From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BB604C4332F for ; Tue, 18 Oct 2022 00:08:42 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1oka9w-00052M-86; Tue, 18 Oct 2022 00:08:40 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1oka9v-00052F-1J for linux-f2fs-devel@lists.sourceforge.net; Tue, 18 Oct 2022 00:08:39 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=KGwFVz4uJ2Qv4bP2XutM8wd6S5bI5s3HX8mAEAf4XYI=; b=QV9vCOcJjeBHgPrrMj+67flEa+ F5uc+0vnNjZKT7RpwsfOr6YndEcq+KvG83TNzPv6gzaOE7BEqvIrop+pSSE7ePWtsfkXosrjAIUPI 7wuyIq01ezcq619bV1MCszO3TbRMsDWJRhyZ5u5Y+DiRac7UbVoOpyakc+KwXS8I6sBo=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=KGwFVz4uJ2Qv4bP2XutM8wd6S5bI5s3HX8mAEAf4XYI=; b=GguyuVKkTTaKUFVovLqvzIcvO9 bUeZe6uPmGM96DzYACFyIXbwaGf8yu6kVNlTmdFqfYSoa2l1U7jJOrv80hAg40FIzJ3NyBXOuf+zn nzdSPRVoSDQtTUupzWJj2V9j3HcCQKxOCfGycg/gdyIPTITYMX8/1h2XyZR7tUKBudDc=; Received: from dfw.source.kernel.org ([139.178.84.217]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1oka9u-007do4-8F for linux-f2fs-devel@lists.sourceforge.net; Tue, 18 Oct 2022 00:08:38 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0E81A612F2; Tue, 18 Oct 2022 00:08:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14F26C433C1; Tue, 18 Oct 2022 00:08:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666051705; bh=DwBh3k3a85YmFQnlqH+Y/yXLx9Oae3VQOD+4zL6+TCg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pj74Ivc9o7L81cPy2aWCS4qNOilh9RYjFuRQ7g5x30Ttb6Hw7XU2Hzda9cr9W3qEn XUXnuU+Bx0R5XxkNdLqpkcDb9KgFeUv6o6ialcsZcQPXvCCUKebwKZe1/+fSMqtVJP FlKOV8+Z0u8vUWoKRi5QbUtqB3ZkiEpWdxG3RCuHZDRZJ1Wtgz67Yx61Lr0mHE2M7f 8uQh6h+7VXRIULrMArdIBCYhCslNwEhzfFzAzEqAt6Ds5fbHVQ7V5akDJRLvlJRwtB 2baZarZyiu9ZWNTmetPmN8DzBcvtGLaoM/mSoaLo3If2G8nfRnhb1oCqzNohfVT8Pu UTUD8iNZwap+A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Date: Mon, 17 Oct 2022 20:07:21 -0400 Message-Id: <20221018000729.2730519-24-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221018000729.2730519-1-sashal@kernel.org> References: <20221018000729.2730519-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-Headers-End: 1oka9u-007do4-8F Subject: [f2fs-dev] [PATCH AUTOSEL 6.0 24/32] f2fs: fix wrong dirty page count when race between mmap and fallocate. X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , Jaegeuk Kim , linux-f2fs-devel@lists.sourceforge.net, Shuqi Zhang Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net From: Shuqi Zhang [ Upstream commit 9b7eadd9bd3a0cc24533a23d83c46430a0ea60ff ] This is a BUG_ON issue as follows when running xfstest-generic-503: WARNING: CPU: 21 PID: 1385 at fs/f2fs/inode.c:762 f2fs_evict_inode+0x847/0xaa0 Modules linked in: CPU: 21 PID: 1385 Comm: umount Not tainted 5.19.0-rc5+ #73 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014 Call Trace: evict+0x129/0x2d0 dispose_list+0x4f/0xb0 evict_inodes+0x204/0x230 generic_shutdown_super+0x5b/0x1e0 kill_block_super+0x29/0x80 kill_f2fs_super+0xe6/0x140 deactivate_locked_super+0x44/0xc0 deactivate_super+0x79/0x90 cleanup_mnt+0x114/0x1a0 __cleanup_mnt+0x16/0x20 task_work_run+0x98/0x100 exit_to_user_mode_prepare+0x3d0/0x3e0 syscall_exit_to_user_mode+0x12/0x30 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Function flow analysis when BUG occurs: f2fs_fallocate mmap do_page_fault pte_spinlock // ---lock_pte do_wp_page