diff options
| -rw-r--r-- | block/bio.c | 57 |
1 files changed, 24 insertions, 33 deletions
diff --git a/block/bio.c b/block/bio.c index 101c2a9b5481..5de54dedab66 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1328,7 +1328,7 @@ struct bio *bio_map_user_iov(struct request_queue *q, struct page **pages; struct bio *bio; int cur_page = 0; - int ret, offset; + int ret; struct iov_iter i; struct iovec iov; struct bio_vec *bvec; @@ -1365,43 +1365,32 @@ struct bio *bio_map_user_iov(struct request_queue *q, if (!pages) goto out; - iov_for_each(iov, i, *iter) { - unsigned long uaddr = (unsigned long) iov.iov_base; - unsigned long len = iov.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; - - ret = get_user_pages_fast(uaddr, local_nr_pages, - (iter->type & WRITE) != WRITE, - &pages[cur_page]); - if (unlikely(ret < local_nr_pages)) { - for (j = cur_page; j < page_limit; j++) { - if (!pages[j]) - break; - put_page(pages[j]); - } - ret = -EFAULT; + i = *iter; + while (iov_iter_count(&i)) { + ssize_t bytes; + size_t offs, added = 0; + int npages; + + bytes = iov_iter_get_pages(&i, pages + cur_page, LONG_MAX, + nr_pages - cur_page, &offs); + if (unlikely(bytes <= 0)) { + ret = bytes ? bytes : -EFAULT; goto out_unmap; } - offset = offset_in_page(uaddr); - for (j = cur_page; j < page_limit; j++) { - unsigned int bytes = PAGE_SIZE - offset; + npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE); + + for (j = cur_page; j < cur_page + npages; j++) { + unsigned int n = PAGE_SIZE - offs; unsigned short prev_bi_vcnt = bio->bi_vcnt; - if (len <= 0) - break; - - if (bytes > len) - bytes = len; + if (n > bytes) + n = bytes; /* * sorry... */ - if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < - bytes) + if (bio_add_pc_page(q, bio, pages[j], n, offs) < n) break; /* @@ -1411,16 +1400,18 @@ struct bio *bio_map_user_iov(struct request_queue *q, if (bio->bi_vcnt == prev_bi_vcnt) put_page(pages[j]); - len -= bytes; - offset = 0; + added += n; + bytes -= n; + offs = 0; } + iov_iter_advance(&i, added); - cur_page = j; /* * release the pages we didn't map into the bio, if any */ - while (j < page_limit) + while (j < cur_page + npages) put_page(pages[j++]); + cur_page = j; } kfree(pages); |