On 3/18/19 5:29 PM, Bart Van Assche wrote:
cmd->rcu is initialized by scsi_initialize_rq(). For passthrough
requests, blk_get_request() calls scsi_initialize_rq(). For filesystem
requests, scsi_init_command() calls scsi_initialize_rq(). Make sure
that destroy_rcu_head() is called for passthrough requests.
Cc: Christoph Hellwig <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Cc: Ewan D. Milne <[email protected]>
Cc: Johannes Thumshirn <[email protected]>
Reported-by: Ewan D. Milne <[email protected]>
Signed-off-by: Bart Van Assche <[email protected]>
---
drivers/scsi/scsi_lib.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 33e1a72d47fa..ed4314f8542e 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -585,9 +585,16 @@ static bool scsi_end_request(struct request *req,
blk_status_t error,
if (!blk_rq_is_scsi(req)) {
WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED));
cmd->flags &= ~SCMD_INITIALIZED;
- destroy_rcu_head(&cmd->rcu);
}
+ /*
+ * Calling rcu_barrier() is not necessary here because the
+ * SCSI error handler guarantees that the function called by
+ * call_rcu() has been called before scsi_end_request() is
+ * called.
+ */
+ destroy_rcu_head(&cmd->rcu);
+
/*
* In the MQ case the command gets freed by __blk_mq_end_request,
* so we have to do all cleanup that depends on it earlier.
Reviewed-by: Hannes Reinecke <[email protected]>
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
[email protected] +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
