NetXen: Fix second rmmod failure observed on PowerPC machines.
[safe/jmp/linux-2.6] / drivers / scsi / scsi_lib.c
index 4c4add5..9f7482d 100644 (file)
@@ -36,7 +36,7 @@
 struct scsi_host_sg_pool {
        size_t          size;
        char            *name; 
-       kmem_cache_t    *slab;
+       struct kmem_cache       *slab;
        mempool_t       *pool;
 };
 
@@ -82,7 +82,7 @@ static void scsi_unprep_request(struct request *req)
 {
        struct scsi_cmnd *cmd = req->special;
 
-       req->flags &= ~REQ_DONTPREP;
+       req->cmd_flags &= ~REQ_DONTPREP;
        req->special = NULL;
 
        scsi_put_command(cmd);
@@ -196,7 +196,8 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
        req->sense_len = 0;
        req->retries = retries;
        req->timeout = timeout;
-       req->flags |= flags | REQ_BLOCK_PC | REQ_SPECIAL | REQ_QUIET;
+       req->cmd_type = REQ_TYPE_BLOCK_PC;
+       req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT;
 
        /*
         * head injection *required* here otherwise quiesce won't work
@@ -240,7 +241,7 @@ struct scsi_io_context {
        char sense[SCSI_SENSE_BUFFERSIZE];
 };
 
-static kmem_cache_t *scsi_io_context_cache;
+static struct kmem_cache *scsi_io_context_cache;
 
 static void scsi_end_async(struct request *req, int uptodate)
 {
@@ -264,13 +265,11 @@ static int scsi_merge_bio(struct request *rq, struct bio *bio)
 
        if (!rq->bio)
                blk_rq_bio_prep(q, rq, bio);
-       else if (!q->back_merge_fn(q, rq, bio))
+       else if (!ll_back_merge_fn(q, rq, bio))
                return -EINVAL;
        else {
                rq->biotail->bi_next = bio;
                rq->biotail = bio;
-               rq->hard_nr_sectors += bio_sectors(bio);
-               rq->nr_sectors = rq->hard_nr_sectors;
        }
 
        return 0;
@@ -389,15 +388,15 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
        int err = 0;
        int write = (data_direction == DMA_TO_DEVICE);
 
-       sioc = kmem_cache_alloc(scsi_io_context_cache, gfp);
+       sioc = kmem_cache_zalloc(scsi_io_context_cache, gfp);
        if (!sioc)
                return DRIVER_ERROR << 24;
-       memset(sioc, 0, sizeof(*sioc));
 
        req = blk_get_request(sdev->request_queue, write, gfp);
        if (!req)
                goto free_sense;
-       req->flags |= REQ_BLOCK_PC | REQ_QUIET;
+       req->cmd_type = REQ_TYPE_BLOCK_PC;
+       req->cmd_flags |= REQ_QUIET;
 
        if (use_sg)
                err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp);
@@ -408,6 +407,7 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
                goto free_req;
 
        req->cmd_len = cmd_len;
+       memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
        memcpy(req->cmd, cmd, req->cmd_len);
        req->sense = sioc->sense;
        req->sense_len = 0;
@@ -424,7 +424,7 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
 free_req:
        blk_put_request(req);
 free_sense:
-       kfree(sioc);
+       kmem_cache_free(scsi_io_context_cache, sioc);
        return DRIVER_ERROR << 24;
 }
 EXPORT_SYMBOL_GPL(scsi_execute_async);
@@ -436,60 +436,16 @@ EXPORT_SYMBOL_GPL(scsi_execute_async);
  *
  * Arguments:   cmd    - command that is ready to be queued.
  *
- * Returns:     Nothing
- *
  * Notes:       This function has the job of initializing a number of
  *              fields related to error handling.   Typically this will
  *              be called once for each command, as required.
  */
-static int scsi_init_cmd_errh(struct scsi_cmnd *cmd)
+static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
 {
        cmd->serial_number = 0;
-
        memset(cmd->sense_buffer, 0, sizeof cmd->sense_buffer);
-
        if (cmd->cmd_len == 0)
                cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
-
-       /*
-        * We need saved copies of a number of fields - this is because
-        * error handling may need to overwrite these with different values
-        * to run different commands, and once error handling is complete,
-        * we will need to restore these values prior to running the actual
-        * command.
-        */
-       cmd->old_use_sg = cmd->use_sg;
-       cmd->old_cmd_len = cmd->cmd_len;
-       cmd->sc_old_data_direction = cmd->sc_data_direction;
-       cmd->old_underflow = cmd->underflow;
-       memcpy(cmd->data_cmnd, cmd->cmnd, sizeof(cmd->cmnd));
-       cmd->buffer = cmd->request_buffer;
-       cmd->bufflen = cmd->request_bufflen;
-
-       return 1;
-}
-
-/*
- * Function:   scsi_setup_cmd_retry()
- *
- * Purpose:    Restore the command state for a retry
- *
- * Arguments:  cmd     - command to be restored
- *
- * Returns:    Nothing
- *
- * Notes:      Immediately prior to retrying a command, we need
- *             to restore certain fields that we saved above.
- */
-void scsi_setup_cmd_retry(struct scsi_cmnd *cmd)
-{
-       memcpy(cmd->cmnd, cmd->data_cmnd, sizeof(cmd->data_cmnd));
-       cmd->request_buffer = cmd->buffer;
-       cmd->request_bufflen = cmd->bufflen;
-       cmd->use_sg = cmd->old_use_sg;
-       cmd->cmd_len = cmd->old_cmd_len;
-       cmd->sc_data_direction = cmd->sc_old_data_direction;
-       cmd->underflow = cmd->old_underflow;
 }
 
 void scsi_device_unbusy(struct scsi_device *sdev)
@@ -595,7 +551,15 @@ static void scsi_run_queue(struct request_queue *q)
                list_del_init(&sdev->starved_entry);
                spin_unlock_irqrestore(shost->host_lock, flags);
 
-               blk_run_queue(sdev->request_queue);
+
+               if (test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) &&
+                   !test_and_set_bit(QUEUE_FLAG_REENTER,
+                                     &sdev->request_queue->queue_flags)) {
+                       blk_run_queue(sdev->request_queue);
+                       clear_bit(QUEUE_FLAG_REENTER,
+                                 &sdev->request_queue->queue_flags);
+               } else
+                       blk_run_queue(sdev->request_queue);
 
                spin_lock_irqsave(shost->host_lock, flags);
                if (unlikely(!list_empty(&sdev->starved_entry)))
@@ -737,7 +701,7 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate,
        return NULL;
 }
 
-static struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
 {
        struct scsi_host_sg_pool *sgp;
        struct scatterlist *sgl;
@@ -778,7 +742,9 @@ static struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_m
        return sgl;
 }
 
-static void scsi_free_sgtable(struct scatterlist *sgl, int index)
+EXPORT_SYMBOL(scsi_alloc_sgtable);
+
+void scsi_free_sgtable(struct scatterlist *sgl, int index)
 {
        struct scsi_host_sg_pool *sgp;
 
@@ -788,6 +754,8 @@ static void scsi_free_sgtable(struct scatterlist *sgl, int index)
        mempool_free(sgl, sgp->pool);
 }
 
+EXPORT_SYMBOL(scsi_free_sgtable);
+
 /*
  * Function:    scsi_release_buffers()
  *
@@ -807,22 +775,13 @@ static void scsi_free_sgtable(struct scatterlist *sgl, int index)
  */
 static void scsi_release_buffers(struct scsi_cmnd *cmd)
 {
-       struct request *req = cmd->request;
-
-       /*
-        * Free up any indirection buffers we allocated for DMA purposes. 
-        */
        if (cmd->use_sg)
                scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
-       else if (cmd->request_buffer != req->buffer)
-               kfree(cmd->request_buffer);
 
        /*
         * Zero these out.  They now point to freed memory, and it is
         * dangerous to hang onto the pointers.
         */
-       cmd->buffer  = NULL;
-       cmd->bufflen = 0;
        cmd->request_buffer = NULL;
        cmd->request_bufflen = 0;
 }
@@ -858,7 +817,7 @@ static void scsi_release_buffers(struct scsi_cmnd *cmd)
 void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 {
        int result = cmd->result;
-       int this_count = cmd->bufflen;
+       int this_count = cmd->request_bufflen;
        request_queue_t *q = cmd->device->request_queue;
        struct request *req = cmd->request;
        int clear_errors = 1;
@@ -866,28 +825,14 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
        int sense_valid = 0;
        int sense_deferred = 0;
 
-       /*
-        * Free up any indirection buffers we allocated for DMA purposes. 
-        * For the case of a READ, we need to copy the data out of the
-        * bounce buffer and into the real buffer.
-        */
-       if (cmd->use_sg)
-               scsi_free_sgtable(cmd->buffer, cmd->sglist_len);
-       else if (cmd->buffer != req->buffer) {
-               if (rq_data_dir(req) == READ) {
-                       unsigned long flags;
-                       char *to = bio_kmap_irq(req->bio, &flags);
-                       memcpy(to, cmd->buffer, cmd->bufflen);
-                       bio_kunmap_irq(to, &flags);
-               }
-               kfree(cmd->buffer);
-       }
+       scsi_release_buffers(cmd);
 
        if (result) {
                sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
                if (sense_valid)
                        sense_deferred = scsi_sense_is_deferred(&sshdr);
        }
+
        if (blk_pc_request(req)) { /* SG_IO ioctl from block level */
                req->errors = result;
                if (result) {
@@ -908,34 +853,23 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
        }
 
        /*
-        * Zero these out.  They now point to freed memory, and it is
-        * dangerous to hang onto the pointers.
-        */
-       cmd->buffer  = NULL;
-       cmd->bufflen = 0;
-       cmd->request_buffer = NULL;
-       cmd->request_bufflen = 0;
-
-       /*
         * Next deal with any sectors which we were able to correctly
         * handle.
         */
-       if (good_bytes > 0) {
-               SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, "
-                                             "%d bytes done.\n",
-                                             req->nr_sectors, good_bytes));
-               SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg));
-
-               if (clear_errors)
-                       req->errors = 0;
-
-               /* A number of bytes were successfully read.  If there
-                * is leftovers and there is some kind of error
-                * (result != 0), retry the rest.
-                */
-               if (scsi_end_request(cmd, 1, good_bytes, !!result) == NULL)
-                       return;
-       }
+       SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, "
+                                     "%d bytes done.\n",
+                                     req->nr_sectors, good_bytes));
+       SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg));
+
+       if (clear_errors)
+               req->errors = 0;
+
+       /* A number of bytes were successfully read.  If there
+        * are leftovers and there is some kind of error
+        * (result != 0), retry the rest.
+        */
+       if (scsi_end_request(cmd, 1, good_bytes, result == 0) == NULL)
+               return;
 
        /* good_bytes = 0, or (inclusive) there were leftovers and
         * result = 0, so scsi_end_request couldn't retry.
@@ -1003,7 +937,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                                        break;
                                }
                        }
-                       if (!(req->flags & REQ_QUIET)) {
+                       if (!(req->cmd_flags & REQ_QUIET)) {
                                scmd_printk(KERN_INFO, cmd,
                                            "Device not ready: ");
                                scsi_print_sense_hdr("", &sshdr);
@@ -1011,10 +945,10 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                        scsi_end_request(cmd, 0, this_count, 1);
                        return;
                case VOLUME_OVERFLOW:
-                       if (!(req->flags & REQ_QUIET)) {
+                       if (!(req->cmd_flags & REQ_QUIET)) {
                                scmd_printk(KERN_INFO, cmd,
                                            "Volume overflow, CDB: ");
-                               __scsi_print_command(cmd->data_cmnd);
+                               __scsi_print_command(cmd->cmnd);
                                scsi_print_sense("", cmd);
                        }
                        /* See SSC3rXX or current. */
@@ -1033,7 +967,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                return;
        }
        if (result) {
-               if (!(req->flags & REQ_QUIET)) {
+               if (!(req->cmd_flags & REQ_QUIET)) {
                        scmd_printk(KERN_INFO, cmd,
                                    "SCSI error: return code = 0x%08x\n",
                                    result);
@@ -1063,25 +997,14 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
        int                count;
 
