LU-9558 lnet: kernel socket accept takes new bool agrument

During the development of the linux 4.11 kernel it was discovered
that the kernel socket layer could get into lockdep situation. To
handle this a new bool argument was added to the accept member
of struct socket. For LNet we can always pass false.

Lustre-commit: 15045c90
Lustre-change: https://review.whamcloud.com/27642



Change-Id: I420cda95b70cf927b1a6e3493b631bc5a3585d74
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/27642


Reviewed-by: Doug Oucharek <doug@cadentcomputing.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: https://review.whamcloud.com/28463


Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>

lnet/autoconf/lustre-lnet.m4

@@ -734,6 +734,27 @@ LB_CHECK_EXPORT([kmap_to_page], [mm/highmem.c],
                 [kmap_to_page is exported by the kernel])])
 ]) # LN_EXPORT_KMAP_TO_PAG
 
+#
+# LN_CONFIG_SOCK_ACCEPT
+#
+# 4.11 commit cdfbabfb2f0ce983fdaa42f20e5f7842178fc01e added a flag
+# to handle a possible lockdep condition kernel socket accept.
+#
+AC_DEFUN([LN_CONFIG_SOCK_ACCEPT], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if 'struct sock' accept function requires a bool argument],
+kern_sock_flag, [
+	#include <linux/net.h>
+],[
+	((struct socket *)0)->ops->accept(NULL, NULL, O_NONBLOCK, false);
+],[
+	AC_DEFINE(HAVE_KERN_SOCK_ACCEPT_FLAG_ARG, 1,
+		['struct sock' accept function requires bool argument])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LN_CONFIG_SOCK_ACCEPT
+
 #
 # LN_PROG_LINUX
 #
@@ -753,10 +774,12 @@ LN_CONFIG_SK_SLEEP
 LN_CONFIG_TCP_SENDPAGE
 # 3.10
 LN_EXPORT_KMAP_TO_PAGE
-# 4.x
-LN_CONFIG_SOCK_CREATE_KERN
 # 3.15
 LN_CONFIG_SK_DATA_READY
+# 4.x
+LN_CONFIG_SOCK_CREATE_KERN
+# 4.11
+LN_CONFIG_SOCK_ACCEPT
 ]) # LN_PROG_LINUX
 
 #

lnet/lnet/lib-socket.c

@@ -582,7 +582,11 @@ lnet_sock_accept(struct socket **newsockp, struct socket *sock)
 
 	newsock->ops = sock->ops;
 
+#ifdef HAVE_KERN_SOCK_ACCEPT_FLAG_ARG
+	rc = sock->ops->accept(sock, newsock, O_NONBLOCK, false);
+#else
 	rc = sock->ops->accept(sock, newsock, O_NONBLOCK);
+#endif
 	if (rc == -EAGAIN) {
 		/* Nothing ready, so wait for activity */
 		init_waitqueue_entry(&wait, current);
@@ -590,7 +594,11 @@ lnet_sock_accept(struct socket **newsockp, struct socket *sock)
 		set_current_state(TASK_INTERRUPTIBLE);
 		schedule();
 		remove_wait_queue(sk_sleep(sock->sk), &wait);
+#ifdef HAVE_KERN_SOCK_ACCEPT_FLAG_ARG
+		rc = sock->ops->accept(sock, newsock, O_NONBLOCK, false);
+#else
 		rc = sock->ops->accept(sock, newsock, O_NONBLOCK);
+#endif
 	}
 
 	if (rc != 0)