Gang He da3627c30d dlm: remove O_NONBLOCK flag in sctp_connect_to_sock ... We should remove O_NONBLOCK flag when calling sock->ops->connect() in sctp_connect_to_sock() function. Why? 1. up to now, sctp socket connect() function ignores the flag argument, that means O_NONBLOCK flag does not take effect, then we should remove it to avoid the confusion (but is not urgent). 2. for the future, there will be a patch to fix this problem, then the flag argument will take effect, the patch has been queued at https://git.kernel.o rg/pub/scm/linux/kernel/git/davem/net.git/commit/net/sctp?id=644fbdeacf1d3ed d366e44b8ba214de9d1dd66a9. But, the O_NONBLOCK flag will make sock->ops->connect() directly return without any wait time, then the connection will not be established, DLM kernel module will call sock->ops->connect() again and again, the bad results are, CPU usage is almost 100%, even trigger soft_lockup problem if the related configurations are enabled, DLM kernel module also prints lots of messages like, [Fri Apr 27 11:23:43 2018] dlm: connecting to 172167592 [Fri Apr 27 11:23:43 2018] dlm: connecting to 172167592 [Fri Apr 27 11:23:43 2018] dlm: connecting to 172167592 [Fri Apr 27 11:23:43 2018] dlm: connecting to 172167592 The upper application (e.g. ocfs2 mount command) is hanged at new_lockspace(), the whole backtrace is as below, tb0307-nd2:~ # cat /proc/2935/stack [<0>] new_lockspace+0x957/0xac0 [dlm] [<0>] dlm_new_lockspace+0xae/0x140 [dlm] [<0>] user_cluster_connect+0xc3/0x3a0 [ocfs2_stack_user] [<0>] ocfs2_cluster_connect+0x144/0x220 [ocfs2_stackglue] [<0>] ocfs2_dlm_init+0x215/0x440 [ocfs2] [<0>] ocfs2_fill_super+0xcb0/0x1290 [ocfs2] [<0>] mount_bdev+0x173/0x1b0 [<0>] mount_fs+0x35/0x150 [<0>] vfs_kern_mount.part.23+0x54/0x100 [<0>] do_mount+0x59a/0xc40 [<0>] SyS_mount+0x80/0xd0 [<0>] do_syscall_64+0x76/0x140 [<0>] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [<0>] 0xffffffffffffffff So, I think we should remove O_NONBLOCK flag here, since DLM kernel module can not handle non-block sockect in connect() properly. Signed-off-by: Gang He <ghe@suse.com> Signed-off-by: David Teigland <teigland@redhat.com>		2018-05-29 10:48:35 -05:00
..
ast.c	DLM: fix overflow dlm_cb_seq	2017-09-25 12:45:21 -05:00
ast.h
config.c	dlm: make config_item_type const	2017-10-19 16:15:22 +02:00
config.h
debug_fs.c
dir.c
dir.h
dlm_internal.h
Kconfig
lock.c	dlm: remove dlm_send_rcom_lookup_dump	2017-10-09 09:29:31 -05:00
lock.h
lockspace.c
lockspace.h
lowcomms.c	dlm: remove O_NONBLOCK flag in sctp_connect_to_sock	2018-05-29 10:48:35 -05:00
lowcomms.h
lvb_table.h
main.c
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
member.c
member.h
memory.c
memory.h
midcomms.c
midcomms.h
netlink.c
plock.c	vfs: do bulk POLL* -> EPOLL* replacement	2018-02-11 14:34:03 -08:00
rcom.c	dlm: remove dlm_send_rcom_lookup_dump	2017-10-09 09:29:31 -05:00
rcom.h	dlm: remove dlm_send_rcom_lookup_dump	2017-10-09 09:29:31 -05:00
recover.c	DLM: retry rcom when dlm_wait_function is timed out.	2017-09-25 12:45:21 -05:00
recover.h
recoverd.c	dlm: recheck kthread_should_stop() before schedule()	2017-09-25 12:48:10 -05:00
recoverd.h
requestqueue.c
requestqueue.h
user.c	vfs: do bulk POLL* -> EPOLL* replacement	2018-02-11 14:34:03 -08:00
user.h
util.c
util.h