Merge with /home/shaggy/git/linus-clean/

4 files changed, 161 insertions, 193 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 74fae2daf87e..c8dbe38c81c8 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -239,7 +239,6 @@ enum cfqq_state_flags {
         CFQ_CFQQ_FLAG_fifo_expire,
         CFQ_CFQQ_FLAG_idle_window,
         CFQ_CFQQ_FLAG_prio_changed,
-        CFQ_CFQQ_FLAG_expired,
 };
 
 #define CFQ_CFQQ_FNS(name)                                              \
@@ -264,7 +263,6 @@ CFQ_CFQQ_FNS(must_dispatch);
 CFQ_CFQQ_FNS(fifo_expire);
 CFQ_CFQQ_FNS(idle_window);
 CFQ_CFQQ_FNS(prio_changed);
-CFQ_CFQQ_FNS(expired);
 #undef CFQ_CFQQ_FNS
 
 enum cfq_rq_state_flags {
@@ -336,7 +334,7 @@ static struct request *cfq_find_rq_hash(struct cfq_data *cfqd, sector_t offset)
  */
 static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
 {
-        if (!cfqd->rq_in_driver && cfqd->busy_queues)
+        if (cfqd->busy_queues)
                 kblockd_schedule_work(&cfqd->unplug_work);
 }
 
@@ -736,13 +734,63 @@ __cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
                 cfqq->slice_left = 0;
                 cfq_clear_cfqq_must_alloc_slice(cfqq);
                 cfq_clear_cfqq_fifo_expire(cfqq);
-                cfq_clear_cfqq_expired(cfqq);
         }
 
         cfqd->active_queue = cfqq;
 }
 
 /*
+ * current cfqq expired its slice (or was too idle), select new one
+ */
+static void
+__cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+                    int preempted)
+{
+        unsigned long now = jiffies;
+
+        if (cfq_cfqq_wait_request(cfqq))
+                del_timer(&cfqd->idle_slice_timer);
+
+        if (!preempted && !cfq_cfqq_dispatched(cfqq)) {
+                cfqq->service_last = now;
+                cfq_schedule_dispatch(cfqd);
+        }
+
+        cfq_clear_cfqq_must_dispatch(cfqq);
+        cfq_clear_cfqq_wait_request(cfqq);
+
+        /*
+         * store what was left of this slice, if the queue idled out
+         * or was preempted
+         */
+        if (time_after(cfqq->slice_end, now))
+                cfqq->slice_left = cfqq->slice_end - now;
+        else
+                cfqq->slice_left = 0;
+
+        if (cfq_cfqq_on_rr(cfqq))
+                cfq_resort_rr_list(cfqq, preempted);
+
+        if (cfqq == cfqd->active_queue)
+                cfqd->active_queue = NULL;
+
+        if (cfqd->active_cic) {
+                put_io_context(cfqd->active_cic->ioc);
+                cfqd->active_cic = NULL;
+        }
+
+        cfqd->dispatch_slice = 0;
+}
+
+static inline void cfq_slice_expired(struct cfq_data *cfqd, int preempted)
+{
+        struct cfq_queue *cfqq = cfqd->active_queue;
+
+        if (cfqq)
+                __cfq_slice_expired(cfqd, cfqq, preempted);
+}
+
+/*
  * 0
  * 0,1
  * 0,1,2
@@ -801,16 +849,7 @@ static int cfq_get_next_prio_level(struct cfq_data *cfqd)
 
 static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd)
 {
-        struct cfq_queue *cfqq;
-
-        /*
-         * if current queue is expired but not done with its requests yet,
-         * wait for that to happen
-         */
-        if ((cfqq = cfqd->active_queue) != NULL) {
-                if (cfq_cfqq_expired(cfqq) && cfq_cfqq_dispatched(cfqq))
-                        return NULL;
-        }
+        struct cfq_queue *cfqq = NULL;
 
         /*
          * if current list is non-empty, grab first entry. if it is empty,
@@ -837,66 +876,11 @@ static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd)
         return cfqq;
 }
 
