Commit dd1cab95 authored by Jens Axboe's avatar Jens Axboe
Browse files

[PATCH] Cleanup blk_rq_map_* interfaces 



Change the blk_rq_map_user() and blk_rq_map_kern() interface to require
a previously allocated request to be passed in. This is both more efficient
for multiple iterations of mapping data to the same request, and it is also
a much nicer API.

Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent b823825e

drivers/block/ll_rw_blk.c

+27 −41
Original line number Diff line number Diff line
@@ -2107,21 +2107,19 @@ EXPORT_SYMBOL(blk_insert_request); 
 *    original bio must be passed back in to blk_rq_unmap_user() for proper

 *    unmapping.

 */

struct request *blk_rq_map_user(request_queue_t *q, int rw, void __user *ubuf,

int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,

		    unsigned int len)

{

	unsigned long uaddr;

	struct request *rq;

	struct bio *bio;

	int reading;



	if (len > (q->max_sectors << 9))

		return ERR_PTR(-EINVAL);

	if ((!len && ubuf) || (len && !ubuf))

		return ERR_PTR(-EINVAL);

		return -EINVAL;

	if (!len || !ubuf)

		return -EINVAL;



	rq = blk_get_request(q, rw, __GFP_WAIT);

	if (!rq)

		return ERR_PTR(-ENOMEM);

	reading = rq_data_dir(rq) == READ;



	/*

	 * if alignment requirement is satisfied, map in user pages for
@@ -2129,9 +2127,9 @@ struct request *blk_rq_map_user(request_queue_t *q, int rw, void __user *ubuf, 
	 */

	uaddr = (unsigned long) ubuf;

	if (!(uaddr & queue_dma_alignment(q)) && !(len & queue_dma_alignment(q)))

		bio = bio_map_user(q, NULL, uaddr, len, rw == READ);

		bio = bio_map_user(q, NULL, uaddr, len, reading);

	else

		bio = bio_copy_user(q, uaddr, len, rw == READ);

		bio = bio_copy_user(q, uaddr, len, reading);



	if (!IS_ERR(bio)) {

		rq->bio = rq->biotail = bio;
@@ -2139,14 +2137,13 @@ struct request *blk_rq_map_user(request_queue_t *q, int rw, void __user *ubuf, 


		rq->buffer = rq->data = NULL;

		rq->data_len = len;

		return rq;

		return 0;

	}



	/*

	 * bio is the err-ptr

	 */

	blk_put_request(rq);

	return (struct request *) bio;

	return PTR_ERR(bio);

}



EXPORT_SYMBOL(blk_rq_map_user);
@@ -2160,7 +2157,7 @@ EXPORT_SYMBOL(blk_rq_map_user); 
 * Description:

 *    Unmap a request previously mapped by blk_rq_map_user().

 */

int blk_rq_unmap_user(struct request *rq, struct bio *bio, unsigned int ulen)

int blk_rq_unmap_user(struct bio *bio, unsigned int ulen)

{

	int ret = 0;
@@ -2171,8 +2168,7 @@ int blk_rq_unmap_user(struct request *rq, struct bio *bio, unsigned int ulen) 
			ret = bio_uncopy_user(bio);

	}



	blk_put_request(rq);

	return ret;

	return 0;

}



EXPORT_SYMBOL(blk_rq_unmap_user);
@@ -2184,24 +2180,21 @@ EXPORT_SYMBOL(blk_rq_unmap_user); 
 * @kbuf:	the kernel buffer

 * @len:	length of user data

 */

struct request *blk_rq_map_kern(request_queue_t *q, int rw, void *kbuf,

int blk_rq_map_kern(request_queue_t *q, struct request *rq, void *kbuf,

		    unsigned int len, unsigned int gfp_mask)

{

	struct request *rq;

	struct bio *bio;



	if (len > (q->max_sectors << 9))

		return ERR_PTR(-EINVAL);

	if ((!len && kbuf) || (len && !kbuf))

		return ERR_PTR(-EINVAL);



	rq = blk_get_request(q, rw, gfp_mask);

	if (!rq)

		return ERR_PTR(-ENOMEM);

		return -EINVAL;

	if (!len || !kbuf)

		return -EINVAL;



	bio = bio_map_kern(q, kbuf, len, gfp_mask);

	if (!IS_ERR(bio)) {

		if (rw)

	if (IS_ERR(bio))

		return PTR_ERR(bio);



	if (rq_data_dir(rq) == WRITE)

		bio->bi_rw |= (1 << BIO_RW);



	rq->bio = rq->biotail = bio;
@@ -2209,14 +2202,7 @@ struct request *blk_rq_map_kern(request_queue_t *q, int rw, void *kbuf, 


	rq->buffer = rq->data = NULL;

	rq->data_len = len;

		return rq;

	}



	/*

	 * bio is the err-ptr

	 */

	blk_put_request(rq);

	return (struct request *) bio;

	return 0;

}



EXPORT_SYMBOL(blk_rq_map_kern);

drivers/block/scsi_ioctl.c

+14 −9
Original line number Diff line number Diff line
@@ -216,7 +216,7 @@ static int sg_io(struct file *file, request_queue_t *q, 
		struct gendisk *bd_disk, struct sg_io_hdr *hdr)

{

	unsigned long start_time;

	int reading, writing;

	int reading, writing, ret;

	struct request *rq;

	struct bio *bio;

	char sense[SCSI_SENSE_BUFFERSIZE];
@@ -255,14 +255,17 @@ static int sg_io(struct file *file, request_queue_t *q, 
			reading = 1;

			break;

		}

	}



		rq = blk_rq_map_user(q, writing ? WRITE : READ, hdr->dxferp,

				     hdr->dxfer_len);

	rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);

	if (!rq)

		return -ENOMEM;



		if (IS_ERR(rq))

			return PTR_ERR(rq);

	} else

		rq = blk_get_request(q, READ, __GFP_WAIT);

	if (reading || writing) {

		ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);

		if (ret)

			goto out;

	}



	/*

	 * fill in request structure
@@ -321,11 +324,13 @@ static int sg_io(struct file *file, request_queue_t *q, 
	}



	if (blk_rq_unmap_user(rq, bio, hdr->dxfer_len))

		return -EFAULT;

		ret = -EFAULT;



	/* may not have succeeded, but output values written to control

	 * structure (struct sg_io_hdr).  */

	return 0;

out:

	blk_put_request(rq);

	return ret;

}



#define OMAX_SB_LEN 16          /* For backward compatibility */

drivers/cdrom/cdrom.c

+9 −4
Original line number Diff line number Diff line
@@ -2097,6 +2097,10 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf, 
	if (!q)

		return -ENXIO;



	rq = blk_get_request(q, READ, GFP_KERNEL);

	if (!rq)

		return -ENOMEM;



	cdi->last_sense = 0;



	while (nframes) {
@@ -2108,9 +2112,9 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf, 


		len = nr * CD_FRAMESIZE_RAW;



		rq = blk_rq_map_user(q, READ, ubuf, len);

		if (IS_ERR(rq))

			return PTR_ERR(rq);

		ret = blk_rq_map_user(q, rq, ubuf, len);

		if (ret)

			break;



		memset(rq->cmd, 0, sizeof(rq->cmd));

		rq->cmd[0] = GPCMD_READ_CD;
@@ -2138,7 +2142,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf, 
			cdi->last_sense = s->sense_key;

		}



		if (blk_rq_unmap_user(rq, bio, len))

		if (blk_rq_unmap_user(bio, len))

			ret = -EFAULT;



		if (ret)
@@ -2149,6 +2153,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf, 
		ubuf += len;

	}



	blk_put_request(rq);

	return ret;

}

include/linux/blkdev.h

+3 −4
Original line number Diff line number Diff line
@@ -558,10 +558,9 @@ extern void blk_sync_queue(struct request_queue *q); 
extern void __blk_stop_queue(request_queue_t *q);

extern void blk_run_queue(request_queue_t *);

extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *);

extern struct request *blk_rq_map_user(request_queue_t *, int, void __user *, unsigned int);

extern int blk_rq_unmap_user(struct request *, struct bio *, unsigned int);

extern struct request *blk_rq_map_kern(request_queue_t *, int, void *,

					unsigned int, unsigned int);

extern int blk_rq_map_user(request_queue_t *, struct request *, void __user *, unsigned int);

extern int blk_rq_unmap_user(struct bio *, unsigned int);

extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, unsigned int);

extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *);



static inline request_queue_t *bdev_get_queue(struct block_device *bdev)

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