userns: Convert fat to use kuid/kgid where appropriate

Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

3 files changed, 17 insertions, 11 deletions

diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 2deeeb86f331..7d8e0dcac5d5 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -23,8 +23,8 @@
 #define FAT_ERRORS_RO           3      /* remount r/o on error */
 
 struct fat_mount_options {
-        uid_t fs_uid;
-        gid_t fs_gid;
+        kuid_t fs_uid;
+        kgid_t fs_gid;
         unsigned short fs_fmask;
         unsigned short fs_dmask;
         unsigned short codepage;  /* Codepage for shortname conversions */
diff --git a/fs/fat/file.c b/fs/fat/file.c
index e007b8bd8e5e..a62e0ecbe2db 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -352,7 +352,7 @@ static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
 {
         umode_t allow_utime = sbi->options.allow_utime;
 
-        if (current_fsuid() != inode->i_uid) {
+        if (!uid_eq(current_fsuid(), inode->i_uid)) {
                 if (in_group_p(inode->i_gid))
                         allow_utime >>= 3;
                 if (allow_utime & MAY_WRITE)
@@ -407,9 +407,9 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr)
         }
 
         if (((attr->ia_valid & ATTR_UID) &&
-             (attr->ia_uid != sbi->options.fs_uid)) ||
+             (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) ||
             ((attr->ia_valid & ATTR_GID) &&
-             (attr->ia_gid != sbi->options.fs_gid)) ||
+             (!gid_eq(attr->ia_gid, sbi->options.fs_gid))) ||
             ((attr->ia_valid & ATTR_MODE) &&
              (attr->ia_mode & ~FAT_VALID_MODE)))
                 error = -EPERM;
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 05e897fe9866..47d9eb0be886 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -791,10 +791,12 @@ static int fat_show_options(struct seq_file *m, struct dentry *root)
         struct fat_mount_options *opts = &sbi->options;
         int isvfat = opts->isvfat;
 
-        if (opts->fs_uid != 0)
-                seq_printf(m, ",uid=%u", opts->fs_uid);
-        if (opts->fs_gid != 0)
-                seq_printf(m, ",gid=%u", opts->fs_gid);
+        if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
+                seq_printf(m, ",uid=%u",
+                                from_kuid_munged(&init_user_ns, opts->fs_uid));
+        if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
+                seq_printf(m, ",gid=%u",
+                                from_kgid_munged(&init_user_ns, opts->fs_gid));
         seq_printf(m, ",fmask=%04o", opts->fs_fmask);
         seq_printf(m, ",dmask=%04o", opts->fs_dmask);
         if (opts->allow_utime)
@@ -1037,12 +1039,16 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat,
                 case Opt_uid:
                         if (match_int(&args[0], &option))
                                 return 0;
-                        opts->fs_uid = option;
+                        opts->fs_uid = make_kuid(current_user_ns(), option);
+                        if (!uid_valid(opts->fs_uid))
+                                return 0;
                         break;
                 case Opt_gid:
                         if (match_int(&args[0], &option))
                                 return 0;
-                        opts->fs_gid = option;
+                        opts->fs_gid = make_kgid(current_user_ns(), option);
+                        if (!gid_valid(opts->fs_gid))
+                                return 0;
                         break;
                 case Opt_umask:
                         if (match_octal(&args[0], &option))