Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753660AbdIFKy0 (ORCPT ); Wed, 6 Sep 2017 06:54:26 -0400 Received: from mail-wm0-f43.google.com ([74.125.82.43]:35644 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752557AbdIFKwu (ORCPT ); Wed, 6 Sep 2017 06:52:50 -0400 X-Google-Smtp-Source: ADKCNb57uWKn6q3F5h62EU2ZStkZChTGC8cebmXo/SrDTEJkblfT4SXQ5P9mn4HneWT0Vjrk8ccR4A== From: "=?UTF-8?q?Javier=20Gonz=C3=A1lez?=" X-Google-Original-From: =?UTF-8?q?Javier=20Gonz=C3=A1lez?= To: mb@lightnvm.io, 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: [PATCH 14/18] lightnvm: pblk: simplify path on REQ_PREFLUSH Date: Wed, 6 Sep 2017 12:51:07 +0200 Message-Id: <1504695071-25928-15-git-send-email-javier@cnexlabs.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1504695071-25928-1-git-send-email-javier@cnexlabs.com> References: <1504695071-25928-1-git-send-email-javier@cnexlabs.com> 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 Content-Length: 2129 Lines: 64 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 1d6b8e3585f1..0d227ef7d1b9 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 74c768ce09ef..05e6b2e9221d 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; } -- 2.7.4