        /*
-        * if this is a rq->data based REQ_BLOCK_PC, setup for a non-sg xfer
-        */
-       if ((req->flags & REQ_BLOCK_PC) && !req->bio) {
-               cmd->request_bufflen = req->data_len;
-               cmd->request_buffer = req->data;
-               req->buffer = req->data;
-               cmd->use_sg = 0;
-               return 0;
-       }
-
-       /*
-        * we used to not use scatter-gather for single segment request,
+        * We used to not use scatter-gather for single segment request,
         * but now we do (it makes highmem I/O easier to support without
         * kmapping pages)
         */
        cmd->use_sg = req->nr_phys_segments;
 
        /*
-        * if sg table allocation fails, requeue request later.
+        * If sg table allocation fails, requeue request later.
         */
        sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
        if (unlikely(!sgpnt)) {
@@ -1089,24 +1012,21 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
                return BLKPREP_DEFER;
        }
 
+       req->buffer = NULL;
        cmd->request_buffer = (char *) sgpnt;
-       cmd->request_bufflen = req->nr_sectors << 9;
        if (blk_pc_request(req))
                cmd->request_bufflen = req->data_len;
-       req->buffer = NULL;
+       else
+               cmd->request_bufflen = req->nr_sectors << 9;
 
        /* 
         * Next, walk the list, and fill in the addresses and sizes of
         * each segment.
         */
        count = blk_rq_map_sg(req->q, req, cmd->request_buffer);
-
-       /*
-        * mapped well, send it off
-        */
        if (likely(count <= cmd->use_sg)) {
                cmd->use_sg = count;
-               return 0;
+               return BLKPREP_OK;
        }
 
        printk(KERN_ERR "Incorrect number of segments after building list\n");
@@ -1136,6 +1056,27 @@ static int scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk,
        return -EOPNOTSUPP;
 }
 
+static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
+               struct request *req)
+{
+       struct scsi_cmnd *cmd;
+
+       if (!req->special) {
+               cmd = scsi_get_command(sdev, GFP_ATOMIC);
+               if (unlikely(!cmd))
+                       return NULL;
+               req->special = cmd;
+       } else {
+               cmd = req->special;
+       }
+
+       /* pull a tag out of the request if we have one */
+       cmd->tag = req->tag;
+       cmd->request = req;
+
+       return cmd;
+}
+
 static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
 {
        BUG_ON(!blk_pc_request(cmd->request));
@@ -1145,14 +1086,42 @@ static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
         * successfully. Since this is a REQ_BLOCK_PC command the
         * caller should check the request's errors value
         */
-       scsi_io_completion(cmd, cmd->bufflen);
+       scsi_io_completion(cmd, cmd->request_bufflen);
 }
 
-static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
+static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
 {
-       struct request *req = cmd->request;
+       struct scsi_cmnd *cmd;
+
+       cmd = scsi_get_cmd_from_req(sdev, req);
+       if (unlikely(!cmd))
+               return BLKPREP_DEFER;
+
+       /*
+        * BLOCK_PC requests may transfer data, in which case they must
+        * a bio attached to them.  Or they might contain a SCSI command
+        * that does not transfer data, in which case they may optionally
+        * submit a request without an attached bio.
+        */
+       if (req->bio) {
+               int ret;
 
-       BUG_ON(sizeof(req->cmd) > sizeof(cmd->cmnd));
+               BUG_ON(!req->nr_phys_segments);
+
+               ret = scsi_init_io(cmd);
+               if (unlikely(ret))
+                       return ret;
+       } else {
+               BUG_ON(req->data_len);
+               BUG_ON(req->data);
+
+               cmd->request_bufflen = 0;
+               cmd->request_buffer = NULL;
+               cmd->use_sg = 0;
+               req->buffer = NULL;
+       }
+
+       BUILD_BUG_ON(sizeof(req->cmd) > sizeof(cmd->cmnd));
        memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd));
        cmd->cmd_len = req->cmd_len;
        if (!req->data_len)
@@ -1166,156 +1135,138 @@ static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
        cmd->allowed = req->retries;
        cmd->timeout_per_command = req->timeout;
        cmd->done = scsi_blk_pc_done;
+       return BLKPREP_OK;
 }
 
-static int scsi_prep_fn(struct request_queue *q, struct request *req)
+/*
+ * 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)
 {
-       struct scsi_device *sdev = q->queuedata;
        struct scsi_cmnd *cmd;
-       int specials_only = 0;
+       struct scsi_driver *drv;
+       int ret;
 
        /*
-        * Just check to see if the device is online.  If it isn't, we
-        * refuse to process any commands.  The device must be brought
-        * online before trying any recovery commands
+        * Filesystem requests must transfer data.
         */
-       if (unlikely(!scsi_device_online(sdev))) {
-               sdev_printk(KERN_ERR, sdev,
-                           "rejecting I/O to offline device\n");
-               goto kill;
-       }
-       if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
-               /* OK, we're not in a running state don't prep
-                * user commands */
-               if (sdev->sdev_state == SDEV_DEL) {
-                       /* Device is fully deleted, no commands
-                        * at all allowed down */
-                       sdev_printk(KERN_ERR, sdev,
-                                   "rejecting I/O to dead device\n");
-                       goto kill;
-               }
-               /* OK, we only allow special commands (i.e. not
-                * user initiated ones */
-               specials_only = sdev->sdev_state;
-       }
+       BUG_ON(!req->nr_phys_segments);
+
+       cmd = scsi_get_cmd_from_req(sdev, req);
+       if (unlikely(!cmd))
+               return BLKPREP_DEFER;
+
+       ret = scsi_init_io(cmd);
+       if (unlikely(ret))
+               return ret;
 
        /*
-        * Find the actual device driver associated with this command.
-        * The SPECIAL requests are things like character device or
-        * ioctls, which did not originate from ll_rw_blk.  Note that
-        * the special field is also used to indicate the cmd for
-        * the remainder of a partially fulfilled request that can 
-        * come up when there is a medium error.  We have to treat
-        * these two cases differently.  We differentiate by looking
-        * at request->cmd, as this tells us the real story.
+        * Initialize the actual SCSI command for this request.
         */
-       if (req->flags & REQ_SPECIAL && req->special) {
-               cmd = req->special;
-       } else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
+       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;
+       }
 
