Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932133Ab1C3LRW (ORCPT ); Wed, 30 Mar 2011 07:17:22 -0400 Received: from mx2.fusionio.com ([64.244.102.31]:35187 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754193Ab1C3LRV (ORCPT ); Wed, 30 Mar 2011 07:17:21 -0400 X-ASG-Debug-ID: 1301483840-01de284cf8daf00001-xx1T2L X-Barracuda-Envelope-From: JAxboe@fusionio.com Message-ID: <4D93113E.2070805@fusionio.com> Date: Wed, 30 Mar 2011 13:17:18 +0200 From: Jens Axboe MIME-Version: 1.0 To: Ryusuke Konishi CC: linux-nilfs , linux-kernel Subject: Re: [PATCH] nilfs2: fix oops due to a bad aops initialization References: <20110330.132555.158630340.ryusuke@osrg.net> <4D930F02.4070409@fusionio.com> X-ASG-Orig-Subj: Re: [PATCH] nilfs2: fix oops due to a bad aops initialization In-Reply-To: <4D930F02.4070409@fusionio.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Barracuda-Connect: mail1.int.fusionio.com[10.101.1.21] X-Barracuda-Start-Time: 1301483840 X-Barracuda-URL: http://10.101.1.181:8000/cgi-mod/mark.cgi X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using global scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=9.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.59400 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3504 Lines: 109 On 2011-03-30 13:07, Jens Axboe wrote: > On 2011-03-30 06:25, Ryusuke Konishi wrote: >> diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c >> index 4d2a1ee..9d2dc6b 100644 >> --- a/fs/nilfs2/page.c >> +++ b/fs/nilfs2/page.c >> @@ -495,12 +495,14 @@ unsigned nilfs_page_count_clean_buffers(struct page *page, >> void nilfs_mapping_init(struct address_space *mapping, >> struct backing_dev_info *bdi) >> { >> + static const struct address_space_operations empty_aops; >> + >> mapping->host = NULL; >> mapping->flags = 0; >> mapping_set_gfp_mask(mapping, GFP_NOFS); >> mapping->assoc_mapping = NULL; >> mapping->backing_dev_info = bdi; >> - mapping->a_ops = NULL; >> + mapping->a_ops = &empty_aops; >> } > > Hmm wait, inode init should set the mapping aops to an empty type > already. Does the OOPS go away if you just remove the mapping->a_ops = > NULL assignment? In any case, I think this is a better fix. diff --git a/fs/inode.c b/fs/inode.c index 5f4e11a..b818730 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -125,6 +125,13 @@ __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_wb_list_lock); static DECLARE_RWSEM(iprune_sem); /* + * Empty aops. Can be used for the cases where the user does not + * define any of the address_space operations. + */ +const struct address_space_operations empty_aops = { +}; + +/* * Statistics gathering.. */ struct inodes_stat_t inodes_stat; @@ -176,7 +183,6 @@ int proc_nr_inodes(ctl_table *table, int write, */ int inode_init_always(struct super_block *sb, struct inode *inode) { - static const struct address_space_operations empty_aops; static const struct inode_operations empty_iops; static const struct file_operations empty_fops; struct address_space *const mapping = &inode->i_data; diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index 4d2a1ee..1168059 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -500,7 +500,7 @@ void nilfs_mapping_init(struct address_space *mapping, mapping_set_gfp_mask(mapping, GFP_NOFS); mapping->assoc_mapping = NULL; mapping->backing_dev_info = bdi; - mapping->a_ops = NULL; + mapping->a_ops = &empty_aops; } /* diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c index c74400f..403c192 100644 --- a/fs/ubifs/xattr.c +++ b/fs/ubifs/xattr.c @@ -80,7 +80,6 @@ enum { }; static const struct inode_operations none_inode_operations; -static const struct address_space_operations none_address_operations; static const struct file_operations none_file_operations; /** @@ -130,7 +129,7 @@ static int create_xattr(struct ubifs_info *c, struct inode *host, } /* Re-define all operations to be "nothing" */ - inode->i_mapping->a_ops = &none_address_operations; + inode->i_mapping->a_ops = &empty_aops; inode->i_op = &none_inode_operations; inode->i_fop = &none_file_operations; diff --git a/include/linux/fs.h b/include/linux/fs.h index 52f283c..1b95af3 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -613,6 +613,8 @@ struct address_space_operations { int (*error_remove_page)(struct address_space *, struct page *); }; +extern const struct address_space_operations empty_aops; + /* * pagecache_write_begin/pagecache_write_end must be used by general code * to write into the pagecache. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/