nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion

In struct nfs4_ace remove the member who and replace it with an
anonymous union holding who_uid and who_gid.  Allowing typesafe
storage uids and gids.

Add a helper pace_gt for sorting posix_acl_entries.

In struct posix_user_ace_state to replace uid with a union
of kuid_t uid and kgid_t gid.

Remove all initializations of the deprecated posic_acl_entry
e_id field.  Which is not present when user namespaces are enabled.

Split find_uid into two functions find_uid and find_gid that work
in a typesafe manner.

In nfs4xdr update nfsd4_encode_fattr to deal with the changes
in struct nfs4_ace.

Rewrite nfsd4_encode_name to take a kuid_t and a kgid_t instead
of a generic id and flag if it is a group or a uid.  Replace
the group flag with a test for a valid gid.

Modify nfsd4_encode_user to take a kuid_t and call the modifed
nfsd4_encode_name.

Modify nfsd4_encode_group to take a kgid_t and call the modified
nfsd4_encode_name.

Modify nfsd4_encode_aclname to take an ace instead of taking the
fields of an ace broken out.  This allows it to detect if the ace is
for a user or a group and to pass the appropriate value while still
being typesafe.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 25 insertions, 16 deletions

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0dc11586682f..3812b06d24b1 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;
 		}
@@ -1926,7 +1926,7 @@ 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 +1935,10 @@ 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 +1948,33 @@ 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 +2235,7 @@ 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)