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authorMark Fasheh <mark.fasheh@oracle.com>2007-03-08 03:46:57 +0300
committerMark Fasheh <mark.fasheh@oracle.com>2007-04-27 02:02:37 +0400
commite48edee2d8eab812f31f0ff62c6ba635ca2e1e21 (patch)
tree6afb9fe59a06ce621cb11d570e432e7d739376ff /fs/ocfs2/alloc.h
parent6af67d8205cf65fbaaa743edc7ebb46e486e34ff (diff)
downloadlinux-e48edee2d8eab812f31f0ff62c6ba635ca2e1e21.tar.xz
ocfs2: make room for unwritten extents flag
Due to the size of our group bitmaps, we'll never have a leaf node extent record with more than 16 bits worth of clusters. Split e_clusters up so that leaf nodes can get a flags field where we can mark unwritten extents. Interior nodes whose length references all the child nodes beneath it can't split their e_clusters field, so we use a union to preserve sizing there. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Diffstat (limited to 'fs/ocfs2/alloc.h')
-rw-r--r--fs/ocfs2/alloc.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h
index 3cb39cd5e478..fbcb5934a081 100644
--- a/fs/ocfs2/alloc.h
+++ b/fs/ocfs2/alloc.h
@@ -85,4 +85,23 @@ int ocfs2_commit_truncate(struct ocfs2_super *osb,
int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
u32 cpos, struct buffer_head **leaf_bh);
+/*
+ * Helper function to look at the # of clusters in an extent record.
+ */
+static inline unsigned int ocfs2_rec_clusters(struct ocfs2_extent_list *el,
+ struct ocfs2_extent_rec *rec)
+{
+ /*
+ * Cluster count in extent records is slightly different
+ * between interior nodes and leaf nodes. This is to support
+ * unwritten extents which need a flags field in leaf node
+ * records, thus shrinking the available space for a clusters
+ * field.
+ */
+ if (el->l_tree_depth)
+ return le32_to_cpu(rec->e_int_clusters);
+ else
+ return le16_to_cpu(rec->e_leaf_clusters);
+}
+
#endif /* OCFS2_ALLOC_H */