2 Unix SMB/CIFS implementation.
4 Copyright (C) Jeremy Allison 1992-2000
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 2 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, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
28 #define DBGC_CLASS DBGC_LOCKING
31 * The POSIX locking database handle.
34 static TDB_CONTEXT
*posix_lock_tdb
;
37 * The pending close database handle.
40 static TDB_CONTEXT
*posix_pending_close_tdb
;
43 * The data in POSIX lock records is an unsorted linear array of these
44 * records. It is unnecessary to store the count as tdb provides the
56 * The data in POSIX pending close records is an unsorted linear array of int
57 * records. It is unnecessary to store the count as tdb provides the
61 /* The key used in both the POSIX databases. */
63 struct posix_lock_key
{
68 /*******************************************************************
69 Form a static locking key for a dev/inode pair.
70 ******************************************************************/
72 static TDB_DATA
locking_key(SMB_DEV_T dev
, SMB_INO_T inode
)
74 static struct posix_lock_key key
;
77 memset(&key
, '\0', sizeof(key
));
80 kbuf
.dptr
= (char *)&key
;
81 kbuf
.dsize
= sizeof(key
);
85 /*******************************************************************
86 Convenience function to get a key from an fsp.
87 ******************************************************************/
89 static TDB_DATA
locking_key_fsp(files_struct
*fsp
)
91 return locking_key(fsp
->dev
, fsp
->inode
);
94 /****************************************************************************
95 Add an fd to the pending close tdb.
96 ****************************************************************************/
98 static BOOL
add_fd_to_close_entry(files_struct
*fsp
)
100 TDB_DATA kbuf
= locking_key_fsp(fsp
);
106 dbuf
= tdb_fetch(posix_pending_close_tdb
, kbuf
);
108 dbuf
.dptr
= SMB_REALLOC(dbuf
.dptr
, dbuf
.dsize
+ sizeof(int));
110 DEBUG(0,("add_fd_to_close_entry: Realloc fail !\n"));
114 memcpy(dbuf
.dptr
+ dbuf
.dsize
, &fsp
->fh
->fd
, sizeof(int));
115 dbuf
.dsize
+= sizeof(int);
117 if (tdb_store(posix_pending_close_tdb
, kbuf
, dbuf
, TDB_REPLACE
) == -1) {
118 DEBUG(0,("add_fd_to_close_entry: tdb_store fail !\n"));
121 SAFE_FREE(dbuf
.dptr
);
125 /****************************************************************************
126 Remove all fd entries for a specific dev/inode pair from the tdb.
127 ****************************************************************************/
129 static void delete_close_entries(files_struct
*fsp
)
131 TDB_DATA kbuf
= locking_key_fsp(fsp
);
133 if (tdb_delete(posix_pending_close_tdb
, kbuf
) == -1)
134 DEBUG(0,("delete_close_entries: tdb_delete fail !\n"));
137 /****************************************************************************
138 Get the array of POSIX pending close records for an open fsp. Caller must
139 free. Returns number of entries.
140 ****************************************************************************/
142 static size_t get_posix_pending_close_entries(files_struct
*fsp
, int **entries
)
144 TDB_DATA kbuf
= locking_key_fsp(fsp
);
151 dbuf
= tdb_fetch(posix_pending_close_tdb
, kbuf
);
157 *entries
= (int *)dbuf
.dptr
;
158 count
= (size_t)(dbuf
.dsize
/ sizeof(int));
163 /****************************************************************************
164 Get the array of POSIX locks for an fsp. Caller must free. Returns
166 ****************************************************************************/
168 static size_t get_posix_lock_entries(files_struct
*fsp
, struct posix_lock
**entries
)
170 TDB_DATA kbuf
= locking_key_fsp(fsp
);
178 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
184 *entries
= (struct posix_lock
*)dbuf
.dptr
;
185 count
= (size_t)(dbuf
.dsize
/ sizeof(struct posix_lock
));
190 /****************************************************************************
191 Deal with pending closes needed by POSIX locking support.
192 Note that posix_locking_close_file() is expected to have been called
193 to delete all locks on this fsp before this function is called.
194 ****************************************************************************/
196 int fd_close_posix(struct connection_struct
*conn
, files_struct
*fsp
)
201 struct posix_lock
*entries
= NULL
;
202 int *fd_array
= NULL
;
203 BOOL locks_on_other_fds
= False
;
205 if (!lp_posix_locking(SNUM(conn
))) {
207 * No POSIX to worry about, just close.
209 ret
= SMB_VFS_CLOSE(fsp
,fsp
->fh
->fd
);
215 * Get the number of outstanding POSIX locks on this dev/inode pair.
218 count
= get_posix_lock_entries(fsp
, &entries
);
221 * Check if there are any outstanding locks belonging to
222 * other fd's. This should never be the case if posix_locking_close_file()
223 * has been called first, but it never hurts to be *sure*.
226 for (i
= 0; i
< count
; i
++) {
227 if (entries
[i
].fd
!= fsp
->fh
->fd
) {
228 locks_on_other_fds
= True
;
233 if (locks_on_other_fds
) {
236 * There are outstanding locks on this dev/inode pair on other fds.
237 * Add our fd to the pending close tdb and set fsp->fh->fd to -1.
240 if (!add_fd_to_close_entry(fsp
)) {
253 * No outstanding POSIX locks. Get the pending close fd's
254 * from the tdb and close them all.
257 count
= get_posix_pending_close_entries(fsp
, &fd_array
);
260 DEBUG(10,("fd_close_posix: doing close on %u fd's.\n", (unsigned int)count
));
262 for(i
= 0; i
< count
; i
++) {
263 if (SMB_VFS_CLOSE(fsp
,fd_array
[i
]) == -1) {
269 * Delete all fd's stored in the tdb
270 * for this dev/inode pair.
273 delete_close_entries(fsp
);
279 * Finally close the fd associated with this fsp.
282 ret
= SMB_VFS_CLOSE(fsp
,fsp
->fh
->fd
);
284 if (saved_errno
!= 0) {
294 /****************************************************************************
296 ****************************************************************************/
298 static const char *posix_lock_type_name(int lock_type
)
300 return (lock_type
== F_RDLCK
) ? "READ" : "WRITE";
303 /****************************************************************************
304 Delete a POSIX lock entry by index number. Used if the tdb add succeeds, but
305 then the POSIX fcntl lock fails.
306 ****************************************************************************/
308 static BOOL
delete_posix_lock_entry_by_index(files_struct
*fsp
, size_t entry
)
310 TDB_DATA kbuf
= locking_key_fsp(fsp
);
312 struct posix_lock
*locks
;
317 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
320 DEBUG(10,("delete_posix_lock_entry_by_index: tdb_fetch failed !\n"));
324 count
= (size_t)(dbuf
.dsize
/ sizeof(struct posix_lock
));
325 locks
= (struct posix_lock
*)dbuf
.dptr
;
328 tdb_delete(posix_lock_tdb
, kbuf
);
330 if (entry
< count
-1) {
331 memmove(&locks
[entry
], &locks
[entry
+1], sizeof(struct posix_lock
)*((count
-1) - entry
));
333 dbuf
.dsize
-= sizeof(struct posix_lock
);
334 tdb_store(posix_lock_tdb
, kbuf
, dbuf
, TDB_REPLACE
);
337 SAFE_FREE(dbuf
.dptr
);
343 SAFE_FREE(dbuf
.dptr
);
347 /****************************************************************************
348 Add an entry into the POSIX locking tdb. We return the index number of the
349 added lock (used in case we need to delete *exactly* this entry). Returns
350 False on fail, True on success.
351 ****************************************************************************/
353 static BOOL
add_posix_lock_entry(files_struct
*fsp
, SMB_OFF_T start
, SMB_OFF_T size
, int lock_type
, size_t *pentry_num
)
355 TDB_DATA kbuf
= locking_key_fsp(fsp
);
357 struct posix_lock pl
;
362 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
364 *pentry_num
= (size_t)(dbuf
.dsize
/ sizeof(struct posix_lock
));
373 pl
.lock_type
= lock_type
;
375 dbuf
.dptr
= SMB_REALLOC(dbuf
.dptr
, dbuf
.dsize
+ sizeof(struct posix_lock
));
377 DEBUG(0,("add_posix_lock_entry: Realloc fail !\n"));
381 memcpy(dbuf
.dptr
+ dbuf
.dsize
, &pl
, sizeof(struct posix_lock
));
382 dbuf
.dsize
+= sizeof(struct posix_lock
);
384 if (tdb_store(posix_lock_tdb
, kbuf
, dbuf
, TDB_REPLACE
) == -1) {
385 DEBUG(0,("add_posix_lock: Failed to add lock entry on file %s\n", fsp
->fsp_name
));
389 SAFE_FREE(dbuf
.dptr
);
391 DEBUG(10,("add_posix_lock: File %s: type = %s: start=%.0f size=%.0f: dev=%.0f inode=%.0f\n",
392 fsp
->fsp_name
, posix_lock_type_name(lock_type
), (double)start
, (double)size
,
393 (double)fsp
->dev
, (double)fsp
->inode
));
399 SAFE_FREE(dbuf
.dptr
);
403 /****************************************************************************
404 Calculate if locks have any overlap at all.
405 ****************************************************************************/
407 static BOOL
does_lock_overlap(SMB_OFF_T start1
, SMB_OFF_T size1
, SMB_OFF_T start2
, SMB_OFF_T size2
)
409 if (start1
>= start2
&& start1
<= start2
+ size2
)
412 if (start1
< start2
&& start1
+ size1
> start2
)
418 /****************************************************************************
419 Delete an entry from the POSIX locking tdb. Returns a copy of the entry being
420 deleted and the number of records that are overlapped by this one, or -1 on error.
421 ****************************************************************************/
423 static int delete_posix_lock_entry(files_struct
*fsp
, SMB_OFF_T start
, SMB_OFF_T size
, struct posix_lock
*pl
)
425 TDB_DATA kbuf
= locking_key_fsp(fsp
);
427 struct posix_lock
*locks
;
430 int num_overlapping_records
= 0;
434 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
437 DEBUG(10,("delete_posix_lock_entry: tdb_fetch failed !\n"));
441 /* There are existing locks - find a match. */
442 locks
= (struct posix_lock
*)dbuf
.dptr
;
443 count
= (size_t)(dbuf
.dsize
/ sizeof(struct posix_lock
));
446 * Search for and delete the first record that matches the
450 for (i
=0; i
<count
; i
++) {
451 struct posix_lock
*entry
= &locks
[i
];
453 if (entry
->fd
== fsp
->fh
->fd
&&
454 entry
->start
== start
&&
455 entry
->size
== size
) {
460 /* Found it - delete it. */
462 tdb_delete(posix_lock_tdb
, kbuf
);
465 memmove(&locks
[i
], &locks
[i
+1], sizeof(struct posix_lock
)*((count
-1) - i
));
467 dbuf
.dsize
-= sizeof(struct posix_lock
);
468 tdb_store(posix_lock_tdb
, kbuf
, dbuf
, TDB_REPLACE
);
480 * Count the number of entries that are
481 * overlapped by this unlock request.
484 for (i
= 0; i
< count
; i
++) {
485 struct posix_lock
*entry
= &locks
[i
];
487 if (fsp
->fh
->fd
== entry
->fd
&&
488 does_lock_overlap( start
, size
, entry
->start
, entry
->size
))
489 num_overlapping_records
++;
492 DEBUG(10,("delete_posix_lock_entry: type = %s: start=%.0f size=%.0f, num_records = %d\n",
493 posix_lock_type_name(pl
->lock_type
), (double)pl
->start
, (double)pl
->size
,
494 (unsigned int)num_overlapping_records
));
496 SAFE_FREE(dbuf
.dptr
);
498 return num_overlapping_records
;
502 SAFE_FREE(dbuf
.dptr
);
506 /****************************************************************************
507 Utility function to map a lock type correctly depending on the open
509 ****************************************************************************/
511 static int map_posix_lock_type( files_struct
*fsp
, enum brl_type lock_type
)
513 if((lock_type
== WRITE_LOCK
) && !fsp
->can_write
) {
515 * Many UNIX's cannot get a write lock on a file opened read-only.
516 * Win32 locking semantics allow this.
517 * Do the best we can and attempt a read-only lock.
519 DEBUG(10,("map_posix_lock_type: Downgrading write lock to read due to read-only file.\n"));
523 /* We no longer open files write-only. */
524 else if((lock_type
== READ_LOCK
) && !fsp
->can_read
) {
526 * Ditto for read locks on write only files.
528 DEBUG(10,("map_posix_lock_type: Changing read lock to write due to write-only file.\n"));
534 * This return should be the most normal, as we attempt
535 * to always open files read/write.
538 return (lock_type
== READ_LOCK
) ? F_RDLCK
: F_WRLCK
;
541 /****************************************************************************
542 Check to see if the given unsigned lock range is within the possible POSIX
543 range. Modifies the given args to be in range if possible, just returns
545 ****************************************************************************/
547 static BOOL
posix_lock_in_range(SMB_OFF_T
*offset_out
, SMB_OFF_T
*count_out
,
548 SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
)
550 SMB_OFF_T offset
= (SMB_OFF_T
)u_offset
;
551 SMB_OFF_T count
= (SMB_OFF_T
)u_count
;
554 * For the type of system we are, attempt to
555 * find the maximum positive lock offset as an SMB_OFF_T.
558 #if defined(MAX_POSITIVE_LOCK_OFFSET) /* Some systems have arbitrary limits. */
560 SMB_OFF_T max_positive_lock_offset
= (MAX_POSITIVE_LOCK_OFFSET
);
562 #elif defined(LARGE_SMB_OFF_T) && !defined(HAVE_BROKEN_FCNTL64_LOCKS)
565 * In this case SMB_OFF_T is 64 bits,
566 * and the underlying system can handle 64 bit signed locks.
569 SMB_OFF_T mask2
= ((SMB_OFF_T
)0x4) << (SMB_OFF_T_BITS
-4);
570 SMB_OFF_T mask
= (mask2
<<1);
571 SMB_OFF_T max_positive_lock_offset
= ~mask
;
573 #else /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
576 * In this case either SMB_OFF_T is 32 bits,
577 * or the underlying system cannot handle 64 bit signed locks.
578 * All offsets & counts must be 2^31 or less.
581 SMB_OFF_T max_positive_lock_offset
= 0x7FFFFFFF;
583 #endif /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
586 * POSIX locks of length zero mean lock to end-of-file.
587 * Win32 locks of length zero are point probes. Ignore
588 * any Win32 locks of length zero. JRA.
