fs: port inode_init_owner() to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

1 files changed, 16 insertions, 22 deletions

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 938032cbc1a8..d8e01bbbf27f 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -202,7 +202,7 @@ static void set_file_temperature(struct f2fs_sb_info *sbi, struct inode *inode,
 		file_set_hot(inode);
 }
 
-static struct inode *f2fs_new_inode(struct user_namespace *mnt_userns,
+static struct inode *f2fs_new_inode(struct mnt_idmap *idmap,
 						struct inode *dir, umode_t mode,
 						const char *name)
 {
@@ -225,7 +225,7 @@ static struct inode *f2fs_new_inode(struct user_namespace *mnt_userns,
 
 	nid_free = true;
 
-	inode_init_owner(mnt_userns, inode, dir, mode);
+	inode_init_owner(idmap, inode, dir, mode);
 
 	inode->i_ino = ino;
 	inode->i_blocks = 0;
@@ -336,7 +336,6 @@ fail_drop:
 static int f2fs_create(struct mnt_idmap *idmap, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	nid_t ino = 0;
@@ -351,7 +350,7 @@ static int f2fs_create(struct mnt_idmap *idmap, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, mode, dentry->d_name.name);
+	inode = f2fs_new_inode(idmap, dir, mode, dentry->d_name.name);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -663,7 +662,6 @@ static const char *f2fs_get_link(struct dentry *dentry,
 static int f2fs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	size_t len = strlen(symname);
@@ -684,7 +682,7 @@ static int f2fs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, S_IFLNK | S_IRWXUGO, NULL);
+	inode = f2fs_new_inode(idmap, dir, S_IFLNK | S_IRWXUGO, NULL);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -744,7 +742,6 @@ out_free_encrypted_link:
 static int f2fs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	int err;
@@ -756,7 +753,7 @@ static int f2fs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, S_IFDIR | mode, NULL);
+	inode = f2fs_new_inode(idmap, dir, S_IFDIR | mode, NULL);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -800,7 +797,6 @@ static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
 static int f2fs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	int err = 0;
@@ -814,7 +810,7 @@ static int f2fs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, mode, NULL);
+	inode = f2fs_new_inode(idmap, dir, mode, NULL);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -841,7 +837,7 @@ out:
 	return err;
 }
 
-static int __f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+static int __f2fs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			  struct file *file, umode_t mode, bool is_whiteout,
 			  struct inode **new_inode)
 {
@@ -853,7 +849,7 @@ static int __f2fs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
 	if (err)
 		return err;
 
-	inode = f2fs_new_inode(mnt_userns, dir, mode, NULL);
+	inode = f2fs_new_inode(idmap, dir, mode, NULL);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
@@ -914,7 +910,6 @@ out:
 static int f2fs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			struct file *file, umode_t mode)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	int err;
 
@@ -923,28 +918,28 @@ static int f2fs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 	if (!f2fs_is_checkpoint_ready(sbi))
 		return -ENOSPC;
 
-	err = __f2fs_tmpfile(mnt_userns, dir, file, mode, false, NULL);
+	err = __f2fs_tmpfile(idmap, dir, file, mode, false, NULL);
 
 	return finish_open_simple(file, err);
 }
 
-static int f2fs_create_whiteout(struct user_namespace *mnt_userns,
+static int f2fs_create_whiteout(struct mnt_idmap *idmap,
 				struct inode *dir, struct inode **whiteout)
 {
 	if (unlikely(f2fs_cp_error(F2FS_I_SB(dir))))
 		return -EIO;
 
-	return __f2fs_tmpfile(mnt_userns, dir, NULL,
+	return __f2fs_tmpfile(idmap, dir, NULL,
 				S_IFCHR | WHITEOUT_MODE, true, whiteout);
 }
 
-int f2fs_get_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
+int f2fs_get_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 		     struct inode **new_inode)
 {
-	return __f2fs_tmpfile(mnt_userns, dir, NULL, S_IFREG, false, new_inode);
+	return __f2fs_tmpfile(idmap, dir, NULL, S_IFREG, false, new_inode);
 }
 
-static int f2fs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+static int f2fs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 			struct dentry *old_dentry, struct inode *new_dir,
 			struct dentry *new_dentry, unsigned int flags)
 {
@@ -984,7 +979,7 @@ static int f2fs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
 	}
 
 	if (flags & RENAME_WHITEOUT) {
-		err = f2fs_create_whiteout(mnt_userns, old_dir, &whiteout);
+		err = f2fs_create_whiteout(idmap, old_dir, &whiteout);
 		if (err)
 			return err;
 	}
@@ -1305,7 +1300,6 @@ static int f2fs_rename2(struct mnt_idmap *idmap,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
 {
-	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 	int err;
 
 	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
@@ -1324,7 +1318,7 @@ static int f2fs_rename2(struct mnt_idmap *idmap,
 	 * VFS has already handled the new dentry existence case,
 	 * here, we just deal with "RENAME_NOREPLACE" as regular rename.
 	 */
-	return f2fs_rename(mnt_userns, old_dir, old_dentry,
+	return f2fs_rename(idmap, old_dir, old_dentry,
 					new_dir, new_dentry, flags);
 }