Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull user namespace and namespace infrastructure changes from Eric W Biederman:
 "This set of changes starts with a few small enhnacements to the user
  namespace.  reboot support, allowing more arbitrary mappings, and
  support for mounting devpts, ramfs, tmpfs, and mqueuefs as just the
  user namespace root.

  I do my best to document that if you care about limiting your
  unprivileged users that when you have the user namespace support
  enabled you will need to enable memory control groups.

  There is a minor bug fix to prevent overflowing the stack if someone
  creates way too many user namespaces.

  The bulk of the changes are a continuation of the kuid/kgid push down
  work through the filesystems.  These changes make using uids and gids
  typesafe which ensures that these filesystems are safe to use when
  multiple user namespaces are in use.  The filesystems converted for
  3.9 are ceph, 9p, afs, ocfs2, gfs2, ncpfs, nfs, nfsd, and cifs.  The
  changes for these filesystems were a little more involved so I split
  the changes into smaller hopefully obviously correct changes.

  XFS is the only filesystem that remains.  I was hoping I could get
  that in this release so that user namespace support would be enabled
  with an allyesconfig or an allmodconfig but it looks like the xfs
  changes need another couple of days before it they are ready."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (93 commits)
  cifs: Enable building with user namespaces enabled.
  cifs: Convert struct cifs_ses to use a kuid_t and a kgid_t
  cifs: Convert struct cifs_sb_info to use kuids and kgids
  cifs: Modify struct smb_vol to use kuids and kgids
  cifs: Convert struct cifsFileInfo to use a kuid
  cifs: Convert struct cifs_fattr to use kuid and kgids
  cifs: Convert struct tcon_link to use a kuid.
  cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t
  cifs: Convert from a kuid before printing current_fsuid
  cifs: Use kuids and kgids SID to uid/gid mapping
  cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_alloc
  cifs: Use BUILD_BUG_ON to validate uids and gids are the same size
  cifs: Override unmappable incoming uids and gids
  nfsd: Enable building with user namespaces enabled.
  nfsd: Properly compare and initialize kuids and kgids
  nfsd: Store ex_anon_uid and ex_anon_gid as kuids and kgids
  nfsd: Modify nfsd4_cb_sec to use kuids and kgids
  nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion
  nfsd: Convert nfsxdr to use kuids and kgids
  nfsd: Convert nfs3xdr to use kuids and kgids
  ...

14 files changed, 158 insertions, 97 deletions

diff --git a/fs/nfsd/acl.h b/fs/nfsd/acl.h
index 34e5c40af5ef..8b186a4955cc 100644
--- a/fs/nfsd/acl.h
+++ b/fs/nfsd/acl.h
@@ -44,8 +44,6 @@
 struct nfs4_acl *nfs4_acl_new(int);
 int nfs4_acl_get_whotype(char *, u32);
 int nfs4_acl_write_who(int who, char *p);
-int nfs4_acl_permission(struct nfs4_acl *acl, uid_t owner, gid_t group,
-		                        uid_t who, u32 mask);
 
 #define NFS4_ACL_TYPE_DEFAULT	0x01
 #define NFS4_ACL_DIR		0x02
diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c
index 34a10d78b839..06cddd572264 100644
--- a/fs/nfsd/auth.c
+++ b/fs/nfsd/auth.c
@@ -47,9 +47,9 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
 		if (!gi)
 			goto oom;
 	} else if (flags & NFSEXP_ROOTSQUASH) {
-		if (!new->fsuid)
+		if (uid_eq(new->fsuid, GLOBAL_ROOT_UID))
 			new->fsuid = exp->ex_anon_uid;
-		if (!new->fsgid)
+		if (gid_eq(new->fsgid, GLOBAL_ROOT_GID))
 			new->fsgid = exp->ex_anon_gid;
 
 		gi = groups_alloc(rqgi->ngroups);
@@ -58,7 +58,7 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
 
 		for (i = 0; i < rqgi->ngroups; i++) {
 			if (gid_eq(GLOBAL_ROOT_GID, GROUP_AT(rqgi, i)))
-				GROUP_AT(gi, i) = make_kgid(&init_user_ns, exp->ex_anon_gid);
+				GROUP_AT(gi, i) = exp->ex_anon_gid;
 			else
 				GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
 		}
@@ -66,9 +66,9 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
 		gi = get_group_info(rqgi);
 	}
 
-	if (new->fsuid == (uid_t) -1)
+	if (uid_eq(new->fsuid, INVALID_UID))
 		new->fsuid = exp->ex_anon_uid;
-	if (new->fsgid == (gid_t) -1)
+	if (gid_eq(new->fsgid, INVALID_GID))
 		new->fsgid = exp->ex_anon_gid;
 
 	ret = set_groups(new, gi);
@@ -76,7 +76,7 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
 	if (ret < 0)
 		goto error;
 
-	if (new->fsuid)
+	if (!uid_eq(new->fsuid, GLOBAL_ROOT_UID))
 		new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
 	else
 		new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
diff --git a/fs/nfsd/auth.h b/fs/nfsd/auth.h
index 78b3c0e93822..53325a12ba62 100644
--- a/fs/nfsd/auth.h
+++ b/fs/nfsd/auth.h
@@ -1,6 +1,5 @@
 /*
  * nfsd-specific authentication stuff.
- * uid/gid mapping not yet implemented.
  *
  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  */
@@ -8,11 +7,6 @@
 #ifndef LINUX_NFSD_AUTH_H
 #define LINUX_NFSD_AUTH_H
 
-#define nfsd_luid(rq, uid)	((u32)(uid))
-#define nfsd_lgid(rq, gid)	((u32)(gid))
-#define nfsd_ruid(rq, uid)	((u32)(uid))
-#define nfsd_rgid(rq, gid)	((u32)(gid))
-
 /*
  * Set the current process's fsuid/fsgid etc to those of the NFS
  * client user
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index a3946cf13fc8..5681c5906f08 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -544,13 +544,17 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
 		err = get_int(&mesg, &an_int);
 		if (err)
 			goto out3;
-		exp.ex_anon_uid= an_int;
+		exp.ex_anon_uid= make_kuid(&init_user_ns, an_int);
+		if (!uid_valid(exp.ex_anon_uid))
+			goto out3;
 
 		/* anon gid */
 		err = get_int(&mesg, &an_int);
 		if (err)
 			goto out3;
-		exp.ex_anon_gid= an_int;
+		exp.ex_anon_gid= make_kgid(&init_user_ns, an_int);
+		if (!gid_valid(exp.ex_anon_gid))
+			goto out3;
 
 		/* fsid */
 		err = get_int(&mesg, &an_int);
@@ -613,7 +617,7 @@ out:
 }
 
 static void exp_flags(struct seq_file *m, int flag, int fsid,
-		uid_t anonu, uid_t anong, struct nfsd4_fs_locations *fslocs);
+		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
 static void show_secinfo(struct seq_file *m, struct svc_export *exp);
 
 static int svc_export_show(struct seq_file *m,
@@ -1179,15 +1183,17 @@ static void show_secinfo(struct seq_file *m, struct svc_export *exp)
 }
 
 static void exp_flags(struct seq_file *m, int flag, int fsid,
-		uid_t anonu, uid_t anong, struct nfsd4_fs_locations *fsloc)
+		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
 {
 	show_expflags(m, flag, NFSEXP_ALLFLAGS);
 	if (flag & NFSEXP_FSID)
 		seq_printf(m, ",fsid=%d", fsid);
-	if (anonu != (uid_t)-2 && anonu != (0x10000-2))
-		seq_printf(m, ",anonuid=%u", anonu);
-	if (anong != (gid_t)-2 && anong != (0x10000-2))
-		seq_printf(m, ",anongid=%u", anong);
+	if (!uid_eq(anonu, make_kuid(&init_user_ns, (uid_t)-2)) &&
+	    !uid_eq(anonu, make_kuid(&init_user_ns, 0x10000-2)))
+		seq_printf(m, ",anonuid=%u", from_kuid(&init_user_ns, anonu));
+	if (!gid_eq(anong, make_kgid(&init_user_ns, (gid_t)-2)) &&
+	    !gid_eq(anong, make_kgid(&init_user_ns, 0x10000-2)))
+		seq_printf(m, ",anongid=%u", from_kgid(&init_user_ns, anong));
 	if (fsloc && fsloc->locations_count > 0) {
 		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
 		int i;
diff --git a/fs/nfsd/idmap.h b/fs/nfsd/idmap.h
index 9d513efc01ba..bf95f6b817a4 100644
--- a/fs/nfsd/idmap.h
+++ b/fs/nfsd/idmap.h
@@ -54,9 +54,9 @@ static inline void nfsd_idmap_shutdown(struct net *net)
 }
 #endif
 
