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 * The POSIX locking database handle.
31 static TDB_CONTEXT
*posix_lock_tdb
;
34 * The pending close database handle.
37 static TDB_CONTEXT
*posix_pending_close_tdb
;
40 * The data in POSIX lock records is an unsorted linear array of these
41 * records. It is unnecessary to store the count as tdb provides the
53 * The data in POSIX pending close records is an unsorted linear array of int
54 * records. It is unnecessary to store the count as tdb provides the
58 /* The key used in both the POSIX databases. */
60 struct posix_lock_key
{
65 /*******************************************************************
66 Form a static locking key for a dev/inode pair.
67 ******************************************************************/
69 static TDB_DATA
locking_key(SMB_DEV_T dev
, SMB_INO_T inode
)
71 static struct posix_lock_key key
;
74 memset(&key
, '\0', sizeof(key
));
77 kbuf
.dptr
= (char *)&key
;
78 kbuf
.dsize
= sizeof(key
);
82 /*******************************************************************
83 Convenience function to get a key from an fsp.
84 ******************************************************************/
86 static TDB_DATA
locking_key_fsp(files_struct
*fsp
)
88 return locking_key(fsp
->dev
, fsp
->inode
);
91 /****************************************************************************
92 Add an fd to the pending close tdb.
93 ****************************************************************************/
95 static BOOL
add_fd_to_close_entry(files_struct
*fsp
)
97 TDB_DATA kbuf
= locking_key_fsp(fsp
);
103 dbuf
= tdb_fetch(posix_pending_close_tdb
, kbuf
);
105 tp
= Realloc(dbuf
.dptr
, dbuf
.dsize
+ sizeof(int));
107 DEBUG(0,("add_fd_to_close_entry: Realloc fail !\n"));
108 SAFE_FREE(dbuf
.dptr
);
113 memcpy(dbuf
.dptr
+ dbuf
.dsize
, &fsp
->fd
, sizeof(int));
114 dbuf
.dsize
+= sizeof(int);
116 if (tdb_store(posix_pending_close_tdb
, kbuf
, dbuf
, TDB_REPLACE
) == -1) {
117 DEBUG(0,("add_fd_to_close_entry: tdb_store fail !\n"));
120 SAFE_FREE(dbuf
.dptr
);
124 /****************************************************************************
125 Remove all fd entries for a specific dev/inode pair from the tdb.
126 ****************************************************************************/
128 static void delete_close_entries(files_struct
*fsp
)
130 TDB_DATA kbuf
= locking_key_fsp(fsp
);
132 if (tdb_delete(posix_pending_close_tdb
, kbuf
) == -1)
133 DEBUG(0,("delete_close_entries: tdb_delete fail !\n"));
136 /****************************************************************************
137 Get the array of POSIX pending close records for an open fsp. Caller must
138 free. Returns number of entries.
139 ****************************************************************************/
141 static size_t get_posix_pending_close_entries(files_struct
*fsp
, int **entries
)
143 TDB_DATA kbuf
= locking_key_fsp(fsp
);
150 dbuf
= tdb_fetch(posix_pending_close_tdb
, kbuf
);
156 *entries
= (int *)dbuf
.dptr
;
157 count
= (size_t)(dbuf
.dsize
/ sizeof(int));
162 /****************************************************************************
163 Get the array of POSIX locks for an fsp. Caller must free. Returns
165 ****************************************************************************/
167 static size_t get_posix_lock_entries(files_struct
*fsp
, struct posix_lock
**entries
)
169 TDB_DATA kbuf
= locking_key_fsp(fsp
);
177 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
183 *entries
= (struct posix_lock
*)dbuf
.dptr
;
184 count
= (size_t)(dbuf
.dsize
/ sizeof(struct posix_lock
));
189 /****************************************************************************
190 Deal with pending closes needed by POSIX locking support.
191 Note that posix_locking_close_file() is expected to have been called
192 to delete all locks on this fsp before this function is called.
193 ****************************************************************************/
195 int fd_close_posix(struct connection_struct
*conn
, files_struct
*fsp
)
200 struct posix_lock
*entries
= NULL
;
201 int *fd_array
= NULL
;
202 BOOL locks_on_other_fds
= False
;
204 if (!lp_posix_locking(SNUM(conn
))) {
206 * No POSIX to worry about, just close.
208 ret
= SMB_VFS_CLOSE(fsp
,fsp
->fd
);
214 * Get the number of outstanding POSIX locks on this dev/inode pair.
217 count
= get_posix_lock_entries(fsp
, &entries
);
220 * Check if there are any outstanding locks belonging to
221 * other fd's. This should never be the case if posix_locking_close_file()
222 * has been called first, but it never hurts to be *sure*.
225 for (i
= 0; i
< count
; i
++) {
226 if (entries
[i
].fd
!= fsp
->fd
) {
227 locks_on_other_fds
= True
;
232 if (locks_on_other_fds
) {
235 * There are outstanding locks on this dev/inode pair on other fds.
236 * Add our fd to the pending close tdb and set fsp->fd to -1.
239 if (!add_fd_to_close_entry(fsp
)) {
252 * No outstanding POSIX locks. Get the pending close fd's
253 * from the tdb and close them all.
256 count
= get_posix_pending_close_entries(fsp
, &fd_array
);
259 DEBUG(10,("fd_close_posix: doing close on %u fd's.\n", (unsigned int)count
));
261 for(i
= 0; i
< count
; i
++) {
262 if (SMB_VFS_CLOSE(fsp
,fd_array
[i
]) == -1) {
268 * Delete all fd's stored in the tdb
269 * for this dev/inode pair.
272 delete_close_entries(fsp
);
278 * Finally close the fd associated with this fsp.
281 ret
= SMB_VFS_CLOSE(fsp
,fsp
->fd
);
283 if (saved_errno
!= 0) {
293 /****************************************************************************
295 ****************************************************************************/
297 static const char *posix_lock_type_name(int lock_type
)
299 return (lock_type
== F_RDLCK
) ? "READ" : "WRITE";
302 /****************************************************************************
303 Delete a POSIX lock entry by index number. Used if the tdb add succeeds, but
304 then the POSIX fcntl lock fails.
305 ****************************************************************************/
307 static BOOL
delete_posix_lock_entry_by_index(files_struct
*fsp
, size_t entry
)
309 TDB_DATA kbuf
= locking_key_fsp(fsp
);
311 struct posix_lock
*locks
;
316 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
319 DEBUG(10,("delete_posix_lock_entry_by_index: tdb_fetch failed !\n"));
323 count
= (size_t)(dbuf
.dsize
/ sizeof(struct posix_lock
));
324 locks
= (struct posix_lock
*)dbuf
.dptr
;
327 tdb_delete(posix_lock_tdb
, kbuf
);
329 if (entry
< count
-1) {
330 memmove(&locks
[entry
], &locks
[entry
+1], sizeof(*locks
)*((count
-1) - entry
));
332 dbuf
.dsize
-= sizeof(*locks
);
333 tdb_store(posix_lock_tdb
, kbuf
, dbuf
, TDB_REPLACE
);
336 SAFE_FREE(dbuf
.dptr
);
342 SAFE_FREE(dbuf
.dptr
);
346 /****************************************************************************
347 Add an entry into the POSIX locking tdb. We return the index number of the
348 added lock (used in case we need to delete *exactly* this entry). Returns
349 False on fail, True on success.
350 ****************************************************************************/
352 static BOOL
add_posix_lock_entry(files_struct
*fsp
, SMB_OFF_T start
, SMB_OFF_T size
, int lock_type
, size_t *pentry_num
)
354 TDB_DATA kbuf
= locking_key_fsp(fsp
);
356 struct posix_lock pl
;
361 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
363 *pentry_num
= (size_t)(dbuf
.dsize
/ sizeof(pl
));
372 pl
.lock_type
= lock_type
;
374 tp
= Realloc(dbuf
.dptr
, dbuf
.dsize
+ sizeof(pl
));
376 DEBUG(0,("add_posix_lock_entry: Realloc fail !\n"));
381 memcpy(dbuf
.dptr
+ dbuf
.dsize
, &pl
, sizeof(pl
));
382 dbuf
.dsize
+= sizeof(pl
);
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(*locks
));
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
->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(*locks
)*((count
-1) - i
));
468 dbuf
.dsize
-= sizeof(*locks
);
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
->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"));
522 } else if((lock_type
== READ_LOCK
) && !fsp
->can_read
) {
524 * Ditto for read locks on write only files.
