Solaris OFD locks.

This commit is contained in:
Nuno Cruces
2023-02-08 12:10:17 +00:00
parent 927e5d94ac
commit f0a14030e5
2 changed files with 51 additions and 53 deletions

View File

@@ -9,7 +9,7 @@ import (
func Test_vfsLock(t *testing.T) {
switch runtime.GOOS {
case "linux", "darwin":
case "linux", "darwin", "solaris":
//
default:
t.Skip()

View File

@@ -14,66 +14,38 @@ func deleteOnClose(f *os.File) {
func (l *vfsFileLocker) GetShared() xErrorCode {
// A PENDING lock is needed before acquiring a SHARED lock.
if err := l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_RDLCK,
Start: _PENDING_BYTE,
Len: 1,
}); err != nil {
return l.errorCode(err, IOERR_LOCK)
if rc := l.readLock(_PENDING_BYTE, 1); rc != _OK {
return rc
}
// Acquire the SHARED lock.
rc := l.errorCode(l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_RDLCK,
Start: _SHARED_FIRST,
Len: _SHARED_SIZE,
}), IOERR_LOCK)
rc := l.readLock(_SHARED_FIRST, _SHARED_SIZE)
// Drop the temporary PENDING lock.
if err := l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_UNLCK,
Start: _PENDING_BYTE,
Len: 1,
}); rc == _OK && err != nil {
return IOERR_UNLOCK
if rc2 := l.unlock(_PENDING_BYTE, 1); rc == _OK {
return rc2
}
return rc
}
func (l *vfsFileLocker) GetReserved() xErrorCode {
// Acquire the RESERVED lock.
return l.errorCode(l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_WRLCK,
Start: _RESERVED_BYTE,
Len: 1,
}), IOERR_LOCK)
return l.writeLock(_RESERVED_BYTE, 1)
}
func (l *vfsFileLocker) GetPending() xErrorCode {
// Acquire the PENDING lock.
return l.errorCode(l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_WRLCK,
Start: _PENDING_BYTE,
Len: 1,
}), IOERR_LOCK)
return l.writeLock(_PENDING_BYTE, 1)
}
func (l *vfsFileLocker) GetExclusive() xErrorCode {
// Acquire the EXCLUSIVE lock.
return l.errorCode(l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_WRLCK,
Start: _SHARED_FIRST,
Len: _SHARED_SIZE,
}), IOERR_LOCK)
return l.writeLock(_SHARED_FIRST, _SHARED_SIZE)
}
func (l *vfsFileLocker) Downgrade() xErrorCode {
// Downgrade to a SHARED lock.
if err := l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_RDLCK,
Start: _SHARED_FIRST,
Len: _SHARED_SIZE,
}); err != nil {
if rc := l.readLock(_SHARED_FIRST, _SHARED_SIZE); rc != _OK {
// In theory, the downgrade to a SHARED cannot fail because another
// process is holding an incompatible lock. If it does, this
// indicates that the other process is not following the locking
@@ -83,32 +55,52 @@ func (l *vfsFileLocker) Downgrade() xErrorCode {
}
// Release the PENDING and RESERVED locks.
if err := l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_UNLCK,
Start: _PENDING_BYTE,
Len: 2,
}); err != nil {
return IOERR_UNLOCK
}
return _OK
return l.unlock(_PENDING_BYTE, 2)
}
func (l *vfsFileLocker) Release() xErrorCode {
// Release all locks.
if err := l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_UNLCK,
}); err != nil {
return l.unlock(0, 0)
}
func (l *vfsFileLocker) CheckReserved() (bool, xErrorCode) {
// Test the RESERVED lock.
return l.checkLock(_RESERVED_BYTE, 1)
}
func (l *vfsFileLocker) unlock(start, len int64) xErrorCode {
err := l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_UNLCK,
Start: start,
Len: len,
})
if err != nil {
return IOERR_UNLOCK
}
return _OK
}
func (l *vfsFileLocker) CheckReserved() (bool, xErrorCode) {
// Test the RESERVED lock.
func (l *vfsFileLocker) readLock(start, len int64) xErrorCode {
return l.errorCode(l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_RDLCK,
Start: start,
Len: len,
}), IOERR_LOCK)
}
func (l *vfsFileLocker) writeLock(start, len int64) xErrorCode {
return l.errorCode(l.fcntlSetLock(&syscall.Flock_t{
Type: syscall.F_WRLCK,
Start: start,
Len: len,
}), IOERR_LOCK)
}
func (l *vfsFileLocker) checkLock(start, len int64) (bool, xErrorCode) {
lock := syscall.Flock_t{
Type: syscall.F_RDLCK,
Start: _RESERVED_BYTE,
Len: 1,
Start: start,
Len: len,
}
if l.fcntlGetLock(&lock) != nil {
return false, IOERR_CHECKRESERVEDLOCK
@@ -125,6 +117,9 @@ func (l *vfsFileLocker) fcntlGetLock(lock *syscall.Flock_t) error {
case "darwin":
// https://github.com/apple/darwin-xnu/blob/main/bsd/sys/fcntl.h
F_GETLK = 92 // F_OFD_GETLK
case "solaris":
// https://github.com/illumos/illumos-gate/blob/master/usr/src/uts/common/sys/fcntl.h
F_GETLK = 47 // F_OFD_GETLK
}
return syscall.FcntlFlock(l.file.Fd(), F_GETLK, lock)
}
@@ -138,6 +133,9 @@ func (l *vfsFileLocker) fcntlSetLock(lock *syscall.Flock_t) error {
case "darwin":
// https://github.com/apple/darwin-xnu/blob/main/bsd/sys/fcntl.h
F_SETLK = 90 // F_OFD_SETLK
case "solaris":
// https://github.com/illumos/illumos-gate/blob/master/usr/src/uts/common/sys/fcntl.h
F_SETLK = 48 // F_OFD_SETLK
}
return syscall.FcntlFlock(l.file.Fd(), F_SETLK, lock)
}