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From: Miklos Szeredi <miklos@szeredi.hu>
To: "Christian König" <christian.koenig@amd.com>
Cc: linux-fsdevel@vger.kernel.org, linux-mm <linux-mm@kvack.org>,
	Chengguang Xu <cgxu519@mykernel.net>,
	overlayfs <linux-unionfs@vger.kernel.org>
Subject: Re: [PATCH] ovl: fix mmap denywrite
Date: Tue, 22 Jun 2021 17:10:05 +0200	[thread overview]
Message-ID: <CAJfpegvTa9wnvCBP-vHumnDQ6f3XWb5vD6Fnpjbrj1V5N8QRig@mail.gmail.com> (raw)
In-Reply-To: <d73a5789-d233-940a-dc19-558b890f9b21@amd.com>

On Tue, 22 Jun 2021 at 14:43, Christian König <christian.koenig@amd.com> wrote:
>
> Am 22.06.21 um 14:30 schrieb Miklos Szeredi:
> > Overlayfs did not honor positive i_writecount on realfile for VM_DENYWRITE
> > mappings.  Similarly negative i_mmap_writable counts were ignored for
> > VM_SHARED mappings.
> >
> > Fix by making vma_set_file() switch the temporary counts obtained and
> > released by mmap_region().
>
> Mhm, I don't fully understand the background but that looks like
> something specific to overlayfs to me.
>
> So why are you changing the common helper?

Need to hold the temporary counts until the final ones are obtained in
vma_link(), which is out of overlayfs' scope.

Thanks,
Miklos

  reply	other threads:[~2021-06-22 15:10 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-22 12:30 [PATCH] ovl: fix mmap denywrite Miklos Szeredi
2021-06-22 12:43 ` Christian König
2021-06-22 15:10   ` Miklos Szeredi [this message]
2021-06-23 11:41     ` Christian König
2021-07-09 13:48       ` Miklos Szeredi
2021-07-12 11:15         ` Christian König
2021-06-23  6:06 ` 回复:[PATCH] " Chengguang Xu

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