[PATCH v4 0/5] Allow the admin to turn off NFSv4 uid/gid mapping

[Trond Myklebust]

The following patches allow the admin to turn off NFSv4 uid/gid mapping
if mounting using AUTH_SYS security.

Minor changes w.r.t. first revision:
- Added documentation in kernel-parameters.txt
- Print a warning if an NFS4ERR_BADOWNER causes us to turn idmapping on again

Changes w.r.t. second revision:
- Ensure we propagate the NFS4ERR_BADOWNER up to the NFSv4 middle layers
- Fix a typo in nfs4_handle_exception

Changes w.r.t. third revision:
- Work around a Linux server bug which causes pre-2.6.37 kernels to return
NFS4ERR_BADNAME in cases where it should be returning NFS4ERR_BADOWNER.

Trond Myklebust (5):
NFSv4: If the server sends us a numeric uid/gid then accept it
NFSv4: Send unmapped uid/gids to the server if the idmapper fails
NFSv4: cleanup idmapper functions to take an nfs_server argument
NFSv4: Propagate the error NFS4ERR_BADOWNER to nfs4_do_setattr
NFSv4: Send unmapped uid/gids to the server when using auth_sys

Documentation/kernel-parameters.txt | 8 +++
fs/nfs/client.c | 16 ++++++
fs/nfs/idmap.c | 87 +++++++++++++++++++++++++++-------
fs/nfs/nfs4proc.c | 18 +++++++-
fs/nfs/nfs4xdr.c | 20 +++-----
include/linux/nfs_fs_sb.h | 1 +
include/linux/nfs_idmap.h | 8 ++--
7 files changed, 123 insertions(+), 35 deletions(-)

[Trond Myklebust]

Signed-off-by: Trond Myklebust <Trond.Myklebust-HgOvQuBEEgTQT0dZR+***@public.gmane.org>
---
fs/nfs/idmap.c | 30 ++++++++++++++++++++++++++----
1 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index cbe6e2f..8518573 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -52,6 +52,11 @@ static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *re
return 1;
}

+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/slab.h>
@@ -252,11 +257,20 @@ int nfs_map_group_to_gid(struct nfs_client *clp, const char *name, size_t namele

int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen)
{
- return nfs_idmap_lookup_name(uid, "user", buf, buflen);
+ int ret;
+ 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(struct nfs_client *clp, __u32 gid, char *buf, size_t buflen)
{
- return nfs_idmap_lookup_name(gid, "group", buf, buflen);
+ int ret;
+
+ 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 */
@@ -736,14 +750,22 @@ int nfs_map_group_to_gid(struct nfs_client *clp, const char *name, size_t namele
int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen)
{
struct idmap *idmap = clp->cl_idmap;
+ int ret;

- return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
+ 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(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen)
{
struct idmap *idmap = clp->cl_idmap;
+ int ret;

- return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
+ ret = nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
+ if (ret < 0)
+ ret = nfs_map_numeric_to_string(uid, buf, buflen);
+ return ret;
}

#endif /* CONFIG_NFS_USE_NEW_IDMAPPER */

[Trond Myklebust]

...instead of the nfs_client.

Signed-off-by: Trond Myklebust <Trond.Myklebust-HgOvQuBEEgTQT0dZR+***@public.gmane.org>
---
fs/nfs/idmap.c | 24 ++++++++++++------------
fs/nfs/nfs4xdr.c | 18 ++++++++----------
include/linux/nfs_idmap.h | 8 ++++----
3 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 8518573..e2d579d 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -241,21 +241,21 @@ static int nfs_idmap_lookup_id(const char *name, size_t namelen,
return ret;
}

-int nfs_map_name_to_uid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
+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(struct nfs_client *clp, const char *name, size_t namelen, __u32 *gid)
+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(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen)
+int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
{
int ret;
ret = nfs_idmap_lookup_name(uid, "user", buf, buflen);
@@ -263,7 +263,7 @@ int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf, size_t buf
ret = nfs_map_numeric_to_string(uid, buf, buflen);
return ret;
}
-int nfs_map_gid_to_group(struct nfs_client *clp, __u32 gid, char *buf, size_t buflen)
+int nfs_map_gid_to_group(const struct nfs_server *server, __u32 gid, char *buf, size_t buflen)
{
int ret;

@@ -729,27 +729,27 @@ static unsigned int fnvhash32(const void *buf, size_t buflen)
return hash;
}

-int nfs_map_name_to_uid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid)
+int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)
{
- struct idmap *idmap = clp->cl_idmap;
+ struct idmap *idmap = server->nfs_client->cl_idmap;

if (nfs_map_string_to_numeric(name, namelen, uid))
return 0;
return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
}

