cregit-Linux how code gets into the kernel

Release 4.10 fs/squashfs/lz4_wrapper.c

Directory: fs/squashfs
 * Copyright (c) 2013, 2014
 * Phillip Lougher <>
 * This work is licensed under the terms of the GNU GPL, version 2. See
 * the COPYING file in the top-level directory.

#include <linux/buffer_head.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/lz4.h>

#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs.h"
#include "decompressor.h"
#include "page_actor.h"

#define LZ4_LEGACY	1

struct lz4_comp_opts {
__le32 version;
__le32 flags;

struct squashfs_lz4 {
void *input;
void *output;

static void *lz4_comp_opts(struct squashfs_sb_info *msblk, void *buff, int len) { struct lz4_comp_opts *comp_opts = buff; /* LZ4 compressed filesystems always have compression options */ if (comp_opts == NULL || len < sizeof(*comp_opts)) return ERR_PTR(-EIO); if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) { /* LZ4 format currently used by the kernel is the 'legacy' * format */ ERROR("Unknown LZ4 version\n"); return ERR_PTR(-EINVAL); } return NULL; }


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static void *lz4_init(struct squashfs_sb_info *msblk, void *buff) { int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); struct squashfs_lz4 *stream; stream = kzalloc(sizeof(*stream), GFP_KERNEL); if (stream == NULL) goto failed; stream->input = vmalloc(block_size); if (stream->input == NULL) goto failed2; stream->output = vmalloc(block_size); if (stream->output == NULL) goto failed3; return stream; failed3: vfree(stream->input); failed2: kfree(stream); failed: ERROR("Failed to initialise LZ4 decompressor\n"); return ERR_PTR(-ENOMEM); }


phillip lougherphillip lougher130100.00%1100.00%

static void lz4_free(void *strm) { struct squashfs_lz4 *stream = strm; if (stream) { vfree(stream->input); vfree(stream->output); } kfree(stream); }


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static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm, struct buffer_head **bh, int b, int offset, int length, struct squashfs_page_actor *output) { struct squashfs_lz4 *stream = strm; void *buff = stream->input, *data; int avail, i, bytes = length, res; size_t dest_len = output->length; for (i = 0; i < b; i++) { avail = min(bytes, msblk->devblksize - offset); memcpy(buff, bh[i]->b_data + offset, avail); buff += avail; bytes -= avail; offset = 0; put_bh(bh[i]); } res = lz4_decompress_unknownoutputsize(stream->input, length, stream->output, &dest_len); if (res) return -EIO; bytes = dest_len; data = squashfs_first_page(output); buff = stream->output; while (data) { if (bytes <= PAGE_SIZE) { memcpy(data, buff, bytes); break; } memcpy(data, buff, PAGE_SIZE); buff += PAGE_SIZE; bytes -= PAGE_SIZE; data = squashfs_next_page(output); } squashfs_finish_page(output); return dest_len; }


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kirill a. shutemovkirill a. shutemov41.71%150.00%

const struct squashfs_decompressor squashfs_lz4_comp_ops = { .init = lz4_init, .comp_opts = lz4_comp_opts, .free = lz4_free, .decompress = lz4_uncompress, .id = LZ4_COMPRESSION, .name = "lz4", .supported = 1 };

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Directory: fs/squashfs
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