From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756355AbaEDQ0J (ORCPT ); Sun, 4 May 2014 12:26:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36337 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754388AbaEDPmG (ORCPT ); Sun, 4 May 2014 11:42:06 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Theodore Tso" , Jan Kara Subject: [PATCH 3.14 151/158] ext4: move ext4_update_i_disksize() into mpage_map_and_submit_extent() Date: Sun, 4 May 2014 11:41:00 -0400 Message-Id: <20140504154050.535983501@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140504154029.975081050@linuxfoundation.org> References: <20140504154029.975081050@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Theodore Ts'o commit 622cad1325e404598fe3b148c3fa640dbaabc235 upstream. The function ext4_update_i_disksize() is used in only one place, in the function mpage_map_and_submit_extent(). Move its code to simplify the code paths, and also move the call to ext4_mark_inode_dirty() into the i_data_sem's critical region, to be consistent with all of the other places where we update i_disksize. That way, we also keep the raw_inode's i_disksize protected, to avoid the following race: CPU #1 CPU #2 down_write(&i_data_sem) Modify i_disk_size up_write(&i_data_sem) down_write(&i_data_sem) Modify i_disk_size Copy i_disk_size to on-disk inode up_write(&i_data_sem) Copy i_disk_size to on-disk inode Signed-off-by: "Theodore Ts'o" Reviewed-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/ext4/ext4.h | 17 ----------------- fs/ext4/inode.c | 14 ++++++++++++-- 2 files changed, 12 insertions(+), 19 deletions(-) --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2462,23 +2462,6 @@ static inline void ext4_update_i_disksiz up_write(&EXT4_I(inode)->i_data_sem); } -/* - * Update i_disksize after writeback has been started. Races with truncate - * are avoided by checking i_size under i_data_sem. - */ -static inline void ext4_wb_update_i_disksize(struct inode *inode, loff_t newsize) -{ - loff_t i_size; - - down_write(&EXT4_I(inode)->i_data_sem); - i_size = i_size_read(inode); - if (newsize > i_size) - newsize = i_size; - if (newsize > EXT4_I(inode)->i_disksize) - EXT4_I(inode)->i_disksize = newsize; - up_write(&EXT4_I(inode)->i_data_sem); -} - struct ext4_group_info { unsigned long bb_state; struct rb_root bb_free_root; --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2236,13 +2236,23 @@ static int mpage_map_and_submit_extent(h return err; } while (map->m_len); - /* Update on-disk size after IO is submitted */ + /* + * Update on-disk size after IO is submitted. Races with + * truncate are avoided by checking i_size under i_data_sem. + */ disksize = ((loff_t)mpd->first_page) << PAGE_CACHE_SHIFT; if (disksize > EXT4_I(inode)->i_disksize) { int err2; + loff_t i_size; - ext4_wb_update_i_disksize(inode, disksize); + down_write(&EXT4_I(inode)->i_data_sem); + i_size = i_size_read(inode); + if (disksize > i_size) + disksize = i_size; + if (disksize > EXT4_I(inode)->i_disksize) + EXT4_I(inode)->i_disksize = disksize; err2 = ext4_mark_inode_dirty(handle, inode); + up_write(&EXT4_I(inode)->i_data_sem); if (err2) ext4_error(inode->i_sb, "Failed to mark inode %lu dirty",