oplock.c

来自「samba-3.0.22.tar.gz 编译smb服务器的源码」· C语言 代码 · 共 894 行 · 第 1/2 页

		remove_oplock(fsp);
		return;
	}

	/* Ensure we're really at level2 state. */
	SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);

	/* Now send a break to none message to our client. */

	break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
	if (break_msg == NULL) {
		exit_server("Could not talloc break_msg\n");
	}

	/* Need to wait before sending a break message if we sent ourselves this message. */
	if (procid_to_pid(&src) == sys_getpid()) {
		wait_before_sending_break();
	}

	/* Save the server smb signing state. */
	sign_state = srv_oplock_set_signing(False);

	show_msg(break_msg);
	if (!send_smb(smbd_server_fd(), break_msg)) {
		exit_server("oplock_break: send_smb failed.");
	}

	/* Restore the sign state to what it was. */
	srv_oplock_set_signing(sign_state);

	talloc_free(break_msg);

	/* Async level2 request, don't send a reply, just remove the oplock. */
	remove_oplock(fsp);
}

/*******************************************************************
 This handles the generic oplock break message from another smbd.
*******************************************************************/

static void process_oplock_break_message(int msg_type, struct process_id src,
					 void *buf, size_t len)
{
	struct share_mode_entry msg;
	files_struct *fsp;
	char *break_msg;
	BOOL break_to_level2 = False;
	BOOL sign_state;

	if (buf == NULL) {
		DEBUG(0, ("Got NULL buffer\n"));
		return;
	}

	if (len != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
		DEBUG(0, ("Got invalid msg len %d\n", (int)len));
		return;
	}

	/* De-linearize incoming message. */
	message_to_share_mode_entry(&msg, buf);

	DEBUG(10, ("Got oplock break message from pid %d: 0x%x/%.0f/%d\n",
		   (int)procid_to_pid(&src), (unsigned int)msg.dev, (double)msg.inode,
		   (int)msg.share_file_id));

	fsp = initial_break_processing(msg.dev, msg.inode,
				       msg.share_file_id);

	if (fsp == NULL) {
		/* a We hit race here. Break messages are sent, and before we
		 * get to process this message, we have closed the file. Reply
		 * with 'ok, oplock broken' */
		DEBUG(3, ("Did not find fsp\n"));
		become_root();

		/* We just send the same message back. */
		message_send_pid(src, MSG_SMB_BREAK_RESPONSE,
				 buf, MSG_SMB_SHARE_MODE_ENTRY_SIZE, True);

		unbecome_root();
		return;
	}

	if (fsp->sent_oplock_break != NO_BREAK_SENT) {
		/* Remember we have to inform the requesting PID when the
		 * client replies */
		msg.pid = src;
		ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
			     &fsp->pending_break_messages,
			     &fsp->num_pending_break_messages);
		return;
	}

	if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
	    !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
		DEBUG(3, ("Already downgraded oplock on 0x%x/%.0f: %s\n",
			  (unsigned int)fsp->dev, (double)fsp->inode,
			  fsp->fsp_name));
		become_root();

		/* We just send the same message back. */
		message_send_pid(src, MSG_SMB_BREAK_RESPONSE,
				 buf, MSG_SMB_SHARE_MODE_ENTRY_SIZE, True);

		unbecome_root();
		return;
	}

	if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) && 
	    !koplocks && /* NOTE: we force levelII off for kernel oplocks -
			  * this will change when it is supported */
	    lp_level2_oplocks(SNUM(fsp->conn))) {
		break_to_level2 = True;
	}

	break_msg = new_break_smb_message(NULL, fsp, break_to_level2 ?
					  OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
	if (break_msg == NULL) {
		exit_server("Could not talloc break_msg\n");
	}

	/* Need to wait before sending a break message if we sent ourselves this message. */
	if (procid_to_pid(&src) == sys_getpid()) {
		wait_before_sending_break();
	}

	/* Save the server smb signing state. */
	sign_state = srv_oplock_set_signing(False);

	show_msg(break_msg);
	if (!send_smb(smbd_server_fd(), break_msg)) {
		exit_server("oplock_break: send_smb failed.");
	}

	/* Restore the sign state to what it was. */
	srv_oplock_set_signing(sign_state);

	talloc_free(break_msg);

	fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;

	msg.pid = src;
	ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
		     &fsp->pending_break_messages,
		     &fsp->num_pending_break_messages);

	add_oplock_timeout_handler(fsp);
}

/*******************************************************************
 This handles the kernel oplock break message.
*******************************************************************/

static void process_kernel_oplock_break(int msg_type, struct process_id src,
					void *buf, size_t len)
{
	SMB_DEV_T dev;
	SMB_INO_T inode;
	unsigned long file_id;
	files_struct *fsp;
	char *break_msg;
	BOOL sign_state;

	if (buf == NULL) {
		DEBUG(0, ("Got NULL buffer\n"));
		return;
	}

	if (len != MSG_SMB_KERNEL_BREAK_SIZE) {
		DEBUG(0, ("Got invalid msg len %d\n", (int)len));
		return;
	}

