Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031028Ab2ERDD3 (ORCPT ); Thu, 17 May 2012 23:03:29 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:38968 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030896Ab2ERDAN (ORCPT ); Thu, 17 May 2012 23:00:13 -0400 From: koverstreet@google.com To: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, linux-fsdevel@vger.kernel.org Cc: Kent Overstreet , tj@kernel.org, axboe@kernel.dk, agk@redhat.com, neilb@suse.de Subject: [PATCH 05/13] block: Only clone bio vecs that are in use Date: Thu, 17 May 2012 22:59:52 -0400 Message-Id: X-Mailer: git-send-email 1.7.9.rc2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2275 Lines: 69 From: Kent Overstreet bcache creates large bios internally, and then splits them according to the device requirements before it sends them down. If a lower level device tries to clone the bio, and the original bio had more than BIO_MAX_PAGES, the clone will fail unecessarily. We can fix this by only cloning the bio vecs that are actually in use. Signed-off-by: Kent Overstreet --- fs/bio.c | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-) diff --git a/fs/bio.c b/fs/bio.c index e2c0970..de0733e 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -435,8 +435,9 @@ EXPORT_SYMBOL(bio_phys_segments); */ void __bio_clone(struct bio *bio, struct bio *bio_src) { - memcpy(bio->bi_io_vec, bio_src->bi_io_vec, - bio_src->bi_max_vecs * sizeof(struct bio_vec)); + memcpy(bio->bi_io_vec, + bio_iovec(bio_src), + bio_segments(bio_src) * sizeof(struct bio_vec)); /* * most users will be overriding ->bi_bdev with a new target, @@ -445,10 +446,10 @@ void __bio_clone(struct bio *bio, struct bio *bio_src) bio->bi_sector = bio_src->bi_sector; bio->bi_bdev = bio_src->bi_bdev; bio->bi_flags |= 1 << BIO_CLONED; + bio->bi_flags &= ~(1 << BIO_SEG_VALID); bio->bi_rw = bio_src->bi_rw; - bio->bi_vcnt = bio_src->bi_vcnt; + bio->bi_vcnt = bio_segments(bio_src); bio->bi_size = bio_src->bi_size; - bio->bi_idx = bio_src->bi_idx; } EXPORT_SYMBOL(__bio_clone); @@ -463,7 +464,7 @@ EXPORT_SYMBOL(__bio_clone); struct bio *bio_clone_bioset(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) { - struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, bs); + struct bio *b = bio_alloc_bioset(gfp_mask, bio_segments(bio), bs); if (!b) return NULL; @@ -493,7 +494,7 @@ EXPORT_SYMBOL(bio_clone); struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask) { - struct bio *b = bio_kmalloc(gfp_mask, bio->bi_max_vecs); + struct bio *b = bio_kmalloc(gfp_mask, bio_segments(bio)); if (!b) return NULL; -- 1.7.9.rc2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/