s3:locking: add brl_req_guid() and brl_req_mem_ctx() helper functions

This allows the vfs backend to detect a retry and keep state between
the retries.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14113

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
(cherry picked from commit 66d92f37c3a643d97489a59bb6d1e75e91528c20)

11 files changed, 106 insertions, 5 deletions

diff --git a/source3/include/locking.h b/source3/include/locking.h
index 3e7560bef9e..0175db2dd47 100644
--- a/source3/include/locking.h
+++ b/source3/include/locking.h
@@ -30,6 +30,7 @@ enum brl_type {READ_LOCK, WRITE_LOCK, UNLOCK_LOCK};
 enum brl_flavour {WINDOWS_LOCK = 0, POSIX_LOCK = 1};
 
 #include "librpc/gen_ndr/server_id.h"
+#include "librpc/gen_ndr/misc.h"
 
 /* This contains elements that differentiate locks. The smbpid is a
    client supplied pid, and is essentially the locking context for
@@ -62,6 +63,7 @@ struct lock_struct {
 };
 
 struct smbd_lock_element {
+	struct GUID req_guid;
 	uint64_t smblctx;
 	enum brl_type brltype;
 	uint64_t offset;
diff --git a/source3/locking/brlock.c b/source3/locking/brlock.c
index 0a85bd0b057..f22580164f9 100644
--- a/source3/locking/brlock.c
+++ b/source3/locking/brlock.c
@@ -46,6 +46,8 @@ static struct db_context *brlock_db;
 
 struct byte_range_lock {
 	struct files_struct *fsp;
+	TALLOC_CTX *req_mem_ctx;
+	const struct GUID *req_guid;
 	unsigned int num_locks;
 	bool modified;
 	struct lock_struct *lock_data;
@@ -84,6 +86,25 @@ struct files_struct *brl_fsp(struct byte_range_lock *brl)
 	return brl->fsp;
 }
 
+TALLOC_CTX *brl_req_mem_ctx(const struct byte_range_lock *brl)
+{
+	if (brl->req_mem_ctx == NULL) {
+		return talloc_get_type_abort(brl, struct byte_range_lock);
+	}
+
+	return brl->req_mem_ctx;
+}
+
+const struct GUID *brl_req_guid(const struct byte_range_lock *brl)
+{
+	if (brl->req_guid == NULL) {
+		static const struct GUID brl_zero_req_guid;
+		return &brl_zero_req_guid;
+	}
+
+	return brl->req_guid;
+}
+
 /****************************************************************************
  See if two locking contexts are equal.
 ****************************************************************************/
@@ -1823,6 +1844,25 @@ struct byte_range_lock *brl_get_locks(TALLOC_CTX *mem_ctx, files_struct *fsp)
 	return br_lck;
 }
 
+struct byte_range_lock *brl_get_locks_for_locking(TALLOC_CTX *mem_ctx,
+						  files_struct *fsp,
+						  TALLOC_CTX *req_mem_ctx,
+						  const struct GUID *req_guid)
+{
+	struct byte_range_lock *br_lck = NULL;
+
+	br_lck = brl_get_locks(mem_ctx, fsp);
+	if (br_lck == NULL) {
+		return NULL;
+	}
+	SMB_ASSERT(req_mem_ctx != NULL);
+	br_lck->req_mem_ctx = req_mem_ctx;
+	SMB_ASSERT(req_guid != NULL);
+	br_lck->req_guid = req_guid;
+
+	return br_lck;
+}
+
 struct brl_get_locks_readonly_state {
 	TALLOC_CTX *mem_ctx;
 	struct byte_range_lock **br_lock;
@@ -1884,14 +1924,11 @@ struct byte_range_lock *brl_get_locks_readonly(files_struct *fsp)
 		/*
 		 * No locks on this file. Return an empty br_lock.
 		 */
-		br_lock = talloc(fsp, struct byte_range_lock);
+		br_lock = talloc_zero(fsp, struct byte_range_lock);
 		if (br_lock == NULL) {
 			return NULL;
 		}
 
