Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755414Ab2EXAD6 (ORCPT ); Wed, 23 May 2012 20:03:58 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:41292 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753750Ab2EXAD0 (ORCPT ); Wed, 23 May 2012 20:03:26 -0400 From: Kent Overstreet To: linux-kernel@vger.kernel.org, linux-bcache@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, drbd-dev@lists.linbit.com, bharrosh@panasas.com, vgoyal@redhat.com, mpatocka@redhat.com, sage@newdream.net, yehuda@hq.newdream.net Subject: [PATCH v2 05/14] block: Only clone bio vecs that are in use Date: Wed, 23 May 2012 17:02:42 -0700 Message-Id: <1337817771-25038-6-git-send-email-koverstreet@google.com> X-Mailer: git-send-email 1.7.9.3.327.g2980b In-Reply-To: <1337817771-25038-1-git-send-email-koverstreet@google.com> References: <1337817771-25038-1-git-send-email-koverstreet@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2235 Lines: 67 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 file 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; -- 1.7.9.3.327.g2980b -- 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/