From: Goldwyn Rodrigues <rgoldwyn@suse.com>
To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>,
Josef Bacik <josef@toxicpanda.com>,
Johannes Thumshirn <johannes.thumshirn@wdc.com>,
David Sterba <dsterba@suse.com>,
"linux-btrfs @ vger . kernel . org" <linux-btrfs@vger.kernel.org>,
Filipe Manana <fdmanana@gmail.com>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>
Subject: Re: [RFC PATCH] btrfs: don't call btrfs_sync_file from iomap context
Date: Tue, 15 Sep 2020 16:48:53 -0500 [thread overview]
Message-ID: <20200915214853.iurg43dt52h5z2gp@fiona> (raw)
In-Reply-To: <20200907000432.GM12096@dread.disaster.area>
On 10:04 07/09, Dave Chinner wrote:
> On Thu, Sep 03, 2020 at 06:32:36PM +0200, Christoph Hellwig wrote:
> > We could trivially do something like this to allow the file system
> > to call iomap_dio_complete without i_rwsem:
>
> That just exposes another deadlock vector:
>
> P0 P1
> inode_lock() fallocate(FALLOC_FL_ZERO_RANGE)
> __iomap_dio_rw() inode_lock()
> <block>
> <submits IO>
> <completes IO>
> inode_unlock()
> <gets inode_lock()>
> inode_dio_wait()
> iomap_dio_complete()
> generic_write_sync()
> btrfs_file_fsync()
> inode_lock()
> <deadlock>
Can inode_dio_end() be called before generic_write_sync(), as it is done
in fs/direct-io.c:dio_complete()?
Christoph's solution is a clean approach and would prefer to use it as
the final solution.
--
Goldwyn
next prev parent reply other threads:[~2020-09-15 21:49 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
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 [this message]
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
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