Re: [PATCH v2 0/7]

[David Sterba <dsterba@suse.cz>]

On Tue, Jul 27, 2021 at 05:01:12PM -0400, Josef Bacik wrote:
> v1->v2:
> - Rework the first patch as it was wrong because we need it for seed devices.
> - Fix another lockdep splat I uncovered while testing against seed devices to
>   make sure I hadn't broken anything.
> 
> --- Original email ---
> 
> Hello,
> 
> The commit 87579e9b7d8d ("loop: use worker per cgroup instead of kworker")
> enabled the use of workqueues for loopback devices, which brought with it
> lockdep annotations for the workqueues for loopback devices.  This uncovered a
> cascade of lockdep warnings because of how we mess with the block_device while
> under the sb writers lock while doing the device removal.
> 
> The first patch seems innocuous but we have a lockdep_assert_held(&uuid_mutex)
> in one of the helpers, which is why I have it first.  The code should never be
> called which is why it is removed, but I'm removing it specifically to remove
> confusion about the role of the uuid_mutex here.
> 
> The next 4 patches are to resolve the lockdep messages as they occur.  There are
> several issues and I address them one at a time until we're no longer getting
> lockdep warnings.
> 
> The final patch doesn't necessarily have to go in right away, it's just a
> cleanup as I noticed we have a lot of duplicated code between the v1 and v2
> device removal handling.  Thanks,
> 
> Josef
> 
> Josef Bacik (7):
>   btrfs: do not call close_fs_devices in btrfs_rm_device
>   btrfs: do not take the uuid_mutex in btrfs_rm_device
>   btrfs: do not read super look for a device path
>   btrfs: update the bdev time directly when closing
>   btrfs: delay blkdev_put until after the device remove
>   btrfs: unify common code for the v1 and v2 versions of device remove
>   btrfs: do not take the device_list_mutex in clone_fs_devices

I've merged what looked ok and did not have comments. Remaining patches
are 1, 3 and 7. Please have a look and resend, thanks.