Messages in this thread | | | Date | Mon, 19 Jun 2006 23:51:36 +0200 | From | Stefan Richter <> | Subject | Re: [RFC] [PATCH 6/8] inode-diet: Move i_cindex from struct inode to struct file |
| |
Theodore Tso wrote: > On Mon, Jun 19, 2006 at 08:37:56PM +0100, Al Viro wrote: >>>NAK. Please, take it to the union into cdev part. >> >>Explanation: the whole point of that sucker is to avoid i_rdev use >>in drivers, switching to i_cdev + i_cindex. _Especially_ in open(). >>There is a bunch of other drivers that would get cleaner from that, >>including a lot of tty code. > > The problem is that we already have more stuff in the cdev union > (list_head's are *big*, especially on Opterons), so moving it there > doesn't actually save us anything. > > Moving it into struct file however should be good enough clean up the > character devices drivers that you are concerned about, however. They > are passed the struct file pointer in the file_operations->open call. > So we can clean up the tty code, et. al, by using file->f_cindex just > as easily. > > Furthermore, the inode->i_cindex isn't guaranteed to be valid until > the high-level vfs open code is called anyway, so you might as well > tell people to reference it from filp->f_cindex in the device driver's > open() routine. > > Does that make sense?
The patch is obviously proper for usage by any file_operations->open() users like the single current one (or two actually, dv1394_open() and video1394_open()). I don't know if there are any contrary usages planned in other subsystems. -- Stefan Richter -=====-=-==- -==- =--== http://arcgraph.de/sr/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |