2 Unix SMB/CIFS implementation.
3 Blocking Locking functions
4 Copyright (C) Jeremy Allison 1998-2003
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #include "smbd/globals.h"
24 #define DBGC_CLASS DBGC_LOCKING
26 /****************************************************************************
27 Determine if this is a secondary element of a chained SMB.
28 **************************************************************************/
30 static void received_unlock_msg(struct messaging_context
*msg
,
33 struct server_id server_id
,
36 static void brl_timeout_fn(struct event_context
*event_ctx
,
37 struct timed_event
*te
,
41 SMB_ASSERT(brl_timeout
== te
);
42 TALLOC_FREE(brl_timeout
);
44 change_to_root_user(); /* TODO: Possibly run all timed events as
47 process_blocking_lock_queue();
50 /****************************************************************************
51 We need a version of timeval_min that treats zero timval as infinite.
52 ****************************************************************************/
54 static struct timeval
timeval_brl_min(const struct timeval
*tv1
,
55 const struct timeval
*tv2
)
57 if (timeval_is_zero(tv1
)) {
60 if (timeval_is_zero(tv2
)) {
63 return timeval_min(tv1
, tv2
);
66 /****************************************************************************
67 After a change to blocking_lock_queue, recalculate the timed_event for the
69 ****************************************************************************/
71 static bool recalc_brl_timeout(void)
73 struct blocking_lock_record
*blr
;
74 struct timeval next_timeout
;
76 TALLOC_FREE(brl_timeout
);
78 next_timeout
= timeval_zero();
80 for (blr
= blocking_lock_queue
; blr
; blr
= blr
->next
) {
81 if (timeval_is_zero(&blr
->expire_time
)) {
83 * If we're blocked on pid 0xFFFFFFFF this is
84 * a POSIX lock, so calculate a timeout of
85 * 10 seconds into the future.
87 if (blr
->blocking_pid
== 0xFFFFFFFF) {
88 struct timeval psx_to
= timeval_current_ofs(10, 0);
89 next_timeout
= timeval_brl_min(&next_timeout
, &psx_to
);
95 next_timeout
= timeval_brl_min(&next_timeout
, &blr
->expire_time
);
98 if (timeval_is_zero(&next_timeout
)) {
99 DEBUG(10, ("Next timeout = Infinite.\n"));
104 struct timeval cur
, from_now
;
106 cur
= timeval_current();
107 from_now
= timeval_until(&cur
, &next_timeout
);
108 DEBUG(10, ("Next timeout = %d.%d seconds from now.\n",
109 (int)from_now
.tv_sec
, (int)from_now
.tv_usec
));
112 if (!(brl_timeout
= event_add_timed(smbd_event_context(), NULL
,
114 brl_timeout_fn
, NULL
))) {
122 /****************************************************************************
123 Function to push a blocking lock request onto the lock queue.
124 ****************************************************************************/
126 bool push_blocking_lock_request( struct byte_range_lock
*br_lck
,
127 struct smb_request
*req
,
132 enum brl_type lock_type
,
133 enum brl_flavour lock_flav
,
136 uint32_t blocking_pid
)
138 struct blocking_lock_record
*blr
;
141 if(req_is_in_chain(req
)) {
142 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
147 * Now queue an entry on the blocking lock queue. We setup
148 * the expiration time here.
151 blr
= talloc(NULL
, struct blocking_lock_record
);
153 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
161 if (lock_timeout
== -1) {
162 blr
->expire_time
.tv_sec
= 0;
163 blr
->expire_time
.tv_usec
= 0; /* Never expire. */
165 blr
->expire_time
= timeval_current_ofs(lock_timeout
/1000,
166 (lock_timeout
% 1000) * 1000);
168 blr
->lock_num
= lock_num
;
169 blr
->lock_pid
= lock_pid
;
170 blr
->blocking_pid
= blocking_pid
;
171 blr
->lock_flav
= lock_flav
;
172 blr
->lock_type
= lock_type
;
173 blr
->offset
= offset
;
176 /* Specific brl_lock() implementations can fill this in. */
177 blr
->blr_private
= NULL
;
179 /* Add a pending lock record for this. */
180 status
= brl_lock(smbd_messaging_context(),
186 lock_type
== READ_LOCK
? PENDING_READ_LOCK
: PENDING_WRITE_LOCK
,
188 lock_timeout
? True
: False
, /* blocking_lock. */
192 if (!NT_STATUS_IS_OK(status
)) {
193 DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
198 SMB_PERFCOUNT_DEFER_OP(&req
->pcd
, &req
->pcd
);
199 blr
->req
= talloc_move(blr
, &req
);
201 DLIST_ADD_END(blocking_lock_queue
, blr
, struct blocking_lock_record
*);
202 recalc_brl_timeout();
204 /* Ensure we'll receive messages when this is unlocked. */
205 if (!blocking_lock_unlock_state
) {
206 messaging_register(smbd_messaging_context(), NULL
,
207 MSG_SMB_UNLOCK
, received_unlock_msg
);
208 blocking_lock_unlock_state
= true;
211 DEBUG(3,("push_blocking_lock_request: lock request blocked with "
212 "expiry time (%u sec. %u usec) (+%d msec) for fnum = %d, name = %s\n",
213 (unsigned int)blr
->expire_time
.tv_sec
,
214 (unsigned int)blr
->expire_time
.tv_usec
, lock_timeout
,
215 blr
->fsp
->fnum
, blr
->fsp
->fsp_name
));
217 /* Push the MID of this packet on the signing queue. */
218 srv_defer_sign_response(blr
->req
->mid
);
223 /****************************************************************************
