From: Kent Overstreet <kent.overstreet@gmail.com>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-xfs@vger.kernel.org, axboe@fb.com,
linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org
Subject: Re: [PATCH 4/5] iomap: implement direct I/O
Date: Sat, 5 Nov 2016 07:10:49 -0800 [thread overview]
Message-ID: <20161105151049.ocvrfh6fjsotnpxx@kmo-pixel> (raw)
In-Reply-To: <1478276479-10749-5-git-send-email-hch@lst.de>
On Fri, Nov 04, 2016 at 10:21:18AM -0600, Christoph Hellwig wrote:
> This adds a full fledget direct I/O implementation using the iomap
> interface. Full fledged in this case means all features are supported:
> AIO, vectored I/O, any iov_iter type including kernel pointers, bvecs
> and pipes, support for hole filling and async apending writes. It does
> not mean supporting all the warts of the old generic code. We expect
> i_rwsem to be held over the duration of the call, and we expect to
> maintain i_dio_count ourselves, and we pass on any kinds of mapping
> to the file system for now.
>
> The algorithm used is very simple: We use iomap_apply to iterate over
> the range of the I/O, and then we use the new bio_iov_iter_get_pages
> helper to lock down the user range for the size of the extent.
> bio_iov_iter_get_pages can currently lock down twice as many pages as
> the old direct I/O code did, which means that we will have a better
> batch factor for everything but overwrites of badly fragmented files.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
next prev parent reply other threads:[~2016-11-05 15:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-04 16:21 an iomap-based direct I/O implementation V2 Christoph Hellwig
2016-11-04 16:21 ` [PATCH 1/5] locking/lockdep: Provide a type check for lock_is_held Christoph Hellwig
2016-11-04 16:21 ` [PATCH 2/5] xfs: remove i_iolock and use i_rwsem in the VFS inode instead Christoph Hellwig
2016-11-04 16:21 ` [PATCH 3/5] fs: make sb_init_dio_done_wq available outside of direct-io.c Christoph Hellwig
2016-11-04 16:21 ` [PATCH 4/5] iomap: implement direct I/O Christoph Hellwig
2016-11-04 20:56 ` Jens Axboe
2016-11-05 15:10 ` Kent Overstreet [this message]
2016-11-05 18:14 ` Avi Kivity
2016-11-06 16:36 ` Christoph Hellwig
2016-11-06 22:40 ` Dave Chinner
2016-11-07 15:08 ` Christoph Hellwig
2016-11-08 1:38 ` Dave Chinner
2016-11-04 16:21 ` [PATCH 5/5] xfs: use iomap_dio_rw Christoph Hellwig
-- strict thread matches above, loose matches on Subject: below --
2016-11-13 19:07 an iomap-based direct I/O implementation V3 Christoph Hellwig
2016-11-13 19:07 ` [PATCH 4/5] iomap: implement direct I/O Christoph Hellwig
2016-11-29 17:28 an iomap-based direct I/O implementation V4 Christoph Hellwig
2016-11-29 17:28 ` [PATCH 4/5] iomap: implement direct I/O Christoph Hellwig
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