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From: Christoph Hellwig <>
To: Martijn Coenen <>
Subject: Re: [PATCH] loop: change queue block size to match when using DIO.
Date: Fri, 30 Aug 2019 08:50:24 -0700	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On Wed, Aug 28, 2019 at 12:32:29PM +0200, Martijn Coenen wrote:
> The loop driver assumes that if the passed in fd is opened with
> O_DIRECT, the caller wants to use direct I/O on the loop device.
> However, if the underlying filesystem has a different block size than
> the loop block queue, direct I/O can't be enabled. Instead of requiring
> userspace to manually change the blocksize and re-enable direct I/O,
> just change the queue block size to match.

Why can't we enable the block device in that case?  All the usual
block filesystems support 512 byte aligned direct I/O with a 4k
file system block size (as long as the underlying block device
sector size is also 512 bytes).

  reply	other threads:[~2019-08-30 15:50 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-28 10:32 [PATCH] loop: change queue block size to match when using DIO Martijn Coenen
2019-08-30 15:50 ` Christoph Hellwig [this message]
2019-09-02 19:37   ` Martijn Coenen
2019-09-04 19:49 ` [PATCH v2] " Martijn Coenen
2019-09-10 10:12   ` Martijn Coenen
2019-09-30  8:24   ` Christoph Hellwig
2019-10-01 10:03     ` Martijn Coenen
2019-10-01 14:10   ` Jens Axboe

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