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);
107 dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
109 tp = SMB_REALLOC(dbuf.dptr, dbuf.dsize + sizeof(int));
111 DEBUG(0,("add_fd_to_close_entry: Realloc fail !\n"));
112 SAFE_FREE(dbuf.dptr);
117 memcpy(dbuf.dptr + dbuf.dsize, &fsp->fh->fd, sizeof(int));
118 dbuf.dsize += sizeof(int);
120 if (tdb_store(posix_pending_close_tdb, kbuf, dbuf, TDB_REPLACE) == -1) {
121 DEBUG(0,("add_fd_to_close_entry: tdb_store fail !\n"));
124 SAFE_FREE(dbuf.dptr);
128 /****************************************************************************
129 Remove all fd entries for a specific dev/inode pair from the tdb.
130 ****************************************************************************/
132 static void delete_close_entries(files_struct *fsp)
134 TDB_DATA kbuf = locking_key_fsp(fsp);
136 if (tdb_delete(posix_pending_close_tdb, kbuf) == -1)
137 DEBUG(0,("delete_close_entries: tdb_delete fail !\n"));
140 /****************************************************************************
141 Get the array of POSIX pending close records for an open fsp. Caller must
142 free. Returns number of entries.
143 ****************************************************************************/
145 static size_t get_posix_pending_close_entries(files_struct *fsp, int **entries)
147 TDB_DATA kbuf = locking_key_fsp(fsp);
154 dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
160 *entries = (int *)dbuf.dptr;
161 count = (size_t)(dbuf.dsize / sizeof(int));
166 /****************************************************************************
167 Get the array of POSIX locks for an fsp. Caller must free. Returns
169 ****************************************************************************/
171 static size_t get_posix_lock_entries(files_struct *fsp, struct posix_lock **entries)
173 TDB_DATA kbuf = locking_key_fsp(fsp);
181 dbuf = tdb_fetch(posix_lock_tdb, kbuf);
187 *entries = (struct posix_lock *)dbuf.dptr;
188 count = (size_t)(dbuf.dsize / sizeof(struct posix_lock));
193 /****************************************************************************
194 Deal with pending closes needed by POSIX locking support.
195 Note that posix_locking_close_file() is expected to have been called
196 to delete all locks on this fsp before this function is called.
197 ****************************************************************************/
199 int fd_close_posix(struct connection_struct *conn, files_struct *fsp)
204 struct posix_lock *entries = NULL;
205 int *fd_array = NULL;
206 BOOL locks_on_other_fds = False;
208 if (!lp_posix_locking(SNUM(conn))) {
210 * No POSIX to worry about, just close.
212 ret = SMB_VFS_CLOSE(fsp,fsp->fh->fd);
218 * Get the number of outstanding POSIX locks on this dev/inode pair.
221 count = get_posix_lock_entries(fsp, &entries);
224 * Check if there are any outstanding locks belonging to
225 * other fd's. This should never be the case if posix_locking_close_file()
226 * has been called first, but it never hurts to be *sure*.
229 for (i = 0; i < count; i++) {
230 if (entries[i].fd != fsp->fh->fd) {
231 locks_on_other_fds = True;
236 if (locks_on_other_fds) {
239 * There are outstanding locks on this dev/inode pair on other fds.
240 * Add our fd to the pending close tdb and set fsp->fh->fd to -1.
243 if (!add_fd_to_close_entry(fsp)) {
256 * No outstanding POSIX locks. Get the pending close fd's
257 * from the tdb and close them all.
260 count = get_posix_pending_close_entries(fsp, &fd_array);
263 DEBUG(10,("fd_close_posix: doing close on %u fd's.\n", (unsigned int)count ));
265 for(i = 0; i < count; i++) {
266 if (SMB_VFS_CLOSE(fsp,fd_array[i]) == -1) {
272 * Delete all fd's stored in the tdb
273 * for this dev/inode pair.
276 delete_close_entries(fsp);
282 * Finally close the fd associated with this fsp.
285 ret = SMB_VFS_CLOSE(fsp,fsp->fh->fd);
287 if (saved_errno != 0) {
297 /****************************************************************************
299 ****************************************************************************/
301 static const char *posix_lock_type_name(int lock_type)
303 return (lock_type == F_RDLCK) ? "READ" : "WRITE";
306 /****************************************************************************
307 Delete a POSIX lock entry by index number. Used if the tdb add succeeds, but
308 then the POSIX fcntl lock fails.
