Re: [patch] zfcp: spin_lock_irqsave() is not nestable

From: Steffen Maier
Date: Thu Oct 13 2016 - 06:49:36 EST

Dan, many thanks for catching this! Sparse did not notice, is there other tooling that would find such things?

James, Martin, could you please queue this as fix for one of my patches that went into the 4.9 merge window, so for 4.9-rc I guess?

On 10/13/2016 10:53 AM, Dan Carpenter wrote:
We accidentally overwrite the original saved value of "flags" so that
we can't re-enable IRQs at the end of the function. Presumably this
function is mostly called with IRQs disabled or it would be obvious in

Fixes: aceeffbb59bb ("zfcp: trace full payload of all SAN records (req,resp,iels)")

Cc: <stable@xxxxxxxxxxxxxxx> #2.6.38+

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

Signed-off-by: Steffen Maier <maier@xxxxxxxxxxxxxxxxxx>

diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index 637cf89..5810019 100644
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -384,7 +384,7 @@ void zfcp_dbf_san(char *tag, struct zfcp_dbf *dbf,
/* if (len > rec_len):
* dump data up to cap_len ignoring small duplicate in rec->payload
- spin_lock_irqsave(&dbf->pay_lock, flags);
+ spin_lock(&dbf->pay_lock);
memset(payload, 0, sizeof(*payload));
memcpy(payload->area, paytag, ZFCP_DBF_TAG_LEN);
payload->fsf_req_id = req_id;

Mit freundlichen Grüßen / Kind regards
Steffen Maier

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