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![Jörn Engel](/assets/img/avatar_default.png)
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
222 lines
5.8 KiB
C
222 lines
5.8 KiB
C
/*
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* JFFS2 -- Journalling Flash File System, Version 2.
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*
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* Copyright (C) 2001-2003 Red Hat, Inc.
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*
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* Created by David Woodhouse <dwmw2@infradead.org>
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*
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* For licensing information, see the file 'LICENCE' in this directory.
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*
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* $Id: compr_zlib.c,v 1.32 2005/11/07 11:14:38 gleixner Exp $
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*
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*/
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#if !defined(__KERNEL__) && !defined(__ECOS)
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#error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
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#endif
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/zlib.h>
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#include <linux/zutil.h>
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#include "nodelist.h"
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#include "compr.h"
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/* Plan: call deflate() with avail_in == *sourcelen,
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avail_out = *dstlen - 12 and flush == Z_FINISH.
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If it doesn't manage to finish, call it again with
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avail_in == 0 and avail_out set to the remaining 12
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bytes for it to clean up.
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Q: Is 12 bytes sufficient?
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*/
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#define STREAM_END_SPACE 12
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static DEFINE_MUTEX(deflate_mutex);
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static DEFINE_MUTEX(inflate_mutex);
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static z_stream inf_strm, def_strm;
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#ifdef __KERNEL__ /* Linux-only */
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <linux/mutex.h>
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static int __init alloc_workspaces(void)
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{
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def_strm.workspace = vmalloc(zlib_deflate_workspacesize());
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if (!def_strm.workspace) {
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printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize());
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return -ENOMEM;
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}
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D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize()));
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inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
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if (!inf_strm.workspace) {
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printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize());
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vfree(def_strm.workspace);
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return -ENOMEM;
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}
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D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize()));
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return 0;
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}
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static void free_workspaces(void)
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{
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vfree(def_strm.workspace);
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vfree(inf_strm.workspace);
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}
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#else
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#define alloc_workspaces() (0)
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#define free_workspaces() do { } while(0)
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#endif /* __KERNEL__ */
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static int jffs2_zlib_compress(unsigned char *data_in,
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unsigned char *cpage_out,
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uint32_t *sourcelen, uint32_t *dstlen,
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void *model)
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{
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int ret;
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if (*dstlen <= STREAM_END_SPACE)
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return -1;
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mutex_lock(&deflate_mutex);
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if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
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printk(KERN_WARNING "deflateInit failed\n");
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mutex_unlock(&deflate_mutex);
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return -1;
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}
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def_strm.next_in = data_in;
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def_strm.total_in = 0;
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def_strm.next_out = cpage_out;
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def_strm.total_out = 0;
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while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) {
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def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE);
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def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out);
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D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n",
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def_strm.avail_in, def_strm.avail_out));
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ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH);
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D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n",
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def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out));
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if (ret != Z_OK) {
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D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret));
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zlib_deflateEnd(&def_strm);
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mutex_unlock(&deflate_mutex);
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return -1;
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}
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}
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def_strm.avail_out += STREAM_END_SPACE;
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def_strm.avail_in = 0;
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ret = zlib_deflate(&def_strm, Z_FINISH);
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zlib_deflateEnd(&def_strm);
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if (ret != Z_STREAM_END) {
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D1(printk(KERN_DEBUG "final deflate returned %d\n", ret));
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ret = -1;
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goto out;
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}
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if (def_strm.total_out >= def_strm.total_in) {
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D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n",
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def_strm.total_in, def_strm.total_out));
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ret = -1;
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goto out;
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}
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D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n",
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def_strm.total_in, def_strm.total_out));
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*dstlen = def_strm.total_out;
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*sourcelen = def_strm.total_in;
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ret = 0;
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out:
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mutex_unlock(&deflate_mutex);
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return ret;
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}
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static int jffs2_zlib_decompress(unsigned char *data_in,
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unsigned char *cpage_out,
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uint32_t srclen, uint32_t destlen,
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void *model)
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{
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int ret;
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int wbits = MAX_WBITS;
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mutex_lock(&inflate_mutex);
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inf_strm.next_in = data_in;
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inf_strm.avail_in = srclen;
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inf_strm.total_in = 0;
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inf_strm.next_out = cpage_out;
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inf_strm.avail_out = destlen;
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inf_strm.total_out = 0;
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/* If it's deflate, and it's got no preset dictionary, then
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we can tell zlib to skip the adler32 check. */
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if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
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((data_in[0] & 0x0f) == Z_DEFLATED) &&
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!(((data_in[0]<<8) + data_in[1]) % 31)) {
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D2(printk(KERN_DEBUG "inflate skipping adler32\n"));
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wbits = -((data_in[0] >> 4) + 8);
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inf_strm.next_in += 2;
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inf_strm.avail_in -= 2;
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} else {
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/* Let this remain D1 for now -- it should never happen */
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D1(printk(KERN_DEBUG "inflate not skipping adler32\n"));
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}
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if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
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printk(KERN_WARNING "inflateInit failed\n");
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mutex_unlock(&inflate_mutex);
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return 1;
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}
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while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
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;
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if (ret != Z_STREAM_END) {
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printk(KERN_NOTICE "inflate returned %d\n", ret);
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}
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zlib_inflateEnd(&inf_strm);
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mutex_unlock(&inflate_mutex);
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return 0;
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}
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static struct jffs2_compressor jffs2_zlib_comp = {
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.priority = JFFS2_ZLIB_PRIORITY,
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.name = "zlib",
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.compr = JFFS2_COMPR_ZLIB,
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.compress = &jffs2_zlib_compress,
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.decompress = &jffs2_zlib_decompress,
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#ifdef JFFS2_ZLIB_DISABLED
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.disabled = 1,
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#else
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.disabled = 0,
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#endif
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};
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int __init jffs2_zlib_init(void)
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{
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int ret;
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ret = alloc_workspaces();
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if (ret)
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return ret;
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ret = jffs2_register_compressor(&jffs2_zlib_comp);
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if (ret)
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free_workspaces();
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return ret;
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}
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void jffs2_zlib_exit(void)
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{
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jffs2_unregister_compressor(&jffs2_zlib_comp);
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free_workspaces();
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}
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