-__be32 nfsd_map_name_to_uid(struct svc_rqst *, const char *, size_t, __u32 *);
-__be32 nfsd_map_name_to_gid(struct svc_rqst *, const char *, size_t, __u32 *);
-int nfsd_map_uid_to_name(struct svc_rqst *, __u32, char *);
-int nfsd_map_gid_to_name(struct svc_rqst *, __u32, char *);
+__be32 nfsd_map_name_to_uid(struct svc_rqst *, const char *, size_t, kuid_t *);
+__be32 nfsd_map_name_to_gid(struct svc_rqst *, const char *, size_t, kgid_t *);
+int nfsd_map_uid_to_name(struct svc_rqst *, kuid_t, char *);
+int nfsd_map_gid_to_name(struct svc_rqst *, kgid_t, char *);
 
 #endif /* LINUX_NFSD_IDMAP_H */
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 324c0baf7cda..925c944bc0bc 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -105,12 +105,14 @@ decode_sattr3(__be32 *p, struct iattr *iap)
 		iap->ia_mode = ntohl(*p++);
 	}
 	if (*p++) {
-		iap->ia_valid |= ATTR_UID;
-		iap->ia_uid = ntohl(*p++);
+		iap->ia_uid = make_kuid(&init_user_ns, ntohl(*p++));
+		if (uid_valid(iap->ia_uid))
+			iap->ia_valid |= ATTR_UID;
 	}
 	if (*p++) {
-		iap->ia_valid |= ATTR_GID;
-		iap->ia_gid = ntohl(*p++);
+		iap->ia_gid = make_kgid(&init_user_ns, ntohl(*p++));
+		if (gid_valid(iap->ia_gid))
+			iap->ia_valid |= ATTR_GID;
 	}
 	if (*p++) {
 		u64	newsize;
@@ -167,8 +169,8 @@ encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
 	*p++ = htonl((u32) stat->mode);
 	*p++ = htonl((u32) stat->nlink);
-	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
-	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
+	*p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
+	*p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
 	} else {
diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
index 9c51aff02ae2..8a50b3c18093 100644
--- a/fs/nfsd/nfs4acl.c
+++ b/fs/nfsd/nfs4acl.c
@@ -264,7 +264,7 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
 			ace->flag = eflag;
 			ace->access_mask = deny_mask_from_posix(deny, flags);
 			ace->whotype = NFS4_ACL_WHO_NAMED;
-			ace->who = pa->e_id;
+			ace->who_uid = pa->e_uid;
 			ace++;
 			acl->naces++;
 		}
@@ -273,7 +273,7 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
 		ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
 						   flags);
 		ace->whotype = NFS4_ACL_WHO_NAMED;
-		ace->who = pa->e_id;
+		ace->who_uid = pa->e_uid;
 		ace++;
 		acl->naces++;
 		pa++;
@@ -300,7 +300,7 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
 		ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
 						   flags);
 		ace->whotype = NFS4_ACL_WHO_NAMED;
-		ace->who = pa->e_id;
+		ace->who_gid = pa->e_gid;
 		ace++;
 		acl->naces++;
 		pa++;
@@ -329,7 +329,7 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
 			ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
 			ace->access_mask = deny_mask_from_posix(deny, flags);
 			ace->whotype = NFS4_ACL_WHO_NAMED;
-			ace->who = pa->e_id;
+			ace->who_gid = pa->e_gid;
 			ace++;
 			acl->naces++;
 		}
@@ -345,6 +345,18 @@ _posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
 	acl->naces++;
 }
 
+static bool
+pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
+{
+	if (pace1->e_tag != pace2->e_tag)
+		return pace1->e_tag > pace2->e_tag;
+	if (pace1->e_tag == ACL_USER)
+		return uid_gt(pace1->e_uid, pace2->e_uid);
+	if (pace1->e_tag == ACL_GROUP)
+		return gid_gt(pace1->e_gid, pace2->e_gid);
+	return false;
+}
+
 static void
 sort_pacl_range(struct posix_acl *pacl, int start, int end) {
 	int sorted = 0, i;
@@ -355,8 +367,8 @@ sort_pacl_range(struct posix_acl *pacl, int start, int end) {
 	while (!sorted) {
 		sorted = 1;
 		for (i = start; i < end; i++) {
-			if (pacl->a_entries[i].e_id
-					> pacl->a_entries[i+1].e_id) {
+			if (pace_gt(&pacl->a_entries[i],
+				    &pacl->a_entries[i+1])) {
 				sorted = 0;
 				tmp = pacl->a_entries[i];
 				pacl->a_entries[i] = pacl->a_entries[i+1];
@@ -398,7 +410,10 @@ struct posix_ace_state {
 };
 
 struct posix_user_ace_state {
-	uid_t uid;
+	union {
+		kuid_t uid;
+		kgid_t gid;
+	};
 	struct posix_ace_state perms;
 };
 
@@ -521,7 +536,6 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
 	if (error)
 		goto out_err;
 	low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
-	pace->e_id = ACL_UNDEFINED_ID;
 
 	for (i=0; i < state->users->n; i++) {
 		pace++;
@@ -531,7 +545,7 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
 			goto out_err;
 		low_mode_from_nfs4(state->users->aces[i].perms.allow,
 					&pace->e_perm, flags);
-		pace->e_id = state->users->aces[i].uid;
+		pace->e_uid = state->users->aces[i].uid;
 		add_to_mask(state, &state->users->aces[i].perms);
 	}
 
@@ -541,7 +555,6 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
 	if (error)
 		goto out_err;
 	low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
-	pace->e_id = ACL_UNDEFINED_ID;
 	add_to_mask(state, &state->group);
 
 	for (i=0; i < state->groups->n; i++) {
@@ -552,14 +565,13 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
 			goto out_err;
 		low_mode_from_nfs4(state->groups->aces[i].perms.allow,
 					&pace->e_perm, flags);
-		pace->e_id = state->groups->aces[i].uid;
+		pace->e_gid = state->groups->aces[i].gid;
 		add_to_mask(state, &state->groups->aces[i].perms);
 	}
 
 	pace++;
 	pace->e_tag = ACL_MASK;
 	low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
-	pace->e_id = ACL_UNDEFINED_ID;
 
 	pace++;
 	pace->e_tag = ACL_OTHER;
@@ -567,7 +579,6 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
 	if (error)
 		goto out_err;
 	low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
-	pace->e_id = ACL_UNDEFINED_ID;
 
 	return pacl;
 out_err:
@@ -587,12 +598,13 @@ static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
 	astate->deny |= mask & ~astate->allow;
 }
 
-static int find_uid(struct posix_acl_state *state, struct posix_ace_state_array *a, uid_t uid)
+static int find_uid(struct posix_acl_state *state, kuid_t uid)
 {
+	struct posix_ace_state_array *a = state->users;
 	int i;
 
 	for (i = 0; i < a->n; i++)
-		if (a->aces[i].uid == uid)
+		if (uid_eq(a->aces[i].uid, uid))
 			return i;
 	/* Not found: */
 	a->n++;
@@ -603,6 +615,23 @@ static int find_uid(struct posix_acl_state *state, struct posix_ace_state_array
 	return i;
 }
 
