From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 51A98D5B857 for ; Mon, 15 Dec 2025 17:09:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A75916B0006; Mon, 15 Dec 2025 12:09:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A4D6C6B0007; Mon, 15 Dec 2025 12:09:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9400A6B0008; Mon, 15 Dec 2025 12:09:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 847886B0006 for ; Mon, 15 Dec 2025 12:09:22 -0500 (EST) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 21A941A02F9 for ; Mon, 15 Dec 2025 17:09:22 +0000 (UTC) X-FDA: 84222341364.17.D30DEE3 Received: from fhigh-a2-smtp.messagingengine.com (fhigh-a2-smtp.messagingengine.com [103.168.172.153]) by imf12.hostedemail.com (Postfix) with ESMTP id F16AA4000B for ; Mon, 15 Dec 2025 17:09:19 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=bsbernd.com header.s=fm3 header.b=DBmsQD4o; dkim=pass header.d=messagingengine.com header.s=fm1 header.b="Z 9u8MS0"; spf=pass (imf12.hostedemail.com: domain of bernd@bsbernd.com designates 103.168.172.153 as permitted sender) smtp.mailfrom=bernd@bsbernd.com; dmarc=pass (policy=none) header.from=bsbernd.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1765818560; 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=xVWwiXFD+0T8MSjifsQoEy4fskO/HVJ0qZSwyVu4ZIM=; b=dTSqGqTE/fIfdrlEvu81YB+B4SgsQfNe52qrr0rlBReLCNtATPF01c4pfXC+f1bzGIi725 0XfeJhgFL3klTU45ARtndItYkzOkTYhB9hmw9Ky8qh2UPyy/ilJKjgHHyNZg+9j9YnawWr UzjrVVtvfC5z3tkQ3oM/GLc+KP2gfBo= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=bsbernd.com header.s=fm3 header.b=DBmsQD4o; dkim=pass header.d=messagingengine.com header.s=fm1 header.b="Z 9u8MS0"; spf=pass (imf12.hostedemail.com: domain of bernd@bsbernd.com designates 103.168.172.153 as permitted sender) smtp.mailfrom=bernd@bsbernd.com; dmarc=pass (policy=none) header.from=bsbernd.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1765818560; a=rsa-sha256; cv=none; b=C9hzZ0+CMl4X3Ij/oExM2ghT4E7W0Nbkwi8mkoYsap69KISQvQgpTDI8hJI1vYyLYoa2iz Qw9RelztRX2CyuMuBB6DEuKjwlWng+KmGDW2V+I22JuJRAKr1viCEN2RERdFiUHffVivJG ox6AJ+WHDY2/Ws5TxbxVlls7bvmstCo= Received: from phl-compute-03.internal (phl-compute-03.internal [10.202.2.43]) by mailfhigh.phl.internal (Postfix) with ESMTP id 3EE6614001F1; Mon, 15 Dec 2025 12:09:19 -0500 (EST) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-03.internal (MEProxy); Mon, 15 Dec 2025 12:09:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsbernd.com; h= cc:cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm3; t=1765818559; x=1765904959; bh=xVWwiXFD+0T8MSjifsQoEy4fskO/HVJ0qZSwyVu4ZIM=; b= DBmsQD4oMM0qgWntCWtu0WtfgCf/MbXQL0FUzxGBYcCdiKwv6Ob824yeOfiSuBdV P1B90i6yCqsvXITHwrN+TSar2UAJcowbupdnIalHEtW8LBAmrSWKUhvHvbIaLJ4k jShsXUCGfXrijIeeaSbeTEJwxU4C/+fWMjhxWYiyvxVvmBUtKRer9/QvmRJQbDQT o1sXVzHHZuS+vFq+ZxmBtaSoS7krHEYHF8xglr2nqgbTh25V9wXTBWmzwb/EEc9d jvGwGI/vlrCEkHUzawnhwuFrN9HUs1ezWODsu0QFVWuuzv2pE/YTZhP/K1KEvjlV Uu2DLXq9S/ln1gdbpSN6FA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t=1765818559; x= 1765904959; bh=xVWwiXFD+0T8MSjifsQoEy4fskO/HVJ0qZSwyVu4ZIM=; b=Z 9u8MS08Ik++NoxS3z66EZ0cJMm5KvLl6hGst26/iYdACNhfPrRO94El2ktlKhugD J80UG5N4Pw/OL78tsDsmMjLopfPrabQUp8gS4BbA6YRoReroHKpoYsk2wYnP1iHP p9zpvahy7mx4UjOLQyB2EvDXX88qBCYGxUPif6HJF+r/OAGzb/lfdjlSMXKOfy6U mRbpgHMmpET+yL1BZRMcdDxQZTZzOn0GhNlyI9qszF7/D1VGRTJBX4kqWVrJQJFr kkjlVZbgzkwcbArq2jtbKlhmFPmcfAt/Hqkj/VUV1pF9Fk6BrdGVZK3S/0EfrK2g HHxlroYaIcnqDyYLh3f5w== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefgedrtddtgdefjeefjecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpuffrtefokffrpgfnqfghnecuuegr ihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjug hrpefkffggfgfuvfevfhfhjggtgfesthekredttddvjeenucfhrhhomhepuegvrhhnugcu ufgthhhusggvrhhtuceosggvrhhnugessghssggvrhhnugdrtghomheqnecuggftrfgrth htvghrnhepfeeggeefffekudduleefheelleehgfffhedujedvgfetvedvtdefieehfeel gfdvnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepsg gvrhhnugessghssggvrhhnugdrtghomhdpnhgspghrtghpthhtohepuddtpdhmohguvgep shhmthhpohhuthdprhgtphhtthhopehjohgrnhhnvghlkhhoohhnghesghhmrghilhdrtg homhdprhgtphhtthhopegrkhhpmheslhhinhhugidqfhhouhhnuggrthhiohhnrdhorhhg pdhrtghpthhtohepuggrvhhiugesrhgvughhrghtrdgtohhmpdhrtghpthhtohepmhhikh hlohhssehsiigvrhgvughirdhhuhdprhgtphhtthhopehlihhnuhigqdhmmheskhhvrggt khdrohhrghdprhgtphhtthhopegrthhhuhhlrdhkrhhishhhnhgrrdhkrhesphhrohhtoh hnmhgrihhlrdgtohhmpdhrtghpthhtohepjhdrnhgvuhhstghhrggvfhgvrhesghhmgidr nhgvthdprhgtphhtthhopegtrghrnhhilhesuggvsghirghnrdhorhhgpdhrtghpthhtoh eplhhinhhugidqfhhsuggvvhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrgh X-ME-Proxy: Feedback-ID: i5c2e48a5:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 15 Dec 2025 12:09:17 -0500 (EST) Message-ID: <2410c88d-380a-4aef-898e-857307a57959@bsbernd.com> Date: Mon, 15 Dec 2025 18:09:16 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/1] fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes() To: Joanne Koong , akpm@linux-foundation.org Cc: david@redhat.com, miklos@szeredi.hu, linux-mm@kvack.org, athul.krishna.kr@protonmail.com, j.neuschaefer@gmx.net, carnil@debian.org, linux-fsdevel@vger.kernel.org, stable@vger.kernel.org References: <20251215030043.1431306-1-joannelkoong@gmail.com> <20251215030043.1431306-2-joannelkoong@gmail.com> From: Bernd Schubert Content-Language: en-US In-Reply-To: <20251215030043.1431306-2-joannelkoong@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Stat-Signature: 7ph6zidzru6k8ytj419z8wdh3rbrprzg X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: F16AA4000B X-HE-Tag: 1765818559-464626 X-HE-Meta: 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 aMBc62bs 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 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 12/15/25 04:00, Joanne Koong wrote: > Skip waiting on writeback for inodes that belong to mappings that do not > have data integrity guarantees (denoted by the AS_NO_DATA_INTEGRITY > mapping flag). > > This restores fuse back to prior behavior where syncs are no-ops. This > is needed because otherwise, if a system is running a faulty fuse > server that does not reply to issued write requests, this will cause > wait_sb_inodes() to wait forever. > > Fixes: 0c58a97f919c ("fuse: remove tmp folio for writebacks and internal rb tree") > Reported-by: Athul Krishna > Reported-by: J. Neuschäfer > Cc: stable@vger.kernel.org > Signed-off-by: Joanne Koong > --- > fs/fs-writeback.c | 3 ++- > fs/fuse/file.c | 4 +++- > include/linux/pagemap.h | 11 +++++++++++ > 3 files changed, 16 insertions(+), 2 deletions(-) > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index 6800886c4d10..ab2e279ed3c2 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -2751,7 +2751,8 @@ static void wait_sb_inodes(struct super_block *sb) > * do not have the mapping lock. Skip it here, wb completion > * will remove it. > */ > - if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) > + if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK) || > + mapping_no_data_integrity(mapping)) > continue; > > spin_unlock_irq(&sb->s_inode_wblist_lock); > diff --git a/fs/fuse/file.c b/fs/fuse/file.c > index 01bc894e9c2b..3b2a171e652f 100644 > --- a/fs/fuse/file.c > +++ b/fs/fuse/file.c > @@ -3200,8 +3200,10 @@ void fuse_init_file_inode(struct inode *inode, unsigned int flags) > > inode->i_fop = &fuse_file_operations; > inode->i_data.a_ops = &fuse_file_aops; > - if (fc->writeback_cache) > + if (fc->writeback_cache) { > mapping_set_writeback_may_deadlock_on_reclaim(&inode->i_data); > + mapping_set_no_data_integrity(&inode->i_data); > + } For a future commit, maybe we could add a FUSE_INIT flag that allows privileged fuse server to not set this? Maybe even in combination with an enforced request timeout? > > INIT_LIST_HEAD(&fi->write_files); > INIT_LIST_HEAD(&fi->queued_writes); > diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h > index 31a848485ad9..ec442af3f886 100644 > --- a/include/linux/pagemap.h > +++ b/include/linux/pagemap.h > @@ -210,6 +210,7 @@ enum mapping_flags { > AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM = 9, > AS_KERNEL_FILE = 10, /* mapping for a fake kernel file that shouldn't > account usage to user cgroups */ > + AS_NO_DATA_INTEGRITY = 11, /* no data integrity guarantees */ > /* Bits 16-25 are used for FOLIO_ORDER */ > AS_FOLIO_ORDER_BITS = 5, > AS_FOLIO_ORDER_MIN = 16, > @@ -345,6 +346,16 @@ static inline bool mapping_writeback_may_deadlock_on_reclaim(const struct addres > return test_bit(AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM, &mapping->flags); > } > > +static inline void mapping_set_no_data_integrity(struct address_space *mapping) > +{ > + set_bit(AS_NO_DATA_INTEGRITY, &mapping->flags); > +} > + > +static inline bool mapping_no_data_integrity(const struct address_space *mapping) > +{ > + return test_bit(AS_NO_DATA_INTEGRITY, &mapping->flags); > +} > + > static inline gfp_t mapping_gfp_mask(const struct address_space *mapping) > { > return mapping->gfp_mask; Reviewed-by: Bernd Schubert