Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...
[~shefty/rdma-dev.git] / fs / btrfs / extent-tree.c
index f0d5718d2587a43c96101c3408a0749fc4abefa0..2ad813674d77e3cb119fa5049c6e5b7407832645 100644 (file)
@@ -5107,11 +5107,11 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans,
        struct btrfs_root *root = orig_root->fs_info->extent_root;
        struct btrfs_free_cluster *last_ptr = NULL;
        struct btrfs_block_group_cache *block_group = NULL;
+       struct btrfs_block_group_cache *used_block_group;
        int empty_cluster = 2 * 1024 * 1024;
        int allowed_chunk_alloc = 0;
        int done_chunk_alloc = 0;
        struct btrfs_space_info *space_info;
-       int last_ptr_loop = 0;
        int loop = 0;
        int index = 0;
        int alloc_type = (data & BTRFS_BLOCK_GROUP_DATA) ?
@@ -5173,6 +5173,7 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans,
 ideal_cache:
                block_group = btrfs_lookup_block_group(root->fs_info,
                                                       search_start);
+               used_block_group = block_group;
                /*
                 * we don't want to use the block group if it doesn't match our
                 * allocation bits, or if its not cached.
@@ -5210,6 +5211,7 @@ search:
                u64 offset;
                int cached;
 
+               used_block_group = block_group;
                btrfs_get_block_group(block_group);
                search_start = block_group->key.objectid;
 
@@ -5286,71 +5288,62 @@ alloc:
                spin_unlock(&block_group->free_space_ctl->tree_lock);
 
                /*
-                * Ok we want to try and use the cluster allocator, so lets look
-                * there, unless we are on LOOP_NO_EMPTY_SIZE, since we will
-                * have tried the cluster allocator plenty of times at this
-                * point and not have found anything, so we are likely way too
-                * fragmented for the clustering stuff to find anything, so lets
-                * just skip it and let the allocator find whatever block it can
-                * find
+                * Ok we want to try and use the cluster allocator, so
+                * lets look there
                 */
-               if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) {
+               if (last_ptr) {
                        /*
                         * the refill lock keeps out other
                         * people trying to start a new cluster
                         */
                        spin_lock(&last_ptr->refill_lock);
-                       if (!last_ptr->block_group ||
-                           last_ptr->block_group->ro ||
-                           !block_group_bits(last_ptr->block_group, data))
+                       used_block_group = last_ptr->block_group;
+                       if (used_block_group != block_group &&
+                           (!used_block_group ||
+                            used_block_group->ro ||
+                            !block_group_bits(used_block_group, data))) {
+                               used_block_group = block_group;
                                goto refill_cluster;
+                       }
+
+                       if (used_block_group != block_group)
+                               btrfs_get_block_group(used_block_group);
 
-                       offset = btrfs_alloc_from_cluster(block_group, last_ptr,
-                                                num_bytes, search_start);
+                       offset = btrfs_alloc_from_cluster(used_block_group,
+                         last_ptr, num_bytes, used_block_group->key.objectid);
                        if (offset) {
                                /* we have a block, we're done */
                                spin_unlock(&last_ptr->refill_lock);
                                goto checks;
                        }
 
