CVS commit: src/sys/kern

[David Young <dyoung%netbsd.org@localhost>]

Module Name:    src
Committed By:   dyoung
Date:           Fri Jun 26 18:53:07 UTC 2009

Modified Files:
        src/sys/kern: vfs_subr.c

Log Message:
Keep a generation number, mountgen, that increases every time a
filesystem is mounted.  Synchronize access to the number with a
mutex.  When a struct mount, mp, is allocated, assign the current
generation number to mp->mnt_gen.  Introduce vfs_unmount_forceone()
that forcefully unmounts the most recently mounted filesystem.

Refactor: extract vfs_shutdown1() from vfs_shutdown().  Extract
vfs_sync_all() from vfs_shutdown1().

Print more progress indications while we're unmounting all of the
filesystems during shutdown.

We increase the reference count on mp before calling dounmount(mp),
but we do not decrease it if dounmount(mp) fails, and neither does
dounmount(mp).  So decrease the reference count if dounmount(mp)
fails.

Change the loop terminating condition in vfs_unmountall1() to (mp
!= (void *)&mountlist) from !CIRCLEQ_EMPTY(&mountlist), because we
may not ever empty the list, especially if we're not forcing the
filesystems to unmount.


To generate a diff of this commit:
cvs rdiff -u -r1.381 -r1.382 src/sys/kern/vfs_subr.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.