nfs_common: Update the translation between nfsv3 acls linux posix acls

- Use kuid_t and kgit in struct nfsacl_encode_desc.
- Convert from kuids and kgids when generating on the wire values.
- Convert on the wire values to kuids and kgids when read.
- Modify cmp_acl_entry to be type safe comparison on posix acls.
  Only acls with type ACL_USER and ACL_GROUP can appear more
  than once and as such need to compare more than their tag.
- The e_id field is being removed from posix acls so don't initialize it.

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, 26 insertions, 15 deletions

diff --git a/fs/nfs_common/nfsacl.c b/fs/nfs_common/nfsacl.c
index 6940439bd609..ed628f71274c 100644
--- a/fs/nfs_common/nfsacl.c
+++ b/fs/nfs_common/nfsacl.c
@@ -38,8 +38,8 @@ struct nfsacl_encode_desc {
         unsigned int count;
         struct posix_acl *acl;
         int typeflag;
-        uid_t uid;
-        gid_t gid;
+        kuid_t uid;
+        kgid_t gid;
 };
 
 struct nfsacl_simple_acl {
@@ -60,14 +60,16 @@ xdr_nfsace_encode(struct xdr_array2_desc *desc, void *elem)
         *p++ = htonl(entry->e_tag | nfsacl_desc->typeflag);
         switch(entry->e_tag) {
                 case ACL_USER_OBJ:
-                        *p++ = htonl(nfsacl_desc->uid);
+                        *p++ = htonl(from_kuid(&init_user_ns, nfsacl_desc->uid));
                         break;
                 case ACL_GROUP_OBJ:
-                        *p++ = htonl(nfsacl_desc->gid);
+                        *p++ = htonl(from_kgid(&init_user_ns, nfsacl_desc->gid));
                         break;
                 case ACL_USER:
+                        *p++ = htonl(from_kuid(&init_user_ns, entry->e_uid));
+                        break;
                 case ACL_GROUP:
-                        *p++ = htonl(entry->e_id);
+                        *p++ = htonl(from_kgid(&init_user_ns, entry->e_gid));
                         break;
                 default:  /* Solaris depends on that! */
                         *p++ = 0;
@@ -148,6 +150,7 @@ xdr_nfsace_decode(struct xdr_array2_desc *desc, void *elem)
                 (struct nfsacl_decode_desc *) desc;
         __be32 *p = elem;
         struct posix_acl_entry *entry;
+        unsigned int id;
 
         if (!nfsacl_desc->acl) {
                 if (desc->array_len > NFS_ACL_MAX_ENTRIES)
@@ -160,14 +163,22 @@ xdr_nfsace_decode(struct xdr_array2_desc *desc, void *elem)
 
         entry = &nfsacl_desc->acl->a_entries[nfsacl_desc->count++];
         entry->e_tag = ntohl(*p++) & ~NFS_ACL_DEFAULT;
-        entry->e_id = ntohl(*p++);
+        id = ntohl(*p++);
         entry->e_perm = ntohl(*p++);
 
         switch(entry->e_tag) {
-                case ACL_USER_OBJ:
                 case ACL_USER:
-                case ACL_GROUP_OBJ:
+                        entry->e_uid = make_kuid(&init_user_ns, id);
+                        if (!uid_valid(entry->e_uid))
+                                return -EINVAL;
+                        break;
                 case ACL_GROUP:
+                        entry->e_gid = make_kgid(&init_user_ns, id);
+                        if (!gid_valid(entry->e_gid))
+                                return -EINVAL;
+                        break;
+                case ACL_USER_OBJ:
+                case ACL_GROUP_OBJ:
                 case ACL_OTHER:
                         if (entry->e_perm & ~S_IRWXO)
                                 return -EINVAL;
@@ -190,9 +201,13 @@ cmp_acl_entry(const void *x, const void *y)
 
         if (a->e_tag != b->e_tag)
                 return a->e_tag - b->e_tag;
-        else if (a->e_id > b->e_id)
+        else if ((a->e_tag == ACL_USER) && uid_gt(a->e_uid, b->e_uid))
+                return 1;
+        else if ((a->e_tag == ACL_USER) && uid_lt(a->e_uid, b->e_uid))
+                return -1;
+        else if ((a->e_tag == ACL_GROUP) && gid_gt(a->e_gid, b->e_gid))
                 return 1;
-        else if (a->e_id < b->e_id)
+        else if ((a->e_tag == ACL_GROUP) && gid_lt(a->e_gid, b->e_gid))
                 return -1;
         else
                 return 0;
@@ -213,22 +228,18 @@ posix_acl_from_nfsacl(struct posix_acl *acl)
         sort(acl->a_entries, acl->a_count, sizeof(struct posix_acl_entry),
              cmp_acl_entry, NULL);
 
-        /* Clear undefined identifier fields and find the ACL_GROUP_OBJ
-           and ACL_MASK entries. */
+        /* Find the ACL_GROUP_OBJ and ACL_MASK entries. */
         FOREACH_ACL_ENTRY(pa, acl, pe) {
                 switch(pa->e_tag) {
                         case ACL_USER_OBJ:
-                                pa->e_id = ACL_UNDEFINED_ID;
                                 break;
                         case ACL_GROUP_OBJ:
-                                pa->e_id = ACL_UNDEFINED_ID;
                                 group_obj = pa;
                                 break;
                         case ACL_MASK:
                                 mask = pa;
                                 /* fall through */
                         case ACL_OTHER:
-                                pa->e_id = ACL_UNDEFINED_ID;
                                 break;
                 }
         }