fs: port vfs_*() helpers to struct 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, 12 insertions, 12 deletions

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index f3cd00fac9c3..d2c5a8c55322 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -139,7 +139,7 @@ static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
 		if (d_unhashed(lower_dentry))
 			rc = -EINVAL;
 		else
-			rc = vfs_unlink(&init_user_ns, lower_dir, lower_dentry,
+			rc = vfs_unlink(&nop_mnt_idmap, lower_dir, lower_dentry,
 					NULL);
 	}
 	if (rc) {
@@ -180,7 +180,7 @@ ecryptfs_do_create(struct inode *directory_inode,
 
 	rc = lock_parent(ecryptfs_dentry, &lower_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_create(&init_user_ns, lower_dir,
+		rc = vfs_create(&nop_mnt_idmap, lower_dir,
 				lower_dentry, mode, true);
 	if (rc) {
 		printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
@@ -191,7 +191,7 @@ ecryptfs_do_create(struct inode *directory_inode,
 	inode = __ecryptfs_get_inode(d_inode(lower_dentry),
 				     directory_inode->i_sb);
 	if (IS_ERR(inode)) {
-		vfs_unlink(&init_user_ns, lower_dir, lower_dentry, NULL);
+		vfs_unlink(&nop_mnt_idmap, lower_dir, lower_dentry, NULL);
 		goto out_lock;
 	}
 	fsstack_copy_attr_times(directory_inode, lower_dir);
@@ -434,7 +434,7 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
 	lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
 	rc = lock_parent(new_dentry, &lower_new_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_link(lower_old_dentry, &init_user_ns, lower_dir,
+		rc = vfs_link(lower_old_dentry, &nop_mnt_idmap, lower_dir,
 			      lower_new_dentry, NULL);
 	if (rc || d_really_is_negative(lower_new_dentry))
 		goto out_lock;
@@ -478,7 +478,7 @@ static int ecryptfs_symlink(struct user_namespace *mnt_userns,
 						  strlen(symname));
 	if (rc)
 		goto out_lock;
-	rc = vfs_symlink(&init_user_ns, lower_dir, lower_dentry,
+	rc = vfs_symlink(&nop_mnt_idmap, lower_dir, lower_dentry,
 			 encoded_symname);
 	kfree(encoded_symname);
 	if (rc || d_really_is_negative(lower_dentry))
@@ -504,7 +504,7 @@ static int ecryptfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 
 	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_mkdir(&init_user_ns, lower_dir,
+		rc = vfs_mkdir(&nop_mnt_idmap, lower_dir,
 			       lower_dentry, mode);
 	if (rc || d_really_is_negative(lower_dentry))
 		goto out;
@@ -533,7 +533,7 @@ static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
 		if (d_unhashed(lower_dentry))
 			rc = -EINVAL;
 		else
-			rc = vfs_rmdir(&init_user_ns, lower_dir, lower_dentry);
+			rc = vfs_rmdir(&nop_mnt_idmap, lower_dir, lower_dentry);
 	}
 	if (!rc) {
 		clear_nlink(d_inode(dentry));
@@ -557,7 +557,7 @@ ecryptfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 
 	rc = lock_parent(dentry, &lower_dentry, &lower_dir);
 	if (!rc)
-		rc = vfs_mknod(&init_user_ns, lower_dir,
+		rc = vfs_mknod(&nop_mnt_idmap, lower_dir,
 			       lower_dentry, mode, dev);
 	if (rc || d_really_is_negative(lower_dentry))
 		goto out;
@@ -616,10 +616,10 @@ ecryptfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
 		goto out_lock;
 	}
 
-	rd.old_mnt_userns	= &init_user_ns;
+	rd.old_mnt_idmap	= &nop_mnt_idmap;
 	rd.old_dir		= d_inode(lower_old_dir_dentry);
 	rd.old_dentry		= lower_old_dentry;
-	rd.new_mnt_userns	= &init_user_ns;
+	rd.new_mnt_idmap	= &nop_mnt_idmap;
 	rd.new_dir		= d_inode(lower_new_dir_dentry);
 	rd.new_dentry		= lower_new_dentry;
 	rc = vfs_rename(&rd);
@@ -856,7 +856,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 		struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
 
 		inode_lock(d_inode(lower_dentry));
-		rc = notify_change(&init_user_ns, lower_dentry,
+		rc = notify_change(&nop_mnt_idmap, lower_dentry,
 				   &lower_ia, NULL);
 		inode_unlock(d_inode(lower_dentry));
 	}
@@ -965,7 +965,7 @@ static int ecryptfs_setattr(struct user_namespace *mnt_userns,
 		lower_ia.ia_valid &= ~ATTR_MODE;
 
 	inode_lock(d_inode(lower_dentry));
-	rc = notify_change(&init_user_ns, lower_dentry, &lower_ia, NULL);
+	rc = notify_change(&nop_mnt_idmap, lower_dentry, &lower_ia, NULL);
 	inode_unlock(d_inode(lower_dentry));
 out:
 	fsstack_copy_attr_all(inode, lower_inode);