src/patches/samba/samba-3.6.99-fix_printcap_cpu_utilization.patch

   1 From 61c58824cc9117ffe206ae7c126929bfa2384486 Mon Sep 17 00:00:00 2001
   2 From: David Disseldorp <ddiss@samba.org>
   3 Date: Thu, 10 Jul 2014 00:18:10 +0200
   4 Subject: [PATCH 1/7] PATCHSET18: printing: traverse_read the printer list for
   5  share updates
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 The printcap update procedure involves the background printer process
  11 obtaining the printcap information from the printing backend, writing
  12 this to printer_list.tdb, and then notifying all smbd processes of the
  13 new list. The processes then all attempt to simultaneously traverse
  14 printer_list.tdb, in order to update their local share lists.
  15
  16 With a large number of printers, and a large number of per-client smbd
  17 processes, this traversal results in significant lock contention, mostly
  18 due to the fact that the traversal is unnecessarily done with an
  19 exclusive (write) lock on the printer_list.tdb database.
  20
  21 This commit changes the share update code path to perform a read-only
  22 traversal.
  23
  24 Bug: https://bugzilla.samba.org/show_bug.cgi?id=10652
  25
  26 Reported-by: Alex K <korobkin+samba@gmail.com>
  27 Reported-by: Franz Pförtsch <franz.pfoertsch@brose.com>
  28 Signed-off-by: David Disseldorp <ddiss@samba.org>
  29 ---
  30  source3/printing/load.c         |  2 +-
  31  source3/printing/pcap.c         |  4 ++--
  32  source3/printing/pcap.h         |  2 +-
  33  source3/printing/printer_list.c | 17 +++++++++++------
  34  source3/printing/printer_list.h |  4 ++--
  35  5 files changed, 17 insertions(+), 12 deletions(-)
  36
  37 diff --git a/source3/printing/load.c b/source3/printing/load.c
  38 index 829c3e3..0a3de73 100644
  39 --- a/source3/printing/load.c
  40 +++ b/source3/printing/load.c
  41 @@ -70,5 +70,5 @@ void load_printers(struct tevent_context *ev,
  42
  43         /* load all printcap printers */
  44         if (lp_load_printers() && lp_servicenumber(PRINTERS_NAME) >= 0)
  45 -               pcap_printer_fn(lp_add_one_printer, NULL);
  46 +               pcap_printer_read_fn(lp_add_one_printer, NULL);
  47  }
  48 diff --git a/source3/printing/pcap.c b/source3/printing/pcap.c
  49 index 62db4f5..6ad8e33 100644
  50 --- a/source3/printing/pcap.c
  51 +++ b/source3/printing/pcap.c
  52 @@ -229,11 +229,11 @@ void pcap_printer_fn_specific(const struct pcap_cache *pc,
  53         return;
  54  }
  55
  56 -void pcap_printer_fn(void (*fn)(const char *, const char *, const char *, void *), void *pdata)
  57 +void pcap_printer_read_fn(void (*fn)(const char *, const char *, const char *, void *), void *pdata)
  58  {
  59         NTSTATUS status;
  60
  61 -       status = printer_list_run_fn(fn, pdata);
  62 +       status = printer_list_read_run_fn(fn, pdata);
  63         if (!NT_STATUS_IS_OK(status)) {
  64                 DEBUG(3, ("Failed to run fn for all printers!\n"));
  65         }
  66 diff --git a/source3/printing/pcap.h b/source3/printing/pcap.h
  67 index 7056213..6c062c3 100644
  68 --- a/source3/printing/pcap.h
  69 +++ b/source3/printing/pcap.h
  70 @@ -39,7 +39,7 @@ bool pcap_cache_add(const char *name, const char *comment, const char *location)
  71  bool pcap_cache_loaded(void);
  72  bool pcap_cache_replace(const struct pcap_cache *cache);
  73  void pcap_printer_fn_specific(const struct pcap_cache *, void (*fn)(const char *, const char *, const char *, void *), void *);
  74 -void pcap_printer_fn(void (*fn)(const char *, const char *, const char *, void *), void *);
  75 +void pcap_printer_read_fn(void (*fn)(const char *, const char *, const char *, void *), void *);
  76
  77  void pcap_cache_reload(struct tevent_context *ev,
  78                        struct messaging_context *msg_ctx,
  79 diff --git a/source3/printing/printer_list.c b/source3/printing/printer_list.c
  80 index 603ce4b..b24bf83 100644
  81 --- a/source3/printing/printer_list.c
  82 +++ b/source3/printing/printer_list.c
  83 @@ -280,7 +280,8 @@ done:
  84  typedef int (printer_list_trv_fn_t)(struct db_record *, void *);
  85
  86  static NTSTATUS printer_list_traverse(printer_list_trv_fn_t *fn,
  87 -                                               void *private_data)
  88 +                                     void *private_data,
  89 +                                     bool read_only)
  90  {
  91         struct db_context *db;
  92         int ret;
  93 @@ -290,7 +291,11 @@ static NTSTATUS printer_list_traverse(printer_list_trv_fn_t *fn,
  94                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
  95         }
  96
  97 -       ret = db->traverse(db, fn, private_data);
  98 +       if (read_only) {
  99 +               ret = db->traverse_read(db, fn, private_data);
 100 +       } else {
 101 +               ret = db->traverse(db, fn, private_data);
 102 +       }
 103         if (ret < 0) {
 104                 return NT_STATUS_UNSUCCESSFUL;
 105         }
 106 @@ -357,7 +362,7 @@ NTSTATUS printer_list_clean_old(void)
 107
 108         state.status = NT_STATUS_OK;
 109
 110 -       status = printer_list_traverse(printer_list_clean_fn, &state);
 111 +       status = printer_list_traverse(printer_list_clean_fn, &state, false);
 112         if (NT_STATUS_EQUAL(status, NT_STATUS_UNSUCCESSFUL) &&
 113             !NT_STATUS_IS_OK(state.status)) {
 114                 status = state.status;
 115 @@ -404,8 +409,8 @@ static int printer_list_exec_fn(struct db_record *rec, void *private_data)
 116         return 0;
 117  }
 118
 119 -NTSTATUS printer_list_run_fn(void (*fn)(const char *, const char *, const char *, void *),
 120 -                            void *private_data)
 121 +NTSTATUS printer_list_read_run_fn(void (*fn)(const char *, const char *, const char *, void *),
 122 +                                 void *private_data)
 123  {
 124         struct printer_list_exec_state state;
 125         NTSTATUS status;
 126 @@ -414,7 +419,7 @@ NTSTATUS printer_list_run_fn(void (*fn)(const char *, const char *, const char *
 127         state.private_data = private_data;
 128         state.status = NT_STATUS_OK;
 129
 130 -       status = printer_list_traverse(printer_list_exec_fn, &state);
 131 +       status = printer_list_traverse(printer_list_exec_fn, &state, true);
 132         if (NT_STATUS_EQUAL(status, NT_STATUS_UNSUCCESSFUL) &&
 133             !NT_STATUS_IS_OK(state.status)) {
 134                 status = state.status;
 135 diff --git a/source3/printing/printer_list.h b/source3/printing/printer_list.h
 136 index fb2e007..b12c192 100644
 137 --- a/source3/printing/printer_list.h
 138 +++ b/source3/printing/printer_list.h
 139 @@ -100,6 +100,6 @@ NTSTATUS printer_list_mark_reload(void);
 140   */
 141  NTSTATUS printer_list_clean_old(void);
 142
 143 -NTSTATUS printer_list_run_fn(void (*fn)(const char *, const char *, const char *, void *),
 144 -                            void *private_data);
 145 +NTSTATUS printer_list_read_run_fn(void (*fn)(const char *, const char *, const char *, void *),
 146 +                                 void *private_data);
 147  #endif /* _PRINTER_LIST_H_ */
 148 --
 149 2.1.0
 150
 151
 152 From 18b15f127b656ad9232789b073460c95b1aaa835 Mon Sep 17 00:00:00 2001
 153 From: David Disseldorp <ddiss@samba.org>
 154 Date: Fri, 11 Jul 2014 17:00:05 +0200
 155 Subject: [PATCH 2/7] PATCHSET18: printing: only reload printer shares on
 156  client enum
 157
 158 Currently, automatic printer share updates are handled in the following
 159 way:
 160 - Background printer process (BPP) forked on startup
 161 - Parent smbd and per-client children await MSG_PRINTER_PCAP messages
 162 - BPP periodically polls the printing backend for printcap data
 163         - printcap data written to printer_list.tdb
 164         - MSG_PRINTER_PCAP sent to all smbd processes following update
 165 - smbd processes all read the latest printer_list.tdb data, and update
 166   their share listings
 167
 168 This procedure is not scalable, as all smbd processes hit
 169 printer_list.tdb in parallel, resulting in a large spike in CPU usage.
 170
 171 This change sees smbd processes only update their printer share lists
 172 only when a client asks for this information, e.g. via NetShareEnum or
 173 EnumPrinters.
 174
 175 Bug: https://bugzilla.samba.org/show_bug.cgi?id=10652
 176
 177 Suggested-by: Volker Lendecke <vl@samba.org>
 178 Signed-off-by: David Disseldorp <ddiss@samba.org>
 179 ---
 180  source3/printing/spoolssd.c                 | 17 +----------------
 181  source3/rpc_server/spoolss/srv_spoolss_nt.c | 11 ++++++++++-
 182  source3/rpc_server/srvsvc/srv_srvsvc_nt.c   |  1 +
 183  source3/smbd/lanman.c                       |  3 +++
 184  source3/smbd/server.c                       | 27 +++++----------------------
 185  5 files changed, 20 insertions(+), 39 deletions(-)
 186
 187 diff --git a/source3/printing/spoolssd.c b/source3/printing/spoolssd.c
 188 index 83727df..7953237 100644
 189 --- a/source3/printing/spoolssd.c
 190 +++ b/source3/printing/spoolssd.c
 191 @@ -74,20 +74,6 @@ static void smb_conf_updated(struct messaging_context *msg,
 192         spoolss_reopen_logs();
 193  }
 194
 195 -static void spoolss_pcap_updated(struct messaging_context *msg,
 196 -                                void *private_data,
 197 -                                uint32_t msg_type,
 198 -                                struct server_id server_id,
 199 -                                DATA_BLOB *data)
 200 -{
 201 -       struct tevent_context *ev_ctx = talloc_get_type_abort(private_data,
 202 -                                                            struct tevent_context);
 203 -
 204 -       DEBUG(10, ("Got message saying pcap was updated. Reloading.\n"));
 205 -       change_to_root_user();
 206 -       reload_printers(ev_ctx, msg);
 207 -}
 208 -
 209  static void spoolss_sig_term_handler(struct tevent_context *ev,
 210                                      struct tevent_signal *se,
 211                                      int signum,
 212 @@ -206,12 +192,11 @@ void start_spoolssd(struct tevent_context *ev_ctx,
 213                 exit(1);
 214         }
 215
 216 +       /* printer shares updated from printer_list.tdb on client enumeration */
 217         messaging_register(msg_ctx, NULL,
 218                            MSG_PRINTER_UPDATE, print_queue_receive);
 219         messaging_register(msg_ctx, ev_ctx,
 220                            MSG_SMB_CONF_UPDATED, smb_conf_updated);
 221 -       messaging_register(msg_ctx, ev_ctx,
 222 -                          MSG_PRINTER_PCAP, spoolss_pcap_updated);
 223
 224         /*
 225          * Initialize spoolss with an init function to convert printers first.
 226 diff --git a/source3/rpc_server/spoolss/srv_spoolss_nt.c b/source3/rpc_server/spoolss/srv_spoolss_nt.c
 227 index 516b7dc..db48574 100644
 228 --- a/source3/rpc_server/spoolss/srv_spoolss_nt.c
 229 +++ b/source3/rpc_server/spoolss/srv_spoolss_nt.c
 230 @@ -4316,12 +4316,21 @@ static WERROR enum_all_printers_info_level(TALLOC_CTX *mem_ctx,
 231                                            uint32_t *count_p)
 232  {
 233         int snum;
 234 -       int n_services = lp_numservices();
 235 +       int n_services;
 236         union spoolss_PrinterInfo *info = NULL;
 237         uint32_t count = 0;
 238         WERROR result = WERR_OK;
 239         struct dcerpc_binding_handle *b = NULL;
 240
 241 +       /*
 242 +        * printer shares are only updated on client enumeration. The background
 243 +        * printer process updates printer_list.tdb at regular intervals.
 244 +        */
 245 +       become_root();
 246 +       reload_printers(messaging_event_context(msg_ctx), msg_ctx);
 247 +       unbecome_root();
 248 +
 249 +       n_services = lp_numservices();
 250         *count_p = 0;
 251         *info_p = NULL;
 252
 253 diff --git a/source3/rpc_server/srvsvc/srv_srvsvc_nt.c b/source3/rpc_server/srvsvc/srv_srvsvc_nt.c
 254 index b9345d6..4600da3 100644
 255 --- a/source3/rpc_server/srvsvc/srv_srvsvc_nt.c
 256 +++ b/source3/rpc_server/srvsvc/srv_srvsvc_nt.c
 257 @@ -568,6 +568,7 @@ static WERROR init_srv_share_info_ctr(struct pipes_struct *p,
 258
 259         /* Ensure all the usershares are loaded. */
 260         become_root();
 261 +       reload_printers(messaging_event_context(p->msg_ctx), p->msg_ctx);
 262         load_usershare_shares();
 263         load_registry_shares();
 264         num_services = lp_numservices();
 265 diff --git a/source3/smbd/lanman.c b/source3/smbd/lanman.c
 266 index f56ea30..49f7583 100644
 267 --- a/source3/smbd/lanman.c
 268 +++ b/source3/smbd/lanman.c
 269 @@ -43,6 +43,7 @@
 270  #include "passdb/machine_sid.h"
 271  #include "auth.h"
 272  #include "rpc_server/rpc_ncacn_np.h"
 273 +#include "messages.h"
 274
 275  #ifdef CHECK_TYPES
 276  #undef CHECK_TYPES
 277 @@ -2091,6 +2092,8 @@ static bool api_RNetShareEnum(struct smbd_server_connection *sconn,
 278
 279         /* Ensure all the usershares are loaded. */
 280         become_root();
 281 +       reload_printers(messaging_event_context(sconn->msg_ctx),
 282 +                       sconn->msg_ctx);
 283         load_registry_shares();
 284         count = load_usershare_shares();
 285         unbecome_root();
 286 diff --git a/source3/smbd/server.c b/source3/smbd/server.c
 287 index a26dbc4..102e8dd 100644
 288 --- a/source3/smbd/server.c
 289 +++ b/source3/smbd/server.c
 290 @@ -111,24 +111,6 @@ static void smb_conf_updated(struct messaging_context *msg,
 291         /* printer reload triggered by background printing process */
 292  }
 293
 294 -/*******************************************************************
 295 - What to do when printcap is updated.
 296 - ********************************************************************/
 297 -
 298 -static void smb_pcap_updated(struct messaging_context *msg,
 299 -                            void *private_data,
 300 -                            uint32_t msg_type,
 301 -                            struct server_id server_id,
 302 -                            DATA_BLOB *data)
 303 -{
 304 -       struct tevent_context *ev_ctx =
 305 -               talloc_get_type_abort(private_data, struct tevent_context);
 306 -
 307 -       DEBUG(10,("Got message saying pcap was updated. Reloading.\n"));
 308 -       change_to_root_user();
 309 -       reload_printers(ev_ctx, msg);
 310 -}
 311 -
 312  static void smbd_sig_term_handler(struct tevent_context *ev,
 313                                   struct tevent_signal *se,
 314                                   int signum,
 315 @@ -1287,10 +1269,11 @@ extern void build_options(bool screen);
 316
 317         if (is_daemon && !interactive
 318             && lp_parm_bool(-1, "smbd", "backgroundqueue", true)) {
 319 -               /* background queue is responsible for printcap cache updates */
 320 -               messaging_register(smbd_server_conn->msg_ctx,
 321 -                                  smbd_event_context(),
 322 -                                  MSG_PRINTER_PCAP, smb_pcap_updated);
 323 +               /*
 324 +                * background queue is responsible for printcap cache updates.
 325 +                * Other smbd processes only reload printers when a client
 326 +                * issues an enumeration request.