309 ****************************************************************************/
311 static BOOL delete_posix_lock_entry_by_index(files_struct *fsp, size_t entry)
313 TDB_DATA kbuf = locking_key_fsp(fsp);
315 struct posix_lock *locks;
320 dbuf = tdb_fetch(posix_lock_tdb, kbuf);
323 DEBUG(10,("delete_posix_lock_entry_by_index: tdb_fetch failed !\n"));
327 count = (size_t)(dbuf.dsize / sizeof(struct posix_lock));
328 locks = (struct posix_lock *)dbuf.dptr;
331 tdb_delete(posix_lock_tdb, kbuf);
333 if (entry < count-1) {
334 memmove(&locks[entry], &locks[entry+1], sizeof(struct posix_lock)*((count-1) - entry));
336 dbuf.dsize -= sizeof(struct posix_lock);
337 tdb_store(posix_lock_tdb, kbuf, dbuf, TDB_REPLACE);
340 SAFE_FREE(dbuf.dptr);
346 SAFE_FREE(dbuf.dptr);
350 /****************************************************************************
351 Add an entry into the POSIX locking tdb. We return the index number of the
352 added lock (used in case we need to delete *exactly* this entry). Returns
353 False on fail, True on success.
354 ****************************************************************************/
356 static BOOL add_posix_lock_entry(files_struct *fsp, SMB_OFF_T start, SMB_OFF_T size, int lock_type, size_t *pentry_num)
358 TDB_DATA kbuf = locking_key_fsp(fsp);
360 struct posix_lock pl;
366 dbuf = tdb_fetch(posix_lock_tdb, kbuf);
368 *pentry_num = (size_t)(dbuf.dsize / sizeof(struct posix_lock));
377 pl.lock_type = lock_type;
379 tp = SMB_REALLOC(dbuf.dptr, dbuf.dsize + sizeof(struct posix_lock));
381 DEBUG(0,("add_posix_lock_entry: Realloc fail !\n"));
386 memcpy(dbuf.dptr + dbuf.dsize, &pl, sizeof(struct posix_lock));
387 dbuf.dsize += sizeof(struct posix_lock);
389 if (tdb_store(posix_lock_tdb, kbuf, dbuf, TDB_REPLACE) == -1) {
390 DEBUG(0,("add_posix_lock: Failed to add lock entry on file %s\n", fsp->fsp_name));
394 SAFE_FREE(dbuf.dptr);
396 DEBUG(10,("add_posix_lock: File %s: type = %s: start=%.0f size=%.0f: dev=%.0f inode=%.0f\n",
397 fsp->fsp_name, posix_lock_type_name(lock_type), (double)start, (double)size,
398 (double)fsp->dev, (double)fsp->inode ));
404 SAFE_FREE(dbuf.dptr);
408 /****************************************************************************
409 Calculate if locks have any overlap at all.
410 ****************************************************************************/
412 static BOOL does_lock_overlap(SMB_OFF_T start1, SMB_OFF_T size1, SMB_OFF_T start2, SMB_OFF_T size2)
414 if (start1 >= start2 && start1 <= start2 + size2)
417 if (start1 < start2 && start1 + size1 > start2)
423 /****************************************************************************
424 Delete an entry from the POSIX locking tdb. Returns a copy of the entry being
425 deleted and the number of records that are overlapped by this one, or -1 on error.
426 ****************************************************************************/
428 static int delete_posix_lock_entry(files_struct *fsp, SMB_OFF_T start, SMB_OFF_T size, struct posix_lock *pl)
430 TDB_DATA kbuf = locking_key_fsp(fsp);
432 struct posix_lock *locks;
435 int num_overlapping_records = 0;
439 dbuf = tdb_fetch(posix_lock_tdb, kbuf);
442 DEBUG(10,("delete_posix_lock_entry: tdb_fetch failed !\n"));
446 /* There are existing locks - find a match. */
447 locks = (struct posix_lock *)dbuf.dptr;
448 count = (size_t)(dbuf.dsize / sizeof(struct posix_lock));
451 * Search for and delete the first record that matches the
455 for (i=0; i<count; i++) {
456 struct posix_lock *entry = &locks[i];
458 if (entry->fd == fsp->fh->fd &&
459 entry->start == start &&
460 entry->size == size) {
462 /* Make a copy if requested. */
466 /* Found it - delete it. */
468 tdb_delete(posix_lock_tdb, kbuf);
471 memmove(&locks[i], &locks[i+1], sizeof(struct posix_lock)*((count-1) - i));
473 dbuf.dsize -= sizeof(struct posix_lock);
474 tdb_store(posix_lock_tdb, kbuf, dbuf, TDB_REPLACE);
486 * Count the number of entries that are
487 * overlapped by this unlock request.
