Re: [Ocfs2-devel] [PATCH v2 5/5] ocfs2: rewrite error handling of ocfs2_fill_super - Heming Zhao via Ocfs2-devel

From: Heming Zhao via Ocfs2-devel <ocfs2-devel@oss.oracle.com>
To: Joseph Qi <joseph.qi@linux.alibaba.com>, ocfs2-devel@oss.oracle.com
Subject: Re: [Ocfs2-devel] [PATCH v2 5/5] ocfs2: rewrite error handling of ocfs2_fill_super
Date: Wed, 13 Apr 2022 21:11:05 +0800	[thread overview]
Message-ID: <20220413131105.7k7xpmlzemwgw44x@c73> (raw)
In-Reply-To: <dcceb610-3c1b-d46c-493b-c836317e6d4b@linux.alibaba.com>

On Wed, Apr 13, 2022 at 07:37:59PM +0800, Joseph Qi wrote:
> It mostly looks good to me.
> Have you done error injection test after this patchset applied?
> I'm afraid ocfs2-test can't cover this as of now.
> 

I plan to write a debugfs api for error injection test.
The code only for these patches test

My idea:
echo N > /sys/kernel/debug/ocfs2/xxx/error
N: 1,2,3,4,...

"echo N" will make ocfs2 trigger Nth error point become true:

```
 	status = ocfs2_initialize_super(sb, bh, sector_size, &stats);
 	brelse(bh);
 	bh = NULL;
-	if (status < 0)
+	if (error_inject(n)) //eg. "echo 1 > xx" will trigger there "if()" becomes true.
 		goto out;
```

What's your opinion about my idea?
Or do you have other method to test?

