Re: [PATCH net-next v3 5/5] netns: enable to dump full nsid translation table
Hi Nicolas,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on net-next/master]
url:
https://github.com/0day-ci/linux/commits/Nicolas-Dichtel/netns-remove-net-arg-from-rtnl_net_fill/20181126-035032
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All warnings (new ones prefixed by >>):
include/linux/slab.h:332:43: warning: dubious: x & !y
include/linux/slab.h:332:43: warning: dubious: x & !y
>> net/core/net_namespace.c:963:23: warning: context imbalance in
>> 'rtnl_net_dumpid' - different lock contexts for basic block
vim +/rtnl_net_dumpid +963 net/core/net_namespace.c
5589651eb Nicolas Dichtel 2018-11-22 929
a143c40c3 Nicolas Dichtel 2015-04-07 930 static int rtnl_net_dumpid(struct
sk_buff *skb, struct netlink_callback *cb)
a143c40c3 Nicolas Dichtel 2015-04-07 931 {
a143c40c3 Nicolas Dichtel 2015-04-07 932 struct rtnl_net_dump_cb net_cb
= {
5589651eb Nicolas Dichtel 2018-11-22 933 .tgt_net =
sock_net(skb->sk),
a143c40c3 Nicolas Dichtel 2015-04-07 934 .skb = skb,
70955fc94 Nicolas Dichtel 2018-11-22 935 .fillargs = {
70955fc94 Nicolas Dichtel 2018-11-22 936 .portid =
NETLINK_CB(cb->skb).portid,
70955fc94 Nicolas Dichtel 2018-11-22 937 .seq =
cb->nlh->nlmsg_seq,
70955fc94 Nicolas Dichtel 2018-11-22 938 .flags =
NLM_F_MULTI,
70955fc94 Nicolas Dichtel 2018-11-22 939 .cmd =
RTM_NEWNSID,
70955fc94 Nicolas Dichtel 2018-11-22 940 },
a143c40c3 Nicolas Dichtel 2015-04-07 941 .idx = 0,
a143c40c3 Nicolas Dichtel 2015-04-07 942 .s_idx = cb->args[0],
a143c40c3 Nicolas Dichtel 2015-04-07 943 };
5589651eb Nicolas Dichtel 2018-11-22 944 int err = 0;
a143c40c3 Nicolas Dichtel 2015-04-07 945
5589651eb Nicolas Dichtel 2018-11-22 946 if (cb->strict_check) {
5589651eb Nicolas Dichtel 2018-11-22 947 err =
rtnl_valid_dump_net_req(cb->nlh, skb->sk, _cb, cb);
5589651eb Nicolas Dichtel 2018-11-22 948 if (err < 0)
5589651eb Nicolas Dichtel 2018-11-22 949 goto end;
f80f14c36 David Ahern 2018-10-07 950 }
f80f14c36 David Ahern 2018-10-07 951
5589651eb Nicolas Dichtel 2018-11-22 952
spin_lock_bh(_cb.tgt_net->nsid_lock);
8a46e1ccc Nicolas Dichtel 2018-11-22 953 if (net_cb.fillargs.add_ref &&
8a46e1ccc Nicolas Dichtel 2018-11-22 954 !net_eq(net_cb.ref_net,
net_cb.tgt_net) &&
8a46e1ccc Nicolas Dichtel 2018-11-22 955
!spin_trylock_bh(_cb.ref_net->nsid_lock)) {
8a46e1ccc Nicolas Dichtel 2018-11-22 956 err = -EAGAIN;
8a46e1ccc Nicolas Dichtel 2018-11-22 957 goto end;
8a46e1ccc Nicolas Dichtel 2018-11-22 958 }
5589651eb Nicolas Dichtel 2018-11-22 959
idr_for_each(_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, _cb);
8a46e1ccc Nicolas Dichtel 2018-11-22 960 if (net_cb.fillargs.add_ref &&
8a46e1ccc Nicolas Dichtel 2018-11-22 961 !net_eq(net_cb.ref_net,
net_cb.tgt_net))
8a46e1ccc Nicolas Dichtel 2018-11-22 962
spin_unlock_bh(_cb.ref_net->nsid_lock);
5589651eb Nicolas Dichtel 2018-11-22 @963
spin_unlock_bh(_cb.tgt_net->nsid_lock);
a143c40c3 Nicolas Dichtel 2015-04-07 964
a143c40c3 Nicolas Dichtel 2015-04-07 965 cb->args[0] = net_cb.idx;
5589651eb Nicolas Dichtel 2018-11-22 966 end:
8a46e1ccc Nicolas Dichtel 2018-11-22 967 if (net_cb.fillargs.add_ref)
5589651eb Nicolas Dichtel 2018-11-22 968 put_net(net_cb.tgt_net);
5589651eb Nicolas Dichtel 2018-11-22 969 return err < 0 ? err : skb->len;
a143c40c3 Nicolas Dichtel 2015-04-07 970 }
a143c40c3 Nicolas Dichtel 2015-04-07 971
:: The code at line 963 was first introduced by commit
:: 5589651eb5e06b32107a1d8830af4be67aa58b85 netns: add support of
NETNSA_TARGET_NSID
:: TO: Nicolas Dichtel
:: CC: 0day robot
---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
.config.gz
Description: application/gzip
Re: [PATCH net-next v3 5/5] netns: enable to dump full nsid translation table
On 11/22/18 3:22 PM, Nicolas Dichtel wrote: > Like the previous patch, the goal is to ease to convert nsids from one > netns to another netns. > A new attribute (NETNSA_CURRENT_NSID) is added to the kernel answer when > NETNSA_TARGET_NSID is provided, thus the user can easily convert nsids. > > Signed-off-by: Nicolas Dichtel > --- > include/uapi/linux/net_namespace.h | 1 + > net/core/net_namespace.c | 31 -- > 2 files changed, 26 insertions(+), 6 deletions(-) > Reviewed-by: David Ahern
[PATCH net-next v3 5/5] netns: enable to dump full nsid translation table
Like the previous patch, the goal is to ease to convert nsids from one
netns to another netns.
A new attribute (NETNSA_CURRENT_NSID) is added to the kernel answer when
NETNSA_TARGET_NSID is provided, thus the user can easily convert nsids.
Signed-off-by: Nicolas Dichtel
---
include/uapi/linux/net_namespace.h | 1 +
net/core/net_namespace.c | 31 --
2 files changed, 26 insertions(+), 6 deletions(-)
diff --git a/include/uapi/linux/net_namespace.h
b/include/uapi/linux/net_namespace.h
index 0ed9dd61d32a..9f9956809565 100644
--- a/include/uapi/linux/net_namespace.h
+++ b/include/uapi/linux/net_namespace.h
@@ -17,6 +17,7 @@ enum {
NETNSA_PID,
NETNSA_FD,
NETNSA_TARGET_NSID,
+ NETNSA_CURRENT_NSID,
__NETNSA_MAX,
};
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index dd25fb22ad45..2f25d7f2a43b 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -736,6 +736,7 @@ static int rtnl_net_get_size(void)
{
return NLMSG_ALIGN(sizeof(struct rtgenmsg))
+ nla_total_size(sizeof(s32)) /* NETNSA_NSID */
+ + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */
;
}
@@ -745,6 +746,8 @@ struct net_fill_args {
int flags;
int cmd;
int nsid;
+ bool add_ref;
+ int ref_nsid;
};
static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
@@ -763,6 +766,10 @@ static int rtnl_net_fill(struct sk_buff *skb, struct
net_fill_args *args)
if (nla_put_s32(skb, NETNSA_NSID, args->nsid))
goto nla_put_failure;
+ if (args->add_ref &&
+ nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))
+ goto nla_put_failure;
+
nlmsg_end(skb, nlh);
return 0;
@@ -782,7 +789,6 @@ static int rtnl_net_getid(struct sk_buff *skb, struct
nlmsghdr *nlh,
.cmd = RTM_NEWNSID,
};
struct net *peer, *target = net;
- bool put_target = false;
struct nlattr *nla;
struct sk_buff *msg;
int err;
@@ -824,7 +830,8 @@ static int rtnl_net_getid(struct sk_buff *skb, struct
nlmsghdr *nlh,
err = PTR_ERR(target);
goto out;
}
- put_target = true;
+ fillargs.add_ref = true;
+ fillargs.ref_nsid = peernet2id(net, peer);
}
msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
@@ -844,7 +851,7 @@ static int rtnl_net_getid(struct sk_buff *skb, struct
nlmsghdr *nlh,
err_out:
nlmsg_free(msg);
out:
- if (put_target)
+ if (fillargs.add_ref)
put_net(target);
put_net(peer);
return err;
@@ -852,11 +859,11 @@ static int rtnl_net_getid(struct sk_buff *skb, struct
nlmsghdr *nlh,
struct rtnl_net_dump_cb {
struct net *tgt_net;
+ struct net *ref_net;
struct sk_buff *skb;
struct net_fill_args fillargs;
int idx;
int s_idx;
- bool put_tgt_net;
};
static int rtnl_net_dumpid_one(int id, void *peer, void *data)
@@ -868,6 +875,8 @@ static int rtnl_net_dumpid_one(int id, void *peer, void
*data)
goto cont;
net_cb->fillargs.nsid = id;
+ if (net_cb->fillargs.add_ref)
+ net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);
ret = rtnl_net_fill(net_cb->skb, _cb->fillargs);
if (ret < 0)
return ret;
@@ -904,8 +913,9 @@ static int rtnl_valid_dump_net_req(const struct nlmsghdr
*nlh, struct sock *sk,
"Invalid target network
namespace id");
return PTR_ERR(net);
}
+ net_cb->fillargs.add_ref = true;
+ net_cb->ref_net = net_cb->tgt_net;
net_cb->tgt_net = net;
- net_cb->put_tgt_net = true;
} else {
NL_SET_BAD_ATTR(extack, tb[i]);
NL_SET_ERR_MSG(extack,
@@ -940,12 +950,21 @@ static int rtnl_net_dumpid(struct sk_buff *skb, struct
netlink_callback *cb)
}
spin_lock_bh(_cb.tgt_net->nsid_lock);
+ if (net_cb.fillargs.add_ref &&
+ !net_eq(net_cb.ref_net, net_cb.tgt_net) &&
+ !spin_trylock_bh(_cb.ref_net->nsid_lock)) {
+ err = -EAGAIN;
+ goto end;
+ }
idr_for_each(_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, _cb);
+ if (net_cb.fillargs.add_ref &&
+ !net_eq(net_cb.ref_net, net_cb.tgt_net))
+ spin_unlock_bh(_cb.ref_net->nsid_lock);
spin_unlock_bh(_cb.tgt_net->nsid_lock);
cb->args[0] = net_cb.idx;
end:
- if (net_cb.put_tgt_net)
+ if (net_cb.fillargs.add_ref)
put_net(net_cb.tgt_net);
return err < 0 ? err : skb->len;
}
--
2.18.0
