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Jiri Bohac authored
commit 01462405 upstream. This fixes an old regression introduced by commit b0d0d915 (ipx: remove the BKL). When a recvmsg syscall blocks waiting for new data, no data can be sent on the same socket with sendmsg because ipx_recvmsg() sleeps with the socket locked. This breaks mars-nwe (NetWare emulator): - the ncpserv process reads the request using recvmsg - ncpserv forks and spawns nwconn - ncpserv calls a (blocking) recvmsg and waits for new requests - nwconn deadlocks in sendmsg on the same socket Commit b0d0d915 has simply replaced BKL locking with lock_sock/release_sock. Unlike now, BKL got unlocked while sleeping, so a blocking recvmsg did not block a concurrent sendmsg. Only keep the socket locked while actually working with the socket data and release it prior to calling skb_recv_datagram(). Signed-off-by:
Jiri Bohac <jbohac@suse.cz> Reviewed-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
Luis Henriques <luis.henriques@canonical.com>
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