591 if (count
== (SMB_OFF_T
)0) {
592 DEBUG(10,("posix_lock_in_range: count = 0, ignoring.\n"));
597 * If the given offset was > max_positive_lock_offset then we cannot map this at all
601 if (u_offset
& ~((SMB_BIG_UINT
)max_positive_lock_offset
)) {
602 DEBUG(10,("posix_lock_in_range: (offset = %.0f) offset > %.0f and we cannot handle this. Ignoring lock.\n",
603 (double)u_offset
, (double)((SMB_BIG_UINT
)max_positive_lock_offset
) ));
608 * We must truncate the count to less than max_positive_lock_offset.
611 if (u_count
& ~((SMB_BIG_UINT
)max_positive_lock_offset
))
612 count
= max_positive_lock_offset
;
615 * Truncate count to end at max lock offset.
618 if (offset
+ count
< 0 || offset
+ count
> max_positive_lock_offset
)
619 count
= max_positive_lock_offset
- offset
;
622 * If we ate all the count, ignore this lock.
626 DEBUG(10,("posix_lock_in_range: Count = 0. Ignoring lock u_offset = %.0f, u_count = %.0f\n",
627 (double)u_offset
, (double)u_count
));
632 * The mapping was successful.
635 DEBUG(10,("posix_lock_in_range: offset_out = %.0f, count_out = %.0f\n",
636 (double)offset
, (double)count
));
638 *offset_out
= offset
;
644 /****************************************************************************
645 Actual function that does POSIX locks. Copes with 64 -> 32 bit cruft and
646 broken NFS implementations.
647 ****************************************************************************/
649 static BOOL
posix_fcntl_lock(files_struct
*fsp
, int op
, SMB_OFF_T offset
, SMB_OFF_T count
, int type
)
653 DEBUG(8,("posix_fcntl_lock %d %d %.0f %.0f %d\n",fsp
->fh
->fd
,op
,(double)offset
,(double)count
,type
));
655 ret
= SMB_VFS_LOCK(fsp
,fsp
->fh
->fd
,op
,offset
,count
,type
);
657 if (!ret
&& ((errno
== EFBIG
) || (errno
== ENOLCK
) || (errno
== EINVAL
))) {
659 DEBUG(0,("posix_fcntl_lock: WARNING: lock request at offset %.0f, length %.0f returned\n",
660 (double)offset
,(double)count
));
661 DEBUG(0,("an %s error. This can happen when using 64 bit lock offsets\n", strerror(errno
)));
662 DEBUG(0,("on 32 bit NFS mounted file systems.\n"));
665 * If the offset is > 0x7FFFFFFF then this will cause problems on
666 * 32 bit NFS mounted filesystems. Just ignore it.
669 if (offset
& ~((SMB_OFF_T
)0x7fffffff)) {
670 DEBUG(0,("Offset greater than 31 bits. Returning success.\n"));
674 if (count
& ~((SMB_OFF_T
)0x7fffffff)) {
675 /* 32 bit NFS file system, retry with smaller offset */
676 DEBUG(0,("Count greater than 31 bits - retrying with 31 bit truncated length.\n"));
679 ret
= SMB_VFS_LOCK(fsp
,fsp
->fh
->fd
,op
,offset
,count
,type
);
683 DEBUG(8,("posix_fcntl_lock: Lock call %s\n", ret
? "successful" : "failed"));
687 /****************************************************************************
688 Actual function that gets POSIX locks. Copes with 64 -> 32 bit cruft and
689 broken NFS implementations.
690 ****************************************************************************/
692 static BOOL
posix_fcntl_getlock(files_struct
*fsp
, SMB_OFF_T
*poffset
, SMB_OFF_T
*pcount
, int *ptype
)
697 DEBUG(8,("posix_fcntl_getlock %d %.0f %.0f %d\n",
698 fsp
->fh
->fd
,(double)*poffset
,(double)*pcount
,*ptype
));
700 ret
= SMB_VFS_GETLOCK(fsp
,fsp
->fh
->fd
,poffset
,pcount
,ptype
,&pid
);
702 if (!ret
&& ((errno
== EFBIG
) || (errno
== ENOLCK
) || (errno
== EINVAL
))) {
704 DEBUG(0,("posix_fcntl_getlock: WARNING: lock request at offset %.0f, length %.0f returned\n",
705 (double)*poffset
,(double)*pcount
));
706 DEBUG(0,("an %s error. This can happen when using 64 bit lock offsets\n", strerror(errno
)));
707 DEBUG(0,("on 32 bit NFS mounted file systems.\n"));
710 * If the offset is > 0x7FFFFFFF then this will cause problems on
711 * 32 bit NFS mounted filesystems. Just ignore it.
714 if (*poffset
& ~((SMB_OFF_T
)0x7fffffff)) {
715 DEBUG(0,("Offset greater than 31 bits. Returning success.\n"));
719 if (*pcount
& ~((SMB_OFF_T
)0x7fffffff)) {
720 /* 32 bit NFS file system, retry with smaller offset */
721 DEBUG(0,("Count greater than 31 bits - retrying with 31 bit truncated length.\n"));
723 *pcount
&= 0x7fffffff;
724 ret
= SMB_VFS_GETLOCK(fsp
,fsp
->fh
->fd
,poffset
,pcount
,ptype
,&pid
);
728 DEBUG(8,("posix_fcntl_getlock: Lock query call %s\n", ret
? "successful" : "failed"));
733 /****************************************************************************
734 POSIX function to see if a file region is locked. Returns True if the
735 region is locked, False otherwise.
