tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
48static void 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 */
66static struct 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 bio->bi_end_io = bio_put;
103 return bio;
104}
105
106int rnbd_dev_submit_io(struct rnbd_dev *dev, sector_t sector, void *data,
107 size_t len, u32 bi_size, enum rnbd_io_flags flags,
108 short prio, void *priv)
109{
110 struct rnbd_dev_blk_io *io;
111 struct bio *bio;
112
113 /* Generate bio with pages pointing to the rdma buffer */
114 bio = rnbd_bio_map_kern(data, dev->ibd_bio_set, len, GFP_KERNEL);
115 if (IS_ERR(bio))
116 return PTR_ERR(bio);
117
118 io = container_of(bio, struct rnbd_dev_blk_io, bio);
119
120 io->dev = dev;
121 io->priv = priv;
122
123 bio->bi_end_io = rnbd_dev_bi_end_io;
124 bio->bi_private = io;
125 bio->bi_opf = rnbd_to_bio_flags(flags);
126 bio->bi_iter.bi_sector = sector;
127 bio->bi_iter.bi_size = bi_size;
128 bio_set_prio(bio, prio);
129 bio_set_dev(bio, dev->bdev);
130
131 submit_bio(bio);
132
133 return 0;
134}