# This license differs from the rest of public-inbox
#
# This module is Copyright (c) 2005 Six Apart, Ltd.
-# Copyright (C) 2019-2021 all contributors <meta@public-inbox.org>
+# Copyright (C) all contributors <meta@public-inbox.org>
#
# All rights reserved.
#
# License or the Artistic License, as specified in the Perl README file.
package PublicInbox::Syscall;
use strict;
+use v5.10.1;
use parent qw(Exporter);
-use POSIX qw(ENOSYS O_NONBLOCK);
+use POSIX qw(ENOENT EEXIST ENOSYS EINVAL O_NONBLOCK);
use Config;
# $VERSION = '0.25'; # Sys::Syscall version
EPOLLIN EPOLLOUT EPOLLET
EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
EPOLLONESHOT EPOLLEXCLUSIVE
- signalfd SFD_NONBLOCK);
+ signalfd rename_noreplace);
our %EXPORT_TAGS = (epoll => [qw(epoll_ctl epoll_create epoll_wait
EPOLLIN EPOLLOUT
EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
$SYS_epoll_ctl,
$SYS_epoll_wait,
$SYS_signalfd4,
+ $SYS_renameat2,
);
+my $SYS_fstatfs; # don't need fstatfs64, just statfs.f_type
+my ($FS_IOC_GETFLAGS, $FS_IOC_SETFLAGS);
my $SFD_CLOEXEC = 02000000; # Perl does not expose O_CLOEXEC
-sub SFD_NONBLOCK () { O_NONBLOCK }
our $no_deprecated = 0;
if ($^O eq "linux") {
- my $machine = (POSIX::uname())[-1];
+ my (undef, undef, $release, undef, $machine) = POSIX::uname();
+ my ($maj, $min) = ($release =~ /\A([0-9]+)\.([0-9]+)/);
+ $SYS_renameat2 = 0 if "$maj.$min" < 3.15;
# whether the machine requires 64-bit numbers to be on 8-byte
# boundaries.
my $u64_mod_8 = 0;
$SYS_epoll_ctl = 255;
$SYS_epoll_wait = 256;
$SYS_signalfd4 = 327;
+ $SYS_renameat2 //= 353;
+ $SYS_fstatfs = 100;
+ $FS_IOC_GETFLAGS = 0x80046601;
+ $FS_IOC_SETFLAGS = 0x40046602;
} elsif ($machine eq "x86_64") {
$SYS_epoll_create = 213;
$SYS_epoll_ctl = 233;
$SYS_epoll_wait = 232;
$SYS_signalfd4 = 289;
+ $SYS_renameat2 //= 316;
+ $SYS_fstatfs = 138;
+ $FS_IOC_GETFLAGS = 0x80086601;
+ $FS_IOC_SETFLAGS = 0x40086602;
} elsif ($machine eq 'x32') {
$SYS_epoll_create = 1073742037;
$SYS_epoll_ctl = 1073742057;
$SYS_epoll_wait = 1073742056;
$SYS_signalfd4 = 1073742113;
+ $SYS_renameat2 //= 0x40000000 + 316;
+ $SYS_fstatfs = 138;
+ $FS_IOC_GETFLAGS = 0x80046601;
+ $FS_IOC_SETFLAGS = 0x40046602;
} elsif ($machine eq 'sparc64') {
$SYS_epoll_create = 193;
$SYS_epoll_ctl = 194;
$SYS_epoll_wait = 195;
$u64_mod_8 = 1;
$SYS_signalfd4 = 317;
+ $SYS_renameat2 //= 345;
$SFD_CLOEXEC = 020000000;
+ $SYS_fstatfs = 158;
+ $FS_IOC_GETFLAGS = 0x40086601;
+ $FS_IOC_SETFLAGS = 0x80086602;
} elsif ($machine =~ m/^parisc/) {
$SYS_epoll_create = 224;
$SYS_epoll_ctl = 225;
$SYS_epoll_wait = 238;
$u64_mod_8 = 1;
$SYS_signalfd4 = 313;
+ $SYS_renameat2 //= 357;
+ $SYS_fstatfs = 100;
+ $FS_IOC_GETFLAGS = 0x40086601;
+ $FS_IOC_SETFLAGS = 0x80086602;
} elsif ($machine eq "ppc") {
$SYS_epoll_create = 236;
$SYS_epoll_ctl = 237;
$SYS_epoll_wait = 238;
$u64_mod_8 = 1;
$SYS_signalfd4 = 313;
+ $SYS_renameat2 //= 357;
+ $SYS_fstatfs = 100;
+ $FS_IOC_GETFLAGS = 0x40086601;
+ $FS_IOC_SETFLAGS = 0x80086602;
} elsif ($machine =~ m/^s390/) {
$SYS_epoll_create = 249;
$SYS_epoll_ctl = 250;
$SYS_epoll_wait = 251;
$u64_mod_8 = 1;
$SYS_signalfd4 = 322;
+ $SYS_renameat2 //= 347;
+ $SYS_fstatfs = 100;
} elsif ($machine eq "ia64") {
$SYS_epoll_create = 1243;
$SYS_epoll_ctl = 1244;
$u64_mod_8 = 1;
$no_deprecated = 1;
$SYS_signalfd4 = 74;
+ $SYS_renameat2 //= 276;
+ $SYS_fstatfs = 44;
+ $FS_IOC_GETFLAGS = 0x80086601;
+ $FS_IOC_SETFLAGS = 0x40086602;
} elsif ($machine =~ m/arm(v\d+)?.*l/) {
# ARM OABI
$SYS_epoll_create = 250;
$SYS_epoll_wait = 252;
$u64_mod_8 = 1;
$SYS_signalfd4 = 355;
+ $SYS_renameat2 //= 382;
+ $SYS_fstatfs = 100;
} elsif ($machine =~ m/^mips64/) {
$SYS_epoll_create = 5207;
$SYS_epoll_ctl = 5208;
$SYS_epoll_wait = 5209;
$u64_mod_8 = 1;
$SYS_signalfd4 = 5283;
+ $SYS_renameat2 //= 5311;
+ $SYS_fstatfs = 5135;
+ $FS_IOC_GETFLAGS = 0x40046601;
+ $FS_IOC_SETFLAGS = 0x80046602;
} elsif ($machine =~ m/^mips/) {
$SYS_epoll_create = 4248;
$SYS_epoll_ctl = 4249;
$SYS_epoll_wait = 4250;
$u64_mod_8 = 1;
$SYS_signalfd4 = 4324;
+ $SYS_renameat2 //= 4351;
+ $SYS_fstatfs = 4100;
+ $FS_IOC_GETFLAGS = 0x40046601;
+ $FS_IOC_SETFLAGS = 0x80046602;
} else {
# as a last resort, try using the *.ph files which may not
# exist or may be wrong
}
}
-sub signalfd ($$$) {
- my ($fd, $signos, $flags) = @_;
+sub signalfd ($$) {
+ my ($signos, $nonblock) = @_;
if ($SYS_signalfd4) {
my $set = POSIX::SigSet->new(@$signos);
- syscall($SYS_signalfd4, $fd, "$$set",
+ syscall($SYS_signalfd4, -1, "$$set",
# $Config{sig_count} is NSIG, so this is NSIG/8:
int($Config{sig_count}/8),
- $flags|$SFD_CLOEXEC);
+ # SFD_NONBLOCK == O_NONBLOCK for every architecture
+ ($nonblock ? O_NONBLOCK : 0) |$SFD_CLOEXEC);
} else {
$! = ENOSYS;
undef;
}
}
+sub _rename_noreplace_racy ($$) {
+ my ($old, $new) = @_;
+ if (link($old, $new)) {
+ warn "unlink $old: $!\n" if !unlink($old) && $! != ENOENT;
+ 1
+ } else {
+ undef;
+ }
+}
+
+# TODO: support FD args?
+sub rename_noreplace ($$) {
+ my ($old, $new) = @_;
+ if ($SYS_renameat2) { # RENAME_NOREPLACE = 1, AT_FDCWD = -100
+ my $ret = syscall($SYS_renameat2, -100, $old, -100, $new, 1);
+ if ($ret == 0) {
+ 1; # like rename() perlop
+ } elsif ($! == ENOSYS || $! == EINVAL) {
+ undef $SYS_renameat2;
+ _rename_noreplace_racy($old, $new);
+ } else {
+ undef
+ }
+ } else {
+ _rename_noreplace_racy($old, $new);
+ }
+}
+
+sub nodatacow_fh {
+ return if !defined($SYS_fstatfs);
+ my $buf = '';
+ vec($buf, 120 * 8 - 1, 1) = 0;
+ my ($fh) = @_;
+ syscall($SYS_fstatfs, fileno($fh), $buf) == 0 or
+ return warn("fstatfs: $!\n");
+ my $f_type = unpack('l!', $buf); # statfs.f_type is a signed word
+ return if $f_type != 0x9123683E; # BTRFS_SUPER_MAGIC
+
+ $FS_IOC_GETFLAGS //
+ return warn('FS_IOC_GETFLAGS undefined for platform');
+ ioctl($fh, $FS_IOC_GETFLAGS, $buf) //
+ return warn("FS_IOC_GETFLAGS: $!\n");
+ my $attr = unpack('l!', $buf);
+ return if ($attr & 0x00800000); # FS_NOCOW_FL;
+ ioctl($fh, $FS_IOC_SETFLAGS, pack('l', $attr | 0x00800000)) //
+ warn("FS_IOC_SETFLAGS: $!\n");
+}
+
+sub nodatacow_dir {
+ if (open my $fh, '<', $_[0]) { nodatacow_fh($fh) }
+}
+
1;
=head1 WARRANTY