From patchwork Wed Jul 12 21:11:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kent Overstreet X-Patchwork-Id: 13310892 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6ABEBC001DE for ; Wed, 12 Jul 2023 21:13:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233066AbjGLVNi (ORCPT ); Wed, 12 Jul 2023 17:13:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233103AbjGLVMf (ORCPT ); Wed, 12 Jul 2023 17:12:35 -0400 Received: from out-30.mta1.migadu.com (out-30.mta1.migadu.com [IPv6:2001:41d0:203:375::1e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17E362D54 for ; Wed, 12 Jul 2023 14:11:55 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1689196298; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FQIFhUqpaGDOWzE1yHnvTxX4EVy7v8panA3oqA36kSA=; b=DuRaDz8oKa7WhaBdL3TSBM/C20dZYJhltRM8sbfKp0t5CEqxOQnbhbTXHDch0TXpNWiWOT HlUoONNwjSA+t9fvp5k6w8fyp6pxL22ZBoYPwa/dEQbLxoOU4KkMCjUs8O3BOmo1pQ0O20 sqWLZy4zHvQG/vEpVSvzhmTPJei8u+w= From: Kent Overstreet To: linux-bcachefs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Kent Overstreet , Kent Overstreet Subject: [PATCH 09/20] lib/string_helpers: string_get_size() now returns characters wrote Date: Wed, 12 Jul 2023 17:11:04 -0400 Message-Id: <20230712211115.2174650-10-kent.overstreet@linux.dev> In-Reply-To: <20230712211115.2174650-1-kent.overstreet@linux.dev> References: <20230712211115.2174650-1-kent.overstreet@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Kent Overstreet 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 --- include/linux/string_helpers.h | 4 ++-- lib/string_helpers.c | 10 ++++++---- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h index fae6beaaa2..44148f8feb 100644 --- a/include/linux/string_helpers.h +++ b/include/linux/string_helpers.h @@ -23,8 +23,8 @@ 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); int parse_int_array_user(const char __user *from, size_t count, int **array); diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 230020a2e0..b9a34eb386 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -31,9 +31,11 @@ * giving the size in the required units. @buf should have room for * at least 9 bytes and will always be zero terminated. * + * Return value: number of characters of output that would have been written + * (which may be greater than len, if output was truncated). */ -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" @@ -126,8 +128,8 @@ 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);