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
) {
457 /* Make a copy if requested. */
461 /* Found it - delete it. */
463 tdb_delete(posix_lock_tdb
, kbuf
);
466 memmove(&locks
[i
], &locks
[i
+1], sizeof(struct posix_lock
)*((count
-1) - i
));
468 dbuf
.dsize
-= sizeof(struct posix_lock
);
469 tdb_store(posix_lock_tdb
, kbuf
, dbuf
, TDB_REPLACE
);
481 * Count the number of entries that are
482 * overlapped by this unlock request.
485 for (i
= 0; i
< count
; i
++) {
486 struct posix_lock
*entry
= &locks
[i
];
488 if (fsp
->fh
->fd
== entry
->fd
&&
489 does_lock_overlap( start
, size
, entry
->start
, entry
->size
))
490 num_overlapping_records
++;
493 DEBUG(10,("delete_posix_lock_entry: type = %s: start=%.0f size=%.0f, num_records = %d\n",
494 posix_lock_type_name(pl
->lock_type
), (double)pl
->start
, (double)pl
->size
,
495 (unsigned int)num_overlapping_records
));
497 SAFE_FREE(dbuf
.dptr
);
499 return num_overlapping_records
;
503 SAFE_FREE(dbuf
.dptr
);
507 /****************************************************************************
508 Utility function to map a lock type correctly depending on the open
510 ****************************************************************************/
512 static int map_posix_lock_type( files_struct
*fsp
, enum brl_type lock_type
)
514 if((lock_type
== WRITE_LOCK
) && !fsp
->can_write
) {
516 * Many UNIX's cannot get a write lock on a file opened read-only.
517 * Win32 locking semantics allow this.
518 * Do the best we can and attempt a read-only lock.
520 DEBUG(10,("map_posix_lock_type: Downgrading write lock to read due to read-only file.\n"));
524 /* We no longer open files write-only. */
525 else if((lock_type
== READ_LOCK
) && !fsp
->can_read
) {
527 * Ditto for read locks on write only files.
529 DEBUG(10,("map_posix_lock_type: Changing read lock to write due to write-only file.\n"));
535 * This return should be the most normal, as we attempt
536 * to always open files read/write.
539 return (lock_type
== READ_LOCK
) ? F_RDLCK
: F_WRLCK
;
542 /****************************************************************************
543 Check to see if the given unsigned lock range is within the possible POSIX
544 range. Modifies the given args to be in range if possible, just returns
546 ****************************************************************************/
548 static BOOL
posix_lock_in_range(SMB_OFF_T
*offset_out
, SMB_OFF_T
*count_out
,
549 SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
)
551 SMB_OFF_T offset
= (SMB_OFF_T
)u_offset
;
552 SMB_OFF_T count
= (SMB_OFF_T
)u_count
;
555 * For the type of system we are, attempt to
556 * find the maximum positive lock offset as an SMB_OFF_T.
559 #if defined(MAX_POSITIVE_LOCK_OFFSET) /* Some systems have arbitrary limits. */
561 SMB_OFF_T max_positive_lock_offset
= (MAX_POSITIVE_LOCK_OFFSET
);
563 #elif defined(LARGE_SMB_OFF_T) && !defined(HAVE_BROKEN_FCNTL64_LOCKS)
566 * In this case SMB_OFF_T is 64 bits,
567 * and the underlying system can handle 64 bit signed locks.
570 SMB_OFF_T mask2
= ((SMB_OFF_T
)0x4) << (SMB_OFF_T_BITS
-4);
571 SMB_OFF_T mask
= (mask2
<<1);
572 SMB_OFF_T max_positive_lock_offset
= ~mask
;
574 #else /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
577 * In this case either SMB_OFF_T is 32 bits,
578 * or the underlying system cannot handle 64 bit signed locks.
579 * All offsets & counts must be 2^31 or less.
582 SMB_OFF_T max_positive_lock_offset
= 0x7FFFFFFF;
584 #endif /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
587 * POSIX locks of length zero mean lock to end-of-file.
588 * Win32 locks of length zero are point probes. Ignore
589 * any Win32 locks of length zero. JRA.
592 if (count
== (SMB_OFF_T
)0) {
593 DEBUG(10,("posix_lock_in_range: count = 0, ignoring.\n"));
598 * If the given offset was > max_positive_lock_offset then we cannot map this at all
602 if (u_offset
& ~((SMB_BIG_UINT
)max_positive_lock_offset
)) {
603 DEBUG(10,("posix_lock_in_range: (offset = %.0f) offset > %.0f and we cannot handle this. Ignoring lock.\n",
604 (double)u_offset
, (double)((SMB_BIG_UINT
)max_positive_lock_offset
) ));
609 * We must truncate the count to less than max_positive_lock_offset.
612 if (u_count
& ~((SMB_BIG_UINT
)max_positive_lock_offset
))
613 count
= max_positive_lock_offset
;
616 * Truncate count to end at max lock offset.
619 if (offset
+ count
< 0 || offset
+ count
> max_positive_lock_offset
)
620 count
= max_positive_lock_offset
- offset
;
623 * If we ate all the count, ignore this lock.
627 DEBUG(10,("posix_lock_in_range: Count = 0. Ignoring lock u_offset = %.0f, u_count = %.0f\n",
628 (double)u_offset
, (double)u_count
));
633 * The mapping was successful.
636 DEBUG(10,("posix_lock_in_range: offset_out = %.0f, count_out = %.0f\n",
637 (double)offset
, (double)count
));
639 *offset_out
= offset
;
645 /****************************************************************************
646 Actual function that does POSIX locks. Copes with 64 -> 32 bit cruft and
647 broken NFS implementations.
648 ****************************************************************************/
650 static BOOL
posix_fcntl_lock(files_struct
*fsp
, int op
, SMB_OFF_T offset
, SMB_OFF_T count
, int type
)
654 DEBUG(8,("posix_fcntl_lock %d %d %.0f %.0f %d\n",fsp
->fh
->fd
,op
,(double)offset
,(double)count
,type
));
656 ret
= SMB_VFS_LOCK(fsp
,fsp
->fh
->fd
,op
,offset
,count
,type
);
658 if (!ret
&& ((errno
== EFBIG
) || (errno
== ENOLCK
) || (errno
== EINVAL
))) {
660 DEBUG(0,("posix_fcntl_lock: WARNING: lock request at offset %.0f, length %.0f returned\n",
661 (double)offset
,(double)count
));
662 DEBUG(0,("an %s error. This can happen when using 64 bit lock offsets\n", strerror(errno
)));
663 DEBUG(0,("on 32 bit NFS mounted file systems.\n"));
666 * If the offset is > 0x7FFFFFFF then this will cause problems on
667 * 32 bit NFS mounted filesystems. Just ignore it.
670 if (offset
& ~((SMB_OFF_T
)0x7fffffff)) {
671 DEBUG(0,("Offset greater than 31 bits. Returning success.\n"));
675 if (count
& ~((SMB_OFF_T
)0x7fffffff)) {
676 /* 32 bit NFS file system, retry with smaller offset */
677 DEBUG(0,("Count greater than 31 bits - retrying with 31 bit truncated length.\n"));
680 ret
= SMB_VFS_LOCK(fsp
,fsp
->fh
->fd
,op
,offset
,count
,type
);
684 DEBUG(8,("posix_fcntl_lock: Lock call %s\n", ret
? "successful" : "failed"));
689 /****************************************************************************
690 POSIX function to see if a file region is locked. Returns True if the
691 region is locked, False otherwise.
692 ****************************************************************************/
694 BOOL
is_posix_locked(files_struct
*fsp
, SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
, enum brl_type lock_type
)
698 int posix_lock_type
= map_posix_lock_type(fsp
,lock_type
);
700 DEBUG(10,("is_posix_locked: File %s, offset = %.0f, count = %.0f, type = %s\n",
701 fsp
->fsp_name
, (double)u_offset
, (double)u_count
, posix_lock_type_name(lock_type
) ));
704 * If the requested lock won't fit in the POSIX range, we will
705 * never set it, so presume it is not locked.
708 if(!posix_lock_in_range(&offset
, &count
, u_offset
, u_count
))
712 * Note that most UNIX's can *test* for a write lock on
713 * a read-only fd, just not *set* a write lock on a read-only
714 * fd. So we don't need to use map_lock_type here.
717 return posix_fcntl_lock(fsp
,SMB_F_GETLK
,offset
,count
,posix_lock_type
);
721 * Structure used when splitting a lock range
722 * into a POSIX lock range. Doubly linked list.
