fs: port ->setattr() to pass 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>

3 files changed, 8 insertions, 8 deletions

diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index c7d1fa526dea..35b9b8ec1cbe 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -3262,21 +3262,21 @@ static ssize_t reiserfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 	return ret;
 }
 
-int reiserfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int reiserfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	unsigned int ia_valid;
 	int error;
 
-	error = setattr_prepare(&init_user_ns, dentry, attr);
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 	if (error)
 		return error;
 
 	/* must be turned off for recursive notify_change calls */
 	ia_valid = attr->ia_valid &= ~(ATTR_KILL_SUID|ATTR_KILL_SGID);
 
-	if (is_quota_modification(mnt_userns, inode, attr)) {
+	if (is_quota_modification(&init_user_ns, inode, attr)) {
 		error = dquot_initialize(inode);
 		if (error)
 			return error;
@@ -3359,7 +3359,7 @@ int reiserfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		reiserfs_write_unlock(inode->i_sb);
 		if (error)
 			goto out;
-		error = dquot_transfer(mnt_userns, inode, attr);
+		error = dquot_transfer(&init_user_ns, inode, attr);
 		reiserfs_write_lock(inode->i_sb);
 		if (error) {
 			journal_end(&th);
@@ -3398,7 +3398,7 @@ int reiserfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 	}
 
 	if (!error) {
-		setattr_copy(&init_user_ns, inode, attr);
+		setattr_copy(&nop_mnt_idmap, inode, attr);
 		mark_inode_dirty(inode);
 	}
 
diff --git a/fs/reiserfs/reiserfs.h b/fs/reiserfs/reiserfs.h
index 3aa928ec527a..9a4a7f7897fe 100644
--- a/fs/reiserfs/reiserfs.h
+++ b/fs/reiserfs/reiserfs.h
@@ -3100,7 +3100,7 @@ static inline void reiserfs_update_sd(struct reiserfs_transaction_handle *th,
 }
 
 void sd_attrs_to_i_attrs(__u16 sd_attrs, struct inode *inode);
-int reiserfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+int reiserfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		     struct iattr *attr);
 
 int __reiserfs_write_begin(struct page *page, unsigned from, unsigned len);
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 8b2d52443f41..af6137f53cf8 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -352,7 +352,7 @@ static int chown_one_xattr(struct dentry *dentry, void *data)
 	 * ATTR_MODE is set.
 	 */
 	attrs->ia_valid &= (ATTR_UID|ATTR_GID);
-	err = reiserfs_setattr(&init_user_ns, dentry, attrs);
+	err = reiserfs_setattr(&nop_mnt_idmap, dentry, attrs);
 	attrs->ia_valid = ia_valid;
 
 	return err;
@@ -597,7 +597,7 @@ reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *th,
 		inode_lock_nested(d_inode(dentry), I_MUTEX_XATTR);
 		inode_dio_wait(d_inode(dentry));
 
-		err = reiserfs_setattr(&init_user_ns, dentry, &newattrs);
+		err = reiserfs_setattr(&nop_mnt_idmap, dentry, &newattrs);
 		inode_unlock(d_inode(dentry));
 	} else
 		update_ctime(inode);