All of lore.kernel.org
 help / color / mirror / Atom feed
From: Josef Bacik <josef@toxicpanda.com>
To: Johannes Thumshirn <Johannes.Thumshirn@wdc.com>,
	Dave Chinner <david@fromorbit.com>
Cc: David Sterba <dsterba@suse.com>,
	"linux-btrfs @ vger . kernel . org" <linux-btrfs@vger.kernel.org>,
	Filipe Manana <fdmanana@gmail.com>,
	Christoph Hellwig <hch@lst.de>,
	Linux FS Devel <linux-fsdevel@vger.kernel.org>
Subject: Re: [RFC PATCH] btrfs: don't call btrfs_sync_file from iomap context
Date: Wed, 2 Sep 2020 07:10:08 -0400	[thread overview]
Message-ID: <43272cc6-4d40-caf7-8777-4ef1e1725c97@toxicpanda.com> (raw)
In-Reply-To: <SN4PR0401MB3598CDEB0ADC4E43179DE2E29B2F0@SN4PR0401MB3598.namprd04.prod.outlook.com>

On 9/2/20 3:12 AM, Johannes Thumshirn wrote:
> On 02/09/2020 02:22, Josef Bacik wrote:
>> Instead now we have to rip
>> it out until we figure out what to do about it.
> 
> I don't think we need to rip out the iomap conversion. We can
> take my fix albeit not pretty, until we have reworked the locking
> around ->fsync(). Probably with a big fat comment attached to it.
> 

We do, because your fix breaks DSYNC for AIO.  You didn't hit this with 
direct io, you hit it with AIO, and the reason you hit it is because you 
are on zram, so your bio's completed before we exited iomap_dio_rw.  So 
that was the last put on the iomap_dio, and thus we ran
iomap_dio_complete() and deadlocked.  We can't just drop the DSYNC thing 
for AIO because in the normal case where this doesn't happen we need to 
know when the last thing is finished in order to run ->fsync(), we can't 
just run it after submission.  Thanks,

Josef

  reply	other threads:[~2020-09-02 11:10 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-01 13:06 [RFC PATCH] btrfs: don't call btrfs_sync_file from iomap context Johannes Thumshirn
2020-09-01 13:11 ` Johannes Thumshirn
2020-09-01 14:17 ` Goldwyn Rodrigues
2020-09-01 14:20   ` Johannes Thumshirn
2020-09-01 14:37 ` Filipe Manana
2020-09-01 14:44   ` Johannes Thumshirn
2020-09-01 18:40     ` Goldwyn Rodrigues
2020-09-01 15:11 ` Josef Bacik
2020-09-01 17:45   ` Darrick J. Wong
2020-09-01 17:55     ` Josef Bacik
2020-09-01 21:46   ` Dave Chinner
2020-09-01 22:19     ` Josef Bacik
2020-09-01 23:58       ` Dave Chinner
2020-09-02  0:22         ` Josef Bacik
2020-09-02  7:12           ` Johannes Thumshirn
2020-09-02 11:10             ` Josef Bacik [this message]
2020-09-02 16:29               ` Darrick J. Wong
2020-09-02 16:47                 ` Josef Bacik
2020-09-02 11:44         ` Matthew Wilcox
2020-09-02 12:20           ` Dave Chinner
2020-09-02 12:42             ` Josef Bacik
2020-09-03  2:28               ` Dave Chinner
2020-09-03  9:49                 ` Filipe Manana
2020-09-03 16:32   ` Christoph Hellwig
2020-09-03 16:46     ` Josef Bacik
2020-09-07  0:04     ` Dave Chinner
2020-09-15 21:48       ` Goldwyn Rodrigues
2020-09-17  3:09         ` Dave Chinner
2020-09-17  5:52           ` Christoph Hellwig
2020-09-17  6:29             ` Dave Chinner
2020-09-17  6:42               ` Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=43272cc6-4d40-caf7-8777-4ef1e1725c97@toxicpanda.com \
    --to=josef@toxicpanda.com \
    --cc=Johannes.Thumshirn@wdc.com \
    --cc=david@fromorbit.com \
    --cc=dsterba@suse.com \
    --cc=fdmanana@gmail.com \
    --cc=hch@lst.de \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.