From 0b188e7784a3f58810f871bf63d10d8a691ecbae Mon Sep 17 00:00:00 2001 From: David Disseldorp Date: Thu, 23 Dec 2010 12:14:21 +0100 Subject: s3-printing: Initiate pcap reload from parent smbd MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since commit 7022554, smbds share a printcap cache (printer_list.tdb), therefore ordering of events between smbd processes is important when updating printcap cache information. Consider the following two process example: 1) smbd1 receives HUP or printcap cache time expiry 2) smbd1 checks whether pcap needs refresh, it does 3) smbd1 marks pcap as refreshed 4) smbd1 forks child1 to obtain cups printer info 5) smbd2 receives HUP or printcap cache time expiry 6) smbd2 checks whether pcap needs refresh, it does not (due to step 3) 7) smbd2 reloads printer shares prior to child1 completion (stale pcap) 8) child1 completion, pcap cache (printer_list.tdb) is updated by smbd1 9) smbd1 reloads printer shares based on new pcap information In this case both smbd1 and smbd2 are reliant on the pcap update performed on child1 completion. The prior commit "reload shares after pcap cache fill" ensures that smbd1 only reloads printer shares following pcap update, however smbd2 continues to present shares based on stale pcap data. This commit addresses the above problem by driving pcap cache and printer share updates from the parent smbd process. 1) smbd0 (parent) receives a HUP or printcap cache time expiry 2) smbd0 forks child0 to obtain cups printer info 3) child0 completion, pcap cache (printer_list.tdb) is updated by smbd0 4) smbd0 reloads printer shares 5) smbd0 notifies child smbds of pcap update via message_send_all() 6) child smbds read fresh pcap data and reload printer shares This architecture has the additional advantage that only a single process (the parent smbd) requests printer information from the printcap backend. Use time_mono in housekeeping functions As suggested by Björn Jacke. --- source3/include/local.h | 1 + source3/include/proto.h | 2 ++ 2 files changed, 3 insertions(+) (limited to 'source3/include') diff --git a/source3/include/local.h b/source3/include/local.h index a8889af376..bb73840757 100644 --- a/source3/include/local.h +++ b/source3/include/local.h @@ -139,6 +139,7 @@ #define LPQ_LOCK_TIMEOUT (5) #define NMBD_INTERFACES_RELOAD (120) #define NMBD_UNEXPECTED_TIMEOUT (15) +#define SMBD_HOUSEKEEPING_INTERVAL SMBD_SELECT_TIMEOUT /* the following are in milliseconds */ #define LOCK_RETRY_TIMEOUT (100) diff --git a/source3/include/proto.h b/source3/include/proto.h index 91d3ef165e..338c27db03 100644 --- a/source3/include/proto.h +++ b/source3/include/proto.h @@ -5405,6 +5405,8 @@ void reload_printers(struct tevent_context *ev, struct messaging_context *msg_ctx); bool reload_services(struct messaging_context *msg_ctx, int smb_sock, bool test); +void reload_pcap_change_notify(struct tevent_context *ev, + struct messaging_context *msg_ctx); void exit_server(const char *const explanation); void exit_server_cleanly(const char *const explanation); void exit_server_fault(void); -- cgit