From 6e12253068b835a2369b8dafb3f8b27de16842c3 Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Wed, 12 Feb 2014 10:13:19 -0800 Subject: [PATCH] s3: printing: Fix problem with server taking too long to respond to a MSG_PRINTER_DRVUPGRADE message. Receiving a MSG_PRINTER_DRVUPGRADE causes smbd to iterate over all printers looking for ones that uses the driver. This is a very expensive operation requiring a read of all registry printer parameters. On a system with a large number of printers, this causes the clients to timeout (smbd can take longer than 60 seconds to respond). This patch fixes the problem by forwarding the MSG_PRINTER_DRVUPGRADE to the background lpq queue updater process and allowing it to take care of the updating of the changeid in the registry, allowing the smbd connected to the client to return to processing requests immediately. https://bugzilla.samba.org/show_bug.cgi?id=9942 Signed-off-by: Jeremy Allison Reviewed-by: Andreas Schneider Autobuild-User(master): Andreas Schneider Autobuild-Date(master): Tue Feb 18 17:48:30 CET 2014 on sn-devel-104 (cherry picked from commit cd655715b8ee0a4e681d67b3996f71017b941401) --- source3/printing/nt_printing.c | 29 +++++++++++++++++++++++++++-- source3/printing/queue_process.c | 6 ++++++ source3/rpc_server/spoolss/srv_spoolss_nt.c | 1 + 3 files changed, 34 insertions(+), 2 deletions(-) diff --git a/source3/printing/nt_printing.c b/source3/printing/nt_printing.c index 5050a5d..5aaae4d 100644 --- a/source3/printing/nt_printing.c +++ b/source3/printing/nt_printing.c @@ -75,6 +75,31 @@ static const struct print_architecture_table_node archi_table[]= { }; /**************************************************************************** + Forward a MSG_PRINTER_DRVUPGRADE message from another smbd to the + background lpq updater. +****************************************************************************/ + +static void forward_drv_upgrade_printer_msg(struct messaging_context *msg, + void *private_data, + uint32_t msg_type, + struct server_id server_id, + DATA_BLOB *data) +{ + extern pid_t background_lpq_updater_pid; + + if (background_lpq_updater_pid == -1) { + DEBUG(3,("no background lpq queue updater\n")); + return; + } + + messaging_send_buf(msg, + pid_to_procid(background_lpq_updater_pid), + MSG_PRINTER_DRVUPGRADE, + data->data, + data->length); +} + +/**************************************************************************** Open the NT printing tdbs. Done once before fork(). ****************************************************************************/ @@ -88,10 +113,10 @@ bool nt_printing_init(struct messaging_context *msg_ctx) /* * register callback to handle updating printers as new - * drivers are installed + * drivers are installed. Forwards to background lpq updater. */ messaging_register(msg_ctx, NULL, MSG_PRINTER_DRVUPGRADE, - do_drv_upgrade_printer); + forward_drv_upgrade_printer_msg); /* of course, none of the message callbacks matter if you don't tell messages.c that you interested in receiving PRINT_GENERAL diff --git a/source3/printing/queue_process.c b/source3/printing/queue_process.c index 3d142dd..0969c7b 100644 --- a/source3/printing/queue_process.c +++ b/source3/printing/queue_process.c @@ -31,6 +31,7 @@ #include "smbd/smbd.h" #include "rpc_server/rpc_config.h" #include "printing/load.h" +#include "rpc_server/spoolss/srv_spoolss_nt.h" extern pid_t start_spoolssd(struct event_context *ev_ctx, struct messaging_context *msg_ctx); @@ -311,6 +312,11 @@ pid_t start_background_queue(struct tevent_context *ev, bq_smb_conf_updated); messaging_register(msg_ctx, NULL, MSG_PRINTER_UPDATE, print_queue_receive); + /* Remove previous forwarder message set in parent. */ + messaging_deregister(msg_ctx, MSG_PRINTER_DRVUPGRADE, NULL); + + messaging_register(msg_ctx, NULL, MSG_PRINTER_DRVUPGRADE, + do_drv_upgrade_printer); fde = tevent_add_fd(ev, ev, pause_pipe[1], TEVENT_FD_READ, printing_pause_fd_handler, diff --git a/source3/rpc_server/spoolss/srv_spoolss_nt.c b/source3/rpc_server/spoolss/srv_spoolss_nt.c index 3703349..c878679 100644 --- a/source3/rpc_server/spoolss/srv_spoolss_nt.c +++ b/source3/rpc_server/spoolss/srv_spoolss_nt.c @@ -1513,6 +1513,7 @@ void srv_spoolss_cleanup(void) /********************************************************************** callback to receive a MSG_PRINTER_DRVUPGRADE message and interate over all printers, upgrading ones as necessary + This is now *ONLY* called inside the background lpq updater. JRA. **********************************************************************/ void do_drv_upgrade_printer(struct messaging_context *msg, -- 1.9.0.rc1.175.g0b1dcb5