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Revert "cifs: reconnect work should have reference on server struct"

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[ Upstream commit 823342524868168bf681f135d01b4ae10f5863ec ]

This reverts commit 19a4b9d6c372cab6a3b2c9a061a236136fe95274.

This earlier commit was making an assumption that each mod_delayed_work
called for the reconnect work would result in smb2_reconnect_server
being called twice. This assumption turns out to be untrue. So reverting
this change for now.

I will submit a follow-up patch to fix the actual problem in a different
way.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: 78e727e58e54 ("cifs: update iface_last_update on each query-and-update")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Shyam Prasad N 2023-12-06 16:37:37 +00:00 committed by Greg Kroah-Hartman
parent 3e1615361b
commit 3a0ef868fb
2 changed files with 16 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
fs/smb/client/connect.c
View File

@ -401,13 +401,7 @@ static int __cifs_reconnect(struct TCP_Server_Info *server,
spin_unlock(&server->srv_lock);
cifs_swn_reset_server_dstaddr(server);
cifs_server_unlock(server);
/* increase ref count which reconnect work will drop */
spin_lock(&cifs_tcp_ses_lock);
server->srv_count++;
spin_unlock(&cifs_tcp_ses_lock);
if (mod_delayed_work(cifsiod_wq, &server->reconnect, 0))
cifs_put_tcp_session(server, false);
mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
}
} while (server->tcpStatus == CifsNeedReconnect);
@ -537,13 +531,7 @@ static int reconnect_dfs_server(struct TCP_Server_Info *server)
spin_unlock(&server->srv_lock);
cifs_swn_reset_server_dstaddr(server);
cifs_server_unlock(server);
/* increase ref count which reconnect work will drop */
spin_lock(&cifs_tcp_ses_lock);
server->srv_count++;
spin_unlock(&cifs_tcp_ses_lock);
if (mod_delayed_work(cifsiod_wq, &server->reconnect, 0))
cifs_put_tcp_session(server, false);
mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
} while (server->tcpStatus == CifsNeedReconnect);
mutex_lock(&server->refpath_lock);
@ -1630,19 +1618,16 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
cancel_delayed_work_sync(&server->echo);
if (from_reconnect) {
if (from_reconnect)
/*
* Avoid deadlock here: reconnect work calls
* cifs_put_tcp_session() at its end. Need to be sure
* that reconnect work does nothing with server pointer after
* that step.
*/
if (cancel_delayed_work(&server->reconnect))
cifs_put_tcp_session(server, from_reconnect);
} else {
if (cancel_delayed_work_sync(&server->reconnect))
cifs_put_tcp_session(server, from_reconnect);
}
cancel_delayed_work(&server->reconnect);
else
cancel_delayed_work_sync(&server->reconnect);
spin_lock(&server->srv_lock);
server->tcpStatus = CifsExiting;

23
fs/smb/client/smb2pdu.c
View File

@ -3981,6 +3981,12 @@ void smb2_reconnect_server(struct work_struct *work)
}
spin_unlock(&ses->chan_lock);
}
/*
* Get the reference to server struct to be sure that the last call of
* cifs_put_tcon() in the loop below won't release the server pointer.
*/
if (tcon_exist || ses_exist)
server->srv_count++;
spin_unlock(&cifs_tcp_ses_lock);
@ -4028,17 +4034,13 @@ void smb2_reconnect_server(struct work_struct *work)
done:
cifs_dbg(FYI, "Reconnecting tcons and channels finished\n");
if (resched) {
if (resched)
queue_delayed_work(cifsiod_wq, &server->reconnect, 2 * HZ);
mutex_unlock(&pserver->reconnect_mutex);
/* no need to put tcp session as we're retrying */
return;
}
mutex_unlock(&pserver->reconnect_mutex);
/* now we can safely release srv struct */
cifs_put_tcp_session(server, true);
if (tcon_exist || ses_exist)
cifs_put_tcp_session(server, 1);
}
int
@ -4058,12 +4060,7 @@ SMB2_echo(struct TCP_Server_Info *server)
server->ops->need_neg(server)) {
spin_unlock(&server->srv_lock);
/* No need to send echo on newly established connections */
spin_lock(&cifs_tcp_ses_lock);
server->srv_count++;
spin_unlock(&cifs_tcp_ses_lock);
if (mod_delayed_work(cifsiod_wq, &server->reconnect, 0))
cifs_put_tcp_session(server, false);
mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
return rc;
}
spin_unlock(&server->srv_lock);