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[209.85.167.42]) by smtp.gmail.com with ESMTPSA id l18sm53000ljj.60.2020.11.24.15.31.45 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 24 Nov 2020 15:31:45 -0800 (PST) Received: by mail-lf1-f42.google.com with SMTP id d17so494305lfq.10 for ; Tue, 24 Nov 2020 15:31:45 -0800 (PST) X-Received: by 2002:a19:ed0f:: with SMTP id y15mr172684lfy.352.1606260312243; Tue, 24 Nov 2020 15:25:12 -0800 (PST) MIME-Version: 1.0 References: <000000000000d3a33205add2f7b2@google.com> <20200828100755.GG7072@quack2.suse.cz> <20200831100340.GA26519@quack2.suse.cz> <20201124121912.GZ4327@casper.infradead.org> <20201124183351.GD4327@casper.infradead.org> <20201124201552.GE4327@casper.infradead.org> In-Reply-To: From: Linus Torvalds Date: Tue, 24 Nov 2020 15:24:56 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: kernel BUG at fs/ext4/inode.c:LINE! To: Hugh Dickins Cc: Matthew Wilcox , Jan Kara , syzbot , Andreas Dilger , Ext4 Developers List , Linux Kernel Mailing List , syzkaller-bugs , "Theodore Ts'o" , Linux-MM , Oleg Nesterov , Andrew Morton , "Kirill A. Shutemov" , Nicholas Piggin , Alex Shi , Qian Cai , Christoph Hellwig , "Darrick J. Wong" , William Kucharski , Jens Axboe , linux-fsdevel , linux-xfs Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Tue, Nov 24, 2020 at 1:47 PM Hugh Dickins wrote: > > I think the unreferenced struct page asks for trouble. I do agree. I've applied your second patch (the smaller one that just takes a ref around the critical section). If somebody comes up with some great alternative, we can always revisit this. Linus