24.10.2013, 18:20, "Konstantin Tokarev" <[email protected]>:
> 23.10.2013, 22:26, "Yann Collet" <[email protected]>:
>
>> UBIFS error (pid 4288): ubifs_decompress: cannot decompress 12 bytes,
>> (...)
>> data size 12
>> data:
>> 00000000: 1f 00 01 00 ff e8 50 00 00 00 00 00
>>
>> The compressed format is correct.
>> It describes a flow of 00, of size ~500.
>>
>> So the problem seems more likely on the decompression side.
>>
>> Are you sure you are providing "12" as the "input size" parameter ? and that
>> the "maximum output size" parameter is correctly provided ? (i.e. >= to
>> original data size)
>
> Decompression code in kernel[1] is heavily modified. In particular,
> lz4_uncompress
> function (used in this case) does not have input size parameter at all,
> while it's present in lz4_uncompress_unknownoutputsize.
>
> [1] lib/lz4/lz4_decompress.c
Attached patch to crypto API wrapper for lz4hc seems to fix the issue. I can
save
and read files on LZ4HC-compressed volume, and I'm running on LZ4HC-compressed
rootfs,
flashed from mkfs.ubifs generated image (patch by Elie De Brauwer). My software
works correctly.
Unfortunately, on my board LZ4HC-compressed UBIFS volume performs noticeable
worse
than LZO, while still faster than zlib. I guess the reason is that CPU is no
longer a
bottleneck for my system, but NAND speed.
Thank you all for your help!
--
Regards,
Konstantin
diff --git a/crypto/lz4.c b/crypto/lz4.c
index 4586dd1..91a0613 100644
--- a/crypto/lz4.c
+++ b/crypto/lz4.c
@@ -66,9 +66,8 @@ static int lz4_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
{
int err;
size_t tmp_len = *dlen;
- size_t __slen = slen;
- err = lz4_decompress(src, &__slen, dst, tmp_len);
+ err = lz4_decompress_unknownoutputsize(src, slen, dst, &tmp_len);
if (err < 0)
return -EINVAL;
diff --git a/crypto/lz4hc.c b/crypto/lz4hc.c
index 151ba31..9987741 100644
--- a/crypto/lz4hc.c
+++ b/crypto/lz4hc.c
@@ -66,9 +66,8 @@ static int lz4hc_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
{
int err;
size_t tmp_len = *dlen;
- size_t __slen = slen;
- err = lz4_decompress(src, &__slen, dst, tmp_len);
+ err = lz4_decompress_unknownoutputsize(src, slen, dst, &tmp_len);
if (err < 0)
return -EINVAL;
