2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 1992-2000
5 Copyright (C) Jeremy Allison 1992-2006
6 Copyright (C) Volker Lendecke 2005
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
23 12 aug 96: Erik.Devriendt@te6.siemens.be
24 added support for shared memory implementation of share mode locking
26 May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode
27 locking to deal with multiple share modes per open file.
29 September 1997. Jeremy Allison (jallison@whistle.com). Added oplock
32 rewritten completely to use new tdb code. Tridge, Dec '99
34 Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
35 Added Unix Extensions POSIX locking support. Jeremy Allison Mar 2006.
39 #include "system/filesys.h"
40 #include "locking/proto.h"
41 #include "smbd/globals.h"
42 #include "dbwrap/dbwrap.h"
43 #include "dbwrap/dbwrap_open.h"
44 #include "../libcli/security/security.h"
48 #include "../librpc/gen_ndr/ndr_open_files.h"
49 #include "source3/lib/dbwrap/dbwrap_watch.h"
50 #include "locking/leases_db.h"
51 #include "../lib/util/memcache.h"
54 #define DBGC_CLASS DBGC_LOCKING
56 #define NO_LOCKING_COUNT (-1)
58 /* the locking database handle */
59 static struct db_context *lock_db;
61 static bool locking_init_internal(bool read_only)
70 db_path = lock_path("locking.tdb");
71 if (db_path == NULL) {
75 lock_db = db_open(NULL, db_path,
76 SMB_OPEN_DATABASE_TDB_HASH_SIZE,
77 TDB_DEFAULT|TDB_VOLATILE|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
78 read_only?O_RDONLY:O_RDWR|O_CREAT, 0644,
79 DBWRAP_LOCK_ORDER_1, DBWRAP_FLAG_NONE);
82 DEBUG(0,("ERROR: Failed to initialise locking database\n"));
86 if (!posix_locking_init(read_only))
89 dbwrap_watch_db(lock_db, server_messaging_context());
94 bool locking_init(void)
96 return locking_init_internal(false);
99 bool locking_init_readonly(void)
101 return locking_init_internal(true);
104 /*******************************************************************
105 Deinitialize the share_mode management.
106 ******************************************************************/
108 bool locking_end(void)
111 TALLOC_FREE(lock_db);
115 /*******************************************************************
116 Form a static locking key for a dev/inode pair.
117 ******************************************************************/
119 static TDB_DATA locking_key(const struct file_id *id)
121 return make_tdb_data((const uint8_t *)id, sizeof(*id));
124 /*******************************************************************
125 Share mode cache utility functions that store/delete/retrieve
126 entries from memcache.
128 For now share the statcache (global cache) memory space. If
129 a lock record gets orphaned (which shouldn't happen as we're
130 using the same locking_key data as lookup) it will eventually
131 fall out of the cache via the normal LRU trim mechanism. If
132 necessary we can always make this a separate (smaller) cache.
133 ******************************************************************/
135 static const DATA_BLOB memcache_key(const struct file_id *id)
137 return data_blob_const((const void *)id, sizeof(*id));
140 static void share_mode_memcache_delete(struct share_mode_data *d)
142 const DATA_BLOB key = memcache_key(&d->id);
144 DEBUG(10,("deleting entry for file %s seq 0x%llu key %s\n",
146 (unsigned long long) d->sequence_number,
147 file_id_string(talloc_tos(), &d->id)));
149 memcache_delete(NULL,
150 SHARE_MODE_LOCK_CACHE,
154 static void share_mode_memcache_store(struct share_mode_data *d)
156 const DATA_BLOB key = memcache_key(&d->id);
158 DEBUG(10,("stored entry for file %s seq 0x%llu key %s\n",
160 (unsigned long long) d->sequence_number,
161 file_id_string(talloc_tos(), &d->id)));
163 /* Ensure everything stored in the cache is pristine. */
168 * Ensure the memory going into the cache
169 * doesn't have a destructor so it can be
170 * cleanly freed by share_mode_memcache_delete().
172 talloc_set_destructor(d, NULL);
174 /* Cache will own d after this call. */
175 memcache_add_talloc(NULL,
176 SHARE_MODE_LOCK_CACHE,
182 * NB. We use ndr_pull_hyper on a stack-created
183 * struct ndr_pull with no talloc allowed, as we
184 * need this to be really fast as an ndr-peek into
185 * the first 8 bytes of the blob.
188 static enum ndr_err_code get_blob_sequence_number(DATA_BLOB *blob,
191 struct ndr_pull ndr = {.data = blob->data, .data_size = blob->length};
192 NDR_CHECK(ndr_pull_hyper(&ndr, NDR_SCALARS, pseq));
193 return NDR_ERR_SUCCESS;
196 static int share_mode_data_nofree_destructor(struct share_mode_data *d)
201 static struct share_mode_data *share_mode_memcache_fetch(TALLOC_CTX *mem_ctx,
202 const TDB_DATA id_key,
205 enum ndr_err_code ndr_err;
206 struct share_mode_data *d;
207 uint64_t sequence_number;
212 /* Ensure this is a locking_key record. */
213 if (id_key.dsize != sizeof(id)) {
217 memcpy(&id, id_key.dptr, id_key.dsize);
218 key = memcache_key(&id);
220 ptr = memcache_lookup_talloc(NULL,
221 SHARE_MODE_LOCK_CACHE,
224 DEBUG(10,("failed to find entry for key %s\n",
225 file_id_string(mem_ctx, &id)));
228 /* sequence number key is at start of blob. */
229 ndr_err = get_blob_sequence_number(blob, &sequence_number);
230 if (ndr_err != NDR_ERR_SUCCESS) {
231 /* Bad blob. Remove entry. */
232 DEBUG(10,("bad blob %u key %s\n",
233 (unsigned int)ndr_err,
234 file_id_string(mem_ctx, &id)));
235 memcache_delete(NULL,
236 SHARE_MODE_LOCK_CACHE,
241 d = (struct share_mode_data *)ptr;
242 if (d->sequence_number != sequence_number) {
243 DEBUG(10,("seq changed (cached 0x%llu) (new 0x%llu) "
245 (unsigned long long)d->sequence_number,
246 (unsigned long long)sequence_number,
247 file_id_string(mem_ctx, &id)));
248 /* Cache out of date. Remove entry. */
249 memcache_delete(NULL,
250 SHARE_MODE_LOCK_CACHE,
255 /* Move onto mem_ctx. */
256 d = talloc_move(mem_ctx, &ptr);
259 * Now we own d, prevent the cache from freeing it
260 * when we delete the entry.
262 talloc_set_destructor(d, share_mode_data_nofree_destructor);
264 /* Remove from the cache. We own it now. */
265 memcache_delete(NULL,
266 SHARE_MODE_LOCK_CACHE,
269 /* And reset the destructor to none. */
270 talloc_set_destructor(d, NULL);
272 DEBUG(10,("fetched entry for file %s seq 0x%llu key %s\n",
274 (unsigned long long)d->sequence_number,
275 file_id_string(mem_ctx, &id)));
280 /*******************************************************************
281 Get all share mode entries for a dev/inode pair.
282 ********************************************************************/
284 static struct share_mode_data *parse_share_modes(TALLOC_CTX *mem_ctx,
288 struct share_mode_data *d;
289 enum ndr_err_code ndr_err;
293 blob.data = dbuf.dptr;
294 blob.length = dbuf.dsize;
296 /* See if we already have a cached copy of this key. */
297 d = share_mode_memcache_fetch(mem_ctx, key, &blob);
302 d = talloc(mem_ctx, struct share_mode_data);
304 DEBUG(0, ("talloc failed\n"));
308 ndr_err = ndr_pull_struct_blob_all(
309 &blob, d, d, (ndr_pull_flags_fn_t)ndr_pull_share_mode_data);
310 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
311 DEBUG(1, ("ndr_pull_share_mode_lock failed: %s\n",
312 ndr_errstr(ndr_err)));
317 * Initialize the values that are [skip] in the idl. The NDR code does
318 * not initialize them.
321 for (i=0; i<d->num_share_modes; i++) {
322 struct share_mode_entry *e = &d->share_modes[i];
326 if (e->op_type != LEASE_OPLOCK) {
329 if (e->lease_idx >= d->num_leases) {
332 e->lease = &d->leases[e->lease_idx];
337 if (DEBUGLEVEL >= 10) {
338 DEBUG(10, ("parse_share_modes:\n"));
339 NDR_PRINT_DEBUG(share_mode_data, d);
348 /*******************************************************************
349 Create a storable data blob from a modified share_mode_data struct.
350 ********************************************************************/
352 static TDB_DATA unparse_share_modes(struct share_mode_data *d)
355 enum ndr_err_code ndr_err;
357 if (DEBUGLEVEL >= 10) {
358 DEBUG(10, ("unparse_share_modes:\n"));
359 NDR_PRINT_DEBUG(share_mode_data, d);
362 share_mode_memcache_delete(d);
364 /* Update the sequence number. */
365 d->sequence_number += 1;
367 remove_stale_share_mode_entries(d);
369 if (d->num_share_modes == 0) {
370 DEBUG(10, ("No used share mode found\n"));
371 return make_tdb_data(NULL, 0);
374 ndr_err = ndr_push_struct_blob(
375 &blob, d, d, (ndr_push_flags_fn_t)ndr_push_share_mode_data);
376 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
377 smb_panic("ndr_push_share_mode_lock failed");
380 return make_tdb_data(blob.data, blob.length);
383 /*******************************************************************
384 If modified, store the share_mode_data back into the database.
385 ********************************************************************/
387 static int share_mode_data_destructor(struct share_mode_data *d)
396 data = unparse_share_modes(d);
398 if (data.dptr == NULL) {
400 /* There has been an entry before, delete it */
402 status = dbwrap_record_delete(d->record);
403 if (!NT_STATUS_IS_OK(status)) {
406 DEBUG(0, ("delete_rec returned %s\n",
409 if (asprintf(&errmsg, "could not delete share "
411 nt_errstr(status)) == -1) {
412 smb_panic("could not delete share"
419 * Nothing to store in cache - allow the normal
420 * release of record lock and memory free.
425 status = dbwrap_record_store(d->record, data, TDB_REPLACE);
426 if (!NT_STATUS_IS_OK(status)) {
429 DEBUG(0, ("store returned %s\n", nt_errstr(status)));
431 if (asprintf(&errmsg, "could not store share mode entry: %s",
432 nt_errstr(status)) == -1) {
433 smb_panic("could not store share mode entry");
439 * Release the record lock before putting in the cache.
441 TALLOC_FREE(d->record);
444 * Reparent d into the in-memory cache so it can be reused if the
445 * sequence number matches. See parse_share_modes()
449 share_mode_memcache_store(d);
453 /*******************************************************************
454 Allocate a new share_mode_data struct, mark it unmodified.
455 fresh is set to note that currently there is no database entry.
456 ********************************************************************/
458 static struct share_mode_data *fresh_share_mode_lock(
459 TALLOC_CTX *mem_ctx, const char *servicepath,
460 const struct smb_filename *smb_fname,
461 const struct timespec *old_write_time)
463 struct share_mode_data *d;
465 if ((servicepath == NULL) || (smb_fname == NULL) ||
466 (old_write_time == NULL)) {
470 d = talloc_zero(mem_ctx, struct share_mode_data);
474 /* New record - new sequence number. */
475 generate_random_buffer((uint8_t *)&d->sequence_number, 8);
477 d->base_name = talloc_strdup(d, smb_fname->base_name);
478 if (d->base_name == NULL) {
481 if (smb_fname->stream_name != NULL) {
482 d->stream_name = talloc_strdup(d, smb_fname->stream_name);
483 if (d->stream_name == NULL) {
487 d->servicepath = talloc_strdup(d, servicepath);
488 if (d->servicepath == NULL) {
491 d->old_write_time = *old_write_time;
496 DEBUG(0, ("talloc failed\n"));
501 /*******************************************************************
502 Either fetch a share mode from the database, or allocate a fresh
503 one if the record doesn't exist.
