19c06a46fSPhillip Lougher /* 29c06a46fSPhillip Lougher * Copyright (c) 2013, 2014 39c06a46fSPhillip Lougher * Phillip Lougher <phillip@squashfs.org.uk> 49c06a46fSPhillip Lougher * 59c06a46fSPhillip Lougher * This work is licensed under the terms of the GNU GPL, version 2. See 69c06a46fSPhillip Lougher * the COPYING file in the top-level directory. 79c06a46fSPhillip Lougher */ 89c06a46fSPhillip Lougher 99c06a46fSPhillip Lougher #include <linux/buffer_head.h> 109c06a46fSPhillip Lougher #include <linux/mutex.h> 119c06a46fSPhillip Lougher #include <linux/slab.h> 129c06a46fSPhillip Lougher #include <linux/vmalloc.h> 139c06a46fSPhillip Lougher #include <linux/lz4.h> 149c06a46fSPhillip Lougher 159c06a46fSPhillip Lougher #include "squashfs_fs.h" 169c06a46fSPhillip Lougher #include "squashfs_fs_sb.h" 179c06a46fSPhillip Lougher #include "squashfs.h" 189c06a46fSPhillip Lougher #include "decompressor.h" 199c06a46fSPhillip Lougher #include "page_actor.h" 209c06a46fSPhillip Lougher 219c06a46fSPhillip Lougher #define LZ4_LEGACY 1 229c06a46fSPhillip Lougher 239c06a46fSPhillip Lougher struct lz4_comp_opts { 249c06a46fSPhillip Lougher __le32 version; 259c06a46fSPhillip Lougher __le32 flags; 269c06a46fSPhillip Lougher }; 279c06a46fSPhillip Lougher 289c06a46fSPhillip Lougher struct squashfs_lz4 { 299c06a46fSPhillip Lougher void *input; 309c06a46fSPhillip Lougher void *output; 319c06a46fSPhillip Lougher }; 329c06a46fSPhillip Lougher 339c06a46fSPhillip Lougher 349c06a46fSPhillip Lougher static void *lz4_comp_opts(struct squashfs_sb_info *msblk, 359c06a46fSPhillip Lougher void *buff, int len) 369c06a46fSPhillip Lougher { 379c06a46fSPhillip Lougher struct lz4_comp_opts *comp_opts = buff; 389c06a46fSPhillip Lougher 399c06a46fSPhillip Lougher /* LZ4 compressed filesystems always have compression options */ 409c06a46fSPhillip Lougher if (comp_opts == NULL || len < sizeof(*comp_opts)) 419c06a46fSPhillip Lougher return ERR_PTR(-EIO); 429c06a46fSPhillip Lougher 439c06a46fSPhillip Lougher if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) { 449c06a46fSPhillip Lougher /* LZ4 format currently used by the kernel is the 'legacy' 459c06a46fSPhillip Lougher * format */ 469c06a46fSPhillip Lougher ERROR("Unknown LZ4 version\n"); 479c06a46fSPhillip Lougher return ERR_PTR(-EINVAL); 489c06a46fSPhillip Lougher } 499c06a46fSPhillip Lougher 509c06a46fSPhillip Lougher return NULL; 519c06a46fSPhillip Lougher } 529c06a46fSPhillip Lougher 539c06a46fSPhillip Lougher 549c06a46fSPhillip Lougher static void *lz4_init(struct squashfs_sb_info *msblk, void *buff) 559c06a46fSPhillip Lougher { 569c06a46fSPhillip Lougher int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); 579c06a46fSPhillip Lougher struct squashfs_lz4 *stream; 589c06a46fSPhillip Lougher 599c06a46fSPhillip Lougher stream = kzalloc(sizeof(*stream), GFP_KERNEL); 609c06a46fSPhillip Lougher if (stream == NULL) 619c06a46fSPhillip Lougher goto failed; 629c06a46fSPhillip Lougher stream->input = vmalloc(block_size); 639c06a46fSPhillip Lougher if (stream->input == NULL) 649c06a46fSPhillip Lougher goto failed2; 659c06a46fSPhillip Lougher stream->output = vmalloc(block_size); 669c06a46fSPhillip Lougher if (stream->output == NULL) 679c06a46fSPhillip Lougher goto failed3; 689c06a46fSPhillip Lougher 699c06a46fSPhillip Lougher return stream; 709c06a46fSPhillip Lougher 719c06a46fSPhillip Lougher failed3: 729c06a46fSPhillip Lougher vfree(stream->input); 739c06a46fSPhillip Lougher failed2: 749c06a46fSPhillip Lougher kfree(stream); 759c06a46fSPhillip Lougher failed: 769c06a46fSPhillip Lougher ERROR("Failed to initialise LZ4 decompressor\n"); 779c06a46fSPhillip Lougher return ERR_PTR(-ENOMEM); 789c06a46fSPhillip Lougher } 799c06a46fSPhillip Lougher 809c06a46fSPhillip Lougher 819c06a46fSPhillip Lougher static void lz4_free(void *strm) 829c06a46fSPhillip Lougher { 839c06a46fSPhillip Lougher struct squashfs_lz4 *stream = strm; 849c06a46fSPhillip Lougher 859c06a46fSPhillip Lougher if (stream) { 869c06a46fSPhillip Lougher vfree(stream->input); 879c06a46fSPhillip Lougher vfree(stream->output); 889c06a46fSPhillip Lougher } 899c06a46fSPhillip Lougher kfree(stream); 909c06a46fSPhillip Lougher } 919c06a46fSPhillip Lougher 929c06a46fSPhillip Lougher 939c06a46fSPhillip Lougher static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm, 949c06a46fSPhillip Lougher struct buffer_head **bh, int b, int offset, int length, 959c06a46fSPhillip Lougher struct squashfs_page_actor *output) 969c06a46fSPhillip Lougher { 979c06a46fSPhillip Lougher struct squashfs_lz4 *stream = strm; 989c06a46fSPhillip Lougher void *buff = stream->input, *data; 999c06a46fSPhillip Lougher int avail, i, bytes = length, res; 1009c06a46fSPhillip Lougher size_t dest_len = output->length; 1019c06a46fSPhillip Lougher 1029c06a46fSPhillip Lougher for (i = 0; i < b; i++) { 1039c06a46fSPhillip Lougher avail = min(bytes, msblk->devblksize - offset); 1049c06a46fSPhillip Lougher memcpy(buff, bh[i]->b_data + offset, avail); 1059c06a46fSPhillip Lougher buff += avail; 1069c06a46fSPhillip Lougher bytes -= avail; 1079c06a46fSPhillip Lougher offset = 0; 1089c06a46fSPhillip Lougher put_bh(bh[i]); 1099c06a46fSPhillip Lougher } 1109c06a46fSPhillip Lougher 1119c06a46fSPhillip Lougher res = lz4_decompress_unknownoutputsize(stream->input, length, 1129c06a46fSPhillip Lougher stream->output, &dest_len); 1139c06a46fSPhillip Lougher if (res) 1149c06a46fSPhillip Lougher return -EIO; 1159c06a46fSPhillip Lougher 1169c06a46fSPhillip Lougher bytes = dest_len; 1179c06a46fSPhillip Lougher data = squashfs_first_page(output); 1189c06a46fSPhillip Lougher buff = stream->output; 1199c06a46fSPhillip Lougher while (data) { 1209c06a46fSPhillip Lougher if (bytes <= PAGE_CACHE_SIZE) { 1219c06a46fSPhillip Lougher memcpy(data, buff, bytes); 1229c06a46fSPhillip Lougher break; 1239c06a46fSPhillip Lougher } 1249c06a46fSPhillip Lougher memcpy(data, buff, PAGE_CACHE_SIZE); 1259c06a46fSPhillip Lougher buff += PAGE_CACHE_SIZE; 1269c06a46fSPhillip Lougher bytes -= PAGE_CACHE_SIZE; 1279c06a46fSPhillip Lougher data = squashfs_next_page(output); 1289c06a46fSPhillip Lougher } 1299c06a46fSPhillip Lougher squashfs_finish_page(output); 1309c06a46fSPhillip Lougher 1319c06a46fSPhillip Lougher return dest_len; 1329c06a46fSPhillip Lougher } 1339c06a46fSPhillip Lougher 1349c06a46fSPhillip Lougher const struct squashfs_decompressor squashfs_lz4_comp_ops = { 1359c06a46fSPhillip Lougher .init = lz4_init, 1369c06a46fSPhillip Lougher .comp_opts = lz4_comp_opts, 1379c06a46fSPhillip Lougher .free = lz4_free, 1389c06a46fSPhillip Lougher .decompress = lz4_uncompress, 1399c06a46fSPhillip Lougher .id = LZ4_COMPRESSION, 1409c06a46fSPhillip Lougher .name = "lz4", 1419c06a46fSPhillip Lougher .supported = 1 1429c06a46fSPhillip Lougher }; 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