xref: /linux/fs/ocfs2/journal.c (revision bf80eef2212a1e8451df13b52533f4bc31bb4f8e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * journal.c
4  *
5  * Defines functions of journalling api
6  *
7  * Copyright (C) 2003, 2004 Oracle.  All rights reserved.
8  */
9 
10 #include <linux/fs.h>
11 #include <linux/types.h>
12 #include <linux/slab.h>
13 #include <linux/highmem.h>
14 #include <linux/kthread.h>
15 #include <linux/time.h>
16 #include <linux/random.h>
17 #include <linux/delay.h>
18 
19 #include <cluster/masklog.h>
20 
21 #include "ocfs2.h"
22 
23 #include "alloc.h"
24 #include "blockcheck.h"
25 #include "dir.h"
26 #include "dlmglue.h"
27 #include "extent_map.h"
28 #include "heartbeat.h"
29 #include "inode.h"
30 #include "journal.h"
31 #include "localalloc.h"
32 #include "slot_map.h"
33 #include "super.h"
34 #include "sysfile.h"
35 #include "uptodate.h"
36 #include "quota.h"
37 #include "file.h"
38 #include "namei.h"
39 
40 #include "buffer_head_io.h"
41 #include "ocfs2_trace.h"
42 
43 DEFINE_SPINLOCK(trans_inc_lock);
44 
45 #define ORPHAN_SCAN_SCHEDULE_TIMEOUT 300000
46 
47 static int ocfs2_force_read_journal(struct inode *inode);
48 static int ocfs2_recover_node(struct ocfs2_super *osb,
49 			      int node_num, int slot_num);
50 static int __ocfs2_recovery_thread(void *arg);
51 static int ocfs2_commit_cache(struct ocfs2_super *osb);
52 static int __ocfs2_wait_on_mount(struct ocfs2_super *osb, int quota);
53 static int ocfs2_journal_toggle_dirty(struct ocfs2_super *osb,
54 				      int dirty, int replayed);
55 static int ocfs2_trylock_journal(struct ocfs2_super *osb,
56 				 int slot_num);
57 static int ocfs2_recover_orphans(struct ocfs2_super *osb,
58 				 int slot,
59 				 enum ocfs2_orphan_reco_type orphan_reco_type);
60 static int ocfs2_commit_thread(void *arg);
61 static void ocfs2_queue_recovery_completion(struct ocfs2_journal *journal,
62 					    int slot_num,
63 					    struct ocfs2_dinode *la_dinode,
64 					    struct ocfs2_dinode *tl_dinode,
65 					    struct ocfs2_quota_recovery *qrec,
66 					    enum ocfs2_orphan_reco_type orphan_reco_type);
67 
68 static inline int ocfs2_wait_on_mount(struct ocfs2_super *osb)
69 {
70 	return __ocfs2_wait_on_mount(osb, 0);
71 }
72 
73 static inline int ocfs2_wait_on_quotas(struct ocfs2_super *osb)
74 {
75 	return __ocfs2_wait_on_mount(osb, 1);
76 }
77 
78 /*
79  * This replay_map is to track online/offline slots, so we could recover
80  * offline slots during recovery and mount
81  */
82 
83 enum ocfs2_replay_state {
84 	REPLAY_UNNEEDED = 0,	/* Replay is not needed, so ignore this map */
85 	REPLAY_NEEDED, 		/* Replay slots marked in rm_replay_slots */
86 	REPLAY_DONE 		/* Replay was already queued */
87 };
88 
89 struct ocfs2_replay_map {
90 	unsigned int rm_slots;
91 	enum ocfs2_replay_state rm_state;
92 	unsigned char rm_replay_slots[];
93 };
94 
95 static void ocfs2_replay_map_set_state(struct ocfs2_super *osb, int state)
96 {
97 	if (!osb->replay_map)
98 		return;
99 
100 	/* If we've already queued the replay, we don't have any more to do */
101 	if (osb->replay_map->rm_state == REPLAY_DONE)
102 		return;
103 
104 	osb->replay_map->rm_state = state;
105 }
106 
107 int ocfs2_compute_replay_slots(struct ocfs2_super *osb)
108 {
109 	struct ocfs2_replay_map *replay_map;
110 	int i, node_num;
111 
112 	/* If replay map is already set, we don't do it again */
113 	if (osb->replay_map)
114 		return 0;
115 
116 	replay_map = kzalloc(sizeof(struct ocfs2_replay_map) +
117 			     (osb->max_slots * sizeof(char)), GFP_KERNEL);
118 
119 	if (!replay_map) {
120 		mlog_errno(-ENOMEM);
121 		return -ENOMEM;
122 	}
123 
124 	spin_lock(&osb->osb_lock);
125 
126 	replay_map->rm_slots = osb->max_slots;
127 	replay_map->rm_state = REPLAY_UNNEEDED;
128 
129 	/* set rm_replay_slots for offline slot(s) */
130 	for (i = 0; i < replay_map->rm_slots; i++) {
131 		if (ocfs2_slot_to_node_num_locked(osb, i, &node_num) == -ENOENT)
132 			replay_map->rm_replay_slots[i] = 1;
133 	}
134 
135 	osb->replay_map = replay_map;
136 	spin_unlock(&osb->osb_lock);
137 	return 0;
138 }
139 
140 static void ocfs2_queue_replay_slots(struct ocfs2_super *osb,
141 		enum ocfs2_orphan_reco_type orphan_reco_type)
142 {
143 	struct ocfs2_replay_map *replay_map = osb->replay_map;
144 	int i;
145 
146 	if (!replay_map)
147 		return;
148 
149 	if (replay_map->rm_state != REPLAY_NEEDED)
150 		return;
151 
152 	for (i = 0; i < replay_map->rm_slots; i++)
153 		if (replay_map->rm_replay_slots[i])
154 			ocfs2_queue_recovery_completion(osb->journal, i, NULL,
155 							NULL, NULL,
156 							orphan_reco_type);
157 	replay_map->rm_state = REPLAY_DONE;
158 }
159 
160 static void ocfs2_free_replay_slots(struct ocfs2_super *osb)
161 {
162 	struct ocfs2_replay_map *replay_map = osb->replay_map;
163 
164 	if (!osb->replay_map)
165 		return;
166 
167 	kfree(replay_map);
168 	osb->replay_map = NULL;
169 }
170 
171 int ocfs2_recovery_init(struct ocfs2_super *osb)
172 {
173 	struct ocfs2_recovery_map *rm;
174 
175 	mutex_init(&osb->recovery_lock);
176 	osb->disable_recovery = 0;
177 	osb->recovery_thread_task = NULL;
178 	init_waitqueue_head(&osb->recovery_event);
179 
180 	rm = kzalloc(sizeof(struct ocfs2_recovery_map) +
181 		     osb->max_slots * sizeof(unsigned int),
182 		     GFP_KERNEL);
183 	if (!rm) {
184 		mlog_errno(-ENOMEM);
185 		return -ENOMEM;
186 	}
187 
188 	rm->rm_entries = (unsigned int *)((char *)rm +
189 					  sizeof(struct ocfs2_recovery_map));
190 	osb->recovery_map = rm;
191 
192 	return 0;
193 }
194 
195 /* we can't grab the goofy sem lock from inside wait_event, so we use
196  * memory barriers to make sure that we'll see the null task before
197  * being woken up */
198 static int ocfs2_recovery_thread_running(struct ocfs2_super *osb)
199 {
200 	mb();
201 	return osb->recovery_thread_task != NULL;
202 }
203 
204 void ocfs2_recovery_exit(struct ocfs2_super *osb)
205 {
206 	struct ocfs2_recovery_map *rm;
207 
208 	/* disable any new recovery threads and wait for any currently
209 	 * running ones to exit. Do this before setting the vol_state. */
210 	mutex_lock(&osb->recovery_lock);
211 	osb->disable_recovery = 1;
212 	mutex_unlock(&osb->recovery_lock);
213 	wait_event(osb->recovery_event, !ocfs2_recovery_thread_running(osb));
214 
215 	/* At this point, we know that no more recovery threads can be
216 	 * launched, so wait for any recovery completion work to
217 	 * complete. */
218 	if (osb->ocfs2_wq)
219 		flush_workqueue(osb->ocfs2_wq);
220 
221 	/*
222 	 * Now that recovery is shut down, and the osb is about to be
223 	 * freed,  the osb_lock is not taken here.
224 	 */
225 	rm = osb->recovery_map;
226 	/* XXX: Should we bug if there are dirty entries? */
227 
228 	kfree(rm);
229 }
230 
231 static int __ocfs2_recovery_map_test(struct ocfs2_super *osb,
232 				     unsigned int node_num)
233 {
234 	int i;
235 	struct ocfs2_recovery_map *rm = osb->recovery_map;
236 
237 	assert_spin_locked(&osb->osb_lock);
238 
239 	for (i = 0; i < rm->rm_used; i++) {
240 		if (rm->rm_entries[i] == node_num)
241 			return 1;
242 	}
243 
244 	return 0;
245 }
246 
247 /* Behaves like test-and-set.  Returns the previous value */
248 static int ocfs2_recovery_map_set(struct ocfs2_super *osb,
249 				  unsigned int node_num)
250 {
251 	struct ocfs2_recovery_map *rm = osb->recovery_map;
252 
253 	spin_lock(&osb->osb_lock);
254 	if (__ocfs2_recovery_map_test(osb, node_num)) {
255 		spin_unlock(&osb->osb_lock);
256 		return 1;
257 	}
258 
259 	/* XXX: Can this be exploited? Not from o2dlm... */
260 	BUG_ON(rm->rm_used >= osb->max_slots);
261 
262 	rm->rm_entries[rm->rm_used] = node_num;
263 	rm->rm_used++;
264 	spin_unlock(&osb->osb_lock);
265 
266 	return 0;
267 }
268 
269 static void ocfs2_recovery_map_clear(struct ocfs2_super *osb,
270 				     unsigned int node_num)
271 {
272 	int i;
273 	struct ocfs2_recovery_map *rm = osb->recovery_map;
274 
275 	spin_lock(&osb->osb_lock);
276 
277 	for (i = 0; i < rm->rm_used; i++) {
278 		if (rm->rm_entries[i] == node_num)
279 			break;
280 	}
281 
282 	if (i < rm->rm_used) {
283 		/* XXX: be careful with the pointer math */
284 		memmove(&(rm->rm_entries[i]), &(rm->rm_entries[i + 1]),
285 			(rm->rm_used - i - 1) * sizeof(unsigned int));
286 		rm->rm_used--;
287 	}
288 
289 	spin_unlock(&osb->osb_lock);
290 }
291 
292 static int ocfs2_commit_cache(struct ocfs2_super *osb)
293 {
294 	int status = 0;
295 	unsigned int flushed;
296 	struct ocfs2_journal *journal = NULL;
297 
298 	journal = osb->journal;
299 
300 	/* Flush all pending commits and checkpoint the journal. */
301 	down_write(&journal->j_trans_barrier);
302 
303 	flushed = atomic_read(&journal->j_num_trans);
304 	trace_ocfs2_commit_cache_begin(flushed);
305 	if (flushed == 0) {
306 		up_write(&journal->j_trans_barrier);
307 		goto finally;
308 	}
309 
310 	jbd2_journal_lock_updates(journal->j_journal);
311 	status = jbd2_journal_flush(journal->j_journal, 0);
312 	jbd2_journal_unlock_updates(journal->j_journal);
313 	if (status < 0) {
314 		up_write(&journal->j_trans_barrier);
315 		mlog_errno(status);
316 		goto finally;
317 	}
318 
319 	ocfs2_inc_trans_id(journal);
320 
321 	flushed = atomic_read(&journal->j_num_trans);
322 	atomic_set(&journal->j_num_trans, 0);
323 	up_write(&journal->j_trans_barrier);
324 
325 	trace_ocfs2_commit_cache_end(journal->j_trans_id, flushed);
326 
327 	ocfs2_wake_downconvert_thread(osb);
328 	wake_up(&journal->j_checkpointed);
329 finally:
330 	return status;
331 }
332 
333 handle_t *ocfs2_start_trans(struct ocfs2_super *osb, int max_buffs)
334 {
335 	journal_t *journal = osb->journal->j_journal;
336 	handle_t *handle;
337 
338 	BUG_ON(!osb || !osb->journal->j_journal);
339 
340 	if (ocfs2_is_hard_readonly(osb))
341 		return ERR_PTR(-EROFS);
342 
343 	BUG_ON(osb->journal->j_state == OCFS2_JOURNAL_FREE);
344 	BUG_ON(max_buffs <= 0);
345 
346 	/* Nested transaction? Just return the handle... */
347 	if (journal_current_handle())
348 		return jbd2_journal_start(journal, max_buffs);
349 
350 	sb_start_intwrite(osb->sb);
351 
352 	down_read(&osb->journal->j_trans_barrier);
353 
354 	handle = jbd2_journal_start(journal, max_buffs);
355 	if (IS_ERR(handle)) {
356 		up_read(&osb->journal->j_trans_barrier);
357 		sb_end_intwrite(osb->sb);
358 
359 		mlog_errno(PTR_ERR(handle));
360 
361 		if (is_journal_aborted(journal)) {
362 			ocfs2_abort(osb->sb, "Detected aborted journal\n");
363 			handle = ERR_PTR(-EROFS);
364 		}
365 	} else {
366 		if (!ocfs2_mount_local(osb))
367 			atomic_inc(&(osb->journal->j_num_trans));
368 	}
369 
370 	return handle;
371 }
372 
373 int ocfs2_commit_trans(struct ocfs2_super *osb,
374 		       handle_t *handle)
375 {
376 	int ret, nested;
377 	struct ocfs2_journal *journal = osb->journal;
378 
379 	BUG_ON(!handle);
380 
381 	nested = handle->h_ref > 1;
382 	ret = jbd2_journal_stop(handle);
383 	if (ret < 0)
384 		mlog_errno(ret);
385 
386 	if (!nested) {
387 		up_read(&journal->j_trans_barrier);
388 		sb_end_intwrite(osb->sb);
389 	}
390 
391 	return ret;
392 }
393 
394 /*
395  * 'nblocks' is what you want to add to the current transaction.
396  *
397  * This might call jbd2_journal_restart() which will commit dirty buffers
398  * and then restart the transaction. Before calling
399  * ocfs2_extend_trans(), any changed blocks should have been
400  * dirtied. After calling it, all blocks which need to be changed must
401  * go through another set of journal_access/journal_dirty calls.
402  *
403  * WARNING: This will not release any semaphores or disk locks taken
404  * during the transaction, so make sure they were taken *before*
405  * start_trans or we'll have ordering deadlocks.
406  *
407  * WARNING2: Note that we do *not* drop j_trans_barrier here. This is
408  * good because transaction ids haven't yet been recorded on the
409  * cluster locks associated with this handle.
410  */
411 int ocfs2_extend_trans(handle_t *handle, int nblocks)
412 {
413 	int status, old_nblocks;
414 
415 	BUG_ON(!handle);
416 	BUG_ON(nblocks < 0);
417 
418 	if (!nblocks)
419 		return 0;
420 
421 	old_nblocks = jbd2_handle_buffer_credits(handle);
422 
423 	trace_ocfs2_extend_trans(old_nblocks, nblocks);
424 
425 #ifdef CONFIG_OCFS2_DEBUG_FS
426 	status = 1;
427 #else
428 	status = jbd2_journal_extend(handle, nblocks, 0);
429 	if (status < 0) {
430 		mlog_errno(status);
431 		goto bail;
432 	}
433 #endif
434 
435 	if (status > 0) {
436 		trace_ocfs2_extend_trans_restart(old_nblocks + nblocks);
437 		status = jbd2_journal_restart(handle,
438 					      old_nblocks + nblocks);
439 		if (status < 0) {
440 			mlog_errno(status);
441 			goto bail;
442 		}
443 	}
444 
445 	status = 0;
446 bail:
447 	return status;
448 }
449 
450 /*
451  * If we have fewer than thresh credits, extend by OCFS2_MAX_TRANS_DATA.
452  * If that fails, restart the transaction & regain write access for the
453  * buffer head which is used for metadata modifications.
454  * Taken from Ext4: extend_or_restart_transaction()
455  */
456 int ocfs2_allocate_extend_trans(handle_t *handle, int thresh)
457 {
458 	int status, old_nblks;
459 
460 	BUG_ON(!handle);
461 
462 	old_nblks = jbd2_handle_buffer_credits(handle);
463 	trace_ocfs2_allocate_extend_trans(old_nblks, thresh);
464 
465 	if (old_nblks < thresh)
466 		return 0;
467 
468 	status = jbd2_journal_extend(handle, OCFS2_MAX_TRANS_DATA, 0);
469 	if (status < 0) {
470 		mlog_errno(status);
471 		goto bail;
472 	}
473 
474 	if (status > 0) {
475 		status = jbd2_journal_restart(handle, OCFS2_MAX_TRANS_DATA);
476 		if (status < 0)
477 			mlog_errno(status);
478 	}
479 
480 bail:
481 	return status;
482 }
483 
484 
485 struct ocfs2_triggers {
486 	struct jbd2_buffer_trigger_type	ot_triggers;
487 	int				ot_offset;
488 };
489 
490 static inline struct ocfs2_triggers *to_ocfs2_trigger(struct jbd2_buffer_trigger_type *triggers)
491 {
492 	return container_of(triggers, struct ocfs2_triggers, ot_triggers);
493 }
494 
495 static void ocfs2_frozen_trigger(struct jbd2_buffer_trigger_type *triggers,
496 				 struct buffer_head *bh,
497 				 void *data, size_t size)
498 {
499 	struct ocfs2_triggers *ot = to_ocfs2_trigger(triggers);
500 
501 	/*
502 	 * We aren't guaranteed to have the superblock here, so we
503 	 * must unconditionally compute the ecc data.
504 	 * __ocfs2_journal_access() will only set the triggers if
505 	 * metaecc is enabled.
506 	 */
507 	ocfs2_block_check_compute(data, size, data + ot->ot_offset);
508 }
509 
510 /*
511  * Quota blocks have their own trigger because the struct ocfs2_block_check
512  * offset depends on the blocksize.
513  */
514 static void ocfs2_dq_frozen_trigger(struct jbd2_buffer_trigger_type *triggers,
515 				 struct buffer_head *bh,
516 				 void *data, size_t size)
517 {
518 	struct ocfs2_disk_dqtrailer *dqt =
519 		ocfs2_block_dqtrailer(size, data);
520 
521 	/*
522 	 * We aren't guaranteed to have the superblock here, so we
523 	 * must unconditionally compute the ecc data.
524 	 * __ocfs2_journal_access() will only set the triggers if
525 	 * metaecc is enabled.
526 	 */
527 	ocfs2_block_check_compute(data, size, &dqt->dq_check);
528 }
529 
530 /*
531  * Directory blocks also have their own trigger because the
532  * struct ocfs2_block_check offset depends on the blocksize.
533  */
534 static void ocfs2_db_frozen_trigger(struct jbd2_buffer_trigger_type *triggers,
535 				 struct buffer_head *bh,
536 				 void *data, size_t size)
537 {
538 	struct ocfs2_dir_block_trailer *trailer =
539 		ocfs2_dir_trailer_from_size(size, data);
540 
541 	/*
542 	 * We aren't guaranteed to have the superblock here, so we
543 	 * must unconditionally compute the ecc data.
544 	 * __ocfs2_journal_access() will only set the triggers if
545 	 * metaecc is enabled.
546 	 */
547 	ocfs2_block_check_compute(data, size, &trailer->db_check);
548 }
549 
550 static void ocfs2_abort_trigger(struct jbd2_buffer_trigger_type *triggers,
551 				struct buffer_head *bh)
552 {
553 	mlog(ML_ERROR,
554 	     "ocfs2_abort_trigger called by JBD2.  bh = 0x%lx, "
555 	     "bh->b_blocknr = %llu\n",
556 	     (unsigned long)bh,
557 	     (unsigned long long)bh->b_blocknr);
558 
559 	ocfs2_error(bh->b_bdev->bd_super,
560 		    "JBD2 has aborted our journal, ocfs2 cannot continue\n");
561 }
562 
563 static struct ocfs2_triggers di_triggers = {
564 	.ot_triggers = {
565 		.t_frozen = ocfs2_frozen_trigger,
566 		.t_abort = ocfs2_abort_trigger,
567 	},
568 	.ot_offset	= offsetof(struct ocfs2_dinode, i_check),
569 };
570 
571 static struct ocfs2_triggers eb_triggers = {
572 	.ot_triggers = {
573 		.t_frozen = ocfs2_frozen_trigger,
574 		.t_abort = ocfs2_abort_trigger,
575 	},
576 	.ot_offset	= offsetof(struct ocfs2_extent_block, h_check),
577 };
578 
579 static struct ocfs2_triggers rb_triggers = {
580 	.ot_triggers = {
581 		.t_frozen = ocfs2_frozen_trigger,
582 		.t_abort = ocfs2_abort_trigger,
583 	},
584 	.ot_offset	= offsetof(struct ocfs2_refcount_block, rf_check),
585 };
586 
587 static struct ocfs2_triggers gd_triggers = {
588 	.ot_triggers = {
589 		.t_frozen = ocfs2_frozen_trigger,
590 		.t_abort = ocfs2_abort_trigger,
591 	},
592 	.ot_offset	= offsetof(struct ocfs2_group_desc, bg_check),
593 };
594 
595 static struct ocfs2_triggers db_triggers = {
596 	.ot_triggers = {
597 		.t_frozen = ocfs2_db_frozen_trigger,
598 		.t_abort = ocfs2_abort_trigger,
599 	},
600 };
601 
602 static struct ocfs2_triggers xb_triggers = {
603 	.ot_triggers = {
604 		.t_frozen = ocfs2_frozen_trigger,
605 		.t_abort = ocfs2_abort_trigger,
606 	},
607 	.ot_offset	= offsetof(struct ocfs2_xattr_block, xb_check),
608 };
609 
610 static struct ocfs2_triggers dq_triggers = {
611 	.ot_triggers = {
612 		.t_frozen = ocfs2_dq_frozen_trigger,
613 		.t_abort = ocfs2_abort_trigger,
614 	},
615 };
616 
617 static struct ocfs2_triggers dr_triggers = {
618 	.ot_triggers = {
619 		.t_frozen = ocfs2_frozen_trigger,
620 		.t_abort = ocfs2_abort_trigger,
621 	},
622 	.ot_offset	= offsetof(struct ocfs2_dx_root_block, dr_check),
623 };
624 
625 static struct ocfs2_triggers dl_triggers = {
626 	.ot_triggers = {
627 		.t_frozen = ocfs2_frozen_trigger,
628 		.t_abort = ocfs2_abort_trigger,
629 	},
630 	.ot_offset	= offsetof(struct ocfs2_dx_leaf, dl_check),
631 };
632 
633 static int __ocfs2_journal_access(handle_t *handle,
634 				  struct ocfs2_caching_info *ci,
635 				  struct buffer_head *bh,
636 				  struct ocfs2_triggers *triggers,
637 				  int type)
638 {
639 	int status;
640 	struct ocfs2_super *osb =
641 		OCFS2_SB(ocfs2_metadata_cache_get_super(ci));
642 
643 	BUG_ON(!ci || !ci->ci_ops);
644 	BUG_ON(!handle);
645 	BUG_ON(!bh);
646 
647 	trace_ocfs2_journal_access(
648 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
649 		(unsigned long long)bh->b_blocknr, type, bh->b_size);
650 
651 	/* we can safely remove this assertion after testing. */
652 	if (!buffer_uptodate(bh)) {
653 		mlog(ML_ERROR, "giving me a buffer that's not uptodate!\n");
654 		mlog(ML_ERROR, "b_blocknr=%llu, b_state=0x%lx\n",
655 		     (unsigned long long)bh->b_blocknr, bh->b_state);
656 
657 		lock_buffer(bh);
658 		/*
659 		 * A previous transaction with a couple of buffer heads fail
660 		 * to checkpoint, so all the bhs are marked as BH_Write_EIO.
661 		 * For current transaction, the bh is just among those error
662 		 * bhs which previous transaction handle. We can't just clear
663 		 * its BH_Write_EIO and reuse directly, since other bhs are
664 		 * not written to disk yet and that will cause metadata
665 		 * inconsistency. So we should set fs read-only to avoid
666 		 * further damage.
667 		 */
668 		if (buffer_write_io_error(bh) && !buffer_uptodate(bh)) {
669 			unlock_buffer(bh);
670 			return ocfs2_error(osb->sb, "A previous attempt to "
671 					"write this buffer head failed\n");
672 		}
673 		unlock_buffer(bh);
674 	}
675 
676 	/* Set the current transaction information on the ci so
677 	 * that the locking code knows whether it can drop it's locks
678 	 * on this ci or not. We're protected from the commit
679 	 * thread updating the current transaction id until
680 	 * ocfs2_commit_trans() because ocfs2_start_trans() took
681 	 * j_trans_barrier for us. */
682 	ocfs2_set_ci_lock_trans(osb->journal, ci);
683 
684 	ocfs2_metadata_cache_io_lock(ci);
685 	switch (type) {
686 	case OCFS2_JOURNAL_ACCESS_CREATE:
687 	case OCFS2_JOURNAL_ACCESS_WRITE:
688 		status = jbd2_journal_get_write_access(handle, bh);
689 		break;
690 
691 	case OCFS2_JOURNAL_ACCESS_UNDO:
692 		status = jbd2_journal_get_undo_access(handle, bh);
693 		break;
694 
695 	default:
696 		status = -EINVAL;
697 		mlog(ML_ERROR, "Unknown access type!\n");
698 	}
699 	if (!status && ocfs2_meta_ecc(osb) && triggers)
700 		jbd2_journal_set_triggers(bh, &triggers->ot_triggers);
701 	ocfs2_metadata_cache_io_unlock(ci);
702 
703 	if (status < 0)
704 		mlog(ML_ERROR, "Error %d getting %d access to buffer!\n",
705 		     status, type);
706 
707 	return status;
708 }
709 
710 int ocfs2_journal_access_di(handle_t *handle, struct ocfs2_caching_info *ci,
711 			    struct buffer_head *bh, int type)
712 {
713 	return __ocfs2_journal_access(handle, ci, bh, &di_triggers, type);
714 }
715 
716 int ocfs2_journal_access_eb(handle_t *handle, struct ocfs2_caching_info *ci,
717 			    struct buffer_head *bh, int type)
718 {
719 	return __ocfs2_journal_access(handle, ci, bh, &eb_triggers, type);
720 }
721 
722 int ocfs2_journal_access_rb(handle_t *handle, struct ocfs2_caching_info *ci,
723 			    struct buffer_head *bh, int type)
724 {
725 	return __ocfs2_journal_access(handle, ci, bh, &rb_triggers,
726 				      type);
727 }
728 
729 int ocfs2_journal_access_gd(handle_t *handle, struct ocfs2_caching_info *ci,
730 			    struct buffer_head *bh, int type)
731 {
732 	return __ocfs2_journal_access(handle, ci, bh, &gd_triggers, type);
733 }
734 
735 int ocfs2_journal_access_db(handle_t *handle, struct ocfs2_caching_info *ci,
736 			    struct buffer_head *bh, int type)
737 {
738 	return __ocfs2_journal_access(handle, ci, bh, &db_triggers, type);
739 }
740 
741 int ocfs2_journal_access_xb(handle_t *handle, struct ocfs2_caching_info *ci,
742 			    struct buffer_head *bh, int type)
743 {
744 	return __ocfs2_journal_access(handle, ci, bh, &xb_triggers, type);
745 }
746 
747 int ocfs2_journal_access_dq(handle_t *handle, struct ocfs2_caching_info *ci,
748 			    struct buffer_head *bh, int type)
749 {
750 	return __ocfs2_journal_access(handle, ci, bh, &dq_triggers, type);
751 }
752 
753 int ocfs2_journal_access_dr(handle_t *handle, struct ocfs2_caching_info *ci,
754 			    struct buffer_head *bh, int type)
755 {
756 	return __ocfs2_journal_access(handle, ci, bh, &dr_triggers, type);
757 }
758 
759 int ocfs2_journal_access_dl(handle_t *handle, struct ocfs2_caching_info *ci,
760 			    struct buffer_head *bh, int type)
761 {
762 	return __ocfs2_journal_access(handle, ci, bh, &dl_triggers, type);
763 }
764 
765 int ocfs2_journal_access(handle_t *handle, struct ocfs2_caching_info *ci,
766 			 struct buffer_head *bh, int type)
767 {
768 	return __ocfs2_journal_access(handle, ci, bh, NULL, type);
769 }
770 
771 void ocfs2_journal_dirty(handle_t *handle, struct buffer_head *bh)
772 {
773 	int status;
774 
775 	trace_ocfs2_journal_dirty((unsigned long long)bh->b_blocknr);
776 
777 	status = jbd2_journal_dirty_metadata(handle, bh);
778 	if (status) {
779 		mlog_errno(status);
780 		if (!is_handle_aborted(handle)) {
781 			journal_t *journal = handle->h_transaction->t_journal;
782 			struct super_block *sb = bh->b_bdev->bd_super;
783 
784 			mlog(ML_ERROR, "jbd2_journal_dirty_metadata failed. "
785 					"Aborting transaction and journal.\n");
786 			handle->h_err = status;
787 			jbd2_journal_abort_handle(handle);
788 			jbd2_journal_abort(journal, status);
789 			ocfs2_abort(sb, "Journal already aborted.\n");
790 		}
791 	}
792 }
793 
794 #define OCFS2_DEFAULT_COMMIT_INTERVAL	(HZ * JBD2_DEFAULT_MAX_COMMIT_AGE)
795 
796 void ocfs2_set_journal_params(struct ocfs2_super *osb)
797 {
798 	journal_t *journal = osb->journal->j_journal;
799 	unsigned long commit_interval = OCFS2_DEFAULT_COMMIT_INTERVAL;
800 
801 	if (osb->osb_commit_interval)
802 		commit_interval = osb->osb_commit_interval;
803 
804 	write_lock(&journal->j_state_lock);
805 	journal->j_commit_interval = commit_interval;
806 	if (osb->s_mount_opt & OCFS2_MOUNT_BARRIER)
807 		journal->j_flags |= JBD2_BARRIER;
808 	else
809 		journal->j_flags &= ~JBD2_BARRIER;
810 	write_unlock(&journal->j_state_lock);
811 }
812 
813 /*
814  * alloc & initialize skeleton for journal structure.
815  * ocfs2_journal_init() will make fs have journal ability.
816  */
817 int ocfs2_journal_alloc(struct ocfs2_super *osb)
818 {
819 	int status = 0;
820 	struct ocfs2_journal *journal;
821 
822 	journal = kzalloc(sizeof(struct ocfs2_journal), GFP_KERNEL);
823 	if (!journal) {
824 		mlog(ML_ERROR, "unable to alloc journal\n");
825 		status = -ENOMEM;
826 		goto bail;
827 	}
828 	osb->journal = journal;
829 	journal->j_osb = osb;
830 
831 	atomic_set(&journal->j_num_trans, 0);
832 	init_rwsem(&journal->j_trans_barrier);
833 	init_waitqueue_head(&journal->j_checkpointed);
834 	spin_lock_init(&journal->j_lock);
835 	journal->j_trans_id = 1UL;
836 	INIT_LIST_HEAD(&journal->j_la_cleanups);
837 	INIT_WORK(&journal->j_recovery_work, ocfs2_complete_recovery);
838 	journal->j_state = OCFS2_JOURNAL_FREE;
839 
840 bail:
841 	return status;
842 }
843 
844 int ocfs2_journal_init(struct ocfs2_super *osb, int *dirty)
845 {
846 	int status = -1;
847 	struct inode *inode = NULL; /* the journal inode */
848 	journal_t *j_journal = NULL;
849 	struct ocfs2_journal *journal = osb->journal;
850 	struct ocfs2_dinode *di = NULL;
851 	struct buffer_head *bh = NULL;
852 	int inode_lock = 0;
853 
854 	BUG_ON(!journal);
855 	/* already have the inode for our journal */
856 	inode = ocfs2_get_system_file_inode(osb, JOURNAL_SYSTEM_INODE,
857 					    osb->slot_num);
858 	if (inode == NULL) {
859 		status = -EACCES;
860 		mlog_errno(status);
861 		goto done;
862 	}
863 	if (is_bad_inode(inode)) {
864 		mlog(ML_ERROR, "access error (bad inode)\n");
865 		iput(inode);
866 		inode = NULL;
867 		status = -EACCES;
868 		goto done;
869 	}
870 
871 	SET_INODE_JOURNAL(inode);
872 	OCFS2_I(inode)->ip_open_count++;
873 
874 	/* Skip recovery waits here - journal inode metadata never
875 	 * changes in a live cluster so it can be considered an
876 	 * exception to the rule. */
877 	status = ocfs2_inode_lock_full(inode, &bh, 1, OCFS2_META_LOCK_RECOVERY);
878 	if (status < 0) {
879 		if (status != -ERESTARTSYS)
880 			mlog(ML_ERROR, "Could not get lock on journal!\n");
881 		goto done;
882 	}
883 
884 	inode_lock = 1;
885 	di = (struct ocfs2_dinode *)bh->b_data;
886 
887 	if (i_size_read(inode) <  OCFS2_MIN_JOURNAL_SIZE) {
888 		mlog(ML_ERROR, "Journal file size (%lld) is too small!\n",
889 		     i_size_read(inode));
890 		status = -EINVAL;
891 		goto done;
892 	}
893 
894 	trace_ocfs2_journal_init(i_size_read(inode),
895 				 (unsigned long long)inode->i_blocks,
896 				 OCFS2_I(inode)->ip_clusters);
897 
898 	/* call the kernels journal init function now */
899 	j_journal = jbd2_journal_init_inode(inode);
900 	if (j_journal == NULL) {
901 		mlog(ML_ERROR, "Linux journal layer error\n");
902 		status = -EINVAL;
903 		goto done;
904 	}
905 
906 	trace_ocfs2_journal_init_maxlen(j_journal->j_total_len);
907 
908 	*dirty = (le32_to_cpu(di->id1.journal1.ij_flags) &
909 		  OCFS2_JOURNAL_DIRTY_FL);
910 
911 	journal->j_journal = j_journal;
912 	journal->j_journal->j_submit_inode_data_buffers =
913 		jbd2_journal_submit_inode_data_buffers;
914 	journal->j_journal->j_finish_inode_data_buffers =
915 		jbd2_journal_finish_inode_data_buffers;
916 	journal->j_inode = inode;
917 	journal->j_bh = bh;
918 
919 	ocfs2_set_journal_params(osb);
920 
921 	journal->j_state = OCFS2_JOURNAL_LOADED;
922 
923 	status = 0;
924 done:
925 	if (status < 0) {
926 		if (inode_lock)
927 			ocfs2_inode_unlock(inode, 1);
928 		brelse(bh);
929 		if (inode) {
930 			OCFS2_I(inode)->ip_open_count--;
931 			iput(inode);
932 		}
933 	}
934 
935 	return status;
936 }
937 
938 static void ocfs2_bump_recovery_generation(struct ocfs2_dinode *di)
939 {
940 	le32_add_cpu(&(di->id1.journal1.ij_recovery_generation), 1);
941 }
942 
943 static u32 ocfs2_get_recovery_generation(struct ocfs2_dinode *di)
944 {
945 	return le32_to_cpu(di->id1.journal1.ij_recovery_generation);
946 }
947 
948 static int ocfs2_journal_toggle_dirty(struct ocfs2_super *osb,
949 				      int dirty, int replayed)
950 {
951 	int status;
952 	unsigned int flags;
953 	struct ocfs2_journal *journal = osb->journal;
954 	struct buffer_head *bh = journal->j_bh;
955 	struct ocfs2_dinode *fe;
956 
957 	fe = (struct ocfs2_dinode *)bh->b_data;
958 
959 	/* The journal bh on the osb always comes from ocfs2_journal_init()
960 	 * and was validated there inside ocfs2_inode_lock_full().  It's a
961 	 * code bug if we mess it up. */
962 	BUG_ON(!OCFS2_IS_VALID_DINODE(fe));
963 
964 	flags = le32_to_cpu(fe->id1.journal1.ij_flags);
965 	if (dirty)
966 		flags |= OCFS2_JOURNAL_DIRTY_FL;
967 	else
968 		flags &= ~OCFS2_JOURNAL_DIRTY_FL;
969 	fe->id1.journal1.ij_flags = cpu_to_le32(flags);
970 
971 	if (replayed)
972 		ocfs2_bump_recovery_generation(fe);
973 
974 	ocfs2_compute_meta_ecc(osb->sb, bh->b_data, &fe->i_check);
975 	status = ocfs2_write_block(osb, bh, INODE_CACHE(journal->j_inode));
976 	if (status < 0)
977 		mlog_errno(status);
978 
979 	return status;
980 }
981 
982 /*
983  * If the journal has been kmalloc'd it needs to be freed after this
984  * call.
985  */
986 void ocfs2_journal_shutdown(struct ocfs2_super *osb)
987 {
988 	struct ocfs2_journal *journal = NULL;
989 	int status = 0;
990 	struct inode *inode = NULL;
991 	int num_running_trans = 0;
992 
993 	BUG_ON(!osb);
994 
995 	journal = osb->journal;
996 	if (!journal)
997 		goto done;
998 
999 	inode = journal->j_inode;
1000 
1001 	if (journal->j_state != OCFS2_JOURNAL_LOADED)
1002 		goto done;
1003 
1004 	/* need to inc inode use count - jbd2_journal_destroy will iput. */
1005 	if (!igrab(inode))
1006 		BUG();
1007 
1008 	num_running_trans = atomic_read(&(osb->journal->j_num_trans));
1009 	trace_ocfs2_journal_shutdown(num_running_trans);
1010 
1011 	/* Do a commit_cache here. It will flush our journal, *and*
1012 	 * release any locks that are still held.
1013 	 * set the SHUTDOWN flag and release the trans lock.
1014 	 * the commit thread will take the trans lock for us below. */
1015 	journal->j_state = OCFS2_JOURNAL_IN_SHUTDOWN;
1016 
1017 	/* The OCFS2_JOURNAL_IN_SHUTDOWN will signal to commit_cache to not
1018 	 * drop the trans_lock (which we want to hold until we
1019 	 * completely destroy the journal. */
1020 	if (osb->commit_task) {
1021 		/* Wait for the commit thread */
1022 		trace_ocfs2_journal_shutdown_wait(osb->commit_task);
1023 		kthread_stop(osb->commit_task);
1024 		osb->commit_task = NULL;
1025 	}
1026 
1027 	BUG_ON(atomic_read(&(osb->journal->j_num_trans)) != 0);
1028 
1029 	if (ocfs2_mount_local(osb)) {
1030 		jbd2_journal_lock_updates(journal->j_journal);
1031 		status = jbd2_journal_flush(journal->j_journal, 0);
1032 		jbd2_journal_unlock_updates(journal->j_journal);
1033 		if (status < 0)
1034 			mlog_errno(status);
1035 	}
1036 
1037 	/* Shutdown the kernel journal system */
1038 	if (!jbd2_journal_destroy(journal->j_journal) && !status) {
1039 		/*
1040 		 * Do not toggle if flush was unsuccessful otherwise
1041 		 * will leave dirty metadata in a "clean" journal
1042 		 */
1043 		status = ocfs2_journal_toggle_dirty(osb, 0, 0);
1044 		if (status < 0)
1045 			mlog_errno(status);
1046 	}
1047 	journal->j_journal = NULL;
1048 
1049 	OCFS2_I(inode)->ip_open_count--;
1050 
1051 	/* unlock our journal */
1052 	ocfs2_inode_unlock(inode, 1);
1053 
1054 	brelse(journal->j_bh);
1055 	journal->j_bh = NULL;
1056 
1057 	journal->j_state = OCFS2_JOURNAL_FREE;
1058 
1059 done:
1060 	iput(inode);
1061 	kfree(journal);
1062 	osb->journal = NULL;
1063 }
1064 
1065 static void ocfs2_clear_journal_error(struct super_block *sb,
1066 				      journal_t *journal,
1067 				      int slot)
1068 {
1069 	int olderr;
1070 
1071 	olderr = jbd2_journal_errno(journal);
1072 	if (olderr) {
1073 		mlog(ML_ERROR, "File system error %d recorded in "
1074 		     "journal %u.\n", olderr, slot);
1075 		mlog(ML_ERROR, "File system on device %s needs checking.\n",
1076 		     sb->s_id);
1077 
1078 		jbd2_journal_ack_err(journal);
1079 		jbd2_journal_clear_err(journal);
1080 	}
1081 }
1082 
1083 int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
1084 {
1085 	int status = 0;
1086 	struct ocfs2_super *osb;
1087 
1088 	BUG_ON(!journal);
1089 
1090 	osb = journal->j_osb;
1091 
1092 	status = jbd2_journal_load(journal->j_journal);
1093 	if (status < 0) {
1094 		mlog(ML_ERROR, "Failed to load journal!\n");
1095 		goto done;
1096 	}
1097 
1098 	ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
1099 
1100 	if (replayed) {
1101 		jbd2_journal_lock_updates(journal->j_journal);
1102 		status = jbd2_journal_flush(journal->j_journal, 0);
1103 		jbd2_journal_unlock_updates(journal->j_journal);
1104 		if (status < 0)
1105 			mlog_errno(status);
1106 	}
1107 
1108 	status = ocfs2_journal_toggle_dirty(osb, 1, replayed);
1109 	if (status < 0) {
1110 		mlog_errno(status);
1111 		goto done;
1112 	}
1113 
1114 	/* Launch the commit thread */
1115 	if (!local) {
1116 		osb->commit_task = kthread_run(ocfs2_commit_thread, osb,
1117 				"ocfs2cmt-%s", osb->uuid_str);
1118 		if (IS_ERR(osb->commit_task)) {
1119 			status = PTR_ERR(osb->commit_task);
1120 			osb->commit_task = NULL;
1121 			mlog(ML_ERROR, "unable to launch ocfs2commit thread, "
1122 			     "error=%d", status);
1123 			goto done;
1124 		}
1125 	} else
1126 		osb->commit_task = NULL;
1127 
1128 done:
1129 	return status;
1130 }
1131 
1132 
1133 /* 'full' flag tells us whether we clear out all blocks or if we just
1134  * mark the journal clean */
1135 int ocfs2_journal_wipe(struct ocfs2_journal *journal, int full)
1136 {
1137 	int status;
1138 
1139 	BUG_ON(!journal);
1140 
1141 	status = jbd2_journal_wipe(journal->j_journal, full);
1142 	if (status < 0) {
1143 		mlog_errno(status);
1144 		goto bail;
1145 	}
1146 
1147 	status = ocfs2_journal_toggle_dirty(journal->j_osb, 0, 0);
1148 	if (status < 0)
1149 		mlog_errno(status);
1150 
1151 bail:
1152 	return status;
1153 }
1154 
1155 static int ocfs2_recovery_completed(struct ocfs2_super *osb)
1156 {
1157 	int empty;
1158 	struct ocfs2_recovery_map *rm = osb->recovery_map;
1159 
1160 	spin_lock(&osb->osb_lock);
1161 	empty = (rm->rm_used == 0);
1162 	spin_unlock(&osb->osb_lock);
1163 
1164 	return empty;
1165 }
1166 
1167 void ocfs2_wait_for_recovery(struct ocfs2_super *osb)
1168 {
1169 	wait_event(osb->recovery_event, ocfs2_recovery_completed(osb));
1170 }
1171 
1172 /*
1173  * JBD Might read a cached version of another nodes journal file. We
1174  * don't want this as this file changes often and we get no
1175  * notification on those changes. The only way to be sure that we've
1176  * got the most up to date version of those blocks then is to force
1177  * read them off disk. Just searching through the buffer cache won't
1178  * work as there may be pages backing this file which are still marked
1179  * up to date. We know things can't change on this file underneath us
1180  * as we have the lock by now :)
1181  */
1182 static int ocfs2_force_read_journal(struct inode *inode)
1183 {
1184 	int status = 0;
1185 	int i;
1186 	u64 v_blkno, p_blkno, p_blocks, num_blocks;
1187 	struct buffer_head *bh = NULL;
1188 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1189 
1190 	num_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
1191 	v_blkno = 0;
1192 	while (v_blkno < num_blocks) {
1193 		status = ocfs2_extent_map_get_blocks(inode, v_blkno,
1194 						     &p_blkno, &p_blocks, NULL);
1195 		if (status < 0) {
1196 			mlog_errno(status);
1197 			goto bail;
1198 		}
1199 
1200 		for (i = 0; i < p_blocks; i++, p_blkno++) {
1201 			bh = __find_get_block(osb->sb->s_bdev, p_blkno,
1202 					osb->sb->s_blocksize);
1203 			/* block not cached. */
1204 			if (!bh)
1205 				continue;
1206 
1207 			brelse(bh);
1208 			bh = NULL;
1209 			/* We are reading journal data which should not
1210 			 * be put in the uptodate cache.
1211 			 */
1212 			status = ocfs2_read_blocks_sync(osb, p_blkno, 1, &bh);
1213 			if (status < 0) {
1214 				mlog_errno(status);
1215 				goto bail;
1216 			}
1217 
1218 			brelse(bh);
1219 			bh = NULL;
1220 		}
1221 
1222 		v_blkno += p_blocks;
1223 	}
1224 
1225 bail:
1226 	return status;
1227 }
1228 
1229 struct ocfs2_la_recovery_item {
1230 	struct list_head	lri_list;
1231 	int			lri_slot;
1232 	struct ocfs2_dinode	*lri_la_dinode;
1233 	struct ocfs2_dinode	*lri_tl_dinode;
1234 	struct ocfs2_quota_recovery *lri_qrec;
1235 	enum ocfs2_orphan_reco_type  lri_orphan_reco_type;
1236 };
1237 
1238 /* Does the second half of the recovery process. By this point, the
1239  * node is marked clean and can actually be considered recovered,
1240  * hence it's no longer in the recovery map, but there's still some
1241  * cleanup we can do which shouldn't happen within the recovery thread
1242  * as locking in that context becomes very difficult if we are to take
1243  * recovering nodes into account.
1244  *
1245  * NOTE: This function can and will sleep on recovery of other nodes
1246  * during cluster locking, just like any other ocfs2 process.
1247  */
1248 void ocfs2_complete_recovery(struct work_struct *work)
1249 {
1250 	int ret = 0;
1251 	struct ocfs2_journal *journal =
1252 		container_of(work, struct ocfs2_journal, j_recovery_work);
1253 	struct ocfs2_super *osb = journal->j_osb;
1254 	struct ocfs2_dinode *la_dinode, *tl_dinode;
1255 	struct ocfs2_la_recovery_item *item, *n;
1256 	struct ocfs2_quota_recovery *qrec;
1257 	enum ocfs2_orphan_reco_type orphan_reco_type;
1258 	LIST_HEAD(tmp_la_list);
1259 
1260 	trace_ocfs2_complete_recovery(
1261 		(unsigned long long)OCFS2_I(journal->j_inode)->ip_blkno);
1262 
1263 	spin_lock(&journal->j_lock);
1264 	list_splice_init(&journal->j_la_cleanups, &tmp_la_list);
1265 	spin_unlock(&journal->j_lock);
1266 
1267 	list_for_each_entry_safe(item, n, &tmp_la_list, lri_list) {
1268 		list_del_init(&item->lri_list);
1269 
1270 		ocfs2_wait_on_quotas(osb);
1271 
1272 		la_dinode = item->lri_la_dinode;
1273 		tl_dinode = item->lri_tl_dinode;
1274 		qrec = item->lri_qrec;
1275 		orphan_reco_type = item->lri_orphan_reco_type;
1276 
1277 		trace_ocfs2_complete_recovery_slot(item->lri_slot,
1278 			la_dinode ? le64_to_cpu(la_dinode->i_blkno) : 0,
1279 			tl_dinode ? le64_to_cpu(tl_dinode->i_blkno) : 0,
1280 			qrec);
1281 
1282 		if (la_dinode) {
1283 			ret = ocfs2_complete_local_alloc_recovery(osb,
1284 								  la_dinode);
1285 			if (ret < 0)
1286 				mlog_errno(ret);
1287 
1288 			kfree(la_dinode);
1289 		}
1290 
1291 		if (tl_dinode) {
1292 			ret = ocfs2_complete_truncate_log_recovery(osb,
1293 								   tl_dinode);
1294 			if (ret < 0)
1295 				mlog_errno(ret);
1296 
1297 			kfree(tl_dinode);
1298 		}
1299 
1300 		ret = ocfs2_recover_orphans(osb, item->lri_slot,
1301 				orphan_reco_type);
1302 		if (ret < 0)
1303 			mlog_errno(ret);
1304 
1305 		if (qrec) {
1306 			ret = ocfs2_finish_quota_recovery(osb, qrec,
1307 							  item->lri_slot);
1308 			if (ret < 0)
1309 				mlog_errno(ret);
1310 			/* Recovery info is already freed now */
1311 		}
1312 
1313 		kfree(item);
1314 	}
1315 
1316 	trace_ocfs2_complete_recovery_end(ret);
1317 }
1318 
1319 /* NOTE: This function always eats your references to la_dinode and
1320  * tl_dinode, either manually on error, or by passing them to
1321  * ocfs2_complete_recovery */
1322 static void ocfs2_queue_recovery_completion(struct ocfs2_journal *journal,
1323 					    int slot_num,
1324 					    struct ocfs2_dinode *la_dinode,
1325 					    struct ocfs2_dinode *tl_dinode,
1326 					    struct ocfs2_quota_recovery *qrec,
1327 					    enum ocfs2_orphan_reco_type orphan_reco_type)
1328 {
1329 	struct ocfs2_la_recovery_item *item;
1330 
1331 	item = kmalloc(sizeof(struct ocfs2_la_recovery_item), GFP_NOFS);
1332 	if (!item) {
1333 		/* Though we wish to avoid it, we are in fact safe in
1334 		 * skipping local alloc cleanup as fsck.ocfs2 is more
1335 		 * than capable of reclaiming unused space. */
1336 		kfree(la_dinode);
1337 		kfree(tl_dinode);
1338 
1339 		if (qrec)
1340 			ocfs2_free_quota_recovery(qrec);
1341 
1342 		mlog_errno(-ENOMEM);
1343 		return;
1344 	}
1345 
1346 	INIT_LIST_HEAD(&item->lri_list);
1347 	item->lri_la_dinode = la_dinode;
1348 	item->lri_slot = slot_num;
1349 	item->lri_tl_dinode = tl_dinode;
1350 	item->lri_qrec = qrec;
1351 	item->lri_orphan_reco_type = orphan_reco_type;
1352 
1353 	spin_lock(&journal->j_lock);
1354 	list_add_tail(&item->lri_list, &journal->j_la_cleanups);
1355 	queue_work(journal->j_osb->ocfs2_wq, &journal->j_recovery_work);
1356 	spin_unlock(&journal->j_lock);
1357 }
1358 
1359 /* Called by the mount code to queue recovery the last part of
1360  * recovery for it's own and offline slot(s). */
1361 void ocfs2_complete_mount_recovery(struct ocfs2_super *osb)
1362 {
1363 	struct ocfs2_journal *journal = osb->journal;
1364 
1365 	if (ocfs2_is_hard_readonly(osb))
1366 		return;
1367 
1368 	/* No need to queue up our truncate_log as regular cleanup will catch
1369 	 * that */
1370 	ocfs2_queue_recovery_completion(journal, osb->slot_num,
1371 					osb->local_alloc_copy, NULL, NULL,
1372 					ORPHAN_NEED_TRUNCATE);
1373 	ocfs2_schedule_truncate_log_flush(osb, 0);
1374 
1375 	osb->local_alloc_copy = NULL;
1376 
1377 	/* queue to recover orphan slots for all offline slots */
1378 	ocfs2_replay_map_set_state(osb, REPLAY_NEEDED);
1379 	ocfs2_queue_replay_slots(osb, ORPHAN_NEED_TRUNCATE);
1380 	ocfs2_free_replay_slots(osb);
1381 }
1382 
1383 void ocfs2_complete_quota_recovery(struct ocfs2_super *osb)
1384 {
1385 	if (osb->quota_rec) {
1386 		ocfs2_queue_recovery_completion(osb->journal,
1387 						osb->slot_num,
1388 						NULL,
1389 						NULL,
1390 						osb->quota_rec,
1391 						ORPHAN_NEED_TRUNCATE);
1392 		osb->quota_rec = NULL;
1393 	}
1394 }
1395 
1396 static int __ocfs2_recovery_thread(void *arg)
1397 {
1398 	int status, node_num, slot_num;
1399 	struct ocfs2_super *osb = arg;
1400 	struct ocfs2_recovery_map *rm = osb->recovery_map;
1401 	int *rm_quota = NULL;
1402 	int rm_quota_used = 0, i;
1403 	struct ocfs2_quota_recovery *qrec;
1404 
1405 	/* Whether the quota supported. */
1406 	int quota_enabled = OCFS2_HAS_RO_COMPAT_FEATURE(osb->sb,
1407 			OCFS2_FEATURE_RO_COMPAT_USRQUOTA)
1408 		|| OCFS2_HAS_RO_COMPAT_FEATURE(osb->sb,
1409 			OCFS2_FEATURE_RO_COMPAT_GRPQUOTA);
1410 
1411 	status = ocfs2_wait_on_mount(osb);
1412 	if (status < 0) {
1413 		goto bail;
1414 	}
1415 
1416 	if (quota_enabled) {
1417 		rm_quota = kcalloc(osb->max_slots, sizeof(int), GFP_NOFS);
1418 		if (!rm_quota) {
1419 			status = -ENOMEM;
1420 			goto bail;
1421 		}
1422 	}
1423 restart:
1424 	status = ocfs2_super_lock(osb, 1);
1425 	if (status < 0) {
1426 		mlog_errno(status);
1427 		goto bail;
1428 	}
1429 
1430 	status = ocfs2_compute_replay_slots(osb);
1431 	if (status < 0)
1432 		mlog_errno(status);
1433 
1434 	/* queue recovery for our own slot */
1435 	ocfs2_queue_recovery_completion(osb->journal, osb->slot_num, NULL,
1436 					NULL, NULL, ORPHAN_NO_NEED_TRUNCATE);
1437 
1438 	spin_lock(&osb->osb_lock);
1439 	while (rm->rm_used) {
1440 		/* It's always safe to remove entry zero, as we won't
1441 		 * clear it until ocfs2_recover_node() has succeeded. */
1442 		node_num = rm->rm_entries[0];
1443 		spin_unlock(&osb->osb_lock);
1444 		slot_num = ocfs2_node_num_to_slot(osb, node_num);
1445 		trace_ocfs2_recovery_thread_node(node_num, slot_num);
1446 		if (slot_num == -ENOENT) {
1447 			status = 0;
1448 			goto skip_recovery;
1449 		}
1450 
1451 		/* It is a bit subtle with quota recovery. We cannot do it
1452 		 * immediately because we have to obtain cluster locks from
1453 		 * quota files and we also don't want to just skip it because
1454 		 * then quota usage would be out of sync until some node takes
1455 		 * the slot. So we remember which nodes need quota recovery
1456 		 * and when everything else is done, we recover quotas. */
1457 		if (quota_enabled) {
1458 			for (i = 0; i < rm_quota_used
1459 					&& rm_quota[i] != slot_num; i++)
1460 				;
1461 
1462 			if (i == rm_quota_used)
1463 				rm_quota[rm_quota_used++] = slot_num;
1464 		}
1465 
1466 		status = ocfs2_recover_node(osb, node_num, slot_num);
1467 skip_recovery:
1468 		if (!status) {
1469 			ocfs2_recovery_map_clear(osb, node_num);
1470 		} else {
1471 			mlog(ML_ERROR,
1472 			     "Error %d recovering node %d on device (%u,%u)!\n",
1473 			     status, node_num,
1474 			     MAJOR(osb->sb->s_dev), MINOR(osb->sb->s_dev));
1475 			mlog(ML_ERROR, "Volume requires unmount.\n");
1476 		}
1477 
1478 		spin_lock(&osb->osb_lock);
1479 	}
1480 	spin_unlock(&osb->osb_lock);
1481 	trace_ocfs2_recovery_thread_end(status);
1482 
1483 	/* Refresh all journal recovery generations from disk */
1484 	status = ocfs2_check_journals_nolocks(osb);
1485 	status = (status == -EROFS) ? 0 : status;
1486 	if (status < 0)
1487 		mlog_errno(status);
1488 
1489 	/* Now it is right time to recover quotas... We have to do this under
1490 	 * superblock lock so that no one can start using the slot (and crash)
1491 	 * before we recover it */
1492 	if (quota_enabled) {
1493 		for (i = 0; i < rm_quota_used; i++) {
1494 			qrec = ocfs2_begin_quota_recovery(osb, rm_quota[i]);
1495 			if (IS_ERR(qrec)) {
1496 				status = PTR_ERR(qrec);
1497 				mlog_errno(status);
1498 				continue;
1499 			}
1500 			ocfs2_queue_recovery_completion(osb->journal,
1501 					rm_quota[i],
1502 					NULL, NULL, qrec,
1503 					ORPHAN_NEED_TRUNCATE);
1504 		}
1505 	}
1506 
1507 	ocfs2_super_unlock(osb, 1);
1508 
1509 	/* queue recovery for offline slots */
1510 	ocfs2_queue_replay_slots(osb, ORPHAN_NEED_TRUNCATE);
1511 
1512 bail:
1513 	mutex_lock(&osb->recovery_lock);
1514 	if (!status && !ocfs2_recovery_completed(osb)) {
1515 		mutex_unlock(&osb->recovery_lock);
1516 		goto restart;
1517 	}
1518 
1519 	ocfs2_free_replay_slots(osb);
1520 	osb->recovery_thread_task = NULL;
1521 	mb(); /* sync with ocfs2_recovery_thread_running */
1522 	wake_up(&osb->recovery_event);
1523 
1524 	mutex_unlock(&osb->recovery_lock);
1525 
1526 	if (quota_enabled)
1527 		kfree(rm_quota);
1528 
1529 	return status;
1530 }
1531 
1532 void ocfs2_recovery_thread(struct ocfs2_super *osb, int node_num)
1533 {
1534 	mutex_lock(&osb->recovery_lock);
1535 
1536 	trace_ocfs2_recovery_thread(node_num, osb->node_num,
1537 		osb->disable_recovery, osb->recovery_thread_task,
1538 		osb->disable_recovery ?
1539 		-1 : ocfs2_recovery_map_set(osb, node_num));
1540 
1541 	if (osb->disable_recovery)
1542 		goto out;
1543 
1544 	if (osb->recovery_thread_task)
1545 		goto out;
1546 
1547 	osb->recovery_thread_task =  kthread_run(__ocfs2_recovery_thread, osb,
1548 			"ocfs2rec-%s", osb->uuid_str);
1549 	if (IS_ERR(osb->recovery_thread_task)) {
1550 		mlog_errno((int)PTR_ERR(osb->recovery_thread_task));
1551 		osb->recovery_thread_task = NULL;
1552 	}
1553 
1554 out:
1555 	mutex_unlock(&osb->recovery_lock);
1556 	wake_up(&osb->recovery_event);
1557 }
1558 
1559 static int ocfs2_read_journal_inode(struct ocfs2_super *osb,
1560 				    int slot_num,
1561 				    struct buffer_head **bh,
1562 				    struct inode **ret_inode)
1563 {
1564 	int status = -EACCES;
1565 	struct inode *inode = NULL;
1566 
1567 	BUG_ON(slot_num >= osb->max_slots);
1568 
1569 	inode = ocfs2_get_system_file_inode(osb, JOURNAL_SYSTEM_INODE,
1570 					    slot_num);
1571 	if (!inode || is_bad_inode(inode)) {
1572 		mlog_errno(status);
1573 		goto bail;
1574 	}
1575 	SET_INODE_JOURNAL(inode);
1576 
1577 	status = ocfs2_read_inode_block_full(inode, bh, OCFS2_BH_IGNORE_CACHE);
1578 	if (status < 0) {
1579 		mlog_errno(status);
1580 		goto bail;
1581 	}
1582 
1583 	status = 0;
1584 
1585 bail:
1586 	if (inode) {
1587 		if (status || !ret_inode)
1588 			iput(inode);
1589 		else
1590 			*ret_inode = inode;
1591 	}
1592 	return status;
1593 }
1594 
1595 /* Does the actual journal replay and marks the journal inode as
1596  * clean. Will only replay if the journal inode is marked dirty. */
1597 static int ocfs2_replay_journal(struct ocfs2_super *osb,
1598 				int node_num,
1599 				int slot_num)
1600 {
1601 	int status;
1602 	int got_lock = 0;
1603 	unsigned int flags;
1604 	struct inode *inode = NULL;
1605 	struct ocfs2_dinode *fe;
1606 	journal_t *journal = NULL;
1607 	struct buffer_head *bh = NULL;
1608 	u32 slot_reco_gen;
1609 
1610 	status = ocfs2_read_journal_inode(osb, slot_num, &bh, &inode);
1611 	if (status) {
1612 		mlog_errno(status);
1613 		goto done;
1614 	}
1615 
1616 	fe = (struct ocfs2_dinode *)bh->b_data;
1617 	slot_reco_gen = ocfs2_get_recovery_generation(fe);
1618 	brelse(bh);
1619 	bh = NULL;
1620 
1621 	/*
1622 	 * As the fs recovery is asynchronous, there is a small chance that
1623 	 * another node mounted (and recovered) the slot before the recovery
1624 	 * thread could get the lock. To handle that, we dirty read the journal
1625 	 * inode for that slot to get the recovery generation. If it is
1626 	 * different than what we expected, the slot has been recovered.
1627 	 * If not, it needs recovery.
1628 	 */
1629 	if (osb->slot_recovery_generations[slot_num] != slot_reco_gen) {
1630 		trace_ocfs2_replay_journal_recovered(slot_num,
1631 		     osb->slot_recovery_generations[slot_num], slot_reco_gen);
1632 		osb->slot_recovery_generations[slot_num] = slot_reco_gen;
1633 		status = -EBUSY;
1634 		goto done;
1635 	}
1636 
1637 	/* Continue with recovery as the journal has not yet been recovered */
1638 
1639 	status = ocfs2_inode_lock_full(inode, &bh, 1, OCFS2_META_LOCK_RECOVERY);
1640 	if (status < 0) {
1641 		trace_ocfs2_replay_journal_lock_err(status);
1642 		if (status != -ERESTARTSYS)
1643 			mlog(ML_ERROR, "Could not lock journal!\n");
1644 		goto done;
1645 	}
1646 	got_lock = 1;
1647 
1648 	fe = (struct ocfs2_dinode *) bh->b_data;
1649 
1650 	flags = le32_to_cpu(fe->id1.journal1.ij_flags);
1651 	slot_reco_gen = ocfs2_get_recovery_generation(fe);
1652 
1653 	if (!(flags & OCFS2_JOURNAL_DIRTY_FL)) {
1654 		trace_ocfs2_replay_journal_skip(node_num);
1655 		/* Refresh recovery generation for the slot */
1656 		osb->slot_recovery_generations[slot_num] = slot_reco_gen;
1657 		goto done;
1658 	}
1659 
1660 	/* we need to run complete recovery for offline orphan slots */
1661 	ocfs2_replay_map_set_state(osb, REPLAY_NEEDED);
1662 
1663 	printk(KERN_NOTICE "ocfs2: Begin replay journal (node %d, slot %d) on "\
1664 	       "device (%u,%u)\n", node_num, slot_num, MAJOR(osb->sb->s_dev),
1665 	       MINOR(osb->sb->s_dev));
1666 
1667 	OCFS2_I(inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
1668 
1669 	status = ocfs2_force_read_journal(inode);
1670 	if (status < 0) {
1671 		mlog_errno(status);
1672 		goto done;
1673 	}
1674 
1675 	journal = jbd2_journal_init_inode(inode);
1676 	if (journal == NULL) {
1677 		mlog(ML_ERROR, "Linux journal layer error\n");
1678 		status = -EIO;
1679 		goto done;
1680 	}
1681 
1682 	status = jbd2_journal_load(journal);
1683 	if (status < 0) {
1684 		mlog_errno(status);
1685 		BUG_ON(!igrab(inode));
1686 		jbd2_journal_destroy(journal);
1687 		goto done;
1688 	}
1689 
1690 	ocfs2_clear_journal_error(osb->sb, journal, slot_num);
1691 
1692 	/* wipe the journal */
1693 	jbd2_journal_lock_updates(journal);
1694 	status = jbd2_journal_flush(journal, 0);
1695 	jbd2_journal_unlock_updates(journal);
1696 	if (status < 0)
1697 		mlog_errno(status);
1698 
1699 	/* This will mark the node clean */
1700 	flags = le32_to_cpu(fe->id1.journal1.ij_flags);
1701 	flags &= ~OCFS2_JOURNAL_DIRTY_FL;
1702 	fe->id1.journal1.ij_flags = cpu_to_le32(flags);
1703 
1704 	/* Increment recovery generation to indicate successful recovery */
1705 	ocfs2_bump_recovery_generation(fe);
1706 	osb->slot_recovery_generations[slot_num] =
1707 					ocfs2_get_recovery_generation(fe);
1708 
1709 	ocfs2_compute_meta_ecc(osb->sb, bh->b_data, &fe->i_check);
1710 	status = ocfs2_write_block(osb, bh, INODE_CACHE(inode));
1711 	if (status < 0)
1712 		mlog_errno(status);
1713 
1714 	BUG_ON(!igrab(inode));
1715 
1716 	jbd2_journal_destroy(journal);
1717 
1718 	printk(KERN_NOTICE "ocfs2: End replay journal (node %d, slot %d) on "\
1719 	       "device (%u,%u)\n", node_num, slot_num, MAJOR(osb->sb->s_dev),
1720 	       MINOR(osb->sb->s_dev));
1721 done:
1722 	/* drop the lock on this nodes journal */
1723 	if (got_lock)
1724 		ocfs2_inode_unlock(inode, 1);
1725 
1726 	iput(inode);
1727 	brelse(bh);
1728 
1729 	return status;
1730 }
1731 
1732 /*
1733  * Do the most important parts of node recovery:
1734  *  - Replay it's journal
1735  *  - Stamp a clean local allocator file
1736  *  - Stamp a clean truncate log
1737  *  - Mark the node clean
1738  *
1739  * If this function completes without error, a node in OCFS2 can be
1740  * said to have been safely recovered. As a result, failure during the
1741  * second part of a nodes recovery process (local alloc recovery) is
1742  * far less concerning.
1743  */
1744 static int ocfs2_recover_node(struct ocfs2_super *osb,
1745 			      int node_num, int slot_num)
1746 {
1747 	int status = 0;
1748 	struct ocfs2_dinode *la_copy = NULL;
1749 	struct ocfs2_dinode *tl_copy = NULL;
1750 
1751 	trace_ocfs2_recover_node(node_num, slot_num, osb->node_num);
1752 
1753 	/* Should not ever be called to recover ourselves -- in that
1754 	 * case we should've called ocfs2_journal_load instead. */
1755 	BUG_ON(osb->node_num == node_num);
1756 
1757 	status = ocfs2_replay_journal(osb, node_num, slot_num);
1758 	if (status < 0) {
1759 		if (status == -EBUSY) {
1760 			trace_ocfs2_recover_node_skip(slot_num, node_num);
1761 			status = 0;
1762 			goto done;
1763 		}
1764 		mlog_errno(status);
1765 		goto done;
1766 	}
1767 
1768 	/* Stamp a clean local alloc file AFTER recovering the journal... */
1769 	status = ocfs2_begin_local_alloc_recovery(osb, slot_num, &la_copy);
1770 	if (status < 0) {
1771 		mlog_errno(status);
1772 		goto done;
1773 	}
1774 
1775 	/* An error from begin_truncate_log_recovery is not
1776 	 * serious enough to warrant halting the rest of
1777 	 * recovery. */
1778 	status = ocfs2_begin_truncate_log_recovery(osb, slot_num, &tl_copy);
1779 	if (status < 0)
1780 		mlog_errno(status);
1781 
1782 	/* Likewise, this would be a strange but ultimately not so
1783 	 * harmful place to get an error... */
1784 	status = ocfs2_clear_slot(osb, slot_num);
1785 	if (status < 0)
1786 		mlog_errno(status);
1787 
1788 	/* This will kfree the memory pointed to by la_copy and tl_copy */
1789 	ocfs2_queue_recovery_completion(osb->journal, slot_num, la_copy,
1790 					tl_copy, NULL, ORPHAN_NEED_TRUNCATE);
1791 
1792 	status = 0;
1793 done:
1794 
1795 	return status;
1796 }
1797 
1798 /* Test node liveness by trylocking his journal. If we get the lock,
1799  * we drop it here. Return 0 if we got the lock, -EAGAIN if node is
1800  * still alive (we couldn't get the lock) and < 0 on error. */
1801 static int ocfs2_trylock_journal(struct ocfs2_super *osb,
1802 				 int slot_num)
1803 {
1804 	int status, flags;
1805 	struct inode *inode = NULL;
1806 
1807 	inode = ocfs2_get_system_file_inode(osb, JOURNAL_SYSTEM_INODE,
1808 					    slot_num);
1809 	if (inode == NULL) {
1810 		mlog(ML_ERROR, "access error\n");
1811 		status = -EACCES;
1812 		goto bail;
1813 	}
1814 	if (is_bad_inode(inode)) {
1815 		mlog(ML_ERROR, "access error (bad inode)\n");
1816 		iput(inode);
1817 		inode = NULL;
1818 		status = -EACCES;
1819 		goto bail;
1820 	}
1821 	SET_INODE_JOURNAL(inode);
1822 
1823 	flags = OCFS2_META_LOCK_RECOVERY | OCFS2_META_LOCK_NOQUEUE;
1824 	status = ocfs2_inode_lock_full(inode, NULL, 1, flags);
1825 	if (status < 0) {
1826 		if (status != -EAGAIN)
1827 			mlog_errno(status);
1828 		goto bail;
1829 	}
1830 
1831 	ocfs2_inode_unlock(inode, 1);
1832 bail:
1833 	iput(inode);
1834 
1835 	return status;
1836 }
1837 
1838 /* Call this underneath ocfs2_super_lock. It also assumes that the
1839  * slot info struct has been updated from disk. */
1840 int ocfs2_mark_dead_nodes(struct ocfs2_super *osb)
1841 {
1842 	unsigned int node_num;
1843 	int status, i;
1844 	u32 gen;
1845 	struct buffer_head *bh = NULL;
1846 	struct ocfs2_dinode *di;
1847 
1848 	/* This is called with the super block cluster lock, so we
1849 	 * know that the slot map can't change underneath us. */
1850 
1851 	for (i = 0; i < osb->max_slots; i++) {
1852 		/* Read journal inode to get the recovery generation */
1853 		status = ocfs2_read_journal_inode(osb, i, &bh, NULL);
1854 		if (status) {
1855 			mlog_errno(status);
1856 			goto bail;
1857 		}
1858 		di = (struct ocfs2_dinode *)bh->b_data;
1859 		gen = ocfs2_get_recovery_generation(di);
1860 		brelse(bh);
1861 		bh = NULL;
1862 
1863 		spin_lock(&osb->osb_lock);
1864 		osb->slot_recovery_generations[i] = gen;
1865 
1866 		trace_ocfs2_mark_dead_nodes(i,
1867 					    osb->slot_recovery_generations[i]);
1868 
1869 		if (i == osb->slot_num) {
1870 			spin_unlock(&osb->osb_lock);
1871 			continue;
1872 		}
1873 
1874 		status = ocfs2_slot_to_node_num_locked(osb, i, &node_num);
1875 		if (status == -ENOENT) {
1876 			spin_unlock(&osb->osb_lock);
1877 			continue;
1878 		}
1879 
1880 		if (__ocfs2_recovery_map_test(osb, node_num)) {
1881 			spin_unlock(&osb->osb_lock);
1882 			continue;
1883 		}
1884 		spin_unlock(&osb->osb_lock);
1885 
1886 		/* Ok, we have a slot occupied by another node which
1887 		 * is not in the recovery map. We trylock his journal
1888 		 * file here to test if he's alive. */
1889 		status = ocfs2_trylock_journal(osb, i);
1890 		if (!status) {
1891 			/* Since we're called from mount, we know that
1892 			 * the recovery thread can't race us on
1893 			 * setting / checking the recovery bits. */
1894 			ocfs2_recovery_thread(osb, node_num);
1895 		} else if ((status < 0) && (status != -EAGAIN)) {
1896 			mlog_errno(status);
1897 			goto bail;
1898 		}
1899 	}
1900 
1901 	status = 0;
1902 bail:
1903 	return status;
1904 }
1905 
1906 /*
1907  * Scan timer should get fired every ORPHAN_SCAN_SCHEDULE_TIMEOUT. Add some
1908  * randomness to the timeout to minimize multple nodes firing the timer at the
1909  * same time.
1910  */
1911 static inline unsigned long ocfs2_orphan_scan_timeout(void)
1912 {
1913 	unsigned long time;
1914 
1915 	get_random_bytes(&time, sizeof(time));
1916 	time = ORPHAN_SCAN_SCHEDULE_TIMEOUT + (time % 5000);
1917 	return msecs_to_jiffies(time);
1918 }
1919 
1920 /*
1921  * ocfs2_queue_orphan_scan calls ocfs2_queue_recovery_completion for
1922  * every slot, queuing a recovery of the slot on the ocfs2_wq thread. This
1923  * is done to catch any orphans that are left over in orphan directories.
1924  *
1925  * It scans all slots, even ones that are in use. It does so to handle the
1926  * case described below:
1927  *
1928  *   Node 1 has an inode it was using. The dentry went away due to memory
1929  *   pressure.  Node 1 closes the inode, but it's on the free list. The node
1930  *   has the open lock.
1931  *   Node 2 unlinks the inode. It grabs the dentry lock to notify others,
1932  *   but node 1 has no dentry and doesn't get the message. It trylocks the
1933  *   open lock, sees that another node has a PR, and does nothing.
1934  *   Later node 2 runs its orphan dir. It igets the inode, trylocks the
1935  *   open lock, sees the PR still, and does nothing.
1936  *   Basically, we have to trigger an orphan iput on node 1. The only way
1937  *   for this to happen is if node 1 runs node 2's orphan dir.
1938  *
1939  * ocfs2_queue_orphan_scan gets called every ORPHAN_SCAN_SCHEDULE_TIMEOUT
1940  * seconds.  It gets an EX lock on os_lockres and checks sequence number
1941  * stored in LVB. If the sequence number has changed, it means some other
1942  * node has done the scan.  This node skips the scan and tracks the
1943  * sequence number.  If the sequence number didn't change, it means a scan
1944  * hasn't happened.  The node queues a scan and increments the
1945  * sequence number in the LVB.
1946  */
1947 static void ocfs2_queue_orphan_scan(struct ocfs2_super *osb)
1948 {
1949 	struct ocfs2_orphan_scan *os;
1950 	int status, i;
1951 	u32 seqno = 0;
1952 
1953 	os = &osb->osb_orphan_scan;
1954 
1955 	if (atomic_read(&os->os_state) == ORPHAN_SCAN_INACTIVE)
1956 		goto out;
1957 
1958 	trace_ocfs2_queue_orphan_scan_begin(os->os_count, os->os_seqno,
1959 					    atomic_read(&os->os_state));
1960 
1961 	status = ocfs2_orphan_scan_lock(osb, &seqno);
1962 	if (status < 0) {
1963 		if (status != -EAGAIN)
1964 			mlog_errno(status);
1965 		goto out;
1966 	}
1967 
1968 	/* Do no queue the tasks if the volume is being umounted */
1969 	if (atomic_read(&os->os_state) == ORPHAN_SCAN_INACTIVE)
1970 		goto unlock;
1971 
1972 	if (os->os_seqno != seqno) {
1973 		os->os_seqno = seqno;
1974 		goto unlock;
1975 	}
1976 
1977 	for (i = 0; i < osb->max_slots; i++)
1978 		ocfs2_queue_recovery_completion(osb->journal, i, NULL, NULL,
1979 						NULL, ORPHAN_NO_NEED_TRUNCATE);
1980 	/*
1981 	 * We queued a recovery on orphan slots, increment the sequence
1982 	 * number and update LVB so other node will skip the scan for a while
1983 	 */
1984 	seqno++;
1985 	os->os_count++;
1986 	os->os_scantime = ktime_get_seconds();
1987 unlock:
1988 	ocfs2_orphan_scan_unlock(osb, seqno);
1989 out:
1990 	trace_ocfs2_queue_orphan_scan_end(os->os_count, os->os_seqno,
1991 					  atomic_read(&os->os_state));
1992 	return;
1993 }
1994 
1995 /* Worker task that gets fired every ORPHAN_SCAN_SCHEDULE_TIMEOUT millsec */
1996 static void ocfs2_orphan_scan_work(struct work_struct *work)
1997 {
1998 	struct ocfs2_orphan_scan *os;
1999 	struct ocfs2_super *osb;
2000 
2001 	os = container_of(work, struct ocfs2_orphan_scan,
2002 			  os_orphan_scan_work.work);
2003 	osb = os->os_osb;
2004 
2005 	mutex_lock(&os->os_lock);
2006 	ocfs2_queue_orphan_scan(osb);
2007 	if (atomic_read(&os->os_state) == ORPHAN_SCAN_ACTIVE)
2008 		queue_delayed_work(osb->ocfs2_wq, &os->os_orphan_scan_work,
2009 				      ocfs2_orphan_scan_timeout());
2010 	mutex_unlock(&os->os_lock);
2011 }
2012 
2013 void ocfs2_orphan_scan_stop(struct ocfs2_super *osb)
2014 {
2015 	struct ocfs2_orphan_scan *os;
2016 
2017 	os = &osb->osb_orphan_scan;
2018 	if (atomic_read(&os->os_state) == ORPHAN_SCAN_ACTIVE) {
2019 		atomic_set(&os->os_state, ORPHAN_SCAN_INACTIVE);
2020 		mutex_lock(&os->os_lock);
2021 		cancel_delayed_work(&os->os_orphan_scan_work);
2022 		mutex_unlock(&os->os_lock);
2023 	}
2024 }
2025 
2026 void ocfs2_orphan_scan_init(struct ocfs2_super *osb)
2027 {
2028 	struct ocfs2_orphan_scan *os;
2029 
2030 	os = &osb->osb_orphan_scan;
2031 	os->os_osb = osb;
2032 	os->os_count = 0;
2033 	os->os_seqno = 0;
2034 	mutex_init(&os->os_lock);
2035 	INIT_DELAYED_WORK(&os->os_orphan_scan_work, ocfs2_orphan_scan_work);
2036 }
2037 
2038 void ocfs2_orphan_scan_start(struct ocfs2_super *osb)
2039 {
2040 	struct ocfs2_orphan_scan *os;
2041 
2042 	os = &osb->osb_orphan_scan;
2043 	os->os_scantime = ktime_get_seconds();
2044 	if (ocfs2_is_hard_readonly(osb) || ocfs2_mount_local(osb))
2045 		atomic_set(&os->os_state, ORPHAN_SCAN_INACTIVE);
2046 	else {
2047 		atomic_set(&os->os_state, ORPHAN_SCAN_ACTIVE);
2048 		queue_delayed_work(osb->ocfs2_wq, &os->os_orphan_scan_work,
2049 				   ocfs2_orphan_scan_timeout());
2050 	}
2051 }
2052 
2053 struct ocfs2_orphan_filldir_priv {
2054 	struct dir_context	ctx;
2055 	struct inode		*head;
2056 	struct ocfs2_super	*osb;
2057 	enum ocfs2_orphan_reco_type orphan_reco_type;
2058 };
2059 
2060 static bool ocfs2_orphan_filldir(struct dir_context *ctx, const char *name,
2061 				int name_len, loff_t pos, u64 ino,
2062 				unsigned type)
2063 {
2064 	struct ocfs2_orphan_filldir_priv *p =
2065 		container_of(ctx, struct ocfs2_orphan_filldir_priv, ctx);
2066 	struct inode *iter;
2067 
2068 	if (name_len == 1 && !strncmp(".", name, 1))
2069 		return true;
2070 	if (name_len == 2 && !strncmp("..", name, 2))
2071 		return true;
2072 
2073 	/* do not include dio entry in case of orphan scan */
2074 	if ((p->orphan_reco_type == ORPHAN_NO_NEED_TRUNCATE) &&
2075 			(!strncmp(name, OCFS2_DIO_ORPHAN_PREFIX,
2076 			OCFS2_DIO_ORPHAN_PREFIX_LEN)))
2077 		return true;
2078 
2079 	/* Skip bad inodes so that recovery can continue */
2080 	iter = ocfs2_iget(p->osb, ino,
2081 			  OCFS2_FI_FLAG_ORPHAN_RECOVERY, 0);
2082 	if (IS_ERR(iter))
2083 		return true;
2084 
2085 	if (!strncmp(name, OCFS2_DIO_ORPHAN_PREFIX,
2086 			OCFS2_DIO_ORPHAN_PREFIX_LEN))
2087 		OCFS2_I(iter)->ip_flags |= OCFS2_INODE_DIO_ORPHAN_ENTRY;
2088 
2089 	/* Skip inodes which are already added to recover list, since dio may
2090 	 * happen concurrently with unlink/rename */
2091 	if (OCFS2_I(iter)->ip_next_orphan) {
2092 		iput(iter);
2093 		return true;
2094 	}
2095 
2096 	trace_ocfs2_orphan_filldir((unsigned long long)OCFS2_I(iter)->ip_blkno);
2097 	/* No locking is required for the next_orphan queue as there
2098 	 * is only ever a single process doing orphan recovery. */
2099 	OCFS2_I(iter)->ip_next_orphan = p->head;
2100 	p->head = iter;
2101 
2102 	return true;
2103 }
2104 
2105 static int ocfs2_queue_orphans(struct ocfs2_super *osb,
2106 			       int slot,
2107 			       struct inode **head,
2108 			       enum ocfs2_orphan_reco_type orphan_reco_type)
2109 {
2110 	int status;
2111 	struct inode *orphan_dir_inode = NULL;
2112 	struct ocfs2_orphan_filldir_priv priv = {
2113 		.ctx.actor = ocfs2_orphan_filldir,
2114 		.osb = osb,
2115 		.head = *head,
2116 		.orphan_reco_type = orphan_reco_type
2117 	};
2118 
2119 	orphan_dir_inode = ocfs2_get_system_file_inode(osb,
2120 						       ORPHAN_DIR_SYSTEM_INODE,
2121 						       slot);
2122 	if  (!orphan_dir_inode) {
2123 		status = -ENOENT;
2124 		mlog_errno(status);
2125 		return status;
2126 	}
2127 
2128 	inode_lock(orphan_dir_inode);
2129 	status = ocfs2_inode_lock(orphan_dir_inode, NULL, 0);
2130 	if (status < 0) {
2131 		mlog_errno(status);
2132 		goto out;
2133 	}
2134 
2135 	status = ocfs2_dir_foreach(orphan_dir_inode, &priv.ctx);
2136 	if (status) {
2137 		mlog_errno(status);
2138 		goto out_cluster;
2139 	}
2140 
2141 	*head = priv.head;
2142 
2143 out_cluster:
2144 	ocfs2_inode_unlock(orphan_dir_inode, 0);
2145 out:
2146 	inode_unlock(orphan_dir_inode);
2147 	iput(orphan_dir_inode);
2148 	return status;
2149 }
2150 
2151 static int ocfs2_orphan_recovery_can_continue(struct ocfs2_super *osb,
2152 					      int slot)
2153 {
2154 	int ret;
2155 
2156 	spin_lock(&osb->osb_lock);
2157 	ret = !osb->osb_orphan_wipes[slot];
2158 	spin_unlock(&osb->osb_lock);
2159 	return ret;
2160 }
2161 
2162 static void ocfs2_mark_recovering_orphan_dir(struct ocfs2_super *osb,
2163 					     int slot)
2164 {
2165 	spin_lock(&osb->osb_lock);
2166 	/* Mark ourselves such that new processes in delete_inode()
2167 	 * know to quit early. */
2168 	ocfs2_node_map_set_bit(osb, &osb->osb_recovering_orphan_dirs, slot);
2169 	while (osb->osb_orphan_wipes[slot]) {
2170 		/* If any processes are already in the middle of an
2171 		 * orphan wipe on this dir, then we need to wait for
2172 		 * them. */
2173 		spin_unlock(&osb->osb_lock);
2174 		wait_event_interruptible(osb->osb_wipe_event,
2175 					 ocfs2_orphan_recovery_can_continue(osb, slot));
2176 		spin_lock(&osb->osb_lock);
2177 	}
2178 	spin_unlock(&osb->osb_lock);
2179 }
2180 
2181 static void ocfs2_clear_recovering_orphan_dir(struct ocfs2_super *osb,
2182 					      int slot)
2183 {
2184 	ocfs2_node_map_clear_bit(osb, &osb->osb_recovering_orphan_dirs, slot);
2185 }
2186 
2187 /*
2188  * Orphan recovery. Each mounted node has it's own orphan dir which we
2189  * must run during recovery. Our strategy here is to build a list of
2190  * the inodes in the orphan dir and iget/iput them. The VFS does
2191  * (most) of the rest of the work.
