go
/
gvisor
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Document RWF_HIPRI not implemented for preadv2/pwritev2. 

Document limitation of no reasonable implementation for RWF_HIPRI
flag (High Priority Read/Write for block-based file systems).

PiperOrigin-RevId: 264237589
This commit is contained in:
Zach Koopmans 2019-08-19 14:06:22 -07:00 committed by gVisor bot
parent 3ffbdffd7e
commit 67d7864f83
3 changed files with 6 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
pkg/abi/linux/file.go
View File

@ -178,6 +178,8 @@ const (
// Values for preadv2/pwritev2.
const (
// Note: gVisor does not implement the RWF_HIPRI feature, but the flag is
// accepted as a valid flag argument for preadv2/pwritev2.
RWF_HIPRI = 0x00000001
RWF_DSYNC = 0x00000002
RWF_SYNC = 0x00000004

3
pkg/sentry/syscalls/linux/sys_read.go
View File

@ -191,7 +191,6 @@ func Preadv(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
}
// Preadv2 implements linux syscall preadv2(2).
// TODO(b/120162627): Implement RWF_HIPRI functionality.
func Preadv2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
// While the syscall is
// preadv2(int fd, struct iovec* iov, int iov_cnt, off_t offset, int flags)
@ -228,6 +227,8 @@ func Preadv2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca
}
// Check flags field.
// Note: gVisor does not implement the RWF_HIPRI feature, but the flag is
// accepted as a valid flag argument for preadv2.
if flags&^linux.RWF_VALID != 0 {
return 0, nil, syserror.EOPNOTSUPP
}

3
pkg/sentry/syscalls/linux/sys_write.go
View File

@ -191,7 +191,6 @@ func Pwritev(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca
}
// Pwritev2 implements linux syscall pwritev2(2).
// TODO(b/120162627): Implement RWF_HIPRI functionality.
// TODO(b/120161091): Implement O_SYNC and D_SYNC functionality.
func Pwritev2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
// While the syscall is
@ -227,6 +226,8 @@ func Pwritev2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
return 0, nil, syserror.ESPIPE
}
// Note: gVisor does not implement the RWF_HIPRI feature, but the flag is
// accepted as a valid flag argument for pwritev2.
if flags&^linux.RWF_VALID != 0 {
return uintptr(flags), nil, syserror.EOPNOTSUPP
}