+static int find_gid(struct posix_acl_state *state, kgid_t gid)
+{
+	struct posix_ace_state_array *a = state->groups;
+	int i;
+
+	for (i = 0; i < a->n; i++)
+		if (gid_eq(a->aces[i].gid, gid))
+			return i;
+	/* Not found: */
+	a->n++;
+	a->aces[i].gid = gid;
+	a->aces[i].perms.allow = state->everyone.allow;
+	a->aces[i].perms.deny  = state->everyone.deny;
+
+	return i;
+}
+
 static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
 {
 	int i;
@@ -636,7 +665,7 @@ static void process_one_v4_ace(struct posix_acl_state *state,
 		}
 		break;
 	case ACL_USER:
-		i = find_uid(state, state->users, ace->who);
+		i = find_uid(state, ace->who_uid);
 		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 			allow_bits(&state->users->aces[i].perms, mask);
 		} else {
@@ -658,7 +687,7 @@ static void process_one_v4_ace(struct posix_acl_state *state,
 		}
 		break;
 	case ACL_GROUP:
-		i = find_uid(state, state->groups, ace->who);
+		i = find_gid(state, ace->who_gid);
 		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
 			allow_bits(&state->groups->aces[i].perms, mask);
 		} else {
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index a1f10c0a6255..0ce12346df9c 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -65,7 +65,7 @@ MODULE_PARM_DESC(nfs4_disable_idmapping,
 struct ent {
 	struct cache_head h;
 	int               type;		       /* User / Group */
-	uid_t             id;
+	u32               id;
 	char              name[IDMAP_NAMESZ];
 	char              authname[IDMAP_NAMESZ];
 };
@@ -540,7 +540,7 @@ rqst_authname(struct svc_rqst *rqstp)
 
 static __be32
 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
-		uid_t *id)
+		u32 *id)
 {
 	struct ent *item, key = {
 		.type = type,
@@ -564,7 +564,7 @@ idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen
 }
 
 static int
-idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
+idmap_id_to_name(struct svc_rqst *rqstp, int type, u32 id, char *name)
 {
 	struct ent *item, key = {
 		.id = id,
@@ -587,7 +587,7 @@ idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 }
 
 static bool
-numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
+numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 {
 	int ret;
 	char buf[11];
@@ -603,7 +603,7 @@ numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namel
 }
 
 static __be32
-do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
+do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 {
 	if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 		if (numeric_name_to_id(rqstp, type, name, namelen, id))
@@ -616,7 +616,7 @@ do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u
 }
 
 static int
-do_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
+do_id_to_name(struct svc_rqst *rqstp, int type, u32 id, char *name)
 {
 	if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 		return sprintf(name, "%u", id);
@@ -625,26 +625,40 @@ do_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 
 __be32
 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
-		__u32 *id)
+		kuid_t *uid)
 {
-	return do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
+	__be32 status;
+	u32 id = -1;
+	status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
+	*uid = make_kuid(&init_user_ns, id);
+	if (!uid_valid(*uid))
+		status = nfserr_badowner;
+	return status;
 }
 
 __be32
 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
-		__u32 *id)
+		kgid_t *gid)
 {
-	return do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
+	__be32 status;
+	u32 id = -1;
+	status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
+	*gid = make_kgid(&init_user_ns, id);
+	if (!gid_valid(*gid))
+		status = nfserr_badowner;
+	return status;
 }
 
 int
-nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
+nfsd_map_uid_to_name(struct svc_rqst *rqstp, kuid_t uid, char *name)
 {
+	u32 id = from_kuid(&init_user_ns, uid);
 	return do_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 }
 
 int
-nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
+nfsd_map_gid_to_name(struct svc_rqst *rqstp, kgid_t gid, char *name)
 {
+	u32 id = from_kgid(&init_user_ns, gid);
 	return do_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 }
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index ba6fdd4a0455..4914af4a817e 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -73,8 +73,8 @@ nfs4_save_creds(const struct cred **original_creds)
 	if (!new)
 		return -ENOMEM;
 
