unix: fix and test the FIDEDUPERANGE Linux ioctl

The previous implementation didn't match the ioctl spec.

Fixes golang/go#43678

Change-Id: Ia1c292c2dbd4913fb1d7e8331d9f18e23169d64a
GitHub-Last-Rev: 5331c424ef5dd0384afda9effbb76afd7705ecfd
GitHub-Pull-Request: golang/sys#97
Reviewed-on: https://go-review.googlesource.com/c/sys/+/284352
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Ian Lance Taylor <iant@golang.org>
This commit is contained in:
Lluís Batlle i Rossell
2021-02-25 08:00:10 +00:00
committed by Tobias Klauser
parent 683adc9d29
commit 8e9945a547
4 changed files with 171 additions and 7 deletions
+54 -5
View File
@@ -137,12 +137,61 @@ func IoctlFileClone(destFd, srcFd int) error {
return ioctl(destFd, FICLONE, uintptr(srcFd))
}
type FileDedupeRange struct {
Src_offset uint64
Src_length uint64
Reserved1 uint16
Reserved2 uint32
Info []FileDedupeRangeInfo
}
type FileDedupeRangeInfo struct {
Dest_fd int64
Dest_offset uint64
Bytes_deduped uint64
Status int32
Reserved uint32
}
// IoctlFileDedupeRange performs an FIDEDUPERANGE ioctl operation to share the
// range of data conveyed in value with the file associated with the file
// descriptor destFd. See the ioctl_fideduperange(2) man page for details.
func IoctlFileDedupeRange(destFd int, value *FileDedupeRange) error {
err := ioctl(destFd, FIDEDUPERANGE, uintptr(unsafe.Pointer(value)))
runtime.KeepAlive(value)
// range of data conveyed in value from the file associated with the file
// descriptor srcFd to the value.Info destinations. See the
// ioctl_fideduperange(2) man page for details.
func IoctlFileDedupeRange(srcFd int, value *FileDedupeRange) error {
buf := make([]byte, SizeofRawFileDedupeRange+
len(value.Info)*SizeofRawFileDedupeRangeInfo)
rawrange := (*RawFileDedupeRange)(unsafe.Pointer(&buf[0]))
rawrange.Src_offset = value.Src_offset
rawrange.Src_length = value.Src_length
rawrange.Dest_count = uint16(len(value.Info))
rawrange.Reserved1 = value.Reserved1
rawrange.Reserved2 = value.Reserved2
for i := range value.Info {
rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(
uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +
uintptr(i*SizeofRawFileDedupeRangeInfo)))
rawinfo.Dest_fd = value.Info[i].Dest_fd
rawinfo.Dest_offset = value.Info[i].Dest_offset
rawinfo.Bytes_deduped = value.Info[i].Bytes_deduped
rawinfo.Status = value.Info[i].Status
rawinfo.Reserved = value.Info[i].Reserved
}
err := ioctl(srcFd, FIDEDUPERANGE, uintptr(unsafe.Pointer(&buf[0])))
// Output
for i := range value.Info {
rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(
uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +
uintptr(i*SizeofRawFileDedupeRangeInfo)))
value.Info[i].Dest_fd = rawinfo.Dest_fd
value.Info[i].Dest_offset = rawinfo.Dest_offset
value.Info[i].Bytes_deduped = rawinfo.Bytes_deduped
value.Info[i].Status = rawinfo.Status
value.Info[i].Reserved = rawinfo.Reserved
}
return err
}