[PATCH 2/2] null_blk: fix ida error handling in null_add_dev()

[Dan Carpenter <dan.carpenter@oracle.com>]

There needs to be some error checking if ida_simple_get() fails.
Also call ida_free() if there are errors later.

Fixes: 94bc02e30fb8 ("nullb: use ida to manage index")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 drivers/block/null_blk/main.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 016ec3a2f98f..3d334d46d5f6 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -2074,8 +2074,13 @@ static int null_add_dev(struct nullb_device *dev)
 	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, nullb->q);
 
 	mutex_lock(&lock);
-	nullb->index = ida_simple_get(&nullb_indexes, 0, 0, GFP_KERNEL);
-	dev->index = nullb->index;
+	rv = ida_simple_get(&nullb_indexes, 0, 0, GFP_KERNEL);
+	if (rv < 0) {
+		mutex_unlock(&lock);
+		goto out_cleanup_zone;
+	}
+	nullb->index = rv;
+	dev->index = rv;
 	mutex_unlock(&lock);
 
 	blk_queue_logical_block_size(nullb->q, dev->blocksize);
@@ -2101,7 +2106,7 @@ static int null_add_dev(struct nullb_device *dev)
 
 	rv = null_gendisk_register(nullb);
 	if (rv)
-		goto out_cleanup_zone;
+		goto out_ida_free;
 
 	mutex_lock(&lock);
 	list_add_tail(&nullb->list, &nullb_list);
@@ -2110,6 +2115,9 @@ static int null_add_dev(struct nullb_device *dev)
 	pr_info("disk %s created\n", nullb->disk_name);
 
 	return 0;
+
+out_ida_free:
+	ida_free(&nullb_indexes, nullb->index);
 out_cleanup_zone:
 	null_free_zoned_dev(dev);
 out_cleanup_disk:
-- 
2.35.1