-                       spin_lock(&last_ptr->lock);
-                       /*
-                        * whoops, this cluster doesn't actually point to
-                        * this block group.  Get a ref on the block
-                        * group is does point to and try again
-                        */
-                       if (!last_ptr_loop && last_ptr->block_group &&
-                           last_ptr->block_group != block_group &&
-                           index <=
-                                get_block_group_index(last_ptr->block_group)) {
-
-                               btrfs_put_block_group(block_group);
-                               block_group = last_ptr->block_group;
-                               btrfs_get_block_group(block_group);
-                               spin_unlock(&last_ptr->lock);
-                               spin_unlock(&last_ptr->refill_lock);
-
-                               last_ptr_loop = 1;
-                               search_start = block_group->key.objectid;
-                               /*
-                                * we know this block group is properly
-                                * in the list because
-                                * btrfs_remove_block_group, drops the
-                                * cluster before it removes the block
-                                * group from the list
-                                */
-                               goto have_block_group;
+                       WARN_ON(last_ptr->block_group != used_block_group);
+                       if (used_block_group != block_group) {
+                               btrfs_put_block_group(used_block_group);
+                               used_block_group = block_group;
                        }
-                       spin_unlock(&last_ptr->lock);
 refill_cluster:
+                       BUG_ON(used_block_group != block_group);
+                       /* If we are on LOOP_NO_EMPTY_SIZE, we can't
+                        * set up a new clusters, so lets just skip it
+                        * and let the allocator find whatever block
+                        * it can find.  If we reach this point, we
+                        * will have tried the cluster allocator
+                        * plenty of times and not have found
+                        * anything, so we are likely way too
+                        * fragmented for the clustering stuff to find
+                        * anything.  */
+                       if (loop >= LOOP_NO_EMPTY_SIZE) {
+                               spin_unlock(&last_ptr->refill_lock);
+                               goto unclustered_alloc;
+                       }
+
                        /*
                         * this cluster didn't work out, free it and
                         * start over
                         */
                        btrfs_return_cluster_to_free_space(NULL, last_ptr);
 
-                       last_ptr_loop = 0;
-
                        /* allocate a cluster in this block group */
                        ret = btrfs_find_space_cluster(trans, root,
                                               block_group, last_ptr,
@@ -5390,6 +5383,7 @@ refill_cluster:
                        goto loop;
                }
 
+unclustered_alloc:
                offset = btrfs_find_space_for_alloc(block_group, search_start,
                                                    num_bytes, empty_size);
                /*
@@ -5416,14 +5410,14 @@ checks:
                search_start = stripe_align(root, offset);
                /* move on to the next group */
                if (search_start + num_bytes >= search_end) {
-                       btrfs_add_free_space(block_group, offset, num_bytes);
+                       btrfs_add_free_space(used_block_group, offset, num_bytes);
                        goto loop;
                }
 
                /* move on to the next group */
                if (search_start + num_bytes >
-                   block_group->key.objectid + block_group->key.offset) {
-                       btrfs_add_free_space(block_group, offset, num_bytes);
+                   used_block_group->key.objectid + used_block_group->key.offset) {
+                       btrfs_add_free_space(used_block_group, offset, num_bytes);
                        goto loop;
                }
 
@@ -5431,14 +5425,14 @@ checks:
                ins->offset = num_bytes;
 
                if (offset < search_start)
-                       btrfs_add_free_space(block_group, offset,
+                       btrfs_add_free_space(used_block_group, offset,
                                             search_start - offset);
                BUG_ON(offset > search_start);
 
-               ret = btrfs_update_reserved_bytes(block_group, num_bytes,
+               ret = btrfs_update_reserved_bytes(used_block_group, num_bytes,
                                                  alloc_type);
                if (ret == -EAGAIN) {
-                       btrfs_add_free_space(block_group, offset, num_bytes);
+                       btrfs_add_free_space(used_block_group, offset, num_bytes);
                        goto loop;
                }
 
@@ -5447,15 +5441,19 @@ checks:
                ins->offset = num_bytes;
 
                if (offset < search_start)
-                       btrfs_add_free_space(block_group, offset,
+                       btrfs_add_free_space(used_block_group, offset,
                                             search_start - offset);
                BUG_ON(offset > search_start);
+               if (used_block_group != block_group)
+                       btrfs_put_block_group(used_block_group);
                btrfs_put_block_group(block_group);
                break;
 loop:
                failed_cluster_refill = false;
                failed_alloc = false;
                BUG_ON(index != get_block_group_index(block_group));
+               if (used_block_group != block_group)
+                       btrfs_put_block_group(used_block_group);
                btrfs_put_block_group(block_group);
        }
        up_read(&space_info->groups_sem);