ocfs2: btree changes for unwritten extents
Writes to a region marked as unwritten might result in a record split or
merge. We can support splits by making minor changes to the existing insert
code. Merges require left rotations which mostly re-use right rotation
support functions.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 648ef8e..5cc90a4 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -306,6 +306,19 @@
return 0;
}
+static inline int ocfs2_writes_unwritten_extents(struct ocfs2_super *osb)
+{
+ /*
+ * Support for sparse files is a pre-requisite
+ */
+ if (!ocfs2_sparse_alloc(osb))
+ return 0;
+
+ if (osb->s_feature_ro_compat & OCFS2_FEATURE_RO_COMPAT_UNWRITTEN)
+ return 1;
+ return 0;
+}
+
/* set / clear functions because cluster events can make these happen
* in parallel so we want the transitions to be atomic. this also
* means that any future flags osb_flags must be protected by spinlock
