On Wed, Jun 8, 2016 at 10:04 PM, Deepa Dinamani <deepa.kernel@xxxxxxxxx> wrote:
> CURRENT_TIME macro is not appropriate for filesystems as it
> doesn't use the right granularity for filesystem timestamps.
> Use current_fs_time() instead.
Again - using the inode instead fo the syuperblock in tghis patch
would have made the patch much more obvious (it could have been 99%
generated with the sed-script I sent out a week or two ago), and it
would have made it unnecessary to add these kinds of things:
> diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
> index e9f5043..85c12f0 100644
> --- a/drivers/usb/core/devio.c
> +++ b/drivers/usb/core/devio.c
> @@ -2359,6 +2359,7 @@ static long usbdev_do_ioctl(struct file *file, unsigned int cmd,
> {
> struct usb_dev_state *ps = file->private_data;
> struct inode *inode = file_inode(file);
> + struct super_block *sb = inode->i_sb;
> struct usb_device *dev = ps->dev;
> int ret = -ENOTTY;
where we add a new variable just because the calling convention was wrong.
It's not even 100% obvious that a filesystem has to have one single
time representation, so making the time function about the entity
whose time is set is also conceptually a much better model, never mind
that it is just what every single user seems to want anyway.
So I'd *much* rather see
+ inode->i_atime = inode->i_mtime = inode->i_ctime =
current_fs_time(inode);
over seeing either of these two variants::
+ inode->i_atime = inode->i_mtime = inode->i_ctime =
current_fs_time(inode->i_sb);
+ ret->i_atime = ret->i_mtime = ret->i_ctime = current_fs_time(sb);
because the first of those variants (grep for current_fs_time() in the
current git tree, and notice that it's the common one) we have the
pointless "let's chase a pointer in every caller"
And while it's true that the second variant is natural for *some*
situations, I've yet to find one where it wasn't equally sane to just
pass in the inode instead.
Linus
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