526 DEBUG(10,("map_posix_lock_type: Changing read lock to write due to write-only file.\n"));
531 * This return should be the most normal, as we attempt
532 * to always open files read/write.
535 return (lock_type
== READ_LOCK
) ? F_RDLCK
: F_WRLCK
;
538 /****************************************************************************
539 Check to see if the given unsigned lock range is within the possible POSIX
540 range. Modifies the given args to be in range if possible, just returns
542 ****************************************************************************/
544 static BOOL
posix_lock_in_range(SMB_OFF_T
*offset_out
, SMB_OFF_T
*count_out
,
545 SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
)
547 SMB_OFF_T offset
= (SMB_OFF_T
)u_offset
;
548 SMB_OFF_T count
= (SMB_OFF_T
)u_count
;
551 * For the type of system we are, attempt to
552 * find the maximum positive lock offset as an SMB_OFF_T.
555 #if defined(MAX_POSITIVE_LOCK_OFFSET) /* Some systems have arbitrary limits. */
557 SMB_OFF_T max_positive_lock_offset
= (MAX_POSITIVE_LOCK_OFFSET
);
559 #elif defined(LARGE_SMB_OFF_T) && !defined(HAVE_BROKEN_FCNTL64_LOCKS)
562 * In this case SMB_OFF_T is 64 bits,
563 * and the underlying system can handle 64 bit signed locks.
566 SMB_OFF_T mask2
= ((SMB_OFF_T
)0x4) << (SMB_OFF_T_BITS
-4);
567 SMB_OFF_T mask
= (mask2
<<1);
568 SMB_OFF_T max_positive_lock_offset
= ~mask
;
570 #else /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
573 * In this case either SMB_OFF_T is 32 bits,
574 * or the underlying system cannot handle 64 bit signed locks.
575 * All offsets & counts must be 2^31 or less.
578 SMB_OFF_T max_positive_lock_offset
= 0x7FFFFFFF;
580 #endif /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
583 * POSIX locks of length zero mean lock to end-of-file.
584 * Win32 locks of length zero are point probes. Ignore
585 * any Win32 locks of length zero. JRA.
588 if (count
== (SMB_OFF_T
)0) {
589 DEBUG(10,("posix_lock_in_range: count = 0, ignoring.\n"));
594 * If the given offset was > max_positive_lock_offset then we cannot map this at all
598 if (u_offset
& ~((SMB_BIG_UINT
)max_positive_lock_offset
)) {
599 DEBUG(10,("posix_lock_in_range: (offset = %.0f) offset > %.0f and we cannot handle this. Ignoring lock.\n",
600 (double)u_offset
, (double)((SMB_BIG_UINT
)max_positive_lock_offset
) ));
605 * We must truncate the count to less than max_positive_lock_offset.
608 if (u_count
& ~((SMB_BIG_UINT
)max_positive_lock_offset
))
609 count
= max_positive_lock_offset
;
612 * Truncate count to end at max lock offset.
615 if (offset
+ count
< 0 || offset
+ count
> max_positive_lock_offset
)
616 count
= max_positive_lock_offset
- offset
;
619 * If we ate all the count, ignore this lock.
623 DEBUG(10,("posix_lock_in_range: Count = 0. Ignoring lock u_offset = %.0f, u_count = %.0f\n",
624 (double)u_offset
, (double)u_count
));
629 * The mapping was successful.
632 DEBUG(10,("posix_lock_in_range: offset_out = %.0f, count_out = %.0f\n",
633 (double)offset
, (double)count
));
635 *offset_out
= offset
;
641 /****************************************************************************
642 Actual function that does POSIX locks. Copes with 64 -> 32 bit cruft and
643 broken NFS implementations.
