X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=fs%2Fcifs%2Fconnect.c;h=3781eee9360affa4e71bc2a60c6e5958b3a5021c;hb=9e723c5380c6e14fb91a8b6950563d040674afdb;hp=01dc45178f66122d6305c85a089fa335098badb4;hpb=93346fb3f669507ba40a8876d1a349557fd0bcf1;p=linux-2.6-microblaze.git diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 01dc45178f66..3781eee9360a 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -78,6 +78,8 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server) int rc; int len; char *unc, *ipaddr = NULL; + time64_t expiry, now; + unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT; if (!server->hostname) return -EINVAL; @@ -91,13 +93,13 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server) } scnprintf(unc, len, "\\\\%s", server->hostname); - rc = dns_resolve_server_name_to_ip(unc, &ipaddr); + rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry); kfree(unc); if (rc < 0) { cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n", __func__, server->hostname, rc); - return rc; + goto requeue_resolve; } spin_lock(&cifs_tcp_ses_lock); @@ -106,7 +108,45 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server) spin_unlock(&cifs_tcp_ses_lock); kfree(ipaddr); - return !rc ? -1 : 0; + /* rc == 1 means success here */ + if (rc) { + now = ktime_get_real_seconds(); + if (expiry && expiry > now) + /* + * To make sure we don't use the cached entry, retry 1s + * after expiry. + */ + ttl = (expiry - now + 1); + } + rc = !rc ? -1 : 0; + +requeue_resolve: + cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n", + __func__, ttl); + mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ)); + + return rc; +} + + +static void cifs_resolve_server(struct work_struct *work) +{ + int rc; + struct TCP_Server_Info *server = container_of(work, + struct TCP_Server_Info, resolve.work); + + mutex_lock(&server->srv_mutex); + + /* + * Resolve the hostname again to make sure that IP address is up-to-date. + */ + rc = reconn_set_ipaddr_from_hostname(server); + if (rc) { + cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n", + __func__, rc); + } + + mutex_unlock(&server->srv_mutex); } #ifdef CONFIG_CIFS_DFS_UPCALL @@ -180,7 +220,7 @@ cifs_reconnect(struct TCP_Server_Info *server) #ifdef CONFIG_CIFS_DFS_UPCALL struct super_block *sb = NULL; struct cifs_sb_info *cifs_sb = NULL; - struct dfs_cache_tgt_list tgt_list = {0}; + struct dfs_cache_tgt_list tgt_list = DFS_CACHE_TGT_LIST_INIT(tgt_list); struct dfs_cache_tgt_iterator *tgt_it = NULL; #endif @@ -680,6 +720,7 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server) spin_unlock(&cifs_tcp_ses_lock); cancel_delayed_work_sync(&server->echo); + cancel_delayed_work_sync(&server->resolve); spin_lock(&GlobalMid_Lock); server->tcpStatus = CifsExiting; @@ -1227,6 +1268,16 @@ cifs_find_tcp_session(struct smb3_fs_context *ctx) spin_lock(&cifs_tcp_ses_lock); list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) { +#ifdef CONFIG_CIFS_DFS_UPCALL + /* + * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for + * DFS connections to do failover properly, so avoid sharing them with regular + * shares or even links that may connect to same server but having completely + * different failover targets. + */ + if (server->is_dfs_conn) + continue; +#endif /* * Skip ses channels since they're only handled in lower layers * (e.g. cifs_send_recv). @@ -1254,12 +1305,16 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect) return; } + /* srv_count can never go negative */ + WARN_ON(server->srv_count < 0); + put_net(cifs_net_ns(server)); list_del_init(&server->tcp_ses_list); spin_unlock(&cifs_tcp_ses_lock); cancel_delayed_work_sync(&server->echo); + cancel_delayed_work_sync(&server->resolve); if (from_reconnect) /* @@ -1342,6 +1397,7 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx) INIT_LIST_HEAD(&tcp_ses->tcp_ses_list); INIT_LIST_HEAD(&tcp_ses->smb_ses_list); INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request); + INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server); INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server); mutex_init(&tcp_ses->reconnect_mutex); memcpy(&tcp_ses->srcaddr, &ctx->srcaddr, @@ -1427,6 +1483,12 @@ smbd_connected: /* queue echo request delayed work */ queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval); + /* queue dns resolution delayed work */ + cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n", + __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT); + + queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ)); + return tcp_ses; out_err_crypto_release: @@ -1605,6 +1667,9 @@ void cifs_put_smb_ses(struct cifs_ses *ses) } spin_unlock(&cifs_tcp_ses_lock); + /* ses_count can never go negative */ + WARN_ON(ses->ses_count < 0); + spin_lock(&GlobalMid_Lock); if (ses->status == CifsGood) ses->status = CifsExiting; @@ -1972,6 +2037,9 @@ cifs_put_tcon(struct cifs_tcon *tcon) return; } + /* tc_count can never go negative */ + WARN_ON(tcon->tc_count < 0); + if (tcon->use_witness) { int rc; @@ -2910,6 +2978,23 @@ static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, } #ifdef CONFIG_CIFS_DFS_UPCALL +static int mount_get_dfs_conns(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb, + unsigned int *xid, struct TCP_Server_Info **nserver, + struct cifs_ses **nses, struct cifs_tcon **ntcon) +{ + int rc; + + ctx->nosharesock = true; + rc = mount_get_conns(ctx, cifs_sb, xid, nserver, nses, ntcon); + if (*nserver) { + cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__); + spin_lock(&cifs_tcp_ses_lock); + (*nserver)->is_dfs_conn = true; + spin_unlock(&cifs_tcp_ses_lock); + } + return rc; +} + /* * cifs_build_path_to_root returns full path to root when we do not have an * existing connection (tcon) @@ -3045,7 +3130,7 @@ static int do_dfs_failover(const char *path, const char *full_path, struct cifs_ { int rc; char *npath = NULL; - struct dfs_cache_tgt_list tgt_list = {0}; + struct dfs_cache_tgt_list tgt_list = DFS_CACHE_TGT_LIST_INIT(tgt_list); struct dfs_cache_tgt_iterator *tgt_it = NULL; struct smb3_fs_context tmp_ctx = {NULL}; @@ -3105,7 +3190,7 @@ static int do_dfs_failover(const char *path, const char *full_path, struct cifs_ tmp_ctx.prepath); mount_put_conns(cifs_sb, *xid, *server, *ses, *tcon); - rc = mount_get_conns(&tmp_ctx, cifs_sb, xid, server, ses, tcon); + rc = mount_get_dfs_conns(&tmp_ctx, cifs_sb, xid, server, ses, tcon); if (!rc || (*server && *ses)) { /* * We were able to connect to new target server. Update current context with @@ -3404,7 +3489,12 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) goto error; } - ctx->nosharesock = true; + mount_put_conns(cifs_sb, xid, server, ses, tcon); + /* + * Ignore error check here because we may failover to other targets from cached a + * referral. + */ + (void)mount_get_dfs_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon); /* Get path of DFS root */ ref_path = build_unc_path_to_root(ctx, cifs_sb, false); @@ -3433,7 +3523,7 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) /* Connect to new DFS target only if we were redirected */ if (oldmnt != cifs_sb->ctx->mount_options) { mount_put_conns(cifs_sb, xid, server, ses, tcon); - rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon); + rc = mount_get_dfs_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon); } if (rc && !server && !ses) { /* Failed to connect. Try to connect to other targets in the referral. */ @@ -3459,7 +3549,7 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) rc = -ELOOP; } while (rc == -EREMOTE); - if (rc || !tcon) + if (rc || !tcon || !ses) goto error; kfree(ref_path); @@ -4095,7 +4185,8 @@ int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const stru if (!tree) return -ENOMEM; - if (!tcon->dfs_path) { + /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */ + if (!tcon->dfs_path || dfs_cache_noreq_find(tcon->dfs_path + 1, &ref, &tl)) { if (tcon->ipc) { scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname); rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc); @@ -4105,9 +4196,6 @@ int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const stru goto out; } - rc = dfs_cache_noreq_find(tcon->dfs_path + 1, &ref, &tl); - if (rc) - goto out; isroot = ref.server_type == DFS_TYPE_ROOT; free_dfs_info_param(&ref);