[linux-cifs-client] [PATCH] CIFS: Add nodfs mount option

[Martin Koegler]

Older samba server (eg. 3.0.24 from Debian etch) don't work correctly,
if DFS paths are used. Such server claim that they support DFS, but fail
to process some requests with DFS paths. Starting with Linux 2.6.26,
the cifs clients starts sending DFS paths in such situations, rendering
it unuseable with older samba servers.

The nodfs mount options forces a share to be used with non DFS paths,
even if the server claims, that it supports it.

Signed-off-by: Martin Koegler <mkoegler at auto.tuwien.ac.at>
---

This patch makes my home directory on a samba server useable for Linux 2.6.26
again. It still needs more testing. Should apply to linux 2.6.27 too.

Would it be possible to support something like this in the offical CIFS client?

diff a/fs/cifs/connect.c b/fs/cifs/connect.c
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -90,6 +90,7 @@ struct smb_vol {
 	bool nocase:1;     /* request case insensitive filenames */
 	bool nobrl:1;      /* disable sending byte range locks to srv */
 	bool seal:1;       /* request transport encryption on share */
+	bool nodfs:1;
 	unsigned int rsize;
 	unsigned int wsize;
 	unsigned int sockopt;
@@ -1223,6 +1224,8 @@ cifs_parse_mount_options(char *options, 
 			vol->sfu_emul = 1;
 		} else if (strnicmp(data, "nosfu", 5) == 0) {
 			vol->sfu_emul = 0;
+		} else if (strnicmp(data, "nodfs", 5) == 0) {
+			vol->nodfs = 1;
 		} else if (strnicmp(data, "posixpaths", 10) == 0) {
 			vol->posix_paths = 1;
 		} else if (strnicmp(data, "noposixpaths", 12) == 0) {
@@ -2167,6 +2170,10 @@ cifs_mount(struct super_block *sb, struc
 						volume_info.UNC,
 						tcon, cifs_sb->local_nls);
 					cFYI(1, ("CIFS Tcon rc = %d", rc));
+					if (volume_info.nodfs) {
+						tcon->Flags &= ~SMB_SHARE_IS_IN_DFS;
+						cFYI(1, ("CIFS DFS disabeld (%d)", tcon->Flags));
+					}
 				}
 				if (!rc) {
 					atomic_inc(&pSesInfo->inUse);
--