mainline inclusion from mainline-v7.3-rc1 commit f8d21c590e55d629abed675554b186291ac08915 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/9153 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- The NBD_ATTR_SOCKETS walk is duplicated in nbd_genl_connect (add sockets) and nbd_genl_reconfigure (reconnect). Factor out a single helper that walks the list and calls a callback per fd; with a NULL callback it is a pure counter, used by a later patch to learn nr_hw_queues before the device exists. Returns the number of fds walked (>= 0) or a negative errno; a callback >0 will stops early. Reviewed-by: Yu Kuai <yukuai@fygo.io> Signed-off-by: Yang Erkun <yangerkun@huawei.com> Link: https://patch.msgid.link/20260805122930.57647-7-yangerkun@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Yang Erkun <yangerkun@huawei.com> --- drivers/block/nbd.c | 128 +++++++++++++++++++++----------------------- 1 file changed, 62 insertions(+), 66 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 8f2032e533de..73dfa216de1f 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1219,7 +1219,7 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, return err; } -static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg) +static int nbd_genl_reconnect_sock_cb(struct nbd_device *nbd, unsigned long arg) { struct nbd_config *config = nbd->config; struct socket *sock, *old; @@ -1274,11 +1274,12 @@ static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg) atomic_inc(&config->live_connections); wake_up(&config->conn_wait); + dev_info(nbd_to_dev(nbd), "reconnected socket\n"); return 0; } sockfd_put(sock); kfree(args); - return -ENOSPC; + return 1; } static void nbd_bdev_reset(struct nbd_device *nbd) @@ -1987,6 +1988,58 @@ static int nbd_genl_size_set(struct genl_info *info, struct nbd_device *nbd) return 0; } +/* + * Walk the NBD_ATTR_SOCKETS nested list can call @cb for each socket fd. + * + * Return the number of fds walked, or a negative errno. + */ +static int nbd_genl_foreach_sock(struct genl_info *info, + int (*cb)(struct nbd_device *nbd, unsigned long fd), + struct nbd_device *nbd) +{ + struct nlattr *attr; + int rem, count = 0; + + if (!info->attrs[NBD_ATTR_SOCKETS]) + return 0; + + nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS], rem) { + struct nlattr *socks[NBD_SOCK_MAX + 1]; + int ret; + + if (nla_type(attr) != NBD_SOCK_ITEM) { + pr_err("socks must be embedded in a SOCK_ITEM attr\n"); + return -EINVAL; + } + + if (nla_parse_nested_deprecated(socks, NBD_SOCK_MAX, + attr, + nbd_sock_policy, + info->extack)) { + pr_err("error processing sock list\n"); + return -EINVAL; + } + + if (!socks[NBD_SOCK_FD]) + continue; + + count++; + if (cb) { + ret = cb(nbd, (int)nla_get_u32(socks[NBD_SOCK_FD])); + if (ret > 0) + return count; + if (ret < 0) + return ret; + } + } + return count; +} + +static int nbd_genl_connect_sock_cb(struct nbd_device *nbd, unsigned long fd) +{ + return nbd_add_socket(nbd, fd, true); +} + static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info) { struct nbd_device *nbd; @@ -2106,36 +2159,9 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info) } } - if (info->attrs[NBD_ATTR_SOCKETS]) { - struct nlattr *attr; - int rem, fd; - - nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS], - rem) { - struct nlattr *socks[NBD_SOCK_MAX+1]; - - if (nla_type(attr) != NBD_SOCK_ITEM) { - pr_err("socks must be embedded in a SOCK_ITEM attr\n"); - ret = -EINVAL; - goto out; - } - ret = nla_parse_nested_deprecated(socks, NBD_SOCK_MAX, - attr, - nbd_sock_policy, - info->extack); - if (ret != 0) { - pr_err("error processing sock list\n"); - ret = -EINVAL; - goto out; - } - if (!socks[NBD_SOCK_FD]) - continue; - fd = (int)nla_get_u32(socks[NBD_SOCK_FD]); - ret = nbd_add_socket(nbd, fd, true); - if (ret) - goto out; - } - } + ret = nbd_genl_foreach_sock(info, nbd_genl_connect_sock_cb, nbd); + if (ret < 0) + goto out; if (info->attrs[NBD_ATTR_BACKEND_IDENTIFIER]) { nbd->backend = nla_strdup(info->attrs[NBD_ATTR_BACKEND_IDENTIFIER], @@ -2320,40 +2346,10 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info) } } - if (info->attrs[NBD_ATTR_SOCKETS]) { - struct nlattr *attr; - int rem, fd; - - nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS], - rem) { - struct nlattr *socks[NBD_SOCK_MAX+1]; - - if (nla_type(attr) != NBD_SOCK_ITEM) { - pr_err("socks must be embedded in a SOCK_ITEM attr\n"); - ret = -EINVAL; - goto out; - } - ret = nla_parse_nested_deprecated(socks, NBD_SOCK_MAX, - attr, - nbd_sock_policy, - info->extack); - if (ret != 0) { - pr_err("error processing sock list\n"); - ret = -EINVAL; - goto out; - } - if (!socks[NBD_SOCK_FD]) - continue; - fd = (int)nla_get_u32(socks[NBD_SOCK_FD]); - ret = nbd_reconnect_socket(nbd, fd); - if (ret) { - if (ret == -ENOSPC) - ret = 0; - goto out; - } - dev_info(nbd_to_dev(nbd), "reconnected socket\n"); - } - } + ret = nbd_genl_foreach_sock(info, nbd_genl_reconnect_sock_cb, nbd); + /* foreach_sock returns a positive count on success; doit must return 0 */ + if (ret >= 0) + ret = 0; out: mutex_unlock(&nbd->config_lock); nbd_config_put(nbd); -- 2.52.0