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author | Mark Fasheh <mark.fasheh@oracle.com> | 2007-03-08 03:46:57 +0300 |
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committer | Mark Fasheh <mark.fasheh@oracle.com> | 2007-04-27 02:02:37 +0400 |
commit | e48edee2d8eab812f31f0ff62c6ba635ca2e1e21 (patch) | |
tree | 6afb9fe59a06ce621cb11d570e432e7d739376ff /fs/ocfs2/alloc.h | |
parent | 6af67d8205cf65fbaaa743edc7ebb46e486e34ff (diff) | |
download | linux-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.h | 19 |
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 */ |