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From:   Jagdish Gediya <jvgediya@linux.ibm.com>
To:     linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc:     willy@infradead.org, ying.huang@intel.com, dave.hansen@intel.com,
        Jonathan.Cameron@huawei.com, adobriyan@gmail.com,
        akpm@linux-foundation.org, andriy.shevchenko@linux.intel.com,
        rf@opensource.cirrus.com, pmladek@suse.com,
        Jagdish Gediya <jvgediya@linux.ibm.com>
Subject: [PATCH v3 1/2] lib/kstrtox.c: Add "false"/"true" support to kstrtobool()
Date:   Tue, 26 Apr 2022 23:32:02 +0530
Message-Id: <20220426180203.70782-1-jvgediya@linux.ibm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

At many places in kernel, It is necessary to convert sysfs input
to corrosponding bool value e.g. "false" or "0" need to be converted
to bool false, "true" or "1" need to be converted to bool true,
places where such conversion is needed currently check the input
string manually, kstrtobool() can be utilized at such places but
currently it doesn't have support to accept "false"/"true".

Add support to accept "false"/"true" as valid string in kstrtobool().

Signed-off-by: Jagdish Gediya <jvgediya@linux.ibm.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
Chnages in v2:
- kstrtobool to kstrtobool() in commit message.
- Split single patch into 2
- Remove strcmp usage from kstrtobool() and instead compare 1st
  character only.

Changes in v3:
- Covert -> Convert in patch 2 subject
- Collected Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>

 lib/kstrtox.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/kstrtox.c b/lib/kstrtox.c
index 886510d248e5..465e31e4d70d 100644
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -340,7 +340,7 @@ EXPORT_SYMBOL(kstrtos8);
  * @s: input string
  * @res: result
  *
- * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
+ * This routine returns 0 if the first character is one of 'YyTt1NnFf0', or
  * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL.  Value
  * pointed to by res is updated upon finding a match.
  */
@@ -353,11 +353,15 @@ int kstrtobool(const char *s, bool *res)
 	switch (s[0]) {
 	case 'y':
 	case 'Y':
+	case 't':
+	case 'T':
 	case '1':
 		*res = true;
 		return 0;
 	case 'n':
 	case 'N':
+	case 'f':
+	case 'F':
 	case '0':
 		*res = false;
 		return 0;
-- 
2.35.1