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=1794331099; b=Sw1rNYkzTbP7BYBYuxDa6LULU+fiLYClRKnvLOxJyD1gMwJzWBDsSHz7DsE5s4iKG5DN S553xkB6dtgViLZsT/wfAcMb9KlRD1+HwjtJ0e6bCu42AKTMi8O7nP1GJS8bygS/KNq3z ny9IqxatJzczdQkZKy3P45bCQxE76dwh/YP5Nr+Jv5HABCoFSrkCb+T8Ob/1FsMwShA9c M2CzR2cuXa53AYpiZ5d4O9wdinSwmaMGdV6Kt0q8c/P4iN/k0iEuL++S/AamnuUYaH2iv MG/F9b7XSXnxt3l1G6wBBykeQ+uOOUj9GVtwX4PpaMtcrrGuDuwhL4WzVFiDTNGLuuA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794331099; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=4Tk/Aj+/GmJv8VYrhqdO/bkdjhVf01tbOreedTtB2z4=; b=UvBAX/6VBuBU7xVKoOzrUb4PKxkYVCzX14AAvXoYUYqDMj81s6+jFEpOfFzsoq+91LFk wOY/AfFxZQCrZC9pUkYf0pdrcMyI38wALJMmq/ohGOcjYcKTm/+Xpg8usU9Kd5fK0FLWc /2p7D6djTYXoNZGHI7+9yx7QVOS2l8b7T28+/V0pV3/WM2/wM3iYmZDOfq+KEK2493LHz QaxhjyRgQCknOQorI9fcOsG0pg905lkEZE3E6OyCk8hQivNPhxFF/s8J/F9Y39LPoNegS Tr38rVuneWlZlXJXjlZjUk7e8r4oPJe89VUgO8WuJzH0sVaPcLnXGHYGnyUR9ajXTAg== 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=cyognTs+; 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 E63FD606A31C for ; Tue, 10 Nov 2026 17:18:18 +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=cyognTs+ Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB6731F008A2; Tue, 10 Nov 2026 17:18:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794331098; bh=4Tk/Aj+/GmJv8VYrhqdO/bkdjhVf01tbOreedTtB2z4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cyognTs+a5rCH/5soKbfqIksBv0ILaq2k+F8PdTEkFd1BxU0yFYhLyWBfK19O+lyT zShUCym97+v7AMIJt5hFKEnmNxyMIQs2BPCdhfSvTlZfa3uGTq47rrKUGV+z2yik1w i3gLJcdw1RBJ3abjGKarYnbDXQfpbIsaiQG6O/HmFM0izTaVftriIGPUy3ED80UstM 9E6O0kRMLks0qJMRTJdFVMq/n7ygX+wbXlAwn636Jw2jJpfXNUwgJRarM8zvO1eHc2 KwdeXzRlP8JgKFVkrjP3Fq3dKVbQEHJGPkBoT0v5SGXTII9hyMlinMG5Bm5lnzVrYE Xhjhqjkmx3izw== From: Sasha Levin To: stable@vger.kernel.org Cc: Nanzhe Zhao , Chao Yu , Barry Song , Jaegeuk Kim , Sasha Levin Subject: [PATCH 6.6.y 3/3] f2fs: remove mappedtodisk flag usage in mmap write path Date: Tue, 10 Nov 2026 12:18:14 -0500 Message-ID: <20261110171210.2630515-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261110171210.2630515-1-sashal@kernel.org> References: <20261107053437-failed-6.6-b3c984358925@kernel.org> <20261110171210.2630515-1-sashal@kernel.org> 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-Transfer-Encoding: 8bit From: Nanzhe Zhao [ Upstream commit b3c9843589257631bac18f30655e82d88970688a ] PG_mappedtodisk was inherited from the nobh/buffer-head era. However, f2fs has no buffer heads and the flag is no longer meaningful. The only user of the flag is the "no holes" shortcut in f2fs_vm_page_mkwrite(), which makes mmap write faults skip marking the folio dirty. Moreover, it causes the following race condition with filesystem freezing: CPU0 (write fault) CPU1 (freeze_super) ---- ---- f2fs_vm_page_mkwrite() sb_start_pagefault() /* shortcut: no dirty */ sb_end_pagefault() sb_wait_write(SB_FREEZE_PAGEFAULT) /* no waiter, passes */ sync_filesystem() /* folio not dirty, skipped */ finish_fault() /* PTE writable */ fault_dirty_shared_page() folio_mark_dirty() /* dirty folio on a frozen fs */ It will also skip APP_MAPPED_IO iostat/REQ_TIME updates and post-EOF folio zeroing. Remove this shortcut in f2fs_vm_page_mkwrite() and stop setting it in f2fs_read_single_page(). Reported-by: Chao Yu Link: https://lore.kernel.org/linux-f2fs-devel/496b913c-eb81-4fa8-be72-c6a06a10aba2@kernel.org/ Reviewed-by: Chao Yu Reviewed-by: Barry Song Fixes: fbfa2cc58d53 ("f2fs: add file operations") Cc: stable@vger.kernel.org Signed-off-by: Nanzhe Zhao Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/data.c | 1 - fs/f2fs/file.c | 6 ------ 2 files changed, 7 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index e1c66f64aff38..288de302e83be 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2136,7 +2136,6 @@ static int f2fs_read_single_page(struct inode *inode, struct folio *folio, got_it: if ((map->m_flags & F2FS_MAP_MAPPED)) { block_nr = map->m_pblk + block_in_file - map->m_lblk; - folio_set_mappedtodisk(folio); if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode), block_nr, DATA_GENERIC_ENHANCE_READ)) { diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 7ec8d054bf1ee..f4863d7331802 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -215,12 +215,6 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) /* wait for GCed page writeback via META_MAPPING */ f2fs_wait_on_block_writeback(inode, dn.data_blkaddr); - /* - * check to see if the page is mapped already (no holes) - */ - if (folio_test_mappedtodisk(folio)) - goto out_sem; - /* page is wholly or partially inside EOF */ if (((loff_t)(folio->index + 1) << PAGE_SHIFT) > isize) { loff_t offset; -- 2.53.0