 327 +                */
 328                 start_background_queue(server_event_context(),
 329                                        smbd_server_conn->msg_ctx);
 330         } else {
 331 --
 332 2.1.0
 333
 334
 335 From 52196380547dde4784e42c35c46135bb5230a08d Mon Sep 17 00:00:00 2001
 336 From: David Disseldorp <ddiss@samba.org>
 337 Date: Tue, 22 Jul 2014 20:17:38 +0200
 338 Subject: [PATCH 3/7] PATCHSET18: printing: reload printer_list.tdb from in
 339  memory list
 340
 341 This will allow in future for a single atomic printer_list.tdb update.
 342
 343 Bug: https://bugzilla.samba.org/show_bug.cgi?id=10652
 344
 345 Signed-off-by: David Disseldorp <ddiss@samba.org>
 346 ---
 347  source3/printing/pcap.c           | 26 +++++++++++---------------
 348  source3/printing/pcap.h           |  8 ++++----
 349  source3/printing/print_aix.c      | 17 ++++++++++++++---
 350  source3/printing/print_iprint.c   | 16 ++++++++++------
 351  source3/printing/print_standard.c |  8 ++++++--
 352  source3/printing/print_svid.c     | 11 +++++++----
 353  6 files changed, 52 insertions(+), 34 deletions(-)
 354
 355 diff --git a/source3/printing/pcap.c b/source3/printing/pcap.c
 356 index 6ad8e33..5173fc9 100644
 357 --- a/source3/printing/pcap.c
 358 +++ b/source3/printing/pcap.c
 359 @@ -83,7 +83,7 @@ void pcap_cache_destroy_specific(struct pcap_cache **pp_cache)
 360         *pp_cache = NULL;
 361  }
 362
 363 -bool pcap_cache_add(const char *name, const char *comment, const char *location)
 364 +static bool pcap_cache_add(const char *name, const char *comment, const char *location)
 365  {
 366         NTSTATUS status;
 367         time_t t = time_mono(NULL);
 368 @@ -132,8 +132,8 @@ void pcap_cache_reload(struct tevent_context *ev,
 369  {
 370         const char *pcap_name = lp_printcapname();
 371         bool pcap_reloaded = False;
 372 -       NTSTATUS status;
 373         bool post_cache_fill_fn_handled = false;
 374 +       struct pcap_cache *pcache = NULL;
 375
 376         DEBUG(3, ("reloading printcap cache\n"));
 377
 378 @@ -143,12 +143,6 @@ void pcap_cache_reload(struct tevent_context *ev,
 379                 return;
 380         }
 381
 382 -       status = printer_list_mark_reload();
 383 -       if (!NT_STATUS_IS_OK(status)) {
 384 -               DEBUG(0, ("Failed to mark printer list for reload!\n"));
 385 -               return;
 386 -       }
 387 -
 388  #ifdef HAVE_CUPS
 389         if (strequal(pcap_name, "cups")) {
 390                 pcap_reloaded = cups_cache_reload(ev, msg_ctx,
 391 @@ -164,26 +158,26 @@ void pcap_cache_reload(struct tevent_context *ev,
 392
 393  #ifdef HAVE_IPRINT
 394         if (strequal(pcap_name, "iprint")) {
 395 -               pcap_reloaded = iprint_cache_reload();
 396 +               pcap_reloaded = iprint_cache_reload(&pcache);
 397                 goto done;
 398         }
 399  #endif
 400
 401  #if defined(SYSV) || defined(HPUX)
 402         if (strequal(pcap_name, "lpstat")) {
 403 -               pcap_reloaded = sysv_cache_reload();
 404 +               pcap_reloaded = sysv_cache_reload(&pcache);
 405                 goto done;
 406         }
 407  #endif
 408
 409  #ifdef AIX
 410         if (strstr_m(pcap_name, "/qconfig") != NULL) {
 411 -               pcap_reloaded = aix_cache_reload();
 412 +               pcap_reloaded = aix_cache_reload(&pcache);
 413                 goto done;
 414         }
 415  #endif
 416
 417 -       pcap_reloaded = std_pcap_cache_reload(pcap_name);
 418 +       pcap_reloaded = std_pcap_cache_reload(pcap_name, &pcache);
 419
 420  done:
 421         DEBUG(3, ("reload status: %s\n", (pcap_reloaded) ? "ok" : "error"));
 422 @@ -192,14 +186,16 @@ done:
 423                 /* cleanup old entries only if the operation was successful,
 424                  * otherwise keep around the old entries until we can
 425                  * successfuly reaload */
 426 -               status = printer_list_clean_old();
 427 -               if (!NT_STATUS_IS_OK(status)) {
 428 -                       DEBUG(0, ("Failed to cleanup printer list!\n"));
 429 +
 430 +               if (!pcap_cache_replace(pcache)) {
 431 +                       DEBUG(0, ("Failed to replace printer list!\n"));
 432                 }
 433 +
 434                 if (post_cache_fill_fn != NULL) {
 435                         post_cache_fill_fn(ev, msg_ctx);
 436                 }
 437         }
 438 +       pcap_cache_destroy_specific(&pcache);
 439
 440         return;
 441  }
 442 diff --git a/source3/printing/pcap.h b/source3/printing/pcap.h
 443 index 6c062c3..d388d7d 100644
 444 --- a/source3/printing/pcap.h
 445 +++ b/source3/printing/pcap.h
 446 @@ -49,7 +49,7 @@ bool pcap_printername_ok(const char *printername);
 447
 448  /* The following definitions come from printing/print_aix.c  */
 449
 450 -bool aix_cache_reload(void);
 451 +bool aix_cache_reload(struct pcap_cache **_pcache);
 452
 453  /* The following definitions come from printing/print_cups.c  */
 454
 455 @@ -60,13 +60,13 @@ bool cups_cache_reload(struct tevent_context *ev,
 456
 457  /* The following definitions come from printing/print_iprint.c  */
 458
 459 -bool iprint_cache_reload(void);
 460 +bool iprint_cache_reload(struct pcap_cache **_pcache);
 461
 462  /* The following definitions come from printing/print_svid.c  */
 463
 464 -bool sysv_cache_reload(void);
 465 +bool sysv_cache_reload(struct pcap_cache **_pcache);
 466
 467  /* The following definitions come from printing/print_standard.c  */
 468 -bool std_pcap_cache_reload(const char *pcap_name);
 469 +bool std_pcap_cache_reload(const char *pcap_name, struct pcap_cache **_pcache);
 470
 471  #endif /* _PRINTING_PCAP_H_ */
 472 diff --git a/source3/printing/print_aix.c b/source3/printing/print_aix.c
 473 index 23d9a86..927a71b 100644
 474 --- a/source3/printing/print_aix.c
 475 +++ b/source3/printing/print_aix.c
 476 @@ -29,12 +29,13 @@
 477  #include "printing/pcap.h"
 478
 479  #ifdef AIX
 480 -bool aix_cache_reload(void)
 481 +bool aix_cache_reload(struct pcap_cache **_pcache)
 482  {
 483         int iEtat;
 484         XFILE *pfile;
 485         char *line = NULL, *p;
 486         char *name = NULL;
 487 +       struct pcap_cache *pcache = NULL;
 488         TALLOC_CTX *ctx = talloc_init("aix_cache_reload");
 489
 490         if (!ctx) {
 491 @@ -52,6 +53,8 @@ bool aix_cache_reload(void)
 492         iEtat = 0;
 493         /* scan qconfig file for searching <printername>:       */
 494         for (;(line = fgets_slash(NULL, 1024, pfile)); free(line)) {
 495 +               bool ok;
 496 +
 497                 if (*line == '*' || *line == 0)
 498                         continue;
 499
 500 @@ -67,6 +70,7 @@ bool aix_cache_reload(void)
 501                                 if (strcmp(p, "bsh") != 0) {
 502                                         name = talloc_strdup(ctx, p);
 503                                         if (!name) {
 504 +                                               pcap_cache_destroy_specific(&pcache);
 505                                                 SAFE_FREE(line);
 506                                                 x_fclose(pfile);
 507                                                 TALLOC_FREE(ctx);
 508 @@ -86,7 +90,10 @@ bool aix_cache_reload(void)
 509                                 /* name is found without stanza device  */
 510                                 /* probably a good printer ???          */
 511                                 iEtat = 0;
 512 -                               if (!pcap_cache_add(name, NULL, NULL)) {
 513 +                               ok = pcap_cache_add_specific(&pcache,
 514 +                                                            name, NULL, NULL);
 515 +                               if (!ok) {
 516 +                                       pcap_cache_destroy_specific(&pcache);
 517                                         SAFE_FREE(line);
 518                                         x_fclose(pfile);
 519                                         TALLOC_FREE(ctx);
 520 @@ -101,7 +108,10 @@ bool aix_cache_reload(void)
 521                         } else if (strstr_m(line, "device")) {
 522                                 /* it's a good virtual printer */
 523                                 iEtat = 0;
 524 -                               if (!pcap_cache_add(name, NULL, NULL)) {
 525 +                               ok = pcap_cache_add_specific(&pcache,
 526 +                                                            name, NULL, NULL);
 527 +                               if (!ok) {
 528 +                                       pcap_cache_destroy_specific(&pcache);
 529                                         SAFE_FREE(line);
 530                                         x_fclose(pfile);
 531                                         TALLOC_FREE(ctx);
 532 @@ -113,6 +123,7 @@ bool aix_cache_reload(void)
 533                 }
 534         }
 535
 536 +       *_pcache = pcache;
 537         x_fclose(pfile);
 538         TALLOC_FREE(ctx);
 539         return true;
 540 diff --git a/source3/printing/print_iprint.c b/source3/printing/print_iprint.c
 541 index 529f0dd..6e91747 100644
 542 --- a/source3/printing/print_iprint.c
 543 +++ b/source3/printing/print_iprint.c
 544 @@ -204,7 +204,8 @@ static int iprint_get_server_version(http_t *http, char* serviceUri)
 545
 546  static int iprint_cache_add_printer(http_t *http,
 547                                    int reqId,
 548 -                                  char* url)
 549 +                                  char *url,
 550 +                                  struct pcap_cache **pcache)
 551  {
 552         ipp_t           *request = NULL,        /* IPP Request */
 553                         *response = NULL;       /* IPP Response */
 554 @@ -340,7 +341,7 @@ static int iprint_cache_add_printer(http_t *http,
 555                 */
