From 0fae4d37ab6f11496b4e2297871050dbc769f005 Mon Sep 17 00:00:00 2001 From: David Disseldorp Date: Fri, 11 Jul 2014 17:00:05 +0200 Subject: printing: only reload printer shares on client enum Currently, automatic printer share updates are handled in the following way: - Background printer process (BPP) forked on startup - Parent smbd and per-client children await MSG_PRINTER_PCAP messages - BPP periodically polls the printing backend for printcap data - printcap data written to printer_list.tdb - MSG_PRINTER_PCAP sent to all smbd processes following update - smbd processes all read the latest printer_list.tdb data, and update their share listings This procedure is not scalable, as all smbd processes hit printer_list.tdb in parallel, resulting in a large spike in CPU usage. This change sees smbd processes only update their printer share lists only when a client asks for this information, e.g. via NetShareEnum or EnumPrinters. Bug: https://bugzilla.samba.org/show_bug.cgi?id=10652 Suggested-by: Volker Lendecke Signed-off-by: David Disseldorp Reviewed-by: Andreas Schneider (cherry picked from commit 4f4501ac1f35ab15f25d207c0d33e7c4d1abdf38) --- source3/printing/spoolssd.c | 34 +++++------------------------ source3/rpc_server/spoolss/srv_spoolss_nt.c | 11 +++++++++- source3/rpc_server/srvsvc/srv_srvsvc_nt.c | 1 + source3/smbd/lanman.c | 1 + source3/smbd/server.c | 20 ----------------- 5 files changed, 17 insertions(+), 50 deletions(-) diff --git a/source3/printing/spoolssd.c b/source3/printing/spoolssd.c index 7525fd1c2b..c9c8a6972e 100644 --- a/source3/printing/spoolssd.c +++ b/source3/printing/spoolssd.c @@ -132,27 +132,6 @@ static void smb_conf_updated(struct messaging_context *msg, update_conf(ev_ctx, msg); } -static void update_pcap(struct tevent_context *ev_ctx, - struct messaging_context *msg_ctx) -{ - change_to_root_user(); - delete_and_reload_printers(ev_ctx, msg_ctx); -} - -static void pcap_updated(struct messaging_context *msg, - void *private_data, - uint32_t msg_type, - struct server_id server_id, - DATA_BLOB *data) -{ - struct tevent_context *ev_ctx; - - ev_ctx = talloc_get_type_abort(private_data, struct tevent_context); - - DEBUG(10, ("Got message that pcap updated. Reloading.\n")); - update_pcap(ev_ctx, msg); -} - static void spoolss_sig_term_handler(struct tevent_context *ev, struct tevent_signal *se, int signum, @@ -318,8 +297,6 @@ static bool spoolss_child_init(struct tevent_context *ev_ctx, messaging_register(msg_ctx, ev_ctx, MSG_SMB_CONF_UPDATED, smb_conf_updated); - messaging_register(msg_ctx, ev_ctx, MSG_PRINTER_PCAP, - pcap_updated); messaging_register(msg_ctx, ev_ctx, MSG_PREFORK_PARENT_EVENT, parent_ping); @@ -739,15 +716,14 @@ pid_t start_spoolssd(struct tevent_context *ev_ctx, MSG_SMB_CONF_UPDATED, smb_conf_updated); messaging_register(msg_ctx, NULL, MSG_PRINTER_UPDATE, print_queue_forward); - messaging_register(msg_ctx, ev_ctx, MSG_PRINTER_PCAP, - pcap_updated); messaging_register(msg_ctx, ev_ctx, MSG_PREFORK_CHILD_EVENT, child_ping); - /* As soon as messaging is up check if pcap has been loaded already. - * If so then we probably missed a message and should load_printers() - * ourselves. If pcap has not been loaded yet, then ignore, we will get - * a message as soon as the bq process completes the reload. */ + /* + * As soon as messaging is up check if pcap has been loaded already. + * If pcap has not been loaded yet, then ignore, as we will reload on + * client enumeration anyway. + */ if (pcap_cache_loaded()) { load_printers(ev_ctx, msg_ctx); } diff --git a/source3/rpc_server/spoolss/srv_spoolss_nt.c b/source3/rpc_server/spoolss/srv_spoolss_nt.c index 64f5cbed2f..010d0dfc9e 100644 --- a/source3/rpc_server/spoolss/srv_spoolss_nt.c +++ b/source3/rpc_server/spoolss/srv_spoolss_nt.c @@ -4307,7 +4307,7 @@ static WERROR enum_all_printers_info_level(TALLOC_CTX *mem_ctx, uint32_t *count_p) { int snum; - int n_services = lp_numservices(); + int n_services; union spoolss_PrinterInfo *info = NULL; uint32_t count = 0; WERROR result = WERR_OK; @@ -4319,6 +4319,15 @@ static WERROR enum_all_printers_info_level(TALLOC_CTX *mem_ctx, return WERR_NOMEM; } + /* + * printer shares are only updated on client enumeration. The background + * printer process updates printer_list.tdb at regular intervals. + */ + become_root(); + delete_and_reload_printers(server_event_context(), msg_ctx); + unbecome_root(); + + n_services = lp_numservices(); *count_p = 0; *info_p = NULL; diff --git a/source3/rpc_server/srvsvc/srv_srvsvc_nt.c b/source3/rpc_server/srvsvc/srv_srvsvc_nt.c index 011d41fa52..7b9ec5c87d 100644 --- a/source3/rpc_server/srvsvc/srv_srvsvc_nt.c +++ b/source3/rpc_server/srvsvc/srv_srvsvc_nt.c @@ -484,6 +484,7 @@ static WERROR init_srv_share_info_ctr(struct pipes_struct *p, /* Ensure all the usershares are loaded. */ become_root(); + delete_and_reload_printers(server_event_context(), p->msg_ctx); load_usershare_shares(NULL, connections_snum_used); load_registry_shares(); num_services = lp_numservices(); diff --git a/source3/smbd/lanman.c b/source3/smbd/lanman.c index 0a0ab6b975..d0dae36db2 100644 --- a/source3/smbd/lanman.c +++ b/source3/smbd/lanman.c @@ -2091,6 +2091,7 @@ static bool api_RNetShareEnum(struct smbd_server_connection *sconn, /* Ensure all the usershares are loaded. */ become_root(); + delete_and_reload_printers(sconn->ev_ctx, sconn->msg_ctx); load_registry_shares(); count = load_usershare_shares(NULL, connections_snum_used); unbecome_root(); diff --git a/source3/smbd/server.c b/source3/smbd/server.c index 918fb88111..8856f43be5 100644 --- a/source3/smbd/server.c +++ b/source3/smbd/server.c @@ -108,24 +108,6 @@ static void smbd_parent_conf_updated(struct messaging_context *msg, printing_subsystem_update(ev_ctx, msg, false); } -/******************************************************************* - What to do when printcap is updated. - ********************************************************************/ - -static void smb_pcap_updated(struct messaging_context *msg, - void *private_data, - uint32_t msg_type, - struct server_id server_id, - DATA_BLOB *data) -{ - struct tevent_context *ev_ctx = - talloc_get_type_abort(private_data, struct tevent_context); - - DEBUG(10,("Got message saying pcap was updated. Reloading.\n")); - change_to_root_user(); - delete_and_reload_printers(ev_ctx, msg); -} - /******************************************************************* Delete a statcache entry. ********************************************************************/ @@ -881,8 +863,6 @@ static bool open_sockets_smbd(struct smbd_parent_context *parent, messaging_register(msg_ctx, NULL, MSG_SMB_STAT_CACHE_DELETE, smb_stat_cache_delete); messaging_register(msg_ctx, NULL, MSG_DEBUG, smbd_msg_debug); - messaging_register(msg_ctx, ev_ctx, MSG_PRINTER_PCAP, - smb_pcap_updated); messaging_register(msg_ctx, NULL, MSG_SMB_BRL_VALIDATE, brl_revalidate); messaging_register(msg_ctx, NULL, MSG_SMB_FORCE_TDIS, -- cgit v1.2.3