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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16A4CC4363A for ; Fri, 30 Oct 2020 11:47:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92B052076E for ; Fri, 30 Oct 2020 11:47:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="dXqD0cl7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726083AbgJ3Lrs (ORCPT ); Fri, 30 Oct 2020 07:47:48 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:58830 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725993AbgJ3Lrs (ORCPT ); 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Fri, 30 Oct 2020 11:47:44 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 34cwuqvsmn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 Oct 2020 11:47:44 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 09UBlh0D022927; Fri, 30 Oct 2020 11:47:43 GMT Received: from mwanda (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 30 Oct 2020 04:47:42 -0700 Date: Fri, 30 Oct 2020 14:47:37 +0300 From: Dan Carpenter To: mfo@canonical.com Cc: linux-ext4@vger.kernel.org Subject: [bug report] ext4: data=journal: fixes for ext4_page_mkwrite() Message-ID: <20201030114737.GC3251003@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9789 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxscore=0 bulkscore=0 spamscore=0 adultscore=0 malwarescore=0 mlxlogscore=999 suspectscore=3 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010300091 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9789 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 adultscore=0 malwarescore=0 spamscore=0 clxscore=1011 mlxscore=0 suspectscore=3 priorityscore=1501 impostorscore=0 bulkscore=0 phishscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010300091 Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Hello Mauricio Faria de Oliveira, The patch 64a9f1449950: "ext4: data=journal: fixes for ext4_page_mkwrite()" from Oct 5, 2020, leads to the following static checker warning: fs/ext4/inode.c:6136 ext4_page_mkwrite() error: uninitialized symbol 'get_block'. fs/ext4/inode.c 6040 vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf) 6041 { 6042 struct vm_area_struct *vma = vmf->vma; 6043 struct page *page = vmf->page; 6044 loff_t size; 6045 unsigned long len; 6046 int err; 6047 vm_fault_t ret; 6048 struct file *file = vma->vm_file; 6049 struct inode *inode = file_inode(file); 6050 struct address_space *mapping = inode->i_mapping; 6051 handle_t *handle; 6052 get_block_t *get_block; ^^^^^^^^^^^^^^^^^^^^^^ 6053 int retries = 0; 6054 6055 if (unlikely(IS_IMMUTABLE(inode))) 6056 return VM_FAULT_SIGBUS; 6057 6058 sb_start_pagefault(inode->i_sb); 6059 file_update_time(vma->vm_file); 6060 6061 down_read(&EXT4_I(inode)->i_mmap_sem); 6062 6063 err = ext4_convert_inline_data(inode); 6064 if (err) 6065 goto out_ret; 6066 6067 /* 6068 * On data journalling we skip straight to the transaction handle: 6069 * there's no delalloc; page truncated will be checked later; the 6070 * early return w/ all buffers mapped (calculates size/len) can't 6071 * be used; and there's no dioread_nolock, so only ext4_get_block. 6072 */ 6073 if (ext4_should_journal_data(inode)) 6074 goto retry_alloc; ^^^^^^^^^^^^^^^^ This goto is new. 6075 6076 /* Delalloc case is easy... */ 6077 if (test_opt(inode->i_sb, DELALLOC) && 6078 !ext4_nonda_switch(inode->i_sb)) { 6079 do { 6080 err = block_page_mkwrite(vma, vmf, 6081 ext4_da_get_block_prep); 6082 } while (err == -ENOSPC && 6083 ext4_should_retry_alloc(inode->i_sb, &retries)); 6084 goto out_ret; 6085 } 6086 6087 lock_page(page); 6088 size = i_size_read(inode); 6089 /* Page got truncated from under us? */ 6090 if (page->mapping != mapping || page_offset(page) > size) { 6091 unlock_page(page); 6092 ret = VM_FAULT_NOPAGE; 6093 goto out; 6094 } 6095 6096 if (page->index == size >> PAGE_SHIFT) 6097 len = size & ~PAGE_MASK; 6098 else 6099 len = PAGE_SIZE; 6100 /* 6101 * Return if we have all the buffers mapped. This avoids the need to do 6102 * journal_start/journal_stop which can block and take a long time 6103 * 6104 * This cannot be done for data journalling, as we have to add the 6105 * inode to the transaction's list to writeprotect pages on commit. 6106 */ 6107 if (page_has_buffers(page)) { 6108 if (!ext4_walk_page_buffers(NULL, page_buffers(page), 6109 0, len, NULL, 6110 ext4_bh_unmapped)) { 6111 /* Wait so that we don't change page under IO */ 6112 wait_for_stable_page(page); 6113 ret = VM_FAULT_LOCKED; 6114 goto out; 6115 } 6116 } 6117 unlock_page(page); 6118 /* OK, we need to fill the hole... */ 6119 if (ext4_should_dioread_nolock(inode)) 6120 get_block = ext4_get_block_unwritten; 6121 else 6122 get_block = ext4_get_block; ^^^^^^^^^^^^^^^^^^^^^^^^^^ Initialized here. 6123 retry_alloc: 6124 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, 6125 ext4_writepage_trans_blocks(inode)); 6126 if (IS_ERR(handle)) { 6127 ret = VM_FAULT_SIGBUS; 6128 goto out; 6129 } 6130 /* 6131 * Data journalling can't use block_page_mkwrite() because it 6132 * will set_buffer_dirty() before do_journal_get_write_access() 6133 * thus might hit warning messages for dirty metadata buffers. 6134 */ 6135 if (!ext4_should_journal_data(inode)) { 6136 err = block_page_mkwrite(vma, vmf, get_block); ^^^^^^^^^ Smatch warning here. 6137 } else { 6138 lock_page(page); 6139 size = i_size_read(inode); 6140 /* Page got truncated from under us? */ 6141 if (page->mapping != mapping || page_offset(page) > size) { 6142 ret = VM_FAULT_NOPAGE; 6143 goto out_error; regards, dan carpenter