726 struct lock_list
*next
;
727 struct lock_list
*prev
;
732 /****************************************************************************
733 Create a list of lock ranges that don't overlap a given range. Used in calculating
734 POSIX locks and unlocks. This is a difficult function that requires ASCII art to
736 ****************************************************************************/
738 static struct lock_list
*posix_lock_list(TALLOC_CTX
*ctx
, struct lock_list
*lhead
, files_struct
*fsp
)
740 TDB_DATA kbuf
= locking_key_fsp(fsp
);
742 struct posix_lock
*locks
;
747 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
752 locks
= (struct posix_lock
*)dbuf
.dptr
;
753 num_locks
= (size_t)(dbuf
.dsize
/ sizeof(struct posix_lock
));
756 * Check the current lock list on this dev/inode pair.
757 * Quit if the list is deleted.
760 DEBUG(10,("posix_lock_list: curr: start=%.0f,size=%.0f\n",
761 (double)lhead
->start
, (double)lhead
->size
));
763 for (i
=0; i
<num_locks
&& lhead
; i
++) {
765 struct posix_lock
*lock
= &locks
[i
];
766 struct lock_list
*l_curr
;
769 * Walk the lock list, checking for overlaps. Note that
770 * the lock list can expand within this loop if the current
771 * range being examined needs to be split.
774 for (l_curr
= lhead
; l_curr
;) {
776 DEBUG(10,("posix_lock_list: lock: fd=%d: start=%.0f,size=%.0f:type=%s", lock
->fd
,
777 (double)lock
->start
, (double)lock
->size
, posix_lock_type_name(lock
->lock_type
) ));
779 if ( (l_curr
->start
>= (lock
->start
+ lock
->size
)) ||
780 (lock
->start
>= (l_curr
->start
+ l_curr
->size
))) {
782 /* No overlap with this lock - leave this range alone. */
783 /*********************************************
794 **********************************************/
796 DEBUG(10,("no overlap case.\n" ));
798 l_curr
= l_curr
->next
;
800 } else if ( (l_curr
->start
>= lock
->start
) &&
801 (l_curr
->start
+ l_curr
->size
<= lock
->start
+ lock
->size
) ) {
804 * This unlock is completely overlapped by this existing lock range
805 * and thus should have no effect (not be unlocked). Delete it from the list.
807 /*********************************************
811 +---------------------------+
813 +---------------------------+
814 **********************************************/
815 /* Save the next pointer */
816 struct lock_list
*ul_next
= l_curr
->next
;
818 DEBUG(10,("delete case.\n" ));
820 DLIST_REMOVE(lhead
, l_curr
);
822 break; /* No more list... */
826 } else if ( (l_curr
->start
>= lock
->start
) &&
827 (l_curr
->start
< lock
->start
+ lock
->size
) &&
828 (l_curr
->start
+ l_curr
->size
> lock
->start
+ lock
->size
) ) {
831 * This unlock overlaps the existing lock range at the high end.
832 * Truncate by moving start to existing range end and reducing size.
834 /*********************************************
845 **********************************************/
847 l_curr
->size
= (l_curr
->start
+ l_curr
->size
) - (lock
->start
+ lock
->size
);
848 l_curr
->start
= lock
->start
+ lock
->size
;
850 DEBUG(10,("truncate high case: start=%.0f,size=%.0f\n",
851 (double)l_curr
->start
, (double)l_curr
->size
));
853 l_curr
= l_curr
->next
;
855 } else if ( (l_curr
->start
< lock
->start
) &&
856 (l_curr
->start
+ l_curr
->size
> lock
->start
) &&
857 (l_curr
->start
+ l_curr
->size
<= lock
->start
+ lock
->size
) ) {
860 * This unlock overlaps the existing lock range at the low end.
861 * Truncate by reducing size.
863 /*********************************************
874 **********************************************/
876 l_curr
->size
= lock
->start
- l_curr
->start
;
878 DEBUG(10,("truncate low case: start=%.0f,size=%.0f\n",
879 (double)l_curr
->start
, (double)l_curr
->size
));
881 l_curr
= l_curr
->next
;
883 } else if ( (l_curr
->start
< lock
->start
) &&
884 (l_curr
->start
+ l_curr
->size
> lock
->start
+ lock
->size
) ) {
886 * Worst case scenario. Unlock request completely overlaps an existing
887 * lock range. Split the request into two, push the new (upper) request
888 * into the dlink list, and continue with the entry after ul_new (as we
889 * know that ul_new will not overlap with this lock).
891 /*********************************************
892 +---------------------------+
894 +---------------------------+
899 +-------+ +---------+
901 +-------+ +---------+
902 **********************************************/
903 struct lock_list
*l_new
= TALLOC_P(ctx
, struct lock_list
);
906 DEBUG(0,("posix_lock_list: talloc fail.\n"));
907 return NULL
; /* The talloc_destroy takes care of cleanup. */
911 l_new
->start
= lock
->start
+ lock
->size
;
912 l_new
->size
= l_curr
->start
+ l_curr
->size
- l_new
->start
;
914 /* Truncate the l_curr. */
915 l_curr
->size
= lock
->start
- l_curr
->start
;
917 DEBUG(10,("split case: curr: start=%.0f,size=%.0f \
918 new: start=%.0f,size=%.0f\n", (double)l_curr
->start
, (double)l_curr
->size
,
919 (double)l_new
->start
, (double)l_new
->size
));
922 * Add into the dlink list after the l_curr point - NOT at lhead.
923 * Note we can't use DLINK_ADD here as this inserts at the head of the given list.
926 l_new
->prev
= l_curr
;
927 l_new
->next
= l_curr
->next
;
928 l_curr
->next
= l_new
;
930 /* And move after the link we added. */
931 l_curr
= l_new
->next
;
936 * This logic case should never happen. Ensure this is the
937 * case by forcing an abort.... Remove in production.
941 slprintf(msg
, sizeof(msg
)-1, "logic flaw in cases: l_curr: start = %.0f, size = %.0f : \
942 lock: start = %.0f, size = %.0f\n", (double)l_curr
->start
, (double)l_curr
->size
, (double)lock
->start
, (double)lock
->size
);
946 } /* end for ( l_curr = lhead; l_curr;) */
947 } /* end for (i=0; i<num_locks && ul_head; i++) */
949 SAFE_FREE(dbuf
.dptr
);
954 /****************************************************************************
955 POSIX function to acquire a lock. Returns True if the
956 lock could be granted, False if not.
957 ****************************************************************************/
959 BOOL
set_posix_lock(files_struct
*fsp
, SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
, enum brl_type lock_type
)
964 size_t entry_num
= 0;
966 TALLOC_CTX
*l_ctx
= NULL
;
967 struct lock_list
*llist
= NULL
;
968 struct lock_list
*ll
= NULL
;
969 int posix_lock_type
= map_posix_lock_type(fsp
,lock_type
);
971 DEBUG(5,("set_posix_lock: File %s, offset = %.0f, count = %.0f, type = %s\n",
972 fsp
->fsp_name
, (double)u_offset
, (double)u_count
, posix_lock_type_name(lock_type
) ));
975 * If the requested lock won't fit in the POSIX range, we will
976 * pretend it was successful.
979 if(!posix_lock_in_range(&offset
, &count
, u_offset
, u_count
))
983 * Windows is very strange. It allows read locks to be overlayed
984 * (even over a write lock), but leaves the write lock in force until the first
985 * unlock. It also reference counts the locks. This means the following sequence :
988 * ------------------------------------------------------------------------
989 * WRITE LOCK : start = 2, len = 10
990 * READ LOCK: start =0, len = 10 - FAIL
991 * READ LOCK : start = 0, len = 14
992 * READ LOCK: start =0, len = 10 - FAIL
993 * UNLOCK : start = 2, len = 10
994 * READ LOCK: start =0, len = 10 - OK
996 * Under POSIX, the same sequence in steps 1 and 2 would not be reference counted, but
997 * would leave a single read lock over the 0-14 region. In order to
998 * re-create Windows semantics mapped to POSIX locks, we create multiple TDB
999 * entries, one for each overlayed lock request. We are guarenteed by the brlock
1000 * semantics that if a write lock is added, then it will be first in the array.
1003 if ((l_ctx
= talloc_init("set_posix_lock")) == NULL
) {
1004 DEBUG(0,("set_posix_lock: unable to init talloc context.\n"));
1005 return True
; /* Not a fatal error. */
1008 if ((ll
= TALLOC_P(l_ctx
, struct lock_list
)) == NULL
) {
1009 DEBUG(0,("set_posix_lock: unable to talloc unlock list.\n"));
1010 talloc_destroy(l_ctx
);
1011 return True
; /* Not a fatal error. */
1015 * Create the initial list entry containing the
1016 * lock we want to add.
1023 DLIST_ADD(llist
, ll
);
1026 * The following call calculates if there are any
1027 * overlapping locks held by this process on
1028 * fd's open on the same file and splits this list
1029 * into a list of lock ranges that do not overlap with existing
1033 llist
= posix_lock_list(l_ctx
, llist
, fsp
);
1036 * Now we have the list of ranges to lock it is safe to add the
1037 * entry into the POSIX lock tdb. We take note of the entry we
1038 * added here in case we have to remove it on POSIX lock fail.
