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[176.7.199.185]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-493eb670a41sm123554875e9.0.2026.07.10.03.16.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jul 2026 03:16:11 -0700 (PDT) From: Abd-Alrhman Masalkhi To: song@kernel.org, yukuai@fygo.io, magiclinan@didiglobal.com, xiao@kernel.org, axboe@kernel.dk, vverma@digitalocean.com, john.g.garry@oracle.com, martin.petersen@oracle.com, abd.masalkhi@gmail.com, linux-kernel@vger.kernel.org Cc: linux-raid@vger.kernel.org Subject: [PATCH v4 4/7] md/raid10: remove unnecessary barrier around bio_submit_split_bioset() Date: Fri, 10 Jul 2026 10:15:18 +0000 Message-ID: <20260710101521.1714-5-abd.masalkhi@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260710101521.1714-1-abd.masalkhi@gmail.com> References: <20260710101521.1714-1-abd.masalkhi@gmail.com> Precedence: bulk X-Mailing-List: linux-raid@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit raid10_write_request() drops the barrier before calling bio_submit_split_bioset() and reacquires it afterwards. This is no longer necessary because the split bio cannot re-enter raid10_write_request() while the barrier is held. The allow_barrier()/wait_barrier() pair was introduced by commit e820d55cb99d ("md: fix raid10 hang issue caused by barrier") when submit_flushes() called md_handle_request() directly, allowing re-entry into raid10_write_request(). Since v5.2, submit_flushes() has instead gone through submit_bio(), eliminating that recursion. submit_flushes() was later removed entirely by commit b75197e86e6d ("md: Remove flush handling"). Currently, raid10_write_request() is only entered from the bio submission path, so the split bio submitted by bio_submit_split_bioset() cannot recurse back into wait_barrier(). Remove the redundant allow_barrier()/wait_barrier() pair around bio_submit_split_bioset(). Signed-off-by: Abd-Alrhman Masalkhi --- Changes in v4: - No changes. - Link to v3: https://lore.kernel.org/linux-raid/20260708101341.473750-5-abd.masalkhi@gmail.com/ Changes in v3: - No changes. - Link to v2: https://lore.kernel.org/linux-raid/20260628142420.1051027-5-abd.masalkhi@gmail.com/ Changes in v2: - Expand the commit message to explain why the allow_barrier()/wait_barrier() pair is no longer needed. - Link to v1: https://lore.kernel.org/linux-raid/20260623072456.333437-5-abd.masalkhi@gmail.com/ --- drivers/md/raid10.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 3480fc7907f0..2574f60dd771 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1487,10 +1487,8 @@ static bool raid10_write_request(struct mddev *mddev, struct bio *bio, if (atomic) goto err_handle; - allow_barrier(conf); bio = bio_submit_split_bioset(bio, r10_bio->sectors, &conf->bio_split); - wait_barrier(conf, false); if (!bio) { set_bit(R10BIO_Returned, &r10_bio->state); goto err_handle; -- 2.43.0