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

[Sébastien Szymanski]

Hello,

I am working on a i.MX6UL based board with a 4GB eMMC partitioned as
following:

Device     Boot   Start     End Sectors  Size Id Type
/dev/sdb1          2048  264191  262144  128M 83 Linux
/dev/sdb2        264192 4458495 4194304    2G 83 Linux
/dev/sdb3       4458496 7634943 3176448  1.5G 83 Linux

On the 2nd partition, I write this ext4 filesystem file generated by
Buildroot:
Filesystem volume name:   "ROOTFS"
Last mounted on:          <not available>
Filesystem UUID:          b9833a36-e89d-429a-b120-c3b00bcb7785
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal dir_index filetype extent
sparse_super uninit_bg
Filesystem flags:         signed_directory_hash
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Unknown (continue)
Filesystem OS type:       Linux
Inode count:              3456
Block count:              91756
Reserved block count:     4587
Free blocks:              13458
Free inodes:              488
First block:              1
Block size:               1024
Fragment size:            1024
Blocks per group:         7648
Fragments per group:      7648
Inodes per group:         288
Inode blocks per group:   36
Last mount time:          n/a
Last write time:          Tue Nov 29 09:44:52 2016
Mount count:              0
Maximum mount count:      -1
Last checked:             Tue Nov 29 09:44:52 2016
Check interval:           0 (<none>)
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:               128
Journal inode:            8
Default directory hash:   half_md4
Directory Hash Seed:      a583a07f-6b59-442d-8e08-9be305f78d17
Journal backup:           inode blocks

This filesystem is written with the following commands:

BIOS> setexpr nbblocks ${filesize} / 0x200
BIOS> setexpr nbblocks ${nbblocks} + 1
BIOS> mmc write ${loadaddr} 0x40800 ${nbblocks}
MMC write: dev # 0, block # 264192, count 183513 ... 183513 blocks
written: OK

I can boot Linux with it without any issues, however if I try to write a
file in it I get the following crash:

BIOS> ext4write mmc 0:2 ${loadaddr} /boot/${kernelimg} ${filesize}

File System is consistent
file found, deleting
update journal finished
File System is consistent
update journal finished
data abort
pc : [<8ff783ac>]          lr : [<8ff86c95>]
reloc pc : [<8780e3ac>]    lr : [<8781cc95>]
sp : 8ef696b8  ip : 00000000     fp : 8ffbc6d8
r10: 00000200  r9 : 8ef69ee8     r8 : 8ffbc744
r7 : 8ef9f600  r6 : 8ef999b6     r5 : 00000003  r4 : 8ffa35fc
r3 : 8ef999b8  r2 : 00000001     r1 : fffffffe  r0 : 8ef999c0
Flags: NzCv  IRQs off  FIQs off  Mode SVC_32
Resetting CPU ...

resetting ...

I have investigated a bit and I found that the crash is in the
ext4fs_deinit() function provoked by the free() call at line 722
(fs/ext4/ext4_write.c) and the ext4fs_deinit() is called in
ext4fs_write() at line 980.

If I resize the filesystem under Linux, I don't get the crash but the
following error:

ext4fs_devread read outside partition 4294967294
error in File System init
** Error ext4fs_write() **
** Unable to write file /boot/opos6ul-linux.bin **

Any idea ?

Regards,

-- 
Sébastien Szymanski
Software Engineer, Armadeus Systems
sebastien.szymanski at armadeus.com
Tel: +33 (0)9 72 29 41 44
Fax: +33 (0)9 72 28 79 26