unix: FreeBSD 12 ino64 support

Background: The 64-bit inode project was merged into the upcoming FreeBSD 12 release. It changes the ABI for structs holding inodes: stat, statfs, dirent. New system call numbers were introduced which accept the new struct layouts, the old ones were marked as COMPAT11. Their equivalent libc wrappers are using ELF symbol versioning. The new wrappers have moved from @FBSD_1.0 to @FBSD_1.5. Backward and forward compatability is achieved by always using the new struct layouts while converting the old struct instance to the new layout on old kernels. https://svnweb.freebsd.org/base?view=revision&revision=318736 https://svnweb.freebsd.org/base?view=revision&revision=320278 The same approach is used for Go: The new Stat_t, Statfs_t and Dirent types hold 64-bit inodes and additional ABI changes, they are generated from their C definitions in FreeBSD-12 using cgo -godefs. Each type has an unexported *_freebsd11 counterpart generated the same way. Previous directly exposed syscalls like Fstat have now a wrapper in place calling either fstat or fstat_freebsd12 zsyscall wrapper based on the kern.osreldate. If an old syscall needs to be used, then the returned *_freebsd11 result is converted to the new layout before returning from the wrapper. Introduce supportsABI() call to check the kern.osreldate sysctl for the ABI version. Drop the old struct stat8 definition in favour of the <sys/stat.h> version. Run the mktypes part of GOOS=freebsd GOARCH={386,amd64,arm} ./mkall.sh on FreeBSD-12.0-ALPHA6 (r338675), updating all types except Kevent. Expose Mknodat, both COMPAT11 version (currently missing) and the FreeBSD 12 one. Some COMPAT11 syscalls have no direct FreeBSD 12 counterpart, in those cases an *at(AT_FDCWD, ...) is used instead. Updates golang/go#22448 Change-Id: I87940b88ae358db88103cdcd06f9cafbf4694cfc Reviewed-on: https://go-review.googlesource.com/c/136816 Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Giovanni Bajo <rasky@develer.com> Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
2026-09-02 15:17:31 -04:00 · 2018-10-22 06:42:59 +00:00
parent eda9bb28ed
commit 5535b4e6bf
8 changed files with 1086 additions and 400 deletions
@@ -13,9 +13,34 @@
 package unix

 import (
+	"sync"
 	"unsafe"
 )

+const (
+	SYS_FSTAT_FREEBSD12         = 551 // { int fstat(int fd, _Out_ struct stat *sb); }
+	SYS_FSTATAT_FREEBSD12       = 552 // { int fstatat(int fd, _In_z_ char *path, \
+	SYS_GETDIRENTRIES_FREEBSD12 = 554 // { ssize_t getdirentries(int fd, \
+	SYS_STATFS_FREEBSD12        = 555 // { int statfs(_In_z_ char *path, \
+	SYS_FSTATFS_FREEBSD12       = 556 // { int fstatfs(int fd, \
+	SYS_GETFSSTAT_FREEBSD12     = 557 // { int getfsstat( \
+	SYS_MKNODAT_FREEBSD12       = 559 // { int mknodat(int fd, _In_z_ char *path, \
+)
+
+// See https://www.freebsd.org/doc/en_US.ISO8859-1/books/porters-handbook/versions.html.
+var (
+	osreldateOnce sync.Once
+	osreldate     uint32
+)
+
+// INO64_FIRST from /usr/src/lib/libc/sys/compat-ino64.h
+const _ino64First = 1200031
+
+func supportsABI(ver uint32) bool {
+	osreldateOnce.Do(func() { osreldate, _ = SysctlUint32("kern.osreldate") })
+	return osreldate >= ver
+}
+
 // SockaddrDatalink implements the Sockaddr interface for AF_LINK type sockets.
