1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (c) 2019 Christoph Hellwig.
4*4882a593Smuzhiyun */
5*4882a593Smuzhiyun #include "xfs.h"
6*4882a593Smuzhiyun
bio_max_vecs(unsigned int count)7*4882a593Smuzhiyun static inline unsigned int bio_max_vecs(unsigned int count)
8*4882a593Smuzhiyun {
9*4882a593Smuzhiyun return min_t(unsigned, howmany(count, PAGE_SIZE), BIO_MAX_PAGES);
10*4882a593Smuzhiyun }
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun int
xfs_rw_bdev(struct block_device * bdev,sector_t sector,unsigned int count,char * data,unsigned int op)13*4882a593Smuzhiyun xfs_rw_bdev(
14*4882a593Smuzhiyun struct block_device *bdev,
15*4882a593Smuzhiyun sector_t sector,
16*4882a593Smuzhiyun unsigned int count,
17*4882a593Smuzhiyun char *data,
18*4882a593Smuzhiyun unsigned int op)
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun {
21*4882a593Smuzhiyun unsigned int is_vmalloc = is_vmalloc_addr(data);
22*4882a593Smuzhiyun unsigned int left = count;
23*4882a593Smuzhiyun int error;
24*4882a593Smuzhiyun struct bio *bio;
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun if (is_vmalloc && op == REQ_OP_WRITE)
27*4882a593Smuzhiyun flush_kernel_vmap_range(data, count);
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun bio = bio_alloc(GFP_KERNEL, bio_max_vecs(left));
30*4882a593Smuzhiyun bio_set_dev(bio, bdev);
31*4882a593Smuzhiyun bio->bi_iter.bi_sector = sector;
32*4882a593Smuzhiyun bio->bi_opf = op | REQ_META | REQ_SYNC;
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun do {
35*4882a593Smuzhiyun struct page *page = kmem_to_page(data);
36*4882a593Smuzhiyun unsigned int off = offset_in_page(data);
37*4882a593Smuzhiyun unsigned int len = min_t(unsigned, left, PAGE_SIZE - off);
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun while (bio_add_page(bio, page, len, off) != len) {
40*4882a593Smuzhiyun struct bio *prev = bio;
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun bio = bio_alloc(GFP_KERNEL, bio_max_vecs(left));
43*4882a593Smuzhiyun bio_copy_dev(bio, prev);
44*4882a593Smuzhiyun bio->bi_iter.bi_sector = bio_end_sector(prev);
45*4882a593Smuzhiyun bio->bi_opf = prev->bi_opf;
46*4882a593Smuzhiyun bio_chain(prev, bio);
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun submit_bio(prev);
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun data += len;
52*4882a593Smuzhiyun left -= len;
53*4882a593Smuzhiyun } while (left > 0);
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun error = submit_bio_wait(bio);
56*4882a593Smuzhiyun bio_put(bio);
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun if (is_vmalloc && op == REQ_OP_READ)
59*4882a593Smuzhiyun invalidate_kernel_vmap_range(data, count);
60*4882a593Smuzhiyun return error;
61*4882a593Smuzhiyun }
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