zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/block/blk-exec.c b/ap/os/linux/linux-3.4.x/block/blk-exec.c
new file mode 100644
index 0000000..1b5cb66
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/block/blk-exec.c
@@ -0,0 +1,131 @@
+/*
+ * Functions related to setting various queue properties from drivers
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+
+#include "blk.h"
+
+/*
+ * for max sense size
+ */
+#include <scsi/scsi_cmnd.h>
+
+/**
+ * blk_end_sync_rq - executes a completion event on a request
+ * @rq: request to complete
+ * @error: end I/O status of the request
+ */
+static void blk_end_sync_rq(struct request *rq, int error)
+{
+ struct completion *waiting = rq->end_io_data;
+
+ rq->end_io_data = NULL;
+ __blk_put_request(rq->q, rq);
+
+ /*
+ * complete last, if this is a stack request the process (and thus
+ * the rq pointer) could be invalid right after this complete()
+ */
+ complete(waiting);
+}
+
+/**
+ * blk_execute_rq_nowait - insert a request into queue for execution
+ * @q: queue to insert the request in
+ * @bd_disk: matching gendisk
+ * @rq: request to insert
+ * @at_head: insert request at head or tail of queue
+ * @done: I/O completion handler
+ *
+ * Description:
+ * Insert a fully prepared request at the back of the I/O scheduler queue
+ * for execution. Don't wait for completion.
+ */
+void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
+ struct request *rq, int at_head,
+ rq_end_io_fn *done)
+{
+ int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
+ bool is_pm_resume;
+
+ WARN_ON(irqs_disabled());
+
+ rq->rq_disk = bd_disk;
+ rq->end_io = done;
+ /*
+ * need to check this before __blk_run_queue(), because rq can
+ * be freed before that returns.
+ */
+ is_pm_resume = rq->cmd_type == REQ_TYPE_PM_RESUME;
+
+ spin_lock_irq(q->queue_lock);
+
+ if (unlikely(blk_queue_dead(q))) {
+ spin_unlock_irq(q->queue_lock);
+ rq->errors = -ENXIO;
+ if (rq->end_io)
+ rq->end_io(rq, rq->errors);
+ return;
+ }
+
+ rq->rq_disk = bd_disk;
+ rq->end_io = done;
+ __elv_add_request(q, rq, where);
+ __blk_run_queue(q);
+ /* the queue is stopped so it won't be run */
+ if (is_pm_resume)
+ q->request_fn(q);
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
+
+/**
+ * blk_execute_rq - insert a request into queue for execution
+ * @q: queue to insert the request in
+ * @bd_disk: matching gendisk
+ * @rq: request to insert
+ * @at_head: insert request at head or tail of queue
+ *
+ * Description:
+ * Insert a fully prepared request at the back of the I/O scheduler queue
+ * for execution and wait for completion.
+ */
+int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
+ struct request *rq, int at_head)
+{
+ DECLARE_COMPLETION_ONSTACK(wait);
+ char sense[SCSI_SENSE_BUFFERSIZE];
+ int err = 0;
+ unsigned long hang_check;
+
+ /*
+ * we need an extra reference to the request, so we can look at
+ * it after io completion
+ */
+ rq->ref_count++;
+
+ if (!rq->sense) {
+ memset(sense, 0, sizeof(sense));
+ rq->sense = sense;
+ rq->sense_len = 0;
+ }
+
+ rq->end_io_data = &wait;
+ blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
+
+ /* Prevent hang_check timer from firing at us during very long I/O */
+ hang_check = sysctl_hung_task_timeout_secs;
+ if (hang_check)
+ while (!wait_for_completion_timeout(&wait, hang_check * (HZ/2)));
+ else
+ wait_for_completion(&wait);
+
+ if (rq->errors)
+ err = -EIO;
+
+ return err;
+}
+EXPORT_SYMBOL(blk_execute_rq);