| /* |
| * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. |
| * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved. |
| * |
| * This file is released under the GPL. |
| */ |
| |
| #include "dm.h" |
| |
| #include <linux/module.h> |
| #include <linux/vmalloc.h> |
| #include <linux/miscdevice.h> |
| #include <linux/init.h> |
| #include <linux/wait.h> |
| #include <linux/slab.h> |
| #include <linux/dm-ioctl.h> |
| #include <linux/hdreg.h> |
| #include <linux/compat.h> |
| |
| #include <asm/uaccess.h> |
| |
| #define DM_MSG_PREFIX "ioctl" |
| #define DM_DRIVER_EMAIL "dm-devel@redhat.com" |
| |
| /*----------------------------------------------------------------- |
| * The ioctl interface needs to be able to look up devices by |
| * name or uuid. |
| *---------------------------------------------------------------*/ |
| struct hash_cell { |
| struct list_head name_list; |
| struct list_head uuid_list; |
| |
| char *name; |
| char *uuid; |
| struct mapped_device *md; |
| struct dm_table *new_map; |
| }; |
| |
| struct vers_iter { |
| size_t param_size; |
| struct dm_target_versions *vers, *old_vers; |
| char *end; |
| uint32_t flags; |
| }; |
| |
| |
| #define NUM_BUCKETS 64 |
| #define MASK_BUCKETS (NUM_BUCKETS - 1) |
| static struct list_head _name_buckets[NUM_BUCKETS]; |
| static struct list_head _uuid_buckets[NUM_BUCKETS]; |
| |
| static void dm_hash_remove_all(int keep_open_devices); |
| |
| /* |
| * Guards access to both hash tables. |
| */ |
| static DECLARE_RWSEM(_hash_lock); |
| |
| /* |
| * Protects use of mdptr to obtain hash cell name and uuid from mapped device. |
| */ |
| static DEFINE_MUTEX(dm_hash_cells_mutex); |
| |
| static void init_buckets(struct list_head *buckets) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < NUM_BUCKETS; i++) |
| INIT_LIST_HEAD(buckets + i); |
| } |
| |
| static int dm_hash_init(void) |
| { |
| init_buckets(_name_buckets); |
| init_buckets(_uuid_buckets); |
| return 0; |
| } |
| |
| static void dm_hash_exit(void) |
| { |
| dm_hash_remove_all(0); |
| } |
| |
| /*----------------------------------------------------------------- |
| * Hash function: |
| * We're not really concerned with the str hash function being |
| * fast since it's only used by the ioctl interface. |
| *---------------------------------------------------------------*/ |
| static unsigned int hash_str(const char *str) |
| { |
| const unsigned int hash_mult = 2654435387U; |
| unsigned int h = 0; |
| |
| while (*str) |
| h = (h + (unsigned int) *str++) * hash_mult; |
| |
| return h & MASK_BUCKETS; |
| } |
| |
| /*----------------------------------------------------------------- |
| * Code for looking up a device by name |
| *---------------------------------------------------------------*/ |
| static struct hash_cell *__get_name_cell(const char *str) |
| { |
| struct hash_cell *hc; |
| unsigned int h = hash_str(str); |
| |
| list_for_each_entry (hc, _name_buckets + h, name_list) |
| if (!strcmp(hc->name, str)) { |
| dm_get(hc->md); |
| return hc; |
| } |
| |
| return NULL; |
| } |
| |
| static struct hash_cell *__get_uuid_cell(const char *str) |
| { |
| struct hash_cell *hc; |
| unsigned int h = hash_str(str); |
| |
| list_for_each_entry (hc, _uuid_buckets + h, uuid_list) |
| if (!strcmp(hc->uuid, str)) { |
| dm_get(hc->md); |
| return hc; |
| } |
| |
| return NULL; |
| } |
| |
| /*----------------------------------------------------------------- |
| * Inserting, removing and renaming a device. |
| *---------------------------------------------------------------*/ |
| static struct hash_cell *alloc_cell(const char *name, const char *uuid, |
| struct mapped_device *md) |
| { |
| struct hash_cell *hc; |
| |
| hc = kmalloc(sizeof(*hc), GFP_KERNEL); |
| if (!hc) |
| return NULL; |
| |
| hc->name = kstrdup(name, GFP_KERNEL); |
| if (!hc->name) { |
| kfree(hc); |
| return NULL; |
| } |
| |
| if (!uuid) |
| hc->uuid = NULL; |
| |
| else { |
