unix: Added posix_fadvise support for Linux and FreeBSD

Support includes 386, amd64, and arm for both Linux and FreeBSD.
FreeBSD changes courtesy Dave Chapeskie <dchapeskie@gmail.com>

Change-Id: I89dc18533d7178e74ae6c442a2e6272c9bd9692c
Reviewed-on: https://go-review.googlesource.com/8055Reviewed-by: Rob Pike <r@golang.org>

unix/syscall_freebsd.go

@@ -394,6 +394,7 @@ func Llistxattr(link string, dest []byte) (sz int, err error) {
 //sys	ExtattrSetLink(link string, attrnamespace int, attrname string, data uintptr, nbytes int) (ret int, err error)
 //sys	ExtattrDeleteLink(link string, attrnamespace int, attrname string) (err error)
 //sys	ExtattrListLink(link string, attrnamespace int, data uintptr, nbytes int) (ret int, err error)
+//sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_POSIX_FADVISE
 //sys	Fchdir(fd int) (err error)
 //sys	Fchflags(fd int, flags int) (err error)
 //sys	Fchmod(fd int, mode uint32) (err error)

unix/syscall_linux.go

@@ -799,6 +799,7 @@ func Mount(source string, target string, fstype string, flags uintptr, data stri
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Exit(code int) = SYS_EXIT_GROUP
 //sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
+//sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fallocate(fd int, mode uint32, off int64, len int64) (err error)
 //sys	Fchdir(fd int) (err error)
 //sys	Fchmod(fd int, mode uint32) (err error)
@@ -930,7 +931,6 @@ func Munmap(b []byte) (err error) {
 // EpollWaitOld
 // Eventfd
 // Execve
-// Fadvise64
 // Fgetxattr
 // Flistxattr
 // Fork

unix/syscall_linux_386.go

@@ -34,6 +34,7 @@ func NsecToTimeval(nsec int64) (tv Timeval) {
 // 64-bit file system and 32-bit uid calls
 // (386 default is 32-bit file system and 16-bit uid).
 //sys	Chown(path string, uid int, gid int) (err error) = SYS_CHOWN32
+//sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64_64
 //sys	Fchown(fd int, uid int, gid int) (err error) = SYS_FCHOWN32
 //sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64
 //sys	Ftruncate(fd int, length int64) (err error) = SYS_FTRUNCATE64

unix/syscall_linux_arm.go

@@ -86,6 +86,7 @@ func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
 //sys   Pread(fd int, p []byte, offset int64) (n int, err error) = SYS_PREAD64
 //sys   Pwrite(fd int, p []byte, offset int64) (n int, err error) = SYS_PWRITE64
 //sys	Truncate(path string, length int64) (err error) = SYS_TRUNCATE64
+//sys	Fadvise(fd int, advice int64, offset int64, length int) = SYS_FADVISE64
 //sys	Ftruncate(fd int, length int64) (err error) = SYS_FTRUNCATE64
 
 //sys	mmap2(addr uintptr, length uintptr, prot int, flags int, fd int, pageOffset uintptr) (xaddr uintptr, err error)

unix/types_freebsd.go

@@ -210,6 +210,17 @@ type Dirent C.struct_dirent
 
 type Fsid C.struct_fsid
 
+// Advice to Fadvise
+
+const (
+	FADV_NORMAL     = C.POSIX_FADV_NORMAL
+	FADV_RANDOM     = C.POSIX_FADV_RANDOM
+	FADV_SEQUENTIAL = C.POSIX_FADV_SEQUENTIAL
+	FADV_WILLNEED   = C.POSIX_FADV_WILLNEED
+	FADV_DONTNEED   = C.POSIX_FADV_DONTNEED
+	FADV_NOREUSE    = C.POSIX_FADV_NOREUSE
+)
+
 // Sockets
 
