Commit df3df923 authored Nov 22, 2019 by Paulo Alcantara (SUSE) Committed by Steve French Nov 25, 2019

cifs: Fix lookup of root ses in DFS referral cache



We don't care about module aliasing validation in
cifs_compose_mount_options(..., is_smb3) when finding the root SMB
session of an DFS namespace in order to refresh DFS referral cache.

The following issue has been observed when mounting with '-t smb3' and
then specifying 'vers=2.0':

...
Nov 08 15:27:08 tw kernel: address conversion returned 0 for FS0.WIN.LOCAL
Nov 08 15:27:08 tw kernel: [kworke] ==> dns_query((null),FS0.WIN.LOCAL,13,(null))
Nov 08 15:27:08 tw kernel: [kworke] call request_key(,FS0.WIN.LOCAL,)
Nov 08 15:27:08 tw kernel: [kworke] ==> dns_resolver_cmp(FS0.WIN.LOCAL,FS0.WIN.LOCAL)
Nov 08 15:27:08 tw kernel: [kworke] <== dns_resolver_cmp() = 1
Nov 08 15:27:08 tw kernel: [kworke] <== dns_query() = 13
Nov 08 15:27:08 tw kernel: fs/cifs/dns_resolve.c: dns_resolve_server_name_to_ip: resolved: FS0.WIN.LOCAL to 192.168.30.26
===> Nov 08 15:27:08 tw kernel: CIFS VFS: vers=2.0 not permitted when mounting with smb3
Nov 08 15:27:08 tw kernel: fs/cifs/dfs_cache.c: CIFS VFS: leaving refresh_tcon (xid = 26) rc = -22
...

Fixes: 5072010c ("cifs: Fix DFS cache refresher for DFS links")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

parent 8354d88e

fs/cifs/dfs_cache.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -1317,7 +1317,6 @@ static struct cifs_ses find_root_ses(struct dfs_cache_vol_info vi,
		int rc;
		struct dfs_info3_param ref = {0};
		char mdata = NULL, devname = NULL;
		bool is_smb3 = tcon->ses->server->vals->header_preamble_size == 0;
		struct TCP_Server_Info *server;
		struct cifs_ses *ses;
		struct smb_vol vol;
		@@ -1344,7 +1343,7 @@ static struct cifs_ses find_root_ses(struct dfs_cache_vol_info vi,
		goto out;
		}

		rc = cifs_setup_volume_info(&vol, mdata, devname, is_smb3);
		rc = cifs_setup_volume_info(&vol, mdata, devname, false);
		kfree(devname);

		if (rc) {

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