2 Unix SMB/Netbios implementation.
4 shared memory locking implementation
5 Copyright (C) Andrew Tridgell 1992-1997
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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 October 1997 - split into separate file (tridge)
35 #ifdef FAST_SHARE_MODES
38 extern int DEBUGLEVEL;
39 extern connection_struct Connections[];
40 extern files_struct Files[];
42 static struct shmem_ops *shmops;
44 /* share mode record pointed to in shared memory hash bucket */
47 int next_offset; /* offset of next record in chain from hash bucket */
51 int num_share_mode_entries;
52 int share_mode_entries; /* Chain of share mode entries for this file */
56 /* share mode entry pointed to by share_mode_record struct */
59 int next_share_mode_entry;
61 } shm_share_mode_entry;
66 /* Conversion to hash entry index from device and inode numbers. */
67 #define HASH_ENTRY(dev,ino) ((((uint32)(dev)) ^ ((uint32)(ino))) % shmops->hash_size())
70 /*******************************************************************
71 deinitialize the shared memory for share_mode management
72 ******************************************************************/
73 static BOOL shm_stop_share_mode_mgmt(void)
75 return shmops->shm_close();
78 /*******************************************************************
79 lock a hash bucket entry in shared memory for share_mode management
80 ******************************************************************/
81 static BOOL shm_lock_share_entry(int cnum, uint32 dev, uint32 inode, int *ptok)
83 return shmops->lock_hash_entry(HASH_ENTRY(dev, inode));
86 /*******************************************************************
87 unlock a hash bucket entry in shared memory for share_mode management
88 ******************************************************************/
89 static BOOL shm_unlock_share_entry(int cnum, uint32 dev, uint32 inode, int token)
91 return shmops->unlock_hash_entry(HASH_ENTRY(dev, inode));
94 /*******************************************************************
95 get all share mode entries in shared memory for a dev/inode pair.
96 ********************************************************************/
97 static int shm_get_share_modes(int cnum, int token, uint32 dev, uint32 inode,
98 share_mode_entry **old_shares)
101 unsigned int hash_entry = HASH_ENTRY(dev, inode);
102 share_mode_record *file_scanner_p;
103 share_mode_record *file_prev_p;
104 shm_share_mode_entry *entry_scanner_p;
105 shm_share_mode_entry *entry_prev_p;
107 int num_entries_copied;
109 share_mode_entry *share_array = (share_mode_entry *)0;
113 mode_array = (int *)shmops->offset2addr(shmops->get_userdef_off());
115 if(mode_array[hash_entry] == 0)
117 DEBUG(5,("get_share_modes hash bucket %d empty\n", hash_entry));
121 file_scanner_p = (share_mode_record *)shmops->offset2addr(mode_array[hash_entry]);
122 file_prev_p = file_scanner_p;
123 while(file_scanner_p)
125 if( (file_scanner_p->st_dev == dev) && (file_scanner_p->st_ino == inode) )
132 file_prev_p = file_scanner_p ;
133 file_scanner_p = (share_mode_record *)shmops->offset2addr(
134 file_scanner_p->next_offset);
140 DEBUG(5,("get_share_modes no entry for file dev = %d ino = %d\n",
145 if(file_scanner_p->locking_version != LOCKING_VERSION)
147 DEBUG(0,("ERROR: get_share_modes Deleting old share mode v1 %d dev=%d ino=%d\n",
