userns: Convert ext4 to user kuid/kgid where appropriate

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

6 files changed, 54 insertions, 34 deletions

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 4bbd07a6fa18..c45c41129a35 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -461,8 +461,8 @@ static int ext4_has_free_clusters(struct ext4_sb_info *sbi,
                 return 1;
 
         /* Hm, nope.  Are (enough) root reserved clusters available? */
-        if (sbi->s_resuid == current_fsuid() ||
-            ((sbi->s_resgid != 0) && in_group_p(sbi->s_resgid)) ||
+        if (uid_eq(sbi->s_resuid, current_fsuid()) ||
+            (!gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) && in_group_p(sbi->s_resgid)) ||
             capable(CAP_SYS_RESOURCE) ||
                 (flags & EXT4_MB_USE_ROOT_BLOCKS)) {
 
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ab2594a30f86..0b4aeb24593c 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1153,8 +1153,8 @@ struct ext4_sb_info {
         unsigned int s_mount_flags;
         unsigned int s_def_mount_opt;
         ext4_fsblk_t s_sb_block;
-        uid_t s_resuid;
-        gid_t s_resgid;
+        kuid_t s_resuid;
+        kgid_t s_resgid;
         unsigned short s_mount_state;
         unsigned short s_pad;
         int s_addr_per_block_bits;
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 409c2ee7750a..9f9acac6c43f 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -808,8 +808,8 @@ got:
         }
         if (owner) {
                 inode->i_mode = mode;
-                inode->i_uid = owner[0];
-                inode->i_gid = owner[1];
+                i_uid_write(inode, owner[0]);
+                i_gid_write(inode, owner[1]);
         } else if (test_opt(sb, GRPID)) {
                 inode->i_mode = mode;
                 inode->i_uid = current_fsuid();
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c77b0bd2c711..07eaf565fdcb 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3630,6 +3630,8 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
         journal_t *journal = EXT4_SB(sb)->s_journal;
         long ret;
         int block;
+        uid_t i_uid;
+        gid_t i_gid;
 
         inode = iget_locked(sb, ino);
         if (!inode)
@@ -3645,12 +3647,14 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                 goto bad_inode;
         raw_inode = ext4_raw_inode(&iloc);
         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
-        inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
-        inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
+        i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
+        i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
         if (!(test_opt(inode->i_sb, NO_UID32))) {
-                inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
-                inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
+                i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
+                i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
         }
+        i_uid_write(inode, i_uid);
+        i_gid_write(inode, i_gid);
         set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 
         ext4_clear_state_flags(ei);     /* Only relevant on 32-bit archs */
@@ -3870,6 +3874,8 @@ static int ext4_do_update_inode(handle_t *handle,
         struct ext4_inode_info *ei = EXT4_I(inode);
         struct buffer_head *bh = iloc->bh;
         int err = 0, rc, block;
+        uid_t i_uid;
+        gid_t i_gid;
 
         /* For fields not not tracking in the in-memory inode,
          * initialise them to zero for new inodes. */
@@ -3878,27 +3884,27 @@ static int ext4_do_update_inode(handle_t *handle,
 
         ext4_get_inode_flags(ei);
         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
+        i_uid = i_uid_read(inode);
+        i_gid = i_gid_read(inode);
         if (!(test_opt(inode->i_sb, NO_UID32))) {
-                raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
-                raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
+                raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
+                raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
 /*
  * Fix up interoperability with old kernels. Otherwise, old inodes get
  * re-used with the upper 16 bits of the uid/gid intact
  */
                 if (!ei->i_dtime) {
                         raw_inode->i_uid_high =
-                                cpu_to_le16(high_16_bits(inode->i_uid));
+                                cpu_to_le16(high_16_bits(i_uid));
                         raw_inode->i_gid_high =
-                                cpu_to_le16(high_16_bits(inode->i_gid));
+                                cpu_to_le16(high_16_bits(i_gid));
                 } else {
                         raw_inode->i_uid_high = 0;
                         raw_inode->i_gid_high = 0;
                 }
         } else {
-                raw_inode->i_uid_low =
-                        cpu_to_le16(fs_high2lowuid(inode->i_uid));
-                raw_inode->i_gid_low =
-                        cpu_to_le16(fs_high2lowgid(inode->i_gid));
+                raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
+                raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
                 raw_inode->i_uid_high = 0;
                 raw_inode->i_gid_high = 0;
         }
@@ -4084,8 +4090,8 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 
         if (is_quota_modification(inode, attr))
                 dquot_initialize(inode);
-        if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
-                (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
+        if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
+            (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
                 handle_t *handle;
 
                 /* (user+group)*(old+new) structure, inode write (sb,
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index f39f80f8f2c5..f1bb32ec0169 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -466,8 +466,8 @@ int ext4_ext_migrate(struct inode *inode)
         }
         goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) *
                 EXT4_INODES_PER_GROUP(inode->i_sb)) + 1;
-        owner[0] = inode->i_uid;
-        owner[1] = inode->i_gid;
+        owner[0] = i_uid_read(inode);
+        owner[1] = i_gid_read(inode);
         tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
                                    S_IFREG, NULL, goal, owner);
         if (IS_ERR(tmp_inode)) {
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ceebaf853beb..9d8eba0de27d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1448,6 +1448,8 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 {
         struct ext4_sb_info *sbi = EXT4_SB(sb);
         const struct mount_opts *m;
+        kuid_t uid;
+        kgid_t gid;
         int arg = 0;
 
         if (args->from && match_int(args, &arg))
@@ -1464,10 +1466,20 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
                          "Ignoring removed %s option", opt);
                 return 1;
         case Opt_resuid:
-                sbi->s_resuid = arg;
+                uid = make_kuid(current_user_ns(), arg);
+                if (!uid_valid(uid)) {
+                        ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
+                        return -1;
+                }
+                sbi->s_resuid = uid;
                 return 1;
         case Opt_resgid:
-                sbi->s_resgid = arg;
+                gid = make_kgid(current_user_ns(), arg);
+                if (!gid_valid(gid)) {
+                        ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
+                        return -1;
+                }
+                sbi->s_resgid = gid;
                 return 1;
         case Opt_abort:
                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
@@ -1732,12 +1744,14 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
                 SEQ_OPTS_PRINT("%s", token2str(m->token));
         }
 
-        if (nodefs || sbi->s_resuid != EXT4_DEF_RESUID ||
+        if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
-                SEQ_OPTS_PRINT("resuid=%u", sbi->s_resuid);
-        if (nodefs || sbi->s_resgid != EXT4_DEF_RESGID ||
+                SEQ_OPTS_PRINT("resuid=%u",
+                                from_kuid_munged(&init_user_ns, sbi->s_resuid));
+        if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
-                SEQ_OPTS_PRINT("resgid=%u", sbi->s_resgid);
+                SEQ_OPTS_PRINT("resgid=%u",
+                                from_kgid_munged(&init_user_ns, sbi->s_resgid));
         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
                 SEQ_OPTS_PUTS("errors=remount-ro");
@@ -2996,8 +3010,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
         }
         sb->s_fs_info = sbi;
         sbi->s_mount_opt = 0;
-        sbi->s_resuid = EXT4_DEF_RESUID;
-        sbi->s_resgid = EXT4_DEF_RESGID;
+        sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
+        sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
         sbi->s_sb_block = sb_block;
         if (sb->s_bdev->bd_part)
@@ -3076,8 +3090,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
         if (def_mount_opts & EXT4_DEFM_DISCARD)
                 set_opt(sb, DISCARD);
 
-        sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
-        sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
+        sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
+        sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
@@ -4229,8 +4243,8 @@ static int ext4_unfreeze(struct super_block *sb)
 struct ext4_mount_options {
         unsigned long s_mount_opt;
         unsigned long s_mount_opt2;
-        uid_t s_resuid;
-        gid_t s_resgid;
+        kuid_t s_resuid;
+        kgid_t s_resgid;
         unsigned long s_commit_interval;
         u32 s_min_batch_time, s_max_batch_time;
 #ifdef CONFIG_QUOTA