-int nfs_map_group_to_gid(struct nfs_client *clp, 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 *uid)
{
- struct idmap *idmap = clp->cl_idmap;
+ struct idmap *idmap = server->nfs_client->cl_idmap;

if (nfs_map_string_to_numeric(name, namelen, uid))
return 0;
return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
}

-int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen)
+int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
{
- struct idmap *idmap = clp->cl_idmap;
+ struct idmap *idmap = server->nfs_client->cl_idmap;
int ret;

ret = nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
@@ -757,9 +757,9 @@ int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf, size_t buf
ret = nfs_map_numeric_to_string(uid, buf, buflen);
return ret;
}
-int nfs_map_gid_to_group(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen)
+int nfs_map_gid_to_group(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
{
- struct idmap *idmap = clp->cl_idmap;
+ struct idmap *idmap = server->nfs_client->cl_idmap;
int ret;

ret = nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 8e49688..bc205ab 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -844,7 +844,7 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap, const
if (iap->ia_valid & ATTR_MODE)
len += 4;
if (iap->ia_valid & ATTR_UID) {
- owner_namelen = nfs_map_uid_to_name(server->nfs_client, iap->ia_uid, owner_name, IDMAP_NAMESZ);
+ owner_namelen = nfs_map_uid_to_name(server, iap->ia_uid, owner_name, IDMAP_NAMESZ);
if (owner_namelen < 0) {
dprintk("nfs: couldn't resolve uid %d to string\n",
iap->ia_uid);
@@ -856,7 +856,7 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap, const
len += 4 + (XDR_QUADLEN(owner_namelen) << 2);
}
if (iap->ia_valid & ATTR_GID) {
- owner_grouplen = nfs_map_gid_to_group(server->nfs_client, iap->ia_gid, owner_group, IDMAP_NAMESZ);
+ owner_grouplen = nfs_map_gid_to_group(server, iap->ia_gid, owner_group, IDMAP_NAMESZ);
if (owner_grouplen < 0) {
dprintk("nfs: couldn't resolve gid %d to string\n",
iap->ia_gid);
@@ -3382,7 +3382,7 @@ out_overflow:
}

static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap,
- struct nfs_client *clp, uint32_t *uid, int may_sleep)
+ const struct nfs_server *server, uint32_t *uid, int may_sleep)
{
uint32_t len;
__be32 *p;
@@ -3402,7 +3402,7 @@ static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap,
if (!may_sleep) {
/* do nothing */
} else if (len < XDR_MAX_NETOBJ) {
- if (nfs_map_name_to_uid(clp, (char *)p, len, uid) == 0)
+ if (nfs_map_name_to_uid(server, (char *)p, len, uid) == 0)
ret = NFS_ATTR_FATTR_OWNER;
else
dprintk("%s: nfs_map_name_to_uid failed!\n",
@@ -3420,7 +3420,7 @@ out_overflow:
}

static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap,
- struct nfs_client *clp, uint32_t *gid, int may_sleep)
+ const struct nfs_server *server, uint32_t *gid, int may_sleep)
{
uint32_t len;
__be32 *p;
@@ -3440,7 +3440,7 @@ static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap,
if (!may_sleep) {
/* do nothing */
} else if (len < XDR_MAX_NETOBJ) {
- if (nfs_map_group_to_gid(clp, (char *)p, len, gid) == 0)
+ if (nfs_map_group_to_gid(server, (char *)p, len, gid) == 0)
ret = NFS_ATTR_FATTR_GROUP;
else
dprintk("%s: nfs_map_group_to_gid failed!\n",
@@ -3939,14 +3939,12 @@ static int decode_getfattr_attrs(struct xdr_stream *xdr, uint32_t *bitmap,
goto xdr_error;
fattr->valid |= status;

- status = decode_attr_owner(xdr, bitmap, server->nfs_client,
- &fattr->uid, may_sleep);
+ status = decode_attr_owner(xdr, bitmap, server, &fattr->uid, may_sleep);
if (status < 0)
goto xdr_error;
fattr->valid |= status;

- status = decode_attr_group(xdr, bitmap, server->nfs_client,
- &fattr->gid, may_sleep);
+ status = decode_attr_group(xdr, bitmap, server, &fattr->gid, may_sleep);
if (status < 0)
goto xdr_error;
fattr->valid |= status;
diff --git a/include/linux/nfs_idmap.h b/include/linux/nfs_idmap.h
index e8352dc..ee97767 100644
--- a/include/linux/nfs_idmap.h
+++ b/include/linux/nfs_idmap.h
@@ -96,10 +96,10 @@ void nfs_idmap_delete(struct nfs_client *);

