1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * RDMA Network Block Driver
4 *
5 * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
6 * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
7 * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
8 */
9#undef pr_fmt
10#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
11
12#include "rnbd-srv-dev.h"
13#include "rnbd-log.h"
14
15struct rnbd_dev *rnbd_dev_open(const char *path, fmode_t flags,
16			       struct bio_set *bs)
17{
18	struct rnbd_dev *dev;
19	int ret;
20
21	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
22	if (!dev)
23		return ERR_PTR(-ENOMEM);
24
25	dev->blk_open_flags = flags;
26	dev->bdev = blkdev_get_by_path(path, flags, THIS_MODULE);
27	ret = PTR_ERR_OR_ZERO(dev->bdev);
28	if (ret)
29		goto err;
30
31	dev->blk_open_flags = flags;
32	bdevname(dev->bdev, dev->name);
33	dev->ibd_bio_set = bs;
34
35	return dev;
36
37err:
38	kfree(dev);
39	return ERR_PTR(ret);
40}
41
42void rnbd_dev_close(struct rnbd_dev *dev)
43{
44	blkdev_put(dev->bdev, dev->blk_open_flags);
45	kfree(dev);
46}
47
48void rnbd_dev_bi_end_io(struct bio *bio)
49{
50	struct rnbd_dev_blk_io *io = bio->bi_private;
51
52	rnbd_endio(io->priv, blk_status_to_errno(bio->bi_status));
53	bio_put(bio);
54}
55
56/**
57 *	rnbd_bio_map_kern	-	map kernel address into bio
58 *	@data: pointer to buffer to map
59 *	@bs: bio_set to use.
60 *	@len: length in bytes
61 *	@gfp_mask: allocation flags for bio allocation
62 *
63 *	Map the kernel address into a bio suitable for io to a block
64 *	device. Returns an error pointer in case of error.
65 */
66struct bio *rnbd_bio_map_kern(void *data, struct bio_set *bs,
67			      unsigned int len, gfp_t gfp_mask)
68{
69	unsigned long kaddr = (unsigned long)data;
70	unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
71	unsigned long start = kaddr >> PAGE_SHIFT;
72	const int nr_pages = end - start;
73	int offset, i;
74	struct bio *bio;
75
76	bio = bio_alloc_bioset(gfp_mask, nr_pages, bs);
77	if (!bio)
78		return ERR_PTR(-ENOMEM);
79
80	offset = offset_in_page(kaddr);
81	for (i = 0; i < nr_pages; i++) {
82		unsigned int bytes = PAGE_SIZE - offset;
83
84		if (len <= 0)
85			break;
86
87		if (bytes > len)
88			bytes = len;
89
90		if (bio_add_page(bio, virt_to_page(data), bytes,
91				    offset) < bytes) {
92			/* we don't support partial mappings */
93			bio_put(bio);
94			return ERR_PTR(-EINVAL);
95		}
96
97		data += bytes;
98		len -= bytes;
99		offset = 0;
100	}
101
102	return bio;
103}
104