[Patch 4/4] dm: ioctl interface

Joe Thornber
2003-12-09T13:01:21Z

ioctl interface for dm
--- diff/arch/mips64/kernel/ioctl32.c 2003-08-26 13:50:03.000000000 +0100
+++ source/arch/mips64/kernel/ioctl32.c 2003-12-09 11:04:13.000000000 +0000
@@ -37,6 +37,7 @@
#include <linux/ext2_fs.h>
#include <linux/raid/md_u.h>
#include <linux/serial.h>
+#include <linux/dm-ioctl.h>

#include <scsi/scsi.h>
#undef __KERNEL__ /* This file was born to be ugly ... */
@@ -1222,6 +1223,22 @@
IOCTL32_DEFAULT(RESTART_ARRAY_RW),
#endif /* CONFIG_MD */

+#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE)
+ IOCTL32_DEFAULT(DM_VERSION),
+ IOCTL32_DEFAULT(DM_REMOVE_ALL),
+ IOCTL32_DEFAULT(DM_DEV_CREATE),
+ IOCTL32_DEFAULT(DM_DEV_REMOVE),
+ IOCTL32_DEFAULT(DM_TABLE_LOAD),
+ IOCTL32_DEFAULT(DM_DEV_SUSPEND),
+ IOCTL32_DEFAULT(DM_DEV_RENAME),
+ IOCTL32_DEFAULT(DM_TABLE_DEPS),
+ IOCTL32_DEFAULT(DM_DEV_STATUS),
+ IOCTL32_DEFAULT(DM_TABLE_STATUS),
+ IOCTL32_DEFAULT(DM_DEV_WAIT),
+ IOCTL32_DEFAULT(DM_LIST_DEVICES),
+ IOCTL32_DEFAULT(DM_TABLE_CLEAR),
+#endif /* CONFIG_BLK_DEV_DM */
+
#ifdef CONFIG_SIBYTE_TBPROF
IOCTL32_DEFAULT(SBPROF_ZBSTART),
IOCTL32_DEFAULT(SBPROF_ZBSTOP),
--- diff/arch/parisc/kernel/ioctl32.c 2003-08-26 13:50:03.000000000 +0100
+++ source/arch/parisc/kernel/ioctl32.c 2003-12-09 11:04:13.000000000 +0000
@@ -55,6 +55,7 @@
#define max max */
#include <linux/lvm.h>
#endif /* LVM */
+#include <linux/dm-ioctl.h>

#include <scsi/scsi.h>
/* Ugly hack. */
@@ -3423,6 +3424,22 @@
COMPATIBLE_IOCTL(LV_BMAP)
COMPATIBLE_IOCTL(LV_SNAPSHOT_USE_RATE)
#endif /* LVM */
+/* Device-Mapper */
+#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE)
+COMPATIBLE_IOCTL(DM_VERSION)
+COMPATIBLE_IOCTL(DM_REMOVE_ALL)
+COMPATIBLE_IOCTL(DM_DEV_CREATE)
+COMPATIBLE_IOCTL(DM_DEV_REMOVE)
+COMPATIBLE_IOCTL(DM_TABLE_LOAD)
+COMPATIBLE_IOCTL(DM_DEV_SUSPEND)
+COMPATIBLE_IOCTL(DM_DEV_RENAME)
+COMPATIBLE_IOCTL(DM_TABLE_DEPS)
+COMPATIBLE_IOCTL(DM_DEV_STATUS)
+COMPATIBLE_IOCTL(DM_TABLE_STATUS)
+COMPATIBLE_IOCTL(DM_DEV_WAIT)
+COMPATIBLE_IOCTL(DM_LIST_DEVICES)
+COMPATIBLE_IOCTL(DM_TABLE_CLEAR)
+#endif /* CONFIG_BLK_DEV_DM */
#if defined(CONFIG_DRM) || defined(CONFIG_DRM_MODULE)
COMPATIBLE_IOCTL(DRM_IOCTL_GET_MAGIC)
COMPATIBLE_IOCTL(DRM_IOCTL_IRQ_BUSID)
--- diff/arch/ppc64/kernel/ioctl32.c 2003-08-26 13:50:04.000000000 +0100
+++ source/arch/ppc64/kernel/ioctl32.c 2003-12-09 11:04:13.000000000 +0000
@@ -66,6 +66,7 @@
#if defined(CONFIG_BLK_DEV_LVM) || defined(CONFIG_BLK_DEV_LVM_MODULE)
#include <linux/lvm.h>
#endif /* LVM */
+#include <linux/dm-ioctl.h>

#include <scsi/scsi.h>
/* Ugly hack. */
@@ -4435,6 +4436,22 @@
COMPATIBLE_IOCTL(NBD_PRINT_DEBUG),
COMPATIBLE_IOCTL(NBD_SET_SIZE_BLOCKS),
COMPATIBLE_IOCTL(NBD_DISCONNECT),
+/* device-mapper */
+#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE)
+COMPATIBLE_IOCTL(DM_VERSION),
+COMPATIBLE_IOCTL(DM_REMOVE_ALL),
+COMPATIBLE_IOCTL(DM_DEV_CREATE),
+COMPATIBLE_IOCTL(DM_DEV_REMOVE),
+COMPATIBLE_IOCTL(DM_TABLE_LOAD),
+COMPATIBLE_IOCTL(DM_DEV_SUSPEND),
+COMPATIBLE_IOCTL(DM_DEV_RENAME),
+COMPATIBLE_IOCTL(DM_TABLE_DEPS),
+COMPATIBLE_IOCTL(DM_DEV_STATUS),
+COMPATIBLE_IOCTL(DM_TABLE_STATUS),
+COMPATIBLE_IOCTL(DM_DEV_WAIT),
+COMPATIBLE_IOCTL(DM_LIST_DEVICES),
+COMPATIBLE_IOCTL(DM_TABLE_CLEAR),
+#endif /* CONFIG_BLK_DEV_DM */
/* Remove *PRIVATE in 2.5 */
COMPATIBLE_IOCTL(SIOCDEVPRIVATE),
COMPATIBLE_IOCTL(SIOCDEVPRIVATE+1),
--- diff/arch/s390x/kernel/ioctl32.c 2003-08-26 13:50:04.000000000 +0100
+++ source/arch/s390x/kernel/ioctl32.c 2003-12-09 11:04:13.000000000 +0000
@@ -30,6 +30,7 @@
#include <linux/blk.h>
#include <linux/elevator.h>
#include <linux/raw.h>
+#include <linux/dm-ioctl.h>
#include <asm/types.h>
#include <asm/uaccess.h>
#include <asm/dasd.h>
@@ -627,6 +628,20 @@

IOCTL32_DEFAULT(SIOCGSTAMP),

+ IOCTL32_DEFAULT(DM_VERSION),
+ IOCTL32_DEFAULT(DM_REMOVE_ALL),
+ IOCTL32_DEFAULT(DM_DEV_CREATE),
+ IOCTL32_DEFAULT(DM_DEV_REMOVE),
+ IOCTL32_DEFAULT(DM_TABLE_LOAD),
+ IOCTL32_DEFAULT(DM_DEV_SUSPEND),
+ IOCTL32_DEFAULT(DM_DEV_RENAME),
+ IOCTL32_DEFAULT(DM_TABLE_DEPS),
+ IOCTL32_DEFAULT(DM_DEV_STATUS),
+ IOCTL32_DEFAULT(DM_TABLE_STATUS),
+ IOCTL32_DEFAULT(DM_DEV_WAIT),
+ IOCTL32_DEFAULT(DM_LIST_DEVICES),
+ IOCTL32_DEFAULT(DM_TABLE_CLEAR),
+
IOCTL32_DEFAULT(LOOP_SET_FD),
IOCTL32_DEFAULT(LOOP_CLR_FD),

--- diff/arch/sparc64/kernel/ioctl32.c 2003-12-09 10:25:25.000000000 +0000
+++ source/arch/sparc64/kernel/ioctl32.c 2003-12-09 11:04:13.000000000 +0000
@@ -56,6 +56,7 @@
#if defined(CONFIG_BLK_DEV_LVM) || defined(CONFIG_BLK_DEV_LVM_MODULE)
#include <linux/lvm.h>
#endif /* LVM */
+#include <linux/dm-ioctl.h>

#include <scsi/scsi.h>
/* Ugly hack. */
@@ -5086,6 +5087,22 @@
COMPATIBLE_IOCTL(NBD_PRINT_DEBUG)
COMPATIBLE_IOCTL(NBD_SET_SIZE_BLOCKS)
COMPATIBLE_IOCTL(NBD_DISCONNECT)
+/* device-mapper */
+#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE)
+COMPATIBLE_IOCTL(DM_VERSION)
+COMPATIBLE_IOCTL(DM_REMOVE_ALL)
+COMPATIBLE_IOCTL(DM_DEV_CREATE)
+COMPATIBLE_IOCTL(DM_DEV_REMOVE)
+COMPATIBLE_IOCTL(DM_TABLE_LOAD)
+COMPATIBLE_IOCTL(DM_DEV_SUSPEND)
+COMPATIBLE_IOCTL(DM_DEV_RENAME)
+COMPATIBLE_IOCTL(DM_TABLE_DEPS)
+COMPATIBLE_IOCTL(DM_DEV_STATUS)
+COMPATIBLE_IOCTL(DM_TABLE_STATUS)
+COMPATIBLE_IOCTL(DM_DEV_WAIT)
+COMPATIBLE_IOCTL(DM_LIST_DEVICES)
+COMPATIBLE_IOCTL(DM_TABLE_CLEAR)
+#endif /* CONFIG_BLK_DEV_DM */
/* Linux-1394 */
#if defined(CONFIG_IEEE1394) || defined(CONFIG_IEEE1394_MODULE)
COMPATIBLE_IOCTL(AMDTP_IOC_CHANNEL)
--- diff/arch/x86_64/ia32/ia32_ioctl.c 2003-12-09 10:25:25.000000000 +0000
+++ source/arch/x86_64/ia32/ia32_ioctl.c 2003-12-09 11:04:14.000000000 +0000
@@ -67,6 +67,7 @@
#define max max
#include <linux/lvm.h>
#endif /* LVM */
+#include <linux/dm-ioctl.h>

#include <scsi/scsi.h>
/* Ugly hack. */
@@ -4051,6 +4052,22 @@
COMPATIBLE_IOCTL(LV_BMAP)
COMPATIBLE_IOCTL(LV_SNAPSHOT_USE_RATE)
#endif /* LVM */
+/* Device-Mapper */
+#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE)
+COMPATIBLE_IOCTL(DM_VERSION)
+COMPATIBLE_IOCTL(DM_REMOVE_ALL)
+COMPATIBLE_IOCTL(DM_DEV_CREATE)
+COMPATIBLE_IOCTL(DM_DEV_REMOVE)
+COMPATIBLE_IOCTL(DM_TABLE_LOAD)
+COMPATIBLE_IOCTL(DM_DEV_SUSPEND)
+COMPATIBLE_IOCTL(DM_DEV_RENAME)
+COMPATIBLE_IOCTL(DM_TABLE_DEPS)
+COMPATIBLE_IOCTL(DM_DEV_STATUS)
+COMPATIBLE_IOCTL(DM_TABLE_STATUS)
+COMPATIBLE_IOCTL(DM_DEV_WAIT)
+COMPATIBLE_IOCTL(DM_LIST_DEVICES)
+COMPATIBLE_IOCTL(DM_TABLE_CLEAR)
+#endif /* CONFIG_BLK_DEV_DM */
#ifdef CONFIG_AUTOFS_FS
COMPATIBLE_IOCTL(AUTOFS_IOC_READY)
COMPATIBLE_IOCTL(AUTOFS_IOC_FAIL)
--- diff/drivers/md/Makefile 2003-12-09 11:03:47.000000000 +0000
+++ source/drivers/md/Makefile 2003-12-09 11:02:02.000000000 +0000
@@ -8,7 +8,8 @@

list-multi := lvm-mod.o dm-mod.o dm-mirror-mod.o
lvm-mod-objs := lvm.o lvm-snap.o lvm-fs.o
-dm-mod-objs := dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o
+dm-mod-objs := dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \
+ dm-ioctl.o

# Note: link order is important. All raid personalities
# and xor.o must come before md.o, as they each initialise
--- diff/drivers/md/dm-ioctl.c 1970-01-01 01:00:00.000000000 +0100
+++ source/drivers/md/dm-ioctl.c 2003-12-09 11:01:41.000000000 +0000
@@ -0,0 +1,1284 @@
+/*
+ * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm.h"
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/miscdevice.h>
+#include <linux/dm-ioctl.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/blk.h>
+#include <linux/slab.h>
+
+#include <asm/uaccess.h>
+
+#define DM_DRIVER_EMAIL "dm@uk.sistina.com"
+
+/*-----------------------------------------------------------------
+ * The ioctl interface needs to be able to look up devices by
+ * name or uuid.
+ *---------------------------------------------------------------*/
+struct hash_cell {
+ struct list_head name_list;
+ struct list_head uuid_list;
+
+ char *name;
+ char *uuid;
+ struct mapped_device *md;
+ struct dm_table *new_map;
+
+ /* I hate devfs */
+ devfs_handle_t devfs_entry;
+};
+
+#define NUM_BUCKETS 64
+#define MASK_BUCKETS (NUM_BUCKETS - 1)
+static struct list_head _name_buckets[NUM_BUCKETS];
+static struct list_head _uuid_buckets[NUM_BUCKETS];
+
+static devfs_handle_t _dev_dir;
+void dm_hash_remove_all(void);
+
+/*
+ * Guards access to both hash tables.
+ */
+static DECLARE_RWSEM(_hash_lock);
+
+static void init_buckets(struct list_head *buckets)
+{
+ unsigned int i;
+
+ for (i = 0; i < NUM_BUCKETS; i++)
+ INIT_LIST_HEAD(buckets + i);
+}
+
+int dm_hash_init(void)
+{
+ init_buckets(_name_buckets);
+ init_buckets(_uuid_buckets);
+ _dev_dir = devfs_mk_dir(0, DM_DIR, NULL);
+ return 0;
+}
+
+void dm_hash_exit(void)
+{
+ dm_hash_remove_all();
+ devfs_unregister(_dev_dir);
+}
+
+/*-----------------------------------------------------------------
+ * Hash function:
+ * We're not really concerned with the str hash function being
+ * fast since it's only used by the ioctl interface.
+ *---------------------------------------------------------------*/
+static unsigned int hash_str(const char *str)
+{
+ const unsigned int hash_mult = 2654435387U;
+ unsigned int h = 0;
+
+ while (*str)
+ h = (h + (unsigned int) *str++) * hash_mult;
+
+ return h & MASK_BUCKETS;
+}
+
+/*-----------------------------------------------------------------
+ * Code for looking up a device by name
+ *---------------------------------------------------------------*/
+static struct hash_cell *__get_name_cell(const char *str)
+{
+ struct list_head *tmp;
+ struct hash_cell *hc;
+ unsigned int h = hash_str(str);
+
+ list_for_each (tmp, _name_buckets + h) {
+ hc = list_entry(tmp, struct hash_cell, name_list);
+ if (!strcmp(hc->name, str))
+ return hc;
+ }
+
+ return NULL;
+}
+
+static struct hash_cell *__get_uuid_cell(const char *str)
+{
+ struct list_head *tmp;
+ struct hash_cell *hc;
+ unsigned int h = hash_str(str);
+
+ list_for_each (tmp, _uuid_buckets + h) {
+ hc = list_entry(tmp, struct hash_cell, uuid_list);
+ if (!strcmp(hc->uuid, str))
+ return hc;
+ }
+
+ return NULL;
+}
+
+/*-----------------------------------------------------------------
+ * Inserting, removing and renaming a device.
+ *---------------------------------------------------------------*/
+static inline char *kstrdup(const char *str)
+{
+ char *r = kmalloc(strlen(str) + 1, GFP_KERNEL);
+ if (r)
+ strcpy(r, str);
+ return r;
+}
+
+static struct hash_cell *alloc_cell(const char *name, const char *uuid,
+ struct mapped_device *md)
+{
+ struct hash_cell *hc;
+
+ hc = kmalloc(sizeof(*hc), GFP_KERNEL);
+ if (!hc)
+ return NULL;
+
+ hc->name = kstrdup(name);
+ if (!hc->name) {
+ kfree(hc);
+ return NULL;
+ }
+
+ if (!uuid)
+ hc->uuid = NULL;
+
+ else {
+ hc->uuid = kstrdup(uuid);
+ if (!hc->uuid) {
+ kfree(hc->name);
+ kfree(hc);
+ return NULL;
+ }
+ }
+
+ INIT_LIST_HEAD(&hc->name_list);
+ INIT_LIST_HEAD(&hc->uuid_list);
+ hc->md = md;
+ hc->new_map = NULL;
+ return hc;
+}
+
+static void free_cell(struct hash_cell *hc)
+{
+ if (hc) {
+ kfree(hc->name);
+ kfree(hc->uuid);
+ kfree(hc);
+ }
+}
+
+/*
+ * devfs stuff.