2192  *
2193  * Orphan recovery can happen at any time, not just mount so we have a
2194  * couple of extra considerations.
2195  *
2196  * - We grab as many inodes as we can under the orphan dir lock -
2197  *   doing iget() outside the orphan dir risks getting a reference on
2198  *   an invalid inode.
2199  * - We must be sure not to deadlock with other processes on the
2200  *   system wanting to run delete_inode(). This can happen when they go
2201  *   to lock the orphan dir and the orphan recovery process attempts to
2202  *   iget() inside the orphan dir lock. This can be avoided by
2203  *   advertising our state to ocfs2_delete_inode().
2204  */
2205 static int ocfs2_recover_orphans(struct ocfs2_super *osb,
2206 				 int slot,
2207 				 enum ocfs2_orphan_reco_type orphan_reco_type)
2208 {
2209 	int ret = 0;
2210 	struct inode *inode = NULL;
2211 	struct inode *iter;
2212 	struct ocfs2_inode_info *oi;
2213 	struct buffer_head *di_bh = NULL;
2214 	struct ocfs2_dinode *di = NULL;
2215 
2216 	trace_ocfs2_recover_orphans(slot);
2217 
2218 	ocfs2_mark_recovering_orphan_dir(osb, slot);
2219 	ret = ocfs2_queue_orphans(osb, slot, &inode, orphan_reco_type);
2220 	ocfs2_clear_recovering_orphan_dir(osb, slot);
2221 
2222 	/* Error here should be noted, but we want to continue with as
2223 	 * many queued inodes as we've got. */
2224 	if (ret)
2225 		mlog_errno(ret);
2226 
2227 	while (inode) {
2228 		oi = OCFS2_I(inode);
2229 		trace_ocfs2_recover_orphans_iput(
2230 					(unsigned long long)oi->ip_blkno);
2231 
2232 		iter = oi->ip_next_orphan;
2233 		oi->ip_next_orphan = NULL;
2234 
2235 		if (oi->ip_flags & OCFS2_INODE_DIO_ORPHAN_ENTRY) {
2236 			inode_lock(inode);
2237 			ret = ocfs2_rw_lock(inode, 1);
2238 			if (ret < 0) {
2239 				mlog_errno(ret);
2240 				goto unlock_mutex;
2241 			}
2242 			/*
2243 			 * We need to take and drop the inode lock to
2244 			 * force read inode from disk.
2245 			 */
2246 			ret = ocfs2_inode_lock(inode, &di_bh, 1);
2247 			if (ret) {
2248 				mlog_errno(ret);
2249 				goto unlock_rw;
2250 			}
2251 
2252 			di = (struct ocfs2_dinode *)di_bh->b_data;
2253 
2254 			if (di->i_flags & cpu_to_le32(OCFS2_DIO_ORPHANED_FL)) {
2255 				ret = ocfs2_truncate_file(inode, di_bh,
2256 						i_size_read(inode));
2257 				if (ret < 0) {
2258 					if (ret != -ENOSPC)
2259 						mlog_errno(ret);
2260 					goto unlock_inode;
2261 				}
2262 
2263 				ret = ocfs2_del_inode_from_orphan(osb, inode,
2264 						di_bh, 0, 0);
2265 				if (ret)
2266 					mlog_errno(ret);
2267 			}
2268 unlock_inode:
2269 			ocfs2_inode_unlock(inode, 1);
2270 			brelse(di_bh);
2271 			di_bh = NULL;
2272 unlock_rw:
2273 			ocfs2_rw_unlock(inode, 1);
2274 unlock_mutex:
2275 			inode_unlock(inode);
2276 
2277 			/* clear dio flag in ocfs2_inode_info */
2278 			oi->ip_flags &= ~OCFS2_INODE_DIO_ORPHAN_ENTRY;
2279 		} else {
2280 			spin_lock(&oi->ip_lock);
2281 			/* Set the proper information to get us going into
2282 			 * ocfs2_delete_inode. */
2283 			oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
2284 			spin_unlock(&oi->ip_lock);
2285 		}
2286 
2287 		iput(inode);
2288 		inode = iter;
2289 	}
2290 
2291 	return ret;
2292 }
2293 
2294 static int __ocfs2_wait_on_mount(struct ocfs2_super *osb, int quota)
2295 {
2296 	/* This check is good because ocfs2 will wait on our recovery
2297 	 * thread before changing it to something other than MOUNTED
2298 	 * or DISABLED. */
2299 	wait_event(osb->osb_mount_event,
2300 		  (!quota && atomic_read(&osb->vol_state) == VOLUME_MOUNTED) ||
2301 		   atomic_read(&osb->vol_state) == VOLUME_MOUNTED_QUOTAS ||
2302 		   atomic_read(&osb->vol_state) == VOLUME_DISABLED);
2303 
2304 	/* If there's an error on mount, then we may never get to the
2305 	 * MOUNTED flag, but this is set right before
2306 	 * dismount_volume() so we can trust it. */
2307 	if (atomic_read(&osb->vol_state) == VOLUME_DISABLED) {
2308 		trace_ocfs2_wait_on_mount(VOLUME_DISABLED);
2309 		mlog(0, "mount error, exiting!\n");
2310 		return -EBUSY;
2311 	}
2312 
2313 	return 0;
2314 }
2315 
2316 static int ocfs2_commit_thread(void *arg)
2317 {
2318 	int status;
2319 	struct ocfs2_super *osb = arg;
2320 	struct ocfs2_journal *journal = osb->journal;
2321 
2322 	/* we can trust j_num_trans here because _should_stop() is only set in
2323 	 * shutdown and nobody other than ourselves should be able to start
2324 	 * transactions.  committing on shutdown might take a few iterations
2325 	 * as final transactions put deleted inodes on the list */
2326 	while (!(kthread_should_stop() &&
2327 		 atomic_read(&journal->j_num_trans) == 0)) {
2328 
2329 		wait_event_interruptible(osb->checkpoint_event,
2330 					 atomic_read(&journal->j_num_trans)
2331 					 || kthread_should_stop());
2332 
2333 		status = ocfs2_commit_cache(osb);
2334 		if (status < 0) {
2335 			static unsigned long abort_warn_time;
2336 
2337 			/* Warn about this once per minute */
2338 			if (printk_timed_ratelimit(&abort_warn_time, 60*HZ))
2339 				mlog(ML_ERROR, "status = %d, journal is "
2340 						"already aborted.\n", status);
2341 			/*
2342 			 * After ocfs2_commit_cache() fails, j_num_trans has a
2343 			 * non-zero value.  Sleep here to avoid a busy-wait
2344 			 * loop.
2345 			 */
2346 			msleep_interruptible(1000);
2347 		}
2348 
2349 		if (kthread_should_stop() && atomic_read(&journal->j_num_trans)){
2350 			mlog(ML_KTHREAD,
2351 			     "commit_thread: %u transactions pending on "
2352 			     "shutdown\n",
2353 			     atomic_read(&journal->j_num_trans));
2354 		}
2355 	}
2356 
2357 	return 0;
2358 }
2359 
2360 /* Reads all the journal inodes without taking any cluster locks. Used
2361  * for hard readonly access to determine whether any journal requires
2362  * recovery. Also used to refresh the recovery generation numbers after
2363  * a journal has been recovered by another node.
2364  */
2365 int ocfs2_check_journals_nolocks(struct ocfs2_super *osb)
2366 {
2367 	int ret = 0;
2368 	unsigned int slot;
2369 	struct buffer_head *di_bh = NULL;
2370 	struct ocfs2_dinode *di;
2371 	int journal_dirty = 0;
2372 
2373 	for(slot = 0; slot < osb->max_slots; slot++) {
2374 		ret = ocfs2_read_journal_inode(osb, slot, &di_bh, NULL);
2375 		if (ret) {
2376 			mlog_errno(ret);
2377 			goto out;
2378 		}
2379 
2380 		di = (struct ocfs2_dinode *) di_bh->b_data;
2381 
2382 		osb->slot_recovery_generations[slot] =
2383 					ocfs2_get_recovery_generation(di);
2384 
2385 		if (le32_to_cpu(di->id1.journal1.ij_flags) &
2386 		    OCFS2_JOURNAL_DIRTY_FL)
2387 			journal_dirty = 1;
2388 
2389 		brelse(di_bh);
2390 		di_bh = NULL;
2391 	}
2392 
2393 out:
2394 	if (journal_dirty)
2395 		ret = -EROFS;
2396 	return ret;
2397 }
2398