Re: remove get_super

[Jan Kara <jack@suse.cz>]

On Thu 14-09-23 14:03:20, David Sterba wrote:
> On Thu, Sep 14, 2023 at 10:48:09AM +0200, Jan Kara wrote:
> > On Tue 12-09-23 19:42:45, David Sterba wrote:
> > > On Fri, Aug 11, 2023 at 12:08:11PM +0200, Christoph Hellwig wrote:
> > > > Hi all,
> > > > 
> > > > this series against the VFS vfs.super branch finishes off the work to remove
> > > > get_super and move (almost) all upcalls to use the holder ops.
> > > > 
> > > > The first part is the missing btrfs bits so that all file systems use the
> > > > super_block as holder.
> > > > 
> > > > The second part is various block driver cleanups so that we use proper
> > > > interfaces instead of raw calls to __invalidate_device and fsync_bdev.
> > > > 
> > > > The last part than replaces __invalidate_device and fsync_bdev with upcalls
> > > > to the file system through the holder ops, and finally removes get_super.
> > > > 
> > > > It leaves user_get_super and get_active_super around.  The former is not
> > > > used for upcalls in the traditional sense, but for legacy UAPI that for
> > > > some weird reason take a dev_t argument (ustat) or a block device path
> > > > (quotactl).  get_active_super is only used for calling into the file system
> > > > on freeze and should get a similar treatment, but given that Darrick has
> > > > changes to that code queued up already this will be handled in the next
> > > > merge window.
> > > > 
> > > > A git tree is available here:
> > > > 
> > > >     git://git.infradead.org/users/hch/misc.git remove-get_super
> > > 
> > > FYI, I've added patches 2-5 as a topic branch to btrfs for-next.
> > 
> > Hum, I don't see them there. Some glitch somewhere?
> 
> There will be a delay before the patches show up in the pushed for-next
> branch, some tests failed (maybe not related to this series) and there
> are other merge conflicts that I need to resolve first.

Thanks for picking up the patches, I can see them in your tree now. But
I've also noticed (by comparing my local branch with your tree), that in
this series is also a patch 6/17 "btrfs: use the super_block as holder when
mounting file systems" which you didn't pick up. It actually fixes block
device freezing for btrfs as a sideeffect as Christian found out [1]. Can
you please pick it up as well? Thanks!

								Honza

[1] https://lore.kernel.org/all/20230908-merklich-bebauen-11914a630db4@brauner

-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR