Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...
[pandora-kernel.git] / fs / btrfs / volumes.c
index c440c89..c7367ae 100644 (file)
@@ -151,22 +151,25 @@ static noinline int run_scheduled_bios(struct btrfs_device *device)
        struct bio *cur;
        int again = 0;
        unsigned long num_run;
-       unsigned long num_sync_run;
        unsigned long batch_run = 0;
        unsigned long limit;
        unsigned long last_waited = 0;
        int force_reg = 0;
+       struct blk_plug plug;
+
+       /*
+        * this function runs all the bios we've collected for
+        * a particular device.  We don't want to wander off to
+        * another device without first sending all of these down.
+        * So, setup a plug here and finish it off before we return
+        */
+       blk_start_plug(&plug);
 
        bdi = blk_get_backing_dev_info(device->bdev);
        fs_info = device->dev_root->fs_info;
        limit = btrfs_async_submit_limit(fs_info);
        limit = limit * 2 / 3;
 
-       /* we want to make sure that every time we switch from the sync
-        * list to the normal list, we unplug
-        */
-       num_sync_run = 0;
-
 loop:
        spin_lock(&device->io_lock);
 
@@ -212,15 +215,6 @@ loop_lock:
 
        spin_unlock(&device->io_lock);
 
-       /*
-        * if we're doing the regular priority list, make sure we unplug
-        * for any high prio bios we've sent down
-        */
-       if (pending_bios == &device->pending_bios && num_sync_run > 0) {
-               num_sync_run = 0;
-               blk_run_backing_dev(bdi, NULL);
-       }
-
        while (pending) {
 
                rmb();
@@ -248,19 +242,11 @@ loop_lock:
 
                BUG_ON(atomic_read(&cur->bi_cnt) == 0);
 
-               if (cur->bi_rw & REQ_SYNC)
-                       num_sync_run++;
-
                submit_bio(cur->bi_rw, cur);
                num_run++;
                batch_run++;
-               if (need_resched()) {
-                       if (num_sync_run) {
-                               blk_run_backing_dev(bdi, NULL);
-                               num_sync_run = 0;
-                       }
+               if (need_resched())
                        cond_resched();
-               }
 
                /*
                 * we made progress, there is more work to do and the bdi
@@ -293,13 +279,8 @@ loop_lock:
                                 * against it before looping
                                 */
                                last_waited = ioc->last_waited;
-                               if (need_resched()) {
-                                       if (num_sync_run) {
-                                               blk_run_backing_dev(bdi, NULL);
-                                               num_sync_run = 0;
-                                       }
+                               if (need_resched())
                                        cond_resched();
-                               }
                                continue;
                        }
                        spin_lock(&device->io_lock);
@@ -312,22 +293,6 @@ loop_lock:
                }
        }
 
-       if (num_sync_run) {
-               num_sync_run = 0;
-               blk_run_backing_dev(bdi, NULL);
-       }
-       /*
-        * IO has already been through a long path to get here.  Checksumming,
-        * async helper threads, perhaps compression.  We've done a pretty
-        * good job of collecting a batch of IO and should just unplug
-        * the device right away.
-        *
-        * This will help anyone who is waiting on the IO, they might have
-        * already unplugged, but managed to do so before the bio they
-        * cared about found its way down here.
-        */
-       blk_run_backing_dev(bdi, NULL);
-
        cond_resched();
        if (again)
                goto loop;
@@ -338,6 +303,7 @@ loop_lock:
        spin_unlock(&device->io_lock);
 
 done:
+       blk_finish_plug(&plug);
        return 0;
 }
 
@@ -2949,7 +2915,7 @@ static int find_live_mirror(struct map_lookup *map, int first, int num,
 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
                             u64 logical, u64 *length,
                             struct btrfs_multi_bio **multi_ret,
-                            int mirror_num, struct page *unplug_page)
+                            int mirror_num)
 {
        struct extent_map *em;
        struct map_lookup *map;
@@ -2984,11 +2950,6 @@ again:
        em = lookup_extent_mapping(em_tree, logical, *length);
        read_unlock(&em_tree->lock);
 
-       if (!em && unplug_page) {
-               kfree(multi);
-               return 0;
-       }
-
        if (!em) {
                printk(KERN_CRIT "unable to find logical %llu len %llu\n",
                       (unsigned long long)logical,
@@ -3055,7 +3016,7 @@ again:
                *length = em->len - offset;
        }
 
