[WATCHDOG] Fix s3c2410_wdt driver coding style issues
[safe/jmp/linux-2.6] / drivers / scsi / scsi_lib.c
index d6743b9..ff5d56b 100644 (file)
@@ -8,6 +8,7 @@
  */
 
 #include <linux/bio.h>
+#include <linux/bitops.h>
 #include <linux/blkdev.h>
 #include <linux/completion.h>
 #include <linux/kernel.h>
@@ -17,6 +18,7 @@
 #include <linux/pci.h>
 #include <linux/delay.h>
 #include <linux/hardirq.h>
+#include <linux/scatterlist.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
 
 
 #define SG_MEMPOOL_NR          ARRAY_SIZE(scsi_sg_pools)
-#define SG_MEMPOOL_SIZE                32
+#define SG_MEMPOOL_SIZE                2
 
 struct scsi_host_sg_pool {
        size_t          size;
-       char            *name; 
-       kmem_cache_t    *slab;
+       char            *name;
+       struct kmem_cache       *slab;
        mempool_t       *pool;
 };
 
-#if (SCSI_MAX_PHYS_SEGMENTS < 32)
-#error SCSI_MAX_PHYS_SEGMENTS is too small
+#define SP(x) { x, "sgpool-" __stringify(x) }
+#if (SCSI_MAX_SG_SEGMENTS < 32)
+#error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater)
 #endif
-
-#define SP(x) { x, "sgpool-" #x } 
 static struct scsi_host_sg_pool scsi_sg_pools[] = {
        SP(8),
        SP(16),
+#if (SCSI_MAX_SG_SEGMENTS > 32)
        SP(32),
-#if (SCSI_MAX_PHYS_SEGMENTS > 32)
+#if (SCSI_MAX_SG_SEGMENTS > 64)
        SP(64),
-#if (SCSI_MAX_PHYS_SEGMENTS > 64)
+#if (SCSI_MAX_SG_SEGMENTS > 128)
        SP(128),
-#if (SCSI_MAX_PHYS_SEGMENTS > 128)
-       SP(256),
-#if (SCSI_MAX_PHYS_SEGMENTS > 256)
-#error SCSI_MAX_PHYS_SEGMENTS is too large
+#if (SCSI_MAX_SG_SEGMENTS > 256)
+#error SCSI_MAX_SG_SEGMENTS is too large (256 MAX)
 #endif
 #endif
 #endif
 #endif
-};     
+       SP(SCSI_MAX_SG_SEGMENTS)
+};
 #undef SP
 
+struct kmem_cache *scsi_sdb_cache;
+
 static void scsi_run_queue(struct request_queue *q);
 
 /*
@@ -82,7 +85,7 @@ 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);
@@ -173,9 +176,9 @@ int scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
  * @retries:   number of times to retry request
  * @flags:     or into request flags;
  *
- * returns the req->errors value which is the the scsi_cmnd result
+ * returns the req->errors value which is the scsi_cmnd result
  * field.
- **/
+ */
 int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
                 int data_direction, void *buffer, unsigned bufflen,
                 unsigned char *sense, int timeout, int retries, int flags)
@@ -196,13 +199,23 @@ 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
         */
        blk_execute_rq(req->q, NULL, req, 1);
 
+       /*
+        * Some devices (USB mass-storage in particular) may transfer
+        * garbage data together with a residue indicating that the data
+        * is invalid.  Prevent the garbage from being misinterpreted
+        * and prevent security leaks by zeroing out the excess data.
+        */
+       if (unlikely(req->data_len > 0 && req->data_len <= bufflen))
+               memset(buffer + (bufflen - req->data_len), 0, req->data_len);
+
        ret = req->errors;
  out:
        blk_put_request(req);
@@ -240,7 +253,7 @@ 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)
 {
@@ -262,33 +275,18 @@ static int scsi_merge_bio(struct request *rq, struct bio *bio)
                bio->bi_rw |= (1 << BIO_RW);
        blk_queue_bounce(q, &bio);
 
-       if (!rq->bio)
-               blk_rq_bio_prep(q, rq, bio);
-       else if (!q->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;
+       return blk_rq_append_bio(q, rq, bio);
 }
 
-static int scsi_bi_endio(struct bio *bio, unsigned int bytes_done, int error)
+static void scsi_bi_endio(struct bio *bio, int error)
 {
-       if (bio->bi_size)
-               return 1;
-
        bio_put(bio);
-       return 0;
 }
 
 /**
  * scsi_req_map_sg - map a scatterlist into a request
  * @rq:                request to fill
- * @sg:                scatterlist
+ * @sgl:       scatterlist
  * @nsegs:     number of elements
  * @bufflen:   len of buffer
  * @gfp:       memory allocation flags
@@ -302,19 +300,25 @@ 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 scatterlist *sg;
        struct page *page;
        struct bio *bio = NULL;
        int i, err, nr_vecs = 0;
 
-       for (i = 0; i < nsegs; i++) {
-               page = sgl[i].page;
-               off = sgl[i].offset;
-               len = sgl[i].length;
-               data_len += len;
+       for_each_sg(sgl, sg, nsegs, i) {
+               page = sg_page(sg);
+               off = sg->offset;
+               len = sg->length;
 
