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-rw-r--r--pkg/sentry/syscalls/linux/linux64.go2
-rw-r--r--pkg/sentry/syscalls/linux/sys_sync.go63
2 files changed, 64 insertions, 1 deletions
diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index 13084c0ef..9912ab2b5 100644
--- a/pkg/sentry/syscalls/linux/linux64.go
+++ b/pkg/sentry/syscalls/linux/linux64.go
@@ -325,7 +325,7 @@ var AMD64 = &kernel.SyscallTable{
274: syscalls.Error(syscall.ENOSYS), // GetRobustList, obsolete
// 275: Splice, TODO
// 276: Tee, TODO
- // 277: SyncFileRange, TODO
+ 277: SyncFileRange,
// 278: Vmsplice, TODO
279: syscalls.CapError(linux.CAP_SYS_NICE), // MovePages, requires cap_sys_nice (mostly)
280: Utimensat,
diff --git a/pkg/sentry/syscalls/linux/sys_sync.go b/pkg/sentry/syscalls/linux/sys_sync.go
index 826c6869d..68488330f 100644
--- a/pkg/sentry/syscalls/linux/sys_sync.go
+++ b/pkg/sentry/syscalls/linux/sys_sync.go
@@ -15,6 +15,7 @@
package linux
import (
+ "gvisor.googlesource.com/gvisor/pkg/abi/linux"
"gvisor.googlesource.com/gvisor/pkg/sentry/arch"
"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
@@ -73,3 +74,65 @@ func Fdatasync(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys
err := file.Fsync(t, 0, fs.FileMaxOffset, fs.SyncData)
return 0, nil, syserror.ConvertIntr(err, kernel.ERESTARTSYS)
}
+
+// SyncFileRange implements linux syscall sync_file_rage(2)
+func SyncFileRange(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ var err error
+
+ offset := args[1].Int64()
+ nbytes := args[2].Int64()
+ uflags := args[3].Uint()
+
+ if offset < 0 || offset+nbytes < offset {
+ return 0, nil, syserror.EINVAL
+ }
+
+ if uflags&^(linux.SYNC_FILE_RANGE_WAIT_BEFORE|
+ linux.SYNC_FILE_RANGE_WRITE|
+ linux.SYNC_FILE_RANGE_WAIT_AFTER) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ if nbytes == 0 {
+ nbytes = fs.FileMaxOffset
+ }
+
+ fd := kdefs.FD(args[0].Int())
+ file := t.FDMap().GetFile(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // SYNC_FILE_RANGE_WAIT_BEFORE waits upon write-out of all pages in the
+ // specified range that have already been submitted to the device
+ // driver for write-out before performing any write.
+ if uflags&linux.SYNC_FILE_RANGE_WAIT_BEFORE != 0 &&
+ uflags&linux.SYNC_FILE_RANGE_WAIT_AFTER == 0 {
+ t.Kernel().EmitUnimplementedEvent(t)
+ return 0, nil, syserror.ENOSYS
+ }
+
+ // SYNC_FILE_RANGE_WRITE initiates write-out of all dirty pages in the
+ // specified range which are not presently submitted write-out.
+ //
+ // It looks impossible to implement this functionality without a
+ // massive rework of the vfs subsystem. file.Fsync() take a file lock
+ // for the entire operation, so even if it is running in a go routing,
+ // it blocks other file operations instead of flushing data in the
+ // background.
+ //
+ // It should be safe to skipped this flag while nobody uses
+ // SYNC_FILE_RANGE_WAIT_BEFORE.
+
+ // SYNC_FILE_RANGE_WAIT_AFTER waits upon write-out of all pages in the
+ // range after performing any write.
+ //
+ // In Linux, sync_file_range() doesn't writes out the file's
+ // meta-data, but fdatasync() does if a file size is changed.
+ if uflags&linux.SYNC_FILE_RANGE_WAIT_AFTER != 0 {
+ err = file.Fsync(t, offset, fs.FileMaxOffset, fs.SyncData)
+ }
+
+ return 0, nil, syserror.ConvertIntr(err, kernel.ERESTARTSYS)
+}