Messages in this thread | | | From | Heiko Thiery <> | Date | Fri, 14 May 2021 12:22:22 +0200 | Subject | Re: [PATCH iproute2-next v3] lib/fs: fix issue when {name,open}_to_handle_at() is not implemented |
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Hi David,
Am Mo., 10. Mai 2021 um 00:20 Uhr schrieb David Ahern <dsahern@gmail.com>: > > On 5/8/21 12:49 AM, Heiko Thiery wrote: > > With commit d5e6ee0dac64 the usage of functions name_to_handle_at() and > > open_by_handle_at() are introduced. But these function are not available > > e.g. in uclibc-ng < 1.0.35. To have a backward compatibility check for the > > availability in the configure script and in case of absence do a direct > > syscall. > > > > Fixes: d5e6ee0dac64 ("ss: introduce cgroup2 cache and helper functions") > > Cc: Dmitry Yakunin <zeil@yandex-team.ru> > > Cc: Petr Vorel <petr.vorel@gmail.com> > > Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com> > > --- > > v3: > > - use correct syscall number (thanks to Petr Vorel) > > - add #include <sys/syscall.h> (thanks to Petr Vorel) > > - remove bogus parameters (thanks to Petr Vorel) > > - fix #ifdef (thanks to Petr Vorel) > > - added Fixes tag (thanks to David Ahern) > > - build test with buildroot 2020.08.3 using uclibc 1.0.34 > > > > v2: > > - small correction to subject > > - removed IP_CONFIG_HANDLE_AT:=y option since it is not required > > - fix indentation in check function > > - removed empty lines (thanks to Petr Vorel) > > - add #define _GNU_SOURCE in check (thanks to Petr Vorel) > > - check only for name_to_handle_at (thanks to Petr Vorel) > > > > configure | 28 ++++++++++++++++++++++++++++ > > lib/fs.c | 25 +++++++++++++++++++++++++ > > 2 files changed, 53 insertions(+) > > > > diff --git a/configure b/configure > > index 2c363d3b..179eae08 100755 > > --- a/configure > > +++ b/configure > > @@ -202,6 +202,31 @@ EOF > > rm -f $TMPDIR/setnstest.c $TMPDIR/setnstest > > } > > > > +check_name_to_handle_at() > > +{ > > + cat >$TMPDIR/name_to_handle_at_test.c <<EOF > > +#define _GNU_SOURCE > > +#include <sys/types.h> > > +#include <sys/stat.h> > > +#include <fcntl.h> > > +int main(int argc, char **argv) > > +{ > > + struct file_handle *fhp; > > + int mount_id, flags, dirfd; > > + char *pathname; > > + name_to_handle_at(dirfd, pathname, fhp, &mount_id, flags); > > + return 0; > > +} > > +EOF > > + if $CC -I$INCLUDE -o $TMPDIR/name_to_handle_at_test $TMPDIR/name_to_handle_at_test.c >/dev/null 2>&1; then > > + echo "yes" > > + echo "CFLAGS += -DHAVE_HANDLE_AT" >>$CONFIG > > + else > > + echo "no" > > + fi > > + rm -f $TMPDIR/name_to_handle_at_test.c $TMPDIR/name_to_handle_at_test > > +} > > + > > check_ipset() > > { > > cat >$TMPDIR/ipsettest.c <<EOF > > @@ -492,6 +517,9 @@ fi > > echo -n "libc has setns: " > > check_setns > > > > +echo -n "libc has name_to_handle_at: " > > +check_name_to_handle_at > > + > > echo -n "SELinux support: " > > check_selinux > > > > diff --git a/lib/fs.c b/lib/fs.c > > index f161d888..05697a7e 100644 > > --- a/lib/fs.c > > +++ b/lib/fs.c > > @@ -25,11 +25,36 @@ > > > > #include "utils.h" > > > > +#ifndef HAVE_HANDLE_AT > > +# include <sys/syscall.h> > > +#endif > > + > > #define CGROUP2_FS_NAME "cgroup2" > > > > /* if not already mounted cgroup2 is mounted here for iproute2's use */ > > #define MNT_CGRP2_PATH "/var/run/cgroup2" > > > > + > > +#ifndef HAVE_HANDLE_AT > > +struct file_handle { > > + unsigned handle_bytes; > > + int handle_type; > > + unsigned char f_handle[]; > > +}; > > + > > +static int name_to_handle_at(int dirfd, const char *pathname, > > + struct file_handle *handle, int *mount_id, int flags) > > +{ > > + return syscall(__NR_name_to_handle_at, dirfd, pathname, handle, > > + mount_id, flags); > > +} > > + > > +static int open_by_handle_at(int mount_fd, struct file_handle *handle, int flags) > > +{ > > + return syscall(__NR_open_by_handle_at, mount_fd, handle, flags); > > +} > > +#endif > > + > > /* return mount path of first occurrence of given fstype */ > > static char *find_fs_mount(const char *fs_to_find) > > { > > > > This causes compile failures if anyone is reusing a tree. It would be > good to require config.mk to be updated if configure is newer.
Do you mean the config.mk should have a dependency to configure in the Makefile? Wouldn't that be better as a separate patch?
Thanks -- Heiko
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