btrfs: Do not restrict writes to btrfs devices

Btrfs device probing code needs adaptation so that it works when writes
are restricted to its mounted devices. Since btrfs maintainer wants to
merge these changes through btrfs tree and there are review bandwidth
issues with that, let's not block all other filesystems and just not
restrict writes to btrfs devices for now.

CC: <linux-btrfs@vger.kernel.org>
CC: David Sterba <dsterba@suse.com>
CC: Josef Bacik <josef@toxicpanda.com>
CC: Chris Mason <clm@fb.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231101174325.10596-4-jack@suse.cz
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f638dc339693bc1a65c1d5637d58b998ad5b95d4..fc06aee293fae124b8ba93ab21fb47f6adc22d44 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1403,6 +1403,8 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
                        return ERR_PTR(error);
        }
 
+       /* No support for restricting writes to btrfs devices yet... */
+       mode &= ~BLK_OPEN_RESTRICT_WRITES;
        /*
         * Setup a dummy root and fs_info for test/set super.  This is because
         * we don't actually fill this stuff out until open_ctree, but we need