490 for (i = 0; i < count; i++) {
491 struct posix_lock *entry = &locks[i];
493 if (fsp->fh->fd == entry->fd &&
494 does_lock_overlap( start, size, entry->start, entry->size))
495 num_overlapping_records++;
498 DEBUG(10,("delete_posix_lock_entry: type = %s: start=%.0f size=%.0f, num_records = %d\n",
499 posix_lock_type_name(pl->lock_type), (double)pl->start, (double)pl->size,
500 (unsigned int)num_overlapping_records ));
502 SAFE_FREE(dbuf.dptr);
504 return num_overlapping_records;
508 SAFE_FREE(dbuf.dptr);
512 /****************************************************************************
513 Utility function to map a lock type correctly depending on the open
515 ****************************************************************************/
517 static int map_posix_lock_type( files_struct *fsp, enum brl_type lock_type)
519 if((lock_type == WRITE_LOCK) && !fsp->can_write) {
521 * Many UNIX's cannot get a write lock on a file opened read-only.
522 * Win32 locking semantics allow this.
523 * Do the best we can and attempt a read-only lock.
525 DEBUG(10,("map_posix_lock_type: Downgrading write lock to read due to read-only file.\n"));
529 /* We no longer open files write-only. */
530 else if((lock_type == READ_LOCK) && !fsp->can_read) {
532 * Ditto for read locks on write only files.
534 DEBUG(10,("map_posix_lock_type: Changing read lock to write due to write-only file.\n"));
540 * This return should be the most normal, as we attempt
541 * to always open files read/write.
544 return (lock_type == READ_LOCK) ? F_RDLCK : F_WRLCK;
547 /****************************************************************************
548 Check to see if the given unsigned lock range is within the possible POSIX
549 range. Modifies the given args to be in range if possible, just returns
551 ****************************************************************************/
553 static BOOL posix_lock_in_range(SMB_OFF_T *offset_out, SMB_OFF_T *count_out,
554 SMB_BIG_UINT u_offset, SMB_BIG_UINT u_count)
556 SMB_OFF_T offset = (SMB_OFF_T)u_offset;
557 SMB_OFF_T count = (SMB_OFF_T)u_count;
560 * For the type of system we are, attempt to
561 * find the maximum positive lock offset as an SMB_OFF_T.
564 #if defined(MAX_POSITIVE_LOCK_OFFSET) /* Some systems have arbitrary limits. */
566 SMB_OFF_T max_positive_lock_offset = (MAX_POSITIVE_LOCK_OFFSET);
568 #elif defined(LARGE_SMB_OFF_T) && !defined(HAVE_BROKEN_FCNTL64_LOCKS)
571 * In this case SMB_OFF_T is 64 bits,
572 * and the underlying system can handle 64 bit signed locks.
575 SMB_OFF_T mask2 = ((SMB_OFF_T)0x4) << (SMB_OFF_T_BITS-4);
576 SMB_OFF_T mask = (mask2<<1);
577 SMB_OFF_T max_positive_lock_offset = ~mask;
579 #else /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
582 * In this case either SMB_OFF_T is 32 bits,
583 * or the underlying system cannot handle 64 bit signed locks.
584 * All offsets & counts must be 2^31 or less.
587 SMB_OFF_T max_positive_lock_offset = 0x7FFFFFFF;
589 #endif /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
592 * POSIX locks of length zero mean lock to end-of-file.
593 * Win32 locks of length zero are point probes. Ignore
594 * any Win32 locks of length zero. JRA.
