From a5d16333612718569ffd26064270e535cb9c3928 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 7 Dec 2011 20:08:40 -0500 Subject: [PATCH] Btrfs: check if the to-be-added device is writable If we call ioctl(BTRFS_IOC_ADD_DEV) directly, we'll succeed in adding a readonly device to a btrfs filesystem, and btrfs will write to that device, emitting kernel errors: [ 3109.833692] lost page write due to I/O error on loop2 [ 3109.833720] lost page write due to I/O error on loop2 ... Signed-off-by: Li Zefan Signed-off-by: Chris Mason --- fs/btrfs/volumes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index c37433d3cd82..0a8c8f8304b1 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1611,7 +1611,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path) if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding) return -EINVAL; - bdev = blkdev_get_by_path(device_path, FMODE_EXCL, + bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL, root->fs_info->bdev_holder); if (IS_ERR(bdev)) return PTR_ERR(bdev); -- 2.20.1