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fs/squashfs/zlib_wrapper.c
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81f7e3824 Initial Release, ... |
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/* * Squashfs - a compressed read only filesystem for Linux * * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 * Phillip Lougher <phillip@squashfs.org.uk> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2, * or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * * zlib_wrapper.c */ #include <linux/mutex.h> #include <linux/buffer_head.h> #include <linux/slab.h> #include <linux/zlib.h> #include <linux/vmalloc.h> #include "squashfs_fs.h" #include "squashfs_fs_sb.h" #include "squashfs.h" #include "decompressor.h" #include "page_actor.h" static void *zlib_init(struct squashfs_sb_info *dummy, void *buff) { z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL); if (stream == NULL) goto failed; stream->workspace = vmalloc(zlib_inflate_workspacesize()); if (stream->workspace == NULL) goto failed; return stream; failed: ERROR("Failed to allocate zlib workspace "); kfree(stream); return ERR_PTR(-ENOMEM); } static void zlib_free(void *strm) { z_stream *stream = strm; if (stream) vfree(stream->workspace); kfree(stream); } static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm, struct buffer_head **bh, int b, int offset, int length, struct squashfs_page_actor *output) { void *buf = NULL; int zlib_err, zlib_init = 0, k = 0; z_stream *stream = strm; stream->avail_out = PAGE_SIZE; stream->next_out = squashfs_first_page(output); stream->avail_in = 0; do { if (stream->avail_in == 0 && k < b) { int avail = min(length, msblk->devblksize - offset); length -= avail; stream->next_in = bh[k]->b_data + offset; stream->avail_in = avail; offset = 0; } if (stream->avail_out == 0) { stream->next_out = squashfs_next_page(output); if (!IS_ERR(stream->next_out)) stream->avail_out = PAGE_SIZE; } if (!stream->next_out) { if (!buf) { buf = kmalloc(PAGE_SIZE, GFP_ATOMIC); if (!buf) goto out; } stream->next_out = buf; } if (!zlib_init) { zlib_err = zlib_inflateInit(stream); if (zlib_err != Z_OK) { squashfs_finish_page(output); goto out; } zlib_init = 1; } zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH); if (stream->avail_in == 0 && k < b) put_bh(bh[k++]); } while (zlib_err == Z_OK); squashfs_finish_page(output); if (zlib_err != Z_STREAM_END) goto out; zlib_err = zlib_inflateEnd(stream); if (zlib_err != Z_OK) goto out; if (k < b) goto out; kfree(buf); return stream->total_out; out: for (; k < b; k++) put_bh(bh[k]); kfree(buf); return -EIO; } const struct squashfs_decompressor squashfs_zlib_comp_ops = { .init = zlib_init, .free = zlib_free, .decompress = zlib_uncompress, .id = ZLIB_COMPRESSION, .name = "zlib", .supported = 1 }; |