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2154 lines
48 KiB
2154 lines
48 KiB
/* |
|
* Copyright (C) 2001, 2002 Sistina Software (UK) Limited. |
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* Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved. |
|
* |
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* This file is released under the GPL. |
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*/ |
|
|
|
#include "dm-core.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> |
|
#include <linux/sched/mm.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/dm-ioctl.h> |
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#include <linux/hdreg.h> |
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#include <linux/compat.h> |
|
|
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#include <linux/uaccess.h> |
|
|
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#define DM_MSG_PREFIX "ioctl" |
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#define DM_DRIVER_EMAIL "[email protected]" |
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|
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struct dm_file { |
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/* |
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* poll will wait until the global event number is greater than |
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* this value. |
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*/ |
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volatile unsigned global_event_nr; |
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}; |
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|
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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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|
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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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|
|
|
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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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|
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static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred); |
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|
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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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/* |
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* Protects use of mdptr to obtain hash cell name and uuid from mapped device. |
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*/ |
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static DEFINE_MUTEX(dm_hash_cells_mutex); |
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|
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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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|
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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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|
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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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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(false, false, false); |
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} |
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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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|
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while (*str) |
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h = (h + (unsigned int) *str++) * hash_mult; |
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|
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return h & MASK_BUCKETS; |
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} |
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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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|
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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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dm_get(hc->md); |
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return hc; |
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} |
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|
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return NULL; |
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} |
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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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dm_get(hc->md); |
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return hc; |
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} |
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|
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return NULL; |
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} |
|
|
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static struct hash_cell *__get_dev_cell(uint64_t dev) |
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{ |
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struct mapped_device *md; |
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struct hash_cell *hc; |
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|
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md = dm_get_md(huge_decode_dev(dev)); |
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if (!md) |
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return NULL; |
|
|
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hc = dm_get_mdptr(md); |
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if (!hc) { |
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dm_put(md); |
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return NULL; |
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} |
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|
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return hc; |
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} |
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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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|
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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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|
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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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|
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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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/* |
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* The kdev_t and uuid of a device can never change once it is |
|
* 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, *hc; |
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|
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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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hc = __get_name_cell(name); |
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if (hc) { |
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dm_put(hc->md); |
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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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hc = __get_uuid_cell(uuid); |
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if (hc) { |
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list_del(&cell->name_list); |
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dm_put(hc->md); |
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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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dm_get(md); |
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mutex_lock(&dm_hash_cells_mutex); |
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dm_set_mdptr(md, cell); |
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mutex_unlock(&dm_hash_cells_mutex); |
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up_write(&_hash_lock); |
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|
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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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|
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static struct dm_table *__hash_remove(struct hash_cell *hc) |
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{ |
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struct dm_table *table; |
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int srcu_idx; |
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|
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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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mutex_lock(&dm_hash_cells_mutex); |
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dm_set_mdptr(hc->md, NULL); |
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mutex_unlock(&dm_hash_cells_mutex); |
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|
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table = dm_get_live_table(hc->md, &srcu_idx); |
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if (table) |
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dm_table_event(table); |
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dm_put_live_table(hc->md, srcu_idx); |
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|
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table = NULL; |
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if (hc->new_map) |
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table = hc->new_map; |
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dm_put(hc->md); |
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free_cell(hc); |
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|
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return table; |
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} |
|
|
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static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred) |
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{ |
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int i, dev_skipped; |
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struct hash_cell *hc; |
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struct mapped_device *md; |
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struct dm_table *t; |
|
|
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retry: |
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dev_skipped = 0; |
|
|
|
down_write(&_hash_lock); |
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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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md = hc->md; |
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dm_get(md); |
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|
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if (keep_open_devices && |
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dm_lock_for_deletion(md, mark_deferred, only_deferred)) { |
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dm_put(md); |
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dev_skipped++; |
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continue; |
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} |
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t = __hash_remove(hc); |
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up_write(&_hash_lock); |
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|
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if (t) { |
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dm_sync_table(md); |
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dm_table_destroy(t); |
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} |
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dm_put(md); |
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if (likely(keep_open_devices)) |
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dm_destroy(md); |
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else |
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dm_destroy_immediate(md); |
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|
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/* |
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* Some mapped devices may be using other mapped |
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* devices, so repeat until we make no further |
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* progress. If a new mapped device is created |
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* here it will also get removed. |
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*/ |
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goto retry; |
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} |
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} |
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|
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up_write(&_hash_lock); |
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|
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if (dev_skipped) |
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DMWARN("remove_all left %d open device(s)", dev_skipped); |
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} |
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|
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/* |
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* Set the uuid of a hash_cell that isn't already set. |
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*/ |
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static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid) |
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{ |
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mutex_lock(&dm_hash_cells_mutex); |
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hc->uuid = new_uuid; |
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mutex_unlock(&dm_hash_cells_mutex); |
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|
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list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid)); |
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} |
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|
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/* |
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* Changes the name of a hash_cell and returns the old name for |
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* the caller to free. |
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*/ |
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static char *__change_cell_name(struct hash_cell *hc, char *new_name) |
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{ |
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char *old_name; |
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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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list_del(&hc->name_list); |
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old_name = hc->name; |
|
|
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mutex_lock(&dm_hash_cells_mutex); |
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hc->name = new_name; |
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mutex_unlock(&dm_hash_cells_mutex); |
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|
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list_add(&hc->name_list, _name_buckets + hash_str(new_name)); |
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|
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return old_name; |
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} |
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|
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static struct mapped_device *dm_hash_rename(struct dm_ioctl *param, |
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const char *new) |
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{ |
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char *new_data, *old_name = NULL; |
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struct hash_cell *hc; |
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struct dm_table *table; |
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struct mapped_device *md; |
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unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0; |
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int srcu_idx; |
|
|
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/* |
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* duplicate new. |
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*/ |
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new_data = kstrdup(new, GFP_KERNEL); |
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if (!new_data) |
|
return ERR_PTR(-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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if (change_uuid) |
|
hc = __get_uuid_cell(new); |
|
else |
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hc = __get_name_cell(new); |
|
|
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if (hc) { |
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DMWARN("Unable to change %s on mapped device %s to one that " |
|
"already exists: %s", |
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change_uuid ? "uuid" : "name", |
|
param->name, new); |
|
dm_put(hc->md); |
|
up_write(&_hash_lock); |
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kfree(new_data); |
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return ERR_PTR(-EBUSY); |
|
} |
|
|
|
/* |
|
* Is there such a device as 'old' ? |
|
*/ |
|
hc = __get_name_cell(param->name); |
|
if (!hc) { |
|
DMWARN("Unable to rename non-existent device, %s to %s%s", |
|
param->name, change_uuid ? "uuid " : "", new); |
|
up_write(&_hash_lock); |
|
kfree(new_data); |
|
return ERR_PTR(-ENXIO); |
|
} |
|
|
|
/* |
|
* Does this device already have a uuid? |
|
*/ |
|
if (change_uuid && hc->uuid) { |
|
DMWARN("Unable to change uuid of mapped device %s to %s " |
|
"because uuid is already set to %s", |
|
param->name, new, hc->uuid); |
|
dm_put(hc->md); |
|
up_write(&_hash_lock); |
|
kfree(new_data); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
if (change_uuid) |
|
__set_cell_uuid(hc, new_data); |
|
else |
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old_name = __change_cell_name(hc, new_data); |
|
|
|
/* |
|
* Wake up any dm event waiters. |
|
*/ |
|
table = dm_get_live_table(hc->md, &srcu_idx); |
|
if (table) |
|
dm_table_event(table); |
|
dm_put_live_table(hc->md, srcu_idx); |
|
|
|
if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr)) |
|
param->flags |= DM_UEVENT_GENERATED_FLAG; |
|
|
|
md = hc->md; |
|
up_write(&_hash_lock); |
|
kfree(old_name); |
|
|
|
return md; |
|
} |
|
|
|
void dm_deferred_remove(void) |
|
{ |
|
dm_hash_remove_all(true, false, true); |
|
} |
|
|
|
/*----------------------------------------------------------------- |
|
* Implementation of the ioctl commands |
|
*---------------------------------------------------------------*/ |
|
/* |
|
* All the ioctl commands get dispatched to functions with this |
|
* prototype. |
|
*/ |
|
typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size); |
|
|
|
static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false); |
|
param->data_size = 0; |
|
return 0; |
|
} |
|
|
|
/* |
|
* Round up the ptr to an 8-byte boundary. |
|
*/ |
|
#define ALIGN_MASK 7 |
|
static inline size_t align_val(size_t val) |
|
{ |
|
return (val + ALIGN_MASK) & ~ALIGN_MASK; |
|
} |
|
static inline void *align_ptr(void *ptr) |
|
{ |
|
return (void *)align_val((size_t)ptr); |
|
} |
|
|
|
/* |
|
* 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 file *filp, 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 *orig_nl, *nl, *old_nl = NULL; |
|
uint32_t *event_nr; |
|
|
|
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 += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1); |
|
needed += align_val(sizeof(uint32_t)); |
|
} |
|
} |
|
|
|
/* |
|
* Grab our output buffer. |
|
*/ |
|
nl = orig_nl = get_result_buffer(param, param_size, &len); |
|
if (len < needed || len < sizeof(nl->dev)) { |
|
param->flags |= DM_BUFFER_FULL_FLAG; |
|
goto out; |
|
} |
|
param->data_size = param->data_start + needed; |
|
|
|
nl->dev = 0; /* Flags no data */ |
|
|
|
/* |
|
* Now loop through filling out the names. |
|
*/ |
|
for (i = 0; i < NUM_BUCKETS; i++) { |
|
list_for_each_entry (hc, _name_buckets + i, name_list) { |
|
if (old_nl) |
|
old_nl->next = (uint32_t) ((void *) nl - |
|
(void *) old_nl); |
|
disk = dm_disk(hc->md); |
|
nl->dev = huge_encode_dev(disk_devt(disk)); |
|
nl->next = 0; |
|
strcpy(nl->name, hc->name); |
|
|
|
old_nl = nl; |
|
event_nr = align_ptr(nl->name + strlen(hc->name) + 1); |
|
*event_nr = dm_get_event_nr(hc->md); |
|
nl = align_ptr(event_nr + 1); |
|
} |
|
} |
|
/* |
|
* If mismatch happens, security may be compromised due to buffer |
|
* overflow, so it's better to crash. |
|
*/ |
|
BUG_ON((char *)nl - (char *)orig_nl != needed); |
|
|
|
out: |
|
up_write(&_hash_lock); |
|
return 0; |
|
} |
|
|
|
static void list_version_get_needed(struct target_type *tt, void *needed_param) |
|
{ |
|
size_t *needed = needed_param; |
|
|
|
*needed += sizeof(struct dm_target_versions); |
|
*needed += strlen(tt->name); |
|
*needed += ALIGN_MASK; |
|
} |
|
|
|
static void list_version_get_info(struct target_type *tt, void *param) |
|
{ |
|
struct vers_iter *info = param; |
|
|
|
/* Check space - it might have changed since the first iteration */ |
|
if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > |
|
info->end) { |
|
|
|
info->flags = DM_BUFFER_FULL_FLAG; |
|
return; |
|
} |
|
|
|
if (info->old_vers) |
|
info->old_vers->next = (uint32_t) ((void *)info->vers - |
|
(void *)info->old_vers); |
|
info->vers->version[0] = tt->version[0]; |
|
info->vers->version[1] = tt->version[1]; |
|
info->vers->version[2] = tt->version[2]; |
|
info->vers->next = 0; |
|
strcpy(info->vers->name, tt->name); |
|
|
|
info->old_vers = info->vers; |
|
info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1); |
|
} |
|
|
|
static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name) |
|
{ |
|
size_t len, needed = 0; |
|
struct dm_target_versions *vers; |
|
struct vers_iter iter_info; |
|
struct target_type *tt = NULL; |
|
|
|
if (name) { |
|
tt = dm_get_target_type(name); |
|
if (!tt) |
|
return -EINVAL; |
|
} |
|
|
|
/* |
|
* Loop through all the devices working out how much |
|
* space we need. |
|
*/ |
|
if (!tt) |
|
dm_target_iterate(list_version_get_needed, &needed); |
|
else |
|
list_version_get_needed(tt, &needed); |
|
|
|
/* |
|
* Grab our output buffer. |
|
*/ |
|
vers = 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; |
|
|
|
iter_info.param_size = param_size; |
|
iter_info.old_vers = NULL; |
|
iter_info.vers = vers; |
|
iter_info.flags = 0; |
|
iter_info.end = (char *)vers+len; |
|
|
|
/* |
|
* Now loop through filling out the names & versions. |
|
*/ |
|
if (!tt) |
|
dm_target_iterate(list_version_get_info, &iter_info); |
|
else |
|
list_version_get_info(tt, &iter_info); |
|
param->flags |= iter_info.flags; |
|
|
|
out: |
|
if (tt) |
|
dm_put_target_type(tt); |
|
return 0; |
|
} |
|
|
|
static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
return __list_versions(param, param_size, NULL); |
|
} |
|
|
|
static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
return __list_versions(param, param_size, param->name); |
|
} |
|
|
|
static int check_name(const char *name) |
|
{ |
|
if (strchr(name, '/')) { |
|
DMWARN("invalid device name"); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* On successful return, the caller must not attempt to acquire |
|
* _hash_lock without first calling dm_put_live_table, because dm_table_destroy |
|
* waits for this dm_put_live_table and could be called under this lock. |
|
*/ |
|
static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx) |
|
{ |
|
struct hash_cell *hc; |
|
struct dm_table *table = NULL; |
|
|
|
/* increment rcu count, we don't care about the table pointer */ |
|
dm_get_live_table(md, srcu_idx); |
|
|
|
down_read(&_hash_lock); |
|
hc = dm_get_mdptr(md); |
|
if (!hc || hc->md != md) { |
|
DMWARN("device has been removed from the dev hash table."); |
|
goto out; |
|
} |
|
|
|
table = hc->new_map; |
|
|
|
out: |
|
up_read(&_hash_lock); |
|
|
|
return table; |
|
} |
|
|
|
static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md, |
|
struct dm_ioctl *param, |
|
int *srcu_idx) |
|
{ |
|
return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ? |
|
dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx); |
|
} |
|
|
|
/* |
|
* Fills in a dm_ioctl structure, ready for sending back to |
|
* userland. |
|
*/ |
|
static void __dev_status(struct mapped_device *md, struct dm_ioctl *param) |
|
{ |
|
struct gendisk *disk = dm_disk(md); |
|
struct dm_table *table; |
|
int srcu_idx; |
|
|
|
param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG | |
|
DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG); |
|
|
|
if (dm_suspended_md(md)) |
|
param->flags |= DM_SUSPEND_FLAG; |
|
|
|
if (dm_suspended_internally_md(md)) |
|
param->flags |= DM_INTERNAL_SUSPEND_FLAG; |
|
|
|
if (dm_test_deferred_remove_flag(md)) |
|
param->flags |= DM_DEFERRED_REMOVE; |
|
|
|
param->dev = huge_encode_dev(disk_devt(disk)); |
|
|
|
/* |
|
* Yes, this will be out of date by the time it gets back |
|
* to userland, but it is still very useful for |
|
* debugging. |
|
*/ |
|
param->open_count = dm_open_count(md); |
|
|
|
param->event_nr = dm_get_event_nr(md); |
|
param->target_count = 0; |
|
|
|
table = dm_get_live_table(md, &srcu_idx); |
|
if (table) { |
|
if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) { |
|
if (get_disk_ro(disk)) |
|
param->flags |= DM_READONLY_FLAG; |
|
param->target_count = dm_table_get_num_targets(table); |
|
} |
|
|
|
param->flags |= DM_ACTIVE_PRESENT_FLAG; |
|
} |
|
dm_put_live_table(md, srcu_idx); |
|
|
|
if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) { |
|
int srcu_idx; |
|
table = dm_get_inactive_table(md, &srcu_idx); |
|
if (table) { |
|
if (!(dm_table_get_mode(table) & FMODE_WRITE)) |
|
param->flags |= DM_READONLY_FLAG; |
|
param->target_count = dm_table_get_num_targets(table); |
|
} |
|
dm_put_live_table(md, srcu_idx); |
|
} |
|
} |
|
|
|
static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
int r, m = DM_ANY_MINOR; |
|
struct mapped_device *md; |
|
|
|
r = check_name(param->name); |
|
if (r) |
|
return r; |
|
|
|
if (param->flags & DM_PERSISTENT_DEV_FLAG) |
|
m = MINOR(huge_decode_dev(param->dev)); |
|
|
|
r = dm_create(m, &md); |
|
if (r) |
|
return r; |
|
|
|
r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md); |
|
if (r) { |
|
dm_put(md); |
|
dm_destroy(md); |
|
return r; |
|
} |
|
|
|
param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
|
|
|
__dev_status(md, param); |
|
|
|
dm_put(md); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* 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) |
|
{ |
|
struct hash_cell *hc = NULL; |
|
|
|
if (*param->uuid) { |
|
if (*param->name || param->dev) |
|
return NULL; |
|
|
|
hc = __get_uuid_cell(param->uuid); |
|
if (!hc) |
|
return NULL; |
|
} else if (*param->name) { |
|
if (param->dev) |
|
return NULL; |
|
|
|
hc = __get_name_cell(param->name); |
|
if (!hc) |
|
return NULL; |
|
} else if (param->dev) { |
|
hc = __get_dev_cell(param->dev); |
|
if (!hc) |
|
return NULL; |
|
} else |
|
return NULL; |
|
|
|
/* |
|
* 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'; |
|
|
|
if (hc->new_map) |
|
param->flags |= DM_INACTIVE_PRESENT_FLAG; |
|
else |
|
param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
|
|
|
return hc; |
|
} |
|
|
|
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; |
|
up_read(&_hash_lock); |
|
|
|
return md; |
|
} |
|
|
|
static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
struct hash_cell *hc; |
|
struct mapped_device *md; |
|
int r; |
|
struct dm_table *t; |
|
|
|
down_write(&_hash_lock); |
|
hc = __find_device_hash_cell(param); |
|
|
|
if (!hc) { |
|
DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); |
|
up_write(&_hash_lock); |
|
return -ENXIO; |
|
} |
|
|
|
md = hc->md; |
|
|
|
/* |
|
* Ensure the device is not open and nothing further can open it. |
|
*/ |
|
r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false); |
|
if (r) { |
|
if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) { |
|
up_write(&_hash_lock); |
|
dm_put(md); |
|
return 0; |
|
} |
|
DMDEBUG_LIMIT("unable to remove open device %s", hc->name); |
|
up_write(&_hash_lock); |
|
dm_put(md); |
|
return r; |
|
} |
|
|
|
t = __hash_remove(hc); |
|
up_write(&_hash_lock); |
|
|
|
if (t) { |
|
dm_sync_table(md); |
|
dm_table_destroy(t); |
|
} |
|
|
|
param->flags &= ~DM_DEFERRED_REMOVE; |
|
|
|
if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr)) |
|
param->flags |= DM_UEVENT_GENERATED_FLAG; |
|
|
|
dm_put(md); |
|
dm_destroy(md); |
|
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 file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
int r; |
|
char *new_data = (char *) param + param->data_start; |
|
struct mapped_device *md; |
|
unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0; |
|
|
|
if (new_data < param->data || |
|
invalid_str(new_data, (void *) param + param_size) || !*new_data || |
|
strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) { |
|
DMWARN("Invalid new mapped device name or uuid string supplied."); |
|
return -EINVAL; |
|
} |
|
|
|
if (!change_uuid) { |
|
r = check_name(new_data); |
|
if (r) |
|
return r; |
|
} |
|
|
|
md = dm_hash_rename(param, new_data); |
|
if (IS_ERR(md)) |
|
return PTR_ERR(md); |
|
|
|
__dev_status(md, param); |
|
dm_put(md); |
|
|
|
return 0; |
|
} |
|
|
|
static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
int r = -EINVAL, x; |
|
struct mapped_device *md; |
|
struct hd_geometry geometry; |
|
unsigned long indata[4]; |
|
char *geostr = (char *) param + param->data_start; |
|
char dummy; |
|
|
|
md = find_device(param); |
|
if (!md) |
|
return -ENXIO; |
|
|
|
if (geostr < param->data || |
|
invalid_str(geostr, (void *) param + param_size)) { |
|
DMWARN("Invalid geometry supplied."); |
|
goto out; |
|
} |
|
|
|
x = sscanf(geostr, "%lu %lu %lu %lu%c", indata, |
|
indata + 1, indata + 2, indata + 3, &dummy); |
|
|
|
if (x != 4) { |
|
DMWARN("Unable to interpret geometry settings."); |
|
goto out; |
|
} |
|
|
|
if (indata[0] > 65535 || indata[1] > 255 || |
|
indata[2] > 255 || indata[3] > ULONG_MAX) { |
|
DMWARN("Geometry exceeds range limits."); |
|
goto out; |
|
} |
|
|
|
geometry.cylinders = indata[0]; |
|
geometry.heads = indata[1]; |
|
geometry.sectors = indata[2]; |
|
geometry.start = indata[3]; |
|
|
|
r = dm_set_geometry(md, &geometry); |
|
|
|
param->data_size = 0; |
|
|
|
out: |
|
dm_put(md); |
|
return r; |
|
} |
|
|
|
static int do_suspend(struct dm_ioctl *param) |
|
{ |
|
int r = 0; |
|
unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG; |
|
struct mapped_device *md; |
|
|
|
md = find_device(param); |
|
if (!md) |
|
return -ENXIO; |
|
|
|
if (param->flags & DM_SKIP_LOCKFS_FLAG) |
|
suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; |
|
if (param->flags & DM_NOFLUSH_FLAG) |
|
suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; |
|
|
|
if (!dm_suspended_md(md)) { |
|
r = dm_suspend(md, suspend_flags); |
|
if (r) |
|
goto out; |
|
} |
|
|
|
__dev_status(md, param); |
|
|
|
out: |
|
dm_put(md); |
|
|
|
return r; |
|
} |
|
|
|
static int do_resume(struct dm_ioctl *param) |
|
{ |
|
int r = 0; |
|
unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG; |
|
struct hash_cell *hc; |
|
struct mapped_device *md; |
|
struct dm_table *new_map, *old_map = NULL; |
|
|
|
down_write(&_hash_lock); |
|
|
|
hc = __find_device_hash_cell(param); |
|
if (!hc) { |
|
DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); |
|
up_write(&_hash_lock); |
|
return -ENXIO; |
|
} |
|
|
|
md = hc->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) |
|
suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; |
|
if (param->flags & DM_NOFLUSH_FLAG) |
|
suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; |
|
if (!dm_suspended_md(md)) |
|
dm_suspend(md, suspend_flags); |
|
|
|
old_map = dm_swap_table(md, new_map); |
|
if (IS_ERR(old_map)) { |
|
dm_sync_table(md); |
|
dm_table_destroy(new_map); |
|
dm_put(md); |
|
return PTR_ERR(old_map); |
|
} |
|
|
|
if (dm_table_get_mode(new_map) & FMODE_WRITE) |
|
set_disk_ro(dm_disk(md), 0); |
|
else |
|
set_disk_ro(dm_disk(md), 1); |
|
} |
|
|
|
if (dm_suspended_md(md)) { |
|
r = dm_resume(md); |
|
if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr)) |
|
param->flags |= DM_UEVENT_GENERATED_FLAG; |
|
} |
|
|
|
/* |
|
* Since dm_swap_table synchronizes RCU, nobody should be in |
|
* read-side critical section already. |
|
*/ |
|
if (old_map) |
|
dm_table_destroy(old_map); |
|
|
|
if (!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 file *filp, 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 file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
struct mapped_device *md; |
|
|
|
md = find_device(param); |
|
if (!md) |
|
return -ENXIO; |
|
|
|
__dev_status(md, param); |
|
dm_put(md); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* 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; |
|
unsigned status_flags = 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); |
|
size_t l; |
|
|
|
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) - 1); |
|
|
|
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 (param->flags & DM_NOFLUSH_FLAG) |
|
status_flags |= DM_STATUS_NOFLUSH_FLAG; |
|
ti->type->status(ti, type, status_flags, outptr, remaining); |
|
} else |
|
outptr[0] = '\0'; |
|
|
|
l = strlen(outptr) + 1; |
|
if (l == remaining) { |
|
param->flags |= DM_BUFFER_FULL_FLAG; |
|
break; |
|
} |
|
|
|
outptr += l; |
|
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 file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
int r = 0; |
|
struct mapped_device *md; |
|
struct dm_table *table; |
|
int srcu_idx; |
|
|
|
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. |
|
*/ |
|
__dev_status(md, param); |
|
|
|
table = dm_get_live_or_inactive_table(md, param, &srcu_idx); |
|
if (table) |
|
retrieve_status(table, param, param_size); |
|
dm_put_live_table(md, srcu_idx); |
|
|
|
out: |
|
dm_put(md); |
|
|
|
return r; |
|
} |
|
|
|
/* |
|
* Remember the global event number and make it possible to poll |
|
* for further events. |
|
*/ |
|
static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
struct dm_file *priv = filp->private_data; |
|
|
|
priv->global_event_nr = atomic_read(&dm_global_event_nr); |
|
|
|
return 0; |
|
} |
|
|
|
static inline fmode_t get_mode(struct dm_ioctl *param) |
|
{ |
|
fmode_t 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 bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new) |
|
{ |
|
if (cur == new || |
|
(cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED)) |
|
return true; |
|
|
|
return false; |
|
} |
|
|
|
static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
int r; |
|
struct hash_cell *hc; |
|
struct dm_table *t, *old_map = NULL; |
|
struct mapped_device *md; |
|
struct target_type *immutable_target_type; |
|
|
|
md = find_device(param); |
|
if (!md) |
|
return -ENXIO; |
|
|
|
r = dm_table_create(&t, get_mode(param), param->target_count, md); |
|
if (r) |
|
goto err; |
|
|
|
/* Protect md->type and md->queue against concurrent table loads. */ |
|
dm_lock_md_type(md); |
|
r = populate_table(t, param, param_size); |
|
if (r) |
|
goto err_unlock_md_type; |
|
|
|
immutable_target_type = dm_get_immutable_target_type(md); |
|
if (immutable_target_type && |
|
(immutable_target_type != dm_table_get_immutable_target_type(t)) && |
|
!dm_table_get_wildcard_target(t)) { |
|
DMWARN("can't replace immutable target type %s", |
|
immutable_target_type->name); |
|
r = -EINVAL; |
|
goto err_unlock_md_type; |
|
} |
|
|
|
if (dm_get_md_type(md) == DM_TYPE_NONE) { |
|
/* Initial table load: acquire type of table. */ |
|
dm_set_md_type(md, dm_table_get_type(t)); |
|
|
|
/* setup md->queue to reflect md's type (may block) */ |
|
r = dm_setup_md_queue(md, t); |
|
if (r) { |
|
DMWARN("unable to set up device queue for new table."); |
|
goto err_unlock_md_type; |
|
} |
|
} else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) { |
|
DMWARN("can't change device type (old=%u vs new=%u) after initial table load.", |
|
dm_get_md_type(md), dm_table_get_type(t)); |
|
r = -EINVAL; |
|
goto err_unlock_md_type; |
|
} |
|
|
|
dm_unlock_md_type(md); |
|
|
|
/* stage inactive table */ |
|
down_write(&_hash_lock); |
|
hc = dm_get_mdptr(md); |
|
if (!hc || hc->md != md) { |
|
DMWARN("device has been removed from the dev hash table."); |
|
up_write(&_hash_lock); |
|
r = -ENXIO; |
|
goto err_destroy_table; |
|
} |
|
|
|
if (hc->new_map) |
|
old_map = hc->new_map; |
|
hc->new_map = t; |
|
up_write(&_hash_lock); |
|
|
|
param->flags |= DM_INACTIVE_PRESENT_FLAG; |
|
__dev_status(md, param); |
|
|
|
if (old_map) { |
|
dm_sync_table(md); |
|
dm_table_destroy(old_map); |
|
} |
|
|
|
dm_put(md); |
|
|
|
return 0; |
|
|
|
err_unlock_md_type: |
|
dm_unlock_md_type(md); |
|
err_destroy_table: |
|
dm_table_destroy(t); |
|
err: |
|
dm_put(md); |
|
|
|
return r; |
|
} |
|
|
|
static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
struct hash_cell *hc; |
|
struct mapped_device *md; |
|
struct dm_table *old_map = NULL; |
|
|
|
down_write(&_hash_lock); |
|
|
|
hc = __find_device_hash_cell(param); |
|
if (!hc) { |
|
DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); |
|
up_write(&_hash_lock); |
|
return -ENXIO; |
|
} |
|
|
|
if (hc->new_map) { |
|
old_map = hc->new_map; |
|
hc->new_map = NULL; |
|
} |
|
|
|
param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
|
|
|
__dev_status(hc->md, param); |
|
md = hc->md; |
|
up_write(&_hash_lock); |
|
if (old_map) { |
|
dm_sync_table(md); |
|
dm_table_destroy(old_map); |
|
} |
|
dm_put(md); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* 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_internal *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 = struct_size(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->dm_dev->bdev->bd_dev); |
|
|
|
param->data_size = param->data_start + needed; |
|
} |
|
|
|
static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
struct mapped_device *md; |
|
struct dm_table *table; |
|
int srcu_idx; |
|
|
|
md = find_device(param); |
|
if (!md) |
|
return -ENXIO; |
|
|
|
__dev_status(md, param); |
|
|
|
table = dm_get_live_or_inactive_table(md, param, &srcu_idx); |
|
if (table) |
|
retrieve_deps(table, param, param_size); |
|
dm_put_live_table(md, srcu_idx); |
|
|
|
dm_put(md); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Return the status of a device as a text string for each |
|
* target. |
|
*/ |
|
static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size) |
|
{ |
|
struct mapped_device *md; |
|
struct dm_table *table; |
|
int srcu_idx; |
|
|
|
md = find_device(param); |
|
if (!md) |
|
return -ENXIO; |
|
|
|
__dev_status(md, param); |
|
|
|
table = dm_get_live_or_inactive_table(md, param, &srcu_idx); |
|
if (table) |
|
retrieve_status(table, param, param_size); |
|
dm_put_live_table(md, srcu_idx); |
|
|
|
dm_put(md); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Process device-mapper dependent messages. Messages prefixed with '@' |
|
* are processed by the DM core. All others are delivered to the target. |
|
* Returns a number <= 1 if message was processed by device mapper. |
|
* Returns 2 if message should be delivered to the target. |
|
*/ |
|
static int message_for_md(struct mapped_device *md, unsigned argc, char **argv, |
|
char *result, unsigned maxlen) |
|
{ |
|
int r; |
|
|
|
if (**argv != '@') |
|
return 2; /* no '@' prefix, deliver to target */ |
|
|
|
if (!strcasecmp(argv[0], "@cancel_deferred_remove")) { |
|
if (argc != 1) { |
|
DMERR("Invalid arguments for @cancel_deferred_remove"); |
|
return -EINVAL; |
|
} |
|
return dm_cancel_deferred_remove(md); |
|
} |
|
|
|
r = dm_stats_message(md, argc, argv, result, maxlen); |
|
if (r < 2) |
|
return r; |
|
|
|
DMERR("Unsupported message sent to DM core: %s", argv[0]); |
|
return -EINVAL; |
|
} |
|
|
|
/* |
|
* Pass a message to the target that's at the supplied device offset. |
|
*/ |
|
static int target_message(struct file *filp, 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; |
|
size_t maxlen; |
|
char *result = get_result_buffer(param, param_size, &maxlen); |
|
int srcu_idx; |
|
|
|
md = find_device(param); |
|
if (!md) |
|
return -ENXIO; |
|
|
|
if (tmsg < (struct dm_target_msg *) param->data || |
|
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; |
|
} |
|
|
|
if (!argc) { |
|
DMWARN("Empty message received."); |
|
r = -EINVAL; |
|
goto out_argv; |
|
} |
|
|
|
r = message_for_md(md, argc, argv, result, maxlen); |
|
if (r <= 1) |
|
goto out_argv; |
|
|
|
table = dm_get_live_table(md, &srcu_idx); |
|
if (!table) |
|
goto out_table; |
|
|
|
if (dm_deleting_md(md)) { |
|
r = -ENXIO; |
|
goto out_table; |
|
} |
|
|
|
ti = dm_table_find_target(table, tmsg->sector); |
|
if (!ti) { |
|
DMWARN("Target message sector outside device."); |
|
r = -EINVAL; |
|
} else if (ti->type->message) |
|
r = ti->type->message(ti, argc, argv, result, maxlen); |
|
else { |
|
DMWARN("Target type does not support messages"); |
|
r = -EINVAL; |
|
} |
|
|
|
out_table: |
|
dm_put_live_table(md, srcu_idx); |
|
out_argv: |
|
kfree(argv); |
|
out: |
|
if (r >= 0) |
|
__dev_status(md, param); |
|
|
|
if (r == 1) { |
|
param->flags |= DM_DATA_OUT_FLAG; |
|
if (dm_message_test_buffer_overflow(result, maxlen)) |
|
param->flags |= DM_BUFFER_FULL_FLAG; |
|
else |
|
param->data_size = param->data_start + strlen(result) + 1; |
|
r = 0; |
|
} |
|
|
|
dm_put(md); |
|
return r; |
|
} |
|
|
|
/* |
|
* The ioctl parameter block consists of two parts, a dm_ioctl struct |
|
* followed by a data buffer. This flag is set if the second part, |
|
* which has a variable size, is not used by the function processing |
|
* the ioctl. |
|
*/ |
|
#define IOCTL_FLAGS_NO_PARAMS 1 |
|
#define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2 |
|
|
|
/*----------------------------------------------------------------- |
|
* Implementation of open/close/ioctl on the special char |
|
* device. |
|
*---------------------------------------------------------------*/ |
|
static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags) |
|
{ |
|
static const struct { |
|
int cmd; |
|
int flags; |
|
ioctl_fn fn; |
|
} _ioctls[] = { |
|
{DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */ |
|
{DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all}, |
|
{DM_LIST_DEVICES_CMD, 0, list_devices}, |
|
|
|
{DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create}, |
|
{DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove}, |
|
{DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename}, |
|
{DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend}, |
|
{DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status}, |
|
{DM_DEV_WAIT_CMD, 0, dev_wait}, |
|
|
|
{DM_TABLE_LOAD_CMD, 0, table_load}, |
|
{DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear}, |
|
{DM_TABLE_DEPS_CMD, 0, table_deps}, |
|
{DM_TABLE_STATUS_CMD, 0, table_status}, |
|
|
|
{DM_LIST_VERSIONS_CMD, 0, list_versions}, |
|
|
|
{DM_TARGET_MSG_CMD, 0, target_message}, |
|
{DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry}, |
|
{DM_DEV_ARM_POLL, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll}, |
|
{DM_GET_TARGET_VERSION, 0, get_target_version}, |
|
}; |
|
|
|
if (unlikely(cmd >= ARRAY_SIZE(_ioctls))) |
|
return NULL; |
|
|
|
*ioctl_flags = _ioctls[cmd].flags; |
|
return _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; |
|
} |
|
|
|
#define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */ |
|
#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */ |
|
|
|
static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags) |
|
{ |
|
if (param_flags & DM_WIPE_BUFFER) |
|
memset(param, 0, param_size); |
|
|
|
if (param_flags & DM_PARAMS_MALLOC) |
|
kvfree(param); |
|
} |
|
|
|
static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel, |
|
int ioctl_flags, struct dm_ioctl **param, int *param_flags) |
|
{ |
|
struct dm_ioctl *dmi; |
|
int secure_data; |
|
const size_t minimum_data_size = offsetof(struct dm_ioctl, data); |
|
unsigned noio_flag; |
|
|
|
if (copy_from_user(param_kernel, user, minimum_data_size)) |
|
return -EFAULT; |
|
|
|
if (param_kernel->data_size < minimum_data_size) |
|
return -EINVAL; |
|
|
|
secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG; |
|
|
|
*param_flags = secure_data ? DM_WIPE_BUFFER : 0; |
|
|
|
if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) { |
|
dmi = param_kernel; |
|
dmi->data_size = minimum_data_size; |
|
goto data_copied; |
|
} |
|
|
|
/* |
|
* Use __GFP_HIGH to avoid low memory issues when a device is |
|
* suspended and the ioctl is needed to resume it. |
|
* Use kmalloc() rather than vmalloc() when we can. |
|
*/ |
|
dmi = NULL; |
|
noio_flag = memalloc_noio_save(); |
|
dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH); |
|
memalloc_noio_restore(noio_flag); |
|
|
|
if (!dmi) { |
|
if (secure_data && clear_user(user, param_kernel->data_size)) |
|
return -EFAULT; |
|
return -ENOMEM; |
|
} |
|
|
|
*param_flags |= DM_PARAMS_MALLOC; |
|
|
|
/* Copy from param_kernel (which was already copied from user) */ |
|
memcpy(dmi, param_kernel, minimum_data_size); |
|
|
|
if (copy_from_user(&dmi->data, (char __user *)user + minimum_data_size, |
|
param_kernel->data_size - minimum_data_size)) |
|
goto bad; |
|
data_copied: |
|
/* Wipe the user buffer so we do not return it to userspace */ |
|
if (secure_data && clear_user(user, param_kernel->data_size)) |
|
goto bad; |
|
|
|
*param = dmi; |
|
return 0; |
|
|
|
bad: |
|
free_params(dmi, param_kernel->data_size, *param_flags); |
|
|
|
return -EFAULT; |
|
} |
|
|
|
static int validate_params(uint cmd, struct dm_ioctl *param) |
|
{ |
|
/* Always clear this flag */ |
|
param->flags &= ~DM_BUFFER_FULL_FLAG; |
|
param->flags &= ~DM_UEVENT_GENERATED_FLAG; |
|
param->flags &= ~DM_SECURE_DATA_FLAG; |
|
param->flags &= ~DM_DATA_OUT_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 file *file, uint command, struct dm_ioctl __user *user) |
|
{ |
|
int r = 0; |
|
int ioctl_flags; |
|
int param_flags; |
|
unsigned int cmd; |
|
struct dm_ioctl *param; |
|
ioctl_fn fn = NULL; |
|
size_t input_param_size; |
|
struct dm_ioctl param_kernel; |
|
|
|
/* 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, &ioctl_flags); |
|
if (!fn) { |
|
DMWARN("dm_ctl_ioctl: unknown command 0x%x", command); |
|
return -ENOTTY; |
|
} |
|
|
|
/* |
|
* Copy the parameters into kernel space. |
|
*/ |
|
r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags); |
|
|
|
if (r) |
|
return r; |
|
|
|
input_param_size = param->data_size; |
|
r = validate_params(cmd, param); |
|
if (r) |
|
goto out; |
|
|
|
param->data_size = offsetof(struct dm_ioctl, data); |
|
r = fn(file, param, input_param_size); |
|
|
|
if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) && |
|
unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS)) |
|
DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd); |
|
|
|
if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT) |
|
dm_issue_global_event(); |
|
|
|
/* |
|
* Copy the results back to userland. |
|
*/ |
|
if (!r && copy_to_user(user, param, param->data_size)) |
|
r = -EFAULT; |
|
|
|
out: |
|
free_params(param, input_param_size, param_flags); |
|
return r; |
|
} |
|
|
|
static long dm_ctl_ioctl(struct file *file, uint command, ulong u) |
|
{ |
|
return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u); |
|
} |
|
|
|
#ifdef CONFIG_COMPAT |
|
static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u) |
|
{ |
|
return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u)); |
|
} |
|
#else |
|
#define dm_compat_ctl_ioctl NULL |
|
#endif |
|
|
|
static int dm_open(struct inode *inode, struct file *filp) |
|
{ |
|
int r; |
|
struct dm_file *priv; |
|
|
|
r = nonseekable_open(inode, filp); |
|
if (unlikely(r)) |
|
return r; |
|
|
|
priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL); |
|
if (!priv) |
|
return -ENOMEM; |
|
|
|
priv->global_event_nr = atomic_read(&dm_global_event_nr); |
|
|
|
return 0; |
|
} |
|
|
|
static int dm_release(struct inode *inode, struct file *filp) |
|
{ |
|
kfree(filp->private_data); |
|
return 0; |
|
} |
|
|
|
static __poll_t dm_poll(struct file *filp, poll_table *wait) |
|
{ |
|
struct dm_file *priv = filp->private_data; |
|
__poll_t mask = 0; |
|
|
|
poll_wait(filp, &dm_global_eventq, wait); |
|
|
|
if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0) |
|
mask |= EPOLLIN; |
|
|
|
return mask; |
|
} |
|
|
|
static const struct file_operations _ctl_fops = { |
|
.open = dm_open, |
|
.release = dm_release, |
|
.poll = dm_poll, |
|
.unlocked_ioctl = dm_ctl_ioctl, |
|
.compat_ioctl = dm_compat_ctl_ioctl, |
|
.owner = THIS_MODULE, |
|
.llseek = noop_llseek, |
|
}; |
|
|
|
static struct miscdevice _dm_misc = { |
|
.minor = MAPPER_CTRL_MINOR, |
|
.name = DM_NAME, |
|
.nodename = DM_DIR "/" DM_CONTROL_NODE, |
|
.fops = &_ctl_fops |
|
}; |
|
|
|
MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR); |
|
MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE); |
|
|
|
/* |
|
* 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) |
|
{ |
|
misc_deregister(&_dm_misc); |
|
dm_hash_exit(); |
|
} |
|
|
|
/** |
|
* dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers |
|
* @md: Pointer to mapped_device |
|
* @name: Buffer (size DM_NAME_LEN) for name |
|
* @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined |
|
*/ |
|
int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid) |
|
{ |
|
int r = 0; |
|
struct hash_cell *hc; |
|
|
|
if (!md) |
|
return -ENXIO; |
|
|
|
mutex_lock(&dm_hash_cells_mutex); |
|
hc = dm_get_mdptr(md); |
|
if (!hc || hc->md != md) { |
|
r = -ENXIO; |
|
goto out; |
|
} |
|
|
|
if (name) |
|
strcpy(name, hc->name); |
|
if (uuid) |
|
strcpy(uuid, hc->uuid ? : ""); |
|
|
|
out: |
|
mutex_unlock(&dm_hash_cells_mutex); |
|
|
|
return r; |
|
} |
|
EXPORT_SYMBOL_GPL(dm_copy_name_and_uuid); |
|
|
|
/** |
|
* dm_early_create - create a mapped device in early boot. |
|
* |
|
* @dmi: Contains main information of the device mapping to be created. |
|
* @spec_array: array of pointers to struct dm_target_spec. Describes the |
|
* mapping table of the device. |
|
* @target_params_array: array of strings with the parameters to a specific |
|
* target. |
|
* |
|
* Instead of having the struct dm_target_spec and the parameters for every |
|
* target embedded at the end of struct dm_ioctl (as performed in a normal |
|
* ioctl), pass them as arguments, so the caller doesn't need to serialize them. |
|
* The size of the spec_array and target_params_array is given by |
|
* @dmi->target_count. |
|
* This function is supposed to be called in early boot, so locking mechanisms |
|
* to protect against concurrent loads are not required. |
|
*/ |
|
int __init dm_early_create(struct dm_ioctl *dmi, |
|
struct dm_target_spec **spec_array, |
|
char **target_params_array) |
|
{ |
|
int r, m = DM_ANY_MINOR; |
|
struct dm_table *t, *old_map; |
|
struct mapped_device *md; |
|
unsigned int i; |
|
|
|
if (!dmi->target_count) |
|
return -EINVAL; |
|
|
|
r = check_name(dmi->name); |
|
if (r) |
|
return r; |
|
|
|
if (dmi->flags & DM_PERSISTENT_DEV_FLAG) |
|
m = MINOR(huge_decode_dev(dmi->dev)); |
|
|
|
/* alloc dm device */ |
|
r = dm_create(m, &md); |
|
if (r) |
|
return r; |
|
|
|
/* hash insert */ |
|
r = dm_hash_insert(dmi->name, *dmi->uuid ? dmi->uuid : NULL, md); |
|
if (r) |
|
goto err_destroy_dm; |
|
|
|
/* alloc table */ |
|
r = dm_table_create(&t, get_mode(dmi), dmi->target_count, md); |
|
if (r) |
|
goto err_hash_remove; |
|
|
|
/* add targets */ |
|
for (i = 0; i < dmi->target_count; i++) { |
|
r = dm_table_add_target(t, spec_array[i]->target_type, |
|
(sector_t) spec_array[i]->sector_start, |
|
(sector_t) spec_array[i]->length, |
|
target_params_array[i]); |
|
if (r) { |
|
DMWARN("error adding target to table"); |
|
goto err_destroy_table; |
|
} |
|
} |
|
|
|
/* finish table */ |
|
r = dm_table_complete(t); |
|
if (r) |
|
goto err_destroy_table; |
|
|
|
md->type = dm_table_get_type(t); |
|
/* setup md->queue to reflect md's type (may block) */ |
|
r = dm_setup_md_queue(md, t); |
|
if (r) { |
|
DMWARN("unable to set up device queue for new table."); |
|
goto err_destroy_table; |
|
} |
|
|
|
/* Set new map */ |
|
dm_suspend(md, 0); |
|
old_map = dm_swap_table(md, t); |
|
if (IS_ERR(old_map)) { |
|
r = PTR_ERR(old_map); |
|
goto err_destroy_table; |
|
} |
|
set_disk_ro(dm_disk(md), !!(dmi->flags & DM_READONLY_FLAG)); |
|
|
|
/* resume device */ |
|
r = dm_resume(md); |
|
if (r) |
|
goto err_destroy_table; |
|
|
|
DMINFO("%s (%s) is ready", md->disk->disk_name, dmi->name); |
|
dm_put(md); |
|
return 0; |
|
|
|
err_destroy_table: |
|
dm_table_destroy(t); |
|
err_hash_remove: |
|
(void) __hash_remove(__get_name_cell(dmi->name)); |
|
/* release reference from __get_name_cell */ |
|
dm_put(md); |
|
err_destroy_dm: |
|
dm_put(md); |
|
dm_destroy(md); |
|
return r; |
|
}
|
|
|