1041 if (!add_posix_lock_entry(fsp
,offset
,count
,posix_lock_type
,&entry_num
)) {
1042 DEBUG(0,("set_posix_lock: Unable to create posix lock entry !\n"));
1043 talloc_destroy(l_ctx
);
1048 * Add the POSIX locks on the list of ranges returned.
1049 * As the lock is supposed to be added atomically, we need to
1050 * back out all the locks if any one of these calls fail.
1053 for (lock_count
= 0, ll
= llist
; ll
; ll
= ll
->next
, lock_count
++) {
1057 DEBUG(5,("set_posix_lock: Real lock: Type = %s: offset = %.0f, count = %.0f\n",
1058 posix_lock_type_name(posix_lock_type
), (double)offset
, (double)count
));
1060 if (!posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,posix_lock_type
)) {
1061 DEBUG(5,("set_posix_lock: Lock fail !: Type = %s: offset = %.0f, count = %.0f. Errno = %s\n",
1062 posix_lock_type_name(posix_lock_type
), (double)offset
, (double)count
, strerror(errno
) ));
1071 * Back out all the POSIX locks we have on fail.
1074 for (ll
= llist
; lock_count
; ll
= ll
->next
, lock_count
--) {
1078 DEBUG(5,("set_posix_lock: Backing out locks: Type = %s: offset = %.0f, count = %.0f\n",
1079 posix_lock_type_name(posix_lock_type
), (double)offset
, (double)count
));
1081 posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,F_UNLCK
);
1085 * Remove the tdb entry for this lock.
1088 delete_posix_lock_entry_by_index(fsp
,entry_num
);
1091 talloc_destroy(l_ctx
);
1095 /****************************************************************************
1096 POSIX function to release a lock. Returns True if the
1097 lock could be released, False if not.
1098 ****************************************************************************/
1100 BOOL
release_posix_lock(files_struct
*fsp
, SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
)
1105 TALLOC_CTX
*ul_ctx
= NULL
;
1106 struct lock_list
*ulist
= NULL
;
1107 struct lock_list
*ul
= NULL
;
1108 struct posix_lock deleted_lock
;
1109 int num_overlapped_entries
;
1111 DEBUG(5,("release_posix_lock: File %s, offset = %.0f, count = %.0f\n",
1112 fsp
->fsp_name
, (double)u_offset
, (double)u_count
));
1115 * If the requested lock won't fit in the POSIX range, we will
1116 * pretend it was successful.
1119 if(!posix_lock_in_range(&offset
, &count
, u_offset
, u_count
))
1123 * We treat this as one unlock request for POSIX accounting purposes even
1124 * if it may later be split into multiple smaller POSIX unlock ranges.
1125 * num_overlapped_entries is the number of existing locks that have any
1126 * overlap with this unlock request.
1129 num_overlapped_entries
= delete_posix_lock_entry(fsp
, offset
, count
, &deleted_lock
);
1131 if (num_overlapped_entries
== -1) {
1132 smb_panic("release_posix_lock: unable find entry to delete !\n");
1136 * If num_overlapped_entries is > 0, and the lock_type we just deleted from the tdb was
1137 * a POSIX write lock, then before doing the unlock we need to downgrade
1138 * the POSIX lock to a read lock. This allows any overlapping read locks
1139 * to be atomically maintained.
1142 if (num_overlapped_entries
> 0 && deleted_lock
.lock_type
== F_WRLCK
) {
1143 if (!posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,F_RDLCK
)) {
1144 DEBUG(0,("release_posix_lock: downgrade of lock failed with error %s !\n", strerror(errno
) ));
1149 if ((ul_ctx
= talloc_init("release_posix_lock")) == NULL
) {
1150 DEBUG(0,("release_posix_lock: unable to init talloc context.\n"));
1151 return True
; /* Not a fatal error. */
1154 if ((ul
= TALLOC_P(ul_ctx
, struct lock_list
)) == NULL
) {
1155 DEBUG(0,("release_posix_lock: unable to talloc unlock list.\n"));
1156 talloc_destroy(ul_ctx
);
1157 return True
; /* Not a fatal error. */
1161 * Create the initial list entry containing the
1162 * lock we want to remove.
1169 DLIST_ADD(ulist
, ul
);
1172 * The following call calculates if there are any
1173 * overlapping locks held by this process on
1174 * fd's open on the same file and creates a
1175 * list of unlock ranges that will allow
1176 * POSIX lock ranges to remain on the file whilst the
1177 * unlocks are performed.
