xref: /dragonfly/sys/vfs/hammer/hammer_object.c (revision c5adbbb2c02e01757e1c4f5b2f06026e513b58bf)
1 /*
2  * Copyright (c) 2007-2008 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 
35 #include "hammer.h"
36 
37 static int hammer_mem_lookup(hammer_cursor_t cursor);
38 static int hammer_mem_first(hammer_cursor_t cursor);
39 static int hammer_frontend_trunc_callback(hammer_record_t record,
40                                         void *data __unused);
41 static int hammer_bulk_scan_callback(hammer_record_t record, void *data);
42 static int hammer_record_needs_overwrite_delete(hammer_record_t record);
43 static int hammer_delete_general(hammer_cursor_t cursor, hammer_inode_t ip,
44                                         hammer_btree_leaf_elm_t leaf);
45 static int hammer_cursor_localize_data(hammer_mount_t hmp, hammer_data_ondisk_t data,
46                                         hammer_btree_leaf_elm_t leaf);
47 
48 struct rec_trunc_info {
49           uint16_t  rec_type;
50           int64_t             trunc_off;
51 };
52 
53 struct hammer_bulk_info {
54           hammer_record_t record;
55           hammer_record_t conflict;
56 };
57 
58 /*
59  * Red-black tree support.  Comparison code for insertion.
60  */
61 static int
hammer_rec_rb_compare(hammer_record_t rec1,hammer_record_t rec2)62 hammer_rec_rb_compare(hammer_record_t rec1, hammer_record_t rec2)
63 {
64           if (rec1->leaf.base.rec_type < rec2->leaf.base.rec_type)
65                     return(-1);
66           if (rec1->leaf.base.rec_type > rec2->leaf.base.rec_type)
67                     return(1);
68 
69           if (rec1->leaf.base.key < rec2->leaf.base.key)
70                     return(-1);
71           if (rec1->leaf.base.key > rec2->leaf.base.key)
72                     return(1);
73 
74           /*
75            * For search & insertion purposes records deleted by the
76            * frontend or deleted/committed by the backend are silently
77            * ignored.  Otherwise pipelined insertions will get messed
78            * up.
79            *
80            * rec1 is greater then rec2 if rec1 is marked deleted.
81            * rec1 is less then rec2 if rec2 is marked deleted.
82            *
83            * Multiple deleted records may be present, do not return 0
84            * if both are marked deleted.
85            */
86           if (rec1->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE |
87                                  HAMMER_RECF_COMMITTED)) {
88                     return(1);
89           }
90           if (rec2->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE |
91                                  HAMMER_RECF_COMMITTED)) {
92                     return(-1);
93           }
94 
95         return(0);
96 }
97 
98 /*
99  * Basic record comparison code similar to hammer_btree_cmp().
100  *
101  * obj_id is not compared and may not yet be assigned in the record.
102  */
103 static int
hammer_rec_cmp(hammer_base_elm_t elm,hammer_record_t rec)104 hammer_rec_cmp(hammer_base_elm_t elm, hammer_record_t rec)
105 {
106           if (elm->rec_type < rec->leaf.base.rec_type)
107                     return(-3);
108           if (elm->rec_type > rec->leaf.base.rec_type)
109                     return(3);
110 
111         if (elm->key < rec->leaf.base.key)
112                 return(-2);
113         if (elm->key > rec->leaf.base.key)
114                 return(2);
115 
116           /*
117            * Never match against an item deleted by the frontend
118            * or backend, or committed by the backend.
119            *
120            * elm is less then rec if rec is marked deleted.
121            */
122           if (rec->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE |
123                                 HAMMER_RECF_COMMITTED)) {
124                     return(-1);
125           }
126         return(0);
127 }
128 
129 /*
130  * Ranged scan to locate overlapping record(s).  This is used by
131  * hammer_ip_get_bulk() to locate an overlapping record.  We have
132  * to use a ranged scan because the keys for data records with the
133  * same file base offset can be different due to differing data_len's.
134  *
135  * NOTE: The base file offset of a data record is (key - data_len), not (key).
136  */
137 static int
hammer_rec_overlap_cmp(hammer_record_t rec,void * data)138 hammer_rec_overlap_cmp(hammer_record_t rec, void *data)
139 {
140           struct hammer_bulk_info *info = data;
141           hammer_btree_leaf_elm_t leaf = &info->record->leaf;
142 
143           if (rec->leaf.base.rec_type < leaf->base.rec_type)
144                     return(-3);
145           if (rec->leaf.base.rec_type > leaf->base.rec_type)
146                     return(3);
147 
148           /*
149            * Overlap compare
150            */
151           if (leaf->base.rec_type == HAMMER_RECTYPE_DATA) {
152                     /* rec_beg >= leaf_end */
153                     if (rec->leaf.base.key - rec->leaf.data_len >= leaf->base.key)
154                               return(2);
155                     /* rec_end <= leaf_beg */
156                     if (rec->leaf.base.key <= leaf->base.key - leaf->data_len)
157                               return(-2);
158           } else {
159                     if (rec->leaf.base.key < leaf->base.key)
160                               return(-2);
161                     if (rec->leaf.base.key > leaf->base.key)
162                               return(2);
163           }
164 
165           /*
166            * We have to return 0 at this point, even if DELETED_FE is set,
167            * because returning anything else will cause the scan to ignore
168            * one of the branches when we really want it to check both.
169            */
170         return(0);
171 }
172 
173 /*
174  * RB_SCAN comparison code for hammer_mem_first().  The argument order
175  * is reversed so the comparison result has to be negated.  key_beg and
176  * key_end are both range-inclusive.
177  *
178  * Localized deletions are not cached in-memory.
179  */
180 static
181 int
hammer_rec_scan_cmp(hammer_record_t rec,void * data)182 hammer_rec_scan_cmp(hammer_record_t rec, void *data)
183 {
184           hammer_cursor_t cursor = data;
185           int r;
186 
187           r = hammer_rec_cmp(&cursor->key_beg, rec);
188           if (r > 1)
189                     return(-1);
190           r = hammer_rec_cmp(&cursor->key_end, rec);
191           if (r < -1)
192                     return(1);
193           return(0);
194 }
195 
196 /*
197  * This compare function is used when simply looking up key_beg.
198  */
199 static
200 int
hammer_rec_find_cmp(hammer_record_t rec,void * data)201 hammer_rec_find_cmp(hammer_record_t rec, void *data)
202 {
203           hammer_cursor_t cursor = data;
204           int r;
205 
206           r = hammer_rec_cmp(&cursor->key_beg, rec);
207           if (r > 1)
208                     return(-1);
209           if (r < -1)
210                     return(1);
211           return(0);
212 }
213 
214 /*
215  * Locate blocks within the truncation range.  Partial blocks do not count.
216  */
217 static
218 int
hammer_rec_trunc_cmp(hammer_record_t rec,void * data)219 hammer_rec_trunc_cmp(hammer_record_t rec, void *data)
220 {
221           struct rec_trunc_info *info = data;
222 
223           if (rec->leaf.base.rec_type < info->rec_type)
224                     return(-1);
225           if (rec->leaf.base.rec_type > info->rec_type)
226                     return(1);
227 
228           switch(rec->leaf.base.rec_type) {
229           case HAMMER_RECTYPE_DB:
230                     /*
231                      * DB record key is not beyond the truncation point, retain.
232                      */
233                     if (rec->leaf.base.key < info->trunc_off)
234                               return(-1);
235                     break;
236           case HAMMER_RECTYPE_DATA:
237                     /*
238                      * DATA record offset start is not beyond the truncation point,
239                      * retain.
240                      */
241                     if (rec->leaf.base.key - rec->leaf.data_len < info->trunc_off)
242                               return(-1);
243                     break;
244           default:
245                     hpanic("unexpected record type");
246           }
247 
248           /*
249            * The record start is >= the truncation point, return match,
250            * the record should be destroyed.
251            */
252           return(0);
253 }
254 
255 RB_GENERATE(hammer_rec_rb_tree, hammer_record, rb_node, hammer_rec_rb_compare);
256 
257 /*
258  * Allocate a record for the caller to finish filling in.  The record is
259  * returned referenced.  In order to manually set data call this function
260  * with data_len=0 and then manually set record->leaf.data_len and
261  * record->data later.
262  */
263 hammer_record_t
hammer_alloc_mem_record(hammer_inode_t ip,int data_len)264 hammer_alloc_mem_record(hammer_inode_t ip, int data_len)
265 {
266           hammer_record_t record;
267           hammer_mount_t hmp;
268 
269           hmp = ip->hmp;
270           ++hammer_count_records;
271           record = kmalloc(sizeof(*record), hmp->m_misc,
272                                M_WAITOK | M_ZERO | M_USE_RESERVE);
273           record->flush_state = HAMMER_FST_IDLE;
274           record->ip = ip;
275           record->leaf.base.btype = HAMMER_BTREE_TYPE_RECORD;
276           record->leaf.data_len = data_len;
277           hammer_ref(&record->lock);
278 
279           if (data_len) {
280                     record->data = kmalloc(data_len, hmp->m_misc, M_WAITOK | M_ZERO);
281                     record->flags |= HAMMER_RECF_ALLOCDATA;
282                     ++hammer_count_record_datas;
283           }
284 
285           return (record);
286 }
287 
288 void
hammer_wait_mem_record_ident(hammer_record_t record,const char * ident)289 hammer_wait_mem_record_ident(hammer_record_t record, const char *ident)
290 {
291           while (record->flush_state == HAMMER_FST_FLUSH) {
292                     record->flags |= HAMMER_RECF_WANTED;
293                     tsleep(record, 0, ident, 0);
294           }
295 }
296 
297 /*
298  * Called from the backend, hammer_inode.c, after a record has been
299  * flushed to disk.  The record has been exclusively locked by the
300  * caller and interlocked with BE.
301  *
302  * We clean up the state, unlock, and release the record (the record
303  * was referenced by the fact that it was in the HAMMER_FST_FLUSH state).
304  */
305 void
hammer_flush_record_done(hammer_record_t record,int error)306 hammer_flush_record_done(hammer_record_t record, int error)
307 {
308           hammer_inode_t target_ip;
309 
310           KKASSERT(record->flush_state == HAMMER_FST_FLUSH);
311           KKASSERT(record->flags & HAMMER_RECF_INTERLOCK_BE);
312 
313           /*
314            * If an error occured, the backend was unable to sync the
315            * record to its media.  Leave the record intact.
316            */
317           if (error) {
318                     hammer_critical_error(record->ip->hmp, record->ip, error,
319                                               "while flushing record");
320           }
321 
322           --record->flush_group->refs;
323           record->flush_group = NULL;
324 
325           /*
326            * Adjust the flush state and dependancy based on success or
327            * failure.
328            */
329           if (record->flags & (HAMMER_RECF_DELETED_BE | HAMMER_RECF_COMMITTED)) {
330                     if ((target_ip = record->target_ip) != NULL) {
331                               TAILQ_REMOVE(&target_ip->target_list, record,
332                                              target_entry);
333                               record->target_ip = NULL;
334                               hammer_test_inode(target_ip);
335                     }
336                     record->flush_state = HAMMER_FST_IDLE;
337           } else {
338                     if (record->target_ip) {
339                               record->flush_state = HAMMER_FST_SETUP;
340                               hammer_test_inode(record->ip);
341                               hammer_test_inode(record->target_ip);
342                     } else {
343                               record->flush_state = HAMMER_FST_IDLE;
344                     }
345           }
346           record->flags &= ~HAMMER_RECF_INTERLOCK_BE;
347 
348           /*
349            * Cleanup
350            */
351           if (record->flags & HAMMER_RECF_WANTED) {
352                     record->flags &= ~HAMMER_RECF_WANTED;
353                     wakeup(record);
354           }
355           hammer_rel_mem_record(record);
356 }
357 
358 /*
359  * Release a memory record.  Records marked for deletion are immediately
360  * removed from the RB-Tree but otherwise left intact until the last ref
361  * goes away.
362  */
363 void
hammer_rel_mem_record(hammer_record_t record)364 hammer_rel_mem_record(hammer_record_t record)
365 {
366           hammer_mount_t hmp;
367           hammer_reserve_t resv;
368           hammer_inode_t ip;
369           hammer_inode_t target_ip;
370           int diddrop;
371 
372           hammer_rel(&record->lock);
373 
374           if (hammer_norefs(&record->lock)) {
375                     /*
376                      * Upon release of the last reference wakeup any waiters.
377                      * The record structure may get destroyed so callers will
378                      * loop up and do a relookup.
379                      *
380                      * WARNING!  Record must be removed from RB-TREE before we
381                      * might possibly block.  hammer_test_inode() can block!
382                      */
383                     ip = record->ip;
384                     hmp = ip->hmp;
385 
386                     /*
387                      * Upon release of the last reference a record marked deleted
388                      * by the front or backend, or committed by the backend,
389                      * is destroyed.
390                      */
391                     if (record->flags & (HAMMER_RECF_DELETED_FE |
392                                              HAMMER_RECF_DELETED_BE |
393                                              HAMMER_RECF_COMMITTED)) {
394                               KKASSERT(hammer_isactive(&ip->lock) > 0);
395                               KKASSERT(record->flush_state != HAMMER_FST_FLUSH);
396 
397                               /*
398                                * target_ip may have zero refs, we have to ref it
399                                * to prevent it from being ripped out from under
400                                * us.
