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;
}
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);
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
#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
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;
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).
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)
/*
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,
/* 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:
}
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;
return;
}
+ /* tc_count can never go negative */
+ WARN_ON(tcon->tc_count < 0);
+
if (tcon->use_witness) {
int rc;
}
#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)
{
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};
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
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);
/* 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. */
rc = -ELOOP;
} while (rc == -EREMOTE);
- if (rc || !tcon)
+ if (rc || !tcon || !ses)
goto error;
kfree(ref_path);
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);
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);
projects / linux-2.6-microblaze.git / blobdiff