[Buildroot] [PATCH 15/16] support/testing: update logical eraseblock and physical eraseblock size for qemu >= 2.9

[Romain Naour]

Hello Yann,

Le 17/10/2021 à 21:51, Yann E. MORIN a écrit :
> Romain, All,
> 
> On 2021-09-12 16:11 +0200, Romain Naour spake thusly:
>> The current ubi/ubifs test (test_ubi.py) rely on a Qemu bug present in
>> 2.8.0 that was fixed in Qemu 2.9.0 [1]. The ubi/ubifs settings is
>> updated to run with Qemu >= 2.9.0 using the new multiple chip handling.
>>
>> If needed, the old behavior can be enabled using the pflash01 property
>> "old-multiple-chip-handling" [2].
>>
>> The issue was not detected until now since we are sill using an old
>> qemu (2.8 from Debian stretch) for testing in gitlab (using the
>> Buildroot Docker image used by gitlab-ci.yml).
>>
>> First the logical eraseblock size (LEB) must be updated to the value
>> 0x3ff80 reported by the kernel when using qemu >= 2.9.0.
>>
>>   UBIFS (ubi0:0): Mounting in unauthenticated mode
>>   UBIFS error (ubi0:0 pid 1): ubifs_read_superblock: LEB size mismatch: 524160 in superblock, 262016 real
>>   UBIFS error (ubi0:0 pid 1): ubifs_read_superblock: bad superblock, error 1
>>
>> But the system is still failing to boot:
>>
>>  UBIFS error (ubi0:0 pid 1): ubifs_scan: garbage
>>  UBIFS error (ubi0:0 pid 1): ubifs_recover_master_node: failed to recover master node
>>
>> ubifs is reading garbage since Qemu >= 2.9.0 report a sector
>> length per device divided by the number of devices (see commit [1]).
>>
>> The kernel detect two flash devices (dmesg):
>>
>>   Concatenating MTD devices:
>>   (0): "40000000.flash"
>>   (1): "40000000.flash"
>>   into device "40000000.flash"
>>
>> Divide the physical eraseblock (PEB) size by two.
>>
>> Tested with qemu 2.9.0, 5.1.0.
>>
>> Fixes:
>> https://gitlab.com/kubu93/buildroot/-/jobs/1543100932
>>
>> [1] https://git.qemu.org/?p=qemu.git;a=commitdiff;h=feb0b1aa11f14ee71660aba46b46387d1f923c9e
>> [2] http://lists.busybox.net/pipermail/buildroot/2021-September/622069.html
> 
> I am not sure I understood that reference: the patch in [2] was never
> applied, it is no longer present in patchwork, but I could not find a
> discsuuion about it either... Did you withdraw that patch?

Yes, the patch [2] was a first attempt to fix the issue.
Thanks to this patch, it's not needed anymore.

Best regards,
Romain


> 
>> Signed-off-by: Romain Naour <romain.naour at gmail.com>
>> Cc: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
> 
> Applied to master, thanks.
> 
> Regards,
> Yann E. MORIN.
> 
>> ---
>>  support/testing/tests/fs/test_ubi.py | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/support/testing/tests/fs/test_ubi.py b/support/testing/tests/fs/test_ubi.py
>> index eeb55b1d59..7c687c1982 100644
>> --- a/support/testing/tests/fs/test_ubi.py
>> +++ b/support/testing/tests/fs/test_ubi.py
>> @@ -8,10 +8,10 @@ class TestUbi(infra.basetest.BRTest):
>>      config = infra.basetest.BASIC_TOOLCHAIN_CONFIG + \
>>          """
>>          BR2_TARGET_ROOTFS_UBIFS=y
>> -        BR2_TARGET_ROOTFS_UBIFS_LEBSIZE=0x7ff80
>> +        BR2_TARGET_ROOTFS_UBIFS_LEBSIZE=0x3ff80
>>          BR2_TARGET_ROOTFS_UBIFS_MINIOSIZE=0x1
>>          BR2_TARGET_ROOTFS_UBI=y
>> -        BR2_TARGET_ROOTFS_UBI_PEBSIZE=0x80000
>> +        BR2_TARGET_ROOTFS_UBI_PEBSIZE=0x40000
>>          BR2_TARGET_ROOTFS_UBI_SUBSIZE=1
>>          """
>>  
>> -- 
>> 2.31.1
>>
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>