Btrfs: block group switching

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 61 insertions, 24 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a366415e03a6..b6dc020bdde9 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -232,6 +232,7 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
         struct btrfs_block_group_cache *found_group = NULL;
         struct btrfs_fs_info *info = root->fs_info;
         struct radix_tree_root *radix;
+        struct radix_tree_root *swap_radix;
         u64 used;
         u64 last = 0;
         u64 hint_last;
@@ -239,14 +240,18 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
         int ret;
         int full_search = 0;
         int factor = 8;
+        int data_swap = 0;
 
         if (!owner)
                 factor = 5;
 
-        if (data)
+        if (data) {
                 radix = &info->block_group_data_radix;
-        else
+                swap_radix = &info->block_group_radix;
+        } else {
                 radix = &info->block_group_radix;
+                swap_radix = &info->block_group_data_radix;
+        }
 
         if (search_start) {
                 struct btrfs_block_group_cache *shint;
@@ -334,15 +339,27 @@ again:
                 cond_resched();
         }
         if (!full_search) {
-printk("find block group doing full search data %d start %Lu\n", data, search_start);
                 last = search_start;
                 full_search = 1;
                 goto again;
         }
+        if (!data_swap) {
+                struct radix_tree_root *tmp = radix;
+                data_swap = 1;
+                radix = swap_radix;
+                swap_radix = tmp;
+                last = search_start;
+                goto again;
+        }
         if (!found_group) {
 printk("find block group bailing to zero data %d\n", data);
                 ret = radix_tree_gang_lookup(radix,
                                              (void **)&found_group, 0, 1);
+                if (ret == 0) {
+                        ret = radix_tree_gang_lookup(swap_radix,
+                                                     (void **)&found_group,
+                                                     0, 1);
+                }
                 BUG_ON(ret != 1);
         }
 found:
@@ -552,7 +569,8 @@ int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
 
 static int update_block_group(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
-                              u64 blocknr, u64 num, int alloc, int mark_free)
+                              u64 blocknr, u64 num, int alloc, int mark_free,
+                              int data)
 {
         struct btrfs_block_group_cache *cache;
         struct btrfs_fs_info *info = root->fs_info;
@@ -560,6 +578,7 @@ static int update_block_group(struct btrfs_trans_handle *trans,
         u64 old_val;
         u64 block_in_group;
         u64 i;
+        int ret;
 
         while(total) {
                 cache = lookup_block_group(info, blocknr);
@@ -577,7 +596,6 @@ static int update_block_group(struct btrfs_trans_handle *trans,
                 old_val = btrfs_block_group_used(&cache->item);
                 num = min(total, cache->key.offset - block_in_group);
                 if (alloc) {
-                        old_val += num;
                         if (blocknr > cache->last_alloc)
                                 cache->last_alloc = blocknr;
                         if (!cache->data) {
@@ -586,6 +604,30 @@ static int update_block_group(struct btrfs_trans_handle *trans,
                                                         blocknr + i);
                                 }
                         }
+                        if (cache->data != data &&
+                            old_val < cache->key.offset / 2) {
+printk("changing block group %Lu from %d to %d\n", cache->key.objectid, cache->data, data);
+                                cache->data = data;
+                                radix_tree_delete(cache->radix,
+                                                  cache->key.objectid +
+                                                  cache->key.offset - 1);
+
+                                if (data) {
+                                        cache->radix =
+                                                &info->block_group_data_radix;
+                                        cache->item.flags |=
+                                                BTRFS_BLOCK_GROUP_DATA;
+                                } else {
+                                        cache->radix = &info->block_group_radix;
+                                        cache->item.flags &=
+                                                ~BTRFS_BLOCK_GROUP_DATA;
+                                }
+                                ret = radix_tree_insert(cache->radix,
+                                                        cache->key.objectid +
+                                                        cache->key.offset - 1,
+                                                        (void *)cache);
+                        }
+                        old_val += num;
                 } else {
                         old_val -= num;
                         if (blocknr < cache->first_free)
@@ -596,8 +638,8 @@ static int update_block_group(struct btrfs_trans_handle *trans,
                                                       blocknr + i);
                                 }
                         }
-                        if (old_val < (cache->key.offset * 5) / 10 &&
-                            old_val + num >= (cache->key.offset * 5) / 10) {
+                        if (old_val < cache->key.offset / 2 &&
+                            old_val + num >= cache->key.offset / 2) {
 printk("group %Lu now available\n", cache->key.objectid);
                                 radix_tree_tag_set(cache->radix,
                                                    cache->key.objectid +
@@ -779,7 +821,7 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
                 if (ret)
                         BUG();
                 ret = update_block_group(trans, root, blocknr, num_blocks, 0,
-                                         mark_free);
+                                         mark_free, 0);
                 BUG_ON(ret);
         }
         btrfs_free_path(path);
@@ -909,10 +951,7 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
         }
 
 check_failed:
-        if (!full_scan && block_group->data != data)
-                WARN_ON(1);
-
-        if (!data)
+        if (!block_group->data)
                 search_start = find_search_start(root, &block_group,
                                                  search_start, total_needed);
         else
@@ -1142,7 +1181,7 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                 info->extent_tree_insert[info->extent_tree_insert_nr++] =
                         ins->objectid;
                 ret = update_block_group(trans, root,
-                                         ins->objectid, ins->offset, 1, 0);
+                                         ins->objectid, ins->offset, 1, 0, 0);
                 BUG_ON(ret);
                 return 0;
         }
@@ -1208,7 +1247,8 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
         if (pending_ret) {
                 return pending_ret;
         }
-        ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
+        ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0,
+                                 data);
         return 0;
 }
 
@@ -1477,7 +1517,6 @@ int btrfs_read_block_groups(struct btrfs_root *root)
         struct btrfs_leaf *leaf;
         u64 group_size_blocks = BTRFS_BLOCK_GROUP_SIZE / root->blocksize;
         u64 used;
-        u64 nr = 0;
 
         root = info->extent_root;
         key.objectid = 0;
@@ -1505,13 +1544,16 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                         break;
                 }
 
-                if (nr % 3)
+                bi = btrfs_item_ptr(leaf, path->slots[0],
+                                    struct btrfs_block_group_item);
+                if (bi->flags & BTRFS_BLOCK_GROUP_DATA) {
                         radix = &info->block_group_data_radix;
-                else
+                        cache->data = 1;
+                } else {
                         radix = &info->block_group_radix;
+                        cache->data = 0;
+                }
 
-                bi = btrfs_item_ptr(leaf, path->slots[0],
-                                    struct btrfs_block_group_item);
                 memcpy(&cache->item, bi, sizeof(*bi));
                 memcpy(&cache->key, &found_key, sizeof(found_key));
                 cache->last_alloc = cache->key.objectid;
@@ -1520,10 +1562,6 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                 cache->pinned = 0;
                 cache->cached = 0;
 
-                if (nr % 3)
-                        cache->data = 1;
-                else
-                        cache->data = 0;
                 cache->radix = radix;
 
                 key.objectid = found_key.objectid + found_key.offset;
@@ -1541,7 +1579,6 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                 if (key.objectid >=
                     btrfs_super_total_blocks(info->disk_super))
                         break;
-                nr++;
         }
 
         btrfs_free_path(path);