Commit 9f7cdbc3 authored Feb 27, 2010 by Dmitry Monakhov Committed by Jens Axboe Feb 28, 2010

blkdev: fix merge_bvec_fn return value checks



merge_bvec_fn() returns bvec->bv_len on success. So we have to check
against this value. But in case of fs_optimization merge we compare
with wrong value. This patch must be included in
 b428cd6da7e6559aca69aa2e3a526037d3f20403
But accidentally i've forgot to add this in the initial patch.
To make things straight let's replace all such checks.
In fact this makes code easy to understand.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

parent 53c583d2

fs/bio.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -555,7 +555,7 @@ static int __bio_add_page(struct request_queue q, struct bio bio, struct page
		.bi_rw = bio->bi_rw,
		};

		if (q->merge_bvec_fn(q, &bvm, prev) < len) {
		if (q->merge_bvec_fn(q, &bvm, prev) != prev->bv_len) {
		prev->bv_len -= len;
		return 0;
		}
		@@ -608,7 +608,7 @@ static int __bio_add_page(struct request_queue q, struct bio bio, struct page
		* merge_bvec_fn() returns number of bytes it can accept
		* at this offset
		*/
		if (q->merge_bvec_fn(q, &bvm, bvec) < len) {
		if (q->merge_bvec_fn(q, &bvm, bvec) != bvec->bv_len) {
		bvec->bv_page = NULL;
		bvec->bv_len = 0;
		bvec->bv_offset = 0;

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