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Message-ID: <20220620185151.65294-5-kuniyu@amazon.com>
Date: Mon, 20 Jun 2022 11:51:49 -0700
From: Kuniyuki Iwashima <kuniyu@...zon.com>
To: "David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>
CC: Amit Shah <aams@...zon.com>, Kuniyuki Iwashima <kuniyu@...zon.com>,
Kuniyuki Iwashima <kuni1840@...il.com>,
<netdev@...r.kernel.org>
Subject: [PATCH v2 net-next 4/6] af_unix: Acquire/Release per-netns hash table's locks.
This commit adds extra spin_lock/spin_unlock() for a per-netns
hash table inside the existing ones for unix_table_locks.
As of this commit, sockets are still linked in the global hash
table. After putting sockets in a per-netns hash table and
removing the old one in the next patch, we remove the global
locks in the last patch.
Signed-off-by: Kuniyuki Iwashima <kuniyu@...zon.com>
---
net/unix/af_unix.c | 75 +++++++++++++++++++++++++++++++---------------
net/unix/diag.c | 23 +++++++++-----
2 files changed, 66 insertions(+), 32 deletions(-)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index cdd12881a39d..79f8fc5cdce8 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -158,7 +158,8 @@ static unsigned int unix_abstract_hash(struct sockaddr_un *sunaddr,
return hash & UNIX_HASH_MOD;
}
-static void unix_table_double_lock(unsigned int hash1, unsigned int hash2)
+static void unix_table_double_lock(struct net *net,
+ unsigned int hash1, unsigned int hash2)
{
/* hash1 and hash2 is never the same because
* one is between 0 and UNIX_HASH_MOD, and
@@ -169,10 +170,17 @@ static void unix_table_double_lock(unsigned int hash1, unsigned int hash2)
spin_lock(&unix_table_locks[hash1]);
spin_lock_nested(&unix_table_locks[hash2], SINGLE_DEPTH_NESTING);
+
+ spin_lock(&net->unx.table.locks[hash1]);
+ spin_lock_nested(&net->unx.table.locks[hash2], SINGLE_DEPTH_NESTING);
}
-static void unix_table_double_unlock(unsigned int hash1, unsigned int hash2)
+static void unix_table_double_unlock(struct net *net,
+ unsigned int hash1, unsigned int hash2)
{
+ spin_unlock(&net->unx.table.locks[hash1]);
+ spin_unlock(&net->unx.table.locks[hash2]);
+
spin_unlock(&unix_table_locks[hash1]);
spin_unlock(&unix_table_locks[hash2]);
}
@@ -316,17 +324,21 @@ static void __unix_set_addr_hash(struct sock *sk, struct unix_address *addr,
__unix_insert_socket(sk);
}
-static void unix_remove_socket(struct sock *sk)
+static void unix_remove_socket(struct net *net, struct sock *sk)
{
spin_lock(&unix_table_locks[sk->sk_hash]);
+ spin_lock(&net->unx.table.locks[sk->sk_hash]);
__unix_remove_socket(sk);
+ spin_unlock(&net->unx.table.locks[sk->sk_hash]);
spin_unlock(&unix_table_locks[sk->sk_hash]);
}
-static void unix_insert_unbound_socket(struct sock *sk)
+static void unix_insert_unbound_socket(struct net *net, struct sock *sk)
{
spin_lock(&unix_table_locks[sk->sk_hash]);
+ spin_lock(&net->unx.table.locks[sk->sk_hash]);
__unix_insert_socket(sk);
+ spin_unlock(&net->unx.table.locks[sk->sk_hash]);
spin_unlock(&unix_table_locks[sk->sk_hash]);
}
@@ -356,28 +368,33 @@ static inline struct sock *unix_find_socket_byname(struct net *net,
struct sock *s;
spin_lock(&unix_table_locks[hash]);
+ spin_lock(&net->unx.table.locks[hash]);
s = __unix_find_socket_byname(net, sunname, len, hash);
if (s)
sock_hold(s);
+ spin_unlock(&net->unx.table.locks[hash]);
spin_unlock(&unix_table_locks[hash]);
return s;
}
-static struct sock *unix_find_socket_byinode(struct inode *i)
+static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i)
{
unsigned int hash = unix_bsd_hash(i);
struct sock *s;
spin_lock(&unix_table_locks[hash]);
+ spin_lock(&net->unx.table.locks[hash]);
sk_for_each(s, &unix_socket_table[hash]) {
struct dentry *dentry = unix_sk(s)->path.dentry;
if (dentry && d_backing_inode(dentry) == i) {
sock_hold(s);
+ spin_unlock(&net->unx.table.locks[hash]);
spin_unlock(&unix_table_locks[hash]);
return s;
}
}
+ spin_unlock(&net->unx.table.locks[hash]);
spin_unlock(&unix_table_locks[hash]);
return NULL;
}
@@ -576,12 +593,12 @@ static void unix_sock_destructor(struct sock *sk)
static void unix_release_sock(struct sock *sk, int embrion)
{
struct unix_sock *u = unix_sk(sk);
- struct path path;
struct sock *skpair;
struct sk_buff *skb;
+ struct path path;
int state;
- unix_remove_socket(sk);
+ unix_remove_socket(sock_net(sk), sk);
/* Clear state */
unix_state_lock(sk);
@@ -930,7 +947,7 @@ static struct sock *unix_create1(struct net *net, struct socket *sock, int kern,
init_waitqueue_head(&u->peer_wait);
init_waitqueue_func_entry(&u->peer_wake, unix_dgram_peer_wake_relay);
memset(&u->scm_stat, 0, sizeof(struct scm_stat));
- unix_insert_unbound_socket(sk);
+ unix_insert_unbound_socket(net, sk);
sock_prot_inuse_add(net, sk->sk_prot, 1);
@@ -1015,7 +1032,7 @@ static struct sock *unix_find_bsd(struct net *net, struct sockaddr_un *sunaddr,
if (!S_ISSOCK(inode->i_mode))
goto path_put;
- sk = unix_find_socket_byinode(inode);
+ sk = unix_find_socket_byinode(net, inode);
if (!sk)
goto path_put;
@@ -1074,6 +1091,7 @@ static int unix_autobind(struct sock *sk)
{
unsigned int new_hash, old_hash = sk->sk_hash;
struct unix_sock *u = unix_sk(sk);
+ struct net *net = sock_net(sk);
struct unix_address *addr;
u32 lastnum, ordernum;
int err;
@@ -1102,11 +1120,10 @@ static int unix_autobind(struct sock *sk)
sprintf(addr->name->sun_path + 1, "%05x", ordernum);
new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type);
- unix_table_double_lock(old_hash, new_hash);
+ unix_table_double_lock(net, old_hash, new_hash);
- if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len,
- new_hash)) {
- unix_table_double_unlock(old_hash, new_hash);
+ if (__unix_find_socket_byname(net, addr->name, addr->len, new_hash)) {
+ unix_table_double_unlock(net, old_hash, new_hash);
/* __unix_find_socket_byname() may take long time if many names
* are already in use.
@@ -1124,7 +1141,7 @@ static int unix_autobind(struct sock *sk)
}
__unix_set_addr_hash(sk, addr, new_hash);
- unix_table_double_unlock(old_hash, new_hash);
+ unix_table_double_unlock(net, old_hash, new_hash);
err = 0;
out: mutex_unlock(&u->bindlock);
@@ -1138,6 +1155,7 @@ static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr,
(SOCK_INODE(sk->sk_socket)->i_mode & ~current_umask());
unsigned int new_hash, old_hash = sk->sk_hash;
struct unix_sock *u = unix_sk(sk);
+ struct net *net = sock_net(sk);
struct user_namespace *ns; // barf...
struct unix_address *addr;
struct dentry *dentry;
@@ -1178,11 +1196,11 @@ static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr,
goto out_unlock;
new_hash = unix_bsd_hash(d_backing_inode(dentry));
- unix_table_double_lock(old_hash, new_hash);
+ unix_table_double_lock(net, old_hash, new_hash);
u->path.mnt = mntget(parent.mnt);
u->path.dentry = dget(dentry);
__unix_set_addr_hash(sk, addr, new_hash);
- unix_table_double_unlock(old_hash, new_hash);
+ unix_table_double_unlock(net, old_hash, new_hash);
mutex_unlock(&u->bindlock);
done_path_create(&parent, dentry);
return 0;
@@ -1205,6 +1223,7 @@ static int unix_bind_abstract(struct sock *sk, struct sockaddr_un *sunaddr,
{
unsigned int new_hash, old_hash = sk->sk_hash;
struct unix_sock *u = unix_sk(sk);
+ struct net *net = sock_net(sk);
struct unix_address *addr;
int err;
@@ -1222,19 +1241,18 @@ static int unix_bind_abstract(struct sock *sk, struct sockaddr_un *sunaddr,
}
new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type);
- unix_table_double_lock(old_hash, new_hash);
+ unix_table_double_lock(net, old_hash, new_hash);
- if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len,
- new_hash))
+ if (__unix_find_socket_byname(net, addr->name, addr->len, new_hash))
goto out_spin;
__unix_set_addr_hash(sk, addr, new_hash);
- unix_table_double_unlock(old_hash, new_hash);
+ unix_table_double_unlock(net, old_hash, new_hash);
mutex_unlock(&u->bindlock);
return 0;
out_spin:
- unix_table_double_unlock(old_hash, new_hash);
+ unix_table_double_unlock(net, old_hash, new_hash);
err = -EADDRINUSE;
out_mutex:
mutex_unlock(&u->bindlock);
@@ -3237,15 +3255,18 @@ static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos)
static struct sock *unix_get_first(struct seq_file *seq, loff_t *pos)
{
unsigned long bucket = get_bucket(*pos);
+ struct net *net = seq_file_net(seq);
