1 files changed, 90 insertions, 135 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 9db097a28a74..9f841df6add8 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -512,68 +512,6 @@ void scsi_run_host_queues(struct Scsi_Host *shost)
                 scsi_run_queue(sdev->request_queue);
 }
 
-static void __scsi_release_buffers(struct scsi_cmnd *, int);
-
-/*
- * Function:    scsi_end_request()
- *
- * Purpose:     Post-processing of completed commands (usually invoked at end
- *              of upper level post-processing and scsi_io_completion).
- *
- * Arguments:   cmd      - command that is complete.
- *              error    - 0 if I/O indicates success, < 0 for I/O error.
- *              bytes    - number of bytes of completed I/O
- *              requeue  - indicates whether we should requeue leftovers.
- *
- * Lock status: Assumed that lock is not held upon entry.
- *
- * Returns:     cmd if requeue required, NULL otherwise.
- *
- * Notes:       This is called for block device requests in order to
- *              mark some number of sectors as complete.
- * 
- *              We are guaranteeing that the request queue will be goosed
- *              at some point during this call.
- * Notes:       If cmd was requeued, upon return it will be a stale pointer.
- */
-static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
-                                          int bytes, int requeue)
-{
-        struct request_queue *q = cmd->device->request_queue;
-        struct request *req = cmd->request;
-
-        /*
-         * If there are blocks left over at the end, set up the command
-         * to queue the remainder of them.
-         */
-        if (blk_end_request(req, error, bytes)) {
-                /* kill remainder if no retrys */
-                if (error && scsi_noretry_cmd(cmd))
-                        blk_end_request_all(req, error);
-                else {
-                        if (requeue) {
-                                /*
-                                 * Bleah.  Leftovers again.  Stick the
-                                 * leftovers in the front of the
-                                 * queue, and goose the queue again.
-                                 */
-                                scsi_release_buffers(cmd);
-                                scsi_requeue_command(q, cmd);
-                                cmd = NULL;
-                        }
-                        return cmd;
-                }
-        }
-
-        /*
-         * This will goose the queue request function at the end, so we don't
-         * need to worry about launching another command.
-         */
-        __scsi_release_buffers(cmd, 0);
-        scsi_next_command(cmd);
-        return NULL;
-}
-
 static inline unsigned int scsi_sgtable_index(unsigned short nents)
 {
         unsigned int index;
@@ -625,30 +563,10 @@ static void scsi_free_sgtable(struct scsi_data_buffer *sdb)
         __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
 }
 
-static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check)
-{
-
-        if (cmd->sdb.table.nents)
-                scsi_free_sgtable(&cmd->sdb);
-
-        memset(&cmd->sdb, 0, sizeof(cmd->sdb));
-
-        if (do_bidi_check && scsi_bidi_cmnd(cmd)) {
-                struct scsi_data_buffer *bidi_sdb =
-                        cmd->request->next_rq->special;
-                scsi_free_sgtable(bidi_sdb);
-                kmem_cache_free(scsi_sdb_cache, bidi_sdb);
-                cmd->request->next_rq->special = NULL;
-        }
-
-        if (scsi_prot_sg_count(cmd))
-                scsi_free_sgtable(cmd->prot_sdb);
-}
-
 /*
  * Function:    scsi_release_buffers()
  *
- * Purpose:     Completion processing for block device I/O requests.
+ * Purpose:     Free resources allocate for a scsi_command.
  *
  * Arguments:   cmd     - command that we are bailing.
  *
@@ -659,15 +577,29 @@ static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check)
  * Notes:       In the event that an upper level driver rejects a
  *              command, we must release resources allocated during
  *              the __init_io() function.  Primarily this would involve
- *              the scatter-gather table, and potentially any bounce
- *              buffers.
+ *              the scatter-gather table.
  */
 void scsi_release_buffers(struct scsi_cmnd *cmd)
 {
-        __scsi_release_buffers(cmd, 1);
+        if (cmd->sdb.table.nents)
+                scsi_free_sgtable(&cmd->sdb);
+
+        memset(&cmd->sdb, 0, sizeof(cmd->sdb));
+
+        if (scsi_prot_sg_count(cmd))
+                scsi_free_sgtable(cmd->prot_sdb);
 }
 EXPORT_SYMBOL(scsi_release_buffers);
 
+static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd)
+{
+        struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special;
+
+        scsi_free_sgtable(bidi_sdb);
+        kmem_cache_free(scsi_sdb_cache, bidi_sdb);
+        cmd->request->next_rq->special = NULL;
+}
+
 /**
  * __scsi_error_from_host_byte - translate SCSI error code into errno
  * @cmd:        SCSI command (unused)
@@ -725,16 +657,9 @@ static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result)
  *
  * Returns:     Nothing
  *
- * Notes:       This function is matched in terms of capabilities to
- *              the function that created the scatter-gather list.
- *              In other words, if there are no bounce buffers
- *              (the normal case for most drivers), we don't need
- *              the logic to deal with cleaning up afterwards.
- *
- *              We must call scsi_end_request().  This will finish off
- *              the specified number of sectors.  If we are done, the
- *              command block will be released and the queue function
- *              will be goosed.  If we are not done then we have to
+ * Notes:       We will finish off the specified number of sectors.  If we
+ *              are done, the command block will be released and the queue
+ *              function will be goosed.  If we are not done then we have to
  *              figure out what to do next:
  *
  *              a) We can call scsi_requeue_command().  The request
@@ -743,7 +668,7 @@ static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result)
  *                 be used if we made forward progress, or if we want
  *                 to switch from READ(10) to READ(6) for example.
  *
- *              b) We can call scsi_queue_insert().  The request will
+ *              b) We can call __scsi_queue_insert().  The request will
  *                 be put back on the queue and retried using the same
  *                 command as before, possibly after a delay.
  *
@@ -801,6 +726,8 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                         req->next_rq->resid_len = scsi_in(cmd)->resid;
 
                         scsi_release_buffers(cmd);
+                        scsi_release_bidi_buffers(cmd);
+
                         blk_end_request_all(req, 0);
 
                         scsi_next_command(cmd);
@@ -840,12 +767,25 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
         }
 
         /*
-         * A number of bytes were successfully read.  If there
-         * are leftovers and there is some kind of error
-         * (result != 0), retry the rest.
+         * If we finished all bytes in the request we are done now.
          */
-        if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL)
-                return;
+        if (!blk_end_request(req, error, good_bytes))
+                goto next_command;
+
+        /*
+         * Kill remainder if no retrys.
+         */
+        if (error && scsi_noretry_cmd(cmd)) {
+                blk_end_request_all(req, error);
+                goto next_command;
+        }
+
+        /*
+         * If there had been no error, but we have leftover bytes in the
+         * requeues just queue the command up again.
+         */
+        if (result == 0)
+                goto requeue;
 
         error = __scsi_error_from_host_byte(cmd, result);
 
@@ -973,7 +913,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
         switch (action) {
         case ACTION_FAIL:
                 /* Give up and fail the remainder of the request */
-                scsi_release_buffers(cmd);
                 if (!(req->cmd_flags & REQ_QUIET)) {
                         if (description)
                                 scmd_printk(KERN_INFO, cmd, "%s\n",
@@ -983,12 +922,11 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                                 scsi_print_sense("", cmd);
                         scsi_print_command(cmd);
                 }
-                if (blk_end_request_err(req, error))
-                        scsi_requeue_command(q, cmd);
-                else
-                        scsi_next_command(cmd);
-                break;
+                if (!blk_end_request_err(req, error))
+                        goto next_command;
+                /*FALLTHRU*/
         case ACTION_REPREP:
+        requeue:
                 /* Unprep the request and put it back at the head of the queue.
                  * A new command will be prepared and issued.
                  */
@@ -1004,6 +942,11 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
                 break;
         }
+        return;
+
+next_command:
+        scsi_release_buffers(cmd);
+        scsi_next_command(cmd);
 }
 
 static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
@@ -1130,15 +1073,7 @@ static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
 
 int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
 {
-        struct scsi_cmnd *cmd;
-        int ret = scsi_prep_state_check(sdev, req);
-
-        if (ret != BLKPREP_OK)
-                return ret;
-
-        cmd = scsi_get_cmd_from_req(sdev, req);
-        if (unlikely(!cmd))
-                return BLKPREP_DEFER;
+        struct scsi_cmnd *cmd = req->special;
 
         /*
          * BLOCK_PC requests may transfer data, in which case they must
@@ -1182,15 +1117,11 @@ EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
  */
 int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
 {
-        struct scsi_cmnd *cmd;
-        int ret = scsi_prep_state_check(sdev, req);
-
-        if (ret != BLKPREP_OK)
-                return ret;
+        struct scsi_cmnd *cmd = req->special;
 
         if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh
                          && sdev->scsi_dh_data->scsi_dh->prep_fn)) {
-                ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req);
+                int ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req);
                 if (ret != BLKPREP_OK)
                         return ret;
         }
@@ -1200,16 +1131,13 @@ int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
          */
         BUG_ON(!req->nr_phys_segments);
 
-        cmd = scsi_get_cmd_from_req(sdev, req);
-        if (unlikely(!cmd))
-                return BLKPREP_DEFER;
-
         memset(cmd->cmnd, 0, BLK_MAX_CDB);
         return scsi_init_io(cmd, GFP_ATOMIC);
 }
 EXPORT_SYMBOL(scsi_setup_fs_cmnd);
 
-int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
+static int
+scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
 {
         int ret = BLKPREP_OK;
 
@@ -1261,9 +1189,9 @@ int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
         }
         return ret;
 }
-EXPORT_SYMBOL(scsi_prep_state_check);
 
-int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
+static int
+scsi_prep_return(struct request_queue *q, struct request *req, int ret)
 {
         struct scsi_device *sdev = q->queuedata;
 
@@ -1294,18 +1222,44 @@ int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
 
         return ret;
 }
-EXPORT_SYMBOL(scsi_prep_return);
 
-int scsi_prep_fn(struct request_queue *q, struct request *req)
+static int scsi_prep_fn(struct request_queue *q, struct request *req)
 {
         struct scsi_device *sdev = q->queuedata;
-        int ret = BLKPREP_KILL;
+        struct scsi_cmnd *cmd;
+        int ret;
 
-        if (req->cmd_type == REQ_TYPE_BLOCK_PC)
+        ret = scsi_prep_state_check(sdev, req);
+        if (ret != BLKPREP_OK)
+                goto out;
+
+        cmd = scsi_get_cmd_from_req(sdev, req);
+        if (unlikely(!cmd)) {
+                ret = BLKPREP_DEFER;
+                goto out;
+        }
+
+        if (req->cmd_type == REQ_TYPE_FS)
+                ret = scsi_cmd_to_driver(cmd)->init_command(cmd);
+        else if (req->cmd_type == REQ_TYPE_BLOCK_PC)
                 ret = scsi_setup_blk_pc_cmnd(sdev, req);
+        else
+                ret = BLKPREP_KILL;
+
+out:
         return scsi_prep_return(q, req, ret);
 }
-EXPORT_SYMBOL(scsi_prep_fn);
+
+static void scsi_unprep_fn(struct request_queue *q, struct request *req)
+{
+        if (req->cmd_type == REQ_TYPE_FS) {
+                struct scsi_cmnd *cmd = req->special;
+                struct scsi_driver *drv = scsi_cmd_to_driver(cmd);
+
+                if (drv->uninit_command)
+                        drv->uninit_command(cmd);
+        }
+}
 
 /*
  * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
@@ -1726,6 +1680,7 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
                 return NULL;
 
         blk_queue_prep_rq(q, scsi_prep_fn);
+        blk_queue_unprep_rq(q, scsi_unprep_fn);
         blk_queue_softirq_done(q, scsi_softirq_done);
         blk_queue_rq_timed_out(q, scsi_times_out);
         blk_queue_lld_busy(q, scsi_lld_busy);