On 2019/11/13 下午6:27, Johannes Thumshirn wrote:
> This series attempts to remove the BUG_ON()s in btrfs_close_one_device().
> Therefore some reorganization of btrfs_close_one_device() and
> close_fs_devices() was needed.
> 
> Forthermore a new BUG_ON() had to be temporarily introduced but is removed
> again in the last patch of theis series.
> 
> Although it is generally legal to return -ENOMEM on umount(2), the error
> handling up until close_ctree() as neither close_ctree() nor btrfs_put_super()
> would be able to handle the error.
> 
> This series has passed fstests without any deviation from the baseline and
> also the new error handling was tested via error injection using this snippet:
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 7c55169c0613..c58802c9c39c 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1069,6 +1069,9 @@ static int btrfs_close_one_device(struct btrfs_device *device)
>  
>  	new_device = btrfs_alloc_device(NULL, &device->devid,
>  					device->uuid);
> +	btrfs_free_device(new_device);
> +	pr_err("%s() INJECTING -ENOMEM\n", __func__);
> +	new_device = ERR_PTR(-ENOMEM);
>  	if (IS_ERR(new_device))
>  		return PTR_ERR(new_device);
> 
> Changes to v1:
> 
> Fixed the decremt of btrfs_fs_devices::seeding.
> 
> In addition to this, I've added two patches changing btrfs_fs_devices::seeding
> and btrfs_fs_devices::rotating to bool, as they are in fact used as booleans.

Reviewed-by: Qu Wenruo <wqu@suse.com>

Thanks,
Qu

> 
> Johannes Thumshirn (7):
>   btrfs: decrement number of open devices after closing the device not
>     before
>   btrfs: handle device allocation failure in btrfs_close_one_device()
>   btrfs: handle allocation failure in strdup
>   btrfs: handle error return of close_fs_devices()
>   btrfs: remove final BUG_ON() in close_fs_devices()
>   btrfs: change btrfs_fs_devices::seeing to bool
>   btrfs: change btrfs_fs_devices::rotating to bool
> 
>  fs/btrfs/volumes.c | 81 ++++++++++++++++++++++++++++++++++++------------------
>  fs/btrfs/volumes.h |  4 +--
>  2 files changed, 56 insertions(+), 29 deletions(-)
>