fs/squashfs/file.c

14  * compressed fragment block (tail-end packed block).   The compressed size
15  * of each datablock is stored in a block list contained within the
20  * block index to datablock location on disk.
23  * retaining a simple and space-efficient block list on disk.  The cache
158  * Read the next n blocks from the block list, starting from
159  * metadata block <start_block, offset>.
165 	long long block = 0;
179 			ERROR("read_indexes: reading block [%llx:%x]\n",
190 			block += SQUASHFS_COMPRESSED_SIZE_BLOCK(size);
196 	return block;
206  * can cache one index -> datablock/blocklist-block mapping.  We wish
225  * on-disk locations of the datablock and block list metadata block
270 		 * If necessary grow cache slot by reading block list.  Cache
327 static int read_blocklist(struct inode *inode, int index, u64 *block)
333 	int res = fill_meta_index(inode, index, &start, &offset, block);
336 		       " 0x%x, block 0x%llx\n", res, index, start, offset,
337 			*block);
346 	 * extra block indexes needed.
352 		*block += blks;
356 	 * Read length of block specified by index.
393 	 * many PAGE_SIZE pages (default block size is 128 KiB) explicitly
421 /* Read datablock stored packed inside a fragment (tail-end packed block) */
431 		ERROR("Unable to read page, block %llx, size %x\n",
461 	TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n",
470 		u64 block = 0;
472 		res = read_blocklist(inode, index, &block);
479 			res = squashfs_readpage_block(page, block, res, expected);
560 		u64 block = 0;
591 		bsize = read_blocklist(inode, index, &block);
600 		res = squashfs_read_data(inode->i_sb, block, bsize, NULL, actor);