From: Tejun Heo Date: Tue, 1 Jul 2014 16:29:17 +0000 (-0600) Subject: block, blk-mq: draining can't be skipped even if bypass_depth was non-zero X-Git-Tag: omap-for-v3.17/fixes-against-rc2~75^2~14 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=776687bce42bb22cce48b5da950e48ebbb9a948f;p=pandora-kernel.git block, blk-mq: draining can't be skipped even if bypass_depth was non-zero Currently, both blk_queue_bypass_start() and blk_mq_freeze_queue() skip queue draining if bypass_depth was already above zero. The assumption is that the one which bumped the bypass_depth should have performed draining already; however, there's nothing which prevents a new instance of bypassing/freezing from starting before the previous one finishes draining. The current code may allow the later bypassing/freezing instances to complete while there still are in-flight requests which haven't finished draining. Fix it by draining regardless of bypass_depth. We still skip draining from blk_queue_bypass_start() while the queue is initializing to avoid introducing excessive delays during boot. INIT_DONE setting is moved above the initial blk_queue_bypass_end() so that bypassing attempts can't slip inbetween. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Nicholas A. Bellinger Signed-off-by: Jens Axboe --- Reading git-diff-tree failed