1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright © 2007 Nokia Corporation. All rights reserved. 5 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> 6 * 7 * Created by Richard Purdie <rpurdie@openedhand.com> 8 * 9 * For licensing information, see the file 'LICENCE' in this directory. 10 * 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/sched.h> 15 #include <linux/vmalloc.h> 16 #include <linux/init.h> 17 #include <linux/lzo.h> 18 #include "compr.h" 19 20 static void *lzo_mem; 21 static void *lzo_compress_buf; 22 static DEFINE_MUTEX(deflate_mutex); /* for lzo_mem and lzo_compress_buf */ 23 24 static void free_workspace(void) 25 { 26 vfree(lzo_mem); 27 vfree(lzo_compress_buf); 28 } 29 30 static int __init alloc_workspace(void) 31 { 32 lzo_mem = vmalloc(LZO1X_MEM_COMPRESS); 33 lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE)); 34 35 if (!lzo_mem || !lzo_compress_buf) { 36 free_workspace(); 37 return -ENOMEM; 38 } 39 40 return 0; 41 } 42 43 static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out, 44 uint32_t *sourcelen, uint32_t *dstlen) 45 { 46 size_t compress_size; 47 int ret; 48 49 mutex_lock(&deflate_mutex); 50 ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem); 51 if (ret != LZO_E_OK) 52 goto fail; 53 54 if (compress_size > *dstlen) 55 goto fail; 56 57 memcpy(cpage_out, lzo_compress_buf, compress_size); 58 mutex_unlock(&deflate_mutex); 59 60 *dstlen = compress_size; 61 return 0; 62 63 fail: 64 mutex_unlock(&deflate_mutex); 65 return -1; 66 } 67 68 static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out, 69 uint32_t srclen, uint32_t destlen) 70 { 71 size_t dl = destlen; 72 int ret; 73 74 ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl); 75 76 if (ret != LZO_E_OK || dl != destlen) 77 return -1; 78 79 return 0; 80 } 81 82 static struct jffs2_compressor jffs2_lzo_comp = { 83 .priority = JFFS2_LZO_PRIORITY, 84 .name = "lzo", 85 .compr = JFFS2_COMPR_LZO, 86 .compress = &jffs2_lzo_compress, 87 .decompress = &jffs2_lzo_decompress, 88 .disabled = 0, 89 }; 90 91 int __init jffs2_lzo_init(void) 92 { 93 int ret; 94 95 ret = alloc_workspace(); 96 if (ret < 0) 97 return ret; 98 99 ret = jffs2_register_compressor(&jffs2_lzo_comp); 100 if (ret) 101 free_workspace(); 102 103 return ret; 104 } 105 106 void jffs2_lzo_exit(void) 107 { 108 jffs2_unregister_compressor(&jffs2_lzo_comp); 109 free_workspace(); 110 } 111