diff options
Diffstat (limited to 'drivers/md/dm-ioctl.c')
| -rw-r--r-- | drivers/md/dm-ioctl.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index a6794293158..d19854c9818 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -56,6 +56,11 @@ static void dm_hash_remove_all(int keep_open_devices); */ 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; @@ -206,7 +211,9 @@ static int dm_hash_insert(const char *name, const char *uuid, struct mapped_devi 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; @@ -224,7 +231,9 @@ static void __hash_remove(struct hash_cell *hc) /* 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_table(hc->md); if (table) { @@ -321,7 +330,9 @@ static int dm_hash_rename(uint32_t cookie, const char *old, const char *new) */ 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)); /* @@ -1582,8 +1593,7 @@ int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid) if (!md) return -ENXIO; - dm_get(md); - down_read(&_hash_lock); + mutex_lock(&dm_hash_cells_mutex); hc = dm_get_mdptr(md); if (!hc || hc->md != md) { r = -ENXIO; @@ -1596,8 +1606,7 @@ int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid) strcpy(uuid, hc->uuid ? : ""); out: - up_read(&_hash_lock); - dm_put(md); + mutex_unlock(&dm_hash_cells_mutex); return r; } |