736 ****************************************************************************/
738 BOOL
is_posix_locked(files_struct
*fsp
,
739 SMB_BIG_UINT
*pu_offset
,
740 SMB_BIG_UINT
*pu_count
,
741 enum brl_type
*plock_type
,
742 enum brl_flavour lock_flav
)
746 int posix_lock_type
= map_posix_lock_type(fsp
,*plock_type
);
748 DEBUG(10,("is_posix_locked: File %s, offset = %.0f, count = %.0f, type = %s\n",
749 fsp
->fsp_name
, (double)*pu_offset
, (double)*pu_count
, posix_lock_type_name(*plock_type
) ));
752 * If the requested lock won't fit in the POSIX range, we will
753 * never set it, so presume it is not locked.
756 if(!posix_lock_in_range(&offset
, &count
, *pu_offset
, *pu_count
)) {
760 if (!posix_fcntl_getlock(fsp
,&offset
,&count
,&posix_lock_type
)) {
764 if (posix_lock_type
== F_UNLCK
) {
768 if (lock_flav
== POSIX_LOCK
) {
769 /* Only POSIX lock queries need to know the details. */
770 *pu_offset
= (SMB_BIG_UINT
)offset
;
771 *pu_count
= (SMB_BIG_UINT
)count
;
772 *plock_type
= (posix_lock_type
== F_RDLCK
) ? READ_LOCK
: WRITE_LOCK
;
778 * Structure used when splitting a lock range
779 * into a POSIX lock range. Doubly linked list.
783 struct lock_list
*next
;
784 struct lock_list
*prev
;
789 /****************************************************************************
790 Create a list of lock ranges that don't overlap a given range. Used in calculating
791 POSIX locks and unlocks. This is a difficult function that requires ASCII art to
793 ****************************************************************************/
795 static struct lock_list
*posix_lock_list(TALLOC_CTX
*ctx
, struct lock_list
*lhead
, files_struct
*fsp
)
797 TDB_DATA kbuf
= locking_key_fsp(fsp
);
799 struct posix_lock
*locks
;
804 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
809 locks
= (struct posix_lock
*)dbuf
.dptr
;
810 num_locks
= (size_t)(dbuf
.dsize
/ sizeof(struct posix_lock
));
813 * Check the current lock list on this dev/inode pair.
814 * Quit if the list is deleted.
817 DEBUG(10,("posix_lock_list: curr: start=%.0f,size=%.0f\n",
818 (double)lhead
->start
, (double)lhead
->size
));
820 for (i
=0; i
<num_locks
&& lhead
; i
++) {
822 struct posix_lock
*lock
= &locks
[i
];
823 struct lock_list
*l_curr
;
826 * Walk the lock list, checking for overlaps. Note that
827 * the lock list can expand within this loop if the current
828 * range being examined needs to be split.
831 for (l_curr
= lhead
; l_curr
;) {
833 DEBUG(10,("posix_lock_list: lock: fd=%d: start=%.0f,size=%.0f:type=%s", lock
->fd
,
834 (double)lock
->start
, (double)lock
->size
, posix_lock_type_name(lock
->lock_type
) ));
836 if ( (l_curr
->start
>= (lock
->start
+ lock
->size
)) ||
837 (lock
->start
>= (l_curr
->start
+ l_curr
->size
))) {
839 /* No overlap with this lock - leave this range alone. */
840 /*********************************************
851 **********************************************/
853 DEBUG(10,("no overlap case.\n" ));
855 l_curr
= l_curr
->next
;
857 } else if ( (l_curr
->start
>= lock
->start
) &&
858 (l_curr
->start
+ l_curr
->size
<= lock
->start
+ lock
->size
) ) {
861 * This unlock is completely overlapped by this existing lock range
862 * and thus should have no effect (not be unlocked). Delete it from the list.
864 /*********************************************
868 +---------------------------+
870 +---------------------------+
871 **********************************************/
872 /* Save the next pointer */
873 struct lock_list
*ul_next
= l_curr
->next
;
875 DEBUG(10,("delete case.\n" ));
877 DLIST_REMOVE(lhead
, l_curr
);
879 break; /* No more list... */
883 } else if ( (l_curr
->start
>= lock
->start
) &&
884 (l_curr
->start
< lock
->start
+ lock
->size
) &&
885 (l_curr
->start
+ l_curr
->size
> lock
->start
+ lock
->size
) ) {
888 * This unlock overlaps the existing lock range at the high end.
889 * Truncate by moving start to existing range end and reducing size.
891 /*********************************************
902 **********************************************/
904 l_curr
->size
= (l_curr
->start
+ l_curr
->size
) - (lock
->start
+ lock
->size
);
905 l_curr
->start
= lock
->start
+ lock
->size
;
907 DEBUG(10,("truncate high case: start=%.0f,size=%.0f\n",
908 (double)l_curr
->start
, (double)l_curr
->size
));
910 l_curr
= l_curr
->next
;
912 } else if ( (l_curr
->start
< lock
->start
) &&
913 (l_curr
->start
+ l_curr
->size
> lock
->start
) &&
914 (l_curr
->start
+ l_curr
->size
<= lock
->start
+ lock
->size
) ) {
917 * This unlock overlaps the existing lock range at the low end.
918 * Truncate by reducing size.
920 /*********************************************
931 **********************************************/
933 l_curr
->size
= lock
->start
- l_curr
->start
;
935 DEBUG(10,("truncate low case: start=%.0f,size=%.0f\n",
936 (double)l_curr
->start
, (double)l_curr
->size
));
938 l_curr
= l_curr
->next
;
940 } else if ( (l_curr
->start
< lock
->start
) &&
941 (l_curr
->start
+ l_curr
->size
> lock
->start
+ lock
->size
) ) {
943 * Worst case scenario. Unlock request completely overlaps an existing
944 * lock range. Split the request into two, push the new (upper) request
945 * into the dlink list, and continue with the entry after ul_new (as we
946 * know that ul_new will not overlap with this lock).
948 /*********************************************
949 +---------------------------+
951 +---------------------------+
956 +-------+ +---------+
958 +-------+ +---------+
959 **********************************************/
960 struct lock_list
*l_new
= TALLOC_P(ctx
, struct lock_list
);
963 DEBUG(0,("posix_lock_list: talloc fail.\n"));
964 return NULL
; /* The talloc_destroy takes care of cleanup. */
968 l_new
->start
= lock
->start
+ lock
->size
;
969 l_new
->size
= l_curr
->start
+ l_curr
->size
- l_new
->start
;
971 /* Truncate the l_curr. */
972 l_curr
->size
= lock
->start
- l_curr
->start
;
974 DEBUG(10,("split case: curr: start=%.0f,size=%.0f \
975 new: start=%.0f,size=%.0f\n", (double)l_curr
->start
, (double)l_curr
->size
,
976 (double)l_new
->start
, (double)l_new
->size
));
979 * Add into the dlink list after the l_curr point - NOT at lhead.
980 * Note we can't use DLINK_ADD here as this inserts at the head of the given list.
983 l_new
->prev
= l_curr
;
984 l_new
->next
= l_curr
->next
;
985 l_curr
->next
= l_new
;
987 /* And move after the link we added. */
988 l_curr
= l_new
->next
;
993 * This logic case should never happen. Ensure this is the
994 * case by forcing an abort.... Remove in production.
998 slprintf(msg
, sizeof(msg
)-1, "logic flaw in cases: l_curr: start = %.0f, size = %.0f : \
999 lock: start = %.0f, size = %.0f\n", (double)l_curr
->start
, (double)l_curr
->size
, (double)lock
->start
, (double)lock
->size
);
1003 } /* end for ( l_curr = lhead; l_curr;) */
1004 } /* end for (i=0; i<num_locks && ul_head; i++) */
1006 SAFE_FREE(dbuf
.dptr
);
1011 /****************************************************************************
1012 POSIX function to acquire a lock. Returns True if the
1013 lock could be granted, False if not.
1014 TODO -- Fix POSIX lock flavour semantics.
1015 ****************************************************************************/
1017 BOOL
set_posix_lock(files_struct
*fsp
,
1018 SMB_BIG_UINT u_offset
,
1019 SMB_BIG_UINT u_count
,
1020 enum brl_type lock_type
,
1021 enum brl_flavour lock_flav
)
1026 size_t entry_num
= 0;
1028 TALLOC_CTX
*l_ctx
= NULL
;
1029 struct lock_list
*llist
= NULL
;
1030 struct lock_list
*ll
= NULL
;
1031 int posix_lock_type
= map_posix_lock_type(fsp
,lock_type
);
1033 DEBUG(5,("set_posix_lock: File %s, offset = %.0f, count = %.0f, type = %s\n",
1034 fsp
->fsp_name
, (double)u_offset
, (double)u_count
, posix_lock_type_name(lock_type
) ));
1037 * If the requested lock won't fit in the POSIX range, we will
1038 * pretend it was successful.
1041 if(!posix_lock_in_range(&offset
, &count
, u_offset
, u_count
))
1045 * Windows is very strange. It allows read locks to be overlayed
1046 * (even over a write lock), but leaves the write lock in force until the first
1047 * unlock. It also reference counts the locks. This means the following sequence :
1050 * ------------------------------------------------------------------------
1051 * WRITE LOCK : start = 2, len = 10
1052 * READ LOCK: start =0, len = 10 - FAIL
1053 * READ LOCK : start = 0, len = 14
1054 * READ LOCK: start =0, len = 10 - FAIL
1055 * UNLOCK : start = 2, len = 10
1056 * READ LOCK: start =0, len = 10 - OK
1058 * Under POSIX, the same sequence in steps 1 and 2 would not be reference counted, but
1059 * would leave a single read lock over the 0-14 region. In order to
1060 * re-create Windows semantics mapped to POSIX locks, we create multiple TDB
1061 * entries, one for each overlayed lock request. We are guarenteed by the brlock
1062 * semantics that if a write lock is added, then it will be first in the array.
