From e6b4b873896f0e9298f70d25726f4bb1e1b265ba Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 24 Nov 2021 11:14:29 +0900 Subject: af_unix: Save hash in sk_hash. To replace unix_table_lock with per-hash locks in the next patch, we need to save a hash in each socket because /proc/net/unix or BPF prog iterate sockets while holding a hash table lock and release it later in a different function. Currently, we store a real/pseudo hash in struct unix_address. However, we do not allocate it to unbound sockets, nor should we do just for that. For this purpose, we can use sk_hash. Then, we no longer use the hash field in struct unix_address and can remove it. Also, this patch does - rename unix_insert_socket() to unix_insert_unbound_socket() - remove the redundant list argument from __unix_insert_socket() and unix_insert_unbound_socket() - use 'unsigned int' instead of 'unsigned' in __unix_set_addr_hash() - remove 'inline' from unix_remove_socket() and unix_insert_unbound_socket(). Signed-off-by: Kuniyuki Iwashima Signed-off-by: Jakub Kicinski --- net/unix/af_unix.c | 42 +++++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 19 deletions(-) (limited to 'net/unix') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 076d0297450d..bd9fbfe0e7bb 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -280,31 +280,33 @@ static void __unix_remove_socket(struct sock *sk) sk_del_node_init(sk); } -static void __unix_insert_socket(struct hlist_head *list, struct sock *sk) +static void __unix_insert_socket(struct sock *sk) { WARN_ON(!sk_unhashed(sk)); - sk_add_node(sk, list); + sk_add_node(sk, &unix_socket_table[sk->sk_hash]); } -static void __unix_set_addr(struct sock *sk, struct unix_address *addr, - unsigned hash) +static void __unix_set_addr_hash(struct sock *sk, struct unix_address *addr, + unsigned int hash) { __unix_remove_socket(sk); smp_store_release(&unix_sk(sk)->addr, addr); - __unix_insert_socket(&unix_socket_table[hash], sk); + + sk->sk_hash = hash; + __unix_insert_socket(sk); } -static inline void unix_remove_socket(struct sock *sk) +static void unix_remove_socket(struct sock *sk) { spin_lock(&unix_table_lock); __unix_remove_socket(sk); spin_unlock(&unix_table_lock); } -static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk) +static void unix_insert_unbound_socket(struct sock *sk) { spin_lock(&unix_table_lock); - __unix_insert_socket(list, sk); + __unix_insert_socket(sk); spin_unlock(&unix_table_lock); } @@ -893,6 +895,7 @@ static struct sock *unix_create1(struct net *net, struct socket *sock, int kern, sock_init_data(sock, sk); + sk->sk_hash = unix_unbound_hash(sk); sk->sk_allocation = GFP_KERNEL_ACCOUNT; sk->sk_write_space = unix_write_space; sk->sk_max_ack_backlog = net->unx.sysctl_max_dgram_qlen; @@ -908,7 +911,7 @@ 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_socket(&unix_socket_table[unix_unbound_hash(sk)], sk); + unix_insert_unbound_socket(sk); sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); @@ -1054,6 +1057,7 @@ static int unix_autobind(struct sock *sk) struct unix_address *addr; unsigned int retries = 0; static u32 ordernum = 1; + unsigned int new_hash; int err; err = mutex_lock_interruptible(&u->bindlock); @@ -1075,13 +1079,13 @@ static int unix_autobind(struct sock *sk) retry: addr->len = sprintf(addr->name->sun_path + 1, "%05x", ordernum) + offsetof(struct sockaddr_un, sun_path) + 1; - addr->hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type); + new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type); spin_lock(&unix_table_lock); ordernum = (ordernum+1)&0xFFFFF; if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len, - addr->hash)) { + new_hash)) { spin_unlock(&unix_table_lock); /* * __unix_find_socket_byname() may take long time if many names @@ -1097,7 +1101,7 @@ retry: goto retry; } - __unix_set_addr(sk, addr, addr->hash); + __unix_set_addr_hash(sk, addr, new_hash); spin_unlock(&unix_table_lock); err = 0; @@ -1113,9 +1117,9 @@ static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr, struct unix_sock *u = unix_sk(sk); struct user_namespace *ns; // barf... struct unix_address *addr; + unsigned int new_hash; struct dentry *dentry; struct path parent; - unsigned int hash; int err; unix_mkname_bsd(sunaddr, addr_len); @@ -1151,12 +1155,11 @@ static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr, if (u->addr) goto out_unlock; - addr->hash = UNIX_HASH_SIZE; - hash = unix_bsd_hash(d_backing_inode(dentry)); + new_hash = unix_bsd_hash(d_backing_inode(dentry)); spin_lock(&unix_table_lock); u->path.mnt = mntget(parent.mnt); u->path.dentry = dget(dentry); - __unix_set_addr(sk, addr, hash); + __unix_set_addr_hash(sk, addr, new_hash); spin_unlock(&unix_table_lock); mutex_unlock(&u->bindlock); done_path_create(&parent, dentry); @@ -1180,6 +1183,7 @@ static int unix_bind_abstract(struct sock *sk, struct sockaddr_un *sunaddr, { struct unix_sock *u = unix_sk(sk); struct unix_address *addr; + unsigned int new_hash; int err; addr = unix_create_addr(sunaddr, addr_len); @@ -1195,14 +1199,14 @@ static int unix_bind_abstract(struct sock *sk, struct sockaddr_un *sunaddr, goto out_mutex; } - addr->hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type); + new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type); spin_lock(&unix_table_lock); if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len, - addr->hash)) + new_hash)) goto out_spin; - __unix_set_addr(sk, addr, addr->hash); + __unix_set_addr_hash(sk, addr, new_hash); spin_unlock(&unix_table_lock); mutex_unlock(&u->bindlock); return 0; -- cgit v1.2.3