[GitHub/mt8127/android_kernel_alcatel_ttab.git] / block / blk-exec.c

/*
 * Functions related to setting various queue properties from drivers
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/bio.h>
#include <linux/blkdev.h>

#include "blk.h"

/*
 * for max sense size
 */
#include <scsi/scsi_cmnd.h>

/**
 * blk_end_sync_rq - executes a completion event on a request
 * @rq: request to complete
 * @error: end I/O status of the request
 */
static void blk_end_sync_rq(struct request *rq, int error)
{
	struct completion *waiting = rq->end_io_data;

	rq->end_io_data = NULL;
	__blk_put_request(rq->q, rq);

	/*
	 * complete last, if this is a stack request the process (and thus
	 * the rq pointer) could be invalid right after this complete()
	 */
	complete(waiting);
}

/**
 * blk_execute_rq_nowait - insert a request into queue for execution
 * @q:		queue to insert the request in
 * @bd_disk:	matching gendisk
 * @rq:		request to insert
 * @at_head:    insert request at head or tail of queue
 * @done:	I/O completion handler
 *
 * Description:
 *    Insert a fully prepared request at the back of the I/O scheduler queue
 *    for execution.  Don't wait for completion.
 */
void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
			   struct request *rq, int at_head,
			   rq_end_io_fn *done)
{
	int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;

	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
		rq->errors = -ENXIO;
		if (rq->end_io)
			rq->end_io(rq, rq->errors);
		return;
	}

	rq->rq_disk = bd_disk;
	rq->end_io = done;
	WARN_ON(irqs_disabled());
	spin_lock_irq(q->queue_lock);
	__elv_add_request(q, rq, where);
	__blk_run_queue(q);
	/* the queue is stopped so it won't be run */
	if (rq->cmd_type == REQ_TYPE_PM_RESUME)
		q->request_fn(q);
	spin_unlock_irq(q->queue_lock);
}
EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);

/**
 * blk_execute_rq - insert a request into queue for execution
 * @q:		queue to insert the request in
 * @bd_disk:	matching gendisk
 * @rq:		request to insert
 * @at_head:    insert request at head or tail of queue
 *
 * Description:
 *    Insert a fully prepared request at the back of the I/O scheduler queue
 *    for execution and wait for completion.
 */
int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
		   struct request *rq, int at_head)
{
	DECLARE_COMPLETION_ONSTACK(wait);
	char sense[SCSI_SENSE_BUFFERSIZE];
	int err = 0;
	unsigned long hang_check;

	/*
	 * we need an extra reference to the request, so we can look at
	 * it after io completion
	 */
	rq->ref_count++;

	if (!rq->sense) {
		memset(sense, 0, sizeof(sense));
		rq->sense = sense;
		rq->sense_len = 0;
	}

	rq->end_io_data = &wait;
	blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);

	/* Prevent hang_check timer from firing at us during very long I/O */
	hang_check = sysctl_hung_task_timeout_secs;
	if (hang_check)
		while (!wait_for_completion_timeout(&wait, hang_check * (HZ/2)));
	else
		wait_for_completion(&wait);

	if (rq->errors)
		err = -EIO;

	return err;
}
EXPORT_SYMBOL(blk_execute_rq);
Commit	Line	Data
86db1e29 JA	1	/*
	2	* Functions related to setting various queue properties from drivers
	3	*/
	4	#include <linux/kernel.h>
	5	#include <linux/module.h>
	6	#include <linux/bio.h>
	7	#include <linux/blkdev.h>
	8
	9	#include "blk.h"
	10
	11	/*
	12	* for max sense size
	13	*/
	14	#include <scsi/scsi_cmnd.h>
	15
	16	/**
	17	* blk_end_sync_rq - executes a completion event on a request
	18	* @rq: request to complete
710027a4	19	* @error: end I/O status of the request
86db1e29	20	*/
681a561b	21	static void blk_end_sync_rq(struct request *rq, int error)
86db1e29 JA	22	{
	23	struct completion *waiting = rq->end_io_data;
	24
	25	rq->end_io_data = NULL;
	26	__blk_put_request(rq->q, rq);
	27
	28	/*
	29	* complete last, if this is a stack request the process (and thus
	30	* the rq pointer) could be invalid right after this complete()
	31	*/
	32	complete(waiting);
	33	}
86db1e29 JA	34
	35	/**
	36	* blk_execute_rq_nowait - insert a request into queue for execution
	37	* @q: queue to insert the request in
	38	* @bd_disk: matching gendisk
	39	* @rq: request to insert
	40	* @at_head: insert request at head or tail of queue
	41	* @done: I/O completion handler
	42	*
	43	* Description:
710027a4	44	* Insert a fully prepared request at the back of the I/O scheduler queue
86db1e29 JA	45	* for execution. Don't wait for completion.
	46	*/
	47	void blk_execute_rq_nowait(struct request_queue q, struct gendisk bd_disk,
	48	struct request *rq, int at_head,
	49	rq_end_io_fn *done)
	50	{
	51	int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
	52
bfe159a5 JB	53	if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags))) {
	54	rq->errors = -ENXIO;
	55	if (rq->end_io)
	56	rq->end_io(rq, rq->errors);
	57	return;
	58	}
	59
86db1e29	60	rq->rq_disk = bd_disk;
86db1e29 JA	61	rq->end_io = done;
	62	WARN_ON(irqs_disabled());
	63	spin_lock_irq(q->queue_lock);
7eaceacc	64	__elv_add_request(q, rq, where);
24ecfbe2	65	__blk_run_queue(q);
addd0a09	66	/* the queue is stopped so it won't be run */
33659ebb	67	if (rq->cmd_type == REQ_TYPE_PM_RESUME)
9a2d43b7	68	q->request_fn(q);
86db1e29 JA	69	spin_unlock_irq(q->queue_lock);
	70	}
	71	EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
	72
	73	/**
	74	* blk_execute_rq - insert a request into queue for execution
	75	* @q: queue to insert the request in
	76	* @bd_disk: matching gendisk
	77	* @rq: request to insert
	78	* @at_head: insert request at head or tail of queue
	79	*
	80	* Description:
710027a4	81	* Insert a fully prepared request at the back of the I/O scheduler queue
86db1e29 JA	82	* for execution and wait for completion.
	83	*/
	84	int blk_execute_rq(struct request_queue q, struct gendisk bd_disk,
	85	struct request *rq, int at_head)
	86	{
	87	DECLARE_COMPLETION_ONSTACK(wait);
	88	char sense[SCSI_SENSE_BUFFERSIZE];
	89	int err = 0;
4b197769	90	unsigned long hang_check;
86db1e29 JA	91
	92	/*
	93	* we need an extra reference to the request, so we can look at
	94	* it after io completion
	95	*/
	96	rq->ref_count++;
	97
	98	if (!rq->sense) {
	99	memset(sense, 0, sizeof(sense));
	100	rq->sense = sense;
	101	rq->sense_len = 0;
	102	}
	103
	104	rq->end_io_data = &wait;
	105	blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
4b197769 ML	106
	107	/* Prevent hang_check timer from firing at us during very long I/O */
	108	hang_check = sysctl_hung_task_timeout_secs;
	109	if (hang_check)
	110	while (!wait_for_completion_timeout(&wait, hang_check * (HZ/2)));
	111	else
	112	wait_for_completion(&wait);
86db1e29 JA	113
	114	if (rq->errors)
	115	err = -EIO;
	116
	117	return err;
	118	}
86db1e29	119	EXPORT_SYMBOL(blk_execute_rq);