#endif /* CONFIG_NFS_USE_NEW_IDMAPPER */

-int nfs_map_name_to_uid(struct nfs_client *, const char *, size_t, __u32 *);
-int nfs_map_group_to_gid(struct nfs_client *, const char *, size_t, __u32 *);
-int nfs_map_uid_to_name(struct nfs_client *, __u32, char *, size_t);
-int nfs_map_gid_to_group(struct nfs_client *, __u32, char *, size_t);
+int nfs_map_name_to_uid(const struct nfs_server *, const char *, size_t, __u32 *);
+int nfs_map_group_to_gid(const struct nfs_server *, const char *, size_t, __u32 *);
+int nfs_map_uid_to_name(const struct nfs_server *, __u32, char *, size_t);
+int nfs_map_gid_to_group(const struct nfs_server *, __u32, char *, size_t);

extern unsigned int nfs_idmap_cache_timeout;
#endif /* __KERNEL__ */

[Trond Myklebust]

This will be required in order to switch uid/gid mapping back on if the
admin has tried to disable it.

Note that we also propagate NFS4ERR_BADNAME at the same time, in order to
work around a Linux server bug.

Signed-off-by: Trond Myklebust <Trond.Myklebust-HgOvQuBEEgTQT0dZR+***@public.gmane.org>
---
fs/nfs/nfs4proc.c | 3 +++
fs/nfs/nfs4xdr.c | 2 --
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 2aede9c..39a2e3c 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -84,6 +84,9 @@ static int nfs4_map_errors(int err)
switch (err) {
case -NFS4ERR_RESOURCE:
return -EREMOTEIO;
+ case -NFS4ERR_BADOWNER:
+ case -NFS4ERR_NAME:
+ return -EINVAL;
default:
dprintk("%s could not handle NFSv4 error %d\n",
__func__, -err);
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index bc205ab..1de6b22 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -6174,8 +6174,6 @@ static struct {
{ NFS4ERR_DQUOT, -EDQUOT },
{ NFS4ERR_STALE, -ESTALE },
{ NFS4ERR_BADHANDLE, -EBADHANDLE },
- { NFS4ERR_BADOWNER, -EINVAL },
- { NFS4ERR_BADNAME, -EINVAL },
{ NFS4ERR_BAD_COOKIE, -EBADCOOKIE },
{ NFS4ERR_NOTSUPP, -ENOTSUPP },
{ NFS4ERR_TOOSMALL, -ETOOSMALL },

[Trond Myklebust]

The new behaviour is enabled using the new module parameter
'nfs4_disable_idmapping'.

Note that if the server rejects an unmapped uid or gid, then
the client will automatically switch back to using the idmapper.

Signed-off-by: Trond Myklebust <Trond.Myklebust-HgOvQuBEEgTQT0dZR+***@public.gmane.org>
---
Documentation/kernel-parameters.txt | 8 ++++++++
fs/nfs/client.c | 16 ++++++++++++++++
fs/nfs/idmap.c | 21 +++++++++++++--------
fs/nfs/nfs4proc.c | 15 ++++++++++++++-
include/linux/nfs_fs_sb.h | 1 +
5 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index cdd2a6e..51a74a3 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1573,6 +1573,14 @@ and is between 256 and 4096 characters. It is defined in the file
of returning the full 64-bit number.
The default is to return 64-bit inode numbers.

+ nfs.nfs4_disable_idmapping=
+ [NFSv4] When set, this option disables the NFSv4
+ idmapper on the client, but only if the mount
+ is using the 'sec=sys' security flavour. This may
+ make migration from legacy NFSv2/v3 systems easier
+ provided that the server has the appropriate support.
+ The default is to always enable NFSv4 idmapping.
+
nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take
when a NMI is triggered.
Format: [state][,regs][,debounce][,die]
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 7908530..a6c0324 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -58,6 +58,11 @@ static LIST_HEAD(nfs_volume_list);
static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);

/*
+ * Turn off NFSv4 uid/gid mapping when using AUTH_SYS
+ */
+static int nfs4_disable_idmapping = 0;
+
+/*
* RPC cruft for NFS
*/
static struct rpc_version *nfs_version[5] = {
@@ -1447,6 +1452,13 @@ static int nfs4_init_server(struct nfs_server *server,
if (error < 0)
goto error;

+ /*
+ * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
+ * authentication.
+ */
+ if (nfs4_disable_idmapping && data->auth_flavors[0] == RPC_AUTH_UNIX)
+ server->caps |= NFS_CAP_UIDGID_NOMAP;
+
if (data->rsize)
server->rsize = nfs_block_size(data->rsize, NULL);
if (data->wsize)
@@ -1864,3 +1876,7 @@ void nfs_fs_proc_exit(void)
}

#endif /* CONFIG_PROC_FS */
+
+module_param(nfs4_disable_idmapping, bool, 0644);
+MODULE_PARM_DESC(nfs4_disable_idmapping,
+ "Turn off NFSv4 idmapping when using 'sec=sys'");
diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index e2d579d..ee4ab8f 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -257,17 +257,20 @@ int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size

int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
{
- int ret;
- ret = nfs_idmap_lookup_name(uid, "user", buf, 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;
+ int ret = -EINVAL;

