From: Al Viro <viro@zeniv.linux.org.uk>
To: John Hubbard <jhubbard@nvidia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Jens Axboe <axboe@kernel.dk>, Miklos Szeredi <miklos@szeredi.hu>,
Christoph Hellwig <hch@infradead.org>,
"Darrick J . Wong" <djwong@kernel.org>,
Trond Myklebust <trond.myklebust@hammerspace.com>,
Anna Schumaker <anna@kernel.org>, Jan Kara <jack@suse.cz>,
Logan Gunthorpe <logang@deltatee.com>,
linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 5/6] NFS: direct-io: convert to FOLL_PIN pages
Date: Sun, 28 Aug 2022 01:38:56 +0100 [thread overview]
Message-ID: <Ywq5ILRNxsbWvFQe@ZenIV> (raw)
In-Reply-To: <353f18ac-0792-2cb7-6675-868d0bd41d3d@nvidia.com>
On Sat, Aug 27, 2022 at 04:55:18PM -0700, John Hubbard wrote:
> On 8/27/22 15:48, Al Viro wrote:
> > On Sat, Aug 27, 2022 at 01:36:06AM -0700, John Hubbard wrote:
> >> Convert the NFS Direct IO layer to use pin_user_pages_fast() and
> >> unpin_user_page(), instead of get_user_pages_fast() and put_page().
> >
> > Again, this stuff can be hit with ITER_BVEC iterators
> >
> >> - result = iov_iter_get_pages_alloc2(iter, &pagevec,
> >> + result = dio_w_iov_iter_pin_pages_alloc(iter, &pagevec,
> >> rsize, &pgbase);
> >
> > and this will break on those.
>
> If anyone has an example handy, of a user space program that leads
> to this situation (O_DIRECT with ITER_BVEC), it would really help
> me reach enlightenment a lot quicker in this area. :)
Er... splice(2) to O_DIRECT-opened file on e.g. ext4? Or
sendfile(2) to the same, for that matter...
next prev parent reply other threads:[~2022-08-28 0:39 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-27 8:36 [PATCH 0/6] convert most filesystems to pin_user_pages_fast() John Hubbard
2022-08-27 8:36 ` [PATCH 1/6] mm/gup: introduce pin_user_page() John Hubbard
2022-08-29 12:07 ` David Hildenbrand
2022-08-29 19:33 ` John Hubbard
2022-08-30 12:17 ` David Hildenbrand
2022-08-30 21:42 ` John Hubbard
2022-08-31 0:06 ` John Hubbard
2022-08-27 8:36 ` [PATCH 2/6] block: add dio_w_*() wrappers for pin, unpin user pages John Hubbard
2022-08-27 22:27 ` Andrew Morton
2022-08-27 23:59 ` John Hubbard
2022-08-28 0:12 ` Andrew Morton
2022-08-28 0:31 ` John Hubbard
2022-08-28 1:07 ` John Hubbard
2022-08-27 8:36 ` [PATCH 3/6] iov_iter: new iov_iter_pin_pages*() routines John Hubbard
2022-08-27 22:46 ` Al Viro
2022-08-27 22:48 ` John Hubbard
2022-08-27 8:36 ` [PATCH 4/6] block, bio, fs: convert most filesystems to pin_user_pages_fast() John Hubbard
2022-08-27 8:36 ` [PATCH 5/6] NFS: direct-io: convert to FOLL_PIN pages John Hubbard
2022-08-27 22:48 ` Al Viro
2022-08-27 23:55 ` John Hubbard
2022-08-28 0:38 ` Al Viro [this message]
2022-08-28 0:39 ` Al Viro
2022-08-28 0:46 ` John Hubbard
2022-08-29 4:59 ` John Hubbard
2022-08-29 16:08 ` Jan Kara
2022-08-29 19:59 ` John Hubbard
2022-08-31 9:43 ` Jan Kara
2022-08-31 18:02 ` John Hubbard
2022-09-01 0:38 ` Al Viro
2022-09-01 9:06 ` Jan Kara
2022-08-27 8:36 ` [PATCH 6/6] fuse: convert direct IO paths to use FOLL_PIN John Hubbard
-- strict thread matches above, loose matches on Subject: below --
2022-02-27 9:34 [PATCH 0/6] block, fs: convert most Direct IO cases to FOLL_PIN jhubbard.send.patches
2022-02-27 9:34 ` [PATCH 5/6] NFS: direct-io: convert to FOLL_PIN pages jhubbard.send.patches
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