3 files changed, 93 insertions, 41 deletions

diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index b210fdb31c98..b1fc28f63882 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -99,6 +99,8 @@ struct ubiblock {
 
 /* Linked list of all ubiblock instances */
 static LIST_HEAD(ubiblock_devices);
+static DEFINE_IDR(ubiblock_minor_idr);
+/* Protects ubiblock_devices and ubiblock_minor_idr */
 static DEFINE_MUTEX(devices_mutex);
 static int ubiblock_major;
 
@@ -351,8 +353,6 @@ static const struct blk_mq_ops ubiblock_mq_ops = {
 	.init_request	= ubiblock_init_request,
 };
 
-static DEFINE_IDR(ubiblock_minor_idr);
-
 int ubiblock_create(struct ubi_volume_info *vi)
 {
 	struct ubiblock *dev;
@@ -365,14 +365,15 @@ int ubiblock_create(struct ubi_volume_info *vi)
 	/* Check that the volume isn't already handled */
 	mutex_lock(&devices_mutex);
 	if (find_dev_nolock(vi->ubi_num, vi->vol_id)) {
-		mutex_unlock(&devices_mutex);
-		return -EEXIST;
+		ret = -EEXIST;
+		goto out_unlock;
 	}
-	mutex_unlock(&devices_mutex);
 
 	dev = kzalloc(sizeof(struct ubiblock), GFP_KERNEL);
-	if (!dev)
-		return -ENOMEM;
+	if (!dev) {
+		ret = -ENOMEM;
+		goto out_unlock;
+	}
 
 	mutex_init(&dev->dev_mutex);
 
@@ -437,14 +438,13 @@ int ubiblock_create(struct ubi_volume_info *vi)
 		goto out_free_queue;
 	}
 
-	mutex_lock(&devices_mutex);
 	list_add_tail(&dev->list, &ubiblock_devices);
-	mutex_unlock(&devices_mutex);
 
 	/* Must be the last step: anyone can call file ops from now on */
 	add_disk(dev->gd);
 	dev_info(disk_to_dev(dev->gd), "created from ubi%d:%d(%s)",
 		 dev->ubi_num, dev->vol_id, vi->name);
+	mutex_unlock(&devices_mutex);
 	return 0;
 
 out_free_queue:
@@ -457,6 +457,8 @@ out_put_disk:
 	put_disk(dev->gd);
 out_free_dev:
 	kfree(dev);
+out_unlock:
+	mutex_unlock(&devices_mutex);
 
 	return ret;
 }
@@ -478,30 +480,36 @@ static void ubiblock_cleanup(struct ubiblock *dev)
 int ubiblock_remove(struct ubi_volume_info *vi)
 {
 	struct ubiblock *dev;
+	int ret;
 
 	mutex_lock(&devices_mutex);
 	dev = find_dev_nolock(vi->ubi_num, vi->vol_id);
 	if (!dev) {
-		mutex_unlock(&devices_mutex);
-		return -ENODEV;
+		ret = -ENODEV;
+		goto out_unlock;
 	}
 
 	/* Found a device, let's lock it so we can check if it's busy */
 	mutex_lock(&dev->dev_mutex);
 	if (dev->refcnt > 0) {
-		mutex_unlock(&dev->dev_mutex);
-		mutex_unlock(&devices_mutex);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto out_unlock_dev;
 	}
 
 	/* Remove from device list */
 	list_del(&dev->list);
-	mutex_unlock(&devices_mutex);
-
 	ubiblock_cleanup(dev);
 	mutex_unlock(&dev->dev_mutex);
+	mutex_unlock(&devices_mutex);
+
 	kfree(dev);
 	return 0;
+
+out_unlock_dev:
+	mutex_unlock(&dev->dev_mutex);
+out_unlock:
+	mutex_unlock(&devices_mutex);
+	return ret;
 }
 
 static int ubiblock_resize(struct ubi_volume_info *vi)
@@ -630,6 +638,7 @@ static void ubiblock_remove_all(void)
 	struct ubiblock *next;
 	struct ubiblock *dev;
 
+	mutex_lock(&devices_mutex);
 	list_for_each_entry_safe(dev, next, &ubiblock_devices, list) {
 		/* The module is being forcefully removed */
 		WARN_ON(dev->desc);
@@ -638,6 +647,7 @@ static void ubiblock_remove_all(void)
 		ubiblock_cleanup(dev);
 		kfree(dev);
 	}
+	mutex_unlock(&devices_mutex);
 }
 
 int __init ubiblock_init(void)
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index 85237cf661f9..3fd8d7ff7a02 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -270,6 +270,12 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
 			vol->last_eb_bytes = vol->usable_leb_size;
 	}
 
