diff options
| -rw-r--r-- | drivers/block/ll_rw_blk.c | 64 | ||||
| -rw-r--r-- | drivers/block/scsi_ioctl.c | 34 | ||||
| -rw-r--r-- | fs/bio.c | 150 | ||||
| -rw-r--r-- | include/linux/bio.h | 4 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 1 |
5 files changed, 191 insertions, 62 deletions
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c index 42c4f36..874e46f 100644 --- a/drivers/block/ll_rw_blk.c +++ b/drivers/block/ll_rw_blk.c @@ -2149,6 +2149,50 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf, EXPORT_SYMBOL(blk_rq_map_user); /** + * blk_rq_map_user_iov - map user data to a request, for REQ_BLOCK_PC usage + * @q: request queue where request should be inserted + * @rq: request to map data to + * @iov: pointer to the iovec + * @iov_count: number of elements in the iovec + * + * Description: + * Data will be mapped directly for zero copy io, if possible. Otherwise + * a kernel bounce buffer is used. + * + * A matching blk_rq_unmap_user() must be issued at the end of io, while + * still in process context. + * + * Note: The mapped bio may need to be bounced through blk_queue_bounce() + * before being submitted to the device, as pages mapped may be out of + * reach. It's the callers responsibility to make sure this happens. The + * original bio must be passed back in to blk_rq_unmap_user() for proper + * unmapping. + */ +int blk_rq_map_user_iov(request_queue_t *q, struct request *rq, + struct sg_iovec *iov, int iov_count) +{ + struct bio *bio; + + if (!iov || iov_count <= 0) + return -EINVAL; + + /* we don't allow misaligned data like bio_map_user() does. If the + * user is using sg, they're expected to know the alignment constraints + * and respect them accordingly */ + bio = bio_map_user_iov(q, NULL, iov, iov_count, rq_data_dir(rq)== READ); + if (IS_ERR(bio)) + return PTR_ERR(bio); + + rq->bio = rq->biotail = bio; + blk_rq_bio_prep(q, rq, bio); + rq->buffer = rq->data = NULL; + rq->data_len = bio->bi_size; + return 0; +} + +EXPORT_SYMBOL(blk_rq_map_user_iov); + +/** * blk_rq_unmap_user - unmap a request with user data * @rq: request to be unmapped * @bio: bio for the request @@ -2207,6 +2251,19 @@ int blk_rq_map_kern(request_queue_t *q, struct request *rq, void *kbuf, EXPORT_SYMBOL(blk_rq_map_kern); +void blk_execute_rq_nowait(request_queue_t *q, struct gendisk *bd_disk, + struct request *rq, int at_head, + void (*done)(struct request *)) +{ + int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK; + + rq->rq_disk = bd_disk; + rq->flags |= REQ_NOMERGE; + rq->end_io = done; + elv_add_request(q, rq, where, 1); + generic_unplug_device(q); +} + /** * blk_execute_rq - insert a request into queue for execution * @q: queue to insert the request in @@ -2224,8 +2281,6 @@ int blk_execute_rq(request_queue_t *q, struct gendisk *bd_disk, char sense[SCSI_SENSE_BUFFERSIZE]; int err = 0; - rq->rq_disk = bd_disk; - /* * we need an extra reference to the request, so we can look at * it after io completion @@ -2238,11 +2293,8 @@ int blk_execute_rq(request_queue_t *q, struct gendisk *bd_disk, rq->sense_len = 0; } - rq->flags |= REQ_NOMERGE; rq->waiting = &wait; - rq->end_io = blk_end_sync_rq; - elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 1); - generic_unplug_device(q); + blk_execute_rq_nowait(q, bd_disk, rq, 0, blk_end_sync_rq); wait_for_completion(&wait); rq->waiting = NULL; diff --git a/drivers/block/scsi_ioctl.c b/drivers/block/scsi_ioctl.c index 93c4ca8..09a7e73 100644 --- a/drivers/block/scsi_ioctl.c +++ b/drivers/block/scsi_ioctl.c @@ -231,17 +231,11 @@ static int sg_io(struct file *file, request_queue_t *q, if (verify_command(file, cmd)) return -EPERM; - /* - * we'll do that later - */ - if (hdr->iovec_count) - return -EOPNOTSUPP; - if (hdr->dxfer_len > (q->max_sectors << 9)) return -EIO; reading = writing = 0; - if (hdr->dxfer_len) { + if (hdr->dxfer_len) switch (hdr->dxfer_direction) { default: return -EINVAL; @@ -261,11 +255,29 @@ static int sg_io(struct file *file, request_queue_t *q, if (!rq) return -ENOMEM; - if (reading || writing) { - ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len); - if (ret) + if (hdr->iovec_count) { + const int size = sizeof(struct sg_iovec) * hdr->iovec_count; + struct sg_iovec *iov; + + iov = kmalloc(size, GFP_KERNEL); + if (!iov) { + ret = -ENOMEM; goto out; - } + } + + if (copy_from_user(iov, hdr->dxferp, size)) { + kfree(iov); + ret = -EFAULT; + goto out; + } + + ret = blk_rq_map_user_iov(q, rq, iov, hdr->iovec_count); + kfree(iov); + } else if (hdr->dxfer_len) + ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len); + + if (ret) + goto out; /* * fill in request structure @@ -25,6 +25,7 @@ #include <linux/module.h> #include <linux/mempool.h> #include <linux/workqueue.h> +#include <scsi/sg.h> /* for struct sg_iovec */ #define BIO_POOL_SIZE 256 @@ -549,22 +550,34 @@ out_bmd: return ERR_PTR(ret); } -static struct bio *__bio_map_user(request_queue_t *q, struct block_device *bdev, - unsigned long uaddr, unsigned int len, - int write_to_vm) +static struct bio *__bio_map_user_iov(request_queue_t *q, + struct block_device *bdev, + struct sg_iovec *iov, int iov_count, + int write_to_vm) { - unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; - unsigned long start = uaddr >> PAGE_SHIFT; - const int nr_pages = end - start; - int ret, offset, i; + int i, j; + int nr_pages = 0; struct page **pages; struct bio *bio; + int cur_page = 0; + int ret, offset; - /* - * transfer and buffer must be aligned to at least hardsector - * size for now, in the future we can relax this restriction - */ - if ((uaddr & queue_dma_alignment(q)) || (len & queue_dma_alignment(q))) + for (i = 0; i < iov_count; i++) { + unsigned long uaddr = (unsigned long)iov[i].iov_base; + unsigned long len = iov[i].iov_len; + unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned long start = uaddr >> PAGE_SHIFT; + + nr_pages += end - start; + /* + * transfer and buffer must be aligned to at least hardsector + * size for now, in the future we can relax this restriction + */ + if ((uaddr & queue_dma_alignment(q)) || (len & queue_dma_alignment(q))) + return ERR_PTR(-EINVAL); + } + + if (!nr_pages) return ERR_PTR(-EINVAL); bio = bio_alloc(GFP_KERNEL, nr_pages); @@ -576,42 +589,54 @@ static struct bio *__bio_map_user(request_queue_t *q, struct block_device *bdev, if (!pages) goto out; - down_read(¤t->mm->mmap_sem); - ret = get_user_pages(current, current->mm, uaddr, nr_pages, - write_to_vm, 0, pages, NULL); - up_read(¤t->mm->mmap_sem); - - if (ret < nr_pages) - goto out; - - bio->bi_bdev = bdev; - - offset = uaddr & ~PAGE_MASK; - for (i = 0; i < nr_pages; i++) { - unsigned int bytes = PAGE_SIZE - offset; - - if (len <= 0) - break; - - if (bytes > len) - bytes = len; + memset(pages, 0, nr_pages * sizeof(struct page *)); + + for (i = 0; i < iov_count; i++) { + unsigned long uaddr = (unsigned long)iov[i].iov_base; + unsigned long len = iov[i].iov_len; + unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned long start = uaddr >> PAGE_SHIFT; + const int local_nr_pages = end - start; + const int page_limit = cur_page + local_nr_pages; + + down_read(¤t->mm->mmap_sem); + ret = get_user_pages(current, current->mm, uaddr, + local_nr_pages, + write_to_vm, 0, &pages[cur_page], NULL); + up_read(¤t->mm->mmap_sem); + + if (ret < local_nr_pages) + goto out_unmap; + + + offset = uaddr & ~PAGE_MASK; + for (j = cur_page; j < page_limit; j++) { + unsigned int bytes = PAGE_SIZE - offset; + + if (len <= 0) + break; + + if (bytes > len) + bytes = len; + + /* + * sorry... + */ + if (__bio_add_page(q, bio, pages[j], bytes, offset) < bytes) + break; + + len -= bytes; + offset = 0; + } + cur_page = j; /* - * sorry... + * release the pages we didn't map into the bio, if any */ - if (__bio_add_page(q, bio, pages[i], bytes, offset) < bytes) - break; - - len -= bytes; - offset = 0; + while (j < page_limit) + page_cache_release(pages[j++]); } - /* - * release the pages we didn't map into the bio, if any - */ - while (i < nr_pages) - page_cache_release(pages[i++]); - kfree(pages); /* @@ -620,9 +645,17 @@ static struct bio *__bio_map_user(request_queue_t *q, struct block_device *bdev, if (!write_to_vm) bio->bi_rw |= (1 << BIO_RW); + bio->bi_bdev = bdev; bio->bi_flags |= (1 << BIO_USER_MAPPED); return bio; -out: + + out_unmap: + for (i = 0; i < nr_pages; i++) { + if(!pages[i]) + break; + page_cache_release(pages[i]); + } + out: kfree(pages); bio_put(bio); return ERR_PTR(ret); @@ -642,9 +675,33 @@ out: struct bio *bio_map_user(request_queue_t *q, struct block_device *bdev, unsigned long uaddr, unsigned int len, int write_to_vm) { + struct sg_iovec iov; + + iov.iov_base = (__user void *)uaddr; + iov.iov_len = len; + + return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm); +} + +/** + * bio_map_user_iov - map user sg_iovec table into bio + * @q: the request_queue_t for the bio + * @bdev: destination block device + * @iov: the iovec. + * @iov_count: number of elements in the iovec + * @write_to_vm: bool indicating writing to pages or not + * + * Map the user space address into a bio suitable for io to a block + * device. Returns an error pointer in case of error. + */ +struct bio *bio_map_user_iov(request_queue_t *q, struct block_device *bdev, + struct sg_iovec *iov, int iov_count, + int write_to_vm) +{ struct bio *bio; + int len = 0, i; - bio = __bio_map_user(q, bdev, uaddr, len, write_to_vm); + bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm); if (IS_ERR(bio)) return bio; @@ -657,6 +714,9 @@ struct bio *bio_map_user(request_queue_t *q, struct block_device *bdev, */ bio_get(bio); + for (i = 0; i < iov_count; i++) + len += iov[i].iov_len; + if (bio->bi_size == len) return bio; diff --git a/include/linux/bio.h b/include/linux/bio.h index 1dd2bc2..ebcd03b 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -281,6 +281,10 @@ extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); extern int bio_get_nr_vecs(struct block_device *); extern struct bio *bio_map_user(struct request_queue *, struct block_device *, unsigned long, unsigned int, int); +struct sg_iovec; +extern struct bio *bio_map_user_iov(struct request_queue *, + struct block_device *, + struct sg_iovec *, int, int); extern void bio_unmap_user(struct bio *); extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int, unsigned int); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index fc0dce0..0430ea3 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -561,6 +561,7 @@ extern void blk_queue_activity_fn(request_queue_t *, activity_fn *, void *); 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_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, 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) |