Btrfs: Make ACLs return EOPNOTSUPP for now

There was a slight problem with ACL's returning EINVAL when you tried to set an
ACL.  This isn't correct, we should be returning EOPNOTSUPP, so I did a very
ugly thing and just commented everybody out and made them return EOPNOTSUPP.
This is only temporary, I'm going back to implement ACL's, but Chris wants to
push out a release so this will suffice for now.

Also Yan suggested setting reada to -1 in the delete case to enable backwards
readahead, and in the listxattr case I moved path->reada = 2; to after the if
(!path) check so we can avoid a possible null dereference.  Thank you,

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index aee9f06..889ba89 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -23,32 +23,50 @@
 #include "ctree.h"
 #include "xattr.h"
 
+/*
+ * FIXME: At this point this is all place holder stuff, we just return
+ * -EOPNOTSUPP so cp won't complain when it tries to copy over a file with an
+ *  acl on it.
+ */
+
 static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
 				      void *value, size_t size)
 {
+	/*
 	return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
 			       value, size);
+	*/
+	return -EOPNOTSUPP;
 }
 
 static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
 				      const void *value, size_t size, int flags)
 {
+	/*
 	return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
 			       value, size, flags);
+	*/
+	return -EOPNOTSUPP;
 }
 
 static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
 				       void *value, size_t size)
 {
+	/*
 	return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
 			       name, value, size);
+	*/
+	return -EOPNOTSUPP;
 }
 
 static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
 				       const void *value, size_t size, int flags)
 {
+	/*
 	return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
 			       name, value, size, flags);
+	*/
+	return -EOPNOTSUPP;
 }
 
 struct xattr_handler btrfs_xattr_acl_default_handler = {