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From: Johannes Thumshirn <jthumshirn@suse.de>
To: Ming Lei <tom.leiming@gmail.com>, Shaohua Li <shli@kernel.org>,
	Jens Axboe <axboe@fb.com>,
	linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
	linux-block@vger.kernel.org,
	Christoph Hellwig <hch@infradead.org>, NeilBrown <neilb@suse.com>
Subject: Re: [PATCH 02/17] block: introduce bio_remove_last_page()
Date: Thu, 16 Feb 2017 13:08:22 +0100	[thread overview]
Message-ID: <b443b3a1-ecc9-8238-1b3d-90870a25c793@suse.de> (raw)
In-Reply-To: <1487245547-24384-3-git-send-email-tom.leiming@gmail.com>

On 02/16/2017 12:45 PM, Ming Lei wrote:
> MD need this helper to remove the last added page, so introduce
> it.
> 
> Signed-off-by: Ming Lei <tom.leiming@gmail.com>
> ---
>  block/bio.c         | 23 +++++++++++++++++++++++
>  include/linux/bio.h |  1 +
>  2 files changed, 24 insertions(+)
> 
> diff --git a/block/bio.c b/block/bio.c
> index 5eec5e08417f..0ce7ffcd7939 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -837,6 +837,29 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page
>  EXPORT_SYMBOL(bio_add_pc_page);
>  
>  /**
> + *	bio_remove_last_page	-	remove the last added page
> + *	@bio: destination bio
> + *
> + *	Attempt to remove the last added page from the bio_vec maplist.
> + */
> +void bio_remove_last_page(struct bio *bio)
> +{
> +	/*
> +	 * cloned bio must not modify vec list
> +	 */
> +	if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
> +		return;
> +
> +	if (bio->bi_vcnt > 0) {

In patch 1 you introduce bio_segments_all() with the log message 'So
that we can replace the direct access to .bi_vcnt.' Here you introduce a
new direct access to it (plus the duplicated WARN_ON_ONCE()).

Maybe use the helper directly here (I admit I haven't gone through the
whole series yet, so I can't see if the change is made later).

Byte,
	Johannes

-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

  reply	other threads:[~2017-02-16 12:08 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-16 11:45 [PATCH 00/17] md: cleanup on direct access to bvec table Ming Lei
2017-02-16 11:45 ` [PATCH 01/17] block: introduce bio_segments_all() Ming Lei
2017-02-16 11:45 ` [PATCH 02/17] block: introduce bio_remove_last_page() Ming Lei
2017-02-16 12:08   ` Johannes Thumshirn [this message]
2017-02-16 13:30     ` Ming Lei
2017-02-16 13:40       ` Johannes Thumshirn
2017-02-16 13:59         ` Ming Lei
2017-02-16 14:10           ` Johannes Thumshirn
2017-02-16 11:45 ` [PATCH 03/17] md: raid1/raid10: use bio_remove_last_page() Ming Lei
2017-02-16 11:45 ` [PATCH 04/17] md: introduce helpers for dealing with fetch/store preallocated pages in bio Ming Lei
2017-02-16 11:45 ` [PATCH 05/17] md: raid1/raid10: use the introduced helpers Ming Lei
2017-02-16 11:45 ` [PATCH 06/17] md: raid1/raid10: borrow .bi_error as pre-allocated page index Ming Lei
2017-02-16 11:45 ` [PATCH 07/17] md: raid1/raid10: don't use .bi_vcnt to check if all pages are added Ming Lei
2017-02-16 11:45 ` [PATCH 08/17] md: raid1: simplify r1buf_pool_free() Ming Lei
2017-02-16 11:45 ` [PATCH 09/17] md: raid1/raid10: use bio helper in *_pool_free Ming Lei
2017-02-16 11:45 ` [PATCH 10/17] md: raid1: remove direct access to bvec table in fix_sync_read_error Ming Lei
2017-02-16 11:45 ` [PATCH 11/17] md: raid1: use bio helper in process_checks() Ming Lei
2017-02-16 11:45 ` [PATCH 12/17] md: raid1: avoid direct access to bvec table " Ming Lei
2017-02-17  8:33   ` kbuild test robot
2017-02-16 11:45 ` [PATCH 13/17] md: raid1: use bio_segments_all() Ming Lei
2017-02-16 12:35   ` Johannes Thumshirn
2017-02-16 13:32     ` Ming Lei
2017-02-16 13:34       ` Johannes Thumshirn
2017-02-16 13:38         ` Ming Lei
2017-02-16 11:45 ` [PATCH 14/17] md: raid10: avoid direct access to bvec table in sync_request_write() Ming Lei
2017-02-16 11:45 ` [PATCH 15/17] md: raid10: avoid direct access to bvec table in fix_recovery_read_error Ming Lei
2017-02-16 11:45 ` [PATCH 16/17] md: raid10: avoid direct access to bvec table in reshape_request Ming Lei
2017-02-16 11:45 ` [PATCH 17/17] md: raid10: avoid direct access to bvec table in handle_reshape_read_error Ming Lei
2017-02-16 22:16 ` [PATCH 00/17] md: cleanup on direct access to bvec table Shaohua Li
2017-02-17  1:25   ` Ming Lei
2017-02-17  4:16     ` Shaohua Li

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