projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * uncompress.c | |
| 3 | * | |
| 4 | * (C) Copyright 1999 Linus Torvalds | |
| 5 | * | |
| 6 | * cramfs interfaces to the uncompression library. There's really just | |
| 7 | * three entrypoints: | |
| 8 | * | |
| 9 | * - cramfs_uncompress_init() - called to initialize the thing. | |
| 10 | * - cramfs_uncompress_exit() - tell me when you're done | |
| 11 | * - cramfs_uncompress_block() - uncompress a block. | |
| 12 | * | |
| 13 | * NOTE NOTE NOTE! The uncompression is entirely single-threaded. We | |
| 14 | * only have one stream, and we'll initialize it only once even if it | |
| 15 | * then is used by multiple filesystems. | |
| 16 | */ | |
| 17 | ||
| 4f21e1ea FF |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 19 | ||
| 1da177e4 LT |
20 | #include <linux/kernel.h> |
| 21 | #include <linux/errno.h> | |
| 22 | #include <linux/vmalloc.h> | |
| 23 | #include <linux/zlib.h> | |
| f7f4f4dd | 24 | #include "internal.h" |
| 1da177e4 LT |
25 | |
| 26 | static z_stream stream; | |
| 27 | static int initialized; | |
| 28 | ||
| 29 | /* Returns length of decompressed data. */ | |
| 30 | int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen) | |
| 31 | { | |
| 32 | int err; | |
| 33 | ||
| 34 | stream.next_in = src; | |
| 35 | stream.avail_in = srclen; | |
| 36 | ||
| 37 | stream.next_out = dst; | |
| 38 | stream.avail_out = dstlen; | |
| 39 | ||
| 40 | err = zlib_inflateReset(&stream); | |
| 41 | if (err != Z_OK) { | |
| f175ff81 | 42 | pr_err("zlib_inflateReset error %d\n", err); |
| 1da177e4 LT |
43 | zlib_inflateEnd(&stream); |
| 44 | zlib_inflateInit(&stream); | |
| 45 | } | |
| 46 | ||
| 47 | err = zlib_inflate(&stream, Z_FINISH); | |
| 48 | if (err != Z_STREAM_END) | |
| 49 | goto err; | |
| 50 | return stream.total_out; | |
| 51 | ||
| 52 | err: | |
| f175ff81 FF |
53 | pr_err("Error %d while decompressing!\n", err); |
| 54 | pr_err("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen); | |
| 98310e58 | 55 | return -EIO; |
| 1da177e4 LT |
56 | } |
| 57 | ||
| 58 | int cramfs_uncompress_init(void) | |
| 59 | { | |
| 60 | if (!initialized++) { | |
| 61 | stream.workspace = vmalloc(zlib_inflate_workspacesize()); | |
| 31d92e55 | 62 | if (!stream.workspace) { |
| 1da177e4 LT |
63 | initialized = 0; |
| 64 | return -ENOMEM; | |
| 65 | } | |
| 66 | stream.next_in = NULL; | |
| 67 | stream.avail_in = 0; | |
| 68 | zlib_inflateInit(&stream); | |
| 69 | } | |
| 70 | return 0; | |
| 71 | } | |
| 72 | ||
| 368bdb3d | 73 | void cramfs_uncompress_exit(void) |
| 1da177e4 LT |
74 | { |
| 75 | if (!--initialized) { | |
| 76 | zlib_inflateEnd(&stream); | |
| 77 | vfree(stream.workspace); | |
| 78 | } | |
| 1da177e4 | 79 | } |