Re: btrfs regression since 4.X kernel NULL pointer dereference

[Stefan Priebe - Profihost AG <s.priebe@profihost.ag>]

Am 25.08.2015 um 11:00 schrieb Christoph Hellwig:
> I think this is btrfs using a struct block_device that doesn't have
> a valid queue pointer in it's gendisk for ->s_bdev.  And there are
> some fishy looking ->s_bdev assignments in the code which I suspect
> are related to it:
> 
> fs/btrfs/dev-replace.c: if (fs_info->sb->s_bdev == src_device->bdev)
> fs/btrfs/dev-replace.c:         fs_info->sb->s_bdev = tgt_device->bdev;
> fs/btrfs/volumes.c:     if (device->bdev == root->fs_info->sb->s_bdev)
> fs/btrfs/volumes.c:             root->fs_info->sb->s_bdev = next_device->bdev;
> fs/btrfs/volumes.c:     if (tgtdev->bdev == fs_info->sb->s_bdev)
> fs/btrfs/volumes.c:             fs_info->sb->s_bdev = next_device->bdev;
> 

Would be very nice if anyone from btrfs can pick this up.

Stefan