diff options
| author | Anand Jain <Anand.Jain@oracle.com> | 2014-01-15 17:22:28 +0800 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2014-02-15 08:03:09 -0800 |
| commit | f085381e6d08f4c8d6882825f31accd455c54d70 (patch) | |
| tree | a2288e14def975689e3f32c9960c9a0f68aa6d19 | |
| parent | 3a0dfa6a12e4bb64a434426ecb17d4842092db5e (diff) | |
| download | linux-f085381e6d08f4c8d6882825f31accd455c54d70.tar.bz2 | |
btrfs: fix null pointer deference at btrfs_sysfs_add_one+0x105
bdev is null when disk has disappeared and mounted with
the degrade option
stack trace
---------
btrfs_sysfs_add_one+0x105/0x1c0 [btrfs]
open_ctree+0x15f3/0x1fe0 [btrfs]
btrfs_mount+0x5db/0x790 [btrfs]
? alloc_pages_current+0xa4/0x160
mount_fs+0x34/0x1b0
vfs_kern_mount+0x62/0xf0
do_mount+0x22e/0xa80
? __get_free_pages+0x9/0x40
? copy_mount_options+0x31/0x170
SyS_mount+0x7e/0xc0
system_call_fastpath+0x16/0x1b
---------
reproducer:
-------
mkfs.btrfs -draid1 -mraid1 /dev/sdc /dev/sdd
(detach a disk)
devmgt detach /dev/sdc [1]
mount -o degrade /dev/sdd /btrfs
-------
[1] github.com/anajain/devmgt.git
Signed-off-by: Anand Jain <Anand.Jain@oracle.com>
Tested-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
| -rw-r--r-- | fs/btrfs/sysfs.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 782374d8fd19..865f4cf9a769 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -578,8 +578,14 @@ static int add_device_membership(struct btrfs_fs_info *fs_info) return -ENOMEM; list_for_each_entry(dev, &fs_devices->devices, dev_list) { - struct hd_struct *disk = dev->bdev->bd_part; - struct kobject *disk_kobj = &part_to_dev(disk)->kobj; + struct hd_struct *disk; + struct kobject *disk_kobj; + + if (!dev->bdev) + continue; + + disk = dev->bdev->bd_part; + disk_kobj = &part_to_dev(disk)->kobj; error = sysfs_create_link(fs_info->device_dir_kobj, disk_kobj, disk_kobj->name); |