diff options
Diffstat (limited to 'lib/PublicInbox/Syscall.pm')
| -rw-r--r-- | lib/PublicInbox/Syscall.pm | 49 |
1 files changed, 46 insertions, 3 deletions
diff --git a/lib/PublicInbox/Syscall.pm b/lib/PublicInbox/Syscall.pm index 7ab42911..c00385b9 100644 --- a/lib/PublicInbox/Syscall.pm +++ b/lib/PublicInbox/Syscall.pm @@ -13,8 +13,9 @@ # 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 O_NONBLOCK); use Config; # $VERSION = '0.25'; # Sys::Syscall version @@ -22,7 +23,7 @@ our @EXPORT_OK = qw(epoll_ctl epoll_create epoll_wait EPOLLIN EPOLLOUT EPOLLET EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD EPOLLONESHOT EPOLLEXCLUSIVE - signalfd); + 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 @@ -64,13 +65,16 @@ our ( $SYS_epoll_ctl, $SYS_epoll_wait, $SYS_signalfd4, + $SYS_renameat2, ); my $SFD_CLOEXEC = 02000000; # Perl does not expose O_CLOEXEC 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 $u64_mod_8 = 0; @@ -91,22 +95,26 @@ if ($^O eq "linux") { $SYS_epoll_ctl = 255; $SYS_epoll_wait = 256; $SYS_signalfd4 = 327; + $SYS_renameat2 //= 353; } elsif ($machine eq "x86_64") { $SYS_epoll_create = 213; $SYS_epoll_ctl = 233; $SYS_epoll_wait = 232; $SYS_signalfd4 = 289; + $SYS_renameat2 //= 316; } elsif ($machine eq 'x32') { $SYS_epoll_create = 1073742037; $SYS_epoll_ctl = 1073742057; $SYS_epoll_wait = 1073742056; $SYS_signalfd4 = 1073742113; + $SYS_renameat2 //= 0x40000000 + 316; } elsif ($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; $SFD_CLOEXEC = 020000000; } elsif ($machine =~ m/^parisc/) { $SYS_epoll_create = 224; @@ -120,18 +128,21 @@ if ($^O eq "linux") { $SYS_epoll_wait = 238; $u64_mod_8 = 1; $SYS_signalfd4 = 313; + $SYS_renameat2 //= 357; } elsif ($machine eq "ppc") { $SYS_epoll_create = 236; $SYS_epoll_ctl = 237; $SYS_epoll_wait = 238; $u64_mod_8 = 1; $SYS_signalfd4 = 313; + $SYS_renameat2 //= 357; } elsif ($machine =~ m/^s390/) { $SYS_epoll_create = 249; $SYS_epoll_ctl = 250; $SYS_epoll_wait = 251; $u64_mod_8 = 1; $SYS_signalfd4 = 322; + $SYS_renameat2 //= 347; } elsif ($machine eq "ia64") { $SYS_epoll_create = 1243; $SYS_epoll_ctl = 1244; @@ -153,6 +164,7 @@ if ($^O eq "linux") { $u64_mod_8 = 1; $no_deprecated = 1; $SYS_signalfd4 = 74; + $SYS_renameat2 //= 276; } elsif ($machine =~ m/arm(v\d+)?.*l/) { # ARM OABI $SYS_epoll_create = 250; @@ -160,18 +172,21 @@ if ($^O eq "linux") { $SYS_epoll_wait = 252; $u64_mod_8 = 1; $SYS_signalfd4 = 355; + $SYS_renameat2 //= 382; } elsif ($machine =~ m/^mips64/) { $SYS_epoll_create = 5207; $SYS_epoll_ctl = 5208; $SYS_epoll_wait = 5209; $u64_mod_8 = 1; $SYS_signalfd4 = 5283; + $SYS_renameat2 //= 5311; } elsif ($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; } else { # as a last resort, try using the *.ph files which may not # exist or may be wrong @@ -280,6 +295,34 @@ sub signalfd ($$) { } } +sub _rename_noreplace_racy ($$) { + 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) { + undef $SYS_renameat2; + _rename_noreplace_racy($old, $new); + } else { + undef + } + } else { + _rename_noreplace_racy($old, $new); + } +} + 1; =head1 WARRANTY |