2017-02-28 10:40 GMT-08:00 Aurelien Aptel <aaptel@xxxxxxxx>: > in SMB2+ the get_dfs_refer operation uses a FSCTL. The request can be > made on any Tree Connection according to the specs. Since Samba only > accepted it on an IPC connection until recently, try that first. > > https://lists.samba.org/archive/samba-technical/2017-February/118859.html > > 3.2.4.20.3 Application Requests DFS Referral Information: >> The client MUST search for an existing Session and TreeConnect to any >> share on the server identified by ServerName for the user identified by >> UserCredentials. If no Session and TreeConnect are found, the client >> MUST establish a new Session and TreeConnect to IPC$ on the target >> server as described in section 3.2.4.2 using the supplied ServerName and >> UserCredentials. > > Signed-off-by: Aurelien Aptel <aaptel@xxxxxxxx> > --- > fs/cifs/smb2ops.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > fs/cifs/smb2pdu.h | 8 +++++ > 2 files changed, 108 insertions(+) > > diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c > index 02937cc..fcd524d 100644 > --- a/fs/cifs/smb2ops.c > +++ b/fs/cifs/smb2ops.c > @@ -1104,6 +1104,102 @@ smb2_new_lease_key(struct cifs_fid *fid) > generate_random_uuid(fid->lease_key); > } > > +static int > +smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses, > + const char *search_name, > + struct dfs_info3_param **target_nodes, > + unsigned int *num_of_nodes, > + const struct nls_table *nls_codepage, int remap) > +{ > + int rc; > + __le16 *utf16_path = NULL; > + int utf16_path_len = 0; > + struct cifs_tcon *tcon; > + struct fsctl_get_dfs_referral_req *dfs_req = NULL; > + struct get_dfs_referral_rsp *dfs_rsp = NULL; > + u32 dfs_req_size = 0, dfs_rsp_size = 0; > + > + cifs_dbg(FYI, "smb2_get_dfs_refer path <%s>\n", search_name); > + > + /* > + * Use any tcon from the current session. Here, the first one. > + */ > + spin_lock(&cifs_tcp_ses_lock); > + tcon = list_first_entry_or_null(&ses->tcon_list, struct cifs_tcon, tcon_list); > + if (tcon) > + tcon->tc_count++; > + spin_unlock(&cifs_tcp_ses_lock); > + > + if (!tcon) { > + cifs_dbg(VFS, "session %p has no tcon available for a dfs referral request\n", > + ses); > + rc = -ENOTCONN; > + goto out; > + } > + > + utf16_path = cifs_strndup_to_utf16(search_name, PATH_MAX, > + &utf16_path_len, > + nls_codepage, remap); > + if (!utf16_path) { > + rc = -ENOMEM; > + goto out; > + } > + > + dfs_req_size = sizeof(*dfs_req) + utf16_path_len; > + dfs_req = kzalloc(dfs_req_size, GFP_KERNEL); > + if (!dfs_req) { > + rc = -ENOMEM; > + goto out; > + } > + > + /* Highest DFS referral version understood */ > + dfs_req->MaxReferralLevel = cpu_to_le16(DFS_VERSION); > + > + /* Path to resolve in an UTF-16 null-terminated string */ > + memcpy(dfs_req->RequestFileName, utf16_path, utf16_path_len); > + > + do { > + /* try first with IPC */ > + rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID, > + FSCTL_DFS_GET_REFERRALS, > + true /* is_fsctl */, true /* use_ipc */, > + (char *)dfs_req, dfs_req_size, > + (char **)&dfs_rsp, &dfs_rsp_size); > + if (rc == -ENOTCONN) { > + /* try with normal tcon */ > + rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID, > + FSCTL_DFS_GET_REFERRALS, > + true /* is_fsctl */, false /*use_ipc*/, > + (char *)dfs_req, dfs_req_size, > + (char **)&dfs_rsp, &dfs_rsp_size); > + } > + } while (rc == -EAGAIN); > + > + if (rc) { > + cifs_dbg(VFS, "ioctl error in smb2_get_dfs_refer rc=%d\n", rc); > + goto out; > + } During the local testing with cthon and xfstests with DFS is being involved I see a bunch of error messages like the one below: CIFS VFS: ioctl error in smb2_get_dfs_refer rc=-2 Should we lower a debug level to FYI here? -- Best regards, Pavel Shilovsky -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