-	new->fsuid = 0;
-	new->fsgid = 0;
+	new->fsuid = GLOBAL_ROOT_UID;
+	new->fsgid = GLOBAL_ROOT_GID;
 	*original_creds = override_creds(new);
 	put_cred(new);
 	return 0;
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 499e957510e7..9e7103b6e0ad 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1202,7 +1202,7 @@ static bool groups_equal(struct group_info *g1, struct group_info *g2)
 	if (g1->ngroups != g2->ngroups)
 		return false;
 	for (i=0; i<g1->ngroups; i++)
-		if (GROUP_AT(g1, i) != GROUP_AT(g2, i))
+		if (!gid_eq(GROUP_AT(g1, i), GROUP_AT(g2, i)))
 			return false;
 	return true;
 }
@@ -1227,8 +1227,8 @@ static bool
 same_creds(struct svc_cred *cr1, struct svc_cred *cr2)
 {
 	if ((is_gss_cred(cr1) != is_gss_cred(cr2))
-		|| (cr1->cr_uid != cr2->cr_uid)
-		|| (cr1->cr_gid != cr2->cr_gid)
+		|| (!uid_eq(cr1->cr_uid, cr2->cr_uid))
+		|| (!gid_eq(cr1->cr_gid, cr2->cr_gid))
 		|| !groups_equal(cr1->cr_group_info, cr2->cr_group_info))
 		return false;
 	if (cr1->cr_principal == cr2->cr_principal)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0dc11586682f..2d1d06bae3a7 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -293,13 +293,13 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
 			ace->whotype = nfs4_acl_get_whotype(buf, dummy32);
 			status = nfs_ok;
 			if (ace->whotype != NFS4_ACL_WHO_NAMED)
-				ace->who = 0;
+				;
 			else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
 				status = nfsd_map_name_to_gid(argp->rqstp,
-						buf, dummy32, &ace->who);
+						buf, dummy32, &ace->who_gid);
 			else
 				status = nfsd_map_name_to_uid(argp->rqstp,
-						buf, dummy32, &ace->who);
+						buf, dummy32, &ace->who_uid);
 			if (status)
 				return status;
 		}
@@ -464,9 +464,16 @@ static __be32 nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_
 			READ32(dummy);
 			READ_BUF(dummy * 4);
 			if (cbs->flavor == (u32)(-1)) {
-				cbs->uid = uid;
-				cbs->gid = gid;
-				cbs->flavor = RPC_AUTH_UNIX;
+				kuid_t kuid = make_kuid(&init_user_ns, uid);
+				kgid_t kgid = make_kgid(&init_user_ns, gid);
+				if (uid_valid(kuid) && gid_valid(kgid)) {
+					cbs->uid = kuid;
+					cbs->gid = kgid;
+					cbs->flavor = RPC_AUTH_UNIX;
+				} else {
+					dprintk("RPC_AUTH_UNIX with invalid"
+						"uid or gid ignoring!\n");
+				}
 			}
 			break;
 		case RPC_AUTH_GSS:
@@ -1926,7 +1933,7 @@ static u32 nfs4_file_type(umode_t mode)
 }
 
 static __be32
-nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
+nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, kuid_t uid, kgid_t gid,
 			__be32 **p, int *buflen)
 {
 	int status;
@@ -1935,10 +1942,10 @@ nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
 		return nfserr_resource;
 	if (whotype != NFS4_ACL_WHO_NAMED)
 		status = nfs4_acl_write_who(whotype, (u8 *)(*p + 1));
-	else if (group)
-		status = nfsd_map_gid_to_name(rqstp, id, (u8 *)(*p + 1));
+	else if (gid_valid(gid))
+		status = nfsd_map_gid_to_name(rqstp, gid, (u8 *)(*p + 1));
 	else
-		status = nfsd_map_uid_to_name(rqstp, id, (u8 *)(*p + 1));
+		status = nfsd_map_uid_to_name(rqstp, uid, (u8 *)(*p + 1));
 	if (status < 0)
 		return nfserrno(status);
 	*p = xdr_encode_opaque(*p, NULL, status);
@@ -1948,22 +1955,33 @@ nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
 }
 
 static inline __be32
-nfsd4_encode_user(struct svc_rqst *rqstp, uid_t uid, __be32 **p, int *buflen)
+nfsd4_encode_user(struct svc_rqst *rqstp, kuid_t user, __be32 **p, int *buflen)
 {
-	return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, uid, 0, p, buflen);
+	return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, user, INVALID_GID,
+				 p, buflen);
 }
 
 static inline __be32
-nfsd4_encode_group(struct svc_rqst *rqstp, uid_t gid, __be32 **p, int *buflen)
+nfsd4_encode_group(struct svc_rqst *rqstp, kgid_t group, __be32 **p, int *buflen)
 {
-	return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, gid, 1, p, buflen);
+	return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, INVALID_UID, group,
+				 p, buflen);
 }
 
 static inline __be32
-nfsd4_encode_aclname(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
+nfsd4_encode_aclname(struct svc_rqst *rqstp, struct nfs4_ace *ace,
 		__be32 **p, int *buflen)
 {
-	return nfsd4_encode_name(rqstp, whotype, id, group, p, buflen);
+	kuid_t uid = INVALID_UID;
+	kgid_t gid = INVALID_GID;
+
+	if (ace->whotype == NFS4_ACL_WHO_NAMED) {
+		if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
+			gid = ace->who_gid;
+		else
+			uid = ace->who_uid;
+	}
+	return nfsd4_encode_name(rqstp, ace->whotype, uid, gid, p, buflen);
 }
 
