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author | Joern Engel <joern@logfs.org> | 2009-11-20 20:13:39 +0100 |
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committer | Joern Engel <joern@logfs.org> | 2009-11-20 20:13:39 +0100 |
commit | 5db53f3e80dee2d9dff5e534f9e9fe1db17c9936 (patch) | |
tree | 066f2873eeb7eb86466f6389e45892d957db3de2 /fs/logfs/compr.c | |
parent | Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/c... (diff) | |
download | linux-5db53f3e80dee2d9dff5e534f9e9fe1db17c9936.tar.xz linux-5db53f3e80dee2d9dff5e534f9e9fe1db17c9936.zip |
[LogFS] add new flash file system
This is a new flash file system. See
Documentation/filesystems/logfs.txt
Signed-off-by: Joern Engel <joern@logfs.org>
Diffstat (limited to 'fs/logfs/compr.c')
-rw-r--r-- | fs/logfs/compr.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/fs/logfs/compr.c b/fs/logfs/compr.c new file mode 100644 index 000000000000..44bbfd249abc --- /dev/null +++ b/fs/logfs/compr.c @@ -0,0 +1,95 @@ +/* + * fs/logfs/compr.c - compression routines + * + * As should be obvious for Linux kernel code, license is GPLv2 + * + * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> + */ +#include "logfs.h" +#include <linux/vmalloc.h> +#include <linux/zlib.h> + +#define COMPR_LEVEL 3 + +static DEFINE_MUTEX(compr_mutex); +static struct z_stream_s stream; + +int logfs_compress(void *in, void *out, size_t inlen, size_t outlen) +{ + int err, ret; + + ret = -EIO; + mutex_lock(&compr_mutex); + err = zlib_deflateInit(&stream, COMPR_LEVEL); + if (err != Z_OK) + goto error; + + stream.next_in = in; + stream.avail_in = inlen; + stream.total_in = 0; + stream.next_out = out; + stream.avail_out = outlen; + stream.total_out = 0; + + err = zlib_deflate(&stream, Z_FINISH); + if (err != Z_STREAM_END) + goto error; + + err = zlib_deflateEnd(&stream); + if (err != Z_OK) + goto error; + + if (stream.total_out >= stream.total_in) + goto error; + + ret = stream.total_out; +error: + mutex_unlock(&compr_mutex); + return ret; +} + +int logfs_uncompress(void *in, void *out, size_t inlen, size_t outlen) +{ + int err, ret; + + ret = -EIO; + mutex_lock(&compr_mutex); + err = zlib_inflateInit(&stream); + if (err != Z_OK) + goto error; + + stream.next_in = in; + stream.avail_in = inlen; + stream.total_in = 0; + stream.next_out = out; + stream.avail_out = outlen; + stream.total_out = 0; + + err = zlib_inflate(&stream, Z_FINISH); + if (err != Z_STREAM_END) + goto error; + + err = zlib_inflateEnd(&stream); + if (err != Z_OK) + goto error; + + ret = 0; +error: + mutex_unlock(&compr_mutex); + return ret; +} + +int __init logfs_compr_init(void) +{ + size_t size = max(zlib_deflate_workspacesize(), + zlib_inflate_workspacesize()); + stream.workspace = vmalloc(size); + if (!stream.workspace) + return -ENOMEM; + return 0; +} + +void logfs_compr_exit(void) +{ + vfree(stream.workspace); +} |