enable fallocate punch hole ("fallocate -p") for SMB3

Implement FALLOC_FL_PUNCH_HOLE (which does not change the file size
fortunately so this matches the behavior of the equivalent SMB3
fsctl call) for SMB3 mounts.  This allows "fallocate -p" to work.
It requires that the server support setting files as sparse
(which Windows allows).

Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 69f3595d3952..fbe486c285a9 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -573,6 +573,12 @@ struct copychunk_ioctl {
 	__u32 Reserved2;
 } __packed;
 
+/* this goes in the ioctl buffer when doing FSCTL_SET_ZERO_DATA */
+struct file_zero_data_information {
+	__le64	FileOffset;
+	__le64	BeyondFinalZero;
+} __packed;
+
 struct copychunk_ioctl_rsp {
 	__le32 ChunksWritten;
 	__le32 ChunkBytesWritten;