 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
@@ -2224,9 +2242,7 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
 			WRITE32(ace->type);
 			WRITE32(ace->flag);
 			WRITE32(ace->access_mask & NFS4_ACE_MASK_ALL);
-			status = nfsd4_encode_aclname(rqstp, ace->whotype,
-				ace->who, ace->flag & NFS4_ACE_IDENTIFIER_GROUP,
-				&p, &buflen);
+			status = nfsd4_encode_aclname(rqstp, ace, &p, &buflen);
 			if (status == nfserr_resource)
 				goto out_resource;
 			if (status)
diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
index 979b42106979..4201ede0ec91 100644
--- a/fs/nfsd/nfsxdr.c
+++ b/fs/nfsd/nfsxdr.c
@@ -100,12 +100,14 @@ decode_sattr(__be32 *p, struct iattr *iap)
 		iap->ia_mode = tmp;
 	}
 	if ((tmp = ntohl(*p++)) != (u32)-1) {
-		iap->ia_valid |= ATTR_UID;
-		iap->ia_uid = tmp;
+		iap->ia_uid = make_kuid(&init_user_ns, tmp);
+		if (uid_valid(iap->ia_uid))
+			iap->ia_valid |= ATTR_UID;
 	}
 	if ((tmp = ntohl(*p++)) != (u32)-1) {
-		iap->ia_valid |= ATTR_GID;
-		iap->ia_gid = tmp;
+		iap->ia_gid = make_kgid(&init_user_ns, tmp);
+		if (gid_valid(iap->ia_gid))
+			iap->ia_valid |= ATTR_GID;
 	}
 	if ((tmp = ntohl(*p++)) != (u32)-1) {
 		iap->ia_valid |= ATTR_SIZE;
@@ -151,8 +153,8 @@ encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 	*p++ = htonl(nfs_ftypes[type >> 12]);
 	*p++ = htonl((u32) stat->mode);
 	*p++ = htonl((u32) stat->nlink);
-	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
-	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
+	*p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
+	*p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
 
 	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
 		*p++ = htonl(NFS_MAXPATHLEN);
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index d1c229feed52..1a8c7391f7ae 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -152,8 +152,8 @@ struct nfsd4_channel_attrs {
 
 struct nfsd4_cb_sec {
 	u32	flavor; /* (u32)(-1) used to mean "no valid flavor" */
-	u32	uid;
-	u32	gid;
+	kuid_t	uid;
+	kgid_t	gid;
 };
 
 struct nfsd4_create_session {
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index d586117fa94a..31ff1d642e31 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -401,8 +401,8 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 
 	/* Revoke setuid/setgid on chown */
 	if (!S_ISDIR(inode->i_mode) &&
-	    (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) ||
-	     ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) {
+	    (((iap->ia_valid & ATTR_UID) && !uid_eq(iap->ia_uid, inode->i_uid)) ||
+	     ((iap->ia_valid & ATTR_GID) && !gid_eq(iap->ia_gid, inode->i_gid)))) {
 		iap->ia_valid |= ATTR_KILL_PRIV;
 		if (iap->ia_valid & ATTR_MODE) {
 			/* we're setting mode too, just clear the s*id bits */
@@ -1205,7 +1205,7 @@ nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
 	 * send along the gid on create when it tries to implement
 	 * setgid directories via NFS:
 	 */
-	if (current_fsuid() != 0)
+	if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
 		iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
 	if (iap->ia_valid)
 		return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
@@ -2150,7 +2150,7 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
 	 * with NFSv3.
 	 */
 	if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
-	    inode->i_uid == current_fsuid())
+	    uid_eq(inode->i_uid, current_fsuid()))
 		return 0;
 
 	/* This assumes  NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */