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authorMark Fasheh <mark.fasheh@oracle.com>2007-04-23 18:53:12 -0700
committerMark Fasheh <mark.fasheh@oracle.com>2007-04-26 15:10:40 -0700
commit83418978827324918a8cd25ce5227312de1d4468 (patch)
treef7baefb1fc8721d6d8d1f1f937bc55535b13e18f /fs/ocfs2/extent_map.h
parent7cdfc3a1c3971c9125c317cb8c2525745851798e (diff)
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ocfs2: Cache extent records
The extent map code was ripped out earlier because of an inability to deal with holes. This patch adds back a simpler caching scheme requiring far less code. Our old extent map caching was designed back when meta data block caching in Ocfs2 didn't work very well, resulting in many disk reads. These days our metadata caching is much better, resulting in no un-necessary disk reads. As a result, extent caching doesn't have to be as fancy, nor does it have to cache as many extents. Keeping the last 3 extents seen should be sufficient to give us a small performance boost on some streaming workloads. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Diffstat (limited to 'fs/ocfs2/extent_map.h')
-rw-r--r--fs/ocfs2/extent_map.h20
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h
index 1d745e174afc..de91e3e41a22 100644
--- a/fs/ocfs2/extent_map.h
+++ b/fs/ocfs2/extent_map.h
@@ -25,6 +25,26 @@
#ifndef _EXTENT_MAP_H
#define _EXTENT_MAP_H
+struct ocfs2_extent_map_item {
+ unsigned int ei_cpos;
+ unsigned int ei_phys;
+ unsigned int ei_clusters;
+ unsigned int ei_flags;
+
+ struct list_head ei_list;
+};
+
+#define OCFS2_MAX_EXTENT_MAP_ITEMS 3
+struct ocfs2_extent_map {
+ unsigned int em_num_items;
+ struct list_head em_list;
+};
+
+void ocfs2_extent_map_init(struct inode *inode);
+void ocfs2_extent_map_trunc(struct inode *inode, unsigned int cluster);
+void ocfs2_extent_map_insert_rec(struct inode *inode,
+ struct ocfs2_extent_rec *rec);
+
int ocfs2_get_clusters(struct inode *inode, u32 v_cluster, u32 *p_cluster,
u32 *num_clusters, unsigned int *extent_flags);
int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,