Messages in this thread | | | Subject | Re: a problem tcp_v4_err() | From | Eric Dumazet <> | Date | Fri, 12 Nov 2010 19:33:23 +0100 |
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Le vendredi 12 novembre 2010 à 21:29 +0300, Alexey Kuznetsov a écrit : > Hello! > > On Fri, Nov 12, 2010 at 07:12:58PM +0100, Eric Dumazet wrote: > > I see socket is locked around line 368, > > > > bh_lock_sock(sk); > > /* If too many ICMPs get dropped on busy > > * servers this needs to be solved differently. > > */ > > if (sock_owned_by_user(sk)) > > NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); > > > > > > Hmm, maybe some goto is missing ;) > > It is not missing, sock_owned_by_user() is checked later when some operation which > cannot be done without lock is required. It was done to save error in sk_err_soft even > when socket is locked. > > This code also _understands_ this: look at > > } else if (sock_owned_by_user(sk)) { > /* RTO revert clocked out retransmission, > * but socket is locked. Will defer. */ > inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, > HZ/20, TCP_RTO_MAX); > > but somehow it considers the manipulations with rto/backoff/write_queue as safe. > Seems, they are not.
Indeed, right you are, I came to same conclusion.
I CC Damian Lukowski in my previous answer (and this one too)
Thanks !
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