Fastfail: Device flag?

From: Rogier Wolff
Date: Fri Aug 25 2006 - 07:03:26 EST



Hi,

The "md" and "multpath" drivers set a flag called "fastfail". I would
like this to become a flag that could also be set/cleared on a
per-device basis.

I'd rather not spend the time doing the retries, and get an error
immediately. This is an application issue, and I would like to make
that choice myself.....

If there is a chance I won't have to patch kernels until eternity,
I'll write the patch to make this settable from userspace.

The current situation is that the IDE driver thinks it knows which
errors stand a chance of retrying (sectoridnotfound), and which don't
(datacrcerror). This was probably true of some disk in some distant
past.

I'd rather not spend the time doing the retries, and get an error
immediately. This is an application issue....


I was thinking about adding a flag to genhd->flags, and then centrally
in "make_request" set the flag on the specific request if that flag is
set. But if I'm not mistaken, make_request has disappeared (possibly
changed into generic_make_request), and thus this change would have to
be in all "make_request" functions. I'd rather have a single line. So if
anbody has a hint as to where to put it, feel free to point me in the
right direction... ;-)

Comments?

Roger.

--
** R.E.Wolff@xxxxxxxxxxxx ** http://www.BitWizard.nl/ ** +31-15-2600998 **
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