From mboxrd@z Thu Jan 1 00:00:00 1970 From: hch@lst.de (Christoph Hellwig) Date: Fri, 16 Nov 2018 14:55:12 +0100 Subject: [PATCH V10 17/19] block: don't use bio->bi_vcnt to figure out segment number In-Reply-To: <20181115085306.9910-18-ming.lei@redhat.com> References: <20181115085306.9910-1-ming.lei@redhat.com> <20181115085306.9910-18-ming.lei@redhat.com> Message-ID: <20181116135512.GM3165@lst.de> On Thu, Nov 15, 2018@04:53:04PM +0800, Ming Lei wrote: > It is wrong to use bio->bi_vcnt to figure out how many segments > there are in the bio even though CLONED flag isn't set on this bio, > because this bio may be splitted or advanced. > > So always use bio_segments() in blk_recount_segments(), and it shouldn't > cause any performance loss now because the physical segment number is figured > out in blk_queue_split() and BIO_SEG_VALID is set meantime since > bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"). Looks good, but shouldn't this go to the beginning of the series? Reviewed-by: Christoph Hellwig