From: Dan Williams Date: Fri, 22 Jun 2012 06:25:32 +0000 (-0700) Subject: fix eh wakeup (scsi_schedule_eh vs scsi_restart_operations) X-Git-Tag: v3.2.25~17 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c6e92669dd2703bd2243c2b16cd5a5283135151b;p=pandora-kernel.git fix eh wakeup (scsi_schedule_eh vs scsi_restart_operations) commit 57fc2e335fd3c2f898ee73570dc81426c28dc7b4 upstream. Rapid ata hotplug on a libsas controller results in cases where libsas is waiting indefinitely on eh to perform an ata probe. A race exists between scsi_schedule_eh() and scsi_restart_operations() in the case when scsi_restart_operations() issues i/o to other devices in the sas domain. When this happens the host state transitions from SHOST_RECOVERY (set by scsi_schedule_eh) back to SHOST_RUNNING and ->host_busy is non-zero so we put the eh thread to sleep even though ->host_eh_scheduled is active. Before putting the error handler to sleep we need to check if the host_state needs to return to SHOST_RECOVERY for another trip through eh. Since i/o that is released by scsi_restart_operations has been blocked for at least one eh cycle, this implementation allows those i/o's to run before another eh cycle starts to discourage hung task timeouts. Reported-by: Tom Jackson Tested-by: Tom Jackson Signed-off-by: Dan Williams Signed-off-by: James Bottomley Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed