Patch to add support for advertising FULLSYNC to Mac OSX Clients

[Ralph Böhme]

Hi Kevin,

On Sun, Apr 02, 2017 at 10:40:06PM -0400, Kevin Anderson wrote:
> Hi Ralph,
>    I started an attempt to implement the remaining piece of this patch
> and I have parsed out the reserved1 field in the
> smbd_smb2_request_process_flush function. Does that seem appropriate
> to you? If so, I only have to determine the best way to pass the fsync
> to the actual file. Can/should the fsync be handled in the fruit
> module? I would be open to any advice that you have as I have tried a
> number of things already but they were unsuccessful.

maybe something like the attached. Just cobbled together, completely untested.

Jeremy, can you take a look as well please?

Cheerio!
-slow
-------------- next part --------------
From 2c3ec983cfec3dceda77e979784e2ea34a0ef03e Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow at samba.org>
Date: Tue, 4 Apr 2017 13:13:30 +0200
Subject: [PATCH 1/2] s3/smbd: add aapl_enabled flag to fsp

This will be needed in the next commit to implement macOS fullsync extension.
---
 source3/include/vfs.h       | 1 +
 source3/modules/vfs_fruit.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/source3/include/vfs.h b/source3/include/vfs.h
index 0810fc2..fa964c0 100644
--- a/source3/include/vfs.h
+++ b/source3/include/vfs.h
@@ -289,6 +289,7 @@ typedef struct files_struct {
 	bool is_sparse;
 	bool backup_intent; /* Handle was successfully opened with backup intent
 				and opener has privilege to do so. */
+	bool aapl_enabled; /* macOS client with extensions enabled */
 	bool aapl_copyfile_supported;
 	bool use_ofd_locks; /* Are we using open file description locks ? */
 	struct smb_filename *fsp_name;
diff --git a/source3/modules/vfs_fruit.c b/source3/modules/vfs_fruit.c
index 0b5558a..bf149ab 100644
--- a/source3/modules/vfs_fruit.c
+++ b/source3/modules/vfs_fruit.c
@@ -4945,6 +4945,8 @@ static NTSTATUS fruit_create_file(vfs_handle_struct *handle,
 	fsp = *result;
 
 	if (global_fruit_config.nego_aapl) {
+		fsp->aapl_enabled = true;
+
 		if (config->copyfile_enabled) {
 			/*
 			 * Set a flag in the fsp. Gets used in
-- 
2.9.3


From 5c49e46489fc3496acc4c6653f036a8ec11d9bd9 Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow at samba.org>
Date: Tue, 4 Apr 2017 13:10:00 +0200
Subject: [PATCH 2/2] s3/smbd: macOS fullsync

---
 source3/smbd/smb2_flush.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/source3/smbd/smb2_flush.c b/source3/smbd/smb2_flush.c
index d077c62..e4ce0a0 100644
--- a/source3/smbd/smb2_flush.c
+++ b/source3/smbd/smb2_flush.c
@@ -27,7 +27,8 @@
 static struct tevent_req *smbd_smb2_flush_send(TALLOC_CTX *mem_ctx,
 					       struct tevent_context *ev,
 					       struct smbd_smb2_request *smb2req,
-					       struct files_struct *fsp);
+					       struct files_struct *fsp,
+					       uint16_t flush_reserved1);
 static NTSTATUS smbd_smb2_flush_recv(struct tevent_req *req);
 
 static void smbd_smb2_request_flush_done(struct tevent_req *subreq);
@@ -37,6 +38,7 @@ NTSTATUS smbd_smb2_request_process_flush(struct smbd_smb2_request *req)
 	const uint8_t *inbody;
 	uint64_t in_file_id_persistent;
 	uint64_t in_file_id_volatile;
+	uint16_t in_flush_reserved1;
 	struct files_struct *in_fsp;
 	struct tevent_req *subreq;
 
@@ -46,6 +48,7 @@ NTSTATUS smbd_smb2_request_process_flush(struct smbd_smb2_request *req)
 	}
 	inbody = SMBD_SMB2_IN_BODY_PTR(req);
 
+	in_flush_reserved1	= SVAL(inbody, 0x2);
 	in_file_id_persistent	= BVAL(inbody, 0x08);
 	in_file_id_volatile	= BVAL(inbody, 0x10);
 
@@ -55,7 +58,7 @@ NTSTATUS smbd_smb2_request_process_flush(struct smbd_smb2_request *req)
 	}
 
 	subreq = smbd_smb2_flush_send(req, req->sconn->ev_ctx,
-				      req, in_fsp);
+				      req, in_fsp, in_flush_reserved1);
 	if (subreq == NULL) {
 		return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
 	}
@@ -115,7 +118,8 @@ static void smbd_smb2_flush_done(struct tevent_req *subreq);
 static struct tevent_req *smbd_smb2_flush_send(TALLOC_CTX *mem_ctx,
 					       struct tevent_context *ev,
 					       struct smbd_smb2_request *smb2req,
-					       struct files_struct *fsp)
+					       struct files_struct *fsp,
+					       uint16_t flush_reserved1)
 {
 	struct tevent_req *req;
 	struct tevent_req *subreq;
@@ -153,6 +157,22 @@ static struct tevent_req *smbd_smb2_flush_send(TALLOC_CTX *mem_ctx,
 		return tevent_req_post(req, ev);
 	}
 
+	if (fsp->aapl_enabled && (flush_reserved1 == 0xffff)) {
+		/*
+		 * macOS specific fullsync, cf https://goo.gl/Lw5bdz
+		 */
+		ret = SMB_VFS_FSYNC(fsp);
+		if (ret != 0) {
+			DBG_ERR("flush of [%s] failed: %s",
+				fsp_str_dbg(fsp), strerror(errno));
+			tevent_req_nterror(req,  map_nt_error_from_unix(errno));
+			return tevent_req_post(req, ev);
+		}
+
+		tevent_req_done(req);
+		return tevent_req_post(req, ev);
+	}
+
 	if (!lp_strict_sync(SNUM(smbreq->conn))) {
 		/*
 		 * No strict sync. Don't really do
-- 
2.9.3