From f78a5fda9116525809d088917638be912b85f838 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Fri, 16 Sep 2011 19:34:00 -0400 Subject: Revert "Scm: Remove unnecessary pid & credential references in Unix socket's send and receive path" This reverts commit 0856a304091b33a8e8f9f9c98e776f425af2b625. As requested by Eric Dumazet, it has various ref-counting problems and has introduced regressions. Eric will add a more suitable version of this performance fix. Signed-off-by: David S. Miller --- net/unix/af_unix.c | 45 ++++++++++++++++----------------------------- 1 file changed, 16 insertions(+), 29 deletions(-) (limited to 'net/unix/af_unix.c') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index e6d9d1014ed..ec68e1c05b8 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1378,17 +1378,11 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) return max_level; } -static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, - bool send_fds, bool ref) +static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds) { int err = 0; - if (ref) { - UNIXCB(skb).pid = get_pid(scm->pid); - UNIXCB(skb).cred = get_cred(scm->cred); - } else { - UNIXCB(skb).pid = scm->pid; - UNIXCB(skb).cred = scm->cred; - } + UNIXCB(skb).pid = get_pid(scm->pid); + UNIXCB(skb).cred = get_cred(scm->cred); UNIXCB(skb).fp = NULL; if (scm->fp && send_fds) err = unix_attach_fds(scm, skb); @@ -1413,7 +1407,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, int namelen = 0; /* fake GCC */ int err; unsigned hash; - struct sk_buff *skb = NULL; + struct sk_buff *skb; long timeo; struct scm_cookie tmp_scm; int max_level; @@ -1454,7 +1448,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, if (skb == NULL) goto out; - err = unix_scm_to_skb(siocb->scm, skb, true, false); + err = unix_scm_to_skb(siocb->scm, skb, true); if (err < 0) goto out_free; max_level = err + 1; @@ -1550,7 +1544,7 @@ restart: unix_state_unlock(other); other->sk_data_ready(other, len); sock_put(other); - scm_release(siocb->scm); + scm_destroy(siocb->scm); return len; out_unlock: @@ -1560,8 +1554,7 @@ out_free: out: if (other) sock_put(other); - if (skb == NULL) - scm_destroy(siocb->scm); + scm_destroy(siocb->scm); return err; } @@ -1573,7 +1566,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, struct sock *sk = sock->sk; struct sock *other = NULL; int err, size; - struct sk_buff *skb = NULL; + struct sk_buff *skb; int sent = 0; struct scm_cookie tmp_scm; bool fds_sent = false; @@ -1638,11 +1631,11 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, size = min_t(int, size, skb_tailroom(skb)); - /* Only send the fds and no ref to pid in the first buffer */ - err = unix_scm_to_skb(siocb->scm, skb, !fds_sent, fds_sent); + /* Only send the fds in the first buffer */ + err = unix_scm_to_skb(siocb->scm, skb, !fds_sent); if (err < 0) { kfree_skb(skb); - goto out; + goto out_err; } max_level = err + 1; fds_sent = true; @@ -1650,7 +1643,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); if (err) { kfree_skb(skb); - goto out; + goto out_err; } unix_state_lock(other); @@ -1667,10 +1660,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, sent += size; } - if (skb) - scm_release(siocb->scm); - else - scm_destroy(siocb->scm); + scm_destroy(siocb->scm); siocb->scm = NULL; return sent; @@ -1683,9 +1673,7 @@ pipe_err: send_sig(SIGPIPE, current, 0); err = -EPIPE; out_err: - if (skb == NULL) - scm_destroy(siocb->scm); -out: + scm_destroy(siocb->scm); siocb->scm = NULL; return sent ? : err; } @@ -1789,7 +1777,7 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, siocb->scm = &tmp_scm; memset(&tmp_scm, 0, sizeof(tmp_scm)); } - scm_set_cred_noref(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); + scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); unix_set_secdata(siocb->scm, skb); if (!(flags & MSG_PEEK)) { @@ -1951,8 +1939,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, } } else { /* Copy credentials */ - scm_set_cred_noref(siocb->scm, UNIXCB(skb).pid, - UNIXCB(skb).cred); + scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred); check_creds = 1; } -- cgit v1.2.3