GFS2: Clean up reservation removal

The reservation for an inode should be cleared when it is truncated so
that we can start again at a different offset for future allocations.
We could try and do better than that, by resetting the search based on
where the truncation started from, but this is only a first step.

In addition, there are three callers of gfs2_rs_delete() but only one
of those should really be testing the value of i_writecount. While
we get away with that in the other cases currently, I think it would
be better if we made that test specific to the one case which
requires it.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 285dd36..d4d10fa 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -661,14 +661,13 @@
 /**
  * gfs2_rs_delete - delete a multi-block reservation
  * @ip: The inode for this reservation
+ * @wcount: The inode's write count, or NULL
  *
  */
-void gfs2_rs_delete(struct gfs2_inode *ip)
+void gfs2_rs_delete(struct gfs2_inode *ip, atomic_t *wcount)
 {
-	struct inode *inode = &ip->i_inode;
-
 	down_write(&ip->i_rw_mutex);
-	if (ip->i_res && atomic_read(&inode->i_writecount) <= 1) {
+	if (ip->i_res && ((wcount == NULL) || (atomic_read(wcount) <= 1))) {
 		gfs2_rs_deltree(ip->i_res);
 		BUG_ON(ip->i_res->rs_free);
 		kmem_cache_free(gfs2_rsrv_cachep, ip->i_res);