1065 if ((l_ctx
= talloc_init("set_posix_lock")) == NULL
) {
1066 DEBUG(0,("set_posix_lock: unable to init talloc context.\n"));
1067 return True
; /* Not a fatal error. */
1070 if ((ll
= TALLOC_P(l_ctx
, struct lock_list
)) == NULL
) {
1071 DEBUG(0,("set_posix_lock: unable to talloc unlock list.\n"));
1072 talloc_destroy(l_ctx
);
1073 return True
; /* Not a fatal error. */
1077 * Create the initial list entry containing the
1078 * lock we want to add.
1085 DLIST_ADD(llist
, ll
);
1088 * The following call calculates if there are any
1089 * overlapping locks held by this process on
1090 * fd's open on the same file and splits this list
1091 * into a list of lock ranges that do not overlap with existing
1095 llist
= posix_lock_list(l_ctx
, llist
, fsp
);
1098 * Now we have the list of ranges to lock it is safe to add the
1099 * entry into the POSIX lock tdb. We take note of the entry we
1100 * added here in case we have to remove it on POSIX lock fail.
1103 if (!add_posix_lock_entry(fsp
,offset
,count
,posix_lock_type
,&entry_num
)) {
1104 DEBUG(0,("set_posix_lock: Unable to create posix lock entry !\n"));
1105 talloc_destroy(l_ctx
);
1110 * Add the POSIX locks on the list of ranges returned.
1111 * As the lock is supposed to be added atomically, we need to
1112 * back out all the locks if any one of these calls fail.
1115 for (lock_count
= 0, ll
= llist
; ll
; ll
= ll
->next
, lock_count
++) {
1119 DEBUG(5,("set_posix_lock: Real lock: Type = %s: offset = %.0f, count = %.0f\n",
1120 posix_lock_type_name(posix_lock_type
), (double)offset
, (double)count
));
1122 if (!posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,posix_lock_type
)) {
1123 DEBUG(5,("set_posix_lock: Lock fail !: Type = %s: offset = %.0f, count = %.0f. Errno = %s\n",
1124 posix_lock_type_name(posix_lock_type
), (double)offset
, (double)count
, strerror(errno
) ));
1133 * Back out all the POSIX locks we have on fail.
1136 for (ll
= llist
; lock_count
; ll
= ll
->next
, lock_count
--) {
1140 DEBUG(5,("set_posix_lock: Backing out locks: Type = %s: offset = %.0f, count = %.0f\n",
1141 posix_lock_type_name(posix_lock_type
), (double)offset
, (double)count
));
1143 posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,F_UNLCK
);
1147 * Remove the tdb entry for this lock.
1150 delete_posix_lock_entry_by_index(fsp
,entry_num
);
1153 talloc_destroy(l_ctx
);
1157 /****************************************************************************
1158 POSIX function to release a lock. Returns True if the
1159 lock could be released, False if not.
1160 ****************************************************************************/
1162 BOOL
release_posix_lock(files_struct
*fsp
, SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
)
1167 TALLOC_CTX
*ul_ctx
= NULL
;
1168 struct lock_list
*ulist
= NULL
;
1169 struct lock_list
*ul
= NULL
;
1170 struct posix_lock deleted_lock
;
1171 int num_overlapped_entries
;
1173 DEBUG(5,("release_posix_lock: File %s, offset = %.0f, count = %.0f\n",
1174 fsp
->fsp_name
, (double)u_offset
, (double)u_count
));
1177 * If the requested lock won't fit in the POSIX range, we will
1178 * pretend it was successful.
1181 if(!posix_lock_in_range(&offset
, &count
, u_offset
, u_count
))
1185 * We treat this as one unlock request for POSIX accounting purposes even
1186 * if it may later be split into multiple smaller POSIX unlock ranges.
1187 * num_overlapped_entries is the number of existing locks that have any
1188 * overlap with this unlock request.
1191 num_overlapped_entries
= delete_posix_lock_entry(fsp
, offset
, count
, &deleted_lock
);
1193 if (num_overlapped_entries
== -1) {
1194 smb_panic("release_posix_lock: unable find entry to delete !\n");
1198 * If num_overlapped_entries is > 0, and the lock_type we just deleted from the tdb was
1199 * a POSIX write lock, then before doing the unlock we need to downgrade
1200 * the POSIX lock to a read lock. This allows any overlapping read locks
1201 * to be atomically maintained.
1204 if (num_overlapped_entries
> 0 && deleted_lock
.lock_type
== F_WRLCK
) {
1205 if (!posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,F_RDLCK
)) {
1206 DEBUG(0,("release_posix_lock: downgrade of lock failed with error %s !\n", strerror(errno
) ));
1211 if ((ul_ctx
= talloc_init("release_posix_lock")) == NULL
) {
1212 DEBUG(0,("release_posix_lock: unable to init talloc context.\n"));
1213 return True
; /* Not a fatal error. */
1216 if ((ul
= TALLOC_P(ul_ctx
, struct lock_list
)) == NULL
) {
1217 DEBUG(0,("release_posix_lock: unable to talloc unlock list.\n"));
1218 talloc_destroy(ul_ctx
);
1219 return True
; /* Not a fatal error. */
1223 * Create the initial list entry containing the
1224 * lock we want to remove.