-               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);
@@ -338,7 +342,7 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
                        if (bio->bi_vcnt >= nr_vecs) {
                                err = scsi_merge_bio(rq, bio);
                                if (err) {
-                                       bio_endio(bio, bio->bi_size, 0);
+                                       bio_endio(bio, 0);
                                        goto free_bios;
                                }
                                bio = NULL;
@@ -346,12 +350,13 @@ 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:
@@ -360,7 +365,7 @@ free_bios:
                /*
                 * call endio instead of bio_put incase it was bounced
                 */
-               bio_endio(bio, bio->bi_size, 0);
+               bio_endio(bio, 0);
        }
 
        return err;
@@ -371,14 +376,16 @@ free_bios:
  * @sdev:      scsi device
  * @cmd:       scsi command
  * @cmd_len:   length of scsi cdb
- * @data_direction: data direction
+ * @data_direction: DMA_TO_DEVICE, DMA_FROM_DEVICE, or DMA_NONE
  * @buffer:    data buffer (this can be a kernel buffer or scatterlist)
  * @bufflen:   len of buffer
  * @use_sg:    if buffer is a scatterlist this is the number of elements
  * @timeout:   request timeout in seconds
  * @retries:   number of times to retry request
- * @flags:     or into request flags
- **/
+ * @privdata:  data passed to done()
+ * @done:      callback function when done
+ * @gfp:       memory allocation flags
+ */
 int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
                       int cmd_len, int data_direction, void *buffer, unsigned bufflen,
                       int use_sg, int timeout, int retries, void *privdata,
@@ -389,15 +396,15 @@ 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 +415,7 @@ 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 +432,7 @@ 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);
@@ -443,9 +451,10 @@ EXPORT_SYMBOL_GPL(scsi_execute_async);
 static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
 {
        cmd->serial_number = 0;
-       memset(cmd->sense_buffer, 0, sizeof cmd->sense_buffer);
+       scsi_set_resid(cmd, 0);
+       memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
        if (cmd->cmd_len == 0)
-               cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
+               cmd->cmd_len = scsi_command_size(cmd->cmnd);
 }
 
 void scsi_device_unbusy(struct scsi_device *sdev)
@@ -528,7 +537,7 @@ static void scsi_run_queue(struct request_queue *q)
        struct Scsi_Host *shost = sdev->host;
        unsigned long flags;
 
-       if (sdev->single_lun)
+       if (scsi_target(sdev)->single_lun)
                scsi_single_lun_run(sdev);
 
        spin_lock_irqsave(shost->host_lock, flags);
@@ -536,6 +545,9 @@ static void scsi_run_queue(struct request_queue *q)
               !shost->host_blocked && !shost->host_self_blocked &&
                !((shost->can_queue > 0) &&
                  (shost->host_busy >= shost->can_queue))) {
+
+               int flagset;
+
                /*
                 * As long as shost is accepting commands and we have
                 * starved queues, call blk_run_queue. scsi_request_fn
@@ -549,19 +561,20 @@ static void scsi_run_queue(struct request_queue *q)
                sdev = list_entry(shost->starved_list.next,
                                          struct scsi_device, starved_entry);
                list_del_init(&sdev->starved_entry);
-               spin_unlock_irqrestore(shost->host_lock, flags);
+               spin_unlock(shost->host_lock);
+
+               spin_lock(sdev->request_queue->queue_lock);
+               flagset = test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) &&
+                               !test_bit(QUEUE_FLAG_REENTER,
+                                       &sdev->request_queue->queue_flags);
+               if (flagset)
+                       queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue);
+               __blk_run_queue(sdev->request_queue);
+               if (flagset)
+                       queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue);
+               spin_unlock(sdev->request_queue->queue_lock);
 
-
-               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);
+               spin_lock(shost->host_lock);
                if (unlikely(!list_empty(&sdev->starved_entry)))
                        /*
                         * sdev lost a race, and was put back on the
@@ -636,7 +649,7 @@ void scsi_run_host_queues(struct Scsi_Host *shost)
  *             of upper level post-processing and scsi_io_completion).
  *
  * Arguments:   cmd     - command that is complete.
- *              uptodate - 1 if I/O indicates success, <= 0 for I/O error.
+ *              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.
  *
@@ -651,26 +664,25 @@ void scsi_run_host_queues(struct Scsi_Host *shost)
  *             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 uptodate,
+static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
                                          int bytes, int requeue)
 {
-       request_queue_t *q = cmd->device->request_queue;
+       struct request_queue *q = cmd->device->request_queue;
        struct request *req = cmd->request;
-       unsigned long flags;
 
        /*
         * If there are blocks left over at the end, set up the command
         * to queue the remainder of them.
         */
-       if (end_that_request_chunk(req, uptodate, bytes)) {
+       if (blk_end_request(req, error, bytes)) {
                int leftover = (req->hard_nr_sectors << 9);
 
                if (blk_pc_request(req))
                        leftover = req->data_len;
 
                /* kill remainder if no retrys */
-               if (!uptodate && blk_noretry_request(req))
-                       end_that_request_chunk(req, 0, leftover);
+               if (error && blk_noretry_request(req))
+                       blk_end_request(req, error, leftover);
                else {
                        if (requeue) {
                                /*
@@ -685,14 +697,6 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate,
                }
        }
 
-       add_disk_randomness(req->rq_disk);
-
-       spin_lock_irqsave(q->queue_lock, flags);
-       if (blk_rq_tagged(req))
-               blk_queue_end_tag(q, req);
-       end_that_request_last(req, uptodate);
-       spin_unlock_irqrestore(q->queue_lock, flags);
-
        /*
         * This will goose the queue request function at the end, so we don't
         * need to worry about launching another command.
@@ -701,57 +705,57 @@ 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)
+static inline unsigned int scsi_sgtable_index(unsigned short nents)
 {
-       struct scsi_host_sg_pool *sgp;
-       struct scatterlist *sgl;
+       unsigned int index;
 
-       BUG_ON(!cmd->use_sg);
+       BUG_ON(nents > SCSI_MAX_SG_SEGMENTS);
 
-       switch (cmd->use_sg) {
-       case 1 ... 8:
-               cmd->sglist_len = 0;
-               break;
-       case 9 ... 16:
-               cmd->sglist_len = 1;
-               break;
-       case 17 ... 32:
-               cmd->sglist_len = 2;
-               break;
-#if (SCSI_MAX_PHYS_SEGMENTS > 32)
-       case 33 ... 64:
-               cmd->sglist_len = 3;
-               break;
-#if (SCSI_MAX_PHYS_SEGMENTS > 64)
-       case 65 ... 128:
-               cmd->sglist_len = 4;
-               break;
-#if (SCSI_MAX_PHYS_SEGMENTS  > 128)
-       case 129 ... 256:
-               cmd->sglist_len = 5;
-               break;
-#endif
-#endif
-#endif
-       default:
-               return NULL;
-       }
+       if (nents <= 8)
+               index = 0;
+       else
+               index = get_count_order(nents) - 3;
 
-       sgp = scsi_sg_pools + cmd->sglist_len;
-       sgl = mempool_alloc(sgp->pool, gfp_mask);
-       return sgl;
+       return index;
 }
 
-static void scsi_free_sgtable(struct scatterlist *sgl, int index)
+static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents)
 {
        struct scsi_host_sg_pool *sgp;
 
-       BUG_ON(index >= SG_MEMPOOL_NR);
-
-       sgp = scsi_sg_pools + index;
+       sgp = scsi_sg_pools + scsi_sgtable_index(nents);
        mempool_free(sgl, sgp->pool);
 }
 
+static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
+{
+       struct scsi_host_sg_pool *sgp;
+
+       sgp = scsi_sg_pools + scsi_sgtable_index(nents);
+       return mempool_alloc(sgp->pool, gfp_mask);
+}
+
+static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents,
+                             gfp_t gfp_mask)
+{
+       int ret;
+
+       BUG_ON(!nents);
+
+       ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS,
+                              gfp_mask, scsi_sg_alloc);
+       if (unlikely(ret))
+               __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS,
+                               scsi_sg_free);
+
+       return ret;
+}
+
+static void scsi_free_sgtable(struct scsi_data_buffer *sdb)
+{
+       __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
+}
+
 /*
  * Function:    scsi_release_buffers()
  *
@@ -769,17 +773,52 @@ static void scsi_free_sgtable(struct scatterlist *sgl, int index)
  *             the scatter-gather table, and potentially any bounce
  *             buffers.
  */
-static void scsi_release_buffers(struct scsi_cmnd *cmd)
+void scsi_release_buffers(struct scsi_cmnd *cmd)
 {
-       if (cmd->use_sg)
-               scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
+       if (cmd->sdb.table.nents)
+               scsi_free_sgtable(&cmd->sdb);
+
+       memset(&cmd->sdb, 0, sizeof(cmd->sdb));
+
+       if (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);
+}
+EXPORT_SYMBOL(scsi_release_buffers);
+
+/*
+ * Bidi commands Must be complete as a whole, both sides at once.
+ * If part of the bytes were written and lld returned
+ * scsi_in()->resid and/or scsi_out()->resid this information will be left
+ * in req->data_len and req->next_rq->data_len. The upper-layer driver can
+ * decide what to do with this information.
+ */
+static void scsi_end_bidi_request(struct scsi_cmnd *cmd)
+{
+       struct request *req = cmd->request;
+       unsigned int dlen = req->data_len;
+       unsigned int next_dlen = req->next_rq->data_len;
+
+       req->data_len = scsi_out(cmd)->resid;
+       req->next_rq->data_len = scsi_in(cmd)->resid;
+
+       /* The req and req->next_rq have not been completed */
+       BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen));
+
+       scsi_release_buffers(cmd);
 
        /*
-        * Zero these out.  They now point to freed memory, and it is
-        * dangerous to hang onto the pointers.
+        * This will goose the queue request function at the end, so we don't
+        * need to worry about launching another command.
         */
-       cmd->request_buffer = NULL;
-       cmd->request_bufflen = 0;
+       scsi_next_command(cmd);
 }
 
 /*
@@ -813,16 +852,14 @@ 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->request_bufflen;
-       request_queue_t *q = cmd->device->request_queue;
+       int this_count = scsi_bufflen(cmd);
+       struct request_queue *q = cmd->device->request_queue;
        struct request *req = cmd->request;
-       int clear_errors = 1;
+       int error = 0;
        struct scsi_sense_hdr sshdr;
        int sense_valid = 0;
        int sense_deferred = 0;
 
-       scsi_release_buffers(cmd);
-
        if (result) {
                sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
                if (sense_valid)
@@ -832,7 +869,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
        if (blk_pc_request(req)) { /* SG_IO ioctl from block level */
                req->errors = result;
                if (result) {
-                       clear_errors = 0;
                        if (sense_valid && req->sense) {
                                /*
                                 * SG_IO wants current and deferred errors
@@ -844,10 +880,20 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                                memcpy(req->sense, cmd->sense_buffer,  len);
                                req->sense_len = len;
                        }
-               } else
-                       req->data_len = cmd->resid;
+                       if (!sense_deferred)
+                               error = -EIO;
+               }
+               if (scsi_bidi_cmnd(cmd)) {
+                       /* will also release_buffers */
+                       scsi_end_bidi_request(cmd);
+                       return;
+               }
+               req->data_len = scsi_get_resid(cmd);
        }
 
+       BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */
+       scsi_release_buffers(cmd);
+
        /*
         * Next deal with any sectors which we were able to correctly
         * handle.
@@ -855,16 +901,12 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
        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)
+       if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL)
                return;
 
        /* good_bytes = 0, or (inclusive) there were leftovers and
@@ -878,7 +920,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                                 * and quietly refuse further access.
                                 */
                                cmd->device->changed = 1;
-                               scsi_end_request(cmd, 0, this_count, 1);
+                               scsi_end_request(cmd, -EIO, this_count, 1);
                                return;
                        } else {
                                /* Must have been a power glitch, or a
@@ -908,9 +950,14 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                                 * 6-byte command.
                                 */
                                scsi_requeue_command(q, cmd);
-                               return;
-                       } else {
-                               scsi_end_request(cmd, 0, this_count, 1);
+                       } else if (sshdr.asc == 0x10) /* DIX */
+                               scsi_end_request(cmd, -EIO, this_count, 0);
+                       else
+                               scsi_end_request(cmd, -EIO, this_count, 1);
+                       return;
+               case ABORTED_COMMAND:
+                       if (sshdr.asc == 0x10) { /* DIF */
+                               scsi_end_request(cmd, -EIO, this_count, 0);
                                return;
                        }
                        break;
@@ -933,22 +980,22 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                                        break;
                                }
                        }
-                       if (!(req->flags & REQ_QUIET)) {
-                               scmd_printk(KERN_INFO, cmd,
-                                           "Device not ready: ");
-                               scsi_print_sense_hdr("", &sshdr);
-                       }
-                       scsi_end_request(cmd, 0, this_count, 1);
+                       if (!(req->cmd_flags & REQ_QUIET))
+                               scsi_cmd_print_sense_hdr(cmd,
+                                                        "Device not ready",
+                                                        &sshdr);
+
+                       scsi_end_request(cmd, -EIO, 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->cmnd);
                                scsi_print_sense("", cmd);
                        }
                        /* See SSC3rXX or current. */
-                       scsi_end_request(cmd, 0, this_count, 1);
+                       scsi_end_request(cmd, -EIO, this_count, 1);
                        return;
                default:
                        break;
@@ -963,17 +1010,43 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
                return;
        }
        if (result) {
-               if (!(req->flags & REQ_QUIET)) {
-                       scmd_printk(KERN_INFO, cmd,
-                                   "SCSI error: return code = 0x%08x\n",
-                                   result);
+               if (!(req->cmd_flags & REQ_QUIET)) {
+                       scsi_print_result(cmd);
                        if (driver_byte(result) & DRIVER_SENSE)
                                scsi_print_sense("", cmd);
                }
        }
-       scsi_end_request(cmd, 0, this_count, !result);
+       scsi_end_request(cmd, -EIO, this_count, !result);
+}
+
+static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
+                            gfp_t gfp_mask)
+{
+       int count;
+
+       /*
+        * If sg table allocation fails, requeue request later.
+        */
+       if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments,
+                                       gfp_mask))) {
+               return BLKPREP_DEFER;
+       }
+
+       req->buffer = NULL;
+
+       /* 
+        * Next, walk the list, and fill in the addresses and sizes of
+        * each segment.
+        */
+       count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
+       BUG_ON(count > sdb->table.nents);
+       sdb->table.nents = count;
+       if (blk_pc_request(req))
+               sdb->length = req->data_len;
+       else
+               sdb->length = req->nr_sectors << 9;
+       return BLKPREP_OK;
 }
-EXPORT_SYMBOL(scsi_io_completion);
 
 /*
  * Function:    scsi_init_io()
@@ -986,104 +1059,117 @@ EXPORT_SYMBOL(scsi_io_completion);
  *             BLKPREP_DEFER if the failure is retryable
  *             BLKPREP_KILL if the failure is fatal
  */
-static int scsi_init_io(struct scsi_cmnd *cmd)
+int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
 {
-       struct request     *req = cmd->request;
-       struct scatterlist *sgpnt;
-       int                count;
+       int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask);
+       if (error)
+               goto err_exit;
+
+       if (blk_bidi_rq(cmd->request)) {
+               struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc(
+                       scsi_sdb_cache, GFP_ATOMIC);
+               if (!bidi_sdb) {
+                       error = BLKPREP_DEFER;
+                       goto err_exit;
+               }
 
-       /*
-        * 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;
+               cmd->request->next_rq->special = bidi_sdb;
+               error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb,
+                                                                   GFP_ATOMIC);
+               if (error)
+                       goto err_exit;
        }
 
-       /*
-        * 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 (blk_integrity_rq(cmd->request)) {
+               struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
+               int ivecs, count;
 
-       /*
-        * if sg table allocation fails, requeue request later.
-        */
-       sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
-       if (unlikely(!sgpnt)) {
-               scsi_unprep_request(req);
-               return BLKPREP_DEFER;
-       }
+               BUG_ON(prot_sdb == NULL);
+               ivecs = blk_rq_count_integrity_sg(cmd->request);
 
-       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;
+               if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) {
+                       error = BLKPREP_DEFER;
+                       goto err_exit;
+               }
 
-       /* 
-        * 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);
+               count = blk_rq_map_integrity_sg(cmd->request,
+                                               prot_sdb->table.sgl);
+               BUG_ON(unlikely(count > ivecs));
 
-       /*
-        * mapped well, send it off
-        */
-       if (likely(count <= cmd->use_sg)) {
-               cmd->use_sg = count;
-               return 0;
+               cmd->prot_sdb = prot_sdb;
+               cmd->prot_sdb->table.nents = count;
        }
 
-       printk(KERN_ERR "Incorrect number of segments after building list\n");
-       printk(KERN_ERR "counted %d, received %d\n", count, cmd->use_sg);
-       printk(KERN_ERR "req nr_sec %lu, cur_nr_sec %u\n", req->nr_sectors,
-                       req->current_nr_sectors);
+       return BLKPREP_OK ;
 
-       /* release the command and kill it */
+err_exit:
        scsi_release_buffers(cmd);
-       scsi_put_command(cmd);
-       return BLKPREP_KILL;
+       if (error == BLKPREP_KILL)
+               scsi_put_command(cmd);
+       else /* BLKPREP_DEFER */
+               scsi_unprep_request(cmd->request);
+
+       return error;
 }
+EXPORT_SYMBOL(scsi_init_io);
 
-static int scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk,
-                              sector_t *error_sector)
+static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
+               struct request *req)
 {
-       struct scsi_device *sdev = q->queuedata;
-       struct scsi_driver *drv;
+       struct scsi_cmnd *cmd;
 
-       if (sdev->sdev_state != SDEV_RUNNING)
-               return -ENXIO;
+       if (!req->special) {
+               cmd = scsi_get_command(sdev, GFP_ATOMIC);
+               if (unlikely(!cmd))
+                       return NULL;
+               req->special = cmd;
+       } else {
+               cmd = req->special;
+       }
 
-       drv = *(struct scsi_driver **) disk->private_data;
-       if (drv->issue_flush)
-               return drv->issue_flush(&sdev->sdev_gendev, error_sector);
+       /* pull a tag out of the request if we have one */
+       cmd->tag = req->tag;
+       cmd->request = req;
+
+       cmd->cmnd = req->cmd;
 
-       return -EOPNOTSUPP;
+       return cmd;
 }
 
-static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
+int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
 {
-       BUG_ON(!blk_pc_request(cmd->request));
+       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;
+
        /*
-        * 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
+        * 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.
         */
-       scsi_io_completion(cmd, cmd->request_bufflen);
-}
+       if (req->bio) {
+               int ret;
 
-static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
-{
-       struct request *req = cmd->request;
+               BUG_ON(!req->nr_phys_segments);
+
+               ret = scsi_init_io(cmd, GFP_ATOMIC);
+               if (unlikely(ret))
+                       return ret;
+       } else {
+               BUG_ON(req->data_len);
+               BUG_ON(req->data);
+
+               memset(&cmd->sdb, 0, sizeof(cmd->sdb));
+               req->buffer = NULL;
+       }
 
-       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)
                cmd->sc_data_direction = DMA_NONE;
@@ -1095,157 +1181,136 @@ static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
        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);
 
-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.
+ */
+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;
+       int ret = scsi_prep_state_check(sdev, req);
 
-       /*
-        * 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
-        */
-       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;
+       if (ret != BLKPREP_OK)
+               return ret;
+
+       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);
+               if (ret != BLKPREP_OK)
+                       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.
+        * Filesystem requests must transfer data.
         */
-       if (req->flags & REQ_SPECIAL && req->special) {
-               cmd = req->special;
-       } else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
+       BUG_ON(!req->nr_phys_segments);
 
-               if(unlikely(specials_only) && !(req->flags & REQ_SPECIAL)) {
-                       if(specials_only == SDEV_QUIESCE ||
-                                       specials_only == SDEV_BLOCK)
-                               goto defer;
-                       
+       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)
+{
+       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 device being removed\n");
-                       goto kill;
+                                   "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 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;
        }
-       
-       /* 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;
+       return ret;
+}
+EXPORT_SYMBOL(scsi_prep_state_check);
 
-               /*
-                * This will do a couple of things:
-                *  1) Fill in the actual SCSI command.
-                *  2) Fill in any other upper-level specific fields
-                * (timeout).
-                *
-                * 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.
-                */
+int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
+{
+       struct scsi_device *sdev = q->queuedata;
 
-               /* 
-                * 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;
+       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:
                /*
-                * 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;
+       return ret;
+}
+EXPORT_SYMBOL(scsi_prep_return);
 
- 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;
+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);
 }
 
 /*
@@ -1300,7 +1365,6 @@ static inline int scsi_host_queue_ready(struct request_queue *q,
                                printk("scsi%d unblocking host at zero depth\n",
                                        shost->host_no));
                } else {
-                       blk_plug_device(q);
                        return 0;
                }
        }
@@ -1321,7 +1385,7 @@ static inline int scsi_host_queue_ready(struct request_queue *q,
 /*
  * Kill a request for a dead device
  */
-static void scsi_kill_request(struct request *req, request_queue_t *q)
+static void scsi_kill_request(struct request *req, struct request_queue *q)
 {
        struct scsi_cmnd *cmd = req->special;
        struct scsi_device *sdev = cmd->device;
@@ -1331,7 +1395,7 @@ static void scsi_kill_request(struct request *req, request_queue_t *q)
 
        if (unlikely(cmd == NULL)) {
                printk(KERN_CRIT "impossible request in %s.\n",
-                                __FUNCTION__);
+                                __func__);
                BUG();
        }
 
@@ -1378,7 +1442,7 @@ 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);
@@ -1454,15 +1518,31 @@ 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",
-                                        __FUNCTION__);
+                                        "linux-scsi@vger.kernel.org\n",
+                                        __func__);
+                       blk_dump_rq_flags(req, "foo");
                        BUG();
                }
                spin_lock(shost->host_lock);
 
+               /*
+                * We hit this when the driver is using a host wide
+                * tag map. For device level tag maps the queue_depth check
+                * in the device ready fn would prevent us from trying
+                * to allocate a tag. Since the map is a shared host resource
+                * we add the dev to the starved list so it eventually gets
+                * a run when a tag is freed.
+                */
+               if (blk_queue_tagged(q) && !blk_rq_tagged(req)) {
+                       if (list_empty(&sdev->starved_entry))
+                               list_add_tail(&sdev->starved_entry,
+                                             &shost->starved_list);
+                       goto not_ready;
+               }
+
                if (!scsi_host_queue_ready(q, shost, sdev))
                        goto not_ready;
-               if (sdev->single_lun) {
+               if (scsi_target(sdev)->single_lun) {
                        if (scsi_target(sdev)->starget_sdev_user &&
                            scsi_target(sdev)->starget_sdev_user != sdev)
                                goto not_ready;
@@ -1546,27 +1626,54 @@ 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;
+       struct device *dev = shost->shost_gendev.parent;
 
-       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);
-
+       /*
+        * this limit is imposed by hardware restrictions
+        */
        blk_queue_max_hw_segments(q, shost->sg_tablesize);
-       blk_queue_max_phys_segments(q, SCSI_MAX_PHYS_SEGMENTS);
+       blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_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);
+       dma_set_seg_boundary(dev, shost->dma_boundary);
+
+       blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
 
+       /* New queue, no concurrency on queue_flags */
        if (!shost->use_clustering)
-               clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
+               queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q);
+
+       /*
+        * set a reasonable default alignment on word boundaries: the
+        * host and device may alter it using
+        * blk_queue_update_dma_alignment() later.
+        */
+       blk_queue_dma_alignment(q, 0x03);
+
+       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_softirq_done(q, scsi_softirq_done);
        return q;
 }
 
@@ -1630,21 +1737,30 @@ int __init scsi_init_queue(void)
 
        scsi_io_context_cache = kmem_cache_create("scsi_io_context",
                                        sizeof(struct scsi_io_context),
-                                       0, 0, NULL, NULL);
+                                       0, 0, NULL);
        if (!scsi_io_context_cache) {
                printk(KERN_ERR "SCSI: can't init scsi io context cache\n");
                return -ENOMEM;
        }
 
+       scsi_sdb_cache = kmem_cache_create("scsi_data_buffer",
+                                          sizeof(struct scsi_data_buffer),
+                                          0, 0, NULL);
+       if (!scsi_sdb_cache) {
+               printk(KERN_ERR "SCSI: can't init scsi sdb cache\n");
+               goto cleanup_io_context;
+       }
+
        for (i = 0; i < SG_MEMPOOL_NR; i++) {
                struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
                int size = sgp->size * sizeof(struct scatterlist);
 
                sgp->slab = kmem_cache_create(sgp->name, size, 0,
-                               SLAB_HWCACHE_ALIGN, NULL, NULL);
+                               SLAB_HWCACHE_ALIGN, NULL);
                if (!sgp->slab) {
                        printk(KERN_ERR "SCSI: can't init sg slab %s\n",
                                        sgp->name);
+                       goto cleanup_sdb;
                }
 
                sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE,
@@ -1652,10 +1768,25 @@ int __init scsi_init_queue(void)
                if (!sgp->pool) {
                        printk(KERN_ERR "SCSI: can't init sg mempool %s\n",
                                        sgp->name);
+                       goto cleanup_sdb;
                }
        }
 
        return 0;
+
+cleanup_sdb:
+       for (i = 0; i < SG_MEMPOOL_NR; i++) {
+               struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
+               if (sgp->pool)
+                       mempool_destroy(sgp->pool);
+               if (sgp->slab)
+                       kmem_cache_destroy(sgp->slab);
+       }
+       kmem_cache_destroy(scsi_sdb_cache);
+cleanup_io_context:
+       kmem_cache_destroy(scsi_io_context_cache);
+
+       return -ENOMEM;
 }
 
 void scsi_exit_queue(void)
@@ -1663,6 +1794,7 @@ void scsi_exit_queue(void)
        int i;
 
        kmem_cache_destroy(scsi_io_context_cache);
+       kmem_cache_destroy(scsi_sdb_cache);
 
        for (i = 0; i < SG_MEMPOOL_NR; i++) {
                struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
@@ -1682,7 +1814,7 @@ void scsi_exit_queue(void)
  *     @timeout: command timeout
  *     @retries: number of retries before failing
  *     @data: returns a structure abstracting the mode header data
- *     @sense: place to put sense data (or NULL if no sense to be collected).
+ *     @sshdr: place to put sense data (or NULL if no sense to be collected).
  *             must be SCSI_SENSE_BUFFERSIZE big.
  *
  *     Returns zero if successful; negative error number or scsi
@@ -1749,8 +1881,7 @@ scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage,
 EXPORT_SYMBOL_GPL(scsi_mode_select);
 
 /**
- *     scsi_mode_sense - issue a mode sense, falling back from 10 to 
- *             six bytes if necessary.
+ *     scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
  *     @sdev:  SCSI device to be queried
  *     @dbd:   set if mode sense will allow block descriptors to be returned
  *     @modepage: mode page being requested
@@ -1759,13 +1890,13 @@ EXPORT_SYMBOL_GPL(scsi_mode_select);
  *     @timeout: command timeout
  *     @retries: number of retries before failing
  *     @data: returns a structure abstracting the mode header data
- *     @sense: place to put sense data (or NULL if no sense to be collected).
+ *     @sshdr: place to put sense data (or NULL if no sense to be collected).
  *             must be SCSI_SENSE_BUFFERSIZE big.
  *
  *     Returns zero if unsuccessful, or the header offset (either 4
  *     or 8 depending on whether a six or ten byte command was
  *     issued) if successful.
- **/
+ */
 int
 scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
                  unsigned char *buffer, int len, int timeout, int retries,
@@ -1859,40 +1990,69 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
 }
 EXPORT_SYMBOL(scsi_mode_sense);
 
+/**
+ *     scsi_test_unit_ready - test if unit is ready
+ *     @sdev:  scsi device to change the state of.
+ *     @timeout: command timeout
+ *     @retries: number of retries before failing
+ *     @sshdr_external: Optional pointer to struct scsi_sense_hdr for
+ *             returning sense. Make sure that this is cleared before passing
+ *             in.
+ *
+ *     Returns zero if unsuccessful or an error if TUR failed.  For
+ *     removable media, a return of NOT_READY or UNIT_ATTENTION is
+ *     translated to success, with the ->changed flag updated.
+ **/
 int
-scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries)
+scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
+                    struct scsi_sense_hdr *sshdr_external)
 {
        char cmd[] = {
                TEST_UNIT_READY, 0, 0, 0, 0, 0,
        };
-       struct scsi_sense_hdr sshdr;
+       struct scsi_sense_hdr *sshdr;
        int result;
-       
-       result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, &sshdr,
-                                 timeout, retries);
+
+       if (!sshdr_external)
+               sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
+       else
+               sshdr = sshdr_external;
+
+       /* try to eat the UNIT_ATTENTION if there are enough retries */
+       do {
+               result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
+                                         timeout, retries);
+       } while ((driver_byte(result) & DRIVER_SENSE) &&
+                sshdr && sshdr->sense_key == UNIT_ATTENTION &&
+                --retries);
+
+       if (!sshdr)
+               /* could not allocate sense buffer, so can't process it */
+               return result;
 
        if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) {
 
-               if ((scsi_sense_valid(&sshdr)) &&
-                   ((sshdr.sense_key == UNIT_ATTENTION) ||
-                    (sshdr.sense_key == NOT_READY))) {
+               if ((scsi_sense_valid(sshdr)) &&
+                   ((sshdr->sense_key == UNIT_ATTENTION) ||
+                    (sshdr->sense_key == NOT_READY))) {
                        sdev->changed = 1;
                        result = 0;
                }
        }
+       if (!sshdr_external)
+               kfree(sshdr);
        return result;
 }
 EXPORT_SYMBOL(scsi_test_unit_ready);
 
 /**
- *     scsi_device_set_state - Take the given device through the device
- *             state model.
+ *     scsi_device_set_state - Take the given device through the device state model.
  *     @sdev:  scsi device to change the state of.
  *     @state: state to change to.
  *
  *     Returns zero if unsuccessful or an error if the requested 
  *     transition is illegal.
- **/
+ */
 int
 scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
 {
@@ -1993,6 +2153,147 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
 EXPORT_SYMBOL(scsi_device_set_state);
 
 /**
+ *     sdev_evt_emit - emit a single SCSI device uevent
+ *     @sdev: associated SCSI device
+ *     @evt: event to emit
+ *
+ *     Send a single uevent (scsi_event) to the associated scsi_device.
+ */
+static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
+{
+       int idx = 0;
+       char *envp[3];
+
+       switch (evt->evt_type) {
+       case SDEV_EVT_MEDIA_CHANGE:
+               envp[idx++] = "SDEV_MEDIA_CHANGE=1";
+               break;
+
+       default:
+               /* do nothing */
+               break;
+       }
+
+       envp[idx++] = NULL;
+
+       kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
+}
+
+/**
+ *     sdev_evt_thread - send a uevent for each scsi event
+ *     @work: work struct for scsi_device
+ *
+ *     Dispatch queued events to their associated scsi_device kobjects
+ *     as uevents.
+ */
+void scsi_evt_thread(struct work_struct *work)
+{
+       struct scsi_device *sdev;
+       LIST_HEAD(event_list);
+
+       sdev = container_of(work, struct scsi_device, event_work);
+
+       while (1) {
+               struct scsi_event *evt;
+               struct list_head *this, *tmp;
+               unsigned long flags;
+
+               spin_lock_irqsave(&sdev->list_lock, flags);
+               list_splice_init(&sdev->event_list, &event_list);
+               spin_unlock_irqrestore(&sdev->list_lock, flags);
+
+               if (list_empty(&event_list))
+                       break;
+
+               list_for_each_safe(this, tmp, &event_list) {
+                       evt = list_entry(this, struct scsi_event, node);
+                       list_del(&evt->node);
+                       scsi_evt_emit(sdev, evt);
+                       kfree(evt);
+               }
+       }
+}
+
+/**
+ *     sdev_evt_send - send asserted event to uevent thread
+ *     @sdev: scsi_device event occurred on
+ *     @evt: event to send
+ *
+ *     Assert scsi device event asynchronously.
+ */
+void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt)
+{
+       unsigned long flags;
+
+#if 0
+       /* FIXME: currently this check eliminates all media change events
+        * for polled devices.  Need to update to discriminate between AN
+        * and polled events */
+       if (!test_bit(evt->evt_type, sdev->supported_events)) {
+               kfree(evt);
+               return;
+       }
+#endif
+
+       spin_lock_irqsave(&sdev->list_lock, flags);
+       list_add_tail(&evt->node, &sdev->event_list);
+       schedule_work(&sdev->event_work);
+       spin_unlock_irqrestore(&sdev->list_lock, flags);
+}
+EXPORT_SYMBOL_GPL(sdev_evt_send);
+
+/**
+ *     sdev_evt_alloc - allocate a new scsi event
+ *     @evt_type: type of event to allocate
+ *     @gfpflags: GFP flags for allocation
+ *
+ *     Allocates and returns a new scsi_event.
+ */
+struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
+                                 gfp_t gfpflags)
+{
+       struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags);
+       if (!evt)
+               return NULL;
+
+       evt->evt_type = evt_type;
+       INIT_LIST_HEAD(&evt->node);
+
+       /* evt_type-specific initialization, if any */
+       switch (evt_type) {
+       case SDEV_EVT_MEDIA_CHANGE:
+       default:
+               /* do nothing */
+               break;
+       }
+
+       return evt;
+}
+EXPORT_SYMBOL_GPL(sdev_evt_alloc);
+
+/**
+ *     sdev_evt_send_simple - send asserted event to uevent thread
+ *     @sdev: scsi_device event occurred on
+ *     @evt_type: type of event to send
+ *     @gfpflags: GFP flags for allocation
+ *
+ *     Assert scsi device event asynchronously, given an event type.
+ */
+void sdev_evt_send_simple(struct scsi_device *sdev,
+                         enum scsi_device_event evt_type, gfp_t gfpflags)
+{
+       struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
+       if (!evt) {
+               sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
+                           evt_type);
+               return;
+       }
+
+       sdev_evt_send(sdev, evt);
+}
+EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
+
+/**
  *     scsi_device_quiesce - Block user issued commands.
  *     @sdev:  scsi device to quiesce.
  *
@@ -2006,7 +2307,7 @@ EXPORT_SYMBOL(scsi_device_set_state);
  *     Must be called with user context, may sleep.
  *
  *     Returns zero if unsuccessful or an error if not.
- **/
+ */
 int
 scsi_device_quiesce(struct scsi_device *sdev)
 {
@@ -2031,7 +2332,7 @@ EXPORT_SYMBOL(scsi_device_quiesce);
  *     queues.
  *
  *     Must be called with user context, may sleep.
- **/
+ */
 void
 scsi_device_resume(struct scsi_device *sdev)
 {
@@ -2068,8 +2369,7 @@ scsi_target_resume(struct scsi_target *starget)
 EXPORT_SYMBOL(scsi_target_resume);
 
