diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index be74606724c7..91878e84c637 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -939,7 +939,6 @@ struct cifs_ses { struct ntlmssp_auth *ntlmssp; /* ciphertext, flags, server challenge */ enum securityEnum sectype; /* what security flavor was specified? */ bool sign; /* is signing required? */ - bool need_reconnect:1; /* connection reset, uid now invalid */ bool domainAuto:1; bool binding:1; /* are we binding the session? */ __u16 session_flags; @@ -969,11 +968,25 @@ struct cifs_ses { spinlock_t chan_lock; /* ========= begin: protected by chan_lock ======== */ #define CIFS_MAX_CHANNELS 16 +#define CIFS_ALL_CHANNELS_SET(ses) \ + ((1UL << (ses)->chan_count) - 1) +#define CIFS_ALL_CHANS_NEED_RECONNECT(ses) \ + ((ses)->chans_need_reconnect == CIFS_ALL_CHANNELS_SET(ses)) +#define CIFS_CHAN_NEEDS_RECONNECT(ses, index) \ + test_bit((index), &(ses)->chans_need_reconnect) + struct cifs_chan chans[CIFS_MAX_CHANNELS]; struct cifs_chan *binding_chan; size_t chan_count; size_t chan_max; atomic_t chan_seq; /* round robin state */ + + /* + * chans_need_reconnect is a bitmap indicating which of the channels + * under this smb session needs to be reconnected. + * If not multichannel session, only one bit will be used. + */ + unsigned long chans_need_reconnect; /* ========= end: protected by chan_lock ======== */ }; diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index 4f5a3e857df4..2a821a8801d2 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -601,6 +601,19 @@ bool is_server_using_iface(struct TCP_Server_Info *server, bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface); void cifs_ses_mark_for_reconnect(struct cifs_ses *ses); +unsigned int +cifs_ses_get_chan_index(struct cifs_ses *ses, + struct TCP_Server_Info *server); +void +cifs_chan_set_need_reconnect(struct cifs_ses *ses, + struct TCP_Server_Info *server); +void +cifs_chan_clear_need_reconnect(struct cifs_ses *ses, + struct TCP_Server_Info *server); +bool +cifs_chan_needs_reconnect(struct cifs_ses *ses, + struct TCP_Server_Info *server); + void extract_unc_hostname(const char *unc, const char **h, size_t *len); int copy_path_name(char *dst, const char *src); int smb2_parse_query_directory(struct cifs_tcon *tcon, struct kvec *rsp_iov, diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 243d17696f06..cbb0d55c1267 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -166,8 +166,12 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) retries = server->nr_targets; } - if (!ses->need_reconnect && !tcon->need_reconnect) + spin_lock(&ses->chan_lock); + if (!cifs_chan_needs_reconnect(ses, server) && !tcon->need_reconnect) { + spin_unlock(&ses->chan_lock); return 0; + } + spin_unlock(&ses->chan_lock); nls_codepage = load_nls_default(); @@ -188,8 +192,25 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) goto out; } + /* + * need to prevent multiple threads trying to simultaneously + * reconnect the same SMB session + */ + spin_lock(&ses->chan_lock); + if (!cifs_chan_needs_reconnect(ses, server)) { + spin_unlock(&ses->chan_lock); + /* this just means that we only need to tcon */ + if (tcon->need_reconnect) + goto skip_sess_setup; + + rc = -EHOSTDOWN; + mutex_unlock(&ses->session_mutex); + goto out; + } + spin_unlock(&ses->chan_lock); + rc = cifs_negotiate_protocol(0, ses); - if (rc == 0 && ses->need_reconnect) + if (!rc) rc = cifs_setup_session(0, ses, nls_codepage); /* do we need to reconnect tcon? */ @@ -198,6 +219,7 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command) goto out; } +skip_sess_setup: cifs_mark_open_files_invalid(tcon); rc = cifs_tree_connect(0, tcon, nls_codepage); mutex_unlock(&ses->session_mutex); @@ -337,8 +359,13 @@ static int smb_init_no_reconnect(int smb_command, int wct, struct cifs_tcon *tcon, void **request_buf, void **response_buf) { - if (tcon->ses->need_reconnect || tcon->need_reconnect) + spin_lock(&tcon->ses->chan_lock); + if (cifs_chan_needs_reconnect(tcon->ses, tcon->ses->server) || + tcon->need_reconnect) { + spin_unlock(&tcon->ses->chan_lock); return -EHOSTDOWN; + } + spin_unlock(&tcon->ses->chan_lock); return __smb_init(smb_command, wct, tcon, request_buf, response_buf); } @@ -600,8 +627,12 @@ CIFSSMBTDis(const unsigned int xid, struct cifs_tcon *tcon) * the tcon is no longer on the list, so no need to take lock before * checking this. */ - if ((tcon->need_reconnect) || (tcon->ses->need_reconnect)) - return 0; + spin_lock(&tcon->ses->chan_lock); + if ((tcon->need_reconnect) || CIFS_ALL_CHANS_NEED_RECONNECT(tcon->ses)) { + spin_unlock(&tcon->ses->chan_lock); + return -EIO; + } + spin_unlock(&tcon->ses->chan_lock); rc = small_smb_init(SMB_COM_TREE_DISCONNECT, 0, tcon, (void **)&smb_buffer); @@ -696,9 +727,14 @@ CIFSSMBLogoff(const unsigned int xid, struct cifs_ses *ses) return -EIO; mutex_lock(&ses->session_mutex); - if (ses->need_reconnect) + spin_lock(&ses->chan_lock); + if (CIFS_ALL_CHANS_NEED_RECONNECT(ses)) { + spin_unlock(&ses->chan_lock); goto session_already_dead; /* no need to send SMBlogoff if uid already closed due to reconnect */ + } + spin_unlock(&ses->chan_lock); + rc = small_smb_init(SMB_COM_LOGOFF_ANDX, 2, NULL, (void **)&pSMB); if (rc) { mutex_unlock(&ses->session_mutex); diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 1060164b984a..fa80a23f9fcf 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -191,11 +191,23 @@ static void cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server spin_lock(&cifs_tcp_ses_lock); list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) { - ses->need_reconnect = true; + spin_lock(&ses->chan_lock); + if (cifs_chan_needs_reconnect(ses, server)) + goto next_session; + + cifs_chan_set_need_reconnect(ses, server); + + /* If all channels need reconnect, then tcon needs reconnect */ + if (!CIFS_ALL_CHANS_NEED_RECONNECT(ses)) + goto next_session; + list_for_each_entry(tcon, &ses->tcon_list, tcon_list) tcon->need_reconnect = true; if (ses->tcon_ipc) ses->tcon_ipc->need_reconnect = true; + +next_session: + spin_unlock(&ses->chan_lock); } spin_unlock(&cifs_tcp_ses_lock); @@ -1988,7 +2000,9 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) ses->status); mutex_lock(&ses->session_mutex); - if (ses->need_reconnect) { + spin_lock(&ses->chan_lock); + if (cifs_chan_needs_reconnect(ses, server)) { + spin_unlock(&ses->chan_lock); cifs_dbg(FYI, "Session needs reconnect\n"); rc = cifs_negotiate_protocol(xid, ses); @@ -2009,7 +2023,9 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) free_xid(xid); return ERR_PTR(rc); } + spin_lock(&ses->chan_lock); } + spin_unlock(&ses->chan_lock); mutex_unlock(&ses->session_mutex); /* existing SMB ses has a server reference already */ @@ -2067,6 +2083,7 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) ses->chans[0].server = server; ses->chan_count = 1; ses->chan_max = ctx->multichannel ? ctx->max_channels:1; + ses->chans_need_reconnect = 1; spin_unlock(&ses->chan_lock); rc = cifs_negotiate_protocol(xid, ses); @@ -2081,7 +2098,11 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) if (rc) goto get_ses_fail; - /* success, put it on the list and add it as first channel */ + /* + * success, put it on the list and add it as first channel + * note: the session becomes active soon after this. So you'll + * need to lock before changing something in the session. + */ spin_lock(&cifs_tcp_ses_lock); list_add(&ses->smb_ses_list, &server->smb_ses_list); spin_unlock(&cifs_tcp_ses_lock); @@ -2161,6 +2182,9 @@ cifs_put_tcon(struct cifs_tcon *tcon) /* tc_count can never go negative */ WARN_ON(tcon->tc_count < 0); + list_del_init(&tcon->tcon_list); + spin_unlock(&cifs_tcp_ses_lock); + if (tcon->use_witness) { int rc; @@ -2171,9 +2195,6 @@ cifs_put_tcon(struct cifs_tcon *tcon) } } - list_del_init(&tcon->tcon_list); - spin_unlock(&cifs_tcp_ses_lock); - xid = get_xid(); if (ses->server->ops->tree_disconnect) ses->server->ops->tree_disconnect(xid, tcon); diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c index 035dc3e245dc..ba8543ccb298 100644 --- a/fs/cifs/sess.c +++ b/fs/cifs/sess.c @@ -65,6 +65,53 @@ bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface) return false; } +unsigned int +cifs_ses_get_chan_index(struct cifs_ses *ses, + struct TCP_Server_Info *server) +{ + unsigned int i; + + for (i = 0; i < ses->chan_count; i++) { + if (ses->chans[i].server == server) + return i; + } + + /* If we didn't find the channel, it is likely a bug */ + WARN_ON(1); + return 0; +} + +void +cifs_chan_set_need_reconnect(struct cifs_ses *ses, + struct TCP_Server_Info *server) +{ + unsigned int chan_index = cifs_ses_get_chan_index(ses, server); + + set_bit(chan_index, &ses->chans_need_reconnect); + cifs_dbg(FYI, "Set reconnect bitmask for chan %u; now 0x%lx\n", + chan_index, ses->chans_need_reconnect); +} + +void +cifs_chan_clear_need_reconnect(struct cifs_ses *ses, + struct TCP_Server_Info *server) +{ + unsigned int chan_index = cifs_ses_get_chan_index(ses, server); + + clear_bit(chan_index, &ses->chans_need_reconnect); + cifs_dbg(FYI, "Cleared reconnect bitmask for chan %u; now 0x%lx\n", + chan_index, ses->chans_need_reconnect); +} + +bool +cifs_chan_needs_reconnect(struct cifs_ses *ses, + struct TCP_Server_Info *server) +{ + unsigned int chan_index = cifs_ses_get_chan_index(ses, server); + + return CIFS_CHAN_NEEDS_RECONNECT(ses, chan_index); +} + /* returns number of channels added */ int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses) { @@ -306,11 +353,21 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, spin_lock(&ses->chan_lock); ses->chan_count++; atomic_set(&ses->chan_seq, 0); + + /* Mark this channel as needing connect/setup */ + cifs_chan_set_need_reconnect(ses, chan->server); spin_unlock(&ses->chan_lock); out: ses->binding = false; ses->binding_chan = NULL; + + if (rc && chan->server) { + /* we rely on all bits beyond chan_count to be clear */ + cifs_chan_clear_need_reconnect(ses, chan->server); + ses->chan_count--; + } + mutex_unlock(&ses->session_mutex); if (rc && chan->server) @@ -998,9 +1055,15 @@ sess_establish_session(struct sess_data *sess_data) mutex_unlock(&ses->server->srv_mutex); cifs_dbg(FYI, "CIFS session established successfully\n"); + if (ses->binding) + cifs_chan_clear_need_reconnect(ses, ses->binding_chan->server); + else + cifs_chan_clear_need_reconnect(ses, ses->server); + + /* keep existing ses state if binding */ spin_lock(&GlobalMid_Lock); - ses->status = CifsGood; - ses->need_reconnect = false; + if (!ses->binding) + ses->status = CifsGood; spin_unlock(&GlobalMid_Lock); return 0; diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 8b3670388cda..f3b2eef36ec1 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -232,8 +232,15 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon, retries = server->nr_targets; } - if (!tcon->ses->need_reconnect && !tcon->need_reconnect) + spin_lock(&ses->chan_lock); + if (!cifs_chan_needs_reconnect(ses, server) && !tcon->need_reconnect) { + spin_unlock(&ses->chan_lock); return 0; + } + cifs_dbg(FYI, "sess reconnect mask: 0x%lx, tcon reconnect: %d", + tcon->ses->chans_need_reconnect, + tcon->need_reconnect); + spin_unlock(&ses->chan_lock); nls_codepage = load_nls_default(); @@ -262,8 +269,26 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon, ses->binding_chan = cifs_ses_find_chan(ses, server); } + /* + * need to prevent multiple threads trying to simultaneously + * reconnect the same SMB session + */ + spin_lock(&ses->chan_lock); + if (!cifs_chan_needs_reconnect(ses, server)) { + spin_unlock(&ses->chan_lock); + + /* this just means that we only need to tcon */ + if (tcon->need_reconnect) + goto skip_sess_setup; + + rc = -EHOSTDOWN; + mutex_unlock(&ses->session_mutex); + goto out; + } + spin_unlock(&ses->chan_lock); + rc = cifs_negotiate_protocol(0, tcon->ses); - if (!rc && tcon->ses->need_reconnect) { + if (!rc) { rc = cifs_setup_session(0, tcon->ses, nls_codepage); if ((rc == -EACCES) && !tcon->retry) { rc = -EHOSTDOWN; @@ -284,6 +309,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon, goto out; } +skip_sess_setup: cifs_mark_open_files_invalid(tcon); if (tcon->use_persistent) tcon->need_reopen_files = true; @@ -1359,13 +1385,19 @@ SMB2_sess_establish_session(struct SMB2_sess_data *sess_data) mutex_unlock(&server->srv_mutex); cifs_dbg(FYI, "SMB2/3 session established successfully\n"); + + spin_lock(&ses->chan_lock); + if (ses->binding) + cifs_chan_clear_need_reconnect(ses, ses->binding_chan->server); + else + cifs_chan_clear_need_reconnect(ses, ses->server); + spin_unlock(&ses->chan_lock); + /* keep existing ses state if binding */ - if (!ses->binding) { - spin_lock(&GlobalMid_Lock); + spin_lock(&GlobalMid_Lock); + if (!ses->binding) ses->status = CifsGood; - ses->need_reconnect = false; - spin_unlock(&GlobalMid_Lock); - } + spin_unlock(&GlobalMid_Lock); return rc; } @@ -1704,8 +1736,12 @@ SMB2_logoff(const unsigned int xid, struct cifs_ses *ses) return -EIO; /* no need to send SMB logoff if uid already closed due to reconnect */ - if (ses->need_reconnect) + spin_lock(&ses->chan_lock); + if (CIFS_ALL_CHANS_NEED_RECONNECT(ses)) { + spin_unlock(&ses->chan_lock); goto smb2_session_already_dead; + } + spin_unlock(&ses->chan_lock); rc = smb2_plain_req_init(SMB2_LOGOFF, NULL, ses->server, (void **) &req, &total_len); @@ -1913,8 +1949,13 @@ SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon) if (!ses || !(ses->server)) return -EIO; - if ((tcon->need_reconnect) || (tcon->ses->need_reconnect)) + spin_lock(&ses->chan_lock); + if ((tcon->need_reconnect) || + (CIFS_ALL_CHANS_NEED_RECONNECT(tcon->ses))) { + spin_unlock(&ses->chan_lock); return 0; + } + spin_unlock(&ses->chan_lock); close_cached_dir_lease(&tcon->crfid);