Btrfs: fs_info variable for join_transaction

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 36422254ef6765c14290a2373fa6d83cf2d364d5..eb2bd826bb043442a4874e9321cb6291e160be72 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -55,48 +55,49 @@ static noinline void switch_commit_root(struct btrfs_root *root)
 static noinline int join_transaction(struct btrfs_root *root, int nofail)
 {
        struct btrfs_transaction *cur_trans;
+       struct btrfs_fs_info *fs_info = root->fs_info;
 
-       spin_lock(&root->fs_info->trans_lock);
+       spin_lock(&fs_info->trans_lock);
 loop:
        /* The file system has been taken offline. No new transactions. */
-       if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
-               spin_unlock(&root->fs_info->trans_lock);
+       if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+               spin_unlock(&fs_info->trans_lock);
                return -EROFS;
        }
 
-       if (root->fs_info->trans_no_join) {
+       if (fs_info->trans_no_join) {
                if (!nofail) {
-                       spin_unlock(&root->fs_info->trans_lock);
+                       spin_unlock(&fs_info->trans_lock);
                        return -EBUSY;
                }
        }
 
-       cur_trans = root->fs_info->running_transaction;
+       cur_trans = fs_info->running_transaction;
        if (cur_trans) {
                if (cur_trans->aborted) {
-                       spin_unlock(&root->fs_info->trans_lock);
+                       spin_unlock(&fs_info->trans_lock);
                        return cur_trans->aborted;
                }
                atomic_inc(&cur_trans->use_count);
                atomic_inc(&cur_trans->num_writers);
                cur_trans->num_joined++;
-               spin_unlock(&root->fs_info->trans_lock);
+               spin_unlock(&fs_info->trans_lock);
                return 0;
        }
-       spin_unlock(&root->fs_info->trans_lock);
+       spin_unlock(&fs_info->trans_lock);
 
        cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
        if (!cur_trans)
                return -ENOMEM;
 
-       spin_lock(&root->fs_info->trans_lock);
-       if (root->fs_info->running_transaction) {
+       spin_lock(&fs_info->trans_lock);
+       if (fs_info->running_transaction) {
                /*
                 * someone started a transaction after we unlocked.  Make sure
                 * to redo the trans_no_join checks above
                 */
                kmem_cache_free(btrfs_transaction_cachep, cur_trans);
-               cur_trans = root->fs_info->running_transaction;
+               cur_trans = fs_info->running_transaction;
                goto loop;
        }
 
@@ -127,14 +128,14 @@ loop:
        INIT_LIST_HEAD(&cur_trans->delayed_refs.seq_head);
 
        INIT_LIST_HEAD(&cur_trans->pending_snapshots);
-       list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
+       list_add_tail(&cur_trans->list, &fs_info->trans_list);
        extent_io_tree_init(&cur_trans->dirty_pages,
-                            root->fs_info->btree_inode->i_mapping);
-       root->fs_info->generation++;
-       cur_trans->transid = root->fs_info->generation;
-       root->fs_info->running_transaction = cur_trans;
+                            fs_info->btree_inode->i_mapping);
+       fs_info->generation++;
+       cur_trans->transid = fs_info->generation;
+       fs_info->running_transaction = cur_trans;
        cur_trans->aborted = 0;
-       spin_unlock(&root->fs_info->trans_lock);
+       spin_unlock(&fs_info->trans_lock);
 
        return 0;
 }