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 * $DragonFly: src/sys/vfs/hammer/hammer_ondisk.c,v 1.76 2008/08/29 20:19:08 dillon Exp $
35 */
36 /*
37 * Manage HAMMER's on-disk structures. These routines are primarily
38 * responsible for interfacing with the kernel's I/O subsystem and for
39 * managing in-memory structures.
40 */
41
42 #include "hammer.h"
43 #include <sys/fcntl.h>
44 #include <sys/nlookup.h>
45 #include <sys/buf.h>
46
47 #include <sys/buf2.h>
48
49 static void hammer_free_volume(hammer_volume_t volume);
50 static int hammer_load_volume(hammer_volume_t volume);
51 static int hammer_load_buffer(hammer_buffer_t buffer, int isnew);
52 static int hammer_load_node(hammer_transaction_t trans,
53 hammer_node_t node, int isnew);
54 static void _hammer_rel_node(hammer_node_t node, int locked);
55
56 static int
57 hammer_vol_rb_compare(hammer_volume_t vol1, hammer_volume_t vol2)
58 {
59 if (vol1->vol_no < vol2->vol_no)
60 return(-1);
61 if (vol1->vol_no > vol2->vol_no)
62 return(1);
63 return(0);
64 }
65
66 /*
67 * hammer_buffer structures are indexed via their zoneX_offset, not
68 * their zone2_offset.
69 */
70 static int
71 hammer_buf_rb_compare(hammer_buffer_t buf1, hammer_buffer_t buf2)
72 {
73 if (buf1->zoneX_offset < buf2->zoneX_offset)
74 return(-1);
75 if (buf1->zoneX_offset > buf2->zoneX_offset)
76 return(1);
77 return(0);
78 }
79
80 static int
81 hammer_nod_rb_compare(hammer_node_t node1, hammer_node_t node2)
82 {
83 if (node1->node_offset < node2->node_offset)
84 return(-1);
85 if (node1->node_offset > node2->node_offset)
86 return(1);
87 return(0);
88 }
89
90 RB_GENERATE2(hammer_vol_rb_tree, hammer_volume, rb_node,
91 hammer_vol_rb_compare, int32_t, vol_no);
92 RB_GENERATE2(hammer_buf_rb_tree, hammer_buffer, rb_node,
93 hammer_buf_rb_compare, hammer_off_t, zoneX_offset);
94 RB_GENERATE2(hammer_nod_rb_tree, hammer_node, rb_node,
95 hammer_nod_rb_compare, hammer_off_t, node_offset);
96
97 /************************************************************************
98 * VOLUMES *
99 ************************************************************************
100 *
101 * Load a HAMMER volume by name. Returns 0 on success or a positive error
102 * code on failure. Volumes must be loaded at mount time, get_volume() will
103 * not load a new volume.
104 *
105 * The passed devvp is vref()'d but not locked. This function consumes the
106 * ref (typically by associating it with the volume structure).
107 *
108 * Calls made to hammer_load_volume() or single-threaded
109 */
110 int
111 hammer_install_volume(struct hammer_mount *hmp, const char *volname,
112 struct vnode *devvp)
113 {
114 struct mount *mp;
115 hammer_volume_t volume;
116 struct hammer_volume_ondisk *ondisk;
117 struct nlookupdata nd;
118 struct buf *bp = NULL;
119 int error;
120 int ronly;
121 int setmp = 0;
122
123 mp = hmp->mp;
124 ronly = ((mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
125
126 /*
127 * Allocate a volume structure
128 */
129 ++hammer_count_volumes;
130 volume = kmalloc(sizeof(*volume), hmp->m_misc, M_WAITOK|M_ZERO);
131 volume->vol_name = kstrdup(volname, hmp->m_misc);
132 volume->io.hmp = hmp; /* bootstrap */
133 hammer_io_init(&volume->io, volume, HAMMER_STRUCTURE_VOLUME);
134 volume->io.offset = 0LL;
135 volume->io.bytes = HAMMER_BUFSIZE;
136
137 /*
138 * Get the device vnode
139 */
140 if (devvp == NULL) {
141 error = nlookup_init(&nd, volume->vol_name, UIO_SYSSPACE, NLC_FOLLOW);
142 if (error == 0)
143 error = nlookup(&nd);
144 if (error == 0)
145 error = cache_vref(&nd.nl_nch, nd.nl_cred, &volume->devvp);
146 nlookup_done(&nd);
147 } else {
148 error = 0;
149 volume->devvp = devvp;
150 }
151
152 if (error == 0) {
153 if (vn_isdisk(volume->devvp, &error)) {
154 error = vfs_mountedon(volume->devvp);
155 }
156 }
157 if (error == 0 && vcount(volume->devvp) > 0)
158 error = EBUSY;
159 if (error == 0) {
160 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
161 error = vinvalbuf(volume->devvp, V_SAVE, 0, 0);
162 if (error == 0) {
163 error = VOP_OPEN(volume->devvp,
164 (ronly ? FREAD : FREAD|FWRITE),
165 FSCRED, NULL);
166 }
167 vn_unlock(volume->devvp);
168 }
169 if (error) {
170 hammer_free_volume(volume);
171 return(error);
172 }
173 volume->devvp->v_rdev->si_mountpoint = mp;
174 setmp = 1;
175
176 /*
177 * Extract the volume number from the volume header and do various
178 * sanity checks.
179 */
180 error = bread(volume->devvp, 0LL, HAMMER_BUFSIZE, &bp);
181 if (error)
182 goto late_failure;
183 ondisk = (void *)bp->b_data;
184 if (ondisk->vol_signature != HAMMER_FSBUF_VOLUME) {
185 kprintf("hammer_mount: volume %s has an invalid header\n",
186 volume->vol_name);
187 error = EFTYPE;
188 goto late_failure;
189 }
190 volume->vol_no = ondisk->vol_no;
191 volume->buffer_base = ondisk->vol_buf_beg;
192 volume->vol_flags = ondisk->vol_flags;
193 volume->nblocks = ondisk->vol_nblocks;
194 volume->maxbuf_off = HAMMER_ENCODE_RAW_BUFFER(volume->vol_no,
195 ondisk->vol_buf_end - ondisk->vol_buf_beg);
196 volume->maxraw_off = ondisk->vol_buf_end;
197
198 if (RB_EMPTY(&hmp->rb_vols_root)) {
199 hmp->fsid = ondisk->vol_fsid;
200 } else if (bcmp(&hmp->fsid, &ondisk->vol_fsid, sizeof(uuid_t))) {
201 kprintf("hammer_mount: volume %s's fsid does not match "
202 "other volumes\n", volume->vol_name);
203 error = EFTYPE;
204 goto late_failure;
205 }
206
207 /*
208 * Insert the volume structure into the red-black tree.
209 */
210 if (RB_INSERT(hammer_vol_rb_tree, &hmp->rb_vols_root, volume)) {
211 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n",
212 volume->vol_name, volume->vol_no);
213 error = EEXIST;
214 }
215
216 /*
217 * Set the root volume . HAMMER special cases rootvol the structure.
218 * We do not hold a ref because this would prevent related I/O
219 * from being flushed.
