Commit 49c6f736f34f901117c20960ebd7d5e60f12fcac( btrfs: dev replace should replace the sysfs entry) added the missing sysfs entry in the process of device replace, but didn't take missing devices into account, so now we have BUG: unable to handle kernel NULL pointer dereference at 0000000000000088 IP: [<ffffffffa0268551>] btrfs_kobj_rm_device+0x21/0x40 [btrfs] ... To reproduce it, 1. mkfs.btrfs -f disk1 disk2 2. mkfs.ext4 disk1 3. mount disk2 /mnt -odegraded 4. btrfs replace start -B 1 disk3 /mnt -------------------------- This fixes the problem. Reported-by: Chris Murphy <lists@colorremedies.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> --- fs/btrfs/sysfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 7869936..12e5355 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -614,7 +614,7 @@ int btrfs_kobj_rm_device(struct btrfs_fs_info *fs_info, if (!fs_info->device_dir_kobj) return -EINVAL; - if (one_device) { + if (one_device && one_device->bdev) { disk = one_device->bdev->bd_part; disk_kobj = &part_to_dev(disk)->kobj; -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html