168252eb5SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 2e6a6d379SPhillip Lougher /* 3e6a6d379SPhillip Lougher * Squashfs - a compressed read only filesystem for Linux 4e6a6d379SPhillip Lougher * 5e6a6d379SPhillip Lougher * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 6d7f2ff67SPhillip Lougher * Phillip Lougher <phillip@squashfs.org.uk> 7e6a6d379SPhillip Lougher * 8e6a6d379SPhillip Lougher * zlib_wrapper.c 9e6a6d379SPhillip Lougher */ 10e6a6d379SPhillip Lougher 11e6a6d379SPhillip Lougher 12e6a6d379SPhillip Lougher #include <linux/mutex.h> 13e6a6d379SPhillip Lougher #include <linux/buffer_head.h> 145a0e3ad6STejun Heo #include <linux/slab.h> 15e6a6d379SPhillip Lougher #include <linux/zlib.h> 16117a91e0SPhillip Lougher #include <linux/vmalloc.h> 17e6a6d379SPhillip Lougher 18e6a6d379SPhillip Lougher #include "squashfs_fs.h" 19e6a6d379SPhillip Lougher #include "squashfs_fs_sb.h" 20e6a6d379SPhillip Lougher #include "squashfs.h" 214c0f0bb2SPhillip Lougher #include "decompressor.h" 22846b730eSPhillip Lougher #include "page_actor.h" 23e6a6d379SPhillip Lougher 249508c6b9SPhillip Lougher static void *zlib_init(struct squashfs_sb_info *dummy, void *buff) 25f1a40359SPhillip Lougher { 26f1a40359SPhillip Lougher z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL); 27f1a40359SPhillip Lougher if (stream == NULL) 28f1a40359SPhillip Lougher goto failed; 29117a91e0SPhillip Lougher stream->workspace = vmalloc(zlib_inflate_workspacesize()); 30f1a40359SPhillip Lougher if (stream->workspace == NULL) 31f1a40359SPhillip Lougher goto failed; 32f1a40359SPhillip Lougher 33f1a40359SPhillip Lougher return stream; 34f1a40359SPhillip Lougher 35f1a40359SPhillip Lougher failed: 36f1a40359SPhillip Lougher ERROR("Failed to allocate zlib workspace\n"); 37f1a40359SPhillip Lougher kfree(stream); 38b7fc0ff0SPhillip Lougher return ERR_PTR(-ENOMEM); 39f1a40359SPhillip Lougher } 40f1a40359SPhillip Lougher 41f1a40359SPhillip Lougher 424c0f0bb2SPhillip Lougher static void zlib_free(void *strm) 43f1a40359SPhillip Lougher { 44f1a40359SPhillip Lougher z_stream *stream = strm; 45f1a40359SPhillip Lougher 46f1a40359SPhillip Lougher if (stream) 47117a91e0SPhillip Lougher vfree(stream->workspace); 48f1a40359SPhillip Lougher kfree(stream); 49f1a40359SPhillip Lougher } 50f1a40359SPhillip Lougher 51f1a40359SPhillip Lougher 529508c6b9SPhillip Lougher static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm, 53846b730eSPhillip Lougher struct buffer_head **bh, int b, int offset, int length, 54846b730eSPhillip Lougher struct squashfs_page_actor *output) 55e6a6d379SPhillip Lougher { 56846b730eSPhillip Lougher int zlib_err, zlib_init = 0, k = 0; 579508c6b9SPhillip Lougher z_stream *stream = strm; 58e6a6d379SPhillip Lougher 5909cbfeafSKirill A. Shutemov stream->avail_out = PAGE_SIZE; 60846b730eSPhillip Lougher stream->next_out = squashfs_first_page(output); 61f1a40359SPhillip Lougher stream->avail_in = 0; 62e6a6d379SPhillip Lougher 63e6a6d379SPhillip Lougher do { 64f1a40359SPhillip Lougher if (stream->avail_in == 0 && k < b) { 65170cf021SPhillip Lougher int avail = min(length, msblk->devblksize - offset); 66170cf021SPhillip Lougher length -= avail; 67f1a40359SPhillip Lougher stream->next_in = bh[k]->b_data + offset; 68f1a40359SPhillip Lougher stream->avail_in = avail; 69e6a6d379SPhillip Lougher offset = 0; 70e6a6d379SPhillip Lougher } 71e6a6d379SPhillip Lougher 72846b730eSPhillip Lougher if (stream->avail_out == 0) { 73846b730eSPhillip Lougher stream->next_out = squashfs_next_page(output); 74846b730eSPhillip Lougher if (stream->next_out != NULL) 7509cbfeafSKirill A. Shutemov stream->avail_out = PAGE_SIZE; 76e6a6d379SPhillip Lougher } 77e6a6d379SPhillip Lougher 78e6a6d379SPhillip Lougher if (!zlib_init) { 79f1a40359SPhillip Lougher zlib_err = zlib_inflateInit(stream); 80846b730eSPhillip Lougher if (zlib_err != Z_OK) { 81846b730eSPhillip Lougher squashfs_finish_page(output); 829508c6b9SPhillip Lougher goto out; 83846b730eSPhillip Lougher } 84e6a6d379SPhillip Lougher zlib_init = 1; 85e6a6d379SPhillip Lougher } 86e6a6d379SPhillip Lougher 87f1a40359SPhillip Lougher zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH); 88e6a6d379SPhillip Lougher 89f1a40359SPhillip Lougher if (stream->avail_in == 0 && k < b) 90e6a6d379SPhillip Lougher put_bh(bh[k++]); 91e6a6d379SPhillip Lougher } while (zlib_err == Z_OK); 92e6a6d379SPhillip Lougher 93846b730eSPhillip Lougher squashfs_finish_page(output); 94846b730eSPhillip Lougher 959508c6b9SPhillip Lougher if (zlib_err != Z_STREAM_END) 969508c6b9SPhillip Lougher goto out; 97e6a6d379SPhillip Lougher 98f1a40359SPhillip Lougher zlib_err = zlib_inflateEnd(stream); 999508c6b9SPhillip Lougher if (zlib_err != Z_OK) 1009508c6b9SPhillip Lougher goto out; 101e6a6d379SPhillip Lougher 1029508c6b9SPhillip Lougher if (k < b) 1039508c6b9SPhillip Lougher goto out; 104e7ee11f0SPhillip Lougher 1059508c6b9SPhillip Lougher return stream->total_out; 106e6a6d379SPhillip Lougher 1079508c6b9SPhillip Lougher out: 108e6a6d379SPhillip Lougher for (; k < b; k++) 109e6a6d379SPhillip Lougher put_bh(bh[k]); 110e6a6d379SPhillip Lougher 111e6a6d379SPhillip Lougher return -EIO; 112e6a6d379SPhillip Lougher } 1134c0f0bb2SPhillip Lougher 1144c0f0bb2SPhillip Lougher const struct squashfs_decompressor squashfs_zlib_comp_ops = { 1154c0f0bb2SPhillip Lougher .init = zlib_init, 1164c0f0bb2SPhillip Lougher .free = zlib_free, 1174c0f0bb2SPhillip Lougher .decompress = zlib_uncompress, 1184c0f0bb2SPhillip Lougher .id = ZLIB_COMPRESSION, 1194c0f0bb2SPhillip Lougher .name = "zlib", 1204c0f0bb2SPhillip Lougher .supported = 1 1214c0f0bb2SPhillip Lougher }; 1224c0f0bb2SPhillip Lougher 123