From: Anand Jain Date: Wed, 20 Aug 2014 02:56:56 +0000 (+0800) Subject: btrfs: replace seed device followed by unmount causes kernel WARNING X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=25e8e9113d340f0c32161ced0d4655eff8fed757;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git btrfs: replace seed device followed by unmount causes kernel WARNING reproducer: mount /dev/sdb /btrfs btrfs dev add /dev/sdc /btrfs btrfs rep start -B /dev/sdb /dev/sdd /btrfs umount /btrfs WARNING: CPU: 0 PID: 12661 at fs/btrfs/volumes.c:891 __btrfs_close_devices+0x1b0/0x200 [btrfs]() :: __btrfs_close_devices() :: WARN_ON(fs_devices->open_devices); After the seed device has been replaced the new target device is no more a seed device. So we need to update the device numbers in the fs_devices as pointed by the fs_info. Signed-off-by: Anand Jain Reviewed-by: Miao Xie Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 096b4a3dc5a9..361a66e2c179 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1819,7 +1819,13 @@ void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info, WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex)); - fs_devices = fs_info->fs_devices; + /* + * in case of fs with no seed, srcdev->fs_devices will point + * to fs_devices of fs_info. However when the dev being replaced is + * a seed dev it will point to the seed's local fs_devices. In short + * srcdev will have its correct fs_devices in both the cases. + */ + fs_devices = srcdev->fs_devices; list_del_rcu(&srcdev->dev_list); list_del_rcu(&srcdev->dev_alloc_list);