mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-06 02:50:43 +00:00
![Christoph Hellwig](/assets/img/avatar_default.png)
Use bvec_virt instead of open coding it. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210804095634.460779-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
187 lines
3.8 KiB
C
187 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Squashfs - a compressed read only filesystem for Linux
|
|
*
|
|
* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
|
|
* Phillip Lougher <phillip@squashfs.org.uk>
|
|
*
|
|
* xz_wrapper.c
|
|
*/
|
|
|
|
|
|
#include <linux/mutex.h>
|
|
#include <linux/bio.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/xz.h>
|
|
#include <linux/bitops.h>
|
|
|
|
#include "squashfs_fs.h"
|
|
#include "squashfs_fs_sb.h"
|
|
#include "squashfs.h"
|
|
#include "decompressor.h"
|
|
#include "page_actor.h"
|
|
|
|
struct squashfs_xz {
|
|
struct xz_dec *state;
|
|
struct xz_buf buf;
|
|
};
|
|
|
|
struct disk_comp_opts {
|
|
__le32 dictionary_size;
|
|
__le32 flags;
|
|
};
|
|
|
|
struct comp_opts {
|
|
int dict_size;
|
|
};
|
|
|
|
static void *squashfs_xz_comp_opts(struct squashfs_sb_info *msblk,
|
|
void *buff, int len)
|
|
{
|
|
struct disk_comp_opts *comp_opts = buff;
|
|
struct comp_opts *opts;
|
|
int err = 0, n;
|
|
|
|
opts = kmalloc(sizeof(*opts), GFP_KERNEL);
|
|
if (opts == NULL) {
|
|
err = -ENOMEM;
|
|
goto out2;
|
|
}
|
|
|
|
if (comp_opts) {
|
|
/* check compressor options are the expected length */
|
|
if (len < sizeof(*comp_opts)) {
|
|
err = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
opts->dict_size = le32_to_cpu(comp_opts->dictionary_size);
|
|
|
|
/* the dictionary size should be 2^n or 2^n+2^(n+1) */
|
|
n = ffs(opts->dict_size) - 1;
|
|
if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) +
|
|
(1 << (n + 1))) {
|
|
err = -EIO;
|
|
goto out;
|
|
}
|
|
} else
|
|
/* use defaults */
|
|
opts->dict_size = max_t(int, msblk->block_size,
|
|
SQUASHFS_METADATA_SIZE);
|
|
|
|
return opts;
|
|
|
|
out:
|
|
kfree(opts);
|
|
out2:
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
|
|
static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff)
|
|
{
|
|
struct comp_opts *comp_opts = buff;
|
|
struct squashfs_xz *stream;
|
|
int err;
|
|
|
|
stream = kmalloc(sizeof(*stream), GFP_KERNEL);
|
|
if (stream == NULL) {
|
|
err = -ENOMEM;
|
|
goto failed;
|
|
}
|
|
|
|
stream->state = xz_dec_init(XZ_PREALLOC, comp_opts->dict_size);
|
|
if (stream->state == NULL) {
|
|
kfree(stream);
|
|
err = -ENOMEM;
|
|
goto failed;
|
|
}
|
|
|
|
return stream;
|
|
|
|
failed:
|
|
ERROR("Failed to initialise xz decompressor\n");
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
|
|
static void squashfs_xz_free(void *strm)
|
|
{
|
|
struct squashfs_xz *stream = strm;
|
|
|
|
if (stream) {
|
|
xz_dec_end(stream->state);
|
|
kfree(stream);
|
|
}
|
|
}
|
|
|
|
|
|
static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
|
|
struct bio *bio, int offset, int length,
|
|
struct squashfs_page_actor *output)
|
|
{
|
|
struct bvec_iter_all iter_all = {};
|
|
struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
|
|
int total = 0, error = 0;
|
|
struct squashfs_xz *stream = strm;
|
|
|
|
xz_dec_reset(stream->state);
|
|
stream->buf.in_pos = 0;
|
|
stream->buf.in_size = 0;
|
|
stream->buf.out_pos = 0;
|
|
stream->buf.out_size = PAGE_SIZE;
|
|
stream->buf.out = squashfs_first_page(output);
|
|
|
|
for (;;) {
|
|
enum xz_ret xz_err;
|
|
|
|
if (stream->buf.in_pos == stream->buf.in_size) {
|
|
const void *data;
|
|
int avail;
|
|
|
|
if (!bio_next_segment(bio, &iter_all)) {
|
|
/* XZ_STREAM_END must be reached. */
|
|
error = -EIO;
|
|
break;
|
|
}
|
|
|
|
avail = min(length, ((int)bvec->bv_len) - offset);
|
|
data = bvec_virt(bvec);
|
|
length -= avail;
|
|
stream->buf.in = data + offset;
|
|
stream->buf.in_size = avail;
|
|
stream->buf.in_pos = 0;
|
|
offset = 0;
|
|
}
|
|
|
|
if (stream->buf.out_pos == stream->buf.out_size) {
|
|
stream->buf.out = squashfs_next_page(output);
|
|
if (stream->buf.out != NULL) {
|
|
stream->buf.out_pos = 0;
|
|
total += PAGE_SIZE;
|
|
}
|
|
}
|
|
|
|
xz_err = xz_dec_run(stream->state, &stream->buf);
|
|
if (xz_err == XZ_STREAM_END)
|
|
break;
|
|
if (xz_err != XZ_OK) {
|
|
error = -EIO;
|
|
break;
|
|
}
|
|
}
|
|
|
|
squashfs_finish_page(output);
|
|
|
|
return error ? error : total + stream->buf.out_pos;
|
|
}
|
|
|
|
const struct squashfs_decompressor squashfs_xz_comp_ops = {
|
|
.init = squashfs_xz_init,
|
|
.comp_opts = squashfs_xz_comp_opts,
|
|
.free = squashfs_xz_free,
|
|
.decompress = squashfs_xz_uncompress,
|
|
.id = XZ_COMPRESSION,
|
|
.name = "xz",
|
|
.supported = 1
|
|
};
|