segfault at sys_readv () from /lib64/libvma.so

[syspro4]

segfault at sys_readv () from /lib64/libvma.so

[syspro4]

Thanks for the reply!
I will change the gluster code and replace glusterfs->sys_readv to new_sys_readv() and try to use libvma.

[igor-ivanov]

Hello @syspro4
Thank you for reporting the issue.
I think that this issue might happen because of symbol sys_readv conflict. It exists in glusterfs and libvma

glusterfs: https://github.com/gluster/glusterfs/blob/2ff6e2d5e217ab555ff63026017151edf2ba1adf/rpc/rpc-transport/socket/src/socket.c#L557

libvma:

libvma/src/vma/lwip/tcp_out.c

Line 123 in bcc3670

sys_readv_fn sys_readv;

Solution will be planned.

[syspro4]

I fixed gluserfs->sys_readv to new_sys_readv() and now I can start glusterd with libvma.
But now it fails to spawn new process (glusterfsd). glusterfsd is a daemon process which does actual IOs to the underlying file system. Does libvma supports fork/execvp() system call?

In the log I see following error messages:

[2021-11-29 22:37:07.547610 +0000] I [glusterfsd.c:2418:daemonize] 0-glusterfs: Pid of current running process is 6511
[2021-11-29 22:37:10.928985 +0000] I [socket.c:929:__socket_server_bind] 0-socket.glusterfsd: closing (AF_UNIX) reuse check socket 103
[2021-11-29 22:37:10.929176 +0000] E [MSGID: 101187] [event-epoll.c:429:event_register_epoll] 0-epoll: failed to add fd to epoll [{fd=102}, {epoll_fd=52}, {errno=9}, {error=Bad file descriptor}]
[2021-11-29 22:37:10.929196 +0000] W [socket.c:3779:socket_listen] 0-socket.glusterfsd: could not register socket 102 with events; closing socket
[2021-11-29 22:37:10.929218 +0000] W [rpcsvc.c:1993:rpcsvc_create_listener] 0-rpc-service: listening on transport failed

Thanks

[igor-ivanov]

Nice to see that sys_readv issue can be overcome.
libvma supports fork()/exec() case. See 24bd173
and
related test as https://github.com/Mellanox/libvma/tree/master/tests/simple_fork
VMA_TRACELEVEL=4 can be used to display VMA output.

[syspro4]

Thanks for the reply.
But I am getting error while running the Gluster services (glusterd & glusterfsd) in demonize mode while using libvma.
I always get same error:

[event-epoll.c:429:event_register_epoll] 0-epoll: failed to add fd to epoll [{fd=102}, {epoll_fd=52}, {errno=9}, {error=Bad file descriptor}]

Is it possible that while forking()/execing() some FDs are getting closed & hence the epoll_ctl(,EPOLL_CTL_ADD, fd, ) call is failing?

[igor-ivanov]

1. I would like to inform that current master should not have symbol conflict initially reported.
2. About #969 (comment)
   Do you know if Gluster application uses flow described at #816?
   Could you try VMA_TRACELEVEL=4 and see suspicuos VMA output around [event-epoll.c:429:event_register_epoll] 0-epoll: failed to add fd to epoll [{fd=102}, {epoll_fd=52}, {errno=9}, {error=Bad file descriptor}]