linux/fs/squashfs/lzo_wrapper.c
Philippe Liard 93e72b3c61 squashfs: migrate from ll_rw_block usage to BIO
ll_rw_block() function has been deprecated in favor of BIO which appears
to come with large performance improvements.

This patch decreases boot time by close to 40% when using squashfs for
the root file-system.  This is observed at least in the context of
starting an Android VM on Chrome OS using crosvm.  The patch was tested
on 4.19 as well as master.

This patch is largely based on Adrien Schildknecht's patch that was
originally sent as https://lkml.org/lkml/2017/9/22/814 though with some
significant changes and simplifications while also taking Phillip
Lougher's feedback into account, around preserving support for
FILE_CACHE in particular.

[akpm@linux-foundation.org: fix build error reported by Randy]
  Link: http://lkml.kernel.org/r/319997c2-5fc8-f889-2ea3-d913308a7c1f@infradead.org
Signed-off-by: Philippe Liard <pliard@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Adrien Schildknecht <adrien+dev@schischi.me>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Daniel Rosenberg <drosen@google.com>
Link: https://chromium.googlesource.com/chromiumos/platform/crosvm
Link: http://lkml.kernel.org/r/20191106074238.186023-1-pliard@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:05 -07:00

121 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Squashfs - a compressed read only filesystem for Linux
*
* Copyright (c) 2010 LG Electronics
* Chan Jeong <chan.jeong@lge.com>
*
* lzo_wrapper.c
*/
#include <linux/mutex.h>
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/lzo.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs.h"
#include "decompressor.h"
#include "page_actor.h"
struct squashfs_lzo {
void *input;
void *output;
};
static void *lzo_init(struct squashfs_sb_info *msblk, void *buff)
{
int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
if (stream == NULL)
goto failed;
stream->input = vmalloc(block_size);
if (stream->input == NULL)
goto failed;
stream->output = vmalloc(block_size);
if (stream->output == NULL)
goto failed2;
return stream;
failed2:
vfree(stream->input);
failed:
ERROR("Failed to allocate lzo workspace\n");
kfree(stream);
return ERR_PTR(-ENOMEM);
}
static void lzo_free(void *strm)
{
struct squashfs_lzo *stream = strm;
if (stream) {
vfree(stream->input);
vfree(stream->output);
}
kfree(stream);
}
static int lzo_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);
struct squashfs_lzo *stream = strm;
void *buff = stream->input, *data;
int bytes = length, res;
size_t out_len = output->length;
while (bio_next_segment(bio, &iter_all)) {
int avail = min(bytes, ((int)bvec->bv_len) - offset);
data = page_address(bvec->bv_page) + bvec->bv_offset;
memcpy(buff, data + offset, avail);
buff += avail;
bytes -= avail;
offset = 0;
}
res = lzo1x_decompress_safe(stream->input, (size_t)length,
stream->output, &out_len);
if (res != LZO_E_OK)
goto failed;
res = bytes = (int)out_len;
data = squashfs_first_page(output);
buff = stream->output;
while (data) {
if (bytes <= PAGE_SIZE) {
memcpy(data, buff, bytes);
break;
} else {
memcpy(data, buff, PAGE_SIZE);
buff += PAGE_SIZE;
bytes -= PAGE_SIZE;
data = squashfs_next_page(output);
}
}
squashfs_finish_page(output);
return res;
failed:
return -EIO;
}
const struct squashfs_decompressor squashfs_lzo_comp_ops = {
.init = lzo_init,
.free = lzo_free,
.decompress = lzo_uncompress,
.id = LZO_COMPRESSION,
.name = "lzo",
.supported = 1
};