From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 235F2606A323 for ; Wed, 28 Oct 2026 08:16:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=jCDyC8ok Received: by kanga.kvack.org (Postfix) id 34BC46B05B8; Wed, 28 Oct 2026 04:16:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2D2EC6B05BB; Wed, 28 Oct 2026 04:16:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 176916B05BE; Wed, 28 Oct 2026 04:16:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id CE55B6B05B8 for ; Wed, 28 Oct 2026 04:16:54 -0400 (EDT) Received: from smtpin06.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 6C701140BEE for ; Wed, 28 Oct 2026 08:16:53 +0000 (UTC) X-FDA: 85371329106.06.C5929A4 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf18.hostedemail.com (Postfix) with ESMTP id 9C4E61C0005 for ; Wed, 28 Oct 2026 08:16:51 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=jCDyC8ok; spf=pass (imf18.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793175411; 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=2SbShK97MZ85y0KD6EulcgImPc0M61Sq9vGvevV4OQY=; b=0rr8gN9IkMjztrRJTKMVqQCbFPoh9Jxoj+Fa4We7z4ct8zg+iBGL7k0DczUzu40kmDuf7O 6O6NfvLMcQVHaFN7zYJHqSq57j50KqWfLOmIfHyw2krjldInTCZRA/MJxWguRqbzOHPebf IYFL2ToBdy05Qh0XuzJVP5ZwSPHrpaw= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793175411; b=40jTHkiss8DHspgg4v3olUl5EbXISf8Cgr2zBCRjFioquFAT/gZQZanyomnppIcN1aFjtO ObLXy2rRmBP8nyX//4QrfPBFHEG4OlPRBLqjlnTCywTBQiqjkA9luKowyoOLxAFHkpzxhn iV6hTN9DPZikH7F+MQCYt0qlygEAN5Y= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=jCDyC8ok; spf=pass (imf18.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id B7FC142208; Wed, 28 Oct 2026 08:16:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66B7C1F01825; Wed, 28 Oct 2026 08:16:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793175410; bh=2SbShK97MZ85y0KD6EulcgImPc0M61Sq9vGvevV4OQY=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=jCDyC8ok1EAtBemPTyE0fEaa8zBu8wdILXDuDlpXS9nnr+VVOWOsINKYRo0N2twMr xVJ3b6czM53QXz06HU/Eb9nkPGbrgrb96WXdGDd7kqo000v7zbKenf3euRolPgTN5D 0GH5kIUbRcDn3KhovrrLfbOjYbIeO65d0eK0SO8S/0Qc/7eEA9FqKbxAWx3tHaN+0O b9EEoHYN49L9Hk3N7i9dpabSSf8s5Zj/VOKbJ/ZpjQaAyA7h+1dKAMfwjAQP/Gvb6p cNBn8nXLmRSE5/VmahsYgyjtVPBc3vVMJ/vfR9rM4LOLQnYvedSEg9WTh2qXSaoJpa LPh8rswVKh3TQ== Message-ID: <032c036d-f80e-4b3b-b650-2b30b7a2f3fb@kernel.org> Date: Wed, 28 Oct 2026 09:16:31 +0100 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 13/46] mm/huge_memory: fix truncate racing with PMD zapping To: Zi Yan , Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Chris Mason , stable@vger.kernel.org References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> <20261027-fixes_core-v1-13-6f74bec9a5bb@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 9C4E61C0005 X-Stat-Signature: w9qe9uzrsaj7j79bik4ouw689rzg7a3n X-Rspam-User: X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=4.0.1 X-HE-Tag: 1793175411-986852 X-HE-Meta: U2FsdGVkX1/ZpXxXUU/bwb1TJntgDt8bcXQI1UolrzXXq4kOuGiol/K58fJP88huo0npkyokSLQaj2s4NLk2QXu3lIO4dumcL6q3T8332+Ps8DbC67jemAkO5B1DW1BjdNXX5416mgktrd1dHYt9v1sQk+We3f9bGmdc1LDS/OC2qTwqZkWh5KtyMywDHM8Z2WlTLU1jQUFPn75KcqgiGPIFLI18MaIH9sIiNhOxNXCSUDtZ8Vp5p347Z0rC4uWtPtIRKEGFLOVIlAMhrx8Gx/Z9BxUrt3MvlZutAdFy2fetUVhzAhid6JznOu0e0LkKG+QAw72RO6+kVoJxzKhIXKNfnNRLmDvjFSZuOcwf3gV7Nl6B0Ord0dQ8iC8xdu7wkpk1+c1FA2VnJIxxXX1XgURsDUEi/vA7cVjr3D6T7YuYuo+PK9AjIWsVGFHyGbwcEAcueys30nfrxAOpRpiN46jkG/4Yqr7IJo27QeOtpQUFZ6Y5RFwWI4D5LZlWeCTM39eYJHSgDmaESWKOqnoYfEh9sEmKbMEhvN4OFq+bC4pCJj42OtAHCy3BvUgg1oyEztoQNtQYURNpF2FJY3Yq7gIEyBaZ9LALrHHpckbIm+1fBboki5tGcNrmDhVRuEABE+jpQQBfQciGabgfzwi8FT5ACisOtdGSuastfmNCqHGXIIolZAOaFMlTUp2R128SlwqGzC0oYjgvdrr9E8RUjHhk7W1V8j1G9/doYO6G4oxP9clcocR+2W4BHhc+YHGn1bJAoSArcA3SFb0zdV1cgLZJoGuGf3XSFCwwnKPDHqQiF0vs2NdudMZjFR2R+b7aNU2u0qEIGPhsETYxHkqltp+yltL6mJ1f8e5obQPb+YYlXRC/jwhN06ZCdo5qDsM2m1HwZ7CEIU3slZv5b/KI1JS+r//FdROs9NqIISwE+rxWksTIrPv64ECJlS+bMpza9qWhxyLfcThfvLfM3uQ lj29nQO0 6KqpVrzcHg+Q5uw9l5GD+CK8i9peJnSABjgeo/inzzic7q1W7sxVPr5zCd3+VoO6hkBUcBrMaGwUBpP607sBILM3URpX4GGU6eY2PQgytdwqx+Y94Iw3q/gJjvJloBhIZoRitYQwPB8HhRqRUSZo97Lks6UFl+RRrFccLkX/c7/RL3uh0tMNhMMh3A645EqpkuxveUE0tHWiZDbRogQh4CA8eVRgtFKD1XTTXj8+u2Rn3sUvsDEAagBUd9L6ajvWGW53FitCXuykiAF/A+Cb7hBW1fUXDVFqARFrzrFY5X9N9Ejxd1SWauoPA/jSotW3hIRVyhq0Y8xZZqrs3lwb3XlopEYqJupiq3EUxUE8tetaNtsh5+FnKg4Z4UD/J92GkU4NEcinu1Lt3wdiPKj9xCzzx2w== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 10/28/26 03:54, Zi Yan wrote: > On Mon Oct 26, 2026 at 7:17 PM EDT, David Hildenbrand (Arm) wrote: >> From: Chris Mason >> >> zap_huge_pmd_folio() removes the rmap before calling folio_mark_dirty(). >> If this was the last mapping, truncation can skip unmapping the folio >> and proceed without waiting for the PMD lock, racing with dirtying. >> >> ifs_set_range_dirty() can oops if MADV_DONTNEED races with >> ftruncate() on XFS, when we get the folio set dirty after it was found >> to not be mapped anymore. >> >> Move folio_mark_dirty() and folio_mark_accessed() before rmap removal, >> matching the PTE zap path. This keeps the folio mapped while updating >> its state, so truncation must wait for the page table lock. >> >> Fix generated by an LLM and sent by Chris Mason in private. >> >> Fixes: fe6cf984939d ("mm/huge_memory: transfer the pmd dirty bit to the folio on zap") >> Cc: stable@vger.kernel.org >> Signed-off-by: Chris Mason >> [ david: simplify comment and description ] >> Signed-off-by: David Hildenbrand (Arm) >> --- >> mm/huge_memory.c | 14 ++++++++------ >> 1 file changed, 8 insertions(+), 6 deletions(-) >> > > It seems to me that moving the rmap removal code after folio_mark_*() > matches zap_present_folio_ptes() closer. Yes, can do that! Thanks! -- Cheers, David