xref: /dflybsd-src/sys/vfs/hammer/hammer_ioctl.c (revision c4bf625e67439f34b29bfd33c4e2555ffea63ce9)
1 /*
2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/vfs/hammer/hammer_ioctl.c,v 1.7 2008/03/20 06:08:40 dillon Exp $
35  */
36 
37 #include "hammer.h"
38 
39 static int hammer_ioc_prune(hammer_transaction_t trans, hammer_inode_t ip,
40 				struct hammer_ioc_prune *prune);
41 static int hammer_ioc_gethistory(hammer_transaction_t trans, hammer_inode_t ip,
42 				struct hammer_ioc_history *hist);
43 
44 int
45 hammer_ioctl(hammer_inode_t ip, u_long com, caddr_t data, int fflag,
46 	     struct ucred *cred)
47 {
48 	struct hammer_transaction trans;
49 	int error;
50 
51 	error = suser_cred(cred, PRISON_ROOT);
52 
53 	hammer_start_transaction(&trans, ip->hmp);
54 
55 	switch(com) {
56 	case HAMMERIOC_PRUNE:
57 		if (error == 0) {
58 			error = hammer_ioc_prune(&trans, ip,
59 					(struct hammer_ioc_prune *)data);
60 		}
61 		break;
62 	case HAMMERIOC_GETHISTORY:
63 		error = hammer_ioc_gethistory(&trans, ip,
64 					(struct hammer_ioc_history *)data);
65 		break;
66 	case HAMMERIOC_REBLOCK:
67 		error = hammer_ioc_reblock(&trans, ip,
68 					(struct hammer_ioc_reblock *)data);
69 		break;
70 	default:
71 		error = EOPNOTSUPP;
72 		break;
73 	}
74 	hammer_commit_transaction(&trans);
75 	return (error);
76 }
77 
78 /*
79  * Iterate through the specified range of object ids and remove any
80  * deleted records that fall entirely within a prune modulo.
81  *
82  * A reverse iteration is used to prevent overlapping records from being
83  * created during the iteration due to alignments.  This also allows us
84  * to adjust alignments without blowing up the B-Tree.
85  */
86 static int check_prune(struct hammer_ioc_prune *prune, hammer_btree_elm_t elm,
87 			int *realign_cre, int *realign_del);
88 static int realign_prune(struct hammer_ioc_prune *prune, hammer_cursor_t cursor,
89 			int realign_cre, int realign_del);
90 
91 static int
92 hammer_ioc_prune(hammer_transaction_t trans, hammer_inode_t ip,
93 		 struct hammer_ioc_prune *prune)
94 {
95 	struct hammer_cursor cursor;
96 	hammer_btree_elm_t elm;
97 	int error;
98 	int isdir;
99 	int realign_cre;
100 	int realign_del;
101 
102 	if (prune->nelms < 0 || prune->nelms > HAMMER_MAX_PRUNE_ELMS)
103 		return(EINVAL);
104 	if (prune->beg_obj_id >= prune->end_obj_id)
105 		return(EINVAL);
106 	if ((prune->flags & HAMMER_IOC_PRUNE_ALL) && prune->nelms)
107 		return(EINVAL);
108 
109 retry:
110 	error = hammer_init_cursor(trans, &cursor, NULL);
111 	if (error) {
112 		hammer_done_cursor(&cursor);
113 		return(error);
114 	}
115 	cursor.key_beg.obj_id = prune->beg_obj_id;
116 	cursor.key_beg.key = HAMMER_MIN_KEY;
117 	cursor.key_beg.create_tid = 1;
118 	cursor.key_beg.delete_tid = 0;
119 	cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
120 	cursor.key_beg.obj_type = 0;
121 
122 	cursor.key_end.obj_id = prune->cur_obj_id;
123 	cursor.key_end.key = prune->cur_key;
124 	cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
125 	cursor.key_end.delete_tid = 0;
126 	cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
127 	cursor.key_end.obj_type = 0;
128 
129 	cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
130 
131 	error = hammer_btree_last(&cursor);
132 	while (error == 0) {
133 		elm = &cursor.node->ondisk->elms[cursor.index];
134 		prune->cur_obj_id = elm->base.obj_id;
135 		prune->cur_key = elm->base.key;
136 
137 		if (prune->stat_oldest_tid > elm->leaf.base.create_tid)
138 			prune->stat_oldest_tid = elm->leaf.base.create_tid;
139 
