From patchwork Wed Apr 9 18:29:13 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 14045227 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 06609C36002 for ; Wed, 9 Apr 2025 18:30:38 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u2aB4-0003d1-A8; Wed, 09 Apr 2025 14:29:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1u2aB0-0003ZU-BB for qemu-devel@nongnu.org; Wed, 09 Apr 2025 14:29:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1u2aAy-0003DC-1L for qemu-devel@nongnu.org; Wed, 09 Apr 2025 14:29:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744223367; 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=05QS0QHdDxiiuQhSNYD6PZLJSNQ2FxI3qlDTmUS6LBg=; b=ZqYHxGLbZlWSLRF4+5Dz7gkQL00I/N5vAvcCv5z29rM+Hs/Ka4AsFRkeuUxUv2ehgbT4kk w6xNGX2z7AMS2IrjriVn0sTXZIGHwHwkB9Orc3QpeByPe1GWyFQLQc6d/djylBFMSOCtMD h4RGPKy35+EyZGK2kOhb/x3WKol8PSI= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-425-5EyBneETOp2No7KPys6uRQ-1; Wed, 09 Apr 2025 14:29:24 -0400 X-MC-Unique: 5EyBneETOp2No7KPys6uRQ-1 X-Mimecast-MFC-AGG-ID: 5EyBneETOp2No7KPys6uRQ_1744223362 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 04A0D1809CA3; Wed, 9 Apr 2025 18:29:21 +0000 (UTC) Received: from localhost (unknown [10.2.16.144]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id F100E180B48C; Wed, 9 Apr 2025 18:29:19 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Fam Zheng , , Stefan Hajnoczi , Hanna Czenczek , Kevin Wolf Subject: [PATCH 1/2] file-posix: probe discard alignment on Linux block devices Date: Wed, 9 Apr 2025 14:29:13 -0400 Message-ID: <20250409182914.4725-2-stefanha@redhat.com> In-Reply-To: <20250409182914.4725-1-stefanha@redhat.com> References: <20250409182914.4725-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.505, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Populate the pdiscard_alignment block limit so the block layer is able align discard requests correctly. Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake --- block/file-posix.c | 56 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 55 insertions(+), 1 deletion(-) diff --git a/block/file-posix.c b/block/file-posix.c index 56d1972d15..2a1e1f48c0 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -1276,10 +1276,10 @@ static int get_sysfs_zoned_model(struct stat *st, BlockZoneModel *zoned) } #endif /* defined(CONFIG_BLKZONED) */ +#ifdef CONFIG_LINUX /* * Get a sysfs attribute value as a long integer. */ -#ifdef CONFIG_LINUX static long get_sysfs_long_val(struct stat *st, const char *attribute) { g_autofree char *str = NULL; @@ -1299,6 +1299,30 @@ static long get_sysfs_long_val(struct stat *st, const char *attribute) } return ret; } + +/* + * Get a sysfs attribute value as a uint32_t. + */ +static int get_sysfs_u32_val(struct stat *st, const char *attribute, + uint32_t *u32) +{ + g_autofree char *str = NULL; + const char *end; + unsigned int val; + int ret; + + ret = get_sysfs_str_val(st, attribute, &str); + if (ret < 0) { + return ret; + } + + /* The file is ended with '\n', pass 'end' to accept that. */ + ret = qemu_strtoui(str, &end, 10, &val); + if (ret == 0 && end && *end == '\0') { + *u32 = val; + } + return ret; +} #endif static int hdev_get_max_segments(int fd, struct stat *st) @@ -1318,6 +1342,23 @@ static int hdev_get_max_segments(int fd, struct stat *st) #endif } +/* + * Fills in *dalign with the discard alignment and returns 0 on success, + * -errno otherwise. + */ +static int hdev_get_pdiscard_alignment(struct stat *st, uint32_t *dalign) +{ +#ifdef CONFIG_LINUX + /* + * Note that Linux "discard_granularity" is QEMU "discard_alignment". Linux + * "discard_alignment" is something else. + */ + return get_sysfs_u32_val(st, "discard_granularity", dalign); +#else + return -ENOTSUP; +#endif +} + #if defined(CONFIG_BLKZONED) /* * If the reset_all flag is true, then the wps of zone whose state is @@ -1527,6 +1568,19 @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp) } } + if (S_ISBLK(st.st_mode)) { + uint32_t dalign = 0; + int ret; + + ret = hdev_get_pdiscard_alignment(&st, &dalign); + if (ret == 0) { + /* Must be a multiple of request_alignment */ + assert(dalign % bs->bl.request_alignment == 0); + + bs->bl.pdiscard_alignment = dalign; + } + } + raw_refresh_zoned_limits(bs, &st, errp); }