From patchwork Fri Mar 10 06:00:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 9615077 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 18E0060414 for ; Fri, 10 Mar 2017 06:02:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0BD2326212 for ; Fri, 10 Mar 2017 06:02:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 003F628518; Fri, 10 Mar 2017 06:02:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 81B6F26212 for ; Fri, 10 Mar 2017 06:02:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754107AbdCJGB5 (ORCPT ); Fri, 10 Mar 2017 01:01:57 -0500 Received: from mx2.suse.de ([195.135.220.15]:43923 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753863AbdCJGB4 (ORCPT ); Fri, 10 Mar 2017 01:01:56 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id A4863AAB4; Fri, 10 Mar 2017 06:01:53 +0000 (UTC) From: NeilBrown To: Jens Axboe Date: Fri, 10 Mar 2017 17:00:47 +1100 Subject: [PATCH 1/5] blk: Ensure users for current->bio_list can see the full list. Cc: linux-block@vger.kernel.org, Mike Snitzer , LKML , linux-raid@vger.kernel.org, device-mapper development , Mikulas Patocka , Pavel Machek , Jack Wang , Lars Ellenberg , Kent Overstreet Message-ID: <148912564686.4002.16905512808005503136.stgit@noble> In-Reply-To: <148912539296.4002.219258660543808741.stgit@noble> References: <148912539296.4002.219258660543808741.stgit@noble> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit 79bd99596b73 ("blk: improve order of bio handling in generic_make_request()") changed current->bio_list so that it did not contain *all* of the queued bios, but only those submitted by the currently running make_request_fn. There are two places which walk the list and requeue selected bios, and others that check if the list is empty. These are no longer correct. So redefine current->bio_list to point to an array of two lists, which contain all queued bios, and adjust various code to test or walk both lists. Signed-off-by: NeilBrown --- block/bio.c | 12 +++++++++--- block/blk-core.c | 30 ++++++++++++++++++------------ drivers/md/dm.c | 29 ++++++++++++++++------------- drivers/md/raid10.c | 3 ++- 4 files changed, 45 insertions(+), 29 deletions(-) diff --git a/block/bio.c b/block/bio.c index 5eec5e08417f..e75878f8b14a 100644 --- a/block/bio.c +++ b/block/bio.c @@ -376,10 +376,14 @@ static void punt_bios_to_rescuer(struct bio_set *bs) bio_list_init(&punt); bio_list_init(&nopunt); - while ((bio = bio_list_pop(current->bio_list))) + while ((bio = bio_list_pop(¤t->bio_list[0]))) bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); + current->bio_list[0] = nopunt; - *current->bio_list = nopunt; + bio_list_init(&nopunt); + while ((bio = bio_list_pop(¤t->bio_list[1]))) + bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio); + current->bio_list[1] = nopunt; spin_lock(&bs->rescue_lock); bio_list_merge(&bs->rescue_list, &punt); @@ -466,7 +470,9 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) * we retry with the original gfp_flags. */ - if (current->bio_list && !bio_list_empty(current->bio_list)) + if (current->bio_list && + (!bio_list_empty(¤t->bio_list[0]) || + !bio_list_empty(¤t->bio_list[1]))) gfp_mask &= ~__GFP_DIRECT_RECLAIM; p = mempool_alloc(bs->bio_pool, gfp_mask); diff --git a/block/blk-core.c b/block/blk-core.c index 0eeb99ef654f..d772c221cc17 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1973,7 +1973,14 @@ generic_make_request_checks(struct bio *bio) */ blk_qc_t generic_make_request(struct bio *bio) { - struct bio_list bio_list_on_stack; + /* + * bio_list_on_stack[0] contains bios submitted by the current + * make_request_fn. + * bio_list_on_stack[1] contains bios that were submitted before + * the