93e72b3c61
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>
144 lines
2.9 KiB
C
144 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2013, 2014
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* Phillip Lougher <phillip@squashfs.org.uk>
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*/
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#include <linux/bio.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/lz4.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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#define LZ4_LEGACY 1
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struct lz4_comp_opts {
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__le32 version;
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__le32 flags;
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};
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struct squashfs_lz4 {
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void *input;
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void *output;
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};
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static void *lz4_comp_opts(struct squashfs_sb_info *msblk,
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void *buff, int len)
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{
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struct lz4_comp_opts *comp_opts = buff;
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/* LZ4 compressed filesystems always have compression options */
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if (comp_opts == NULL || len < sizeof(*comp_opts))
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return ERR_PTR(-EIO);
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if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) {
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/* LZ4 format currently used by the kernel is the 'legacy'
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* format */
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ERROR("Unknown LZ4 version\n");
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return ERR_PTR(-EINVAL);
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}
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return NULL;
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}
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static void *lz4_init(struct squashfs_sb_info *msblk, void *buff)
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{
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int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
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struct squashfs_lz4 *stream;
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stream = kzalloc(sizeof(*stream), GFP_KERNEL);
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if (stream == NULL)
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goto failed;
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stream->input = vmalloc(block_size);
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if (stream->input == NULL)
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goto failed2;
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stream->output = vmalloc(block_size);
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if (stream->output == NULL)
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goto failed3;
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return stream;
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failed3:
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vfree(stream->input);
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failed2:
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kfree(stream);
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failed:
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ERROR("Failed to initialise LZ4 decompressor\n");
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return ERR_PTR(-ENOMEM);
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}
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static void lz4_free(void *strm)
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{
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struct squashfs_lz4 *stream = strm;
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if (stream) {
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vfree(stream->input);
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vfree(stream->output);
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}
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kfree(stream);
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}
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static int lz4_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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struct squashfs_lz4 *stream = strm;
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void *buff = stream->input, *data;
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int bytes = length, res;
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while (bio_next_segment(bio, &iter_all)) {
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int avail = min(bytes, ((int)bvec->bv_len) - offset);
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data = page_address(bvec->bv_page) + bvec->bv_offset;
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memcpy(buff, data + offset, avail);
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buff += avail;
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bytes -= avail;
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offset = 0;
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}
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res = LZ4_decompress_safe(stream->input, stream->output,
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length, output->length);
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if (res < 0)
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return -EIO;
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bytes = res;
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data = squashfs_first_page(output);
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buff = stream->output;
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while (data) {
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if (bytes <= PAGE_SIZE) {
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memcpy(data, buff, bytes);
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break;
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}
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memcpy(data, buff, PAGE_SIZE);
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buff += PAGE_SIZE;
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bytes -= PAGE_SIZE;
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data = squashfs_next_page(output);
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}
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squashfs_finish_page(output);
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return res;
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}
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const struct squashfs_decompressor squashfs_lz4_comp_ops = {
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.init = lz4_init,
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.comp_opts = lz4_comp_opts,
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.free = lz4_free,
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.decompress = lz4_uncompress,
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.id = LZ4_COMPRESSION,
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.name = "lz4",
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.supported = 1
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};
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