Commit 9d51c7dc authored by Li Nan's avatar Li Nan
Browse files

nbd: fold nbd config initialization into nbd_alloc_config() 

mainline inclusion
from mainline-v6.7-rc3
commit 1b59860540a4018e8071dc18d4893ec389506b7d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8P7B3

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1b59860540a4018e8071dc18d4893ec389506b7d



--------------------------------

There are no functional changes, make the code cleaner and prepare to
fix null-ptr-dereference while accessing 'nbd->config'.

Signed-off-by: default avatarLi Nan <linan122@huawei.com>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20231116162316.1740402-2-linan666@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1f57ba4e

drivers/block/nbd.c

+19 −22
Original line number Diff line number Diff line
@@ -1530,17 +1530,20 @@ static int nbd_ioctl(struct block_device *bdev, blk_mode_t mode, 
	return error;

}



static struct nbd_config *nbd_alloc_config(void)

static int nbd_alloc_and_init_config(struct nbd_device *nbd)

{

	struct nbd_config *config;



	if (WARN_ON(nbd->config))

		return -EINVAL;



	if (!try_module_get(THIS_MODULE))

		return ERR_PTR(-ENODEV);

		return -ENODEV;



	config = kzalloc(sizeof(struct nbd_config), GFP_NOFS);

	if (!config) {

		module_put(THIS_MODULE);

		return ERR_PTR(-ENOMEM);

		return -ENOMEM;

	}



	atomic_set(&config->recv_threads, 0);
@@ -1548,7 +1551,10 @@ static struct nbd_config *nbd_alloc_config(void) 
	init_waitqueue_head(&config->conn_wait);

	config->blksize_bits = NBD_DEF_BLKSIZE_BITS;

	atomic_set(&config->live_connections, 0);

	return config;

	nbd->config = config;

	refcount_set(&nbd->config_refs, 1);



	return 0;

}



static int nbd_open(struct gendisk *disk, blk_mode_t mode)
@@ -1567,21 +1573,17 @@ static int nbd_open(struct gendisk *disk, blk_mode_t mode) 
		goto out;

	}

	if (!refcount_inc_not_zero(&nbd->config_refs)) {

		struct nbd_config *config;



		mutex_lock(&nbd->config_lock);

		if (refcount_inc_not_zero(&nbd->config_refs)) {

			mutex_unlock(&nbd->config_lock);

			goto out;

		}

		config = nbd_alloc_config();

		if (IS_ERR(config)) {

			ret = PTR_ERR(config);

		ret = nbd_alloc_and_init_config(nbd);

		if (ret) {

			mutex_unlock(&nbd->config_lock);

			goto out;

		}

		nbd->config = config;

		refcount_set(&nbd->config_refs, 1);



		refcount_inc(&nbd->refs);

		mutex_unlock(&nbd->config_lock);

		if (max_part)
@@ -1990,22 +1992,17 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info) 
		pr_err("nbd%d already in use\n", index);

		return -EBUSY;

	}

	if (WARN_ON(nbd->config)) {

		mutex_unlock(&nbd->config_lock);

		nbd_put(nbd);

		return -EINVAL;

	}

	config = nbd_alloc_config();

	if (IS_ERR(config)) {



	ret = nbd_alloc_and_init_config(nbd);

	if (ret) {

		mutex_unlock(&nbd->config_lock);

		nbd_put(nbd);

		pr_err("couldn't allocate config\n");

		return PTR_ERR(config);

		return ret;

	}

	nbd->config = config;

	refcount_set(&nbd->config_refs, 1);

	set_bit(NBD_RT_BOUND, &config->runtime_flags);



	config = nbd->config;

	set_bit(NBD_RT_BOUND, &config->runtime_flags);

	ret = nbd_genl_size_set(info, nbd);

	if (ret)

		goto out;