Lou Gosselin: > I tried to detect locked branches based on the paths as mentioned below. > However I'm finding that the below algorithm does not reliably determine > the branch that a file lock is on.
As I wrote, there are some complicated cases in real world. > >mkdir union a b > >cp /bin/sh a > >cp /bin/sh b > >mount -t aufs aufs union -o br:a > > # From another shell > >union/sh > > # Original shell > >mount union -o remount,prepend:b > > # Now, the algorithm discussed tells us that the file lock for "sh" lock > is on "b", but it's not. > # The manual confirms that mmap files don't change branches, which is > the case with executables. You are misunderstanding. When union/sh was invoked, there were only one branch in union and only one real file "sh" in union. This only one real file was mmap-ed and executed. The description in the manual means that the mmap-ed file on the branch "a" will never be refreshed and changed to the branch "b". Deleting a branch is very similar to unmounting a regular filesystem. Once you run # mount /dev/sda1 /mnt You will not be able to unmount /mnt as long as any file is in-use in /mnt. I hope you will understand that you can unmount /mnt if you are running /mnt/sh. J. R. Okajima ------------------------------------------------------------------------------ The Palm PDK Hot Apps Program offers developers who use the Plug-In Development Kit to bring their C/C++ apps to Palm for a share of $1 Million in cash or HP Products. Visit us here for more details: http://p.sf.net/sfu/dev2dev-palm
