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nbd: fold nbd config initialization into nbd_alloc_config()

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

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20231116162316.1740402-2-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Li Nan 2023-11-17 00:23:14 +08:00 committed by Jens Axboe
parent 8a554c6234
commit 1b59860540
1 changed files with 19 additions and 22 deletions
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41
drivers/block/nbd.c
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@ -1530,17 +1530,20 @@ static int nbd_ioctl(struct block_device *bdev, blk_mode_t mode,
return error; 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; struct nbd_config *config;
if (WARN_ON(nbd->config))
return -EINVAL;
if (!try_module_get(THIS_MODULE)) if (!try_module_get(THIS_MODULE))
return ERR_PTR(-ENODEV); return -ENODEV;
config = kzalloc(sizeof(struct nbd_config), GFP_NOFS); config = kzalloc(sizeof(struct nbd_config), GFP_NOFS);
if (!config) { if (!config) {
module_put(THIS_MODULE); module_put(THIS_MODULE);
return ERR_PTR(-ENOMEM); return -ENOMEM;
} }
atomic_set(&config->recv_threads, 0); atomic_set(&config->recv_threads, 0);
@ -1548,7 +1551,10 @@ static struct nbd_config *nbd_alloc_config(void)
init_waitqueue_head(&config->conn_wait); init_waitqueue_head(&config->conn_wait);
config->blksize_bits = NBD_DEF_BLKSIZE_BITS; config->blksize_bits = NBD_DEF_BLKSIZE_BITS;
atomic_set(&config->live_connections, 0); 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) 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; goto out;
} }
if (!refcount_inc_not_zero(&nbd->config_refs)) { if (!refcount_inc_not_zero(&nbd->config_refs)) {
struct nbd_config *config;
mutex_lock(&nbd->config_lock); mutex_lock(&nbd->config_lock);
if (refcount_inc_not_zero(&nbd->config_refs)) { if (refcount_inc_not_zero(&nbd->config_refs)) {
mutex_unlock(&nbd->config_lock); mutex_unlock(&nbd->config_lock);
goto out; goto out;
} }
config = nbd_alloc_config(); ret = nbd_alloc_and_init_config(nbd);
if (IS_ERR(config)) { if (ret) {
ret = PTR_ERR(config);
mutex_unlock(&nbd->config_lock); mutex_unlock(&nbd->config_lock);
goto out; goto out;
} }
nbd->config = config;
refcount_set(&nbd->config_refs, 1);
refcount_inc(&nbd->refs); refcount_inc(&nbd->refs);
mutex_unlock(&nbd->config_lock); mutex_unlock(&nbd->config_lock);
if (max_part) 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); pr_err("nbd%d already in use\n", index);
return -EBUSY; return -EBUSY;
} }
if (WARN_ON(nbd->config)) {
mutex_unlock(&nbd->config_lock); ret = nbd_alloc_and_init_config(nbd);
nbd_put(nbd); if (ret) {
return -EINVAL;
}
config = nbd_alloc_config();
if (IS_ERR(config)) {
mutex_unlock(&nbd->config_lock); mutex_unlock(&nbd->config_lock);
nbd_put(nbd); nbd_put(nbd);
pr_err("couldn't allocate config\n"); 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); ret = nbd_genl_size_set(info, nbd);
if (ret) if (ret)
goto out; goto out;