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authorGerald Carter <jerry@samba.org>2004-12-08 03:02:29 +0000
committerGerald (Jerry) Carter <jerry@samba.org>2007-10-10 10:53:34 -0500
commitbc7142ce2373993e87511ff401815efd60b1c1dd (patch)
tree5ff2852e958acf9ee4ebdff5c77a7a41ca31587c /source3/printing
parentc5dcd2d57234c8474ea2d95553f5a84ff682df90 (diff)
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r4094: BUG 2107: fix memory bloating caused by large numbers of print_queue_updates() requests sent via messages.tdb
(This used to be commit 56b1110c71b17eeb2ebdb7d506d86deb6b81f0d5)
Diffstat (limited to 'source3/printing')
-rw-r--r--source3/printing/printing.c171
1 files changed, 136 insertions, 35 deletions
diff --git a/source3/printing/printing.c b/source3/printing/printing.c
index 5c8790e34b..b5785440ae 100644
--- a/source3/printing/printing.c
+++ b/source3/printing/printing.c
@@ -44,9 +44,9 @@ static BOOL remove_from_jobs_changed(const char* sharename, uint32 jobid);
*/
struct print_queue_update_context {
- fstring sharename;
+ char* sharename;
enum printing_types printing_type;
- pstring lpqcommand;
+ char* lpqcommand;
};
@@ -993,16 +993,17 @@ static void check_job_changed(const char *sharename, TDB_DATA data, uint32 jobid
Check if the print queue has been updated recently enough.
****************************************************************************/
-static BOOL print_cache_expired(const char *sharename)
+static BOOL print_cache_expired(const char *sharename, BOOL check_pending)
{
fstring key;
time_t last_qscan_time, time_now = time(NULL);
struct tdb_print_db *pdb = get_print_db_byname(sharename);
+ BOOL result = False;
if (!pdb)
return False;
- slprintf(key, sizeof(key), "CACHE/%s", sharename);
+ snprintf(key, sizeof(key), "CACHE/%s", sharename);
last_qscan_time = (time_t)tdb_fetch_int32(pdb->tdb, key);
/*
@@ -1019,15 +1020,37 @@ static BOOL print_cache_expired(const char *sharename)
|| (time_now - last_qscan_time) >= lp_lpqcachetime()
|| last_qscan_time > (time_now + MAX_CACHE_VALID_TIME))
{
- DEBUG(3, ("print cache expired for queue %s "
+ time_t msg_pending_time;
+
+ DEBUG(4, ("print_cache_expired: cache expired for queue %s "
"(last_qscan_time = %d, time now = %d, qcachetime = %d)\n",
sharename, (int)last_qscan_time, (int)time_now,
(int)lp_lpqcachetime() ));
- release_print_db(pdb);
- return True;
+
+ /* check if another smbd has already sent a message to update the
+ queue. Give the pending message one minute to clear and
+ then send another message anyways. Make sure to check for
+ clocks that have been run forward and then back again. */
+
+ snprintf(key, sizeof(key), "MSG_PENDING/%s", sharename);
+
+ if ( check_pending
+ && tdb_fetch_uint32( pdb->tdb, key, &msg_pending_time )
+ && msg_pending_time > 0
+ && msg_pending_time <= time_now
+ && (time_now - msg_pending_time) < 60 )
+ {
+ DEBUG(4,("print_cache_expired: message already pending for %s. Accepting cache\n",
+ sharename));
+ goto done;
+ }
+
+ result = True;
}
+
+done:
release_print_db(pdb);
- return False;
+ return result;
}
/****************************************************************************
@@ -1052,7 +1075,7 @@ static void print_queue_update_internal( const char *sharename,
DEBUG(5,("print_queue_update_internal: printer = %s, type = %d, lpq command = [%s]\n",
sharename, current_printif->type, lpq_command));
- if ( !print_cache_expired(sharename) ) {
+ if ( !print_cache_expired(sharename, False) ) {
DEBUG(5,("print_queue_update_internal: print cache for %s is still ok\n", sharename));
return;
}
@@ -1166,6 +1189,20 @@ static void print_queue_update_internal( const char *sharename,
slprintf(keystr, sizeof(keystr)-1, "CACHE/%s", sharename);
tdb_store_int32(pdb->tdb, keystr, (int32)time(NULL));
+ /* clear the msg pending record for this queue */
+
+ snprintf(keystr, sizeof(keystr), "MSG_PENDING/%s", sharename);
+
+ if ( !tdb_store_uint32( pdb->tdb, keystr, 0 ) ) {
+ /* log a message but continue on */
+
+ DEBUG(0,("print_queue_update: failed to store MSG_PENDING flag for [%s]!\n",
+ sharename));
+ }
+
+ release_print_db( pdb );
+
+ return;
}
/****************************************************************************
@@ -1255,19 +1292,31 @@ static void print_queue_update_with_lock(int snum)
/****************************************************************************
this is the receive function of the background lpq updater
****************************************************************************/
-static void print_queue_receive(int msg_type, pid_t src, void *buf, size_t len)
+static void print_queue_receive(int msg_type, pid_t src, void *buf, size_t msglen)
{
struct print_queue_update_context ctx;
+ fstring sharename;
+ pstring lpqcommand;
+ size_t len;
+
+ len = tdb_unpack( buf, msglen, "fdP",
+ sharename,
+ &ctx.printing_type,
+ lpqcommand );
- if (len != sizeof(struct print_queue_update_context)) {
- DEBUG(1, ("Got invalid print queue update message\n"));
+ if ( len == -1 ) {
+ DEBUG(0,("print_queue_receive: Got invalid print queue update message\n"));
return;
}
- memcpy(&ctx, buf, sizeof(struct print_queue_update_context));
+ ctx.sharename = sharename;
+ ctx.lpqcommand = lpqcommand;
+
print_queue_update_internal(ctx.sharename,
get_printer_fns_from_type(ctx.printing_type),
ctx.lpqcommand );
+
+ return;
}
static pid_t background_lpq_updater_pid = -1;
@@ -1333,32 +1382,84 @@ update the internal database from the system print queue for a queue
static void print_queue_update(int snum)
{
struct print_queue_update_context ctx;
+ fstring key;
+ fstring sharename;
+ pstring lpqcommand;
+ char *buffer = NULL;
+ size_t len = 0;
+ size_t newlen;
+ struct tdb_print_db *pdb;
/*
* Make sure that the background queue process exists.
