[SCSI] use scatter lists for all block pc requests and simplify hw handlers
Original From: Mike Christie <michaelc@cs.wisc.edu>
Add scsi_execute_req() as a replacement for scsi_wait_req()
Fixed up various pieces (added REQ_SPECIAL and caught req use after
free)
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 60f07b6..b8212c5 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -246,7 +246,7 @@
unsigned bufflen, int timeout, int retries)
{
DECLARE_COMPLETION(wait);
- int write = sreq->sr_data_direction == DMA_TO_DEVICE;
+ int write = (sreq->sr_data_direction == DMA_TO_DEVICE);
struct request *req;
req = blk_get_request(sreq->sr_device->request_queue, write,
@@ -281,6 +281,55 @@
EXPORT_SYMBOL(scsi_wait_req);
+/**
+ * scsi_execute_req - insert request and wait for the result
+ * @sdev: scsi device
+ * @cmd: scsi command
+ * @data_direction: data direction
+ * @buffer: data buffer
+ * @bufflen: len of buffer
+ * @sense: optional sense buffer
+ * @timeout: request timeout in seconds
+ * @retries: number of times to retry request
+ *
+ * scsi_execute_req returns the req->errors value which is the
+ * the scsi_cmnd result field.
+ **/
+int scsi_execute_req(struct scsi_device *sdev, unsigned char *cmd,
+ int data_direction, void *buffer, unsigned bufflen,
+ unsigned char *sense, int timeout, int retries)
+{
+ struct request *req;
+ int write = (data_direction == DMA_TO_DEVICE);
+ int ret = DRIVER_ERROR << 24;
+
+ req = blk_get_request(sdev->request_queue, write, __GFP_WAIT);
+
+ if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
+ buffer, bufflen, __GFP_WAIT))
+ goto out;
+
+ req->cmd_len = COMMAND_SIZE(cmd[0]);
+ memcpy(req->cmd, cmd, req->cmd_len);
+ req->sense = sense;
+ req->sense_len = 0;
+ req->timeout = timeout;
+ req->flags |= REQ_BLOCK_PC | REQ_SPECIAL;
+
+ /*
+ * head injection *required* here otherwise quiesce won't work
+ */
+ blk_execute_rq(req->q, NULL, req, 1);
+
+ ret = req->errors;
+ out:
+ blk_put_request(req);
+
+ return ret;
+}
+
+EXPORT_SYMBOL(scsi_execute_req);
+
/*
* Function: scsi_init_cmd_errh()
*
