[SCSI] tgt: fix sesnse buffer problems

This patch simplify the way to notify LLDs of the command completion
and addresses the following sense buffer problems:

- can't handle both data and sense.
- forces user-space to use aligned sense buffer

tgt copies sense_data from userspace to cmnd->sense_buffer (if
necessary), maps user-space pages (if necessary) and then calls
host->transfer_response (host->transfer_data is removed).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 9 insertions, 16 deletions

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 7f1f411..965b6b8 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -129,6 +129,11 @@ struct scsi_host_template {
 	 * the LLD. When the driver is finished processing the command
 	 * the done callback is invoked.
 	 *
+	 * This is called to inform the LLD to transfer
+	 * cmd->request_bufflen bytes. The cmd->use_sg speciefies the
+	 * number of scatterlist entried in the command and
+	 * cmd->request_buffer contains the scatterlist.
+	 *
 	 * return values: see queuecommand
 	 *
 	 * If the LLD accepts the cmd, it should set the result to an
@@ -139,20 +144,6 @@ struct scsi_host_template {
 	/* TODO: rename */
 	int (* transfer_response)(struct scsi_cmnd *,
 				  void (*done)(struct scsi_cmnd *));
-	/*
-	 * This is called to inform the LLD to transfer cmd->request_bufflen
-	 * bytes of the cmd at cmd->offset in the cmd. The cmd->use_sg
-	 * speciefies the number of scatterlist entried in the command
-	 * and cmd->request_buffer contains the scatterlist.
-	 *
-	 * If the command cannot be processed in one transfer_data call
-	 * becuase a scatterlist within the LLD's limits cannot be
-	 * created then transfer_data will be called multiple times.
-	 * It is initially called from process context, and later
-	 * calls are from the interrup context.
-	 */
-	int (* transfer_data)(struct scsi_cmnd *,
-			      void (*done)(struct scsi_cmnd *));
 
 	/* Used as callback for the completion of task management request. */
 	int (* tsk_mgmt_response)(u64 mid, int result);
diff --git a/include/scsi/scsi_tgt_if.h b/include/scsi/scsi_tgt_if.h
index 07d6e77..4cf9dff 100644
--- a/include/scsi/scsi_tgt_if.h
+++ b/include/scsi/scsi_tgt_if.h
@@ -45,11 +45,13 @@ struct tgt_event {
 		/* user-> kernel */
 		struct {
 			int host_no;
-			uint32_t len;
 			int result;
+			aligned_u64 tag;
 			aligned_u64 uaddr;
+			aligned_u64 sense_uaddr;
+			uint32_t len;
+			uint32_t sense_len;
 			uint8_t rw;
-			aligned_u64 tag;
 		} cmd_rsp;
 		struct {
 			int host_no;