224 Return a lockingX success SMB.
225 *****************************************************************************/
227 static void reply_lockingX_success(struct blocking_lock_record
*blr
)
229 reply_outbuf(blr
->req
, 2, 0);
232 * As this message is a lockingX call we must handle
233 * any following chained message correctly.
234 * This is normally handled in construct_reply(),
235 * but as that calls switch_message, we can't use
236 * that here and must set up the chain info manually.
239 chain_reply(blr
->req
);
240 TALLOC_FREE(blr
->req
->outbuf
);
243 /****************************************************************************
244 Return a generic lock fail error blocking call.
245 *****************************************************************************/
247 static void generic_blocking_lock_error(struct blocking_lock_record
*blr
, NTSTATUS status
)
249 /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
250 FILE_LOCK_CONFLICT! (tridge) */
251 if (NT_STATUS_EQUAL(status
, NT_STATUS_LOCK_NOT_GRANTED
)) {
252 status
= NT_STATUS_FILE_LOCK_CONFLICT
;
255 if (NT_STATUS_EQUAL(status
, NT_STATUS_FILE_LOCK_CONFLICT
)) {
256 /* Store the last lock error. */
257 files_struct
*fsp
= blr
->fsp
;
260 fsp
->last_lock_failure
.context
.smbpid
= blr
->lock_pid
;
261 fsp
->last_lock_failure
.context
.tid
= fsp
->conn
->cnum
;
262 fsp
->last_lock_failure
.context
.pid
= procid_self();
263 fsp
->last_lock_failure
.start
= blr
->offset
;
264 fsp
->last_lock_failure
.size
= blr
->count
;
265 fsp
->last_lock_failure
.fnum
= fsp
->fnum
;
266 fsp
->last_lock_failure
.lock_type
= READ_LOCK
; /* Don't care. */
267 fsp
->last_lock_failure
.lock_flav
= blr
->lock_flav
;
271 reply_nterror(blr
->req
, status
);
272 if (!srv_send_smb(smbd_server_fd(), (char *)blr
->req
->outbuf
,
273 blr
->req
->encrypted
, NULL
)) {
274 exit_server_cleanly("generic_blocking_lock_error: srv_send_smb failed.");
276 TALLOC_FREE(blr
->req
->outbuf
);
279 /****************************************************************************
280 Return a lock fail error for a lockingX call. Undo all the locks we have
282 *****************************************************************************/
284 static void reply_lockingX_error(struct blocking_lock_record
*blr
, NTSTATUS status
)
286 files_struct
*fsp
= blr
->fsp
;
287 uint16 num_ulocks
= SVAL(blr
->req
->vwv
+6, 0);
288 uint64_t count
= (uint64_t)0, offset
= (uint64_t) 0;
290 unsigned char locktype
= CVAL(blr
->req
->vwv
+3, 0);
291 bool large_file_format
= (locktype
& LOCKING_ANDX_LARGE_FILES
);
295 data
= (uint8_t *)blr
->req
->buf
296 + ((large_file_format
? 20 : 10)*num_ulocks
);
299 * Data now points at the beginning of the list
300 * of smb_lkrng structs.
304 * Ensure we don't do a remove on the lock that just failed,
305 * as under POSIX rules, if we have a lock already there, we
306 * will delete it (and we shouldn't) .....
309 for(i
= blr
->lock_num
- 1; i
>= 0; i
--) {
312 lock_pid
= get_lock_pid( data
, i
, large_file_format
);
313 count
= get_lock_count( data
, i
, large_file_format
);
314 offset
= get_lock_offset( data
, i
, large_file_format
, &err
);
317 * We know err cannot be set as if it was the lock
318 * request would never have been queued. JRA.
321 do_unlock(smbd_messaging_context(),
329 generic_blocking_lock_error(blr
, status
);
332 /****************************************************************************
333 Return a lock fail error.
334 *****************************************************************************/
336 static void blocking_lock_reply_error(struct blocking_lock_record
*blr
, NTSTATUS status
)
338 DEBUG(10, ("Replying with error=%s. BLR = %p\n", nt_errstr(status
), blr
));
340 switch(blr
->req
->cmd
) {
342 reply_lockingX_error(blr
, status
);
346 reply_nterror(blr
->req
, status
);
349 * construct_reply_common has done us the favor to pre-fill
350 * the command field with SMBtranss2 which is wrong :-)
352 SCVAL(blr
->req
->outbuf
,smb_com
,SMBtrans2
);
354 if (!srv_send_smb(smbd_server_fd(),
355 (char *)blr
->req
->outbuf
,
356 IS_CONN_ENCRYPTED(blr
->fsp
->conn
),
358 exit_server_cleanly("blocking_lock_reply_error: "
359 "srv_send_smb failed.");
361 TALLOC_FREE(blr
->req
->outbuf
);
364 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
365 exit_server("PANIC - unknown type on blocking lock queue");
369 /****************************************************************************
370 Attempt to finish off getting all pending blocking locks for a lockingX call.
371 Returns True if we want to be removed from the list.
372 *****************************************************************************/
374 static bool process_lockingX(struct blocking_lock_record
*blr
)
376 unsigned char locktype
= CVAL(blr
->req
->vwv
+3, 0);
377 files_struct
*fsp
= blr
->fsp
;
378 uint16 num_ulocks
= SVAL(blr
->req
->vwv
+6, 0);
379 uint16 num_locks
= SVAL(blr
->req
->vwv
+7, 0);
380 uint64_t count
= (uint64_t)0, offset
= (uint64_t)0;
382 bool large_file_format
= (locktype
& LOCKING_ANDX_LARGE_FILES
);
384 NTSTATUS status
= NT_STATUS_OK
;
386 data
= (uint8_t *)blr
->req
->buf
387 + ((large_file_format
? 20 : 10)*num_ulocks
);
390 * Data now points at the beginning of the list
391 * of smb_lkrng structs.
394 for(; blr
->lock_num
< num_locks
; blr
->lock_num
++) {
395 struct byte_range_lock
*br_lck
= NULL
;
398 lock_pid
= get_lock_pid( data
, blr
->lock_num
, large_file_format
);
399 count
= get_lock_count( data
, blr
->lock_num
, large_file_format
);
400 offset
= get_lock_offset( data
, blr
->lock_num
, large_file_format
, &err
);
403 * We know err cannot be set as if it was the lock
404 * request would never have been queued. JRA.
407 br_lck
= do_lock(smbd_messaging_context(),
412 ((locktype
& LOCKING_ANDX_SHARED_LOCK
) ?
413 READ_LOCK
: WRITE_LOCK
),
422 if (NT_STATUS_IS_ERR(status
)) {
427 if(blr
->lock_num
== num_locks
) {
429 * Success - we got all the locks.
432 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
433 fsp
->fsp_name
, fsp
->fnum
, (unsigned int)locktype
, num_locks
) );
435 reply_lockingX_success(blr
);
439 if (!NT_STATUS_EQUAL(status
,NT_STATUS_LOCK_NOT_GRANTED
) &&
440 !NT_STATUS_EQUAL(status
,NT_STATUS_FILE_LOCK_CONFLICT
)) {
442 * We have other than a "can't get lock"
443 * error. Free any locks we had and return an error.
444 * Return True so we get dequeued.
446 blocking_lock_reply_error(blr
, status
);
451 * Still can't get all the locks - keep waiting.
454 DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
456 blr
->lock_num
, num_locks
, fsp
->fsp_name
, fsp
->fnum
));
461 /****************************************************************************
462 Attempt to get the posix lock request from a SMBtrans2 call.
463 Returns True if we want to be removed from the list.
464 *****************************************************************************/
466 static bool process_trans2(struct blocking_lock_record
*blr
)
470 struct byte_range_lock
*br_lck
= do_lock(smbd_messaging_context(),
483 if (!NT_STATUS_IS_OK(status
)) {
484 if (ERROR_WAS_LOCK_DENIED(status
)) {
485 /* Still can't get the lock, just keep waiting. */
489 * We have other than a "can't get lock"
490 * error. Send an error and return True so we get dequeued.
