Re: [PATCH RFC 01/12] userns: Support 9p interacting with multiple user namespaces

Re: [PATCH RFC 01/12] userns: Support 9p interacting with multiple user namespaces

[Zhao Hongjiang]

On 2012/11/20 20:43, Eric W. Biederman wrote:
> From: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>

> diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
> index d934f04..1c750ab 100644
> --- a/fs/9p/v9fs.c
> +++ b/fs/9p/v9fs.c
> @@ -161,7 +161,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
>  				ret = r;
>  				continue;
>  			}
> -			v9ses->dfltuid = option;
> +			v9ses->dfltuid = make_kuid(&init_user_ns, option);

I think the init_user_ns should be current_user_ns() cause the value is come from userspace
and in kernel we should mapping it to its own user_ns.

Hongjiang

> +			if (!uid_valid(v9ses->dfltuid)) {
> +				p9_debug(P9_DEBUG_ERROR,
> +					 "uid field, but not a uid?\n");
> +				ret = -EINVAL;
> +				continue;
> +			}
>  			break;
>  		case Opt_dfltgid:
>  			r = match_int(&args[0], &option);
> @@ -171,7 +177,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
>  				ret = r;
>  				continue;
>  			}
> -			v9ses->dfltgid = option;
> +			v9ses->dfltgid = make_kgid(&init_user_ns, option);

And this one.

> +			if (!gid_valid(v9ses->dfltgid)) {
> +				p9_debug(P9_DEBUG_ERROR,
> +					 "gid field, but not a gid?\n");
> +				ret = -EINVAL;
> +				continue;
> +			}
>  			break;
>  		case Opt_afid:
>  			r = match_int(&args[0], &option);
> @@ -248,8 +260,9 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
>  			else if (strcmp(s, "client") == 0) {
>  				v9ses->flags |= V9FS_ACCESS_CLIENT;
>  			} else {
> +				uid_t uid;
>  				v9ses->flags |= V9FS_ACCESS_SINGLE;
> -				v9ses->uid = simple_strtoul(s, &e, 10);
> +				uid = simple_strtoul(s, &e, 10);
>  				if (*e != '\0') {
>  					ret = -EINVAL;
>  					pr_info("Unknown access argument %s\n",
> @@ -257,6 +270,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
>  					kfree(s);
>  					goto free_and_return;
>  				}
> +				v9ses->uid = make_kuid(&init_user_ns, uid);

Also this one.

> +				if (!uid_valid(v9ses->uid)) {
> +					ret = -EINVAL;
> +					pr_info("Uknown uid %s\n", s);
> +					kfree(s);
> +					goto free_and_return;
> +				}
>  			}
>
>  			kfree(s);




.

Re: [PATCH RFC 01/12] userns: Support 9p interacting with multiple user namespaces

[Eric W. Biederman]

Zhao Hongjiang <zhaohongjiang37-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:

> On 2012/11/20 20:43, Eric W. Biederman wrote:
>> From: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
>
>> diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
>> index d934f04..1c750ab 100644
>> --- a/fs/9p/v9fs.c
>> +++ b/fs/9p/v9fs.c
>> @@ -161,7 +161,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
>>  				ret = r;
>>  				continue;
>>  			}
>> -			v9ses->dfltuid = option;
>> +			v9ses->dfltuid = make_kuid(&init_user_ns, option);
>
> I think the init_user_ns should be current_user_ns() cause the value is come from userspace
> and in kernel we should mapping it to its own user_ns.

Good point.  current_user_ns() is more appropriate and maintainable.

For now you can only mount 9p when current_user_ns() == &init_user_ns
but that might change in the future.

Thanks,
Eric

[PATCH RFC 0/12] Final userns conversions

[Eric W. Biederman]

This patchset contain the basic user namespace changes for filesystems
that have needed nontrivial work.  Along with the 2 patches that depend
on these changes.

I belive these patches to be correct for allowing the remaining
filesystems to work in the presence of user namespaces.  At the same
time I would like to give all of these much deeper scrutiny, just
because there is so much going on.  Unfortunately these patches
individually are not obviously correct.

Since I won't have much time until after Thanksgiving and because the
merge window is looming I figure I will put these changes out there and
let people see I am looking at these changes, and see if anyone happens
to spot anything.

If I can figure out how to responsibly get these changes into linux-next
I want to get these changes into linux-next so that user namespace bugs
show up in allyesconfig builds.

For people who want to see what else I am cooking my git tree is at:
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git

Eric W. Biederman (12):
      userns: Support 9p interacting with multiple user namespaces
      userns: Convert afs to use kuid/kgid where appropriate
      userns: Convert ceph to use kuid/kgid where appropriate
      userns: Convert cifs to use kuid/kgid where appropriate
      userns: Convert coda's to use kuid/kgid where appropriate
      userns: Convert gfs2 to use kuid/kgid where appropriate
      userns: Convert ncpfs to use kuid and kgid where appropriate
      userns: Convert nfs and nfsd to use kuid/kgid where appropriate
      userns: Convert ocfs2 to use kuid and kgid where appropriate
      userns: Convert xfs to use kuid/kgid/kprojid where appropriate
      userns: Now that everything has been converted remove the unnecessary infrastructure
      userns: Remove the EXPERMINTAL kconfig tag

