motiejus/zig
1
Fork 0
Code Releases Activity

std: Make copy_file_range checks run at compile-time

Browse Source 
* Avoid emitting the copy_file_range symbol at all to prevent link-time
  errors.
* Fix a bug in the check logic, the has_copy_file_range_syscall was
  set to the wrong value in case of ENOSYS
* If link_libc is true don't fall-back to the raw syscall approach,
  there's no policy about what to do in this case but let's follow what
  the other impls do.

Fixes #9146
This commit is contained in:
LemonBoy
2021-06-18 10:27:37 +02:00
committed by Andrew Kelley
parent c7dd3cc535
commit b72d55ea5f
1 changed files with 9 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
lib/std/os.zig
View File

@@ -5532,10 +5532,7 @@ pub const CopyFileRangeError = error{
FileBusy,
} || PReadError || PWriteError || UnexpectedError;
var has_copy_file_range_syscall = init: {
const kernel_has_syscall = std.Target.current.os.isAtLeast(.linux, .{ .major = 4, .minor = 5 }) orelse true;
break :init std.atomic.Atomic(bool).init(kernel_has_syscall);
};
var has_copy_file_range_syscall = std.atomic.Atomic(bool).init(true);
/// Transfer data between file descriptors at specified offsets.
/// Returns the number of bytes written, which can less than requested.
@@ -5563,18 +5560,17 @@ var has_copy_file_range_syscall = init: {
///
/// Maximum offsets on Linux are `math.maxInt(i64)`.
pub fn copy_file_range(fd_in: fd_t, off_in: u64, fd_out: fd_t, off_out: u64, len: usize, flags: u32) CopyFileRangeError!usize {
const use_c = std.c.versionCheck(.{ .major = 2, .minor = 27, .patch = 0 }).ok;
if (std.Target.current.os.tag == .linux and
(use_c or has_copy_file_range_syscall.load(.Monotonic)))
{
const sys = if (use_c) std.c else linux;
const call_cfr = comptime if (builtin.link_libc)
std.c.versionCheck(.{ .major = 2, .minor = 27, .patch = 0 }).ok
else
std.Target.current.os.isAtLeast(.linux, .{ .major = 4, .minor = 5 }) orelse true;
if (call_cfr and has_copy_file_range_syscall.load(.Monotonic)) {
var off_in_copy = @bitCast(i64, off_in);
var off_out_copy = @bitCast(i64, off_out);
const rc = sys.copy_file_range(fd_in, &off_in_copy, fd_out, &off_out_copy, len, flags);
switch (sys.getErrno(rc)) {
const rc = system.copy_file_range(fd_in, &off_in_copy, fd_out, &off_out_copy, len, flags);
switch (system.getErrno(rc)) {
0 => return @intCast(usize, rc),
EBADF => return error.FilesOpenedWithWrongFlags,
EFBIG => return error.FileTooBig,
@@ -5591,7 +5587,7 @@ pub fn copy_file_range(fd_in: fd_t, off_in: u64, fd_out: fd_t, off_out: u64, len
EXDEV => {},
// syscall added in Linux 4.5, use fallback
ENOSYS => {
has_copy_file_range_syscall.store(true, .Monotonic);
has_copy_file_range_syscall.store(false, .Monotonic);
},
else => |err| return unexpectedErrno(err),
}