From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753167AbaINWOz (ORCPT ); Sun, 14 Sep 2014 18:14:55 -0400 Received: from mail.kernel.org ([198.145.19.201]:32918 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753108AbaINWOh (ORCPT ); Sun, 14 Sep 2014 18:14:37 -0400 From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: Jaegeuk Kim Subject: [PATCH 10/10] f2fs: fix double lock for inode page during roll-foward recovery Date: Sun, 14 Sep 2014 15:14:24 -0700 Message-Id: <1410732864-53069-10-git-send-email-jaegeuk@kernel.org> X-Mailer: git-send-email 1.8.5.2 (Apple Git-48) In-Reply-To: <1410732864-53069-1-git-send-email-jaegeuk@kernel.org> References: <1410732864-53069-1-git-send-email-jaegeuk@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If the inode is same and its data index are needed to truncate, we can fall into double lock for its inode page via get_dnode_of_data. Error case is like this. 1. write data 1, 2, 3, 4, 5 in inode #4. 2. write data 100, 102, 103, 104, 105 in dnode #6 of inode #4. 3. sync 4. update data 100->106 in dnode #6. 5. fsync inode #4. 6. power-cut -> Then, 1. go back to #3's checkpoint 2. in do_recover_data, get_dnode_of_data() gets inode #4. 3. detect 100->106 in dnode #6. 4. check_index_in_prev_nodes tries to truncate 100 in dnode #6. 5. to trigger truncate_hole, get_dnode_of_data should grab inode #4. 6. detect *kernel hang* This patch should resolve that bug. Signed-off-by: Jaegeuk Kim --- fs/f2fs/recovery.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c index dbeb32d..5638c05 100644 --- a/fs/f2fs/recovery.c +++ b/fs/f2fs/recovery.c @@ -306,16 +306,30 @@ got_it: ino = ino_of_node(node_page); f2fs_put_page(node_page, 1); - /* Deallocate previous index in the node page */ - inode = f2fs_iget(sbi->sb, ino); - if (IS_ERR(inode)) - return PTR_ERR(inode); + if (ino != dn->inode->i_ino) { + /* Deallocate previous index in the node page */ + inode = f2fs_iget(sbi->sb, ino); + if (IS_ERR(inode)) + return PTR_ERR(inode); + } else { + inode = dn->inode; + } bidx = start_bidx_of_node(offset, F2FS_I(inode)) + - le16_to_cpu(sum.ofs_in_node); + le16_to_cpu(sum.ofs_in_node); - truncate_hole(inode, bidx, bidx + 1); - iput(inode); + if (ino != dn->inode->i_ino) { + truncate_hole(inode, bidx, bidx + 1); + iput(inode); + } else { + struct dnode_of_data tdn; + set_new_dnode(&tdn, inode, dn->inode_page, NULL, 0); + if (get_dnode_of_data(&tdn, bidx, LOOKUP_NODE)) + return 0; + if (tdn.data_blkaddr != NULL_ADDR) + truncate_data_blocks_range(&tdn, 1); + f2fs_put_page(tdn.node_page, 1); + } return 0; } -- 1.8.5.2 (Apple Git-48)