Re: [PATCH v3] mm: fix race between MADV_FREE reclaim and blkdev direct IO read
From: Mauricio Faria de Oliveira <hidden>
Date: 2022-02-01 02:24:07
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linux-mm
On Mon, Jan 31, 2022 at 8:43 PM Andrew Morton [off-list ref] wrote:
On Mon, 31 Jan 2022 20:02:55 -0300 Mauricio Faria de Oliveira [off-list ref] wrote:quoted
Problem: ======= Userspace might read the zero-page instead of actual data from a direct IO read on a block device if the buffers have been called madvise(MADV_FREE) on earlier (this is discussed below) due to a race between page reclaim on MADV_FREE and blkdev direct IO read. ... Fixes: 802a3a92ad7a ("mm: reclaim MADV_FREE pages")Five years ago. As it doesn't seem urgent I targeted 5.18-rc1 for this, and added a cc:stable so it will trickle back into earlier trees. How does this plan sound?
That sounds good; it's not urgent, indeed. Thanks! -- Mauricio Faria de Oliveira