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| author | Andrey Vagin <avagin@openvz.org> | 2011-02-21 02:40:47 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-02-28 12:18:12 -0800 |
| commit | b44d211e166b4b0dae8ce379f9d2e3ac164b5b60 (patch) | |
| tree | 1af9b2e472f35813e0fb99d183a6610a90bf7195 /net/netlink/af_netlink.c | |
| parent | dad3d44dcb054e9d0514fbf65ee4a2d88cf1698f (diff) | |
| download | blackbird-op-linux-b44d211e166b4b0dae8ce379f9d2e3ac164b5b60.tar.gz blackbird-op-linux-b44d211e166b4b0dae8ce379f9d2e3ac164b5b60.zip | |
netlink: handle errors from netlink_dump()
netlink_dump() may failed, but nobody handle its error.
It generates output data, when a previous portion has been returned to
user space. This mechanism works when all data isn't go in skb. If we
enter in netlink_recvmsg() and skb is absent in the recv queue, the
netlink_dump() will not been executed. So if netlink_dump() is failed
one time, the new data never appear and the reader will sleep forever.
netlink_dump() is called from two places:
1. from netlink_sendmsg->...->netlink_dump_start().
In this place we can report error directly and it will be returned
by sendmsg().
2. from netlink_recvmsg
There we can't report error directly, because we have a portion of
valid output data and call netlink_dump() for prepare the next portion.
If netlink_dump() is failed, the socket will be mark as error and the
next recvmsg will be failed.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink/af_netlink.c')
| -rw-r--r-- | net/netlink/af_netlink.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 478181d53c55..1f924595bdef 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1407,7 +1407,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, int noblock = flags&MSG_DONTWAIT; size_t copied; struct sk_buff *skb, *data_skb; - int err; + int err, ret; if (flags&MSG_OOB) return -EOPNOTSUPP; @@ -1470,8 +1470,13 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, skb_free_datagram(sk, skb); - if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) - netlink_dump(sk); + if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { + ret = netlink_dump(sk); + if (ret) { + sk->sk_err = ret; + sk->sk_error_report(sk); + } + } scm_recv(sock, msg, siocb->scm, flags); out: @@ -1736,6 +1741,7 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, struct netlink_callback *cb; struct sock *sk; struct netlink_sock *nlk; + int ret; cb = kzalloc(sizeof(*cb), GFP_KERNEL); if (cb == NULL) @@ -1764,9 +1770,13 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, nlk->cb = cb; mutex_unlock(nlk->cb_mutex); - netlink_dump(sk); + ret = netlink_dump(sk); + sock_put(sk); + if (ret) + return ret; + /* We successfully started a dump, by returning -EINTR we * signal not to send ACK even if it was requested. */ |