wp_page_shared pte_unmap_unlock // unlock_pte do_page_mkwrite f2fs_vm_page_mkwrite down_read(invalidate_lock) lock_page if (PageMappedToDisk(page)) goto out; // set_page_dirty --NOT RUN out: up_read(invalidate_lock); finish_mkwrite_fault // unlock_pte f2fs_collapse_range down_write(i_mmap_sem) truncate_pagecache unmap_mapping_pages i_mmap_lock_write // down_write(i_mmap_rwsem) ...... zap_pte_range pte_offset_map_lock // ---lock_pte set_page_dirty f2fs_dirty_data_folio if (!folio_test_dirty(folio)) { fault_dirty_shared_page set_page_dirty f2fs_dirty_data_folio if (!folio_test_dirty(folio)) { filemap_dirty_folio f2fs_update_dirty_folio // ++ } unlock_page filemap_dirty_folio f2fs_update_dirty_folio // page count++ } pte_unmap_unlock // --unlock_pte i_mmap_unlock_write // up_write(i_mmap_rwsem) truncate_inode_pages up_write(i_mmap_sem) When race happens between mmap-do_page_fault-wp_page_shared and fallocate-truncate_pagecache-zap_pte_range, the zap_pte_range calls function set_page_dirty without page lock. Besides, though truncate_pagecache has immap and pte lock, wp_page_shared calls fault_dirty_shared_page without any. In this case, two threads race in f2fs_dirty_data_folio function. Page is set to dirty only ONCE, but the count is added TWICE by calling filemap_dirty_folio. Thus the count of dirty page cannot accord with the real dirty pages. Following is the solution to in case of race happens without any lock. Since folio_test_set_dirty in filemap_dirty_folio is atomic, judge return value will not be at risk of race. Signed-off-by: Shuqi Zhang Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/checkpoint.c | 3 +-- fs/f2fs/data.c | 3 +-- fs/f2fs/node.c | 3 +-- 3 files changed, 3 insertions(+), 6 deletions(-) diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index 8259e0fa97e1..3a3329bf1033 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -448,8 +448,7 @@ static bool f2fs_dirty_meta_folio(struct address_space *mapping, if (!folio_test_uptodate(folio)) folio_mark_uptodate(folio); - if (!folio_test_dirty(folio)) { - filemap_dirty_folio(mapping, folio); + if (filemap_dirty_folio(mapping, folio)) { inc_page_count(F2FS_M_SB(mapping), F2FS_DIRTY_META); set_page_private_reference(&folio->page); return true; diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index aa3ccddfa037..16c39bd948a0 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -3697,8 +3697,7 @@ static bool f2fs_dirty_data_folio(struct address_space *mapping, folio_mark_uptodate(folio); BUG_ON(folio_test_swapcache(folio)); - if (!folio_test_dirty(folio)) { - filemap_dirty_folio(mapping, folio); + if (filemap_dirty_folio(mapping, folio)) { f2fs_update_dirty_folio(inode, folio); return true; } diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index e06a0c478b39..3506ffcb31f8 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -2147,8 +2147,7 @@ static bool f2fs_dirty_node_folio(struct address_space *mapping, if (IS_INODE(&folio->page)) f2fs_inode_chksum_set(F2FS_M_SB(mapping), &folio->page); #endif - if (!folio_test_dirty(folio)) { - filemap_dirty_folio(mapping, folio); + if (filemap_dirty_folio(mapping, folio)) { inc_page_count(F2FS_M_SB(mapping), F2FS_DIRTY_NODES); set_page_private_reference(&folio->page); return true; -- 2.35.1 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel