From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794047894; b=Yxb/q853mrjazl1fBsdwOVFHBce3ztItThVGU8yewMVzfte84yRSAfOniJ+gpLj/KgZZ aYFxLLvyiXkeRftCALst5Lrd4RBiie+LSd4w0V6TEqvuCOMdXlEfWxdKUxTRDwh4ZaTrh tIrs0EXXAWk1JFrT7RZBM1ncbJfA4xKZ6sCrnjGMcpjYIPKZYxfQj1b9E1AnewP2poQmI ZSPrD3wchnJdr69PU6kNjUzy213t6J9ZC0r10cmqT8EWv+bERCSTva/0bk5R0sYw2lD1F iVfhEZiTbmrrswjWIU4r16PNCd2nQINWBqmcMmIJ1x/ldBtnlFgn0BN6XnI6dohHXpw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047894; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=TIJWuwXSig47/Phj0+wuwVDI3h7uBWxOhj2JKnr69SQ=; b=LgYoGnGa3PZjlgxb71qmI3OQXlftmw+kFUFevmalY+Q2SSLy0YuyQTj7sfyo37zBurHd ZnUmoZhAT+wxke8acasV88eqq2tQUPe6h/zZh0zgjMyaA6eFqYgvXHvwjhzvdpVBNWvAm AIyix2xV1ElYU3HB8ySs4RTz2pQ5zeTE0vZqEOpSWn1sqdreHF/KaIKWAsXjrbiuexYJb nFAUYYoNMruCeLHx6oO6zk8hbCF63AH3bNfwSLey76KvVXJli2YeuLCL1bQ1+kHAiaUh+ yJOC0UjBMlylHGkgDrrUJqNQ/R00Px6hWSTPqhUNOAUVbu385tRbRxuMHwSd87SMQRg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="J/jtDpGb"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E574F606A326 for ; Sat, 7 Nov 2026 10:38:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=J/jtDpGb Received: by smtp.kernel.org (Postfix) with ESMTPSA id 347E51F0089F; Sat, 7 Nov 2026 10:38:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047893; bh=TIJWuwXSig47/Phj0+wuwVDI3h7uBWxOhj2JKnr69SQ=; h=From:To:Cc:Subject:Date; b=J/jtDpGbOj6mLUChX6IqNa7pH7ibs2L7rtcl8LpQ6RKcKWIHTC2S+pL3WVjWJUgN0 yS9AUb0xkhS8EKvMX2Ji5bIc+nOIfnpkywV5ripR5TCxYgowdJCKHg78fIdZrFk9By AiiiTwkQuqF99Ci8F7D1XpvYLEtw1rbybvEx8sgLMlovCV9zCxOxwWr/yQAbxU9Jbq hbrhSFTlZrHmEr3N6sVZpr9fcZKSNGOTLfA02cW/0phPkDSV0y1EIDCQP0ajtSe34y tanr/pule2qqgdm98h4tu0Q7Sw3tfmIU9xvhQWtoI/oksRdFYWJaBuvfJRVXOYAmiK nYJ7n+L15ZoVg== From: Sasha Levin To: nick@karaolidis.com, jack@suse.cz, chengzhihao1@huawei.com, brauner@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] fs: rotate inodes whose page cache could not be dropped" failed to apply to 6.6-stable tree Date: Sat, 7 Nov 2026 05:38:12 -0500 Message-ID: <20261107053812-failed-6.6-8ee09f597763@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 8ee09f597763acfd31c62a578ba88b792fc41b24 # git commit -s git send-email --to '' --in-reply-to '20261107053812-failed-6.6-8ee09f597763@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 8ee09f597763acfd31c62a578ba88b792fc41b24 Mon Sep 17 00:00:00 2001 From: Nikolaos Karaolidis Date: Fri, 16 Oct 2026 10:25:15 +0000 Subject: [PATCH] fs: rotate inodes whose page cache could not be dropped When inode_lru_isolate() drops the page cache of an unused inode, it has to unlock the list, so it returns LRU_RETRY and the walk restarts at the head of the list, where the inode still is. If invalidate_mapping_pages() could not empty the mapping, the restarted walk strips the same inode again, and so on until nr_to_walk runs out. Every walk of that list then ends on this inode, and nothing behind it is reclaimed for as long as its cache stays. Before commit 2a0629834cd8 ("vfs: Don't evict inode under the inode lru traversing context") the walker pinned the inode with a reference, and dropping it in iput_final() set I_REFERENCED, so the restarted walk rotated the inode to the tail. Set I_REFERENCED again when the mapping is still populated after the invalidation, in the same i_lock section that clears I_LRU_ISOLATING. inode_unpin_lru_isolating() now expects i_lock to be held, like inode_pin_lru_isolating(). On CONFIG_HIGHMEM kernels this can happen to any unused inode: a folio is left behind if it is locked, under writeback, spliced into a pipe, or still in another CPU's LRU-add batch after being read. Without HIGHMEM it happens to DAX inodes whose only entry is at index 0, which mapping_shrinkable() lets onto the LRU and invalidate_mapping_pages() never removes. Fixes: 2a0629834cd8 ("vfs: Don't evict inode under the inode lru traversing context") Cc: stable@vger.kernel.org Signed-off-by: Nikolaos Karaolidis Link: https://patch.msgid.link/20261016102515.111285-1-nick@karaolidis.com Reviewed-by: Jan Kara Reviewed-by: Zhihao Cheng Signed-off-by: Christian Brauner (Amutable) --- fs/inode.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index 1cb6293b237a3..d6353b8d1e634 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -593,12 +593,11 @@ static void inode_pin_lru_isolating(struct inode *inode) static void inode_unpin_lru_isolating(struct inode *inode) { - spin_lock(&inode->i_lock); + lockdep_assert_held(&inode->i_lock); WARN_ON(!(inode_state_read(inode) & I_LRU_ISOLATING)); inode_state_clear(inode, I_LRU_ISOLATING); /* Called with inode->i_lock which ensures memory ordering. */ inode_wake_up_bit(inode, __I_LRU_ISOLATING); - spin_unlock(&inode->i_lock); } static void inode_wait_for_lru_isolating(struct inode *inode) @@ -981,7 +980,13 @@ static enum lru_status inode_lru_isolate(struct list_head *item, else __count_vm_events(PGINODESTEAL, reap); mm_account_reclaimed_pages(reap); + + spin_lock(&inode->i_lock); + /* The walk restarts here: don't retry leftovers right away */ + if (!mapping_empty(&inode->i_data)) + inode_state_set(inode, I_REFERENCED); inode_unpin_lru_isolating(inode); + spin_unlock(&inode->i_lock); return LRU_RETRY; } -- 2.53.0