1231 DLIST_ADD(ulist
, ul
);
1234 * The following call calculates if there are any
1235 * overlapping locks held by this process on
1236 * fd's open on the same file and creates a
1237 * list of unlock ranges that will allow
1238 * POSIX lock ranges to remain on the file whilst the
1239 * unlocks are performed.
1242 ulist
= posix_lock_list(ul_ctx
, ulist
, fsp
);
1245 * Release the POSIX locks on the list of ranges returned.
1248 for(; ulist
; ulist
= ulist
->next
) {
1249 offset
= ulist
->start
;
1250 count
= ulist
->size
;
1252 DEBUG(5,("release_posix_lock: Real unlock: offset = %.0f, count = %.0f\n",
1253 (double)offset
, (double)count
));
1255 if (!posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,F_UNLCK
))
1259 talloc_destroy(ul_ctx
);
1264 /****************************************************************************
1265 Remove all lock entries for a specific dev/inode pair from the tdb.
1266 ****************************************************************************/
1268 static void delete_posix_lock_entries(files_struct
*fsp
)
1270 TDB_DATA kbuf
= locking_key_fsp(fsp
);
1272 if (tdb_delete(posix_lock_tdb
, kbuf
) == -1)
1273 DEBUG(0,("delete_close_entries: tdb_delete fail !\n"));
1276 /****************************************************************************
1278 ****************************************************************************/
1280 static void dump_entry(struct posix_lock
*pl
)
1282 DEBUG(10,("entry: start=%.0f, size=%.0f, type=%d, fd=%i\n",
1283 (double)pl
->start
, (double)pl
->size
, (int)pl
->lock_type
, pl
->fd
));
1286 /****************************************************************************
1287 Remove any locks on this fd. Called from file_close().
1288 ****************************************************************************/
1290 void posix_locking_close_file(files_struct
*fsp
)
1292 struct posix_lock
*entries
= NULL
;
1296 * Optimization for the common case where we are the only
1297 * opener of a file. If all fd entries are our own, we don't
1298 * need to explicitly release all the locks via the POSIX functions,
1299 * we can just remove all the entries in the tdb and allow the
1300 * close to remove the real locks.
1303 count
= get_posix_lock_entries(fsp
, &entries
);
1306 DEBUG(10,("posix_locking_close_file: file %s has no outstanding locks.\n", fsp
->fsp_name
));
1310 for (i
= 0; i
< count
; i
++) {
1311 if (entries
[i
].fd
!= fsp
->fh
->fd
)
1314 dump_entry(&entries
[i
]);
1318 /* All locks are ours. */
1319 DEBUG(10,("posix_locking_close_file: file %s has %u outstanding locks, but all on one fd.\n",
1320 fsp
->fsp_name
, (unsigned int)count
));
1322 delete_posix_lock_entries(fsp
);
1327 * Difficult case. We need to delete all our locks, whilst leaving
1328 * all other POSIX locks in place.
1331 for (i
= 0; i
< count
; i
++) {
1332 struct posix_lock
*pl
= &entries
[i
];
1333 if (pl
->fd
== fsp
->fh
->fd
)
1334 release_posix_lock(fsp
, (SMB_BIG_UINT
)pl
->start
, (SMB_BIG_UINT
)pl
->size
);
1339 /*******************************************************************
1340 Create the in-memory POSIX lock databases.
1341 ********************************************************************/
1343 BOOL
posix_locking_init(int read_only
)
1345 if (posix_lock_tdb
&& posix_pending_close_tdb
)
1348 if (!posix_lock_tdb
)
1349 posix_lock_tdb
= tdb_open_log(NULL
, 0, TDB_INTERNAL
,
1350 read_only
?O_RDONLY
:(O_RDWR
|O_CREAT
), 0644);
1351 if (!posix_lock_tdb
) {
1352 DEBUG(0,("Failed to open POSIX byte range locking database.\n"));
1355 if (!posix_pending_close_tdb
)
1356 posix_pending_close_tdb
= tdb_open_log(NULL
, 0, TDB_INTERNAL
,
1357 read_only
?O_RDONLY
:(O_RDWR
|O_CREAT
), 0644);
1358 if (!posix_pending_close_tdb
) {
1359 DEBUG(0,("Failed to open POSIX pending close database.\n"));
1366 /*******************************************************************
1367 Delete the in-memory POSIX lock databases.
1368 ********************************************************************/
1370 BOOL
posix_locking_end(void)
1372 if (posix_lock_tdb
&& tdb_close(posix_lock_tdb
) != 0)
1374 if (posix_pending_close_tdb
&& tdb_close(posix_pending_close_tdb
) != 0)