From patchwork Wed Aug 14 04:52:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13762832 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7207B365; Wed, 14 Aug 2024 04:52:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723611162; cv=none; b=W+R1RhD9CYZ9XSVzOfCqWxnvsd2v2KwKA1BZqHFlLd4Yaub85FiIHyYLs3QZjuuudwUlp7R+Q7/U3IOiZHk15yuWD1dzF61bl0Apq5cP6rQ1Re7bUGI28ajOS+TLDI9BbdR1U8dVkXFl0Ts0XDBFlXQfJ1PFkI1UKO37sbux6TU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723611162; c=relaxed/simple; bh=FwkxUtA85ZvpMvh2lhqmJu3bVm/8V7EiKneeXMlzM4w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DVz+D2+Eay0HQ+efNnm/jj6tPIrjhn662Hwb+sZ1Fq4CdvRaFDMUTXkZbNJkL/D+S1m5pzJtDZJKVeR42CdeDm4mwObQn11h1AWZ3r4dMX8NpyFX2zb6i/5QBuN+k3yVvKOXzY4mPpXHnXs2Ke2FTaMdmS9YTcMxlnD8dzfxvfY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=P9i074bz; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="P9i074bz" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=DujxcGjdRTBQfRrN5G4VMYkrTO1OM4IYiQKSOFoAUVU=; b=P9i074bzvGHgazegXUeTNWbMrp g52ghoYubviqTChk1j6X/OVf9gk7S0GFCsOpvrtWoPV38RzDr4mBwBwRw2vf7oDX0zqFcDQP6W7PZ wETNQO+WvVJmXqxKyeJV/gmMbYco+5ZDL5djE/qK+fYvJjJt4zgU1I3scHHdyoVVGIS6cZ3e3ona6 lJ/bDjdP5ZRdJzWzr1ZPl+9HHCmRDhstxAwpKBwVU6RKyI+7tdAjuuiTQ2/5mX9u3cWea+zVEhqGH jlGBL8uk/3S2E+S6tyZ9EjLTSL6zKYWL8+svKxWFMk27FZwS5z1sMCq0NerSXycOmx3idHdKMCdIQ FckwGe3A==; Received: from 2a02-8389-2341-5b80-fd16-64b9-63e2-2d30.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:fd16:64b9:63e2:2d30] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1se5zz-00000005jLF-2GsN; Wed, 14 Aug 2024 04:52:39 +0000 From: Christoph Hellwig To: Zorro Lang Cc: "Darrick J. Wong" , fstests@vger.kernel.org, linux-xfs@vger.kernel.org Subject: [PATCH 2/5] add a new min_dio_alignment helper Date: Wed, 14 Aug 2024 06:52:11 +0200 Message-ID: <20240814045232.21189-3-hch@lst.de> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240814045232.21189-1-hch@lst.de> References: <20240814045232.21189-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Add a new C program to find the minimum direct I/O alignment. This uses the statx stx_dio_offset_align field if provided, then falls back to the BLKSSZGET ioctl for block backed file systems and finally the page size. It is intended as a more capable replacement for the _min_dio_alignment bash helper. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong --- .gitignore | 1 + src/Makefile | 2 +- src/min_dio_alignment.c | 66 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 68 insertions(+), 1 deletion(-) create mode 100644 src/min_dio_alignment.c diff --git a/.gitignore b/.gitignore index 97c7e0014..36083e9d3 100644 --- a/.gitignore +++ b/.gitignore @@ -207,6 +207,7 @@ tags /src/log-writes/replay-log /src/perf/*.pyc /src/fiemap-fault +/src/min_dio_alignment # Symlinked files /tests/generic/035.out diff --git a/src/Makefile b/src/Makefile index 559209be9..b3da59a0e 100644 --- a/src/Makefile +++ b/src/Makefile @@ -34,7 +34,7 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \ attr_replace_test swapon mkswap t_attr_corruption t_open_tmpfiles \ fscrypt-crypt-util bulkstat_null_ocount splice-test chprojid_fail \ detached_mounts_propagation ext4_resize t_readdir_3 splice2pipe \ - uuid_ioctl t_snapshot_deleted_subvolume fiemap-fault + uuid_ioctl t_snapshot_deleted_subvolume fiemap-fault min_dio_alignment EXTRA_EXECS = dmerror fill2attr fill2fs fill2fs_check scaleread.sh \ btrfs_crc32c_forged_name.py popdir.pl popattr.py \ diff --git a/src/min_dio_alignment.c b/src/min_dio_alignment.c new file mode 100644 index 000000000..131f60236 --- /dev/null +++ b/src/min_dio_alignment.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2024 Christoph Hellwig + */ +#include +#include +#include +#include +#include +#include +#include +#include "statx.h" + +static int min_dio_alignment(const char *mntpnt, const char *devname) +{ + struct statx stx = { }; + struct stat st; + int fd; + + /* + * If the file system supports STATX_DIOALIGN, use the dio_offset_align + * member, as that reports exactly the information that we are asking + * for. + * + * STATX_DIOALIGN is only reported on regular files, so use O_TMPFILE + * to create one without leaving a trace. + */ + fd = open(mntpnt, O_TMPFILE | O_RDWR | O_EXCL, 0600); + if (fd >= 0 && + xfstests_statx(fd, "", AT_EMPTY_PATH, STATX_DIOALIGN, &stx) == 0 && + (stx.stx_mask & STATX_DIOALIGN)) + return stx.stx_dio_offset_align; + + /* + * If we are on a block device and no explicit aligned is reported, use + * the logical block size as a guestimate. + */ + if (stat(devname, &st) == 0 && S_ISBLK(st.st_mode)) { + int dev_fd = open(devname, O_RDONLY); + int logical_block_size; + + if (dev_fd > 0 && + fstat(dev_fd, &st) == 0 && + S_ISBLK(st.st_mode) && + ioctl(dev_fd, BLKSSZGET, &logical_block_size)) { + return logical_block_size; + } + } + + /* + * No support for STATX_DIOALIGN and not a block device: + * default to PAGE_SIZE. + */ + return getpagesize(); +} + +int main(int argc, char **argv) +{ + if (argc != 3) { + fprintf(stderr, "usage: %s mountpoint devicename\n", argv[0]); + exit(1); + } + + printf("%d\n", min_dio_alignment(argv[1], argv[2])); + exit(0); +}