cvs commit: src/sbin/umount umount.c

[Nate Lawson]

On Sat, 19 Jul 2003, Ian Dowse wrote:
>   Modified files:
>     sbin/umount          umount.c
>   Log:
>   Take advantage of the use of file system IDs to simplify umount(8)
>   and make it work more reliably in a number of cases that have
>   traditionally been troublesome. The new behaviour is:
>    1) If the filesystem can be determined by the fsid or device,
>       or uniquely identified by the mountpoint, then just go ahead
>       and call unmount(2) using the file system ID.
>    2) Otherwise use fstatfs(2) to resolve the path into a file system
>       ID (checking with stat(2) that it is a filesystem root directory).
>
>   Case 2 can potentially block if an NFS server is down, but it can
>   always be avoided by using an unambiguous specification. It handles
>   all the hard cases such as symlinks and mismatches between the mount
>   list and reality. For example, if a filesystem was mounted as /mnt
>   inside a chroot, it will show up in the mount list as /mnt, but now
>   you can unmount it from outside the chroot with "umount /chroot_path/mnt".
>
>   Revision  Changes    Path
>   1.39      +144 -298  src/sbin/umount/umount.c

Excellent stuff!

-Nate