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path: root/drivers/md/dm-ioctl.c
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Diffstat (limited to 'drivers/md/dm-ioctl.c')
-rw-r--r--drivers/md/dm-ioctl.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index a67942931582..d19854c98184 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;
}