All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jan Kara <jack@suse.cz>
To: Ming Lei <ming.lei@redhat.com>
Cc: Martin Wilck <mwilck@suse.com>, Jens Axboe <axboe@kernel.dk>,
	Jan Kara <jack@suse.com>, Hannes Reinecke <hare@suse.de>,
	Johannes Thumshirn <jthumshirn@suse.de>,
	Kent Overstreet <kent.overstreet@gmail.com>,
	Christoph Hellwig <hch@lst.de>,
	linux-block@vger.kernel.org, Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [PATCH 2/2] blkdev: __blkdev_direct_IO_simple: make sure to fill up the bio
Date: Thu, 19 Jul 2018 12:37:13 +0200	[thread overview]
Message-ID: <20180719103713.tfuqzagme7zze6md@quack2.suse.cz> (raw)
In-Reply-To: <20180719102122.GA20700@ming.t460p>

On Thu 19-07-18 18:21:23, Ming Lei wrote:
> On Thu, Jul 19, 2018 at 11:39:18AM +0200, Martin Wilck wrote:
> > bio_iov_iter_get_pages() returns only pages for a single non-empty
> > segment of the input iov_iter's iovec. This may be much less than the number
> > of pages __blkdev_direct_IO_simple() is supposed to process. Call
> 
> In bio_iov_iter_get_pages(), iov_iter_get_pages() supposes to retrieve
> as many as possible pages since both 'maxsize' and 'maxpages' are provided
> to cover all.
> 
> So the question is why iov_iter_get_pages() doesn't work as expected?

Well, there has never been a promise that it will grab *all* pages in the
iter AFAIK. Practically, I think that it was just too hairy to implement in
the macro magic that iter processing is... Al might know more (added to
CC).

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

  reply	other threads:[~2018-07-19 10:37 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-12 14:36 Silent data corruption in blkdev_direct_IO() Hannes Reinecke
2018-07-12 15:08 ` Jens Axboe
2018-07-12 16:11   ` Martin Wilck
2018-07-12 16:14   ` Hannes Reinecke
2018-07-12 16:20     ` Jens Axboe
2018-07-12 16:42       ` Jens Axboe
2018-07-13  6:47         ` Martin Wilck
2018-07-13 16:56         ` Martin Wilck
2018-07-13 18:00           ` Jens Axboe
2018-07-13 18:50             ` Jens Axboe
2018-07-13 22:21               ` Martin Wilck
2018-07-13 20:48             ` Martin Wilck
2018-07-13 20:52               ` Jens Axboe
2018-07-16 19:05                 ` Martin Wilck
2018-07-12 23:29 ` Ming Lei
2018-07-13 18:54   ` Jens Axboe
2018-07-13 22:29     ` Martin Wilck
2018-07-16 11:45       ` Ming Lei
2018-07-18  0:07         ` Martin Wilck
2018-07-18  2:48           ` Ming Lei
2018-07-18  7:32             ` Martin Wilck
2018-07-18  7:54               ` Ming Lei
2018-07-18  9:20                 ` Johannes Thumshirn
2018-07-18 11:40                   ` Jan Kara
2018-07-18 11:57                     ` Jan Kara
2018-07-19  9:39                 ` [PATCH 0/2] Fix silent " Martin Wilck
2018-07-19  9:39                   ` [PATCH 1/2] block: bio_iov_iter_get_pages: fix size of last iovec Martin Wilck
2018-07-19 10:05                     ` Hannes Reinecke
2018-07-19 10:09                     ` Ming Lei
2018-07-19 10:20                     ` Jan Kara
2018-07-19 14:52                     ` Christoph Hellwig
2018-07-19  9:39                   ` [PATCH 2/2] blkdev: __blkdev_direct_IO_simple: make sure to fill up the bio Martin Wilck
2018-07-19 10:06                     ` Hannes Reinecke
2018-07-19 10:21                     ` Ming Lei
2018-07-19 10:37                       ` Jan Kara [this message]
2018-07-19 10:46                         ` Ming Lei
2018-07-19 11:08                         ` Al Viro
2018-07-19 14:53                           ` Christoph Hellwig
2018-07-19 15:06                             ` Jan Kara
2018-07-19 15:11                               ` Christoph Hellwig
2018-07-19 19:21                                 ` Martin Wilck
2018-07-19 19:34                             ` Martin Wilck
2018-07-19 10:45                     ` Jan Kara
2018-07-19 12:23                       ` Martin Wilck
2018-07-19 15:15                         ` Jan Kara
2018-07-19 20:01                           ` Martin Wilck
2018-07-19 11:04                     ` Ming Lei
2018-07-19 11:56                       ` Jan Kara
2018-07-19 12:20                         ` Ming Lei
2018-07-19 15:21                           ` Jan Kara
2018-07-19 19:06                             ` Martin Wilck
2018-07-19 12:25                         ` Martin Wilck
2018-07-19 10:08                   ` [PATCH 0/2] Fix silent data corruption in blkdev_direct_IO() Hannes Reinecke
2018-07-19 14:50                   ` Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180719103713.tfuqzagme7zze6md@quack2.suse.cz \
    --to=jack@suse.cz \
    --cc=axboe@kernel.dk \
    --cc=hare@suse.de \
    --cc=hch@lst.de \
    --cc=jack@suse.com \
    --cc=jthumshirn@suse.de \
    --cc=kent.overstreet@gmail.com \
    --cc=linux-block@vger.kernel.org \
    --cc=ming.lei@redhat.com \
    --cc=mwilck@suse.com \
    --cc=viro@ZenIV.linux.org.uk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.