xfs_bio_io.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 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
12int
13xfs_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		done = 0, added;
22	int			error;
23	struct bio		*bio;
24
25	op |= REQ_META | REQ_SYNC;
26	if (!is_vmalloc_addr(data))
27		return bdev_rw_virt(bdev, sector, data, count, op);
28
29	bio = bio_alloc(bdev, bio_max_vecs(count), op, GFP_KERNEL);
30	bio->bi_iter.bi_sector = sector;
31
32	do {
33		added = bio_add_vmalloc_chunk(bio, data + done, count - done);
34		if (!added) {
35			struct bio	*prev = bio;
36
37			bio = bio_alloc(prev->bi_bdev,
38					bio_max_vecs(count - done),
39					prev->bi_opf, GFP_KERNEL);
40			bio->bi_iter.bi_sector = bio_end_sector(prev);
41			bio_chain(prev, bio);
42			submit_bio(prev);
43		}
44		done += added;
45	} while (done < count);
46
47	error = submit_bio_wait(bio);
48	bio_put(bio);
49
50	if (op == REQ_OP_READ)
51		invalidate_kernel_vmap_range(data, count);
52	return error;
53}