140 		if (check_prune(prune, elm, &realign_cre, &realign_del) == 0) {
141 			if (hammer_debug_general & 0x0200) {
142 				kprintf("check %016llx %016llx: DELETE\n",
143 					elm->base.obj_id, elm->base.key);
144 			}
145 
146 			/*
147 			 * NOTE: This can return EDEADLK
148 			 */
149 			isdir = (elm->base.rec_type == HAMMER_RECTYPE_DIRENTRY);
150 
151 			error = hammer_delete_at_cursor(&cursor,
152 							&prune->stat_bytes);
153 			if (error)
154 				break;
155 
156 			if (isdir)
157 				++prune->stat_dirrecords;
158 			else
159 				++prune->stat_rawrecords;
160 		} else if (realign_cre >= 0 || realign_del >= 0) {
161 			error = realign_prune(prune, &cursor,
162 					      realign_cre, realign_del);
163 			if (error == 0) {
164 				cursor.flags |= HAMMER_CURSOR_ATEDISK;
165 				if (hammer_debug_general & 0x0200) {
166 					kprintf("check %016llx %016llx: "
167 						"REALIGN\n",
168 						elm->base.obj_id,
169 						elm->base.key);
170 				}
171 			}
172 		} else {
173 			cursor.flags |= HAMMER_CURSOR_ATEDISK;
174 			if (hammer_debug_general & 0x0100) {
175 				kprintf("check %016llx %016llx: SKIP\n",
176 					elm->base.obj_id, elm->base.key);
177 			}
178 		}
179 		error = hammer_signal_check(trans->hmp);
180 		if (error == 0)
181 			error = hammer_btree_iterate_reverse(&cursor);
182 	}
183 	if (error == ENOENT)
184 		error = 0;
185 	hammer_done_cursor(&cursor);
186 	if (error == EDEADLK)
187 		goto retry;
188 	return(error);
189 }
190 
191 /*
192  * Check pruning list.  The list must be sorted in descending order.
193  */
194 static int
195 check_prune(struct hammer_ioc_prune *prune, hammer_btree_elm_t elm,
196 	    int *realign_cre, int *realign_del)
197 {
198 	struct hammer_ioc_prune_elm *scan;
199 	int i;
200 
201 	*realign_cre = -1;
202 	*realign_del = -1;
203 
204 	/*
205 	 * If pruning everything remove all records with a non-zero
206 	 * delete_tid.
207 	 */
208 	if (prune->flags & HAMMER_IOC_PRUNE_ALL) {
209 		if (elm->base.delete_tid != 0)
210 			return(0);
211 		return(-1);
212 	}
213 
214 	for (i = 0; i < prune->nelms; ++i) {
215 		scan = &prune->elms[i];
216 
217 		/*
218 		 * Locate the scan index covering the create and delete TIDs.
219 		 */
220 		if (*realign_cre < 0 &&
221 		    elm->base.create_tid >= scan->beg_tid &&
222 		    elm->base.create_tid < scan->end_tid) {
223 			*realign_cre = i;
224 		}
225 		if (*realign_del < 0 && elm->base.delete_tid &&
226 		    elm->base.delete_tid > scan->beg_tid &&
227 		    elm->base.delete_tid <= scan->end_tid) {
228 			*realign_del = i;
229 		}
230 
231 		/*
232 		 * Now check for loop termination.
233 		 */
234 		if (elm->base.create_tid >= scan->end_tid ||
235 		    elm->base.delete_tid > scan->end_tid) {
236 			break;
237 		}
238 
239 		/*
240 		 * Now determine if we can delete the record.
241 		 */
242 		if (elm->base.delete_tid &&
243 		    elm->base.create_tid >= scan->beg_tid &&
244 		    elm->base.delete_tid <= scan->end_tid &&
245 		    elm->base.create_tid / scan->mod_tid ==
246 		    elm->base.delete_tid / scan->mod_tid) {
247 			return(0);
248 		}
249 	}
250 	return(-1);
251 }
252 
253 /*
254  * Align the record to cover any gaps created through the deletion of
255  * records within the pruning space.  If we were to just delete the records
256  * there would be gaps which in turn would cause a snapshot that is NOT on
257  * a pruning boundary to appear corrupt to the user.  Forcing alignment
258  * of the create_tid and delete_tid for retained records 'reconnects'
259  * the previously contiguous space, making it contiguous again after the
260  * deletions.
261  *
262  * The use of a reverse iteration allows us to safely align the records and
263  * related elements without creating temporary overlaps.  XXX we should
264  * add ordering dependancies for record buffers to guarantee consistency
265  * during recovery.
266  */
267 static int
268 realign_prune(struct hammer_ioc_prune *prune,
269 	      hammer_cursor_t cursor, int realign_cre, int realign_del)
270 {
271 	hammer_btree_elm_t elm;
272 	hammer_tid_t delta;
273 	hammer_tid_t mod;
274 	hammer_tid_t tid;
275 	int error;
276 
277 	hammer_cursor_downgrade(cursor);
278 
279 	elm = &cursor->node->ondisk->elms[cursor->index];
280 	++prune->stat_realignments;
281 
282 	/*
283 	 * Align the create_tid.  By doing a reverse iteration we guarantee
284 	 * that all records after our current record have already been
285 	 * aligned, allowing us to safely correct the right-hand-boundary
286 	 * (because no record to our right if otherwise exactly matching
287 	 * will have a create_tid to the left of our aligned create_tid).
288 	 *
289 	 * Ordering is important here XXX but disk write ordering for
290 	 * inter-cluster corrections is not currently guaranteed.
291 	 */
292 	error = 0;
293 	if (realign_cre >= 0) {
294 		mod = prune->elms[realign_cre].mod_tid;
295 		delta = elm->leaf.base.create_tid % mod;
296 		if (delta) {
297 			tid = elm->leaf.base.create_tid - delta + mod;
298 
299 			/* can EDEADLK */
300 			error = hammer_btree_correct_rhb(cursor, tid + 1);
301 			if (error == 0) {
302 				error = hammer_btree_extract(cursor,
303 						     HAMMER_CURSOR_GET_RECORD);
304 			}
305 			if (error == 0) {
306 				/* can EDEADLK */
307 				error = hammer_cursor_upgrade(cursor);
308 			}
309 			if (error == 0) {
310 				hammer_modify_buffer(cursor->trans,
311 						     cursor->record_buffer,
312 						     NULL, 0);
313 				cursor->record->base.base.create_tid = tid;
314 				hammer_modify_node(cursor->trans, cursor->node,
315 						   elm, sizeof(*elm));
316 				elm->leaf.base.create_tid = tid;
317 			}
318 		}
319 	}
320 
321 	/*
322 	 * Align the delete_tid.  This only occurs if the record is historical
323 	 * was deleted at some point.  Realigning the delete_tid does not
324 	 * move the record within the B-Tree but may cause it to temporarily
325 	 * overlap a record that has not yet been pruned.
326 	 */
327 	if (error == 0 && realign_del >= 0) {
328 		mod = prune->elms[realign_del].mod_tid;
329 		delta = elm->leaf.base.delete_tid % mod;
330 		hammer_modify_node(cursor->trans, cursor->node,
331 				   elm, sizeof(*elm));
332 		if (delta) {
333 			error = hammer_btree_extract(cursor,
334 						     HAMMER_CURSOR_GET_RECORD);
335 			if (error == 0) {
336 				elm->leaf.base.delete_tid =
337 						elm->leaf.base.delete_tid -
338 						delta + mod;
339 				hammer_modify_buffer(cursor->trans, cursor->record_buffer, &cursor->record->base.base.delete_tid, sizeof(hammer_tid_t));
340 				cursor->record->base.base.delete_tid =
341 						elm->leaf.base.delete_tid;
342 			}
343 		}
344 	}
345 	return (error);
346 }
347 
348 /*
349  * Iterate through an object's inode or an object's records and record
350  * modification TIDs.
351  */
352 static void add_history(hammer_inode_t ip, struct hammer_ioc_history *hist,
353 			hammer_btree_elm_t elm);
354 
355 static
356 int
357 hammer_ioc_gethistory(hammer_transaction_t trans, hammer_inode_t ip,
358 		      struct hammer_ioc_history *hist)
359 {
360 	struct hammer_cursor cursor;
361 	hammer_btree_elm_t elm;
362 	int error;
363 
364 	/*
365 	 * Validate the structure and initialize for return.
366 	 */
367 	if (hist->beg_tid > hist->end_tid)
368 		return(EINVAL);
369 	if (hist->flags & HAMMER_IOC_HISTORY_ATKEY) {
370 		if (hist->key > hist->nxt_key)
371 			return(EINVAL);
372 	}
373 
374 	hist->obj_id = ip->obj_id;
375 	hist->count = 0;
376 	hist->nxt_tid = hist->end_tid;
377 	hist->flags &= ~HAMMER_IOC_HISTORY_NEXT_TID;
378 	hist->flags &= ~HAMMER_IOC_HISTORY_NEXT_KEY;
379 	hist->flags &= ~HAMMER_IOC_HISTORY_EOF;
380 	hist->flags &= ~HAMMER_IOC_HISTORY_UNSYNCED;
381 	if ((ip->flags & HAMMER_INODE_MODMASK) & ~HAMMER_INODE_ITIMES)
382 		hist->flags |= HAMMER_IOC_HISTORY_UNSYNCED;
383 
384 	/*
385 	 * Setup the cursor.  We can't handle undeletable records
386 	 * (create_tid of 0) at the moment.  A create_tid of 0 has
387 	 * a special meaning and cannot be specified in the cursor.
388 	 */
389 	error = hammer_init_cursor(trans, &cursor, &ip->cache[0]);
390 	if (error) {
391 		hammer_done_cursor(&cursor);
392 		return(error);
393 	}
394 
395 	cursor.key_beg.obj_id = hist->obj_id;
396 	cursor.key_beg.create_tid = hist->beg_tid;
397 	cursor.key_beg.delete_tid = 0;
398 	cursor.key_beg.obj_type = 0;
399 	if (cursor.key_beg.create_tid == HAMMER_MIN_TID)
400 		cursor.key_beg.create_tid = 1;
401 
402 	cursor.key_end.obj_id = hist->obj_id;
403 	cursor.key_end.create_tid = hist->end_tid;
404 	cursor.key_end.delete_tid = 0;
405 	cursor.key_end.obj_type = 0;
406 
407 	cursor.flags |= HAMMER_CURSOR_END_EXCLUSIVE;
408 
409 	if (hist->flags & HAMMER_IOC_HISTORY_ATKEY) {
410 		/*
411 		 * key-range within the file.  For a regular file the
412 		 * on-disk key represents BASE+LEN, not BASE, so the
413 		 * first possible record containing the offset 'key'
414 		 * has an on-disk key of (key + 1).
415 		 */
416 		cursor.key_beg.key = hist->key;
417 		cursor.key_end.key = HAMMER_MAX_KEY;
418 
419 		switch(ip->ino_rec.base.base.obj_type) {
420 		case HAMMER_OBJTYPE_REGFILE:
421 			++cursor.key_beg.key;
422 			cursor.key_beg.rec_type = HAMMER_RECTYPE_DATA;
423 			break;
424 		case HAMMER_OBJTYPE_DIRECTORY:
425 			cursor.key_beg.rec_type = HAMMER_RECTYPE_DIRENTRY;
426 			break;
427 		case HAMMER_OBJTYPE_DBFILE:
428 			cursor.key_beg.rec_type = HAMMER_RECTYPE_DB;
429 			break;
430 		default:
431 			error = EINVAL;
432 			break;
433 		}
434 		cursor.key_end.rec_type = cursor.key_beg.rec_type;
435 	} else {
436 		/*
437 		 * The inode itself.
438 		 */
439 		cursor.key_beg.key = 0;
440 		cursor.key_end.key = 0;
441 		cursor.key_beg.rec_type = HAMMER_RECTYPE_INODE;
442 		cursor.key_end.rec_type = HAMMER_RECTYPE_INODE;
443 	}
444 
445 	error = hammer_btree_first(&cursor);
446 	while (error == 0) {
447 		elm = &cursor.node->ondisk->elms[cursor.index];
448 
449 		add_history(ip, hist, elm);
450 		if (hist->flags & (HAMMER_IOC_HISTORY_NEXT_TID |
451 				  HAMMER_IOC_HISTORY_NEXT_KEY |
452 				  HAMMER_IOC_HISTORY_EOF)) {
453 			break;
454 		}
455 		error = hammer_btree_iterate(&cursor);
456 	}
457 	if (error == ENOENT) {
458 		hist->flags |= HAMMER_IOC_HISTORY_EOF;
459 		error = 0;
460 	}
461 	hammer_done_cursor(&cursor);
462 	return(error);
463 }
464 
465 /*
466  * Add the scanned element to the ioctl return structure.  Some special
467  * casing is required for regular files to accomodate how data ranges are
468  * stored on-disk.
469  */
470 static void
471 add_history(hammer_inode_t ip, struct hammer_ioc_history *hist,
472 	    hammer_btree_elm_t elm)
473 {
474 	if (elm->base.btype != HAMMER_BTREE_TYPE_RECORD)
475 		return;
476 	if ((hist->flags & HAMMER_IOC_HISTORY_ATKEY) &&
477 	    ip->ino_rec.base.base.obj_type == HAMMER_OBJTYPE_REGFILE) {
478 		/*
479 		 * Adjust nxt_key
480 		 */
481 		if (hist->nxt_key > elm->leaf.base.key - elm->leaf.data_len &&
482 		    hist->key < elm->leaf.base.key - elm->leaf.data_len) {
483 			hist->nxt_key = elm->leaf.base.key - elm->leaf.data_len;
484 		}
485 		if (hist->nxt_key > elm->leaf.base.key)
486 			hist->nxt_key = elm->leaf.base.key;
487 
488 		/*
489 		 * Record is beyond MAXPHYS, there won't be any more records
490 		 * in the iteration covering the requested offset (key).
491 		 */
492 		if (elm->leaf.base.key >= MAXPHYS &&
493 		    elm->leaf.base.key - MAXPHYS > hist->key) {
494 			hist->flags |= HAMMER_IOC_HISTORY_NEXT_KEY;
495 		}
496 
497 		/*
498 		 * Data-range of record does not cover the key.
499 		 */
500 		if (elm->leaf.base.key - elm->leaf.data_len > hist->key)
501 			return;
502 
503 	} else if (hist->flags & HAMMER_IOC_HISTORY_ATKEY) {
504 		/*
505 		 * Adjust nxt_key
506 		 */
507 		if (hist->nxt_key > elm->leaf.base.key &&
508 		    hist->key < elm->leaf.base.key) {
509 			hist->nxt_key = elm->leaf.base.key;
510 		}
511 
512 		/*
513 		 * Record is beyond the requested key.
514 		 */
515 		if (elm->leaf.base.key > hist->key)
516 			hist->flags |= HAMMER_IOC_HISTORY_NEXT_KEY;
517 	}
518 
519 	/*
520 	 * Add create_tid if it is in-bounds.
521 	 */
522 	if ((hist->count == 0 ||
523 	     elm->leaf.base.create_tid != hist->tid_ary[hist->count - 1]) &&
524 	    elm->leaf.base.create_tid >= hist->beg_tid &&
525 	    elm->leaf.base.create_tid < hist->end_tid) {
526 		if (hist->count == HAMMER_MAX_HISTORY_ELMS) {
527 			hist->nxt_tid = elm->leaf.base.create_tid;
528 			hist->flags |= HAMMER_IOC_HISTORY_NEXT_TID;
529 			return;
530 		}
531 		hist->tid_ary[hist->count++] = elm->leaf.base.create_tid;
532 	}
533 
534 	/*
535 	 * Add delete_tid if it is in-bounds.  Note that different portions
536 	 * of the history may have overlapping data ranges with different
537 	 * delete_tid's.  If this case occurs the delete_tid may match the
538 	 * create_tid of a following record.  XXX
539 	 *
540 	 *	[        ]
541 	 *            [     ]
542 	 */
543 	if (elm->leaf.base.delete_tid &&
544 	    elm->leaf.base.delete_tid >= hist->beg_tid &&
545 	    elm->leaf.base.delete_tid < hist->end_tid) {
546 		if (hist->count == HAMMER_MAX_HISTORY_ELMS) {
547 			hist->nxt_tid = elm->leaf.base.delete_tid;
548 			hist->flags |= HAMMER_IOC_HISTORY_NEXT_TID;
549 			return;
550 		}
551 		hist->tid_ary[hist->count++] = elm->leaf.base.delete_tid;
552 	}
553 }
554 
555