Btrfs: Add block group pinned accounting back

This patch adds a helper function 'update_pinned_extents' to
extent-tree.c. The usage of the helper function is similar to
'update_block_group',  the last parameter of the function indicates
pin vs unpin.

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

3 files changed, 44 insertions, 16 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 27cadae1af63..56b977ffe918 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -292,8 +292,8 @@ struct btrfs_block_group_cache {
         struct btrfs_block_group_item item;
         int data;
         int cached;
+        u64 pinned;
 };
-
 struct btrfs_fs_info {
         u8 fsid[BTRFS_FSID_SIZE];
         struct btrfs_root *extent_root;
@@ -324,8 +324,9 @@ struct btrfs_fs_info {
         struct completion kobj_unregister;
         int do_barriers;
         int closing;
-};
 
+        u64 total_pinned;
+};
 /*
  * in ram representation of the tree.  extent_root is used for all allocations
  * and for the extent tree extent_root root.
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 6c8533fba7c9..3e16cca72b49 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -569,6 +569,7 @@ struct btrfs_root *open_ctree(struct super_block *sb)
                              fs_info->btree_inode->i_mapping, GFP_NOFS);
         fs_info->do_barriers = 1;
         fs_info->closing = 0;
+        fs_info->total_pinned = 0;
 
         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
         BTRFS_I(fs_info->btree_inode)->root = tree_root;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7405bd5301af..4ef6dc3d7d32 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -277,7 +277,8 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
                 if (shint && (shint->data == data ||
                               shint->data == BTRFS_BLOCK_GROUP_MIXED)) {
                         used = btrfs_block_group_used(&shint->item);
-                        if (used < div_factor(shint->key.offset, factor)) {
+                        if (used + shint->pinned <
+                            div_factor(shint->key.offset, factor)) {
                                 return shint;
                         }
                 }
@@ -285,7 +286,8 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
         if (hint && (hint->data == data ||
                      hint->data == BTRFS_BLOCK_GROUP_MIXED)) {
                 used = btrfs_block_group_used(&hint->item);
-                if (used < div_factor(hint->key.offset, factor)) {
+                if (used + hint->pinned <
+                    div_factor(hint->key.offset, factor)) {
                         return hint;
                 }
                 last = hint->key.objectid + hint->key.offset;
@@ -317,8 +319,7 @@ again:
                         free_check = cache->key.offset;
                 else
                         free_check = div_factor(cache->key.offset, factor);
-
-                if (used < free_check) {
+                if (used + cache->pinned < free_check) {
                         found_group = cache;
                         goto found;
                 }
@@ -664,6 +665,37 @@ static int update_block_group(struct btrfs_trans_handle *trans,
         }
         return 0;
 }
+static int update_pinned_extents(struct btrfs_root *root,
+                                u64 bytenr, u64 num, int pin)
+{
+        u64 len;
+        struct btrfs_block_group_cache *cache;
+        struct btrfs_fs_info *fs_info = root->fs_info;
+
+        if (pin) {
+                set_extent_dirty(&fs_info->pinned_extents,
+                                bytenr, bytenr + num - 1, GFP_NOFS);
+        } else {
+                clear_extent_dirty(&fs_info->pinned_extents,
+                                bytenr, bytenr + num - 1, GFP_NOFS);
+        }
+        while (num > 0) {
+                cache = btrfs_lookup_block_group(fs_info, bytenr);
+                WARN_ON(!cache);
+                len = min(num, cache->key.offset -
+                          (bytenr - cache->key.objectid));
+                if (pin) {
+                        cache->pinned += len;
+                        fs_info->total_pinned += len;
+                } else {
+                        cache->pinned -= len;
+                        fs_info->total_pinned -= len;
+                }
+                bytenr += len;
+                num -= len;
+        }
+        return 0;
+}
 
 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_map_tree *copy)
 {
@@ -691,9 +723,7 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
         u64 start;
         u64 end;
         int ret;
-        struct extent_map_tree *pinned_extents = &root->fs_info->pinned_extents;
         struct extent_map_tree *free_space_cache;
-
         free_space_cache = &root->fs_info->free_space_cache;
 
         while(1) {
@@ -701,9 +731,7 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
                                             EXTENT_DIRTY);
                 if (ret)
                         break;
-
-                clear_extent_dirty(pinned_extents, start, end,
-                                   GFP_NOFS);
+                update_pinned_extents(root, start, end + 1 - start, 0);
                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
                 set_extent_dirty(free_space_cache, start, end, GFP_NOFS);
         }
@@ -761,8 +789,7 @@ static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
                         }
                         free_extent_buffer(buf);
                 }
-                set_extent_dirty(&root->fs_info->pinned_extents,
-                                 bytenr, bytenr + num_bytes - 1, GFP_NOFS);
+                update_pinned_extents(root, bytenr, num_bytes, 1);
         } else {
                 set_extent_bits(&root->fs_info->pending_del,
                                 bytenr, bytenr + num_bytes - 1,
@@ -866,8 +893,7 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct
                                             EXTENT_LOCKED);
                 if (ret)
                         break;
-
-                set_extent_dirty(pinned_extents, start, end, GFP_NOFS);
+                update_pinned_extents(extent_root, start, end + 1 - start, 1);
                 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
                                   GFP_NOFS);
                 ret = __free_extent(trans, extent_root,
@@ -1579,7 +1605,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                                    sizeof(cache->item));
                 memcpy(&cache->key, &found_key, sizeof(found_key));
                 cache->cached = 0;
-
+                cache->pinned = 0;
                 key.objectid = found_key.objectid + found_key.offset;
                 btrfs_release_path(root, path);