From patchwork Thu Feb 16 21:06:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 13143913 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 2C383C636CC for ; Thu, 16 Feb 2023 21:06:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230092AbjBPVGH (ORCPT ); Thu, 16 Feb 2023 16:06:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40504 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230078AbjBPVGG (ORCPT ); Thu, 16 Feb 2023 16:06:06 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2AD71505D3 for ; Thu, 16 Feb 2023 13:06:05 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D7462B8217A for ; Thu, 16 Feb 2023 21:06:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85B27C433D2; Thu, 16 Feb 2023 21:06:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676581562; bh=49CSVlrWibAsZstRHwNy0rgc8vpFgWoeaHThscIc0Uw=; h=Date:Subject:From:To:Cc:In-Reply-To:References:From; b=ezNZk218xsHD7YOYE/VGXxdUMYYgHAwlPuSdQx/MR9BvSfb4zH67yd67fwqVNkJR9 63yAvtx1k57eJjFEYbl11QB9LvB2kNAyDuDNL2q14KSbfPLVK/Y+KTQtURu21sW2Yi liucyOONqz6TjSldZ2nWCgLTV0WTwOZR2Qhq2l/GgEha/PmPTenXb5SZ9czv5rs+pm 5W3jxseWCt8TvKrhHsNbgZuZ95Mh8Qiv0AyKu8JrhL6CYGC82eEiky8zfL97BxplaX E42L0UTsfT3KvJj2BBhmlfnK0CrlZmZ4UGwcVkjUqIAZGbA2Zud0CpImSlhlW/Af/l nDhbRvgAvbO2Q== Date: Thu, 16 Feb 2023 13:06:02 -0800 Subject: [PATCH 1/4] libxfs: add xfile support From: "Darrick J. Wong" To: djwong@kernel.org Cc: allison.henderson@oracle.com, linux-xfs@vger.kernel.org Message-ID: <167657880693.3477371.11194291382483826413.stgit@magnolia> In-Reply-To: <167657880680.3477371.18364607478868446486.stgit@magnolia> References: <167657880680.3477371.18364607478868446486.stgit@magnolia> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Darrick J. Wong Port the xfile functionality (anonymous pageable file-index memory) from the kernel. In userspace, we try to use memfd() to create tmpfs files that are not in any namespace, matching the kernel. Signed-off-by: Darrick J. Wong --- configure.ac | 3 + include/builddefs.in | 3 + libxfs/Makefile | 12 +++ libxfs/xfile.c | 224 +++++++++++++++++++++++++++++++++++++++++++++++++ libxfs/xfile.h | 56 ++++++++++++ m4/package_libcdev.m4 | 50 +++++++++++ repair/xfs_repair.c | 15 +++ 7 files changed, 363 insertions(+) create mode 100644 libxfs/xfile.c create mode 100644 libxfs/xfile.h diff --git a/configure.ac b/configure.ac index 63cc18cc..2472b32f 100644 --- a/configure.ac +++ b/configure.ac @@ -251,6 +251,9 @@ AC_CHECK_SIZEOF([char *]) AC_TYPE_UMODE_T AC_MANUAL_FORMAT AC_HAVE_LIBURCU_ATOMIC64 +AC_HAVE_MEMFD_CLOEXEC +AC_HAVE_O_TMPFILE +AC_HAVE_MKOSTEMP_CLOEXEC AC_CONFIG_FILES([include/builddefs]) AC_OUTPUT diff --git a/include/builddefs.in b/include/builddefs.in index e0a2f3cb..60c1320a 100644 --- a/include/builddefs.in +++ b/include/builddefs.in @@ -127,6 +127,9 @@ SYSTEMD_SYSTEM_UNIT_DIR = @systemd_system_unit_dir@ HAVE_CROND = @have_crond@ CROND_DIR = @crond_dir@ HAVE_LIBURCU_ATOMIC64 = @have_liburcu_atomic64@ +HAVE_MEMFD_CLOEXEC = @have_memfd_cloexec@ +HAVE_O_TMPFILE = @have_o_tmpfile@ +HAVE_MKOSTEMP_CLOEXEC = @have_mkostemp_cloexec@ GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall # -Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl diff --git a/libxfs/Makefile b/libxfs/Makefile index 89d29dc9..17978006 100644 --- a/libxfs/Makefile +++ b/libxfs/Makefile @@ -26,6 +26,7 @@ HFILES = \ libxfs_priv.h \ linux-err.h \ topology.h \ + xfile.h \ xfs_ag_resv.h \ xfs_alloc.h \ xfs_alloc_btree.h \ @@ -66,6 +67,7 @@ CFILES = cache.c \ topology.c \ trans.c \ util.c \ + xfile.c \ xfs_ag.c \ xfs_ag_resv.c \ xfs_alloc.c \ @@ -113,6 +115,16 @@ CFILES = cache.c \ # #LCFLAGS += +ifeq ($(HAVE_MEMFD_CLOEXEC),yes) + LCFLAGS += -DHAVE_MEMFD_CLOEXEC +endif +ifeq ($(HAVE_O_TMPFILE),yes) + LCFLAGS += -DHAVE_O_TMPFILE +endif +ifeq ($(HAVE_MKOSTEMP_CLOEXEC),yes) + LCFLAGS += -DHAVE_MKOSTEMP_CLOEXEC +endif + FCFLAGS = -I. LTLIBS = $(LIBPTHREAD) $(LIBRT) diff --git a/libxfs/xfile.c b/libxfs/xfile.c new file mode 100644 index 00000000..f551aef5 --- /dev/null +++ b/libxfs/xfile.c @@ -0,0 +1,224 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2022 Oracle. All Rights Reserved. + * Author: Darrick J. Wong + */ +#include "libxfs_priv.h" +#include "libxfs.h" +#include "libxfs/xfile.h" +#include +#include +#include + +/* + * Swappable Temporary Memory + * ========================== + * + * Offline checking sometimes needs to be able to stage a large amount of data + * in memory. This information might not fit in the available memory and it + * doesn't all need to be accessible at all times. In other words, we want an + * indexed data buffer to store data that can be paged out. + * + * memfd files meet those requirements. Therefore, the xfile mechanism uses + * one to store our staging data. The xfile must be freed with xfile_destroy. + * + * xfiles assume that the caller will handle all required concurrency + * management; file locks are not taken. + */ + +/* + * Open a memory-backed fd to back an xfile. We require close-on-exec here, + * because these memfd files function as windowed RAM and hence should never + * be shared with other processes. + */ +static int +xfile_create_fd( + const char *description) +{ + int fd = -1; + +#ifdef HAVE_MEMFD_CLOEXEC + /* memfd_create exists in kernel 3.17 (2014) and glibc 2.27 (2018). */ + fd = memfd_create(description, MFD_CLOEXEC); + if (fd >= 0) + return fd; +#endif + +#ifdef HAVE_O_TMPFILE + /* + * O_TMPFILE exists as of kernel 3.11 (2013), which means that if we + * find it, we're pretty safe in assuming O_CLOEXEC exists too. + */ + fd = open("/dev/shm", O_TMPFILE | O_CLOEXEC | O_RDWR, 0600); + if (fd >= 0) + return fd; + + fd = open("/tmp", O_TMPFILE | O_CLOEXEC | O_RDWR, 0600); + if (fd >= 0) + return fd; +#endif + +#ifdef HAVE_MKOSTEMP_CLOEXEC + /* + * mkostemp exists as of glibc 2.7 (2007) and O_CLOEXEC exists as of + * kernel 2.6.23 (2007). + */ + fd = mkostemp("libxfsXXXXXX", O_CLOEXEC); + if (fd >= 0) + return fd; +#endif + +#if !defined(HAVE_MEMFD_CLOEXEC) && \ + !defined(HAVE_O_TMPFILE) && \ + !defined(HAVE_MKOSTEMP_CLOEXEC) +# error System needs memfd_create, O_TMPFILE, or O_CLOEXEC to build! +#endif + + return fd; +} + +/* + * Create an xfile of the given size. The description will be used in the + * trace output. + */ +int +xfile_create( + struct xfs_mount *mp, + const char *description, + struct xfile **xfilep) +{ + struct xfile *xf; + char fname[MAXNAMELEN]; + int error; + + snprintf(fname, MAXNAMELEN - 1, "XFS (%s): %s", mp->m_fsname, + description); + fname[MAXNAMELEN - 1] = 0; + + xf = kmem_alloc(sizeof(struct xfile), KM_MAYFAIL); + if (!xf) + return -ENOMEM; + + xf->fd = xfile_create_fd(fname); + if (xf->fd < 0) { + error = -errno; + kmem_free(xf); + return error; + } + + *xfilep = xf; + return 0; +} + +/* Close the file and release all resources. */ +void +xfile_destroy( + struct xfile *xf) +{ + close(xf->fd); + kmem_free(xf); +} + +static inline loff_t +xfile_maxbytes( + struct xfile *xf) +{ + if (sizeof(loff_t) == 8) + return LLONG_MAX; + return LONG_MAX; +} + +/* + * Read a memory object directly from the xfile's page cache. Unlike regular + * pread, we return -E2BIG and -EFBIG for reads that are too large or at too + * high an offset, instead of truncating the read. Otherwise, we return + * bytes read or an error code, like regular pread. + */ +ssize_t +xfile_pread( + struct xfile *xf, + void *buf, + size_t count, + loff_t pos) +{ + ssize_t ret; + + if (count > INT_MAX) + return -E2BIG; + if (xfile_maxbytes(xf) - pos < count) + return -EFBIG; + + ret = pread(xf->fd, buf, count, pos); + if (ret >= 0) + return ret; + return -errno; +} + +/* + * Write a memory object directly to the xfile's page cache. Unlike regular + * pwrite, we return -E2BIG and -EFBIG for writes that are too large or at too + * high an offset, instead of truncating the write. Otherwise, we return + * bytes written or an error code, like regular pwrite. + */ +ssize_t +xfile_pwrite( + struct xfile *xf, + const void *buf, + size_t count, + loff_t pos) +{ + ssize_t ret; + + if (count > INT_MAX) + return -E2BIG; + if (xfile_maxbytes(xf) - pos < count) + return -EFBIG; + + ret = pwrite(xf->fd, buf, count, pos); + if (ret >= 0) + return ret; + return -errno; +} + +/* Query stat information for an xfile. */ +int +xfile_stat( + struct xfile *xf, + struct xfile_stat *statbuf) +{ + struct stat ks; + int error; + + error = fstat(xf->fd, &ks); + if (error) + return -errno; + + statbuf->size = ks.st_size; + statbuf->bytes = (unsigned long long)ks.st_blocks << 9; + return 0; +} + +/* Dump an xfile to stdout. */ +int +xfile_dump( + struct xfile *xf) +{ + char *argv[] = {"od", "-tx1", "-Ad", "-c", NULL}; + pid_t child; + int i; + + child = fork(); + if (child != 0) { + int wstatus; + + wait(&wstatus); + return wstatus == 0 ? 0 : -EIO; + } + + /* reroute our xfile to stdin and shut everything else */ + dup2(xf->fd, 0); + for (i = 3; i < 1024; i++) + close(i); + + return execvp("od", argv); +} diff --git a/libxfs/xfile.h b/libxfs/xfile.h new file mode 100644 index 00000000..1389ff8f --- /dev/null +++ b/libxfs/xfile.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2022 Oracle. All Rights Reserved. + * Author: Darrick J. Wong + */ +#ifndef __LIBXFS_XFILE_H__ +#define __LIBXFS_XFILE_H__ + +struct xfile { + int fd; +}; + +int xfile_create(struct xfs_mount *mp, const char *description, + struct xfile **xfilep); +void xfile_destroy(struct xfile *xf); + +ssize_t xfile_pread(struct xfile *xf, void *buf, size_t count, loff_t pos); +ssize_t xfile_pwrite(struct xfile *xf, const void *buf, size_t count, loff_t pos); + +/* + * Load an object. Since we're treating this file as "memory", any error or + * short IO is treated as a failure to allocate memory. + */ +static inline int +xfile_obj_load(struct xfile *xf, void *buf, size_t count, loff_t pos) +{ + ssize_t ret = xfile_pread(xf, buf, count, pos); + + if (ret < 0 || ret != count) + return -ENOMEM; + return 0; +} + +/* + * Store an object. Since we're treating this file as "memory", any error or + * short IO is treated as a failure to allocate memory. + */ +static inline int +xfile_obj_store(struct xfile *xf, const void *buf, size_t count, loff_t pos) +{ + ssize_t ret = xfile_pwrite(xf, buf, count, pos); + + if (ret < 0 || ret != count) + return -ENOMEM; + return 0; +} + +struct xfile_stat { + loff_t size; + unsigned long long bytes; +}; + +int xfile_stat(struct xfile *xf, struct xfile_stat *statbuf); +int xfile_dump(struct xfile *xf); + +#endif /* __LIBXFS_XFILE_H__ */ diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4 index bb1ab49c..119d1bda 100644 --- a/m4/package_libcdev.m4 +++ b/m4/package_libcdev.m4 @@ -507,3 +507,53 @@ AC_DEFUN([AC_PACKAGE_CHECK_LTO], AC_SUBST(lto_cflags) AC_SUBST(lto_ldflags) ]) + +# +# Check if we have a memfd_create syscall with a MFD_CLOEXEC flag +# +AC_DEFUN([AC_HAVE_MEMFD_CLOEXEC], + [ AC_MSG_CHECKING([for memfd_fd and MFD_CLOEXEC]) + AC_LINK_IFELSE([AC_LANG_PROGRAM([[ +#define _GNU_SOURCE +#include + ]], [[ + return memfd_create("xfs", MFD_CLOEXEC); + ]])],[have_memfd_cloexec=yes + AC_MSG_RESULT(yes)],[AC_MSG_RESULT(no)]) + AC_SUBST(have_memfd_cloexec) + ]) + +# +# Check if we have the O_TMPFILE flag +# +AC_DEFUN([AC_HAVE_O_TMPFILE], + [ AC_MSG_CHECKING([for O_TMPFILE]) + AC_LINK_IFELSE([AC_LANG_PROGRAM([[ +#define _GNU_SOURCE +#include +#include +#include + ]], [[ + return open("nowhere", O_TMPFILE, 0600); + ]])],[have_o_tmpfile=yes + AC_MSG_RESULT(yes)],[AC_MSG_RESULT(no)]) + AC_SUBST(have_o_tmpfile) + ]) + +# +# Check if we have mkostemp with the O_CLOEXEC flag +# +AC_DEFUN([AC_HAVE_MKOSTEMP_CLOEXEC], + [ AC_MSG_CHECKING([for mkostemp and O_CLOEXEC]) + AC_LINK_IFELSE([AC_LANG_PROGRAM([[ +#define _GNU_SOURCE +#include +#include +#include +#include + ]], [[ + return mkostemp("nowhere", O_TMPFILE); + ]])],[have_mkostemp_cloexec=yes + AC_MSG_RESULT(yes)],[AC_MSG_RESULT(no)]) + AC_SUBST(have_mkostemp_cloexec) + ]) diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c index ff29bea9..65cb9387 100644 --- a/repair/xfs_repair.c +++ b/repair/xfs_repair.c @@ -953,6 +953,20 @@ phase_end(int phase) platform_crash(); } +/* Try to allow as many memfds as possible. */ +static void +bump_max_fds(void) +{ + struct rlimit rlim = { }; + int ret; + + ret = getrlimit(RLIMIT_NOFILE, &rlim); + if (!ret) { + rlim.rlim_cur = rlim.rlim_max; + setrlimit(RLIMIT_NOFILE, &rlim); + } +} + int main(int argc, char **argv) { @@ -972,6 +986,7 @@ main(int argc, char **argv) bindtextdomain(PACKAGE, LOCALEDIR); textdomain(PACKAGE); dinode_bmbt_translation_init(); + bump_max_fds(); temp_mp = &xfs_m; setbuf(stdout, NULL);