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Sat, 02 Apr 2022 20:41:12 -0700 (PDT) Received: from localhost.localdomain ([183.156.181.188]) by smtp.googlemail.com with ESMTPSA id x14-20020aa784ce000000b004fa79973c94sm7215598pfn.165.2022.04.02.20.41.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 02 Apr 2022 20:41:12 -0700 (PDT) From: Xiaomeng Tong To: agk@redhat.com, snitzer@redhat.com, dm-devel@redhat.com Date: Sun, 3 Apr 2022 11:41:01 +0800 Message-Id: <20220403034101.14735-1-xiam0nd.tong@gmail.com> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 X-Mailman-Approved-At: Mon, 04 Apr 2022 06:48:34 +0000 Subject: [dm-devel] [PATCH v2] md: dm-mpath: use list iterator only inside the loop X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Xiaomeng Tong , linux-kernel@vger.kernel.org MIME-Version: 1.0 Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com To move the declare of list iterator into the list_for_each_entry_*() macro in the future, it should be avoided to use the list iterator variable after the loop body [1]. Because the cases (the list is empty or no entry is found) have been checked prior to iterating m->priority_groups, it is fine to move the bypass_pg(m, pg, bypassed); inside the loop when entry is found. [1]: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ Signed-off-by: Xiaomeng Tong --- changes since v1: - it is not a bug, have checked before (Mike Snitzer) - tweak code to avoid dead code "return -EINVAL;" (Xiaomeng Tong) v1: https://lore.kernel.org/lkml/20220327053742.2942-1-xiam0nd.tong@gmail.com/ --- drivers/md/dm-mpath.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index f4719b65e5e3..13c65eab32a2 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -1496,11 +1496,12 @@ static int bypass_pg_num(struct multipath *m, const char *pgstr, bool bypassed) } list_for_each_entry(pg, &m->priority_groups, list) { - if (!--pgnum) + if (!--pgnum) { + bypass_pg(m, pg, bypassed); break; + } } - bypass_pg(m, pg, bypassed); return 0; }