Re: [PATCH 02/17] block: introduce bio_remove_last_page()
From: Johannes Thumshirn <hidden>
Date: 2017-02-16 12:08:26
Also in:
linux-block, lkml
On 02/16/2017 12:45 PM, Ming Lei wrote:
quoted hunk ↗ jump to hunk
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 GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850