On Sat, Apr 23, 2011 at 4:32 PM, Tom Gundersen <[email protected]> wrote: > Hi guys, > > On shutdown we unmount/remount most filesystems. However, we make > exception fro the "api" filesystems as they might still be useful and > they are anyway not backed by a block device. > > The problem is that umount does not easily let us make exception based > on mountpoints, but we have to use mounttype instead. For /sys and > /proc this is ok, but /dev might be tmpfs, so we have until now > avoided unmounting any tmpfs filesystems. > > This might be a problem if a tmpfs system is a submount of a > blockdevice, as this will block the unmounting of the parent device. > > The attached patch (originally by Gerardo) fixes this problem when > /dev is mounted as devtmpfs and keeps the old behavior if /dev is > tmpfs. > > I made some adjustments, as noted in the commit message (Gerardo, > please let me know if this looks ok with you). > > If someone knows of any reason not to unmount tmpfs or ramfs on > shutdown, please speak up. I"m happy you ask this. Because your mail subject remember me an old story about win98 (i guess), which have a big improvment from 95, by don't unloading some driver at shutdown because it was unecessary. This "improvment" speed up the shutdown. So the question, was, is there a reason to unmount ramfs at shutdown? I understand the unmount chaining issue, but i don't see which case is problematic, do you have a ticket # ?
2 small points about your patch: - You should use /bin/grep and not grep, like everywhere else. - A comment before the if then else to explain why we do this will be cool. -- Sébastien Luttringer www.seblu.net
