tcp: replace hard coded GFP_KERNEL with sk_allocation
This fixed a lockdep warning which appeared when doing stress
memory tests over NFS:
inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
page reclaim => nfs_writepage => tcp_sendmsg => lock sk_lock
mount_root => nfs_root_data => tcp_close => lock sk_lock =>
tcp_send_fin => alloc_skb_fclone => page reclaim
David raised a concern that if the allocation fails in tcp_send_fin(), and it's
GFP_ATOMIC, we are going to yield() (which sleeps) and loop endlessly waiting
for the allocation to succeed.
But fact is, the original GFP_KERNEL also sleeps. GFP_ATOMIC+yield() looks
weird, but it is no worse the implicit sleep inside GFP_KERNEL. Both could
loop endlessly under memory pressure.
CC: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
CC: David S. Miller <davem@davemloft.net>
CC: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index df50bc4..b71a446 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1186,7 +1186,7 @@
#define tcp_twsk_md5_key(twsk) NULL
#endif
-extern struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void);
+extern struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(struct sock *);
extern void tcp_free_md5sig_pool(void);
extern struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu);