unix: add Statx on Linux

statx(2) allows to get enhanced file status information (not currently
available through the existing stat syscalls), lightweight stat,
heavyweight stat. The Statx_t type used by Statx has consistent field
sizes on all arches (with year-2038-capable timestamps) and is closer to
the BSD implementation of Stat_t.

See http://man7.org/linux/man-pages/man2/statx.2.html for details. The
syscall was added in Linux kernel 4.11.

See https://github.com/tklauser/statx for an example of how this
function and types can be used to report stat(1)-like file status
information.

Change-Id: I9e9642b5b42a393f94fd532453888ce9ba4f0003
Reviewed-on: https://go-review.googlesource.com/87555
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Tobias Klauser
2018-01-15 08:58:44 +00:00
committed by Tobias Klauser
parent 52ba35ddf9
commit fff93fa7cd
38 changed files with 952 additions and 37 deletions
+90
View File
@@ -314,6 +314,96 @@ func TestSchedSetaffinity(t *testing.T) {
}
}
func TestStatx(t *testing.T) {
var stx unix.Statx_t
err := unix.Statx(unix.AT_FDCWD, ".", 0, 0, &stx)
if err == unix.ENOSYS {
t.Skip("statx syscall is not available, skipping test")
} else if err != nil {
t.Fatalf("Statx: %v", err)
}
defer chtmpdir(t)()
touch(t, "file1")
var st unix.Stat_t
err = unix.Stat("file1", &st)
if err != nil {
t.Fatalf("Stat: %v", err)
}
flags := unix.AT_STATX_SYNC_AS_STAT
err = unix.Statx(unix.AT_FDCWD, "file1", flags, unix.STATX_ALL, &stx)
if err != nil {
t.Fatalf("Statx: %v", err)
}
if uint32(stx.Mode) != st.Mode {
t.Errorf("Statx: returned stat mode does not match Stat")
}
atime := unix.StatxTimestamp{Sec: int64(st.Atim.Sec), Nsec: uint32(st.Atim.Nsec)}
ctime := unix.StatxTimestamp{Sec: int64(st.Ctim.Sec), Nsec: uint32(st.Ctim.Nsec)}
mtime := unix.StatxTimestamp{Sec: int64(st.Mtim.Sec), Nsec: uint32(st.Mtim.Nsec)}
if stx.Atime != atime {
t.Errorf("Statx: returned stat atime does not match Stat")
}
if stx.Ctime != ctime {
t.Errorf("Statx: returned stat ctime does not match Stat")
}
if stx.Mtime != mtime {
t.Errorf("Statx: returned stat mtime does not match Stat")
}
err = os.Symlink("file1", "symlink1")
if err != nil {
t.Fatal(err)
}
err = unix.Lstat("symlink1", &st)
if err != nil {
t.Fatalf("Lstat: %v", err)
}
err = unix.Statx(unix.AT_FDCWD, "symlink1", flags, unix.STATX_BASIC_STATS, &stx)
if err != nil {
t.Fatalf("Statx: %v", err)
}
// follow symlink, expect a regulat file
if stx.Mode&unix.S_IFREG == 0 {
t.Errorf("Statx: didn't follow symlink")
}
err = unix.Statx(unix.AT_FDCWD, "symlink1", flags|unix.AT_SYMLINK_NOFOLLOW, unix.STATX_ALL, &stx)
if err != nil {
t.Fatalf("Statx: %v", err)
}
// follow symlink, expect a symlink
if stx.Mode&unix.S_IFLNK == 0 {
t.Errorf("Statx: unexpectedly followed symlink")
}
if uint32(stx.Mode) != st.Mode {
t.Errorf("Statx: returned stat mode does not match Lstat")
}
atime = unix.StatxTimestamp{Sec: int64(st.Atim.Sec), Nsec: uint32(st.Atim.Nsec)}
ctime = unix.StatxTimestamp{Sec: int64(st.Ctim.Sec), Nsec: uint32(st.Ctim.Nsec)}
mtime = unix.StatxTimestamp{Sec: int64(st.Mtim.Sec), Nsec: uint32(st.Mtim.Nsec)}
if stx.Atime != atime {
t.Errorf("Statx: returned stat atime does not match Lstat")
}
if stx.Ctime != ctime {
t.Errorf("Statx: returned stat ctime does not match Lstat")
}
if stx.Mtime != mtime {
t.Errorf("Statx: returned stat mtime does not match Lstat")
}
}
// utilities taken from os/os_test.go
func touch(t *testing.T, name string) {