net: remove sock_iocb
The sock_iocb structure is allocate on stack for each read/write-like
operation on sockets, and contains various fields of which only the
embedded msghdr and sometimes a pointer to the scm_cookie is ever used.
Get rid of the sock_iocb and put a msghdr directly on the stack and pass
the scm_cookie explicitly to netlink_mmap_sendmsg.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 8e1b102..526b6ed 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1445,7 +1445,6 @@
static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
struct msghdr *msg, size_t len)
{
- struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
struct sock *sk = sock->sk;
struct net *net = sock_net(sk);
struct unix_sock *u = unix_sk(sk);
@@ -1456,14 +1455,12 @@
unsigned int hash;
struct sk_buff *skb;
long timeo;
- struct scm_cookie tmp_scm;
+ struct scm_cookie scm;
int max_level;
int data_len = 0;
- if (NULL == siocb->scm)
- siocb->scm = &tmp_scm;
wait_for_unix_gc();
- err = scm_send(sock, msg, siocb->scm, false);
+ err = scm_send(sock, msg, &scm, false);
if (err < 0)
return err;
@@ -1507,11 +1504,11 @@
if (skb == NULL)
goto out;
- err = unix_scm_to_skb(siocb->scm, skb, true);
+ err = unix_scm_to_skb(&scm, skb, true);
if (err < 0)
goto out_free;
max_level = err + 1;
- unix_get_secdata(siocb->scm, skb);
+ unix_get_secdata(&scm, skb);
skb_put(skb, len - data_len);
skb->data_len = data_len;
@@ -1606,7 +1603,7 @@
unix_state_unlock(other);
other->sk_data_ready(other);
sock_put(other);
- scm_destroy(siocb->scm);
+ scm_destroy(&scm);
return len;
out_unlock:
@@ -1616,7 +1613,7 @@
out:
if (other)
sock_put(other);
- scm_destroy(siocb->scm);
+ scm_destroy(&scm);
return err;
}
@@ -1628,21 +1625,18 @@
static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
struct msghdr *msg, size_t len)
{
- struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
struct sock *sk = sock->sk;
struct sock *other = NULL;
int err, size;
struct sk_buff *skb;
int sent = 0;
- struct scm_cookie tmp_scm;
+ struct scm_cookie scm;
bool fds_sent = false;
int max_level;
int data_len;
- if (NULL == siocb->scm)
- siocb->scm = &tmp_scm;
wait_for_unix_gc();
- err = scm_send(sock, msg, siocb->scm, false);
+ err = scm_send(sock, msg, &scm, false);
if (err < 0)
return err;
@@ -1683,7 +1677,7 @@
goto out_err;
/* Only send the fds in the first buffer */
- err = unix_scm_to_skb(siocb->scm, skb, !fds_sent);
+ err = unix_scm_to_skb(&scm, skb, !fds_sent);
if (err < 0) {
kfree_skb(skb);
goto out_err;
@@ -1715,8 +1709,7 @@
sent += size;
}
- scm_destroy(siocb->scm);
- siocb->scm = NULL;
+ scm_destroy(&scm);
return sent;
@@ -1728,8 +1721,7 @@
send_sig(SIGPIPE, current, 0);
err = -EPIPE;
out_err:
- scm_destroy(siocb->scm);
- siocb->scm = NULL;
+ scm_destroy(&scm);
return sent ? : err;
}
@@ -1778,8 +1770,7 @@
struct msghdr *msg, size_t size,
int flags)
{
- struct sock_iocb *siocb = kiocb_to_siocb(iocb);
- struct scm_cookie tmp_scm;
+ struct scm_cookie scm;
struct sock *sk = sock->sk;
struct unix_sock *u = unix_sk(sk);
int noblock = flags & MSG_DONTWAIT;
@@ -1831,16 +1822,14 @@
if (sock_flag(sk, SOCK_RCVTSTAMP))
__sock_recv_timestamp(msg, sk, skb);
- if (!siocb->scm) {
- siocb->scm = &tmp_scm;
- memset(&tmp_scm, 0, sizeof(tmp_scm));
- }
- scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
- unix_set_secdata(siocb->scm, skb);
+ memset(&scm, 0, sizeof(scm));
+
+ scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
+ unix_set_secdata(&scm, skb);
if (!(flags & MSG_PEEK)) {
if (UNIXCB(skb).fp)
- unix_detach_fds(siocb->scm, skb);
+ unix_detach_fds(&scm, skb);
sk_peek_offset_bwd(sk, skb->len);
} else {
@@ -1860,11 +1849,11 @@
sk_peek_offset_fwd(sk, size);
if (UNIXCB(skb).fp)
- siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
+ scm.fp = scm_fp_dup(UNIXCB(skb).fp);
}
err = (flags & MSG_TRUNC) ? skb->len - skip : size;
- scm_recv(sock, msg, siocb->scm, flags);
+ scm_recv(sock, msg, &scm, flags);
out_free:
skb_free_datagram(sk, skb);
@@ -1915,8 +1904,7 @@
struct msghdr *msg, size_t size,
int flags)
{
- struct sock_iocb *siocb = kiocb_to_siocb(iocb);
- struct scm_cookie tmp_scm;
+ struct scm_cookie scm;
struct sock *sk = sock->sk;
struct unix_sock *u = unix_sk(sk);
DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name);
@@ -1943,10 +1931,7 @@
* while sleeps in memcpy_tomsg
*/
- if (!siocb->scm) {
- siocb->scm = &tmp_scm;
- memset(&tmp_scm, 0, sizeof(tmp_scm));
- }
+ memset(&scm, 0, sizeof(scm));
err = mutex_lock_interruptible(&u->readlock);
if (unlikely(err)) {
@@ -2012,13 +1997,13 @@
if (check_creds) {
/* Never glue messages from different writers */
- if ((UNIXCB(skb).pid != siocb->scm->pid) ||
- !uid_eq(UNIXCB(skb).uid, siocb->scm->creds.uid) ||
- !gid_eq(UNIXCB(skb).gid, siocb->scm->creds.gid))
+ if ((UNIXCB(skb).pid != scm.pid) ||
+ !uid_eq(UNIXCB(skb).uid, scm.creds.uid) ||
+ !gid_eq(UNIXCB(skb).gid, scm.creds.gid))
break;
} else if (test_bit(SOCK_PASSCRED, &sock->flags)) {
/* Copy credentials */
- scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
+ scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
check_creds = 1;
}
@@ -2045,7 +2030,7 @@
sk_peek_offset_bwd(sk, chunk);
if (UNIXCB(skb).fp)
- unix_detach_fds(siocb->scm, skb);
+ unix_detach_fds(&scm, skb);
if (unix_skb_len(skb))
break;
@@ -2053,13 +2038,13 @@
skb_unlink(skb, &sk->sk_receive_queue);
consume_skb(skb);
- if (siocb->scm->fp)
+ if (scm.fp)
break;
} else {
/* It is questionable, see note in unix_dgram_recvmsg.
*/
if (UNIXCB(skb).fp)
- siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
+ scm.fp = scm_fp_dup(UNIXCB(skb).fp);
sk_peek_offset_fwd(sk, chunk);
@@ -2068,7 +2053,7 @@
} while (size);
mutex_unlock(&u->readlock);
- scm_recv(sock, msg, siocb->scm, flags);
+ scm_recv(sock, msg, &scm, flags);
out:
return copied ? : err;
}