From: Christoph Hellwig <hch@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>,
Jens Axboe <axboe@kernel.dk>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
linux-fsdevel@vger.kernel.org, Theodore Ts'o <tytso@mit.edu>,
linux-ext4 <linux-ext4@vger.kernel.org>
Subject: Re: BLKZEROOUT + pread should return zeroes, right?
Date: Tue, 14 Oct 2014 02:21:28 -0700 [thread overview]
Message-ID: <20141014092128.GA23656@infradead.org> (raw)
In-Reply-To: <20141014042711.GJ5267@dastard>
On Tue, Oct 14, 2014 at 03:27:11PM +1100, Dave Chinner wrote:
> Broken usage, IMO. If you are going to use the block layer ioctls to
> manipulate data int eh block device, you should be using direct Io
> for all your data IO to the block device. Otherwise, coherency
> problems occur....
I'd say BLKZEROOUT semantics are broken. Having an ioctl exposed
that maniulates on-disk data without cache coherence is a nightmare
that people trip over easily. Even experienced people like Darrick.
next prev parent reply other threads:[~2014-10-14 9:21 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-14 3:01 BLKZEROOUT + pread should return zeroes, right? Darrick J. Wong
2014-10-14 4:27 ` Dave Chinner
2014-10-14 6:02 ` Darrick J. Wong
2014-10-14 6:32 ` Theodore Ts'o
2014-10-15 1:25 ` Darrick J. Wong
2014-10-15 1:32 ` Martin K. Petersen
2014-10-16 20:04 ` Darrick J. Wong
2014-10-15 10:02 ` Theodore Ts'o
2014-10-15 12:09 ` Martin K. Petersen
2014-10-18 0:03 ` [RFC PATCH] block: make BLKZEROOUT invalidate page cache contents Darrick J. Wong
2014-10-14 9:21 ` Christoph Hellwig [this message]
2014-10-14 13:44 ` BLKZEROOUT + pread should return zeroes, right? Martin K. Petersen
2014-10-14 18:57 ` Zach Brown
2014-10-14 20:21 ` Dave Chinner
2014-10-15 1:02 ` Martin K. Petersen
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