| /* |
| * JFFS2 -- Journalling Flash File System, Version 2. |
| * |
| * Copyright © 2001-2007 Red Hat, Inc. |
| * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> |
| * |
| * Created by David Woodhouse <dwmw2@infradead.org> |
| * |
| * For licensing information, see the file 'LICENCE' in this directory. |
| * |
| */ |
| |
| #if !defined(__KERNEL__) && !defined(__ECOS) |
| #error "The userspace support got too messy and was removed. Update your mkfs.jffs2" |
| #endif |
| |
| #include <linux/kernel.h> |
| #include <linux/zlib.h> |
| #include <linux/zutil.h> |
| #include "nodelist.h" |
| #include "compr.h" |
| |
| /* Plan: call deflate() with avail_in == *sourcelen, |
| avail_out = *dstlen - 12 and flush == Z_FINISH. |
| If it doesn't manage to finish, call it again with |
| avail_in == 0 and avail_out set to the remaining 12 |
| bytes for it to clean up. |
| Q: Is 12 bytes sufficient? |
| */ |
| #define STREAM_END_SPACE 12 |
| |
| static DEFINE_MUTEX(deflate_mutex); |
| static DEFINE_MUTEX(inflate_mutex); |
| static z_stream inf_strm, def_strm; |
| |
| #ifdef __KERNEL__ /* Linux-only */ |
| #include <linux/vmalloc.h> |
| #include <linux/init.h> |
| #include <linux/mutex.h> |
| |
| static int __init alloc_workspaces(void) |
| { |
| def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS, |
| MAX_MEM_LEVEL)); |
| if (!def_strm.workspace) |
| return -ENOMEM; |
| |
| jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n", |
| zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL)); |
| inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); |
| if (!inf_strm.workspace) { |
| vfree(def_strm.workspace); |
| return -ENOMEM; |
| } |
| jffs2_dbg(1, "Allocated %d bytes for inflate workspace\n", |
| zlib_inflate_workspacesize()); |
| return 0; |
| } |
| |
| static void free_workspaces(void) |
| { |
| vfree(def_strm.workspace); |
| vfree(inf_strm.workspace); |
| } |
| #else |
| #define alloc_workspaces() (0) |
| #define free_workspaces() do { } while(0) |
| #endif /* __KERNEL__ */ |
| |
| static int jffs2_zlib_compress(unsigned char *data_in, |
| unsigned char *cpage_out, |
| uint32_t *sourcelen, uint32_t *dstlen) |
| { |
| int ret; |
| |
| if (*dstlen <= STREAM_END_SPACE) |
| return -1; |
| |
| mutex_lock(&deflate_mutex); |
| |
| if (Z_OK != zlib_deflateInit(&def_strm, 3)) { |
| printk(KERN_WARNING "deflateInit failed\n"); |
| mutex_unlock(&deflate_mutex); |
| return -1; |
| } |
| |
| def_strm.next_in = data_in; |
| def_strm.total_in = 0; |
| |
| def_strm.next_out = cpage_out; |
| def_strm.total_out = 0; |
| |
| while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { |
| def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); |
| def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); |
| jffs2_dbg(1, "calling deflate with avail_in %d, avail_out %d\n", |
| def_strm.avail_in, def_strm.avail_out); |
| ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); |
| jffs2_dbg(1, "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", |
| def_strm.avail_in, def_strm.avail_out, |
| def_strm.total_in, def_strm.total_out); |
| if (ret != Z_OK) { |
| jffs2_dbg(1, "deflate in loop returned %d\n", ret); |
| zlib_deflateEnd(&def_strm); |
| mutex_unlock(&deflate_mutex); |
| return -1; |
| } |
| } |
| def_strm.avail_out += STREAM_END_SPACE; |
| def_strm.avail_in = 0; |
| ret = zlib_deflate(&def_strm, Z_FINISH); |
| zlib_deflateEnd(&def_strm); |
| |
| if (ret != Z_STREAM_END) { |
| jffs2_dbg(1, "final deflate returned %d\n", ret); |
| ret = -1; |
| goto out; |
| } |
| |
| if (def_strm.total_out >= def_strm.total_in) { |
| jffs2_dbg(1, "zlib compressed %ld bytes into %ld; failing\n", |
| def_strm.total_in, def_strm.total_out); |
| ret = -1; |
| goto out; |
| } |
| |
| jffs2_dbg(1, "zlib compressed %ld bytes into %ld\n", |
| def_strm.total_in, def_strm.total_out); |
| |
| *dstlen = def_strm.total_out; |
| *sourcelen = def_strm.total_in; |
| ret = 0; |
| out: |
| mutex_unlock(&deflate_mutex); |
| return ret; |
| } |
| |
| static int jffs2_zlib_decompress(unsigned char *data_in, |
| unsigned char *cpage_out, |
| uint32_t srclen, uint32_t destlen) |
| { |
| int ret; |
| int wbits = MAX_WBITS; |
| |
| mutex_lock(&inflate_mutex); |
| |
| inf_strm.next_in = data_in; |
| inf_strm.avail_in = srclen; |
| inf_strm.total_in = 0; |
| |
| inf_strm.next_out = cpage_out; |
| inf_strm.avail_out = destlen; |
| inf_strm.total_out = 0; |
| |
| /* If it's deflate, and it's got no preset dictionary, then |
| we can tell zlib to skip the adler32 check. */ |
| if (srclen > 2 && !(data_in[1] & PRESET_DICT) && |
| ((data_in[0] & 0x0f) == Z_DEFLATED) && |
| !(((data_in[0]<<8) + data_in[1]) % 31)) { |
| |
| jffs2_dbg(2, "inflate skipping adler32\n"); |
| wbits = -((data_in[0] >> 4) + 8); |
| inf_strm.next_in += 2; |
| inf_strm.avail_in -= 2; |
| } else { |
| /* Let this remain D1 for now -- it should never happen */ |
| jffs2_dbg(1, "inflate not skipping adler32\n"); |
| } |
| |
| |
| if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { |
| printk(KERN_WARNING "inflateInit failed\n"); |
| mutex_unlock(&inflate_mutex); |
| return 1; |
| } |
| |
| while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) |
| ; |
| if (ret != Z_STREAM_END) { |
| printk(KERN_NOTICE "inflate returned %d\n", ret); |
| } |
| zlib_inflateEnd(&inf_strm); |
| mutex_unlock(&inflate_mutex); |
| return 0; |
| } |
| |
| static struct jffs2_compressor jffs2_zlib_comp = { |
| .priority = JFFS2_ZLIB_PRIORITY, |
| .name = "zlib", |
| .compr = JFFS2_COMPR_ZLIB, |
| .compress = &jffs2_zlib_compress, |
| .decompress = &jffs2_zlib_decompress, |
| #ifdef JFFS2_ZLIB_DISABLED |
| .disabled = 1, |
| #else |
| .disabled = 0, |
| #endif |
| }; |
| |
| int __init jffs2_zlib_init(void) |
| { |
| int ret; |
| |
| ret = alloc_workspaces(); |
| if (ret) |
| return ret; |
| |
| ret = jffs2_register_compressor(&jffs2_zlib_comp); |
| if (ret) |
| free_workspaces(); |
| |
| return ret; |
| } |
| |
| void jffs2_zlib_exit(void) |
| { |
| jffs2_unregister_compressor(&jffs2_zlib_comp); |
| free_workspaces(); |
| } |