-		br_lock->num_locks = 0;
-		br_lock->lock_data = NULL;
-
 	} else if (!NT_STATUS_IS_OK(status)) {
 		DEBUG(3, ("Could not parse byte range lock record: "
 			  "%s\n", nt_errstr(status)));
diff --git a/source3/locking/locking.c b/source3/locking/locking.c
index d87a882d14f..8fa1237d6ad 100644
--- a/source3/locking/locking.c
+++ b/source3/locking/locking.c
@@ -232,6 +232,8 @@ static void decrement_current_lock_count(files_struct *fsp,
 
 struct do_lock_state {
 	struct files_struct *fsp;
+	TALLOC_CTX *req_mem_ctx;
+	const struct GUID *req_guid;
 	uint64_t smblctx;
 	uint64_t count;
 	uint64_t offset;
@@ -251,7 +253,10 @@ static void do_lock_fn(
 	struct do_lock_state *state = private_data;
 	struct byte_range_lock *br_lck = NULL;
 
-	br_lck = brl_get_locks(talloc_tos(), state->fsp);
+	br_lck = brl_get_locks_for_locking(talloc_tos(),
+					   state->fsp,
+					   state->req_mem_ctx,
+					   state->req_guid);
 	if (br_lck == NULL) {
 		state->status = NT_STATUS_NO_MEMORY;
 		return;
@@ -272,6 +277,8 @@ static void do_lock_fn(
 }
 
 NTSTATUS do_lock(files_struct *fsp,
+		 TALLOC_CTX *req_mem_ctx,
+		 const struct GUID *req_guid,
 		 uint64_t smblctx,
 		 uint64_t count,
 		 uint64_t offset,
@@ -282,6 +289,8 @@ NTSTATUS do_lock(files_struct *fsp,
 {
 	struct do_lock_state state = {
 		.fsp = fsp,
+		.req_mem_ctx = req_mem_ctx,
+		.req_guid = req_guid,
 		.smblctx = smblctx,
 		.count = count,
 		.offset = offset,
diff --git a/source3/locking/proto.h b/source3/locking/proto.h
index 7cb8bf3e3c9..7cf681561bc 100644
--- a/source3/locking/proto.h
+++ b/source3/locking/proto.h
@@ -30,6 +30,8 @@ void brl_shutdown(void);
 
 unsigned int brl_num_locks(const struct byte_range_lock *brl);
 struct files_struct *brl_fsp(struct byte_range_lock *brl);
+TALLOC_CTX *brl_req_mem_ctx(const struct byte_range_lock *brl);
+const struct GUID *brl_req_guid(const struct byte_range_lock *brl);
 
 bool byte_range_valid(uint64_t ofs, uint64_t len);
 bool byte_range_overlap(uint64_t ofs1,
@@ -76,6 +78,10 @@ int brl_forall(void (*fn)(struct file_id id, struct server_id pid,
 			  br_off start, br_off size,
 			  void *private_data),
 	       void *private_data);
+struct byte_range_lock *brl_get_locks_for_locking(TALLOC_CTX *mem_ctx,
+						  files_struct *fsp,
+						  TALLOC_CTX *req_mem_ctx,
+						  const struct GUID *req_guid);
 struct byte_range_lock *brl_get_locks(TALLOC_CTX *mem_ctx,
 					files_struct *fsp);
 struct byte_range_lock *brl_get_locks_readonly(files_struct *fsp);
@@ -100,6 +106,8 @@ NTSTATUS query_lock(files_struct *fsp,
 			enum brl_type *plock_type,
 			enum brl_flavour lock_flav);
 NTSTATUS do_lock(files_struct *fsp,
+		 TALLOC_CTX *req_mem_ctx,
+		 const struct GUID *req_guid,
 		 uint64_t smblctx,
 		 uint64_t count,
 		 uint64_t offset,
diff --git a/source3/modules/vfs_fruit.c b/source3/modules/vfs_fruit.c
index 0be7f20e9af..85c7af21d58 100644
--- a/source3/modules/vfs_fruit.c
+++ b/source3/modules/vfs_fruit.c
@@ -2621,6 +2621,7 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
 	bool netatalk_already_open_for_writing = false;
 	bool netatalk_already_open_with_deny_read = false;
 	bool netatalk_already_open_with_deny_write = false;
+	struct GUID req_guid = GUID_random();
 