597 if (count == (SMB_OFF_T)0) {
598 DEBUG(10,("posix_lock_in_range: count = 0, ignoring.\n"));
603 * If the given offset was > max_positive_lock_offset then we cannot map this at all
607 if (u_offset & ~((SMB_BIG_UINT)max_positive_lock_offset)) {
608 DEBUG(10,("posix_lock_in_range: (offset = %.0f) offset > %.0f and we cannot handle this. Ignoring lock.\n",
609 (double)u_offset, (double)((SMB_BIG_UINT)max_positive_lock_offset) ));
614 * We must truncate the count to less than max_positive_lock_offset.
617 if (u_count & ~((SMB_BIG_UINT)max_positive_lock_offset))
618 count = max_positive_lock_offset;
621 * Truncate count to end at max lock offset.
624 if (offset + count < 0 || offset + count > max_positive_lock_offset)
625 count = max_positive_lock_offset - offset;
628 * If we ate all the count, ignore this lock.
632 DEBUG(10,("posix_lock_in_range: Count = 0. Ignoring lock u_offset = %.0f, u_count = %.0f\n",
633 (double)u_offset, (double)u_count ));
638 * The mapping was successful.
641 DEBUG(10,("posix_lock_in_range: offset_out = %.0f, count_out = %.0f\n",
642 (double)offset, (double)count ));
644 *offset_out = offset;
650 /****************************************************************************
651 Actual function that does POSIX locks. Copes with 64 -> 32 bit cruft and
652 broken NFS implementations.
653 ****************************************************************************/
655 static BOOL posix_fcntl_lock(files_struct *fsp, int op, SMB_OFF_T offset, SMB_OFF_T count, int type)
659 DEBUG(8,("posix_fcntl_lock %d %d %.0f %.0f %d\n",fsp->fh->fd,op,(double)offset,(double)count,type));
661 ret = SMB_VFS_LOCK(fsp,fsp->fh->fd,op,offset,count,type);
663 if (!ret && ((errno == EFBIG) || (errno == ENOLCK) || (errno == EINVAL))) {
665 DEBUG(0,("posix_fcntl_lock: WARNING: lock request at offset %.0f, length %.0f returned\n",
666 (double)offset,(double)count));
667 DEBUG(0,("an %s error. This can happen when using 64 bit lock offsets\n", strerror(errno)));
668 DEBUG(0,("on 32 bit NFS mounted file systems.\n"));
671 * If the offset is > 0x7FFFFFFF then this will cause problems on
672 * 32 bit NFS mounted filesystems. Just ignore it.
675 if (offset & ~((SMB_OFF_T)0x7fffffff)) {
676 DEBUG(0,("Offset greater than 31 bits. Returning success.\n"));
680 if (count & ~((SMB_OFF_T)0x7fffffff)) {
681 /* 32 bit NFS file system, retry with smaller offset */
682 DEBUG(0,("Count greater than 31 bits - retrying with 31 bit truncated length.\n"));
685 ret = SMB_VFS_LOCK(fsp,fsp->fh->fd,op,offset,count,type);
689 DEBUG(8,("posix_fcntl_lock: Lock call %s\n", ret ? "successful" : "failed"));
694 /****************************************************************************
695 POSIX function to see if a file region is locked. Returns True if the
696 region is locked, False otherwise.
697 ****************************************************************************/
699 BOOL is_posix_locked(files_struct *fsp, SMB_BIG_UINT u_offset, SMB_BIG_UINT u_count, enum brl_type lock_type)
703 int posix_lock_type = map_posix_lock_type(fsp,lock_type);
705 DEBUG(10,("is_posix_locked: File %s, offset = %.0f, count = %.0f, type = %s\n",
706 fsp->fsp_name, (double)u_offset, (double)u_count, posix_lock_type_name(lock_type) ));
709 * If the requested lock won't fit in the POSIX range, we will
710 * never set it, so presume it is not locked.
713 if(!posix_lock_in_range(&offset, &count, u_offset, u_count))
717 * Note that most UNIX's can *test* for a write lock on
718 * a read-only fd, just not *set* a write lock on a read-only
719 * fd. So we don't need to use map_lock_type here.
722 return posix_fcntl_lock(fsp,SMB_F_GETLK,offset,count,posix_lock_type);
726 * Structure used when splitting a lock range
727 * into a POSIX lock range. Doubly linked list.