644 ****************************************************************************/
646 static BOOL
posix_fcntl_lock(files_struct
*fsp
, int op
, SMB_OFF_T offset
, SMB_OFF_T count
, int type
)
650 DEBUG(8,("posix_fcntl_lock %d %d %.0f %.0f %d\n",fsp
->fd
,op
,(double)offset
,(double)count
,type
));
652 ret
= SMB_VFS_LOCK(fsp
,fsp
->fd
,op
,offset
,count
,type
);
654 if (!ret
&& ((errno
== EFBIG
) || (errno
== ENOLCK
) || (errno
== EINVAL
))) {
656 DEBUG(0,("posix_fcntl_lock: WARNING: lock request at offset %.0f, length %.0f returned\n",
657 (double)offset
,(double)count
));
658 DEBUG(0,("an %s error. This can happen when using 64 bit lock offsets\n", strerror(errno
)));
659 DEBUG(0,("on 32 bit NFS mounted file systems.\n"));
662 * If the offset is > 0x7FFFFFFF then this will cause problems on
663 * 32 bit NFS mounted filesystems. Just ignore it.
666 if (offset
& ~((SMB_OFF_T
)0x7fffffff)) {
667 DEBUG(0,("Offset greater than 31 bits. Returning success.\n"));
671 if (count
& ~((SMB_OFF_T
)0x7fffffff)) {
672 /* 32 bit NFS file system, retry with smaller offset */
673 DEBUG(0,("Count greater than 31 bits - retrying with 31 bit truncated length.\n"));
676 ret
= SMB_VFS_LOCK(fsp
,fsp
->fd
,op
,offset
,count
,type
);
680 DEBUG(8,("posix_fcntl_lock: Lock call %s\n", ret
? "successful" : "failed"));
685 /****************************************************************************
686 POSIX function to see if a file region is locked. Returns True if the
687 region is locked, False otherwise.
688 ****************************************************************************/
690 BOOL
is_posix_locked(files_struct
*fsp
, SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
, enum brl_type lock_type
)
694 int posix_lock_type
= map_posix_lock_type(fsp
,lock_type
);
696 DEBUG(10,("is_posix_locked: File %s, offset = %.0f, count = %.0f, type = %s\n",
697 fsp
->fsp_name
, (double)u_offset
, (double)u_count
, posix_lock_type_name(lock_type
) ));
700 * If the requested lock won't fit in the POSIX range, we will
701 * never set it, so presume it is not locked.
704 if(!posix_lock_in_range(&offset
, &count
, u_offset
, u_count
))
708 * Note that most UNIX's can *test* for a write lock on
709 * a read-only fd, just not *set* a write lock on a read-only
710 * fd. So we don't need to use map_lock_type here.
713 return posix_fcntl_lock(fsp
,SMB_F_GETLK
,offset
,count
,posix_lock_type
);
717 * Structure used when splitting a lock range
718 * into a POSIX lock range. Doubly linked list.
722 struct lock_list
*next
;
723 struct lock_list
*prev
;
728 /****************************************************************************
729 Create a list of lock ranges that don't overlap a given range. Used in calculating
730 POSIX locks and unlocks. This is a difficult function that requires ASCII art to
732 ****************************************************************************/
734 static struct lock_list
*posix_lock_list(TALLOC_CTX
*ctx
, struct lock_list
*lhead
, files_struct
*fsp
)
736 TDB_DATA kbuf
= locking_key_fsp(fsp
);
738 struct posix_lock
*locks
;
743 dbuf
= tdb_fetch(posix_lock_tdb
, kbuf
);
748 locks
= (struct posix_lock
*)dbuf
.dptr
;
749 num_locks
= (size_t)(dbuf
.dsize
/ sizeof(*locks
));
752 * Check the current lock list on this dev/inode pair.
753 * Quit if the list is deleted.
756 DEBUG(10,("posix_lock_list: curr: start=%.0f,size=%.0f\n",
757 (double)lhead
->start
, (double)lhead
->size
));
759 for (i
=0; i
<num_locks
&& lhead
; i
++) {
761 struct posix_lock
*lock
= &locks
[i
];
762 struct lock_list
*l_curr
;
765 * Walk the lock list, checking for overlaps. Note that
766 * the lock list can expand within this loop if the current
767 * range being examined needs to be split.
770 for (l_curr
= lhead
; l_curr
;) {
772 DEBUG(10,("posix_lock_list: lock: fd=%d: start=%.0f,size=%.0f:type=%s", lock
->fd
,
773 (double)lock
->start
, (double)lock
->size
, posix_lock_type_name(lock
->lock_type
) ));
775 if ( (l_curr
->start
>= (lock
->start
+ lock
->size
)) ||
776 (lock
->start
>= (l_curr
->start
+ l_curr
->size
))) {
778 /* No overlap with this lock - leave this range alone. */
779 /*********************************************
790 **********************************************/
792 DEBUG(10,("no overlap case.\n" ));
794 l_curr
= l_curr
->next
;
796 } else if ( (l_curr
->start
>= lock
->start
) &&
797 (l_curr
->start
+ l_curr
->size
<= lock
->start
+ lock
->size
) ) {
800 * This unlock is completely overlapped by this existing lock range
801 * and thus should have no effect (not be unlocked). Delete it from the list.
803 /*********************************************
807 +---------------------------+
809 +---------------------------+
810 **********************************************/
811 /* Save the next pointer */
812 struct lock_list
*ul_next
= l_curr
->next
;
814 DEBUG(10,("delete case.\n" ));
816 DLIST_REMOVE(lhead
, l_curr
);
818 break; /* No more list... */
822 } else if ( (l_curr
->start
>= lock
->start
) &&
823 (l_curr
->start
< lock
->start
+ lock
->size
) &&
824 (l_curr
->start
+ l_curr
->size
> lock
->start
+ lock
->size
) ) {
827 * This unlock overlaps the existing lock range at the high end.
828 * Truncate by moving start to existing range end and reducing size.
830 /*********************************************
841 **********************************************/
843 l_curr
->size
= (l_curr
->start
+ l_curr
->size
) - (lock
->start
+ lock
->size
);
844 l_curr
->start
= lock
->start
+ lock
->size
;
846 DEBUG(10,("truncate high case: start=%.0f,size=%.0f\n",
847 (double)l_curr
->start
, (double)l_curr
->size
));
849 l_curr
= l_curr
->next
;
851 } else if ( (l_curr
->start
< lock
->start
) &&
852 (l_curr
->start
+ l_curr
->size
> lock
->start
) &&
853 (l_curr
->start
+ l_curr
->size
<= lock
->start
+ lock
->size
) ) {
856 * This unlock overlaps the existing lock range at the low end.
857 * Truncate by reducing size.
859 /*********************************************
870 **********************************************/
872 l_curr
->size
= lock
->start
- l_curr
->start
;
874 DEBUG(10,("truncate low case: start=%.0f,size=%.0f\n",
875 (double)l_curr
->start
, (double)l_curr
->size
));
877 l_curr
= l_curr
->next
;
879 } else if ( (l_curr
->start
< lock
->start
) &&
880 (l_curr
->start
+ l_curr
->size
> lock
->start
+ lock
->size
) ) {
882 * Worst case scenario. Unlock request completely overlaps an existing
883 * lock range. Split the request into two, push the new (upper) request
884 * into the dlink list, and continue with the entry after ul_new (as we
885 * know that ul_new will not overlap with this lock).
887 /*********************************************
888 +---------------------------+
890 +---------------------------+
895 +-------+ +---------+
897 +-------+ +---------+
898 **********************************************/
899 struct lock_list
*l_new
= (struct lock_list
*)talloc(ctx
,
900 sizeof(struct lock_list
));
903 DEBUG(0,("posix_lock_list: talloc fail.\n"));
904 return NULL
; /* The talloc_destroy takes care of cleanup. */
908 l_new
->start
= lock
->start
+ lock
->size
;
909 l_new
->size
= l_curr
->start
+ l_curr
->size
- l_new
->start
;
911 /* Truncate the l_curr. */
912 l_curr
->size
= lock
->start
- l_curr
->start
;
914 DEBUG(10,("split case: curr: start=%.0f,size=%.0f \
915 new: start=%.0f,size=%.0f\n", (double)l_curr
->start
, (double)l_curr
->size
,
916 (double)l_new
->start
, (double)l_new
->size
));
919 * Add into the dlink list after the l_curr point - NOT at lhead.
920 * Note we can't use DLINK_ADD here as this inserts at the head of the given list.
923 l_new
->prev
= l_curr
;
924 l_new
->next
= l_curr
->next
;
925 l_curr
->next
= l_new
;
927 /* And move after the link we added. */
928 l_curr
= l_new
->next
;
933 * This logic case should never happen. Ensure this is the
934 * case by forcing an abort.... Remove in production.
938 slprintf(msg
, sizeof(msg
)-1, "logic flaw in cases: l_curr: start = %.0f, size = %.0f : \
939 lock: start = %.0f, size = %.0f\n", (double)l_curr
->start
, (double)l_curr
->size
, (double)lock
->start
, (double)lock
->size
);
943 } /* end for ( l_curr = lhead; l_curr;) */
944 } /* end for (i=0; i<num_locks && ul_head; i++) */
946 SAFE_FREE(dbuf
.dptr
);
951 /****************************************************************************
952 POSIX function to acquire a lock. Returns True if the
953 lock could be granted, False if not.
954 ****************************************************************************/
956 BOOL
set_posix_lock(files_struct
*fsp
, SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
, enum brl_type lock_type
)
961 size_t entry_num
= 0;
963 TALLOC_CTX
*l_ctx
= NULL
;
964 struct lock_list
*llist
= NULL
;
965 struct lock_list
*ll
= NULL
;
966 int posix_lock_type
= map_posix_lock_type(fsp
,lock_type
);
968 DEBUG(5,("set_posix_lock: File %s, offset = %.0f, count = %.0f, type = %s\n",
969 fsp
->fsp_name
, (double)u_offset
, (double)u_count
, posix_lock_type_name(lock_type
) ));
972 * If the requested lock won't fit in the POSIX range, we will
973 * pretend it was successful.
976 if(!posix_lock_in_range(&offset
, &count
, u_offset
, u_count
))
980 * Windows is very strange. It allows read locks to be overlayed
981 * (even over a write lock), but leaves the write lock in force until the first
982 * unlock. It also reference counts the locks. This means the following sequence :
985 * ------------------------------------------------------------------------
986 * WRITE LOCK : start = 2, len = 10
987 * READ LOCK: start =0, len = 10 - FAIL
988 * READ LOCK : start = 0, len = 14
989 * READ LOCK: start =0, len = 10 - FAIL
990 * UNLOCK : start = 2, len = 10
991 * READ LOCK: start =0, len = 10 - OK
993 * Under POSIX, the same sequence in steps 1 and 2 would not be reference counted, but
994 * would leave a single read lock over the 0-14 region. In order to
995 * re-create Windows semantics mapped to POSIX locks, we create multiple TDB
996 * entries, one for each overlayed lock request. We are guarenteed by the brlock
997 * semantics that if a write lock is added, then it will be first in the array.
1000 if ((l_ctx
= talloc_init("set_posix_lock")) == NULL
) {
1001 DEBUG(0,("set_posix_lock: unable to init talloc context.\n"));
1002 return True
; /* Not a fatal error. */
1005 if ((ll
= (struct lock_list
*)talloc(l_ctx
, sizeof(struct lock_list
))) == NULL
) {
1006 DEBUG(0,("set_posix_lock: unable to talloc unlock list.\n"));
1007 talloc_destroy(l_ctx
);
1008 return True
; /* Not a fatal error. */
1012 * Create the initial list entry containing the
1013 * lock we want to add.
1020 DLIST_ADD(llist
, ll
);
1023 * The following call calculates if there are any
1024 * overlapping locks held by this process on
1025 * fd's open on the same file and splits this list
1026 * into a list of lock ranges that do not overlap with existing
1030 llist
= posix_lock_list(l_ctx
, llist
, fsp
);
1033 * Now we have the list of ranges to lock it is safe to add the
1034 * entry into the POSIX lock tdb. We take note of the entry we
1035 * added here in case we have to remove it on POSIX lock fail.
1038 if (!add_posix_lock_entry(fsp
,offset
,count
,posix_lock_type
,&entry_num
)) {
1039 DEBUG(0,("set_posix_lock: Unable to create posix lock entry !\n"));
1040 talloc_destroy(l_ctx
);
1045 * Add the POSIX locks on the list of ranges returned.
1046 * As the lock is supposed to be added atomically, we need to
1047 * back out all the locks if any one of these calls fail.
