From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj2-f5.google.com (mail-pj2-f5.google.com [74.125.227.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 16F6B4EBADA for ; Tue, 13 Oct 2026 11:56:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791892602; cv=none; b=MAPg7KEHz4H6dzItMKkx0Bk5btSeeRs5QM7xtSDOUgadSd4XxHabI7QNLHe+nB5MJTd4PMykX13dbiNl9Psa9DCHZcXG8NEok0l+aHiHKLH0q9UYM11Sjgjni9iiaYnWmWEQZx8/5Znho1IHaykkVwXf4twku7qjc9AV/TD/PnE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791892602; c=relaxed/simple; bh=jta5wjdiHYkDEBCD2FaUvr4GTFcZOd1wWSt7UE0AljA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=q9K27s6oq17MfQaQ0UDDOvIk8dPmzes8HImADZq/WTzo0QlbEV13F8WzVFDlwxGpYoQUMCNp5qtYvMS/9nIgDjxUfnxsXS0vXpQxiCA3JmJMBv7c+R2k5hBKlTuWUwufHa0FDxiYWnO+ElSXLjDCnA0sBbvOOK/MbAlQ1tu8jEE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=qScQltUU; arc=none smtp.client-ip=74.125.227.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qScQltUU" Received: by mail-pj2-f5.google.com with SMTP id d9443c01a7336-2d6f230d1easo1824185ad.1 for ; Tue, 13 Oct 2026 04:56:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1791892600; x=1792497400; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=ggaf4ZWPiCf8BenJlAZtFehpccMR0Zs42ekbOs3yAZc=; b=qScQltUUkP9Q+z5kB8A7OofnHSzWQqrhr3a/VQ/zI5TwxMGaRqJU8/XFKWb9q41jDx vR5KXzMNlbB/IcXe/OwXN5q8ry4JMd8Ttn1Uvt++tTWzzp5ACDY7RZgaDPz/jExn8GjM HIWY3AKXqK/HhAvlnlW3184j9H0RsDqJDb4hlpa4HMMN6XHHYWGkd0Vd5iKmH/F1S0+R L8M8PBEEke8SHq1IN63vVIA0SG1mRPcsmP0+rKwalS9o1jPLNhPco/uY/6KspURLZdwz +aCvnIW8ZD1aNSOEzqRSLgVT+85jZ76KeRDvI5tiOnlZuwNqKDomC/3LQQiSL41KKc24 jBzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791892600; x=1792497400; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=ggaf4ZWPiCf8BenJlAZtFehpccMR0Zs42ekbOs3yAZc=; b=jYk/wd0OaQU1uZnUzU8LnrNCpAYGMrpVp+TVCnxleg+gZ0SCdK8fSskMazTJ+YFrjI emYZazE8M9M6L/0lYMBwqlfkwfi0HMn1PE97veKMdfiTCaaiVgwc7X39fol96oZ7XzAU vtYUT/Gk2PV58wkKaHSIEv3jhEFvjeMDe+44QwD/qg1WM95tvUbBn4Xba/o09rCg60ea HVCq/bboGLEVlbpwNmxVTupChpZQBht6B2pLj7+66aBoTmVcghCUi60/GzZE1vaLQjeP Inb9Wa1OjYEocUtwOtIrQ5xc0r8tmml5mwIQM9UGnhRYnLTycORV/mF6PVCvHk37E6Mn wwkA== X-Forwarded-Encrypted: i=1; AKwUvByc+/7A/UwD26KQvvP+GiWmsvol3QCUyhCE9nxY4LbhN6z1CLDLcefXC7vtNniCeiI8GfLQGRpjkrpYsL0=@vger.kernel.org X-Gm-Message-State: AFq9FYLGTuAhctLv4b9CJ8/8jgucXztJzNKFagHVaASYxv74kXnzQd56 j38Rz6MX24H1r09DkAaI3N1GCIsMGRfqBnxAzO2x0wcB4P3NUE6nd77I X-Gm-Gg: AYBFou06s0w6NH9fHxPbCr3PV2kwI+FaaasKSc1JHnPmAiMmjK+8DLSk2FqQ2waK+2d qp472itd/vAgdB1QJg4GBfmOTMNqG1XKyPsQubQE9M79Z/K+biy7c77L1iYQPXcp2I/u3zhcAf6 jJ2Sn5wsnAzD/I4fiqY2BLS7vht5tCDb8yvY/o+/Gm4tbcjloR4As+g0pE3VFsTpFp0n67vChNC swVtd5AHyqEYHEC8zxf9ZFu8sQqZvKAO2/zt020pbJ+mLXls/U3yPs7ogh9s88dOgju0lk6abw+ R+r5t2oHXzUbCPdDiVLj5CDZw6cmq7vvgvmPYsnLAa6X/B+V5WInK/qNFitzTlOD/RRNjytdHfn 18F7910zgKNKG4cTP9rVLyYWj2n/gRITERi7YRFrVMzrlQhai3+VbJw/sjReJjrG1SZURKCykeY V6//NhZSKcWzYWekkQux4BR4jBei8M7t9D2A5AUz6S0msFoxkTgpkkIQ/7FRQNVGXVe80l49EeN 5707ZQx//2e4XwmO4avnVY+ZsfAoRibR1Hk X-Received: by 2002:a17:90b:3a48:b0:3a8:337d:228a with SMTP id 98e67ed59e1d1-3ab3a367926mr6555917a91.6.1791892600332; Tue, 13 Oct 2026 04:56:40 -0700 (PDT) Received: from nzzhao-ThinkCentre-M760t.mioffice.cn ([43.224.245.179]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3ab37139b59sm21248516a91.13.2026.10.13.04.56.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Oct 2026 04:56:39 -0700 (PDT) From: Nanzhe Zhao To: linux-f2fs-devel@lists.sourceforge.net, Jaegeuk Kim , Chao Yu Cc: Barry Song , Nanzhe Zhao , Juan Yescas , Daeho Jeong , Dev Jain , David Hildenbrand , linux-kernel@vger.kernel.org, Bo Zhang , Kalesh Singh , Nanzhe Zhao , Pengfei Li , Ryan Roberts , stable@vger.kernel.org Subject: [PATCH v4 02/18] f2fs: remove mappedtodisk flag usage in mmap write path Date: Tue, 13 Oct 2026 19:56:05 +0800 Message-ID: <20261013115621.968742-3-nzzhao.sigma@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261013115621.968742-1-nzzhao.sigma@gmail.com> References: <20261013115621.968742-1-nzzhao.sigma@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Nanzhe Zhao 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 --- 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 29c4a81eb..f2d2f0106 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2481,7 +2481,6 @@ static int f2fs_read_single_page(struct inode *inode, struct fsverity_info *vi, 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 fc959cdb9..d680f6f8a 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -225,12 +225,6 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) /* wait for GCed page writeback via generic cache */ 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; -- 2.43.0