* [RFC 3/3] dm: v4 ioctl interface
2003-07-01 14:58 [RFC] device-mapper v4 ioctl interface implementation Joe Thornber
2003-07-01 15:01 ` [RFC 1/3] dm: fix memory leak Joe Thornber
2003-07-01 15:01 ` [RFC 2/3] dm: avoid event race Joe Thornber
@ 2003-07-01 15:02 ` Joe Thornber
2003-07-01 20:05 ` Kevin Corry
2003-07-06 0:39 ` [dm-devel] [RFC] device-mapper v4 ioctl interface implementation Alasdair G Kergon
3 siblings, 1 reply; 14+ messages in thread
From: Joe Thornber @ 2003-07-01 15:02 UTC (permalink / raw)
To: Joe Thornber; +Cc: Linux Mailing List, dm-devel
v4 of the ioctl interface. Note there never was a v2 or a v3 except
in an unofficial EVMS way.
There is now a config option to allow the user to select v1 or v4, it
defaults to v1. If you want to use v4 you will have to update your
tools (libdevmapper/lvm), these new tools have not been released at
the time of writing.
dm-ioctl.[hc] just #includes dm-ioctl-v[14].[hc] depending on the
config option.
--- diff/drivers/md/Kconfig 2003-05-21 11:50:15.000000000 +0100
+++ source/drivers/md/Kconfig 2003-07-01 15:36:42.000000000 +0100
@@ -145,5 +145,12 @@
If unsure, say N.
+config DM_IOCTL_V4
+ bool "ioctl interface version 4"
+ depends on BLK_DEV_DM
+ ---help---
+ Recent tools use a new version of the ioctl interface, only
+ select this option if you intend using such tools.
+
endmenu
--- diff/drivers/md/dm-ioctl.c 2003-06-30 17:12:49.000000000 +0100
+++ source/drivers/md/dm-ioctl.c 2003-07-01 15:36:42.000000000 +0100
@@ -1,1133 +1,13 @@
/*
- * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
+ * Copyright (C) 2003 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 <linux/devfs_fs_kernel.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;
-};
-
-#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];
-
-void dm_hash_remove_all(void);
-
-/*
- * Guards access to all three 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);
- devfs_mk_dir(DM_DIR);
- return 0;
-}
-
-void dm_hash_exit(void)
-{
- dm_hash_remove_all();
- devfs_remove(DM_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;
- 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)
-{
- struct gendisk *disk = dm_disk(hc->md);
-
- devfs_mk_bdev(MKDEV(disk->major, disk->first_minor),
- S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
- DM_DIR "/%s", hc->name);
- return 0;
-}
-
-static int unregister_with_devfs(struct hash_cell *hc)
-{
- devfs_remove(DM_DIR"/%s", hc->name);
- 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 all three 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);
- 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.
- */
- unregister_with_devfs(hc);
-
- 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 */
- 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, struct dm_ioctl *user);
-
-/*
- * Check a string doesn't overrun the chunk of
- * memory we copied from userland.
- */
-static int valid_str(char *str, void *begin, void *end)
-{
- while (((void *) str >= begin) && ((void *) str < end))
- if (!*str++)
- return 0;
-
- return -EINVAL;
-}
-
-static int next_target(struct dm_target_spec *last, uint32_t next,
- void *begin, void *end,
- struct dm_target_spec **spec, char **params)
-{
- *spec = (struct dm_target_spec *)
- ((unsigned char *) last + next);
- *params = (char *) (*spec + 1);
-
- if (*spec < (last + 1) || ((void *) *spec > end))
- return -EINVAL;
-
- return valid_str(*params, begin, end);
-}
-
-static int populate_table(struct dm_table *table, struct dm_ioctl *args)
-{
- int r, first = 1;
- unsigned int i = 0;
- struct dm_target_spec *spec;
- char *params;
- void *begin, *end;
-
- if (!args->target_count) {
- DMWARN("populate_table: no targets specified");
- return -EINVAL;
- }
-
- begin = (void *) args;
- end = begin + args->data_size;
-
- for (i = 0; i < args->target_count; i++) {
-
- if (first)
- r = next_target((struct dm_target_spec *) args,
- args->data_start,
- begin, end, &spec, ¶ms);
- else
- r = next_target(spec, spec->next, begin, end,
- &spec, ¶ms);
-
- if (r) {
- DMWARN("unable to find target");
- return -EINVAL;
- }
-
- r = dm_table_add_target(table, spec->target_type,
- (sector_t) spec->sector_start,
- (sector_t) spec->length,
- params);
- if (r) {
- DMWARN("internal error adding target to table");
- return -EINVAL;
- }
-
- first = 0;
- }
-
- return dm_table_complete(table);
-}
-
-/*
- * Round up the ptr to the next 'align' boundary. Obviously
- * 'align' must be a power of 2.
- */
-static inline void *align_ptr(void *ptr, unsigned int align)
-{
- align--;
- return (void *) (((unsigned long) (ptr + align)) & ~align);
-}
-
-/*
- * Copies a dm_ioctl and an optional additional payload to
- * userland.
- */
-static int results_to_user(struct dm_ioctl *user, struct dm_ioctl *param,
- void *data, uint32_t len)
-{
- int r;
- void *ptr = NULL;
-
- if (data) {
- ptr = align_ptr(user + 1, sizeof(unsigned long));
- param->data_start = ptr - (void *) user;
- }
-
- /*
- * The version number has already been filled in, so we
- * just copy later fields.
- */
- r = copy_to_user(&user->data_size, ¶m->data_size,
- sizeof(*param) - sizeof(param->version));
- if (r)
- return -EFAULT;
-
- if (data) {
- if (param->data_start + len > param->data_size)
- return -ENOSPC;
-
- if (copy_to_user(ptr, data, len))
- r = -EFAULT;
- }
-
- return r;
-}
-
-/*
- * Fills in a dm_ioctl structure, ready for sending back to
- * userland.
- */
-static int __info(struct mapped_device *md, struct dm_ioctl *param)
-{
- struct dm_table *table;
- struct block_device *bdev;
- struct gendisk *disk = dm_disk(md);
-
- param->flags = DM_EXISTS_FLAG;
- if (dm_suspended(md))
- param->flags |= DM_SUSPEND_FLAG;
-
- bdev = bdget_disk(disk, 0);
- if (!bdev)
- return -ENXIO;
-
- param->dev = bdev->bd_dev;
- param->open_count = bdev->bd_openers;
- bdput(bdev);
-
- if (disk->policy)
- param->flags |= DM_READONLY_FLAG;
-
- table = dm_get_table(md);
- param->target_count = dm_table_get_num_targets(table);
- dm_table_put(table);
-
- return 0;
-}
-
-/*
- * Always use UUID for lookups if it's present, otherwise use 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 = *param->uuid ? __get_uuid_cell(param->uuid) :
- __get_name_cell(param->name);
- if (hc) {
- md = hc->md;
-
- /*
- * Sneakily write in both the name and the uuid
- * while we have the cell.
- */
- strlcpy(param->name, hc->name, sizeof(param->name));
- if (hc->uuid)
- strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
- else
- param->uuid[0] = '\0';
-
- dm_get(md);
- }
- up_read(&_hash_lock);
-
- return md;
-}
-
-#define ALIGNMENT sizeof(int)
-static void *_align(void *ptr, unsigned int a)
-{
- register unsigned long align = --a;
-
- return (void *) (((unsigned long) ptr + align) & ~align);
-}
-
-/*
- * Copies device info back to user space, used by
- * the create and info ioctls.
- */
-static int info(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- struct mapped_device *md;
-
- param->flags = 0;
-
- md = find_device(param);
- if (!md)
- /*
- * Device not found - returns cleared exists flag.
- */
- goto out;
-
- __info(md, param);
- dm_put(md);
-
- out:
- return results_to_user(user, param, NULL, 0);
-}
-
-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 check_name(const char *name)
-{
- if (name[0] == '/') {
- DMWARN("invalid device name");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static int create(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- int r;
- struct dm_table *t;
- struct mapped_device *md;
-
- r = check_name(param->name);
- if (r)
- return r;
-
- r = dm_table_create(&t, get_mode(param));
- if (r)
- return r;
-
- r = populate_table(t, param);
- if (r) {
- dm_table_put(t);
- return r;
- }
-
- if (param->flags & DM_PERSISTENT_DEV_FLAG)
- r = dm_create_with_minor(minor(to_kdev_t(param->dev)), t, &md);
- else
- r = dm_create(t, &md);
-
- if (r) {
- dm_table_put(t);
- return r;
- }
- dm_table_put(t); /* md will have grabbed its own reference */
-
- set_disk_ro(dm_disk(md), (param->flags & DM_READONLY_FLAG) ? 1 : 0);
- r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
- dm_put(md);
-
- return r ? r : info(param, user);
-}
-
-/*
- * Build up the status struct for each target
- */
-static int __status(struct mapped_device *md, struct dm_ioctl *param,
- char *outbuf, size_t *len)
-{
- unsigned int i, num_targets;
- struct dm_target_spec *spec;
- char *outptr;
- status_type_t type;
- struct dm_table *table = dm_get_table(md);
-
- if (param->flags & DM_STATUS_TABLE_FLAG)
- type = STATUSTYPE_TABLE;
- else
- type = STATUSTYPE_INFO;
-
- outptr = outbuf;
-
- /* 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);
-
- if (outptr - outbuf +
- sizeof(struct dm_target_spec) > param->data_size) {
- dm_table_put(table);
- return -ENOMEM;
- }
-
- spec = (struct dm_target_spec *) outptr;
-
- spec->status = 0;
- spec->sector_start = ti->begin;
- spec->length = ti->len;
- strlcpy(spec->target_type, ti->type->name,
- sizeof(spec->target_type));
-
- outptr += sizeof(struct dm_target_spec);
-
- /* Get the status/table string from the target driver */
- if (ti->type->status)
- ti->type->status(ti, type, outptr,
- outbuf + param->data_size - outptr);
- else
- outptr[0] = '\0';
-
- outptr += strlen(outptr) + 1;
- _align(outptr, ALIGNMENT);
- spec->next = outptr - outbuf;
- }
-
- param->target_count = num_targets;
- *len = outptr - outbuf;
- dm_table_put(table);
-
- return 0;
-}
-
-/*
- * Return the status of a device as a text string for each
- * target.
- */
-static int get_status(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- struct mapped_device *md;
- size_t len = 0;
- int ret;
- char *outbuf = NULL;
-
- md = find_device(param);
- if (!md)
- /*
- * Device not found - returns cleared exists flag.
- */
- goto out;
-
- /* We haven't a clue how long the resultant data will be so
- just allocate as much as userland has allowed us and make sure
- we don't overun it */
- outbuf = kmalloc(param->data_size, GFP_KERNEL);
- if (!outbuf)
- goto out;
- /*
- * Get the status of all targets
- */
- __status(md, param, outbuf, &len);
-
- /*
- * Setup the basic dm_ioctl structure.
- */
- __info(md, param);
-
- out:
- if (md)
- dm_put(md);
-
- ret = results_to_user(user, param, outbuf, len);
-
- if (outbuf)
- kfree(outbuf);
-
- return ret;
-}
-
-/*
- * Wait for a device to report an event
- */
-static int wait_device_event(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- struct mapped_device *md;
- DECLARE_WAITQUEUE(wq, current);
-
- md = find_device(param);
- if (!md)
- /*
- * Device not found - returns cleared exists flag.
- */
- goto out;
-
- /*
- * Setup the basic dm_ioctl structure.
- */
- __info(md, param);
-
- /*
- * Wait for a notification event
- */
- set_current_state(TASK_INTERRUPTIBLE);
- if (!dm_add_wait_queue(md, &wq, dm_get_event_nr(md))) {
- yield();
- dm_remove_wait_queue(md, &wq);
- }
- set_current_state(TASK_RUNNING);
- dm_put(md);
-
- out:
- return results_to_user(user, param, NULL, 0);
-}
-
-/*
- * Retrieves a list of devices used by a particular dm device.
- */
-static int dep(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- int r;
- unsigned int count;
- struct mapped_device *md;
- struct list_head *tmp;
- size_t len = 0;
- struct dm_target_deps *deps = NULL;
- struct dm_table *table;
-
- md = find_device(param);
- if (!md)
- goto out;
- table = dm_get_table(md);
-
- /*
- * Setup the basic dm_ioctl structure.
- */
- __info(md, param);
-
- /*
- * Count the devices.
- */
- count = 0;
- list_for_each(tmp, dm_table_get_devices(table))
- count++;
-
- /*
- * Allocate a kernel space version of the dm_target_status
- * struct.
- */
- if (array_too_big(sizeof(*deps), sizeof(*deps->dev), count)) {
- dm_table_put(table);
- dm_put(md);
- return -ENOMEM;
- }
-
- len = sizeof(*deps) + (sizeof(*deps->dev) * count);
- deps = kmalloc(len, GFP_KERNEL);
- if (!deps) {
- dm_table_put(table);
- dm_put(md);
- return -ENOMEM;
- }
-
- /*
- * 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;
- }
- dm_table_put(table);
- dm_put(md);
-
- out:
- r = results_to_user(user, param, deps, len);
-
- kfree(deps);
- return r;
-}
-
-static int remove(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- struct hash_cell *hc;
-
- down_write(&_hash_lock);
- hc = *param->uuid ? __get_uuid_cell(param->uuid) :
- __get_name_cell(param->name);
- if (!hc) {
- DMWARN("device doesn't appear to be in the dev hash table.");
- up_write(&_hash_lock);
- return -EINVAL;
- }
-
- /*
- * You may ask the interface to drop its reference to an
- * in use device. This is no different to unlinking a
- * file that someone still has open. The device will not
- * actually be destroyed until the last opener closes it.
- * The name and uuid of the device (both are interface
- * properties) will be available for reuse immediately.
- *
- * You don't want to drop a _suspended_ device from the
- * interface, since that will leave you with no way of
- * resuming it.
- */
- if (dm_suspended(hc->md)) {
- DMWARN("refusing to remove a suspended device.");
- up_write(&_hash_lock);
- return -EPERM;
- }
-
- __hash_remove(hc);
- up_write(&_hash_lock);
- return 0;
-}
-
-static int remove_all(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- dm_hash_remove_all();
- return 0;
-}
-
-static int suspend(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- int r;
- struct mapped_device *md;
-
- md = find_device(param);
- if (!md)
- return -ENXIO;
-
- if (param->flags & DM_SUSPEND_FLAG)
- r = dm_suspend(md);
- else
- r = dm_resume(md);
-
- dm_put(md);
- return r;
-}
-
-static int reload(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- int r;
- struct mapped_device *md;
- struct dm_table *t;
-
- r = dm_table_create(&t, get_mode(param));
- if (r)
- return r;
-
- r = populate_table(t, param);
- if (r) {
- dm_table_put(t);
- return r;
- }
-
- md = find_device(param);
- if (!md) {
- dm_table_put(t);
- return -ENXIO;
- }
-
- r = dm_swap_table(md, t);
- if (r) {
- dm_put(md);
- dm_table_put(t);
- return r;
- }
- dm_table_put(t); /* md will have taken its own reference */
-
- set_disk_ro(dm_disk(md), (param->flags & DM_READONLY_FLAG) ? 1 : 0);
- dm_put(md);
-
- r = info(param, user);
- return r;
-}
-
-static int rename(struct dm_ioctl *param, struct dm_ioctl *user)
-{
- int r;
- char *new_name = (char *) param + param->data_start;
-
- if (valid_str(new_name, (void *) param,
- (void *) param + param->data_size)) {
- DMWARN("Invalid new logical volume name supplied.");
- return -EINVAL;
- }
-
- r = check_name(new_name);
- if (r)
- return r;
-
- return dm_hash_rename(param->name, new_name);
-}
-
-
-/*-----------------------------------------------------------------
- * 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_DEV_CREATE_CMD, create},
- {DM_DEV_REMOVE_CMD, remove},
- {DM_DEV_RELOAD_CMD, reload},
- {DM_DEV_RENAME_CMD, rename},
- {DM_DEV_SUSPEND_CMD, suspend},
- {DM_DEV_DEPS_CMD, dep},
- {DM_DEV_STATUS_CMD, info},
- {DM_TARGET_STATUS_CMD, get_status},
- {DM_TARGET_WAIT_CMD, wait_device_event},
- };
-
- 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)
-{
- /* Ignores parameters */
- if (cmd == DM_REMOVE_ALL_CMD)
- return 0;
-
- /* Unless creating, either name of 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");
- 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;
-
- /* 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 kernels 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;
- }
-
- /*
- * Copy the parameters into kernel space.
