Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits)
  block: add request clone interface (v2)
  floppy: fix hibernation
  ramdisk: remove long-deprecated "ramdisk=" boot-time parameter
  fs/bio.c: add missing __user annotation
  block: prevent possible io_context->refcount overflow
  Add serial number support for virtio_blk, V4a
  block: Add missing bounce_pfn stacking and fix comments
  Revert "block: Fix bounce limit setting in DM"
  cciss: decode unit attention in SCSI error handling code
  cciss: Remove no longer needed sendcmd reject processing code
  cciss: change SCSI error handling routines to work with interrupts enabled.
  cciss: separate error processing and command retrying code in sendcmd_withirq_core()
  cciss: factor out fix target status processing code from sendcmd functions
  cciss: simplify interface of sendcmd() and sendcmd_withirq()
  cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code
  cciss: Use schedule_timeout_uninterruptible in SCSI error handling code
  block: needs to set the residual length of a bidi request
  Revert "block: implement blkdev_readpages"
  block: Fix bounce limit setting in DM
  Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt
  ...

Manually fix conflicts with tracing updates in:
	block/blk-sysfs.c
	drivers/ide/ide-atapi.c
	drivers/ide/ide-cd.c
	drivers/ide/ide-floppy.c
	drivers/ide/ide-tape.c
	include/trace/events/block.h
	kernel/trace/blktrace.c

1 files changed, 36 insertions, 149 deletions

diff --git a/block/elevator.c b/block/elevator.c
index e220f0c543e3..ca861927ba41 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -51,8 +51,7 @@ static const int elv_hash_shift = 6;
 #define ELV_HASH_FN(sec)        \
                 (hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift))
 #define ELV_HASH_ENTRIES        (1 << elv_hash_shift)
-#define rq_hash_key(rq)         ((rq)->sector + (rq)->nr_sectors)
-#define ELV_ON_HASH(rq)         (!hlist_unhashed(&(rq)->hash))
+#define rq_hash_key(rq)         (blk_rq_pos(rq) + blk_rq_sectors(rq))
 
 /*
  * Query io scheduler to see if the current process issuing bio may be
@@ -116,9 +115,9 @@ static inline int elv_try_merge(struct request *__rq, struct bio *bio)
          * we can merge and sequence is ok, check if it's possible
          */
         if (elv_rq_merge_ok(__rq, bio)) {
-                if (__rq->sector + __rq->nr_sectors == bio->bi_sector)
+                if (blk_rq_pos(__rq) + blk_rq_sectors(__rq) == bio->bi_sector)
                         ret = ELEVATOR_BACK_MERGE;
-                else if (__rq->sector - bio_sectors(bio) == bio->bi_sector)
+                else if (blk_rq_pos(__rq) - bio_sectors(bio) == bio->bi_sector)
                         ret = ELEVATOR_FRONT_MERGE;
         }
 
@@ -306,22 +305,6 @@ void elevator_exit(struct elevator_queue *e)
 }
 EXPORT_SYMBOL(elevator_exit);
 
-static void elv_activate_rq(struct request_queue *q, struct request *rq)
-{
-        struct elevator_queue *e = q->elevator;
-
-        if (e->ops->elevator_activate_req_fn)
-                e->ops->elevator_activate_req_fn(q, rq);
-}
-
-static void elv_deactivate_rq(struct request_queue *q, struct request *rq)
-{
-        struct elevator_queue *e = q->elevator;
-
-        if (e->ops->elevator_deactivate_req_fn)
-                e->ops->elevator_deactivate_req_fn(q, rq);
-}
-
 static inline void __elv_rqhash_del(struct request *rq)
 {
         hlist_del_init(&rq->hash);
@@ -383,9 +366,9 @@ struct request *elv_rb_add(struct rb_root *root, struct request *rq)
                 parent = *p;
                 __rq = rb_entry(parent, struct request, rb_node);
 
-                if (rq->sector < __rq->sector)
+                if (blk_rq_pos(rq) < blk_rq_pos(__rq))
                         p = &(*p)->rb_left;
-                else if (rq->sector > __rq->sector)
+                else if (blk_rq_pos(rq) > blk_rq_pos(__rq))
                         p = &(*p)->rb_right;
                 else
                         return __rq;
@@ -413,9 +396,9 @@ struct request *elv_rb_find(struct rb_root *root, sector_t sector)
         while (n) {
                 rq = rb_entry(n, struct request, rb_node);
 
-                if (sector < rq->sector)
+                if (sector < blk_rq_pos(rq))
                         n = n->rb_left;
-                else if (sector > rq->sector)
+                else if (sector > blk_rq_pos(rq))
                         n = n->rb_right;
                 else
                         return rq;
@@ -454,14 +437,14 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
                         break;
                 if (pos->cmd_flags & stop_flags)
                         break;
-                if (rq->sector >= boundary) {
-                        if (pos->sector < boundary)
+                if (blk_rq_pos(rq) >= boundary) {
+                        if (blk_rq_pos(pos) < boundary)
                                 continue;
                 } else {
-                        if (pos->sector >= boundary)
+                        if (blk_rq_pos(pos) >= boundary)
                                 break;
                 }
-                if (rq->sector >= pos->sector)
+                if (blk_rq_pos(rq) >= blk_rq_pos(pos))
                         break;
         }
 
@@ -559,7 +542,7 @@ void elv_requeue_request(struct request_queue *q, struct request *rq)
          * in_flight count again
          */
         if (blk_account_rq(rq)) {
-                q->in_flight--;
+                q->in_flight[rq_is_sync(rq)]--;
                 if (blk_sorted_rq(rq))
                         elv_deactivate_rq(q, rq);
         }
@@ -588,6 +571,9 @@ void elv_drain_elevator(struct request_queue *q)
  */
 void elv_quiesce_start(struct request_queue *q)
 {
+        if (!q->elevator)
+                return;
+
         queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
 
         /*
@@ -595,7 +581,7 @@ void elv_quiesce_start(struct request_queue *q)
          */
         elv_drain_elevator(q);
         while (q->rq.elvpriv) {
-                blk_start_queueing(q);
+                __blk_run_queue(q);
                 spin_unlock_irq(q->queue_lock);
                 msleep(10);
                 spin_lock_irq(q->queue_lock);
@@ -639,8 +625,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
                  *   with anything.  There's no point in delaying queue
                  *   processing.
                  */
-                blk_remove_plug(q);
-                blk_start_queueing(q);
+                __blk_run_queue(q);
                 break;
 
         case ELEVATOR_INSERT_SORT:
@@ -699,7 +684,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
 
         if (unplug_it && blk_queue_plugged(q)) {
                 int nrq = q->rq.count[BLK_RW_SYNC] + q->rq.count[BLK_RW_ASYNC]
-                        - q->in_flight;
+                                - queue_in_flight(q);
 
                 if (nrq >= q->unplug_thresh)
                         __generic_unplug_device(q);
@@ -755,117 +740,6 @@ void elv_add_request(struct request_queue *q, struct request *rq, int where,
 }
 EXPORT_SYMBOL(elv_add_request);
 
