Re: FAILED: patch "[PATCH] ext4: do not update s_last_mounted of a frozen fs" failed to apply to 4.17-stable tree

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Jul 09, 2018 at 03:52:58PM +0200, Jan Kara wrote:
> On Thu 05-07-18 20:07:32, Amir Goldstein wrote:
> > On Thu, Jul 5, 2018 at 7:29 PM, Greg KH <gregkh@linuxfoundation.org> wrote:
> > > On Thu, Jul 05, 2018 at 06:27:01PM +0200, Greg KH wrote:
> > >> On Fri, Jun 22, 2018 at 12:25:43AM +0300, Amir Goldstein wrote:
> > >> > On Fri, Jun 22, 2018 at 12:15 AM,  <gregkh@linuxfoundation.org> wrote:
> > >> > >
> > >> > > The patch below does not apply to the 4.17-stable tree.
> > >> >
> > >> > There is a [backport hint] at the end of the commit message.
> > >> > Need to take the 2 prep commits.
> > >> > Same for all stable branches.
> > >> >
> > >> > Cheers,
> > >> > Amir.
> > >> >
> > >> > > If someone wants it applied there, or to any other stable or longterm
> > >> > > tree, then please email the backport, including the original git commit
> > >> > > id to <stable@vger.kernel.org>.
> > >> > >
> > >> > > thanks,
> > >> > >
> > >> > > greg k-h
> > >> > >
> > >> > > ------------------ original commit in Linus's tree ------------------
> > >> > >
> > >> > > From db6516a5e7ddb6dc72d167b920f2f272596ea22d Mon Sep 17 00:00:00 2001
> > >> > > From: Amir Goldstein <amir73il@gmail.com>
> > >> > > Date: Sun, 13 May 2018 22:54:44 -0400
> > >> > > Subject: [PATCH] ext4: do not update s_last_mounted of a frozen fs
> > >> > >
> > >> > > If fs is frozen after mount and before the first file open, the
> > >> > > update of s_last_mounted bypasses freeze protection and prints out
> > >> > > a WARNING splat:
> > >> > >
> > >> > > $ mount /vdf
> > >> > > $ fsfreeze -f /vdf
> > >> > > $ cat /vdf/foo
> > >> > >
> > >> > > [   31.578555] WARNING: CPU: 1 PID: 1415 at
> > >> > > fs/ext4/ext4_jbd2.c:53 ext4_journal_check_start+0x48/0x82
> > >> > >
> > >> > > [   31.614016] Call Trace:
> > >> > > [   31.614997]  __ext4_journal_start_sb+0xe4/0x1a4
> > >> > > [   31.616771]  ? ext4_file_open+0xb6/0x189
> > >> > > [   31.618094]  ext4_file_open+0xb6/0x189
> > >> > >
> > >> > > If fs is frozen, skip s_last_mounted update.
> > >> > >
> > >> > > [backport hint: to apply to stable tree, need to apply also patches
> > >> > >  vfs: add the sb_start_intwrite_trylock() helper
> > >> > >  ext4: factor out helper ext4_sample_last_mounted()]
> > >>
> > >> For "hints", can you provide the git commit id in the future so I don't
> > >> have to dig them out myself?
> > >
> > 
> > That would be chicken and egg.
> > I wrote the hint when I posted the series so there was no upstream commit id
> > at the time. Maybe I should have written "need to apply the 2 previous patches"
> > as a hint... or could have tried to push back on review comments to split the
> > patches.
> > 
> > > And those backports don't apply properly :(
> > >
> > > Can you please provide a series of patches backported to the stable
> > > trees you feel these should go to, so I can apply them?
> > >
> > 
> > I can look into that sometime, but frankly, I don't feel strongly
> > either way about applying those patches to stable.
> > If anybody from ext4 developers can find the time to look into
> > that, I wouldn't object at all..
> 
> I will be probably eventually backporting these patches to SLE kernels so I
> can forward them to stable then as well. But since this is really more of
> an annoyance than a serious problem, it doesn't have high priority.

Ok, given that this really isn't a big deal, I'll leave it as-is and
wait for backports to show up if you all happen to do them.

thanks,

greg k-h