 type SockaddrDatalink struct {
 	Len    uint8
@@ -121,17 +146,39 @@ func Getwd() (string, error) {
 }

 func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
-	var _p0 unsafe.Pointer
-	var bufsize uintptr
+	var (
+		_p0          unsafe.Pointer
+		bufsize      uintptr
+		oldBuf       []statfs_freebsd11_t
+		needsConvert bool
+	)
+
 	if len(buf) > 0 {
-		_p0 = unsafe.Pointer(&buf[0])
-		bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))
+		if supportsABI(_ino64First) {
+			_p0 = unsafe.Pointer(&buf[0])
+			bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))
+		} else {
+			n := len(buf)
+			oldBuf = make([]statfs_freebsd11_t, n)
+			_p0 = unsafe.Pointer(&oldBuf[0])
+			bufsize = unsafe.Sizeof(statfs_freebsd11_t{}) * uintptr(n)
+			needsConvert = true
+		}
 	}
-	r0, _, e1 := Syscall(SYS_GETFSSTAT, uintptr(_p0), bufsize, uintptr(flags))
+	var sysno uintptr = SYS_GETFSSTAT
+	if supportsABI(_ino64First) {
+		sysno = SYS_GETFSSTAT_FREEBSD12
+	}
+	r0, _, e1 := Syscall(sysno, uintptr(_p0), bufsize, uintptr(flags))
 	n = int(r0)
 	if e1 != 0 {
 		err = e1
 	}
+	if e1 == 0 && needsConvert {
+		for i := range oldBuf {
+			buf[i].convertFrom(&oldBuf[i])
+		}
+	}
 	return
 }

@@ -225,6 +272,234 @@ func Uname(uname *Utsname) error {
 	return nil
 }

+func Stat(path string, st *Stat_t) (err error) {
+	var oldStat stat_freebsd11_t
+	if supportsABI(_ino64First) {
+		return fstatat_freebsd12(AT_FDCWD, path, st, 0)
+	}
+	err = stat(path, &oldStat)
+	if err != nil {
+		return err
+	}
+
+	st.convertFrom(&oldStat)
+	return nil
+}
+
+func Lstat(path string, st *Stat_t) (err error) {
+	var oldStat stat_freebsd11_t
+	if supportsABI(_ino64First) {
+		return fstatat_freebsd12(AT_FDCWD, path, st, AT_SYMLINK_NOFOLLOW)
+	}
+	err = lstat(path, &oldStat)
+	if err != nil {
+		return err
+	}
+
+	st.convertFrom(&oldStat)
+	return nil
+}
+
+func Fstat(fd int, st *Stat_t) (err error) {
+	var oldStat stat_freebsd11_t
+	if supportsABI(_ino64First) {
+		return fstat_freebsd12(fd, st)
+	}
+	err = fstat(fd, &oldStat)
+	if err != nil {
+		return err
+	}
+
+	st.convertFrom(&oldStat)
+	return nil
+}
+
+func Fstatat(fd int, path string, st *Stat_t, flags int) (err error) {
+	var oldStat stat_freebsd11_t
+	if supportsABI(_ino64First) {
+		return fstatat_freebsd12(fd, path, st, flags)
+	}
+	err = fstatat(fd, path, &oldStat, flags)
+	if err != nil {
+		return err
+	}
+
+	st.convertFrom(&oldStat)
+	return nil
+}
+
+func Statfs(path string, st *Statfs_t) (err error) {
+	var oldStatfs statfs_freebsd11_t
+	if supportsABI(_ino64First) {
+		return statfs_freebsd12(path, st)
+	}
+	err = statfs(path, &oldStatfs)
+	if err != nil {
+		return err
+	}
+
+	st.convertFrom(&oldStatfs)
+	return nil
+}
+
+func Fstatfs(fd int, st *Statfs_t) (err error) {
+	var oldStatfs statfs_freebsd11_t
+	if supportsABI(_ino64First) {
+		return fstatfs_freebsd12(fd, st)
+	}
+	err = fstatfs(fd, &oldStatfs)
+	if err != nil {
+		return err
+	}
+
+	st.convertFrom(&oldStatfs)
+	return nil
+}
+
+func Getdents(fd int, buf []byte) (n int, err error) {
+	return Getdirentries(fd, buf, nil)
+}
+
+func Getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error) {
+	if supportsABI(_ino64First) {
+		return getdirentries_freebsd12(fd, buf, basep)
+	}
+
+	// The old syscall entries are smaller than the new. Use 1/4 of the original
+	// buffer size rounded up to DIRBLKSIZ (see /usr/src/lib/libc/sys/getdirentries.c).
