diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/bio.c | 158 |
1 files changed, 117 insertions, 41 deletions
@@ -444,22 +444,27 @@ int bio_add_page(struct bio *bio, struct page *page, unsigned int len, struct bio_map_data { struct bio_vec *iovecs; - void __user *userptr; + int nr_sgvecs; + struct sg_iovec *sgvecs; }; -static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio) +static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio, + struct sg_iovec *iov, int iov_count) { memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt); + memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count); + bmd->nr_sgvecs = iov_count; bio->bi_private = bmd; } static void bio_free_map_data(struct bio_map_data *bmd) { kfree(bmd->iovecs); + kfree(bmd->sgvecs); kfree(bmd); } -static struct bio_map_data *bio_alloc_map_data(int nr_segs) +static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count) { struct bio_map_data *bmd = kmalloc(sizeof(*bmd), GFP_KERNEL); @@ -467,13 +472,71 @@ static struct bio_map_data *bio_alloc_map_data(int nr_segs) return NULL; bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, GFP_KERNEL); - if (bmd->iovecs) + if (!bmd->iovecs) { + kfree(bmd); + return NULL; + } + + bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, GFP_KERNEL); + if (bmd->sgvecs) return bmd; + kfree(bmd->iovecs); kfree(bmd); return NULL; } +static int __bio_copy_iov(struct bio *bio, struct sg_iovec *iov, int iov_count, + int uncopy) +{ + int ret = 0, i; + struct bio_vec *bvec; + int iov_idx = 0; + unsigned int iov_off = 0; + int read = bio_data_dir(bio) == READ; + + __bio_for_each_segment(bvec, bio, i, 0) { + char *bv_addr = page_address(bvec->bv_page); + unsigned int bv_len = bvec->bv_len; + + while (bv_len && iov_idx < iov_count) { + unsigned int bytes; + char *iov_addr; + + bytes = min_t(unsigned int, + iov[iov_idx].iov_len - iov_off, bv_len); + iov_addr = iov[iov_idx].iov_base + iov_off; + + if (!ret) { + if (!read && !uncopy) + ret = copy_from_user(bv_addr, iov_addr, + bytes); + if (read && uncopy) + ret = copy_to_user(iov_addr, bv_addr, + bytes); + + if (ret) + ret = -EFAULT; + } + + bv_len -= bytes; + bv_addr += bytes; + iov_addr += bytes; + iov_off += bytes; + + if (iov[iov_idx].iov_len == iov_off) { + iov_idx++; + iov_off = 0; + } + } + + if (uncopy) + __free_page(bvec->bv_page); + } + + return ret; +} + /** * bio_uncopy_user - finish previously mapped bio * @bio: bio being terminated @@ -484,55 +547,56 @@ static struct bio_map_data *bio_alloc_map_data(int nr_segs) int bio_uncopy_user(struct bio *bio) { struct bio_map_data *bmd = bio->bi_private; - const int read = bio_data_dir(bio) == READ; - struct bio_vec *bvec; - int i, ret = 0; + int ret; - __bio_for_each_segment(bvec, bio, i, 0) { - char *addr = page_address(bvec->bv_page); - unsigned int len = bmd->iovecs[i].bv_len; + ret = __bio_copy_iov(bio, bmd->sgvecs, bmd->nr_sgvecs, 1); - if (read && !ret && copy_to_user(bmd->userptr, addr, len)) - ret = -EFAULT; - - __free_page(bvec->bv_page); - bmd->userptr += len; - } bio_free_map_data(bmd); bio_put(bio); return ret; } /** - * bio_copy_user - copy user data to bio + * bio_copy_user_iov - copy user data to bio * @q: destination block queue - * @uaddr: start of user address - * @len: length in bytes + * @iov: the iovec. + * @iov_count: number of elements in the iovec * @write_to_vm: bool indicating writing to pages or not * * Prepares and returns a bio for indirect user io, bouncing data * to/from kernel pages as necessary. Must be paired with * call bio_uncopy_user() on io completion. */ -struct bio *bio_copy_user(struct request_queue *q, unsigned long uaddr, - unsigned int len, int write_to_vm) +struct bio *bio_copy_user_iov(struct request_queue *q, 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; struct bio_map_data *bmd; struct bio_vec *bvec; struct page *page; struct bio *bio; int i, ret; + int nr_pages = 0; + unsigned int len = 0; - bmd = bio_alloc_map_data(end - start); + for (i = 0; i < iov_count; i++) { + unsigned long uaddr; + unsigned long end; + unsigned long start; + + uaddr = (unsigned long)iov[i].iov_base; + end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; + start = uaddr >> PAGE_SHIFT; + + nr_pages += end - start; + len += iov[i].iov_len; + } + + bmd = bio_alloc_map_data(nr_pages, iov_count); if (!bmd) return ERR_PTR(-ENOMEM); - bmd->userptr = (void __user *) uaddr; - ret = -ENOMEM; - bio = bio_alloc(GFP_KERNEL, end - start); + bio = bio_alloc(GFP_KERNEL, nr_pages); if (!bio) goto out_bmd; @@ -564,22 +628,12 @@ struct bio *bio_copy_user(struct request_queue *q, unsigned long uaddr, * success */ if (!write_to_vm) { - char __user *p = (char __user *) uaddr; - - /* - * for a write, copy in data to kernel pages - */ - ret = -EFAULT; - bio_for_each_segment(bvec, bio, i) { - char *addr = page_address(bvec->bv_page); - - if (copy_from_user(addr, p, bvec->bv_len)) - goto cleanup; - p += bvec->bv_len; - } + ret = __bio_copy_iov(bio, iov, iov_count, 0); + if (ret) + goto cleanup; } - bio_set_map_data(bmd, bio); + bio_set_map_data(bmd, bio, iov, iov_count); return bio; cleanup: bio_for_each_segment(bvec, bio, i) @@ -591,6 +645,28 @@ out_bmd: return ERR_PTR(ret); } +/** + * bio_copy_user - copy user data to bio + * @q: destination block queue + * @uaddr: start of user address + * @len: length in bytes + * @write_to_vm: bool indicating writing to pages or not + * + * Prepares and returns a bio for indirect user io, bouncing data + * to/from kernel pages as necessary. Must be paired with + * call bio_uncopy_user() on io completion. + */ +struct bio *bio_copy_user(struct request_queue *q, unsigned long uaddr, + unsigned int len, int write_to_vm) +{ + struct sg_iovec iov; + + iov.iov_base = (void __user *)uaddr; + iov.iov_len = len; + + return bio_copy_user_iov(q, &iov, 1, write_to_vm); +} + static struct bio *__bio_map_user_iov(struct request_queue *q, struct block_device *bdev, struct sg_iovec *iov, int iov_count, |