23.10.2013, 16:49, "Brent Taylor" <[email protected]>: > On Wed, Oct 23, 2013 at 2:40 AM, Konstantin Tokarev <[email protected]> wrote: > >> 23.10.2013, 09:26, "Brent Taylor" <[email protected]>: >>> Konstantin, >>> I did my testing with data from /dev/urandom (which I now realize >>> wasn't the best choice of data source), but if I use /dev/zero (which >>> actually causes data compression to occur), the decompressor fails. I >>> don't know the internal workings of the lz4hc compressor or the lz4 >>> decompressor. I couldn't find any examples of any code in the kernel >>> actually using the compressor. I've cc'ed the maintainers of the >>> lz4hc_compress.c to see if they my have some more insight to the >>> issue. >> Does decompressor fail for you with the same error messages? >> >> Have you tried to copy my file to the volume? It looks like minimal test >> case >> for my board, if I remove any line decompressor works fine. >> >> -- >> Regards, >> Konstantin > > Yes, I get the same error, here's a dump from UBIFS when I cat a file > filled with data from /dev/zero: > > UBIFS error (pid 4288): ubifs_decompress: cannot decompress 12 bytes, > compressor lz4hc, error -22 > UBIFS error (pid 4288): read_block: bad data node (block 0, inode 71) > magic 0x6101831 > crc 0xff61a078 > node_type 1 (data node) > group_type 0 (no node group) > sqnum 2700 > len 60 > key (71, data, 0) > size 512 > compr_typ 3 > data size 12 > data: > 00000000: 1f 00 01 00 ff e8 50 00 00 00 00 00 > UBIFS error (pid 4288): do_readpage: cannot read page 0 of inode 71, error -22 > cat: /opt/data/zero.bin: Input/output error > > Steps to reproduce are: > 1. Create a file with all zeros: dd if=/dev/zero bs=512 count=1 > of=/opt/data/zero.bin > 2. Unmount ubifs and detach ubi partition > 3. attach ubi partition and mount ubifs > 4. cat /opt/data/zero.bin
Reproduced here. -- Regards, Konstantin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