struct sock *sk;
while (bucket < UNIX_HASH_SIZE) {
spin_lock(&unix_table_locks[bucket]);
+ spin_lock(&net->unx.table.locks[bucket]);
sk = unix_from_bucket(seq, pos);
if (sk)
return sk;
+ spin_unlock(&net->unx.table.locks[bucket]);
spin_unlock(&unix_table_locks[bucket]);
*pos = set_bucket_offset(++bucket, 1);
@@ -3258,11 +3279,13 @@ static struct sock *unix_get_next(struct seq_file *seq, struct sock *sk,
loff_t *pos)
{
unsigned long bucket = get_bucket(*pos);
+ struct net *net = seq_file_net(seq);
for (sk = sk_next(sk); sk; sk = sk_next(sk))
- if (sock_net(sk) == seq_file_net(seq))
+ if (sock_net(sk) == net)
return sk;
+ spin_unlock(&net->unx.table.locks[bucket]);
spin_unlock(&unix_table_locks[bucket]);
*pos = set_bucket_offset(++bucket, 1);
@@ -3292,8 +3315,10 @@ static void unix_seq_stop(struct seq_file *seq, void *v)
{
struct sock *sk = v;
- if (sk)
+ if (sk) {
+ spin_unlock(&seq_file_net(seq)->unx.table.locks[sk->sk_hash]);
spin_unlock(&unix_table_locks[sk->sk_hash]);
+ }
}
static int unix_seq_show(struct seq_file *seq, void *v)
@@ -3381,6 +3406,7 @@ static int bpf_iter_unix_hold_batch(struct seq_file *seq, struct sock *start_sk)
{
struct bpf_unix_iter_state *iter = seq->private;
+ struct net *net = seq_file_net(seq);
unsigned int expected = 1;
struct sock *sk;
@@ -3388,7 +3414,7 @@ static int bpf_iter_unix_hold_batch(struct seq_file *seq, struct sock *start_sk)
iter->batch[iter->end_sk++] = start_sk;
for (sk = sk_next(start_sk); sk; sk = sk_next(sk)) {
- if (sock_net(sk) != seq_file_net(seq))
+ if (sock_net(sk) != net)
continue;
if (iter->end_sk < iter->max_sk) {
@@ -3399,6 +3425,7 @@ static int bpf_iter_unix_hold_batch(struct seq_file *seq, struct sock *start_sk)
expected++;
}
+ spin_unlock(&net->unx.table.locks[start_sk->sk_hash]);
spin_unlock(&unix_table_locks[start_sk->sk_hash]);
return expected;
diff --git a/net/unix/diag.c b/net/unix/diag.c
index c5d1cca72aa5..7fc377435114 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -195,9 +195,9 @@ static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_r
static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
- struct unix_diag_req *req;
- int num, s_num, slot, s_slot;
struct net *net = sock_net(skb->sk);
+ int num, s_num, slot, s_slot;
+ struct unix_diag_req *req;
req = nlmsg_data(cb->nlh);
@@ -209,6 +209,7 @@ static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
num = 0;
spin_lock(&unix_table_locks[slot]);
+ spin_lock(&net->unx.table.locks[slot]);
sk_for_each(sk, &unix_socket_table[slot]) {
if (!net_eq(sock_net(sk), net))
continue;
@@ -220,12 +221,14 @@ static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
NLM_F_MULTI) < 0) {
+ spin_unlock(&net->unx.table.locks[slot]);
spin_unlock(&unix_table_locks[slot]);
goto done;
}
next:
num++;
}
+ spin_unlock(&net->unx.table.locks[slot]);
spin_unlock(&unix_table_locks[slot]);
}
done:
@@ -235,19 +238,22 @@ static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
return skb->len;
}
-static struct sock *unix_lookup_by_ino(unsigned int ino)
+static struct sock *unix_lookup_by_ino(struct net *net, unsigned int ino)
{
struct sock *sk;
int i;
for (i = 0; i < UNIX_HASH_SIZE; i++) {
spin_lock(&unix_table_locks[i]);
+ spin_lock(&net->unx.table.locks[i]);
sk_for_each(sk, &unix_socket_table[i])
if (ino == sock_i_ino(sk)) {
sock_hold(sk);
+ spin_unlock(&net->unx.table.locks[i]);
spin_unlock(&unix_table_locks[i]);
return sk;
}
+ spin_unlock(&net->unx.table.locks[i]);
spin_unlock(&unix_table_locks[i]);
}
return NULL;
@@ -257,16 +263,17 @@ static int unix_diag_get_exact(struct sk_buff *in_skb,
const struct nlmsghdr *nlh,
struct unix_diag_req *req)
{
- int err = -EINVAL;
- struct sock *sk;
- struct sk_buff *rep;
- unsigned int extra_len;
struct net *net = sock_net(in_skb->sk);
+ unsigned int extra_len;
+ struct sk_buff *rep;
+ struct sock *sk;
+ int err;
+ err = -EINVAL;
if (req->udiag_ino == 0)
goto out_nosk;
- sk = unix_lookup_by_ino(req->udiag_ino);
+ sk = unix_lookup_by_ino(net, req->udiag_ino);
err = -ENOENT;
if (sk == NULL)
goto out_nosk;
--
2.30.2
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