492 blocking_lock_reply_error(blr
, status
);
496 /* We finally got the lock, return success. */
499 /* Fake up max_data_bytes here - we know it fits. */
500 send_trans2_replies(blr
->fsp
->conn
, blr
->req
, params
, 2, NULL
, 0, 0xffff);
505 /****************************************************************************
506 Process a blocking lock SMB.
507 Returns True if we want to be removed from the list.
508 *****************************************************************************/
510 static bool blocking_lock_record_process(struct blocking_lock_record
*blr
)
512 switch(blr
->req
->cmd
) {
514 return process_lockingX(blr
);
517 return process_trans2(blr
);
519 DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
520 exit_server("PANIC - unknown type on blocking lock queue");
522 return False
; /* Keep compiler happy. */
525 /****************************************************************************
526 Cancel entries by fnum from the blocking lock pending queue.
527 *****************************************************************************/
529 void cancel_pending_lock_requests_by_fid(files_struct
*fsp
, struct byte_range_lock
*br_lck
)
531 struct blocking_lock_record
*blr
, *blr_cancelled
, *next
= NULL
;
533 for(blr
= blocking_lock_queue
; blr
; blr
= next
) {
534 unsigned char locktype
= 0;
537 if (blr
->fsp
->fnum
!= fsp
->fnum
) {
541 if (blr
->req
->cmd
== SMBlockingX
) {
542 locktype
= CVAL(blr
->req
->vwv
+3, 0);
545 DEBUG(10, ("remove_pending_lock_requests_by_fid - removing "
546 "request type %d for file %s fnum = %d\n",
547 blr
->req
->cmd
, fsp
->fsp_name
, fsp
->fnum
));
549 blr_cancelled
= blocking_lock_cancel(fsp
,
555 NT_STATUS_RANGE_NOT_LOCKED
);
557 SMB_ASSERT(blr_cancelled
== blr
);
559 brl_lock_cancel(br_lck
,
567 /* We're closing the file fsp here, so ensure
568 * we don't have a dangling pointer. */
573 /****************************************************************************
574 Delete entries by mid from the blocking lock pending queue. Always send reply.
575 *****************************************************************************/
577 void remove_pending_lock_requests_by_mid(int mid
)
579 struct blocking_lock_record
*blr
, *next
= NULL
;
581 for(blr
= blocking_lock_queue
; blr
; blr
= next
) {
583 struct byte_range_lock
*br_lck
;
587 if (blr
->req
->mid
!= mid
) {
592 br_lck
= brl_get_locks(talloc_tos(), fsp
);
595 DEBUG(10, ("remove_pending_lock_requests_by_mid - "
596 "removing request type %d for file %s fnum "
597 "= %d\n", blr
->req
->cmd
, fsp
->fsp_name
,
600 brl_lock_cancel(br_lck
,
610 blocking_lock_reply_error(blr
,NT_STATUS_FILE_LOCK_CONFLICT
);
611 DLIST_REMOVE(blocking_lock_queue
, blr
);
616 /****************************************************************************
617 Is this mid a blocking lock request on the queue ?
618 *****************************************************************************/
620 bool blocking_lock_was_deferred(int mid
)
622 struct blocking_lock_record
*blr
, *next
= NULL
;
624 for(blr
= blocking_lock_queue
; blr
; blr
= next
) {
626 if(blr
->req
->mid
== mid
) {
633 /****************************************************************************
634 Set a flag as an unlock request affects one of our pending locks.
635 *****************************************************************************/
637 static void received_unlock_msg(struct messaging_context
*msg
,
640 struct server_id server_id
,
643 DEBUG(10,("received_unlock_msg\n"));
644 process_blocking_lock_queue();
647 /****************************************************************************
648 Process the blocking lock queue. Note that this is only called as root.
649 *****************************************************************************/
651 void process_blocking_lock_queue(void)
653 struct timeval tv_curr
= timeval_current();
654 struct blocking_lock_record
*blr
, *next
= NULL
;
655 bool recalc_timeout
= False
;
658 * Go through the queue and see if we can get any of the locks.
661 for (blr
= blocking_lock_queue
; blr
; blr
= next
) {
666 * Go through the remaining locks and try and obtain them.
667 * The call returns True if all locks were obtained successfully
668 * and False if we still need to wait.