 fs/9p/fid.c                       |   17 +++--
 fs/9p/v9fs.c                      |   34 ++++++++--
 fs/9p/v9fs.h                      |   10 ++--
 fs/9p/vfs_inode.c                 |    8 +-
 fs/9p/vfs_inode_dotl.c            |   22 +++---
 fs/afs/afs.h                      |    4 +-
 fs/afs/fsclient.c                 |   14 +++-
 fs/afs/inode.c                    |    6 +-
 fs/ceph/caps.c                    |   16 ++--
 fs/ceph/inode.c                   |   18 +++---
 fs/ceph/mds_client.c              |    4 +-
 fs/ceph/super.h                   |    4 +-
 fs/cifs/cifs_fs_sb.h              |    8 +-
 fs/cifs/cifs_spnego.c             |    4 +-
 fs/cifs/cifsacl.c                 |  115 +++++++++++++++++++++++++--------
 fs/cifs/cifsacl.h                 |   16 ++++-
 fs/cifs/cifsfs.c                  |   12 ++-
 fs/cifs/cifsglob.h                |   22 +++---
 fs/cifs/cifspdu.h                 |    2 +
 fs/cifs/cifsproto.h               |    9 ++-
 fs/cifs/cifssmb.c                 |   11 +++-
 fs/cifs/connect.c                 |   58 +++++++++++++----
 fs/cifs/dir.c                     |   18 +++---
 fs/cifs/file.c                    |    8 +-
 fs/cifs/inode.c                   |   28 ++++----
 fs/cifs/misc.c                    |    2 +-
 fs/coda/cache.c                   |    4 +-
 fs/coda/coda_fs_i.h               |    2 +-
 fs/coda/coda_linux.c              |    8 +-
 fs/coda/inode.c                   |    2 +-
 fs/coda/upcall.c                  |    6 +-
 fs/gfs2/acl.c                     |    2 +-
 fs/gfs2/bmap.c                    |    2 +-
 fs/gfs2/dir.c                     |    2 +-
 fs/gfs2/glops.c                   |    4 +-
 fs/gfs2/incore.h                  |    3 +-
 fs/gfs2/inode.c                   |   36 ++++++-----
 fs/gfs2/quota.c                   |  128 ++++++++++++++++---------------------
 fs/gfs2/quota.h                   |   15 ++--
 fs/gfs2/super.c                   |    6 +-
 fs/gfs2/sys.c                     |   14 ++++-
 fs/gfs2/xattr.c                   |    4 +-
 fs/ncpfs/inode.c                  |   55 ++++++++++------
 fs/ncpfs/ioctl.c                  |   25 ++++---
 fs/ncpfs/ncp_fs_sb.h              |    6 +-
 fs/nfs/idmap.c                    |   45 ++++++++-----
 fs/nfs/inode.c                    |   12 ++--
 fs/nfs/nfs2xdr.c                  |    8 +-
 fs/nfs/nfs3xdr.c                  |    8 +-
 fs/nfs/nfs4xdr.c                  |   16 ++--
 fs/nfs_common/nfsacl.c            |   37 ++++++----
 fs/nfsd/acl.h                     |    2 -
 fs/nfsd/auth.c                    |   12 ++--
 fs/nfsd/export.c                  |   22 ++++--
 fs/nfsd/idmap.h                   |    8 +-
 fs/nfsd/nfs3xdr.c                 |    9 ++-
 fs/nfsd/nfs4acl.c                 |   63 +++++++++++++-----
 fs/nfsd/nfs4idmap.c               |   34 ++++++----
 fs/nfsd/nfs4recover.c             |    4 +-
 fs/nfsd/nfs4state.c               |    6 +-
 fs/nfsd/nfs4xdr.c                 |   42 ++++++++-----
 fs/nfsd/nfsxdr.c                  |    9 ++-
 fs/nfsd/vfs.c                     |    8 +-
 fs/ocfs2/acl.c                    |   31 ++++++++-
 fs/ocfs2/dlmglue.c                |    8 +-
 fs/ocfs2/file.c                   |   11 ++--
 fs/ocfs2/inode.c                  |   12 ++--
 fs/ocfs2/namei.c                  |    4 +-
 fs/ocfs2/refcounttree.c           |    2 +-
 fs/xfs/xfs_acl.c                  |   23 ++++++-
 fs/xfs/xfs_dquot.c                |   36 +++++++----
 fs/xfs/xfs_dquot.h                |    5 +-
 fs/xfs/xfs_inode.c                |   33 ++++++----
 fs/xfs/xfs_inode.h                |   32 ++--------
 fs/xfs/xfs_ioctl.c                |   23 +++++--
 fs/xfs/xfs_iops.c                 |   18 +++---
 fs/xfs/xfs_itable.c               |    8 +-
 fs/xfs/xfs_qm.c                   |   87 +++++++++++++------------
 fs/xfs/xfs_qm.h                   |    4 +-
 fs/xfs/xfs_qm_bhv.c               |    3 +-
 fs/xfs/xfs_qm_syscalls.c          |   24 ++++---
 fs/xfs/xfs_quota.h                |    4 +-
 fs/xfs/xfs_quotaops.c             |   20 +-----
 fs/xfs/xfs_rename.c               |    2 +-
 fs/xfs/xfs_trans_dquot.c          |    6 +--
 fs/xfs/xfs_utils.c                |    2 +-
 fs/xfs/xfs_utils.h                |    2 +-
 fs/xfs/xfs_vnodeops.c             |   14 ++--
 include/linux/coda_psdev.h        |    2 +-
 include/linux/nfs4.h              |    6 ++-
 include/linux/nfs_idmap.h         |   10 ++--
 include/linux/nfs_xdr.h           |    4 +-
 include/linux/nfsd/export.h       |    4 +-
 include/linux/posix_acl.h         |    3 -
 include/linux/projid.h            |   15 ----
 include/linux/sunrpc/auth.h       |    7 +-
 include/linux/sunrpc/svcauth.h    |    4 +-
 include/linux/uidgid.h            |   22 ------
 include/net/9p/client.h           |   12 ++--
 init/Kconfig                      |   40 +-----------
 net/9p/client.c                   |   28 +++++----
 net/sunrpc/auth.c                 |    6 +-
 net/sunrpc/auth_generic.c         |   16 +++--
 net/sunrpc/auth_gss/auth_gss.c    |   33 ++++++----
 net/sunrpc/auth_gss/svcauth_gss.c |   14 ++++-
 net/sunrpc/auth_unix.c            |   36 ++++------
 net/sunrpc/svcauth_unix.c         |   40 +++++++-----
 107 files changed, 1035 insertions(+), 820 deletions(-)

[PATCH RFC 01/12] userns: Support 9p interacting with multiple user namespaces

[Eric W. Biederman]

From: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>

Use kuid_t and kgid_t in struct v9fs_session_info and struct 9p_fid.

Cc: Eric Van Hensbergen <ericvh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Ron Minnich <rminnich-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Latchesar Ionkov <lucho-OnYtXJJ0/fesTnJN9+BGXg@public.gmane.org>
Acked-by: Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
Signed-off-by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
---
 fs/9p/fid.c             |   17 +++++++++--------
 fs/9p/v9fs.c            |   34 +++++++++++++++++++++++++++-------
 fs/9p/v9fs.h            |   10 +++++-----
 fs/9p/vfs_inode.c       |    8 ++++----
 fs/9p/vfs_inode_dotl.c  |   22 +++++++++++-----------
 include/net/9p/client.h |   12 ++++++------
 init/Kconfig            |    4 ----
 net/9p/client.c         |   28 ++++++++++++++++------------
 8 files changed, 78 insertions(+), 57 deletions(-)

diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index da8eefb..afd4724 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -74,19 +74,20 @@ int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
  *
  */
 
-static struct p9_fid *v9fs_fid_find(struct dentry *dentry, u32 uid, int any)
+static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any)
 {
 	struct v9fs_dentry *dent;
 	struct p9_fid *fid, *ret;
 
 	p9_debug(P9_DEBUG_VFS, " dentry: %s (%p) uid %d any %d\n",
-		 dentry->d_name.name, dentry, uid, any);
+		 dentry->d_name.name, dentry, from_kuid(&init_user_ns, uid),
+		 any);
 	dent = (struct v9fs_dentry *) dentry->d_fsdata;
 	ret = NULL;
 	if (dent) {
 		spin_lock(&dent->lock);
 		list_for_each_entry(fid, &dent->fidlist, dlist) {
-			if (any || fid->uid == uid) {
+			if (any || uid_eq(fid->uid, uid)) {
 				ret = fid;
 				break;
 			}
@@ -126,7 +127,7 @@ err_out:
 }
 
 static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
-					       uid_t uid, int any)
+					       kuid_t uid, int any)
 {
 	struct dentry *ds;
 	char **wnames, *uname;
@@ -233,7 +234,7 @@ err_out:
 
 struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 {
-	uid_t uid;
+	kuid_t uid;
 	int  any, access;
 	struct v9fs_session_info *v9ses;
 
@@ -253,7 +254,7 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 		break;
 
 	default:
-		uid = ~0;
+		uid = INVALID_UID;
 		any = 0;
 		break;
 	}
@@ -272,7 +273,7 @@ struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
 	return ret;
 }
 
-static struct p9_fid *v9fs_fid_clone_with_uid(struct dentry *dentry, uid_t uid)
+static struct p9_fid *v9fs_fid_clone_with_uid(struct dentry *dentry, kuid_t uid)
 {
 	struct p9_fid *fid, *ret;
 
@@ -289,7 +290,7 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry)
 	int err;
 	struct p9_fid *fid;
 