731 struct lock_list *next;
732 struct lock_list *prev;
737 /****************************************************************************
738 Create a list of lock ranges that don't overlap a given range. Used in calculating
739 POSIX locks and unlocks. This is a difficult function that requires ASCII art to
741 ****************************************************************************/
743 static struct lock_list *posix_lock_list(TALLOC_CTX *ctx, struct lock_list *lhead, files_struct *fsp)
745 TDB_DATA kbuf = locking_key_fsp(fsp);
747 struct posix_lock *locks;
752 dbuf = tdb_fetch(posix_lock_tdb, kbuf);
757 locks = (struct posix_lock *)dbuf.dptr;
758 num_locks = (size_t)(dbuf.dsize / sizeof(struct posix_lock));
761 * Check the current lock list on this dev/inode pair.
762 * Quit if the list is deleted.
765 DEBUG(10,("posix_lock_list: curr: start=%.0f,size=%.0f\n",
766 (double)lhead->start, (double)lhead->size ));
768 for (i=0; i<num_locks && lhead; i++) {
770 struct posix_lock *lock = &locks[i];
771 struct lock_list *l_curr;
774 * Walk the lock list, checking for overlaps. Note that
775 * the lock list can expand within this loop if the current
776 * range being examined needs to be split.
779 for (l_curr = lhead; l_curr;) {
781 DEBUG(10,("posix_lock_list: lock: fd=%d: start=%.0f,size=%.0f:type=%s", lock->fd,
782 (double)lock->start, (double)lock->size, posix_lock_type_name(lock->lock_type) ));
784 if ( (l_curr->start >= (lock->start + lock->size)) ||
785 (lock->start >= (l_curr->start + l_curr->size))) {
787 /* No overlap with this lock - leave this range alone. */
788 /*********************************************
799 **********************************************/
801 DEBUG(10,("no overlap case.\n" ));
803 l_curr = l_curr->next;
805 } else if ( (l_curr->start >= lock->start) &&
806 (l_curr->start + l_curr->size <= lock->start + lock->size) ) {
809 * This unlock is completely overlapped by this existing lock range
810 * and thus should have no effect (not be unlocked). Delete it from the list.
812 /*********************************************
816 +---------------------------+
818 +---------------------------+
819 **********************************************/
820 /* Save the next pointer */
821 struct lock_list *ul_next = l_curr->next;
823 DEBUG(10,("delete case.\n" ));
825 DLIST_REMOVE(lhead, l_curr);
827 break; /* No more list... */
831 } else if ( (l_curr->start >= lock->start) &&
832 (l_curr->start < lock->start + lock->size) &&
833 (l_curr->start + l_curr->size > lock->start + lock->size) ) {
836 * This unlock overlaps the existing lock range at the high end.
837 * Truncate by moving start to existing range end and reducing size.
839 /*********************************************
850 **********************************************/
852 l_curr->size = (l_curr->start + l_curr->size) - (lock->start + lock->size);
853 l_curr->start = lock->start + lock->size;
855 DEBUG(10,("truncate high case: start=%.0f,size=%.0f\n",
856 (double)l_curr->start, (double)l_curr->size ));
858 l_curr = l_curr->next;
860 } else if ( (l_curr->start < lock->start) &&
861 (l_curr->start + l_curr->size > lock->start) &&
862 (l_curr->start + l_curr->size <= lock->start + lock->size) ) {
865 * This unlock overlaps the existing lock range at the low end.
866 * Truncate by reducing size.
868 /*********************************************
879 **********************************************/
881 l_curr->size = lock->start - l_curr->start;
883 DEBUG(10,("truncate low case: start=%.0f,size=%.0f\n",
884 (double)l_curr->start, (double)l_curr->size ));
886 l_curr = l_curr->next;
888 } else if ( (l_curr->start < lock->start) &&
889 (l_curr->start + l_curr->size > lock->start + lock->size) ) {
891 * Worst case scenario. Unlock request completely overlaps an existing
892 * lock range. Split the request into two, push the new (upper) request
893 * into the dlink list, and continue with the entry after ul_new (as we
894 * know that ul_new will not overlap with this lock).
