Re: root MD array is still in use upon shutdown possible fix

From: Czigola Gabor
Date: Sun Oct 15 2006 - 21:57:40 EST


Thank you for your answer!

On Mon, 9 Oct 2006, Neil Brown wrote:

if you get e.g.
md: md0 still in use.
*after* that message then there might be a problem. Otherwise
everything should be fine.

Yes, I've got exactly that, and rarely after such a reboot the array started to resync.

That being said, it is possible that your patch is OK. I've been
meaning to review the rules for switching an array to read-only for
ages, but it never got to the top of the todo list. e.g. do you want
to be able to switch an array to read-only when a filesystem is
mounted read-write off it. If you don't, how do you check? If you
do, what about in-flight write requests? Do you need to wait for them
to complete? How? It isn't as straight forward as one might like.

NeilBrown

I realised afterwrds, that this patch makes it possible to stop an array even it has a rw mounted filesystem on it. But I can easily remember not to switch the array to ro before umounting (remouning ro) the filesystem(s) on it, in return the array stops surely sync-d.

Of course, this isn't a solution for the kernel. But wouldn't it be possible to get the required information from the mount tables of the kernel? About pending write request to the md device does the subsystem already know.

--
Czigola, Gabor
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