- */
- r = copy_params(user, ¶m);
- if (r)
- return r;
-
- r = validate_params(cmd, param);
- if (r) {
- free_params(param);
- return r;
- }
-
- r = fn(param, user);
- free_params(param);
- return r;
-}
-
-static struct file_operations _ctl_fops = {
- .ioctl = ctl_ioctl,
- .owner = THIS_MODULE,
-};
-
-static struct miscdevice _dm_misc = {
- .minor = MISC_DYNAMIC_MINOR,
- .name = DM_NAME,
- .devfs_name = "mapper/control",
- .fops = &_ctl_fops
-};
-
-/*
- * Create misc character device and link to DM_DIR/control.
- */
-int __init dm_interface_init(void)
-{
- int r;
-
- 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;
- }
-
- DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
- DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
- DM_DRIVER_EMAIL);
- return 0;
-
- if (misc_deregister(&_dm_misc) < 0)
- DMERR("misc_deregister failed for control device");
- 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();
-}
+#ifdef CONFIG_DM_IOCTL_V4
+#include "dm-ioctl-v4.c"
+#else
+#include "dm-ioctl-v1.c"
+#endif
--- diff/drivers/md/dm.c 2003-06-30 17:12:16.000000000 +0100
+++ source/drivers/md/dm.c 2003-07-01 15:36:42.000000000 +0100
@@ -516,6 +516,11 @@
down_read(&md->lock);
}
+ if (!md->map) {
+ bio_io_error(bio, bio->bi_size);
+ return 0;
+ }
+
__split_bio(md, bio);
up_read(&md->lock);
return 0;
@@ -672,6 +677,9 @@
static void __unbind(struct mapped_device *md)
{
+ if (!md->map)
+ return;
+
dm_table_event_callback(md->map, NULL, NULL);
dm_table_put(md->map);
md->map = NULL;
@@ -682,35 +690,26 @@
* Constructor for a new device.
*/
static int create_aux(unsigned int minor, int persistent,
- struct dm_table *table, struct mapped_device **result)
+ struct mapped_device **result)
{
- int r;
struct mapped_device *md;
md = alloc_dev(minor, persistent);
if (!md)
return -ENXIO;
- r = __bind(md, table);
- if (r) {
- free_dev(md);
- return r;
- }
- dm_table_resume_targets(md->map);
-
*result = md;
return 0;
}
-int dm_create(struct dm_table *table, struct mapped_device **result)
+int dm_create(struct mapped_device **result)
{
- return create_aux(0, 0, table, result);
+ return create_aux(0, 0, result);
}
-int dm_create_with_minor(unsigned int minor,
- struct dm_table *table, struct mapped_device **result)
+int dm_create_with_minor(unsigned int minor, struct mapped_device **result)
{
- return create_aux(minor, 1, table, result);
+ return create_aux(minor, 1, result);
}
void dm_get(struct mapped_device *md)
@@ -721,7 +720,7 @@
void dm_put(struct mapped_device *md)
{
if (atomic_dec_and_test(&md->holders)) {
- if (!test_bit(DMF_SUSPENDED, &md->flags))
+ if (!test_bit(DMF_SUSPENDED, &md->flags) && md->map)
dm_table_suspend_targets(md->map);
__unbind(md);
free_dev(md);
@@ -812,7 +811,8 @@
down_write(&md->lock);
remove_wait_queue(&md->wait, &wait);
set_bit(DMF_SUSPENDED, &md->flags);
- dm_table_suspend_targets(md->map);
+ if (md->map)
+ dm_table_suspend_targets(md->map);
up_write(&md->lock);
return 0;
@@ -823,7 +823,8 @@
struct deferred_io *def;
down_write(&md->lock);
- if (!test_bit(DMF_SUSPENDED, &md->flags) ||
+ if (!md->map ||
+ !test_bit(DMF_SUSPENDED, &md->flags) ||
!dm_table_get_size(md->map)) {
up_write(&md->lock);
return -EINVAL;
@@ -893,7 +894,8 @@
down_read(&md->lock);
t = md->map;
- dm_table_get(t);
+ if (t)
+ dm_table_get(t);
up_read(&md->lock);
return t;
--- diff/drivers/md/dm.h 2003-06-30 17:11:07.000000000 +0100
+++ source/drivers/md/dm.h 2003-07-01 15:36:42.000000000 +0100
@@ -51,9 +51,8 @@
* Functions for manipulating a struct mapped_device.
* Drop the reference with dm_put when you finish with the object.
*---------------------------------------------------------------*/
-int dm_create(struct dm_table *table, struct mapped_device **md);
-int dm_create_with_minor(unsigned int minor, struct dm_table *table,
- struct mapped_device **md);
+int dm_create(struct mapped_device **md);
+int dm_create_with_minor(unsigned int minor, struct mapped_device **md);
/*
* Reference counting for md.
--- diff/include/linux/dm-ioctl.h 2002-12-30 10:17:13.000000000 +0000
+++ source/include/linux/dm-ioctl.h 2003-07-01 15:36:42.000000000 +0100
@@ -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
--- diff/drivers/md/dm-ioctl-v1.c 1970-01-01 01:00:00.000000000 +0100
+++ source/drivers/md/dm-ioctl-v1.c 2003-07-01 15:36:42.000000000 +0100
@@ -0,0 +1,1160 @@
+/*
+ * 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 <linux/devfs_fs_kernel.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;
+};
+
+#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];
+
+void dm_hash_remove_all(void);
+
+/*
+ * Guards access to all three 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);
+ devfs_mk_dir(DM_DIR);
+ return 0;
+}
+
+void dm_hash_exit(void)
+{
+ dm_hash_remove_all();
+ devfs_remove(DM_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;
+ 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)
+{
+ struct gendisk *disk = dm_disk(hc->md);
+
+ devfs_mk_bdev(MKDEV(disk->major, disk->first_minor),
+ S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
+ DM_DIR "/%s", hc->name);
+ return 0;
+}
+
+static int unregister_with_devfs(struct hash_cell *hc)
+{
+ devfs_remove(DM_DIR"/%s", hc->name);
+ 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 all three 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);
+ 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.
+ */
+ unregister_with_devfs(hc);
+
+ 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 */
+ 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, struct dm_ioctl *user);
+
+/*
+ * Check a string doesn't overrun the chunk of
+ * memory we copied from userland.
+ */
+static int valid_str(char *str, void *begin, void *end)
+{
+ while (((void *) str >= begin) && ((void *) str < end))
+ if (!*str++)
+ return 0;
+
+ return -EINVAL;
+}
+
+static int next_target(struct dm_target_spec *last, uint32_t next,
+ void *begin, void *end,
+ struct dm_target_spec **spec, char **params)
+{
+ *spec = (struct dm_target_spec *)
+ ((unsigned char *) last + next);
+ *params = (char *) (*spec + 1);
+
+ if (*spec < (last + 1) || ((void *) *spec > end))
+ return -EINVAL;
+
+ return valid_str(*params, begin, end);
+}
+
+static int populate_table(struct dm_table *table, struct dm_ioctl *args)
+{
+ int r, first = 1;
+ unsigned int i = 0;
+ struct dm_target_spec *spec;
+ char *params;
+ void *begin, *end;
+
+ if (!args->target_count) {
+ DMWARN("populate_table: no targets specified");
+ return -EINVAL;
+ }
+
+ begin = (void *) args;
+ end = begin + args->data_size;
+
+ for (i = 0; i < args->target_count; i++) {
+
+ if (first)
+ r = next_target((struct dm_target_spec *) args,
+ args->data_start,
+ begin, end, &spec, ¶ms);
+ else
+ r = next_target(spec, spec->next, begin, end,
+ &spec, ¶ms);
+
+ if (r) {
+ DMWARN("unable to find target");
+ return -EINVAL;
+ }
+
+ r = dm_table_add_target(table, spec->target_type,
+ (sector_t) spec->sector_start,
+ (sector_t) spec->length,
+ params);
+ if (r) {
+ DMWARN("internal error adding target to table");
+ return -EINVAL;
+ }
+
+ first = 0;
+ }
+
+ return dm_table_complete(table);
+}
+
+/*
+ * Round up the ptr to the next 'align' boundary. Obviously
+ * 'align' must be a power of 2.
+ */
+static inline void *align_ptr(void *ptr, unsigned int align)
+{
+ align--;
+ return (void *) (((unsigned long) (ptr + align)) & ~align);
+}
+
+/*
+ * Copies a dm_ioctl and an optional additional payload to
+ * userland.
+ */
+static int results_to_user(struct dm_ioctl *user, struct dm_ioctl *param,
+ void *data, uint32_t len)
+{
+ int r;
+ void *ptr = NULL;
+
+ if (data) {
+ ptr = align_ptr(user + 1, sizeof(unsigned long));
+ param->data_start = ptr - (void *) user;
+ }
+
+ /*
+ * The version number has already been filled in, so we
+ * just copy later fields.
+ */
+ r = copy_to_user(&user->data_size, ¶m->data_size,
+ sizeof(*param) - sizeof(param->version));
+ if (r)
+ return -EFAULT;
+
+ if (data) {
+ if (param->data_start + len > param->data_size)
+ return -ENOSPC;
+
+ if (copy_to_user(ptr, data, len))
+ r = -EFAULT;
+ }
+
+ return r;
+}
+
+/*
+ * Fills in a dm_ioctl structure, ready for sending back to
+ * userland.
+ */
+static int __info(struct mapped_device *md, struct dm_ioctl *param)
+{
+ struct dm_table *table;
+ struct block_device *bdev;
+ struct gendisk *disk = dm_disk(md);
+
+ param->flags = DM_EXISTS_FLAG;
+ if (dm_suspended(md))
+ param->flags |= DM_SUSPEND_FLAG;
+
+ bdev = bdget_disk(disk, 0);
+ if (!bdev)
+ return -ENXIO;
+
+ param->dev = bdev->bd_dev;
+ param->open_count = bdev->bd_openers;
+ bdput(bdev);
+
+ if (disk->policy)
+ param->flags |= DM_READONLY_FLAG;
+
+ table = dm_get_table(md);
+ param->target_count = dm_table_get_num_targets(table);
+ dm_table_put(table);
+
+ return 0;
+}
+
+/*
+ * Always use UUID for lookups if it's present, otherwise use 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 = *param->uuid ? __get_uuid_cell(param->uuid) :
+ __get_name_cell(param->name);
+ if (hc) {
+ md = hc->md;
+
+ /*
+ * Sneakily write in both the name and the uuid
+ * while we have the cell.
+ */
+ strlcpy(param->name, hc->name, sizeof(param->name));
+ if (hc->uuid)
+ strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
+ else
+ param->uuid[0] = '\0';
+
+ dm_get(md);
+ }
+ up_read(&_hash_lock);
+
+ return md;
+}
+
+#define ALIGNMENT sizeof(int)
+static void *_align(void *ptr, unsigned int a)
+{
+ register unsigned long align = --a;
+
+ return (void *) (((unsigned long) ptr + align) & ~align);
+}
+
+/*
+ * Copies device info back to user space, used by
+ * the create and info ioctls.
+ */
+static int info(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ struct mapped_device *md;
+
+ param->flags = 0;
+
+ md = find_device(param);
+ if (!md)
+ /*
+ * Device not found - returns cleared exists flag.
+ */
+ goto out;
+
+ __info(md, param);
+ dm_put(md);
+
+ out:
+ return results_to_user(user, param, NULL, 0);
+}
+
+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 check_name(const char *name)
+{
+ if (name[0] == '/') {
+ DMWARN("invalid device name");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int create(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ int r;
+ struct dm_table *t;
+ struct mapped_device *md;
+
+ r = check_name(param->name);
+ if (r)
+ return r;
+
+ r = dm_table_create(&t, get_mode(param));
+ if (r)
+ return r;
+
+ r = populate_table(t, param);
+ if (r) {
+ dm_table_put(t);
+ return r;
+ }
+
+ if (param->flags & DM_PERSISTENT_DEV_FLAG)
+ r = dm_create_with_minor(minor(to_kdev_t(param->dev)), &md);
+ else
+ r = dm_create(&md);
+
+ if (r) {
+ dm_table_put(t);
+ return r;
+ }
+
+ /* suspend the device */
+ r = dm_suspend(md);
+ if (r) {
+ DMWARN("suspend failed");
+ dm_table_put(t);
+ dm_put(md);
+ return r;
+ }
+ /* swap in the table */
+ r = dm_swap_table(md, t);
+ if (r) {
+ DMWARN("table swap failed");
+ dm_table_put(t);
+ dm_put(md);
+ return r;
+ }
+
+ /* resume the device */
+ r = dm_resume(md);
+ if (r) {
+ DMWARN("resume failed");
+ dm_table_put(t);
+ dm_put(md);
+ return r;
+ }
+
+ dm_table_put(t); /* md will have grabbed its own reference */
+
+ set_disk_ro(dm_disk(md), (param->flags & DM_READONLY_FLAG) ? 1 : 0);
+ r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
+ dm_put(md);
+
+ return r ? r : info(param, user);
+}
+
+/*
+ * Build up the status struct for each target
+ */
+static int __status(struct mapped_device *md, struct dm_ioctl *param,
+ char *outbuf, size_t *len)
+{
+ unsigned int i, num_targets;
+ struct dm_target_spec *spec;
+ char *outptr;
+ status_type_t type;
+ struct dm_table *table = dm_get_table(md);
+
+ if (param->flags & DM_STATUS_TABLE_FLAG)
+ type = STATUSTYPE_TABLE;
+ else
+ type = STATUSTYPE_INFO;
+
+ outptr = outbuf;
+
+ /* 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);
+
+ if (outptr - outbuf +
+ sizeof(struct dm_target_spec) > param->data_size) {
+ dm_table_put(table);
+ return -ENOMEM;
+ }
+
+ spec = (struct dm_target_spec *) outptr;
+
+ spec->status = 0;
+ spec->sector_start = ti->begin;
+ spec->length = ti->len;
+ strlcpy(spec->target_type, ti->type->name,
+ sizeof(spec->target_type));
+
+ outptr += sizeof(struct dm_target_spec);
+
+ /* Get the status/table string from the target driver */
+ if (ti->type->status)
+ ti->type->status(ti, type, outptr,
+ outbuf + param->data_size - outptr);
+ else
+ outptr[0] = '\0';
+
+ outptr += strlen(outptr) + 1;
+ _align(outptr, ALIGNMENT);
+ spec->next = outptr - outbuf;
+ }
+
+ param->target_count = num_targets;
+ *len = outptr - outbuf;
+ dm_table_put(table);
+
+ return 0;
+}
+
+/*
+ * Return the status of a device as a text string for each
+ * target.
+ */
+static int get_status(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ struct mapped_device *md;
+ size_t len = 0;
+ int ret;
+ char *outbuf = NULL;
+
+ md = find_device(param);
+ if (!md)
+ /*
+ * Device not found - returns cleared exists flag.
+ */
+ goto out;
+
+ /* We haven't a clue how long the resultant data will be so
+ just allocate as much as userland has allowed us and make sure
+ we don't overun it */
+ outbuf = kmalloc(param->data_size, GFP_KERNEL);
+ if (!outbuf)
+ goto out;
+ /*
+ * Get the status of all targets
+ */
+ __status(md, param, outbuf, &len);
+
+ /*
+ * Setup the basic dm_ioctl structure.
+ */
+ __info(md, param);
+
+ out:
+ if (md)
+ dm_put(md);
+
+ ret = results_to_user(user, param, outbuf, len);
+
+ if (outbuf)
+ kfree(outbuf);
+
+ return ret;
+}
+
+/*
+ * Wait for a device to report an event
+ */
+static int wait_device_event(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ struct mapped_device *md;
+ DECLARE_WAITQUEUE(wq, current);
+
+ md = find_device(param);
+ if (!md)
+ /*
+ * Device not found - returns cleared exists flag.
+ */
+ goto out;
+
+ /*
+ * Setup the basic dm_ioctl structure.
+ */
+ __info(md, param);
+
+ /*
+ * Wait for a notification event
+ */
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (!dm_add_wait_queue(md, &wq, dm_get_event_nr(md))) {
+ yield();
+ dm_remove_wait_queue(md, &wq);
+ }
+ set_current_state(TASK_RUNNING);
+ dm_put(md);
+
+ out:
+ return results_to_user(user, param, NULL, 0);
+}
+
+/*
+ * Retrieves a list of devices used by a particular dm device.
+ */
+static int dep(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ int r;
+ unsigned int count;
+ struct mapped_device *md;
+ struct list_head *tmp;
+ size_t len = 0;
+ struct dm_target_deps *deps = NULL;
+ struct dm_table *table;
+
+ md = find_device(param);
+ if (!md)
+ goto out;
+ table = dm_get_table(md);
+
+ /*
+ * Setup the basic dm_ioctl structure.
+ */
+ __info(md, param);
+
+ /*
+ * Count the devices.
+ */
+ count = 0;
+ list_for_each(tmp, dm_table_get_devices(table))
+ count++;
+
+ /*
+ * Allocate a kernel space version of the dm_target_status
+ * struct.
+ */
+ if (array_too_big(sizeof(*deps), sizeof(*deps->dev), count)) {
+ dm_table_put(table);
+ dm_put(md);
+ return -ENOMEM;
+ }
+
+ len = sizeof(*deps) + (sizeof(*deps->dev) * count);
+ deps = kmalloc(len, GFP_KERNEL);
+ if (!deps) {
+ dm_table_put(table);
+ dm_put(md);
+ return -ENOMEM;
+ }
+
+ /*
+ * 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;
+ }
+ dm_table_put(table);
+ dm_put(md);
+
+ out:
+ r = results_to_user(user, param, deps, len);
+
+ kfree(deps);
+ return r;
+}
+
+static int remove(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ struct hash_cell *hc;
+
+ down_write(&_hash_lock);
+ hc = *param->uuid ? __get_uuid_cell(param->uuid) :
+ __get_name_cell(param->name);
+ if (!hc) {
+ DMWARN("device doesn't appear to be in the dev hash table.");
+ up_write(&_hash_lock);
+ return -EINVAL;
+ }
+
+ /*
+ * You may ask the interface to drop its reference to an
+ * in use device. This is no different to unlinking a
+ * file that someone still has open. The device will not
+ * actually be destroyed until the last opener closes it.
+ * The name and uuid of the device (both are interface
+ * properties) will be available for reuse immediately.
+ *
+ * You don't want to drop a _suspended_ device from the
+ * interface, since that will leave you with no way of
+ * resuming it.
+ */
+ if (dm_suspended(hc->md)) {
+ DMWARN("refusing to remove a suspended device.");
+ up_write(&_hash_lock);
+ return -EPERM;
+ }
+
+ __hash_remove(hc);
+ up_write(&_hash_lock);
+ return 0;
+}
+
+static int remove_all(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ dm_hash_remove_all();
+ return 0;
+}
+
+static int suspend(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ int r;
+ struct mapped_device *md;
+
+ md = find_device(param);
+ if (!md)
+ return -ENXIO;
+
+ if (param->flags & DM_SUSPEND_FLAG)
+ r = dm_suspend(md);
+ else
+ r = dm_resume(md);
+
+ dm_put(md);
+ return r;
+}
+
+static int reload(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ int r;
+ struct mapped_device *md;
+ struct dm_table *t;
+
+ r = dm_table_create(&t, get_mode(param));
+ if (r)
+ return r;
+
+ r = populate_table(t, param);
+ if (r) {
+ dm_table_put(t);
+ return r;
+ }
+
+ md = find_device(param);
+ if (!md) {
+ dm_table_put(t);
+ return -ENXIO;
+ }
+
+ r = dm_swap_table(md, t);
+ if (r) {
+ dm_put(md);
+ dm_table_put(t);
+ return r;
+ }
+ dm_table_put(t); /* md will have taken its own reference */
+
+ set_disk_ro(dm_disk(md), (param->flags & DM_READONLY_FLAG) ? 1 : 0);
+ dm_put(md);
+
+ r = info(param, user);
+ return r;
+}
+
+static int rename(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ int r;
+ char *new_name = (char *) param + param->data_start;
+
+ if (valid_str(new_name, (void *) param,
+ (void *) param + param->data_size)) {
+ DMWARN("Invalid new logical volume name supplied.");
+ return -EINVAL;
+ }
+
+ r = check_name(new_name);
+ if (r)
+ return r;
+
+ return dm_hash_rename(param->name, new_name);
+}
+
+
+/*-----------------------------------------------------------------
+ * 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_DEV_CREATE_CMD, create},
+ {DM_DEV_REMOVE_CMD, remove},
+ {DM_DEV_RELOAD_CMD, reload},
+ {DM_DEV_RENAME_CMD, rename},
+ {DM_DEV_SUSPEND_CMD, suspend},
+ {DM_DEV_DEPS_CMD, dep},
+ {DM_DEV_STATUS_CMD, info},
+ {DM_TARGET_STATUS_CMD, get_status},
+ {DM_TARGET_WAIT_CMD, wait_device_event},
+ };
+
+ 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)
+{
+ /* Ignores parameters */
+ if (cmd == DM_REMOVE_ALL_CMD)
+ return 0;
+
+ /* Unless creating, either name of 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");
+ 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;
+
+ /* 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 kernels 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;
+ }
+
+ /*
+ * Copy the parameters into kernel space.
+ */
+ r = copy_params(user, ¶m);
+ if (r)
+ return r;
+
+ r = validate_params(cmd, param);
+ if (r) {
+ free_params(param);
+ return r;
+ }
+
+ r = fn(param, user);
+ free_params(param);
+ return r;
+}
+
+static struct file_operations _ctl_fops = {
+ .ioctl = ctl_ioctl,
+ .owner = THIS_MODULE,
+};
+
+static struct miscdevice _dm_misc = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = DM_NAME,
+ .devfs_name = "mapper/control",
+ .fops = &_ctl_fops
+};
+
+/*
+ * Create misc character device and link to DM_DIR/control.
+ */
+int __init dm_interface_init(void)
+{
+ int r;
+
+ 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;
+ }
+
+ DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
+ DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
+ DM_DRIVER_EMAIL);
+ return 0;
+
+ if (misc_deregister(&_dm_misc) < 0)
+ DMERR("misc_deregister failed for control device");
+ 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/drivers/md/dm-ioctl-v4.c 1970-01-01 01:00:00.000000000 +0100
+++ source/drivers/md/dm-ioctl-v4.c 2003-07-01 15:36:42.000000000 +0100
@@ -0,0 +1,1248 @@
+/*
+ * 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/init.h>
+#include <linux/wait.h>
+#include <linux/blk.h>
+#include <linux/slab.h>
+#include <linux/devfs_fs_kernel.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;
+};
+
+#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];
+
+void dm_hash_remove_all(void);
+
+/*
+ * Guards access to all three 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);
+ devfs_mk_dir(DM_DIR);
+ return 0;
+}
+
+void dm_hash_exit(void)
+{
+ dm_hash_remove_all();
+ devfs_remove(DM_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)
+{
+ struct gendisk *disk = dm_disk(hc->md);
+
+ devfs_mk_bdev(MKDEV(disk->major, disk->first_minor),
+ S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
+ DM_DIR "/%s", hc->name);
+ return 0;
+}
+
+static int unregister_with_devfs(struct hash_cell *hc)
+{
+ devfs_remove(DM_DIR"/%s", hc->name);
+ 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 all three 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 gendisk *disk;
+ 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 = (__u32) ((void *) nl -
+ (void *) old_nl);
+ disk = dm_disk(hc->md);
+ nl->dev = MKDEV(disk->major, disk->first_minor);
+ 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)
+{
+ struct gendisk *disk = dm_disk(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;
+
+ bdev = bdget_disk(disk, 0);
+ if (!bdev)
+ return -ENXIO;
+
+ param->dev = MKDEV(disk->major, disk->first_minor);
+
+ /*
+ * Yes, this will be out of date by the time it gets back
+ * to userland, but it is still very useful ofr
+ * debugging.
+ */
+ param->open_count = bdev->bd_openers;
+ bdput(bdev);
+
+ if (disk->policy)
+ 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;
+
+ return 0;
+}
+
+static int dev_create(struct dm_ioctl *param, size_t param_size)
+{
+ int r;
+ struct mapped_device *md;
+
+ r = check_name(param->name);
+ if (r)
+ return r;
+
+ if (param->flags & DM_PERSISTENT_DEV_FLAG)
+ r = dm_create_with_minor(minor(to_kdev_t(param->dev)), &md);
+ else
+ r = dm_create(&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 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 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_disk_ro(dm_disk(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 suspend(param);
+
+ return 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;
+}
+
+/*
+ * 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;
+ 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);
+ }
+
+ /*
+ * 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);
+
+ 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, __u32 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;
+ __u32 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));
+ 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;
+ }
+
+ 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 = 0;
+ 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;
+}
+
+/*
+ * 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;
+}
+
+/*
+ * 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)
+{
+ __u32 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;
+ }
+
+ /*
+ * 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, ¶m);
+ if (r) {
+ current->flags &= ~PF_MEMALLOC;
+ return r;
+ }
+
+ /*
+ * FIXME: eventually we will remove the PF_MEMALLOC flag
+ * here. However the tools still do nasty things like
+ * 'load' while a device is suspended.
+ */
+
+ 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 struct miscdevice _dm_misc = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = DM_NAME,
+ .devfs_name = "mapper/control",
+ .fops = &_ctl_fops
+};
+
+/*
+ * Create misc character device and link to DM_DIR/control.
+ */
+int __init dm_interface_init(void)
+{
+ int r;
+
+ 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;
+ }
+
+ DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
+ DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
+ DM_DRIVER_EMAIL);
+ return 0;
+}
+
+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-v1.h 1970-01-01 01:00:00.000000000 +0100
+++ source/include/linux/dm-ioctl-v1.h 2003-07-01 15:36:42.000000000 +0100
@@ -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/include/linux/dm-ioctl-v4.h 1970-01-01 01:00:00.000000000 +0100
+++ source/include/linux/dm-ioctl-v4.h 2003-07-01 15:36:42.000000000 +0100
@@ -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.
+ */
+ __u32 version[3]; /* in/out */
+ __u32 data_size; /* total size of data passed in
+ * including this struct */
+
+ __u32 data_start; /* offset to start of data
+ * relative to start of this struct */
+
+ __u32 target_count; /* in/out */
+ __s32 open_count; /* out */
+ __u32 flags; /* in/out */
+ __u32 event_nr; /* in/out */
+ __u32 padding;
+
+ __u64 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 {
+ __u64 sector_start;
+ __u64 length;
+ __s32 status; /* used when reading from kernel only */
+
+ /*
+ * Offset in bytes (from the start of this struct) to
+ * next target_spec.
+ */
+ __u32 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 {
+ __u32 count; /* Array size */
+ __u32 padding; /* unused */
+ __u64 dev[0]; /* out */
+};
+
+/*
+ * Used to get a list of all dm devices.
+ */
+struct dm_name_list {
+ __u64 dev;
+ __u32 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 */
^ permalink raw reply [flat|nested] 14+ messages in thread