Btrfs: Fix per root used space accounting

The bytes_used field in root item was originally planned to
trace the amount of used data and tree blocks. But it never
worked right since we can't trace freeing of data accurately.
This patch changes it to only trace the amount of tree blocks.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 9d4ba3470c1737396ee756b9c96a6369ee3c1f69..c4bc570a396eebf5ede775dc39b004c9ff493227 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -456,9 +456,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
                extent_buffer_get(cow);
                spin_unlock(&root->node_lock);
 
-               btrfs_free_extent(trans, root, buf->start, buf->len,
-                                 parent_start, root->root_key.objectid,
-                                 level, 0);
+               btrfs_free_tree_block(trans, root, buf->start, buf->len,
+                               parent_start, root->root_key.objectid, level);
                free_extent_buffer(buf);
                add_root_to_dirty_list(root);
        } else {
@@ -473,9 +472,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
                btrfs_set_node_ptr_generation(parent, parent_slot,
                                              trans->transid);
                btrfs_mark_buffer_dirty(parent);
-               btrfs_free_extent(trans, root, buf->start, buf->len,
-                                 parent_start, root->root_key.objectid,
-                                 level, 0);
+               btrfs_free_tree_block(trans, root, buf->start, buf->len,
+                               parent_start, root->root_key.objectid, level);
        }
        if (unlock_orig)
                btrfs_tree_unlock(buf);
@@ -1035,8 +1033,8 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                btrfs_tree_unlock(mid);
                /* once for the path */
                free_extent_buffer(mid);
-               ret = btrfs_free_extent(trans, root, mid->start, mid->len,
-                                       0, root->root_key.objectid, level, 1);
+               ret = btrfs_free_tree_block(trans, root, mid->start, mid->len,
+                                           0, root->root_key.objectid, level);
                /* once for the root ptr */
                free_extent_buffer(mid);
                return ret;
@@ -1100,10 +1098,10 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                                       1);
                        if (wret)
                                ret = wret;
-                       wret = btrfs_free_extent(trans, root, bytenr,
-                                                blocksize, 0,
-                                                root->root_key.objectid,
-                                                level, 0);
+                       wret = btrfs_free_tree_block(trans, root,
+                                                    bytenr, blocksize, 0,
+                                                    root->root_key.objectid,
+                                                    level);
                        if (wret)
                                ret = wret;
                } else {
@@ -1148,9 +1146,8 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                wret = del_ptr(trans, root, path, level + 1, pslot);
                if (wret)
                        ret = wret;
-               wret = btrfs_free_extent(trans, root, bytenr, blocksize,
-                                        0, root->root_key.objectid,
-                                        level, 0);
+               wret = btrfs_free_tree_block(trans, root, bytenr, blocksize,
+                                        0, root->root_key.objectid, level);
                if (wret)
                        ret = wret;
        } else {
@@ -3794,8 +3791,8 @@ static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
         */
        btrfs_unlock_up_safe(path, 0);
 
-       ret = btrfs_free_extent(trans, root, leaf->start, leaf->len,
-                               0, root->root_key.objectid, 0, 0);
+       ret = btrfs_free_tree_block(trans, root, leaf->start, leaf->len,
+                                   0, root->root_key.objectid, 0);
        return ret;
 }
 /*

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1983c889bb1ce95ac5e0b6a44a307594bace3594..9f806dd04c2704899bf28e5324eebaa14a923e27 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1982,6 +1982,10 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                                        u64 parent, u64 root_objectid,
                                        struct btrfs_disk_key *key, int level,
                                        u64 hint, u64 empty_size);
+int btrfs_free_tree_block(struct btrfs_trans_handle *trans,
+                         struct btrfs_root *root,
+                         u64 bytenr, u32 blocksize,
+                         u64 parent, u64 root_objectid, int level);
 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
                                            struct btrfs_root *root,
                                            u64 bytenr, u32 blocksize,

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fcdccfa4600401c9add4995ed0d0dfd5c692b0e4..44d7a322ec286a977e0fad4bbdfcdb1317267fb2 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3454,14 +3454,6 @@ static int update_block_group(struct btrfs_trans_handle *trans,
        else
                old_val -= num_bytes;
        btrfs_set_super_bytes_used(&info->super_copy, old_val);
-
-       /* block accounting for root item */
-       old_val = btrfs_root_used(&root->root_item);
-       if (alloc)
-               old_val += num_bytes;
-       else
-               old_val -= num_bytes;
-       btrfs_set_root_used(&root->root_item, old_val);
        spin_unlock(&info->delalloc_lock);
 
        while (total) {
@@ -4049,6 +4041,21 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans,
        return ret;
 }
 
+int btrfs_free_tree_block(struct btrfs_trans_handle *trans,
+                         struct btrfs_root *root,
+                         u64 bytenr, u32 blocksize,
+                         u64 parent, u64 root_objectid, int level)
+{
+       u64 used;
+       spin_lock(&root->node_lock);
+       used = btrfs_root_used(&root->root_item) - blocksize;
+       btrfs_set_root_used(&root->root_item, used);
+       spin_unlock(&root->node_lock);
+
+       return btrfs_free_extent(trans, root, bytenr, blocksize,
+                                parent, root_objectid, level, 0);
+}
+
 static u64 stripe_align(struct btrfs_root *root, u64 val)
 {
        u64 mask = ((u64)root->stripesize - 1);
@@ -4897,6 +4904,14 @@ static int alloc_tree_block(struct btrfs_trans_handle *trans,
                                        extent_op);
                BUG_ON(ret);
        }
+
+       if (root_objectid == root->root_key.objectid) {
+               u64 used;
+               spin_lock(&root->node_lock);
+               used = btrfs_root_used(&root->root_item) + num_bytes;
+               btrfs_set_root_used(&root->root_item, used);
+               spin_unlock(&root->node_lock);
+       }
        return ret;
 }
 

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3d6b33871afe5f8c0a68df30391acf181fafae80..645a17927a8f7c8edf9b9b1866695f3ab6982b23 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -289,7 +289,7 @@ static noinline int create_subvol(struct btrfs_root *root,
        btrfs_set_root_generation(&root_item, trans->transid);
        btrfs_set_root_level(&root_item, 0);
        btrfs_set_root_refs(&root_item, 1);
-       btrfs_set_root_used(&root_item, 0);
+       btrfs_set_root_used(&root_item, leaf->len);
        btrfs_set_root_last_snapshot(&root_item, 0);
 
        memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 75b31caade29aa58810d73d780a84825856cf55e..b2acc79f1b342e651a4c31da168c2952efa57ff2 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -501,13 +501,16 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
 {
        int ret;
        u64 old_root_bytenr;
+       u64 old_root_used;
        struct btrfs_root *tree_root = root->fs_info->tree_root;
 
+       old_root_used = btrfs_root_used(&root->root_item);
        btrfs_write_dirty_block_groups(trans, root);
 
        while (1) {
                old_root_bytenr = btrfs_root_bytenr(&root->root_item);
-               if (old_root_bytenr == root->node->start)
+               if (old_root_bytenr == root->node->start &&
+                   old_root_used == btrfs_root_used(&root->root_item))
                        break;
 
                btrfs_set_root_node(&root->root_item, root->node);
@@ -516,6 +519,7 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
                                        &root->root_item);
                BUG_ON(ret);
 
+               old_root_used = btrfs_root_used(&root->root_item);
                ret = btrfs_write_dirty_block_groups(trans, root);
                BUG_ON(ret);
        }