-	fid = v9fs_fid_clone_with_uid(dentry, 0);
+	fid = v9fs_fid_clone_with_uid(dentry, GLOBAL_ROOT_UID);
 	if (IS_ERR(fid))
 		goto error_out;
 	/*
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index d934f04..1c750ab 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -161,7 +161,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 				ret = r;
 				continue;
 			}
-			v9ses->dfltuid = option;
+			v9ses->dfltuid = make_kuid(&init_user_ns, option);
+			if (!uid_valid(v9ses->dfltuid)) {
+				p9_debug(P9_DEBUG_ERROR,
+					 "uid field, but not a uid?\n");
+				ret = -EINVAL;
+				continue;
+			}
 			break;
 		case Opt_dfltgid:
 			r = match_int(&args[0], &option);
@@ -171,7 +177,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 				ret = r;
 				continue;
 			}
-			v9ses->dfltgid = option;
+			v9ses->dfltgid = make_kgid(&init_user_ns, option);
+			if (!gid_valid(v9ses->dfltgid)) {
+				p9_debug(P9_DEBUG_ERROR,
+					 "gid field, but not a gid?\n");
+				ret = -EINVAL;
+				continue;
+			}
 			break;
 		case Opt_afid:
 			r = match_int(&args[0], &option);
@@ -248,8 +260,9 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 			else if (strcmp(s, "client") == 0) {
 				v9ses->flags |= V9FS_ACCESS_CLIENT;
 			} else {
+				uid_t uid;
 				v9ses->flags |= V9FS_ACCESS_SINGLE;
-				v9ses->uid = simple_strtoul(s, &e, 10);
+				uid = simple_strtoul(s, &e, 10);
 				if (*e != '\0') {
 					ret = -EINVAL;
 					pr_info("Unknown access argument %s\n",
@@ -257,6 +270,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 					kfree(s);
 					goto free_and_return;
 				}
+				v9ses->uid = make_kuid(&init_user_ns, uid);
+				if (!uid_valid(v9ses->uid)) {
+					ret = -EINVAL;
+					pr_info("Uknown uid %s\n", s);
+					kfree(s);
+					goto free_and_return;
+				}
 			}
 
 			kfree(s);
@@ -319,7 +339,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	list_add(&v9ses->slist, &v9fs_sessionlist);
 	spin_unlock(&v9fs_sessionlist_lock);
 
-	v9ses->uid = ~0;
+	v9ses->uid = INVALID_UID;
 	v9ses->dfltuid = V9FS_DEFUID;
 	v9ses->dfltgid = V9FS_DEFGID;
 
@@ -364,7 +384,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 
 		v9ses->flags &= ~V9FS_ACCESS_MASK;
 		v9ses->flags |= V9FS_ACCESS_ANY;
-		v9ses->uid = ~0;
+		v9ses->uid = INVALID_UID;
 	}
 	if (!v9fs_proto_dotl(v9ses) ||
 		!((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
@@ -375,7 +395,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		v9ses->flags &= ~V9FS_ACL_MASK;
 	}
 
-	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
+	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
 							v9ses->aname);
 	if (IS_ERR(fid)) {
 		retval = PTR_ERR(fid);
@@ -387,7 +407,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
 		fid->uid = v9ses->uid;
 	else
-		fid->uid = ~0;
+		fid->uid = INVALID_UID;
 
 #ifdef CONFIG_9P_FSCACHE
 	/* register the session for caching */
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 34c59f1..a8e127c 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -109,9 +109,9 @@ struct v9fs_session_info {
 	char *uname;		/* user name to mount as */
 	char *aname;		/* name of remote hierarchy being mounted */
 	unsigned int maxdata;	/* max data for client interface */
-	unsigned int dfltuid;	/* default uid/muid for legacy support */
-	unsigned int dfltgid;	/* default gid for legacy support */
-	u32 uid;		/* if ACCESS_SINGLE, the uid that has access */
+	kuid_t dfltuid;		/* default uid/muid for legacy support */
+	kgid_t dfltgid;		/* default gid for legacy support */
+	kuid_t uid;		/* if ACCESS_SINGLE, the uid that has access */
 	struct p9_client *clnt;	/* 9p client */
 	struct list_head slist; /* list of sessions registered with v9fs */
 	struct backing_dev_info bdi;
@@ -165,8 +165,8 @@ extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 #define V9FS_PORT	564
 #define V9FS_DEFUSER	"nobody"
 #define V9FS_DEFANAME	""
-#define V9FS_DEFUID	(-2)
-#define V9FS_DEFGID	(-2)
+#define V9FS_DEFUID	KUIDT_INIT(-2)
+#define V9FS_DEFGID	KGIDT_INIT(-2)
 
 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 {
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 890bed5..2c0f777 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1137,10 +1137,10 @@ static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 
 	if (v9fs_proto_dotu(v9ses)) {
 		if (iattr->ia_valid & ATTR_UID)
-			wstat.n_uid = iattr->ia_uid;
+			wstat.n_uid = from_kuid(&init_user_ns, iattr->ia_uid);
 
 		if (iattr->ia_valid & ATTR_GID)
-			wstat.n_gid = iattr->ia_gid;
+			wstat.n_gid = from_kgid(&init_user_ns, iattr->ia_gid);
 	}
 
 	/* Write all dirty data */
@@ -1191,8 +1191,8 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 	inode->i_gid = v9ses->dfltgid;
 
 	if (v9fs_proto_dotu(v9ses)) {
-		inode->i_uid = stat->n_uid;
-		inode->i_gid = stat->n_gid;
+		i_uid_write(inode, stat->n_uid);
+		i_gid_write(inode, stat->n_gid);
 	}
 	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
 		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 4089554..e8695df 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -57,7 +57,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
  * group of the new file system object.
  */
 
-static gid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
+static kgid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
 {
 	BUG_ON(dir_inode == NULL);
 
@@ -246,7 +246,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 			  int *opened)
 {
 	int err = 0;
-	gid_t gid;
+	kgid_t gid;
 	umode_t mode;
 	char *name = NULL;
 	struct p9_qid qid;
@@ -391,7 +391,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir,
 	int err;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid = NULL, *dfid = NULL;
-	gid_t gid;
+	kgid_t gid;
 	char *name;
 	umode_t mode;
 	struct inode *inode;
@@ -576,8 +576,8 @@ int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
 
 	p9attr.valid = v9fs_mapped_iattr_valid(iattr->ia_valid);
 	p9attr.mode = iattr->ia_mode;
-	p9attr.uid = iattr->ia_uid;
-	p9attr.gid = iattr->ia_gid;
+	p9attr.uid = from_kuid(&init_user_ns, iattr->ia_uid);
+	p9attr.gid = from_kgid(&init_user_ns, iattr->ia_gid);
 	p9attr.size = iattr->ia_size;
 	p9attr.atime_sec = iattr->ia_atime.tv_sec;
 	p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
@@ -635,8 +635,8 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 		inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
 		inode->i_ctime.tv_sec = stat->st_ctime_sec;
 		inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
-		inode->i_uid = stat->st_uid;
-		inode->i_gid = stat->st_gid;
+		i_uid_write(inode, stat->st_uid);
+		i_gid_write(inode, stat->st_gid);
 		set_nlink(inode, stat->st_nlink);
 
 		mode = stat->st_mode & S_IALLUGO;
@@ -659,9 +659,9 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 			inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
 		}
 		if (stat->st_result_mask & P9_STATS_UID)
-			inode->i_uid = stat->st_uid;
+			i_uid_write(inode, stat->st_uid);
 		if (stat->st_result_mask & P9_STATS_GID)
-			inode->i_gid = stat->st_gid;
+			i_gid_write(inode, stat->st_gid);
 		if (stat->st_result_mask & P9_STATS_NLINK)
 			set_nlink(inode, stat->st_nlink);
 		if (stat->st_result_mask & P9_STATS_MODE) {
@@ -692,7 +692,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
 		const char *symname)
 {
 	int err;
-	gid_t gid;
+	kgid_t gid;
 	char *name;
 	struct p9_qid qid;
 	struct inode *inode;
@@ -832,7 +832,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 		dev_t rdev)
 {
 	int err;
-	gid_t gid;
+	kgid_t gid;
 	char *name;
 	umode_t mode;
 	struct v9fs_session_info *v9ses;
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index fc9b90b..4d05d94 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -187,7 +187,7 @@ struct p9_fid {
 	int mode;
 	struct p9_qid qid;
 	u32 iounit;
-	uid_t uid;
+	kuid_t uid;
 
 	void *rdir;
 
