Bug 27044

Summary: remounting a r/w filesystem read-only causes shutdown problem
Product: Base System Reporter: Archie Cobbs <archie>
Component: kernAssignee: freebsd-bugs (Nobody) <bugs>
Status: Closed FIXED    
Severity: Affects Only Me    
Priority: Normal    
Version: 4.3-RELEASE   
Hardware: Any   
OS: Any   

Description Archie Cobbs 2001-05-03 00:50:01 UTC 
	Sometimes FreeBSD has problems "syncing buffers" when shutting
	down, and then it "gives up". I'm not sure why this happens, but
	the practical result is an unclean (and possibly screwed up)
	filesystem at the next reboot, so it's definitely a bad thing.

	I can reproducibly get this to happen by mounting a filesystem
	read-write, mucking with some files, and then remounting
	it read-only (ie., updating the mount: "mount -u -o ro"), and
	then rebooting.

Fix: 

Skip the "mount -u -o ro /foo" step.
How-To-Repeat: 
	mount /foo
	cp -R /var /foo
	mount -u -o ro /foo
	reboot

	By the way, /foo has soft updates enabled.
Comment 1 Kirk McKusick freebsd_committer freebsd_triage 2002-02-11 06:25:54 UTC 
State Changed
From-To: open->closed

This bug was fixed by revision 1.167 to /sys/ufs/ffs/ffs_vfsops.c.