- ret = nfs_idmap_lookup_name(gid, "group", buf, buflen);
+ 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;
@@ -750,9 +753,10 @@ int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size
int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
- int ret;
+ int ret = -EINVAL;

- ret = nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
+ if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
+ 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;
@@ -760,9 +764,10 @@ int nfs_map_uid_to_name(const struct nfs_server *server, __u32 uid, char *buf, s
int nfs_map_gid_to_group(const struct nfs_server *server, __u32 uid, char *buf, size_t buflen)
{
struct idmap *idmap = server->nfs_client->cl_idmap;
- int ret;
+ int ret = -EINVAL;

- ret = nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
+ if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
+ ret = nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
if (ret < 0)
ret = nfs_map_numeric_to_string(uid, buf, buflen);
return ret;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 39a2e3c..e06b531 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -243,7 +243,7 @@ static int nfs4_delay(struct rpc_clnt *clnt, long *timeout)
/* This is the error handling routine for processes that are allowed
* to sleep.
*/
-static int nfs4_handle_exception(const struct nfs_server *server, int errorcode, struct nfs4_exception *exception)
+static int nfs4_handle_exception(struct nfs_server *server, int errorcode, struct nfs4_exception *exception)
{
struct nfs_client *clp = server->nfs_client;
struct nfs4_state *state = exception->state;
@@ -294,6 +294,19 @@ static int nfs4_handle_exception(const struct nfs_server *server, int errorcode,
break;
case -NFS4ERR_OLD_STATEID:
exception->retry = 1;
+ break;
+ case -NFS4ERR_BADOWNER:
+ /* The following works around a Linux server bug! */
+ case -NFS4ERR_BADNAME:
+ if (server->caps & NFS_CAP_UIDGID_NOMAP) {
+ server->caps &= ~NFS_CAP_UIDGID_NOMAP;
+ exception->retry = 1;
+ printk(KERN_WARNING "NFS: v4 server %s "
+ "does not accept raw "
+ "uid/gids. "
+ "Reenabling the idmapper.\n",
+ server->nfs_client->cl_hostname);
+ }
}
/* We failed to handle the error */
return nfs4_map_errors(ret);
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index b197563..8fa77c6 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -180,6 +180,7 @@ struct nfs_server {
#define NFS_CAP_CTIME (1U << 12)
#define NFS_CAP_MTIME (1U << 13)
#define NFS_CAP_POSIX_LOCK (1U << 14)
+#define NFS_CAP_UIDGID_NOMAP (1U << 15)


/* maximum number of slots to use */

[Trond Myklebust]

Signed-off-by: Trond Myklebust <Trond.Myklebust-HgOvQuBEEgTQT0dZR+***@public.gmane.org>
---
fs/nfs/idmap.c | 28 ++++++++++++++++++++++++++--
1 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 1869688..cbe6e2f 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -33,6 +33,24 @@
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+
+static int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
+{
+ unsigned long val;
+ char buf[16];
+
+ if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
+ return 0;
+ memcpy(buf, name, namelen);
+ buf[namelen] = '\0';
+ if (strict_strtoul(buf, 0, &val) != 0)
+ return 0;
+ *res = val;
+ return 1;
+}

#ifdef CONFIG_NFS_USE_NEW_IDMAPPER

@@ -42,7 +60,6 @@
#include <linux/keyctl.h>
#include <linux/key-type.h>
#include <linux/rcupdate.h>
-#include <linux/kernel.h>
#include <linux/err.h>

#include <keys/user-type.h>
@@ -221,11 +238,15 @@ static int nfs_idmap_lookup_id(const char *name, size_t namelen,

int nfs_map_name_to_uid(struct nfs_client *clp, 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(struct nfs_client *clp, 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);
}

@@ -243,7 +264,6 @@ int nfs_map_gid_to_group(struct nfs_client *clp, __u32 gid, char *buf, size_t bu
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/init.h>
-#include <linux/types.h>
#include <linux/slab.h>
#include <linux/socket.h>
#include <linux/in.h>
@@ -699,6 +719,8 @@ int nfs_map_name_to_uid(struct nfs_client *clp, const char *name, size_t namelen
{
struct idmap *idmap = clp->cl_idmap;

+ if (nfs_map_string_to_numeric(name, namelen, uid))
+ return 0;
return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
}

@@ -706,6 +728,8 @@ int nfs_map_group_to_gid(struct nfs_client *clp, const char *name, size_t namele
{
struct idmap *idmap = clp->cl_idmap;

+ if (nfs_map_string_to_numeric(name, namelen, uid))
+ return 0;
return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
}