Re: [PATCH 3/5] fuzzy: add a custom xfs find utility for scrub stress tests

["Darrick J. Wong" <djwong@kernel.org>]

On Sun, Feb 05, 2023 at 08:57:47PM +0800, Zorro Lang wrote:
> On Fri, Dec 30, 2022 at 02:19:06PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> > 
> > Create a new find(1) like utility that doesn't crash on directory tree
> > changes (like find does due to bugs in its loop detector) and actually
> > implements the custom xfs attribute predicates that we need for scrub
> > stress tests.  This program will be needed for a future patch where we
> > add stress tests for scrub and repair of file metadata.
> > 
> > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> > ---
> >  configure.ac          |    5 +
> >  include/builddefs.in  |    4 +
> >  m4/package_libcdev.m4 |   47 ++++++++
> >  m4/package_xfslibs.m4 |   16 +++
> >  src/Makefile          |   10 ++
> >  src/xfsfind.c         |  290 +++++++++++++++++++++++++++++++++++++++++++++++++
> >  6 files changed, 372 insertions(+)
> >  create mode 100644 src/xfsfind.c
> > 
> > 
> > diff --git a/configure.ac b/configure.ac
> > index cbf8377988..e92bd6b26d 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -66,6 +66,11 @@ AC_PACKAGE_WANT_LINUX_FS_H
> >  AC_PACKAGE_WANT_LIBBTRFSUTIL
> >  
> >  AC_HAVE_COPY_FILE_RANGE
> > +AC_HAVE_SEEK_DATA
> > +AC_HAVE_BMV_OF_SHARED
> > +AC_HAVE_NFTW
> > +AC_HAVE_RLIMIT_NOFILE
> > +
> >  AC_CHECK_FUNCS([renameat2])
> >  AC_CHECK_FUNCS([reallocarray])
> >  AC_CHECK_TYPES([struct mount_attr], [], [], [[#include <linux/mount.h>]])
> > diff --git a/include/builddefs.in b/include/builddefs.in
> > index 6641209f81..dab10c968f 100644
> > --- a/include/builddefs.in
> > +++ b/include/builddefs.in
> > @@ -68,6 +68,10 @@ HAVE_FIEMAP = @have_fiemap@
> >  HAVE_FALLOCATE = @have_fallocate@
> >  HAVE_COPY_FILE_RANGE = @have_copy_file_range@
> >  HAVE_LIBBTRFSUTIL = @have_libbtrfsutil@
> > +HAVE_SEEK_DATA = @have_seek_data@
> > +HAVE_NFTW = @have_nftw@
> > +HAVE_BMV_OF_SHARED = @have_bmv_of_shared@
> > +HAVE_RLIMIT_NOFILE = @have_rlimit_nofile@
> >  
> >  GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall
> >  
> > diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
> > index 5c76c0f73e..e1b381c16f 100644
> > --- a/m4/package_libcdev.m4
> > +++ b/m4/package_libcdev.m4
> > @@ -110,3 +110,50 @@ AC_DEFUN([AC_HAVE_COPY_FILE_RANGE],
> >      AC_SUBST(have_copy_file_range)
> >    ])
> >  
> > +# Check if we have SEEK_DATA
> > +AC_DEFUN([AC_HAVE_SEEK_DATA],
> > +  [ AC_MSG_CHECKING([for SEEK_DATA])
> > +    AC_TRY_LINK([
> 
> The AC_TRY_LINK is obsolete by autoconf, refer to:
> https://www.gnu.org/software/autoconf/manual/autoconf-2.69/html_node/Obsolete-Macros.html
> 
> So as the suggestion of above link, we'd better to replace:
>           Macro: AC_TRY_LINK (includes, function-body, [action-if-true], [action-if-false])
> with:
>           AC_LINK_IFELSE(
>             [AC_LANG_PROGRAM([[includes]],
>                [[function-body]])],
>             [action-if-true],
>             [action-if-false])
> 
> For example (hope it's right:)

Yeah... this patch was written so long ago I wasn't even aware of the
deprecations.  I've run autoupdate to fix the problems and will repost.

--D

> diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
> index e1b381c1..7f1767a4 100644
> --- a/m4/package_libcdev.m4
> +++ b/m4/package_libcdev.m4
> @@ -113,13 +113,13 @@ AC_DEFUN([AC_HAVE_COPY_FILE_RANGE],
>  # Check if we have SEEK_DATA
>  AC_DEFUN([AC_HAVE_SEEK_DATA],
>    [ AC_MSG_CHECKING([for SEEK_DATA])
> -    AC_TRY_LINK([
> +    AC_LINK_IFELSE([AC_LANG_PROGRAM([[
>  #define _GNU_SOURCE
>  #include <sys/types.h>
>  #include <unistd.h>
> -    ], [
> +    ]], [[
>           lseek(-1, 0, SEEK_DATA);
> -    ], have_seek_data=yes
> +    ]])], have_seek_data=yes
>         AC_MSG_RESULT(yes),
>         AC_MSG_RESULT(no))
>      AC_SUBST(have_seek_data)
> 
> > +#define _GNU_SOURCE
> > +#include <sys/types.h>
> > +#include <unistd.h>
> > +    ], [
> > +         lseek(-1, 0, SEEK_DATA);
> > +    ], have_seek_data=yes
> > +       AC_MSG_RESULT(yes),
> > +       AC_MSG_RESULT(no))
> > +    AC_SUBST(have_seek_data)
> > +  ])
> > +
> > +# Check if we have nftw
> > +AC_DEFUN([AC_HAVE_NFTW],
> > +  [ AC_MSG_CHECKING([for nftw])
> > +    AC_TRY_LINK([
> 
> Same as above
> 
> > +#define _GNU_SOURCE
> > +#include <stddef.h>
> > +#include <ftw.h>
> > +    ], [
> > +         nftw("/", (int (*)(const char *, const struct stat *, int, struct FTW *))1, 0, 0);
> > +    ], have_nftw=yes
> > +       AC_MSG_RESULT(yes),
> > +       AC_MSG_RESULT(no))
> > +    AC_SUBST(have_nftw)
> > +  ])
> > +
> > +# Check if we have RLIMIT_NOFILE
> > +AC_DEFUN([AC_HAVE_RLIMIT_NOFILE],
> > +  [ AC_MSG_CHECKING([for RLIMIT_NOFILE])
> > +    AC_TRY_LINK([
> 
> Same as above
> 
> > +#define _GNU_SOURCE
> > +#include <sys/time.h>
> > +#include <sys/resource.h>
> > +    ], [
> > +         struct rlimit rlimit;
> > +
> > +         rlimit.rlim_cur = 0;
> > +         getrlimit(RLIMIT_NOFILE, &rlimit);
> > +    ], have_rlimit_nofile=yes
> > +       AC_MSG_RESULT(yes),
> > +       AC_MSG_RESULT(no))
> > +    AC_SUBST(have_rlimit_nofile)
> > +  ])
> > diff --git a/m4/package_xfslibs.m4 b/m4/package_xfslibs.m4
> > index 0746cd1dc5..479f30a29b 100644
> > --- a/m4/package_xfslibs.m4
> > +++ b/m4/package_xfslibs.m4
> > @@ -104,3 +104,19 @@ AC_DEFUN([AC_PACKAGE_NEED_XFSCTL_MACRO],
> >          exit 1
> >        ])
> >    ])
> > +
> > +# Check if we have BMV_OF_SHARED from the GETBMAPX ioctl
> > +AC_DEFUN([AC_HAVE_BMV_OF_SHARED],
> > +  [ AC_MSG_CHECKING([for BMV_OF_SHARED])
> > +    AC_TRY_LINK([
> 
> Same as above
> 
> Thanks,
> Zorro
> 
> > +#define _GNU_SOURCE
> > +#include <xfs/xfs.h>
> > +    ], [
> > +         struct getbmapx obj;
> > +         ioctl(-1, XFS_IOC_GETBMAPX, &obj);
> > +         obj.bmv_oflags |= BMV_OF_SHARED;
> > +    ], have_bmv_of_shared=yes
> > +       AC_MSG_RESULT(yes),
> > +       AC_MSG_RESULT(no))
> > +    AC_SUBST(have_bmv_of_shared)
> > +  ])
> > diff --git a/src/Makefile b/src/Makefile
> > index afdf6b30c5..7807ca89a5 100644
> > --- a/src/Makefile
> > +++ b/src/Makefile
> > @@ -83,6 +83,16 @@ ifeq ($(HAVE_LIBCAP), true)
> >  LLDLIBS += -lcap
> >  endif
> >  
> > +ifeq ($(HAVE_SEEK_DATA), yes)
> > + ifeq ($(HAVE_NFTW), yes)
> > +  ifeq ($(HAVE_BMV_OF_SHARED), yes)
> > +   ifeq ($(HAVE_RLIMIT_NOFILE), yes)
> > +     TARGETS += xfsfind
> > +   endif
> > +  endif
> > + endif
> > +endif
> > +
> >  CFILES = $(TARGETS:=.c)
> >  LDIRT = $(TARGETS) fssum
> >  
> > diff --git a/src/xfsfind.c b/src/xfsfind.c
> > new file mode 100644
> > index 0000000000..6b0a93e793
> > --- /dev/null
> > +++ b/src/xfsfind.c
> > @@ -0,0 +1,290 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * find(1) but with special predicates for finding XFS attributes.
> > + * Copyright (C) 2022 Oracle.
> > + */
> > +#include <sys/time.h>
> > +#include <sys/resource.h>
> > +#include <sys/types.h>
> > +#include <stdio.h>
> > +#include <unistd.h>
> > +#include <ftw.h>
> > +#include <linux/fs.h>
> > +#include <xfs/xfs.h>
> > +
> > +#include "global.h"
> > +
> > +static int want_anyfile;
> > +static int want_datafile;
> > +static int want_attrfile;
> > +static int want_dir;
> > +static int want_regfile;
> > +static int want_sharedfile;
> > +static int report_errors = 1;
> > +
> > +static int
> > +check_datafile(
> > +	const char		*path,
> > +	int			fd)
> > +{
> > +	off_t			off;
> > +
> > +	off = lseek(fd, 0, SEEK_DATA);
> > +	if (off >= 0)
> > +		return 1;
> > +
> > +	if (errno == ENXIO)
> > +		return 0;
> > +
> > +	if (report_errors)
> > +		perror(path);
> > +
> > +	return -1;
> > +}
> > +
> > +static int
> > +check_attrfile(
> > +	const char		*path,
> > +	int			fd)
> > +{
> > +	struct fsxattr		fsx;
> > +	int			ret;
> > +
> > +	ret = ioctl(fd, XFS_IOC_FSGETXATTR, &fsx);
> > +	if (ret) {
> > +		if (report_errors)
> > +			perror(path);
> > +		return -1;
> > +	}
> > +
> > +	if (want_attrfile && (fsx.fsx_xflags & XFS_XFLAG_HASATTR))
> > +		return 1;
> > +	return 0;
> > +}
> > +
> > +#define BMAP_NR			33
> > +static struct getbmapx		bmaps[BMAP_NR];
> > +
> > +static int
> > +check_sharedfile(
> > +	const char		*path,
> > +	int			fd)
> > +{
> > +	struct getbmapx		*key = &bmaps[0];
> > +	unsigned int		i;
> > +	int			ret;
> > +
> > +	memset(key, 0, sizeof(struct getbmapx));
> > +	key->bmv_length = ULLONG_MAX;
> > +	/* no holes and don't flush dirty pages */
> > +	key->bmv_iflags = BMV_IF_DELALLOC | BMV_IF_NO_HOLES;
> > +	key->bmv_count = BMAP_NR;
> > +
> > +	while ((ret = ioctl(fd, XFS_IOC_GETBMAPX, bmaps)) == 0) {
> > +		struct getbmapx	*p = &bmaps[1];
> > +		xfs_off_t	new_off;
> > +
> > +		for (i = 0; i < key->bmv_entries; i++, p++) {
> > +			if (p->bmv_oflags & BMV_OF_SHARED)
> > +				return 1;
> > +		}
> > +
> > +		if (key->bmv_entries == 0)
> > +			break;
> > +		p = key + key->bmv_entries;
> > +		if (p->bmv_oflags & BMV_OF_LAST)
> > +			return 0;
> > +
> > +		new_off = p->bmv_offset + p->bmv_length;
> > +		key->bmv_length -= new_off - key->bmv_offset;
> > +		key->bmv_offset = new_off;
> > +	}
> > +	if (ret < 0) {
> > +		if (report_errors)
> > +			perror(path);
> > +		return -1;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static void
> > +print_help(
> > +	const char		*name)
> > +{
> > +	printf("Usage: %s [OPTIONS] path\n", name);
> > +	printf("\n");
> > +	printf("Print all file paths matching any of the given predicates.\n");
> > +	printf("\n");
> > +	printf("-a	Match files with xattrs.\n");
> > +	printf("-b	Match files with data blocks.\n");
> > +	printf("-d	Match directories.\n");
> > +	printf("-q	Ignore errors while walking directory tree.\n");
> > +	printf("-r	Match regular files.\n");
> > +	printf("-s	Match files with shared blocks.\n");
> > +	printf("\n");
> > +	printf("If no matching options are given, match all files found.\n");
> > +}
> > +
> > +static int
> > +visit(
> > +	const char		*path,
> > +	const struct stat	*sb,
> > +	int			typeflag,
> > +	struct FTW		*ftwbuf)
> > +{
> > +	int			printme = 1;
> > +	int			fd = -1;
> > +	int			retval = FTW_CONTINUE;
> > +
> > +	if (want_anyfile)
> > +		goto out;
> > +	if (want_regfile && typeflag == FTW_F)
> > +		goto out;
> > +	if (want_dir && typeflag == FTW_D)
> > +		goto out;
> > +
> > +	/*
> > +	 * We can only open directories and files; screen out everything else.
> > +	 * Note that nftw lies and reports FTW_F for device files, so check the
> > +	 * statbuf mode too.
> > +	 */
> > +	if (typeflag != FTW_F && typeflag != FTW_D) {
> > +		printme = 0;
> > +		goto out;
> > +	}
> > +
> > +	if (!S_ISREG(sb->st_mode) && !S_ISDIR(sb->st_mode)) {
> > +		printme = 0;
> > +		goto out;
> > +	}
> > +
> > +	fd = open(path, O_RDONLY);
> > +	if (fd < 0) {
> > +		if (report_errors) {
> > +			perror(path);
> > +			return FTW_STOP;
> > +		}
> > +
> > +		return FTW_CONTINUE;
> > +	}
> > +
> > +	if (want_datafile && typeflag == FTW_F) {
> > +		int ret = check_datafile(path, fd);
> > +		if (ret < 0 && report_errors) {
> > +			printme = 0;
> > +			retval = FTW_STOP;
> > +			goto out_fd;
> > +		}
> > +
> > +		if (ret == 1)
> > +			goto out_fd;
> > +	}
> > +
> > +	if (want_attrfile) {
> > +		int ret = check_attrfile(path, fd);
> > +		if (ret < 0 && report_errors) {
> > +			printme = 0;
> > +			retval = FTW_STOP;
> > +			goto out_fd;
> > +		}
> > +
> > +		if (ret == 1)
> > +			goto out_fd;
> > +	}
> > +
> > +	if (want_sharedfile) {
> > +		int ret = check_sharedfile(path, fd);
> > +		if (ret < 0 && report_errors) {
> > +			printme = 0;
> > +			retval = FTW_STOP;
> > +			goto out_fd;
> > +		}
> > +
> > +		if (ret == 1)
> > +			goto out_fd;
> > +	}
> > +
> > +	printme = 0;
> > +out_fd:
> > +	close(fd);
> > +out:
> > +	if (printme)
> > +		printf("%s\n", path);
> > +	return retval;
> > +}
> > +
> > +static void
> > +handle_sigabrt(
> > +	int		signal,
> > +	siginfo_t	*info,
> > +	void		*ucontext)
> > +{
> > +	fprintf(stderr, "Signal %u, exiting.\n", signal);
> > +	exit(2);
> > +}
> > +
> > +int
> > +main(
> > +	int			argc,
> > +	char			*argv[])
> > +{
> > +	struct rlimit		rlimit;
> > +	struct sigaction	abrt = {
> > +		.sa_sigaction	= handle_sigabrt,
> > +		.sa_flags	= SA_SIGINFO,
> > +	};
> > +	int			c;
> > +	int			ret;
> > +
> > +	while ((c = getopt(argc, argv, "abdqrs")) >= 0) {
> > +		switch (c) {
> > +		case 'a':	want_attrfile = 1;   break;
> > +		case 'b':	want_datafile = 1;   break;
> > +		case 'd':	want_dir = 1;        break;
> > +		case 'q':	report_errors = 0;   break;
> > +		case 'r':	want_regfile = 1;    break;
> > +		case 's':	want_sharedfile = 1; break;
> > +		default:
> > +			print_help(argv[0]);
> > +			return 1;
> > +		}
> > +	}
> > +
> > +	ret = getrlimit(RLIMIT_NOFILE, &rlimit);
> > +	if (ret) {
> > +		perror("RLIMIT_NOFILE");
> > +		return 1;
> > +	}
> > +
> > +	if (!want_attrfile && !want_datafile && !want_dir && !want_regfile &&
> > +	    !want_sharedfile)
> > +		want_anyfile = 1;
> > +
> > +	/*
> > +	 * nftw is known to abort() if a directory it is walking disappears out
> > +	 * from under it.  Handle this with grace if the caller wants us to run
> > +	 * quietly.
> > +	 */
> > +	if (!report_errors) {
> > +		ret = sigaction(SIGABRT, &abrt, NULL);
> > +		if (ret) {
> > +			perror("SIGABRT handler");
> > +			return 1;
> > +		}
> > +	}
> > +
> > +	for (c = optind; c < argc; c++) {
> > +		ret = nftw(argv[c], visit, rlimit.rlim_cur - 5,
> > +				FTW_ACTIONRETVAL | FTW_CHDIR | FTW_MOUNT |
> > +				FTW_PHYS);
> > +		if (ret && report_errors) {
> > +			perror(argv[c]);
> > +			break;
> > +		}
> > +	}
> > +
> > +	if (ret)
> > +		return 1;
> > +	return 0;
> > +}
> > 
>