| 1 | |
| 2 | |
| 3 | * Copyright (c) 2013
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| 4 | * Phillip Lougher <[email protected]>
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| 5 |
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| 6 |
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| 7 | #include <linux/types.h>
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| 8 | #include <linux/mutex.h>
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| 9 | #include <linux/slab.h>
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| 10 | #include <linux/bio.h>
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| 11 |
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| 12 | #include "squashfs_fs.h"
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| 13 | #include "squashfs_fs_sb.h"
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| 14 | #include "decompressor.h"
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| 15 | #include "squashfs.h"
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| 16 |
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| 17 | |
| 18 | * This file implements single-threaded decompression in the
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| 19 | * decompressor framework
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| 20 |
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| 21 |
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| 22 | struct squashfs_stream {
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| 23 | void *stream;
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| 24 | struct mutex mutex;
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| 25 | };
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| 26 |
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| 27 | static void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
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| 28 | void *comp_opts)
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| 29 | {
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| 30 | struct squashfs_stream *stream;
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| 31 | int err = -ENOMEM;
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| 32 |
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| 33 | stream = kmalloc_obj(*stream);
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| 34 | if (stream == NULL)
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| 35 | goto out;
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| 36 |
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| 37 | stream->stream = msblk->decompressor->init(msblk, comp_opts);
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| 38 | if (IS_ERR(stream->stream)) {
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| 39 | err = PTR_ERR(stream->stream);
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| 40 | goto out;
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| 41 | }
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| 42 |
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| 43 | kfree(comp_opts);
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| 44 | mutex_init(&stream->mutex);
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| 45 | return stream;
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| 46 |
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| 47 | out:
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| 48 | kfree(stream);
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| 49 | return ERR_PTR(err);
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| 50 | }
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| 51 |
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| 52 | static void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
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| 53 | {
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| 54 | struct squashfs_stream *stream = msblk->stream;
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| 55 |
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| 56 | if (stream) {
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| 57 | msblk->decompressor->free(stream->stream);
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| 58 | kfree(stream);
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| 59 | }
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| 60 | }
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| 61 |
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| 62 | static int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
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| 63 | int offset, int length,
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| 64 | struct squashfs_page_actor *output)
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| 65 | {
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| 66 | int res;
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| 67 | struct squashfs_stream *stream = msblk->stream;
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| 68 |
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| 69 | mutex_lock(&stream->mutex);
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| 70 | res = msblk->decompressor->decompress(msblk, stream->stream, bio,
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| 71 | offset, length, output);
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| 72 | mutex_unlock(&stream->mutex);
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| 73 |
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| 74 | if (res < 0)
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| 75 | ERROR("%s decompression failed, data probably corrupt\n",
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| 76 | msblk->decompressor->name);
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| 77 |
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| 78 | return res;
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| 79 | }
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| 80 |
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| 81 | static int squashfs_max_decompressors(void)
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| 82 | {
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| 83 | return 1;
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| 84 | }
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| 85 |
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| 86 | const struct squashfs_decompressor_thread_ops squashfs_decompressor_single = {
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| 87 | .create = squashfs_decompressor_create,
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| 88 | .destroy = squashfs_decompressor_destroy,
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| 89 | .decompress = squashfs_decompress,
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| 90 | .max_decompressors = squashfs_max_decompressors,
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| 91 | };
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