cifs: avoid race conditions with parallel reconnects
When multiple processes/channels do reconnects in parallel we used to return success immediately negotiate/session-setup/tree-connect, causing race conditions between processes that enter the function in parallel. This caused several errors related to session not found to show up during parallel reconnects. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Cc: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Shyam Prasad N
Steve French
Родитель
fddc6ccc48
Коммит
bc962159e8
|
|
@ -212,31 +212,42 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
|
|||
cifs_chan_update_iface(ses, server);
|
||||
|
||||
spin_lock(&ses->chan_lock);
|
||||
if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
|
||||
goto next_session;
|
||||
if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) {
|
||||
spin_unlock(&ses->chan_lock);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (mark_smb_session)
|
||||
CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
|
||||
else
|
||||
cifs_chan_set_need_reconnect(ses, server);
|
||||
|
||||
/* If all channels need reconnect, then tcon needs reconnect */
|
||||
if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
|
||||
goto next_session;
|
||||
cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
|
||||
__func__, ses->chans_need_reconnect);
|
||||
|
||||
/* If all channels need reconnect, then tcon needs reconnect */
|
||||
if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
|
||||
spin_unlock(&ses->chan_lock);
|
||||
continue;
|
||||
}
|
||||
spin_unlock(&ses->chan_lock);
|
||||
|
||||
spin_lock(&ses->ses_lock);
|
||||
ses->ses_status = SES_NEED_RECON;
|
||||
spin_unlock(&ses->ses_lock);
|
||||
|
||||
list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
|
||||
tcon->need_reconnect = true;
|
||||
spin_lock(&tcon->tc_lock);
|
||||
tcon->status = TID_NEED_RECON;
|
||||
spin_unlock(&tcon->tc_lock);
|
||||
}
|
||||
if (ses->tcon_ipc) {
|
||||
ses->tcon_ipc->need_reconnect = true;
|
||||
spin_lock(&ses->tcon_ipc->tc_lock);
|
||||
ses->tcon_ipc->status = TID_NEED_RECON;
|
||||
spin_unlock(&ses->tcon_ipc->tc_lock);
|
||||
}
|
||||
|
||||
next_session:
|
||||
spin_unlock(&ses->chan_lock);
|
||||
}
|
||||
spin_unlock(&cifs_tcp_ses_lock);
|
||||
}
|
||||
|
|
@ -3653,11 +3664,19 @@ cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
|
|||
|
||||
/* only send once per connect */
|
||||
spin_lock(&server->srv_lock);
|
||||
if (!server->ops->need_neg(server) ||
|
||||
if (server->tcpStatus != CifsGood &&
|
||||
server->tcpStatus != CifsNew &&
|
||||
server->tcpStatus != CifsNeedNegotiate) {
|
||||
spin_unlock(&server->srv_lock);
|
||||
return -EHOSTDOWN;
|
||||
}
|
||||
|
||||
if (!server->ops->need_neg(server) &&
|
||||
server->tcpStatus == CifsGood) {
|
||||
spin_unlock(&server->srv_lock);
|
||||
return 0;
|
||||
}
|
||||
|
||||
server->tcpStatus = CifsInNegotiate;
|
||||
spin_unlock(&server->srv_lock);
|
||||
|
||||
|
|
@ -3691,23 +3710,28 @@ cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
|
|||
bool is_binding = false;
|
||||
|
||||
spin_lock(&ses->ses_lock);
|
||||
cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
|
||||
__func__, ses->chans_need_reconnect);
|
||||
|
||||
if (ses->ses_status != SES_GOOD &&
|
||||
ses->ses_status != SES_NEW &&
|
||||
ses->ses_status != SES_NEED_RECON) {
|
||||
spin_unlock(&ses->ses_lock);
|
||||
return 0;
|
||||
return -EHOSTDOWN;
|
||||
}
|
||||
|
||||
/* only send once per connect */
