From 27500c2ad045ac870ec8f5368b5fa7e61530cd36 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 --- 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 376dcfa..6a5f2d7 100644 --- a/source3/printing/nt_printing.c +++ b/source3/printing/nt_printing.c @@ -132,6 +132,31 @@ static bool print_driver_directories_init(void) } /**************************************************************************** + 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(). ****************************************************************************/ @@ -149,10 +174,10 @@ 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 bc6c33f..aa0d0fb 100644 --- a/source3/printing/queue_process.c +++ b/source3/printing/queue_process.c @@ -32,6 +32,7 @@ #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 tevent_context *ev_ctx, struct messaging_context *msg_ctx); @@ -314,6 +315,11 @@ 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 dc90b77..1305b10 100644 --- a/source3/rpc_server/spoolss/srv_spoolss_nt.c +++ b/source3/rpc_server/spoolss/srv_spoolss_nt.c @@ -1515,6 +1515,7 @@ 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