 	/* FIXME: hardcoded data fork, add resource fork */
 	enum apple_fork fork_type = APPLE_FORK_DATA;
@@ -2684,8 +2685,11 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
 	/* Set NetAtalk locks matching our access */
 	if (access_mask & FILE_READ_DATA) {
 		off = access_to_netatalk_brl(fork_type, FILE_READ_DATA);
+		req_guid.time_hi_and_version = __LINE__;
 		status = do_lock(
 			fsp,
+			talloc_tos(),
+			&req_guid,
 			fsp->op->global->open_persistent_id,
 			1,
 			off,
@@ -2701,8 +2705,11 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
 
 	if (!share_for_read) {
 		off = denymode_to_netatalk_brl(fork_type, DENY_READ);
+		req_guid.time_hi_and_version = __LINE__;
 		status = do_lock(
 			fsp,
+			talloc_tos(),
+			&req_guid,
 			fsp->op->global->open_persistent_id,
 			1,
 			off,
@@ -2718,8 +2725,11 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
 
 	if (access_mask & FILE_WRITE_DATA) {
 		off = access_to_netatalk_brl(fork_type, FILE_WRITE_DATA);
+		req_guid.time_hi_and_version = __LINE__;
 		status = do_lock(
 			fsp,
+			talloc_tos(),
+			&req_guid,
 			fsp->op->global->open_persistent_id,
 			1,
 			off,
@@ -2735,8 +2745,11 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
 
 	if (!share_for_write) {
 		off = denymode_to_netatalk_brl(fork_type, DENY_WRITE);
+		req_guid.time_hi_and_version = __LINE__;
 		status = do_lock(
 			fsp,
+			talloc_tos(),
+			&req_guid,
 			fsp->op->global->open_persistent_id,
 			1,
 			off,
diff --git a/source3/smbd/blocking.c b/source3/smbd/blocking.c
index fbd1ea812f3..94e75a9b405 100644
--- a/source3/smbd/blocking.c
+++ b/source3/smbd/blocking.c
@@ -45,6 +45,8 @@ NTSTATUS smbd_do_locks_try(
 
 		status = do_lock(
 			fsp,
+			locks, /* req_mem_ctx */
+			&e->req_guid,
 			e->smblctx,
 			e->count,
 			e->offset,
diff --git a/source3/smbd/globals.c b/source3/smbd/globals.c
index 6bc448b901d..0cdce20d122 100644
--- a/source3/smbd/globals.c
+++ b/source3/smbd/globals.c
@@ -109,3 +109,21 @@ void smbd_init_globals(void)
 
 	ZERO_STRUCT(sec_ctx_stack);
 }
+
+struct GUID smbd_request_guid(struct smb_request *smb1req, uint16_t idx)
+{
+	struct GUID v = {
+		.time_low = (uint32_t)smb1req->mid,
+		.time_hi_and_version = idx,
+	};
+
+	if (smb1req->smb2req != NULL) {
+		v.time_mid = (uint16_t)smb1req->smb2req->current_idx;
+	} else {
+		v.time_mid = (uint16_t)(uintptr_t)smb1req->vwv;
+	}
+
+	SBVAL((uint8_t *)&v, 8, (uintptr_t)smb1req->xconn);
+
+	return v;
+}
diff --git a/source3/smbd/globals.h b/source3/smbd/globals.h
index 03d50882d16..47916ba29a1 100644
--- a/source3/smbd/globals.h
+++ b/source3/smbd/globals.h
@@ -115,6 +115,8 @@ DATA_BLOB negprot_spnego(TALLOC_CTX *ctx, struct smbXsrv_connection *xconn);
 void smbd_lock_socket(struct smbXsrv_connection *xconn);
 void smbd_unlock_socket(struct smbXsrv_connection *xconn);
 
