[PATCH] btrfs: do not restrict writes to devices

[Josef Bacik <josef@toxicpanda.com>]

This is a version of ead622674df5 ("btrfs: Do not restrict writes to
btrfs devices"), which pushes this restriction closer to where we use
bdev_open_by_path.  This was in the mount path, and changed when we
switched to the new mount api, and with that loss we suddenly weren't
able to mount.  Move this closer to where we use bdev_open_by_path so
changes on the upper layers don't mess anything up, and then we can
remove this when we merge the bdev holder patches.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
- This needs to go in before the new mount API patches when we rebase onto
  linus/master for the merge request, otherwise we won't be able to mount file
  systems.  I've put this at the beginning of the for-next branch in the github
  linux tree, which is rebased onto recent linus.

 fs/btrfs/volumes.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d67785be2c77..9c8de7fad86e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -474,6 +474,9 @@ btrfs_get_bdev_and_sb(const char *device_path, blk_mode_t flags, void *holder,
 	struct block_device *bdev;
 	int ret;
 
+	/* No support for restricting writes to btrfs devices yet... */
+	flags &= ~BLK_OPEN_RESTRICT_WRITES;
+
 	*bdev_handle = bdev_open_by_path(device_path, flags, holder, NULL);
 
 	if (IS_ERR(*bdev_handle)) {
@@ -1322,6 +1325,9 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, blk_mode_t flags,
 
 	lockdep_assert_held(&uuid_mutex);
 
+	/* No support for restricting writes to btrfs devices yet... */
+	flags &= ~BLK_OPEN_RESTRICT_WRITES;
+
 	/*
 	 * we would like to check all the supers, but that would make
 	 * a btrfs mount succeed after a mkfs from a different FS.
-- 
2.43.0