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From: Richard Weinberger <richard@nod.at>
To: Sascha Hauer <s.hauer@pengutronix.de>
Cc: linux-mtd@lists.infradead.org, kernel@pengutronix.de
Subject: Re: [PATCH] ubifs: drop false positive assertion
Date: Sat, 15 Sep 2018 09:30:45 +0200
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Sascha,

Am Mittwoch, 12. September 2018, 14:51:38 CEST schrieb Sascha Hauer:
> The following sequence triggers
> 
> 	ubifs_assert(c, c->lst.taken_empty_lebs > 0);
> 
> at the end of ubifs_remount_fs():
> 
> mount -t ubifs /dev/ubi0_0 /mnt
> echo 1 > /sys/kernel/debug/ubifs/ubi0_0/ro_error
> umount /mnt
> mount -t ubifs -o ro /dev/ubix_y /mnt
> mount -o remount,ro /mnt

Ahh, ok. You have a unclean mount and then a read-only mount.
Therefore UBIFs is still not clean but cannot do anything about that.

> The resulting
> 
> UBIFS assert failed in ubifs_remount_fs at 1878 (pid 161)
> 
> is a false positive. In the case above c->lst.taken_empty_lebs has
> never been changed from its initial zero value. This will only happen
> when th> e deferred recovery is done.
> 
> Fix this by doing the assertion only when recovery has been done
> already.

Makes sense!

Thanks,
//richard