Re: [PATCH v2] f2fs: remain written times to update inode during fsync

[Chao Yu <yuchao0@huawei.com>]

On 2018/3/31 0:30, Jaegeuk Kim wrote:
> Change log from v1:
>  - add more description
> 
> This fixes xfstests/generic/392.
> 
> The failure was caused by different times between 1) one marked in the last
> fsync(2) call and 2) the other given by roll-forward recovery after power-cut.
> The reason was that we skipped updating inode block at 1), since its i_size
> was recoverable along with 4KB-aligned data writes, which was fixed by:
>   "f2fs: fix a wrong condition in f2fs_skip_inode_update"
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
>  fs/f2fs/f2fs.h  | 15 +++++++++++++++
>  fs/f2fs/inode.c |  4 ++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 000f93f6767e..675c39d85111 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -664,6 +664,7 @@ struct f2fs_inode_info {
>  	kprojid_t i_projid;		/* id for project quota */
>  	int i_inline_xattr_size;	/* inline xattr size */
>  	struct timespec i_crtime;	/* inode creation time */
> +	struct timespec i_disk_time[4];	/* inode disk times */
>  };
>  
>  static inline void get_extent_info(struct extent_info *ext,
> @@ -2457,6 +2458,11 @@ static inline void clear_file(struct inode *inode, int type)
>  	f2fs_mark_inode_dirty_sync(inode, true);
>  }
>  
> +static inline bool time_equal(struct timespec a, struct timespec b)
> +{
> +	return (a.tv_sec == b.tv_sec) && (a.tv_nsec == b.tv_nsec);
> +}

We can use existing timespec_equal in <linux/time.h> instead of defining a
duplicated one?

> +
>  static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync)
>  {
>  	bool ret;
> @@ -2474,6 +2480,15 @@ static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync)
>  			i_size_read(inode) & ~PAGE_MASK)
>  		return false;
>  
> +	if (!time_equal(F2FS_I(inode)->i_disk_time[0], inode->i_atime))
> +		return false;
> +	if (!time_equal(F2FS_I(inode)->i_disk_time[1], inode->i_ctime))
> +		return false;
> +	if (!time_equal(F2FS_I(inode)->i_disk_time[2], inode->i_mtime))
> +		return false;
> +	if (!time_equal(F2FS_I(inode)->i_disk_time[3], F2FS_I(inode)->i_crtime))
> +		return false;
> +
>  	down_read(&F2FS_I(inode)->i_sem);
>  	ret = F2FS_I(inode)->last_disk_size == i_size_read(inode);
>  	up_read(&F2FS_I(inode)->i_sem);
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index 401f09ccce7e..70aba580f4b0 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -444,6 +444,10 @@ void update_inode(struct inode *inode, struct page *node_page)
>  	if (inode->i_nlink == 0)
>  		clear_inline_node(node_page);
>  
> +	F2FS_I(inode)->i_disk_time[0] = inode->i_atime;
> +	F2FS_I(inode)->i_disk_time[1] = inode->i_ctime;
> +	F2FS_I(inode)->i_disk_time[2] = inode->i_mtime;
> +	F2FS_I(inode)->i_disk_time[3] = F2FS_I(inode)->i_crtime;

We need initialize them in do_read_inode?

Thanks,

>  }
>  
>  void update_inode_page(struct inode *inode)
>