nvdimm/blk: avoid calling del_gendisk() on early failures

If nd_integrity_init() fails we'd get del_gendisk() called,
but that's not correct as we should only call that if we're
done with device_add_disk(). Fix this by providing unwinding
prior to the devm call being registered and moving the devm
registration to the very end.

This should fix calling del_gendisk() if nd_integrity_init()
fails. I only spotted this issue through code inspection. It
does not fix any real world bug.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211103230437.1639990-4-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
index b6c6866..4eef679 100644 (file)
--- a/drivers/nvdimm/blk.c
+++ b/drivers/nvdimm/blk.c
@@ -239,6 +239,7 @@ static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
        resource_size_t available_disk_size;
        struct gendisk *disk;
        u64 internal_nlba;
+       int rc;
 
        internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk));
        available_disk_size = internal_nlba * nsblk_sector_size(nsblk);
@@ -255,20 +256,26 @@ static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
        blk_queue_logical_block_size(disk->queue, nsblk_sector_size(nsblk));
        blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
 
-       if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk))
-               return -ENOMEM;
-
        if (nsblk_meta_size(nsblk)) {
-               int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));
+               rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));
 
                if (rc)
-                       return rc;
+                       goto out_before_devm_err;
        }
 
        set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
        device_add_disk(dev, disk, NULL);
+
+       /* nd_blk_release_disk() is called if this fails */
+       if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk))
+               return -ENOMEM;
+
        nvdimm_check_and_set_ro(disk);
        return 0;
+
+out_before_devm_err:
+       blk_cleanup_disk(disk);
+       return rc;
 }
 
 static int nd_blk_probe(struct device *dev)