-static inline struct request *__elv_next_request(struct request_queue *q)
-{
-        struct request *rq;
-
-        while (1) {
-                while (!list_empty(&q->queue_head)) {
-                        rq = list_entry_rq(q->queue_head.next);
-                        if (blk_do_ordered(q, &rq))
-                                return rq;
-                }
-
-                if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
-                        return NULL;
-        }
-}
-
-struct request *elv_next_request(struct request_queue *q)
-{
-        struct request *rq;
-        int ret;
-
-        while ((rq = __elv_next_request(q)) != NULL) {
-                if (!(rq->cmd_flags & REQ_STARTED)) {
-                        /*
-                         * This is the first time the device driver
-                         * sees this request (possibly after
-                         * requeueing).  Notify IO scheduler.
-                         */
-                        if (blk_sorted_rq(rq))
-                                elv_activate_rq(q, rq);
-
-                        /*
-                         * just mark as started even if we don't start
-                         * it, a request that has been delayed should
-                         * not be passed by new incoming requests
-                         */
-                        rq->cmd_flags |= REQ_STARTED;
-                        trace_block_rq_issue(q, rq);
-                }
-
-                if (!q->boundary_rq || q->boundary_rq == rq) {
-                        q->end_sector = rq_end_sector(rq);
-                        q->boundary_rq = NULL;
-                }
-
-                if (rq->cmd_flags & REQ_DONTPREP)
-                        break;
-
-                if (q->dma_drain_size && rq->data_len) {
-                        /*
-                         * make sure space for the drain appears we
-                         * know we can do this because max_hw_segments
-                         * has been adjusted to be one fewer than the
-                         * device can handle
-                         */
-                        rq->nr_phys_segments++;
-                }
-
-                if (!q->prep_rq_fn)
-                        break;
-
-                ret = q->prep_rq_fn(q, rq);
-                if (ret == BLKPREP_OK) {
-                        break;
-                } else if (ret == BLKPREP_DEFER) {
-                        /*
-                         * the request may have been (partially) prepped.
-                         * we need to keep this request in the front to
-                         * avoid resource deadlock.  REQ_STARTED will
-                         * prevent other fs requests from passing this one.
-                         */
-                        if (q->dma_drain_size && rq->data_len &&
-                            !(rq->cmd_flags & REQ_DONTPREP)) {
-                                /*
-                                 * remove the space for the drain we added
-                                 * so that we don't add it again
-                                 */
-                                --rq->nr_phys_segments;
-                        }
-
-                        rq = NULL;
-                        break;
-                } else if (ret == BLKPREP_KILL) {
-                        rq->cmd_flags |= REQ_QUIET;
-                        __blk_end_request(rq, -EIO, blk_rq_bytes(rq));
-                } else {
-                        printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
-                        break;
-                }
-        }
-
-        return rq;
-}
-EXPORT_SYMBOL(elv_next_request);
-
-void elv_dequeue_request(struct request_queue *q, struct request *rq)
-{
-        BUG_ON(list_empty(&rq->queuelist));
-        BUG_ON(ELV_ON_HASH(rq));
-
-        list_del_init(&rq->queuelist);
-
-        /*
-         * the time frame between a request being removed from the lists
-         * and to it is freed is accounted as io that is in progress at
-         * the driver side.
-         */
-        if (blk_account_rq(rq))
-                q->in_flight++;
-}
-
 int elv_queue_empty(struct request_queue *q)
 {
         struct elevator_queue *e = q->elevator;
@@ -935,7 +809,12 @@ void elv_abort_queue(struct request_queue *q)
                 rq = list_entry_rq(q->queue_head.next);
                 rq->cmd_flags |= REQ_QUIET;
                 trace_block_rq_abort(q, rq);
-                __blk_end_request(rq, -EIO, blk_rq_bytes(rq));
+                /*
+                 * Mark this request as started so we don't trigger
+                 * any debug logic in the end I/O path.
+                 */
+                blk_start_request(rq);
+                __blk_end_request_all(rq, -EIO);
         }
 }
 EXPORT_SYMBOL(elv_abort_queue);
@@ -948,7 +827,7 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
          * request is released from the driver, io must be done
          */
         if (blk_account_rq(rq)) {
-                q->in_flight--;
+                q->in_flight[rq_is_sync(rq)]--;
                 if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn)
                         e->ops->elevator_completed_req_fn(q, rq);
         }
@@ -963,11 +842,11 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
                 if (!list_empty(&q->queue_head))
                         next = list_entry_rq(q->queue_head.next);
 
-                if (!q->in_flight &&
+                if (!queue_in_flight(q) &&
                     blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
                     (!next || blk_ordered_req_seq(next) > QUEUE_ORDSEQ_DRAIN)) {
                         blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
-                        blk_start_queueing(q);
+                        __blk_run_queue(q);
                 }
         }
 }
@@ -1175,6 +1054,9 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
         char elevator_name[ELV_NAME_MAX];
         struct elevator_type *e;
 
+        if (!q->elevator)
+                return count;
+
         strlcpy(elevator_name, name, sizeof(elevator_name));
         strstrip(elevator_name);
 
@@ -1198,10 +1080,15 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
 ssize_t elv_iosched_show(struct request_queue *q, char *name)
 {
         struct elevator_queue *e = q->elevator;
-        struct elevator_type *elv = e->elevator_type;
+        struct elevator_type *elv;
         struct elevator_type *__e;
         int len = 0;
 
+        if (!q->elevator)
+                return sprintf(name, "none\n");
+
+        elv = e->elevator_type;
+
         spin_lock(&elv_list_lock);
         list_for_each_entry(__e, &elv_list, list) {
                 if (!strcmp(elv->elevator_name, __e->elevator_name))