![Philippe Liard](/assets/img/avatar_default.png)
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>
128 lines
2.6 KiB
C
128 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Squashfs - a compressed read only filesystem for Linux
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*
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* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
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* Phillip Lougher <phillip@squashfs.org.uk>
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*
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* zlib_wrapper.c
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*/
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#include <linux/mutex.h>
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#include <linux/bio.h>
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#include <linux/slab.h>
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#include <linux/zlib.h>
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#include <linux/vmalloc.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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static void *zlib_init(struct squashfs_sb_info *dummy, void *buff)
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{
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z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL);
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if (stream == NULL)
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goto failed;
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stream->workspace = vmalloc(zlib_inflate_workspacesize());
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if (stream->workspace == NULL)
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goto failed;
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return stream;
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failed:
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ERROR("Failed to allocate zlib workspace\n");
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kfree(stream);
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return ERR_PTR(-ENOMEM);
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}
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static void zlib_free(void *strm)
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{
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z_stream *stream = strm;
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if (stream)
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vfree(stream->workspace);
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kfree(stream);
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}
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static int zlib_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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int zlib_init = 0, error = 0;
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z_stream *stream = strm;
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stream->avail_out = PAGE_SIZE;
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stream->next_out = squashfs_first_page(output);
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stream->avail_in = 0;
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for (;;) {
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int zlib_err;
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if (stream->avail_in == 0) {
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const void *data;
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int avail;
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if (!bio_next_segment(bio, &iter_all)) {
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/* Z_STREAM_END must be reached. */
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error = -EIO;
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break;
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}
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avail = min(length, ((int)bvec->bv_len) - offset);
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data = page_address(bvec->bv_page) + bvec->bv_offset;
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length -= avail;
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stream->next_in = data + offset;
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stream->avail_in = avail;
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offset = 0;
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}
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if (stream->avail_out == 0) {
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stream->next_out = squashfs_next_page(output);
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if (stream->next_out != NULL)
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stream->avail_out = PAGE_SIZE;
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}
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if (!zlib_init) {
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zlib_err = zlib_inflateInit(stream);
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if (zlib_err != Z_OK) {
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error = -EIO;
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break;
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}
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zlib_init = 1;
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}
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zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
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if (zlib_err == Z_STREAM_END)
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break;
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if (zlib_err != Z_OK) {
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error = -EIO;
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break;
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}
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}
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squashfs_finish_page(output);
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if (!error)
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if (zlib_inflateEnd(stream) != Z_OK)
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error = -EIO;
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return error ? error : stream->total_out;
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}
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const struct squashfs_decompressor squashfs_zlib_comp_ops = {
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.init = zlib_init,
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.free = zlib_free,
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.decompress = zlib_uncompress,
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.id = ZLIB_COMPRESSION,
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.name = "zlib",
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.supported = 1
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};
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