671 DEBUG(10, ("Processing BLR = %p\n", blr
));
673 if(blocking_lock_record_process(blr
)) {
674 struct byte_range_lock
*br_lck
= brl_get_locks(
675 talloc_tos(), blr
->fsp
);
677 DEBUG(10, ("BLR_process returned true: cancelling and "
678 "removing lock. BLR = %p\n", blr
));
681 brl_lock_cancel(br_lck
,
691 DLIST_REMOVE(blocking_lock_queue
, blr
);
693 recalc_timeout
= True
;
698 * We couldn't get the locks for this record on the list.
699 * If the time has expired, return a lock error.
702 if (!timeval_is_zero(&blr
->expire_time
) && timeval_compare(&blr
->expire_time
, &tv_curr
) <= 0) {
703 struct byte_range_lock
*br_lck
= brl_get_locks(
704 talloc_tos(), blr
->fsp
);
706 DEBUG(10, ("Lock timed out! BLR = %p\n", blr
));
709 * Lock expired - throw away all previously
710 * obtained locks and return lock error.
714 DEBUG(5,("process_blocking_lock_queue: "
715 "pending lock fnum = %d for file %s "
716 "timed out.\n", blr
->fsp
->fnum
,
717 blr
->fsp
->fsp_name
));
719 brl_lock_cancel(br_lck
,
729 blocking_lock_reply_error(blr
,NT_STATUS_FILE_LOCK_CONFLICT
);
730 DLIST_REMOVE(blocking_lock_queue
, blr
);
732 recalc_timeout
= True
;
736 if (recalc_timeout
) {
737 recalc_brl_timeout();
741 /****************************************************************************
742 Handle a cancel message. Lock already moved onto the cancel queue.
743 *****************************************************************************/
745 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(struct blocking_lock_record *) + sizeof(NTSTATUS))
747 static void process_blocking_lock_cancel_message(struct messaging_context
*ctx
,
750 struct server_id server_id
,
754 const char *msg
= (const char *)data
->data
;
755 struct blocking_lock_record
*blr
;
757 if (data
->data
== NULL
) {
758 smb_panic("process_blocking_lock_cancel_message: null msg");
761 if (data
->length
!= MSG_BLOCKING_LOCK_CANCEL_SIZE
) {
762 DEBUG(0, ("process_blocking_lock_cancel_message: "
763 "Got invalid msg len %d\n", (int)data
->length
));
764 smb_panic("process_blocking_lock_cancel_message: bad msg");
767 memcpy(&blr
, msg
, sizeof(blr
));
768 memcpy(&err
, &msg
[sizeof(blr
)], sizeof(NTSTATUS
));
770 DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
773 blocking_lock_reply_error(blr
, err
);
774 DLIST_REMOVE(blocking_lock_cancelled_queue
, blr
);
778 /****************************************************************************
779 Send ourselves a blocking lock cancelled message. Handled asynchronously above.
780 Returns the blocking_lock_record that is being cancelled.
781 *****************************************************************************/
783 struct blocking_lock_record
*blocking_lock_cancel(files_struct
*fsp
,
787 enum brl_flavour lock_flav
,
788 unsigned char locktype
,
791 char msg
[MSG_BLOCKING_LOCK_CANCEL_SIZE
];
792 struct blocking_lock_record
*blr
;
794 if (!blocking_lock_cancel_state
) {
795 /* Register our message. */
796 messaging_register(smbd_messaging_context(), NULL
,
797 MSG_SMB_BLOCKING_LOCK_CANCEL
,
798 process_blocking_lock_cancel_message
);
800 blocking_lock_cancel_state
= True
;
803 for (blr
= blocking_lock_queue
; blr
; blr
= blr
->next
) {
804 if (fsp
== blr
->fsp
&&
805 lock_pid
== blr
->lock_pid
&&
806 offset
== blr
->offset
&&
807 count
== blr
->count
&&
808 lock_flav
== blr
->lock_flav
) {
817 /* Check the flags are right. */
818 if (blr
->req
->cmd
== SMBlockingX
&&
819 (locktype
& LOCKING_ANDX_LARGE_FILES
) !=
820 (CVAL(blr
->req
->vwv
+3, 0) & LOCKING_ANDX_LARGE_FILES
)) {
824 /* Move to cancelled queue. */
825 DLIST_REMOVE(blocking_lock_queue
, blr
);
826 DLIST_ADD(blocking_lock_cancelled_queue
, blr
);
828 /* Create the message. */
829 memcpy(msg
, &blr
, sizeof(blr
));
830 memcpy(&msg
[sizeof(blr
)], &err
, sizeof(NTSTATUS
));
832 messaging_send_buf(smbd_messaging_context(), procid_self(),
833 MSG_SMB_BLOCKING_LOCK_CANCEL
,
834 (uint8
*)&msg
, sizeof(msg
));