Re: Regression in handling of unsafe UBI shutdown

From: Artem Bityutskiy
Date: Tue Jul 19 2011 - 11:01:15 EST

On Tue, 2011-07-19 at 15:57 +0200, Daniel Mack wrote:
> Hey,
> we're facing a new behaviour with 3.0-rc7 kernels wrt UBI file systems
> that are not properly unmounted on shut down. The newest kernel we're
> using in production is, and this version doesn't show the
> effect.
> When our devices boot up, the bootloader (U-Boot) initializes its UBI
> code, reads in the uImage from the root partition and executes it.
> This worked very well in thousands of installations previously (with
> kernels up to version, and generally, it still does work
> well with the latest cutting edge when the kernel is shut down
> properly and unmounts the UBI partitions safely. However, if the power
> is removed out of a sudden from a running system, U-Boot now doesn't
> like the FS anymore upon the next boot:
> Creating 1 MTD partitions on "nand0":
> 0x00120000-0x08000000 : "mtd=3"
> UBI: attaching mtd1 to ubi0
> UBI: physical eraseblock size: 131072 bytes (128 KiB)
> UBI: logical eraseblock size: 126976 bytes
> UBI: smallest flash I/O unit: 2048
> UBI: VID header offset: 2048 (aligned 2048)
> UBI: data offset: 4096
> UBI: attached mtd1 to ubi0
> UBI: MTD device name: "mtd=3"
> UBI: MTD device size: 126 MiB
> UBI: number of good PEBs: 1014
> UBI: number of bad PEBs: 1
> UBI: max. allowed volumes: 128
> UBI: wear-leveling threshold: 4096
> UBI: number of internal volumes: 1
> UBI: number of user volumes: 2
> UBI: available PEBs: 8
> UBI: total number of reserved PEBs: 1006
> UBI: number of PEBs reserved for bad PEB handling: 10
> UBI: max/mean erase counter: 4/3
> UBIFS: recovery needed
> Error reading superblock on volume 'ubi:RootFS'!
> UBIFS not mounted, use ubifs mount to mount volume first!
> Wrong Image Format for bootm command
> ERROR: can't get kernel image!
> Hence my question is: were there any radical changes in the UBI/UBIFS
> code on the kernel side that make older code not like the new content
> anymore?

Not sure if there were radical changes, but please, enable UBIFS
debugging and provide UBIFS messages. Here are some hints:

Best Regards,
Artem Bityutskiy

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