[PATCH] [38/275] libsas: fix runaway error handler problem

From: Andi Kleen
Date: Wed Mar 30 2011 - 18:05:26 EST


2.6.35-longterm review patch. If anyone has any objections, please let me know.

------------------
From: James Bottomley <James.Bottomley@xxxxxxx>

commit 9ee91f7fb550a4c82f82d9818e42493484c754af upstream.

libsas makes use of scsi_schedule_eh() but forgets to clear the
host_eh_scheduled flag in its error handling routine. Because of this,
the error handler thread never gets to sleep; it's constantly awake and
trying to run the error routine leading to console spew and inability to
run anything else (at least on a UP system). The fix is to clear the
flag as we splice the work queue.

Signed-off-by: James Bottomley <James.Bottomley@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
drivers/scsi/libsas/sas_scsi_host.c | 1 +
1 file changed, 1 insertion(+)

Index: linux-2.6.35.y/drivers/scsi/libsas/sas_scsi_host.c
===================================================================
--- linux-2.6.35.y.orig/drivers/scsi/libsas/sas_scsi_host.c 2011-03-29 22:51:53.815346169 -0700
+++ linux-2.6.35.y/drivers/scsi/libsas/sas_scsi_host.c 2011-03-29 23:02:58.973326440 -0700
@@ -649,6 +649,7 @@

spin_lock_irqsave(shost->host_lock, flags);
list_splice_init(&shost->eh_cmd_q, &eh_work_q);
+ shost->host_eh_scheduled = 0;
spin_unlock_irqrestore(shost->host_lock, flags);

SAS_DPRINTK("Enter %s\n", __func__);
--
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