ubifs_decompress: cannot decompress 2293 bytes, compressor lzo, error -22

[Miquel Raynal]

Hi Scott,

macromarship at gmail.com wrote on Fri, 15 Apr 2022 00:45:23 +0800:

> Hello. Everyone.
>      I encountered a strange problem about ubifs. My embed linux runs
> well normally. But after about 3-4 days, developing php application,
> copying files etc.. the /opt partition when read, the system become
> very slow. After check dmesg
> the output contains full of debug logs as below.
> 
> [17588.040000] UBIFS error (ubi0:0 pid 15691): do_readpage: cannot
> read page 15 of inode 396, error -22
> [17590.080000] UBIFS error (ubi0:0 pid 15695): ubifs_decompress:
> cannot decompress 2293 bytes, compressor lzo, error -22
> [17590.090000] UBIFS error (ubi0:0 pid 15695): do_readpage: bad data
> node (block 15, inode 396)
> lots of hex dump, seems normal data
> 
> Based on my understanding of ubi and ubi fs. The bottomest nand driver
> has the ecc correction, then ubi has crc32 to verify data write and
> read. Then when data come to ubifs, the data should be always correct.
> Anything wrong will be reported firstly by ubi below or mtd nand
> driver below.
> So the msg shows above confuse me. Why did decompress fail for passed
> crc32 data？
> Is there anyway to simple drop the block 15, inode 396 so no warning
> anymore. Even so many logs dumped ,the system continues runs , but
> ramdomly hangs. Maybe no hang, the linux run led continues blink,
> network led blink, the ping ip is not react.
> Because I port the nand driver myself, and port everything to make
> nand working. So Is there a possibility I make ecc checksum wrong,
> then get this wierd problem?
> 
> I googled first, and only see related discuss on 2011 but can't see it help.
> https://linux-mtd.infradead.narkive.com/c65SedYp/ubifs-decompress-cannot-decompress

Hello Scott, if you are unsure about your NAND implementation you can
run all the nand/ubi tests available in the mtd-utils test suite (also
available as a Buildroot package):
https://git.infradead.org/mtd-utils.git

Thanks,
Miquèl