-               if(unlikely(specials_only) && !(req->flags & REQ_SPECIAL)) {
-                       if(specials_only == SDEV_QUIESCE ||
-                                       specials_only == SDEV_BLOCK)
-                               goto defer;
-                       
+       return BLKPREP_OK;
+}
+
+static int scsi_prep_fn(struct request_queue *q, struct request *req)
+{
+       struct scsi_device *sdev = q->queuedata;
+       int ret = BLKPREP_OK;
+
+       /*
+        * If the device is not in running state we will reject some
+        * or all commands.
+        */
+       if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
+               switch (sdev->sdev_state) {
+               case SDEV_OFFLINE:
+                       /*
+                        * If the device is offline we refuse to process any
+                        * commands.  The device must be brought online
+                        * before trying any recovery commands.
+                        */
+                       sdev_printk(KERN_ERR, sdev,
+                                   "rejecting I/O to offline device\n");
+                       ret = BLKPREP_KILL;
+                       break;
+               case SDEV_DEL:
+                       /*
+                        * If the device is fully deleted, we refuse to
+                        * process any commands as well.
+                        */
                        sdev_printk(KERN_ERR, sdev,
-                                   "rejecting I/O to device being removed\n");
-                       goto kill;
+                                   "rejecting I/O to dead device\n");
+                       ret = BLKPREP_KILL;
+                       break;
+               case SDEV_QUIESCE:
+               case SDEV_BLOCK:
+                       /*
+                        * If the devices is blocked we defer normal commands.
+                        */
+                       if (!(req->cmd_flags & REQ_PREEMPT))
+                               ret = BLKPREP_DEFER;
+                       break;
+               default:
+                       /*
+                        * For any other not fully online state we only allow
+                        * special commands.  In particular any user initiated
+                        * command is not allowed.
+                        */
+                       if (!(req->cmd_flags & REQ_PREEMPT))
+                               ret = BLKPREP_KILL;
+                       break;
                }
-                       
-                       
-               /*
-                * Now try and find a command block that we can use.
-                */
-               if (!req->special) {
-                       cmd = scsi_get_command(sdev, GFP_ATOMIC);
-                       if (unlikely(!cmd))
-                               goto defer;
-               } else
-                       cmd = req->special;
-               
-               /* pull a tag out of the request if we have one */
-               cmd->tag = req->tag;
-       } else {
-               blk_dump_rq_flags(req, "SCSI bad req");
-               goto kill;
+
+               if (ret != BLKPREP_OK)
+                       goto out;
        }
-       
-       /* note the overloading of req->special.  When the tag
-        * is active it always means cmd.  If the tag goes
-        * back for re-queueing, it may be reset */
-       req->special = cmd;
-       cmd->request = req;
-       
-       /*
-        * FIXME: drop the lock here because the functions below
-        * expect to be called without the queue lock held.  Also,
-        * previously, we dequeued the request before dropping the
-        * lock.  We hope REQ_STARTED prevents anything untoward from
-        * happening now.
-        */
-       if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
-               int ret;
 
+       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:
                /*
-                * This will do a couple of things:
-                *  1) Fill in the actual SCSI command.
-                *  2) Fill in any other upper-level specific fields
-                * (timeout).
+                * All other command types are not supported.
                 *
-                * If this returns 0, it means that the request failed
-                * (reading past end of disk, reading offline device,
-                * etc).   This won't actually talk to the device, but
-                * some kinds of consistency checking may cause the     
-                * request to be rejected immediately.
+                * 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;
+       }
 
-               /* 
-                * This sets up the scatter-gather table (allocating if
-                * required).
-                */
-               ret = scsi_init_io(cmd);
-               switch(ret) {
-                       /* For BLKPREP_KILL/DEFER the cmd was released */
-               case BLKPREP_KILL:
-                       goto kill;
-               case BLKPREP_DEFER:
-                       goto defer;
-               }
-               
+ out:
+       switch (ret) {
+       case BLKPREP_KILL:
+               req->errors = DID_NO_CONNECT << 16;
+               break;
+       case BLKPREP_DEFER:
                /*
-                * Initialize the actual SCSI command for this request.
+                * If we defer, the elv_next_request() returns NULL, but the
+                * queue must be restarted, so we plug here if no returning
+                * command will automatically do that.
                 */
-               if (req->flags & REQ_BLOCK_PC) {
-                       scsi_setup_blk_pc_cmnd(cmd);
-               } else if (req->rq_disk) {
-                       struct scsi_driver *drv;
-
-                       drv = *(struct scsi_driver **)req->rq_disk->private_data;
-                       if (unlikely(!drv->init_command(cmd))) {
-                               scsi_release_buffers(cmd);
-                               scsi_put_command(cmd);
-                               goto kill;
-                       }
-               }
+               if (sdev->device_busy == 0)
+                       blk_plug_device(q);
+               break;
+       default:
+               req->cmd_flags |= REQ_DONTPREP;
        }
 