+ */
+static int register_with_devfs(struct hash_cell *hc)
+{
+ kdev_t dev = dm_kdev(hc->md);
+
+ hc->devfs_entry =
+ devfs_register(_dev_dir, hc->name, DEVFS_FL_CURRENT_OWNER,
+ major(dev), minor(dev),
+ S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
+ &dm_blk_dops, NULL);
+
+ return 0;
+}
+
+static int unregister_with_devfs(struct hash_cell *hc)
+{
+ devfs_unregister(hc->devfs_entry);
+ return 0;
+}
+
+/*
+ * The kdev_t and uuid of a device can never change once it is
+ * initially inserted.
+ */
+int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
+{
+ struct hash_cell *cell;
+
+ /*
+ * Allocate the new cells.
+ */
+ cell = alloc_cell(name, uuid, md);
+ if (!cell)
+ return -ENOMEM;
+
+ /*
+ * Insert the cell into both hash tables.
+ */
+ down_write(&_hash_lock);
+ if (__get_name_cell(name))
+ goto bad;
+
+ list_add(&cell->name_list, _name_buckets + hash_str(name));
+
+ if (uuid) {
+ if (__get_uuid_cell(uuid)) {
+ list_del(&cell->name_list);
+ goto bad;
+ }
+ list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
+ }
+ register_with_devfs(cell);
+ dm_get(md);
+ up_write(&_hash_lock);
+
+ return 0;
+
+ bad:
+ up_write(&_hash_lock);
+ free_cell(cell);
+ return -EBUSY;
+}
+
+void __hash_remove(struct hash_cell *hc)
+{
+ /* remove from the dev hash */
+ list_del(&hc->uuid_list);
+ list_del(&hc->name_list);
+ unregister_with_devfs(hc);
+ dm_put(hc->md);
+ if (hc->new_map)
+ dm_table_put(hc->new_map);
+ free_cell(hc);
+}
+
+void dm_hash_remove_all(void)
+{
+ int i;
+ struct hash_cell *hc;
+ struct list_head *tmp, *n;
+
+ down_write(&_hash_lock);
+ for (i = 0; i < NUM_BUCKETS; i++) {
+ list_for_each_safe (tmp, n, _name_buckets + i) {
+ hc = list_entry(tmp, struct hash_cell, name_list);
+ __hash_remove(hc);
+ }
+ }
+ up_write(&_hash_lock);
+}
+
+int dm_hash_rename(const char *old, const char *new)
+{
+ char *new_name, *old_name;
+ struct hash_cell *hc;
+
+ /*
+ * duplicate new.
+ */
+ new_name = kstrdup(new);
+ if (!new_name)
+ return -ENOMEM;
+
+ down_write(&_hash_lock);
+
+ /*
+ * Is new free ?
+ */
+ hc = __get_name_cell(new);
+ if (hc) {
+ DMWARN("asked to rename to an already existing name %s -> %s",
+ old, new);
+ up_write(&_hash_lock);
+ kfree(new_name);
+ return -EBUSY;
+ }
+
+ /*
+ * Is there such a device as 'old' ?
+ */
+ hc = __get_name_cell(old);
+ if (!hc) {
+ DMWARN("asked to rename a non existent device %s -> %s",
+ old, new);
+ up_write(&_hash_lock);
+ kfree(new_name);
+ return -ENXIO;
+ }
+
+ /*
+ * rename and move the name cell.
+ */
+ list_del(&hc->name_list);
+ old_name = hc->name;
+ hc->name = new_name;
+ list_add(&hc->name_list, _name_buckets + hash_str(new_name));
+
+ /* rename the device node in devfs */
+ unregister_with_devfs(hc);
+ register_with_devfs(hc);
+
+ up_write(&_hash_lock);
+ kfree(old_name);
+ return 0;
+}
+
+/*-----------------------------------------------------------------
+ * Implementation of the ioctl commands
+ *---------------------------------------------------------------*/
+/*
+ * All the ioctl commands get dispatched to functions with this
+ * prototype.
+ */
+typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
+
+static int remove_all(struct dm_ioctl *param, size_t param_size)
+{
+ dm_hash_remove_all();
+ param->data_size = 0;
+ return 0;
+}
+
+/*
+ * Round up the ptr to an 8-byte boundary.
+ */
+#define ALIGN_MASK 7
+static inline void *align_ptr(void *ptr)
+{
+ return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
+}
+
+/*
+ * Retrieves the data payload buffer from an already allocated
+ * struct dm_ioctl.
+ */
+static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
+ size_t *len)
+{
+ param->data_start = align_ptr(param + 1) - (void *) param;
+
+ if (param->data_start < param_size)
+ *len = param_size - param->data_start;
+ else
+ *len = 0;
+
+ return ((void *) param) + param->data_start;
+}
+
+static int list_devices(struct dm_ioctl *param, size_t param_size)
+{
+ unsigned int i;
+ struct hash_cell *hc;
+ size_t len, needed = 0;
+ struct dm_name_list *nl, *old_nl = NULL;
+
+ down_write(&_hash_lock);
+
+ /*
+ * Loop through all the devices working out how much
+ * space we need.
+ */
+ for (i = 0; i < NUM_BUCKETS; i++) {
+ list_for_each_entry (hc, _name_buckets + i, name_list) {
+ needed += sizeof(struct dm_name_list);
+ needed += strlen(hc->name);
+ needed += ALIGN_MASK;
+ }
+ }
+
+ /*
+ * Grab our output buffer.
+ */
+ nl = get_result_buffer(param, param_size, &len);
+ if (len < needed) {
+ param->flags |= DM_BUFFER_FULL_FLAG;
+ goto out;
+ }
+ param->data_size = param->data_start + needed;
+
+ nl->dev = 0; /* Flags no data */
+
+ /*
+ * Now loop through filling out the names.
