Bug 26618

Summary:	unmount(2) can't unmount a filesystem whose device has been lost
Product:	Base System	Reporter:	fredette <fredette>
Component:	kern	Assignee:	Edward Tomasz Napierala <trasz>
Status:	Closed FIXED
Severity:	Affects Only Me
Priority:	Normal
Version:	Unspecified
Hardware:	Any
OS:	Any

Description fredette 2001-04-16 18:00:00 UTC

unmount(2) can't unmount a filesystem on a device that has been lost.
When the namei() call on the mountpoint fails with ENXIO, unmount
gives up and returns immediately.

Fix: 

When namei() returns ENXIO on the mountpoint, umount could walk
the list of mounted filesystems looking for the mountpoint itself.
I'll attach a patch to this PR that does this in a followup email.
How-To-Repeat: Mount a single filesystem read-only from a SCSI disk.  Power down
the disk, use 'camcontrol rescan' as appropriate to lose the device.
Now try to unmount the filesystem.

Comment 1 iedowse freebsd_committer

2003-10-11 14:40:21 UTC

Responsible Changed
From-To: freebsd-bugs->iedowse


I'll take this one; it is possible that the read-only mount case 
has already been improved in -CURRENT, as unmount(8) no longer calls 
namei().

Comment 2 Mark Linimon freebsd_committer

2007-07-31 15:53:09 UTC

Responsible Changed
From-To: iedowse->freebsd-bugs

With permission, reassign from committer who is away from FreeBSD work for now.

Comment 3 Edward Tomasz Napierala freebsd_committer

2009-07-08 13:33:53 UTC

Responsible Changed
From-To: freebsd-bugs->trasz

I'll take it.

Comment 4 Edward Tomasz Napierala freebsd_committer

2009-07-08 13:34:00 UTC

State Changed
From-To: open->feedback

Can you still reproduce it with FreeBSD 7.2?  It should be fixed already.

Comment 5 Edward Tomasz Napierala freebsd_committer

2009-07-08 15:52:49 UTC

State Changed
From-To: feedback->closed

Originator's mail bounces, and I believe the problem is fixed.