|
||||
spin_lock(&ses->chan_lock);
|
||||
if (CIFS_ALL_CHANS_GOOD(ses) ||
|
||||
cifs_chan_in_reconnect(ses, server)) {
|
||||
if (CIFS_ALL_CHANS_GOOD(ses)) {
|
||||
if (ses->ses_status == SES_NEED_RECON)
|
||||
ses->ses_status = SES_GOOD;
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
return 0;
|
||||
}
|
||||
is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
|
||||
|
||||
cifs_chan_set_in_reconnect(ses, server);
|
||||
is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
|
||||
spin_unlock(&ses->chan_lock);
|
||||
|
||||
if (!is_binding)
|
||||
|
|
|
|||
|
|
@ -203,6 +203,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
|
|||
}
|
||||
spin_unlock(&server->srv_lock);
|
||||
|
||||
again:
|
||||
rc = cifs_wait_for_server_reconnect(server, tcon->retry);
|
||||
if (rc)
|
||||
return rc;
|
||||
|
|
@ -221,6 +222,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
|
|||
|
||||
nls_codepage = load_nls_default();
|
||||
|
||||
mutex_lock(&ses->session_mutex);
|
||||
/*
|
||||
* Recheck after acquire mutex. If another thread is negotiating
|
||||
* and the server never sends an answer the socket will be closed
|
||||
|
|
@ -229,6 +231,11 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
|
|||
spin_lock(&server->srv_lock);
|
||||
if (server->tcpStatus == CifsNeedReconnect) {
|
||||
spin_unlock(&server->srv_lock);
|
||||
mutex_unlock(&ses->session_mutex);
|
||||
|
||||
if (tcon->retry)
|
||||
goto again;
|
||||
|
||||
rc = -EHOSTDOWN;
|
||||
goto out;
|
||||
}
|
||||
|
|
@ -238,19 +245,22 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
|
|||
* need to prevent multiple threads trying to simultaneously
|
||||
* reconnect the same SMB session
|
||||
*/
|
||||
spin_lock(&ses->ses_lock);
|
||||
spin_lock(&ses->chan_lock);
|
||||
if (!cifs_chan_needs_reconnect(ses, server)) {
|
||||
if (!cifs_chan_needs_reconnect(ses, server) &&
|
||||
ses->ses_status == SES_GOOD) {
|
||||
spin_unlock(&ses->chan_lock);
|
||||
|
||||
spin_unlock(&ses->ses_lock);
|
||||
/* this means that we only need to tree connect */
|
||||
if (tcon->need_reconnect)
|
||||
goto skip_sess_setup;
|
||||
|
||||
mutex_unlock(&ses->session_mutex);
|
||||
goto out;
|
||||
}
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
|
||||
mutex_lock(&ses->session_mutex);
|
||||
rc = cifs_negotiate_protocol(0, ses, server);
|
||||
if (!rc) {
|
||||
rc = cifs_setup_session(0, ses, server, nls_codepage);
|
||||
|
|
@ -266,10 +276,8 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
|
|||
mutex_unlock(&ses->session_mutex);
|
||||
goto out;
|
||||
}
|
||||
mutex_unlock(&ses->session_mutex);
|
||||
|
||||
skip_sess_setup:
|
||||
mutex_lock(&ses->session_mutex);
|
||||
if (!tcon->need_reconnect) {
|
||||
mutex_unlock(&ses->session_mutex);
|
||||
goto out;
|
||||
|
|
@ -284,7 +292,7 @@ skip_sess_setup:
|
|||
cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
|
||||
if (rc) {
|
||||
/* If sess reconnected but tcon didn't, something strange ... */
|
||||
pr_warn_once("reconnect tcon failed rc = %d\n", rc);
|
||||
cifs_dbg(VFS, "reconnect tcon failed rc = %d\n", rc);
|
||||
goto out;
|
||||
}
|
||||
|
||||
|
|
@ -1256,9 +1264,9 @@ SMB2_sess_alloc_buffer(struct SMB2_sess_data *sess_data)
|
|||
if (rc)
|
||||
return rc;
|
||||
|
||||
spin_lock(&ses->chan_lock);
|
||||
is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_lock(&ses->ses_lock);
|
||||
is_binding = (ses->ses_status == SES_GOOD);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