+	oldBufLen := roundup(len(buf)/4, _dirblksiz)
+	oldBuf := make([]byte, oldBufLen)
+	n, err = getdirentries(fd, oldBuf, basep)
+	if err == nil && n > 0 {
+		n = convertFromDirents11(buf, oldBuf[:n])
+	}
+	return
+}
+
+func Mknod(path string, mode uint32, dev uint64) (err error) {
+	var oldDev int
+	if supportsABI(_ino64First) {
+		return mknodat_freebsd12(AT_FDCWD, path, mode, dev)
+	}
+	oldDev = int(dev)
+	return mknod(path, mode, oldDev)
+}
+
+func Mknodat(fd int, path string, mode uint32, dev uint64) (err error) {
+	var oldDev int
+	if supportsABI(_ino64First) {
+		return mknodat_freebsd12(fd, path, mode, dev)
+	}
+	oldDev = int(dev)
+	return mknodat(fd, path, mode, oldDev)
+}
+
+// round x to the nearest multiple of y, larger or equal to x.
+//
+// from /usr/include/sys/param.h Macros for counting and rounding.
+// #define roundup(x, y)   ((((x)+((y)-1))/(y))*(y))
+func roundup(x, y int) int {
+	return ((x + y - 1) / y) * y
+}
+
+func (s *Stat_t) convertFrom(old *stat_freebsd11_t) {
+	*s = Stat_t{
+		Dev:      uint64(old.Dev),
+		Ino:      uint64(old.Ino),
+		Nlink:    uint64(old.Nlink),
+		Mode:     old.Mode,
+		Uid:      old.Uid,
+		Gid:      old.Gid,
+		Rdev:     uint64(old.Rdev),
+		Atim:     old.Atim,
+		Mtim:     old.Mtim,
+		Ctim:     old.Ctim,
+		Birthtim: old.Birthtim,
+		Size:     old.Size,
+		Blocks:   old.Blocks,
+		Blksize:  old.Blksize,
+		Flags:    old.Flags,
+		Gen:      uint64(old.Gen),
+	}
+}
+
+func (s *Statfs_t) convertFrom(old *statfs_freebsd11_t) {
+	*s = Statfs_t{
+		Version:     _statfsVersion,
+		Type:        old.Type,
+		Flags:       old.Flags,
+		Bsize:       old.Bsize,
+		Iosize:      old.Iosize,
+		Blocks:      old.Blocks,
+		Bfree:       old.Bfree,
+		Bavail:      old.Bavail,
+		Files:       old.Files,
+		Ffree:       old.Ffree,
+		Syncwrites:  old.Syncwrites,
+		Asyncwrites: old.Asyncwrites,
+		Syncreads:   old.Syncreads,
+		Asyncreads:  old.Asyncreads,
+		// Spare
+		Namemax: old.Namemax,
+		Owner:   old.Owner,
+		Fsid:    old.Fsid,
+		// Charspare
+		// Fstypename
+		// Mntfromname
+		// Mntonname
+	}
+
+	sl := old.Fstypename[:]
+	n := clen(*(*[]byte)(unsafe.Pointer(&sl)))
+	copy(s.Fstypename[:], old.Fstypename[:n])
+
+	sl = old.Mntfromname[:]
+	n = clen(*(*[]byte)(unsafe.Pointer(&sl)))
+	copy(s.Mntfromname[:], old.Mntfromname[:n])
+
+	sl = old.Mntonname[:]
+	n = clen(*(*[]byte)(unsafe.Pointer(&sl)))
+	copy(s.Mntonname[:], old.Mntonname[:n])
+}
+
+func convertFromDirents11(buf []byte, old []byte) int {
+	const (
+		fixedSize    = int(unsafe.Offsetof(Dirent{}.Name))
+		oldFixedSize = int(unsafe.Offsetof(dirent_freebsd11{}.Name))
+	)
+
+	dstPos := 0
+	srcPos := 0
+	for dstPos+fixedSize < len(buf) && srcPos+oldFixedSize < len(old) {
+		dstDirent := (*Dirent)(unsafe.Pointer(&buf[dstPos]))
+		srcDirent := (*dirent_freebsd11)(unsafe.Pointer(&old[srcPos]))
+
+		reclen := roundup(fixedSize+int(srcDirent.Namlen)+1, 8)
+		if dstPos+reclen > len(buf) {
+			break
+		}
+
+		dstDirent.Fileno = uint64(srcDirent.Fileno)
+		dstDirent.Off = 0
+		dstDirent.Reclen = uint16(reclen)
+		dstDirent.Type = srcDirent.Type
+		dstDirent.Pad0 = 0
+		dstDirent.Namlen = uint16(srcDirent.Namlen)
+		dstDirent.Pad1 = 0
+
+		copy(dstDirent.Name[:], srcDirent.Name[:srcDirent.Namlen])