* Otherwise just do the update ourselves
*/
-
- if ( background_lpq_updater_pid != -1 ) {
- fstrcpy(ctx.sharename, lp_const_servicename(snum));
- ctx.printing_type = lp_printing(snum);
+
+ if ( background_lpq_updater_pid == -1 ) {
+ print_queue_update_with_lock( snum );
+ return;
+ }
+
+ fstrcpy( sharename, lp_const_servicename(snum));
+
+ ctx.printing_type = lp_printing(snum);
+
+ pstrcpy( lpqcommand, lp_lpqcommand(snum));
+ pstring_sub( lpqcommand, "%p", PRINTERNAME(snum) );
+ standard_sub_snum( snum, lpqcommand, sizeof(lpqcommand) );
+
+ ctx.sharename = SMB_STRDUP( sharename );
+ ctx.lpqcommand = SMB_STRDUP( lpqcommand );
+
+ /* get the length */
+
+ len = tdb_pack( buffer, len, "fdP",
+ ctx.sharename,
+ ctx.printing_type,
+ ctx.lpqcommand );
- pstrcpy(ctx.lpqcommand, lp_lpqcommand(snum));
- pstring_sub( ctx.lpqcommand, "%p", PRINTERNAME(snum) );
- standard_sub_snum( snum, ctx.lpqcommand, sizeof(ctx.lpqcommand) );
+ buffer = SMB_XMALLOC_ARRAY( char, len );
- DEBUG(10,("print_queue_update: Sending message -> printer = %s, "
- "type = %d, lpq command = [%s]\n",
- ctx.sharename, ctx.printing_type, ctx.lpqcommand ));
+ /* now pack the buffer */
+ newlen = tdb_pack( buffer, len, "fdP",
+ ctx.sharename,
+ ctx.printing_type,
+ ctx.lpqcommand );
+
+ SMB_ASSERT( newlen == len );
+
+ DEBUG(10,("print_queue_update: Sending message -> printer = %s, "
+ "type = %d, lpq command = [%s]\n",
+ ctx.sharename, ctx.printing_type, ctx.lpqcommand ));
+
+ /* here we set a msg pending record for other smbd processes
+ to throttle the number of duplicate print_queue_update msgs
+ sent. */
+
+ pdb = get_print_db_byname(sharename);
+ snprintf(key, sizeof(key), "MSG_PENDING/%s", sharename);
+
+ if ( !tdb_store_uint32( pdb->tdb, key, time(NULL) ) ) {
+ /* log a message but continue on */
+
+ DEBUG(0,("print_queue_update: failed to store MSG_PENDING flag for [%s]!\n",
+ sharename));
+ }
+
+ release_print_db( pdb );
+ /* finally send the message */
- become_root();
- message_send_pid(background_lpq_updater_pid,
- MSG_PRINTER_UPDATE, &ctx, sizeof(ctx),
- False);
- unbecome_root();
- } else
- print_queue_update_with_lock( snum );
+ become_root();
+ message_send_pid(background_lpq_updater_pid,
+ MSG_PRINTER_UPDATE, buffer, len, False);
+ unbecome_root();
+
+ SAFE_FREE( ctx.sharename );
+ SAFE_FREE( ctx.lpqcommand );
+ SAFE_FREE( buffer );
+
+ return;
}
/****************************************************************************
@@ -2001,7 +2102,7 @@ int print_queue_length(int snum, print_status_struct *pstatus)
int len;
/* make sure the database is up to date */
- if (print_cache_expired(lp_const_servicename(snum)))
+ if (print_cache_expired(lp_const_servicename(snum), True))
print_queue_update(snum);
/* also fetch the queue status */
@@ -2316,7 +2417,7 @@ BOOL print_job_end(int snum, uint32 jobid, BOOL normal_close)
pjob_store(sharename, jobid, pjob);
/* make sure the database is up to date */
- if (print_cache_expired(lp_const_servicename(snum)))
+ if (print_cache_expired(lp_const_servicename(snum), True))
print_queue_update(snum);
return True;
@@ -2348,7 +2449,7 @@ static BOOL get_stored_queue_info(struct tdb_print_db *pdb, int snum, int *pcoun
const char* sharename = lp_servicename(snum);
/* make sure the database is up to date */
- if (print_cache_expired(lp_const_servicename(snum)))
+ if (print_cache_expired(lp_const_servicename(snum), True))
print_queue_update(snum);
*pcount = 0;
@@ -2469,7 +2570,7 @@ int print_queue_status(int snum,
/* make sure the database is up to date */
- if (print_cache_expired(lp_const_servicename(snum)))
+ if (print_cache_expired(lp_const_servicename(snum), True))
print_queue_update(snum);
/* return if we are done */
@@ -2569,7 +2670,7 @@ BOOL print_queue_resume(struct current_user *user, int snum, WERROR *errcode)
}
/* make sure the database is up to date */
- if (print_cache_expired(lp_const_servicename(snum)))
+ if (print_cache_expired(lp_const_servicename(snum), True))
print_queue_update(snum);
/* Send a printer notify message */