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spf=pass (imf20.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1763669286; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=wNa9iwEAN9AZjnVq0r0weyR2GTqJY3I3qxY4R8Ltv9E=; b=nNlBcdMIaao/Cxu23UJhqE1RqqZxj4muLUKyaQMzDTKQQLYVJNGkkkc7HsaLyofxY+Azh2 l1kOqpZDc6Gyf+aPUNxr2xgBuK3qAOnXJGjJSIxjU0zfm36yQSn+UO8bZXesD7iIYnhdiS xOQG7UOAg0y3xBXDl4dgq//geUZTmuU= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 308B660017; Thu, 20 Nov 2025 20:08:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EFE1C4CEF1; Thu, 20 Nov 2025 20:08:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763669285; bh=VVP8DdbSUeK/J4HV2SMoyh6buJCbiFpKSw4KcUAUqQY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=FUgR5We2tVWz3KOYVUlN9XBm2aT9NIJuOBtVwZlHkIk4HijQ9xaoL+hJIAJzVu+1+ kldFCboZhalUhd1A6glgmSWS/am1dk6WrKFWuw3nWY/EqbPTlBjKcfpoJ8EbqdFi3g O+NozSCVx3VB+rhgZnQj4yJT6++vwZZFZ2iN7liJIq42i19RJ9GsWPvnneOVvnmkEP YVnYefGXWT/BwT5aKviXdVcq3J5EWu/bsgSaZiwmY1rL2ykMW8tSzOpU52YpNL1g1p +s2vMiv7ehxSoD/sOABpJbOO/joYPl6Dou5XevL7Zm/WpOcVu4c53FBlovBXLvWOCJ 6rkhH4KPoRbGg== Message-ID: <7fae20ca-d7b0-4786-8c31-288648db8ad0@kernel.org> Date: Thu, 20 Nov 2025 21:08:01 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/2] mm: rename AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM to AS_WRITEBACK_MAY_HANG To: Joanne Koong , akpm@linux-foundation.org Cc: linux-mm@kvack.org, shakeel.butt@linux.dev, athul.krishna.kr@protonmail.com, miklos@szeredi.hu, stable@vger.kernel.org References: <20251120184211.2379439-1-joannelkoong@gmail.com> <20251120184211.2379439-2-joannelkoong@gmail.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <20251120184211.2379439-2-joannelkoong@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: B33DD1C0016 X-Stat-Signature: dsu91bf15d55wwb1y3ass4znrc3sqbq4 X-Rspam-User: X-HE-Tag: 1763669286-615738 X-HE-Meta: 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 fNFCloY5 TO5O+OQ3J+G3TLuKG7bFBJagyHvOFzDIW0z3UPxt4h26pjQguGdD+m28TGskmmp8Z5iYf1AtVhjRjaYWyn2G4G5NXkic/nC/MDxr6uYZYAk4iWkC+fEXFbN9HpZPscwZqodhJj7YcMMmLD00xgo664QB+xHgDbP7m8QTnkfqgh6mzpD75NHFXq+eZ6rSndTsfu2vzs3i7CS+i1V10ymhxqe0jjlEcPi79pwDFWVe1hjejLRiPfQy9MYBvDAOiGH0HRKmLw4pjmVoKxv0E7vPMFJmcPEB+K8ECQpYSMqUbGAYq98jta8J3PYwMTw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 11/20/25 19:42, Joanne Koong wrote: > AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM was added to avoid waiting on > writeback during reclaim for inodes belonging to filesystems where > a) waiting on writeback in reclaim may lead to a deadlock or > b) a writeback request may never complete due to the nature of the > filesystem (unrelated to reclaim) > > Rename AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM to the more generic > AS_WRITEBACK_MAY_HANG to reflect mappings where writeback may hang where > the cause could be unrelated to reclaim. > > This allows us to later use AS_WRITEBACK_MAY_HANG to mitigate other > scenarios such as possible hangs when sync waits on writeback. Hmm, there is a difference whether writeback may hang or whether writeback may deadlock. In particular, isn't it the case that writeback on any filesystem might effectively hang forever on I/O errors etc? Is this going back to the previous flag semantics before we decided on AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM? (I'd have to look at the previous discussions, but "writeback may take an indefinite amount" in patch #2 pretty much looks like what I remember there) -- Cheers David