148 file_scanner_p->locking_version, dev, inode));
149 if(file_prev_p == file_scanner_p)
150 mode_array[hash_entry] = file_scanner_p->next_offset;
152 file_prev_p->next_offset = file_scanner_p->next_offset;
153 shmops->shm_free(shmops->addr2offset(file_scanner_p));
157 /* Allocate the old_shares array */
158 num_entries = file_scanner_p->num_share_mode_entries;
161 *old_shares = share_array = (share_mode_entry *)
162 malloc(num_entries * sizeof(share_mode_entry));
165 DEBUG(0,("get_share_modes: malloc fail!\n"));
170 num_entries_copied = 0;
172 entry_scanner_p = (shm_share_mode_entry*)shmops->offset2addr(
173 file_scanner_p->share_mode_entries);
174 entry_prev_p = entry_scanner_p;
175 while(entry_scanner_p)
177 int pid = entry_scanner_p->e.pid;
179 if (pid && !process_exists(pid))
181 /* Delete this share mode entry */
182 shm_share_mode_entry *delete_entry_p = entry_scanner_p;
184 if(entry_prev_p == entry_scanner_p)
186 /* We are at start of list */
187 file_scanner_p->share_mode_entries = entry_scanner_p->next_share_mode_entry;
188 entry_scanner_p = (shm_share_mode_entry*)shmops->offset2addr(
189 file_scanner_p->share_mode_entries);
190 entry_prev_p = entry_scanner_p;
194 entry_prev_p->next_share_mode_entry = entry_scanner_p->next_share_mode_entry;
195 entry_scanner_p = (shm_share_mode_entry*)
196 shmops->offset2addr(entry_scanner_p->next_share_mode_entry);
198 /* Decrement the number of share mode entries on this share mode record */
199 file_scanner_p->num_share_mode_entries -= 1;
202 if(file_scanner_p->num_share_mode_entries < 0)
204 DEBUG(0,("PANIC ERROR: get_share_mode: entries=%d dev=%d ino=%d\n",
205 file_scanner_p->num_share_mode_entries,dev, inode));
209 DEBUG(0,("get_share_modes: process %d no longer exists\n", pid));
211 shmops->shm_free(shmops->addr2offset(delete_entry_p));
215 /* This is a valid share mode entry and the process that
216 created it still exists. Copy it into the output array.
218 share_array[num_entries_copied].pid = entry_scanner_p->e.pid;
219 share_array[num_entries_copied].share_mode = entry_scanner_p->e.share_mode;
220 share_array[num_entries_copied].op_port = entry_scanner_p->e.op_port;
221 share_array[num_entries_copied].op_type = entry_scanner_p->e.op_type;
222 memcpy(&share_array[num_entries_copied].time, &entry_scanner_p->e.time,
223 sizeof(struct timeval));
224 num_entries_copied++;
225 DEBUG(5,("get_share_modes Read share mode 0x%X pid=%d\n",
226 entry_scanner_p->e.share_mode, entry_scanner_p->e.pid));
227 entry_prev_p = entry_scanner_p;
228 entry_scanner_p = (shm_share_mode_entry *)
229 shmops->offset2addr(entry_scanner_p->next_share_mode_entry);
233 /* If no valid share mode entries were found then this record shouldn't exist ! */
234 if(num_entries_copied == 0)
236 DEBUG(0,("get_share_modes: file with dev %d inode %d empty\n",
239 free((char *)*old_shares);
242 if(file_prev_p == file_scanner_p)
243 mode_array[hash_entry] = file_scanner_p->next_offset;
245 file_prev_p->next_offset = file_scanner_p->next_offset;
246 shmops->shm_free(shmops->addr2offset(file_scanner_p));
249 DEBUG(5,("get_share_modes: file with dev %d inode %d -> %d entries\n",
250 dev, inode, num_entries_copied));
252 return(num_entries_copied);
255 /*******************************************************************
256 del the share mode of a file.
257 ********************************************************************/
258 static void shm_del_share_mode(int token, int fnum)
262 unsigned int hash_entry;
263 share_mode_record *file_scanner_p;
264 share_mode_record *file_prev_p;
265 shm_share_mode_entry *entry_scanner_p;
266 shm_share_mode_entry *entry_prev_p;
270 dev = Files[fnum].fd_ptr->dev;
271 inode = Files[fnum].fd_ptr->inode;
273 hash_entry = HASH_ENTRY(dev, inode);
275 mode_array = (int *)shmops->offset2addr(shmops->get_userdef_off());
277 if(mode_array[hash_entry] == 0)
279 DEBUG(0,("PANIC ERROR:del_share_mode hash bucket %d empty\n",
284 file_scanner_p = (share_mode_record *)shmops->offset2addr(mode_array[hash_entry]);
285 file_prev_p = file_scanner_p;
287 while(file_scanner_p)
289 if( (file_scanner_p->st_dev == dev) && (file_scanner_p->st_ino == inode) )
296 file_prev_p = file_scanner_p ;
297 file_scanner_p = (share_mode_record *)
298 shmops->offset2addr(file_scanner_p->next_offset);
304 DEBUG(0,("ERROR: del_share_mode no entry for dev %d inode %d\n",
309 if(file_scanner_p->locking_version != LOCKING_VERSION)
311 DEBUG(0,("ERROR: del_share_modes Deleting old share mode v1 %d dev=%d ino=%d\n",
312 file_scanner_p->locking_version, dev, inode));
313 if(file_prev_p == file_scanner_p)
314 mode_array[hash_entry] = file_scanner_p->next_offset;
316 file_prev_p->next_offset = file_scanner_p->next_offset;
317 shmops->shm_free(shmops->addr2offset(file_scanner_p));
322 entry_scanner_p = (shm_share_mode_entry*)shmops->offset2addr(
323 file_scanner_p->share_mode_entries);
324 entry_prev_p = entry_scanner_p;
325 while(entry_scanner_p)
327 if( (pid == entry_scanner_p->e.pid) &&
328 (memcmp(&entry_scanner_p->e.time,
329 &Files[fnum].open_time,sizeof(struct timeval)) == 0) )
336 entry_prev_p = entry_scanner_p;
337 entry_scanner_p = (shm_share_mode_entry *)
338 shmops->offset2addr(entry_scanner_p->next_share_mode_entry);
344 /* Decrement the number of entries in the record. */
345 file_scanner_p->num_share_mode_entries -= 1;
347 DEBUG(2,("del_share_modes Deleting share mode entry dev=%d ino=%d\n",
349 if(entry_prev_p == entry_scanner_p)
350 /* We are at start of list */
351 file_scanner_p->share_mode_entries = entry_scanner_p->next_share_mode_entry;
353 entry_prev_p->next_share_mode_entry = entry_scanner_p->next_share_mode_entry;
354 shmops->shm_free(shmops->addr2offset(entry_scanner_p));
357 if(file_scanner_p->num_share_mode_entries < 0)
359 DEBUG(0,("PANIC ERROR:del_share_mode num_share_mode_entries=%d\n",
360 file_scanner_p->num_share_mode_entries));
364 /* If we deleted the last share mode entry then remove the share mode record. */
365 if(file_scanner_p->num_share_mode_entries == 0)
367 DEBUG(2,("del_share_modes num entries = 0, deleting share_mode dev=%d ino=%d\n",
369 if(file_prev_p == file_scanner_p)
370 mode_array[hash_entry] = file_scanner_p->next_offset;
372 file_prev_p->next_offset = file_scanner_p->next_offset;
373 shmops->shm_free(shmops->addr2offset(file_scanner_p));
378 DEBUG(0,("ERROR: del_share_modes No share mode dev=%d ino=%d\n",
383 /*******************************************************************
384 set the share mode of a file. Return False on fail, True on success.
