[Ocfs2-devel] [PATCH 4/4] ocfs2: Fix a deadlock issue in ocfs2_dio_end_io_write()

[Junxiao Bi]

On 11/20/2015 04:23 PM, Ryan Ding wrote:
> Should call ocfs2_free_alloc_context() to free meta_ac & data_ac before calling
> ocfs2_run_deallocs(). Because ocfs2_run_deallocs() will acquire the system
> inode's i_mutex hold by meta_ac. So try to release the lock before
> ocfs2_run_deallocs().
> 
> Fixes: af1310367f41 ("ocfs2: fix sparse file & data ordering issue in direct io.")
Patch looks good. Also we can fold this patch into above commit.

Thanks,
Junxiao.
> Signed-off-by: Ryan Ding <ryan.ding at oracle.com>
> ---
>  fs/ocfs2/aops.c |   12 ++++++++----
>  1 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
> index f33cfe4..182f754 100644
> --- a/fs/ocfs2/aops.c
> +++ b/fs/ocfs2/aops.c
> @@ -2341,6 +2341,10 @@ static void ocfs2_dio_end_io_write(struct inode *inode,
>  
>  	ret = ocfs2_lock_allocators(inode, &et, 0, dwc->dw_zero_count*2,
>  				    &data_ac, &meta_ac);
> +	if (ret) {
> +		mlog_errno(ret);
> +		goto unlock;
> +	}
>  
>  	credits = ocfs2_calc_extend_credits(inode->i_sb, &di->id2.i_list);
>  
> @@ -2380,14 +2384,14 @@ unlock:
>  	ocfs2_inode_unlock(inode, 1);
>  	brelse(di_bh);
>  out:
> -	ocfs2_run_deallocs(osb, &dealloc);
> -	if (locked)
> -		mutex_unlock(&inode->i_mutex);
> -	ocfs2_dio_free_write_ctx(inode, dwc);
>  	if (data_ac)
>  		ocfs2_free_alloc_context(data_ac);
>  	if (meta_ac)
>  		ocfs2_free_alloc_context(meta_ac);
> +	ocfs2_run_deallocs(osb, &dealloc);
> +	if (locked)
> +		mutex_unlock(&inode->i_mutex);
> +	ocfs2_dio_free_write_ctx(inode, dwc);
>  }
>  
>  /*
>