1 files changed, 53 insertions, 70 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 604f4d717933..207f1aa08869 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -288,7 +288,7 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
 {
         struct request_queue *q = rq->q;
         int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
-        unsigned int data_len = 0, len, bytes, off;
+        unsigned int data_len = bufflen, len, bytes, off;
         struct page *page;
         struct bio *bio = NULL;
         int i, err, nr_vecs = 0;
@@ -297,10 +297,15 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
                 page = sgl[i].page;
                 off = sgl[i].offset;
                 len = sgl[i].length;
-                data_len += len;
 
-                while (len > 0) {
+                while (len > 0 && data_len > 0) {
+                        /*
+                         * sg sends a scatterlist that is larger than
+                         * the data_len it wants transferred for certain
+                         * IO sizes
+                         */
                         bytes = min_t(unsigned int, len, PAGE_SIZE - off);
+                        bytes = min(bytes, data_len);
 
                         if (!bio) {
                                 nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
@@ -332,12 +337,13 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
 
                         page++;
                         len -= bytes;
+                        data_len -=bytes;
                         off = 0;
                 }
         }
 
         rq->buffer = rq->data = NULL;
-        rq->data_len = data_len;
+        rq->data_len = bufflen;
         return 0;
 
 free_bios:
@@ -430,6 +436,7 @@ EXPORT_SYMBOL_GPL(scsi_execute_async);
 static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
 {
         cmd->serial_number = 0;
+        cmd->resid = 0;
         memset(cmd->sense_buffer, 0, sizeof cmd->sense_buffer);
         if (cmd->cmd_len == 0)
                 cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
@@ -924,11 +931,11 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                                         break;
                                 }
                         }
-                        if (!(req->cmd_flags & REQ_QUIET)) {
-                                scmd_printk(KERN_INFO, cmd,
-                                            "Device not ready: ");
-                                scsi_print_sense_hdr("", &sshdr);
-                        }
+                        if (!(req->cmd_flags & REQ_QUIET))
+                                scsi_cmd_print_sense_hdr(cmd,
+                                                         "Device not ready",
+                                                         &sshdr);
+
                         scsi_end_request(cmd, 0, this_count, 1);
                         return;
                 case VOLUME_OVERFLOW:
@@ -962,7 +969,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
         }
         scsi_end_request(cmd, 0, this_count, !result);
 }
-EXPORT_SYMBOL(scsi_io_completion);
 
 /*
  * Function:    scsi_init_io()
@@ -1019,9 +1025,6 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
         printk(KERN_ERR "req nr_sec %lu, cur_nr_sec %u\n", req->nr_sectors,
                         req->current_nr_sectors);
 
-        /* release the command and kill it */
-        scsi_release_buffers(cmd);
-        scsi_put_command(cmd);
         return BLKPREP_KILL;
 }
 
@@ -1046,21 +1049,13 @@ static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
         return cmd;
 }
 
-static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
-{
-        BUG_ON(!blk_pc_request(cmd->request));
-        /*
-         * This will complete the whole command with uptodate=1 so
-         * as far as the block layer is concerned the command completed
-         * successfully. Since this is a REQ_BLOCK_PC command the
-         * caller should check the request's errors value
-         */
-        scsi_io_completion(cmd, cmd->request_bufflen);
-}
-
-static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
+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))
@@ -1103,21 +1098,22 @@ static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
         cmd->transfersize = req->data_len;
         cmd->allowed = req->retries;
         cmd->timeout_per_command = req->timeout;
-        cmd->done = scsi_blk_pc_done;
         return BLKPREP_OK;
 }
+EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
 
 /*
  * Setup a REQ_TYPE_FS command.  These are simple read/write request
  * from filesystems that still need to be translated to SCSI CDBs from
  * the ULD.
  */
-static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
+int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
 {
         struct scsi_cmnd *cmd;
-        struct scsi_driver *drv;
-        int ret;
+        int ret = scsi_prep_state_check(sdev, req);
 
+        if (ret != BLKPREP_OK)
+                return ret;
         /*
          * Filesystem requests must transfer data.
          */
@@ -1127,26 +1123,12 @@ static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
         if (unlikely(!cmd))
                 return BLKPREP_DEFER;
 
-        ret = scsi_init_io(cmd);
-        if (unlikely(ret))
-                return ret;
-
-        /*
-         * Initialize the actual SCSI command for this request.
-         */
-        drv = *(struct scsi_driver **)req->rq_disk->private_data;
-        if (unlikely(!drv->init_command(cmd))) {
-                scsi_release_buffers(cmd);
-                scsi_put_command(cmd);
-                return BLKPREP_KILL;
-        }
-
-        return BLKPREP_OK;
+        return scsi_init_io(cmd);
 }
+EXPORT_SYMBOL(scsi_setup_fs_cmnd);
 
-static int scsi_prep_fn(struct request_queue *q, struct request *req)
+int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
 {
-        struct scsi_device *sdev = q->queuedata;
         int ret = BLKPREP_OK;
 
         /*
@@ -1192,35 +1174,25 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
                                 ret = BLKPREP_KILL;
                         break;
                 }
-
-                if (ret != BLKPREP_OK)
-                        goto out;
         }
+        return ret;
+}
+EXPORT_SYMBOL(scsi_prep_state_check);
 
-        switch (req->cmd_type) {
-        case REQ_TYPE_BLOCK_PC:
-                ret = scsi_setup_blk_pc_cmnd(sdev, req);
-                break;
-        case REQ_TYPE_FS:
-                ret = scsi_setup_fs_cmnd(sdev, req);
-                break;
-        default:
-                /*
-                 * All other command types are not supported.
-                 *
-                 * Note that these days the SCSI subsystem does not use
-                 * REQ_TYPE_SPECIAL requests anymore.  These are only used
-                 * (directly or via blk_insert_request) by non-SCSI drivers.
-                 */
-                blk_dump_rq_flags(req, "SCSI bad req");
-                ret = BLKPREP_KILL;
-                break;
-        }
+int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
+{
+        struct scsi_device *sdev = q->queuedata;
 
- out:
         switch (ret) {
         case BLKPREP_KILL:
                 req->errors = DID_NO_CONNECT << 16;
+                /* release the command and kill it */
+                if (req->special) {
+                        struct scsi_cmnd *cmd = req->special;
+                        scsi_release_buffers(cmd);
+                        scsi_put_command(cmd);
+                        req->special = NULL;
+                }
                 break;
         case BLKPREP_DEFER:
                 /*
@@ -1237,6 +1209,17 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
 
         return ret;
 }
+EXPORT_SYMBOL(scsi_prep_return);
+
+static int scsi_prep_fn(struct request_queue *q, struct request *req)
+{
+        struct scsi_device *sdev = q->queuedata;
+        int ret = BLKPREP_KILL;
+
+        if (req->cmd_type == REQ_TYPE_BLOCK_PC)
+                ret = scsi_setup_blk_pc_cmnd(sdev, req);
+        return scsi_prep_return(q, req, ret);
+}
 
 /*
  * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else