Btrfs: fix regression of btrfs device replace

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>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
Liu Bo 2014-07-29 19:09:39 +08:00 committed by Chris Mason
parent 95669976bd
commit 87fa3bb078

View File

@ -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;