401                                */
402                               if ((target_ip = record->target_ip) != NULL) {
403                                         TAILQ_REMOVE(&target_ip->target_list,
404                                                        record, target_entry);
405                                         record->target_ip = NULL;
406                                         hammer_ref(&target_ip->lock);
407                               }
408 
409                               /*
410                                * Remove the record from the RB-Tree
411                                */
412                               if (record->flags & HAMMER_RECF_ONRBTREE) {
413                                         RB_REMOVE(hammer_rec_rb_tree,
414                                                     &ip->rec_tree,
415                                                     record);
416                                         record->flags &= ~HAMMER_RECF_ONRBTREE;
417                                         KKASSERT(ip->rsv_recs > 0);
418                                         if (RB_EMPTY(&ip->rec_tree)) {
419                                                   ip->flags &= ~HAMMER_INODE_XDIRTY;
420                                                   ip->sync_flags &= ~HAMMER_INODE_XDIRTY;
421                                         }
422                                         diddrop = 1;
423                               } else {
424                                         diddrop = 0;
425                               }
426 
427                               /*
428                                * We must wait for any direct-IO to complete before
429                                * we can destroy the record because the bio may
430                                * have a reference to it.
431                                */
432                               if (record->gflags &
433                                  (HAMMER_RECG_DIRECT_IO | HAMMER_RECG_DIRECT_INVAL)) {
434                                         hammer_io_direct_wait(record);
435                               }
436 
437                               /*
438                                * Account for the completion after the direct IO
439                                * has completed.
440                                */
441                               if (diddrop) {
442                                         --hmp->rsv_recs;
443                                         --ip->rsv_recs;
444                                         hmp->rsv_databytes -= record->leaf.data_len;
445 
446                                         if (RB_EMPTY(&ip->rec_tree))
447                                                   hammer_test_inode(ip);
448                                         if ((ip->flags & HAMMER_INODE_RECSW) &&
449                                             ip->rsv_recs <= hammer_limit_inode_recs/2) {
450                                                   ip->flags &= ~HAMMER_INODE_RECSW;
451                                                   wakeup(&ip->rsv_recs);
452                                         }
453                               }
454 
455                               /*
456                                * Do this test after removing record from the RB-Tree.
457                                */
458                               if (target_ip) {
459                                         hammer_test_inode(target_ip);
460                                         hammer_rel_inode(target_ip, 0);
461                               }
462 
463                               if (record->flags & HAMMER_RECF_ALLOCDATA) {
464                                         --hammer_count_record_datas;
465                                         kfree(record->data, hmp->m_misc);
466                                         record->flags &= ~HAMMER_RECF_ALLOCDATA;
467                               }
468 
469                               /*
470                                * Release the reservation.
471                                *
472                                * If the record was not committed we can theoretically
473                                * undo the reservation.  However, doing so might
474                                * create weird edge cases with the ordering of
475                                * direct writes because the related buffer cache
476                                * elements are per-vnode.  So we don't try.
477                                */
478                               if ((resv = record->resv) != NULL) {
479                                         /* XXX undo leaf.data_offset,leaf.data_len */
480                                         hammer_blockmap_reserve_complete(hmp, resv);
481                                         record->resv = NULL;
482                               }
483                               record->data = NULL;
484                               --hammer_count_records;
485                               kfree(record, hmp->m_misc);
486                     }
487           }
488 }
489 
490 /*
491  * Record visibility depends on whether the record is being accessed by
492  * the backend or the frontend.  Backend tests ignore the frontend delete
493  * flag.  Frontend tests do NOT ignore the backend delete/commit flags and
494  * must also check for commit races.
495  *
496  * Return non-zero if the record is visible, zero if it isn't or if it is
497  * deleted.  Returns 0 if the record has been comitted (unless the special
498  * delete-visibility flag is set).  A committed record must be located
499  * via the media B-Tree.  Returns non-zero if the record is good.
500  *
501  * If HAMMER_CURSOR_DELETE_VISIBILITY is set we allow deleted memory
502  * records to be returned.  This is so pending deletions are detected
503  * when using an iterator to locate an unused hash key, or when we need
504  * to locate historical records on-disk to destroy.
505  */
506 static __inline
507 int
hammer_ip_iterate_mem_good(hammer_cursor_t cursor,hammer_record_t record)508 hammer_ip_iterate_mem_good(hammer_cursor_t cursor, hammer_record_t record)
509 {
510           if (cursor->flags & HAMMER_CURSOR_DELETE_VISIBILITY)
511                     return(1);
512           if (cursor->flags & HAMMER_CURSOR_BACKEND) {
513                     if (record->flags & (HAMMER_RECF_DELETED_BE |
514                                              HAMMER_RECF_COMMITTED)) {
515                               return(0);
516                     }
517           } else {
518                     if (record->flags & (HAMMER_RECF_DELETED_FE |
519                                              HAMMER_RECF_DELETED_BE |
520                                              HAMMER_RECF_COMMITTED)) {
521                               return(0);
522                     }
523           }
524           return(1);
525 }
526 
527 /*
528  * This callback is used as part of the RB_SCAN function for in-memory
529  * records.  We terminate it (return -1) as soon as we get a match.
530  *
531  * This routine is used by frontend code.
532  *
533  * The primary compare code does not account for ASOF lookups.  This
534  * code handles that case as well as a few others.
535  */
536 static
537 int
hammer_rec_scan_callback(hammer_record_t rec,void * data)538 hammer_rec_scan_callback(hammer_record_t rec, void *data)
539 {
540           hammer_cursor_t cursor = data;
541 
542           /*
543            * We terminate on success, so this should be NULL on entry.
544            */
545           KKASSERT(cursor->iprec == NULL);
546 
547           /*
548            * Skip if the record was marked deleted or committed.
549            */
550           if (hammer_ip_iterate_mem_good(cursor, rec) == 0)
551                     return(0);
552 
553           /*
554            * Skip if not visible due to our as-of TID
555            */
556         if (cursor->flags & HAMMER_CURSOR_ASOF) {
557                 if (cursor->asof < rec->leaf.base.create_tid)
558                         return(0);
559                 if (rec->leaf.base.delete_tid &&
560                         cursor->asof >= rec->leaf.base.delete_tid) {
561                         return(0);
562                     }
563         }
564 
565           /*
566            * ref the record.  The record is protected from backend B-Tree
567            * interactions by virtue of the cursor's IP lock.
568            */
569           hammer_ref(&rec->lock);
570 
571           /*
572            * The record may have been deleted or committed while we
573            * were blocked.  XXX remove?
574            */
575           if (hammer_ip_iterate_mem_good(cursor, rec) == 0) {
576                     hammer_rel_mem_record(rec);
577                     return(0);
578           }
579 
580           /*
581            * Set the matching record and stop the scan.
582            */
583           cursor->iprec = rec;
584           return(-1);
585 }
586 
587 
588 /*
589  * Lookup an in-memory record given the key specified in the cursor.  Works
590  * just like hammer_btree_lookup() but operates on an inode's in-memory
591  * record list.
592  *
593  * The lookup must fail if the record is marked for deferred deletion.
594  *
595  * The API for mem/btree_lookup() does not mess with the ATE/EOF bits.
596  */
597 static
598 int
hammer_mem_lookup(hammer_cursor_t cursor)599 hammer_mem_lookup(hammer_cursor_t cursor)
600 {
601           KKASSERT(cursor->ip != NULL);
602           if (cursor->iprec) {
603                     hammer_rel_mem_record(cursor->iprec);
604                     cursor->iprec = NULL;
605           }
606           hammer_rec_rb_tree_RB_SCAN(&cursor->ip->rec_tree, hammer_rec_find_cmp,
607                                            hammer_rec_scan_callback, cursor);
608 
609           return (cursor->iprec ? 0 : ENOENT);
610 }
611 
612 /*
613  * hammer_mem_first() - locate the first in-memory record matching the
614  * cursor within the bounds of the key range.
615  *
616  * WARNING!  API is slightly different from btree_first().  hammer_mem_first()
617  * will set ATEMEM the same as MEMEOF, and does not return any error.
618  */
619 static
620 int
hammer_mem_first(hammer_cursor_t cursor)621 hammer_mem_first(hammer_cursor_t cursor)
622 {
623           KKASSERT(cursor->ip != NULL);
624           if (cursor->iprec) {
625                     hammer_rel_mem_record(cursor->iprec);
626                     cursor->iprec = NULL;
627           }
628           hammer_rec_rb_tree_RB_SCAN(&cursor->ip->rec_tree, hammer_rec_scan_cmp,
629                                            hammer_rec_scan_callback, cursor);
630 
631           if (cursor->iprec)
632                     cursor->flags &= ~(HAMMER_CURSOR_MEMEOF | HAMMER_CURSOR_ATEMEM);
633           else
634                     cursor->flags |= HAMMER_CURSOR_MEMEOF | HAMMER_CURSOR_ATEMEM;
635 
636           return (cursor->iprec ? 0 : ENOENT);
637 }
638 
639 /************************************************************************
640  *                       HAMMER IN-MEMORY RECORD FUNCTIONS                      *
641  ************************************************************************
642  *
643  * These functions manipulate in-memory records.  Such records typically
644  * exist prior to being committed to disk or indexed via the on-disk B-Tree.
645  */
646 
647 /*
648  * Add a directory entry (dip,ncp) which references inode (ip).
649  *
650  * Note that the low 32 bits of the namekey are set temporarily to create
651  * a unique in-memory record, and may be modified a second time when the
652  * record is synchronized to disk.  In particular, the low 32 bits cannot be
653  * all 0's when synching to disk, which is not handled here.
654  *
655  * NOTE: bytes does not include any terminating \0 on name, and name might
656  * not be terminated.
657  */
658 int
hammer_ip_add_direntry(hammer_transaction_t trans,hammer_inode_t dip,const char * name,int bytes,hammer_inode_t ip)659 hammer_ip_add_direntry(hammer_transaction_t trans,
660                          hammer_inode_t dip, const char *name, int bytes,
661                          hammer_inode_t ip)
662 {
663           struct hammer_cursor cursor;
664           hammer_record_t record;
665           int error;
666           uint32_t max_iterations;
667 
668           KKASSERT(dip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY);
669 
670           record = hammer_alloc_mem_record(dip, HAMMER_ENTRY_SIZE(bytes));
671 
672           record->type = HAMMER_MEM_RECORD_ADD;
673           record->leaf.base.localization = dip->obj_localization |
674                                                    hammer_dir_localization(dip);
675           record->leaf.base.obj_id = dip->obj_id;
676           record->leaf.base.key = hammer_direntry_namekey(dip, name, bytes,
677                                                                        &max_iterations);
678           record->leaf.base.rec_type = HAMMER_RECTYPE_DIRENTRY;
679           record->leaf.base.obj_type = ip->ino_leaf.base.obj_type;
680           record->data->entry.obj_id = ip->obj_id;
681           record->data->entry.localization = ip->obj_localization;
682           bcopy(name, record->data->entry.name, bytes);
683 
684           ++ip->ino_data.nlinks;
685           ip->ino_data.ctime = trans->time;
686           hammer_modify_inode(trans, ip, HAMMER_INODE_DDIRTY);
687 
688           /*
689            * Find an unused namekey.  Both the in-memory record tree and
690            * the B-Tree are checked.  We do not want historically deleted
691            * names to create a collision as our iteration space may be limited,
692            * and since create_tid wouldn't match anyway an ASOF search
693            * must be used to locate collisions.
694            *
695            * delete-visibility is set so pending deletions do not give us
696            * a false-negative on our ability to use an iterator.
697            *
698            * The iterator must not rollover the key.  Directory keys only
699            * use the positive key space.
700            */
701           hammer_init_cursor(trans, &cursor, &dip->cache[1], dip);
702           cursor.key_beg = record->leaf.base;
703           cursor.flags |= HAMMER_CURSOR_ASOF;
704           cursor.flags |= HAMMER_CURSOR_DELETE_VISIBILITY;
705           cursor.asof = ip->obj_asof;
706 
707           while (hammer_ip_lookup(&cursor) == 0) {
708                     ++record->leaf.base.key;
709                     KKASSERT(record->leaf.base.key > 0);
710                     cursor.key_beg.key = record->leaf.base.key;
711                     if (--max_iterations == 0) {
712                               hammer_rel_mem_record(record);
713                               hmkprintf(trans->hmp, "Failed to find an unused namekey\n");
714                               error = ENOSPC;
715                               goto failed;
716                     }
717           }
718 
719           /*
720            * The target inode and the directory entry are bound together.
721            */
722           record->target_ip = ip;
723           record->flush_state = HAMMER_FST_SETUP;
724           TAILQ_INSERT_TAIL(&ip->target_list, record, target_entry);
725 
726           /*
727            * The inode now has a dependancy and must be taken out of the idle
728            * state.  An inode not in an idle state is given an extra reference.
729            *
730            * When transitioning to a SETUP state flag for an automatic reflush
731            * when the dependancies are disposed of if someone is waiting on
732            * the inode.
733            */
734           if (ip->flush_state == HAMMER_FST_IDLE) {
735                     hammer_ref(&ip->lock);
736                     ip->flush_state = HAMMER_FST_SETUP;
737                     if (ip->flags & HAMMER_INODE_FLUSHW)
738                               ip->flags |= HAMMER_INODE_REFLUSH;
739           }
740           error = hammer_mem_add(record);
741           if (error == 0) {
742                     dip->ino_data.mtime = trans->time;
743                     dip->ino_data.ctime = trans->time;
744                     hammer_modify_inode(trans, dip, HAMMER_INODE_MTIME | HAMMER_INODE_DDIRTY);
745           }
746 failed:
747           hammer_done_cursor(&cursor);
748           return(error);
749 }
750 
751 /*
752  * Delete the directory entry and update the inode link count.  The
753  * cursor must be seeked to the directory entry record being deleted.
754  *
755  * The related inode should be share-locked by the caller.  The caller is
756  * on the frontend.  It could also be NULL indicating that the directory
757  * entry being removed has no related inode.
758  *
759  * This function can return EDEADLK requiring the caller to terminate
760  * the cursor, any locks, wait on the returned record, and retry.
761  */
762 int
hammer_ip_del_direntry(hammer_transaction_t trans,hammer_cursor_t cursor,hammer_inode_t dip,hammer_inode_t ip)763 hammer_ip_del_direntry(hammer_transaction_t trans,
764                          hammer_cursor_t cursor, hammer_inode_t dip,
765                          hammer_inode_t ip)
766 {
767           hammer_record_t record;
768           int error;
769 
770           if (hammer_cursor_inmem(cursor)) {
771                     /*
772                      * In-memory (unsynchronized) records can simply be freed.
773                      *
774                      * Even though the HAMMER_RECF_DELETED_FE flag is ignored
775                      * by the backend, we must still avoid races against the
776                      * backend potentially syncing the record to the media.
777                      *
778                      * We cannot call hammer_ip_delete_record(), that routine may
779                      * only be called from the backend.
780                      */
781                     record = cursor->iprec;
782                     if (record->flags & (HAMMER_RECF_INTERLOCK_BE |
783                                              HAMMER_RECF_DELETED_BE |
784                                              HAMMER_RECF_COMMITTED)) {
785                               KKASSERT(cursor->deadlk_rec == NULL);
786                               hammer_ref(&record->lock);
787                               cursor->deadlk_rec = record;
788                               error = EDEADLK;
789                     } else {
790                               KKASSERT(record->type == HAMMER_MEM_RECORD_ADD);
791                               record->flags |= HAMMER_RECF_DELETED_FE;
792                               error = 0;
793                     }
794           } else {
795                     /*
796                      * If the record is on-disk we have to queue the deletion by
797                      * the record's key.  This also causes lookups to skip the
798                      * record (lookups for the purposes of finding an unused
799                      * directory key do not skip the record).
800                      */
801                     KKASSERT(dip->flags &
802                                (HAMMER_INODE_ONDISK | HAMMER_INODE_DONDISK));
803                     record = hammer_alloc_mem_record(dip, 0);
804                     record->type = HAMMER_MEM_RECORD_DEL;
805                     record->leaf.base = cursor->leaf->base;
806                     KKASSERT(dip->obj_id == record->leaf.base.obj_id);
807 
808                     /*
809                      * ip may be NULL, indicating the deletion of a directory
810                      * entry which has no related inode.
811                      */
812                     record->target_ip = ip;
813                     if (ip) {
814                               record->flush_state = HAMMER_FST_SETUP;
815                               TAILQ_INSERT_TAIL(&ip->target_list, record,
816                                                     target_entry);
817                     } else {
818                               record->flush_state = HAMMER_FST_IDLE;
819                     }
820 
821                     /*
822                      * The inode now has a dependancy and must be taken out of
823                      * the idle state.  An inode not in an idle state is given
824                      * an extra reference.
825                      *
826                      * When transitioning to a SETUP state flag for an automatic
827                      * reflush when the dependancies are disposed of if someone
828                      * is waiting on the inode.
829                      */
830                     if (ip && ip->flush_state == HAMMER_FST_IDLE) {
831                               hammer_ref(&ip->lock);
832                               ip->flush_state = HAMMER_FST_SETUP;
833                               if (ip->flags & HAMMER_INODE_FLUSHW)
834                                         ip->flags |= HAMMER_INODE_REFLUSH;
835                     }
836 
837                     error = hammer_mem_add(record);
838           }
839 
840           /*
841            * One less link.  The file may still be open in the OS even after
842            * all links have gone away.
843            *
844            * We have to terminate the cursor before syncing the inode to
845            * avoid deadlocking against ourselves.  XXX this may no longer
846            * be true.
847            *
848            * If nlinks drops to zero and the vnode is inactive (or there is
849            * no vnode), call hammer_inode_unloadable_check() to zonk the
850            * inode.  If we don't do this here the inode will not be destroyed
851            * on-media until we unmount.
852            */
853           if (error == 0) {
854                     if (ip) {
855                               --ip->ino_data.nlinks;        /* do before we might block */
856                               ip->ino_data.ctime = trans->time;
857                     }
858                     dip->ino_data.mtime = trans->time;
859                     hammer_modify_inode(trans, dip, HAMMER_INODE_MTIME);
860                     if (ip) {
861                               hammer_modify_inode(trans, ip, HAMMER_INODE_DDIRTY);
862                               if (ip->ino_data.nlinks == 0 &&
863                                   (ip->vp == NULL || (ip->vp->v_flag & VINACTIVE))) {
864                                         hammer_done_cursor(cursor);
865                                         hammer_inode_unloadable_check(ip, 1);
866                                         hammer_flush_inode(ip, 0);
867                               }
868                     }
869 
870           }
871           return(error);
872 }
873 
874 /*
875  * Add a record to an inode.
876  *
877  * The caller must allocate the record with hammer_alloc_mem_record(ip,len) and
878  * initialize the following additional fields that are not initialized by these
879  * functions.
880  *
881  * The related inode should be share-locked by the caller.  The caller is
882  * on the frontend.
883  *
884  * record->leaf.base.key
885  * record->leaf.base.rec_type
886  * record->leaf.base.localization
887  */
888 int
hammer_ip_add_record(hammer_transaction_t trans,hammer_record_t record)889 hammer_ip_add_record(hammer_transaction_t trans, hammer_record_t record)
890 {
891           hammer_inode_t ip = record->ip;
892           int error;
893 
894           KKASSERT(record->leaf.base.localization != 0);
895           record->leaf.base.obj_id = ip->obj_id;
896           record->leaf.base.obj_type = ip->ino_leaf.base.obj_type;
897           error = hammer_mem_add(record);
898           return(error);
899 }
900 
901 /*
902  * Locate a pre-existing bulk record in memory.  The caller wishes to
903  * replace the record with a new one.  The existing record may have a
904  * different length (and thus a different key) so we have to use an
905  * overlap check function.
906  */
907 static hammer_record_t
hammer_ip_get_bulk(hammer_record_t record)908 hammer_ip_get_bulk(hammer_record_t record)
909 {
910           struct hammer_bulk_info info;
911           hammer_inode_t ip = record->ip;
912 
913           info.record = record;
914           info.conflict = NULL;
915           hammer_rec_rb_tree_RB_SCAN(&ip->rec_tree, hammer_rec_overlap_cmp,
916                                            hammer_bulk_scan_callback, &info);
917 
918           return(info.conflict);        /* may be NULL */
919 }
920 
921 /*
922  * Take records vetted by overlap_cmp.  The first non-deleted record
923  * (if any) stops the scan.
924  */
925 static int
hammer_bulk_scan_callback(hammer_record_t record,void * data)926 hammer_bulk_scan_callback(hammer_record_t record, void *data)
927 {
928           struct hammer_bulk_info *info = data;
929 
930           if (record->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE |
931                                    HAMMER_RECF_COMMITTED)) {
932                     return(0);
933           }
934           hammer_ref(&record->lock);
935           info->conflict = record;
936           return(-1);                             /* stop scan */
937 }
938 
939 /*
940  * Reserve blockmap space placemarked with an in-memory record.
941  *
942  * This routine is called by the frontend in order to be able to directly
943  * flush a buffer cache buffer.  The frontend has locked the related buffer
944  * cache buffers and we should be able to manipulate any overlapping
945  * in-memory records.
946  *
947  * The caller is responsible for adding the returned record and deleting
948  * the returned conflicting record (if any), typically by calling
949  * hammer_ip_replace_bulk() (via hammer_io_direct_write()).
950  */
951 hammer_record_t
hammer_ip_add_bulk(hammer_inode_t ip,off_t file_offset,void * data,int bytes,int * errorp)952 hammer_ip_add_bulk(hammer_inode_t ip, off_t file_offset, void *data, int bytes,
953                        int *errorp)
954 {
955           hammer_record_t record;
956           int zone;
957 
958           /*
959            * Create a record to cover the direct write.  The record cannot
960            * be added to the in-memory RB tree here as it might conflict
961            * with an existing memory record.  See hammer_io_direct_write().
962            *
963            * The backend is responsible for finalizing the space reserved in
964            * this record.
965            *
966            * XXX bytes not aligned, depend on the reservation code to
967            * align the reservation.
968            */
969           record = hammer_alloc_mem_record(ip, 0);
970           zone = hammer_data_zone_index(bytes);
971           record->resv = hammer_blockmap_reserve(ip->hmp, zone, bytes,
972                                                          &record->leaf.data_offset,
973                                                          errorp);
974           if (record->resv == NULL) {
975                     hdkprintf("reservation failed\n");
976                     hammer_rel_mem_record(record);
977                     return(NULL);
978           }
979           record->type = HAMMER_MEM_RECORD_DATA;
980           record->leaf.base.rec_type = HAMMER_RECTYPE_DATA;
981           record->leaf.base.obj_type = ip->ino_leaf.base.obj_type;
982           record->leaf.base.obj_id = ip->obj_id;
983           record->leaf.base.key = file_offset + bytes;
984           record->leaf.base.localization = ip->obj_localization |
985                                                    HAMMER_LOCALIZE_MISC;
986           record->leaf.data_len = bytes;
987           hammer_crc_set_leaf(ip->hmp->version, data, &record->leaf);
988           KKASSERT(*errorp == 0);
989 
990           return(record);
991 }
992 
993 /*
994  * Called by hammer_io_direct_write() prior to any possible completion
995  * of the BIO to emplace the memory record associated with the I/O and
996  * to replace any prior memory record which might still be active.
997  *
998  * Setting the FE deleted flag on the old record (if any) avoids any RB
999  * tree insertion conflict, amoung other things.
1000  *
1001  * This has to be done prior to the caller completing any related buffer
1002  * cache I/O or a reinstantiation of the buffer may load data from the
1003  * old media location instead of the new media location.  The holding
1004  * of the locked buffer cache buffer serves to interlock the record
1005  * replacement operation.
1006  */
1007 void
hammer_ip_replace_bulk(hammer_mount_t hmp,hammer_record_t record)1008 hammer_ip_replace_bulk(hammer_mount_t hmp, hammer_record_t record)
1009 {
1010           hammer_record_t conflict;
1011           int error __debugvar;
1012 
1013           while ((conflict = hammer_ip_get_bulk(record)) != NULL) {
1014                     if ((conflict->flags & HAMMER_RECF_INTERLOCK_BE) == 0) {
1015                               conflict->flags |= HAMMER_RECF_DELETED_FE;
1016                               break;
1017                     }
1018                     conflict->flags |= HAMMER_RECF_WANTED;
1019                     tsleep(conflict, 0, "hmrrc3", 0);
1020                     hammer_rel_mem_record(conflict);
1021           }
1022           error = hammer_mem_add(record);
1023           if (conflict)
1024                     hammer_rel_mem_record(conflict);
1025           KKASSERT(error == 0);
1026 }
1027 
1028 /*
1029  * Frontend truncation code.  Scan in-memory records only.  On-disk records
1030  * and records in a flushing state are handled by the backend.  The vnops
1031  * setattr code will handle the block containing the truncation point.
1032  *
1033  * Partial blocks are not deleted.
1034  *
1035  * This code is only called on regular files.
1036  */
1037 int
hammer_ip_frontend_trunc(hammer_inode_t ip,off_t file_size)1038 hammer_ip_frontend_trunc(hammer_inode_t ip, off_t file_size)
1039 {
1040           struct rec_trunc_info info;
1041 
1042           switch(ip->ino_data.obj_type) {
1043           case HAMMER_OBJTYPE_REGFILE:
1044                     info.rec_type = HAMMER_RECTYPE_DATA;
1045                     break;
1046           case HAMMER_OBJTYPE_DBFILE:
1047                     info.rec_type = HAMMER_RECTYPE_DB;
1048                     break;
1049           default:
1050                     return(EINVAL);
1051           }
1052           info.trunc_off = file_size;
1053           hammer_rec_rb_tree_RB_SCAN(&ip->rec_tree, hammer_rec_trunc_cmp,
1054                                            hammer_frontend_trunc_callback, &info);
1055           return(0);
1056 }
1057 
1058 /*
1059  * Scan callback for frontend records to destroy during a truncation.
1060  * We must ensure that DELETED_FE is set on the record or the frontend
1061  * will get confused in future read() calls.