@@ -220,17 +220,17 @@ void p9_client_destroy(struct p9_client *clnt);
 void p9_client_disconnect(struct p9_client *clnt);
 void p9_client_begin_disconnect(struct p9_client *clnt);
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
-					char *uname, u32 n_uname, char *aname);
+					char *uname, kuid_t n_uname, char *aname);
 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
 		char **wnames, int clone);
 int p9_client_open(struct p9_fid *fid, int mode);
 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 							char *extension);
 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, char *newname);
-int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, gid_t gid,
+int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, kgid_t gid,
 							struct p9_qid *qid);
 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
-		gid_t gid, struct p9_qid *qid);
+		kgid_t gid, struct p9_qid *qid);
 int p9_client_clunk(struct p9_fid *fid);
 int p9_client_fsync(struct p9_fid *fid, int datasync);
 int p9_client_remove(struct p9_fid *fid);
@@ -250,9 +250,9 @@ struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
 							u64 request_mask);
 
 int p9_client_mknod_dotl(struct p9_fid *oldfid, char *name, int mode,
-			dev_t rdev, gid_t gid, struct p9_qid *);
+			dev_t rdev, kgid_t gid, struct p9_qid *);
 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
-				gid_t gid, struct p9_qid *);
+				kgid_t gid, struct p9_qid *);
 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
diff --git a/init/Kconfig b/init/Kconfig
index 38c1a1d..35c1b89 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -998,11 +998,7 @@ config UIDGID_CONVERTED
 	bool
 	default y
 
-	# Networking
-	depends on NET_9P = n
-
 	# Filesystems
-	depends on 9P_FS = n
 	depends on AFS_FS = n
 	depends on CEPH_FS = n
 	depends on CIFS = n
diff --git a/net/9p/client.c b/net/9p/client.c
index 34d4176..25d58f4 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1100,7 +1100,7 @@ void p9_client_begin_disconnect(struct p9_client *clnt)
 EXPORT_SYMBOL(p9_client_begin_disconnect);
 
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
-	char *uname, u32 n_uname, char *aname)
+	char *uname, kuid_t n_uname, char *aname)
 {
 	int err = 0;
 	struct p9_req_t *req;
@@ -1118,7 +1118,8 @@ struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 	}
 
 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
-			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
+			afid ? afid->fid : P9_NOFID, uname, aname,
+			from_kuid(&init_user_ns, n_uname));
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -1270,7 +1271,7 @@ error:
 EXPORT_SYMBOL(p9_client_open);
 
 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
-		gid_t gid, struct p9_qid *qid)
+		kgid_t gid, struct p9_qid *qid)
 {
 	int err = 0;
 	struct p9_client *clnt;
@@ -1279,14 +1280,16 @@ int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
 
 	p9_debug(P9_DEBUG_9P,
 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
-			ofid->fid, name, flags, mode, gid);
+			ofid->fid, name, flags, mode,
+			from_kgid(&init_user_ns, gid));
 	clnt = ofid->clnt;
 
 	if (ofid->mode != -1)
 		return -EINVAL;
 
 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddd", ofid->fid, name, flags,
-			mode, gid);
+			mode,
+			from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -1358,7 +1361,7 @@ error:
 }
 EXPORT_SYMBOL(p9_client_fcreate);
 
-int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
+int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
 		struct p9_qid *qid)
 {
 	int err = 0;
@@ -1370,7 +1373,7 @@ int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
 	clnt = dfid->clnt;
 
 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssd", dfid->fid, name, symtgt,
-			gid);
+			from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -2106,7 +2109,7 @@ error:
 EXPORT_SYMBOL(p9_client_readdir);
 
 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
-			dev_t rdev, gid_t gid, struct p9_qid *qid)
+			dev_t rdev, kgid_t gid, struct p9_qid *qid)
 {
 	int err;
 	struct p9_client *clnt;
@@ -2117,7 +2120,8 @@ int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
 	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddd", fid->fid, name, mode,
-		MAJOR(rdev), MINOR(rdev), gid);
+			MAJOR(rdev), MINOR(rdev),
+			from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -2137,7 +2141,7 @@ error:
 EXPORT_SYMBOL(p9_client_mknod_dotl);
 
 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
-				gid_t gid, struct p9_qid *qid)
+				kgid_t gid, struct p9_qid *qid)
 {
 	int err;
 	struct p9_client *clnt;
@@ -2146,9 +2150,9 @@ int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
 	err = 0;
 	clnt = fid->clnt;
 	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
-		 fid->fid, name, mode, gid);
+		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdd", fid->fid, name, mode,
-		gid);
+		from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
-- 
1.7.5.4

[PATCH RFC 01/12] userns: Support 9p interacting with multiple user namespaces

[Eric W. Biederman]

From: "Eric W. Biederman" <ebiederm@xmission.com>

Use kuid_t and kgid_t in struct v9fs_session_info and struct 9p_fid.

Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 fs/9p/fid.c             |   17 +++++++++--------
 fs/9p/v9fs.c            |   34 +++++++++++++++++++++++++++-------
 fs/9p/v9fs.h            |   10 +++++-----
 fs/9p/vfs_inode.c       |    8 ++++----
 fs/9p/vfs_inode_dotl.c  |   22 +++++++++++-----------
 include/net/9p/client.h |   12 ++++++------
 init/Kconfig            |    4 ----
 net/9p/client.c         |   28 ++++++++++++++++------------
 8 files changed, 78 insertions(+), 57 deletions(-)

diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index da8eefb..afd4724 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -74,19 +74,20 @@ int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
  *
  */
 
-static struct p9_fid *v9fs_fid_find(struct dentry *dentry, u32 uid, int any)
+static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any)
 {
 	struct v9fs_dentry *dent;
 	struct p9_fid *fid, *ret;
 
 	p9_debug(P9_DEBUG_VFS, " dentry: %s (%p) uid %d any %d\n",
-		 dentry->d_name.name, dentry, uid, any);
+		 dentry->d_name.name, dentry, from_kuid(&init_user_ns, uid),
+		 any);
 	dent = (struct v9fs_dentry *) dentry->d_fsdata;
 	ret = NULL;
 	if (dent) {
 		spin_lock(&dent->lock);
 		list_for_each_entry(fid, &dent->fidlist, dlist) {
-			if (any || fid->uid == uid) {
+			if (any || uid_eq(fid->uid, uid)) {
 				ret = fid;
 				break;
 			}
@@ -126,7 +127,7 @@ err_out:
 }
 
 static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
-					       uid_t uid, int any)
+					       kuid_t uid, int any)
 {
 	struct dentry *ds;
 	char **wnames, *uname;
@@ -233,7 +234,7 @@ err_out:
 
 struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 {
-	uid_t uid;
+	kuid_t uid;
 	int  any, access;
 	struct v9fs_session_info *v9ses;
 
@@ -253,7 +254,7 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 		break;
 
 	default:
-		uid = ~0;
+		uid = INVALID_UID;
 		any = 0;
 		break;
 	}
@@ -272,7 +273,7 @@ struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
 	return ret;
 }
 
-static struct p9_fid *v9fs_fid_clone_with_uid(struct dentry *dentry, uid_t uid)
+static struct p9_fid *v9fs_fid_clone_with_uid(struct dentry *dentry, kuid_t uid)
 {
 	struct p9_fid *fid, *ret;
 
@@ -289,7 +290,7 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry)
 	int err;
 	struct p9_fid *fid;
 
-	fid = v9fs_fid_clone_with_uid(dentry, 0);
+	fid = v9fs_fid_clone_with_uid(dentry, GLOBAL_ROOT_UID);
 	if (IS_ERR(fid))
 		goto error_out;
 	/*
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index d934f04..1c750ab 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -161,7 +161,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 				ret = r;
 				continue;
 			}
-			v9ses->dfltuid = option;
+			v9ses->dfltuid = make_kuid(&init_user_ns, option);
+			if (!uid_valid(v9ses->dfltuid)) {
+				p9_debug(P9_DEBUG_ERROR,
+					 "uid field, but not a uid?\n");
+				ret = -EINVAL;
+				continue;
+			}
 			break;
 		case Opt_dfltgid:
 			r = match_int(&args[0], &option);
@@ -171,7 +177,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 				ret = r;
 				continue;
 			}
-			v9ses->dfltgid = option;
+			v9ses->dfltgid = make_kgid(&init_user_ns, option);
+			if (!gid_valid(v9ses->dfltgid)) {
+				p9_debug(P9_DEBUG_ERROR,
+					 "gid field, but not a gid?\n");
+				ret = -EINVAL;
+				continue;
+			}
 			break;
 		case Opt_afid:
 			r = match_int(&args[0], &option);
@@ -248,8 +260,9 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 			else if (strcmp(s, "client") == 0) {
 				v9ses->flags |= V9FS_ACCESS_CLIENT;
 			} else {
+				uid_t uid;
 				v9ses->flags |= V9FS_ACCESS_SINGLE;
-				v9ses->uid = simple_strtoul(s, &e, 10);
+				uid = simple_strtoul(s, &e, 10);
 				if (*e != '\0') {
 					ret = -EINVAL;
 					pr_info("Unknown access argument %s\n",
@@ -257,6 +270,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 					kfree(s);
 					goto free_and_return;
 				}
+				v9ses->uid = make_kuid(&init_user_ns, uid);
+				if (!uid_valid(v9ses->uid)) {
+					ret = -EINVAL;
+					pr_info("Uknown uid %s\n", s);
+					kfree(s);
+					goto free_and_return;
+				}
 			}
 
 			kfree(s);
@@ -319,7 +339,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	list_add(&v9ses->slist, &v9fs_sessionlist);
 	spin_unlock(&v9fs_sessionlist_lock);
 
-	v9ses->uid = ~0;
+	v9ses->uid = INVALID_UID;
 	v9ses->dfltuid = V9FS_DEFUID;
 	v9ses->dfltgid = V9FS_DEFGID;
 
@@ -364,7 +384,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 
 		v9ses->flags &= ~V9FS_ACCESS_MASK;
 		v9ses->flags |= V9FS_ACCESS_ANY;
-		v9ses->uid = ~0;
+		v9ses->uid = INVALID_UID;
 	}
 	if (!v9fs_proto_dotl(v9ses) ||
 		!((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
@@ -375,7 +395,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		v9ses->flags &= ~V9FS_ACL_MASK;
 	}
 
-	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
+	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
 							v9ses->aname);
 	if (IS_ERR(fid)) {
 		retval = PTR_ERR(fid);
@@ -387,7 +407,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
 		fid->uid = v9ses->uid;
 	else
-		fid->uid = ~0;
+		fid->uid = INVALID_UID;
 
 #ifdef CONFIG_9P_FSCACHE
 	/* register the session for caching */
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 34c59f1..a8e127c 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -109,9 +109,9 @@ struct v9fs_session_info {
 	char *uname;		/* user name to mount as */
 	char *aname;		/* name of remote hierarchy being mounted */
 	unsigned int maxdata;	/* max data for client interface */
-	unsigned int dfltuid;	/* default uid/muid for legacy support */
-	unsigned int dfltgid;	/* default gid for legacy support */
-	u32 uid;		/* if ACCESS_SINGLE, the uid that has access */
+	kuid_t dfltuid;		/* default uid/muid for legacy support */
+	kgid_t dfltgid;		/* default gid for legacy support */
+	kuid_t uid;		/* if ACCESS_SINGLE, the uid that has access */
 	struct p9_client *clnt;	/* 9p client */
 	struct list_head slist; /* list of sessions registered with v9fs */
 	struct backing_dev_info bdi;
@@ -165,8 +165,8 @@ extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 #define V9FS_PORT	564
 #define V9FS_DEFUSER	"nobody"
 #define V9FS_DEFANAME	""
-#define V9FS_DEFUID	(-2)
-#define V9FS_DEFGID	(-2)
+#define V9FS_DEFUID	KUIDT_INIT(-2)
+#define V9FS_DEFGID	KGIDT_INIT(-2)
 
 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 {
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 890bed5..2c0f777 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1137,10 +1137,10 @@ static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 
 	if (v9fs_proto_dotu(v9ses)) {
 		if (iattr->ia_valid & ATTR_UID)
-			wstat.n_uid = iattr->ia_uid;
+			wstat.n_uid = from_kuid(&init_user_ns, iattr->ia_uid);
 
 		if (iattr->ia_valid & ATTR_GID)
-			wstat.n_gid = iattr->ia_gid;
+			wstat.n_gid = from_kgid(&init_user_ns, iattr->ia_gid);
 	}
 
 	/* Write all dirty data */
@@ -1191,8 +1191,8 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 	inode->i_gid = v9ses->dfltgid;
 
 	if (v9fs_proto_dotu(v9ses)) {
-		inode->i_uid = stat->n_uid;
-		inode->i_gid = stat->n_gid;
+		i_uid_write(inode, stat->n_uid);
+		i_gid_write(inode, stat->n_gid);
 	}
 	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
 		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 4089554..e8695df 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -57,7 +57,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
  * group of the new file system object.
  */
 
-static gid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
+static kgid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
 {
 	BUG_ON(dir_inode == NULL);
 
@@ -246,7 +246,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 			  int *opened)
 {
 	int err = 0;
-	gid_t gid;
+	kgid_t gid;
 	umode_t mode;
 	char *name = NULL;
 	struct p9_qid qid;
@@ -391,7 +391,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir,
 	int err;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid = NULL, *dfid = NULL;
-	gid_t gid;
+	kgid_t gid;
 	char *name;
 	umode_t mode;
 	struct inode *inode;
@@ -576,8 +576,8 @@ int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
 
 	p9attr.valid = v9fs_mapped_iattr_valid(iattr->ia_valid);
 	p9attr.mode = iattr->ia_mode;
-	p9attr.uid = iattr->ia_uid;
-	p9attr.gid = iattr->ia_gid;
+	p9attr.uid = from_kuid(&init_user_ns, iattr->ia_uid);
+	p9attr.gid = from_kgid(&init_user_ns, iattr->ia_gid);
 	p9attr.size = iattr->ia_size;
 	p9attr.atime_sec = iattr->ia_atime.tv_sec;
 	p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
@@ -635,8 +635,8 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 		inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
 		inode->i_ctime.tv_sec = stat->st_ctime_sec;
 		inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
-		inode->i_uid = stat->st_uid;
-		inode->i_gid = stat->st_gid;
+		i_uid_write(inode, stat->st_uid);
+		i_gid_write(inode, stat->st_gid);
 		set_nlink(inode, stat->st_nlink);
 
