1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (c) 2019 Christoph Hellwig. |
4 | */ |
5 | #include "xfs.h" |
6 | |
7 | static inline unsigned int bio_max_vecs(unsigned int count) |
8 | { |
9 | return bio_max_segs(howmany(count, PAGE_SIZE)); |
10 | } |
11 | |
12 | int |
13 | xfs_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(x: 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(vaddr: data, size: count); |
28 | |
29 | bio = bio_alloc(bdev, nr_vecs: bio_max_vecs(count: left), opf: 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(addr: 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(bdev: prev->bi_bdev, nr_vecs: bio_max_vecs(count: left), |
42 | opf: prev->bi_opf, GFP_KERNEL); |
43 | bio->bi_iter.bi_sector = bio_end_sector(prev); |
44 | bio_chain(prev, bio); |
45 | |
46 | submit_bio(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(vaddr: data, size: count); |
58 | return error; |
59 | } |
60 | |