| hc->uuid = kstrdup(uuid, GFP_KERNEL); |
| if (!hc->uuid) { |
| kfree(hc->name); |
| kfree(hc); |
| return NULL; |
| } |
| } |
| |
| INIT_LIST_HEAD(&hc->name_list); |
| INIT_LIST_HEAD(&hc->uuid_list); |
| hc->md = md; |
| hc->new_map = NULL; |
| return hc; |
| } |
| |
| static void free_cell(struct hash_cell *hc) |
| { |
| if (hc) { |
| kfree(hc->name); |
| kfree(hc->uuid); |
| kfree(hc); |
| } |
| } |
| |
| /* |
| * The kdev_t and uuid of a device can never change once it is |
| * initially inserted. |
| */ |
| static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md) |
| { |
| struct hash_cell *cell, *hc; |
| |
| /* |
| * Allocate the new cells. |
| */ |
| cell = alloc_cell(name, uuid, md); |
| if (!cell) |
| return -ENOMEM; |
| |
| /* |
| * Insert the cell into both hash tables. |
| */ |
| down_write(&_hash_lock); |
| hc = __get_name_cell(name); |
| if (hc) { |
| dm_put(hc->md); |
| goto bad; |
| } |
| |
| list_add(&cell->name_list, _name_buckets + hash_str(name)); |
| |
| if (uuid) { |
| hc = __get_uuid_cell(uuid); |
| if (hc) { |
| list_del(&cell->name_list); |
| dm_put(hc->md); |
| goto bad; |
| } |
| list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid)); |
| } |
| dm_get(md); |
| mutex_lock(&dm_hash_cells_mutex); |
| dm_set_mdptr(md, cell); |
| mutex_unlock(&dm_hash_cells_mutex); |
| up_write(&_hash_lock); |
| |
| return 0; |
| |
| bad: |
| up_write(&_hash_lock); |
| free_cell(cell); |
| return -EBUSY; |
| } |
| |
| static void __hash_remove(struct hash_cell *hc) |
| { |
| struct dm_table *table; |
| |
| /* remove from the dev hash */ |
| list_del(&hc->uuid_list); |
| list_del(&hc->name_list); |
| mutex_lock(&dm_hash_cells_mutex); |
| dm_set_mdptr(hc->md, NULL); |
| mutex_unlock(&dm_hash_cells_mutex); |
| |
| table = dm_get_live_table(hc->md); |
| if (table) { |
| dm_table_event(table); |
| dm_table_put(table); |
| } |
| |
| if (hc->new_map) |
| dm_table_destroy(hc->new_map); |
| dm_put(hc->md); |
| free_cell(hc); |
| } |
| |
| static void dm_hash_remove_all(int keep_open_devices) |
| { |
| int i, dev_skipped, dev_removed; |
| struct hash_cell *hc; |
| struct list_head *tmp, *n; |
| |
| down_write(&_hash_lock); |
| |
| retry: |
| dev_skipped = dev_removed = 0; |
| for (i = 0; i < NUM_BUCKETS; i++) { |
| list_for_each_safe (tmp, n, _name_buckets + i) { |
| hc = list_entry(tmp, struct hash_cell, name_list); |
| |
| if (keep_open_devices && |
| dm_lock_for_deletion(hc->md)) { |
| dev_skipped++; |
| continue; |
| } |
| __hash_remove(hc); |
| dev_removed = 1; |
| } |
| } |
| |
| /* |
| * Some mapped devices may be using other mapped devices, so if any |
| * still exist, repeat until we make no further progress. |
| */ |
| if (dev_skipped) { |
| if (dev_removed) |
| goto retry; |
| |
| DMWARN("remove_all left %d open device(s)", dev_skipped); |
| } |
| |
| up_write(&_hash_lock); |
| } |
| |
| static int dm_hash_rename(uint32_t cookie, const char *old, const char *new) |
| { |
| char *new_name, *old_name; |
| struct hash_cell *hc; |
| struct dm_table *table; |
| |
| /* |
| * duplicate new. |
| */ |
| new_name = kstrdup(new, GFP_KERNEL); |
| if (!new_name) |
| return -ENOMEM; |
| |
| down_write(&_hash_lock); |
| |
| /* |
| * Is new free ? |
| */ |
| hc = __get_name_cell(new); |
| if (hc) { |
| DMWARN("asked to rename to an already existing name %s -> %s", |
| old, new); |
| dm_put(hc->md); |
| up_write(&_hash_lock); |
| kfree(new_name); |
| return -EBUSY; |
| } |
| |
| /* |
| * Is there such a device as 'old' ? |
| */ |
| hc = __get_name_cell(old); |
| if (!hc) { |
| DMWARN("asked to rename a non existent device %s -> %s", |
| old, new); |
| up_write(&_hash_lock); |
| kfree(new_name); |
| return -ENXIO; |
| } |
| |
| /* |
| * rename and move the name cell. |
| */ |
| list_del(&hc->name_list); |
| old_name = hc->name; |
| mutex_lock(&dm_hash_cells_mutex); |
| hc->name = new_name; |
| mutex_unlock(&dm_hash_cells_mutex); |
| list_add(&hc->name_list, _name_buckets + hash_str(new_name)); |
| |
| /* |
| * Wake up any dm event waiters. |
| */ |
| table = dm_get_live_table(hc->md); |
| if (table) { |
| dm_table_event(table); |
| dm_table_put(table); |
| } |
| |
| dm_kobject_uevent(hc->md, KOBJ_CHANGE, cookie); |
| |
| dm_put(hc->md); |
| up_write(&_hash_lock); |
| kfree(old_name); |
| return 0; |
| } |
| |
| /*----------------------------------------------------------------- |
| * Implementation of the ioctl commands |
| *---------------------------------------------------------------*/ |
| /* |
| * All the ioctl commands get dispatched to functions with this |
| * prototype. |
| */ |
| typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size); |
| |
| static int remove_all(struct dm_ioctl *param, size_t param_size) |
| { |
| dm_hash_remove_all(1); |
| param->data_size = 0; |
| return 0; |
| } |
| |
| /* |
| * Round up the ptr to an 8-byte boundary. |
| */ |
| #define ALIGN_MASK 7 |
| static inline void *align_ptr(void *ptr) |
| { |
| return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK); |
| } |
| |
| /* |
| * Retrieves the data payload buffer from an already allocated |
| * struct dm_ioctl. |
| */ |
| static void *get_result_buffer(struct dm_ioctl *param, size_t param_size, |
| size_t *len) |
| { |
| param->data_start = align_ptr(param + 1) - (void *) param; |
| |
| if (param->data_start < param_size) |
| *len = param_size - param->data_start; |
| else |
| *len = 0; |
| |
| return ((void *) param) + param->data_start; |
| } |
| |
| static int list_devices(struct dm_ioctl *param, size_t param_size) |
| { |
| unsigned int i; |
| struct hash_cell *hc; |
| size_t len, needed = 0; |
| struct gendisk *disk; |
| struct dm_name_list *nl, *old_nl = NULL; |
| |
| down_write(&_hash_lock); |
| |
| /* |
| * Loop through all the devices working out how much |
| * space we need. |
| */ |
| for (i = 0; i < NUM_BUCKETS; i++) { |
| list_for_each_entry (hc, _name_buckets + i, name_list) { |
| needed += sizeof(struct dm_name_list); |
| needed += strlen(hc->name) + 1; |
| needed += ALIGN_MASK; |
| } |
| } |
| |
| /* |
| * Grab our output buffer. |
| */ |
| nl = get_result_buffer(param, param_size, &len); |
| if (len < needed) { |
| param->flags |= DM_BUFFER_FULL_FLAG; |
| goto out; |
| } |
| param->data_size = param->data_start + needed; |
| |
| nl->dev = 0; /* Flags no data */ |
| |
| /* |
| * Now loop through filling out the names. |
| */ |
| for (i = 0; i < NUM_BUCKETS; i++) { |
| list_for_each_entry (hc, _name_buckets + i, name_list) { |
| if (old_nl) |
| old_nl->next = (uint32_t) ((void *) nl - |
| (void *) old_nl); |
| disk = dm_disk(hc->md); |
| nl->dev = huge_encode_dev(disk_devt(disk)); |
| nl->next = 0; |
| strcpy(nl->name, hc->name); |
| |
| old_nl = nl; |
| nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1); |
| } |
| } |
| |
| out: |
| up_write(&_hash_lock); |
| return 0; |
| } |
| |
| static 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) |
| { |
| size_t len, needed = 0; |
| struct dm_target_versions *vers; |
| struct vers_iter iter_info; |
| |
| /* |
| * Loop through all the devices working out how much |
| * space we need. |
| */ |
| dm_target_iterate(list_version_get_needed, &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. |
| */ |
| dm_target_iterate(list_version_get_info, &iter_info); |
| param->flags |= iter_info.flags; |
| |
| out: |
| return 0; |
| } |
| |
| 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_table_put, because dm_table_destroy |
| * waits for this dm_table_put and could be called under this lock. |
| */ |
| static struct dm_table *dm_get_inactive_table(struct mapped_device *md) |
| { |
| struct hash_cell *hc; |
| struct dm_table *table = NULL; |
| |
| 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; |
| if (table) |
| dm_table_get(table); |
| |
| 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) |
| { |
| return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ? |
| dm_get_inactive_table(md) : dm_get_live_table(md); |
| } |
| |
| /* |
| * Fills in a dm_ioctl structure, ready for sending back to |
| * userland. |
| */ |
| static int __dev_status(struct mapped_device *md, struct dm_ioctl *param) |
| { |
| struct gendisk *disk = dm_disk(md); |
| struct dm_table *table; |
| |
| param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG | |
| DM_ACTIVE_PRESENT_FLAG); |
| |
| if (dm_suspended_md(md)) |
| param->flags |= DM_SUSPEND_FLAG; |
| |
| 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); |
| 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); |
| } |
| dm_table_put(table); |
| |
| param->flags |= DM_ACTIVE_PRESENT_FLAG; |
| } |
| |
| if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) { |
| table = dm_get_inactive_table(md); |
| 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_table_put(table); |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int dev_create(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); |
| 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) |
| { |
| struct mapped_device *md; |
| void *mdptr = NULL; |
| |
| if (*param->uuid) |
| return __get_uuid_cell(param->uuid); |
| |
| if (*param->name) |
| return __get_name_cell(param->name); |
| |
| md = dm_get_md(huge_decode_dev(param->dev)); |
| if (!md) |
| goto out; |
| |
| mdptr = dm_get_mdptr(md); |
| if (!mdptr) |
| dm_put(md); |
| |
| out: |
| return mdptr; |
| } |
| |
| 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; |
| |
| /* |
| * 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; |
| } |
| up_read(&_hash_lock); |
| |
| return md; |
| } |
| |
| static int dev_remove(struct dm_ioctl *param, size_t param_size) |
| { |
| struct hash_cell *hc; |
| struct mapped_device *md; |
| int r; |
| |
| down_write(&_hash_lock); |
| hc = __find_device_hash_cell(param); |
| |
| if (!hc) { |
| DMWARN("device doesn't appear to be in the dev hash table."); |
| up_write(&_hash_lock); |
| return -ENXIO; |
| } |
| |
| md = hc->md; |
| |
| /* |
| * Ensure the device is not open and nothing further can open it. |
| */ |
| r = dm_lock_for_deletion(md); |
| if (r) { |
| DMWARN("unable to remove open device %s", hc->name); |
| up_write(&_hash_lock); |
| dm_put(md); |
| return r; |
| } |
| |
| __hash_remove(hc); |
| up_write(&_hash_lock); |
| |
| dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr); |
| |
| dm_put(md); |
| 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 < param->data || |
| invalid_str(new_name, (void *) param + param_size) || |
| strlen(new_name) > DM_NAME_LEN - 1) { |
| 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->event_nr, param->name, new_name); |
| } |
| |
| static int dev_set_geometry(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; |
| |
| 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", indata, |
| indata + 1, indata + 2, indata + 3); |
| |
| 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); |
| if (!r) |
| r = __dev_status(md, param); |
| |
| 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) |
| r = __dev_status(md, param); |
| |
| 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) { |
| DMWARN("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_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); |
| } |
| |
| if (old_map) |
| dm_table_destroy(old_map); |
| |
| 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_live_or_inactive_table(md, param); |
| if (table) { |
| retrieve_status(table, param, param_size); |
| dm_table_put(table); |
| } |
| |
| out: |
| dm_put(md); |
| return r; |
| } |
| |
| 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; |
| } |
| |
| r = dm_table_set_type(table); |
| if (r) { |
| DMWARN("unable to set table type"); |
| return r; |
| } |
| |
| return dm_table_complete(table); |
| } |
| |
| static int table_prealloc_integrity(struct dm_table *t, |
| struct mapped_device *md) |
| { |
| struct list_head *devices = dm_table_get_devices(t); |
| struct dm_dev_internal *dd; |
| |
| list_for_each_entry(dd, devices, list) |
| if (bdev_get_integrity(dd->dm_dev.bdev)) |
| return blk_integrity_register(dm_disk(md), NULL); |
| |
| return 0; |
| } |
| |
| static int table_load(struct dm_ioctl *param, size_t param_size) |
| { |
| int r; |
| struct hash_cell *hc; |
| struct dm_table *t; |
| struct mapped_device *md; |
| |
| md = find_device(param); |
| if (!md) |
| return -ENXIO; |
| |
| r = dm_table_create(&t, get_mode(param), param->target_count, md); |
| if (r) |
| goto out; |
| |
| r = populate_table(t, param, param_size); |
| if (r) { |
| dm_table_destroy(t); |
| goto out; |
| } |
| |
| r = table_prealloc_integrity(t, md); |
| if (r) { |
| DMERR("%s: could not register integrity profile.", |
| dm_device_name(md)); |
| dm_table_destroy(t); |
| goto out; |
| } |
| |
| r = dm_table_alloc_md_mempools(t); |
| if (r) { |
| DMWARN("unable to allocate mempools for this table"); |
| dm_table_destroy(t); |
| goto out; |
| } |
| |
| down_write(&_hash_lock); |
| hc = dm_get_mdptr(md); |
| if (!hc || hc->md != md) { |
| DMWARN("device has been removed from the dev hash table."); |
| dm_table_destroy(t); |
| up_write(&_hash_lock); |
| r = -ENXIO; |
| goto out; |
| } |
| |
| if (hc->new_map) |
| dm_table_destroy(hc->new_map); |
| hc->new_map = t; |
| up_write(&_hash_lock); |
| |
| param->flags |= DM_INACTIVE_PRESENT_FLAG; |
| r = __dev_status(md, param); |
| |
| out: |
| dm_put(md); |
| |
| return r; |
| } |
| |
| static int table_clear(struct dm_ioctl *param, size_t param_size) |
| { |
| int r; |
| struct hash_cell *hc; |
| struct mapped_device *md; |
| |
| 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_destroy(hc->new_map); |
| hc->new_map = NULL; |
| } |
| |
| param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
| |
| r = __dev_status(hc->md, param); |
| md = hc->md; |
| up_write(&_hash_lock); |
| dm_put(md); |
| 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_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 = 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->dm_dev.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_live_or_inactive_table(md, param); |
| 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_live_or_inactive_table(md, param); |
| 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->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; |
| } |
| |
| table = dm_get_live_table(md); |
| if (!table) |
| goto out_argv; |
| |
| if (dm_deleting_md(md)) { |
| r = -ENXIO; |
| goto out_table; |
| } |
| |
| ti = dm_table_find_target(table, tmsg->sector); |
| if (!dm_target_is_valid(ti)) { |
| DMWARN("Target message sector outside device."); |
| r = -EINVAL; |
| } else 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}, |
| {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry} |
| }; |
| |
| 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) - sizeof(tmp.data))) |
| return -EFAULT; |
| |
| if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data))) |
| return -EINVAL; |
| |
| dmi = 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(uint command, struct dm_ioctl __user *user) |
| { |
| int r = 0; |
| unsigned int cmd; |
| struct dm_ioctl *uninitialized_var(param); |
| 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 long dm_ctl_ioctl(struct file *file, uint command, ulong u) |
| { |
| return (long)ctl_ioctl(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 const struct file_operations _ctl_fops = { |
| .unlocked_ioctl = dm_ctl_ioctl, |
| .compat_ioctl = dm_compat_ctl_ioctl, |
| .owner = THIS_MODULE, |
| }; |
| |
| static struct miscdevice _dm_misc = { |
| .minor = MISC_DYNAMIC_MINOR, |
| .name = DM_NAME, |
| .nodename = "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(); |
| } |
| |
| /** |
| * 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; |
| } |