220 */
221 if (error == 0 && ondisk->vol_rootvol == ondisk->vol_no) {
222 hmp->rootvol = volume;
223 hmp->nvolumes = ondisk->vol_count;
224 if (bp) {
225 brelse(bp);
226 bp = NULL;
227 }
228 hmp->mp->mnt_stat.f_blocks += ondisk->vol0_stat_bigblocks *
229 (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
230 hmp->mp->mnt_vstat.f_blocks += ondisk->vol0_stat_bigblocks *
231 (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
232 }
233 late_failure:
234 if (bp)
235 brelse(bp);
236 if (error) {
237 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/
238 if (setmp)
239 volume->devvp->v_rdev->si_mountpoint = NULL;
240 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
241 VOP_CLOSE(volume->devvp, ronly ? FREAD : FREAD|FWRITE);
242 vn_unlock(volume->devvp);
243 hammer_free_volume(volume);
244 }
245 return (error);
246 }
247
248 /*
249 * This is called for each volume when updating the mount point from
250 * read-write to read-only or vise-versa.
251 */
252 int
253 hammer_adjust_volume_mode(hammer_volume_t volume, void *data __unused)
254 {
255 if (volume->devvp) {
256 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
257 if (volume->io.hmp->ronly) {
258 /* do not call vinvalbuf */
259 VOP_OPEN(volume->devvp, FREAD, FSCRED, NULL);
260 VOP_CLOSE(volume->devvp, FREAD|FWRITE);
261 } else {
262 /* do not call vinvalbuf */
263 VOP_OPEN(volume->devvp, FREAD|FWRITE, FSCRED, NULL);
264 VOP_CLOSE(volume->devvp, FREAD);
265 }
266 vn_unlock(volume->devvp);
267 }
268 return(0);
269 }
270
271 /*
272 * Unload and free a HAMMER volume. Must return >= 0 to continue scan
273 * so returns -1 on failure.
274 */
275 int
276 hammer_unload_volume(hammer_volume_t volume, void *data __unused)
277 {
278 hammer_mount_t hmp = volume->io.hmp;
279 int ronly = ((hmp->mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
280
281 /*
282 * Clean up the root volume pointer, which is held unlocked in hmp.
283 */
284 if (hmp->rootvol == volume)
285 hmp->rootvol = NULL;
286
287 /*
288 * We must not flush a dirty buffer to disk on umount. It should
289 * have already been dealt with by the flusher, or we may be in
290 * catastrophic failure.
291 */
292 hammer_io_clear_modify(&volume->io, 1);
293 volume->io.waitdep = 1;
294
295 /*
296 * Clean up the persistent ref ioerror might have on the volume
297 */
298 if (volume->io.ioerror)
299 hammer_io_clear_error_noassert(&volume->io);
300
301 /*
302 * This should release the bp. Releasing the volume with flush set
303 * implies the interlock is set.
304 */
305 hammer_ref_interlock_true(&volume->io.lock);
306 hammer_rel_volume(volume, 1);
307 KKASSERT(volume->io.bp == NULL);
308
309 /*
310 * There should be no references on the volume, no clusters, and
311 * no super-clusters.
312 */
313 KKASSERT(hammer_norefs(&volume->io.lock));
314
315 volume->ondisk = NULL;
316 if (volume->devvp) {
317 if (volume->devvp->v_rdev &&
318 volume->devvp->v_rdev->si_mountpoint == hmp->mp
319 ) {
320 volume->devvp->v_rdev->si_mountpoint = NULL;
321 }
322 if (ronly) {
323 /*
324 * Make sure we don't sync anything to disk if we
325 * are in read-only mode (1) or critically-errored
326 * (2). Note that there may be dirty buffers in
327 * normal read-only mode from crash recovery.
328 */
329 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
330 vinvalbuf(volume->devvp, 0, 0, 0);
331 VOP_CLOSE(volume->devvp, FREAD);
332 vn_unlock(volume->devvp);
333 } else {
334 /*
335 * Normal termination, save any dirty buffers
336 * (XXX there really shouldn't be any).
337 */
338 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
339 vinvalbuf(volume->devvp, V_SAVE, 0, 0);
340 VOP_CLOSE(volume->devvp, FREAD|FWRITE);
341 vn_unlock(volume->devvp);
342 }
343 }
344
345 /*
346 * Destroy the structure
347 */
348 RB_REMOVE(hammer_vol_rb_tree, &hmp->rb_vols_root, volume);
349 hammer_free_volume(volume);
350 return(0);
351 }
352
353 static
354 void
355 hammer_free_volume(hammer_volume_t volume)
356 {
357 hammer_mount_t hmp = volume->io.hmp;
358
359 if (volume->vol_name) {
360 kfree(volume->vol_name, hmp->m_misc);
361 volume->vol_name = NULL;
362 }
363 if (volume->devvp) {
364 vrele(volume->devvp);
365 volume->devvp = NULL;
366 }
367 --hammer_count_volumes;
368 kfree(volume, hmp->m_misc);
369 }
370
371 /*
372 * Get a HAMMER volume. The volume must already exist.
373 */
374 hammer_volume_t
375 hammer_get_volume(struct hammer_mount *hmp, int32_t vol_no, int *errorp)
376 {
377 struct hammer_volume *volume;
378
379 /*
380 * Locate the volume structure
381 */
382 volume = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, vol_no);
383 if (volume == NULL) {
384 *errorp = ENOENT;
385 return(NULL);
386 }
387
388 /*
389 * Reference the volume, load/check the data on the 0->1 transition.
390 * hammer_load_volume() will dispose of the interlock on return,
391 * and also clean up the ref count on error.
392 */
393 if (hammer_ref_interlock(&volume->io.lock)) {
394 *errorp = hammer_load_volume(volume);
395 if (*errorp)
396 volume = NULL;
397 } else {
398 KKASSERT(volume->ondisk);
399 *errorp = 0;
400 }
401 return(volume);
402 }
403
404 int
405 hammer_ref_volume(hammer_volume_t volume)
406 {
407 int error;
408
409 /*
410 * Reference the volume and deal with the check condition used to
411 * load its ondisk info.
412 */
413 if (hammer_ref_interlock(&volume->io.lock)) {
414 error = hammer_load_volume(volume);
415 } else {
416 KKASSERT(volume->ondisk);
417 error = 0;
418 }
419 return (error);
420 }
421
422 /*
423 * May be called without fs_token
424 */
425 hammer_volume_t
426 hammer_get_root_volume(struct hammer_mount *hmp, int *errorp)
427 {
428 hammer_volume_t volume;
429
430 volume = hmp->rootvol;
431 KKASSERT(volume != NULL);
432
433 /*
434 * Reference the volume and deal with the check condition used to
435 * load its ondisk info.
436 */
437 if (hammer_ref_interlock(&volume->io.lock)) {
438 lwkt_gettoken(&volume->io.hmp->fs_token);
439 *errorp = hammer_load_volume(volume);
440 lwkt_reltoken(&volume->io.hmp->fs_token);
441 if (*errorp)
442 volume = NULL;
443 } else {
444 KKASSERT(volume->ondisk);
445 *errorp = 0;
446 }
447 return (volume);
448 }
449
450 /*
451 * Load a volume's on-disk information. The volume must be referenced and
452 * the interlock is held on call. The interlock will be released on return.
453 * The reference will also be released on return if an error occurs.