1062  *
1063  * NOTE: DELETED_FE cannot be set while the record interlock (BE) is held.
1064  *         In this rare case we must wait for the interlock to be cleared.
1065  *
1066  * NOTE: This function is only called on regular files.  There are further
1067  *         restrictions to the setting of DELETED_FE on directory records
1068  *         undergoing a flush due to sensitive inode link count calculations.
1069  */
1070 static int
hammer_frontend_trunc_callback(hammer_record_t record,void * data __unused)1071 hammer_frontend_trunc_callback(hammer_record_t record, void *data __unused)
1072 {
1073           if (record->flags & HAMMER_RECF_DELETED_FE)
1074                     return(0);
1075 #if 0
1076           if (record->flush_state == HAMMER_FST_FLUSH)
1077                     return(0);
1078 #endif
1079           hammer_ref(&record->lock);
1080           while (record->flags & HAMMER_RECF_INTERLOCK_BE)
1081                     hammer_wait_mem_record_ident(record, "hmmtrr");
1082           record->flags |= HAMMER_RECF_DELETED_FE;
1083           hammer_rel_mem_record(record);
1084           return(0);
1085 }
1086 
1087 /*
1088  * Return 1 if the caller must check for and delete existing records
1089  * before writing out a new data record.
1090  *
1091  * Return 0 if the caller can just insert the record into the B-Tree without
1092  * checking.
1093  */
1094 static int
hammer_record_needs_overwrite_delete(hammer_record_t record)1095 hammer_record_needs_overwrite_delete(hammer_record_t record)
1096 {
1097           hammer_inode_t ip = record->ip;
1098           int64_t file_offset;
1099           int r;
1100 
1101           if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DBFILE)
1102                     file_offset = record->leaf.base.key;
1103           else
1104                     file_offset = record->leaf.base.key - record->leaf.data_len;
1105           r = (file_offset < ip->save_trunc_off);
1106           if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DBFILE) {
1107                     if (ip->save_trunc_off <= record->leaf.base.key)
1108                               ip->save_trunc_off = record->leaf.base.key + 1;
1109           } else {
1110                     if (ip->save_trunc_off < record->leaf.base.key)
1111                               ip->save_trunc_off = record->leaf.base.key;
1112           }
1113           return(r);
1114 }
1115 
1116 /*
1117  * Backend code.  Sync a record to the media.
1118  */
1119 int
hammer_ip_sync_record_cursor(hammer_cursor_t cursor,hammer_record_t record)1120 hammer_ip_sync_record_cursor(hammer_cursor_t cursor, hammer_record_t record)
1121 {
1122           hammer_transaction_t trans = cursor->trans;
1123           hammer_mount_t hmp = trans->hmp;
1124           int64_t file_offset;
1125           int bytes;
1126           void *bdata;
1127           int error;
1128           int doprop;
1129 
1130           KKASSERT(record->flush_state == HAMMER_FST_FLUSH);
1131           KKASSERT(record->flags & HAMMER_RECF_INTERLOCK_BE);
1132           KKASSERT(record->leaf.base.localization != 0);
1133 
1134           /*
1135            * Any direct-write related to the record must complete before we
1136            * can sync the record to the on-disk media.
1137            */
1138           if (record->gflags & (HAMMER_RECG_DIRECT_IO | HAMMER_RECG_DIRECT_INVAL))
1139                     hammer_io_direct_wait(record);
1140 
1141           /*
1142            * If this is a bulk-data record placemarker there may be an existing
1143            * record on-disk, indicating a data overwrite.  If there is the
1144            * on-disk record must be deleted before we can insert our new record.
1145            *
1146            * We've synthesized this record and do not know what the create_tid
1147            * on-disk is, nor how much data it represents.
1148            *
1149            * Keep in mind that (key) for data records is (base_offset + len),
1150            * not (base_offset).  Also, we only want to get rid of on-disk
1151            * records since we are trying to sync our in-memory record, call
1152            * hammer_ip_delete_range() with truncating set to 1 to make sure
1153            * it skips in-memory records.
1154            *
1155            * It is ok for the lookup to return ENOENT.
1156            *
1157            * NOTE OPTIMIZATION: sync_trunc_off is used to determine if we have
1158            * to call hammer_ip_delete_range() or not.  This also means we must
1159            * update sync_trunc_off() as we write.
1160            */
1161           if (record->type == HAMMER_MEM_RECORD_DATA &&
1162               hammer_record_needs_overwrite_delete(record)) {
1163                     file_offset = record->leaf.base.key - record->leaf.data_len;
1164                     bytes = HAMMER_BUFSIZE_DOALIGN(record->leaf.data_len);
1165                     KKASSERT((file_offset & HAMMER_BUFMASK) == 0);
1166                     error = hammer_ip_delete_range(
1167                                         cursor, record->ip,
1168                                         file_offset, file_offset + bytes - 1,
1169                                         1);
1170                     if (error && error != ENOENT)
1171                               goto done;
1172           }
1173 
1174           /*
1175            * If this is a general record there may be an on-disk version
1176            * that must be deleted before we can insert the new record.
1177            */
1178           if (record->type == HAMMER_MEM_RECORD_GENERAL) {
1179                     error = hammer_delete_general(cursor, record->ip, &record->leaf);
1180                     if (error && error != ENOENT)
1181                               goto done;
1182           }
1183 
1184           /*
1185            * Setup the cursor.
1186            */
1187           hammer_normalize_cursor(cursor);
1188           cursor->key_beg = record->leaf.base;
1189           cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1190           cursor->flags |= HAMMER_CURSOR_BACKEND;
1191           cursor->flags &= ~HAMMER_CURSOR_INSERT;
1192 
1193           /*
1194            * Records can wind up on-media before the inode itself is on-media.
1195            * Flag the case.
1196            */
1197           record->ip->flags |= HAMMER_INODE_DONDISK;
1198 
1199           /*
1200            * If we are deleting a directory entry an exact match must be
1201            * found on-disk.
1202            */
1203           if (record->type == HAMMER_MEM_RECORD_DEL) {
1204                     error = hammer_btree_lookup(cursor);
1205                     if (error == 0) {
1206                               KKASSERT(cursor->iprec == NULL);
1207                               error = hammer_ip_delete_record(cursor, record->ip,
1208                                                                       trans->tid);
1209                               if (error == 0) {
1210                                         record->flags |= HAMMER_RECF_DELETED_BE |
1211                                                              HAMMER_RECF_COMMITTED;
1212                                         ++record->ip->rec_generation;
1213                               }
1214                     }
1215                     goto done;
1216           }
1217 
1218           /*
1219            * We are inserting.
1220            *
1221            * Issue a lookup to position the cursor and locate the insertion
1222            * point.  The target key should not exist.  If we are creating a
1223            * directory entry we may have to iterate the low 32 bits of the
1224            * key to find an unused key.
1225            */
1226           hammer_sync_lock_sh(trans);
1227           cursor->flags |= HAMMER_CURSOR_INSERT;
1228           error = hammer_btree_lookup(cursor);
1229           if (hammer_debug_inode)
1230                     hdkprintf("DOINSERT LOOKUP %d\n", error);
1231           if (error == 0) {
1232                     hdkprintf("duplicate rec at (%016jx)\n",
1233                               (intmax_t)record->leaf.base.key);
1234                     if (hammer_debug_critical)
1235                               Debugger("duplicate record1");
1236                     error = EIO;
1237           }
1238 
1239           if (error != ENOENT)
1240                     goto done_unlock;
1241 
1242           /*
1243            * Allocate the record and data.  The result buffers will be
1244            * marked as being modified and further calls to
1245            * hammer_modify_buffer() will result in unneeded UNDO records.
1246            *
1247            * Support zero-fill records (data == NULL and data_len != 0)
1248            */
1249           if (record->type == HAMMER_MEM_RECORD_DATA) {
1250                     /*
1251                      * The data portion of a bulk-data record has already been
1252                      * committed to disk, we need only adjust the layer2
1253                      * statistics in the same transaction as our B-Tree insert.
1254                      */
1255                     KKASSERT(record->leaf.data_offset != 0);
1256                     error = hammer_blockmap_finalize(trans,
1257                                                              record->resv,
1258                                                              record->leaf.data_offset,
1259                                                              record->leaf.data_len);
1260           } else if (record->data && record->leaf.data_len) {
1261                     /*
1262                      * Wholely cached record, with data.  Allocate the data.
1263                      */
1264                     bdata = hammer_alloc_data(trans, record->leaf.data_len,
1265                                                     record->leaf.base.rec_type,
1266                                                     &record->leaf.data_offset,
1267                                                     &cursor->data_buffer,
1268                                                     0, &error);
1269                     if (bdata == NULL)
1270                               goto done_unlock;
1271                     hammer_crc_set_leaf(hmp->version, record->data, &record->leaf);
1272                     hammer_modify_buffer_noundo(trans, cursor->data_buffer);
1273                     bcopy(record->data, bdata, record->leaf.data_len);
1274                     hammer_modify_buffer_done(cursor->data_buffer);
1275           } else {
1276                     /*
1277                      * Wholely cached record, without data.
1278                      */
1279                     record->leaf.data_offset = 0;
1280                     record->leaf.data_crc = 0;
1281           }
1282 
1283           error = hammer_btree_insert(cursor, &record->leaf, &doprop);
1284           if (hammer_debug_inode && error) {
1285                     hdkprintf("BTREE INSERT error %d @ %016jx:%d key %016jx\n",
1286                               error,
1287                               (intmax_t)cursor->node->node_offset,
1288                               cursor->index,
1289                               (intmax_t)record->leaf.base.key);
1290           }
1291 
1292           /*
1293            * Our record is on-disk and we normally mark the in-memory version
1294            * as having been committed (and not BE-deleted).
1295            *
1296            * If the record represented a directory deletion but we had to
1297            * sync a valid directory entry to disk due to dependancies,
1298            * we must convert the record to a covering delete so the
1299            * frontend does not have visibility on the synced entry.
1300            *
1301            * WARNING: cursor's leaf pointer may have changed after do_propagation
1302            *            returns!
1303            */
1304           if (error == 0) {
1305                     if (doprop) {
1306                               hammer_btree_do_propagation(cursor, &record->leaf);
1307                     }
1308                     if (record->flags & HAMMER_RECF_CONVERT_DELETE) {
1309                               /*
1310                                * Must convert deleted directory entry add
1311                                * to a directory entry delete.
1312                                */
1313                               KKASSERT(record->type == HAMMER_MEM_RECORD_ADD);
1314                               record->flags &= ~HAMMER_RECF_DELETED_FE;
1315                               record->type = HAMMER_MEM_RECORD_DEL;
1316                               KKASSERT(record->ip->obj_id == record->leaf.base.obj_id);
1317                               KKASSERT(record->flush_state == HAMMER_FST_FLUSH);
1318                               record->flags &= ~HAMMER_RECF_CONVERT_DELETE;
1319                               KKASSERT((record->flags & (HAMMER_RECF_COMMITTED |
1320                                                              HAMMER_RECF_DELETED_BE)) == 0);
1321                               /* converted record is not yet committed */
1322                               /* hammer_flush_record_done takes care of the rest */
1323                     } else {
1324                               /*
1325                                * Everything went fine and we are now done with
1326                                * this record.
1327                                */
1328                               record->flags |= HAMMER_RECF_COMMITTED;
1329                               ++record->ip->rec_generation;
1330                     }
1331           } else {
1332                     if (record->leaf.data_offset) {
1333                               hammer_blockmap_free(trans, record->leaf.data_offset,
1334                                                        record->leaf.data_len);
1335                     }
1336           }
1337 done_unlock:
1338           hammer_sync_unlock(trans);
1339 done:
1340           return(error);
1341 }
1342 
1343 /*
1344  * Add the record to the inode's rec_tree.  The low 32 bits of a directory
1345  * entry's key is used to deal with hash collisions in the upper 32 bits.
1346  * A unique 64 bit key is generated in-memory and may be regenerated a
1347  * second time when the directory record is flushed to the on-disk B-Tree.
1348  *
1349  * A referenced record is passed to this function.  This function
1350  * eats the reference.  If an error occurs the record will be deleted.
1351  *
1352  * A copy of the temporary record->data pointer provided by the caller
1353  * will be made.
1354  */
1355 int
hammer_mem_add(hammer_record_t record)1356 hammer_mem_add(hammer_record_t record)
1357 {
1358           hammer_mount_t hmp = record->ip->hmp;
1359 
1360           /*
1361            * Make a private copy of record->data
1362            */
1363           if (record->data)
1364                     KKASSERT(record->flags & HAMMER_RECF_ALLOCDATA);
1365 
1366           /*
1367            * Insert into the RB tree.  A unique key should have already
1368            * been selected if this is a directory entry.
1369            */
1370           if (RB_INSERT(hammer_rec_rb_tree, &record->ip->rec_tree, record)) {
1371                     record->flags |= HAMMER_RECF_DELETED_FE;
1372                     hammer_rel_mem_record(record);
1373                     return (EEXIST);
1374           }
1375           ++hmp->rsv_recs;
1376           ++record->ip->rsv_recs;
1377           record->ip->hmp->rsv_databytes += record->leaf.data_len;
1378           record->flags |= HAMMER_RECF_ONRBTREE;
1379           hammer_modify_inode(NULL, record->ip, HAMMER_INODE_XDIRTY);
1380           hammer_rel_mem_record(record);
1381           return(0);
1382 }
1383 
1384 /************************************************************************
1385  *                       HAMMER INODE MERGED-RECORD FUNCTIONS                   *
1386  ************************************************************************
1387  *
1388  * These functions augment the B-Tree scanning functions in hammer_btree.c
1389  * by merging in-memory records with on-disk records.
1390  */
1391 
1392 /*
1393  * Locate a particular record either in-memory or on-disk.
1394  *
1395  * NOTE: This is basically a standalone routine, hammer_ip_next() may
1396  * NOT be called to iterate results.
1397  */
1398 int
hammer_ip_lookup(hammer_cursor_t cursor)1399 hammer_ip_lookup(hammer_cursor_t cursor)
1400 {
1401           int error;
1402 
1403           /*
1404            * If the element is in-memory return it without searching the
1405            * on-disk B-Tree
1406            */
1407           KKASSERT(cursor->ip);
1408           error = hammer_mem_lookup(cursor);
1409           if (error == 0) {
1410                     cursor->leaf = &cursor->iprec->leaf;
1411                     return(error);
1412           }
1413           if (error != ENOENT)
1414                     return(error);
1415 
1416           /*
1417            * If the inode has on-disk components search the on-disk B-Tree.
1418            */
1419           if ((cursor->ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DONDISK)) == 0)
1420                     return(error);
1421           error = hammer_btree_lookup(cursor);
1422           if (error == 0)
1423                     error = hammer_btree_extract_leaf(cursor);
1424           return(error);
1425 }
1426 
1427 /*
1428  * Helper for hammer_ip_first()/hammer_ip_next()
1429  *
1430  * NOTE: Both ATEDISK and DISKEOF will be set the same.  This sets up
1431  * hammer_ip_first() for calling hammer_ip_next(), and sets up the re-seek
1432  * state if hammer_ip_next() needs to re-seek.
1433  */
1434 static __inline
1435 int
_hammer_ip_seek_btree(hammer_cursor_t cursor)1436 _hammer_ip_seek_btree(hammer_cursor_t cursor)
1437 {
1438           hammer_inode_t ip = cursor->ip;
1439           int error;
1440 
1441           if (ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DONDISK)) {
1442                     error = hammer_btree_lookup(cursor);
1443                     if (error == ENOENT || error == EDEADLK) {
1444                               if (hammer_debug_general & 0x2000) {
1445                                         hdkprintf("error %d node %p %016jx index %d\n",
1446                                                   error, cursor->node,
1447                                                   (intmax_t)cursor->node->node_offset,
1448                                                   cursor->index);
1449                               }
1450                               cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
1451                               error = hammer_btree_iterate(cursor);
1452                     }
1453                     if (error == 0) {
1454                               cursor->flags &= ~(HAMMER_CURSOR_DISKEOF |
1455                                                      HAMMER_CURSOR_ATEDISK);
1456                     } else {
1457                               cursor->flags |= HAMMER_CURSOR_DISKEOF |
1458                                                    HAMMER_CURSOR_ATEDISK;
1459                               if (error == ENOENT)
1460                                         error = 0;
1461                     }
1462           } else {
1463                     cursor->flags |= HAMMER_CURSOR_DISKEOF | HAMMER_CURSOR_ATEDISK;
1464                     error = 0;
1465           }
1466           return(error);
1467 }
1468 
1469 /*
1470  * Helper for hammer_ip_next()
1471  *
1472  * The caller has determined that the media cursor is further along than the
1473  * memory cursor and must be reseeked after a generation number change.
1474  */
1475 static
1476 int
_hammer_ip_reseek(hammer_cursor_t cursor)1477 _hammer_ip_reseek(hammer_cursor_t cursor)
1478 {
1479           struct hammer_base_elm save;
1480           hammer_btree_elm_t elm;
1481           int error __debugvar;
1482           int r;
1483           int again = 0;
1484 
1485           /*
1486            * Do the re-seek.
1487            */
1488           hkprintf("Debug: re-seeked during scan @ino=%016jx\n",
1489                     (intmax_t)cursor->ip->obj_id);
1490           save = cursor->key_beg;
1491           cursor->key_beg = cursor->iprec->leaf.base;
1492           error = _hammer_ip_seek_btree(cursor);
1493           KKASSERT(error == 0);
1494           cursor->key_beg = save;
1495 
1496           /*
1497            * If the memory record was previous returned to
1498            * the caller and the media record matches
1499            * (-1/+1: only create_tid differs), then iterate
1500            * the media record to avoid a double result.
1501            */
1502           if ((cursor->flags & HAMMER_CURSOR_ATEDISK) == 0 &&
1503               (cursor->flags & HAMMER_CURSOR_LASTWASMEM)) {
1504                     elm = &cursor->node->ondisk->elms[cursor->index];
1505                     r = hammer_btree_cmp(&elm->base, &cursor->iprec->leaf.base);
1506                     if (cursor->flags & HAMMER_CURSOR_ASOF) {
1507                               if (r >= -1 && r <= 1) {
1508                                         hkprintf("Debug: iterated after "
1509                                                   "re-seek (asof r=%d)\n", r);
1510                                         cursor->flags |= HAMMER_CURSOR_ATEDISK;
1511                                         again = 1;
1512                               }
1513                     } else {
1514                               if (r == 0) {
1515                                         hkprintf("Debug: iterated after "
1516                                                   "re-seek\n");
1517                                         cursor->flags |= HAMMER_CURSOR_ATEDISK;
1518                                         again = 1;
1519                               }
1520                     }
1521           }
1522           return(again);
1523 }
1524 
1525 /*
1526  * Locate the first record within the cursor's key_beg/key_end range,
1527  * restricted to a particular inode.  0 is returned on success, ENOENT
1528  * if no records matched the requested range, or some other error.
1529  *
1530  * When 0 is returned hammer_ip_next() may be used to iterate additional
1531  * records within the requested range.
1532  *
1533  * This function can return EDEADLK, requiring the caller to terminate
1534  * the cursor and try again.
1535  */
1536 
1537 int
hammer_ip_first(hammer_cursor_t cursor)1538 hammer_ip_first(hammer_cursor_t cursor)
1539 {
1540           hammer_inode_t ip __debugvar = cursor->ip;
1541           int error;
1542 
1543           KKASSERT(ip != NULL);
1544 
1545           /*
1546            * Clean up fields and setup for merged scan
1547            */
1548           cursor->flags &= ~HAMMER_CURSOR_RETEST;
1549 
1550           /*
1551            * Search the in-memory record list (Red-Black tree).  Unlike the
1552            * B-Tree search, mem_first checks for records in the range.
1553            *
1554            * This function will setup both ATEMEM and MEMEOF properly for
1555            * the ip iteration.  ATEMEM will be set if MEMEOF is set.
1556            */
1557           hammer_mem_first(cursor);
1558 
1559           /*
1560            * Detect generation changes during blockages, including
1561            * blockages which occur on the initial btree search.
1562            */
1563           cursor->rec_generation = cursor->ip->rec_generation;
1564 
1565           /*
1566            * Initial search and result
1567            */
1568           error = _hammer_ip_seek_btree(cursor);
1569           if (error == 0)
1570                     error = hammer_ip_next(cursor);
1571 
1572           return (error);
1573 }
1574 
1575 /*
1576  * Retrieve the next record in a merged iteration within the bounds of the
1577  * cursor.  This call may be made multiple times after the cursor has been
1578  * initially searched with hammer_ip_first().
1579  *
1580  * There are numerous special cases in this code to deal with races between
1581  * in-memory records and on-media records.
1582  *
1583  * 0 is returned on success, ENOENT if no further records match the
1584  * requested range, or some other error code is returned.
1585  */
1586 int
hammer_ip_next(hammer_cursor_t cursor)1587 hammer_ip_next(hammer_cursor_t cursor)
1588 {
1589           hammer_btree_elm_t elm;
1590           hammer_record_t rec;
1591           hammer_record_t tmprec;
1592           int error;
1593           int r;
1594 
1595 again:
1596           /*
1597            * Get the next on-disk record
1598            *
1599            * NOTE: If we deleted the last on-disk record we had scanned
1600            *         ATEDISK will be clear and RETEST will be set, forcing
1601            *         a call to iterate.  The fact that ATEDISK is clear causes
1602            *         iterate to re-test the 'current' element.  If ATEDISK is
1603            *         set, iterate will skip the 'current' element.
1604            */
1605           error = 0;
1606           if ((cursor->flags & HAMMER_CURSOR_DISKEOF) == 0) {
1607                     if (cursor->flags & (HAMMER_CURSOR_ATEDISK |
1608                                              HAMMER_CURSOR_RETEST)) {
1609                               error = hammer_btree_iterate(cursor);
1610                               cursor->flags &= ~HAMMER_CURSOR_RETEST;
1611                               if (error == 0) {
1612                                         cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
1613                                         hammer_cache_node(&cursor->ip->cache[1],
1614                                                               cursor->node);
1615                               } else if (error == ENOENT) {
1616                                         cursor->flags |= HAMMER_CURSOR_DISKEOF |
1617                                                              HAMMER_CURSOR_ATEDISK;
1618                                         error = 0;
1619                               }
1620                     }
1621           }
1622 
1623           /*
1624            * If the generation changed the backend has deleted or committed
1625            * one or more memory records since our last check.
1626            *
1627            * When this case occurs if the disk cursor is > current memory record
1628            * or the disk cursor is at EOF, we must re-seek the disk-cursor.
1629            * Since the cursor is ahead it must have not yet been eaten (if
1630            * not at eof anyway). (XXX data offset case?)
1631            *
1632            * NOTE: we are not doing a full check here.  That will be handled
1633            * later on.
1634            *
1635            * If we have exhausted all memory records we do not have to do any
1636            * further seeks.
1637            */
1638           while (cursor->rec_generation != cursor->ip->rec_generation &&
1639                  error == 0) {
1640                     hkprintf("Debug: generation changed during scan @ino=%016jx\n",
1641                               (intmax_t)cursor->ip->obj_id);
1642                     cursor->rec_generation = cursor->ip->rec_generation;
1643                     if (cursor->flags & HAMMER_CURSOR_MEMEOF)
1644                               break;
1645                     if (cursor->flags & HAMMER_CURSOR_DISKEOF) {
1646                               r = 1;
1647                     } else {
1648                               KKASSERT((cursor->flags & HAMMER_CURSOR_ATEDISK) == 0);
1649                               elm = &cursor->node->ondisk->elms[cursor->index];
1650                               r = hammer_btree_cmp(&elm->base,
1651                                                        &cursor->iprec->leaf.base);
1652                     }
1653 
1654                     /*
1655                      * Do we re-seek the media cursor?
1656                      */
1657                     if (r > 0) {
1658                               if (_hammer_ip_reseek(cursor))
1659                                         goto again;
1660                     }
1661           }
1662 
1663           /*
1664            * We can now safely get the next in-memory record.  We cannot
1665            * block here.
1666            *
1667            * hammer_rec_scan_cmp:  Is the record still in our general range,
1668            *                             (non-inclusive of snapshot exclusions)?
1669            * hammer_rec_scan_callback: Is the record in our snapshot?
1670            */
1671           tmprec = NULL;
1672           if ((cursor->flags & HAMMER_CURSOR_MEMEOF) == 0) {
1673                     /*
1674                      * If the current memory record was eaten then get the next
1675                      * one.  Stale records are skipped.
1676                      */
1677                     if (cursor->flags & HAMMER_CURSOR_ATEMEM) {
1678                               tmprec = cursor->iprec;
1679                               cursor->iprec = NULL;
1680                               rec = hammer_rec_rb_tree_RB_NEXT(tmprec);
1681                               while (rec) {
1682                                         if (hammer_rec_scan_cmp(rec, cursor) != 0)
1683                                                   break;
1684                                         if (hammer_rec_scan_callback(rec, cursor) != 0)
1685                                                   break;
1686                                         rec = hammer_rec_rb_tree_RB_NEXT(rec);
1687                               }
1688                               if (cursor->iprec) {
1689                                         KKASSERT(cursor->iprec == rec);
1690                                         cursor->flags &= ~HAMMER_CURSOR_ATEMEM;
1691                               } else {
1692                                         cursor->flags |= HAMMER_CURSOR_MEMEOF;
1693                               }
1694                               cursor->flags &= ~HAMMER_CURSOR_LASTWASMEM;
1695                     }
1696           }
1697 
1698           /*
1699            * MEMORY RECORD VALIDITY TEST
1700            *
1701            * (We still can't block, which is why tmprec is being held so
1702            * long).
1703            *
1704            * If the memory record is no longer valid we skip it.  It may
1705            * have been deleted by the frontend.  If it was deleted or
1706            * committed by the backend the generation change re-seeked the
1707            * disk cursor and the record will be present there.
1708            */
1709           if (error == 0 && (cursor->flags & HAMMER_CURSOR_MEMEOF) == 0) {
1710                     KKASSERT(cursor->iprec);
1711                     KKASSERT((cursor->flags & HAMMER_CURSOR_ATEMEM) == 0);
1712                     if (!hammer_ip_iterate_mem_good(cursor, cursor->iprec)) {
1713                               cursor->flags |= HAMMER_CURSOR_ATEMEM;
1714                               if (tmprec)
1715                                         hammer_rel_mem_record(tmprec);
1716                               goto again;
1717                     }
1718           }
1719           if (tmprec)
1720                     hammer_rel_mem_record(tmprec);
1721 
1722           /*
1723            * Extract either the disk or memory record depending on their
1724            * relative position.
1725            */
1726           error = 0;
1727           switch(cursor->flags & (HAMMER_CURSOR_ATEDISK | HAMMER_CURSOR_ATEMEM)) {
1728           case 0:
1729                     /*
1730                      * Both entries valid.   Compare the entries and nominally
1731                      * return the first one in the sort order.  Numerous cases
1732                      * require special attention, however.
1733                      */
1734                     elm = &cursor->node->ondisk->elms[cursor->index];
1735                     r = hammer_btree_cmp(&elm->base, &cursor->iprec->leaf.base);
1736 
1737                     /*
1738                      * If the two entries differ only by their key (-2/2) or
1739                      * create_tid (-1/1), and are DATA records, we may have a
1740                      * nominal match.  We have to calculate the base file
1741                      * offset of the data.
1742                      */
1743                     if (r <= 2 && r >= -2 && r != 0 &&
1744                         cursor->ip->ino_data.obj_type == HAMMER_OBJTYPE_REGFILE &&
1745                         cursor->iprec->type == HAMMER_MEM_RECORD_DATA) {
1746                               int64_t base1 = elm->leaf.base.key - elm->leaf.data_len;
1747                               int64_t base2 = cursor->iprec->leaf.base.key -
1748                                                   cursor->iprec->leaf.data_len;
1749                               if (base1 == base2)
1750                                         r = 0;
1751                     }
1752 
1753                     if (r < 0) {
1754                               error = hammer_btree_extract_leaf(cursor);
1755                               cursor->flags |= HAMMER_CURSOR_ATEDISK;
1756                               cursor->flags &= ~HAMMER_CURSOR_LASTWASMEM;
1757                               break;
1758                     }
1759 
1760                     /*
1761                      * If the entries match exactly the memory entry is either
1762                      * an on-disk directory entry deletion or a bulk data
1763                      * overwrite.  If it is a directory entry deletion we eat
1764                      * both entries.
1765                      *
1766                      * For the bulk-data overwrite case it is possible to have
1767                      * visibility into both, which simply means the syncer
1768                      * hasn't gotten around to doing the delete+insert sequence
1769                      * on the B-Tree.  Use the memory entry and throw away the
1770                      * on-disk entry.
1771                      *
1772                      * If the in-memory record is not either of these we
1773                      * probably caught the syncer while it was syncing it to
1774                      * the media.  Since we hold a shared lock on the cursor,
1775                      * the in-memory record had better be marked deleted at
1776                      * this point.
1777                      */
1778                     if (r == 0) {
1779                               if (cursor->iprec->type == HAMMER_MEM_RECORD_DEL) {
1780                                         if ((cursor->flags & HAMMER_CURSOR_DELETE_VISIBILITY) == 0) {
1781                                                   cursor->flags |= HAMMER_CURSOR_ATEDISK;
1782                                                   cursor->flags |= HAMMER_CURSOR_ATEMEM;
1783                                                   goto again;
1784                                         }
1785                               } else if (cursor->iprec->type == HAMMER_MEM_RECORD_DATA) {
1786                                         if ((cursor->flags & HAMMER_CURSOR_DELETE_VISIBILITY) == 0) {
1787                                                   cursor->flags |= HAMMER_CURSOR_ATEDISK;
1788                                         }
1789                                         /* fall through to memory entry */
1790                               } else {
1791                                         hpanic("duplicate mem/B-Tree entry %p %d %08x",
1792                                                   cursor->iprec,
1793                                                   cursor->iprec->type,
1794                                                   cursor->iprec->flags);
1795                                         cursor->flags |= HAMMER_CURSOR_ATEMEM;
1796                                         goto again;
1797                               }
1798                     }
1799                     /* fall through to the memory entry */
1800           case HAMMER_CURSOR_ATEDISK:
1801                     /*
1802                      * Only the memory entry is valid.
1803                      */
1804                     cursor->leaf = &cursor->iprec->leaf;
1805                     cursor->flags |= HAMMER_CURSOR_ATEMEM;
1806                     cursor->flags |= HAMMER_CURSOR_LASTWASMEM;
1807 
1808                     /*
1809                      * If the memory entry is an on-disk deletion we should have
1810                      * also had found a B-Tree record.  If the backend beat us
1811                      * to it it would have interlocked the cursor and we should
1812                      * have seen the in-memory record marked DELETED_FE.
1813                      */
1814                     if (cursor->iprec->type == HAMMER_MEM_RECORD_DEL &&
1815                         (cursor->flags & HAMMER_CURSOR_DELETE_VISIBILITY) == 0) {
1816                               hpanic("del-on-disk with no B-Tree entry iprec %p flags %08x",
1817                                         cursor->iprec,
1818                                         cursor->iprec->flags);
1819                     }
1820                     break;
1821           case HAMMER_CURSOR_ATEMEM:
1822                     /*
1823                      * Only the disk entry is valid
1824                      */
1825                     error = hammer_btree_extract_leaf(cursor);
1826                     cursor->flags |= HAMMER_CURSOR_ATEDISK;
1827                     cursor->flags &= ~HAMMER_CURSOR_LASTWASMEM;
1828                     break;
1829           default:
1830                     /*
1831                      * Neither entry is valid
1832                      *
1833                      * XXX error not set properly
1834                      */
1835                     cursor->flags &= ~HAMMER_CURSOR_LASTWASMEM;
1836                     cursor->leaf = NULL;
1837                     error = ENOENT;
1838                     break;
1839           }
1840           return(error);
1841 }
1842 
1843 /*
1844  * Resolve the cursor->data pointer for the current cursor position in
1845  * a merged iteration.
1846  */
1847 int
hammer_ip_resolve_data(hammer_cursor_t cursor)1848 hammer_ip_resolve_data(hammer_cursor_t cursor)
1849 {
1850           hammer_record_t record;
1851           int error;
1852 
1853           if (hammer_cursor_inmem(cursor)) {
1854                     /*
1855                      * The data associated with an in-memory record is usually
1856                      * kmalloced, but reserve-ahead data records will have an
1857                      * on-disk reference.
1858                      *
1859                      * NOTE: Reserve-ahead data records must be handled in the
1860                      *         context of the related high level buffer cache buffer
1861                      *         to interlock against async writes.
1862                      *
1863                      * NOTE: We might catch a direct write in-progress, in which
1864                      *         case we must wait for it to complete.  The wait
1865                      *         function will also clean out any buffer aliases.
1866                      *
1867                      *         (In fact, it is possible that the write had not
1868                      *          even started yet).
1869                      */
1870                     record = cursor->iprec;
1871                     cursor->data = record->data;
1872                     error = 0;
1873                     if (cursor->data == NULL) {
1874                               hammer_io_direct_wait(record);
1875                               KKASSERT(record->leaf.base.rec_type ==
1876                                          HAMMER_RECTYPE_DATA);
1877                               cursor->data = hammer_bread_ext(cursor->trans->hmp,
1878                                                                 record->leaf.data_offset,
1879                                                                 record->leaf.data_len,
1880                                                                 &error,
1881                                                                 &cursor->data_buffer);
1882                     }
1883           } else {
1884                     /*
1885                      * Loading leaf here isn't necessary if it's guaranteed that
1886                      * the cursor is at a leaf node (which basically should be)
1887                      * because hammer_btree_extract_data() does that.
1888                      */
1889                     cursor->leaf = &cursor->node->ondisk->elms[cursor->index].leaf;
1890                     error = hammer_btree_extract_data(cursor);
1891           }
1892           return(error);
1893 }
1894 
1895 /*
1896  * Backend truncation / record replacement - delete records in range.
1897  *
1898  * Delete all records within the specified range for inode ip.  In-memory
1899  * records still associated with the frontend are ignored.
1900  *
1901  * If truncating is non-zero in-memory records associated with the back-end
1902  * are ignored.  If truncating is > 1 we can return EWOULDBLOCK.
1903  *
1904  * NOTES:
1905  *
1906  *        * An unaligned range will cause new records to be added to cover
1907  *        the edge cases. (XXX not implemented yet).
1908  *
1909  *        * Replacement via reservations (see hammer_ip_sync_record_cursor())
1910  *        also do not deal with unaligned ranges.
1911  *
1912  *        * ran_end is inclusive (e.g. 0,1023 instead of 0,1024).
1913  *
1914  *        * Record keys for regular file data have to be special-cased since
1915  *          they indicate the end of the range (key = base + bytes).
1916  *
1917  *        * This function may be asked to delete ridiculously huge ranges, for
1918  *          example if someone truncates or removes a 1TB regular file.  We
1919  *          must be very careful on restarts and we may have to stop w/
1920  *          EWOULDBLOCK to avoid blowing out the buffer cache.
1921  */
1922 int
hammer_ip_delete_range(hammer_cursor_t cursor,hammer_inode_t ip,int64_t ran_beg,int64_t ran_end,int truncating)1923 hammer_ip_delete_range(hammer_cursor_t cursor, hammer_inode_t ip,
1924                            int64_t ran_beg, int64_t ran_end, int truncating)
1925 {
1926           hammer_transaction_t trans = cursor->trans;
1927           hammer_btree_leaf_elm_t leaf;
1928           int error;
1929           int64_t off;
1930           int64_t tmp64;
1931 
1932           KKASSERT(trans->type == HAMMER_TRANS_FLS);
1933 retry:
1934           hammer_normalize_cursor(cursor);
1935           cursor->key_beg.localization = ip->obj_localization |
1936                                                HAMMER_LOCALIZE_MISC;
1937           cursor->key_beg.obj_id = ip->obj_id;
1938           cursor->key_beg.create_tid = 0;
1939           cursor->key_beg.delete_tid = 0;
1940           cursor->key_beg.obj_type = 0;
1941 
1942           if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DBFILE) {
1943                     cursor->key_beg.key = ran_beg;
1944                     cursor->key_beg.rec_type = HAMMER_RECTYPE_DB;
1945           } else {
1946                     /*
1947                      * The key in the B-Tree is (base+bytes), so the first possible
1948                      * matching key is ran_beg + 1.
1949                      */
1950                     cursor->key_beg.key = ran_beg + 1;
1951                     cursor->key_beg.rec_type = HAMMER_RECTYPE_DATA;
1952           }
1953 
1954           cursor->key_end = cursor->key_beg;
1955           if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DBFILE) {
1956                     cursor->key_end.key = ran_end;
1957           } else {
1958                     tmp64 = ran_end + MAXPHYS + 1;          /* work around GCC-4 bug */
1959                     if (tmp64 < ran_end)
1960                               cursor->key_end.key = HAMMER_MAX_KEY;
1961                     else
1962                               cursor->key_end.key = ran_end + MAXPHYS + 1;
1963           }
1964 
1965           cursor->asof = ip->obj_asof;
1966           cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1967           cursor->flags |= HAMMER_CURSOR_ASOF;
1968           cursor->flags |= HAMMER_CURSOR_DELETE_VISIBILITY;
1969           cursor->flags |= HAMMER_CURSOR_BACKEND;
1970           cursor->flags |= HAMMER_CURSOR_END_INCLUSIVE;
1971 
1972           error = hammer_ip_first(cursor);
1973 
1974           /*
1975            * Iterate through matching records and mark them as deleted.
1976            */
1977           while (error == 0) {
1978                     leaf = cursor->leaf;
1979 
1980                     KKASSERT(leaf->base.delete_tid == 0);
1981                     KKASSERT(leaf->base.obj_id == ip->obj_id);
1982 
1983                     /*
1984                      * There may be overlap cases for regular file data.  Also
1985                      * remember the key for a regular file record is (base + len),
1986                      * NOT (base).
1987                      *
1988                      * Note that due to duplicates (mem & media) allowed by
1989                      * DELETE_VISIBILITY, off can wind up less then ran_beg.
1990                      */
1991                     if (leaf->base.rec_type == HAMMER_RECTYPE_DATA) {
1992                               off = leaf->base.key - leaf->data_len;
1993                               /*
1994                                * Check the left edge case.  We currently do not
1995                                * split existing records.
1996                                */
1997                               if (off < ran_beg && leaf->base.key > ran_beg) {
1998                                         hpanic("hammer left edge case %016jx %d",
1999                                                   (intmax_t)leaf->base.key,
2000                                                   leaf->data_len);
2001                               }
2002 
2003                               /*
2004                                * Check the right edge case.  Note that the
2005                                * record can be completely out of bounds, which
2006                                * terminates the search.
2007                                *
2008                                * base->key is exclusive of the right edge while
2009                                * ran_end is inclusive of the right edge.  The
2010                                * (key - data_len) left boundary is inclusive.
2011                                *
2012                                * XXX theory-check this test at some point, are
2013                                * we missing a + 1 somewhere?  Note that ran_end
2014                                * could overflow.
2015                                */
2016                               if (leaf->base.key - 1 > ran_end) {
2017                                         if (leaf->base.key - leaf->data_len > ran_end)
2018                                                   break;
2019                                         hpanic("hammer right edge case");
2020                               }
2021                     } else {
2022                               off = leaf->base.key;
2023                     }
2024 
2025                     /*
2026                      * Delete the record.  When truncating we do not delete
2027                      * in-memory (data) records because they represent data
2028                      * written after the truncation.
2029                      *
2030                      * This will also physically destroy the B-Tree entry and
2031                      * data if the retention policy dictates.  The function
2032                      * will set HAMMER_CURSOR_RETEST to cause hammer_ip_next()
2033                      * to retest the new 'current' element.
2034                      */
2035                     if (truncating == 0 || hammer_cursor_ondisk(cursor)) {
2036                               error = hammer_ip_delete_record(cursor, ip, trans->tid);
2037                               /*
2038                                * If we have built up too many meta-buffers we risk
2039                                * deadlocking the kernel and must stop.  This can
2040                                * occur when deleting ridiculously huge files.
2041                                * sync_trunc_off is updated so the next cycle does
2042                                * not re-iterate records we have already deleted.
2043                                *
2044                                * This is only done with formal truncations.
2045                                */
2046                               if (truncating > 1 && error == 0 &&
2047                                   hammer_flusher_meta_limit(ip->hmp)) {
2048                                         ip->sync_trunc_off = off;
2049                                         error = EWOULDBLOCK;
2050                               }
2051                     }
2052                     if (error)
2053                               break;
2054                     ran_beg = off;      /* for restart */
2055                     error = hammer_ip_next(cursor);
2056           }
2057           if (cursor->node)
2058                     hammer_cache_node(&ip->cache[1], cursor->node);
2059 
2060           if (error == EDEADLK) {
2061                     hammer_done_cursor(cursor);
2062                     error = hammer_init_cursor(trans, cursor, &ip->cache[1], ip);
2063                     if (error == 0)
2064                               goto retry;
2065           }
2066           if (error == ENOENT)
2067                     error = 0;
2068           return(error);
2069 }
2070 
2071 /*
2072  * This backend function deletes the specified record on-disk, similar to
2073  * delete_range but for a specific record.  Unlike the exact deletions
2074  * used when deleting a directory entry this function uses an ASOF search
2075  * like delete_range.
2076  *
2077  * This function may be called with ip->obj_asof set for a slave snapshot,
2078  * so don't use it.  We always delete non-historical records only.
2079  */
2080 static int
hammer_delete_general(hammer_cursor_t cursor,hammer_inode_t ip,hammer_btree_leaf_elm_t leaf)2081 hammer_delete_general(hammer_cursor_t cursor, hammer_inode_t ip,
2082                           hammer_btree_leaf_elm_t leaf)
2083 {
2084           hammer_transaction_t trans = cursor->trans;
2085           int error;
2086 
2087           KKASSERT(trans->type == HAMMER_TRANS_FLS);
2088 retry:
2089           hammer_normalize_cursor(cursor);
2090           cursor->key_beg = leaf->base;
2091           cursor->asof = HAMMER_MAX_TID;
2092           cursor->flags &= ~HAMMER_CURSOR_INITMASK;
2093           cursor->flags |= HAMMER_CURSOR_ASOF;
2094           cursor->flags |= HAMMER_CURSOR_BACKEND;
2095           cursor->flags &= ~HAMMER_CURSOR_INSERT;
2096 
2097           error = hammer_btree_lookup(cursor);
2098           if (error == 0) {
2099                     error = hammer_ip_delete_record(cursor, ip, trans->tid);
2100           }
2101           if (error == EDEADLK) {
2102                     hammer_done_cursor(cursor);
2103                     error = hammer_init_cursor(trans, cursor, &ip->cache[1], ip);
2104                     if (error == 0)
2105                               goto retry;
2106           }
2107           return(error);
2108 }
2109 
2110 /*
2111  * This function deletes remaining auxillary records when an inode is
2112  * being deleted.  This function explicitly does not delete the
2113  * inode record, directory entry, data, or db records.  Those must be
2114  * properly disposed of prior to this call.
2115  */
2116 int
hammer_ip_delete_clean(hammer_cursor_t cursor,hammer_inode_t ip,int * countp)2117 hammer_ip_delete_clean(hammer_cursor_t cursor, hammer_inode_t ip, int *countp)
2118 {
2119           hammer_transaction_t trans = cursor->trans;
2120           hammer_btree_leaf_elm_t leaf __debugvar;
2121           int error;
2122 
2123           KKASSERT(trans->type == HAMMER_TRANS_FLS);
2124 retry:
2125           hammer_normalize_cursor(cursor);
2126           cursor->key_beg.localization = ip->obj_localization |
2127                                                HAMMER_LOCALIZE_MISC;
2128           cursor->key_beg.obj_id = ip->obj_id;
2129           cursor->key_beg.create_tid = 0;
2130           cursor->key_beg.delete_tid = 0;
2131           cursor->key_beg.obj_type = 0;
2132           cursor->key_beg.rec_type = HAMMER_RECTYPE_CLEAN_START;
2133           cursor->key_beg.key = HAMMER_MIN_KEY;
2134 
2135           cursor->key_end = cursor->key_beg;
2136           cursor->key_end.rec_type = HAMMER_RECTYPE_MAX;
2137           cursor->key_end.key = HAMMER_MAX_KEY;
2138 
2139           cursor->asof = ip->obj_asof;
2140           cursor->flags &= ~HAMMER_CURSOR_INITMASK;
2141           cursor->flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF;
2142           cursor->flags |= HAMMER_CURSOR_DELETE_VISIBILITY;
2143           cursor->flags |= HAMMER_CURSOR_BACKEND;
2144 
2145           error = hammer_ip_first(cursor);
2146 
2147           /*
2148            * Iterate through matching records and mark them as deleted.
2149            */
2150           while (error == 0) {
2151                     leaf = cursor->leaf;
2152 
2153                     KKASSERT(leaf->base.delete_tid == 0);
2154 
2155                     /*
2156                      * Mark the record and B-Tree entry as deleted.  This will
2157                      * also physically delete the B-Tree entry, record, and
2158                      * data if the retention policy dictates.  The function
2159                      * will set HAMMER_CURSOR_RETEST to cause hammer_ip_next()
2160                      * to retest the new 'current' element.
2161                      *
2162                      * Directory entries (and delete-on-disk directory entries)
2163                      * must be synced and cannot be deleted.
2164                      */
2165                     error = hammer_ip_delete_record(cursor, ip, trans->tid);
2166                     ++*countp;
2167                     if (error)
2168                               break;
2169                     error = hammer_ip_next(cursor);
2170           }
2171           if (cursor->node)
2172                     hammer_cache_node(&ip->cache[1], cursor->node);
2173           if (error == EDEADLK) {
2174                     hammer_done_cursor(cursor);
2175                     error = hammer_init_cursor(trans, cursor, &ip->cache[1], ip);
2176                     if (error == 0)
2177                               goto retry;
2178           }
2179           if (error == ENOENT)
2180                     error = 0;
2181           return(error);
2182 }
2183 
2184 /*
2185  * Delete the record at the current cursor.  On success the cursor will
2186  * be positioned appropriately for an iteration but may no longer be at
2187  * a leaf node.
2188  *
2189  * This routine is only called from the backend.
2190  *
2191  * NOTE: This can return EDEADLK, requiring the caller to terminate the
2192  * cursor and retry.
2193  */
2194 int
hammer_ip_delete_record(hammer_cursor_t cursor,hammer_inode_t ip,hammer_tid_t tid)2195 hammer_ip_delete_record(hammer_cursor_t cursor, hammer_inode_t ip,
2196                               hammer_tid_t tid)
2197 {
2198           hammer_record_t iprec;
2199           int error;
2200 
2201           KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND);
2202           KKASSERT(tid != 0);
2203 
2204           /*
2205            * In-memory (unsynchronized) records can simply be freed.  This
2206            * only occurs in range iterations since all other records are
2207            * individually synchronized.  Thus there should be no confusion with
2208            * the interlock.
2209            *
2210            * An in-memory record may be deleted before being committed to disk,
2211            * but could have been accessed in the mean time.  The reservation
2212            * code will deal with the case.
2213            */
2214           if (hammer_cursor_inmem(cursor)) {
2215                     iprec = cursor->iprec;
2216                     KKASSERT((iprec->flags & HAMMER_RECF_INTERLOCK_BE) ==0);
2217                     iprec->flags |= HAMMER_RECF_DELETED_FE;
2218                     iprec->flags |= HAMMER_RECF_DELETED_BE;
2219                     KKASSERT(iprec->ip == ip);
2220                     ++ip->rec_generation;
2221                     return(0);
2222           }
2223 
2224           /*
2225            * On-disk records are marked as deleted by updating their delete_tid.
2226            * This does not effect their position in the B-Tree (which is based
2227            * on their create_tid).
2228            *
2229            * Frontend B-Tree operations track inodes so we tell
2230            * hammer_delete_at_cursor() not to.
2231            */
2232           error = hammer_btree_extract_leaf(cursor);
2233           if (error == 0) {
2234                     error = hammer_delete_at_cursor(
2235                                         cursor,
2236                                         HAMMER_DELETE_ADJUST | hammer_nohistory(ip),
2237                                         cursor->trans->tid,
2238                                         cursor->trans->time32,
2239                                         0, NULL);
2240           }
2241           return(error);
2242 }
2243 
2244 /*
2245  * Used to write a generic record w/optional data to the media b-tree
2246  * when no inode context is available.  Used by the mirroring and
2247  * snapshot code.
2248  *
2249  * Caller must set cursor->key_beg to leaf->base.  The cursor must be
2250  * flagged for backend operation and not flagged ASOF (since we are
2251  * doing an insertion).
2252  *
2253  * This function will acquire the appropriate sync lock and will set
2254  * the cursor insertion flag for the operation, do the btree lookup,
2255  * and the insertion, and clear the insertion flag and sync lock before
2256  * returning.  The cursor state will be such that the caller can continue
2257  * scanning (used by the mirroring code).
2258  *
2259  * mode: HAMMER_CREATE_MODE_UMIRROR     copyin data, check crc
2260  *         HAMMER_CREATE_MODE_SYS                 bcopy data, generate crc
2261  *
2262  * NOTE: EDEADLK can be returned.  The caller must do deadlock handling and
2263  *                    retry.
2264  *
2265  *         EALREADY can be returned if the record already exists (WARNING,
2266  *                    because ASOF cannot be used no check is made for illegal
2267  *                    duplicates).
2268  *
2269  * NOTE: Do not use the function for normal inode-related records as this
2270  *         functions goes directly to the media and is not integrated with
2271  *         in-memory records.
2272  */
2273 int
hammer_create_at_cursor(hammer_cursor_t cursor,hammer_btree_leaf_elm_t leaf,void * udata,int mode)2274 hammer_create_at_cursor(hammer_cursor_t cursor, hammer_btree_leaf_elm_t leaf,
2275                               void *udata, int mode)
2276 {
2277           hammer_transaction_t trans;
2278           hammer_mount_t hmp;
2279           hammer_buffer_t data_buffer;
2280           hammer_off_t ndata_offset;
2281           hammer_tid_t high_tid;
2282           void *ndata;
2283           int error;
2284           int doprop;
2285 
2286           trans = cursor->trans;
2287           hmp = trans->hmp;
2288           data_buffer = NULL;
2289           ndata_offset = 0;
2290           doprop = 0;
2291 
2292           KKASSERT((cursor->flags &
2293                       (HAMMER_CURSOR_BACKEND | HAMMER_CURSOR_ASOF)) ==
2294                       (HAMMER_CURSOR_BACKEND));
2295 
2296           hammer_sync_lock_sh(trans);
2297 
2298           if (leaf->data_len) {
2299                     ndata = hammer_alloc_data(trans, leaf->data_len,
2300                                                     leaf->base.rec_type,
2301                                                     &ndata_offset, &data_buffer,
2302                                                     0, &error);
2303                     if (ndata == NULL) {
2304                               hammer_sync_unlock(trans);
2305                               return (error);
2306                     }
2307                     leaf->data_offset = ndata_offset;
2308                     hammer_modify_buffer_noundo(trans, data_buffer);
2309 
2310                     switch(mode) {
2311                     case HAMMER_CREATE_MODE_UMIRROR:
2312                               error = copyin(udata, ndata, leaf->data_len);
2313                               if (error == 0) {
2314                                         if (hammer_crc_test_leaf(hmp->version, ndata, leaf) == 0) {
2315                                                   hdkprintf("CRC DATA @ %016jx/%d MISMATCH ON PIPE\n",
2316                                                             (intmax_t)ndata_offset,
2317                                                             leaf->data_len);
2318                                                   error = EINVAL;
2319                                         } else {
2320                                                   error = hammer_cursor_localize_data(
2321                                                                       hmp, ndata, leaf);
2322                                         }
2323                               }
2324                               break;
2325                     case HAMMER_CREATE_MODE_SYS:
2326                               bcopy(udata, ndata, leaf->data_len);
2327                               error = 0;
2328                               hammer_crc_set_leaf(hmp->version, ndata, leaf);
2329                               break;
2330                     default:
2331                               hpanic("bad mode %d", mode);
2332                               break; /* NOT REACHED */
2333                     }
2334                     hammer_modify_buffer_done(data_buffer);
2335           } else {
2336                     leaf->data_offset = 0;
2337                     error = 0;
2338                     ndata = NULL;
2339           }
2340           if (error)
2341                     goto failed;
2342 
2343           /*
2344            * Do the insertion.  This can fail with a EDEADLK or EALREADY
2345            */
2346           cursor->flags |= HAMMER_CURSOR_INSERT;
2347           error = hammer_btree_lookup(cursor);
2348           if (error != ENOENT) {
2349                     if (error == 0)
2350                               error = EALREADY;
2351                     goto failed;
2352           }
2353           error = hammer_btree_insert(cursor, leaf, &doprop);
2354 
2355           /*
2356            * Cursor is left on current element, we want to skip it now.
2357            * (in case the caller is scanning)
2358            */
2359           cursor->flags |= HAMMER_CURSOR_ATEDISK;
2360           cursor->flags &= ~HAMMER_CURSOR_INSERT;
2361 
2362           /*
2363            * If the insertion happens to be creating (and not just replacing)
2364            * an inode we have to track it.
2365            */
2366           if (error == 0 &&
2367               leaf->base.rec_type == HAMMER_RECTYPE_INODE &&
2368               leaf->base.delete_tid == 0) {
2369                     hammer_modify_volume_field(trans, trans->rootvol,
2370                                                      vol0_stat_inodes);
2371                     ++trans->hmp->rootvol->ondisk->vol0_stat_inodes;
2372                     hammer_modify_volume_done(trans->rootvol);
2373           }
2374 
2375           /*
2376            * vol0_next_tid must track the highest TID stored in the filesystem.
2377            * We do not need to generate undo for this update.
2378            */
2379           high_tid = leaf->base.create_tid;
2380           if (high_tid < leaf->base.delete_tid)
2381                     high_tid = leaf->base.delete_tid;
2382           if (trans->rootvol->ondisk->vol0_next_tid < high_tid) {
2383                     hammer_modify_volume_noundo(trans, trans->rootvol);
2384                     trans->rootvol->ondisk->vol0_next_tid = high_tid;
2385                     hammer_modify_volume_done(trans->rootvol);
2386           }
2387 
2388           /*
2389            * WARNING!  cursor's leaf pointer may have changed after
2390            *             do_propagation returns.
2391            */
2392           if (error == 0 && doprop)
2393                     hammer_btree_do_propagation(cursor, leaf);
2394 
2395 failed:
2396           /*
2397            * Cleanup
2398            */
2399           if (error && leaf->data_offset) {
2400                     hammer_blockmap_free(trans, leaf->data_offset, leaf->data_len);
2401 
2402           }
2403           hammer_sync_unlock(trans);
2404           if (data_buffer)
2405                     hammer_rel_buffer(data_buffer, 0);
2406           return (error);
2407 }
2408 
2409 /*
2410  * Delete the B-Tree element at the current cursor and do any necessary
2411  * mirror propagation.
2412  *
2413  * The cursor must be properly positioned for an iteration on return but
2414  * may be pointing at an internal element.
2415  *
2416  * An element can be un-deleted by passing a delete_tid of 0 with
2417  * HAMMER_DELETE_ADJUST.
2418  *
2419  * This function will store the number of bytes deleted in *stat_bytes
2420  * if stat_bytes is not NULL.
2421  */
2422 int
hammer_delete_at_cursor(hammer_cursor_t cursor,int delete_flags,hammer_tid_t delete_tid,uint32_t delete_ts,int track,int64_t * stat_bytes)2423 hammer_delete_at_cursor(hammer_cursor_t cursor, int delete_flags,
2424                               hammer_tid_t delete_tid, uint32_t delete_ts,
2425                               int track, int64_t *stat_bytes)
2426 {
2427           struct hammer_btree_leaf_elm save_leaf;
2428           hammer_transaction_t trans;
2429           hammer_btree_leaf_elm_t leaf;
2430           hammer_node_t node;
2431           hammer_btree_elm_t elm;
2432           hammer_off_t data_offset;
2433           int32_t data_len;
2434           int64_t bytes;
2435           int ndelete;
2436           int error;
2437           int icount;
2438           int doprop;
2439 
2440           error = hammer_cursor_upgrade(cursor);
2441           if (error)
2442                     return(error);
2443 
2444           trans = cursor->trans;
2445           node = cursor->node;
2446           elm = &node->ondisk->elms[cursor->index];
2447           leaf = &elm->leaf;
2448           KKASSERT(elm->base.btype == HAMMER_BTREE_TYPE_RECORD);
2449 
2450           hammer_sync_lock_sh(trans);
2451           bytes = 0;
2452           doprop = 0;
2453           icount = 0;
2454 
2455           /*
2456            * Adjust the delete_tid.  Update the mirror_tid propagation field
2457            * as well.  delete_tid can be 0 (undelete -- used by mirroring).
2458            */
2459           if (delete_flags & HAMMER_DELETE_ADJUST) {
2460                     if (elm->base.rec_type == HAMMER_RECTYPE_INODE) {
2461                               if (elm->leaf.base.delete_tid == 0 && delete_tid)
2462                                         icount = -1;
2463                               if (elm->leaf.base.delete_tid && delete_tid == 0)
2464                                         icount = 1;
2465                     }
2466 
2467                     hammer_modify_node(trans, node, elm, sizeof(*elm));
2468                     elm->leaf.base.delete_tid = delete_tid;
2469                     elm->leaf.delete_ts = delete_ts;
2470                     hammer_modify_node_done(node);
2471 
2472                     if (elm->leaf.base.delete_tid > node->ondisk->mirror_tid) {
2473                               hammer_modify_node_field(trans, node, mirror_tid);
2474                               node->ondisk->mirror_tid = elm->leaf.base.delete_tid;
2475                               hammer_modify_node_done(node);
2476                               doprop = 1;
2477                               if (hammer_debug_general & 0x0002) {
2478                                         hdkprintf("propagate %016jx @%016jx\n",
2479                                                   (intmax_t)elm->leaf.base.delete_tid,
2480                                                   (intmax_t)node->node_offset);
2481                               }
2482                     }
2483 
2484                     /*
2485                      * Adjust for the iteration.  We have deleted the current
2486                      * element and want to clear ATEDISK so the iteration does
2487                      * not skip the element after, which now becomes the current
2488                      * element.  This element must be re-tested if doing an
2489                      * iteration, which is handled by the RETEST flag.
2490                      */
2491                     if ((cursor->flags & HAMMER_CURSOR_DISKEOF) == 0) {
2492                               cursor->flags |= HAMMER_CURSOR_RETEST;
2493                               cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
2494                     }
2495 
2496                     /*
2497                      * An on-disk record cannot have the same delete_tid
2498                      * as its create_tid.  In a chain of record updates
2499                      * this could result in a duplicate record.
2500                      */
2501                     KKASSERT(elm->leaf.base.delete_tid !=
2502                                elm->leaf.base.create_tid);
2503           }
2504 
2505           /*
2506            * Destroy the B-Tree element if asked (typically if a nohistory
2507            * file or mount, or when called by the pruning code).
2508            *
2509            * Adjust the ATEDISK flag to properly support iterations.
2510            */
2511           if (delete_flags & HAMMER_DELETE_DESTROY) {
2512                     data_offset = elm->leaf.data_offset;
2513                     data_len = elm->leaf.data_len;
2514                     if (doprop) {
2515                               save_leaf = elm->leaf;
2516                               leaf = &save_leaf;
2517                     }
2518                     if (elm->base.rec_type == HAMMER_RECTYPE_INODE &&
2519                         elm->leaf.base.delete_tid == 0) {
2520                               icount = -1;
2521                     }
2522 
2523                     error = hammer_btree_delete(cursor, &ndelete);
2524                     if (error == 0) {
2525                               /*
2526                                * The deletion moves the next element (if any) to
2527                                * the current element position.  We must clear
2528                                * ATEDISK so this element is not skipped and we
2529                                * must set RETEST to force any iteration to re-test
2530                                * the element.
2531                                */
2532                               if ((cursor->flags & HAMMER_CURSOR_DISKEOF) == 0) {
2533                                         cursor->flags |= HAMMER_CURSOR_RETEST;
2534                                         cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
2535                               }
2536                               bytes += (ndelete * sizeof(struct hammer_node_ondisk));
2537 
2538                               switch(HAMMER_ZONE(data_offset)) {
2539                               case HAMMER_ZONE_LARGE_DATA:
2540                               case HAMMER_ZONE_SMALL_DATA:
2541                               case HAMMER_ZONE_META:
2542                                         hammer_blockmap_free(trans,
2543                                                                  data_offset, data_len);
2544                                         bytes += data_len;
2545                                         break;
2546                               default:
2547                                         break;
2548                               }
2549                     }
2550           }
2551 
2552           /*
2553            * Track inode count and next_tid.  This is used by the mirroring
2554            * and PFS code.  icount can be negative, zero, or positive.
2555            */
2556           if (error == 0 && track) {
2557                     if (icount) {
2558                               hammer_modify_volume_field(trans, trans->rootvol,
2559                                                                vol0_stat_inodes);
2560                               trans->rootvol->ondisk->vol0_stat_inodes += icount;
2561                               hammer_modify_volume_done(trans->rootvol);
2562                     }
2563                     if (trans->rootvol->ondisk->vol0_next_tid < delete_tid) {
2564                               hammer_modify_volume_noundo(trans, trans->rootvol);
2565                               trans->rootvol->ondisk->vol0_next_tid = delete_tid;
2566                               hammer_modify_volume_done(trans->rootvol);
2567                     }
2568           }
2569 
2570           /*
2571            * mirror_tid propagation occurs if the node's mirror_tid had to be
2572            * updated while adjusting the delete_tid.
2573            *
2574            * This occurs when deleting even in nohistory mode, but does not
2575            * occur when pruning an already-deleted node.
2576            *
2577            * cursor->ip is NULL when called from the pruning, mirroring,
2578            * and pfs code.  If non-NULL propagation will be conditionalized
2579            * on whether the PFS is in no-history mode or not.
2580            *
2581            * WARNING: cursor's leaf pointer may have changed after do_propagation
2582            *            returns!
2583            */
2584           if (doprop) {
2585                     if (cursor->ip)
2586                               hammer_btree_do_propagation(cursor, leaf);
2587                     else
2588                               hammer_btree_do_propagation(cursor, leaf);
2589           }
2590           if (stat_bytes)
2591                     *stat_bytes = bytes;
2592           hammer_sync_unlock(trans);
2593           return (error);
2594 }
2595 
2596 /*
2597  * Determine whether we can remove a directory.  This routine checks whether
2598  * a directory is empty or not and enforces flush connectivity.
2599  *
2600  * Flush connectivity requires that we block if the target directory is
2601  * currently flushing, otherwise it may not end up in the same flush group.
2602  *
2603  * Returns 0 on success, ENOTEMPTY or EDEADLK (or other errors) on failure.
2604  */
2605 int
hammer_ip_check_directory_empty(hammer_transaction_t trans,hammer_inode_t ip)2606 hammer_ip_check_directory_empty(hammer_transaction_t trans, hammer_inode_t ip)
2607 {
2608           struct hammer_cursor cursor;
2609           int error;
2610 
2611           /*
2612            * Check directory empty
2613            */
2614           hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
2615 
2616           cursor.key_beg.localization = ip->obj_localization |
2617                                               hammer_dir_localization(ip);
2618           cursor.key_beg.obj_id = ip->obj_id;
2619           cursor.key_beg.create_tid = 0;
2620           cursor.key_beg.delete_tid = 0;
2621           cursor.key_beg.obj_type = 0;
2622           cursor.key_beg.rec_type = HAMMER_RECTYPE_ENTRY_START;
2623           cursor.key_beg.key = HAMMER_MIN_KEY;
2624 
2625           cursor.key_end = cursor.key_beg;
2626           cursor.key_end.rec_type = HAMMER_RECTYPE_MAX;
2627           cursor.key_end.key = HAMMER_MAX_KEY;
2628 
2629           cursor.asof = ip->obj_asof;
2630           cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF;
2631 
2632           error = hammer_ip_first(&cursor);
2633           if (error == ENOENT)
2634                     error = 0;
2635           else if (error == 0)
2636                     error = ENOTEMPTY;
2637           hammer_done_cursor(&cursor);
2638           return(error);
2639 }
2640 
2641 /*
2642  * Localize the data payload.  Directory entries may need their
2643  * localization adjusted.
2644  */
2645 static
2646 int
hammer_cursor_localize_data(hammer_mount_t hmp,hammer_data_ondisk_t data,hammer_btree_leaf_elm_t leaf)2647 hammer_cursor_localize_data(hammer_mount_t hmp, hammer_data_ondisk_t data,
2648                                   hammer_btree_leaf_elm_t leaf)
2649 {
2650           uint32_t localization;
2651 
2652           if (leaf->base.rec_type == HAMMER_RECTYPE_DIRENTRY) {
2653                     localization = leaf->base.localization &
2654                                      HAMMER_LOCALIZE_PSEUDOFS_MASK;
2655                     if (data->entry.localization != localization) {
2656                               data->entry.localization = localization;
2657                               hammer_crc_set_leaf(hmp->version, data, leaf);
2658                     }
2659           }
2660           return(0);
2661 }
2662