forked from Minki/linux
f0aad9baad
This provides helper functions for IO submitting to block dev. Link: https://lore.kernel.org/r/20200511135131.27580-22-danil.kipnis@cloud.ionos.com Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com> Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Acked-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
135 lines
3.0 KiB
C
135 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* RDMA Network Block Driver
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*
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* Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
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* Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
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* Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
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*/
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#undef pr_fmt
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#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
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#include "rnbd-srv-dev.h"
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#include "rnbd-log.h"
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struct rnbd_dev *rnbd_dev_open(const char *path, fmode_t flags,
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struct bio_set *bs)
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{
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struct rnbd_dev *dev;
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int ret;
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dev = kzalloc(sizeof(*dev), GFP_KERNEL);
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if (!dev)
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return ERR_PTR(-ENOMEM);
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dev->blk_open_flags = flags;
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dev->bdev = blkdev_get_by_path(path, flags, THIS_MODULE);
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ret = PTR_ERR_OR_ZERO(dev->bdev);
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if (ret)
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goto err;
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dev->blk_open_flags = flags;
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bdevname(dev->bdev, dev->name);
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dev->ibd_bio_set = bs;
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return dev;
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err:
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kfree(dev);
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return ERR_PTR(ret);
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}
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void rnbd_dev_close(struct rnbd_dev *dev)
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{
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blkdev_put(dev->bdev, dev->blk_open_flags);
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kfree(dev);
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}
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static void rnbd_dev_bi_end_io(struct bio *bio)
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{
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struct rnbd_dev_blk_io *io = bio->bi_private;
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rnbd_endio(io->priv, blk_status_to_errno(bio->bi_status));
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bio_put(bio);
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}
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/**
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* rnbd_bio_map_kern - map kernel address into bio
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* @data: pointer to buffer to map
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* @bs: bio_set to use.
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* @len: length in bytes
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* @gfp_mask: allocation flags for bio allocation
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*
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* Map the kernel address into a bio suitable for io to a block
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* device. Returns an error pointer in case of error.
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*/
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static struct bio *rnbd_bio_map_kern(void *data, struct bio_set *bs,
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unsigned int len, gfp_t gfp_mask)
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{
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unsigned long kaddr = (unsigned long)data;
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unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
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unsigned long start = kaddr >> PAGE_SHIFT;
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const int nr_pages = end - start;
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int offset, i;
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struct bio *bio;
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bio = bio_alloc_bioset(gfp_mask, nr_pages, bs);
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if (!bio)
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return ERR_PTR(-ENOMEM);
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offset = offset_in_page(kaddr);
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for (i = 0; i < nr_pages; i++) {
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unsigned int bytes = PAGE_SIZE - offset;
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if (len <= 0)
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break;
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if (bytes > len)
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bytes = len;
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if (bio_add_page(bio, virt_to_page(data), bytes,
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offset) < bytes) {
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/* we don't support partial mappings */
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bio_put(bio);
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return ERR_PTR(-EINVAL);
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}
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data += bytes;
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len -= bytes;
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offset = 0;
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}
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bio->bi_end_io = bio_put;
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return bio;
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}
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int rnbd_dev_submit_io(struct rnbd_dev *dev, sector_t sector, void *data,
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size_t len, u32 bi_size, enum rnbd_io_flags flags,
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short prio, void *priv)
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{
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struct rnbd_dev_blk_io *io;
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struct bio *bio;
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/* Generate bio with pages pointing to the rdma buffer */
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bio = rnbd_bio_map_kern(data, dev->ibd_bio_set, len, GFP_KERNEL);
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if (IS_ERR(bio))
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return PTR_ERR(bio);
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io = container_of(bio, struct rnbd_dev_blk_io, bio);
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io->dev = dev;
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io->priv = priv;
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bio->bi_end_io = rnbd_dev_bi_end_io;
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bio->bi_private = io;
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bio->bi_opf = rnbd_to_bio_flags(flags);
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bio->bi_iter.bi_sector = sector;
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bio->bi_iter.bi_size = bi_size;
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bio_set_prio(bio, prio);
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bio_set_dev(bio, dev->bdev);
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submit_bio(bio);
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return 0;
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}
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