 /**
- * scsi_internal_device_block - internal function to put a device
- *                             temporarily into the SDEV_BLOCK state
+ * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state
  * @sdev:      device to block
  *
  * Block request made by scsi lld's to temporarily stop all
@@ -2084,11 +2384,11 @@ EXPORT_SYMBOL(scsi_target_resume);
  *     state, all commands are deferred until the scsi lld reenables
  *     the device with scsi_device_unblock or device_block_tmo fires.
  *     This routine assumes the host_lock is held on entry.
- **/
+ */
 int
 scsi_internal_device_block(struct scsi_device *sdev)
 {
-       request_queue_t *q = sdev->request_queue;
+       struct request_queue *q = sdev->request_queue;
        unsigned long flags;
        int err = 0;
 
@@ -2124,11 +2424,11 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block);
  *     (which must be a legal transition) allowing the midlayer to
  *     goose the queue for this device.  This routine assumes the 
  *     host_lock is held upon entry.
- **/
+ */
 int
 scsi_internal_device_unblock(struct scsi_device *sdev)
 {
-       request_queue_t *q = sdev->request_queue; 
+       struct request_queue *q = sdev->request_queue; 
        int err;
        unsigned long flags;
        
@@ -2202,23 +2502,26 @@ EXPORT_SYMBOL_GPL(scsi_target_unblock);
 
 /**
  * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
- * @sg:                scatter-gather list
+ * @sgl:       scatter-gather list
  * @sg_count:  number of segments in sg
  * @offset:    offset in bytes into sg, on return offset into the mapped area
  * @len:       bytes to map, on return number of bytes mapped
  *
  * Returns virtual address of the start of the mapped page
  */
-void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
+void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
                          size_t *offset, size_t *len)
 {
        int i;
        size_t sg_len = 0, len_complete = 0;
+       struct scatterlist *sg;
        struct page *page;
 
-       for (i = 0; i < sg_count; i++) {
+       WARN_ON(!irqs_disabled());
+
+       for_each_sg(sgl, sg, sg_count, i) {
                len_complete = sg_len; /* Complete sg-entries */
-               sg_len += sg[i].length;
+               sg_len += sg->length;
                if (sg_len > *offset)
                        break;
        }
@@ -2226,16 +2529,16 @@ void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
        if (unlikely(i == sg_count)) {
                printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
                        "elements %d\n",
-                      __FUNCTION__, sg_len, *offset, sg_count);
+                      __func__, sg_len, *offset, sg_count);
                WARN_ON(1);
                return NULL;
        }
 
        /* Offset starting from the beginning of first page in this sg-entry */
-       *offset = *offset - len_complete + sg[i].offset;
+       *offset = *offset - len_complete + sg->offset;
 
        /* Assumption: contiguous pages can be accessed as "page + i" */
-       page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT));
+       page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
        *offset &= ~PAGE_MASK;
 
        /* Bytes in this sg-entry from *offset to the end of the page */
@@ -2248,8 +2551,7 @@ void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 EXPORT_SYMBOL(scsi_kmap_atomic_sg);
 
 /**
- * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously
- *                        mapped with scsi_kmap_atomic_sg
+ * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
  * @virt:      virtual address to be unmapped
  */
 void scsi_kunmap_atomic_sg(void *virt)