[U-Boot] ext4: crash when writing a file

[Sébastien Szymanski]

Hi,

sorry for the late answer.

> So to restate what you are doing:
> 
> 1. You have a partitioned MMC, where the 2nd partition starts at block 
> 264192/0x40800
> 2. You load a 93958144 byte (~90 MB) file via TFTP to ${loadaddr}
> 3. You write this partition image to 0x40800 using "mmc write"
> 4. You load another 5345128 byte (5 MB) file via TFTP to $loadaddr
> 5. You try to write this file to the 2nd partition, which now is ext4 
> formatted, and already contains a file of the same name, i.e. boot/opos6ul-
> linux.bin

That's right.

> 
> 
> Actually, I can't reproduce the crash. Maybe you have corrupted part of the 
> memory when loading the image, e.g. overwritten part of u-boot or its heap.
> 
> Things you can try:
> a) reboot the system after loading/writing the partion image.
> b) checking the fs contents after the reboot, e.g "ls mmc 0:2 /boot" 

No issue here.

> c) overwriting opos6ul-linux.bin with just a single byte, e.g "ext4write mmc 
> 0:2 0x0 /boot/opos6ul-linux.bin 1"

It doesn't crash here. On the u-boot sandbox I can write up to 256Ko.
When I try 512Ko it crashes.

> d) transferring back the partition image to your host and running fschk on it

The partition is fine when transferred back to my host.

> 
> You may also able to reproduce this using the u-boot sandbox.

I'm able to reproduce it using the u-boot sandbox.

I've created a disk image as explained in board/sandbox/README.sandbox
"Block Device Emulation":

Command (m for help): p
Disk /dev/loop0: 3 GiB, 3221225472 bytes, 6291456 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xd8192f55

Device       Boot  Start     End Sectors  Size Id Type
/dev/loop0p1        2048  264191  262144  128M 83 Linux
/dev/loop0p2      264192 4458495 4194304    2G 83 Linux

Then I use dd to emulate the mmc write command since there is no host
write command:

dd if=/tftproot/opos6ul-rootfs.ext4 of=/dev/loop0p2

The partition seems to be fine according to fsck.ext4:
e2fsck 1.43.3 (04-Sep-2016)
"ROOTFS": clean, 3830/4312 files, 73797/88390 blocks

I can mount it and see its content.

Then under the sandbox I do the following:

U-Boot 2017.01-00002-g558e41e-dirty (Jan 20 2017 - 16:19:47 +0100)

DRAM:  256 MiB
MMC:
Using default environment

In:    serial
Out:   serial
Err:   serial
SCSI:  Net:   No ethernet found.
IDE:   Bus 0: not available

=> host bind 0 /tftproot/rootfs.raw

=> ls host 0:2
<DIR>       1024 .
<DIR>       1024 ..
<DIR>      16384 lost+found
<DIR>       1024 var
<DIR>       1024 run
<DIR>       1024 root
<DIR>       1024 media
<DIR>       1024 mnt
<DIR>       1024 tmp
<SYM>          3 lib32
<DIR>       1024 usr
<DIR>       1024 proc
<DIR>       1024 dev
<DIR>       1024 boot
<DIR>       1024 sys
<DIR>       3072 sbin
<DIR>       3072 bin
<SYM>         11 linuxrc
<DIR>       1024 etc
<DIR>       1024 opt
<DIR>       3072 lib

=> ls host 0:2 /boot
<DIR>       1024 .
<DIR>       1024 ..
           26909 imx6ul-opos6uldev.dtb
<SYM>          1 dtbs
         5359984 opos6ul-linux.bin

=> host load hostfs - 0 /tftproot/opos6ul-linux.bin
5359984 bytes read in 2 ms (2.5 GiB/s)

=> printenv filesize
filesize=51c970

=> ext4write host 0:2 0 /boot/opos6ul-linux.bin ${filesize}
File System is consistent
file found, deleting
update journal finished
File System is consistent
update journal finished
Segmentation fault

Regards,

> 
> Kind regards,
> 
> Stefan


Sébastien Szymanski