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From:   "Matthew Wilcox (Oracle)" <willy@infradead.org>
To:     linux-kernel@vger.kernel.org, pmladek@suse.com,
        Kent Overstreet <kent.overstreet@gmail.com>
Cc:     Andy Shevchenko <andy@kernel.org>
Subject: [PATCH v5 05/32] lib/string_helpers: string_get_size() now returns characters wrote
Date:   Mon,  8 Aug 2022 03:41:01 +0100
Message-Id: <20220808024128.3219082-6-willy@infradead.org>
In-Reply-To: <20220808024128.3219082-1-willy@infradead.org>
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From: Kent Overstreet <kent.overstreet@gmail.com>

printbuf now needs to know the number of characters that would have been
written if the buffer was too small, like snprintf(); this changes
string_get_size() to return the the return value of snprintf().

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Andy Shevchenko <andy@kernel.org>
---
 include/linux/string_helpers.h | 4 ++--
 lib/string_helpers.c           | 7 +++----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index 67de398944e8..52e0f1d283b9 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -19,8 +19,8 @@ enum string_size_units {
 	STRING_UNITS_2,		/* use binary powers of 2^10 */
 };
 
-void string_get_size(u64 size, u64 blk_size, enum string_size_units units,
-		     char *buf, int len);
+int string_get_size(u64 size, u64 blk_size, enum string_size_units units,
+		    char *buf, int len);
 
 #define UNESCAPE_SPACE		BIT(0)
 #define UNESCAPE_OCTAL		BIT(1)
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 7be20bcc6137..d247bf945f16 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -33,8 +33,8 @@
  * at least 9 bytes and will always be zero terminated.
  *
  */
-void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
-		     char *buf, int len)
+int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
+		    char *buf, int len)
 {
 	static const char *const units_10[] = {
 		"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
@@ -127,8 +127,7 @@ void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
 	else
 		unit = units_str[units][i];
 
-	snprintf(buf, len, "%u%s %s", (u32)size,
-		 tmp, unit);
+	return snprintf(buf, len, "%u%s %s", (u32)size, tmp, unit);
 }
 EXPORT_SYMBOL(string_get_size);
 
-- 
2.35.1