Re: [PATCH 01/14] fs: refactor file timestamp update logic

Jan Kara
2025-11-24T11:52:02Z

On Fri 14-11-25 07:26:04, Christoph Hellwig wrote:
> Currently the two high-level APIs use two helper functions to implement
> almost all of the logic. Refactor the two helpers and the common logic
> into a new file_update_time_flags routine that gets the iocb flags or
> 0 in case of file_update_time passed so that the entire logic is
> contained in a single function and can be easily understood and modified.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/inode.c | 54 +++++++++++++++++-------------------------------------
> 1 file changed, 17 insertions(+), 37 deletions(-)
>
> diff --git a/fs/inode.c b/fs/inode.c
> index ec9339024ac3..4884ffa931e7 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -2310,10 +2310,12 @@ struct timespec64 current_time(struct inode *inode)
> }
> EXPORT_SYMBOL(current_time);
>
> -static int inode_needs_update_time(struct inode *inode)
> +static int file_update_time_flags(struct file *file, unsigned int flags)
> {
> + struct inode *inode = file_inode(file);
> struct timespec64 now, ts;
> - int sync_it = 0;
> + int sync_mode = 0;
> + int ret = 0;
>
> /* First try to exhaust all avenues to not sync */
> if (IS_NOCMTIME(inode))
> @@ -2323,29 +2325,23 @@ static int inode_needs_update_time(struct inode *inode)
>
> ts = inode_get_mtime(inode);
> if (!timespec64_equal(&ts, &now))
> - sync_it |= S_MTIME;
> -
> + sync_mode |= S_MTIME;
> ts = inode_get_ctime(inode);
> if (!timespec64_equal(&ts, &now))
> - sync_it |= S_CTIME;
> -
> + sync_mode |= S_CTIME;
> if (IS_I_VERSION(inode) && inode_iversion_need_inc(inode))
> - sync_it |= S_VERSION;
> + sync_mode |= S_VERSION;
>
> - return sync_it;
> -}
> -
> -static int __file_update_time(struct file *file, int sync_mode)
> -{
> - int ret = 0;
> - struct inode *inode = file_inode(file);
> + if (!sync_mode)
> + return 0;
>
> - /* try to update time settings */
> - if (!mnt_get_write_access_file(file)) {
> - ret = inode_update_time(inode, sync_mode);
> - mnt_put_write_access_file(file);
> - }
> + if (flags & IOCB_NOWAIT)
> + return -EAGAIN;
>
> + if (mnt_get_write_access_file(file))
> + return 0;
> + ret = inode_update_time(inode, sync_mode);
> + mnt_put_write_access_file(file);
> return ret;
> }
>
> @@ -2365,14 +2361,7 @@ static int __file_update_time(struct file *file, int sync_mode)
> */
> int file_update_time(struct file *file)
> {
> - int ret;
> - struct inode *inode = file_inode(file);
> -
> - ret = inode_needs_update_time(inode);
> - if (ret <= 0)
> - return ret;
> -
> - return __file_update_time(file, ret);
> + return file_update_time_flags(file, 0);
> }
> EXPORT_SYMBOL(file_update_time);
>
> @@ -2394,7 +2383,6 @@ EXPORT_SYMBOL(file_update_time);
> static int file_modified_flags(struct file *file, int flags)
> {
> int ret;
> - struct inode *inode = file_inode(file);
>
> /*
> * Clear the security bits if the process is not being run by root.
> @@ -2403,17 +2391,9 @@ static int file_modified_flags(struct file *file, int flags)
> ret = file_remove_privs_flags(file, flags);
> if (ret)
> return ret;
> -
> if (unlikely(file->f_mode & FMODE_NOCMTIME))
> return 0;
> -
> - ret = inode_needs_update_time(inode);
> - if (ret <= 0)
> - return ret;
> - if (flags & IOCB_NOWAIT)
> - return -EAGAIN;
> -
> - return __file_update_time(file, ret);
> + return file_update_time_flags(file, flags);
> }
>
> /**
> --
> 2.47.3
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR