},
-#endif /* CONFIG_NFS_USE_NEW_IDMAPPER */
 #endif
 	{
 		.procname	= "nfs_mountpoint_timeout",
diff --git a/include/linux/nfs_idmap.h b/include/linux/nfs_idmap.h
index 308c188..717fa50 100644
--- a/include/linux/nfs_idmap.h
+++ b/include/linux/nfs_idmap.h
@@ -69,36 +69,11 @@ struct nfs_server;
 struct nfs_fattr;
 struct nfs4_string;
 
-#ifdef CONFIG_NFS_USE_NEW_IDMAPPER
-
 int nfs_idmap_init(void);
 void nfs_idmap_quit(void);
-
-static inline int nfs_idmap_new(struct nfs_client *clp)
-{
-	return 0;
-}
-
-static inline void nfs_idmap_delete(struct nfs_client *clp)
-{
-}
-
-#else /* CONFIG_NFS_USE_NEW_IDMAPPER not set */
-
-static inline int nfs_idmap_init(void)
-{
-	return 0;
-}
-
-static inline void nfs_idmap_quit(void)
-{
-}
-
 int nfs_idmap_new(struct nfs_client *);
 void nfs_idmap_delete(struct nfs_client *);
 
-#endif /* CONFIG_NFS_USE_NEW_IDMAPPER */
-
 void nfs_fattr_init_names(struct nfs_fattr *fattr,
 		struct nfs4_string *owner_name,
 		struct nfs4_string *group_name);
-- 
1.7.8.4