454 */
455 static int
456 hammer_load_volume(hammer_volume_t volume)
457 {
458 int error;
459
460 if (volume->ondisk == NULL) {
461 error = hammer_io_read(volume->devvp, &volume->io,
462 HAMMER_BUFSIZE);
463 if (error == 0) {
464 volume->ondisk = (void *)volume->io.bp->b_data;
465 hammer_ref_interlock_done(&volume->io.lock);
466 } else {
467 hammer_rel_volume(volume, 1);
468 }
469 } else {
470 error = 0;
471 }
472 return(error);
473 }
474
475 /*
476 * Release a previously acquired reference on the volume.
477 *
478 * Volumes are not unloaded from memory during normal operation.
479 *
480 * May be called without fs_token
481 */
482 void
483 hammer_rel_volume(hammer_volume_t volume, int locked)
484 {
485 struct buf *bp;
486
487 if (hammer_rel_interlock(&volume->io.lock, locked)) {
488 lwkt_gettoken(&volume->io.hmp->fs_token);
489 volume->ondisk = NULL;
490 bp = hammer_io_release(&volume->io, locked);
491 lwkt_reltoken(&volume->io.hmp->fs_token);
492 hammer_rel_interlock_done(&volume->io.lock, locked);
493 if (bp)
494 brelse(bp);
495 }
496 }
497
498 int
499 hammer_mountcheck_volumes(struct hammer_mount *hmp)
500 {
501 hammer_volume_t vol;
502 int i;
503
504 for (i = 0; i < hmp->nvolumes; ++i) {
505 vol = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, i);
506 if (vol == NULL)
507 return(EINVAL);
508 }
509 return(0);
510 }
511
512 /************************************************************************
513 * BUFFERS *
514 ************************************************************************
515 *
516 * Manage buffers. Currently most blockmap-backed zones are direct-mapped
517 * to zone-2 buffer offsets, without a translation stage. However, the
518 * hammer_buffer structure is indexed by its zoneX_offset, not its
519 * zone2_offset.
520 *
521 * The proper zone must be maintained throughout the code-base all the way
522 * through to the big-block allocator, or routines like hammer_del_buffers()
523 * will not be able to locate all potentially conflicting buffers.
524 */
525
526 /*
527 * Helper function returns whether a zone offset can be directly translated
528 * to a raw buffer index or not. Really only the volume and undo zones
529 * can't be directly translated. Volumes are special-cased and undo zones
530 * shouldn't be aliased accessed in read-only mode.
531 *
532 * This function is ONLY used to detect aliased zones during a read-only
533 * mount.
534 */
535 static __inline int
536 hammer_direct_zone(hammer_off_t buf_offset)
537 {
538 switch(HAMMER_ZONE_DECODE(buf_offset)) {
539 case HAMMER_ZONE_RAW_BUFFER_INDEX:
540 case HAMMER_ZONE_FREEMAP_INDEX:
541 case HAMMER_ZONE_BTREE_INDEX:
542 case HAMMER_ZONE_META_INDEX:
543 case HAMMER_ZONE_LARGE_DATA_INDEX:
544 case HAMMER_ZONE_SMALL_DATA_INDEX:
545 return(1);
546 default:
547 return(0);
548 }
549 /* NOT REACHED */
550 }
551
552 hammer_buffer_t
553 hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset,
554 int bytes, int isnew, int *errorp)
555 {
556 hammer_buffer_t buffer;
557 hammer_volume_t volume;
558 hammer_off_t zone2_offset;
559 hammer_io_type_t iotype;
560 int vol_no;
561 int zone;
562
563 buf_offset &= ~HAMMER_BUFMASK64;
564 again:
565 /*
566 * Shortcut if the buffer is already cached
567 */
568 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, buf_offset);
569 if (buffer) {
570 /*
571 * Once refed the ondisk field will not be cleared by
572 * any other action. Shortcut the operation if the
573 * ondisk structure is valid.
574 */
575 found_aliased:
576 if (hammer_ref_interlock(&buffer->io.lock) == 0) {
577 hammer_io_advance(&buffer->io);
578 KKASSERT(buffer->ondisk);
579 *errorp = 0;
580 return(buffer);
581 }
582
583 /*
584 * 0->1 transition or defered 0->1 transition (CHECK),
585 * interlock now held. Shortcut if ondisk is already
586 * assigned.
587 */
588 atomic_add_int(&hammer_count_refedbufs, 1);
589 if (buffer->ondisk) {
590 hammer_io_advance(&buffer->io);
591 hammer_ref_interlock_done(&buffer->io.lock);
592 *errorp = 0;
593 return(buffer);
594 }
595
596 /*
597 * The buffer is no longer loose if it has a ref, and
598 * cannot become loose once it gains a ref. Loose
599 * buffers will never be in a modified state. This should
600 * only occur on the 0->1 transition of refs.
601 *
602 * lose_list can be modified via a biodone() interrupt
603 * so the io_token must be held.
604 */
605 if (buffer->io.mod_root == &hmp->lose_root) {
606 lwkt_gettoken(&hmp->io_token);
607 if (buffer->io.mod_root == &hmp->lose_root) {
608 RB_REMOVE(hammer_mod_rb_tree,
609 buffer->io.mod_root, &buffer->io);
610 buffer->io.mod_root = NULL;
611 KKASSERT(buffer->io.modified == 0);
612 }
613 lwkt_reltoken(&hmp->io_token);
614 }
615 goto found;
616 } else if (hmp->ronly && hammer_direct_zone(buf_offset)) {
617 /*
618 * If this is a read-only mount there could be an alias
619 * in the raw-zone. If there is we use that buffer instead.
620 *
621 * rw mounts will not have aliases. Also note when going
622 * from ro -> rw the recovered raw buffers are flushed and
623 * reclaimed, so again there will not be any aliases once
624 * the mount is rw.
625 */
626 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
627 (buf_offset & ~HAMMER_OFF_ZONE_MASK) |
628 HAMMER_ZONE_RAW_BUFFER);
629 if (buffer) {
630 kprintf("HAMMER: recovered aliased %016jx\n",
631 (intmax_t)buf_offset);
632 goto found_aliased;
633 }
634 }
635
636 /*
637 * What is the buffer class?
638 */
639 zone = HAMMER_ZONE_DECODE(buf_offset);
640
641 switch(zone) {
642 case HAMMER_ZONE_LARGE_DATA_INDEX:
643 case HAMMER_ZONE_SMALL_DATA_INDEX:
644 iotype = HAMMER_STRUCTURE_DATA_BUFFER;
645 break;
646 case HAMMER_ZONE_UNDO_INDEX:
647 iotype = HAMMER_STRUCTURE_UNDO_BUFFER;
648 break;
649 case HAMMER_ZONE_META_INDEX:
650 default:
651 /*
652 * NOTE: inode data and directory entries are placed in this
653 * zone. inode atime/mtime is updated in-place and thus
654 * buffers containing inodes must be synchronized as
655 * meta-buffers, same as buffers containing B-Tree info.
656 */
657 iotype = HAMMER_STRUCTURE_META_BUFFER;
658 break;
659 }
660
661 /*
662 * Handle blockmap offset translations
663 */
664 if (zone >= HAMMER_ZONE_BTREE_INDEX) {
665 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, errorp);
666 } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
667 zone2_offset = hammer_undo_lookup(hmp, buf_offset, errorp);
668 } else {
669 KKASSERT(zone == HAMMER_ZONE_RAW_BUFFER_INDEX);
670 zone2_offset = buf_offset;
671 *errorp = 0;
672 }
673 if (*errorp)
674 return(NULL);
675
676 /*
677 * NOTE: zone2_offset and maxbuf_off are both full zone-2 offset
678 * specifications.
