From: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
[ Upstream commit bc962159e8e326af634a506508034a375bf2b858 ]
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@xxxxxxxxxxxxx>
Reviewed-by: Paulo Alcantara (SUSE) <pc@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/cifs/connect.c | 48 ++++++++++++++++++++++++++++++-----------
fs/cifs/smb2pdu.c | 44 +++++++++++++++++++++----------------
fs/cifs/smb2transport.c | 17 ++++++++++++---
3 files changed, 76 insertions(+), 33 deletions(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 43637c1283748..077c88c49dfdf 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -261,31 +261,42 @@ 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);
+ 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))
- goto next_session;
+ 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);
}
@@ -4050,11 +4061,19 @@ 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);
@@ -4088,23 +4107,28 @@ 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)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 83d04cd2f9df8..f0b1ae0835d71 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -199,6 +199,7 @@ 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;
@@ -217,6 +218,7 @@ 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
@@ -225,6 +227,11 @@ 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;
}
@@ -234,19 +241,22 @@ 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);
@@ -262,10 +272,8 @@ 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;
@@ -280,7 +288,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
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;
}
@@ -1252,9 +1260,9 @@ 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);
@@ -1412,9 +1420,9 @@ 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) {
@@ -1538,9 +1546,9 @@ 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) {
@@ -1606,9 +1614,9 @@ 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) {
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index d827b7547ffad..790acf65a0926 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -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 @@ int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
*/
memcpy(key, ses->smb3signingkey, SMB3_SIGN_KEY_SIZE);
spin_unlock(&ses->chan_lock);
+ spin_unlock(&ses->ses_lock);
goto out;
}
@@ -119,10 +124,12 @@ int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
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
--
2.39.2
