113 lines
3.3 KiB
C
113 lines
3.3 KiB
C
/*
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* Copyright (c) 2009 Travis Geiselbrecht
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files
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* (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge,
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* publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include <debug.h>
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#include <stdlib.h>
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#include <lib/bio.h>
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#define LOCAL_TRACE 0
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typedef struct {
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// inheirit the usual bits
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bdev_t dev;
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// we're a subdevice of this
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bdev_t *parent;
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// we're this many blocks into it
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bnum_t offset;
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} subdev_t;
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static ssize_t subdev_read(struct bdev *_dev, void *buf, off_t offset, size_t len)
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{
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subdev_t *subdev = (subdev_t *)_dev;
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return bio_read(subdev->parent, buf, offset + subdev->offset * subdev->dev.block_size, len);
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}
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static ssize_t subdev_read_block(struct bdev *_dev, void *buf, bnum_t block, uint count)
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{
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subdev_t *subdev = (subdev_t *)_dev;
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return bio_read_block(subdev->parent, buf, block + subdev->offset, count);
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}
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static ssize_t subdev_write(struct bdev *_dev, const void *buf, off_t offset, size_t len)
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{
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subdev_t *subdev = (subdev_t *)_dev;
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return bio_write(subdev->parent, buf, offset + subdev->offset * subdev->dev.block_size, len);
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}
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static ssize_t subdev_write_block(struct bdev *_dev, const void *buf, bnum_t block, uint count)
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{
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subdev_t *subdev = (subdev_t *)_dev;
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return bio_write_block(subdev->parent, buf, block + subdev->offset, count);
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}
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static ssize_t subdev_erase(struct bdev *_dev, off_t offset, size_t len)
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{
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subdev_t *subdev = (subdev_t *)_dev;
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return bio_erase(subdev->parent, offset + subdev->offset * subdev->dev.block_size, len);
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}
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static void subdev_close(struct bdev *_dev)
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{
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subdev_t *subdev = (subdev_t *)_dev;
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bio_close(subdev->parent);
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subdev->parent = NULL;
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}
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status_t bio_publish_subdevice(const char *parent_dev, const char *subdev, bnum_t startblock, size_t len)
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{
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LTRACEF("parent %s, sub %s, startblock %u, len %zd\n", parent_dev, subdev, startblock, len);
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bdev_t *parent = bio_open(parent_dev);
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if (!parent)
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return -1;
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/* make sure we're able to do this */
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if (startblock + len > parent->block_count)
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return -1;
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subdev_t *sub = malloc(sizeof(subdev_t));
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bio_initialize_bdev(&sub->dev, subdev, parent->block_size, len);
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sub->parent = parent;
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sub->offset = startblock;
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sub->dev.read = &subdev_read;
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sub->dev.read_block = &subdev_read_block;
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sub->dev.write = &subdev_write;
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sub->dev.write_block = &subdev_write_block;
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sub->dev.erase = &subdev_erase;
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sub->dev.close = &subdev_close;
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bio_register_device(&sub->dev);
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return 0;
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}
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