- Heming

> Thanks,
> Joseph
> 
> On 4/13/22 4:29 PM, Heming Zhao wrote:
> > Current ocfs2_fill_super() uses one goto label "read_super_error" to
> > handle all error cases. And with previous serial patches, the error
> > handling should fork more branches to handle different error cases.
> > This patch rewrite the error handling of ocfs2_fill_super.
> > 
> > Signed-off-by: Heming Zhao <heming.zhao@suse.com>
> > ---
> >  fs/ocfs2/super.c | 67 +++++++++++++++++++++++-------------------------
> >  1 file changed, 32 insertions(+), 35 deletions(-)
> > 
> > diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
> > index 5e860d7162d7..72673d40d29c 100644
> > --- a/fs/ocfs2/super.c
> > +++ b/fs/ocfs2/super.c
> > @@ -989,28 +989,27 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  
> >  	if (!ocfs2_parse_options(sb, data, &parsed_options, 0)) {
> >  		status = -EINVAL;
> > -		goto read_super_error;
> > +		goto out;
> >  	}
> >  
> >  	/* probe for superblock */
> >  	status = ocfs2_sb_probe(sb, &bh, &sector_size, &stats);
> >  	if (status < 0) {
> >  		mlog(ML_ERROR, "superblock probe failed!\n");
> > -		goto read_super_error;
> > +		goto out;
> >  	}
> >  
> >  	status = ocfs2_initialize_super(sb, bh, sector_size, &stats);
> > -	osb = OCFS2_SB(sb);
> > -	if (status < 0) {
> > -		mlog_errno(status);
> > -		goto read_super_error;
> > -	}
> >  	brelse(bh);
> >  	bh = NULL;
> > +	if (status < 0)
> > +		goto out;
> > +
> > +	osb = OCFS2_SB(sb);
> >  
> >  	if (!ocfs2_check_set_options(sb, &parsed_options)) {
> >  		status = -EINVAL;
> > -		goto read_super_error;
> > +		goto out_super;
> >  	}
> >  	osb->s_mount_opt = parsed_options.mount_opt;
> >  	osb->s_atime_quantum = parsed_options.atime_quantum;
> > @@ -1027,7 +1026,7 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  
> >  	status = ocfs2_verify_userspace_stack(osb, &parsed_options);
> >  	if (status)
> > -		goto read_super_error;
> > +		goto out_super;
> >  
> >  	sb->s_magic = OCFS2_SUPER_MAGIC;
> >  
> > @@ -1041,7 +1040,7 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  			status = -EACCES;
> >  			mlog(ML_ERROR, "Readonly device detected but readonly "
> >  			     "mount was not specified.\n");
> > -			goto read_super_error;
> > +			goto out_super;
> >  		}
> >  
> >  		/* You should not be able to start a local heartbeat
> > @@ -1050,7 +1049,7 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  			status = -EROFS;
> >  			mlog(ML_ERROR, "Local heartbeat specified on readonly "
> >  			     "device.\n");
> > -			goto read_super_error;
> > +			goto out_super;
> >  		}
> >  
> >  		status = ocfs2_check_journals_nolocks(osb);
> > @@ -1059,9 +1058,7 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  				mlog(ML_ERROR, "Recovery required on readonly "
> >  				     "file system, but write access is "
> >  				     "unavailable.\n");
> > -			else
> > -				mlog_errno(status);
> > -			goto read_super_error;
> > +			goto out_super;
> >  		}
> >  
> >  		ocfs2_set_ro_flag(osb, 1);
> > @@ -1077,10 +1074,8 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  	}
> >  
> >  	status = ocfs2_verify_heartbeat(osb);
> > -	if (status < 0) {
> > -		mlog_errno(status);
> > -		goto read_super_error;
> > -	}
> > +	if (status < 0)
> > +		goto out_super;
> >  
> >  	osb->osb_debug_root = debugfs_create_dir(osb->uuid_str,
> >  						 ocfs2_debugfs_root);
> > @@ -1094,15 +1089,14 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  
> >  	status = ocfs2_mount_volume(sb);
> >  	if (status < 0)
> > -		goto read_super_error;
> > +		goto out_debugfs;
> >  
> >  	if (osb->root_inode)
> >  		inode = igrab(osb->root_inode);
> >  
> >  	if (!inode) {
> >  		status = -EIO;
> > -		mlog_errno(status);
> > -		goto read_super_error;
> > +		goto out_dismount;
> >  	}
> >  
> >  	osb->osb_dev_kset = kset_create_and_add(sb->s_id, NULL,
> > @@ -1110,7 +1104,7 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  	if (!osb->osb_dev_kset) {
> >  		status = -ENOMEM;
> >  		mlog(ML_ERROR, "Unable to create device kset %s.\n", sb->s_id);
> > -		goto read_super_error;
> > +		goto out_dismount;
> >  	}
> >  
> >  	/* Create filecheck sysfs related directories/files at
> > @@ -1119,14 +1113,13 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  		status = -ENOMEM;
> >  		mlog(ML_ERROR, "Unable to create filecheck sysfs directory at "
> >  			"/sys/fs/ocfs2/%s/filecheck.\n", sb->s_id);
> > -		goto read_super_error;
> > +		goto out_dismount;
> >  	}
> >  
> >  	root = d_make_root(inode);
> >  	if (!root) {
> >  		status = -ENOMEM;
> > -		mlog_errno(status);
> > -		goto read_super_error;
> > +		goto out_dismount;
> >  	}
> >  
> >  	sb->s_root = root;
> > @@ -1178,17 +1171,21 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
> >  
> >  	return status;
> >  
> > -read_super_error:
> > -	brelse(bh);
> > -
> > -	if (status)
> > -		mlog_errno(status);
> > +out_dismount:
> > +	atomic_set(&osb->vol_state, VOLUME_DISABLED);
> > +	wake_up(&osb->osb_mount_event);
> > +	ocfs2_dismount_volume(sb, 1);
> > +	goto out;
> >  
> > -	if (osb) {
> > -		atomic_set(&osb->vol_state, VOLUME_DISABLED);
> > -		wake_up(&osb->osb_mount_event);
> > -		ocfs2_dismount_volume(sb, 1);
> > -	}
> > +out_debugfs:
> > +	debugfs_remove_recursive(osb->osb_debug_root);
> > +out_super:
> > +	ocfs2_release_system_inodes(osb);
> > +	kfree(osb->recovery_map);
> > +	ocfs2_delete_osb(osb);
> > +	kfree(osb);
> > +out:
> > +	mlog_errno(status);
> >  
> >  	return status;
> >  }
> 

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