numam-spdk/lib/sock
Ziye Yang d5cd0b13b6 sock: Fix the "sock remove assert bug" in spdk_sock_group_remove_sock
The statement causes this issue is:

assert(group_impl->num_removed_socks < MAX_EVENTS_PER_POLL);

The call trace is:

The previous solution is:
commitid with: e71e81b631

But with this solution, it will always add the sock
into the removed_socks list even if it is not under polling
context by sock_group_impl_poll_count. So it will exceed the size of
removed_socks array if sock_group_impl_poll_count function will not be
called. And we should not use a large array, because it is just a workaround,
it just hides the bug.

So our current solution is:

1 Remove the code in sock layer, i.e., rollback the commit
 e71e81b631. This patch is
not the right fix. The sock->cb_fn's NULL pointer case is
caused by the cb_fn of write operation (if the
spdk_sock_group_remove_sock is inside the cb_fn). And it is not
caused by the epoll related cache issue described in commit
"e7181.." commit, but caused by the following situation:

(1)The socket's cb_fn is set to NULL which is caused by
spdk_sock_group_remove_sock by the socket itself
inside a call back function from a write operation.

(2) And the socket is already in the pending_recv list. It is
not caused by the epoll event issue, e.g., socket A changes Socket B's
cb_fn. By the way, A socket A should never remove a socket B from a polling group.
If it really does it, it should use spdk_thread_sendmsg to make sure
it happens in the next round.

2 Add the code check in each posix, uring implementation module.
If sock->cb_fn is NULL, we will not return the socket to the active socks list.
And this is enough to address the issue.

Signed-off-by: Ziye Yang <ziye.yang@intel.com>
Change-Id: I79187f2f1301c819c46a5c3bdd84372f75534f2f
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/6472
Reviewed-by: Xiaodong Liu <xiaodong.liu@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
2021-02-24 13:06:50 +00:00
..
Makefile so_ver: increase all major versions 2021-02-05 14:43:47 +00:00
sock_rpc.c lib/jsonrpc: Add a new API to send response for writing bool result. 2020-11-16 15:08:47 +00:00
sock.c sock: Fix the "sock remove assert bug" in spdk_sock_group_remove_sock 2021-02-24 13:06:50 +00:00
spdk_sock.map sock: Add new API to set default sock implementation 2020-10-05 08:22:53 +00:00