+ */
+ for (i = 0; i < NUM_BUCKETS; i++) {
+ list_for_each_entry (hc, _name_buckets + i, name_list) {
+ if (old_nl)
+ old_nl->next = (uint32_t) ((void *) nl -
+ (void *) old_nl);
+
+ nl->dev = dm_kdev(hc->md);
+ nl->next = 0;
+ strcpy(nl->name, hc->name);
+
+ old_nl = nl;
+ nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
+ }
+ }
+
+ out:
+ up_write(&_hash_lock);
+ return 0;
+}
+
+static int check_name(const char *name)
+{
+ if (strchr(name, '/')) {
+ DMWARN("invalid device name");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/*
+ * Fills in a dm_ioctl structure, ready for sending back to
+ * userland.
+ */
+static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
+{
+ kdev_t dev = dm_kdev(md);
+ struct dm_table *table;
+ struct block_device *bdev;
+
+ param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
+ DM_ACTIVE_PRESENT_FLAG);
+
+ if (dm_suspended(md))
+ param->flags |= DM_SUSPEND_FLAG;
+
+ param->dev = kdev_t_to_nr(dev);
+
+ if (is_read_only(dev))
+ param->flags |= DM_READONLY_FLAG;
+
+ param->event_nr = dm_get_event_nr(md);
+
+ table = dm_get_table(md);
+ if (table) {
+ param->flags |= DM_ACTIVE_PRESENT_FLAG;
+ param->target_count = dm_table_get_num_targets(table);
+ dm_table_put(table);
+ } else
+ param->target_count = 0;
+
+ bdev = bdget(param->dev);
+ if (!bdev)
+ return -ENXIO;
+ param->open_count = bdev->bd_openers;
+ bdput(bdev);
+
+ return 0;
+}
+
+static int dev_create(struct dm_ioctl *param, size_t param_size)
+{
+ int r;
+ kdev_t dev = 0;
+ struct mapped_device *md;
+
+ r = check_name(param->name);
+ if (r)
+ return r;
+
+ if (param->flags & DM_PERSISTENT_DEV_FLAG)
+ dev = to_kdev_t(param->dev);
+
+ r = dm_create(dev, &md);
+ if (r)
+ return r;
+
+ r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
+ if (r) {
+ dm_put(md);
+ return r;
+ }
+
+ param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
+
+ r = __dev_status(md, param);
+ dm_put(md);
+
+ return r;
+}
+
+/*
+ * Always use UUID for lookups if it's present, otherwise use name.
+ */
+static inline struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
+{
+ return *param->uuid ?
+ __get_uuid_cell(param->uuid) : __get_name_cell(param->name);
+}
+
+static inline struct mapped_device *find_device(struct dm_ioctl *param)
+{
+ struct hash_cell *hc;
+ struct mapped_device *md = NULL;
+
+ down_read(&_hash_lock);
+ hc = __find_device_hash_cell(param);
+ if (hc) {
+ md = hc->md;
+
+ /*
+ * Sneakily write in both the name and the uuid
+ * while we have the cell.
+ */
+ strncpy(param->name, hc->name, sizeof(param->name));
+ if (hc->uuid)
+ strncpy(param->uuid, hc->uuid, sizeof(param->uuid) - 1);
+ else
+ param->uuid[0] = '\0';
+
+ if (hc->new_map)
+ param->flags |= DM_INACTIVE_PRESENT_FLAG;
+ else
+ param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
+
+ dm_get(md);
+ }
+ up_read(&_hash_lock);
+
+ return md;
+}
+
+static int dev_remove(struct dm_ioctl *param, size_t param_size)
+{
+ struct hash_cell *hc;
+
+ down_write(&_hash_lock);
+ hc = __find_device_hash_cell(param);
+
+ if (!hc) {
+ DMWARN("device doesn't appear to be in the dev hash table.");
+ up_write(&_hash_lock);
+ return -ENXIO;
+ }
+
+ __hash_remove(hc);
+ up_write(&_hash_lock);
+ param->data_size = 0;
+ return 0;
+}
+
+/*
+ * Check a string doesn't overrun the chunk of
+ * memory we copied from userland.
+ */
+static int invalid_str(char *str, void *end)
+{
+ while ((void *) str < end)
+ if (!*str++)
+ return 0;
+
+ return -EINVAL;
+}
+
+static int dev_rename(struct dm_ioctl *param, size_t param_size)
+{
+ int r;
+ char *new_name = (char *) param + param->data_start;
+
+ if (new_name < (char *) (param + 1) ||
+ invalid_str(new_name, (void *) param + param_size)) {
+ DMWARN("Invalid new logical volume name supplied.");
+ return -EINVAL;
+ }
+
+ r = check_name(new_name);
+ if (r)
+ return r;
+
+ param->data_size = 0;
+ return dm_hash_rename(param->name, new_name);
+}
+
+static int do_suspend(struct dm_ioctl *param)
+{
+ int r = 0;
+ struct mapped_device *md;
+
+ md = find_device(param);
+ if (!md)
+ return -ENXIO;
+
+ if (!dm_suspended(md))
+ r = dm_suspend(md);
+
+ if (!r)
+ r = __dev_status(md, param);
+
+ dm_put(md);
+ return r;
+}
+
+static int do_resume(struct dm_ioctl *param)
+{
+ int r = 0;
+ struct hash_cell *hc;
+ struct mapped_device *md;
+ struct dm_table *new_map;
+
+ down_write(&_hash_lock);
+
+ hc = __find_device_hash_cell(param);
+ if (!hc) {
+ DMWARN("device doesn't appear to be in the dev hash table.");
+ up_write(&_hash_lock);
+ return -ENXIO;
+ }
+
+ md = hc->md;
+ dm_get(md);
+
+ new_map = hc->new_map;
+ hc->new_map = NULL;
+ param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
+
+ up_write(&_hash_lock);
+
+ /* Do we need to load a new map ? */
+ if (new_map) {
+ /* Suspend if it isn't already suspended */
+ if (!dm_suspended(md))
+ dm_suspend(md);
+
+ r = dm_swap_table(md, new_map);
+ if (r) {
+ dm_put(md);
+ dm_table_put(new_map);
+ return r;
+ }
+
+ if (dm_table_get_mode(new_map) & FMODE_WRITE)
+ set_device_ro(dm_kdev(md), 0);
+ else
+ set_device_ro(dm_kdev(md), 1);
+
+ dm_table_put(new_map);
+ }
+
+ if (dm_suspended(md))
+ r = dm_resume(md);
+
+ if (!r)
+ r = __dev_status(md, param);
+
+ dm_put(md);
+ return r;
+}
+
+/*
+ * Set or unset the suspension state of a device.
