linux-kernel - [PATCH v2 1/2] libnvdimm/badrange: remove two redundant list

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200919104546.3848-2-thunder.leizhen@huawei.com>
Date:   Sat, 19 Sep 2020 18:45:45 +0800
From:   Zhen Lei <thunder.leizhen@...wei.com>
To:     Oliver O'Halloran <oohall@...il.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Vishal Verma <vishal.l.verma@...el.com>,
        "Dave Jiang" <dave.jiang@...el.com>,
        Ira Weiny <ira.weiny@...el.com>,
        Markus Elfring <Markus.Elfring@....de>,
        linux-nvdimm <linux-nvdimm@...ts.01.org>,
        linux-kernel <linux-kernel@...r.kernel.org>
CC:     Zhen Lei <thunder.leizhen@...wei.com>,
        Libin <huawei.libin@...wei.com>,
        Kefeng Wang <wangkefeng.wang@...wei.com>
Subject: [PATCH v2 1/2] libnvdimm/badrange: remove two redundant list_empty() branches

In add_badrange() or badblocks_populate(), the list_empty() branch does
the same things as the code after list_for_each_entry().

The pseudo code is as follows:
1)	if (list_empty()) {
		do things-A
		return Y;
	}

2)	list_for_each_entry()
		do things-B	//can only be entered if !list_empty()

3)	do things-A
        return Y;

It's very clear that, the processing result after deleting 1) is the same
as that before deleting 1).

So delete 1) to simplify code.

Signed-off-by: Zhen Lei <thunder.leizhen@...wei.com>
---
 drivers/nvdimm/badrange.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/drivers/nvdimm/badrange.c b/drivers/nvdimm/badrange.c
index b9eeefa27e3a507..9fdba8c43e8605e 100644
--- a/drivers/nvdimm/badrange.c
+++ b/drivers/nvdimm/badrange.c
@@ -53,13 +53,6 @@ static int add_badrange(struct badrange *badrange, u64 addr, u64 length)
 	bre_new = kzalloc(sizeof(*bre_new), GFP_KERNEL);
 	spin_lock(&badrange->lock);
 
-	if (list_empty(&badrange->list)) {
-		if (!bre_new)
-			return -ENOMEM;
-		append_badrange_entry(badrange, bre_new, addr, length);
-		return 0;
-	}
-
 	/*
 	 * There is a chance this is a duplicate, check for those first.
 	 * This will be the common case as ARS_STATUS returns all known
@@ -215,9 +208,6 @@ static void badblocks_populate(struct badrange *badrange,
 {
 	struct badrange_entry *bre;
 
-	if (list_empty(&badrange->list))
-		return;
-
 	list_for_each_entry(bre, &badrange->list, list) {
 		u64 bre_end = bre->start + bre->length - 1;
 
-- 
1.8.3