cifs: Modify struct smb_vol to use kuids and kgids

Add two helper functions get_option_uid and get_option_gid to handle
the work of parsing uid and gids paramaters from the command line and
making kuids and kgids out of them.

Cc: Steve French <smfrench@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

2 files changed, 45 insertions, 15 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 04aa74e5b348..e308e8bd0772 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -399,11 +399,11 @@ struct smb_vol {
         char *iocharset;  /* local code page for mapping to and from Unicode */
         char source_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* clnt nb name */
         char target_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* srvr nb name */
-        uid_t cred_uid;
-        uid_t linux_uid;
-        gid_t linux_gid;
-        uid_t backupuid;
-        gid_t backupgid;
+        kuid_t cred_uid;
+        kuid_t linux_uid;
+        kgid_t linux_gid;
+        kuid_t backupuid;
+        kgid_t backupgid;
         umode_t file_mode;
         umode_t dir_mode;
         unsigned secFlg;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 541169459223..9bd13a75602d 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -987,6 +987,41 @@ static int get_option_ul(substring_t args[], unsigned long *option)
         return rc;
 }
 
+static int get_option_uid(substring_t args[], kuid_t *result)
+{
+        unsigned long value;
+        kuid_t uid;
+        int rc;
+
+        rc = get_option_ul(args, &value);
+        if (rc)
+                return rc;
+
+        uid = make_kuid(current_user_ns(), value);
+        if (!uid_valid(uid))
+                return -EINVAL;
+
+        *result = uid;
+        return 0;
+}
+
+static int get_option_gid(substring_t args[], kgid_t *result)
+{
+        unsigned long value;
+        kgid_t gid;
+        int rc;
+
+        rc = get_option_ul(args, &value);
+        if (rc)
+                return rc;
+
+        gid = make_kgid(current_user_ns(), value);
+        if (!gid_valid(gid))
+                return -EINVAL;
+
+        *result = gid;
+        return 0;
+}
 
 static int cifs_parse_security_flavors(char *value,
                                        struct smb_vol *vol)
@@ -1424,47 +1459,42 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 
                 /* Numeric Values */
                 case Opt_backupuid:
-                        if (get_option_ul(args, &option)) {
+                        if (get_option_uid(args, &vol->backupuid)) {
                                 cERROR(1, "%s: Invalid backupuid value",
                                         __func__);
                                 goto cifs_parse_mount_err;
                         }
-                        vol->backupuid = option;
                         vol->backupuid_specified = true;
                         break;
                 case Opt_backupgid:
-                        if (get_option_ul(args, &option)) {
+                        if (get_option_gid(args, &vol->backupgid)) {
                                 cERROR(1, "%s: Invalid backupgid value",
                                         __func__);
                                 goto cifs_parse_mount_err;
                         }
-                        vol->backupgid = option;
                         vol->backupgid_specified = true;
                         break;
                 case Opt_uid:
-                        if (get_option_ul(args, &option)) {
+                        if (get_option_uid(args, &vol->linux_uid)) {
                                 cERROR(1, "%s: Invalid uid value",
                                         __func__);
                                 goto cifs_parse_mount_err;
                         }
-                        vol->linux_uid = option;
                         uid_specified = true;
                         break;
                 case Opt_cruid:
-                        if (get_option_ul(args, &option)) {
+                        if (get_option_uid(args, &vol->cred_uid)) {
                                 cERROR(1, "%s: Invalid cruid value",
                                         __func__);
                                 goto cifs_parse_mount_err;
                         }
-                        vol->cred_uid = option;
                         break;
                 case Opt_gid:
-                        if (get_option_ul(args, &option)) {
+                        if (get_option_gid(args, &vol->linux_gid)) {
                                 cERROR(1, "%s: Invalid gid value",
                                                 __func__);
                                 goto cifs_parse_mount_err;
                         }
-                        vol->linux_gid = option;
                         gid_specified = true;
                         break;
                 case Opt_file_mode: