From: Christoph Hellwig <hch@infradead.org>
To: Ming Lei <ming.lei@canonical.com>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-kernel@vger.kernel.org,
"Justin M. Forbes" <jforbes@fedoraproject.org>,
Jeff Moyer <jmoyer@redhat.com>, Tejun Heo <tj@kernel.org>,
Christoph Hellwig <hch@infradead.org>,
linux-api@vger.kernel.org
Subject: Re: [PATCH v7 4/6] block: loop: prepare for supporing direct IO
Date: Mon, 27 Jul 2015 01:40:20 -0700 [thread overview]
Message-ID: <20150727084020.GA28336@infradead.org> (raw)
In-Reply-To: <1437061068-26118-5-git-send-email-ming.lei@canonical.com>
> + /*
> + * loop block's logical block size is 512, now
> + * we support direct I/O only if the backing
> + * block devices' minimize I/O size is 512 and
> + * the offset is aligned with 512.
> + */
> + if (dio) {
> + if (inode->i_sb->s_bdev &&
> + bdev_io_min(inode->i_sb->s_bdev) == 512 &&
> + !(lo->lo_offset & 511))
Why the hardcoded value? I suspect this should be more like:
if (dio && inode->i_sb->s_bdev &&
(lo->lo_offset & (bdev_io_min(inode->i_sb->s_bdev) - 1)) != 0)
dio = false;
> + blk_mq_freeze_queue(lo->lo_queue);
> + lo->use_dio = use_dio;
> + if (use_dio)
> + lo->lo_flags |= LO_FLAGS_DIRECT_IO;
> + else
> + lo->lo_flags &= ~LO_FLAGS_DIRECT_IO;
> + blk_mq_unfreeze_queue(lo->lo_queue);
Locking?
next prev parent reply other threads:[~2015-07-27 8:40 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-16 15:37 [PATCH v7 0/6] block: loop: improve loop with AIO Ming Lei
2015-07-16 15:37 ` [PATCH v7 1/6] fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read Ming Lei
2015-07-16 16:48 ` Dave Kleikamp
2015-07-16 15:37 ` [PATCH v7 2/6] block: loop: set QUEUE_FLAG_NOMERGES for request queue of loop Ming Lei
2015-07-16 15:37 ` [PATCH v7 3/6] block: loop: use kthread_work Ming Lei
2015-07-16 15:37 ` [PATCH v7 4/6] block: loop: prepare for supporing direct IO Ming Lei
2015-07-27 8:40 ` Christoph Hellwig [this message]
2015-07-27 9:41 ` Ming Lei
2015-07-27 9:45 ` Christoph Hellwig
2015-07-27 9:53 ` Ming Lei
2015-07-27 17:33 ` Christoph Hellwig
2015-07-29 7:33 ` Ming Lei
2015-07-29 8:41 ` Dave Chinner
2015-07-29 11:21 ` Ming Lei
2015-07-29 22:08 ` Dave Chinner
2015-07-30 8:01 ` Ming Lei
2015-07-27 22:06 ` Dave Chinner
2015-07-16 15:37 ` [PATCH v7 5/6] block: loop: introduce ioctl command of LOOP_SET_DIRECT_IO Ming Lei
2015-07-16 15:37 ` [PATCH v7 6/6] block: loop: support DIO & AIO Ming Lei
2015-07-23 9:00 ` [PATCH v7 0/6] block: loop: improve loop with AIO Ming Lei
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