 		mode = stat->st_mode & S_IALLUGO;
@@ -659,9 +659,9 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 			inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
 		}
 		if (stat->st_result_mask & P9_STATS_UID)
-			inode->i_uid = stat->st_uid;
+			i_uid_write(inode, stat->st_uid);
 		if (stat->st_result_mask & P9_STATS_GID)
-			inode->i_gid = stat->st_gid;
+			i_gid_write(inode, stat->st_gid);
 		if (stat->st_result_mask & P9_STATS_NLINK)
 			set_nlink(inode, stat->st_nlink);
 		if (stat->st_result_mask & P9_STATS_MODE) {
@@ -692,7 +692,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
 		const char *symname)
 {
 	int err;
-	gid_t gid;
+	kgid_t gid;
 	char *name;
 	struct p9_qid qid;
 	struct inode *inode;
@@ -832,7 +832,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 		dev_t rdev)
 {
 	int err;
-	gid_t gid;
+	kgid_t gid;
 	char *name;
 	umode_t mode;
 	struct v9fs_session_info *v9ses;
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index fc9b90b..4d05d94 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -187,7 +187,7 @@ struct p9_fid {
 	int mode;
 	struct p9_qid qid;
 	u32 iounit;
-	uid_t uid;
+	kuid_t uid;
 
 	void *rdir;
 
@@ -220,17 +220,17 @@ void p9_client_destroy(struct p9_client *clnt);
 void p9_client_disconnect(struct p9_client *clnt);
 void p9_client_begin_disconnect(struct p9_client *clnt);
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
-					char *uname, u32 n_uname, char *aname);
+					char *uname, kuid_t n_uname, char *aname);
 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
 		char **wnames, int clone);
 int p9_client_open(struct p9_fid *fid, int mode);
 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 							char *extension);
 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, char *newname);
-int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, gid_t gid,
+int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, kgid_t gid,
 							struct p9_qid *qid);
 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
-		gid_t gid, struct p9_qid *qid);
+		kgid_t gid, struct p9_qid *qid);
 int p9_client_clunk(struct p9_fid *fid);
 int p9_client_fsync(struct p9_fid *fid, int datasync);
 int p9_client_remove(struct p9_fid *fid);
@@ -250,9 +250,9 @@ struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
 							u64 request_mask);
 
 int p9_client_mknod_dotl(struct p9_fid *oldfid, char *name, int mode,
-			dev_t rdev, gid_t gid, struct p9_qid *);
+			dev_t rdev, kgid_t gid, struct p9_qid *);
 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
-				gid_t gid, struct p9_qid *);
+				kgid_t gid, struct p9_qid *);
 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
diff --git a/init/Kconfig b/init/Kconfig
index 38c1a1d..35c1b89 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -998,11 +998,7 @@ config UIDGID_CONVERTED
 	bool
 	default y
 
-	# Networking
-	depends on NET_9P = n
-
 	# Filesystems
-	depends on 9P_FS = n
 	depends on AFS_FS = n
 	depends on CEPH_FS = n
 	depends on CIFS = n
diff --git a/net/9p/client.c b/net/9p/client.c
index 34d4176..25d58f4 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1100,7 +1100,7 @@ void p9_client_begin_disconnect(struct p9_client *clnt)
 EXPORT_SYMBOL(p9_client_begin_disconnect);
 
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
-	char *uname, u32 n_uname, char *aname)
+	char *uname, kuid_t n_uname, char *aname)
 {
 	int err = 0;
 	struct p9_req_t *req;
@@ -1118,7 +1118,8 @@ struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 	}
 
 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
-			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
+			afid ? afid->fid : P9_NOFID, uname, aname,
+			from_kuid(&init_user_ns, n_uname));
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -1270,7 +1271,7 @@ error:
 EXPORT_SYMBOL(p9_client_open);
 
 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
-		gid_t gid, struct p9_qid *qid)
+		kgid_t gid, struct p9_qid *qid)
 {
 	int err = 0;
 	struct p9_client *clnt;
@@ -1279,14 +1280,16 @@ int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
 
 	p9_debug(P9_DEBUG_9P,
 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
-			ofid->fid, name, flags, mode, gid);
+			ofid->fid, name, flags, mode,
+			from_kgid(&init_user_ns, gid));
 	clnt = ofid->clnt;
 
 	if (ofid->mode != -1)
 		return -EINVAL;
 
 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddd", ofid->fid, name, flags,
-			mode, gid);
+			mode,
+			from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -1358,7 +1361,7 @@ error:
 }
 EXPORT_SYMBOL(p9_client_fcreate);
 
-int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
+int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
 		struct p9_qid *qid)
 {
 	int err = 0;
@@ -1370,7 +1373,7 @@ int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
 	clnt = dfid->clnt;
 
 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssd", dfid->fid, name, symtgt,
-			gid);
+			from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -2106,7 +2109,7 @@ error:
 EXPORT_SYMBOL(p9_client_readdir);
 
 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
-			dev_t rdev, gid_t gid, struct p9_qid *qid)
+			dev_t rdev, kgid_t gid, struct p9_qid *qid)
 {
 	int err;
 	struct p9_client *clnt;
@@ -2117,7 +2120,8 @@ int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
 	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddd", fid->fid, name, mode,
-		MAJOR(rdev), MINOR(rdev), gid);
+			MAJOR(rdev), MINOR(rdev),
+			from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -2137,7 +2141,7 @@ error:
 EXPORT_SYMBOL(p9_client_mknod_dotl);
 
 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
-				gid_t gid, struct p9_qid *qid)
+				kgid_t gid, struct p9_qid *qid)
 {
 	int err;
 	struct p9_client *clnt;
@@ -2146,9 +2150,9 @@ int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
 	err = 0;
 	clnt = fid->clnt;
 	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
-		 fid->fid, name, mode, gid);
+		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdd", fid->fid, name, mode,
-		gid);
+		from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
-- 
1.7.5.4

[PATCH RFC 01/12] userns: Support 9p interacting with multiple user namespaces

[Eric W. Biederman]

From: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>

Use kuid_t and kgid_t in struct v9fs_session_info and struct 9p_fid.

Cc: Eric Van Hensbergen <ericvh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Ron Minnich <rminnich-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Latchesar Ionkov <lucho-OnYtXJJ0/fesTnJN9+BGXg@public.gmane.org>
Acked-by: Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
Signed-off-by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
---
 fs/9p/fid.c             |   17 +++++++++--------
 fs/9p/v9fs.c            |   34 +++++++++++++++++++++++++++-------
 fs/9p/v9fs.h            |   10 +++++-----
 fs/9p/vfs_inode.c       |    8 ++++----
 fs/9p/vfs_inode_dotl.c  |   22 +++++++++++-----------
 include/net/9p/client.h |   12 ++++++------
 init/Kconfig            |    4 ----
 net/9p/client.c         |   28 ++++++++++++++++------------
 8 files changed, 78 insertions(+), 57 deletions(-)

diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index da8eefb..afd4724 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -74,19 +74,20 @@ int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
  *
  */
 
