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> 1393e72b3cSPhilippe Liard #include <linux/bio.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, 5393e72b3cSPhilippe Liard struct bio *bio, int offset, int length, 54846b730eSPhillip Lougher struct squashfs_page_actor *output) 55e6a6d379SPhillip Lougher { 5693e72b3cSPhilippe Liard struct bvec_iter_all iter_all = {}; 5793e72b3cSPhilippe Liard struct bio_vec *bvec = bvec_init_iter_all(&iter_all); 5893e72b3cSPhilippe Liard int zlib_init = 0, error = 0; 599508c6b9SPhillip Lougher z_stream *stream = strm; 60e6a6d379SPhillip Lougher 6109cbfeafSKirill A. Shutemov stream->avail_out = PAGE_SIZE; 62846b730eSPhillip Lougher stream->next_out = squashfs_first_page(output); 63f1a40359SPhillip Lougher stream->avail_in = 0; 64e6a6d379SPhillip Lougher 6593e72b3cSPhilippe Liard for (;;) { 6693e72b3cSPhilippe Liard int zlib_err; 6793e72b3cSPhilippe Liard 6893e72b3cSPhilippe Liard if (stream->avail_in == 0) { 6993e72b3cSPhilippe Liard const void *data; 7093e72b3cSPhilippe Liard int avail; 7193e72b3cSPhilippe Liard 7293e72b3cSPhilippe Liard if (!bio_next_segment(bio, &iter_all)) { 7393e72b3cSPhilippe Liard /* Z_STREAM_END must be reached. */ 7493e72b3cSPhilippe Liard error = -EIO; 7593e72b3cSPhilippe Liard break; 7693e72b3cSPhilippe Liard } 7793e72b3cSPhilippe Liard 7893e72b3cSPhilippe Liard avail = min(length, ((int)bvec->bv_len) - offset); 79*fbc27241SChristoph Hellwig data = bvec_virt(bvec); 80170cf021SPhillip Lougher length -= avail; 8193e72b3cSPhilippe Liard stream->next_in = data + offset; 82f1a40359SPhillip Lougher stream->avail_in = avail; 83e6a6d379SPhillip Lougher offset = 0; 84e6a6d379SPhillip Lougher } 85e6a6d379SPhillip Lougher 86846b730eSPhillip Lougher if (stream->avail_out == 0) { 87846b730eSPhillip Lougher stream->next_out = squashfs_next_page(output); 88846b730eSPhillip Lougher if (stream->next_out != NULL) 8909cbfeafSKirill A. Shutemov stream->avail_out = PAGE_SIZE; 90e6a6d379SPhillip Lougher } 91e6a6d379SPhillip Lougher 92e6a6d379SPhillip Lougher if (!zlib_init) { 93f1a40359SPhillip Lougher zlib_err = zlib_inflateInit(stream); 94846b730eSPhillip Lougher if (zlib_err != Z_OK) { 9593e72b3cSPhilippe Liard error = -EIO; 9693e72b3cSPhilippe Liard break; 97846b730eSPhillip Lougher } 98e6a6d379SPhillip Lougher zlib_init = 1; 99e6a6d379SPhillip Lougher } 100e6a6d379SPhillip Lougher 101f1a40359SPhillip Lougher zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH); 10293e72b3cSPhilippe Liard if (zlib_err == Z_STREAM_END) 10393e72b3cSPhilippe Liard break; 10493e72b3cSPhilippe Liard if (zlib_err != Z_OK) { 10593e72b3cSPhilippe Liard error = -EIO; 10693e72b3cSPhilippe Liard break; 10793e72b3cSPhilippe Liard } 10893e72b3cSPhilippe Liard } 109e6a6d379SPhillip Lougher 110846b730eSPhillip Lougher squashfs_finish_page(output); 111846b730eSPhillip Lougher 11293e72b3cSPhilippe Liard if (!error) 11393e72b3cSPhilippe Liard if (zlib_inflateEnd(stream) != Z_OK) 11493e72b3cSPhilippe Liard error = -EIO; 115e6a6d379SPhillip Lougher 11693e72b3cSPhilippe Liard return error ? error : stream->total_out; 117e6a6d379SPhillip Lougher } 1184c0f0bb2SPhillip Lougher 1194c0f0bb2SPhillip Lougher const struct squashfs_decompressor squashfs_zlib_comp_ops = { 1204c0f0bb2SPhillip Lougher .init = zlib_init, 1214c0f0bb2SPhillip Lougher .free = zlib_free, 1224c0f0bb2SPhillip Lougher .decompress = zlib_uncompress, 1234c0f0bb2SPhillip Lougher .id = ZLIB_COMPRESSION, 1244c0f0bb2SPhillip Lougher .name = "zlib", 1254c0f0bb2SPhillip Lougher .supported = 1 1264c0f0bb2SPhillip Lougher }; 1274c0f0bb2SPhillip Lougher 128