-/*
- * current cfqq expired its slice (or was too idle), select new one
- */
-static void
-__cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
-                    int preempted)
-{
-        unsigned long now = jiffies;
-
-        if (cfq_cfqq_wait_request(cfqq))
-                del_timer(&cfqd->idle_slice_timer);
-
-        if (!preempted && !cfq_cfqq_dispatched(cfqq))
-                cfqq->service_last = now;
-
-        cfq_clear_cfqq_must_dispatch(cfqq);
-        cfq_clear_cfqq_wait_request(cfqq);
-
-        /*
-         * store what was left of this slice, if the queue idled out
-         * or was preempted
-         */
-        if (time_after(cfqq->slice_end, now))
-                cfqq->slice_left = cfqq->slice_end - now;
-        else
-                cfqq->slice_left = 0;
-
-        if (cfq_cfqq_on_rr(cfqq))
-                cfq_resort_rr_list(cfqq, preempted);
-
-        if (cfqq == cfqd->active_queue)
-                cfqd->active_queue = NULL;
-
-        if (cfqd->active_cic) {
-                put_io_context(cfqd->active_cic->ioc);
-                cfqd->active_cic = NULL;
-        }
-
-        cfqd->dispatch_slice = 0;
-}
-
-static inline void cfq_slice_expired(struct cfq_data *cfqd, int preempted)
-{
-        struct cfq_queue *cfqq = cfqd->active_queue;
-
-        if (cfqq) {
-                /*
-                 * use deferred expiry, if there are requests in progress as
-                 * not to disturb the slice of the next queue
-                 */
-                if (cfq_cfqq_dispatched(cfqq))
-                        cfq_mark_cfqq_expired(cfqq);
-                else
-                        __cfq_slice_expired(cfqd, cfqq, preempted);
-        }
-}
-
 static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 
 {
+        unsigned long sl;
+
         WARN_ON(!RB_EMPTY(&cfqq->sort_list));
         WARN_ON(cfqq != cfqd->active_queue);
 
@@ -916,13 +900,8 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
         cfq_mark_cfqq_must_dispatch(cfqq);
         cfq_mark_cfqq_wait_request(cfqq);
 
-        if (!timer_pending(&cfqd->idle_slice_timer)) {
-                unsigned long slice_left = min(cfqq->slice_end - 1, (unsigned long) cfqd->cfq_slice_idle);
-
-                cfqd->idle_slice_timer.expires = jiffies + slice_left;
-                add_timer(&cfqd->idle_slice_timer);
-        }
-
+        sl = min(cfqq->slice_end - 1, (unsigned long) cfqd->cfq_slice_idle);
+        mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
         return 1;
 }
 
@@ -1006,9 +985,6 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
         if (!cfqq)
                 goto new_queue;
 
-        if (cfq_cfqq_expired(cfqq))
-                goto new_queue;
-
         /*
          * slice has expired
          */
@@ -1181,10 +1157,8 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
         BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]);
         BUG_ON(cfq_cfqq_on_rr(cfqq));
 
-        if (unlikely(cfqd->active_queue == cfqq)) {
+        if (unlikely(cfqd->active_queue == cfqq))
                 __cfq_slice_expired(cfqd, cfqq, 0);
-                cfq_schedule_dispatch(cfqd);
-        }
 
         cfq_put_cfqd(cfqq->cfqd);
 
@@ -1245,10 +1219,8 @@ static void cfq_exit_single_io_context(struct cfq_io_context *cic)
 
         spin_lock(q->queue_lock);
 
-        if (unlikely(cic->cfqq == cfqd->active_queue)) {
+        if (unlikely(cic->cfqq == cfqd->active_queue))
                 __cfq_slice_expired(cfqd, cic->cfqq, 0);
-                cfq_schedule_dispatch(cfqd);
-        }
 
         cfq_put_queue(cic->cfqq);
         cic->cfqq = NULL;
@@ -1715,10 +1687,7 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq)
                         cfqq->service_last = now;
                         cfq_resort_rr_list(cfqq, 0);
                 }
-                if (cfq_cfqq_expired(cfqq)) {
-                        __cfq_slice_expired(cfqd, cfqq, 0);
-                        cfq_schedule_dispatch(cfqd);
-                }
+                cfq_schedule_dispatch(cfqd);
         }
 
         if (cfq_crq_is_sync(crq))
diff --git a/block/elevator.c b/block/elevator.c
index c9f424d5399c..24b702d649a9 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -139,35 +139,16 @@ static int elevator_attach(request_queue_t *q, struct elevator_type *e,
 
 static char chosen_elevator[16];
 
