RE: ubifs mount failure

[Naga Sureshkumar Relli]

Hi Sascha,

> -----Original Message-----
> From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Sent: Tuesday, December 3, 2019 2:12 PM
> To: Naga Sureshkumar Relli <nagasure@xxxxxxxxxx>
> Cc: Richard Weinberger <richard@xxxxxx>; Miquel Raynal <miquel.raynal@xxxxxxxxxxx>;
> linux-kernel@xxxxxxxxxxxxxxx; linux-mtd@xxxxxxxxxxxxxxxxxxx; Michal Simek
> <michals@xxxxxxxxxx>; siva.durga.paladugu@xxxxxxxxxxx
> Subject: Re: ubifs mount failure
> 
> Hi,
> 
> On Tue, Dec 03, 2019 at 04:52:32AM +0000, Naga Sureshkumar Relli wrote:
> >    Hi,
> >
> >
> >
> >    We have upgraded our Linux kernel to 5.4 from 4.19.
> >
> >    And I tried mounting ubifs using this kernel on NAND partition with below
> >    command and saw that
> >
> >    There is an issue with memory allocation.
> >
> >    #mount -t ubifs ubi0:data /mnt/
> >
> >    mount: mounting ubi0:data on /mnt/ failed: Cannot allocate memory
> >
> >
> >
> >    I saw that there is a commit on fs/ubifs/sb.c, where it is allocating all
> >    the required memories at one shot.
> >
> >    [1]https://lkml.org/lkml/2018/9/7/724
> >
> >    By reverting the above patch, I am able to mount successfully the ubifs.
> >
> >    By reverting this patch, we are allocating, writing and freeing in a
> >    manner such that, we donât see memory allocation issues.
> 
> Sorry, I can't see how this patch causes failing memory allocations. And no, this is not
> expected. Could you sprinkle some printks and track down where it fails? Is it the obvious
> place here:
Yes, it is failing in this place only.
> 
> 	if (!sup || !mst || !idx || !ino || !cs) {
> 		err = -ENOMEM;
> 		goto out;
> 	}
> 
> If yes, which allocation fails and how much memory did we try to allocate?
Failing at indexing node(idx) allocation
https://elixir.bootlin.com/linux/v5.4/source/fs/ubifs/sb.c#L164
we are trying to allocate 4325376 (~4MB)
> If no, where does it fail? Also, where are you using UBIFS. Is it NAND flash or NOR flash?
It is on NAND flash.

Thanks,
Naga Sureshkumar Relli

> 
> Sascha
> 
> --
> Pengutronix e.K.                           |                             |
> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |