Merge tag 'for-4.15/dm' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mappe...

[linux] / drivers / md / dm.c

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 8aaffa1..de17b71 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -24,6 +24,7 @@
 #include <linux/delay.h>
 #include <linux/wait.h>
 #include <linux/pr.h>
+#include <linux/refcount.h>
 
 #define DM_MSG_PREFIX "core"
 
@@ -98,7 +99,7 @@ struct dm_md_mempools {
 
 struct table_device {
        struct list_head list;
-       atomic_t count;
+       refcount_t count;
        struct dm_dev dm_dev;
 };
 
@@ -685,10 +686,11 @@ int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
 
                format_dev_t(td->dm_dev.name, dev);
 
-               atomic_set(&td->count, 0);
+               refcount_set(&td->count, 1);
                list_add(&td->list, &md->table_devices);
+       } else {
+               refcount_inc(&td->count);
        }
-       atomic_inc(&td->count);
        mutex_unlock(&md->table_devices_lock);
 
        *result = &td->dm_dev;
@@ -701,7 +703,7 @@ void dm_put_table_device(struct mapped_device *md, struct dm_dev *d)
        struct table_device *td = container_of(d, struct table_device, dm_dev);
 
        mutex_lock(&md->table_devices_lock);
-       if (atomic_dec_and_test(&td->count)) {
+       if (refcount_dec_and_test(&td->count)) {
                close_table_device(td, md);
                list_del(&td->list);
                kfree(td);
@@ -718,7 +720,7 @@ static void free_table_devices(struct list_head *devices)
                struct table_device *td = list_entry(tmp, struct table_device, list);
 
                DMWARN("dm_destroy: %s still exists with %d references",
-                      td->dm_dev.name, atomic_read(&td->count));
+                      td->dm_dev.name, refcount_read(&td->count));
                kfree(td);
        }
 }
@@ -1618,17 +1620,6 @@ static void dm_wq_work(struct work_struct *work);
 
 void dm_init_md_queue(struct mapped_device *md)
 {
-       /*
-        * Request-based dm devices cannot be stacked on top of bio-based dm
-        * devices.  The type of this dm device may not have been decided yet.
-        * The type is decided at the first table loading time.
-        * To prevent problematic device stacking, clear the queue flag
-        * for request stacking support until then.
-        *
-        * This queue is new, so no concurrency on the queue_flags.
-        */
-       queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue);
-
        /*
         * Initialize data that will only be used by a non-blk-mq DM queue
         * - must do so here (in alloc_dev callchain) before queue is used
@@ -1695,7 +1686,7 @@ static struct mapped_device *alloc_dev(int minor)
        struct mapped_device *md;
        void *old_md;
 
-       md = kzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
+       md = kvzalloc_node(sizeof(*md), GFP_KERNEL, numa_node_id);
        if (!md) {
                DMWARN("unable to allocate device, out of memory.");
                return NULL;
@@ -1795,7 +1786,7 @@ bad_io_barrier:
 bad_minor:
        module_put(THIS_MODULE);
 bad_module_get:
-       kfree(md);
+       kvfree(md);
        return NULL;
 }
 
@@ -1814,7 +1805,7 @@ static void free_dev(struct mapped_device *md)
        free_minor(minor);
 
        module_put(THIS_MODULE);
-       kfree(md);
+       kvfree(md);
 }
 
 static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
@@ -2072,17 +2063,12 @@ struct mapped_device *dm_get_md(dev_t dev)
        spin_lock(&_minor_lock);
 
        md = idr_find(&_minor_idr, minor);
-       if (md) {
-               if ((md == MINOR_ALLOCED ||
-                    (MINOR(disk_devt(dm_disk(md))) != minor) ||
-                    dm_deleting_md(md) ||
-                    test_bit(DMF_FREEING, &md->flags))) {
-                       md = NULL;
-                       goto out;
-               }
-               dm_get(md);
+       if (!md || md == MINOR_ALLOCED || (MINOR(disk_devt(dm_disk(md))) != minor) ||
+           test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
+               md = NULL;
+               goto out;
        }
-
+       dm_get(md);
 out:
        spin_unlock(&_minor_lock);
 
@@ -2709,11 +2695,15 @@ struct mapped_device *dm_get_from_kobject(struct kobject *kobj)
 
        md = container_of(kobj, struct mapped_device, kobj_holder.kobj);
 
-       if (test_bit(DMF_FREEING, &md->flags) ||
-           dm_deleting_md(md))
-               return NULL;
-
+       spin_lock(&_minor_lock);
+       if (test_bit(DMF_FREEING, &md->flags) || dm_deleting_md(md)) {
+               md = NULL;
+               goto out;
+       }
        dm_get(md);
+out:
+       spin_unlock(&_minor_lock);
+
        return md;
 }