-static void elevator_setup_default(void)
+static int __init elevator_setup(char *str)
 {
-        struct elevator_type *e;
-
-        /*
-         * If default has not been set, use the compiled-in selection.
-         */
-        if (!chosen_elevator[0])
-                strcpy(chosen_elevator, CONFIG_DEFAULT_IOSCHED);
-
         /*
          * Be backwards-compatible with previous kernels, so users
          * won't get the wrong elevator.
          */
-        if (!strcmp(chosen_elevator, "as"))
+        if (!strcmp(str, "as"))
                 strcpy(chosen_elevator, "anticipatory");
-
-        /*
-         * If the given scheduler is not available, fall back to the default
-         */
-        if ((e = elevator_find(chosen_elevator)))
-                elevator_put(e);
         else
-                strcpy(chosen_elevator, CONFIG_DEFAULT_IOSCHED);
-}
-
-static int __init elevator_setup(char *str)
-{
-        strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1);
+                strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1);
         return 0;
 }
 
@@ -184,14 +165,16 @@ int elevator_init(request_queue_t *q, char *name)
         q->end_sector = 0;
         q->boundary_rq = NULL;
 
-        elevator_setup_default();
+        if (name && !(e = elevator_get(name)))
+                return -EINVAL;
 
-        if (!name)
-                name = chosen_elevator;
+        if (!e && *chosen_elevator && !(e = elevator_get(chosen_elevator)))
+                printk("I/O scheduler %s not found\n", chosen_elevator);
 
-        e = elevator_get(name);
-        if (!e)
-                return -EINVAL;
+        if (!e && !(e = elevator_get(CONFIG_DEFAULT_IOSCHED))) {
+                printk("Default I/O scheduler not found, using no-op\n");
+                e = elevator_get("noop");
+        }
 
         eq = kmalloc(sizeof(struct elevator_queue), GFP_KERNEL);
         if (!eq) {
@@ -310,7 +293,7 @@ void elv_requeue_request(request_queue_t *q, struct request *rq)
 
         rq->flags &= ~REQ_STARTED;
 
-        __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE, 0);
+        elv_insert(q, rq, ELEVATOR_INSERT_REQUEUE);
 }
 
 static void elv_drain_elevator(request_queue_t *q)
@@ -327,40 +310,11 @@ static void elv_drain_elevator(request_queue_t *q)
         }
 }
 
-void __elv_add_request(request_queue_t *q, struct request *rq, int where,
-                       int plug)
+void elv_insert(request_queue_t *q, struct request *rq, int where)
 {
         struct list_head *pos;
         unsigned ordseq;
 
-        if (q->ordcolor)
-                rq->flags |= REQ_ORDERED_COLOR;
-
-        if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
-                /*
-                 * toggle ordered color
-                 */
-                q->ordcolor ^= 1;
-
-                /*
-                 * barriers implicitly indicate back insertion
-                 */
-                if (where == ELEVATOR_INSERT_SORT)
-                        where = ELEVATOR_INSERT_BACK;
-
-                /*
-                 * this request is scheduling boundary, update end_sector
-                 */
-                if (blk_fs_request(rq)) {
-                        q->end_sector = rq_end_sector(rq);
-                        q->boundary_rq = rq;
-                }
-        } else if (!(rq->flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT)
-                where = ELEVATOR_INSERT_BACK;
-
-        if (plug)
-                blk_plug_device(q);
-
         rq->q = q;
 
         switch (where) {
@@ -441,6 +395,42 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where,
         }
 }
 
+void __elv_add_request(request_queue_t *q, struct request *rq, int where,
+                       int plug)
+{
+        if (q->ordcolor)
+                rq->flags |= REQ_ORDERED_COLOR;
+
+        if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) {
+                /*
+                 * toggle ordered color
+                 */
+                if (blk_barrier_rq(rq))
+                        q->ordcolor ^= 1;
+
+                /*
+                 * barriers implicitly indicate back insertion
+                 */
+                if (where == ELEVATOR_INSERT_SORT)
+                        where = ELEVATOR_INSERT_BACK;
+
+                /*
+                 * this request is scheduling boundary, update
+                 * end_sector
+                 */
+                if (blk_fs_request(rq)) {
+                        q->end_sector = rq_end_sector(rq);
+                        q->boundary_rq = rq;
+                }
+        } else if (!(rq->flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT)
+                where = ELEVATOR_INSERT_BACK;
+
+        if (plug)
+                blk_plug_device(q);
+
+        elv_insert(q, rq, where);
+}
+
 void elv_add_request(request_queue_t *q, struct request *rq, int where,
                      int plug)
 {
@@ -669,8 +659,10 @@ int elv_register(struct elevator_type *e)
         spin_unlock_irq(&elv_list_lock);
 