1050 for (lock_count
= 0, ll
= llist
; ll
; ll
= ll
->next
, lock_count
++) {
1054 DEBUG(5,("set_posix_lock: Real lock: Type = %s: offset = %.0f, count = %.0f\n",
1055 posix_lock_type_name(posix_lock_type
), (double)offset
, (double)count
));
1057 if (!posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,posix_lock_type
)) {
1058 DEBUG(5,("set_posix_lock: Lock fail !: Type = %s: offset = %.0f, count = %.0f. Errno = %s\n",
1059 posix_lock_type_name(posix_lock_type
), (double)offset
, (double)count
, strerror(errno
) ));
1068 * Back out all the POSIX locks we have on fail.
1071 for (ll
= llist
; lock_count
; ll
= ll
->next
, lock_count
--) {
1075 DEBUG(5,("set_posix_lock: Backing out locks: Type = %s: offset = %.0f, count = %.0f\n",
1076 posix_lock_type_name(posix_lock_type
), (double)offset
, (double)count
));
1078 posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,F_UNLCK
);
1082 * Remove the tdb entry for this lock.
1085 delete_posix_lock_entry_by_index(fsp
,entry_num
);
1088 talloc_destroy(l_ctx
);
1092 /****************************************************************************
1093 POSIX function to release a lock. Returns True if the
1094 lock could be released, False if not.
1095 ****************************************************************************/
1097 BOOL
release_posix_lock(files_struct
*fsp
, SMB_BIG_UINT u_offset
, SMB_BIG_UINT u_count
)
1102 TALLOC_CTX
*ul_ctx
= NULL
;
1103 struct lock_list
*ulist
= NULL
;
1104 struct lock_list
*ul
= NULL
;
1105 struct posix_lock deleted_lock
;
1106 int num_overlapped_entries
;
1108 DEBUG(5,("release_posix_lock: File %s, offset = %.0f, count = %.0f\n",
1109 fsp
->fsp_name
, (double)u_offset
, (double)u_count
));
1112 * If the requested lock won't fit in the POSIX range, we will
1113 * pretend it was successful.
1116 if(!posix_lock_in_range(&offset
, &count
, u_offset
, u_count
))
1120 * We treat this as one unlock request for POSIX accounting purposes even
1121 * if it may later be split into multiple smaller POSIX unlock ranges.
1122 * num_overlapped_entries is the number of existing locks that have any
1123 * overlap with this unlock request.
1126 num_overlapped_entries
= delete_posix_lock_entry(fsp
, offset
, count
, &deleted_lock
);
1128 if (num_overlapped_entries
== -1) {
1129 smb_panic("release_posix_lock: unable find entry to delete !\n");
1133 * If num_overlapped_entries is > 0, and the lock_type we just deleted from the tdb was
1134 * a POSIX write lock, then before doing the unlock we need to downgrade
1135 * the POSIX lock to a read lock. This allows any overlapping read locks
1136 * to be atomically maintained.
1139 if (num_overlapped_entries
> 0 && deleted_lock
.lock_type
== F_WRLCK
) {
1140 if (!posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,F_RDLCK
)) {
1141 DEBUG(0,("release_posix_lock: downgrade of lock failed with error %s !\n", strerror(errno
) ));
1146 if ((ul_ctx
= talloc_init("release_posix_lock")) == NULL
) {
1147 DEBUG(0,("release_posix_lock: unable to init talloc context.\n"));
1148 return True
; /* Not a fatal error. */
1151 if ((ul
= (struct lock_list
*)talloc(ul_ctx
, sizeof(struct lock_list
))) == NULL
) {
1152 DEBUG(0,("release_posix_lock: unable to talloc unlock list.\n"));
1153 talloc_destroy(ul_ctx
);
1154 return True
; /* Not a fatal error. */
1158 * Create the initial list entry containing the
1159 * lock we want to remove.
1166 DLIST_ADD(ulist
, ul
);
1169 * The following call calculates if there are any
1170 * overlapping locks held by this process on
1171 * fd's open on the same file and creates a
1172 * list of unlock ranges that will allow
1173 * POSIX lock ranges to remain on the file whilst the
1174 * unlocks are performed.
1177 ulist
= posix_lock_list(ul_ctx
, ulist
, fsp
);
1180 * Release the POSIX locks on the list of ranges returned.
