Re: [f2fs-dev] [PATCH] f2fs: use inode mutex to keep atomicity of f2fs_falloc

[Jaegeuk Kim <jaegeuk.kim@samsung.com>]

Hi,

2014-01-28 (화), 10:29 +0800, Chao Yu:
> Previously without protection of inode mutex, f2fs_falloc and other data
> correlated operations will interfere with each other.

Could you explain a little bit more what kind of scenarios wrt this?


> So let's use inode mutex to keep atomicity of f2fs_falloc.
> 
> Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> ---
>  fs/f2fs/file.c |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 85e91ca..ece380f 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -559,6 +559,8 @@ static long f2fs_fallocate(struct file *file, int mode,
>  	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
>  		return -EOPNOTSUPP;
>  
> +	mutex_lock(&inode->i_mutex);
> +
>  	if (mode & FALLOC_FL_PUNCH_HOLE)
>  		ret = punch_hole(inode, offset, len);
>  	else
> @@ -568,6 +570,9 @@ static long f2fs_fallocate(struct file *file, int mode,
>  		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
>  		mark_inode_dirty(inode);
>  	}
> +
> +	mutex_unlock(&inode->i_mutex);
> +
>  	trace_f2fs_fallocate(inode, mode, offset, len, ret);
>  	return ret;
>  }

-- 
Jaegeuk Kim
Samsung