[0c0f128] | 1 | /* |
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| 2 | * JFFS2 -- Journalling Flash File System, Version 2. |
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| 3 | * |
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| 4 | * Copyright © 2001-2007 Red Hat, Inc. |
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| 5 | * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> |
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| 6 | * |
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| 7 | * Created by David Woodhouse <dwmw2@infradead.org> |
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| 8 | * |
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| 9 | * For licensing information, see the file 'LICENCE' in this directory. |
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| 10 | * |
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| 11 | */ |
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| 12 | |
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| 13 | #if !defined(__KERNEL__) && !defined(__ECOS) |
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| 14 | #error "The userspace support got too messy and was removed. Update your mkfs.jffs2" |
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| 15 | #endif |
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| 16 | |
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| 17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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| 18 | |
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| 19 | #include <linux/kernel.h> |
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| 20 | #include <linux/zlib.h> |
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| 21 | #include <linux/zutil.h> |
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| 22 | #include "nodelist.h" |
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| 23 | #include "compr.h" |
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| 24 | |
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| 25 | /* Plan: call deflate() with avail_in == *sourcelen, |
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| 26 | avail_out = *dstlen - 12 and flush == Z_FINISH. |
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| 27 | If it doesn't manage to finish, call it again with |
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| 28 | avail_in == 0 and avail_out set to the remaining 12 |
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| 29 | bytes for it to clean up. |
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| 30 | Q: Is 12 bytes sufficient? |
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| 31 | */ |
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| 32 | #define STREAM_END_SPACE 12 |
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| 33 | |
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| 34 | static DEFINE_MUTEX(deflate_mutex); |
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| 35 | static DEFINE_MUTEX(inflate_mutex); |
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| 36 | static z_stream inf_strm, def_strm; |
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| 37 | |
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| 38 | #ifdef __KERNEL__ /* Linux-only */ |
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| 39 | #include <linux/vmalloc.h> |
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| 40 | #include <linux/init.h> |
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| 41 | #include <linux/mutex.h> |
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| 42 | |
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| 43 | static int __init alloc_workspaces(void) |
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| 44 | { |
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| 45 | def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS, |
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| 46 | MAX_MEM_LEVEL)); |
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| 47 | if (!def_strm.workspace) |
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| 48 | return -ENOMEM; |
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| 49 | |
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| 50 | jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n", |
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| 51 | zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL)); |
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| 52 | inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); |
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| 53 | if (!inf_strm.workspace) { |
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| 54 | vfree(def_strm.workspace); |
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| 55 | return -ENOMEM; |
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| 56 | } |
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| 57 | jffs2_dbg(1, "Allocated %d bytes for inflate workspace\n", |
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| 58 | zlib_inflate_workspacesize()); |
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| 59 | return 0; |
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| 60 | } |
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| 61 | |
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| 62 | static void free_workspaces(void) |
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| 63 | { |
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| 64 | vfree(def_strm.workspace); |
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| 65 | vfree(inf_strm.workspace); |
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| 66 | } |
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| 67 | #else |
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| 68 | #define alloc_workspaces() (0) |
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| 69 | #define free_workspaces() do { } while(0) |
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| 70 | #endif /* __KERNEL__ */ |
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| 71 | |
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| 72 | static int jffs2_zlib_compress(unsigned char *data_in, |
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| 73 | unsigned char *cpage_out, |
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| 74 | uint32_t *sourcelen, uint32_t *dstlen) |
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| 75 | { |
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| 76 | int ret; |
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| 77 | |
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| 78 | if (*dstlen <= STREAM_END_SPACE) |
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| 79 | return -1; |
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| 80 | |
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| 81 | mutex_lock(&deflate_mutex); |
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| 82 | |
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| 83 | if (Z_OK != zlib_deflateInit(&def_strm, 3)) { |
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| 84 | pr_warn("deflateInit failed\n"); |
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| 85 | mutex_unlock(&deflate_mutex); |
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| 86 | return -1; |
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| 87 | } |
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| 88 | |
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| 89 | def_strm.next_in = data_in; |
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| 90 | def_strm.total_in = 0; |
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| 91 | |
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| 92 | def_strm.next_out = cpage_out; |
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| 93 | def_strm.total_out = 0; |
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| 94 | |
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| 95 | while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { |
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| 96 | def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); |
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| 97 | def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); |
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| 98 | jffs2_dbg(1, "calling deflate with avail_in %d, avail_out %d\n", |
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| 99 | def_strm.avail_in, def_strm.avail_out); |
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| 100 | ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); |
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| 101 | jffs2_dbg(1, "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", |
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| 102 | def_strm.avail_in, def_strm.avail_out, |
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| 103 | def_strm.total_in, def_strm.total_out); |
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| 104 | if (ret != Z_OK) { |
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| 105 | jffs2_dbg(1, "deflate in loop returned %d\n", ret); |
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| 106 | zlib_deflateEnd(&def_strm); |
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| 107 | mutex_unlock(&deflate_mutex); |
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| 108 | return -1; |