679 */
680 KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) ==
681 HAMMER_ZONE_RAW_BUFFER);
682 vol_no = HAMMER_VOL_DECODE(zone2_offset);
683 volume = hammer_get_volume(hmp, vol_no, errorp);
684 if (volume == NULL)
685 return(NULL);
686
687 KKASSERT(zone2_offset < volume->maxbuf_off);
688
689 /*
690 * Allocate a new buffer structure. We will check for races later.
691 */
692 ++hammer_count_buffers;
693 buffer = kmalloc(sizeof(*buffer), hmp->m_misc,
694 M_WAITOK|M_ZERO|M_USE_RESERVE);
695 buffer->zone2_offset = zone2_offset;
696 buffer->zoneX_offset = buf_offset;
697
698 hammer_io_init(&buffer->io, volume, iotype);
699 buffer->io.offset = volume->ondisk->vol_buf_beg +
700 (zone2_offset & HAMMER_OFF_SHORT_MASK);
701 buffer->io.bytes = bytes;
702 TAILQ_INIT(&buffer->clist);
703 hammer_ref_interlock_true(&buffer->io.lock);
704
705 /*
706 * Insert the buffer into the RB tree and handle late collisions.
707 */
708 if (RB_INSERT(hammer_buf_rb_tree, &hmp->rb_bufs_root, buffer)) {
709 hammer_rel_volume(volume, 0);
710 buffer->io.volume = NULL; /* safety */
711 if (hammer_rel_interlock(&buffer->io.lock, 1)) /* safety */
712 hammer_rel_interlock_done(&buffer->io.lock, 1);
713 --hammer_count_buffers;
714 kfree(buffer, hmp->m_misc);
715 goto again;
716 }
717 atomic_add_int(&hammer_count_refedbufs, 1);
718 found:
719
720 /*
721 * The buffer is referenced and interlocked. Load the buffer
722 * if necessary. hammer_load_buffer() deals with the interlock
723 * and, if an error is returned, also deals with the ref.
724 */
725 if (buffer->ondisk == NULL) {
726 *errorp = hammer_load_buffer(buffer, isnew);
727 if (*errorp)
728 buffer = NULL;
729 } else {
730 hammer_io_advance(&buffer->io);
731 hammer_ref_interlock_done(&buffer->io.lock);
732 *errorp = 0;
733 }
734 return(buffer);
735 }
736
737 /*
738 * This is used by the direct-read code to deal with large-data buffers
739 * created by the reblocker and mirror-write code. The direct-read code
740 * bypasses the HAMMER buffer subsystem and so any aliased dirty or write-
741 * running hammer buffers must be fully synced to disk before we can issue
742 * the direct-read.
743 *
744 * This code path is not considered critical as only the rebocker and
745 * mirror-write code will create large-data buffers via the HAMMER buffer
746 * subsystem. They do that because they operate at the B-Tree level and
747 * do not access the vnode/inode structures.
748 */
749 void
750 hammer_sync_buffers(hammer_mount_t hmp, hammer_off_t base_offset, int bytes)
751 {
752 hammer_buffer_t buffer;
753 int error;
754
755 KKASSERT((base_offset & HAMMER_OFF_ZONE_MASK) ==
756 HAMMER_ZONE_LARGE_DATA);
757
758 while (bytes > 0) {
759 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
760 base_offset);
761 if (buffer && (buffer->io.modified || buffer->io.running)) {
762 error = hammer_ref_buffer(buffer);
763 if (error == 0) {
764 hammer_io_wait(&buffer->io);
765 if (buffer->io.modified) {
766 hammer_io_write_interlock(&buffer->io);
767 hammer_io_flush(&buffer->io, 0);
768 hammer_io_done_interlock(&buffer->io);
769 hammer_io_wait(&buffer->io);
770 }
771 hammer_rel_buffer(buffer, 0);
772 }
773 }
774 base_offset += HAMMER_BUFSIZE;
775 bytes -= HAMMER_BUFSIZE;
776 }
777 }
778
779 /*
780 * Destroy all buffers covering the specified zoneX offset range. This
781 * is called when the related blockmap layer2 entry is freed or when
782 * a direct write bypasses our buffer/buffer-cache subsystem.
783 *
784 * The buffers may be referenced by the caller itself. Setting reclaim
785 * will cause the buffer to be destroyed when it's ref count reaches zero.
786 *
787 * Return 0 on success, EAGAIN if some buffers could not be destroyed due
788 * to additional references held by other threads, or some other (typically
789 * fatal) error.
790 */
791 int
792 hammer_del_buffers(hammer_mount_t hmp, hammer_off_t base_offset,
793 hammer_off_t zone2_offset, int bytes,
794 int report_conflicts)
795 {
796 hammer_buffer_t buffer;
797 hammer_volume_t volume;
798 int vol_no;
799 int error;
800 int ret_error;
801
802 vol_no = HAMMER_VOL_DECODE(zone2_offset);
803 volume = hammer_get_volume(hmp, vol_no, &ret_error);
804 KKASSERT(ret_error == 0);
805
806 while (bytes > 0) {
807 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
808 base_offset);
809 if (buffer) {
810 error = hammer_ref_buffer(buffer);
811 if (hammer_debug_general & 0x20000) {
812 kprintf("hammer: delbufr %016jx "
813 "rerr=%d 1ref=%d\n",
814 (intmax_t)buffer->zoneX_offset,
815 error,
816 hammer_oneref(&buffer->io.lock));
817 }
818 if (error == 0 && !hammer_oneref(&buffer->io.lock)) {
819 error = EAGAIN;
820 hammer_rel_buffer(buffer, 0);
821 }
822 if (error == 0) {
823 KKASSERT(buffer->zone2_offset == zone2_offset);
824 hammer_io_clear_modify(&buffer->io, 1);
825 buffer->io.reclaim = 1;
826 buffer->io.waitdep = 1;
827 KKASSERT(buffer->io.volume == volume);
828 hammer_rel_buffer(buffer, 0);
829 }
830 } else {
831 error = hammer_io_inval(volume, zone2_offset);
832 }
833 if (error) {
834 ret_error = error;
835 if (report_conflicts ||
836 (hammer_debug_general & 0x8000)) {
837 kprintf("hammer_del_buffers: unable to "
838 "invalidate %016llx buffer=%p rep=%d\n",
839 (long long)base_offset,
840 buffer, report_conflicts);
841 }
842 }
843 base_offset += HAMMER_BUFSIZE;
844 zone2_offset += HAMMER_BUFSIZE;
845 bytes -= HAMMER_BUFSIZE;
846 }
847 hammer_rel_volume(volume, 0);
848 return (ret_error);
849 }
850
851 /*
852 * Given a referenced and interlocked buffer load/validate the data.
853 *
854 * The buffer interlock will be released on return. If an error is
855 * returned the buffer reference will also be released (and the buffer
856 * pointer will thus be stale).
857 */
858 static int
859 hammer_load_buffer(hammer_buffer_t buffer, int isnew)
860 {
861 hammer_volume_t volume;
862 int error;
863
864 /*
865 * Load the buffer's on-disk info
866 */
867 volume = buffer->io.volume;
868
869 if (hammer_debug_io & 0x0004) {
870 kprintf("load_buffer %016llx %016llx isnew=%d od=%p\n",
871 (long long)buffer->zoneX_offset,
872 (long long)buffer->zone2_offset,
873 isnew, buffer->ondisk);
874 }
875
876 if (buffer->ondisk == NULL) {
877 /*
878 * Issue the read or generate a new buffer. When reading
879 * the limit argument controls any read-ahead clustering
880 * hammer_io_read() is allowed to do.