+ * If the device already is in the requested state we just return its status.
+ */
+static int dev_suspend(struct dm_ioctl *param, size_t param_size)
+{
+ if (param->flags & DM_SUSPEND_FLAG)
+ return do_suspend(param);
+
+ return do_resume(param);
+}
+
+/*
+ * Copies device info back to user space, used by
+ * the create and info ioctls.
+ */
+static int dev_status(struct dm_ioctl *param, size_t param_size)
+{
+ int r;
+ struct mapped_device *md;
+
+ md = find_device(param);
+ if (!md)
+ return -ENXIO;
+
+ r = __dev_status(md, param);
+ dm_put(md);
+ return r;
+}
+
+/*
+ * Build up the status struct for each target
+ */
+static void retrieve_status(struct dm_table *table, struct dm_ioctl *param,
+ size_t param_size)
+{
+ unsigned int i, num_targets;
+ struct dm_target_spec *spec;
+ char *outbuf, *outptr;
+ status_type_t type;
+ size_t remaining, len, used = 0;
+
+ outptr = outbuf = get_result_buffer(param, param_size, &len);
+
+ if (param->flags & DM_STATUS_TABLE_FLAG)
+ type = STATUSTYPE_TABLE;
+ else
+ type = STATUSTYPE_INFO;
+
+ /* Get all the target info */
+ num_targets = dm_table_get_num_targets(table);
+ for (i = 0; i < num_targets; i++) {
+ struct dm_target *ti = dm_table_get_target(table, i);
+
+ remaining = len - (outptr - outbuf);
+ if (remaining < sizeof(struct dm_target_spec)) {
+ param->flags |= DM_BUFFER_FULL_FLAG;
+ break;
+ }
+
+ spec = (struct dm_target_spec *) outptr;
+
+ spec->status = 0;
+ spec->sector_start = ti->begin;
+ spec->length = ti->len;
+ strncpy(spec->target_type, ti->type->name,
+ sizeof(spec->target_type));
+
+ outptr += sizeof(struct dm_target_spec);
+ remaining = len - (outptr - outbuf);
+
+ /* Get the status/table string from the target driver */
+ if (ti->type->status) {
+ if (ti->type->status(ti, type, outptr, remaining)) {
+ param->flags |= DM_BUFFER_FULL_FLAG;
+ break;
+ }
+ } else
+ outptr[0] = '\0';
+
+ outptr += strlen(outptr) + 1;
+ used = param->data_start + (outptr - outbuf);
+
+ align_ptr(outptr);
+ spec->next = outptr - outbuf;
+ }
+
+ if (used)
+ param->data_size = used;
+
+ param->target_count = num_targets;
+}
+
+/*
+ * Wait for a device to report an event
+ */
+static int dev_wait(struct dm_ioctl *param, size_t param_size)
+{
+ int r;
+ struct mapped_device *md;
+ struct dm_table *table;
+ DECLARE_WAITQUEUE(wq, current);
+
+ md = find_device(param);
+ if (!md)
+ return -ENXIO;
+
+ /*
+ * Wait for a notification event
+ */
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (!dm_add_wait_queue(md, &wq, param->event_nr)) {
+ schedule();
+ dm_remove_wait_queue(md, &wq);
+ }
+ set_current_state(TASK_RUNNING);
+
+ /*
+ * The userland program is going to want to know what
+ * changed to trigger the event, so we may as well tell
+ * him and save an ioctl.
+ */
+ r = __dev_status(md, param);
+ if (r)
+ goto out;
+
+ table = dm_get_table(md);
+ if (table) {
+ retrieve_status(table, param, param_size);
+ dm_table_put(table);
+ }
+
+ out:
+ dm_put(md);
+ return r;
+}
+
+static inline int get_mode(struct dm_ioctl *param)
+{
+ int mode = FMODE_READ | FMODE_WRITE;
+
+ if (param->flags & DM_READONLY_FLAG)
+ mode = FMODE_READ;
+
+ return mode;
+}
+
+static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
+ struct dm_target_spec **spec, char **target_params)
+{
+ *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
+ *target_params = (char *) (*spec + 1);
+
+ if (*spec < (last + 1))
+ return -EINVAL;
+
+ return invalid_str(*target_params, end);
+}
+
+static int populate_table(struct dm_table *table, struct dm_ioctl *param,
+ size_t param_size)
+{
+ int r;
+ unsigned int i = 0;
+ struct dm_target_spec *spec = (struct dm_target_spec *) param;
+ uint32_t next = param->data_start;
+ void *end = (void *) param + param_size;
+ char *target_params;
+
+ if (!param->target_count) {
+ DMWARN("populate_table: no targets specified");
+ return -EINVAL;
+ }
+
+ for (i = 0; i < param->target_count; i++) {
+
+ r = next_target(spec, next, end, &spec, &target_params);
+ if (r) {
+ DMWARN("unable to find target");
+ return r;
+ }
+
+ r = dm_table_add_target(table, spec->target_type,
+ (sector_t) spec->sector_start,
+ (sector_t) spec->length,
+ target_params);
+ if (r) {
+ DMWARN("error adding target to table");
+ return r;
+ }
+
+ next = spec->next;
+ }
+
+ return dm_table_complete(table);
+}
+
+static int table_load(struct dm_ioctl *param, size_t param_size)
+{
+ int r;
+ struct hash_cell *hc;
+ struct dm_table *t;
+
+ r = dm_table_create(&t, get_mode(param), param->target_count);
+ if (r)
+ return r;
+
+ r = populate_table(t, param, param_size);
+ if (r) {
+ dm_table_put(t);
+ return r;
+ }
+
+ down_write(&_hash_lock);
+ hc = __find_device_hash_cell(param);
+ if (!hc) {
+ DMWARN("device doesn't appear to be in the dev hash table.");
+ up_write(&_hash_lock);
+ return -ENXIO;
+ }
+
+ if (hc->new_map)
+ dm_table_put(hc->new_map);
+ hc->new_map = t;
+ param->flags |= DM_INACTIVE_PRESENT_FLAG;
+
+ r = __dev_status(hc->md, param);
+ up_write(&_hash_lock);
+ return r;
+}
+
+static int table_clear(struct dm_ioctl *param, size_t param_size)
+{
+ int r;
+ struct hash_cell *hc;
+
+ down_write(&_hash_lock);
+
+ hc = __find_device_hash_cell(param);
+ if (!hc) {
+ DMWARN("device doesn't appear to be in the dev hash table.");
+ up_write(&_hash_lock);
+ return -ENXIO;
+ }
+
+ if (hc->new_map) {
+ dm_table_put(hc->new_map);
+ hc->new_map = NULL;
+ }
+
+ param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
+
+ r = __dev_status(hc->md, param);
+ up_write(&_hash_lock);
+ return r;
+}
+
+/*
+ * Retrieves a list of devices used by a particular dm device.
