From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f179.google.com (mail-qt1-f179.google.com [209.85.160.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE6A126A0D5 for ; Tue, 2 Sep 2025 09:22:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756804925; cv=none; b=VnnTFsoVFyNomsBc70sV6acIJQP0cegtFyWyz5nrJpKMY5ZUKyUyByD/9ZWTyWtCXQdiRj/7n42Nv52Qo3YwACJK6BsdkMhgudPQEXatBJWUqoio2Ic0dlB03S3Oo4MWUqgKgA38NhEePICkgFAGgBbm9TmuLttA4KzruLMaU6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756804925; c=relaxed/simple; bh=oZ/oMsImSwXy0iurVEV8OYWOj1EK5Ol1S2elCURr6o8=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=UEh2/nZt3L5EgXUrqJAswZ86MkHYRoZS8fHhHX2VfVRXxjaM1AZUPt6SqxQ/+ulalzkoNRSCrF6IlgrB1YKWJy99WcgJd25VQ7g1V55TAibhCZ/SpoPHPycFMUGVMdxDbY0x9gDo6gc03FD5B8wjc7K60f12A4iuhRcAUHsrUR4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=szeredi.hu; spf=pass smtp.mailfrom=szeredi.hu; dkim=pass (1024-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b=pPMk8ro8; arc=none smtp.client-ip=209.85.160.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=szeredi.hu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=szeredi.hu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b="pPMk8ro8" Received: by mail-qt1-f179.google.com with SMTP id d75a77b69052e-4b30d09da9dso37858771cf.1 for ; Tue, 02 Sep 2025 02:22:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; t=1756804922; x=1757409722; darn=vger.kernel.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=KlEqu4WxUDiABf2a30g8zFkM2TpzDalMOcCpeUi3kyM=; b=pPMk8ro8+Yj2e5GcMg+nnrdCbWMa8u1B2AHCvpmpG4WYnwkCAtHfQf/mPrDcLvVJzI vfoKD8hrHyXIyTaeXOhT1Iyo2KSngHpPf6d+8aO/AmL8zWLxIItynXCxDE9ZcClhxjmK LGk4n+XYjMdT7QESQ4oENa+2wZK2c6zlQnh8w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756804922; x=1757409722; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=KlEqu4WxUDiABf2a30g8zFkM2TpzDalMOcCpeUi3kyM=; b=rI9y9Stf+hzmFlYEFrOYgH7BhmEUgvc6w6Bj9uc+Hy2eujkFRddzxiLWaMDSjDbZbS SM8t3Ld/ynIAzohgv3fWxQLbjl0828cgRKYiqtCV4H25/H1wIUXbr4PACXF5AwhoNkA0 FWDjqRzJHanzR5Ct1gKAbtCNGfhqESRNorXGtiLZWwIVZjKGQOgIycRMflSrB2Yh67nf C9EcWmCwkC+xu8chfvwL/pjJ7iUFQHrvzNribpvRpqMVnrkaqaYJVufvu/Jl+6lvSMuH Uj6yTXA9EsDktrqQn+iUcVVA7bVNJhJQ4/CurkTzQlZAqRy/Ar1erXfZQ79Xr6+XBtWh x8cg== X-Forwarded-Encrypted: i=1; AJvYcCWDMLWkfyPH/J6ZWIlEPi5/bmpMk9N8IT8IbcfDaUopLXHBU3s38/0ctIOEI+V4aa3D3n+uNocff18=@vger.kernel.org X-Gm-Message-State: AOJu0YwnHW8DoGGql+kIA9GXbdQzOelyHjsoB4Izn/3yinrzj62VRLjR M+Y6JLTTYA+ilbCqNWSM68jOeonzAjA3yxBroC5wwRsTc4iFwKQ0yw9OOeoU41VWiUuoLMmwSIu l74kLTGoLos14J8y09huenNixygqqWQA4KRUbHxjYzw== X-Gm-Gg: ASbGncu2GyeJzUhv1/dvEhA2Mfha3Ge6Z849gONKzvkNWiVsJ6lOAnl2GE89K6vHZlG ceoduuvbzA13+cNFDeyrnceLhhLY12k5y+4NYgxj2LMdecofDs5GDfgj+Q/iWWNtuZ/8aUJlV0i U6kUzlk/7DP7w9mC/G6dNjy5iMQJVQQ594WmWDA55Zk3AXSjX2p2fcIWSHJ+CKhjoF7jdjIIiV9 /idEoNtgw== X-Google-Smtp-Source: AGHT+IHGEIqkQ7T/iYNa57/nLq67pz6kDXn62sDrEEuPOwlRvgJBGGtL0MCc4sflnVaHrwo9btUA3j959kBW+PZAoRU= X-Received: by 2002:a05:622a:1448:b0:4b1:103b:b67a with SMTP id d75a77b69052e-4b31b9c3777mr140959691cf.32.1756804921620; Tue, 02 Sep 2025 02:22:01 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250829235627.4053234-1-joannelkoong@gmail.com> <20250829235627.4053234-17-joannelkoong@gmail.com> In-Reply-To: <20250829235627.4053234-17-joannelkoong@gmail.com> From: Miklos Szeredi Date: Tue, 2 Sep 2025 11:21:50 +0200 X-Gm-Features: Ac12FXymFicVPinwbFSWp8veqgoTeVOVPPlBCbz_Zbd4N-bMcdXkFmiPs4wTQ0w Message-ID: Subject: Re: [PATCH v1 16/16] fuse: remove fuse_readpages_end() null mapping check To: Joanne Koong Cc: brauner@kernel.org, hch@infradead.org, djwong@kernel.org, linux-fsdevel@vger.kernel.org, kernel-team@meta.com, linux-xfs@vger.kernel.org, linux-doc@vger.kernel.org Content-Type: text/plain; charset="UTF-8" On Sat, 30 Aug 2025 at 01:58, Joanne Koong wrote: > > Remove extra logic in fuse_readpages_end() that checks against null > folio mappings. This was added in commit ce534fb05292 ("fuse: allow > splice to move pages"): > > "Since the remove_from_page_cache() + add_to_page_cache_locked() > are non-atomic it is possible that the page cache is repopulated in > between the two and add_to_page_cache_locked() will fail. This > could be fixed by creating a new atomic replace_page_cache_page() > function. > > fuse_readpages_end() needed to be reworked so it works even if > page->mapping is NULL for some or all pages which can happen if the > add_to_page_cache_locked() failed." > > Commit ef6a3c63112e ("mm: add replace_page_cache_page() function") added > atomic page cache replacement, which means the check against null > mappings can be removed. If I understand correctly this is independent of the patchset and can be applied without it. Thanks, Miklos