881 *
882 * We cannot read-ahead in the large-data zone and we cannot
883 * cross a largeblock boundary as the next largeblock might
884 * use a different buffer size.
885 */
886 if (isnew) {
887 error = hammer_io_new(volume->devvp, &buffer->io);
888 } else if ((buffer->zoneX_offset & HAMMER_OFF_ZONE_MASK) ==
889 HAMMER_ZONE_LARGE_DATA) {
890 error = hammer_io_read(volume->devvp, &buffer->io,
891 buffer->io.bytes);
892 } else {
893 hammer_off_t limit;
894
895 limit = (buffer->zone2_offset +
896 HAMMER_LARGEBLOCK_MASK64) &
897 ~HAMMER_LARGEBLOCK_MASK64;
898 limit -= buffer->zone2_offset;
899 error = hammer_io_read(volume->devvp, &buffer->io,
900 limit);
901 }
902 if (error == 0)
903 buffer->ondisk = (void *)buffer->io.bp->b_data;
904 } else if (isnew) {
905 error = hammer_io_new(volume->devvp, &buffer->io);
906 } else {
907 error = 0;
908 }
909 if (error == 0) {
910 hammer_io_advance(&buffer->io);
911 hammer_ref_interlock_done(&buffer->io.lock);
912 } else {
913 hammer_rel_buffer(buffer, 1);
914 }
915 return (error);
916 }
917
918 /*
919 * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
920 * This routine is only called during unmount or when a volume is
921 * removed.
922 *
923 * If data != NULL, it specifies a volume whoose buffers should
924 * be unloaded.
925 */
926 int
927 hammer_unload_buffer(hammer_buffer_t buffer, void *data)
928 {
929 struct hammer_volume *volume = (struct hammer_volume *) data;
930
931 /*
932 * If volume != NULL we are only interested in unloading buffers
933 * associated with a particular volume.
934 */
935 if (volume != NULL && volume != buffer->io.volume)
936 return 0;
937
938 /*
939 * Clean up the persistent ref ioerror might have on the buffer
940 * and acquire a ref. Expect a 0->1 transition.
941 */
942 if (buffer->io.ioerror) {
943 hammer_io_clear_error_noassert(&buffer->io);
944 atomic_add_int(&hammer_count_refedbufs, -1);
945 }
946 hammer_ref_interlock_true(&buffer->io.lock);
947 atomic_add_int(&hammer_count_refedbufs, 1);
948
949 /*
950 * We must not flush a dirty buffer to disk on umount. It should
951 * have already been dealt with by the flusher, or we may be in
952 * catastrophic failure.
953 *
954 * We must set waitdep to ensure that a running buffer is waited
955 * on and released prior to us trying to unload the volume.
956 */
957 hammer_io_clear_modify(&buffer->io, 1);
958 hammer_flush_buffer_nodes(buffer);
959 buffer->io.waitdep = 1;
960 hammer_rel_buffer(buffer, 1);
961 return(0);
962 }
963
964 /*
965 * Reference a buffer that is either already referenced or via a specially
966 * handled pointer (aka cursor->buffer).
967 */
968 int
969 hammer_ref_buffer(hammer_buffer_t buffer)
970 {
971 hammer_mount_t hmp;
972 int error;
973 int locked;
974
975 /*
976 * Acquire a ref, plus the buffer will be interlocked on the
977 * 0->1 transition.
978 */
979 locked = hammer_ref_interlock(&buffer->io.lock);
980 hmp = buffer->io.hmp;
981
982 /*
983 * At this point a biodone() will not touch the buffer other then
984 * incidental bits. However, lose_list can be modified via
985 * a biodone() interrupt.
986 *
987 * No longer loose. lose_list requires the io_token.
988 */
989 if (buffer->io.mod_root == &hmp->lose_root) {
990 lwkt_gettoken(&hmp->io_token);
991 if (buffer->io.mod_root == &hmp->lose_root) {
992 RB_REMOVE(hammer_mod_rb_tree,
993 buffer->io.mod_root, &buffer->io);
994 buffer->io.mod_root = NULL;
995 }
996 lwkt_reltoken(&hmp->io_token);
997 }
998
999 if (locked) {
1000 atomic_add_int(&hammer_count_refedbufs, 1);
1001 error = hammer_load_buffer(buffer, 0);
1002 /* NOTE: on error the buffer pointer is stale */
1003 } else {
1004 error = 0;
1005 }
1006 return(error);
1007 }
1008
1009 /*
1010 * Release a reference on the buffer. On the 1->0 transition the
1011 * underlying IO will be released but the data reference is left
1012 * cached.
1013 *
1014 * Only destroy the structure itself if the related buffer cache buffer
1015 * was disassociated from it. This ties the management of the structure
1016 * to the buffer cache subsystem. buffer->ondisk determines whether the
1017 * embedded io is referenced or not.
1018 */
1019 void
1020 hammer_rel_buffer(hammer_buffer_t buffer, int locked)
1021 {
1022 hammer_volume_t volume;
1023 hammer_mount_t hmp;
1024 struct buf *bp = NULL;
1025 int freeme = 0;
1026
1027 hmp = buffer->io.hmp;
1028
1029 if (hammer_rel_interlock(&buffer->io.lock, locked) == 0)
1030 return;
1031
1032 /*
1033 * hammer_count_refedbufs accounting. Decrement if we are in
1034 * the error path or if CHECK is clear.
1035 *
1036 * If we are not in the error path and CHECK is set the caller
1037 * probably just did a hammer_ref() and didn't account for it,
1038 * so we don't account for the loss here.
1039 */
1040 if (locked || (buffer->io.lock.refs & HAMMER_REFS_CHECK) == 0)
1041 atomic_add_int(&hammer_count_refedbufs, -1);
1042
1043 /*
1044 * If the caller locked us or the normal released transitions
1045 * from 1->0 (and acquired the lock) attempt to release the
1046 * io. If the called locked us we tell hammer_io_release()
1047 * to flush (which would be the unload or failure path).
1048 */
1049 bp = hammer_io_release(&buffer->io, locked);
1050
1051 /*
1052 * If the buffer has no bp association and no refs we can destroy
1053 * it.
1054 *
1055 * NOTE: It is impossible for any associated B-Tree nodes to have
1056 * refs if the buffer has no additional refs.
1057 */
1058 if (buffer->io.bp == NULL && hammer_norefs(&buffer->io.lock)) {
1059 RB_REMOVE(hammer_buf_rb_tree,
1060 &buffer->io.hmp->rb_bufs_root,
1061 buffer);
1062 volume = buffer->io.volume;
1063 buffer->io.volume = NULL; /* sanity */
1064 hammer_rel_volume(volume, 0);
1065 hammer_io_clear_modlist(&buffer->io);
1066 hammer_flush_buffer_nodes(buffer);
1067 KKASSERT(TAILQ_EMPTY(&buffer->clist));
1068 freeme = 1;
1069 }
1070
1071 /*
1072 * Cleanup
1073 */
1074 hammer_rel_interlock_done(&buffer->io.lock, locked);
1075 if (bp)
1076 brelse(bp);
1077 if (freeme) {
1078 --hammer_count_buffers;
1079 kfree(buffer, hmp->m_misc);
1080 }
1081 }
1082
1083 /*
1084 * Access the filesystem buffer containing the specified hammer offset.