-static struct p9_fid *v9fs_fid_find(struct dentry *dentry, u32 uid, int any)
+static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any)
 {
 	struct v9fs_dentry *dent;
 	struct p9_fid *fid, *ret;
 
 	p9_debug(P9_DEBUG_VFS, " dentry: %s (%p) uid %d any %d\n",
-		 dentry->d_name.name, dentry, uid, any);
+		 dentry->d_name.name, dentry, from_kuid(&init_user_ns, uid),
+		 any);
 	dent = (struct v9fs_dentry *) dentry->d_fsdata;
 	ret = NULL;
 	if (dent) {
 		spin_lock(&dent->lock);
 		list_for_each_entry(fid, &dent->fidlist, dlist) {
-			if (any || fid->uid == uid) {
+			if (any || uid_eq(fid->uid, uid)) {
 				ret = fid;
 				break;
 			}
@@ -126,7 +127,7 @@ err_out:
 }
 
 static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
-					       uid_t uid, int any)
+					       kuid_t uid, int any)
 {
 	struct dentry *ds;
 	char **wnames, *uname;
@@ -233,7 +234,7 @@ err_out:
 
 struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 {
-	uid_t uid;
+	kuid_t uid;
 	int  any, access;
 	struct v9fs_session_info *v9ses;
 
@@ -253,7 +254,7 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 		break;
 
 	default:
-		uid = ~0;
+		uid = INVALID_UID;
 		any = 0;
 		break;
 	}
@@ -272,7 +273,7 @@ struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
 	return ret;
 }
 
-static struct p9_fid *v9fs_fid_clone_with_uid(struct dentry *dentry, uid_t uid)
+static struct p9_fid *v9fs_fid_clone_with_uid(struct dentry *dentry, kuid_t uid)
 {
 	struct p9_fid *fid, *ret;
 
@@ -289,7 +290,7 @@ struct p9_fid *v9fs_writeback_fid(struct dentry *dentry)
 	int err;
 	struct p9_fid *fid;
 
-	fid = v9fs_fid_clone_with_uid(dentry, 0);
+	fid = v9fs_fid_clone_with_uid(dentry, GLOBAL_ROOT_UID);
 	if (IS_ERR(fid))
 		goto error_out;
 	/*
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index d934f04..1c750ab 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -161,7 +161,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 				ret = r;
 				continue;
 			}
-			v9ses->dfltuid = option;
+			v9ses->dfltuid = make_kuid(&init_user_ns, option);
+			if (!uid_valid(v9ses->dfltuid)) {
+				p9_debug(P9_DEBUG_ERROR,
+					 "uid field, but not a uid?\n");
+				ret = -EINVAL;
+				continue;
+			}
 			break;
 		case Opt_dfltgid:
 			r = match_int(&args[0], &option);
@@ -171,7 +177,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 				ret = r;
 				continue;
 			}
-			v9ses->dfltgid = option;
+			v9ses->dfltgid = make_kgid(&init_user_ns, option);
+			if (!gid_valid(v9ses->dfltgid)) {
+				p9_debug(P9_DEBUG_ERROR,
+					 "gid field, but not a gid?\n");
+				ret = -EINVAL;
+				continue;
+			}
 			break;
 		case Opt_afid:
 			r = match_int(&args[0], &option);
@@ -248,8 +260,9 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 			else if (strcmp(s, "client") == 0) {
 				v9ses->flags |= V9FS_ACCESS_CLIENT;
 			} else {
+				uid_t uid;
 				v9ses->flags |= V9FS_ACCESS_SINGLE;
-				v9ses->uid = simple_strtoul(s, &e, 10);
+				uid = simple_strtoul(s, &e, 10);
 				if (*e != '\0') {
 					ret = -EINVAL;
 					pr_info("Unknown access argument %s\n",
@@ -257,6 +270,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 					kfree(s);
 					goto free_and_return;
 				}
+				v9ses->uid = make_kuid(&init_user_ns, uid);
+				if (!uid_valid(v9ses->uid)) {
+					ret = -EINVAL;
+					pr_info("Uknown uid %s\n", s);
+					kfree(s);
+					goto free_and_return;
+				}
 			}
 
 			kfree(s);
@@ -319,7 +339,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	list_add(&v9ses->slist, &v9fs_sessionlist);
 	spin_unlock(&v9fs_sessionlist_lock);
 
-	v9ses->uid = ~0;
+	v9ses->uid = INVALID_UID;
 	v9ses->dfltuid = V9FS_DEFUID;
 	v9ses->dfltgid = V9FS_DEFGID;
 
@@ -364,7 +384,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 
 		v9ses->flags &= ~V9FS_ACCESS_MASK;
 		v9ses->flags |= V9FS_ACCESS_ANY;
-		v9ses->uid = ~0;
+		v9ses->uid = INVALID_UID;
 	}
 	if (!v9fs_proto_dotl(v9ses) ||
 		!((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
@@ -375,7 +395,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		v9ses->flags &= ~V9FS_ACL_MASK;
 	}
 
-	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
+	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
 							v9ses->aname);
 	if (IS_ERR(fid)) {
 		retval = PTR_ERR(fid);
@@ -387,7 +407,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
 		fid->uid = v9ses->uid;
 	else
-		fid->uid = ~0;
+		fid->uid = INVALID_UID;
 
 #ifdef CONFIG_9P_FSCACHE
 	/* register the session for caching */
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 34c59f1..a8e127c 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -109,9 +109,9 @@ struct v9fs_session_info {
 	char *uname;		/* user name to mount as */
 	char *aname;		/* name of remote hierarchy being mounted */
 	unsigned int maxdata;	/* max data for client interface */
-	unsigned int dfltuid;	/* default uid/muid for legacy support */
-	unsigned int dfltgid;	/* default gid for legacy support */
-	u32 uid;		/* if ACCESS_SINGLE, the uid that has access */
+	kuid_t dfltuid;		/* default uid/muid for legacy support */
+	kgid_t dfltgid;		/* default gid for legacy support */
+	kuid_t uid;		/* if ACCESS_SINGLE, the uid that has access */
 	struct p9_client *clnt;	/* 9p client */
 	struct list_head slist; /* list of sessions registered with v9fs */
 	struct backing_dev_info bdi;
@@ -165,8 +165,8 @@ extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 #define V9FS_PORT	564
 #define V9FS_DEFUSER	"nobody"
 #define V9FS_DEFANAME	""
-#define V9FS_DEFUID	(-2)
-#define V9FS_DEFGID	(-2)
+#define V9FS_DEFUID	KUIDT_INIT(-2)
+#define V9FS_DEFGID	KGIDT_INIT(-2)
 
 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 {
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 890bed5..2c0f777 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1137,10 +1137,10 @@ static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 
 	if (v9fs_proto_dotu(v9ses)) {
 		if (iattr->ia_valid & ATTR_UID)
-			wstat.n_uid = iattr->ia_uid;
+			wstat.n_uid = from_kuid(&init_user_ns, iattr->ia_uid);
 
 		if (iattr->ia_valid & ATTR_GID)
-			wstat.n_gid = iattr->ia_gid;
+			wstat.n_gid = from_kgid(&init_user_ns, iattr->ia_gid);
 	}
 
 	/* Write all dirty data */
@@ -1191,8 +1191,8 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 	inode->i_gid = v9ses->dfltgid;
 
 	if (v9fs_proto_dotu(v9ses)) {
-		inode->i_uid = stat->n_uid;
-		inode->i_gid = stat->n_gid;
+		i_uid_write(inode, stat->n_uid);
+		i_gid_write(inode, stat->n_gid);
 	}
 	if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
 		if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 4089554..e8695df 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -57,7 +57,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
  * group of the new file system object.
  */
 
-static gid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
+static kgid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
 {
 	BUG_ON(dir_inode == NULL);
 