-       /*
-        * The request is now prepped, no need to come back here
-        */
-       req->flags |= REQ_DONTPREP;
-       return BLKPREP_OK;
-
- defer:
-       /* If we defer, the elv_next_request() returns NULL, but the
-        * queue must be restarted, so we plug here if no returning
-        * command will automatically do that. */
-       if (sdev->device_busy == 0)
-               blk_plug_device(q);
-       return BLKPREP_DEFER;
- kill:
-       req->errors = DID_NO_CONNECT << 16;
-       return BLKPREP_KILL;
+       return ret;
 }
 
 /*
@@ -1448,7 +1399,7 @@ static void scsi_softirq_done(struct request *rq)
                        scsi_finish_command(cmd);
                        break;
                case NEEDS_RETRY:
-                       scsi_retry_command(cmd);
+                       scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
                        break;
                case ADD_TO_MLQUEUE:
                        scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
@@ -1524,8 +1475,9 @@ static void scsi_request_fn(struct request_queue *q)
                if (unlikely(cmd == NULL)) {
                        printk(KERN_CRIT "impossible request in %s.\n"
                                         "please mail a stack trace to "
-                                        "linux-scsi@vger.kernel.org",
+                                        "linux-scsi@vger.kernel.org\n",
                                         __FUNCTION__);
+                       blk_dump_rq_flags(req, "foo");
                        BUG();
                }
                spin_lock(shost->host_lock);
@@ -1616,29 +1568,40 @@ u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost)
 }
 EXPORT_SYMBOL(scsi_calculate_bounce_limit);
 
-struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
+struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
+                                        request_fn_proc *request_fn)
 {
-       struct Scsi_Host *shost = sdev->host;
        struct request_queue *q;
 
-       q = blk_init_queue(scsi_request_fn, NULL);
+       q = blk_init_queue(request_fn, NULL);
        if (!q)
                return NULL;
 
-       blk_queue_prep_rq(q, scsi_prep_fn);
-
        blk_queue_max_hw_segments(q, shost->sg_tablesize);
        blk_queue_max_phys_segments(q, SCSI_MAX_PHYS_SEGMENTS);
        blk_queue_max_sectors(q, shost->max_sectors);
        blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
        blk_queue_segment_boundary(q, shost->dma_boundary);
-       blk_queue_issue_flush_fn(q, scsi_issue_flush_fn);
-       blk_queue_softirq_done(q, scsi_softirq_done);
 
        if (!shost->use_clustering)
                clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
        return q;
 }
+EXPORT_SYMBOL(__scsi_alloc_queue);
+
+struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
+{
+       struct request_queue *q;
+
+       q = __scsi_alloc_queue(sdev->host, scsi_request_fn);
+       if (!q)
+               return NULL;
+
+       blk_queue_prep_rq(q, scsi_prep_fn);
+       blk_queue_issue_flush_fn(q, scsi_issue_flush_fn);
+       blk_queue_softirq_done(q, scsi_softirq_done);
+       return q;
+}
 
 void scsi_free_queue(struct request_queue *q)
 {
@@ -2026,6 +1989,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
                switch (oldstate) {
                case SDEV_CREATED:
                case SDEV_RUNNING:
+               case SDEV_QUIESCE:
                case SDEV_OFFLINE:
                case SDEV_BLOCK:
                        break;
@@ -2036,6 +2000,9 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
 
        case SDEV_DEL:
                switch (oldstate) {
+               case SDEV_CREATED:
+               case SDEV_RUNNING:
+               case SDEV_OFFLINE:
                case SDEV_CANCEL:
                        break;
                default:
@@ -2282,6 +2249,8 @@ void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
        size_t sg_len = 0, len_complete = 0;
        struct page *page;
 
+       WARN_ON(!irqs_disabled());
+
        for (i = 0; i < sg_count; i++) {
                len_complete = sg_len; /* Complete sg-entries */
                sg_len += sg[i].length;