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=1794049832; b=SW76W3I17kfwCr50CWHbApGeD9WqY3K7GodPHp4J1mUstsvbOlyaldlTzylnNLmjN87I wM7GWnCKUvE5/qU3KAIJgrE3OjQLyqdzzGWKh/4HHblJbMnfgnYc7VOumX0REhdoOpMt5 0cXxZec1v0tEOoD6kJl+SMbxeCbq+6eu3O8JnESt5d/1Eb+mEDPJa28hwnPIJX940Y/gy r3jdPtYuRS37dDtf3izKYdzlXurAjvCwO7+ISbZHH2lKEkShfLWEhXowYhK85wJpZ52It 15UJbe9BlbZWXU5Aug/CNPsxUvAVxVbDyzQ0KV5YBR2X/ishhKe9YrpuTypRDikzPYg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794049832; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=7J0reLjR48Ix1PnJ4xM4OMitrPsoDrqfR4OrKwBk/bM=; b=ZM9jDHfpZuMeeuIHmBXUzwX0lgsBKkwMTspibChififofzdS+p9PGRxm6ijiqMyBkvwN CvDsnevMEfCuSi3JG2Wif/NpU1lGAQKN+qA/aCwDaNa67udVsUB4vfFsXbhtzQ1fJXOs4 ZIyziM5oKgTAwogvfjhea83V36tGD4ZVJ2PJ7DK7QTr82f+masm38fiMQlf8G1whY+UZA xxARUb5YETmU9qiS24dY/b5tfX2Rg1ciQqHZFzvEumaz9y76Uv8O7H3rSw2pT2X0hsDZ0 j+nxWZ6JGACXlnQFAWPxeLu83tyDLs4+tZn+jjtTYUfS1I6jeHRFdNNvwuAbM4EWhhw== 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=Z+5YCiYq; 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 36D51606A326 for ; Sat, 7 Nov 2026 11:10:32 +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=Z+5YCiYq Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7AA961F008A1; Sat, 7 Nov 2026 11:10:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794049832; bh=7J0reLjR48Ix1PnJ4xM4OMitrPsoDrqfR4OrKwBk/bM=; h=From:To:Cc:Subject:Date; b=Z+5YCiYqd790ySAndt7Tlx/KNef6AET6i9Sv3XZPoRfZXYMlmLeC/OPWA8kzJ+Jw+ TSsHe7VvRKSPpHXHSx9TXtA4Ulxbf3KpgbI23NTw9gavX8ysiylhGQQLj9Zkinptbs 40P3g1cqwLs3ApvkJcy4rnhotJGrK84pYkf0/t6nVjV79qICqQxf5bdvztg00plS1n 6okMOzYzohuM3dFjY+NoezuiuTcqnPvbkRkoxRa69CqOf93IVZJ5PtmCU2yH/9RUDM 9l8k/OjTil1tmGTIpDHIKdhzFCVg3/abIk727OeqiHL1IrJGmTTbfECaxPU58ZHmxw 7+IcrfSWtj0rA== 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 5.15-stable tree Date: Sat, 7 Nov 2026 06:10:30 -0500 Message-ID: <20261107061029-failed-5.15-8ee09f597763@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 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x 8ee09f597763acfd31c62a578ba88b792fc41b24 # git commit -s git send-email --to '' --in-reply-to '20261107061029-failed-5.15-8ee09f597763@kernel.org' --subject-prefix 'PATCH 5.15.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