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187 lines
3.8 KiB
187 lines
3.8 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Squashfs - a compressed read only filesystem for Linux |
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* |
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* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
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* Phillip Lougher <[email protected]> |
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* |
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* xz_wrapper.c |
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*/ |
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#include <linux/mutex.h> |
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#include <linux/bio.h> |
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#include <linux/slab.h> |
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#include <linux/xz.h> |
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#include <linux/bitops.h> |
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#include "squashfs_fs.h" |
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#include "squashfs_fs_sb.h" |
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#include "squashfs.h" |
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#include "decompressor.h" |
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#include "page_actor.h" |
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struct squashfs_xz { |
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struct xz_dec *state; |
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struct xz_buf buf; |
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}; |
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struct disk_comp_opts { |
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__le32 dictionary_size; |
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__le32 flags; |
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}; |
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struct comp_opts { |
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int dict_size; |
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}; |
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static void *squashfs_xz_comp_opts(struct squashfs_sb_info *msblk, |
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void *buff, int len) |
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{ |
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struct disk_comp_opts *comp_opts = buff; |
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struct comp_opts *opts; |
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int err = 0, n; |
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opts = kmalloc(sizeof(*opts), GFP_KERNEL); |
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if (opts == NULL) { |
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err = -ENOMEM; |
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goto out2; |
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} |
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if (comp_opts) { |
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/* check compressor options are the expected length */ |
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if (len < sizeof(*comp_opts)) { |
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err = -EIO; |
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goto out; |
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} |
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opts->dict_size = le32_to_cpu(comp_opts->dictionary_size); |
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/* the dictionary size should be 2^n or 2^n+2^(n+1) */ |
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n = ffs(opts->dict_size) - 1; |
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if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) + |
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(1 << (n + 1))) { |
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err = -EIO; |
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goto out; |
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} |
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} else |
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/* use defaults */ |
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opts->dict_size = max_t(int, msblk->block_size, |
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SQUASHFS_METADATA_SIZE); |
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return opts; |
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out: |
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kfree(opts); |
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out2: |
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return ERR_PTR(err); |
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} |
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static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff) |
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{ |
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struct comp_opts *comp_opts = buff; |
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struct squashfs_xz *stream; |
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int err; |
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stream = kmalloc(sizeof(*stream), GFP_KERNEL); |
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if (stream == NULL) { |
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err = -ENOMEM; |
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goto failed; |
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} |
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stream->state = xz_dec_init(XZ_PREALLOC, comp_opts->dict_size); |
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if (stream->state == NULL) { |
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kfree(stream); |
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err = -ENOMEM; |
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goto failed; |
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} |
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return stream; |
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failed: |
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ERROR("Failed to initialise xz decompressor\n"); |
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return ERR_PTR(err); |
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} |
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static void squashfs_xz_free(void *strm) |
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{ |
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struct squashfs_xz *stream = strm; |
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if (stream) { |
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xz_dec_end(stream->state); |
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kfree(stream); |
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} |
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} |
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static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm, |
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struct bio *bio, int offset, int length, |
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struct squashfs_page_actor *output) |
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{ |
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struct bvec_iter_all iter_all = {}; |
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struct bio_vec *bvec = bvec_init_iter_all(&iter_all); |
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int total = 0, error = 0; |
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struct squashfs_xz *stream = strm; |
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xz_dec_reset(stream->state); |
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stream->buf.in_pos = 0; |
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stream->buf.in_size = 0; |
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stream->buf.out_pos = 0; |
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stream->buf.out_size = PAGE_SIZE; |
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stream->buf.out = squashfs_first_page(output); |
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for (;;) { |
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enum xz_ret xz_err; |
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if (stream->buf.in_pos == stream->buf.in_size) { |
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const void *data; |
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int avail; |
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if (!bio_next_segment(bio, &iter_all)) { |
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/* XZ_STREAM_END must be reached. */ |
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error = -EIO; |
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break; |
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} |
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avail = min(length, ((int)bvec->bv_len) - offset); |
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data = page_address(bvec->bv_page) + bvec->bv_offset; |
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length -= avail; |
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stream->buf.in = data + offset; |
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stream->buf.in_size = avail; |
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stream->buf.in_pos = 0; |
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offset = 0; |
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} |
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if (stream->buf.out_pos == stream->buf.out_size) { |
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stream->buf.out = squashfs_next_page(output); |
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if (stream->buf.out != NULL) { |
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stream->buf.out_pos = 0; |
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total += PAGE_SIZE; |
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} |
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} |
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xz_err = xz_dec_run(stream->state, &stream->buf); |
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if (xz_err == XZ_STREAM_END) |
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break; |
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if (xz_err != XZ_OK) { |
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error = -EIO; |
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break; |
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} |
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} |
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squashfs_finish_page(output); |
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return error ? error : total + stream->buf.out_pos; |
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} |
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const struct squashfs_decompressor squashfs_xz_comp_ops = { |
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.init = squashfs_xz_init, |
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.comp_opts = squashfs_xz_comp_opts, |
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.free = squashfs_xz_free, |
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.decompress = squashfs_xz_uncompress, |
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.id = XZ_COMPRESSION, |
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.name = "xz", |
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.supported = 1 |
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};
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