 type RawSockaddrInet4 C.struct_sockaddr_in

unix/types_linux.go

@@ -160,6 +160,17 @@ type Fsid C.fsid_t
 
 type Flock_t C.struct_flock
 
+// Advice to Fadvise
+
+const (
+	FADV_NORMAL     = C.POSIX_FADV_NORMAL
+	FADV_RANDOM     = C.POSIX_FADV_RANDOM
+	FADV_SEQUENTIAL = C.POSIX_FADV_SEQUENTIAL
+	FADV_WILLNEED   = C.POSIX_FADV_WILLNEED
+	FADV_DONTNEED   = C.POSIX_FADV_DONTNEED
+	FADV_NOREUSE    = C.POSIX_FADV_NOREUSE
+)
+
 // Sockets
 
 type RawSockaddrInet4 C.struct_sockaddr_in

unix/zsyscall_freebsd_386.go

@@ -652,6 +652,16 @@ func ExtattrListLink(link string, attrnamespace int, data uintptr, nbytes int) (
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall6(SYS_POSIX_FADVISE, uintptr(fd), uintptr(offset), uintptr(offset>>32), uintptr(length), uintptr(length>>32), uintptr(advice))
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fchdir(fd int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHDIR, uintptr(fd), 0, 0)
 	if e1 != 0 {

unix/zsyscall_freebsd_amd64.go

@@ -652,6 +652,16 @@ func ExtattrListLink(link string, attrnamespace int, data uintptr, nbytes int) (
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall6(SYS_POSIX_FADVISE, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fchdir(fd int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHDIR, uintptr(fd), 0, 0)
 	if e1 != 0 {

unix/zsyscall_freebsd_arm.go

@@ -652,6 +652,16 @@ func ExtattrListLink(link string, attrnamespace int, data uintptr, nbytes int) (
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall9(SYS_POSIX_FADVISE, uintptr(fd), 0, uintptr(offset), uintptr(offset>>32), uintptr(length), uintptr(length>>32), uintptr(advice), 0, 0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fchdir(fd int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHDIR, uintptr(fd), 0, 0)
 	if e1 != 0 {

unix/zsyscall_linux_386.go

@@ -411,6 +411,16 @@ func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(offset>>32), uintptr(length), uintptr(length>>32), uintptr(advice))
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(off>>32), uintptr(len), uintptr(len>>32))
 	if e1 != 0 {
@@ -1409,6 +1419,16 @@ func Chown(path string, uid int, gid int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall6(SYS_FADVISE64_64, uintptr(fd), uintptr(offset), uintptr(offset>>32), uintptr(length), uintptr(length>>32), uintptr(advice))
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fchown(fd int, uid int, gid int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHOWN32, uintptr(fd), uintptr(uid), uintptr(gid))
 	if e1 != 0 {

unix/zsyscall_linux_amd64.go

@@ -411,6 +411,16 @@ func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall6(SYS_FADVISE64, uintptr(fd), uintptr(offset), uintptr(length), uintptr(advice), 0, 0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(len), 0, 0)
 	if e1 != 0 {

unix/zsyscall_linux_arm.go

@@ -411,6 +411,16 @@ func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall9(SYS_FADVISE64, uintptr(fd), 0, uintptr(offset), uintptr(offset>>32), uintptr(length), uintptr(length>>32), uintptr(advice), 0, 0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(off>>32), uintptr(len), uintptr(len>>32))
 	if e1 != 0 {
@@ -1872,6 +1882,13 @@ func Truncate(path string, length int64) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, advice int64, offset int64, length int) {
+	Syscall9(SYS_FADVISE64, uintptr(fd), 0, uintptr(advice), uintptr(advice>>32), uintptr(offset), uintptr(offset>>32), uintptr(length), 0, 0)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Ftruncate(fd int, length int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FTRUNCATE64, uintptr(fd), 0, uintptr(length), uintptr(length>>32), 0, 0)
 	if e1 != 0 {