Revert "Btrfs: don't delay inode ref updates during log, replay"

commit 081fafdd upstream.

This reverts commit 644d1071, upstream
commit 6f896054.

The original patch for mainline, 6f896054 (Btrfs: don't delay
inode ref updates during log replay) lists 1d52c78a (Btrfs: try
not to ENOSPC on log replay) as the only pre-3.18 dependency, but it
also depends on 67de1176 (Btrfs: introduce the delayed inode ref
deletion for the single link inode), which was introduced in 3.14
and isn't in 3.12.y.

The -stable commit added the check to btrfs_delayed_update_inode,
which may look similar to btrfs_delayed_delete_inode_ref, but it's
only superficial.  The tops of both functions handle typical
delayed node boilerplate.  The upshot is that the patch is harmless
since the caller already checks to see if we're doing log recovery,
so we're not breaking anything.  It should be reverted because it
makes it appear as if this issue was fixed for users who did
backport 67de1176, when it is not.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>

fs/btrfs/delayed-inode.c

@@ -1843,14 +1843,6 @@ int btrfs_delayed_update_inode(struct btrfs_trans_handle *trans,
 	struct btrfs_delayed_node *delayed_node;
 	int ret = 0;
 
-	/*
-	 * we don't do delayed inode updates during log recovery because it
-	 * leads to enospc problems.  This means we also can't do
-	 * delayed inode refs
-	 */
-	if (BTRFS_I(inode)->root->fs_info->log_root_recovering)
-		return -EAGAIN;
-
 	delayed_node = btrfs_get_or_create_delayed_node(inode);
 	if (IS_ERR(delayed_node))
 		return PTR_ERR(delayed_node);