[ Upstream commit db983f6eef57a9d78af79bc32389b7e60eb3c47d ]
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 hch@lst.de Cc: Hannes Reinecke hare@suse.com Cc: Ewan D. Milne emilne@redhat.com Cc: Johannes Thumshirn jthumshirn@suse.de Reported-by: Ewan D. Milne emilne@redhat.com Signed-off-by: Bart Van Assche bvanassche@acm.org Reviewed-by: Hannes Reinecke hare@suse.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5a6e8e12701a..655ad26106e4 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -598,9 +598,16 @@ 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.