+		padding := buf[dstPos+fixedSize+int(dstDirent.Namlen) : dstPos+reclen]
+		for i := range padding {
+			padding[i] = 0
+		}
+
+		dstPos += int(dstDirent.Reclen)
+		srcPos += int(srcDirent.Reclen)
+	}
+
+	return dstPos
+}
+
 /*
 * Exposed directly
 */
@@ -264,13 +539,16 @@ func Uname(uname *Utsname) error {
 //sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
 //sys	Flock(fd int, how int) (err error)
 //sys	Fpathconf(fd int, name int) (val int, err error)
-//sys	Fstat(fd int, stat *Stat_t) (err error)
-//sys	Fstatat(fd int, path string, stat *Stat_t, flags int) (err error)
-//sys	Fstatfs(fd int, stat *Statfs_t) (err error)
+//sys	fstat(fd int, stat *stat_freebsd11_t) (err error)
+//sys	fstat_freebsd12(fd int, stat *Stat_t) (err error)
+//sys	fstatat(fd int, path string, stat *stat_freebsd11_t, flags int) (err error)
+//sys	fstatat_freebsd12(fd int, path string, stat *Stat_t, flags int) (err error)
+//sys	fstatfs(fd int, stat *statfs_freebsd11_t) (err error)
+//sys	fstatfs_freebsd12(fd int, stat *Statfs_t) (err error)
 //sys	Fsync(fd int) (err error)
 //sys	Ftruncate(fd int, length int64) (err error)
-//sys	Getdents(fd int, buf []byte) (n int, err error)
-//sys	Getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error)
+//sys	getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error)
+//sys	getdirentries_freebsd12(fd int, buf []byte, basep *uintptr) (n int, err error)
 //sys	Getdtablesize() (size int)
 //sysnb	Getegid() (egid int)
 //sysnb	Geteuid() (uid int)
@@ -292,11 +570,13 @@ func Uname(uname *Utsname) error {
 //sys	Link(path string, link string) (err error)
 //sys	Linkat(pathfd int, path string, linkfd int, link string, flags int) (err error)
 //sys	Listen(s int, backlog int) (err error)
-//sys	Lstat(path string, stat *Stat_t) (err error)
+//sys	lstat(path string, stat *stat_freebsd11_t) (err error)
 //sys	Mkdir(path string, mode uint32) (err error)
 //sys	Mkdirat(dirfd int, path string, mode uint32) (err error)
 //sys	Mkfifo(path string, mode uint32) (err error)
-//sys	Mknod(path string, mode uint32, dev int) (err error)
+//sys	mknod(path string, mode uint32, dev int) (err error)
+//sys	mknodat(fd int, path string, mode uint32, dev int) (err error)
+//sys	mknodat_freebsd12(fd int, path string, mode uint32, dev uint64) (err error)
 //sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
 //sys	Open(path string, mode int, perm uint32) (fd int, err error)
 //sys	Openat(fdat int, path string, mode int, perm uint32) (fd int, err error)
@@ -326,8 +606,9 @@ func Uname(uname *Utsname) error {
 //sysnb	Setsid() (pid int, err error)
 //sysnb	Settimeofday(tp *Timeval) (err error)
 //sysnb	Setuid(uid int) (err error)
-//sys	Stat(path string, stat *Stat_t) (err error)
-//sys	Statfs(path string, stat *Statfs_t) (err error)
+//sys	stat(path string, stat *stat_freebsd11_t) (err error)
+//sys	statfs(path string, stat *statfs_freebsd11_t) (err error)
+//sys	statfs_freebsd12(path string, stat *Statfs_t) (err error)
 //sys	Symlink(path string, link string) (err error)
 //sys	Symlinkat(oldpath string, newdirfd int, newpath string) (err error)
 //sys	Sync() (err error)
@@ -382,6 +663,7 @@ func Uname(uname *Utsname) error {
 // Kqueue_portset
 // Getattrlist
 // Setattrlist
+// Getdents
 // Getdirentriesattr
 // Searchfs
 // Delete