diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/bio.c | 36 |
1 files changed, 22 insertions, 14 deletions
@@ -788,6 +788,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q, int i, ret; int nr_pages = 0; unsigned int len = 0; + unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0; for (i = 0; i < iov_count; i++) { unsigned long uaddr; @@ -814,35 +815,42 @@ struct bio *bio_copy_user_iov(struct request_queue *q, bio->bi_rw |= (!write_to_vm << BIO_RW); ret = 0; - i = 0; + + if (map_data) { + nr_pages = 1 << map_data->page_order; + i = map_data->offset / PAGE_SIZE; + } while (len) { - unsigned int bytes; + unsigned int bytes = PAGE_SIZE; - if (map_data) - bytes = 1U << (PAGE_SHIFT + map_data->page_order); - else - bytes = PAGE_SIZE; + bytes -= offset; if (bytes > len) bytes = len; if (map_data) { - if (i == map_data->nr_entries) { + if (i == map_data->nr_entries * nr_pages) { ret = -ENOMEM; break; } - page = map_data->pages[i++]; - } else + + page = map_data->pages[i / nr_pages]; + page += (i % nr_pages); + + i++; + } else { page = alloc_page(q->bounce_gfp | gfp_mask); - if (!page) { - ret = -ENOMEM; - break; + if (!page) { + ret = -ENOMEM; + break; + } } - if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) + if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) break; len -= bytes; + offset = 0; } if (ret) @@ -851,7 +859,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q, /* * success */ - if (!write_to_vm) { + if (!write_to_vm && (!map_data || !map_data->null_mapped)) { ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0); if (ret) goto cleanup; |