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[Xen-devel] [PATCH 07 of 10] blkfront: Fix blkfront backend switch race

from [Daniel Stodden] [Permanent Link][Original]
To: Xen <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] [PATCH 07 of 10] blkfront: Fix blkfront backend switch race (bdev release)
From: Daniel Stodden <daniel.stodden@xxxxxxxxxx>
Date: Fri, 30 Apr 2010 22:01:21 -0000
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Delivery-date: Fri, 30 Apr 2010 15:15:03 -0700
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We cannot read backend state within bdev operations, because it risks
grabbing the state change before xenbus gets to do it.

Fixed by tracking deferral with a frontend switch to Closing. State
exposure isn't strictly necessary, but the backends won't mind.

For a 'clean' deferral this seems actually a more decent protocol than
raising errors.

Signed-off-by: Daniel Stodden <daniel.stodden@xxxxxxxxxx>

Attachment: blkfront-bdev-release.diff
Description: Text Data

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