On 2025-08-11 08:23:40, Darrick J. Wong wrote:
> On Fri, Aug 08, 2025 at 09:31:56PM +0200, Andrey Albershteyn wrote:
> > This programs uses newly introduced file_getattr and file_setattr
> > syscalls. This program is partially a test of invalid options. This will
> > be used further in the test.
> >
> > Signed-off-by: Andrey Albershteyn <aalbersh@xxxxxxxxxx>
> > ---
> > .gitignore | 1 +
> > configure.ac | 1 +
> > include/builddefs.in | 1 +
> > m4/package_libcdev.m4 | 16 +++
> > src/Makefile | 5 +
> > src/file_attr.c | 277 ++++++++++++++++++++++++++++++++++++++++++++++++++
> > 6 files changed, 301 insertions(+)
> >
> > diff --git a/.gitignore b/.gitignore
> > index 4fd817243dca..1a578eab1ea0 100644
> > --- a/.gitignore
> > +++ b/.gitignore
> > @@ -210,6 +210,7 @@ tags
> > /src/fiemap-fault
> > /src/min_dio_alignment
> > /src/dio-writeback-race
> > +/src/file_attr
> >
> > # Symlinked files
> > /tests/generic/035.out
> > diff --git a/configure.ac b/configure.ac
> > index f3c8c643f0eb..6fe54e8e1d54 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -73,6 +73,7 @@ AC_HAVE_RLIMIT_NOFILE
> > AC_NEED_INTERNAL_XFS_IOC_EXCHANGE_RANGE
> > AC_HAVE_FICLONE
> > AC_HAVE_TRIVIAL_AUTO_VAR_INIT
> > +AC_HAVE_FILE_ATTR
> >
> > AC_CHECK_FUNCS([renameat2])
> > AC_CHECK_FUNCS([reallocarray])
> > diff --git a/include/builddefs.in b/include/builddefs.in
> > index 96d5ed25b3e2..821237339cc7 100644
> > --- a/include/builddefs.in
> > +++ b/include/builddefs.in
> > @@ -74,6 +74,7 @@ HAVE_BMV_OF_SHARED = @have_bmv_of_shared@
> > HAVE_RLIMIT_NOFILE = @have_rlimit_nofile@
> > NEED_INTERNAL_XFS_IOC_EXCHANGE_RANGE = @need_internal_xfs_ioc_exchange_range@
> > HAVE_FICLONE = @have_ficlone@
> > +HAVE_FILE_ATTR = @have_file_attr@
> >
> > GCCFLAGS = -std=gnu11 -funsigned-char -fno-strict-aliasing -Wall
> > SANITIZER_CFLAGS += @autovar_init_cflags@
> > diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
> > index ed8fe6e32ae0..e68a70f7d87e 100644
> > --- a/m4/package_libcdev.m4
> > +++ b/m4/package_libcdev.m4
> > @@ -86,3 +86,19 @@ AC_DEFUN([AC_HAVE_TRIVIAL_AUTO_VAR_INIT],
> > CFLAGS="${OLD_CFLAGS}"
> > AC_SUBST(autovar_init_cflags)
> > ])
> > +
> > +#
> > +# Check if we have a file_getattr/file_setattr system call (Linux)
> > +#
> > +AC_DEFUN([AC_HAVE_FILE_ATTR],
> > + [ AC_MSG_CHECKING([for file_getattr/file_setattr syscalls])
> > + AC_LINK_IFELSE([AC_LANG_PROGRAM([[
> > +#define _GNU_SOURCE
> > +#include <sys/syscall.h>
> > +#include <unistd.h>
> > + ]], [[
> > + syscall(__NR_file_getattr, 0, 0, 0, 0, 0, 0);
> > + ]])],[have_file_attr=yes
> > + AC_MSG_RESULT(yes)],[AC_MSG_RESULT(no)])
> > + AC_SUBST(have_file_attr)
> > + ])
> > diff --git a/src/Makefile b/src/Makefile
> > index 6ac72b366257..f3137acf687f 100644
> > --- a/src/Makefile
> > +++ b/src/Makefile
> > @@ -61,6 +61,11 @@ ifeq ($(HAVE_FALLOCATE), true)
> > LCFLAGS += -DHAVE_FALLOCATE
> > endif
> >
> > +ifeq ($(HAVE_FILE_ATTR), yes)
> > +LINUX_TARGETS += file_attr
> > +LCFLAGS += -DHAVE_FILE_ATTR
> > +endif
> > +
> > ifeq ($(PKG_PLATFORM),linux)
> > TARGETS += $(LINUX_TARGETS)
> > endif
> > diff --git a/src/file_attr.c b/src/file_attr.c
> > new file mode 100644
> > index 000000000000..9756ab265a57
> > --- /dev/null
> > +++ b/src/file_attr.c
> > @@ -0,0 +1,277 @@
> > +#include "global.h"
> > +#include <sys/syscall.h>
> > +#include <getopt.h>
> > +#include <errno.h>
> > +#include <linux/fs.h>
> > +#include <sys/stat.h>
> > +#include <string.h>
> > +#include <getopt.h>
> > +#include <stdlib.h>
> > +#include <unistd.h>
> > +
> > +#ifndef HAVE_FILE_ATTR
> > +#define __NR_file_getattr 468
> > +#define __NR_file_setattr 469
> > +
> > +struct file_attr {
> > + __u32 fa_xflags; /* xflags field value (get/set) */
> > + __u32 fa_extsize; /* extsize field value (get/set)*/
> > + __u32 fa_nextents; /* nextents field value (get) */
> > + __u32 fa_projid; /* project identifier (get/set) */
> > + __u32 fa_cowextsize; /* CoW extsize field value (get/set) */
> > +};
> > +
> > +#endif
> > +
> > +#define SPECIAL_FILE(x) \
> > + (S_ISCHR((x)) \
> > + || S_ISBLK((x)) \
> > + || S_ISFIFO((x)) \
> > + || S_ISLNK((x)) \
> > + || S_ISSOCK((x)))
> > +
> > +static struct option long_options[] = {
> > + {"set", no_argument, 0, 's' },
> > + {"get", no_argument, 0, 'g' },
> > + {"no-follow", no_argument, 0, 'n' },
> > + {"at-cwd", no_argument, 0, 'a' },
> > + {"set-nodump", no_argument, 0, 'd' },
> > + {"invalid-at", no_argument, 0, 'i' },
> > + {"too-big-arg", no_argument, 0, 'b' },
> > + {"too-small-arg", no_argument, 0, 'm' },
> > + {"new-fsx-flag", no_argument, 0, 'x' },
> > + {0, 0, 0, 0 }
> > +};
> > +
> > +static struct xflags {
> > + uint flag;
> > + char *shortname;
> > + char *longname;
> > +} xflags[] = {
> > + { FS_XFLAG_REALTIME, "r", "realtime" },
> > + { FS_XFLAG_PREALLOC, "p", "prealloc" },
> > + { FS_XFLAG_IMMUTABLE, "i", "immutable" },
> > + { FS_XFLAG_APPEND, "a", "append-only" },
> > + { FS_XFLAG_SYNC, "s", "sync" },
> > + { FS_XFLAG_NOATIME, "A", "no-atime" },
> > + { FS_XFLAG_NODUMP, "d", "no-dump" },
> > + { FS_XFLAG_RTINHERIT, "t", "rt-inherit" },
> > + { FS_XFLAG_PROJINHERIT, "P", "proj-inherit" },
> > + { FS_XFLAG_NOSYMLINKS, "n", "nosymlinks" },
> > + { FS_XFLAG_EXTSIZE, "e", "extsize" },
> > + { FS_XFLAG_EXTSZINHERIT, "E", "extsz-inherit" },
> > + { FS_XFLAG_NODEFRAG, "f", "no-defrag" },
> > + { FS_XFLAG_FILESTREAM, "S", "filestream" },
> > + { FS_XFLAG_DAX, "x", "dax" },
> > + { FS_XFLAG_COWEXTSIZE, "C", "cowextsize" },
> > + { FS_XFLAG_HASATTR, "X", "has-xattr" },
> > + { 0, NULL, NULL }
> > +};
> > +
> > +static int
> > +file_getattr(
> > + int dfd,
> > + const char *filename,
> > + struct file_attr *fsx,
> > + size_t usize,
> > + unsigned int at_flags)
> > +{
> > + return syscall(__NR_file_getattr, dfd, filename, fsx, usize, at_flags);
> > +}
> > +
> > +static int
> > +file_setattr(
> > + int dfd,
> > + const char *filename,
> > + struct file_attr *fsx,
> > + size_t usize,
> > + unsigned int at_flags)
> > +{
> > + return syscall(__NR_file_setattr, dfd, filename, fsx, usize, at_flags);
> > +}
> > +
> > +void
> > +printxattr(
> > + uint flags,
> > + int verbose,
> > + int dofname,
> > + const char *fname,
> > + int dobraces,
> > + int doeol)
> > +{
> > + struct xflags *p;
> > + int first = 1;
> > +
> > + if (dobraces)
> > + fputs("[", stdout);
> > + for (p = xflags; p->flag; p++) {
> > + if (flags & p->flag) {
> > + if (verbose) {
> > + if (first)
> > + first = 0;
> > + else
> > + fputs(", ", stdout);
> > + fputs(p->longname, stdout);
> > + } else {
> > + fputs(p->shortname, stdout);
> > + }
> > + } else if (!verbose) {
> > + fputs("-", stdout);
> > + }
> > + }
> > + if (dobraces)
> > + fputs("]", stdout);
> > + if (dofname)
> > + printf(" %s ", fname);
> > + if (doeol)
> > + fputs("\n", stdout);
> > +}
> > +
> > +int main(int argc, char *argv[])
> > +{
> > + int error;
> > + int c;
> > + const char *path = NULL;
> > + const char *path1 = NULL;
> > + const char *path2 = NULL;
> > + unsigned int at_flags = 0;
> > + unsigned int fa_xflags = 0;
> > + int action = 0; /* 0 get; 1 set */
> > + struct file_attr fsx = { };
> > + int fa_size = sizeof(struct file_attr);
> > + struct stat status;
> > + int fd;
> > + int at_fdcwd = 0;
> > + int unknwon_fa_flag = 0;
> > +
> > + while (1) {
> > + int option_index = 0;
> > +
> > + c = getopt_long_only(argc, argv, "", long_options, &option_index);
> > + if (c == -1)
> > + break;
> > +
> > + switch (c) {
> > + case 's':
> > + action = 1;
> > + break;
> > + case 'g':
> > + action = 0;
> > + break;
> > + case 'n':
> > + at_flags |= AT_SYMLINK_NOFOLLOW;
> > + break;
> > + case 'a':
> > + at_fdcwd = 1;
> > + break;
> > + case 'd':
> > + fa_xflags |= FS_XFLAG_NODUMP;
> > + break;
> > + case 'i':
> > + at_flags |= (1 << 25);
> > + break;
> > + case 'b':
> > + fa_size = getpagesize() + 1; /* max size if page size */
> > + break;
> > + case 'm':
> > + fa_size = 19; /* VER0 size of fsxattr is 20 */
> > + break;
> > + case 'x':
> > + unknwon_fa_flag = (1 << 27);
> > + break;
> > + default:
> > + goto usage;
> > + }
> > + }
> > +
> > + if (!path1 && optind < argc)
> > + path1 = argv[optind++];
> > + if (!path2 && optind < argc)
> > + path2 = argv[optind++];
> > +
> > + if (at_fdcwd) {
> > + fd = AT_FDCWD;
> > + path = path1;
> > + } else if (!path2) {
> > + error = stat(path1, &status);
> > + if (error) {
> > + fprintf(stderr,
> > +"Can not get file status of %s: %s\n", path1, strerror(errno));
> > + return error;
> > + }
> > +
> > + if (SPECIAL_FILE(status.st_mode)) {
> > + fprintf(stderr,
> > +"Can not open special file %s without parent dir: %s\n", path1, strerror(errno));
> > + return errno;
> > + }
> > +
> > + fd = open(path1, O_RDONLY);
> > + if (fd == -1) {
> > + fprintf(stderr, "Can not open %s: %s\n", path1,
> > + strerror(errno));
> > + return errno;
> > + }
> > + } else {
> > + fd = open(path1, O_RDONLY);
> > + if (fd == -1) {
> > + fprintf(stderr, "Can not open %s: %s\n", path1,
> > + strerror(errno));
> > + return errno;
> > + }
> > + path = path2;
> > + }
> > +
> > + if (!path)
> > + at_flags |= AT_EMPTY_PATH;
> > +
> > + if (action) {
> > + error = file_getattr(fd, path, &fsx, fa_size,
> > + at_flags);
> > + if (error) {
> > + fprintf(stderr, "Can not get fsxattr on %s: %s\n", path,
> > + strerror(errno));
> > + return error;
> > + }
> > +
> > + fsx.fa_xflags |= (fa_xflags | unknwon_fa_flag);
> > +
> > + error = file_setattr(fd, path, &fsx, fa_size,
> > + at_flags);
> > + if (error) {
> > + fprintf(stderr, "Can not set fsxattr on %s: %s\n", path,
> > + strerror(errno));
> > + return error;
> > + }
> > + } else {
> > + error = file_getattr(fd, path, &fsx, fa_size,
> > + at_flags);
> > + if (error) {
> > + fprintf(stderr, "Can not get fsxattr on %s: %s\n", path,
> > + strerror(errno));
> > + return error;
> > + }
>
> Can the file_getattr be lifted above the if (action) ?
yup
>
> > +
> > + if (path2)
> > + printxattr(fsx.fa_xflags, 0, 1, path, 0, 1);
> > + else
> > + printxattr(fsx.fa_xflags, 0, 1, path1, 0, 1);
> > + }
> > +
> > + return error;
> > +
> > +usage:
> > + printf("Usage: %s [options]\n", argv[0]);
> > + printf("Options:\n");
> > + printf("\t--get\t\tget filesystem inode attributes\n");
> > + printf("\t--set\t\tset filesystem inode attributes\n");
> > + printf("\t--at-cwd\t\topen file at current working directory\n");
> > + printf("\t--no-follow\t\tdon't follow symlinks\n");
> > + printf("\t--set-nodump\t\tset FS_XFLAG_NODUMP on an inode\n");
> > + printf("\t--invalid-at\t\tUse invalida AT_* flag\n");
> > + printf("\t--too-big-arg\t\tSet fsxattr size bigger than PAGE_SIZE\n");
> > + printf("\t--too-small-arg\t\tSet fsxattr size to 27 bytes\n");
>
> 27? I thought you put in 19 above?
ops, forgot to update it here
>
> Also it'd be nice if the help listed the short and long versions.
>
> (Or skip the short cli switches ;))
will add short versions
>
> --D
>
> > + printf("\t--new-fsx-flag\t\tUse unknown fa_flags flag\n");
> > +
> > + return 1;
> > +}
> >
> > --
> > 2.49.0
> >
> >
>
--
- Andrey
