Commit 3eca8945 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag '6.7-rc8-smb3-mchan-fixes' of git://git.samba.org/sfrench/cifs-2.6 

Pull smb client fixes from Steve French:
 "Three important multichannel smb3 client fixes found in recent
  testing:

   - fix oops due to incorrect refcounting of interfaces after
     disabling multichannel

   - fix possible unrecoverable session state after disabling
     multichannel with active sessions

   - fix two places that were missing use of chan_lock"

* tag '6.7-rc8-smb3-mchan-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: do not depend on release_iface for maintaining iface_list
  cifs: cifs_chan_is_iface_active should be called with chan_lock held
  cifs: after disabling multichannel, mark tcon for reconnect
parents 1f874787 09eeb072

fs/smb/client/cifsglob.h

+0 −1
Original line number Diff line number Diff line
@@ -994,7 +994,6 @@ release_iface(struct kref *ref) 
	struct cifs_server_iface *iface = container_of(ref,

						       struct cifs_server_iface,

						       refcount);

	list_del_init(&iface->iface_head);

	kfree(iface);

}

fs/smb/client/connect.c

+17 −10
Original line number Diff line number Diff line
@@ -216,22 +216,29 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server, 
	/* If server is a channel, select the primary channel */

	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;





	spin_lock(&cifs_tcp_ses_lock);

	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {

	/*

		 * if channel has been marked for termination, nothing to do

		 * for the channel. in fact, we cannot find the channel for the

		 * server. So safe to exit here

	 * if the server has been marked for termination, there is a

	 * chance that the remaining channels all need reconnect. To be

	 * on the safer side, mark the session and trees for reconnect

	 * for this scenario. This might cause a few redundant session

	 * setup and tree connect requests, but it is better than not doing

	 * a tree connect when needed, and all following requests failing

	 */

		if (server->terminate)

			break;

	if (server->terminate) {

		mark_smb_session = true;

		server = pserver;

	}



	spin_lock(&cifs_tcp_ses_lock);

	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {

		/* check if iface is still active */

		if (!cifs_chan_is_iface_active(ses, server))

		spin_lock(&ses->chan_lock);

		if (!cifs_chan_is_iface_active(ses, server)) {

			spin_unlock(&ses->chan_lock);

			cifs_chan_update_iface(ses, server);



			spin_lock(&ses->chan_lock);

		}



		if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) {

			spin_unlock(&ses->chan_lock);

			continue;

fs/smb/client/smb2ops.c

+23 −11
Original line number Diff line number Diff line
@@ -595,16 +595,12 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf, 
	}



	/*

	 * Go through iface_list and do kref_put to remove

	 * any unused ifaces. ifaces in use will be removed

	 * when the last user calls a kref_put on it

	 * Go through iface_list and mark them as inactive

	 */

	list_for_each_entry_safe(iface, niface, &ses->iface_list,

				 iface_head) {

				 iface_head)

		iface->is_active = 0;

		kref_put(&iface->refcount, release_iface);

		ses->iface_count--;

	}



	spin_unlock(&ses->iface_lock);



	/*
@@ -678,10 +674,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf, 
					 iface_head) {

			ret = iface_cmp(iface, &tmp_iface);

			if (!ret) {

				/* just get a ref so that it doesn't get picked/freed */

				iface->is_active = 1;

				kref_get(&iface->refcount);

				ses->iface_count++;

				spin_unlock(&ses->iface_lock);

				goto next_iface;

			} else if (ret < 0) {
@@ -748,6 +741,20 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf, 
	}



out:

	/*

	 * Go through the list again and put the inactive entries

	 */

	spin_lock(&ses->iface_lock);

	list_for_each_entry_safe(iface, niface, &ses->iface_list,

				 iface_head) {

		if (!iface->is_active) {

			list_del(&iface->iface_head);

			kref_put(&iface->refcount, release_iface);

			ses->iface_count--;

		}

	}

	spin_unlock(&ses->iface_lock);



	return rc;

}
@@ -784,9 +791,14 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon, bool in_ 
		goto out;



	/* check if iface is still active */

	spin_lock(&ses->chan_lock);

	pserver = ses->chans[0].server;

	if (pserver && !cifs_chan_is_iface_active(ses, pserver))

	if (pserver && !cifs_chan_is_iface_active(ses, pserver)) {

		spin_unlock(&ses->chan_lock);

		cifs_chan_update_iface(ses, pserver);

		spin_lock(&ses->chan_lock);

	}

	spin_unlock(&ses->chan_lock);



out:

	kfree(out_buf);