[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 7f1f411d07af..965b6b8ffec5 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 07d6e77ae895..4cf9dff29a2f 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;