From: David Howells <dhowells@redhat.com>
To: Trond Myklebust <trondmy@hammerspace.com>
Cc: dhowells@redhat.com,
"linux-cachefs@redhat.com" <linux-cachefs@redhat.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
"willy@infradead.org" <willy@infradead.org>,
"anna.schumaker@netapp.com" <anna.schumaker@netapp.com>,
"dwysocha@redhat.com" <dwysocha@redhat.com>
Subject: Re: Can the GFP flags to releasepage() be trusted? -- was Re: [PATCH v2 3/8] nfs: Move to using the alternate fallback fscache I/O API
Date: Tue, 05 Oct 2021 14:15:40 +0100 [thread overview]
Message-ID: <1080874.1633439740@warthog.procyon.org.uk> (raw)
In-Reply-To: <23033528036059af4633f60b8325e48eab95ac36.camel@hammerspace.com>
Trond Myklebust <trondmy@hammerspace.com> wrote:
> To elaborate a bit: we used to have code here that would check whether
> the page had been cleaned but was unstable, and if an argument of
> GFP_KERNEL or above was set, we'd try to call COMMIT to ensure the page
> was synched to disk on the server (and we'd wait for that call to
> complete).
>
> That code would end up deadlocking in all sorts of horrible ways, so we
> ended up having to pull it.
I don't think that a deadlock should be possible with this. PG_fscache is now
only being used to indicate that a DIO write to the cache is in progress on
the page. It will complete and remove the mark at some point.
David
prev parent reply other threads:[~2021-10-05 13:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <97eb17f51c8fd9a89f10d9dd0bf35f1075f6b236.camel@hammerspace.com>
[not found] ` <163189104510.2509237.10805032055807259087.stgit@warthog.procyon.org.uk>
[not found] ` <163189108292.2509237.12615909591150927232.stgit@warthog.procyon.org.uk>
[not found] ` <CALF+zO=165sRYRaxPpDS7DaQCpTe-YOa4FamSoMy5FV2uuG5Yg@mail.gmail.com>
2021-10-01 14:51 ` David Howells
2021-10-01 15:04 ` Trond Myklebust
2021-10-01 19:42 ` Matthew Wilcox
2021-10-05 13:15 ` David Howells [this message]
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