60 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2019 Christoph Hellwig.4 */5#include "xfs.h"6 7static inline unsigned int bio_max_vecs(unsigned int count)8{9 return bio_max_segs(howmany(count, PAGE_SIZE));10}11 12int13xfs_rw_bdev(14 struct block_device *bdev,15 sector_t sector,16 unsigned int count,17 char *data,18 enum req_op op)19 20{21 unsigned int is_vmalloc = is_vmalloc_addr(data);22 unsigned int left = count;23 int error;24 struct bio *bio;25 26 if (is_vmalloc && op == REQ_OP_WRITE)27 flush_kernel_vmap_range(data, count);28 29 bio = bio_alloc(bdev, bio_max_vecs(left), op | REQ_META | REQ_SYNC,30 GFP_KERNEL);31 bio->bi_iter.bi_sector = sector;32 33 do {34 struct page *page = kmem_to_page(data);35 unsigned int off = offset_in_page(data);36 unsigned int len = min_t(unsigned, left, PAGE_SIZE - off);37 38 while (bio_add_page(bio, page, len, off) != len) {39 struct bio *prev = bio;40 41 bio = bio_alloc(prev->bi_bdev, bio_max_vecs(left),42 prev->bi_opf, GFP_KERNEL);43 bio->bi_iter.bi_sector = bio_end_sector(prev);44 bio_chain(prev, bio);45 46 submit_bio(prev);47 }48 49 data += len;50 left -= len;51 } while (left > 0);52 53 error = submit_bio_wait(bio);54 bio_put(bio);55 56 if (is_vmalloc && op == REQ_OP_READ)57 invalidate_kernel_vmap_range(data, count);58 return error;59}60