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=1794063345; b=tvFLQFVa+68T+cT+LFO45fTbF6TMeJYxIJxxfB2j4YKtSND1Xlt9RZ34uoq2XOYwNBWC Mvt/c3AHahHnkNpNWU5UqbFYEB50ayWpl1BHi2qNJJ0WSLVOEVE5TYM9YKHFcqqUS+gEZ Aw+BlnazHy9cN2fs8cU4Blzh4Qxf9wRq6Qkg7Gh0WVL3YcCjJEBBYaVLFnGtNYuPtWXjZ f5bb4+RmSzR862+delIw1x5f0pi1CKQNTcZSi12BBEMI94qmu0lfLxddOMIU9VtdEcNel 2qkKKjkDlHWN0+vv1SXoirp6Zc81WsTjHkpWZqTlRfs4IRkKuXhvuXaCEYxRCPIZ3Yw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063345; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=Ct3nn3H9TvxgHsWKJcYD2reM/kfcsXmbkjEB0+cxErw=; b=HVuvsMDf+3JrPxrv87FNxjCsfB2X7WkUn568RtAQ5upJ+p0hGDUr8aqM84bPpAemH3+N LVfZb6HRSrIkQenRRY08tzLuivkcOLhCHEjp2Z5jF6SwUjhNiOMYmFxLoq7Ha0KLCSz7B A1HauuDZNPBuaByKnLTHVG48lLt5aY++/8eTvNKPqICbzJKqU2XHzP/cX/qt7OI1p88PF bagLzINHwF891g3Wmv0gp0T7HxLzh0SdiTXdjE+0D7FFLNAfU4OkxsP+OZSKEcq+/cXJY j/PoFsQcQUidpIsyYgIghWgb0HbyBCjHbJ66vOeRammPTAlb+A+/7rzp7+gIAX6eZWA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=1C04CkQI; 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 14099606A32C; Sat, 7 Nov 2026 14:55:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=1C04CkQI Received: by smtp.kernel.org (Postfix) with ESMTPSA id B542C1F0089F; Sat, 7 Nov 2026 14:55:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063344; bh=Ct3nn3H9TvxgHsWKJcYD2reM/kfcsXmbkjEB0+cxErw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1C04CkQI20QNE0bbW/4RWb7kDJPR1tOxC+TGoWENe1SI0V+AcSvn3/r4DEoP4QF/Y dzpwRFXXZKq4qPM6yHMCYbbNs5M4591SCr/xTfkAielMzD4pMbAunKumW4A255XDoi 3Ow+K6ExZf/7HMH+qZFL8okbG05JtmP+CbVZcKtc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chao Yu , Barry Song , Nanzhe Zhao , Jaegeuk Kim , Sasha Levin Subject: [PATCH 6.18 527/869] f2fs: remove mappedtodisk flag usage in mmap write path Date: Sat, 7 Nov 2026 08:53:29 -0500 Message-ID: <20261107134911.357353115@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ 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 aa6a844ed34dd..52bdfb2785f06 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2186,7 +2186,6 @@ 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 49febaa660815..e5de7c3557260 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -207,12 +207,6 @@ 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) > i_size_read(inode)) { -- 2.53.0