504 ********************************************************************/
506 static struct share_mode_lock *get_share_mode_lock_internal(
507 TALLOC_CTX *mem_ctx, struct file_id id,
508 const char *servicepath, const struct smb_filename *smb_fname,
509 const struct timespec *old_write_time)
511 struct share_mode_lock *lck;
512 struct share_mode_data *d;
513 struct db_record *rec;
514 TDB_DATA key = locking_key(&id);
517 rec = dbwrap_fetch_locked(lock_db, mem_ctx, key);
519 DEBUG(3, ("Could not lock share entry\n"));
523 value = dbwrap_record_get_value(rec);
525 if (value.dptr == NULL) {
526 d = fresh_share_mode_lock(mem_ctx, servicepath, smb_fname,
529 d = parse_share_modes(mem_ctx, key, value);
533 DEBUG(5, ("get_share_mode_lock_internal: "
534 "Could not get share mode lock\n"));
539 d->record = talloc_move(d, &rec);
540 talloc_set_destructor(d, share_mode_data_destructor);
542 lck = talloc(mem_ctx, struct share_mode_lock);
544 DEBUG(1, ("talloc failed\n"));
548 lck->data = talloc_move(lck, &d);
553 * We can only ever have one share mode locked. Users of
554 * get_share_mode_lock never see this, it will be refcounted by
557 static struct share_mode_lock *the_lock;
558 static struct file_id the_lock_id;
560 static int the_lock_destructor(struct share_mode_lock *l)
563 ZERO_STRUCT(the_lock_id);
567 /*******************************************************************
568 Get a share_mode_lock, Reference counted to allow nested calls.
569 ********************************************************************/
571 struct share_mode_lock *get_share_mode_lock(
574 const char *servicepath,
575 const struct smb_filename *smb_fname,
576 const struct timespec *old_write_time)
578 struct share_mode_lock *lck;
580 lck = talloc(mem_ctx, struct share_mode_lock);
582 DEBUG(1, ("talloc failed\n"));
586 if (the_lock == NULL) {
587 the_lock = get_share_mode_lock_internal(
588 lck, id, servicepath, smb_fname, old_write_time);
589 if (the_lock == NULL) {
592 talloc_set_destructor(the_lock, the_lock_destructor);
595 if (!file_id_equal(&the_lock_id, &id)) {
596 DEBUG(1, ("Can not lock two share modes "
597 "simultaneously\n"));
600 if (talloc_reference(lck, the_lock) == NULL) {
601 DEBUG(1, ("talloc_reference failed\n"));
605 lck->data = the_lock->data;
612 static void fetch_share_mode_unlocked_parser(
613 TDB_DATA key, TDB_DATA data, void *private_data)
615 struct share_mode_lock *lck = talloc_get_type_abort(
616 private_data, struct share_mode_lock);
618 lck->data = parse_share_modes(lck, key, data);
621 /*******************************************************************
622 Get a share_mode_lock without locking the database or reference
623 counting. Used by smbstatus to display existing share modes.
624 ********************************************************************/
626 struct share_mode_lock *fetch_share_mode_unlocked(TALLOC_CTX *mem_ctx,
629 struct share_mode_lock *lck;
630 TDB_DATA key = locking_key(&id);
633 lck = talloc(mem_ctx, struct share_mode_lock);
635 DEBUG(0, ("talloc failed\n"));
638 status = dbwrap_parse_record(
639 lock_db, key, fetch_share_mode_unlocked_parser, lck);
640 if (!NT_STATUS_IS_OK(status) ||
641 (lck->data == NULL)) {
648 struct share_mode_forall_state {
649 int (*fn)(struct file_id fid, const struct share_mode_data *data,
654 static int share_mode_traverse_fn(struct db_record *rec, void *_state)
656 struct share_mode_forall_state *state =
657 (struct share_mode_forall_state *)_state;
662 enum ndr_err_code ndr_err;
663 struct share_mode_data *d;
667 key = dbwrap_record_get_key(rec);
668 value = dbwrap_record_get_value(rec);
670 /* Ensure this is a locking_key record. */
671 if (key.dsize != sizeof(fid)) {
674 memcpy(&fid, key.dptr, sizeof(fid));
676 d = talloc(talloc_tos(), struct share_mode_data);
681 blob.data = value.dptr;
682 blob.length = value.dsize;
684 ndr_err = ndr_pull_struct_blob_all(
685 &blob, d, d, (ndr_pull_flags_fn_t)ndr_pull_share_mode_data);
686 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
687 DEBUG(1, ("ndr_pull_share_mode_lock failed\n"));
690 if (DEBUGLEVEL > 10) {
691 DEBUG(11, ("parse_share_modes:\n"));
692 NDR_PRINT_DEBUG(share_mode_data, d);
694 for (i=0; i<d->num_share_modes; i++) {
695 d->share_modes[i].stale = false; /* [skip] in idl */
698 ret = state->fn(fid, d, state->private_data);
704 int share_mode_forall(int (*fn)(struct file_id fid,
705 const struct share_mode_data *data,
709 struct share_mode_forall_state state = {
711 .private_data = private_data
716 if (lock_db == NULL) {
720 status = dbwrap_traverse_read(lock_db, share_mode_traverse_fn,
722 if (!NT_STATUS_IS_OK(status)) {
729 struct share_entry_forall_state {
730 int (*fn)(const struct share_mode_entry *e,
731 const char *service_path, const char *base_name,
736 static int share_entry_traverse_fn(struct file_id fid,
737 const struct share_mode_data *data,
740 struct share_entry_forall_state *state = private_data;
743 for (i=0; i<data->num_share_modes; i++) {
746 ret = state->fn(&data->share_modes[i],
747 data->servicepath, data->base_name,
748 state->private_data);
757 /*******************************************************************
758 Call the specified function on each entry under management by the
760 ********************************************************************/
762 int share_entry_forall(int (*fn)(const struct share_mode_entry *,
763 const char *, const char *, void *),
766 struct share_entry_forall_state state = {
767 .fn = fn, .private_data = private_data };
769 return share_mode_forall(share_entry_traverse_fn, &state);
772 bool share_mode_cleanup_disconnected(struct file_id fid,
773 uint64_t open_persistent_id)
776 TALLOC_CTX *frame = talloc_stackframe();
778 struct share_mode_data *data;
779 struct share_mode_lock *lck;
782 lck = get_existing_share_mode_lock(frame, fid);
784 DEBUG(5, ("share_mode_cleanup_disconnected: "
785 "Could not fetch share mode entry for %s\n",
786 file_id_string(frame, &fid)));
791 for (n=0; n < data->num_share_modes; n++) {
792 struct share_mode_entry *entry = &data->share_modes[n];
794 if (!server_id_is_disconnected(&entry->pid)) {
795 DEBUG(5, ("share_mode_cleanup_disconnected: "
796 "file (file-id='%s', servicepath='%s', "
797 "base_name='%s%s%s') "
798 "is used by server %s ==> do not cleanup\n",
799 file_id_string(frame, &fid),
802 (data->stream_name == NULL)
803 ? "" : "', stream_name='",
804 (data->stream_name == NULL)
805 ? "" : data->stream_name,
806 server_id_str(frame, &entry->pid)));
809 if (open_persistent_id != entry->share_file_id) {
810 DEBUG(5, ("share_mode_cleanup_disconnected: "
812 "(file-id='%s', servicepath='%s', "
813 "base_name='%s%s%s') "
814 "has share_file_id %llu but expected %llu"
815 "==> do not cleanup\n",
816 file_id_string(frame, &fid),
819 (data->stream_name == NULL)
820 ? "" : "', stream_name='",
821 (data->stream_name == NULL)
822 ? "" : data->stream_name,
823 (unsigned long long)entry->share_file_id,
824 (unsigned long long)open_persistent_id));
829 for (n=0; n < data->num_leases; n++) {
830 struct share_mode_lease *l = &data->leases[n];
833 status = leases_db_del(&l->client_guid, &l->lease_key, &fid);
835 DEBUG(10, ("%s: leases_db_del returned %s\n", __func__,
839 ok = brl_cleanup_disconnected(fid, open_persistent_id);
841 DEBUG(10, ("share_mode_cleanup_disconnected: "
842 "failed to clean up byte range locks associated "
843 "with file (file-id='%s', servicepath='%s', "
844 "base_name='%s%s%s') and open_persistent_id %llu "
845 "==> do not cleanup\n",
846 file_id_string(frame, &fid),
849 (data->stream_name == NULL)
850 ? "" : "', stream_name='",
851 (data->stream_name == NULL)
852 ? "" : data->stream_name,
853 (unsigned long long)open_persistent_id));
857 DEBUG(10, ("share_mode_cleanup_disconnected: "
858 "cleaning up %u entries for file "
859 "(file-id='%s', servicepath='%s', "
860 "base_name='%s%s%s') "
861 "from open_persistent_id %llu\n",
862 data->num_share_modes,
863 file_id_string(frame, &fid),
866 (data->stream_name == NULL)
867 ? "" : "', stream_name='",
868 (data->stream_name == NULL)
869 ? "" : data->stream_name,
870 (unsigned long long)open_persistent_id));
872 data->num_share_modes = 0;
873 data->num_leases = 0;
874 data->modified = true;