/* * JFFS2 -- Journalling Flash File System, Version 2. * * Copyright © 2007 Nokia Corporation. All rights reserved. * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> * * Created by Richard Purdie <rpurdie@openedhand.com> * * For licensing information, see the file 'LICENCE' in this directory. * */ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/vmalloc.h> #include <linux/init.h> #include <linux/lzo.h> #include "compr.h" static void *lzo_mem; static void *lzo_compress_buf; static DEFINE_MUTEX(deflate_mutex); /* for lzo_mem and lzo_compress_buf */ static void free_workspace(void) { vfree(lzo_mem); vfree(lzo_compress_buf); } static int __init alloc_workspace(void) { lzo_mem = vmalloc(LZO1X_MEM_COMPRESS); lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE)); if (!lzo_mem || !lzo_compress_buf) { printk(KERN_WARNING "Failed to allocate lzo deflate workspace\n"); free_workspace(); return -ENOMEM; } return 0; } static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out, uint32_t *sourcelen, uint32_t *dstlen) { size_t compress_size; int ret; mutex_lock(&deflate_mutex); ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem); if (ret != LZO_E_OK) goto fail; if (compress_size > *dstlen) goto fail; memcpy(cpage_out, lzo_compress_buf, compress_size); mutex_unlock(&deflate_mutex); *dstlen = compress_size; return 0; fail: mutex_unlock(&deflate_mutex); return -1; } static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out, uint32_t srclen, uint32_t destlen) { size_t dl = destlen; int ret; ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl); if (ret != LZO_E_OK || dl != destlen) return -1; return 0; } static struct jffs2_compressor jffs2_lzo_comp = { .priority = JFFS2_LZO_PRIORITY, .name = "lzo", .compr = JFFS2_COMPR_LZO, .compress = &jffs2_lzo_compress, .decompress = &jffs2_lzo_decompress, .disabled = 0, }; int __init jffs2_lzo_init(void) { int ret; ret = alloc_workspace(); if (ret < 0) return ret; ret = jffs2_register_compressor(&jffs2_lzo_comp); if (ret) free_workspace(); return ret; } void jffs2_lzo_exit(void) { jffs2_unregister_compressor(&jffs2_lzo_comp); free_workspace(); }