@@ -246,7 +246,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 			  int *opened)
 {
 	int err = 0;
-	gid_t gid;
+	kgid_t gid;
 	umode_t mode;
 	char *name = NULL;
 	struct p9_qid qid;
@@ -391,7 +391,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir,
 	int err;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid = NULL, *dfid = NULL;
-	gid_t gid;
+	kgid_t gid;
 	char *name;
 	umode_t mode;
 	struct inode *inode;
@@ -576,8 +576,8 @@ int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
 
 	p9attr.valid = v9fs_mapped_iattr_valid(iattr->ia_valid);
 	p9attr.mode = iattr->ia_mode;
-	p9attr.uid = iattr->ia_uid;
-	p9attr.gid = iattr->ia_gid;
+	p9attr.uid = from_kuid(&init_user_ns, iattr->ia_uid);
+	p9attr.gid = from_kgid(&init_user_ns, iattr->ia_gid);
 	p9attr.size = iattr->ia_size;
 	p9attr.atime_sec = iattr->ia_atime.tv_sec;
 	p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
@@ -635,8 +635,8 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 		inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
 		inode->i_ctime.tv_sec = stat->st_ctime_sec;
 		inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
-		inode->i_uid = stat->st_uid;
-		inode->i_gid = stat->st_gid;
+		i_uid_write(inode, stat->st_uid);
+		i_gid_write(inode, stat->st_gid);
 		set_nlink(inode, stat->st_nlink);
 
 		mode = stat->st_mode & S_IALLUGO;
@@ -659,9 +659,9 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 			inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
 		}
 		if (stat->st_result_mask & P9_STATS_UID)
-			inode->i_uid = stat->st_uid;
+			i_uid_write(inode, stat->st_uid);
 		if (stat->st_result_mask & P9_STATS_GID)
-			inode->i_gid = stat->st_gid;
+			i_gid_write(inode, stat->st_gid);
 		if (stat->st_result_mask & P9_STATS_NLINK)
 			set_nlink(inode, stat->st_nlink);
 		if (stat->st_result_mask & P9_STATS_MODE) {
@@ -692,7 +692,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
 		const char *symname)
 {
 	int err;
-	gid_t gid;
+	kgid_t gid;
 	char *name;
 	struct p9_qid qid;
 	struct inode *inode;
@@ -832,7 +832,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 		dev_t rdev)
 {
 	int err;
-	gid_t gid;
+	kgid_t gid;
 	char *name;
 	umode_t mode;
 	struct v9fs_session_info *v9ses;
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index fc9b90b..4d05d94 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -187,7 +187,7 @@ struct p9_fid {
 	int mode;
 	struct p9_qid qid;
 	u32 iounit;
-	uid_t uid;
+	kuid_t uid;
 
 	void *rdir;
 
@@ -220,17 +220,17 @@ void p9_client_destroy(struct p9_client *clnt);
 void p9_client_disconnect(struct p9_client *clnt);
 void p9_client_begin_disconnect(struct p9_client *clnt);
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
-					char *uname, u32 n_uname, char *aname);
+					char *uname, kuid_t n_uname, char *aname);
 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
 		char **wnames, int clone);
 int p9_client_open(struct p9_fid *fid, int mode);
 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 							char *extension);
 int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, char *newname);
-int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, gid_t gid,
+int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, kgid_t gid,
 							struct p9_qid *qid);
 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
-		gid_t gid, struct p9_qid *qid);
+		kgid_t gid, struct p9_qid *qid);
 int p9_client_clunk(struct p9_fid *fid);
 int p9_client_fsync(struct p9_fid *fid, int datasync);
 int p9_client_remove(struct p9_fid *fid);
@@ -250,9 +250,9 @@ struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
 							u64 request_mask);
 
 int p9_client_mknod_dotl(struct p9_fid *oldfid, char *name, int mode,
-			dev_t rdev, gid_t gid, struct p9_qid *);
+			dev_t rdev, kgid_t gid, struct p9_qid *);
 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
-				gid_t gid, struct p9_qid *);
+				kgid_t gid, struct p9_qid *);
 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
 struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
diff --git a/init/Kconfig b/init/Kconfig
index 38c1a1d..35c1b89 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -998,11 +998,7 @@ config UIDGID_CONVERTED
 	bool
 	default y
 
-	# Networking
-	depends on NET_9P = n
-
 	# Filesystems
-	depends on 9P_FS = n
 	depends on AFS_FS = n
 	depends on CEPH_FS = n
 	depends on CIFS = n
diff --git a/net/9p/client.c b/net/9p/client.c
index 34d4176..25d58f4 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1100,7 +1100,7 @@ void p9_client_begin_disconnect(struct p9_client *clnt)
 EXPORT_SYMBOL(p9_client_begin_disconnect);
 
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
-	char *uname, u32 n_uname, char *aname)
+	char *uname, kuid_t n_uname, char *aname)
 {
 	int err = 0;
 	struct p9_req_t *req;
@@ -1118,7 +1118,8 @@ struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 	}
 
 	req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
-			afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
+			afid ? afid->fid : P9_NOFID, uname, aname,
+			from_kuid(&init_user_ns, n_uname));
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -1270,7 +1271,7 @@ error:
 EXPORT_SYMBOL(p9_client_open);
 
 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
-		gid_t gid, struct p9_qid *qid)
+		kgid_t gid, struct p9_qid *qid)
 {
 	int err = 0;
 	struct p9_client *clnt;
@@ -1279,14 +1280,16 @@ int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
 
 	p9_debug(P9_DEBUG_9P,
 			">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
-			ofid->fid, name, flags, mode, gid);
+			ofid->fid, name, flags, mode,
+			from_kgid(&init_user_ns, gid));
 	clnt = ofid->clnt;
 
 	if (ofid->mode != -1)
 		return -EINVAL;
 
 	req = p9_client_rpc(clnt, P9_TLCREATE, "dsddd", ofid->fid, name, flags,
-			mode, gid);
+			mode,
+			from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -1358,7 +1361,7 @@ error:
 }
 EXPORT_SYMBOL(p9_client_fcreate);
 
-int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
+int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, kgid_t gid,
 		struct p9_qid *qid)
 {
 	int err = 0;
@@ -1370,7 +1373,7 @@ int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
 	clnt = dfid->clnt;
 
 	req = p9_client_rpc(clnt, P9_TSYMLINK, "dssd", dfid->fid, name, symtgt,
-			gid);
+			from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req)) {
 		err = PTR_ERR(req);
 		goto error;
@@ -2106,7 +2109,7 @@ error:
 EXPORT_SYMBOL(p9_client_readdir);
 
 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
-			dev_t rdev, gid_t gid, struct p9_qid *qid)
+			dev_t rdev, kgid_t gid, struct p9_qid *qid)
 {
 	int err;
 	struct p9_client *clnt;
@@ -2117,7 +2120,8 @@ int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
 	p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
 		"minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
 	req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddd", fid->fid, name, mode,
-		MAJOR(rdev), MINOR(rdev), gid);
+			MAJOR(rdev), MINOR(rdev),
+			from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -2137,7 +2141,7 @@ error:
 EXPORT_SYMBOL(p9_client_mknod_dotl);
 
 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
-				gid_t gid, struct p9_qid *qid)
+				kgid_t gid, struct p9_qid *qid)
 {
 	int err;
 	struct p9_client *clnt;
@@ -2146,9 +2150,9 @@ int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
 	err = 0;
 	clnt = fid->clnt;
 	p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
-		 fid->fid, name, mode, gid);
+		 fid->fid, name, mode, from_kgid(&init_user_ns, gid));
 	req = p9_client_rpc(clnt, P9_TMKDIR, "dsdd", fid->fid, name, mode,
-		gid);
+		from_kgid(&init_user_ns, gid));
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
-- 
1.7.5.4