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Commit 58cde1a6 authored by Alexander Usyskin's avatar Alexander Usyskin Committed by Greg Kroah-Hartman
Browse files

mei: implement fsync 



When write() returns successfully, it is only assumed that a message
was successfully queued. Add fsync syscall implementation to help
user-space ensure that all data is written.

Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dd04eecc

drivers/misc/mei/main.c

+72 −0
Original line number Diff line number Diff line
@@ -585,6 +585,77 @@ static unsigned int mei_poll(struct file *file, poll_table *wait) 
	return mask;

}



/**

 * mei_cl_is_write_queued - check if the client has pending writes.

 *

 * @cl: writing host client

 *

 * Return: true if client is writing, false otherwise.

 */

static bool mei_cl_is_write_queued(struct mei_cl *cl)

{

	struct mei_device *dev = cl->dev;

	struct mei_cl_cb *cb;



	list_for_each_entry(cb, &dev->write_list, list)

		if (cb->cl == cl)

			return true;

	list_for_each_entry(cb, &dev->write_waiting_list, list)

		if (cb->cl == cl)

			return true;

	return false;

}



/**

 * mei_fsync - the fsync handler

 *

 * @fp:       pointer to file structure

 * @start:    unused

 * @end:      unused

 * @datasync: unused

 *

 * Return: 0 on success, -ENODEV if client is not connected

 */

static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)

{

	struct mei_cl *cl = fp->private_data;

	struct mei_device *dev;

	int rets;



	if (WARN_ON(!cl || !cl->dev))

		return -ENODEV;



	dev = cl->dev;



	mutex_lock(&dev->device_lock);



	if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {

		rets = -ENODEV;

		goto out;

	}



	while (mei_cl_is_write_queued(cl)) {

		mutex_unlock(&dev->device_lock);

		rets = wait_event_interruptible(cl->tx_wait,

				cl->writing_state == MEI_WRITE_COMPLETE ||

				!mei_cl_is_connected(cl));

		mutex_lock(&dev->device_lock);

		if (rets) {

			if (signal_pending(current))

				rets = -EINTR;

			goto out;

		}

		if (!mei_cl_is_connected(cl)) {

			rets = -ENODEV;

			goto out;

		}

	}

	rets = 0;

out:

	mutex_unlock(&dev->device_lock);

	return rets;

}



/**

 * mei_fasync - asynchronous io support

 *
@@ -700,6 +771,7 @@ static const struct file_operations mei_fops = { 
	.release = mei_release,

	.write = mei_write,

	.poll = mei_poll,

	.fsync = mei_fsync,

	.fasync = mei_fasync,

	.llseek = no_llseek

};