LXR linux/drivers/block/rnbd/rnbd-srv-dev.c

   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