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| 109 | } |
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| 110 | } |
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| 111 | def_strm.avail_out += STREAM_END_SPACE; |
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| 112 | def_strm.avail_in = 0; |
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| 113 | ret = zlib_deflate(&def_strm, Z_FINISH); |
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| 114 | zlib_deflateEnd(&def_strm); |
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| 115 | |
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| 116 | if (ret != Z_STREAM_END) { |
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| 117 | jffs2_dbg(1, "final deflate returned %d\n", ret); |
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| 118 | ret = -1; |
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| 119 | goto out; |
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| 120 | } |
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| 121 | |
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| 122 | if (def_strm.total_out >= def_strm.total_in) { |
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| 123 | jffs2_dbg(1, "zlib compressed %ld bytes into %ld; failing\n", |
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| 124 | def_strm.total_in, def_strm.total_out); |
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| 125 | ret = -1; |
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| 126 | goto out; |
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| 127 | } |
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| 128 | |
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| 129 | jffs2_dbg(1, "zlib compressed %ld bytes into %ld\n", |
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| 130 | def_strm.total_in, def_strm.total_out); |
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| 131 | |
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| 132 | *dstlen = def_strm.total_out; |
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| 133 | *sourcelen = def_strm.total_in; |
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| 134 | ret = 0; |
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| 135 | out: |
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| 136 | mutex_unlock(&deflate_mutex); |
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| 137 | return ret; |
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| 138 | } |
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| 139 | |
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| 140 | static int jffs2_zlib_decompress(unsigned char *data_in, |
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| 141 | unsigned char *cpage_out, |
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| 142 | uint32_t srclen, uint32_t destlen) |
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| 143 | { |
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| 144 | int ret; |
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| 145 | int wbits = MAX_WBITS; |
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| 146 | |
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| 147 | mutex_lock(&inflate_mutex); |
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| 148 | |
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| 149 | inf_strm.next_in = data_in; |
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| 150 | inf_strm.avail_in = srclen; |
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| 151 | inf_strm.total_in = 0; |
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| 152 | |
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| 153 | inf_strm.next_out = cpage_out; |
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| 154 | inf_strm.avail_out = destlen; |
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| 155 | inf_strm.total_out = 0; |
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| 156 | |
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| 157 | /* If it's deflate, and it's got no preset dictionary, then |
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| 158 | we can tell zlib to skip the adler32 check. */ |
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| 159 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && |
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| 160 | ((data_in[0] & 0x0f) == Z_DEFLATED) && |
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| 161 | !(((data_in[0]<<8) + data_in[1]) % 31)) { |
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| 162 | |
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| 163 | jffs2_dbg(2, "inflate skipping adler32\n"); |
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| 164 | wbits = -((data_in[0] >> 4) + 8); |
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| 165 | inf_strm.next_in += 2; |
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| 166 | inf_strm.avail_in -= 2; |
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| 167 | } else { |
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| 168 | /* Let this remain D1 for now -- it should never happen */ |
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| 169 | jffs2_dbg(1, "inflate not skipping adler32\n"); |
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| 170 | } |
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| 171 | |
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| 172 | |
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| 173 | if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { |
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| 174 | pr_warn("inflateInit failed\n"); |
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| 175 | mutex_unlock(&inflate_mutex); |
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| 176 | return 1; |
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| 177 | } |
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| 178 | |
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| 179 | while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) |
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| 180 | ; |
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| 181 | if (ret != Z_STREAM_END) { |
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| 182 | pr_notice("inflate returned %d\n", ret); |
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| 183 | } |
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| 184 | zlib_inflateEnd(&inf_strm); |
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| 185 | mutex_unlock(&inflate_mutex); |
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| 186 | return 0; |
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| 187 | } |
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| 188 | |
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| 189 | static struct jffs2_compressor jffs2_zlib_comp = { |
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| 190 | .priority = JFFS2_ZLIB_PRIORITY, |
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| 191 | .name = "zlib", |
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| 192 | .compr = JFFS2_COMPR_ZLIB, |
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| 193 | .compress = &jffs2_zlib_compress, |
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| 194 | .decompress = &jffs2_zlib_decompress, |
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| 195 | #ifdef JFFS2_ZLIB_DISABLED |
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| 196 | .disabled = 1, |
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| 197 | #else |
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| 198 | .disabled = 0, |
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| 199 | #endif |
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| 200 | }; |
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| 201 | |
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| 202 | int __init jffs2_zlib_init(void) |
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| 203 | { |
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| 204 | int ret; |
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| 205 | |
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| 206 | ret = alloc_workspaces(); |
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| 207 | if (ret) |
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| 208 | return ret; |
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| 209 | |
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| 210 | ret = jffs2_register_compressor(&jffs2_zlib_comp); |
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| 211 | if (ret) |
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| 212 | free_workspaces(); |
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| 213 | |
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| 214 | return ret; |
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| 215 | } |
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| 216 | |
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| 217 | void jffs2_zlib_exit(void) |
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| 218 | { |
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| 219 | jffs2_unregister_compressor(&jffs2_zlib_comp); |
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| 220 | free_workspaces(); |
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| 221 | } |
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