GFS2: fix bad inode i_goal values during block allocation

This patch checks if i_goal is either zero or if doesn't exist
within any rgrp (i.e gfs2_blk2rgrpd() returns NULL). If so, it
assigns the ip->i_no_addr block as the i_goal.

There are two scenarios where a bad i_goal can result in a
-EBADSLT error.

1. Attempting to allocate to an existing inode:
Control reaches gfs2_inplace_reserve() and ip->i_goal is bad.
We need to fix i_goal here.

2. A new inode is created in a directory whose i_goal is hosed:
In this case, the parent dir's i_goal is copied onto the new
inode. Since the new inode is not yet created, the ip->i_no_addr
field is invalid and so, the fix in gfs2_inplace_reserve() as per
1) won't work in this scenario. We need to catch and fix it sooner
in the parent dir itself (gfs2_create_inode()), before it is
copied to the new inode.

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/inode.c

@@ -672,6 +672,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 	gfs2_set_inode_blocks(inode, 1);
 	munge_mode_uid_gid(dip, inode);
+	check_and_update_goal(dip);
 	ip->i_goal = dip->i_goal;
 	ip->i_diskflags = 0;
 	ip->i_eattr = 0;