lzo_wrapper.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Squashfs - a compressed read only filesystem for Linux
  4 *
  5 * Copyright (c) 2010 LG Electronics
  6 * Chan Jeong <chan.jeong@lge.com>
  7 *
  8 * lzo_wrapper.c
  9 */
 10
 11#include <linux/mutex.h>
 12#include <linux/bio.h>
 13#include <linux/slab.h>
 14#include <linux/vmalloc.h>
 15#include <linux/lzo.h>
 16
 17#include "squashfs_fs.h"
 18#include "squashfs_fs_sb.h"
 19#include "squashfs.h"
 20#include "decompressor.h"
 21#include "page_actor.h"
 22
 23struct squashfs_lzo {
 24	void	*input;
 25	void	*output;
 26};
 27
 28static void *lzo_init(struct squashfs_sb_info *msblk, void *buff)
 29{
 30	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
 31
 32	struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
 33	if (stream == NULL)
 34		goto failed;
 35	stream->input = vmalloc(block_size);
 36	if (stream->input == NULL)
 37		goto failed;
 38	stream->output = vmalloc(block_size);
 39	if (stream->output == NULL)
 40		goto failed2;
 41
 42	return stream;
 43
 44failed2:
 45	vfree(stream->input);
 46failed:
 47	ERROR("Failed to allocate lzo workspace\n");
 48	kfree(stream);
 49	return ERR_PTR(-ENOMEM);
 50}
 51
 52
 53static void lzo_free(void *strm)
 54{
 55	struct squashfs_lzo *stream = strm;
 56
 57	if (stream) {
 58		vfree(stream->input);
 59		vfree(stream->output);
 60	}
 61	kfree(stream);
 62}
 63
 64
 65static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm,
 66	struct bio *bio, int offset, int length,
 67	struct squashfs_page_actor *output)
 68{
 69	struct bvec_iter_all iter_all = {};
 70	struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
 71	struct squashfs_lzo *stream = strm;
 72	void *buff = stream->input, *data;
 73	int bytes = length, res;
 74	size_t out_len = output->length;
 75
 76	while (bio_next_segment(bio, &iter_all)) {
 77		int avail = min(bytes, ((int)bvec->bv_len) - offset);
 78
 79		data = bvec_virt(bvec);
 80		memcpy(buff, data + offset, avail);
 81		buff += avail;
 82		bytes -= avail;
 83		offset = 0;
 84	}
 85
 86	res = lzo1x_decompress_safe(stream->input, (size_t)length,
 87					stream->output, &out_len);
 88	if (res != LZO_E_OK)
 89		goto failed;
 90
 91	res = bytes = (int)out_len;
 92	data = squashfs_first_page(output);
 93	buff = stream->output;
 94	while (data) {
 95		if (bytes <= PAGE_SIZE) {
 96			if (!IS_ERR(data))
 97				memcpy(data, buff, bytes);
 98			break;
 99		} else {
100			if (!IS_ERR(data))
101				memcpy(data, buff, PAGE_SIZE);
102			buff += PAGE_SIZE;
103			bytes -= PAGE_SIZE;
104			data = squashfs_next_page(output);
105		}
106	}
107	squashfs_finish_page(output);
108
109	return res;
110
111failed:
112	return -EIO;
113}
114
115const struct squashfs_decompressor squashfs_lzo_comp_ops = {
116	.init = lzo_init,
117	.free = lzo_free,
118	.decompress = lzo_uncompress,
119	.id = LZO_COMPRESSION,
120	.name = "lzo",
121	.alloc_buffer = 0,
122	.supported = 1
123};