+	/* Make volume "available" before it becomes accessible via sysfs */
+	spin_lock(&ubi->volumes_lock);
+	ubi->volumes[vol_id] = vol;
+	ubi->vol_count += 1;
+	spin_unlock(&ubi->volumes_lock);
+
 	/* Register character device for the volume */
 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
 	vol->cdev.owner = THIS_MODULE;
@@ -298,11 +304,6 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
 	if (err)
 		goto out_sysfs;
 
-	spin_lock(&ubi->volumes_lock);
-	ubi->volumes[vol_id] = vol;
-	ubi->vol_count += 1;
-	spin_unlock(&ubi->volumes_lock);
-
 	ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED);
 	self_check_volumes(ubi);
 	return err;
@@ -315,6 +316,10 @@ out_sysfs:
 	 */
 	cdev_device_del(&vol->cdev, &vol->dev);
 out_mapping:
+	spin_lock(&ubi->volumes_lock);
+	ubi->volumes[vol_id] = NULL;
+	ubi->vol_count -= 1;
+	spin_unlock(&ubi->volumes_lock);
 	ubi_eba_destroy_table(eba_tbl);
 out_acc:
 	spin_lock(&ubi->volumes_lock);
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index b5b8cd6f481c..668b46202507 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -1529,6 +1529,46 @@ static void shutdown_work(struct ubi_device *ubi)
 }
 
 /**
+ * erase_aeb - erase a PEB given in UBI attach info PEB
+ * @ubi: UBI device description object
+ * @aeb: UBI attach info PEB
+ * @sync: If true, erase synchronously. Otherwise schedule for erasure
+ */
+static int erase_aeb(struct ubi_device *ubi, struct ubi_ainf_peb *aeb, bool sync)
+{
+	struct ubi_wl_entry *e;
+	int err;
+
+	e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
+	if (!e)
+		return -ENOMEM;
+
+	e->pnum = aeb->pnum;
+	e->ec = aeb->ec;
+	ubi->lookuptbl[e->pnum] = e;
+
+	if (sync) {
+		err = sync_erase(ubi, e, false);
+		if (err)
+			goto out_free;
+
+		wl_tree_add(e, &ubi->free);
+		ubi->free_count++;
+	} else {
+		err = schedule_erase(ubi, e, aeb->vol_id, aeb->lnum, 0, false);
+		if (err)
+			goto out_free;
+	}
+
+	return 0;
+
+out_free:
+	wl_entry_destroy(ubi, e);
+
+	return err;
+}
+
+/**
  * ubi_wl_init - initialize the WL sub-system using attaching information.
  * @ubi: UBI device description object
  * @ai: attaching information
@@ -1566,18 +1606,10 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 	list_for_each_entry_safe(aeb, tmp, &ai->erase, u.list) {
 		cond_resched();
 
-		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
-		if (!e)
+		err = erase_aeb(ubi, aeb, false);
+		if (err)
 			goto out_free;
 
-		e->pnum = aeb->pnum;
-		e->ec = aeb->ec;
-		ubi->lookuptbl[e->pnum] = e;
-		if (schedule_erase(ubi, e, aeb->vol_id, aeb->lnum, 0, false)) {
-			wl_entry_destroy(ubi, e);
-			goto out_free;
-		}
-
 		found_pebs++;
 	}
 
@@ -1635,6 +1667,8 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 			ubi_assert(!ubi->lookuptbl[e->pnum]);
 			ubi->lookuptbl[e->pnum] = e;
 		} else {
+			bool sync = false;
+
 			/*
 			 * Usually old Fastmap PEBs are scheduled for erasure
 			 * and we don't have to care about them but if we face
@@ -1644,18 +1678,21 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
 			if (ubi->lookuptbl[aeb->pnum])
 				continue;
 
-			e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
-			if (!e)
-				goto out_free;
+			/*
+			 * The fastmap update code might not find a free PEB for
+			 * writing the fastmap anchor to and then reuses the
+			 * current fastmap anchor PEB. When this PEB gets erased
+			 * and a power cut happens before it is written again we
+			 * must make sure that the fastmap attach code doesn't
+			 * find any outdated fastmap anchors, hence we erase the
+			 * outdated fastmap anchor PEBs synchronously here.
+			 */
+			if (aeb->vol_id == UBI_FM_SB_VOLUME_ID)
+				sync = true;
 
-			e->pnum = aeb->pnum;
-			e->ec = aeb->ec;
-			ubi_assert(!ubi->lookuptbl[e->pnum]);
-			ubi->lookuptbl[e->pnum] = e;
-			if (schedule_erase(ubi, e, aeb->vol_id, aeb->lnum, 0, false)) {
-				wl_entry_destroy(ubi, e);
+			err = erase_aeb(ubi, aeb, sync);
+			if (err)
 				goto out_free;
-			}
 		}
 
 		found_pebs++;