diff options
Diffstat (limited to 'drivers/md/dm-ioctl.c')
| -rw-r--r-- | drivers/md/dm-ioctl.c | 1127 |
1 files changed, 832 insertions, 295 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 54ec737195e..51521429fb5 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1,6 +1,6 @@ /* * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. - * Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved. + * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved. * * This file is released under the GPL. */ @@ -13,11 +13,13 @@ #include <linux/init.h> #include <linux/wait.h> #include <linux/slab.h> -#include <linux/devfs_fs_kernel.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" /*----------------------------------------------------------------- @@ -34,6 +36,14 @@ struct hash_cell { struct dm_table *new_map; }; +/* + * A dummy definition to make RCU happy. + * struct dm_table should never be dereferenced in this file. + */ +struct dm_table { + int undefined__; +}; + struct vers_iter { size_t param_size; struct dm_target_versions *vers, *old_vers; @@ -47,13 +57,18 @@ struct vers_iter { static struct list_head _name_buckets[NUM_BUCKETS]; static struct list_head _uuid_buckets[NUM_BUCKETS]; -static void dm_hash_remove_all(void); +static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred); /* * 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; @@ -66,14 +81,12 @@ static int dm_hash_init(void) { init_buckets(_name_buckets); init_buckets(_uuid_buckets); - devfs_mk_dir(DM_DIR); return 0; } static void dm_hash_exit(void) { - dm_hash_remove_all(); - devfs_remove(DM_DIR); + dm_hash_remove_all(false, false, false); } /*----------------------------------------------------------------- @@ -101,8 +114,10 @@ static struct hash_cell *__get_name_cell(const char *str) unsigned int h = hash_str(str); list_for_each_entry (hc, _name_buckets + h, name_list) - if (!strcmp(hc->name, str)) + if (!strcmp(hc->name, str)) { + dm_get(hc->md); return hc; + } return NULL; } @@ -113,12 +128,32 @@ static struct hash_cell *__get_uuid_cell(const char *str) unsigned int h = hash_str(str); list_for_each_entry (hc, _uuid_buckets + h, uuid_list) - if (!strcmp(hc->uuid, str)) + if (!strcmp(hc->uuid, str)) { + dm_get(hc->md); return hc; + } return NULL; } +static struct hash_cell *__get_dev_cell(uint64_t dev) +{ + struct mapped_device *md; + struct hash_cell *hc; + + md = dm_get_md(huge_decode_dev(dev)); + if (!md) + return NULL; + + hc = dm_get_mdptr(md); + if (!hc) { + dm_put(md); + return NULL; + } + + return hc; +} + /*----------------------------------------------------------------- * Inserting, removing and renaming a device. *---------------------------------------------------------------*/ @@ -166,31 +201,12 @@ static void free_cell(struct hash_cell *hc) } /* - * devfs stuff. - */ -static int register_with_devfs(struct hash_cell *hc) -{ - struct gendisk *disk = dm_disk(hc->md); - - devfs_mk_bdev(MKDEV(disk->major, disk->first_minor), - S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP, - DM_DIR "/%s", hc->name); - return 0; -} - -static int unregister_with_devfs(struct hash_cell *hc) -{ - devfs_remove(DM_DIR"/%s", hc->name); - return 0; -} - -/* * The kdev_t and uuid of a device can never change once it is * initially inserted. */ static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md) { - struct hash_cell *cell; + struct hash_cell *cell, *hc; /* * Allocate the new cells. @@ -203,21 +219,27 @@ static int dm_hash_insert(const char *name, const char *uuid, struct mapped_devi * Insert the cell into both hash tables. */ down_write(&_hash_lock); - if (__get_name_cell(name)) + 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) { - if (__get_uuid_cell(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)); } - register_with_devfs(cell); 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; @@ -228,98 +250,210 @@ static int dm_hash_insert(const char *name, const char *uuid, struct mapped_devi return -EBUSY; } -static void __hash_remove(struct hash_cell *hc) +static struct dm_table *__hash_remove(struct hash_cell *hc) { struct dm_table *table; + int srcu_idx; /* remove from the dev hash */ list_del(&hc->uuid_list); list_del(&hc->name_list); - unregister_with_devfs(hc); + mutex_lock(&dm_hash_cells_mutex); dm_set_mdptr(hc->md, NULL); + mutex_unlock(&dm_hash_cells_mutex); - table = dm_get_table(hc->md); - if (table) { + table = dm_get_live_table(hc->md, &srcu_idx); + if (table) dm_table_event(table); - dm_table_put(table); - } + dm_put_live_table(hc->md, srcu_idx); - dm_put(hc->md); + table = NULL; if (hc->new_map) - dm_table_put(hc->new_map); + table = hc->new_map; + dm_put(hc->md); free_cell(hc); + + return table; } -static void dm_hash_remove_all(void) +static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred) { - int i; + int i, dev_skipped; struct hash_cell *hc; - struct list_head *tmp, *n; + struct mapped_device *md; + struct dm_table *t; + +retry: + dev_skipped = 0; down_write(&_hash_lock); + for (i = 0; i < NUM_BUCKETS; i++) { - list_for_each_safe (tmp, n, _name_buckets + i) { - hc = list_entry(tmp, struct hash_cell, name_list); - __hash_remove(hc); + list_for_each_entry(hc, _name_buckets + i, name_list) { + md = hc->md; + dm_get(md); + + if (keep_open_devices && + dm_lock_for_deletion(md, mark_deferred, only_deferred)) { + dm_put(md); + dev_skipped++; + continue; + } + + t = __hash_remove(hc); + + up_write(&_hash_lock); + + if (t) { + dm_sync_table(md); + dm_table_destroy(t); + } + dm_put(md); + if (likely(keep_open_devices)) + dm_destroy(md); + else + dm_destroy_immediate(md); + + /* + * Some mapped devices may be using other mapped + * devices, so repeat until we make no further + * progress. If a new mapped device is created + * here it will also get removed. + */ + goto retry; } } + up_write(&_hash_lock); + + if (dev_skipped) + DMWARN("remove_all left %d open device(s)", dev_skipped); } -static int dm_hash_rename(const char *old, const char *new) +/* + * Set the uuid of a hash_cell that isn't already set. + */ +static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid) { - char *new_name, *old_name; + mutex_lock(&dm_hash_cells_mutex); + hc->uuid = new_uuid; + mutex_unlock(&dm_hash_cells_mutex); + + list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid)); +} + +/* + * Changes the name of a hash_cell and returns the old name for + * the caller to free. + */ +static char *__change_cell_name(struct hash_cell *hc, char *new_name) +{ + char *old_name; + + /* + * 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)); + + return old_name; +} + +static struct mapped_device *dm_hash_rename(struct dm_ioctl *param, + const char *new) +{ + char *new_data, *old_name = NULL; struct hash_cell *hc; + struct dm_table *table; + struct mapped_device *md; + unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0; + int srcu_idx; /* * duplicate new. */ - new_name = kstrdup(new, GFP_KERNEL); - if (!new_name) - return -ENOMEM; + new_data = kstrdup(new, GFP_KERNEL); + if (!new_data) + return ERR_PTR(-ENOMEM); down_write(&_hash_lock); /* * Is new free ? */ - hc = __get_name_cell(new); + if (change_uuid) + hc = __get_uuid_cell(new); + else + hc = __get_name_cell(new); + if (hc) { - DMWARN("asked to rename to an already existing name %s -> %s", - old, new); + DMWARN("Unable to change %s on mapped device %s to one that " + "already exists: %s", + change_uuid ? "uuid" : "name", + param->name, new); + dm_put(hc->md); up_write(&_hash_lock); - kfree(new_name); - return -EBUSY; + kfree(new_data); + return ERR_PTR(-EBUSY); } /* * Is there such a device as 'old' ? */ - hc = __get_name_cell(old); + hc = __get_name_cell(param->name); if (!hc) { - DMWARN("asked to rename a non existent device %s -> %s", - old, new); + DMWARN("Unable to rename non-existent device, %s to %s%s", + param->name, change_uuid ? "uuid " : "", new); up_write(&_hash_lock); - kfree(new_name); - return -ENXIO; + kfree(new_data); + return ERR_PTR(-ENXIO); } /* - * rename and move the name cell. + * Does this device already have a uuid? */ - unregister_with_devfs(hc); + 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); + } - list_del(&hc->name_list); - old_name = hc->name; - hc->name = new_name; - list_add(&hc->name_list, _name_buckets + hash_str(new_name)); + if (change_uuid) + __set_cell_uuid(hc, new_data); + else + old_name = __change_cell_name(hc, new_data); - /* rename the device node in devfs */ - register_with_devfs(hc); + /* + * 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 0; + + return md; +} + +void dm_deferred_remove(void) +{ + dm_hash_remove_all(true, false, true); } /*----------------------------------------------------------------- @@ -333,7 +467,7 @@ 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(); + dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false); param->data_size = 0; return 0; } @@ -407,7 +541,7 @@ static int list_devices(struct dm_ioctl *param, size_t param_size) old_nl->next = (uint32_t) ((void *) nl - (void *) old_nl); disk = dm_disk(hc->md); - nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor)); + nl->dev = huge_encode_dev(disk_devt(disk)); nl->next = 0; strcpy(nl->name, hc->name); @@ -425,8 +559,8 @@ 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 += sizeof(tt->version); *needed += ALIGN_MASK; } @@ -493,8 +627,6 @@ static int list_versions(struct dm_ioctl *param, size_t param_size) return 0; } - - static int check_name(const char *name) { if (strchr(name, '/')) { @@ -506,57 +638,99 @@ static int check_name(const char *name) } /* + * 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, 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 int __dev_status(struct mapped_device *md, struct dm_ioctl *param) +static void __dev_status(struct mapped_device *md, struct dm_ioctl *param) { struct gendisk *disk = dm_disk(md); struct dm_table *table; - struct block_device *bdev; + int srcu_idx; param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG | DM_ACTIVE_PRESENT_FLAG); - if (dm_suspended(md)) + if (dm_suspended_md(md)) param->flags |= DM_SUSPEND_FLAG; - param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor)); - - if (!(param->flags & DM_SKIP_BDGET_FLAG)) { - bdev = bdget_disk(disk, 0); - if (!bdev) - return -ENXIO; + if (dm_test_deferred_remove_flag(md)) + param->flags |= DM_DEFERRED_REMOVE; - /* - * 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 = bdev->bd_openers; - bdput(bdev); - } else - param->open_count = -1; + param->dev = huge_encode_dev(disk_devt(disk)); - if (disk->policy) - param->flags |= DM_READONLY_FLAG; + /* + * 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_table(md); + table = dm_get_live_table(md, &srcu_idx); if (table) { - param->flags |= DM_ACTIVE_PRESENT_FLAG; - param->target_count = dm_table_get_num_targets(table); - dm_table_put(table); - } else - param->target_count = 0; + 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); + } - return 0; + 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 dm_ioctl *param, size_t param_size) { - int r; + int r, m = DM_ANY_MINOR; struct mapped_device *md; r = check_name(param->name); @@ -564,66 +738,83 @@ static int dev_create(struct dm_ioctl *param, size_t param_size) return r; if (param->flags & DM_PERSISTENT_DEV_FLAG) - r = dm_create_with_minor(MINOR(huge_decode_dev(param->dev)), &md); - else - r = dm_create(&md); + 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; - r = __dev_status(md, param); + __dev_status(md, param); + dm_put(md); - return r; + return 0; } /* * Always use UUID for lookups if it's present, otherwise use name or dev. */ -static inline struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param) +static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param) { - if (*param->uuid) - return __get_uuid_cell(param->uuid); - else if (*param->name) - return __get_name_cell(param->name); + 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 - return dm_get_mdptr(huge_decode_dev(param->dev)); + param->flags &= ~DM_INACTIVE_PRESENT_FLAG; + + return hc; } -static inline struct mapped_device *find_device(struct dm_ioctl *param) +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) { + if (hc) md = hc->md; - dm_get(md); - - /* - * Sneakily write in both the name and the uuid - * while we have the cell. - */ - strncpy(param->name, hc->name, sizeof(param->name)); - if (hc->uuid) - strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1); - else - param->uuid[0] = '\0'; - - if (hc->new_map) - param->flags |= DM_INACTIVE_PRESENT_FLAG; - else - param->flags &= ~DM_INACTIVE_PRESENT_FLAG; - } up_read(&_hash_lock); return md; @@ -632,19 +823,52 @@ static inline struct mapped_device *find_device(struct dm_ioctl *param) static int dev_remove(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) { - DMWARN("device doesn't appear to be in the dev hash table."); + DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); up_write(&_hash_lock); return -ENXIO; } - __hash_remove(hc); + 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); - param->data_size = 0; + + 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; } @@ -664,59 +888,127 @@ static int invalid_str(char *str, void *end) static int dev_rename(struct dm_ioctl *param, size_t param_size) { int r; - char *new_name = (char *) param + param->data_start; + char *new_data = (char *) param + param->data_start; + struct mapped_device *md; + unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0; - if (new_name < (char *) (param + 1) || - invalid_str(new_name, (void *) param + param_size)) { - DMWARN("Invalid new logical volume name supplied."); + 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; } - r = check_name(new_name); - if (r) - return r; + 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 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; - return dm_hash_rename(param->name, new_name); + +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 (!dm_suspended(md)) - r = dm_suspend(md); + 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 (!r) - r = __dev_status(md, param); + 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; + 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."); + DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); up_write(&_hash_lock); return -ENXIO; } md = hc->md; - dm_get(md); new_map = hc->new_map; hc->new_map = NULL; @@ -727,29 +1019,42 @@ static int do_resume(struct dm_ioctl *param) /* Do we need to load a new map ? */ if (new_map) { /* Suspend if it isn't already suspended */ - if (!dm_suspended(md)) - dm_suspend(md); - - r = dm_swap_table(md, new_map); - if (r) { + 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); - dm_table_put(new_map); - return r; + 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); - - dm_table_put(new_map); } - if (dm_suspended(md)) + 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) - r = __dev_status(md, param); + __dev_status(md, param); dm_put(md); return r; @@ -773,16 +1078,16 @@ static int dev_suspend(struct dm_ioctl *param, size_t param_size) */ 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); + __dev_status(md, param); dm_put(md); - return r; + + return 0; } /* @@ -796,6 +1101,7 @@ static void retrieve_status(struct dm_table *table, 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); @@ -808,6 +1114,7 @@ static void retrieve_status(struct dm_table *table, 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)) { @@ -832,14 +1139,19 @@ static void retrieve_status(struct dm_table *table, /* 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; - } + 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'; - outptr += strlen(outptr) + 1; + 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); @@ -857,9 +1169,10 @@ static void retrieve_status(struct dm_table *table, */ static int dev_wait(struct dm_ioctl *param, size_t param_size) { - int r; + int r = 0; struct mapped_device *md; struct dm_table *table; + int srcu_idx; md = find_device(param); if (!md) @@ -878,24 +1191,22 @@ static int dev_wait(struct dm_ioctl *param, size_t param_size) * 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; + __dev_status(md, param); - table = dm_get_table(md); - if (table) { + table = dm_get_live_or_inactive_table(md, param, &srcu_idx); + if (table) retrieve_status(table, param, param_size); - dm_table_put(table); - } + dm_put_live_table(md, srcu_idx); - out: +out: dm_put(md); + return r; } -static inline int get_mode(struct dm_ioctl *param) +static inline fmode_t get_mode(struct dm_ioctl *param) { - int mode = FMODE_READ | FMODE_WRITE; + fmode_t mode = FMODE_READ | FMODE_WRITE; if (param->flags & DM_READONLY_FLAG) mode = FMODE_READ; @@ -957,60 +1268,119 @@ static int table_load(struct dm_ioctl *param, size_t param_size) { int r; struct hash_cell *hc; - struct dm_table *t; + 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); + r = dm_table_create(&t, get_mode(param), param->target_count, md); if (r) - return 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))) { + 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)); + else if (dm_get_md_type(md) != dm_table_get_type(t)) { + DMWARN("can't change device type after initial table load."); + r = -EINVAL; + goto err_unlock_md_type; + } + + /* setup md->queue to reflect md's type (may block) */ + r = dm_setup_md_queue(md); if (r) { - dm_table_put(t); - return r; + DMWARN("unable to set up device queue for new table."); + goto err_unlock_md_type; } + dm_unlock_md_type(md); + /* stage inactive table */ down_write(&_hash_lock); - hc = __find_device_hash_cell(param); - if (!hc) { - DMWARN("device doesn't appear to be in the dev hash table."); + hc = dm_get_mdptr(md); + if (!hc || hc->md != md) { + DMWARN("device has been removed from the dev hash table."); up_write(&_hash_lock); - return -ENXIO; + r = -ENXIO; + goto err_destroy_table; } if (hc->new_map) - dm_table_put(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); - r = __dev_status(hc->md, param); - up_write(&_hash_lock); return r; } static int table_clear(struct dm_ioctl *param, size_t param_size) { - int r; struct hash_cell *hc; + struct mapped_device *md; + struct dm_table *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."); + DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); up_write(&_hash_lock); return -ENXIO; } if (hc->new_map) { - dm_table_put(hc->new_map); + old_map = hc->new_map; hc->new_map = NULL; } param->flags &= ~DM_INACTIVE_PRESENT_FLAG; - r = __dev_status(hc->md, param); + __dev_status(hc->md, param); + md = hc->md; up_write(&_hash_lock); - return r; + if (old_map) { + dm_sync_table(md); + dm_table_destroy(old_map); + } + dm_put(md); + + return 0; } /* @@ -1022,7 +1392,7 @@ static void retrieve_deps(struct dm_table *table, unsigned int count = 0; struct list_head *tmp; size_t len, needed; - struct dm_dev *dd; + struct dm_dev_internal *dd; struct dm_target_deps *deps; deps = get_result_buffer(param, param_size, &len); @@ -1048,34 +1418,31 @@ static void retrieve_deps(struct dm_table *table, deps->count = count; count = 0; list_for_each_entry (dd, dm_table_get_devices(table), list) - deps->dev[count++] = huge_encode_dev(dd->bdev->bd_dev); + 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; + int srcu_idx; md = find_device(param); if (!md) return -ENXIO; - r = __dev_status(md, param); - if (r) - goto out; + __dev_status(md, param); - table = dm_get_table(md); - if (table) { + table = dm_get_live_or_inactive_table(md, param, &srcu_idx); + if (table) retrieve_deps(table, param, param_size); - dm_table_put(table); - } + dm_put_live_table(md, srcu_idx); - out: dm_put(md); - return r; + + return 0; } /* @@ -1084,27 +1451,54 @@ static int table_deps(struct dm_ioctl *param, size_t param_size) */ static int table_status(struct dm_ioctl *param, size_t param_size) { - int r; struct mapped_device *md; struct dm_table *table; + int srcu_idx; md = find_device(param); if (!md) return -ENXIO; - r = __dev_status(md, param); - if (r) - goto out; + __dev_status(md, param); - table = dm_get_table(md); - if (table) { + table = dm_get_live_or_inactive_table(md, param, &srcu_idx); + if (table) retrieve_status(table, param, param_size); - dm_table_put(table); - } + dm_put_live_table(md, srcu_idx); - out: dm_put(md); - return r; + + 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; } /* @@ -1118,16 +1512,15 @@ static int target_message(struct dm_ioctl *param, size_t param_size) 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; - r = __dev_status(md, param); - if (r) - goto out; - - if (tmsg < (struct dm_target_msg *) (param + 1) || + if (tmsg < (struct dm_target_msg *) param->data || invalid_str(tmsg->message, (void *) param + param_size)) { DMWARN("Invalid target message parameters."); r = -EINVAL; @@ -1140,18 +1533,29 @@ static int target_message(struct dm_ioctl *param, size_t param_size) goto out; } - table = dm_get_table(md); - if (!table) + if (!argc) { + DMWARN("Empty message received."); + goto out_argv; + } + + r = message_for_md(md, argc, argv, result, maxlen); + if (r <= 1) goto out_argv; - if (tmsg->sector >= dm_table_get_size(table)) { - DMWARN("Target message sector outside device."); - r = -EINVAL; + 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->type->message) + 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"); @@ -1159,47 +1563,72 @@ static int target_message(struct dm_ioctl *param, size_t param_size) } out_table: - dm_table_put(table); + dm_put_live_table(md, srcu_idx); out_argv: kfree(argv); out: - param->data_size = 0; + 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 + /*----------------------------------------------------------------- * Implementation of open/close/ioctl on the special char * device. *---------------------------------------------------------------*/ -static ioctl_fn lookup_ioctl(unsigned int cmd) +static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags) { static struct { int cmd; + int flags; 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_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */ + {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS, remove_all}, + {DM_LIST_DEVICES_CMD, 0, list_devices}, + + {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_create}, + {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_remove}, + {DM_DEV_RENAME_CMD, 0, 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} }; - return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn; + if (unlikely(cmd >= ARRAY_SIZE(_ioctls))) + return NULL; + + *ioctl_flags = _ioctls[cmd].flags; + return _ioctls[cmd].fn; } /* @@ -1236,38 +1665,103 @@ static int check_version(unsigned int cmd, struct dm_ioctl __user *user) return r; } -static void free_params(struct dm_ioctl *param) +#define DM_PARAMS_KMALLOC 0x0001 /* Params alloced with kmalloc */ +#define DM_PARAMS_VMALLOC 0x0002 /* Params alloced with vmalloc */ +#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) { - vfree(param); + if (param_flags & DM_WIPE_BUFFER) + memset(param, 0, param_size); + + if (param_flags & DM_PARAMS_KMALLOC) + kfree(param); + if (param_flags & DM_PARAMS_VMALLOC) + vfree(param); } -static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **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 tmp, *dmi; + struct dm_ioctl *dmi; + int secure_data; + const size_t minimum_data_size = sizeof(*param_kernel) - sizeof(param_kernel->data); - if (copy_from_user(&tmp, user, sizeof(tmp))) + if (copy_from_user(param_kernel, user, minimum_data_size)) return -EFAULT; - if (tmp.data_size < sizeof(tmp)) + if (param_kernel->data_size < minimum_data_size) return -EINVAL; - dmi = (struct dm_ioctl *) vmalloc(tmp.data_size); - if (!dmi) + 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; + } + + /* + * Try to avoid low memory issues when a device is suspended. + * Use kmalloc() rather than vmalloc() when we can. + */ + dmi = NULL; + if (param_kernel->data_size <= KMALLOC_MAX_SIZE) { + dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); + if (dmi) + *param_flags |= DM_PARAMS_KMALLOC; + } + + if (!dmi) { + unsigned noio_flag; + noio_flag = memalloc_noio_save(); + dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL); + memalloc_noio_restore(noio_flag); + if (dmi) + *param_flags |= DM_PARAMS_VMALLOC; + } + + if (!dmi) { + if (secure_data && clear_user(user, param_kernel->data_size)) + return -EFAULT; return -ENOMEM; + } - if (copy_from_user(dmi, user, tmp.data_size)) { - vfree(dmi); - return -EFAULT; + if (copy_from_user(dmi, user, param_kernel->data_size)) + goto bad; + +data_copied: + /* + * Abort if something changed the ioctl data while it was being copied. + */ + if (dmi->data_size != param_kernel->data_size) { + DMERR("rejecting ioctl: data size modified while processing parameters"); + goto bad; } + /* 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 || @@ -1292,15 +1786,16 @@ static int validate_params(uint cmd, struct dm_ioctl *param) return 0; } -static int ctl_ioctl(struct inode *inode, struct file *file, - uint command, ulong u) +static int ctl_ioctl(uint command, struct dm_ioctl __user *user) { int r = 0; + int ioctl_flags; + int param_flags; unsigned int cmd; - struct dm_ioctl *param; - struct dm_ioctl __user *user = (struct dm_ioctl __user *) u; + struct dm_ioctl *uninitialized_var(param); ioctl_fn fn = NULL; - size_t param_size; + size_t input_param_size; + struct dm_ioctl param_kernel; /* only root can play with this */ if (!capable(CAP_SYS_ADMIN)) @@ -1325,40 +1820,31 @@ static int ctl_ioctl(struct inode *inode, struct file *file, if (cmd == DM_VERSION_CMD) return 0; - fn = lookup_ioctl(cmd); + fn = lookup_ioctl(cmd, &ioctl_flags); if (!fn) { DMWARN("dm_ctl_ioctl: unknown command 0x%x", command); return -ENOTTY; } /* - * Trying to avoid low memory issues when a device is - * suspended. - */ - current->flags |= PF_MEMALLOC; - - /* * Copy the parameters into kernel space. */ - r = copy_params(user, ¶m); - if (r) { - current->flags &= ~PF_MEMALLOC; - return r; - } + r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags); - /* - * FIXME: eventually we will remove the PF_MEMALLOC flag - * here. However the tools still do nasty things like - * 'load' while a device is suspended. - */ + if (r) + return r; + input_param_size = param->data_size; r = validate_params(cmd, param); if (r) goto out; - param_size = param->data_size; param->data_size = sizeof(*param); - r = fn(param, param_size); + r = fn(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); /* * Copy the results back to userland. @@ -1366,24 +1852,43 @@ static int ctl_ioctl(struct inode *inode, struct file *file, if (!r && copy_to_user(user, param, param->data_size)) r = -EFAULT; - out: - free_params(param); - current->flags &= ~PF_MEMALLOC; +out: + free_params(param, input_param_size, param_flags); return r; } -static struct file_operations _ctl_fops = { - .ioctl = ctl_ioctl, +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 = { + .open = nonseekable_open, + .unlocked_ioctl = dm_ctl_ioctl, + .compat_ioctl = dm_compat_ctl_ioctl, .owner = THIS_MODULE, + .llseek = noop_llseek, }; static struct miscdevice _dm_misc = { - .minor = MISC_DYNAMIC_MINOR, + .minor = MAPPER_CTRL_MINOR, .name = DM_NAME, - .devfs_name = "mapper/control", + .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. */ @@ -1415,3 +1920,35 @@ void dm_interface_exit(void) 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; +} |