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From: David Sterba <dsterba@suse.cz>
To: Omar Sandoval <osandov@osandov.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>,
	linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	kernel-team@fb.com
Subject: Re: [PATCH 1/3] fs: add initial bh_result->b_private value to __blockdev_direct_IO()
Date: Mon, 14 May 2018 18:35:48 +0200	[thread overview]
Message-ID: <20180514163548.GN6649@twin.jikos.cz> (raw)
In-Reply-To: <20180511203001.GE29366@vader>

On Fri, May 11, 2018 at 01:30:01PM -0700, Omar Sandoval wrote:
> On Fri, May 11, 2018 at 09:05:38PM +0100, Al Viro wrote:
> > On Thu, May 10, 2018 at 11:30:10PM -0700, Omar Sandoval wrote:
> > >  do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
> > >  		      struct block_device *bdev, struct iov_iter *iter,
> > >  		      get_block_t get_block, dio_iodone_t end_io,
> > > -		      dio_submit_t submit_io, int flags)
> > > +		      dio_submit_t submit_io, int flags, void *private)
> > 
> > Oh, dear...  That's what, 9 arguments?  I agree that the hack in question
> > is obscene, but so is this ;-/
> 
> So looking at these one by one, obviously needed:
> 
> - iocb
> - inode
> - iter
> 
> bdev is almost always inode->i_sb->s_bdev, except for Btrfs :(
> 
> These could _maybe_ go in struct kiocb:
> 
> - flags could maybe be folded into ki_flags
> - private could maybe go in iocb->private, but I haven't yet read
>   through to figure out if we're already using iocb->private for direct
>   I/O

I think the kiocb::private can be used for the purpose. There's only one
user, ext4, that also passes some DIO data around so it would in line
with the interface AFAICS.

  parent reply	other threads:[~2018-05-14 16:38 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-11  6:30 [PATCH 0/3] Btrfs: stop abusing current->journal_info for direct I/O Omar Sandoval
2018-05-11  6:30 ` [PATCH 1/3] fs: add initial bh_result->b_private value to __blockdev_direct_IO() Omar Sandoval
2018-05-11 20:05   ` Al Viro
2018-05-11 20:30     ` Omar Sandoval
2018-05-11 20:32       ` Al Viro
2018-05-11 20:41         ` Omar Sandoval
2018-05-14 16:35       ` David Sterba [this message]
2018-06-25 17:16         ` David Sterba
2018-06-29  7:02           ` Omar Sandoval
2018-05-11  6:30 ` [PATCH 2/3] fs: add private argument to dio_submit_t Omar Sandoval
2018-05-11  6:30 ` [PATCH 3/3] Btrfs: stop abusing current->journal_info in btrfs_direct_IO() Omar Sandoval
2018-05-11  9:26 ` [PATCH 0/3] Btrfs: stop abusing current->journal_info for direct I/O David Sterba
2018-05-11  9:53 ` Nikolay Borisov
2018-05-11 10:24   ` David Sterba
2018-05-11 17:28   ` Omar Sandoval

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