kern/105056: FS can not be remounted read-only, if a running process' executable was modified

[Mikhail Teterin]

On Monday 12 March 2007 04:11, Remko Lodder wrote:
= Hi Mikhail,
= 
= As far as I am aware, the filesystem can only be closed when the consumers
= stopped consuming the disk. Perhaps we should move this discussion to -fs
= to see what the FileSystem guru's think so that we know for sure?

Moving... Of course, the filesystem can only be closed, when the consumers 
stop consuming. The point is, however, there are NO read-write consumers -- 
and yet a read-only remount remains impossible.

The problem detailed in the PR is that locking an FS back down to read-only is 
impossible, when earlier-started processes are still running, but have had 
their executables overwritten.

The usual scenario, again, is:

	* remount / read-write for `installworld' to succeed;
	* try to remount / back read-only, and fail...

Note, that no new "consumers" of the FS have started, or have they?..

Yours,

	-mi