From 4e24ec07aed055baac765b3af2e57040a9fc99d7 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Mon, 25 Mar 2019 16:38:23 +0000
Subject: [PATCH] UPSTREAM: vfs: Convert bdev to use the new mount API

Convert the bdev filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Change-Id: Id639f03fca0c45b7b94afc3abb93a14cb575fb79
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/block_dev.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index f196152b36ce..0b81f90c158a 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -25,6 +25,7 @@
 #include <linux/writeback.h>
 #include <linux/mpage.h>
 #include <linux/mount.h>
+#include <linux/pseudo_fs.h>
 #include <linux/uio.h>
 #include <linux/namei.h>
 #include <linux/log2.h>
@@ -802,19 +803,19 @@ static const struct super_operations bdev_sops = {
 	.evict_inode = bdev_evict_inode,
 };
 
-static struct dentry *bd_mount(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data)
+static int bd_init_fs_context(struct fs_context *fc)
 {
-	struct dentry *dent;
-	dent = mount_pseudo(fs_type, &bdev_sops, NULL, BDEVFS_MAGIC);
-	if (!IS_ERR(dent))
-		dent->d_sb->s_iflags |= SB_I_CGROUPWB;
-	return dent;
+	struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC);
+	if (!ctx)
+		return -ENOMEM;
+	fc->s_iflags |= SB_I_CGROUPWB;
+	ctx->ops = &bdev_sops;
+	return 0;
 }
 
 static struct file_system_type bd_type = {
 	.name		= "bdev",
-	.mount		= bd_mount,
+	.init_fs_context = bd_init_fs_context,
 	.kill_sb	= kill_anon_super,
 };