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
  ...

1 files changed, 46 insertions, 17 deletions

diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
index 9c51aff02ae..8a50b3c1809 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 {