From 760c225c3831a9164f11ddf9d5318ad6c3f84bb8 Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Tue, 1 Feb 2022 01:27:50 +0000
Subject: syscall: FS_IOC_*FLAGS: define on per-architecture basis

It turns out these Linux ioctls are unfortunately
architecture-dependent, and not endian-dependent.
Fixup some warning messages while we're at it, too.

Fixes: 14fa0abdcc7b6513 ("rewrite Linux nodatacow use in pure Perl w/o system")
Link: https://public-inbox.org/meta/YfdYqLhDVQRQ9NGT@codewreck.org/
Noticed-by: Dominique Martinet <asmadeus@codewreck.org>
---
 lib/PublicInbox/Syscall.pm | 35 +++++++++++++++++++++++------------
 1 file changed, 23 insertions(+), 12 deletions(-)

(limited to 'lib/PublicInbox/Syscall.pm')

diff --git a/lib/PublicInbox/Syscall.pm b/lib/PublicInbox/Syscall.pm
index 2e3d9cb3..a2b7490a 100644
--- a/lib/PublicInbox/Syscall.pm
+++ b/lib/PublicInbox/Syscall.pm
@@ -69,6 +69,7 @@ our (
      );
 
 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
 our $no_deprecated = 0;
 
@@ -98,6 +99,8 @@ if ($^O eq "linux") {
         $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;
         $SYS_epoll_ctl    = 233;
@@ -105,6 +108,8 @@ if ($^O eq "linux") {
         $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;
         $SYS_epoll_ctl = 1073742057;
@@ -112,6 +117,8 @@ if ($^O eq "linux") {
         $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;
 	$SYS_epoll_ctl = 194;
@@ -121,6 +128,8 @@ if ($^O eq "linux") {
 	$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;
         $SYS_epoll_ctl    = 225;
@@ -135,6 +144,8 @@ if ($^O eq "linux") {
         $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;
         $SYS_epoll_ctl    = 237;
@@ -143,6 +154,8 @@ if ($^O eq "linux") {
         $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;
         $SYS_epoll_ctl    = 250;
@@ -174,6 +187,8 @@ if ($^O eq "linux") {
         $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
         $SYS_epoll_create = 250;
@@ -191,6 +206,8 @@ if ($^O eq "linux") {
         $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;
         $SYS_epoll_ctl    = 4249;
@@ -199,6 +216,8 @@ if ($^O eq "linux") {
         $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
@@ -345,22 +364,14 @@ sub nodatacow_fh {
 	my $f_type = unpack('l!', $buf); # statfs.f_type is a signed word
 	return if $f_type != 0x9123683E; # BTRFS_SUPER_MAGIC
 
-	state ($FS_IOC_GETFLAGS, $FS_IOC_SETFLAGS);
-	unless (defined $FS_IOC_GETFLAGS) {
-		if (substr($Config{byteorder}, 0, 4) eq '1234') {
-			$FS_IOC_GETFLAGS = 0x80086601;
-			$FS_IOC_SETFLAGS = 0x40086602;
-		} else { # Big endian
-			$FS_IOC_GETFLAGS = 0x40086601;
-			$FS_IOC_SETFLAGS = 0x80086602;
-		}
-	}
+	$FS_IOC_GETFLAGS //
+		return warn('FS_IOC_GETFLAGS undefined for platform');
 	ioctl($fh, $FS_IOC_GETFLAGS, $buf) //
-		return warn("FS_IOC_GET_FLAGS: $!\n");
+		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_SET_FLAGS: $!\n");
+		warn("FS_IOC_SETFLAGS: $!\n");
 }
 
 sub nodatacow_dir {
-- 
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