linux-kernel - Re: [REGRESSION] fuse: execve() fails with ETXTBSY due to async fuse

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Message-ID: <e7499d0942a4489086c803dcdf1a5bb4317e973e.camel@bitron.ch>
Date:   Mon, 14 Aug 2023 14:38:44 +0200
From:   Jürg Billeter <j@...ron.ch>
To:     Miklos Szeredi <miklos@...redi.hu>,
        Bernd Schubert <bernd.schubert@...tmail.fm>
Cc:     "Eric W. Biederman" <ebiederm@...ssion.com>,
        Tycho Andersen <tycho@...ho.pizza>,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        regressions@...ts.linux.dev
Subject: Re: [REGRESSION] fuse: execve() fails with ETXTBSY due to async
 fuse_flush

On Mon, 2023-08-14 at 14:28 +0200, Miklos Szeredi wrote:
> On Mon, 14 Aug 2023 at 14:07, Bernd Schubert 
> > fuse: Avoid flush for O_RDONLY
> > 
> > From: Bernd Schubert <bschubert@....com>
> > 
> > A file opened in read-only moded does not have data to be
> > flushed, so no need to send flush at all.
> > 
> > This also mitigates -EBUSY for executables, which is due to
> > async flush with commit 5a8bee63b1.
> 
> Does it?  If I read the bug report correctly, it's the write case that
> causes EBUSY.

Indeed, I see this when trying to execute a file after a process wrote
to (created) that file. As far as I can tell, `ETXTBSY` can't happen on
exec without the file being opened for writing and thus, I don't see
this patch mitigating this bug.

Jürg