1180 ulist
= posix_lock_list(ul_ctx
, ulist
, fsp
);
1183 * Release the POSIX locks on the list of ranges returned.
1186 for(; ulist
; ulist
= ulist
->next
) {
1187 offset
= ulist
->start
;
1188 count
= ulist
->size
;
1190 DEBUG(5,("release_posix_lock: Real unlock: offset = %.0f, count = %.0f\n",
1191 (double)offset
, (double)count
));
1193 if (!posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,F_UNLCK
))
1197 talloc_destroy(ul_ctx
);
1202 /****************************************************************************
1203 Remove all lock entries for a specific dev/inode pair from the tdb.
1204 ****************************************************************************/
1206 static void delete_posix_lock_entries(files_struct
*fsp
)
1208 TDB_DATA kbuf
= locking_key_fsp(fsp
);
1210 if (tdb_delete(posix_lock_tdb
, kbuf
) == -1)
1211 DEBUG(0,("delete_close_entries: tdb_delete fail !\n"));
1214 /****************************************************************************
1216 ****************************************************************************/
1218 static void dump_entry(struct posix_lock
*pl
)
1220 DEBUG(10,("entry: start=%.0f, size=%.0f, type=%d, fd=%i\n",
1221 (double)pl
->start
, (double)pl
->size
, (int)pl
->lock_type
, pl
->fd
));
1224 /****************************************************************************
1225 Remove any locks on this fd. Called from file_close().
1226 ****************************************************************************/
1228 void posix_locking_close_file(files_struct
*fsp
)
1230 struct posix_lock
*entries
= NULL
;
1234 * Optimization for the common case where we are the only
1235 * opener of a file. If all fd entries are our own, we don't
1236 * need to explicitly release all the locks via the POSIX functions,
1237 * we can just remove all the entries in the tdb and allow the
1238 * close to remove the real locks.
1241 count
= get_posix_lock_entries(fsp
, &entries
);
1244 DEBUG(10,("posix_locking_close_file: file %s has no outstanding locks.\n", fsp
->fsp_name
));
1248 for (i
= 0; i
< count
; i
++) {
1249 if (entries
[i
].fd
!= fsp
->fh
->fd
)
1252 dump_entry(&entries
[i
]);
1256 /* All locks are ours. */
1257 DEBUG(10,("posix_locking_close_file: file %s has %u outstanding locks, but all on one fd.\n",
1258 fsp
->fsp_name
, (unsigned int)count
));
1260 delete_posix_lock_entries(fsp
);
1265 * Difficult case. We need to delete all our locks, whilst leaving
1266 * all other POSIX locks in place.
1269 for (i
= 0; i
< count
; i
++) {
1270 struct posix_lock
*pl
= &entries
[i
];
1271 if (pl
->fd
== fsp
->fh
->fd
)
1272 release_posix_lock(fsp
, (SMB_BIG_UINT
)pl
->start
, (SMB_BIG_UINT
)pl
->size
);
1277 /*******************************************************************
1278 Create the in-memory POSIX lock databases.
1279 ********************************************************************/
1281 BOOL
posix_locking_init(int read_only
)
1283 if (posix_lock_tdb
&& posix_pending_close_tdb
)
1286 if (!posix_lock_tdb
)
1287 posix_lock_tdb
= tdb_open_log(NULL
, 0, TDB_INTERNAL
,
1288 read_only
?O_RDONLY
:(O_RDWR
|O_CREAT
), 0644);
1289 if (!posix_lock_tdb
) {
1290 DEBUG(0,("Failed to open POSIX byte range locking database.\n"));
1293 if (!posix_pending_close_tdb
)
1294 posix_pending_close_tdb
= tdb_open_log(NULL
, 0, TDB_INTERNAL
,
1295 read_only
?O_RDONLY
:(O_RDWR
|O_CREAT
), 0644);
1296 if (!posix_pending_close_tdb
) {
1297 DEBUG(0,("Failed to open POSIX pending close database.\n"));
1304 /*******************************************************************
1305 Delete the in-memory POSIX lock databases.
1306 ********************************************************************/
1308 BOOL
posix_locking_end(void)
1310 if (posix_lock_tdb
&& tdb_close(posix_lock_tdb
) != 0)
1312 if (posix_pending_close_tdb
&& tdb_close(posix_pending_close_tdb
) != 0)