ext4: cleanup transaction restarts during inode deletion

During inode deletion, the number of journal credits that will be
needed is hard to determine.  For that reason we have journal
extend/restart calls in several places.  Whenever a transaction is
restarted, filesystem must be in a consistent state because there is
no atomicity guarantee beyond a restart call.

Add ext4_xattr_ensure_credits() helper function which takes care of
journal extend/restart logic.  It also handles getting jbd2 write
access and dirty metadata calls.  This function is called at every
iteration of handling an ea_inode reference.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index adf7615..b2005a2 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -169,7 +169,8 @@ extern int ext4_xattr_set_credits(struct inode *inode, size_t value_len);
 
 extern int ext4_xattr_inode_unlink(struct inode *inode, unsigned long ea_ino);
 extern int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
-				   struct ext4_xattr_inode_array **array);
+				   struct ext4_xattr_inode_array **array,
+				   int extra_credits);
 extern void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *array);
 
 extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,