|
||||
if (is_binding) {
|
||||
req->hdr.SessionId = cpu_to_le64(ses->Suid);
|
||||
|
|
@ -1416,9 +1424,9 @@ SMB2_auth_kerberos(struct SMB2_sess_data *sess_data)
|
|||
goto out_put_spnego_key;
|
||||
}
|
||||
|
||||
spin_lock(&ses->chan_lock);
|
||||
is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_lock(&ses->ses_lock);
|
||||
is_binding = (ses->ses_status == SES_GOOD);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
|
||||
/* keep session key if binding */
|
||||
if (!is_binding) {
|
||||
|
|
@ -1542,9 +1550,9 @@ SMB2_sess_auth_rawntlmssp_negotiate(struct SMB2_sess_data *sess_data)
|
|||
|
||||
cifs_dbg(FYI, "rawntlmssp session setup challenge phase\n");
|
||||
|
||||
spin_lock(&ses->chan_lock);
|
||||
is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_lock(&ses->ses_lock);
|
||||
is_binding = (ses->ses_status == SES_GOOD);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
|
||||
/* keep existing ses id and flags if binding */
|
||||
if (!is_binding) {
|
||||
|
|
@ -1610,9 +1618,9 @@ SMB2_sess_auth_rawntlmssp_authenticate(struct SMB2_sess_data *sess_data)
|
|||
|
||||
rsp = (struct smb2_sess_setup_rsp *)sess_data->iov[0].iov_base;
|
||||
|
||||
spin_lock(&ses->chan_lock);
|
||||
is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_lock(&ses->ses_lock);
|
||||
is_binding = (ses->ses_status == SES_GOOD);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
|
||||
/* keep existing ses id and flags if binding */
|
||||
if (!is_binding) {
|
||||
|
|
|
|||
|
|
@ -81,6 +81,7 @@ int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
|
|||
struct cifs_ses *ses = NULL;
|
||||
int i;
|
||||
int rc = 0;
|
||||
bool is_binding = false;
|
||||
|
||||
spin_lock(&cifs_tcp_ses_lock);
|
||||
|
||||
|
|
@ -97,9 +98,12 @@ int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
|
|||
goto out;
|
||||
|
||||
found:
|
||||
spin_lock(&ses->ses_lock);
|
||||
spin_lock(&ses->chan_lock);
|
||||
if (cifs_chan_needs_reconnect(ses, server) &&
|
||||
!CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
|
||||
|
||||
is_binding = (cifs_chan_needs_reconnect(ses, server) &&
|
||||
ses->ses_status == SES_GOOD);
|
||||
if (is_binding) {
|
||||
/*
|
||||
* If we are in the process of binding a new channel
|
||||
* to an existing session, use the master connection
|
||||
|
|
@ -107,6 +111,7 @@ found:
|
|||
*/
|
||||
memcpy(key, ses->smb3signingkey, SMB3_SIGN_KEY_SIZE);
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
goto out;
|
||||
}
|
||||
|
||||
|
|
@ -119,10 +124,12 @@ found:
|
|||
if (chan->server == server) {
|
||||
memcpy(key, chan->signkey, SMB3_SIGN_KEY_SIZE);
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
|
||||
cifs_dbg(VFS,
|
||||
"%s: Could not find channel signing key for session 0x%llx\n",
|
||||
|
|
@ -392,11 +399,15 @@ generate_smb3signingkey(struct cifs_ses *ses,
|
|||
bool is_binding = false;
|
||||
int chan_index = 0;
|
||||
|
||||
spin_lock(&ses->ses_lock);
|
||||
spin_lock(&ses->chan_lock);
|
||||
is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
|
||||
is_binding = (cifs_chan_needs_reconnect(ses, server) &&
|
||||
ses->ses_status == SES_GOOD);
|
||||
|
||||
chan_index = cifs_ses_get_chan_index(ses, server);
|
||||
/* TODO: introduce ref counting for channels when the can be freed */
|
||||
spin_unlock(&ses->chan_lock);
|
||||
spin_unlock(&ses->ses_lock);
|
||||
|
||||
/*
|
||||
* All channels use the same encryption/decryption keys but
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче