[PATCH] dm: v4 ioctl interface

From: Joe Thornber <thornber@sistina.com>

v4 of the ioctl interface.  Note there never was a v2 or a v3 except in an
unofficial EVMS way.

This works correctly with the 64-bit dev_t patches in -mm kernels.

There is now a config option to allow the user to select v1 or v4, it
defaults to v1.  dm-ioctl.[hc] just #includes dm-ioctl-v[14].[hc] depending
on the config option.

If you want to use v4 you will have to update your tools
(libdevmapper/lvm).  The latest tools at the time of writing are:

dmsetup + libdevmapper + replacement kernel patches for 2.4.20 & 2.4.21:

  ftp://ftp.sistina.com/pub/LVM2/device-mapper/device-mapper-testing-new-version4-interface.tgz

Updated LVM2 tools to work with the above:

  ftp://ftp.sistina.com/pub/LVM2/tools/LVM2.0-testing.tgz

3 files changed, 394 insertions, 139 deletions

diff --git a/include/linux/dm-ioctl-v1.h b/include/linux/dm-ioctl-v1.h
new file mode 100644
index 000000000000..21bef9ec14b0
--- /dev/null
+++ b/include/linux/dm-ioctl-v1.h
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef _LINUX_DM_IOCTL_V1_H
+#define _LINUX_DM_IOCTL_V1_H
+
+#include <linux/types.h>
+
+#define DM_DIR "mapper"	/* Slashes not supported */
+#define DM_MAX_TYPE_NAME 16
+#define DM_NAME_LEN 128
+#define DM_UUID_LEN 129
+
+/*
+ * Implements a traditional ioctl interface to the device mapper.
+ */
+
+/*
+ * All ioctl arguments consist of a single chunk of memory, with
+ * this structure at the start.  If a uuid is specified any
+ * lookup (eg. for a DM_INFO) will be done on that, *not* the
+ * name.
+ */
+struct dm_ioctl {
+	/*
+	 * The version number is made up of three parts:
+	 * major - no backward or forward compatibility,
+	 * minor - only backwards compatible,
+	 * patch - both backwards and forwards compatible.
+	 *
+	 * All clients of the ioctl interface should fill in the
+	 * version number of the interface that they were
+	 * compiled with.
+	 *
+	 * All recognised ioctl commands (ie. those that don't
+	 * return -ENOTTY) fill out this field, even if the
+	 * command failed.
+	 */
+	uint32_t version[3];	/* in/out */
+	uint32_t data_size;	/* total size of data passed in
+				 * including this struct */
+
+	uint32_t data_start;	/* offset to start of data
+				 * relative to start of this struct */
+
+	uint32_t target_count;	/* in/out */
+	uint32_t open_count;	/* out */
+	uint32_t flags;		/* in/out */
+
+	__kernel_dev_t dev;	/* in/out */
+
+	char name[DM_NAME_LEN];	/* device name */
+	char uuid[DM_UUID_LEN];	/* unique identifier for
+				 * the block device */
+};
+
+/*
+ * Used to specify tables.  These structures appear after the
+ * dm_ioctl.
+ */
+struct dm_target_spec {
+	int32_t status;		/* used when reading from kernel only */
+	uint64_t sector_start;
+	uint32_t length;
+
+	/*
+	 * Offset in bytes (from the start of this struct) to
+	 * next target_spec.
+	 */
+	uint32_t next;
+
+	char target_type[DM_MAX_TYPE_NAME];
+
+	/*
+	 * Parameter string starts immediately after this object.
+	 * Be careful to add padding after string to ensure correct
+	 * alignment of subsequent dm_target_spec.
+	 */
+};
+
+/*
+ * Used to retrieve the target dependencies.
+ */
+struct dm_target_deps {
+	uint32_t count;
+
+	__kernel_dev_t dev[0];	/* out */
+};
+
+/*
+ * If you change this make sure you make the corresponding change
+ * to dm-ioctl.c:lookup_ioctl()
+ */
+enum {
+	/* Top level cmds */
+	DM_VERSION_CMD = 0,
+	DM_REMOVE_ALL_CMD,
+
+	/* device level cmds */
+	DM_DEV_CREATE_CMD,
+	DM_DEV_REMOVE_CMD,
+	DM_DEV_RELOAD_CMD,
+	DM_DEV_RENAME_CMD,
+	DM_DEV_SUSPEND_CMD,
+	DM_DEV_DEPS_CMD,
+	DM_DEV_STATUS_CMD,
+
+	/* target level cmds */
+	DM_TARGET_STATUS_CMD,
+	DM_TARGET_WAIT_CMD
+};
+
+#define DM_IOCTL 0xfd
+
+#define DM_VERSION       _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
+#define DM_REMOVE_ALL    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
+
+#define DM_DEV_CREATE    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
+#define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
+#define DM_DEV_RELOAD    _IOWR(DM_IOCTL, DM_DEV_RELOAD_CMD, struct dm_ioctl)
+#define DM_DEV_SUSPEND   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
+#define DM_DEV_RENAME    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
+#define DM_DEV_DEPS      _IOWR(DM_IOCTL, DM_DEV_DEPS_CMD, struct dm_ioctl)
+#define DM_DEV_STATUS    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
+
+#define DM_TARGET_STATUS _IOWR(DM_IOCTL, DM_TARGET_STATUS_CMD, struct dm_ioctl)
+#define DM_TARGET_WAIT   _IOWR(DM_IOCTL, DM_TARGET_WAIT_CMD, struct dm_ioctl)
+
+#define DM_VERSION_MAJOR	1
+#define DM_VERSION_MINOR	0
+#define DM_VERSION_PATCHLEVEL	6
+#define DM_VERSION_EXTRA	"-ioctl (2002-10-15)"
+
+/* Status bits */
+#define DM_READONLY_FLAG	0x00000001
+#define DM_SUSPEND_FLAG		0x00000002
+#define DM_EXISTS_FLAG		0x00000004
+#define DM_PERSISTENT_DEV_FLAG	0x00000008
+
+/*
+ * Flag passed into ioctl STATUS command to get table information
+ * rather than current status.
+ */
+#define DM_STATUS_TABLE_FLAG	0x00000010
+
+#endif				/* _LINUX_DM_IOCTL_H */
diff --git a/include/linux/dm-ioctl-v4.h b/include/linux/dm-ioctl-v4.h
new file mode 100644
index 000000000000..74a8d14b885d
--- /dev/null
+++ b/include/linux/dm-ioctl-v4.h
@@ -0,0 +1,237 @@
+/*
+ * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef _LINUX_DM_IOCTL_V4_H
+#define _LINUX_DM_IOCTL_V4_H
+
+#include <linux/types.h>
+
+#define DM_DIR "mapper"		/* Slashes not supported */
+#define DM_MAX_TYPE_NAME 16
+#define DM_NAME_LEN 128
+#define DM_UUID_LEN 129
+
+/*
+ * A traditional ioctl interface for the device mapper.
+ *
+ * Each device can have two tables associated with it, an
+ * 'active' table which is the one currently used by io passing
+ * through the device, and an 'inactive' one which is a table
+ * that is being prepared as a replacement for the 'active' one.
+ *
+ * DM_VERSION:
+ * Just get the version information for the ioctl interface.
+ *
+ * DM_REMOVE_ALL:
+ * Remove all dm devices, destroy all tables.  Only really used
+ * for debug.
+ *
+ * DM_LIST_DEVICES:
+ * Get a list of all the dm device names.
+ *
+ * DM_DEV_CREATE:
+ * Create a new device, neither the 'active' or 'inactive' table
+ * slots will be filled.  The device will be in suspended state
+ * after creation, however any io to the device will get errored
+ * since it will be out-of-bounds.
+ *
+ * DM_DEV_REMOVE:
+ * Remove a device, destroy any tables.
+ *
+ * DM_DEV_RENAME:
+ * Rename a device.
+ *
+ * DM_SUSPEND:
+ * This performs both suspend and resume, depending which flag is
+ * passed in.
+ * Suspend: This command will not return until all pending io to
+ * the device has completed.  Further io will be deferred until
+ * the device is resumed.
+ * Resume: It is no longer an error to issue this command on an
+ * unsuspended device.  If a table is present in the 'inactive'
+ * slot, it will be moved to the active slot, then the old table
+ * from the active slot will be _destroyed_.  Finally the device
+ * is resumed.
+ *
+ * DM_DEV_STATUS:
+ * Retrieves the status for the table in the 'active' slot.
+ *
+ * DM_DEV_WAIT:
+ * Wait for a significant event to occur to the device.  This
+ * could either be caused by an event triggered by one of the
+ * targets of the table in the 'active' slot, or a table change.
+ *
+ * DM_TABLE_LOAD:
+ * Load a table into the 'inactive' slot for the device.  The
+ * device does _not_ need to be suspended prior to this command.
+ *
+ * DM_TABLE_CLEAR:
+ * Destroy any table in the 'inactive' slot (ie. abort).
+ *
+ * DM_TABLE_DEPS:
+ * Return a set of device dependencies for the 'active' table.
+ *
+ * DM_TABLE_STATUS:
+ * Return the targets status for the 'active' table.
+ */
+
+/*
+ * All ioctl arguments consist of a single chunk of memory, with
+ * this structure at the start.  If a uuid is specified any
+ * lookup (eg. for a DM_INFO) will be done on that, *not* the
+ * name.
+ */
+struct dm_ioctl {
+	/*
+	 * The version number is made up of three parts:
+	 * major - no backward or forward compatibility,
+	 * minor - only backwards compatible,
+	 * patch - both backwards and forwards compatible.
+	 *
+	 * All clients of the ioctl interface should fill in the
+	 * version number of the interface that they were
+	 * compiled with.
+	 *
+	 * All recognised ioctl commands (ie. those that don't
+	 * return -ENOTTY) fill out this field, even if the
+	 * command failed.
+	 */
+	uint32_t version[3];	/* in/out */
+	uint32_t data_size;	/* total size of data passed in
+				 * including this struct */
+
+	uint32_t data_start;	/* offset to start of data
+				 * relative to start of this struct */
+
+	uint32_t target_count;	/* in/out */
+	int32_t open_count;	/* out */
+	uint32_t flags;		/* in/out */
+	uint32_t event_nr;      	/* in/out */
+	uint32_t padding;
+
+	uint64_t dev;		/* in/out */
+
+	char name[DM_NAME_LEN];	/* device name */
+	char uuid[DM_UUID_LEN];	/* unique identifier for
+				 * the block device */
+};
+
+/*
+ * Used to specify tables.  These structures appear after the
+ * dm_ioctl.
+ */
+struct dm_target_spec {
+	uint64_t sector_start;
+	uint64_t length;
+	int32_t status;		/* used when reading from kernel only */
+
+	/*
+	 * Offset in bytes (from the start of this struct) to
+	 * next target_spec.
+	 */
+	uint32_t next;
+
+	char target_type[DM_MAX_TYPE_NAME];
+
+	/*
+	 * Parameter string starts immediately after this object.
+	 * Be careful to add padding after string to ensure correct
+	 * alignment of subsequent dm_target_spec.
+	 */
+};
+
+/*
+ * Used to retrieve the target dependencies.
+ */
+struct dm_target_deps {
+	uint32_t count;	/* Array size */
+	uint32_t padding;	/* unused */
+	uint64_t dev[0];	/* out */
+};
+
+/*
+ * Used to get a list of all dm devices.
+ */
+struct dm_name_list {
+	uint64_t dev;
+	uint32_t next;		/* offset to the next record from
+				   the _start_ of this */
+	char name[0];
+};
+
+/*
+ * If you change this make sure you make the corresponding change
+ * to dm-ioctl.c:lookup_ioctl()
+ */
+enum {
+	/* Top level cmds */
+	DM_VERSION_CMD = 0,
+	DM_REMOVE_ALL_CMD,
+	DM_LIST_DEVICES_CMD,
+
+	/* device level cmds */
+	DM_DEV_CREATE_CMD,
+	DM_DEV_REMOVE_CMD,
+	DM_DEV_RENAME_CMD,
+	DM_DEV_SUSPEND_CMD,
+	DM_DEV_STATUS_CMD,
+	DM_DEV_WAIT_CMD,
+
+	/* Table level cmds */
+	DM_TABLE_LOAD_CMD,
+	DM_TABLE_CLEAR_CMD,
+	DM_TABLE_DEPS_CMD,
+	DM_TABLE_STATUS_CMD,
+};
+
+#define DM_IOCTL 0xfd
+
+#define DM_VERSION       _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
+#define DM_REMOVE_ALL    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
+#define DM_LIST_DEVICES  _IOWR(DM_IOCTL, DM_LIST_DEVICES_CMD, struct dm_ioctl)
+
+#define DM_DEV_CREATE    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
+#define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
+#define DM_DEV_RENAME    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
+#define DM_DEV_SUSPEND   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
+#define DM_DEV_STATUS    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
+#define DM_DEV_WAIT      _IOWR(DM_IOCTL, DM_DEV_WAIT_CMD, struct dm_ioctl)
+
+#define DM_TABLE_LOAD    _IOWR(DM_IOCTL, DM_TABLE_LOAD_CMD, struct dm_ioctl)
+#define DM_TABLE_CLEAR   _IOWR(DM_IOCTL, DM_TABLE_CLEAR_CMD, struct dm_ioctl)
+#define DM_TABLE_DEPS    _IOWR(DM_IOCTL, DM_TABLE_DEPS_CMD, struct dm_ioctl)
+#define DM_TABLE_STATUS  _IOWR(DM_IOCTL, DM_TABLE_STATUS_CMD, struct dm_ioctl)
+
+#define DM_VERSION_MAJOR	4
+#define DM_VERSION_MINOR	0
+#define DM_VERSION_PATCHLEVEL	0
+#define DM_VERSION_EXTRA	"-ioctl (2003-06-04)"
+
+/* Status bits */
+#define DM_READONLY_FLAG	(1 << 0) /* In/Out */
+#define DM_SUSPEND_FLAG		(1 << 1) /* In/Out */
+#define DM_PERSISTENT_DEV_FLAG	(1 << 3) /* In */
+
+/*
+ * Flag passed into ioctl STATUS command to get table information
+ * rather than current status.
+ */
+#define DM_STATUS_TABLE_FLAG	(1 << 4) /* In */
+
+/*
+ * Flags that indicate whether a table is present in either of
+ * the two table slots that a device has.
+ */
+#define DM_ACTIVE_PRESENT_FLAG   (1 << 5) /* Out */
+#define DM_INACTIVE_PRESENT_FLAG (1 << 6) /* Out */
+
+/*
+ * Indicates that the buffer passed in wasn't big enough for the
+ * results.
+ */
+#define DM_BUFFER_FULL_FLAG	(1 << 8) /* Out */
+
+#endif				/* _LINUX_DM_IOCTL_H */
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index 72edd5e19e62..dddbfd9c3cf7 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2001 Sistina Software (UK) Limited.
+ * Copyright (C) 2003 Sistina Software (UK) Limited.
  *
  * This file is released under the LGPL.
  */
@@ -7,143 +7,12 @@
 #ifndef _LINUX_DM_IOCTL_H
 #define _LINUX_DM_IOCTL_H
 
