Btrfs: block group switching

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

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 756ea9d..1bb6286 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -249,10 +249,13 @@ struct btrfs_device_item {
 /* tag for the radix tree of block groups in ram */
 #define BTRFS_BLOCK_GROUP_DIRTY 0
 #define BTRFS_BLOCK_GROUP_AVAIL 1
-#define BTRFS_BLOCK_GROUP_HINTS 8
 #define BTRFS_BLOCK_GROUP_SIZE (256 * 1024 * 1024)
+
+
+#define BTRFS_BLOCK_GROUP_DATA 1
 struct btrfs_block_group_item {
        __le64 used;
+       u8 flags;
 } __attribute__ ((__packed__));
 
 struct btrfs_block_group_cache {

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a366415..b6dc020 100644 (file)
--- 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);