diff options
Diffstat (limited to 'pkg/sentry/syscalls')
| -rwxr-xr-x | pkg/sentry/syscalls/linux/vfs2/read_write.go | 77 |
1 files changed, 69 insertions, 8 deletions
diff --git a/pkg/sentry/syscalls/linux/vfs2/read_write.go b/pkg/sentry/syscalls/linux/vfs2/read_write.go index 6c6998f45..3a7ef24f5 100755 --- a/pkg/sentry/syscalls/linux/vfs2/read_write.go +++ b/pkg/sentry/syscalls/linux/vfs2/read_write.go @@ -15,9 +15,13 @@ package vfs2 import ( + "time" + "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/kernel" + ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time" + "gvisor.dev/gvisor/pkg/sentry/socket" slinux "gvisor.dev/gvisor/pkg/sentry/syscalls/linux" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/syserror" @@ -88,7 +92,12 @@ func Readv(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall func read(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { n, err := file.Read(t, dst, opts) - if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 { + if err != syserror.ErrWouldBlock { + return n, err + } + + allowBlock, deadline, hasDeadline := blockPolicy(t, file) + if !allowBlock { return n, err } @@ -108,7 +117,12 @@ func read(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, opt if err != syserror.ErrWouldBlock { break } - if err := t.Block(ch); err != nil { + + // Wait for a notification that we should retry. + if err = t.BlockWithDeadline(ch, hasDeadline, deadline); err != nil { + if err == syserror.ETIMEDOUT { + err = syserror.ErrWouldBlock + } break } } @@ -233,7 +247,12 @@ func Preadv2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca func pread(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { n, err := file.PRead(t, dst, offset, opts) - if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 { + if err != syserror.ErrWouldBlock { + return n, err + } + + allowBlock, deadline, hasDeadline := blockPolicy(t, file) + if !allowBlock { return n, err } @@ -253,7 +272,12 @@ func pread(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, of if err != syserror.ErrWouldBlock { break } - if err := t.Block(ch); err != nil { + + // Wait for a notification that we should retry. + if err = t.BlockWithDeadline(ch, hasDeadline, deadline); err != nil { + if err == syserror.ETIMEDOUT { + err = syserror.ErrWouldBlock + } break } } @@ -320,7 +344,12 @@ func Writev(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal func write(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { n, err := file.Write(t, src, opts) - if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 { + if err != syserror.ErrWouldBlock { + return n, err + } + + allowBlock, deadline, hasDeadline := blockPolicy(t, file) + if !allowBlock { return n, err } @@ -340,7 +369,12 @@ func write(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, op if err != syserror.ErrWouldBlock { break } - if err := t.Block(ch); err != nil { + + // Wait for a notification that we should retry. + if err = t.BlockWithDeadline(ch, hasDeadline, deadline); err != nil { + if err == syserror.ETIMEDOUT { + err = syserror.ErrWouldBlock + } break } } @@ -465,7 +499,12 @@ func Pwritev2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc func pwrite(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { n, err := file.PWrite(t, src, offset, opts) - if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 { + if err != syserror.ErrWouldBlock { + return n, err + } + + allowBlock, deadline, hasDeadline := blockPolicy(t, file) + if !allowBlock { return n, err } @@ -485,7 +524,12 @@ func pwrite(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, o if err != syserror.ErrWouldBlock { break } - if err := t.Block(ch); err != nil { + + // Wait for a notification that we should retry. + if err = t.BlockWithDeadline(ch, hasDeadline, deadline); err != nil { + if err == syserror.ETIMEDOUT { + err = syserror.ErrWouldBlock + } break } } @@ -494,6 +538,23 @@ func pwrite(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, o return total, err } +func blockPolicy(t *kernel.Task, file *vfs.FileDescription) (allowBlock bool, deadline ktime.Time, hasDeadline bool) { + if file.StatusFlags()&linux.O_NONBLOCK != 0 { + return false, ktime.Time{}, false + } + // Sockets support read/write timeouts. + if s, ok := file.Impl().(socket.SocketVFS2); ok { + dl := s.RecvTimeout() + if dl < 0 { + return false, ktime.Time{}, false + } + if dl > 0 { + return true, t.Kernel().MonotonicClock().Now().Add(time.Duration(dl) * time.Nanosecond), true + } + } + return true, ktime.Time{}, false +} + // Lseek implements Linux syscall lseek(2). func Lseek(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { fd := args[0].Int() |