         printk(KERN_INFO "io scheduler %s registered", e->elevator_name);
-        if (!strcmp(e->elevator_name, chosen_elevator))
-                printk(" (default)");
+        if (!strcmp(e->elevator_name, chosen_elevator) ||
+                        (!*chosen_elevator &&
+                         !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED)))
+                                printk(" (default)");
         printk("\n");
         return 0;
 }
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 8e27d0ab0d7c..0ef2971a9e82 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -304,6 +304,7 @@ static inline void rq_init(request_queue_t *q, struct request *rq)
  * blk_queue_ordered - does this queue support ordered writes
  * @q:        the request queue
  * @ordered:  one of QUEUE_ORDERED_*
+ * @prepare_flush_fn: rq setup helper for cache flush ordered writes
  *
  * Description:
  *   For journalled file systems, doing ordered writes on a commit
@@ -332,6 +333,7 @@ int blk_queue_ordered(request_queue_t *q, unsigned ordered,
                 return -EINVAL;
         }
 
+        q->ordered = ordered;
         q->next_ordered = ordered;
         q->prepare_flush_fn = prepare_flush_fn;
 
@@ -452,7 +454,7 @@ static void queue_flush(request_queue_t *q, unsigned which)
         rq->end_io = end_io;
         q->prepare_flush_fn(q, rq);
 
-        __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
+        elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
 }
 
 static inline struct request *start_ordered(request_queue_t *q,
@@ -488,7 +490,7 @@ static inline struct request *start_ordered(request_queue_t *q,
         else
                 q->ordseq |= QUEUE_ORDSEQ_POSTFLUSH;
 
-        __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
+        elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
 
         if (q->ordered & QUEUE_ORDERED_PREFLUSH) {
                 queue_flush(q, QUEUE_ORDERED_PREFLUSH);
@@ -506,7 +508,7 @@ static inline struct request *start_ordered(request_queue_t *q,
 
 int blk_do_ordered(request_queue_t *q, struct request **rqp)
 {
-        struct request *rq = *rqp, *allowed_rq;
+        struct request *rq = *rqp;
         int is_barrier = blk_fs_request(rq) && blk_barrier_rq(rq);
 
         if (!q->ordseq) {
@@ -530,32 +532,26 @@ int blk_do_ordered(request_queue_t *q, struct request **rqp)
                 }
         }
 
+        /*
+         * Ordered sequence in progress
+         */
+
+        /* Special requests are not subject to ordering rules. */
+        if (!blk_fs_request(rq) &&
+            rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
+                return 1;
+
         if (q->ordered & QUEUE_ORDERED_TAG) {
+                /* Ordered by tag.  Blocking the next barrier is enough. */
                 if (is_barrier && rq != &q->bar_rq)
                         *rqp = NULL;
-                return 1;
-        }
-
-        switch (blk_ordered_cur_seq(q)) {
-        case QUEUE_ORDSEQ_PREFLUSH:
-                allowed_rq = &q->pre_flush_rq;
-                break;
-        case QUEUE_ORDSEQ_BAR:
-                allowed_rq = &q->bar_rq;
-                break;
-        case QUEUE_ORDSEQ_POSTFLUSH:
-                allowed_rq = &q->post_flush_rq;
-                break;
-        default:
-                allowed_rq = NULL;
-                break;
+        } else {
+                /* Ordered by draining.  Wait for turn. */
+                WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
+                if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
+                        *rqp = NULL;
         }
 
-        if (rq != allowed_rq &&
-            (blk_fs_request(rq) || rq == &q->pre_flush_rq ||
-             rq == &q->post_flush_rq))
-                *rqp = NULL;
-
         return 1;
 }
 
