Commit a5d16333 authored Dec 07, 2011 by Li Zefan Committed by Chris Mason Dec 08, 2011

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 <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

parent 274bd4fb

fs/btrfs/volumes.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);

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