896 /*********************************************
897 +---------------------------+
899 +---------------------------+
904 +-------+ +---------+
906 +-------+ +---------+
907 **********************************************/
908 struct lock_list *l_new = TALLOC_P(ctx, struct lock_list);
911 DEBUG(0,("posix_lock_list: talloc fail.\n"));
912 return NULL; /* The talloc_destroy takes care of cleanup. */
916 l_new->start = lock->start + lock->size;
917 l_new->size = l_curr->start + l_curr->size - l_new->start;
919 /* Truncate the l_curr. */
920 l_curr->size = lock->start - l_curr->start;
922 DEBUG(10,("split case: curr: start=%.0f,size=%.0f \
923 new: start=%.0f,size=%.0f\n", (double)l_curr->start, (double)l_curr->size,
924 (double)l_new->start, (double)l_new->size ));
927 * Add into the dlink list after the l_curr point - NOT at lhead.
928 * Note we can't use DLINK_ADD here as this inserts at the head of the given list.
931 l_new->prev = l_curr;
932 l_new->next = l_curr->next;
933 l_curr->next = l_new;
935 /* And move after the link we added. */
936 l_curr = l_new->next;
941 * This logic case should never happen. Ensure this is the
942 * case by forcing an abort.... Remove in production.
946 slprintf(msg, sizeof(msg)-1, "logic flaw in cases: l_curr: start = %.0f, size = %.0f : \
947 lock: start = %.0f, size = %.0f\n", (double)l_curr->start, (double)l_curr->size, (double)lock->start, (double)lock->size );
951 } /* end for ( l_curr = lhead; l_curr;) */
952 } /* end for (i=0; i<num_locks && ul_head; i++) */
954 SAFE_FREE(dbuf.dptr);
959 /****************************************************************************
960 POSIX function to acquire a lock. Returns True if the
961 lock could be granted, False if not.
962 ****************************************************************************/
964 BOOL set_posix_lock(files_struct *fsp, SMB_BIG_UINT u_offset, SMB_BIG_UINT u_count, enum brl_type lock_type)
969 size_t entry_num = 0;
971 TALLOC_CTX *l_ctx = NULL;
972 struct lock_list *llist = NULL;
973 struct lock_list *ll = NULL;
974 int posix_lock_type = map_posix_lock_type(fsp,lock_type);
976 DEBUG(5,("set_posix_lock: File %s, offset = %.0f, count = %.0f, type = %s\n",
977 fsp->fsp_name, (double)u_offset, (double)u_count, posix_lock_type_name(lock_type) ));
980 * If the requested lock won't fit in the POSIX range, we will
981 * pretend it was successful.
984 if(!posix_lock_in_range(&offset, &count, u_offset, u_count))
988 * Windows is very strange. It allows read locks to be overlayed
989 * (even over a write lock), but leaves the write lock in force until the first
990 * unlock. It also reference counts the locks. This means the following sequence :
993 * ------------------------------------------------------------------------
994 * WRITE LOCK : start = 2, len = 10
995 * READ LOCK: start =0, len = 10 - FAIL
996 * READ LOCK : start = 0, len = 14
997 * READ LOCK: start =0, len = 10 - FAIL
998 * UNLOCK : start = 2, len = 10
999 * READ LOCK: start =0, len = 10 - OK
1001 * Under POSIX, the same sequence in steps 1 and 2 would not be reference counted, but
1002 * would leave a single read lock over the 0-14 region. In order to
1003 * re-create Windows semantics mapped to POSIX locks, we create multiple TDB
1004 * entries, one for each overlayed lock request. We are guarenteed by the brlock
1005 * semantics that if a write lock is added, then it will be first in the array.
1008 if ((l_ctx = talloc_init("set_posix_lock")) == NULL) {
1009 DEBUG(0,("set_posix_lock: unable to init talloc context.\n"));
1010 return True; /* Not a fatal error. */
1013 if ((ll = TALLOC_P(l_ctx, struct lock_list)) == NULL) {
1014 DEBUG(0,("set_posix_lock: unable to talloc unlock list.\n"));
1015 talloc_destroy(l_ctx);
1016 return True; /* Not a fatal error. */
1020 * Create the initial list entry containing the
1021 * lock we want to add.
1028 DLIST_ADD(llist, ll);
1031 * The following call calculates if there are any
1032 * overlapping locks held by this process on
1033 * fd's open on the same file and splits this list
1034 * into a list of lock ranges that do not overlap with existing
1038 llist = posix_lock_list(l_ctx, llist, fsp);
1041 * Now we have the list of ranges to lock it is safe to add the
1042 * entry into the POSIX lock tdb. We take note of the entry we
1043 * added here in case we have to remove it on POSIX lock fail.
1046 if (!add_posix_lock_entry(fsp,offset,count,posix_lock_type,&entry_num)) {
1047 DEBUG(0,("set_posix_lock: Unable to create posix lock entry !\n"));
1048 talloc_destroy(l_ctx);
1053 * Add the POSIX locks on the list of ranges returned.
1054 * As the lock is supposed to be added atomically, we need to
1055 * back out all the locks if any one of these calls fail.
1058 for (lock_count = 0, ll = llist; ll; ll = ll->next, lock_count++) {
1062 DEBUG(5,("set_posix_lock: Real lock: Type = %s: offset = %.0f, count = %.0f\n",
1063 posix_lock_type_name(posix_lock_type), (double)offset, (double)count ));
1065 if (!posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,posix_lock_type)) {
1066 DEBUG(5,("set_posix_lock: Lock fail !: Type = %s: offset = %.0f, count = %.0f. Errno = %s\n",
1067 posix_lock_type_name(posix_lock_type), (double)offset, (double)count, strerror(errno) ));
1076 * Back out all the POSIX locks we have on fail.
1079 for (ll = llist; lock_count; ll = ll->next, lock_count--) {
1083 DEBUG(5,("set_posix_lock: Backing out locks: Type = %s: offset = %.0f, count = %.0f\n",
1084 posix_lock_type_name(posix_lock_type), (double)offset, (double)count ));
1086 posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,F_UNLCK);
1090 * Remove the tdb entry for this lock.
1093 delete_posix_lock_entry_by_index(fsp,entry_num);
1096 talloc_destroy(l_ctx);
1100 /****************************************************************************
1101 POSIX function to release a lock. Returns True if the
1102 lock could be released, False if not.
1103 ****************************************************************************/
1105 BOOL release_posix_lock(files_struct *fsp, SMB_BIG_UINT u_offset, SMB_BIG_UINT u_count)
1110 TALLOC_CTX *ul_ctx = NULL;
1111 struct lock_list *ulist = NULL;
1112 struct lock_list *ul = NULL;
1113 struct posix_lock deleted_lock;
1114 int num_overlapped_entries;
1116 DEBUG(5,("release_posix_lock: File %s, offset = %.0f, count = %.0f\n",
1117 fsp->fsp_name, (double)u_offset, (double)u_count ));
1120 * If the requested lock won't fit in the POSIX range, we will
1121 * pretend it was successful.
1124 if(!posix_lock_in_range(&offset, &count, u_offset, u_count))
1128 * We treat this as one unlock request for POSIX accounting purposes even
1129 * if it may later be split into multiple smaller POSIX unlock ranges.
1130 * num_overlapped_entries is the number of existing locks that have any
1131 * overlap with this unlock request.
1134 num_overlapped_entries = delete_posix_lock_entry(fsp, offset, count, &deleted_lock);
1136 if (num_overlapped_entries == -1) {
1137 smb_panic("release_posix_lock: unable find entry to delete !\n");
1141 * If num_overlapped_entries is > 0, and the lock_type we just deleted from the tdb was
1142 * a POSIX write lock, then before doing the unlock we need to downgrade
1143 * the POSIX lock to a read lock. This allows any overlapping read locks
1144 * to be atomically maintained.
1147 if (num_overlapped_entries > 0 && deleted_lock.lock_type == F_WRLCK) {
1148 if (!posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,F_RDLCK)) {
1149 DEBUG(0,("release_posix_lock: downgrade of lock failed with error %s !\n", strerror(errno) ));
1154 if ((ul_ctx = talloc_init("release_posix_lock")) == NULL) {
1155 DEBUG(0,("release_posix_lock: unable to init talloc context.\n"));
1156 return True; /* Not a fatal error. */
1159 if ((ul = TALLOC_P(ul_ctx, struct lock_list)) == NULL) {
1160 DEBUG(0,("release_posix_lock: unable to talloc unlock list.\n"));
1161 talloc_destroy(ul_ctx);
1162 return True; /* Not a fatal error. */
1166 * Create the initial list entry containing the
1167 * lock we want to remove.
1174 DLIST_ADD(ulist, ul);
1177 * The following call calculates if there are any
1178 * overlapping locks held by this process on
1179 * fd's open on the same file and creates a
1180 * list of unlock ranges that will allow
1181 * POSIX lock ranges to remain on the file whilst the
1182 * unlocks are performed.
1185 ulist = posix_lock_list(ul_ctx, ulist, fsp);
1188 * Release the POSIX locks on the list of ranges returned.
1191 for(; ulist; ulist = ulist->next) {
1192 offset = ulist->start;
1193 count = ulist->size;
1195 DEBUG(5,("release_posix_lock: Real unlock: offset = %.0f, count = %.0f\n",
1196 (double)offset, (double)count ));
1198 if (!posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,F_UNLCK))
1202 talloc_destroy(ul_ctx);
1207 /****************************************************************************
1208 Remove all lock entries for a specific dev/inode pair from the tdb.
1209 ****************************************************************************/
1211 static void delete_posix_lock_entries(files_struct *fsp)
1213 TDB_DATA kbuf = locking_key_fsp(fsp);
1215 if (tdb_delete(posix_lock_tdb, kbuf) == -1)
1216 DEBUG(0,("delete_close_entries: tdb_delete fail !\n"));
1219 /****************************************************************************
1221 ****************************************************************************/
1223 static void dump_entry(struct posix_lock *pl)
1225 DEBUG(10,("entry: start=%.0f, size=%.0f, type=%d, fd=%i\n",
1226 (double)pl->start, (double)pl->size, (int)pl->lock_type, pl->fd ));
1229 /****************************************************************************
1230 Remove any locks on this fd. Called from file_close().
1231 ****************************************************************************/
1233 void posix_locking_close_file(files_struct *fsp)
1235 struct posix_lock *entries = NULL;
1239 * Optimization for the common case where we are the only
1240 * opener of a file. If all fd entries are our own, we don't
1241 * need to explicitly release all the locks via the POSIX functions,
1242 * we can just remove all the entries in the tdb and allow the
1243 * close to remove the real locks.
1246 count = get_posix_lock_entries(fsp, &entries);
1249 DEBUG(10,("posix_locking_close_file: file %s has no outstanding locks.\n", fsp->fsp_name ));
1253 for (i = 0; i < count; i++) {
1254 if (entries[i].fd != fsp->fh->fd )
1257 dump_entry(&entries[i]);
1261 /* All locks are ours. */
1262 DEBUG(10,("posix_locking_close_file: file %s has %u outstanding locks, but all on one fd.\n",
1263 fsp->fsp_name, (unsigned int)count ));
1265 delete_posix_lock_entries(fsp);
1270 * Difficult case. We need to delete all our locks, whilst leaving
1271 * all other POSIX locks in place.
1274 for (i = 0; i < count; i++) {
1275 struct posix_lock *pl = &entries[i];
1276 if (pl->fd == fsp->fh->fd)
1277 release_posix_lock(fsp, (SMB_BIG_UINT)pl->start, (SMB_BIG_UINT)pl->size );
1282 /*******************************************************************
1283 Create the in-memory POSIX lock databases.
1284 ********************************************************************/
1286 BOOL posix_locking_init(int read_only)
1288 if (posix_lock_tdb && posix_pending_close_tdb)
1291 if (!posix_lock_tdb)
1292 posix_lock_tdb = tdb_open_log(NULL, 0, TDB_INTERNAL,
1293 read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644);
1294 if (!posix_lock_tdb) {
1295 DEBUG(0,("Failed to open POSIX byte range locking database.\n"));
1298 if (!posix_pending_close_tdb)
1299 posix_pending_close_tdb = tdb_open_log(NULL, 0, TDB_INTERNAL,
1300 read_only?O_RDONLY:(O_RDWR|O_CREAT), 0644);
1301 if (!posix_pending_close_tdb) {
1302 DEBUG(0,("Failed to open POSIX pending close database.\n"));
1309 /*******************************************************************
1310 Delete the in-memory POSIX lock databases.
1311 ********************************************************************/
1313 BOOL posix_locking_end(void)
1315 if (posix_lock_tdb && tdb_close(posix_lock_tdb) != 0)
1317 if (posix_pending_close_tdb && tdb_close(posix_pending_close_tdb) != 0)