	/* Pull the data from the message. */
	dev = DEV_T_VAL(buf, 0);
	inode = INO_T_VAL(buf, 8);
	file_id = (unsigned long)IVAL(buf, 16);

	DEBUG(10, ("Got kernel oplock break message from pid %d: 0x%x/%.0f/%u\n",
		   (int)procid_to_pid(&src), (unsigned int)dev, (double)inode,
		   (unsigned int)file_id));

	fsp = initial_break_processing(dev, inode, file_id);

	if (fsp == NULL) {
		DEBUG(3, ("Got a kernel oplock break message for a file "
			  "I don't know about\n"));
		return;
	}

	if (fsp->sent_oplock_break != NO_BREAK_SENT) {
		/* This is ok, kernel oplocks come in completely async */
		DEBUG(3, ("Got a kernel oplock request while waiting for a "
			  "break reply\n"));
		return;
	}

	break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
	if (break_msg == NULL) {
		exit_server("Could not talloc break_msg\n");
	}

	/* Save the server smb signing state. */
	sign_state = srv_oplock_set_signing(False);

	show_msg(break_msg);
	if (!send_smb(smbd_server_fd(), break_msg)) {
		exit_server("oplock_break: send_smb failed.");
	}

	/* Restore the sign state to what it was. */
	srv_oplock_set_signing(sign_state);

	talloc_free(break_msg);

	fsp->sent_oplock_break = BREAK_TO_NONE_SENT;

	add_oplock_timeout_handler(fsp);
}

void reply_to_oplock_break_requests(files_struct *fsp)
{
	int i;

	become_root();
	for (i=0; i<fsp->num_pending_break_messages; i++) {
		struct share_mode_entry *e = &fsp->pending_break_messages[i];
		char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];

		share_mode_entry_to_message(msg, e);

		message_send_pid(e->pid, MSG_SMB_BREAK_RESPONSE,
				 msg, MSG_SMB_SHARE_MODE_ENTRY_SIZE, True);
	}
	unbecome_root();

	SAFE_FREE(fsp->pending_break_messages);
	fsp->num_pending_break_messages = 0;
	if (fsp->oplock_timeout != NULL) {
		/* Remove the timed event handler. */
		talloc_free(fsp->oplock_timeout);
		fsp->oplock_timeout = NULL;
	}
	return;
}

static void process_oplock_break_response(int msg_type, struct process_id src,
					  void *buf, size_t len)
{
	struct share_mode_entry msg;

	if (buf == NULL) {
		DEBUG(0, ("Got NULL buffer\n"));
		return;
	}

	if (len != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
		DEBUG(0, ("Got invalid msg len %u\n", (unsigned int)len));
		return;
	}

	/* De-linearize incoming message. */
	message_to_share_mode_entry(&msg, buf);

	DEBUG(10, ("Got oplock break response from pid %d: 0x%x/%.0f/%u mid %u\n",
		   (int)procid_to_pid(&src), (unsigned int)msg.dev, (double)msg.inode,
		   (unsigned int)msg.share_file_id, (unsigned int)msg.op_mid));

	/* Here's the hack from open.c, store the mid in the 'port' field */
	schedule_deferred_open_smb_message(msg.op_mid);
}

static void process_open_retry_message(int msg_type, struct process_id src,
				       void *buf, size_t len)
{
	struct share_mode_entry msg;
	
	if (buf == NULL) {
		DEBUG(0, ("Got NULL buffer\n"));
		return;
	}

	if (len != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
		DEBUG(0, ("Got invalid msg len %d\n", (int)len));
		return;
	}

	/* De-linearize incoming message. */
	message_to_share_mode_entry(&msg, buf);

	DEBUG(10, ("Got open retry msg from pid %d: 0x%x/%.0f mid %u\n",
		   (int)procid_to_pid(&src), (unsigned int)msg.dev, (double)msg.inode,
		   (unsigned int)msg.op_mid));

	schedule_deferred_open_smb_message(msg.op_mid);
}

/****************************************************************************
 This function is called on any file modification or lock request. If a file
 is level 2 oplocked then it must tell all other level 2 holders to break to
 none.
****************************************************************************/

void release_level_2_oplocks_on_change(files_struct *fsp)
{
	int i;
	struct share_mode_lock *lck;

	/*
	 * If this file is level II oplocked then we need
	 * to grab the shared memory lock and inform all
	 * other files with a level II lock that they need
	 * to flush their read caches. We keep the lock over
	 * the shared memory area whilst doing this.
	 */

	if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
		return;

	lck = get_share_mode_lock(NULL, fsp->dev, fsp->inode, NULL, NULL);
	if (lck == NULL) {
		DEBUG(0,("release_level_2_oplocks_on_change: failed to lock "
			 "share mode entry for file %s.\n", fsp->fsp_name ));
	}

	DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n", 
		  lck->num_share_modes ));

	for(i = 0; i < lck->num_share_modes; i++) {
		struct share_mode_entry *share_entry = &lck->share_modes[i];
		char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];

		if (!is_valid_share_mode_entry(share_entry)) {
			continue;
		}

		/*
		 * As there could have been multiple writes waiting at the
		 * lock_share_entry gate we may not be the first to
		 * enter. Hence the state of the op_types in the share mode
		 * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
		 * oplock. It will do no harm to re-send break messages to
		 * those smbd's that are still waiting their turn to remove
		 * their LEVEL_II state, and also no harm to ignore existing
		 * NO_OPLOCK states. JRA.
		 */

		DEBUG(10,("release_level_2_oplocks_on_change: "
			  "share_entry[%i]->op_type == %d\n",
			  i, share_entry->op_type ));

		if (share_entry->op_type == NO_OPLOCK) {
			continue;
		}

		/* Paranoia .... */
		if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
			DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
				 "share mode entry %d is an exlusive "
				 "oplock !\n", i ));
			talloc_free(lck);
			abort();
		}

		share_mode_entry_to_message(msg, share_entry);

		become_root();
		message_send_pid(share_entry->pid, MSG_SMB_ASYNC_LEVEL2_BREAK,
				 msg, MSG_SMB_SHARE_MODE_ENTRY_SIZE, True);
		unbecome_root();
	}

	/* We let the message receivers handle removing the oplock state
	   in the share mode lock db. */

	talloc_free(lck);
}

/****************************************************************************
 Linearize a share mode entry struct to an internal oplock break message.
****************************************************************************/

void share_mode_entry_to_message(char *msg, struct share_mode_entry *e)
{
	SIVAL(msg,0,(uint32)e->pid.pid);
	SSVAL(msg,4,e->op_mid);
	SSVAL(msg,6,e->op_type);
	SIVAL(msg,8,e->access_mask);
	SIVAL(msg,12,e->share_access);
	SIVAL(msg,16,e->private_options);
	SIVAL(msg,20,(uint32)e->time.tv_sec);
	SIVAL(msg,24,(uint32)e->time.tv_usec);
	SDEV_T_VAL(msg,28,e->dev);
	SINO_T_VAL(msg,36,e->inode);
	SIVAL(msg,44,e->share_file_id);
}

/****************************************************************************
 De-linearize an internal oplock break message to a share mode entry struct.
****************************************************************************/

void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
{
	e->pid.pid = (pid_t)IVAL(msg,0);
	e->op_mid = SVAL(msg,4);
	e->op_type = SVAL(msg,6);
	e->access_mask = IVAL(msg,8);
	e->share_access = IVAL(msg,12);
	e->private_options = IVAL(msg,16);
	e->time.tv_sec = (time_t)IVAL(msg,20);
	e->time.tv_usec = (int)IVAL(msg,24);
	e->dev = DEV_T_VAL(msg,28);
	e->inode = INO_T_VAL(msg,36);
	e->share_file_id = (unsigned long)IVAL(msg,44);
}

/****************************************************************************
 Setup oplocks for this process.
****************************************************************************/

BOOL init_oplocks(void)
{
	DEBUG(3,("open_oplock_ipc: initializing messages.\n"));

	message_register(MSG_SMB_BREAK_REQUEST,
			 process_oplock_break_message);
	message_register(MSG_SMB_ASYNC_LEVEL2_BREAK,
			 process_oplock_async_level2_break_message);
	message_register(MSG_SMB_BREAK_RESPONSE,
			 process_oplock_break_response);
	message_register(MSG_SMB_KERNEL_BREAK,
			 process_kernel_oplock_break);
	message_register(MSG_SMB_OPEN_RETRY,
			 process_open_retry_message);

	if (lp_kernel_oplocks()) {
#if HAVE_KERNEL_OPLOCKS_IRIX
		koplocks = irix_init_kernel_oplocks();
#elif HAVE_KERNEL_OPLOCKS_LINUX
		koplocks = linux_init_kernel_oplocks();
#endif
	}

	return True;
}