-       if (!multi_ret && !unplug_page)
+       if (!multi_ret)
                goto out;
 
        num_stripes = 1;
@@ -3072,7 +3033,7 @@ again:
                                            stripe_nr_end - stripe_nr_orig);
                stripe_index = do_div(stripe_nr, map->num_stripes);
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
-               if (unplug_page || (rw & (REQ_WRITE | REQ_DISCARD)))
+               if (rw & (REQ_WRITE | REQ_DISCARD))
                        num_stripes = map->num_stripes;
                else if (mirror_num)
                        stripe_index = mirror_num - 1;
@@ -3094,7 +3055,7 @@ again:
                stripe_index = do_div(stripe_nr, factor);
                stripe_index *= map->sub_stripes;
 
-               if (unplug_page || (rw & REQ_WRITE))
+               if (rw & REQ_WRITE)
                        num_stripes = map->sub_stripes;
                else if (rw & REQ_DISCARD)
                        num_stripes = min_t(u64, map->sub_stripes *
@@ -3126,13 +3087,19 @@ again:
 
                        if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
                                u64 stripes;
-                               int last_stripe = (stripe_nr_end - 1) %
-                                       map->num_stripes;
+                               u32 last_stripe = 0;
                                int j;
 
+                               div_u64_rem(stripe_nr_end - 1,
+                                           map->num_stripes,
+                                           &last_stripe);
+
                                for (j = 0; j < map->num_stripes; j++) {
-                                       if ((stripe_nr_end - 1 - j) %
-                                             map->num_stripes == stripe_index)
+                                       u32 test;
+
+                                       div_u64_rem(stripe_nr_end - 1 - j,
+                                                   map->num_stripes, &test);
+                                       if (test == stripe_index)
                                                break;
                                }
                                stripes = stripe_nr_end - 1 - j;
@@ -3153,11 +3120,19 @@ again:
                                int j;
                                int factor = map->num_stripes /
                                             map->sub_stripes;
-                               int last_stripe = (stripe_nr_end - 1) % factor;
+                               u32 last_stripe = 0;
+
+                               div_u64_rem(stripe_nr_end - 1,
+                                           factor, &last_stripe);
                                last_stripe *= map->sub_stripes;
 
                                for (j = 0; j < factor; j++) {
-                                       if ((stripe_nr_end - 1 - j) % factor ==
+                                       u32 test;
+
+                                       div_u64_rem(stripe_nr_end - 1 - j,
+                                                   factor, &test);
+
+                                       if (test ==
                                            stripe_index / map->sub_stripes)
                                                break;
                                }
@@ -3190,26 +3165,12 @@ again:
                }
        } else {
                for (i = 0; i < num_stripes; i++) {
-                       if (unplug_page) {
-                               struct btrfs_device *device;
-                               struct backing_dev_info *bdi;
-
-                               device = map->stripes[stripe_index].dev;
-                               if (device->bdev) {
-                                       bdi = blk_get_backing_dev_info(device->
-                                                                      bdev);
-                                       if (bdi->unplug_io_fn)
-                                               bdi->unplug_io_fn(bdi,
-                                                                 unplug_page);
-                               }
-                       } else {
-                               multi->stripes[i].physical =
-                                       map->stripes[stripe_index].physical +
-                                       stripe_offset +
-                                       stripe_nr * map->stripe_len;
-                               multi->stripes[i].dev =
-                                       map->stripes[stripe_index].dev;
-                       }
+                       multi->stripes[i].physical =
+                               map->stripes[stripe_index].physical +
+                               stripe_offset +
+                               stripe_nr * map->stripe_len;
+                       multi->stripes[i].dev =
+                               map->stripes[stripe_index].dev;
                        stripe_index++;
                }
        }
@@ -3228,7 +3189,7 @@ int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
                      struct btrfs_multi_bio **multi_ret, int mirror_num)
 {
        return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
-                                mirror_num, NULL);
+                                mirror_num);
 }
 
 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
@@ -3296,14 +3257,6 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
        return 0;
 }
 
-int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
-                     u64 logical, struct page *page)
-{
-       u64 length = PAGE_CACHE_SIZE;
-       return __btrfs_map_block(map_tree, READ, logical, &length,
-                                NULL, 0, page);
-}
-
 static void end_bio_multi_stripe(struct bio *bio, int err)
 {
        struct btrfs_multi_bio *multi = bio->bi_private;