Fail to mount cloned disk image with fastmap.

[Bill Pringlemeir]

On 15 Aug 2013, richard.weinberger at gmail.com wrote:

> On Thu, Aug 15, 2013 at 3:29 PM, Bill Pringlemeir wrote:

>> I have back-ported the fastmap code from the 3.0 series to a 2.6.36
>> kernel on an ARM cpu.  It has been running for some time without issue
>> and the boot time is reduced by 1/2 second.  I just ran a test over
>> night with 'pppd' capturing packets and likely filled up the disk.
>>
>> It appears that my kernel does not boot, so I made a clone of the disk
>> and then attempt to mount it on my Ubuntu machine with the following,

> BTW: What exactly does "my kernel does not boot" mean?
> Does it also fail at the said WARN_ON()?

> The WARN_ON() can also trigger if made the image in a wrong way.
> A truncated image would explain both error messages.

Unfortunately, the device where this occurs does not have a serial port
for a console.  So, the boot sequence stops.  My guess was/is that it
just can not mount the 'UbiFS rootfs'; just like trying to mount it on
the 3.8 nandsim doesn't work.

> fm_autoconvert=0 tells UBI to use the fastmap if one is found but
> not to automatically convert non-fastmap images to fastmap.

I thought of this right after 'send'.  At one point there was a '0,1,2'
value that could disable fastmap?  This must have been a different
parameter and I think it has been removed.

> Yes, please try to attach the image with MTD_UBI_FASTMAP=n.

With no changes to 'mtd3', the non-fast map version seems to boot fine.
There is some of the initial kernel logs below.  The 'UbiFs' performed a
'recovery' as well.

>> additional issues are encountered.  But I think that some of the UBI
>> issues might be a problem?  Can I use some other flash with a bigger
>> size so that 'PEBs' can be reserved?

>> Of course, I have the disk image and can send additional information.

> Can you please upload the image somewhere where I can analyze it?

Is there a program to extract the UBI headers?  I can send the data, but
I will have to look through it for some time to make sure there is
nothing I shouldn't give out; downloaded data files, etc. which is
probably a trival amount of the total image.

I will be away for 2 weeks.  It was back ported code and I have just
disabled 'fastmap' for now.  Are you interested in why the more current
code has issues?  Or has someone else reported a similar issue?  The
nand flash controller was an imx25 and I have the NAND driver updates
to,

   commit 657f28f8811c92724db10d18bbbec70d540147d6
   mtd: kill MTD_NAND_VERIFY_WRITE

I can not take the infra-structure changes, only the chipset bug fixes
as we are stuck at 2.6.36 for now.

Thanks,
Bill Pringlemeir.

[    1.650000] UBI: attaching mtd3 to ubi0
[    1.650000] UBI DBG (pid 1): ubi_attach_mtd_dev: sizeof(struct ubi_ainf_peb) 48
[    1.650000] UBI DBG (pid 1): ubi_attach_mtd_dev: sizeof(struct ubi_wl_entry) 20
[    1.650000] UBI DBG (pid 1): io_init: min_io_size      2048
[    1.650000] UBI DBG (pid 1): io_init: max_write_size   2048
[    1.650000] UBI DBG (pid 1): io_init: hdrs_min_io_size 512
[    1.650000] UBI DBG (pid 1): io_init: ec_hdr_alsize    512
[    1.650000] UBI DBG (pid 1): io_init: vid_hdr_alsize   512
[    1.650000] UBI DBG (pid 1): io_init: vid_hdr_offset   512
[    1.650000] UBI DBG (pid 1): io_init: vid_hdr_aloffset 512
[    1.650000] UBI DBG (pid 1): io_init: vid_hdr_shift    0
[    1.650000] UBI DBG (pid 1): io_init: leb_start        2048
[    1.650000] UBI DBG (pid 1): io_init: max_erroneous    191
[    1.650000] UBI: physical eraseblock size:   131072 bytes (128 KiB)
[    1.660000] UBI: logical eraseblock size:    129024 bytes
[    1.670000] UBI: smallest flash I/O unit:    2048
[    1.670000] UBI: sub-page size:              512
[    1.680000] UBI: VID header offset:          512 (aligned 512)
[    1.690000] UBI: data offset:                2048
[    2.640000] UBI DBG (pid 1): scan_all: scanning is finished
[    2.640000] UBI: max. sequence number:       9141
[    2.800000] UBI: attached mtd3 to ubi0
[    2.800000] UBI: MTD device name:            "root"
[    2.800000] UBI: MTD device size:            239 MiB
[    2.800000] UBI: number of good PEBs:        1914
[    2.800000] UBI: number of bad PEBs:         4
[    2.800000] UBI: number of corrupted PEBs:   0
[    2.800000] UBI: max. allowed volumes:       128
[    2.800000] UBI: wear-leveling threshold:    4096
[    2.800000] UBI: number of internal volumes: 1
[    2.800000] UBI: number of user volumes:     1
[    2.800000] UBI: available PEBs:             0
[    2.810000] UBI: total number of reserved PEBs: 1914
[    2.820000] UBI: number of PEBs reserved for bad PEB handling: 19
[    2.830000] UBI: max/mean erase counter: 51/5
[    2.840000] UBI: image sequence number:  739038085
[    2.850000] UBI: background thread "ubi_bgt0d" started, PID 189
[    2.870000] Freeing init memory: 1176K
[    3.520000] UBIFS: background thread "ubifs_bgt0_3" started, PID 212
[    3.560000] UBIFS: recovery needed
[    3.770000] UBIFS: recovery completed
[    3.770000] UBIFS: mounted UBI device 0, volume 3, name "rootfs"
[    3.770000] UBIFS: LEB size: 129024 bytes (126 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[    3.770000] UBIFS: FS size: 242565120 bytes (231 MiB, 1880 LEBs), journal size 9033728 bytes (8 MiB, 71 LEBs)
[    3.770000] UBIFS: reserved for root: 4190434 bytes (4092 KiB)
[    3.770000] UBIFS: media format: w4/r0 (latest is w4/r0), UUID 82867E3B-5B71-485C-B911-409531E9DA4B, small LPT model