1085 * buf_offset is a conglomeration of the volume number and vol_buf_beg
1086 * relative buffer offset. It must also have bit 55 set to be valid.
1087 * (see hammer_off_t in hammer_disk.h).
1088 *
1089 * Any prior buffer in *bufferp will be released and replaced by the
1090 * requested buffer.
1091 *
1092 * NOTE: The buffer is indexed via its zoneX_offset but we allow the
1093 * passed cached *bufferp to match against either zoneX or zone2.
1094 */
1095 static __inline
1096 void *
1097 _hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1098 int *errorp, struct hammer_buffer **bufferp)
1099 {
1100 hammer_buffer_t buffer;
1101 int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
1102
1103 buf_offset &= ~HAMMER_BUFMASK64;
1104 KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) != 0);
1105
1106 buffer = *bufferp;
1107 if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
1108 buffer->zoneX_offset != buf_offset)) {
1109 if (buffer)
1110 hammer_rel_buffer(buffer, 0);
1111 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 0, errorp);
1112 *bufferp = buffer;
1113 } else {
1114 *errorp = 0;
1115 }
1116
1117 /*
1118 * Return a pointer to the buffer data.
1119 */
1120 if (buffer == NULL)
1121 return(NULL);
1122 else
1123 return((char *)buffer->ondisk + xoff);
1124 }
1125
1126 void *
1127 hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset,
1128 int *errorp, struct hammer_buffer **bufferp)
1129 {
1130 return(_hammer_bread(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp));
1131 }
1132
1133 void *
1134 hammer_bread_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1135 int *errorp, struct hammer_buffer **bufferp)
1136 {
1137 bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK;
1138 return(_hammer_bread(hmp, buf_offset, bytes, errorp, bufferp));
1139 }
1140
1141 /*
1142 * Access the filesystem buffer containing the specified hammer offset.
1143 * No disk read operation occurs. The result buffer may contain garbage.
1144 *
1145 * Any prior buffer in *bufferp will be released and replaced by the
1146 * requested buffer.
1147 *
1148 * This function marks the buffer dirty but does not increment its
1149 * modify_refs count.
1150 */
1151 static __inline
1152 void *
1153 _hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1154 int *errorp, struct hammer_buffer **bufferp)
1155 {
1156 hammer_buffer_t buffer;
1157 int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
1158
1159 buf_offset &= ~HAMMER_BUFMASK64;
1160
1161 buffer = *bufferp;
1162 if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
1163 buffer->zoneX_offset != buf_offset)) {
1164 if (buffer)
1165 hammer_rel_buffer(buffer, 0);
1166 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 1, errorp);
1167 *bufferp = buffer;
1168 } else {
1169 *errorp = 0;
1170 }
1171
1172 /*
1173 * Return a pointer to the buffer data.
1174 */
1175 if (buffer == NULL)
1176 return(NULL);
1177 else
1178 return((char *)buffer->ondisk + xoff);
1179 }
1180
1181 void *
1182 hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset,
1183 int *errorp, struct hammer_buffer **bufferp)
1184 {
1185 return(_hammer_bnew(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp));
1186 }
1187
1188 void *
1189 hammer_bnew_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1190 int *errorp, struct hammer_buffer **bufferp)
1191 {
1192 bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK;
1193 return(_hammer_bnew(hmp, buf_offset, bytes, errorp, bufferp));
1194 }
1195
1196 /************************************************************************
1197 * NODES *
1198 ************************************************************************
1199 *
1200 * Manage B-Tree nodes. B-Tree nodes represent the primary indexing
1201 * method used by the HAMMER filesystem.
1202 *
1203 * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
1204 * associated with its buffer, and will only referenced the buffer while
1205 * the node itself is referenced.
1206 *
1207 * A hammer_node can also be passively associated with other HAMMER
1208 * structures, such as inodes, while retaining 0 references. These
1209 * associations can be cleared backwards using a pointer-to-pointer in
1210 * the hammer_node.
1211 *
1212 * This allows the HAMMER implementation to cache hammer_nodes long-term
1213 * and short-cut a great deal of the infrastructure's complexity. In
1214 * most cases a cached node can be reacquired without having to dip into
1215 * either the buffer or cluster management code.
1216 *
1217 * The caller must pass a referenced cluster on call and will retain
1218 * ownership of the reference on return. The node will acquire its own
1219 * additional references, if necessary.
1220 */
1221 hammer_node_t
1222 hammer_get_node(hammer_transaction_t trans, hammer_off_t node_offset,
1223 int isnew, int *errorp)
1224 {
1225 hammer_mount_t hmp = trans->hmp;
1226 hammer_node_t node;
1227 int doload;
1228
1229 KKASSERT((node_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_BTREE);
1230
1231 /*
1232 * Locate the structure, allocating one if necessary.
1233 */
1234 again:
1235 node = RB_LOOKUP(hammer_nod_rb_tree, &hmp->rb_nods_root, node_offset);
1236 if (node == NULL) {
1237 ++hammer_count_nodes;
1238 node = kmalloc(sizeof(*node), hmp->m_misc, M_WAITOK|M_ZERO|M_USE_RESERVE);
1239 node->node_offset = node_offset;
1240 node->hmp = hmp;
1241 TAILQ_INIT(&node->cursor_list);
1242 TAILQ_INIT(&node->cache_list);
1243 if (RB_INSERT(hammer_nod_rb_tree, &hmp->rb_nods_root, node)) {
1244 --hammer_count_nodes;
1245 kfree(node, hmp->m_misc);
1246 goto again;
1247 }
1248 doload = hammer_ref_interlock_true(&node->lock);
1249 } else {
1250 doload = hammer_ref_interlock(&node->lock);
1251 }
1252 if (doload) {
1253 *errorp = hammer_load_node(trans, node, isnew);
1254 trans->flags |= HAMMER_TRANSF_DIDIO;
1255 if (*errorp)
1256 node = NULL;
1257 } else {
1258 KKASSERT(node->ondisk);
1259 *errorp = 0;
1260 hammer_io_advance(&node->buffer->io);
1261 }
1262 return(node);
1263 }
1264
1265 /*
1266 * Reference an already-referenced node. 0->1 transitions should assert
1267 * so we do not have to deal with hammer_ref() setting CHECK.
1268 */
1269 void
1270 hammer_ref_node(hammer_node_t node)
1271 {
1272 KKASSERT(hammer_isactive(&node->lock) && node->ondisk != NULL);
1273 hammer_ref(&node->lock);
1274 }
1275
1276 /*
1277 * Load a node's on-disk data reference. Called with the node referenced
1278 * and interlocked.
1279 *
1280 * On return the node interlock will be unlocked. If a non-zero error code
1281 * is returned the node will also be dereferenced (and the caller's pointer
1282 * will be stale).
1283 */
1284 static int
1285 hammer_load_node(hammer_transaction_t trans, hammer_node_t node, int isnew)
1286 {
1287 hammer_buffer_t buffer;
1288 hammer_off_t buf_offset;
1289 int error;
1290
1291 error = 0;
1292 if (node->ondisk == NULL) {
1293 /*
1294 * This is a little confusing but the jist is that
1295 * node->buffer determines whether the node is on
1296 * the buffer's clist and node->ondisk determines
1297 * whether the buffer is referenced.
