pkg/fileutil: use fcntl syscall wrappers from golang.org/x/sys/unix (#…

…12316)

Direct syscalls using syscall.Syscall(SYS_*, ...) should no longer be
used on darwin, see [1]. Instead, use the fcntl libSystem wrappers
provided by the golang.org/x/sys/unix package which implement the same
functionality.

[1] https://golang.org/doc/go1.12#darwin

bill-of-materials.json

@@ -369,7 +369,7 @@
 		]
 	},
 	{
-		"project": "golang.org/x/sys/unix",
+		"project": "golang.org/x/sys",
 		"licenses": [
 			{
 				"type": "BSD 3-clause \"New\" or \"Revised\" License",

go.mod

@@ -42,6 +42,7 @@ require (
 	go.uber.org/zap v1.15.0
 	golang.org/x/crypto v0.0.0-20191002192127-34f69633bfdc
 	golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7
+	golang.org/x/sys v0.0.0-20200918174421-af09f7315aff
 	golang.org/x/text v0.3.3 // indirect
 	golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2
 	google.golang.org/grpc v1.26.0

go.sum

@@ -185,6 +185,8 @@ golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5 h1:LfCXLvNmTYH9kEmVgqbnsWfruoXZIrh4YBgqVHtDvw0=
 golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200918174421-af09f7315aff h1:1CPUrky56AcgSpxz/KfgzQWzfG09u5YOL8MvPYBlrL8=
+golang.org/x/sys v0.0.0-20200918174421-af09f7315aff/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=

pkg/fileutil/preallocate_darwin.go

@@ -19,7 +19,8 @@ package fileutil
 import (
 	"os"
 	"syscall"
-	"unsafe"
+
+	"golang.org/x/sys/unix"
 )
 
 func preallocExtend(f *os.File, sizeInBytes int64) error {
@@ -32,18 +33,18 @@ func preallocExtend(f *os.File, sizeInBytes int64) error {
 func preallocFixed(f *os.File, sizeInBytes int64) error {
 	// allocate all requested space or no space at all
 	// TODO: allocate contiguous space on disk with F_ALLOCATECONTIG flag
-	fstore := &syscall.Fstore_t{
-		Flags:   syscall.F_ALLOCATEALL,
-		Posmode: syscall.F_PEOFPOSMODE,
-		Length:  sizeInBytes}
-	p := unsafe.Pointer(fstore)
-	_, _, errno := syscall.Syscall(syscall.SYS_FCNTL, f.Fd(), uintptr(syscall.F_PREALLOCATE), uintptr(p))
-	if errno == 0 || errno == syscall.ENOTSUP {
+	fstore := &unix.Fstore_t{
+		Flags:   unix.F_ALLOCATEALL,
+		Posmode: unix.F_PEOFPOSMODE,
+		Length:  sizeInBytes,
+	}
+	err := unix.FcntlFstore(f.Fd(), unix.F_PREALLOCATE, fstore)
+	if err == nil || err == unix.ENOTSUP {
 		return nil
 	}
 
 	// wrong argument to fallocate syscall
-	if errno == syscall.EINVAL {
+	if err == unix.EINVAL {
 		// filesystem "st_blocks" are allocated in the units of
 		// "Allocation Block Size" (run "diskutil info /" command)
 		var stat syscall.Stat_t
@@ -61,5 +62,5 @@ func preallocFixed(f *os.File, sizeInBytes int64) error {
 			return nil
 		}
 	}
-	return errno
+	return err
 }

pkg/fileutil/sync_darwin.go

@@ -18,19 +18,17 @@ package fileutil
 
 import (
 	"os"
-	"syscall"
+
+	"golang.org/x/sys/unix"
 )
 
 // Fsync on HFS/OSX flushes the data on to the physical drive but the drive
 // may not write it to the persistent media for quite sometime and it may be
 // written in out-of-order sequence. Using F_FULLFSYNC ensures that the
 // physical drive's buffer will also get flushed to the media.
 func Fsync(f *os.File) error {
-	_, _, errno := syscall.Syscall(syscall.SYS_FCNTL, f.Fd(), uintptr(syscall.F_FULLFSYNC), uintptr(0))
-	if errno == 0 {
-		return nil
-	}
-	return errno
+	_, err := unix.FcntlInt(f.Fd(), unix.F_FULLFSYNC, 0)
+	return err
 }
 
 // Fdatasync on darwin platform invokes fcntl(F_FULLFSYNC) for actual persistence