ext4: add data structures for the extent status tree
This patch adds two structures that supports extent status tree, extent_status
and ext4_es_tree. Currently extent_status is used to track a delay extent for
an inode, which record the start block and the length of the delay extent.
ext4_es_tree is used to store all extent_status for an inode in memory.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3c20de1..bcc634b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -811,6 +811,8 @@
__u32 ec_len; /* must be 32bit to return holes */
};
+#include "extents_status.h"
+
/*
* fourth extended file system inode data in memory
*/
@@ -888,6 +890,10 @@
struct list_head i_prealloc_list;
spinlock_t i_prealloc_lock;
+ /* extents status tree */
+ struct ext4_es_tree i_es_tree;
+ rwlock_t i_es_lock;
+
/* ialloc */
ext4_group_t i_last_alloc_group;
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
new file mode 100644
index 0000000..8be2ab9
--- /dev/null
+++ b/fs/ext4/extents_status.h
@@ -0,0 +1,25 @@
+/*
+ * fs/ext4/extents_status.h
+ *
+ * Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
+ * Modified by
+ * Allison Henderson <achender@linux.vnet.ibm.com>
+ * Zheng Liu <wenqing.lz@taobao.com>
+ *
+ */
+
+#ifndef _EXT4_EXTENTS_STATUS_H
+#define _EXT4_EXTENTS_STATUS_H
+
+struct extent_status {
+ struct rb_node rb_node;
+ ext4_lblk_t start; /* first block extent covers */
+ ext4_lblk_t len; /* length of extent in block */
+};
+
+struct ext4_es_tree {
+ struct rb_root root;
+ struct extent_status *cache_es; /* recently accessed extent */
+};
+
+#endif /* _EXT4_EXTENTS_STATUS_H */