-#include <linux/types.h>
+#include <linux/config.h>
 
-#define DM_DIR "mapper"	/* Slashes not supported */
-#define DM_MAX_TYPE_NAME 16
-#define DM_NAME_LEN 128
-#define DM_UUID_LEN 129
+#ifdef CONFIG_DM_IOCTL_V4
+#include "dm-ioctl-v4.h"
+#else
+#include "dm-ioctl-v1.h"
+#endif
 
-/*
- * Implements a traditional ioctl interface to the device mapper.
- */
-
-/*
- * All ioctl arguments consist of a single chunk of memory, with
- * this structure at the start.  If a uuid is specified any
- * lookup (eg. for a DM_INFO) will be done on that, *not* the
- * name.
- */
-struct dm_ioctl {
-	/*
-	 * The version number is made up of three parts:
-	 * major - no backward or forward compatibility,
-	 * minor - only backwards compatible,
-	 * patch - both backwards and forwards compatible.
-	 *
-	 * All clients of the ioctl interface should fill in the
-	 * version number of the interface that they were
-	 * compiled with.
-	 *
-	 * All recognised ioctl commands (ie. those that don't
-	 * return -ENOTTY) fill out this field, even if the
-	 * command failed.
-	 */
-	uint32_t version[3];	/* in/out */
-	uint32_t data_size;	/* total size of data passed in
-				 * including this struct */
-
-	uint32_t data_start;	/* offset to start of data
-				 * relative to start of this struct */
-
-	uint32_t target_count;	/* in/out */
-	uint32_t open_count;	/* out */
-	uint32_t flags;		/* in/out */
-
-	__kernel_dev_t dev;	/* in/out */
-
-	char name[DM_NAME_LEN];	/* device name */
-	char uuid[DM_UUID_LEN];	/* unique identifier for
-				 * the block device */
-};
-
-/*
- * Used to specify tables.  These structures appear after the
- * dm_ioctl.
- */
-struct dm_target_spec {
-	int32_t status;		/* used when reading from kernel only */
-	uint64_t sector_start;
-	uint32_t length;
-
-	/*
-	 * Offset in bytes (from the start of this struct) to
-	 * next target_spec.
-	 */
-	uint32_t next;
-
-	char target_type[DM_MAX_TYPE_NAME];
-
-	/*
-	 * Parameter string starts immediately after this object.
-	 * Be careful to add padding after string to ensure correct
-	 * alignment of subsequent dm_target_spec.
-	 */
-};
-
-/*
- * Used to retrieve the target dependencies.
- */
-struct dm_target_deps {
-	uint32_t count;
-
-	__kernel_dev_t dev[0];	/* out */
-};
-
-/*
- * If you change this make sure you make the corresponding change
- * to dm-ioctl.c:lookup_ioctl()
- */
-enum {
-	/* Top level cmds */
-	DM_VERSION_CMD = 0,
-	DM_REMOVE_ALL_CMD,
-
-	/* device level cmds */
-	DM_DEV_CREATE_CMD,
-	DM_DEV_REMOVE_CMD,
-	DM_DEV_RELOAD_CMD,
-	DM_DEV_RENAME_CMD,
-	DM_DEV_SUSPEND_CMD,
-	DM_DEV_DEPS_CMD,
-	DM_DEV_STATUS_CMD,
-
-	/* target level cmds */
-	DM_TARGET_STATUS_CMD,
-	DM_TARGET_WAIT_CMD
-};
-
-#define DM_IOCTL 0xfd
-
-#define DM_VERSION       _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
-#define DM_REMOVE_ALL    _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
-
-#define DM_DEV_CREATE    _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
-#define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
-#define DM_DEV_RELOAD    _IOWR(DM_IOCTL, DM_DEV_RELOAD_CMD, struct dm_ioctl)
-#define DM_DEV_SUSPEND   _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
-#define DM_DEV_RENAME    _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
-#define DM_DEV_DEPS      _IOWR(DM_IOCTL, DM_DEV_DEPS_CMD, struct dm_ioctl)
-#define DM_DEV_STATUS    _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
-
-#define DM_TARGET_STATUS _IOWR(DM_IOCTL, DM_TARGET_STATUS_CMD, struct dm_ioctl)
-#define DM_TARGET_WAIT   _IOWR(DM_IOCTL, DM_TARGET_WAIT_CMD, struct dm_ioctl)
-
-#define DM_VERSION_MAJOR	1
-#define DM_VERSION_MINOR	0
-#define DM_VERSION_PATCHLEVEL	6
-#define DM_VERSION_EXTRA	"-ioctl (2002-10-15)"
-
-/* Status bits */
-#define DM_READONLY_FLAG	0x00000001
-#define DM_SUSPEND_FLAG		0x00000002
-#define DM_EXISTS_FLAG		0x00000004
-#define DM_PERSISTENT_DEV_FLAG	0x00000008
-
-/*
- * Flag passed into ioctl STATUS command to get table information
- * rather than current status.
- */
-#define DM_STATUS_TABLE_FLAG	0x00000010
-
-#endif				/* _LINUX_DM_IOCTL_H */
+#endif