 556
 557                 if (name != NULL && !secure && smb_enabled)
 558 -                       pcap_cache_add(name, info, NULL);
 559 +                       pcap_cache_add_specific(pcache, name, info, NULL);
 560         }
 561
 562   out:
 563 @@ -349,7 +350,7 @@ static int iprint_cache_add_printer(http_t *http,
 564         return(0);
 565  }
 566
 567 -bool iprint_cache_reload(void)
 568 +bool iprint_cache_reload(struct pcap_cache **_pcache)
 569  {
 570         http_t          *http = NULL;           /* HTTP connection to server */
 571         ipp_t           *request = NULL,        /* IPP Request */
 572 @@ -357,7 +358,8 @@ bool iprint_cache_reload(void)
 573         ipp_attribute_t *attr;                  /* Current attribute */
 574         cups_lang_t     *language = NULL;       /* Default language */
 575         int             i;
 576 -       bool ret = False;
 577 +       bool ret = false;
 578 +       struct pcap_cache *pcache = NULL;
 579
 580         DEBUG(5, ("reloading iprint printcap cache\n"));
 581
 582 @@ -439,14 +441,16 @@ bool iprint_cache_reload(void)
 583                                         char *url = ippGetString(attr, i, NULL);
 584                                         if (!url || !strlen(url))
 585                                                 continue;
 586 -                                       iprint_cache_add_printer(http, i+2, url);
 587 +                                       iprint_cache_add_printer(http, i+2, url,
 588 +                                                                &pcache);
 589                                 }
 590                         }
 591                         attr = ippNextAttribute(response);
 592                 }
 593         }
 594
 595 -       ret = True;
 596 +       ret = true;
 597 +       *_pcache = pcache;
 598
 599   out:
 600         if (response)
 601 diff --git a/source3/printing/print_standard.c b/source3/printing/print_standard.c
 602 index c4f9c5b..b5f1056 100644
 603 --- a/source3/printing/print_standard.c
 604 +++ b/source3/printing/print_standard.c
 605 @@ -59,10 +59,11 @@
 606  #include "printing/pcap.h"
 607
 608  /* handle standard printcap - moved from pcap_printer_fn() */
 609 -bool std_pcap_cache_reload(const char *pcap_name)
 610 +bool std_pcap_cache_reload(const char *pcap_name, struct pcap_cache **_pcache)
 611  {
 612         XFILE *pcap_file;
 613         char *pcap_line;
 614 +       struct pcap_cache *pcache = NULL;
 615
 616         if ((pcap_file = x_fopen(pcap_name, O_RDONLY, 0)) == NULL) {
 617                 DEBUG(0, ("Unable to open printcap file %s for read!\n", pcap_name));
 618 @@ -117,12 +118,15 @@ bool std_pcap_cache_reload(const char *pcap_name)
 619                         }
 620                 }
 621
 622 -               if (*name && !pcap_cache_add(name, comment, NULL)) {
 623 +               if ((*name != '\0')
 624 +                && !pcap_cache_add_specific(&pcache, name, comment, NULL)) {
 625                         x_fclose(pcap_file);
 626 +                       pcap_cache_destroy_specific(&pcache);
 627                         return false;
 628                 }
 629         }
 630
 631         x_fclose(pcap_file);
 632 +       *_pcache = pcache;
 633         return true;
 634  }
 635 diff --git a/source3/printing/print_svid.c b/source3/printing/print_svid.c
 636 index 2226493..879661b 100644
 637 --- a/source3/printing/print_svid.c
 638 +++ b/source3/printing/print_svid.c
 639 @@ -35,10 +35,11 @@
 640  #include "printing/pcap.h"
 641
 642  #if defined(SYSV) || defined(HPUX)
 643 -bool sysv_cache_reload(void)
 644 +bool sysv_cache_reload(struct pcap_cache **_pcache)
 645  {
 646         char **lines;
 647         int i;
 648 +       struct pcap_cache *pcache = NULL;
 649
 650  #if defined(HPUX)
 651         DEBUG(5, ("reloading hpux printcap cache\n"));
 652 @@ -111,14 +112,16 @@ bool sysv_cache_reload(void)
 653                         *tmp = '\0';
 654
 655                 /* add it to the cache */
 656 -               if (!pcap_cache_add(name, NULL, NULL)) {
 657 +               if (!pcap_cache_add_specific(&pcache, name, NULL, NULL)) {
 658                         TALLOC_FREE(lines);
 659 -                       return False;
 660 +                       pcap_cache_destroy_specific(&pcache);
 661 +                       return false;
 662                 }
 663         }
 664
 665         TALLOC_FREE(lines);
 666 -       return True;
 667 +       *_pcache = pcache;
 668 +       return true;
 669  }
 670
 671  #else
 672 --
 673 2.1.0
 674
 675
 676 From 91c0b6477fcd4ad20d1cda45f78f160cee8e58ff Mon Sep 17 00:00:00 2001
 677 From: David Disseldorp <ddiss@samba.org>
 678 Date: Fri, 25 Jul 2014 12:18:54 +0200
 679 Subject: [PATCH 4/7] PATCHSET18: printing: remove pcap_cache_add()
 680
 681 All print list updates are now done via pcap_cache_replace(), which can
 682 call into the print_list code directly.
 683
 684 Bug: https://bugzilla.samba.org/show_bug.cgi?id=10652
 685
 686 Signed-off-by: David Disseldorp <ddiss@samba.org>
 687 ---
 688  source3/printing/pcap.c | 16 ++++++----------
 689  source3/printing/pcap.h |  1 -
 690  2 files changed, 6 insertions(+), 11 deletions(-)
 691
 692 diff --git a/source3/printing/pcap.c b/source3/printing/pcap.c
 693 index 5173fc9..5059f20 100644
 694 --- a/source3/printing/pcap.c
 695 +++ b/source3/printing/pcap.c
 696 @@ -83,15 +83,6 @@ void pcap_cache_destroy_specific(struct pcap_cache **pp_cache)
 697         *pp_cache = NULL;
 698  }
 699
 700 -static bool pcap_cache_add(const char *name, const char *comment, const char *location)
 701 -{
 702 -       NTSTATUS status;
 703 -       time_t t = time_mono(NULL);
 704 -
 705 -       status = printer_list_set_printer(talloc_tos(), name, comment, location, t);
 706 -       return NT_STATUS_IS_OK(status);
 707 -}
 708 -
 709  bool pcap_cache_loaded(void)
 710  {
 711         NTSTATUS status;
 712 @@ -105,6 +96,7 @@ bool pcap_cache_replace(const struct pcap_cache *pcache)
 713  {
 714         const struct pcap_cache *p;
 715         NTSTATUS status;
 716 +       time_t t = time_mono(NULL);
 717
 718         status = printer_list_mark_reload();
 719         if (!NT_STATUS_IS_OK(status)) {
 720 @@ -113,7 +105,11 @@ bool pcap_cache_replace(const struct pcap_cache *pcache)
 721         }
 722
 723         for (p = pcache; p; p = p->next) {
 724 -               pcap_cache_add(p->name, p->comment, p->location);
 725 +               status = printer_list_set_printer(talloc_tos(), p->name,
 726 +                                                 p->comment, p->location, t);
 727 +               if (!NT_STATUS_IS_OK(status)) {
 728 +                       return false;
 729 +               }
 730         }
 731
 732         status = printer_list_clean_old();
 733 diff --git a/source3/printing/pcap.h b/source3/printing/pcap.h
 734 index d388d7d..7dccf84 100644
 735 --- a/source3/printing/pcap.h
 736 +++ b/source3/printing/pcap.h
 737 @@ -35,7 +35,6 @@ struct pcap_cache;
 738
 739  bool pcap_cache_add_specific(struct pcap_cache **ppcache, const char *name, const char *comment, const char *location);
 740  void pcap_cache_destroy_specific(struct pcap_cache **ppcache);
 741 -bool pcap_cache_add(const char *name, const char *comment, const char *location);
 742  bool pcap_cache_loaded(void);
 743  bool pcap_cache_replace(const struct pcap_cache *cache);
 744  void pcap_printer_fn_specific(const struct pcap_cache *, void (*fn)(const char *, const char *, const char *, void *), void *);
 745 --
 746 2.1.0
 747
 748
 749 From 10582491e417d5ab5c77afe2337793dbacd98fa8 Mon Sep 17 00:00:00 2001
 750 From: David Disseldorp <ddiss@samba.org>
 751 Date: Wed, 23 Jul 2014 12:12:34 +0200
 752 Subject: [PATCH 5/7] PATCHSET18: printing: return last change time with
 753  pcap_cache_loaded()
 754
 755 Bug: https://bugzilla.samba.org/show_bug.cgi?id=10652
 756
 757 Signed-off-by: David Disseldorp <ddiss@samba.org>
 758 ---
 759  source3/printing/load.c |  2 +-
 760  source3/printing/pcap.c | 10 ++++++++--
 761  source3/printing/pcap.h |  2 +-
 762  source3/web/swat.c      |  4 ++--
 763  4 files changed, 12 insertions(+), 6 deletions(-)
 764
 765 diff --git a/source3/printing/load.c b/source3/printing/load.c
 766 index 0a3de73..83f1095 100644
 767 --- a/source3/printing/load.c
 768 +++ b/source3/printing/load.c
 769 @@ -64,7 +64,7 @@ load automatic printer services from pre-populated pcap cache
 770  void load_printers(struct tevent_context *ev,
 771                    struct messaging_context *msg_ctx)
 772  {
 773 -       SMB_ASSERT(pcap_cache_loaded());
 774 +       SMB_ASSERT(pcap_cache_loaded(NULL));
 775
 776         add_auto_printers();
 777
 778 diff --git a/source3/printing/pcap.c b/source3/printing/pcap.c
 779 index 5059f20..027c1b2 100644
 780 --- a/source3/printing/pcap.c
 781 +++ b/source3/printing/pcap.c
 782 @@ -83,13 +83,19 @@ void pcap_cache_destroy_specific(struct pcap_cache **pp_cache)
 783         *pp_cache = NULL;
 784  }
 785
 786 -bool pcap_cache_loaded(void)
 787 +bool pcap_cache_loaded(time_t *_last_change)
 788  {
 789         NTSTATUS status;
 790         time_t last;
 791
 792         status = printer_list_get_last_refresh(&last);
 793 -       return NT_STATUS_IS_OK(status);
 794 +       if (!NT_STATUS_IS_OK(status)) {
 795 +               return false;
 796 +       }
 797 +       if (_last_change != NULL) {
 798 +               *_last_change = last;
 799 +       }
 800 +       return true;
 801  }
 802
 803  bool pcap_cache_replace(const struct pcap_cache *pcache)
 804 diff --git a/source3/printing/pcap.h b/source3/printing/pcap.h
 805 index 7dccf84..8fc9e9d 100644
 806 --- a/source3/printing/pcap.h
 807 +++ b/source3/printing/pcap.h
 808 @@ -35,7 +35,7 @@ struct pcap_cache;
 809
 810  bool pcap_cache_add_specific(struct pcap_cache **ppcache, const char *name, const char *comment, const char *location);
 811  void pcap_cache_destroy_specific(struct pcap_cache **ppcache);
 812 -bool pcap_cache_loaded(void);
 813 +bool pcap_cache_loaded(time_t *_last_change);
 814  bool pcap_cache_replace(const struct pcap_cache *cache);
 815  void pcap_printer_fn_specific(const struct pcap_cache *, void (*fn)(const char *, const char *, const char *, void *), void *);
 816  void pcap_printer_read_fn(void (*fn)(const char *, const char *, const char *, void *), void *);
 817 diff --git a/source3/web/swat.c b/source3/web/swat.c
 818 index f8933d2..a1a035c 100644
 819 --- a/source3/web/swat.c
 820 +++ b/source3/web/swat.c
 821 @@ -586,7 +586,7 @@ static int save_reload(int snum)
 822                  return 0;
 823          }
 824         iNumNonAutoPrintServices = lp_numservices();
 825 -       if (pcap_cache_loaded()) {
 826 +       if (pcap_cache_loaded(NULL)) {
 827                 load_printers(server_event_context(),
 828                               server_messaging_context());
 829         }
 830 @@ -1572,7 +1572,7 @@ const char *lang_msg_rotate(TALLOC_CTX *ctx, const char *msgid)
 831         reopen_logs();
 832         load_interfaces();
 833         iNumNonAutoPrintServices = lp_numservices();
 834 -       if (pcap_cache_loaded()) {
 835 +       if (pcap_cache_loaded(NULL)) {
 836                 load_printers(server_event_context(),
 837                               server_messaging_context());
