Re: [PATCH] UBI: add ubi_err() to report the failure of leb read

[hujianyang <hujianyang@huawei.com>]

On 2014/12/16 15:54, hujianyang wrote:
> If an error occur while reading from PEBs, for example, an ECC error,
> ubi_io_read() will print some error messages. But it's not enough for
> debugging. These messages don't show the mapping info for a read from
> UBIFS layer.
> 
> Although UBIFS will soon print its error messages after catching the
> return value from UBI layer,  multi-path reading will confuse the
> relationship between LEBs and PEBs showed by these messages.
> 
> This patch adds an ubi_err() to report reading errors in the function
> ubi_eba_read_leb(). The mapping info of LEB and PEB is showed by
> this error message.
> 
> Signed-off-by: hujianyang <hujianyang@huawei.com>
> ---
>  drivers/mtd/ubi/eba.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
> index b698534..b4e69e1 100644
> --- a/drivers/mtd/ubi/eba.c
> +++ b/drivers/mtd/ubi/eba.c
> @@ -477,6 +477,8 @@ out_free:
>  	ubi_free_vid_hdr(ubi, vid_hdr);
>  out_unlock:
>  	leb_read_unlock(ubi, vol_id, lnum);
> +	ubi_err(ubi, "err %d while reading %d bytes from offset %d of LEB %d:%d, PEB %d",
> +		err, len, offset, vol_id, lnum, pnum);
>  	return err;
>  }
> 

Hi,

I met a problem that I was failed to mount a UBIFS partition.

[   38.442770] UBI error: ubi_io_read: error -74 (ECC error) while reading 26624 bytes from PEB 54:104448, read 26624 bytes
[   38.852461] UBI error: ubi_io_read: error -74 (ECC error) while reading 77824 bytes from PEB 346:53248, read 77824 bytes
[   38.864142] UBIFS error (pid 1444): ubifs_recover_leb: corruption -3
[   38.870487] UBIFS error (pid 1444): ubifs_scanned_corruption: corruption at LEB 928:55280
[   38.878625] UBIFS error (pid 1444): ubifs_scanned_corruption: first 8192 bytes from LEB 928:55280
[   38.892117] UBIFS error (pid 1444): ubifs_recover_leb: LEB 928 scanning failed
mount: mounting ubi1:bak on /HFFS2: failed: Structure needs cleaning

I think it is caused by an ECC error of nand flash. Do we have some methods
to mount this partition? Data losing is acceptable.


Thanks,

Hu