Recently there was discussion about an "FIle Extent MAP"(FIEMAP) ioctl for efficiently mapping the extents and holes of a file. This will be many times more efficient than FIBMAP by cutting down the number of ioctls.
This patch adds the FIEMAP header file in include/linux.
Signed-off-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Kalpak Shah <kalpak.shah@sun.com>
Index: linux-2.6.23.1/include/linux/fiemap.h
===================================================================
--- /dev/null
+++ linux-2.6.23.1/include/linux/fiemap.h
@@ -0,0 +1,49 @@
+/*
+ * include/linux/fiemap.h
+ *
+ * Copyright (C) 2007 Sun Microsystems, Inc.
+ *
+ * Author: Kalpak Shah <kalpak.shah@sun.com>
+ * Andreas Dilger <adilger@sun.com>
+ */
+
+#ifndef _LINUX_FIEMAP_H
+#define _LINUX_FIEMAP_H
+
+struct fiemap_extent {
+ __u64 fe_offset; /* offset in bytes for the start of the extent */
+ __u64 fe_length; /* length in bytes for the extent */
+ __u32 fe_flags; /* returned FIEMAP_EXTENT_* flags for the extent */
+ __u32 fe_lun; /* logical device number for extent (starting at 0)*/
+};
+
+struct fiemap {
+ __u64 fm_start; /* logical starting byte offset (in/out) */
+ __u64 fm_length; /* logical length of map (in/out) */
+ __u32 fm_flags; /* FIEMAP_FLAG_* flags for request (in/out) */
+ __u32 fm_extent_count; /* number of extents in fm_extents (in/out) */
+ __u64 fm_end_offset; /* logical offset of end of mapping in last ioctl */
+ struct fiemap_extent fm_extents[0];
+};
+
+#define FIEMAP_FLAG_SYNC 0x00000001 /* sync file data before map */
+#define FIEMAP_FLAG_HSM_READ 0x00000002 /* get data from HSM before map */
+#define FIEMAP_FLAG_NUM_EXTENTS 0x00000004 /* return only number of extents */
+#define FIEMAP_FLAG_INCOMPAT 0xff000000 /* error for unknown flags in here */
+
+#define FIEMAP_FLAG_LUN_OFFSET 0x01000000 /* use lun offsets, instead of
+ * logical file offsets */
+
+#define FIEMAP_EXTENT_HOLE 0x00000001 /* has no data or space allocatio...
