Commit 5919482e authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

block: check if page is mergeable in one helper 



Now the check for deciding if one page is mergeable to current bvec
becomes a bit complicated, and we need to reuse the code before
adding pc page.

So move the check in one dedicated helper.

No function change.

Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 5a8ce240

block/bio.c

+24 −14
Original line number Diff line number Diff line
@@ -647,6 +647,24 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) 
}

EXPORT_SYMBOL(bio_clone_fast);



static inline bool page_is_mergeable(const struct bio_vec *bv,

		struct page *page, unsigned int len, unsigned int off,

		bool same_page)

{

	phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) +

		bv->bv_offset + bv->bv_len - 1;

	phys_addr_t page_addr = page_to_phys(page);



	if (vec_end_addr + 1 != page_addr + off)

		return false;

	if (xen_domain() && !xen_biovec_phys_mergeable(bv, page))

		return false;

	if (same_page && (vec_end_addr & PAGE_MASK) != page_addr)

		return false;



	return true;

}



/**

 *	bio_add_pc_page	-	attempt to add page to passthrough bio

 *	@q: the target queue
@@ -770,21 +788,13 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page, 


	if (bio->bi_vcnt > 0) {

		struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];

		phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) +

			bv->bv_offset + bv->bv_len - 1;

		phys_addr_t page_addr = page_to_phys(page);



		if (vec_end_addr + 1 != page_addr + off)

			return false;

		if (xen_domain() && !xen_biovec_phys_mergeable(bv, page))

			return false;

		if (same_page && (vec_end_addr & PAGE_MASK) != page_addr)

			return false;



		if (page_is_mergeable(bv, page, len, off, same_page)) {

			bv->bv_len += len;

			bio->bi_iter.bi_size += len;

			return true;

		}

	}

	return false;

}

EXPORT_SYMBOL_GPL(__bio_try_merge_page);

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