Re: g_vfs_done():ufs/rootfs[WRITE flood on rpi3

From: Julian Elischer <julian_at_freebsd.org>
Date: Wed, 20 Nov 2019 14:52:48 -0800
On 11/20/19 2:37 PM, bob prohaska wrote:
> While compiling a kernel at r354909 using a system at
> r354845 the serial console flooded with messages of the
> form
> g_vfs_done():ufs/rootfs[WRITE(offset=266534912, length=32768)]error = 5
>
> occasionally interspersed with
>
> mmcsd0: Error indicated: 1 Timeout
> g_vfs_done():ufs/rootfs[WRITE(offset=268697600, length=32768)]emmcsd0: Error indicated: 1 Timeout
>
> It looked like the microSD card had finally failed, but breaking to
> the debugger and rebooting seems to have recovered normally: The kernel
> build picked up where it left off and the new kernel appears to boot
> and run.
There are a few explanations as to how this succeeded.

One thing to note is that during builds, there is a large chance that 
any given write does not to be persisted as it is a temporary write of 
some kind.  As long as the next reader of the file can get it from 
cache, things will succeed.

There is also of course the chance that the write actually succeeded 
but that it happened later or that the response was bad rather than 
the write..  This can happen due to bugs in the firmware of the card.

And finally, potentially when you rebuilt, the failed steps were 
redone.  UFS Soft updates would help that result as it will not allow 
the metadata to be written until the data for the file was 
successfully written..

It will however be worth keeping an eye on that device..
Received on Wed Nov 20 2019 - 21:52:55 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:41:22 UTC