385 ********************************************************************/
386 static BOOL shm_set_share_mode(int token, int fnum, uint16 port, uint16 op_type)
388 files_struct *fs_p = &Files[fnum];
391 unsigned int hash_entry;
392 share_mode_record *file_scanner_p;
393 share_mode_record *file_prev_p;
394 shm_share_mode_entry *new_entry_p;
395 int new_entry_offset;
398 dev = fs_p->fd_ptr->dev;
399 inode = fs_p->fd_ptr->inode;
401 hash_entry = HASH_ENTRY(dev, inode);
403 mode_array = (int *)shmops->offset2addr(shmops->get_userdef_off());
405 file_scanner_p = (share_mode_record *)shmops->offset2addr(mode_array[hash_entry]);
406 file_prev_p = file_scanner_p;
408 while(file_scanner_p)
410 if( (file_scanner_p->st_dev == dev) && (file_scanner_p->st_ino == inode) )
417 file_prev_p = file_scanner_p ;
418 file_scanner_p = (share_mode_record *)
419 shmops->offset2addr(file_scanner_p->next_offset);
425 /* We must create a share_mode_record */
426 share_mode_record *new_mode_p = NULL;
427 int new_offset = shmops->shm_alloc(sizeof(share_mode_record) +
428 strlen(fs_p->name) + 1);
429 if(new_offset == 0) {
430 DEBUG(0,("ERROR:set_share_mode shmops->shm_alloc fail!\n"));
433 new_mode_p = shmops->offset2addr(new_offset);
434 new_mode_p->locking_version = LOCKING_VERSION;
435 new_mode_p->st_dev = dev;
436 new_mode_p->st_ino = inode;
437 new_mode_p->num_share_mode_entries = 0;
438 new_mode_p->share_mode_entries = 0;
439 strcpy(new_mode_p->file_name, fs_p->name);
441 /* Chain onto the start of the hash chain (in the hope we will be used first). */
442 new_mode_p->next_offset = mode_array[hash_entry];
443 mode_array[hash_entry] = new_offset;
445 file_scanner_p = new_mode_p;
447 DEBUG(3,("set_share_mode: Created share record for %s (dev %d inode %d)\n",
448 fs_p->name, dev, inode));
451 /* Now create the share mode entry */
452 new_entry_offset = shmops->shm_alloc(sizeof(shm_share_mode_entry));
453 if(new_entry_offset == 0) {
454 int delete_offset = mode_array[hash_entry];
455 DEBUG(0,("ERROR:set_share_mode: shmops->shm_alloc fail 1!\n"));
456 /* Unlink the damaged record */
457 mode_array[hash_entry] = file_scanner_p->next_offset;
459 shmops->shm_free( delete_offset );
463 new_entry_p = shmops->offset2addr(new_entry_offset);
465 new_entry_p->e.pid = getpid();
466 new_entry_p->e.share_mode = fs_p->share_mode;
467 new_entry_p->e.op_port = port;
468 new_entry_p->e.op_type = op_type;
469 memcpy( (char *)&new_entry_p->e.time, (char *)&fs_p->open_time, sizeof(struct timeval));
471 /* Chain onto the share_mode_record */
472 new_entry_p->next_share_mode_entry = file_scanner_p->share_mode_entries;
473 file_scanner_p->share_mode_entries = new_entry_offset;
476 if(file_scanner_p->num_share_mode_entries < 0)
478 DEBUG(0,("PANIC ERROR:set_share_mode num_share_mode_entries=%d\n",
479 file_scanner_p->num_share_mode_entries));
483 /* Increment the share_mode_entries counter */
484 file_scanner_p->num_share_mode_entries += 1;
486 DEBUG(3,("set_share_mode: Created share entry for %s with mode 0x%X pid=%d\n",
487 fs_p->name, fs_p->share_mode, new_entry_p->e.pid));
492 /*******************************************************************
493 Remove an oplock port and mode entry from a share mode.
494 ********************************************************************/
495 static BOOL shm_remove_share_oplock(int fnum, int token)
499 unsigned int hash_entry;
500 share_mode_record *file_scanner_p;
501 share_mode_record *file_prev_p;
502 shm_share_mode_entry *entry_scanner_p;
503 shm_share_mode_entry *entry_prev_p;
507 dev = Files[fnum].fd_ptr->dev;
508 inode = Files[fnum].fd_ptr->inode;
510 hash_entry = HASH_ENTRY(dev, inode);
512 mode_array = (int *)shmops->offset2addr(shmops->get_userdef_off());
514 if(mode_array[hash_entry] == 0)
516 DEBUG(0,("PANIC ERROR:remove_share_oplock: hash bucket %d empty\n",
521 file_scanner_p = (share_mode_record *)shmops->offset2addr(mode_array[hash_entry]);
522 file_prev_p = file_scanner_p;
524 while(file_scanner_p)