1183 for(; ulist
; ulist
= ulist
->next
) {
1184 offset
= ulist
->start
;
1185 count
= ulist
->size
;
1187 DEBUG(5,("release_posix_lock: Real unlock: offset = %.0f, count = %.0f\n",
1188 (double)offset
, (double)count
));
1190 if (!posix_fcntl_lock(fsp
,SMB_F_SETLK
,offset
,count
,F_UNLCK
))
1194 talloc_destroy(ul_ctx
);
1199 /****************************************************************************
1200 Remove all lock entries for a specific dev/inode pair from the tdb.
1201 ****************************************************************************/
1203 static void delete_posix_lock_entries(files_struct
*fsp
)
1205 TDB_DATA kbuf
= locking_key_fsp(fsp
);
1207 if (tdb_delete(posix_lock_tdb
, kbuf
) == -1)
1208 DEBUG(0,("delete_close_entries: tdb_delete fail !\n"));
1211 /****************************************************************************
1213 ****************************************************************************/
1215 static void dump_entry(struct posix_lock
*pl
)
1217 DEBUG(10,("entry: start=%.0f, size=%.0f, type=%d, fd=%i\n",
1218 (double)pl
->start
, (double)pl
->size
, (int)pl
->lock_type
, pl
->fd
));
1221 /****************************************************************************
1222 Remove any locks on this fd. Called from file_close().
1223 ****************************************************************************/
1225 void posix_locking_close_file(files_struct
*fsp
)
1227 struct posix_lock
*entries
= NULL
;
1231 * Optimization for the common case where we are the only
1232 * opener of a file. If all fd entries are our own, we don't
1233 * need to explicitly release all the locks via the POSIX functions,
1234 * we can just remove all the entries in the tdb and allow the
1235 * close to remove the real locks.
1238 count
= get_posix_lock_entries(fsp
, &entries
);
1241 DEBUG(10,("posix_locking_close_file: file %s has no outstanding locks.\n", fsp
->fsp_name
));
1245 for (i
= 0; i
< count
; i
++) {
1246 if (entries
[i
].fd
!= fsp
->fd
)
1249 dump_entry(&entries
[i
]);
1253 /* All locks are ours. */
1254 DEBUG(10,("posix_locking_close_file: file %s has %u outstanding locks, but all on one fd.\n",
1255 fsp
->fsp_name
, (unsigned int)count
));
1257 delete_posix_lock_entries(fsp
);
1262 * Difficult case. We need to delete all our locks, whilst leaving
1263 * all other POSIX locks in place.
1266 for (i
= 0; i
< count
; i
++) {
1267 struct posix_lock
*pl
= &entries
[i
];
1268 if (pl
->fd
== fsp
->fd
)
1269 release_posix_lock(fsp
, (SMB_BIG_UINT
)pl
->start
, (SMB_BIG_UINT
)pl
->size
);
1274 /*******************************************************************
1275 Create the in-memory POSIX lock databases.
1276 ********************************************************************/
1278 BOOL
posix_locking_init(int read_only
)
1280 if (posix_lock_tdb
&& posix_pending_close_tdb
)
1283 if (!posix_lock_tdb
)
1284 posix_lock_tdb
= tdb_open_log(NULL
, 0, TDB_INTERNAL
,
1285 read_only
?O_RDONLY
:(O_RDWR
|O_CREAT
), 0644);
1286 if (!posix_lock_tdb
) {
1287 DEBUG(0,("Failed to open POSIX byte range locking database.\n"));
1290 if (!posix_pending_close_tdb
)
1291 posix_pending_close_tdb
= tdb_open_log(NULL
, 0, TDB_INTERNAL
,
1292 read_only
?O_RDONLY
:(O_RDWR
|O_CREAT
), 0644);
1293 if (!posix_pending_close_tdb
) {
1294 DEBUG(0,("Failed to open POSIX pending close database.\n"));
1301 /*******************************************************************
1302 Delete the in-memory POSIX lock databases.
1303 ********************************************************************/
1305 BOOL
posix_locking_end(void)
1307 if (posix_lock_tdb
&& tdb_close(posix_lock_tdb
) != 0)
1309 if (posix_pending_close_tdb
&& tdb_close(posix_pending_close_tdb
) != 0)