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
  15 struct 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
  37 err:
  38         kfree(dev);
  39         return ERR_PTR(ret);
  40 }
  41
  42 void rnbd_dev_close(struct rnbd_dev *dev)
  43 {
  44         blkdev_put(dev->bdev, dev->blk_open_flags);
  45         kfree(dev);
  46 }
  47
  48 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  */
  66 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         return bio;
 103 }