 838         }
 839 --
 840 2.1.0
 841
 842
 843 From 484667ff73b54b275f8629264aef27ec9628c7fd Mon Sep 17 00:00:00 2001
 844 From: David Disseldorp <ddiss@samba.org>
 845 Date: Wed, 23 Jul 2014 14:42:00 +0200
 846 Subject: [PATCH 6/7] PATCHSET18: smbd: only reprocess printer_list.tdb if it
 847  changed
 848
 849 The per-client smbd printer share inventory is currently updated from
 850 printer_list.tdb when a client enumerates printers, via EnumPrinters or
 851 NetShareEnum.
 852 printer_list.tdb is populated by the background print process, based on
 853 the latest printcap values retrieved from the printing backend (e.g.
 854 CUPS) at regular intervals.
 855 This change ensures that per-client smbd processes don't reparse
 856 printer_list.tdb if it hasn't been updated since the last enumeration.
 857
 858 Bug: https://bugzilla.samba.org/show_bug.cgi?id=10652
 859
 860 Suggested-by: Volker Lendecke <vl@samba.org>
 861 Signed-off-by: David Disseldorp <ddiss@samba.org>
 862 ---
 863  source3/smbd/server_reload.c | 21 +++++++++++++++++++++
 864  1 file changed, 21 insertions(+)
 865
 866 diff --git a/source3/smbd/server_reload.c b/source3/smbd/server_reload.c
 867 index c4c5a8d..57f7972 100644
 868 --- a/source3/smbd/server_reload.c
 869 +++ b/source3/smbd/server_reload.c
 870 @@ -30,6 +30,13 @@
 871  #include "auth.h"
 872  #include "messages.h"
 873
 874 +/*
 875 + * The persistent pcap cache is populated by the background print process. Per
 876 + * client smbds should only reload their printer share inventories if this
 877 + * information has changed. Use last_reload_time to detect this.
 878 + */
 879 +static time_t reload_last_pcap_time = 0;
 880 +
 881  /****************************************************************************
 882   purge stale printers and reload from pre-populated pcap cache
 883  **************************************************************************/
 884 @@ -40,6 +47,20 @@ void reload_printers(struct tevent_context *ev,
 885         int pnum;
 886         int snum;
 887         const char *pname;
 888 +       bool ok;
 889 +       time_t pcap_last_update;
 890 +
 891 +       ok = pcap_cache_loaded(&pcap_last_update);
 892 +       if (!ok) {
 893 +               DEBUG(1, ("pcap cache not loaded\n"));
 894 +               return;
 895 +       }
 896 +
 897 +       if (reload_last_pcap_time == pcap_last_update) {
 898 +               DEBUG(5, ("skipping printer reload, already up to date.\n"));
 899 +               return;
 900 +       }
 901 +       reload_last_pcap_time = pcap_last_update;
 902
 903         n_services = lp_numservices();
 904         pnum = lp_servicenumber(PRINTERS_NAME);
 905 --
 906 2.1.0
 907
 908
 909 From 08848f939b735b5a68066ebcc995247d77f5fa2d Mon Sep 17 00:00:00 2001
 910 From: David Disseldorp <ddiss@samba.org>
 911 Date: Wed, 6 Aug 2014 14:33:02 +0200
 912 Subject: [PATCH 7/7] PATCHSET18: printing: reload printer shares on
 913  OpenPrinter
 914
 915 The printer share inventory should be reloaded on open _and_
 916 enumeration, as there are some clients, such as cupsaddsmb, that do not
 917 perform an enumeration prior to access.
 918
 919 Bug: https://bugzilla.samba.org/show_bug.cgi?id=10652
 920
 921 Signed-off-by: David Disseldorp <ddiss@samba.org>
 922 ---
 923  source3/rpc_server/spoolss/srv_spoolss_nt.c | 12 +++++++++++-
 924  1 file changed, 11 insertions(+), 1 deletion(-)
 925
 926 diff --git a/source3/rpc_server/spoolss/srv_spoolss_nt.c b/source3/rpc_server/spoolss/srv_spoolss_nt.c
 927 index db48574..fb8f61f 100644
 928 --- a/source3/rpc_server/spoolss/srv_spoolss_nt.c
 929 +++ b/source3/rpc_server/spoolss/srv_spoolss_nt.c
 930 @@ -1737,6 +1737,16 @@ WERROR _spoolss_OpenPrinterEx(struct pipes_struct *p,
 931                 return WERR_INVALID_PARAM;
 932         }
 933
 934 +       /*
 935 +        * The printcap printer share inventory is updated on client
 936 +        * enumeration. For clients that do not perform enumeration prior to
 937 +        * access, such as cupssmbadd, we reinitialise the printer share
 938 +        * inventory on open as well.
 939 +        */
 940 +       become_root();
 941 +       reload_printers(messaging_event_context(p->msg_ctx), p->msg_ctx);
 942 +       unbecome_root();
 943 +
 944         /* some sanity check because you can open a printer or a print server */
 945         /* aka: \\server\printer or \\server */
 946
 947 @@ -4323,7 +4333,7 @@ static WERROR enum_all_printers_info_level(TALLOC_CTX *mem_ctx,
 948         struct dcerpc_binding_handle *b = NULL;
 949
 950         /*
 951 -        * printer shares are only updated on client enumeration. The background
 952 +        * printer shares are updated on client enumeration. The background
 953          * printer process updates printer_list.tdb at regular intervals.
 954          */
 955         become_root();
 956 --
 957 2.1.0
 958