From dd1cab95f356f1395278633565f198463cf6bd24 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 20 Jun 2005 14:06:01 +0200 Subject: [PATCH] [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: Jens Axboe --- drivers/block/ll_rw_blk.c | 68 +++++++++++++++----------------------- drivers/block/scsi_ioctl.c | 23 ++++++++----- drivers/cdrom/cdrom.c | 13 +++++--- include/linux/blkdev.h | 7 ++-- 4 files changed, 53 insertions(+), 58 deletions(-) diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c index 1471aca6fa1..42c4f3651cf 100644 --- a/drivers/block/ll_rw_blk.c +++ b/drivers/block/ll_rw_blk.c @@ -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, - unsigned int len) +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); @@ -2184,39 +2180,29 @@ 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, - unsigned int len, unsigned int gfp_mask) +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) - bio->bi_rw |= (1 << BIO_RW); + if (IS_ERR(bio)) + return PTR_ERR(bio); - rq->bio = rq->biotail = bio; - blk_rq_bio_prep(q, rq, bio); + if (rq_data_dir(rq) == WRITE) + bio->bi_rw |= (1 << BIO_RW); - rq->buffer = rq->data = NULL; - rq->data_len = len; - return rq; - } + rq->bio = rq->biotail = bio; + blk_rq_bio_prep(q, rq, bio); - /* - * bio is the err-ptr - */ - blk_put_request(rq); - return (struct request *) bio; + rq->buffer = rq->data = NULL; + rq->data_len = len; + return 0; } EXPORT_SYMBOL(blk_rq_map_kern); diff --git a/drivers/block/scsi_ioctl.c b/drivers/block/scsi_ioctl.c index 681871ca5d6..93c4ca874be 100644 --- a/drivers/block/scsi_ioctl.c +++ b/drivers/block/scsi_ioctl.c @@ -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 */ diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index beaa561f2ed..6a7d926774a 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -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; } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 67339bc5f6b..fc0dce07861 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -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) -- 2.20.1