current make_request_fn, but that haven't been processed + * yet. + */ + struct bio_list bio_list_on_stack[2]; blk_qc_t ret = BLK_QC_T_NONE; if (!generic_make_request_checks(bio)) @@ -1990,7 +1997,7 @@ blk_qc_t generic_make_request(struct bio *bio) * should be added at the tail */ if (current->bio_list) { - bio_list_add(current->bio_list, bio); + bio_list_add(¤t->bio_list[0], bio); goto out; } @@ -2009,18 +2016,17 @@ blk_qc_t generic_make_request(struct bio *bio) * bio_list, and call into ->make_request() again. */ BUG_ON(bio->bi_next); - bio_list_init(&bio_list_on_stack); - current->bio_list = &bio_list_on_stack; + bio_list_init(&bio_list_on_stack[0]); + current->bio_list = bio_list_on_stack; do { struct request_queue *q = bdev_get_queue(bio->bi_bdev); if (likely(blk_queue_enter(q, false) == 0)) { - struct bio_list hold; struct bio_list lower, same; /* Create a fresh bio_list for all subordinate requests */ - hold = bio_list_on_stack; - bio_list_init(&bio_list_on_stack); + bio_list_on_stack[1] = bio_list_on_stack[0]; + bio_list_init(&bio_list_on_stack[0]); ret = q->make_request_fn(q, bio); blk_queue_exit(q); @@ -2030,19 +2036,19 @@ blk_qc_t generic_make_request(struct bio *bio) */ bio_list_init(&lower); bio_list_init(&same); - while ((bio = bio_list_pop(&bio_list_on_stack)) != NULL) + while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) if (q == bdev_get_queue(bio->bi_bdev)) bio_list_add(&same, bio); else bio_list_add(&lower, bio); /* now assemble so we handle the lowest level first */ - bio_list_merge(&bio_list_on_stack, &lower); - bio_list_merge(&bio_list_on_stack, &same); - bio_list_merge(&bio_list_on_stack, &hold); + bio_list_merge(&bio_list_on_stack[0], &lower); + bio_list_merge(&bio_list_on_stack[0], &same); + bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); } else { bio_io_error(bio); } - bio = bio_list_pop(current->bio_list); + bio = bio_list_pop(&bio_list_on_stack[0]); } while (bio); current->bio_list = NULL; /* deactivate */ diff --git a/drivers/md/dm.c b/drivers/md/dm.c index f4ffd1eb8f44..dfb75979e455 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -989,26 +989,29 @@ static void flush_current_bio_list(struct blk_plug_cb *cb, bool from_schedule) struct dm_offload *o = container_of(cb, struct dm_offload, cb); struct bio_list list; struct bio *bio; + int i; INIT_LIST_HEAD(&o->cb.list); if (unlikely(!current->bio_list)) return; - list = *current->bio_list; - bio_list_init(current->bio_list); - - while ((bio = bio_list_pop(&list))) { - struct bio_set *bs = bio->bi_pool; - if (unlikely(!bs) || bs == fs_bio_set) { - bio_list_add(current->bio_list, bio); - continue; + for (i = 0; i < 2; i++) { + list = current->bio_list[i]; + bio_list_init(¤t->bio_list[i]); + + while ((bio = bio_list_pop(&list))) { + struct bio_set *bs = bio->bi_pool; + if (unlikely(!bs) || bs == fs_bio_set) { + bio_list_add(¤t->bio_list[i], bio); + continue; + } + + spin_lock(&bs->rescue_lock); + bio_list_add(&bs->rescue_list, bio); + queue_work(bs->rescue_workqueue, &bs->rescue_work); + spin_unlock(&bs->rescue_lock); } - - spin_lock(&bs->rescue_lock); - bio_list_add(&bs->rescue_list, bio); - queue_work(bs->rescue_workqueue, &bs->rescue_work); - spin_unlock(&bs->rescue_lock); } } diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 063c43d83b72..0536658c9d40 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -974,7 +974,8 @@ static void wait_barrier(struct r10conf *conf) !conf->barrier || (atomic_read(&conf->nr_pending) && current->bio_list && - !bio_list_empty(current->bio_list)), + (!bio_list_empty(¤t->bio_list[0]) || + !bio_list_empty(¤t->bio_list[1]))), conf->resync_lock); conf->nr_waiting--; if (!conf->nr_waiting)