1 files changed, 62 insertions, 2 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 3574ba935af8..4362dcde74af 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -16,6 +16,7 @@
 #include <linux/init.h>
 #include <linux/pci.h>
 #include <linux/delay.h>
+#include <linux/hardirq.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_dbg.h>
@@ -436,6 +437,7 @@ free_bios:
  * scsi_execute_async - insert request
  * @sdev:	scsi device
  * @cmd:	scsi command
+ * @cmd_len:	length of scsi cdb
  * @data_direction: data direction
  * @buffer:	data buffer (this can be a kernel buffer or scatterlist)
  * @bufflen:	len of buffer
@@ -445,7 +447,7 @@ free_bios:
  * @flags:	or into request flags
  **/
 int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
-		       int data_direction, void *buffer, unsigned bufflen,
+		       int cmd_len, int data_direction, void *buffer, unsigned bufflen,
 		       int use_sg, int timeout, int retries, void *privdata,
 		       void (*done)(void *, char *, int, int), gfp_t gfp)
 {
@@ -472,7 +474,7 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
 	if (err)
 		goto free_req;
 
-	req->cmd_len = COMMAND_SIZE(cmd[0]);
+	req->cmd_len = cmd_len;
 	memcpy(req->cmd, cmd, req->cmd_len);
 	req->sense = sioc->sense;
 	req->sense_len = 0;
@@ -2247,3 +2249,61 @@ scsi_target_unblock(struct device *dev)
 		device_for_each_child(dev, NULL, target_unblock);
 }
 EXPORT_SYMBOL_GPL(scsi_target_unblock);
+
+
+struct work_queue_work {
+	struct work_struct	work;
+	void			(*fn)(void *);
+	void			*data;
+};
+
+static void execute_in_process_context_work(void *data)
+{
+	void (*fn)(void *data);
+	struct work_queue_work *wqw = data;
+
+	fn = wqw->fn;
+	data = wqw->data;
+
+	kfree(wqw);
+
+	fn(data);
+}
+
+/**
+ * scsi_execute_in_process_context - reliably execute the routine with user context
+ * @fn:		the function to execute
+ * @data:	data to pass to the function
+ *
+ * Executes the function immediately if process context is available,
+ * otherwise schedules the function for delayed execution.
+ *
+ * Returns:	0 - function was executed
+ *		1 - function was scheduled for execution
+ *		<0 - error
+ */
+int scsi_execute_in_process_context(void (*fn)(void *data), void *data)
+{
+	struct work_queue_work *wqw;
+
+	if (!in_interrupt()) {
+		fn(data);
+		return 0;
+	}
+
+	wqw = kmalloc(sizeof(struct work_queue_work), GFP_ATOMIC);
+
+	if (unlikely(!wqw)) {
+		printk(KERN_ERR "Failed to allocate memory\n");
+		WARN_ON(1);
+		return -ENOMEM;
+	}
+
+	INIT_WORK(&wqw->work, execute_in_process_context_work, wqw);
+	wqw->fn = fn;
+	wqw->data = data;
+	schedule_work(&wqw->work);
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(scsi_execute_in_process_context);