Re: [PATCH 04/21] fs: Replace CURRENT_TIME with current_fs_time() for inode timestamps
Linus Torvalds <[email protected]>
| Newsgroups | gmane.linux.kernel.mm,gmane.linux.file-systems,gmane.linux.kernel,gmane.linux.kernel.year-2038,gmane.linux.kernel.cifs,gmane.network.samba.internals,gmane.linux.file-systems.logfs,gmane.linux.file-systems.f2fs,gmane.linux.nfs,gmane.linux.network,gmane.linux.cluster.redhat.cluster.devel,gmane.comp.file-systems.ocfs2.devel,gmane.comp.file-systems.btrfs,gmane.comp.file-systems.fuse.devel,gmane.linux.usb.general,gmane.linux.drivers.rdma,gmane.linux.oprofile,gmane.comp.security.selinux,gmane.linux.kernel.lsm,gmane.linux.kernel.autofs,gmane.linux.kernel.efi,gmane.comp.file-systems.pvfs2.devel,gmane.comp.file-systems.nilfs.user |
|---|---|
| Message-ID | <CA+55aFzceGREzGEJda8qt6gv6=iE_yDbM+mO2dJJa0wbu-o-Ww@mail.gmail.com> |
On Wed, Jun 8, 2016 at 10:04 PM, Deepa Dinamani <[email protected]> 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"[email protected]"> [email protected] </a>