Hi All,


I am running UBIFS on freescale i.MX28, kernel 2.6.35.3, based on
freescale's IMX tree:
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/?h=imx_2.6.35_maintain
The flash is NAND, Micron 256MiB (MT29F2G08)

The main mtd partition has 5 UBI volumes on it, one of which is around
20MB UBIFS. This is used as the writeable backing store for a unionfs
filesystem which is mounted over various areas of the readonly root squashfs area.

I noticed on one device which I was testing, that on bootup the whole
UBIFS volume had gone read-only, and I'm trying to figure out why, and if
there is anything that can be done to recover.
I built a kernel with UBIFS debuging and have attached various logs to this email,
I don't currently have access to a console on this device.

What I have seen is that when I mount it, it mounts successfully,
but when I attempt to write a file to it, then it will fail to write
and then remount read-only. This happened on a number of successive ocasions
while i was recording log files, and then later it failed to mount at all.
I don't know what exactly led to this occuring, at the time there was
logging to the UBIFS occuring every 5 seconds, and the device will hard
power down when the battery level drops, which happens regularly.

Does anyone have an idea what is happening here, or any options to
prevent this from happening ?

Thanks in advance,

Matt

------dmesg
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:            "system"
UBI: MTD device size:            248 MiB
UBI: number of good PEBs:        1982
UBI: number of bad PEBs:         2
UBI: max. allowed volumes:       128
UBI: wear-leveling threshold:    4096
UBI: number of internal volumes: 1
UBI: number of user volumes:     5
UBI: available PEBs:             0
UBI: total number of reserved PEBs: 1982
UBI: number of PEBs reserved for bad PEB handling: 19
UBI: max/mean erase counter: 80/60
UBI: image sequence number: 1793180392
UBI: background thread "ubi_bgt0d" started, PID 492
 ubiblka: unknown partition table
 ubiblkb: unknown partition table
 ubiblkc: unknown partition table
 ubiblkd: unknown partition table
 ubiblke: unknown partition table
....
....
UBIFS: mounted UBI device 0, volume 5, name "config"
UBIFS: file system size:   20697088 bytes (20212 KiB, 19 MiB, 163 LEBs)
UBIFS: journal size:       4444160 bytes (4340 KiB, 4 MiB, 35 LEBs)
UBIFS: media format:       w4/r0 (latest is w4/r0)
UBIFS: default compressor: none
UBIFS: reserved for root:  0 bytes (0 KiB)
UBIFS error (pid 616): ubifs_leb_unmap: unmap LEB -1 failed, error -22
UBIFS warning (pid 616): ubifs_ro_mode: switched to read-only mode, error -22
UBIFS error (pid 616): make_reservation: cannot reserve 160 bytes in jhead 1, error -22
UBIFS error (pid 616): ubifs_write_inode: can't write inode 69, error -22

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