1430 строки
29 KiB
C
1430 строки
29 KiB
C
/*
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* Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
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* Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved.
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*
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* This file is released under the GPL.
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*/
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#include "dm.h"
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#include <linux/module.h>
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#include <linux/vmalloc.h>
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#include <linux/miscdevice.h>
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#include <linux/init.h>
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#include <linux/wait.h>
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#include <linux/slab.h>
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#include <linux/devfs_fs_kernel.h>
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#include <linux/dm-ioctl.h>
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#include <asm/uaccess.h>
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#define DM_DRIVER_EMAIL "dm-devel@redhat.com"
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/*-----------------------------------------------------------------
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* The ioctl interface needs to be able to look up devices by
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* name or uuid.
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*---------------------------------------------------------------*/
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struct hash_cell {
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struct list_head name_list;
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struct list_head uuid_list;
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char *name;
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char *uuid;
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struct mapped_device *md;
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struct dm_table *new_map;
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};
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struct vers_iter {
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size_t param_size;
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struct dm_target_versions *vers, *old_vers;
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char *end;
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uint32_t flags;
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};
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#define NUM_BUCKETS 64
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#define MASK_BUCKETS (NUM_BUCKETS - 1)
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static struct list_head _name_buckets[NUM_BUCKETS];
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static struct list_head _uuid_buckets[NUM_BUCKETS];
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static void dm_hash_remove_all(void);
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/*
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* Guards access to both hash tables.
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*/
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static DECLARE_RWSEM(_hash_lock);
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static void init_buckets(struct list_head *buckets)
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{
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unsigned int i;
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for (i = 0; i < NUM_BUCKETS; i++)
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INIT_LIST_HEAD(buckets + i);
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}
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static int dm_hash_init(void)
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{
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init_buckets(_name_buckets);
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init_buckets(_uuid_buckets);
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devfs_mk_dir(DM_DIR);
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return 0;
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}
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static void dm_hash_exit(void)
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{
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dm_hash_remove_all();
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devfs_remove(DM_DIR);
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}
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/*-----------------------------------------------------------------
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* Hash function:
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* We're not really concerned with the str hash function being
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* fast since it's only used by the ioctl interface.
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*---------------------------------------------------------------*/
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static unsigned int hash_str(const char *str)
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{
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const unsigned int hash_mult = 2654435387U;
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unsigned int h = 0;
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while (*str)
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h = (h + (unsigned int) *str++) * hash_mult;
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return h & MASK_BUCKETS;
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}
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/*-----------------------------------------------------------------
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* Code for looking up a device by name
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*---------------------------------------------------------------*/
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static struct hash_cell *__get_name_cell(const char *str)
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{
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struct hash_cell *hc;
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unsigned int h = hash_str(str);
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list_for_each_entry (hc, _name_buckets + h, name_list)
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if (!strcmp(hc->name, str))
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return hc;
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return NULL;
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}
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static struct hash_cell *__get_uuid_cell(const char *str)
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{
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struct hash_cell *hc;
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unsigned int h = hash_str(str);
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list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
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if (!strcmp(hc->uuid, str))
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return hc;
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return NULL;
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}
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/*-----------------------------------------------------------------
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* Inserting, removing and renaming a device.
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*---------------------------------------------------------------*/
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static struct hash_cell *alloc_cell(const char *name, const char *uuid,
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struct mapped_device *md)
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{
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struct hash_cell *hc;
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hc = kmalloc(sizeof(*hc), GFP_KERNEL);
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if (!hc)
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return NULL;
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hc->name = kstrdup(name, GFP_KERNEL);
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if (!hc->name) {
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kfree(hc);
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return NULL;
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}
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if (!uuid)
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hc->uuid = NULL;
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else {
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hc->uuid = kstrdup(uuid, GFP_KERNEL);
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if (!hc->uuid) {
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kfree(hc->name);
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kfree(hc);
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return NULL;
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}
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}
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INIT_LIST_HEAD(&hc->name_list);
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INIT_LIST_HEAD(&hc->uuid_list);
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hc->md = md;
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hc->new_map = NULL;
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return hc;
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}
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static void free_cell(struct hash_cell *hc)
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{
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if (hc) {
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kfree(hc->name);
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kfree(hc->uuid);
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kfree(hc);
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}
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}
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/*
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* devfs stuff.
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*/
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static int register_with_devfs(struct hash_cell *hc)
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{
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struct gendisk *disk = dm_disk(hc->md);
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devfs_mk_bdev(MKDEV(disk->major, disk->first_minor),
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S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
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DM_DIR "/%s", hc->name);
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return 0;
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}
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static int unregister_with_devfs(struct hash_cell *hc)
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{
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devfs_remove(DM_DIR"/%s", hc->name);
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return 0;
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}
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/*
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* The kdev_t and uuid of a device can never change once it is
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* initially inserted.
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*/
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static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
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{
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struct hash_cell *cell;
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/*
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* Allocate the new cells.
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*/
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cell = alloc_cell(name, uuid, md);
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if (!cell)
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return -ENOMEM;
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/*
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* Insert the cell into both hash tables.
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*/
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down_write(&_hash_lock);
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if (__get_name_cell(name))
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goto bad;
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list_add(&cell->name_list, _name_buckets + hash_str(name));
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if (uuid) {
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if (__get_uuid_cell(uuid)) {
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list_del(&cell->name_list);
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goto bad;
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}
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list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
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}
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register_with_devfs(cell);
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dm_get(md);
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dm_set_mdptr(md, cell);
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up_write(&_hash_lock);
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return 0;
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bad:
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up_write(&_hash_lock);
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free_cell(cell);
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return -EBUSY;
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}
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static void __hash_remove(struct hash_cell *hc)
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{
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struct dm_table *table;
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/* remove from the dev hash */
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list_del(&hc->uuid_list);
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list_del(&hc->name_list);
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unregister_with_devfs(hc);
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dm_set_mdptr(hc->md, NULL);
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table = dm_get_table(hc->md);
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if (table) {
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dm_table_event(table);
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dm_table_put(table);
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}
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dm_put(hc->md);
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if (hc->new_map)
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dm_table_put(hc->new_map);
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free_cell(hc);
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}
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static void dm_hash_remove_all(void)
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{
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int i;
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struct hash_cell *hc;
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struct list_head *tmp, *n;
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down_write(&_hash_lock);
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for (i = 0; i < NUM_BUCKETS; i++) {
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list_for_each_safe (tmp, n, _name_buckets + i) {
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hc = list_entry(tmp, struct hash_cell, name_list);
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__hash_remove(hc);
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}
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}
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up_write(&_hash_lock);
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}
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static int dm_hash_rename(const char *old, const char *new)
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{
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char *new_name, *old_name;
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struct hash_cell *hc;
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struct dm_table *table;
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/*
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* duplicate new.
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*/
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new_name = kstrdup(new, GFP_KERNEL);
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if (!new_name)
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return -ENOMEM;
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down_write(&_hash_lock);
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/*
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* Is new free ?
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*/
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hc = __get_name_cell(new);
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if (hc) {
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DMWARN("asked to rename to an already existing name %s -> %s",
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old, new);
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up_write(&_hash_lock);
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kfree(new_name);
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return -EBUSY;
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}
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/*
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* Is there such a device as 'old' ?
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*/
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hc = __get_name_cell(old);
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if (!hc) {
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DMWARN("asked to rename a non existent device %s -> %s",
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old, new);
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up_write(&_hash_lock);
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kfree(new_name);
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return -ENXIO;
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}
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/*
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* rename and move the name cell.
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*/
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unregister_with_devfs(hc);
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list_del(&hc->name_list);
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old_name = hc->name;
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hc->name = new_name;
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list_add(&hc->name_list, _name_buckets + hash_str(new_name));
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/* rename the device node in devfs */
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register_with_devfs(hc);
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/*
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* Wake up any dm event waiters.
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*/
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table = dm_get_table(hc->md);
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if (table) {
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dm_table_event(table);
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dm_table_put(table);
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}
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up_write(&_hash_lock);
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kfree(old_name);
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return 0;
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}
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/*-----------------------------------------------------------------
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* Implementation of the ioctl commands
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*---------------------------------------------------------------*/
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/*
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* All the ioctl commands get dispatched to functions with this
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* prototype.
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*/
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typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
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static int remove_all(struct dm_ioctl *param, size_t param_size)
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{
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dm_hash_remove_all();
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param->data_size = 0;
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return 0;
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}
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/*
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* Round up the ptr to an 8-byte boundary.
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*/
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#define ALIGN_MASK 7
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static inline void *align_ptr(void *ptr)
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{
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return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
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}
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/*
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* Retrieves the data payload buffer from an already allocated
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* struct dm_ioctl.
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*/
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static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
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size_t *len)
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{
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param->data_start = align_ptr(param + 1) - (void *) param;
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if (param->data_start < param_size)
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*len = param_size - param->data_start;
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else
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*len = 0;
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return ((void *) param) + param->data_start;
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}
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static int list_devices(struct dm_ioctl *param, size_t param_size)
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{
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unsigned int i;
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struct hash_cell *hc;
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size_t len, needed = 0;
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struct gendisk *disk;
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struct dm_name_list *nl, *old_nl = NULL;
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down_write(&_hash_lock);
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/*
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* Loop through all the devices working out how much
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* space we need.
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*/
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for (i = 0; i < NUM_BUCKETS; i++) {
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list_for_each_entry (hc, _name_buckets + i, name_list) {
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needed += sizeof(struct dm_name_list);
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needed += strlen(hc->name) + 1;
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needed += ALIGN_MASK;
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}
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}
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/*
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* Grab our output buffer.
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*/
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nl = get_result_buffer(param, param_size, &len);
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if (len < needed) {
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param->flags |= DM_BUFFER_FULL_FLAG;
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goto out;
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}
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param->data_size = param->data_start + needed;
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nl->dev = 0; /* Flags no data */
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/*
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* Now loop through filling out the names.
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*/
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for (i = 0; i < NUM_BUCKETS; i++) {
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list_for_each_entry (hc, _name_buckets + i, name_list) {
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if (old_nl)
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old_nl->next = (uint32_t) ((void *) nl -
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(void *) old_nl);
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disk = dm_disk(hc->md);
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nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
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nl->next = 0;
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strcpy(nl->name, hc->name);
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old_nl = nl;
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nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
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}
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}
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out:
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up_write(&_hash_lock);
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return 0;
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}
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static void list_version_get_needed(struct target_type *tt, void *needed_param)
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{
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size_t *needed = needed_param;
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*needed += sizeof(struct dm_target_versions);
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*needed += strlen(tt->name);
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*needed += ALIGN_MASK;
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}
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static void list_version_get_info(struct target_type *tt, void *param)
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{
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struct vers_iter *info = param;
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/* Check space - it might have changed since the first iteration */
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if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
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info->end) {
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info->flags = DM_BUFFER_FULL_FLAG;
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return;
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}
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if (info->old_vers)
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info->old_vers->next = (uint32_t) ((void *)info->vers -
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(void *)info->old_vers);
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info->vers->version[0] = tt->version[0];
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info->vers->version[1] = tt->version[1];
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info->vers->version[2] = tt->version[2];
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info->vers->next = 0;
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strcpy(info->vers->name, tt->name);
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info->old_vers = info->vers;
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info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
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}
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static int list_versions(struct dm_ioctl *param, size_t param_size)
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{
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size_t len, needed = 0;
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struct dm_target_versions *vers;
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struct vers_iter iter_info;
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/*
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* Loop through all the devices working out how much
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* space we need.
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*/
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dm_target_iterate(list_version_get_needed, &needed);
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/*
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* Grab our output buffer.
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*/
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vers = get_result_buffer(param, param_size, &len);
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if (len < needed) {
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param->flags |= DM_BUFFER_FULL_FLAG;
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goto out;
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}
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param->data_size = param->data_start + needed;
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iter_info.param_size = param_size;
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iter_info.old_vers = NULL;
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iter_info.vers = vers;
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iter_info.flags = 0;
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iter_info.end = (char *)vers+len;
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/*
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* Now loop through filling out the names & versions.
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*/
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dm_target_iterate(list_version_get_info, &iter_info);
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param->flags |= iter_info.flags;
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out:
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return 0;
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}
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static int check_name(const char *name)
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{
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if (strchr(name, '/')) {
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DMWARN("invalid device name");
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return -EINVAL;
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}
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return 0;
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}
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/*
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* Fills in a dm_ioctl structure, ready for sending back to
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* userland.
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*/
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static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
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{
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struct gendisk *disk = dm_disk(md);
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struct dm_table *table;
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struct block_device *bdev;
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param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
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DM_ACTIVE_PRESENT_FLAG);
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if (dm_suspended(md))
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param->flags |= DM_SUSPEND_FLAG;
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param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
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if (!(param->flags & DM_SKIP_BDGET_FLAG)) {
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bdev = bdget_disk(disk, 0);
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if (!bdev)
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return -ENXIO;
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/*
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* Yes, this will be out of date by the time it gets back
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* to userland, but it is still very useful for
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* debugging.
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*/
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param->open_count = bdev->bd_openers;
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bdput(bdev);
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} else
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param->open_count = -1;
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if (disk->policy)
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param->flags |= DM_READONLY_FLAG;
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param->event_nr = dm_get_event_nr(md);
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table = dm_get_table(md);
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if (table) {
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param->flags |= DM_ACTIVE_PRESENT_FLAG;
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param->target_count = dm_table_get_num_targets(table);
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dm_table_put(table);
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} else
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param->target_count = 0;
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return 0;
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}
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static int dev_create(struct dm_ioctl *param, size_t param_size)
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{
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int r;
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struct mapped_device *md;
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r = check_name(param->name);
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if (r)
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return r;
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if (param->flags & DM_PERSISTENT_DEV_FLAG)
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r = dm_create_with_minor(MINOR(huge_decode_dev(param->dev)), &md);
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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 or dev.
|
|
*/
|
|
static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
|
|
{
|
|
if (*param->uuid)
|
|
return __get_uuid_cell(param->uuid);
|
|
else if (*param->name)
|
|
return __get_name_cell(param->name);
|
|
else
|
|
return dm_get_mdptr(huge_decode_dev(param->dev));
|
|
}
|
|
|
|
static 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;
|
|
dm_get(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;
|
|
}
|
|
up_read(&_hash_lock);
|
|
|
|
return md;
|
|
}
|
|
|
|
static int dev_remove(struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
struct hash_cell *hc;
|
|
|
|
down_write(&_hash_lock);
|
|
hc = __find_device_hash_cell(param);
|
|
|
|
if (!hc) {
|
|
DMWARN("device doesn't appear to be in the dev hash table.");
|
|
up_write(&_hash_lock);
|
|
return -ENXIO;
|
|
}
|
|
|
|
__hash_remove(hc);
|
|
up_write(&_hash_lock);
|
|
param->data_size = 0;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Check a string doesn't overrun the chunk of
|
|
* memory we copied from userland.
|
|
*/
|
|
static int invalid_str(char *str, void *end)
|
|
{
|
|
while ((void *) str < end)
|
|
if (!*str++)
|
|
return 0;
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int dev_rename(struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
int r;
|
|
char *new_name = (char *) param + param->data_start;
|
|
|
|
if (new_name < (char *) (param + 1) ||
|
|
invalid_str(new_name, (void *) param + param_size)) {
|
|
DMWARN("Invalid new logical volume name supplied.");
|
|
return -EINVAL;
|
|
}
|
|
|
|
r = check_name(new_name);
|
|
if (r)
|
|
return r;
|
|
|
|
param->data_size = 0;
|
|
return dm_hash_rename(param->name, new_name);
|
|
}
|
|
|
|
static int do_suspend(struct dm_ioctl *param)
|
|
{
|
|
int r = 0;
|
|
int do_lockfs = 1;
|
|
struct mapped_device *md;
|
|
|
|
md = find_device(param);
|
|
if (!md)
|
|
return -ENXIO;
|
|
|
|
if (param->flags & DM_SKIP_LOCKFS_FLAG)
|
|
do_lockfs = 0;
|
|
|
|
if (!dm_suspended(md))
|
|
r = dm_suspend(md, do_lockfs);
|
|
|
|
if (!r)
|
|
r = __dev_status(md, param);
|
|
|
|
dm_put(md);
|
|
return r;
|
|
}
|
|
|
|
static int do_resume(struct dm_ioctl *param)
|
|
{
|
|
int r = 0;
|
|
int do_lockfs = 1;
|
|
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 (param->flags & DM_SKIP_LOCKFS_FLAG)
|
|
do_lockfs = 0;
|
|
if (!dm_suspended(md))
|
|
dm_suspend(md, do_lockfs);
|
|
|
|
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), 0);
|
|
else
|
|
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 do_suspend(param);
|
|
|
|
return do_resume(param);
|
|
}
|
|
|
|
/*
|
|
* Copies device info back to user space, used by
|
|
* the create and info ioctls.
|
|
*/
|
|
static int dev_status(struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
int r;
|
|
struct mapped_device *md;
|
|
|
|
md = find_device(param);
|
|
if (!md)
|
|
return -ENXIO;
|
|
|
|
r = __dev_status(md, param);
|
|
dm_put(md);
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Build up the status struct for each target
|
|
*/
|
|
static void retrieve_status(struct dm_table *table,
|
|
struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
unsigned int i, num_targets;
|
|
struct dm_target_spec *spec;
|
|
char *outbuf, *outptr;
|
|
status_type_t type;
|
|
size_t remaining, len, used = 0;
|
|
|
|
outptr = outbuf = get_result_buffer(param, param_size, &len);
|
|
|
|
if (param->flags & DM_STATUS_TABLE_FLAG)
|
|
type = STATUSTYPE_TABLE;
|
|
else
|
|
type = STATUSTYPE_INFO;
|
|
|
|
/* Get all the target info */
|
|
num_targets = dm_table_get_num_targets(table);
|
|
for (i = 0; i < num_targets; i++) {
|
|
struct dm_target *ti = dm_table_get_target(table, i);
|
|
|
|
remaining = len - (outptr - outbuf);
|
|
if (remaining <= sizeof(struct dm_target_spec)) {
|
|
param->flags |= DM_BUFFER_FULL_FLAG;
|
|
break;
|
|
}
|
|
|
|
spec = (struct dm_target_spec *) outptr;
|
|
|
|
spec->status = 0;
|
|
spec->sector_start = ti->begin;
|
|
spec->length = ti->len;
|
|
strncpy(spec->target_type, ti->type->name,
|
|
sizeof(spec->target_type));
|
|
|
|
outptr += sizeof(struct dm_target_spec);
|
|
remaining = len - (outptr - outbuf);
|
|
if (remaining <= 0) {
|
|
param->flags |= DM_BUFFER_FULL_FLAG;
|
|
break;
|
|
}
|
|
|
|
/* 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);
|
|
|
|
outptr = align_ptr(outptr);
|
|
spec->next = outptr - outbuf;
|
|
}
|
|
|
|
if (used)
|
|
param->data_size = used;
|
|
|
|
param->target_count = num_targets;
|
|
}
|
|
|
|
/*
|
|
* Wait for a device to report an event
|
|
*/
|
|
static int dev_wait(struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
int r;
|
|
struct mapped_device *md;
|
|
struct dm_table *table;
|
|
|
|
md = find_device(param);
|
|
if (!md)
|
|
return -ENXIO;
|
|
|
|
/*
|
|
* Wait for a notification event
|
|
*/
|
|
if (dm_wait_event(md, param->event_nr)) {
|
|
r = -ERESTARTSYS;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* The userland program is going to want to know what
|
|
* changed to trigger the event, so we may as well tell
|
|
* him and save an ioctl.
|
|
*/
|
|
r = __dev_status(md, param);
|
|
if (r)
|
|
goto out;
|
|
|
|
table = dm_get_table(md);
|
|
if (table) {
|
|
retrieve_status(table, param, param_size);
|
|
dm_table_put(table);
|
|
}
|
|
|
|
out:
|
|
dm_put(md);
|
|
return r;
|
|
}
|
|
|
|
static inline int get_mode(struct dm_ioctl *param)
|
|
{
|
|
int mode = FMODE_READ | FMODE_WRITE;
|
|
|
|
if (param->flags & DM_READONLY_FLAG)
|
|
mode = FMODE_READ;
|
|
|
|
return mode;
|
|
}
|
|
|
|
static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
|
|
struct dm_target_spec **spec, char **target_params)
|
|
{
|
|
*spec = (struct dm_target_spec *) ((unsigned char *) last + next);
|
|
*target_params = (char *) (*spec + 1);
|
|
|
|
if (*spec < (last + 1))
|
|
return -EINVAL;
|
|
|
|
return invalid_str(*target_params, end);
|
|
}
|
|
|
|
static int populate_table(struct dm_table *table,
|
|
struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
int r;
|
|
unsigned int i = 0;
|
|
struct dm_target_spec *spec = (struct dm_target_spec *) param;
|
|
uint32_t next = param->data_start;
|
|
void *end = (void *) param + param_size;
|
|
char *target_params;
|
|
|
|
if (!param->target_count) {
|
|
DMWARN("populate_table: no targets specified");
|
|
return -EINVAL;
|
|
}
|
|
|
|
for (i = 0; i < param->target_count; i++) {
|
|
|
|
r = next_target(spec, next, end, &spec, &target_params);
|
|
if (r) {
|
|
DMWARN("unable to find target");
|
|
return r;
|
|
}
|
|
|
|
r = dm_table_add_target(table, spec->target_type,
|
|
(sector_t) spec->sector_start,
|
|
(sector_t) spec->length,
|
|
target_params);
|
|
if (r) {
|
|
DMWARN("error adding target to table");
|
|
return r;
|
|
}
|
|
|
|
next = spec->next;
|
|
}
|
|
|
|
return dm_table_complete(table);
|
|
}
|
|
|
|
static int table_load(struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
int r;
|
|
struct hash_cell *hc;
|
|
struct dm_table *t;
|
|
|
|
r = dm_table_create(&t, get_mode(param), param->target_count);
|
|
if (r)
|
|
return r;
|
|
|
|
r = populate_table(t, param, param_size);
|
|
if (r) {
|
|
dm_table_put(t);
|
|
return r;
|
|
}
|
|
|
|
down_write(&_hash_lock);
|
|
hc = __find_device_hash_cell(param);
|
|
if (!hc) {
|
|
DMWARN("device doesn't appear to be in the dev hash table.");
|
|
up_write(&_hash_lock);
|
|
dm_table_put(t);
|
|
return -ENXIO;
|
|
}
|
|
|
|
if (hc->new_map)
|
|
dm_table_put(hc->new_map);
|
|
hc->new_map = t;
|
|
param->flags |= DM_INACTIVE_PRESENT_FLAG;
|
|
|
|
r = __dev_status(hc->md, param);
|
|
up_write(&_hash_lock);
|
|
return r;
|
|
}
|
|
|
|
static int table_clear(struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
int r;
|
|
struct hash_cell *hc;
|
|
|
|
down_write(&_hash_lock);
|
|
|
|
hc = __find_device_hash_cell(param);
|
|
if (!hc) {
|
|
DMWARN("device doesn't appear to be in the dev hash table.");
|
|
up_write(&_hash_lock);
|
|
return -ENXIO;
|
|
}
|
|
|
|
if (hc->new_map) {
|
|
dm_table_put(hc->new_map);
|
|
hc->new_map = NULL;
|
|
}
|
|
|
|
param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
|
|
|
|
r = __dev_status(hc->md, param);
|
|
up_write(&_hash_lock);
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Retrieves a list of devices used by a particular dm device.
|
|
*/
|
|
static void retrieve_deps(struct dm_table *table,
|
|
struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
unsigned int count = 0;
|
|
struct list_head *tmp;
|
|
size_t len, needed;
|
|
struct dm_dev *dd;
|
|
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_entry (dd, dm_table_get_devices(table), list)
|
|
deps->dev[count++] = huge_encode_dev(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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* Pass a message to the target that's at the supplied device offset.
|
|
*/
|
|
static int target_message(struct dm_ioctl *param, size_t param_size)
|
|
{
|
|
int r, argc;
|
|
char **argv;
|
|
struct mapped_device *md;
|
|
struct dm_table *table;
|
|
struct dm_target *ti;
|
|
struct dm_target_msg *tmsg = (void *) param + param->data_start;
|
|
|
|
md = find_device(param);
|
|
if (!md)
|
|
return -ENXIO;
|
|
|
|
r = __dev_status(md, param);
|
|
if (r)
|
|
goto out;
|
|
|
|
if (tmsg < (struct dm_target_msg *) (param + 1) ||
|
|
invalid_str(tmsg->message, (void *) param + param_size)) {
|
|
DMWARN("Invalid target message parameters.");
|
|
r = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
r = dm_split_args(&argc, &argv, tmsg->message);
|
|
if (r) {
|
|
DMWARN("Failed to split target message parameters");
|
|
goto out;
|
|
}
|
|
|
|
table = dm_get_table(md);
|
|
if (!table)
|
|
goto out_argv;
|
|
|
|
if (tmsg->sector >= dm_table_get_size(table)) {
|
|
DMWARN("Target message sector outside device.");
|
|
r = -EINVAL;
|
|
goto out_table;
|
|
}
|
|
|
|
ti = dm_table_find_target(table, tmsg->sector);
|
|
if (ti->type->message)
|
|
r = ti->type->message(ti, argc, argv);
|
|
else {
|
|
DMWARN("Target type does not support messages");
|
|
r = -EINVAL;
|
|
}
|
|
|
|
out_table:
|
|
dm_table_put(table);
|
|
out_argv:
|
|
kfree(argv);
|
|
out:
|
|
param->data_size = 0;
|
|
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},
|
|
|
|
{DM_LIST_VERSIONS_CMD, list_versions},
|
|
|
|
{DM_TARGET_MSG_CMD, target_message}
|
|
};
|
|
|
|
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 *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 *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 ||
|
|
cmd == DM_LIST_VERSIONS_CMD)
|
|
return 0;
|
|
|
|
if ((cmd == DM_DEV_CREATE_CMD)) {
|
|
if (!*param->name) {
|
|
DMWARN("name not supplied when creating device");
|
|
return -EINVAL;
|
|
}
|
|
} else if ((*param->uuid && *param->name)) {
|
|
DMWARN("only supply one of name or uuid, 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 *user = (struct dm_ioctl __user *) 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);
|
|
|
|
current->flags &= ~PF_MEMALLOC;
|
|
|
|
if (r)
|
|
return r;
|
|
|
|
r = validate_params(cmd, param);
|
|
if (r)
|
|
goto out;
|
|
|
|
param_size = param->data_size;
|
|
param->data_size = sizeof(*param);
|
|
r = fn(param, param_size);
|
|
|
|
/*
|
|
* Copy the results back to userland.
|
|
*/
|
|
if (!r && copy_to_user(user, param, param->data_size))
|
|
r = -EFAULT;
|
|
|
|
out:
|
|
free_params(param);
|
|
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();
|
|
}
|