[xiang:erofs/initrd-fsdax 2/3] drivers/block/brd.c:466 brd_alloc() warn: missing error code 'err'

From: Dan Carpenter
Date: Mon Jun 06 2022 - 09:56:57 EST

tree: https://git.kernel.org/pub/scm/linux/kernel/git/xiang/linux.git erofs/initrd-fsdax
head: e04a723ce39c31ea57edfbfd70c867a2025910e3
commit: a610c807a6b52cbce515911dba9b9cc316a6c117 [2/3] brd: support FSDAX
config: x86_64-rhel-8.3-kselftests (https://download.01.org/0day-ci/archive/20220606/202206062100.MJhGyCcE-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-1) 11.3.0

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

smatch warnings:
drivers/block/brd.c:466 brd_alloc() warn: missing error code 'err'

vim +/err +466 drivers/block/brd.c

7f9b348cb5e942 Christoph Hellwig 2021-05-21 407 static int brd_alloc(int i)
9db5579be4bb53 Nicholas Piggin 2008-02-08 408 {
9db5579be4bb53 Nicholas Piggin 2008-02-08 409 struct brd_device *brd;
9db5579be4bb53 Nicholas Piggin 2008-02-08 410 struct gendisk *disk;
f4be591f1436af Calvin Owens 2021-04-16 411 char buf[DISK_NAME_LEN];
e1528830bd4ebf Luis Chamberlain 2021-10-15 412 int err = -ENOMEM;
9db5579be4bb53 Nicholas Piggin 2008-02-08 413
00358933f66c44 Tetsuo Handa 2022-01-06 414 list_for_each_entry(brd, &brd_devices, brd_list)
00358933f66c44 Tetsuo Handa 2022-01-06 415 if (brd->brd_number == i)
f7bf35862477d6 Tetsuo Handa 2021-09-07 416 return -EEXIST;
9db5579be4bb53 Nicholas Piggin 2008-02-08 417 brd = kzalloc(sizeof(*brd), GFP_KERNEL);
00358933f66c44 Tetsuo Handa 2022-01-06 418 if (!brd)
7f9b348cb5e942 Christoph Hellwig 2021-05-21 419 return -ENOMEM;
9db5579be4bb53 Nicholas Piggin 2008-02-08 420 brd->brd_number = i;
f7bf35862477d6 Tetsuo Handa 2021-09-07 421 list_add_tail(&brd->brd_list, &brd_devices);
f7bf35862477d6 Tetsuo Handa 2021-09-07 422
9db5579be4bb53 Nicholas Piggin 2008-02-08 423 spin_lock_init(&brd->brd_lock);
9db5579be4bb53 Nicholas Piggin 2008-02-08 424 INIT_RADIX_TREE(&brd->brd_pages, GFP_ATOMIC);
9db5579be4bb53 Nicholas Piggin 2008-02-08 425
f4be591f1436af Calvin Owens 2021-04-16 426 snprintf(buf, DISK_NAME_LEN, "ram%d", i);
f4be591f1436af Calvin Owens 2021-04-16 427 if (!IS_ERR_OR_NULL(brd_debugfs_dir))
f4be591f1436af Calvin Owens 2021-04-16 428 debugfs_create_u64(buf, 0444, brd_debugfs_dir,
f4be591f1436af Calvin Owens 2021-04-16 429 &brd->brd_nr_pages);
f4be591f1436af Calvin Owens 2021-04-16 430
7f9b348cb5e942 Christoph Hellwig 2021-05-21 431 disk = brd->brd_disk = blk_alloc_disk(NUMA_NO_NODE);
9db5579be4bb53 Nicholas Piggin 2008-02-08 432 if (!disk)
7f9b348cb5e942 Christoph Hellwig 2021-05-21 433 goto out_free_dev;
7f9b348cb5e942 Christoph Hellwig 2021-05-21 434
9db5579be4bb53 Nicholas Piggin 2008-02-08 435 disk->major = RAMDISK_MAJOR;
937af5ecd0591e Boaz Harrosh 2015-01-07 436 disk->first_minor = i * max_part;
7f9b348cb5e942 Christoph Hellwig 2021-05-21 437 disk->minors = max_part;
9db5579be4bb53 Nicholas Piggin 2008-02-08 438 disk->fops = &brd_fops;
9db5579be4bb53 Nicholas Piggin 2008-02-08 439 disk->private_data = brd;
f4be591f1436af Calvin Owens 2021-04-16 440 strlcpy(disk->disk_name, buf, DISK_NAME_LEN);
9db5579be4bb53 Nicholas Piggin 2008-02-08 441 set_capacity(disk, rd_size * 2);
9db5579be4bb53 Nicholas Piggin 2008-02-08 442
7f9b348cb5e942 Christoph Hellwig 2021-05-21 443 /*
7f9b348cb5e942 Christoph Hellwig 2021-05-21 444 * This is so fdisk will align partitions on 4k, because of
7f9b348cb5e942 Christoph Hellwig 2021-05-21 445 * direct_access API needing 4k alignment, returning a PFN
7f9b348cb5e942 Christoph Hellwig 2021-05-21 446 * (This is only a problem on very small devices <= 4M,
7f9b348cb5e942 Christoph Hellwig 2021-05-21 447 * otherwise fdisk will align on 1M. Regardless this call
7f9b348cb5e942 Christoph Hellwig 2021-05-21 448 * is harmless)
7f9b348cb5e942 Christoph Hellwig 2021-05-21 449 */
7f9b348cb5e942 Christoph Hellwig 2021-05-21 450 blk_queue_physical_block_size(disk->queue, PAGE_SIZE);
7f9b348cb5e942 Christoph Hellwig 2021-05-21 451
316ba5736c9caa SeongJae Park 2018-05-03 452 /* Tell the block layer that this is not a rotational device */
7f9b348cb5e942 Christoph Hellwig 2021-05-21 453 blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
7f9b348cb5e942 Christoph Hellwig 2021-05-21 454 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue);
a610c807a6b52c Gao Xiang 2022-06-05 455
a610c807a6b52c Gao Xiang 2022-06-05 456 if (enable_fsdax)
a610c807a6b52c Gao Xiang 2022-06-05 457 blk_queue_flag_set(QUEUE_FLAG_DAX, disk->queue);
e1528830bd4ebf Luis Chamberlain 2021-10-15 458 err = add_disk(disk);
e1528830bd4ebf Luis Chamberlain 2021-10-15 459 if (err)
e1528830bd4ebf Luis Chamberlain 2021-10-15 460 goto out_cleanup_disk;
316ba5736c9caa SeongJae Park 2018-05-03 461
a610c807a6b52c Gao Xiang 2022-06-05 462 if (enable_fsdax) {
a610c807a6b52c Gao Xiang 2022-06-05 463 brd->dax_dev = alloc_dax(brd, &brd_dax_ops);
a610c807a6b52c Gao Xiang 2022-06-05 464 if (IS_ERR(brd->dax_dev)) {

err = PTR_ERR(brd->dax_dev)

a610c807a6b52c Gao Xiang 2022-06-05 465 brd->dax_dev = NULL;
a610c807a6b52c Gao Xiang 2022-06-05 @466 goto out_del_gendisk;
a610c807a6b52c Gao Xiang 2022-06-05 467 }
a610c807a6b52c Gao Xiang 2022-06-05 468 set_dax_nocache(brd->dax_dev);
a610c807a6b52c Gao Xiang 2022-06-05 469 set_dax_nomc(brd->dax_dev);
a610c807a6b52c Gao Xiang 2022-06-05 470 run_dax(brd->dax_dev);
a610c807a6b52c Gao Xiang 2022-06-05 471 if (dax_add_host(brd->dax_dev, disk))
a610c807a6b52c Gao Xiang 2022-06-05 472 goto out_del_gendisk;


err = dax_add_host(brd->dax_dev, disk);
if (err)
goto out_del_gendisk;

a610c807a6b52c Gao Xiang 2022-06-05 473 }
7f9b348cb5e942 Christoph Hellwig 2021-05-21 474 return 0;
9db5579be4bb53 Nicholas Piggin 2008-02-08 475
a610c807a6b52c Gao Xiang 2022-06-05 476 out_del_gendisk:
a610c807a6b52c Gao Xiang 2022-06-05 477 del_gendisk(disk);
e1528830bd4ebf Luis Chamberlain 2021-10-15 478 out_cleanup_disk:
e1528830bd4ebf Luis Chamberlain 2021-10-15 479 blk_cleanup_disk(disk);
9db5579be4bb53 Nicholas Piggin 2008-02-08 480 out_free_dev:
f7bf35862477d6 Tetsuo Handa 2021-09-07 481 list_del(&brd->brd_list);
9db5579be4bb53 Nicholas Piggin 2008-02-08 482 kfree(brd);
e1528830bd4ebf Luis Chamberlain 2021-10-15 483 return err;
9db5579be4bb53 Nicholas Piggin 2008-02-08 484 }

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