+ */
+static void retrieve_deps(struct dm_table *table, struct dm_ioctl *param,
+ size_t param_size)
+{
+ unsigned int count = 0;
+ struct list_head *tmp;
+ size_t len, needed;
+ struct dm_target_deps *deps;
+
+ deps = get_result_buffer(param, param_size, &len);
+
+ /*
+ * Count the devices.
+ */
+ list_for_each(tmp, dm_table_get_devices(table))
+ count++;
+
+ /*
+ * Check we have enough space.
+ */
+ needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
+ if (len < needed) {
+ param->flags |= DM_BUFFER_FULL_FLAG;
+ return;
+ }
+
+ /*
+ * Fill in the devices.
+ */
+ deps->count = count;
+ count = 0;
+ list_for_each(tmp, dm_table_get_devices(table)) {
+ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
+ deps->dev[count++] = dd->bdev->bd_dev;
+ }
+
+ param->data_size = param->data_start + needed;
+}
+
+static int table_deps(struct dm_ioctl *param, size_t param_size)
+{
+ int r;
+ struct mapped_device *md;
+ struct dm_table *table;
+
+ md = find_device(param);
+ if (!md)
+ return -ENXIO;
+
+ r = __dev_status(md, param);
+ if (r)
+ goto out;
+
+ table = dm_get_table(md);
+ if (table) {
+ retrieve_deps(table, param, param_size);
+ dm_table_put(table);
+ }
+
+ out:
+ dm_put(md);
+ return r;
+}
+
+/*
+ * Return the status of a device as a text string for each
+ * target.
+ */
+static int table_status(struct dm_ioctl *param, size_t param_size)
+{
+ int r;
+ struct mapped_device *md;
+ struct dm_table *table;
+
+ md = find_device(param);
+ if (!md)
+ return -ENXIO;
+
+ r = __dev_status(md, param);
+ if (r)
+ goto out;
+
+ table = dm_get_table(md);
+ if (table) {
+ retrieve_status(table, param, param_size);
+ dm_table_put(table);
+ }
+
+ out:
+ dm_put(md);
+ return r;
+}
+
+/*-----------------------------------------------------------------
+ * Implementation of open/close/ioctl on the special char
+ * device.
+ *---------------------------------------------------------------*/
+static ioctl_fn lookup_ioctl(unsigned int cmd)
+{
+ static struct {
+ int cmd;
+ ioctl_fn fn;
+ } _ioctls[] = {
+ {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
+ {DM_REMOVE_ALL_CMD, remove_all},
+ {DM_LIST_DEVICES_CMD, list_devices},
+
+ {DM_DEV_CREATE_CMD, dev_create},
+ {DM_DEV_REMOVE_CMD, dev_remove},
+ {DM_DEV_RENAME_CMD, dev_rename},
+ {DM_DEV_SUSPEND_CMD, dev_suspend},
+ {DM_DEV_STATUS_CMD, dev_status},
+ {DM_DEV_WAIT_CMD, dev_wait},
+
+ {DM_TABLE_LOAD_CMD, table_load},
+ {DM_TABLE_CLEAR_CMD, table_clear},
+ {DM_TABLE_DEPS_CMD, table_deps},
+ {DM_TABLE_STATUS_CMD, table_status}
+ };
+
+ return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
+}
+
+/*
+ * As well as checking the version compatibility this always
+ * copies the kernel interface version out.
+ */
+static int check_version(unsigned int cmd, struct dm_ioctl *user)
+{
+ uint32_t version[3];
+ int r = 0;
+
+ if (copy_from_user(version, user->version, sizeof(version)))
+ return -EFAULT;
+
+ if ((DM_VERSION_MAJOR != version[0]) ||
+ (DM_VERSION_MINOR < version[1])) {
+ DMWARN("ioctl interface mismatch: "
+ "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
+ DM_VERSION_MAJOR, DM_VERSION_MINOR,
+ DM_VERSION_PATCHLEVEL,
+ version[0], version[1], version[2], cmd);
+ r = -EINVAL;
+ }
+
+ /*
+ * Fill in the kernel version.
