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222 lines
5.5 KiB
222 lines
5.5 KiB
/* |
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* JFFS2 -- Journalling Flash File System, Version 2. |
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* |
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* Copyright © 2001-2007 Red Hat, Inc. |
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* Copyright © 2004-2010 David Woodhouse <[email protected]> |
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* |
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* Created by David Woodhouse <[email protected]> |
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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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*/ |
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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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/kernel.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(MAX_WBITS, |
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MAX_MEM_LEVEL)); |
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if (!def_strm.workspace) |
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return -ENOMEM; |
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jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n", |
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zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL)); |
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inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); |
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if (!inf_strm.workspace) { |
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vfree(def_strm.workspace); |
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return -ENOMEM; |
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} |
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jffs2_dbg(1, "Allocated %d bytes for inflate workspace\n", |
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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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{ |
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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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pr_warn("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_t(unsigned long, |
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(*sourcelen-def_strm.total_in), def_strm.avail_out); |
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jffs2_dbg(1, "calling deflate with avail_in %ld, avail_out %ld\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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jffs2_dbg(1, "deflate returned with avail_in %ld, avail_out %ld, total_in %ld, total_out %ld\n", |
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def_strm.avail_in, def_strm.avail_out, |
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def_strm.total_in, def_strm.total_out); |
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if (ret != Z_OK) { |
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jffs2_dbg(1, "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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jffs2_dbg(1, "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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jffs2_dbg(1, "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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jffs2_dbg(1, "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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{ |
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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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jffs2_dbg(2, "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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jffs2_dbg(1, "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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pr_warn("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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pr_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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