cifs: do not search for channel if server is terminating

In order to scale down the channels, the following sequence
of operations happen:
1. server struct is marked for terminate
2. the channel is deallocated in the ses->chans array
3. at a later point the cifsd thread actually terminates the server

Between 2 and 3, there can be calls to find the channel for
a server struct. When that happens, there can be an ugly warning
that's logged. But this is expected.

So this change does two things:
1. in cifs_ses_get_chan_index, if server->terminate is set, return
2. always make sure server->terminate is set with chan_lock held

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Shyam Prasad N 2024-02-01 11:15:28 +00:00 committed by Steve French
parent e77e15fa5e
commit 88675b22d3
2 changed files with 5 additions and 1 deletions

View File

@ -75,6 +75,10 @@ cifs_ses_get_chan_index(struct cifs_ses *ses,
{
unsigned int i;
/* if the channel is waiting for termination */
if (server->terminate)
return CIFS_INVAL_CHAN_INDEX;
for (i = 0; i < ses->chan_count; i++) {
if (ses->chans[i].server == server)
return i;

View File

@ -178,6 +178,7 @@ cifs_chan_skip_or_disable(struct cifs_ses *ses,
}
ses->chans[chan_index].server = NULL;
server->terminate = true;
spin_unlock(&ses->chan_lock);
/*
@ -188,7 +189,6 @@ cifs_chan_skip_or_disable(struct cifs_ses *ses,
*/
cifs_put_tcp_session(server, from_reconnect);
server->terminate = true;
cifs_signal_cifsd_for_reconnect(server, false);
/* mark primary server as needing reconnect */