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References: <20220423100751.1870771-1-catalin.marinas@arm.com>
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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sat, 23 Apr 2022 09:35:42 -0700
Message-ID: <CAHk-=wgafGgBC9JEu397YxFD8o8qiCZHQS+f5i+BSXOkOFqX3w@mail.gmail.com>
Subject: Re: [PATCH v4 0/3] Avoid live-lock in btrfs fault-in+uaccess loop
To:     Catalin Marinas <catalin.marinas@arm.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Andreas Gruenbacher <agruenba@redhat.com>,
        Josef Bacik <josef@toxicpanda.com>,
        Al Viro <viro@zeniv.linux.org.uk>, Chris Mason <clm@fb.com>,
        David Sterba <dsterba@suse.com>, Will Deacon <will@kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-btrfs <linux-btrfs@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Sat, Apr 23, 2022 at 3:07 AM Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> The series introduces fault_in_subpage_writeable() together with the
> arm64 probing counterpart and the btrfs fix.

Looks fine to me - and I think it can probably go through the arm64
tree since you'd be the only one really testing it anyway.

I assume you checked that btrfs is the only one that uses
fault_in_writeable() in this way? Everybody else updates to the right
byte boundary and retries (or returns immediately)?

             Linus