+ */
+ version[0] = DM_VERSION_MAJOR;
+ version[1] = DM_VERSION_MINOR;
+ version[2] = DM_VERSION_PATCHLEVEL;
+ if (copy_to_user(user->version, version, sizeof(version)))
+ return -EFAULT;
+
+ return r;
+}
+
+static void free_params(struct dm_ioctl *param)
+{
+ vfree(param);
+}
+
+static int copy_params(struct dm_ioctl *user, struct dm_ioctl **param)
+{
+ struct dm_ioctl tmp, *dmi;
+
+ if (copy_from_user(&tmp, user, sizeof(tmp)))
+ return -EFAULT;
+
+ if (tmp.data_size < sizeof(tmp))
+ return -EINVAL;
+
+ dmi = (struct dm_ioctl *) vmalloc(tmp.data_size);
+ if (!dmi)
+ return -ENOMEM;
+
+ if (copy_from_user(dmi, user, tmp.data_size)) {
+ vfree(dmi);
+ return -EFAULT;
+ }
+
+ *param = dmi;
+ return 0;
+}
+
+static int validate_params(uint cmd, struct dm_ioctl *param)
+{
+ /* Always clear this flag */
+ param->flags &= ~DM_BUFFER_FULL_FLAG;
+
+ /* Ignores parameters */
+ if (cmd == DM_REMOVE_ALL_CMD || cmd == DM_LIST_DEVICES_CMD)
+ return 0;
+
+ /* Unless creating, either name or uuid but not both */
+ if (cmd != DM_DEV_CREATE_CMD) {
+ if ((!*param->uuid && !*param->name) ||
+ (*param->uuid && *param->name)) {
+ DMWARN("one of name or uuid must be supplied, cmd(%u)",
+ cmd);
+ return -EINVAL;
+ }
+ }
+
+ /* Ensure strings are terminated */
+ param->name[DM_NAME_LEN - 1] = '\0';
+ param->uuid[DM_UUID_LEN - 1] = '\0';
+
+ return 0;
+}
+
+static int ctl_ioctl(struct inode *inode, struct file *file,
+ uint command, ulong u)
+{
+ int r = 0;
+ unsigned int cmd;
+ struct dm_ioctl *param;
+ struct dm_ioctl *user = (struct dm_ioctl *) u;
+ ioctl_fn fn = NULL;
+ size_t param_size;
+
+ /* only root can play with this */
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (_IOC_TYPE(command) != DM_IOCTL)
+ return -ENOTTY;
+
+ cmd = _IOC_NR(command);
+
+ /*
+ * Check the interface version passed in. This also
+ * writes out the kernel's interface version.
+ */
+ r = check_version(cmd, user);
+ if (r)
+ return r;
+
+ /*
+ * Nothing more to do for the version command.
+ */
+ if (cmd == DM_VERSION_CMD)
+ return 0;
+
+ fn = lookup_ioctl(cmd);
+ if (!fn) {
+ DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
+ return -ENOTTY;
+ }
+
+ /*
+ * FIXME: I don't like this, we're trying to avoid low
+ * memory issues when a device is suspended.
+ */
+ current->flags |= PF_MEMALLOC;
+
+ /*
+ * Copy the parameters into kernel space.
+ */
+ r = copy_params(user, &param);
+ if (r) {
+ current->flags &= ~PF_MEMALLOC;
+ return r;
+ }
+
+ r = validate_params(cmd, param);
+ if (r)
+ goto out;
+
+ param_size = param->data_size;
+ param->data_size = sizeof(*param);
+ r = fn(param, param_size);
+
+ /*
+ * Copy the results back to userland.
+ */
+ if (!r && copy_to_user(user, param, param->data_size))
+ r = -EFAULT;
+
+ out:
+ free_params(param);
+ current->flags &= ~PF_MEMALLOC;
+ return r;
+}
+
+static struct file_operations _ctl_fops = {
+ .ioctl = ctl_ioctl,
+ .owner = THIS_MODULE,
+};
+
+static devfs_handle_t _ctl_handle;
+
+static struct miscdevice _dm_misc = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = DM_NAME,
+ .fops = &_ctl_fops
+};
+
+/*
+ * Create misc character device and link to DM_DIR/control.
+ */
+int __init dm_interface_init(void)
+{
+ int r;
+ char rname[64];
+
+ r = dm_hash_init();
+ if (r)
+ return r;
+
+ r = misc_register(&_dm_misc);
+ if (r) {
+ DMERR("misc_register failed for control device");
+ dm_hash_exit();
+ return r;
+ }
+
+ r = devfs_generate_path(_dm_misc.devfs_handle, rname + 3,
+ sizeof rname - 3);
+ if (r == -ENOSYS)
+ goto done; /* devfs not present */
+
+ if (r < 0) {
+ DMERR("devfs_generate_path failed for control device");
+ goto failed;
+ }
+
+ strncpy(rname + r, "../", 3);
+ r = devfs_mk_symlink(NULL, DM_DIR "/control",
+ DEVFS_FL_DEFAULT, rname + r, &_ctl_handle, NULL);
+ if (r) {
+ DMERR("devfs_mk_symlink failed for control device");
+ goto failed;
+ }
+ devfs_auto_unregister(_dm_misc.devfs_handle, _ctl_handle);
+
+ done:
+ DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
+ DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
+ DM_DRIVER_EMAIL);
+ return 0;
+
+ failed:
+ misc_deregister(&_dm_misc);
+ dm_hash_exit();
+ return r;
+}
+
+void dm_interface_exit(void)
+{
+ if (misc_deregister(&_dm_misc) < 0)
+ DMERR("misc_deregister failed for control device");
+
+ dm_hash_exit();
+}
--- diff/include/linux/dm-ioctl.h 1970-01-01 01:00:00.000000000 +0100
+++ source/include/linux/dm-ioctl.h 2003-12-09 11:01:41.000000000 +0000
@@ -0,0 +1,237 @@
+/*
+ * Copyright (C) 2001 - 2003 Sistina Software (UK) Limited.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef _LINUX_DM_IOCTL_H
+#define _LINUX_DM_IOCTL_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 5
+#define DM_VERSION_EXTRA "-ioctl (2003-11-18)"
+
+/* 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 */