From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758507AbdJMM5c (ORCPT ); Fri, 13 Oct 2017 08:57:32 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:45098 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758160AbdJMMre (ORCPT ); Fri, 13 Oct 2017 08:47:34 -0400 X-Google-Smtp-Source: AOwi7QBZv1SBStOMF41lU8i01pOsqXhADeM39xSUecztFJiC1jQpvFnxHoV4fHEvRfveuIAzIxt/xw== From: =?UTF-8?q?Matias=20Bj=C3=B8rling?= To: axboe@fb.com Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, =?UTF-8?q?Javier=20Gonz=C3=A1lez?= , =?UTF-8?q?Matias=20Bj=C3=B8rling?= Subject: [GIT PULL 28/58] lightnvm: pblk: simplify path on REQ_PREFLUSH Date: Fri, 13 Oct 2017 14:46:17 +0200 Message-Id: <20171013124647.32668-29-m@bjorling.me> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20171013124647.32668-1-m@bjorling.me> References: <20171013124647.32668-1-m@bjorling.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Javier González On REQ_PREFLUSH, directly tag the I/O context flags to signal a flush in the write to cache path, instead of finding the correct entry context and imposing a memory barrier. This simplifies the code and might potentially prevent race conditions when adding functionality to the write path. Signed-off-by: Javier González Signed-off-by: Matias Bjørling --- drivers/lightnvm/pblk-cache.c | 4 +++- drivers/lightnvm/pblk-rb.c | 8 +------- 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/lightnvm/pblk-cache.c b/drivers/lightnvm/pblk-cache.c index 1d6b8e3..0d227ef 100644 --- a/drivers/lightnvm/pblk-cache.c +++ b/drivers/lightnvm/pblk-cache.c @@ -43,8 +43,10 @@ int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags) if (unlikely(!bio_has_data(bio))) goto out; + pblk_ppa_set_empty(&w_ctx.ppa); w_ctx.flags = flags; - pblk_ppa_set_empty(&w_ctx.ppa); + if (bio->bi_opf & REQ_PREFLUSH) + w_ctx.flags |= PBLK_FLUSH_ENTRY; for (i = 0; i < nr_entries; i++) { void *data = bio_data(bio); diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c index 74c768c..05e6b2e 100644 --- a/drivers/lightnvm/pblk-rb.c +++ b/drivers/lightnvm/pblk-rb.c @@ -355,7 +355,6 @@ static int pblk_rb_sync_point_set(struct pblk_rb *rb, struct bio *bio, { struct pblk_rb_entry *entry; unsigned int subm, sync_point; - int flags; subm = READ_ONCE(rb->subm); @@ -369,12 +368,6 @@ static int pblk_rb_sync_point_set(struct pblk_rb *rb, struct bio *bio, sync_point = (pos == 0) ? (rb->nr_entries - 1) : (pos - 1); entry = &rb->entries[sync_point]; - flags = READ_ONCE(entry->w_ctx.flags); - flags |= PBLK_FLUSH_ENTRY; - - /* Release flags on context. Protect from writes */ - smp_store_release(&entry->w_ctx.flags, flags); - /* Protect syncs */ smp_store_release(&rb->sync_point, sync_point); @@ -454,6 +447,7 @@ static int pblk_rb_may_write_flush(struct pblk_rb *rb, unsigned int nr_entries, /* Protect from read count */ smp_store_release(&rb->mem, mem); + return 1; } -- 2.9.3