+struct GUID smbd_request_guid(struct smb_request *smb1req, uint16_t idx);
+
 NTSTATUS smbd_do_unlocking(struct smb_request *req,
 			   files_struct *fsp,
 			   uint16_t num_ulocks,
diff --git a/source3/smbd/reply.c b/source3/smbd/reply.c
index 2622681a2da..dec67a10cae 100644
--- a/source3/smbd/reply.c
+++ b/source3/smbd/reply.c
@@ -3842,6 +3842,7 @@ void reply_lockread(struct smb_request *req)
 	 */
 
 	*lck = (struct smbd_lock_element) {
+		.req_guid = smbd_request_guid(req, 0),
 		.smblctx = req->smbpid,
 		.brltype = WRITE_LOCK,
 		.count = SVAL(req->vwv+1, 0),
@@ -4869,6 +4870,7 @@ void reply_writeunlock(struct smb_request *req)
 
 	if (numtowrite && !fsp->print_file) {
 		struct smbd_lock_element l = {
+			.req_guid = smbd_request_guid(req, 0),
 			.smblctx = req->smbpid,
 			.brltype = UNLOCK_LOCK,
 			.offset = startpos,
@@ -5764,6 +5766,7 @@ void reply_lock(struct smb_request *req)
 	}
 
 	*lck = (struct smbd_lock_element) {
+		.req_guid = smbd_request_guid(req, 0),
 		.smblctx = req->smbpid,
 		.brltype = WRITE_LOCK,
 		.count = IVAL(req->vwv+1, 0),
@@ -5855,6 +5858,7 @@ void reply_unlock(struct smb_request *req)
 	}
 
 	lck = (struct smbd_lock_element) {
+		.req_guid = smbd_request_guid(req, 0),
 		.smblctx = req->smbpid,
 		.brltype = UNLOCK_LOCK,
 		.offset = IVAL(req->vwv+3, 0),
@@ -8433,6 +8437,8 @@ void reply_lockingX(struct smb_request *req)
 		 * smb_unlkrng structs
 		 */
 		for (i = 0; i < num_ulocks; i++) {
+			ulocks[i].req_guid = smbd_request_guid(req,
+				UINT16_MAX - i),
 			ulocks[i].smblctx = get_lock_pid(
 				data, i, large_file_format);
 			ulocks[i].count = get_lock_count(
@@ -8490,6 +8496,7 @@ void reply_lockingX(struct smb_request *req)
 	}
 
 	for (i = 0; i < num_locks; i++) {
+		locks[i].req_guid = smbd_request_guid(req, i),
 		locks[i].smblctx = get_lock_pid(data, i, large_file_format);
 		locks[i].count = get_lock_count(data, i, large_file_format);
 		locks[i].offset = get_lock_offset(data, i, large_file_format);
diff --git a/source3/smbd/smb2_lock.c b/source3/smbd/smb2_lock.c
index 26de8b521ed..381aae6cb60 100644
--- a/source3/smbd/smb2_lock.c
+++ b/source3/smbd/smb2_lock.c
@@ -318,6 +318,7 @@ static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
 			return tevent_req_post(req, ev);
 		}
 
+		locks[i].req_guid = smbd_request_guid(smb2req->smb1req, i);
 		locks[i].smblctx = fsp->op->global->open_persistent_id;
 		locks[i].offset = in_locks[i].offset;
 		locks[i].count  = in_locks[i].length;
diff --git a/source3/smbd/trans2.c b/source3/smbd/trans2.c
index 5b99240e9e8..0539b35bb73 100644
--- a/source3/smbd/trans2.c
+++ b/source3/smbd/trans2.c
@@ -7572,6 +7572,7 @@ static NTSTATUS smb_set_posix_lock(connection_struct *conn,
 
 	if (lock_type == UNLOCK_LOCK) {
 		struct smbd_lock_element l = {
+			.req_guid = smbd_request_guid(req, 0),
 			.smblctx = smblctx,
 			.brltype = UNLOCK_LOCK,
 			.offset = offset,
@@ -7587,6 +7588,7 @@ static NTSTATUS smb_set_posix_lock(connection_struct *conn,
 	}
 
 	*lck = (struct smbd_lock_element) {
+		.req_guid = smbd_request_guid(req, 0),
 		.smblctx = smblctx,
 		.brltype = lock_type,
 		.count = count,