@@ -629,26 +625,31 @@ static inline int ordered_bio_endio(struct request *rq, struct bio *bio,
  *    Different hardware can have different requirements as to what pages
  *    it can do I/O directly to. A low level driver can call
  *    blk_queue_bounce_limit to have lower memory pages allocated as bounce
- *    buffers for doing I/O to pages residing above @page. By default
- *    the block layer sets this to the highest numbered "low" memory page.
+ *    buffers for doing I/O to pages residing above @page.
  **/
 void blk_queue_bounce_limit(request_queue_t *q, u64 dma_addr)
 {
         unsigned long bounce_pfn = dma_addr >> PAGE_SHIFT;
-
-        /*
-         * set appropriate bounce gfp mask -- unfortunately we don't have a
-         * full 4GB zone, so we have to resort to low memory for any bounces.
-         * ISA has its own < 16MB zone.
-         */
-        if (bounce_pfn < blk_max_low_pfn) {
-                BUG_ON(dma_addr < BLK_BOUNCE_ISA);
+        int dma = 0;
+
+        q->bounce_gfp = GFP_NOIO;
+#if BITS_PER_LONG == 64
+        /* Assume anything <= 4GB can be handled by IOMMU.
+           Actually some IOMMUs can handle everything, but I don't
+           know of a way to test this here. */
+        if (bounce_pfn < (0xffffffff>>PAGE_SHIFT))
+                dma = 1;
+        q->bounce_pfn = max_low_pfn;
+#else
+        if (bounce_pfn < blk_max_low_pfn)
+                dma = 1;
+        q->bounce_pfn = bounce_pfn;
+#endif
+        if (dma) {
                 init_emergency_isa_pool();
                 q->bounce_gfp = GFP_NOIO | GFP_DMA;
-        } else
-                q->bounce_gfp = GFP_NOIO;
-
-        q->bounce_pfn = bounce_pfn;
+                q->bounce_pfn = bounce_pfn;
+        }
 }
 
 EXPORT_SYMBOL(blk_queue_bounce_limit);
@@ -662,7 +663,7 @@ EXPORT_SYMBOL(blk_queue_bounce_limit);
  *    Enables a low level driver to set an upper limit on the size of
  *    received requests.
  **/
-void blk_queue_max_sectors(request_queue_t *q, unsigned short max_sectors)
+void blk_queue_max_sectors(request_queue_t *q, unsigned int max_sectors)
 {
         if ((max_sectors << 9) < PAGE_CACHE_SIZE) {
                 max_sectors = 1 << (PAGE_CACHE_SHIFT - 9);
@@ -2577,6 +2578,8 @@ void disk_round_stats(struct gendisk *disk)
         disk->stamp = now;
 }
 
+EXPORT_SYMBOL_GPL(disk_round_stats);
+
 /*
  * queue lock must be held
  */
@@ -2632,6 +2635,7 @@ EXPORT_SYMBOL(blk_put_request);
 /**
  * blk_end_sync_rq - executes a completion event on a request
  * @rq: request to complete
+ * @error: end io status of the request
  */
 void blk_end_sync_rq(struct request *rq, int error)
 {
@@ -3153,7 +3157,7 @@ static int __end_that_request_first(struct request *req, int uptodate,
         if (blk_fs_request(req) && req->rq_disk) {
                 const int rw = rq_data_dir(req);
 
-                __disk_stat_add(req->rq_disk, sectors[rw], nr_bytes >> 9);
+                disk_stat_add(req->rq_disk, sectors[rw], nr_bytes >> 9);
         }
 
         total_bytes = bio_nbytes = 0;
@@ -3448,7 +3452,7 @@ int __init blk_dev_init(void)
         iocontext_cachep = kmem_cache_create("blkdev_ioc",
                         sizeof(struct io_context), 0, SLAB_PANIC, NULL, NULL);
 
-        for (i = 0; i < NR_CPUS; i++)
+        for_each_cpu(i)
                 INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));
 
         open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL);
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index cc72210687eb..24f7af9d0abc 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -310,6 +310,8 @@ static int sg_io(struct file *file, request_queue_t *q,
         if (!rq->timeout)
                 rq->timeout = BLK_DEFAULT_TIMEOUT;
 
+        rq->retries = 0;
+
         start_time = jiffies;
 
         /* ignore return value. All information is passed back to caller
@@ -427,6 +429,7 @@ static int sg_scsi_ioctl(struct file *file, request_queue_t *q,
         rq->data = buffer;
         rq->data_len = bytes;
         rq->flags |= REQ_BLOCK_PC;
+        rq->retries = 0;
 
         blk_execute_rq(q, bd_disk, rq, 0);
         err = rq->errors & 0xff;        /* only 8 bit SCSI status */