Re: [PATCH] ocfs2: use retval instead of status for checking error

[Joseph Qi <joseph.qi@huawei.com>]

On 2015/4/19 13:43, Daeseok Youn wrote:
> The use of 'status' in __ocfs2_add_entry() can return wrong
> value. Some functions' return value in __ocfs2_add_entry(),
> i.e ocfs2_journal_access_di() is saved to 'status'.
> But 'status' is not used in 'bail' label for returning result
> of __ocfs2_add_entry().
> 
> So use retval instead of status.
> 
> Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>

Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
> ---
> This patch was came from 'https://lkml.org/lkml/2015/2/27/655'
> This patch was needed to test but I didn't have any environment
> for testing ocfs2 filesystem. But I have one, now.
> (I'm too busy to make this enviroment. And qemu for this fs is difficult
>  for me. :-(, sorry for that)
> 
> Briefly how to set my environment for testing this fs with qemu.
> 1. Getting and building linux kernel with linux-next branch for x86_64 qemu.
>    And also options of ocfs2 related are enabled(built-in)
> 2. Makes own root file system with 'buildroot' project.
> 3. Getting and building ocfs2-tools.
>   Then binaries after building this tool are moved my rootfs.
> 4. Makes dummy disk image(5G) which will be formatted in qemu.
> 5. Booting qemu with rootfs image and dummy disk image.
> 6. mkfs.ocfs2 --fs-feature=local <device>
>   this maybe possilbe to mount standalone mode.
> 7. tunefs.ocfs2  --fs-features=indexed-dirs,noinline-data <device>
> 8. make a cluster and one node
>   use o2cb_ctl tool.
> 9. o2cb service load and initialize
>   # /etc/init.d/o2cb load && /etc/init.d/o2cb configure
>   # /etc/init.d/o2cb online
> 10. mount ocfs2
>   # mount.ocfs2 <device> <some directory>
> 
> And use GDB for debugging my patch path.
> Connect gdb with qemu and add breakpoint in __ocfs2_add_entry() of fs/ocfs2/dir.c
> 
> And test my patch.
> # cd <some directory mounted with ocfs2>
> # mkdir <specific directory>
> 
> This how-to is not written all my work, just briefly I said.
> 
>  fs/ocfs2/dir.c |   20 ++++++++++----------
>  1 files changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
> index 990e8f7..a9513ff 100644
> --- a/fs/ocfs2/dir.c
> +++ b/fs/ocfs2/dir.c
> @@ -1607,7 +1607,7 @@ int __ocfs2_add_entry(handle_t *handle,
>  	struct ocfs2_dir_entry *de, *de1;
>  	struct ocfs2_dinode *di = (struct ocfs2_dinode *)parent_fe_bh->b_data;
>  	struct super_block *sb = dir->i_sb;
> -	int retval, status;
> +	int retval;
>  	unsigned int size = sb->s_blocksize;
>  	struct buffer_head *insert_bh = lookup->dl_leaf_bh;
>  	char *data_start = insert_bh->b_data;
> @@ -1685,25 +1685,25 @@ int __ocfs2_add_entry(handle_t *handle,
>  			}
>  
>  			if (insert_bh == parent_fe_bh)
> -				status = ocfs2_journal_access_di(handle,
> +				retval = ocfs2_journal_access_di(handle,
>  								 INODE_CACHE(dir),
>  								 insert_bh,
>  								 OCFS2_JOURNAL_ACCESS_WRITE);
>  			else {
> -				status = ocfs2_journal_access_db(handle,
> +				retval = ocfs2_journal_access_db(handle,
>  								 INODE_CACHE(dir),
>  								 insert_bh,
>  					      OCFS2_JOURNAL_ACCESS_WRITE);
>  
> -				if (ocfs2_dir_indexed(dir)) {
> -					status = ocfs2_dx_dir_insert(dir,
> +				if (!retval && ocfs2_dir_indexed(dir))
> +					retval = ocfs2_dx_dir_insert(dir,
>  								handle,
>  								lookup);
> -					if (status) {
> -						mlog_errno(status);
> -						goto bail;
> -					}
> -				}
> +			}
> +
> +			if (retval) {
> +				mlog_errno(retval);
> +				goto bail;
>  			}
>  
>  			/* By now the buffer is marked for journaling */
>