526 if( (file_scanner_p->st_dev == dev) && (file_scanner_p->st_ino == inode) )
533 file_prev_p = file_scanner_p ;
534 file_scanner_p = (share_mode_record *)
535 shmops->offset2addr(file_scanner_p->next_offset);
541 DEBUG(0,("ERROR:remove_share_oplock: no entry found for dev=%d ino=%d\n",
546 if(file_scanner_p->locking_version != LOCKING_VERSION)
548 DEBUG(0,("ERROR: remove_share_oplock: Deleting old share mode v1=%d dev=%d ino=%d\n",
549 file_scanner_p->locking_version, dev, inode));
550 if(file_prev_p == file_scanner_p)
551 mode_array[hash_entry] = file_scanner_p->next_offset;
553 file_prev_p->next_offset = file_scanner_p->next_offset;
554 shmops->shm_free(shmops->addr2offset(file_scanner_p));
559 entry_scanner_p = (shm_share_mode_entry*)shmops->offset2addr(
560 file_scanner_p->share_mode_entries);
561 entry_prev_p = entry_scanner_p;
562 while(entry_scanner_p)
564 if( (pid == entry_scanner_p->e.pid) &&
565 (entry_scanner_p->e.share_mode == Files[fnum].share_mode) &&
566 (memcmp(&entry_scanner_p->e.time,
567 &Files[fnum].open_time,sizeof(struct timeval)) == 0) )
569 /* Delete the oplock info. */
570 entry_scanner_p->e.op_port = 0;
571 entry_scanner_p->e.op_type = 0;
577 entry_prev_p = entry_scanner_p;
578 entry_scanner_p = (shm_share_mode_entry *)
579 shmops->offset2addr(entry_scanner_p->next_share_mode_entry);
585 DEBUG(0,("ERROR: remove_share_oplock: No oplock granted. dev=%d ino=%d\n",
594 /*******************************************************************
595 call the specified function on each entry under management by the
597 ********************************************************************/
598 static int shm_share_forall(void (*fn)(share_mode_entry *, char *))
602 share_mode_record *file_scanner_p;
604 mode_array = (int *)shmops->offset2addr(shmops->get_userdef_off());
606 for( i = 0; i < shmops->hash_size(); i++) {
607 shmops->lock_hash_entry(i);
608 if(mode_array[i] == 0) {
609 shmops->unlock_hash_entry(i);
613 file_scanner_p = (share_mode_record *)shmops->offset2addr(mode_array[i]);
614 while((file_scanner_p != 0) &&
615 (file_scanner_p->num_share_mode_entries != 0)) {
616 shm_share_mode_entry *entry_scanner_p =
617 (shm_share_mode_entry *)
618 shmops->offset2addr(file_scanner_p->share_mode_entries);
620 while(entry_scanner_p != 0) {
622 if (process_exists(entry_scanner_p->e.pid)) {
623 fn(&entry_scanner_p->e,
624 file_scanner_p->file_name);
629 (shm_share_mode_entry *)
631 entry_scanner_p->next_share_mode_entry);
632 } /* end while entry_scanner_p */
633 file_scanner_p = (share_mode_record *)
634 shmops->offset2addr(file_scanner_p->next_offset);
635 } /* end while file_scanner_p */
636 shmops->unlock_hash_entry(i);
643 /*******************************************************************
644 dump the state of the system
645 ********************************************************************/
646 static void shm_share_status(FILE *f)
648 int bytes_free, bytes_used, bytes_overhead, bytes_total;
650 shmops->get_usage(&bytes_free, &bytes_used, &bytes_overhead);
651 bytes_total = bytes_free + bytes_used + bytes_overhead;
653 fprintf(f, "Share mode memory usage (bytes):\n");
654 fprintf(f, " %d(%d%%) free + %d(%d%%) used + %d(%d%%) overhead = %d(100%%) total\n",
655 bytes_free, (bytes_free * 100)/bytes_total,
656 bytes_used, (bytes_used * 100)/bytes_total,
657 bytes_overhead, (bytes_overhead * 100)/bytes_total,
662 static struct share_ops share_ops = {
663 shm_stop_share_mode_mgmt,
664 shm_lock_share_entry,
665 shm_unlock_share_entry,
669 shm_remove_share_oplock,
674 /*******************************************************************
675 initialize the shared memory for share_mode management
676 ******************************************************************/
677 struct share_ops *locking_shm_init(int ronly)
682 shmops = sysv_shm_open(read_only);
683 if (shmops) return &share_ops;
686 shmops = smb_shm_open(read_only);
687 if (shmops) return &share_ops;
693 int locking_shm_dummy_procedure(void)