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From: Muchun Song In-Reply-To: Date: Wed, 29 Apr 2026 12:18:08 +0800 Cc: Muchun Song , Vishal Verma , Ying Huang , Dan Williams , Naoya Horiguchi , linux-mm@kvack.org, linux-cxl@vger.kernel.org, driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org, David Hildenbrand , Greg Kroah-Hartman , Rafael J Wysocki , Danilo Krummrich , Andrew Morton Content-Transfer-Encoding: quoted-printable Message-Id: References: <94F5B89A-008A-4EDB-920F-31B4895C2699@linux.dev> To: Oscar Salvador , Miaohe Lin X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 8B8A420005 X-Stat-Signature: ydtn1hmcfhab7igg7quotc7am531uk5t X-HE-Tag: 1777436345-213013 X-HE-Meta: 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 9hWJbZa8 Ra1qfJenPrTmA1eCH08q+BDd/LIulISROxm3Dv+QzfHprX8bzHssO7ZKEXY+KFzPoszvhrJ2/LzswPr3GVM97tAo20WyL8TrJADdxE6VIEIuNd6g9Hm6/O8r721M/xT7okrKZR0kAQXCO18ITuQpZHxO3Q2nxn+kBTbxSP6Qqn3l3VmB5HTEdDajs7sRDyNh3LlbyA/fhctfzVj1Luai4rNgXoHxlScHC/+LCmTWfSSkhIVqRvy8H8Y7RLQfAqMAXBPcRsyVwpzYptDSLo8pGMBmTWzkgbDgC0XGk8u+HATO5k99jQF3PR1jy/L/tzy/kTML/U6P5PAw9DX9n3ZTAS19VBxWKXEqtDS+d7MnpIJHeJcCOlSTwc5C/Q8fmvfHx2orclzX3Rx8r5oo= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Apr 29, 2026, at 11:32, Oscar Salvador wrote: >=20 > On Wed, Apr 29, 2026 at 11:08:51AM +0800, Miaohe Lin wrote: >> Right, I missed that. Thanks. But I'm still worried that there might = be potential issues. >> For example, this function could be called while lock_page is held. = Acquiring lock_device_hotplug >> while already holding lock_page might cause problems, though I = haven't seen any specific issues yet. >> Also there might be some other potential scenarios that haven't been = considered. Hope I'm just >> overthinking it. :) >=20 > lock_device_hotplug is a mutex lock, and we already take other mutex = locks while > holding lock_folio in other paths, so I am not sure I see what should = be special > in this case. Hi Oscar and Miaohe, I saw sashiko's report [1] related to folio lock and = lock_device_hotplug. Seems it is possible. You can correct me if I am wrong. [1] = https://sashiko.dev/#/patchset/20260428085219.1316047-1-songmuchun%40byted= ance.com We could fix this by calling action_result() without holding folio lock. What do you think? diff --git a/mm/memory-failure.c b/mm/memory-failure.c index ee42d4361309..bc76066547ce 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2534,8 +2534,9 @@ int memory_failure(unsigned long pfn, int flags) * Abort on fail: __filemap_remove_folio() assumes unmapped = page. */ if (!hwpoison_user_mappings(folio, p, pfn, flags)) { + folio_unlock(folio); res =3D action_result(pfn, MF_MSG_UNMAP_FAILED, = MF_FAILED); - goto unlock_page; + goto unlock_mutex; } /* @@ -2543,16 +2544,15 @@ int memory_failure(unsigned long pfn, int flags) */ if (folio_test_lru(folio) && !folio_test_swapcache(folio) && folio->mapping =3D=3D NULL) { + folio_unlock(folio); res =3D action_result(pfn, MF_MSG_TRUNCATED_LRU, = MF_IGNORED); - goto unlock_page; + goto unlock_mutex; } identify_page_state: res =3D identify_page_state(pfn, p, page_flags); mutex_unlock(&mf_mutex); return res; -unlock_page: - folio_unlock(folio); unlock_mutex: mutex_unlock(&mf_mutex); return res; >=20 >=20 > --=20 > Oscar Salvador > SUSE Labs