1298 *
1299 * We could be racing a buffer release, in which case
1300 * node->buffer may become NULL while we are blocked
1301 * referencing the buffer.
1302 */
1303 if ((buffer = node->buffer) != NULL) {
1304 error = hammer_ref_buffer(buffer);
1305 if (error == 0 && node->buffer == NULL) {
1306 TAILQ_INSERT_TAIL(&buffer->clist,
1307 node, entry);
1308 node->buffer = buffer;
1309 }
1310 } else {
1311 buf_offset = node->node_offset & ~HAMMER_BUFMASK64;
1312 buffer = hammer_get_buffer(node->hmp, buf_offset,
1313 HAMMER_BUFSIZE, 0, &error);
1314 if (buffer) {
1315 KKASSERT(error == 0);
1316 TAILQ_INSERT_TAIL(&buffer->clist,
1317 node, entry);
1318 node->buffer = buffer;
1319 }
1320 }
1321 if (error)
1322 goto failed;
1323 node->ondisk = (void *)((char *)buffer->ondisk +
1324 (node->node_offset & HAMMER_BUFMASK));
1325
1326 /*
1327 * Check CRC. NOTE: Neither flag is set and the CRC is not
1328 * generated on new B-Tree nodes.
1329 */
1330 if (isnew == 0 &&
1331 (node->flags & HAMMER_NODE_CRCANY) == 0) {
1332 if (hammer_crc_test_btree(node->ondisk) == 0) {
1333 if (hammer_debug_critical)
1334 Debugger("CRC FAILED: B-TREE NODE");
1335 node->flags |= HAMMER_NODE_CRCBAD;
1336 } else {
1337 node->flags |= HAMMER_NODE_CRCGOOD;
1338 }
1339 }
1340 }
1341 if (node->flags & HAMMER_NODE_CRCBAD) {
1342 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1343 error = EDOM;
1344 else
1345 error = EIO;
1346 }
1347 failed:
1348 if (error) {
1349 _hammer_rel_node(node, 1);
1350 } else {
1351 hammer_ref_interlock_done(&node->lock);
1352 }
1353 return (error);
1354 }
1355
1356 /*
1357 * Safely reference a node, interlock against flushes via the IO subsystem.
1358 */
1359 hammer_node_t
1360 hammer_ref_node_safe(hammer_transaction_t trans, hammer_node_cache_t cache,
1361 int *errorp)
1362 {
1363 hammer_node_t node;
1364 int doload;
1365
1366 node = cache->node;
1367 if (node != NULL) {
1368 doload = hammer_ref_interlock(&node->lock);
1369 if (doload) {
1370 *errorp = hammer_load_node(trans, node, 0);
1371 if (*errorp)
1372 node = NULL;
1373 } else {
1374 KKASSERT(node->ondisk);
1375 if (node->flags & HAMMER_NODE_CRCBAD) {
1376 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1377 *errorp = EDOM;
1378 else
1379 *errorp = EIO;
1380 _hammer_rel_node(node, 0);
1381 node = NULL;
1382 } else {
1383 *errorp = 0;
1384 }
1385 }
1386 } else {
1387 *errorp = ENOENT;
1388 }
1389 return(node);
1390 }
1391
1392 /*
1393 * Release a hammer_node. On the last release the node dereferences
1394 * its underlying buffer and may or may not be destroyed.
1395 *
1396 * If locked is non-zero the passed node has been interlocked by the
1397 * caller and we are in the failure/unload path, otherwise it has not and
1398 * we are doing a normal release.
1399 *
1400 * This function will dispose of the interlock and the reference.
1401 * On return the node pointer is stale.
1402 */
1403 void
1404 _hammer_rel_node(hammer_node_t node, int locked)
1405 {
1406 hammer_buffer_t buffer;
1407
1408 /*
1409 * Deref the node. If this isn't the 1->0 transition we're basically
1410 * done. If locked is non-zero this function will just deref the
1411 * locked node and return TRUE, otherwise it will deref the locked
1412 * node and either lock and return TRUE on the 1->0 transition or
1413 * not lock and return FALSE.
1414 */
1415 if (hammer_rel_interlock(&node->lock, locked) == 0)
1416 return;
1417
1418 /*
1419 * Either locked was non-zero and we are interlocked, or the
1420 * hammer_rel_interlock() call returned non-zero and we are
1421 * interlocked.
1422 *
1423 * The ref-count must still be decremented if locked != 0 so
1424 * the cleanup required still varies a bit.
1425 *
1426 * hammer_flush_node() when called with 1 or 2 will dispose of
1427 * the lock and possible ref-count.
1428 */
1429 if (node->ondisk == NULL) {
1430 hammer_flush_node(node, locked + 1);
1431 /* node is stale now */
1432 return;
1433 }
1434
1435 /*
1436 * Do not disassociate the node from the buffer if it represents
1437 * a modified B-Tree node that still needs its crc to be generated.
1438 */
1439 if (node->flags & HAMMER_NODE_NEEDSCRC) {
1440 hammer_rel_interlock_done(&node->lock, locked);
1441 return;
1442 }
1443
1444 /*
1445 * Do final cleanups and then either destroy the node and leave it
1446 * passively cached. The buffer reference is removed regardless.
1447 */
1448 buffer = node->buffer;
1449 node->ondisk = NULL;
1450
1451 if ((node->flags & HAMMER_NODE_FLUSH) == 0) {
1452 /*
1453 * Normal release.
1454 */
1455 hammer_rel_interlock_done(&node->lock, locked);
1456 } else {
1457 /*
1458 * Destroy the node.
1459 */
1460 hammer_flush_node(node, locked + 1);
1461 /* node is stale */
1462
1463 }
1464 hammer_rel_buffer(buffer, 0);
1465 }
1466
1467 void
1468 hammer_rel_node(hammer_node_t node)
1469 {
1470 _hammer_rel_node(node, 0);
1471 }
1472
1473 /*
1474 * Free space on-media associated with a B-Tree node.
1475 */
1476 void
1477 hammer_delete_node(hammer_transaction_t trans, hammer_node_t node)
1478 {
1479 KKASSERT((node->flags & HAMMER_NODE_DELETED) == 0);
1480 node->flags |= HAMMER_NODE_DELETED;
1481 hammer_blockmap_free(trans, node->node_offset, sizeof(*node->ondisk));
1482 }
1483
1484 /*
1485 * Passively cache a referenced hammer_node. The caller may release
1486 * the node on return.
1487 */
1488 void
1489 hammer_cache_node(hammer_node_cache_t cache, hammer_node_t node)
1490 {
1491 /*
1492 * If the node doesn't exist, or is being deleted, don't cache it!
1493 *
1494 * The node can only ever be NULL in the I/O failure path.
1495 */
1496 if (node == NULL || (node->flags & HAMMER_NODE_DELETED))
1497 return;
1498 if (cache->node == node)
1499 return;
1500 while (cache->node)
1501 hammer_uncache_node(cache);
1502 if (node->flags & HAMMER_NODE_DELETED)
1503 return;
1504 cache->node = node;
1505 TAILQ_INSERT_TAIL(&node->cache_list, cache, entry);
1506 }
1507
1508 void
1509 hammer_uncache_node(hammer_node_cache_t cache)
1510 {
1511 hammer_node_t node;
1512
1513 if ((node = cache->node) != NULL) {
1514 TAILQ_REMOVE(&node->cache_list, cache, entry);
1515 cache->node = NULL;
1516 if (TAILQ_EMPTY(&node->cache_list))
1517 hammer_flush_node(node, 0);
1518 }
1519 }
1520
1521 /*
1522 * Remove a node's cache references and destroy the node if it has no
1523 * other references or backing store.
1524 *
1525 * locked == 0 Normal unlocked operation
1526 * locked == 1 Call hammer_rel_interlock_done(..., 0);
1527 * locked == 2 Call hammer_rel_interlock_done(..., 1);
1528 *
1529 * XXX for now this isn't even close to being MPSAFE so the refs check
1530 * is sufficient.
1531 */
1532 void
1533 hammer_flush_node(hammer_node_t node, int locked)
1534 {
1535 hammer_node_cache_t cache;
1536 hammer_buffer_t buffer;
1537 hammer_mount_t hmp = node->hmp;
1538 int dofree;
1539
1540 while ((cache = TAILQ_FIRST(&node->cache_list)) != NULL) {
1541 TAILQ_REMOVE(&node->cache_list, cache, entry);
1542 cache->node = NULL;
1543 }
1544
1545 /*
1546 * NOTE: refs is predisposed if another thread is blocking and
1547 * will be larger than 0 in that case. We aren't MPSAFE
1548 * here.
1549 */
1550 if (node->ondisk == NULL && hammer_norefs(&node->lock)) {
1551 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1552 RB_REMOVE(hammer_nod_rb_tree, &node->hmp->rb_nods_root, node);
1553 if ((buffer = node->buffer) != NULL) {
1554 node->buffer = NULL;
1555 TAILQ_REMOVE(&buffer->clist, node, entry);
1556 /* buffer is unreferenced because ondisk is NULL */
1557 }
1558 dofree = 1;
1559 } else {
1560 dofree = 0;
1561 }
1562
1563 /*
1564 * Deal with the interlock if locked == 1 or locked == 2.
1565 */
1566 if (locked)
1567 hammer_rel_interlock_done(&node->lock, locked - 1);
1568
1569 /*
1570 * Destroy if requested
1571 */
1572 if (dofree) {
1573 --hammer_count_nodes;
1574 kfree(node, hmp->m_misc);
1575 }
1576 }
1577
1578 /*
1579 * Flush passively cached B-Tree nodes associated with this buffer.
1580 * This is only called when the buffer is about to be destroyed, so
1581 * none of the nodes should have any references. The buffer is locked.
1582 *
1583 * We may be interlocked with the buffer.
1584 */
1585 void
1586 hammer_flush_buffer_nodes(hammer_buffer_t buffer)
1587 {
1588 hammer_node_t node;
1589
1590 while ((node = TAILQ_FIRST(&buffer->clist)) != NULL) {
1591 KKASSERT(node->ondisk == NULL);
1592 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1593
1594 if (hammer_try_interlock_norefs(&node->lock)) {
1595 hammer_ref(&node->lock);
1596 node->flags |= HAMMER_NODE_FLUSH;
1597 _hammer_rel_node(node, 1);
1598 } else {
1599 KKASSERT(node->buffer != NULL);
1600 buffer = node->buffer;
1601 node->buffer = NULL;
1602 TAILQ_REMOVE(&buffer->clist, node, entry);
1603 /* buffer is unreferenced because ondisk is NULL */
1604 }
1605 }
1606 }
1607
1608
1609 /************************************************************************
1610 * ALLOCATORS *
1611 ************************************************************************/
1612
1613 /*
1614 * Allocate a B-Tree node.
1615 */
1616 hammer_node_t
1617 hammer_alloc_btree(hammer_transaction_t trans, hammer_off_t hint, int *errorp)
1618 {
1619 hammer_buffer_t buffer = NULL;
1620 hammer_node_t node = NULL;
1621 hammer_off_t node_offset;
1622
1623 node_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_BTREE_INDEX,
1624 sizeof(struct hammer_node_ondisk),
1625 hint, errorp);
1626 if (*errorp == 0) {
1627 node = hammer_get_node(trans, node_offset, 1, errorp);
1628 hammer_modify_node_noundo(trans, node);
1629 bzero(node->ondisk, sizeof(*node->ondisk));
1630 hammer_modify_node_done(node);
1631 }
1632 if (buffer)
1633 hammer_rel_buffer(buffer, 0);
1634 return(node);
1635 }
1636
1637 /*
1638 * Allocate data. If the address of a data buffer is supplied then
1639 * any prior non-NULL *data_bufferp will be released and *data_bufferp
1640 * will be set to the related buffer. The caller must release it when
1641 * finally done. The initial *data_bufferp should be set to NULL by
1642 * the caller.
1643 *
1644 * The caller is responsible for making hammer_modify*() calls on the
1645 * *data_bufferp.
1646 */
1647 void *
1648 hammer_alloc_data(hammer_transaction_t trans, int32_t data_len,
1649 u_int16_t rec_type, hammer_off_t *data_offsetp,
1650 struct hammer_buffer **data_bufferp,
1651 hammer_off_t hint, int *errorp)
1652 {
1653 void *data;
1654 int zone;
1655
1656 /*
1657 * Allocate data
1658 */
1659 if (data_len) {
1660 switch(rec_type) {
1661 case HAMMER_RECTYPE_INODE:
1662 case HAMMER_RECTYPE_DIRENTRY:
1663 case HAMMER_RECTYPE_EXT:
1664 case HAMMER_RECTYPE_FIX:
1665 case HAMMER_RECTYPE_PFS:
1666 case HAMMER_RECTYPE_SNAPSHOT:
1667 case HAMMER_RECTYPE_CONFIG:
1668 zone = HAMMER_ZONE_META_INDEX;
1669 break;
1670 case HAMMER_RECTYPE_DATA:
1671 case HAMMER_RECTYPE_DB:
1672 if (data_len <= HAMMER_BUFSIZE / 2) {
1673 zone = HAMMER_ZONE_SMALL_DATA_INDEX;
1674 } else {
1675 data_len = (data_len + HAMMER_BUFMASK) &
1676 ~HAMMER_BUFMASK;
1677 zone = HAMMER_ZONE_LARGE_DATA_INDEX;
1678 }
1679 break;
1680 default:
1681 panic("hammer_alloc_data: rec_type %04x unknown",
1682 rec_type);
1683 zone = 0; /* NOT REACHED */
1684 break;
1685 }
1686 *data_offsetp = hammer_blockmap_alloc(trans, zone, data_len,
1687 hint, errorp);
1688 } else {
1689 *data_offsetp = 0;
1690 }
1691 if (*errorp == 0 && data_bufferp) {
1692 if (data_len) {
1693 data = hammer_bread_ext(trans->hmp, *data_offsetp,
1694 data_len, errorp, data_bufferp);
1695 } else {
1696 data = NULL;
1697 }
1698 } else {
1699 data = NULL;
1700 }
1701 return(data);
1702 }
1703
1704 /*
1705 * Sync dirty buffers to the media and clean-up any loose ends.
1706 *
1707 * These functions do not start the flusher going, they simply
1708 * queue everything up to the flusher.
1709 */
1710 static int hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1711
1712 int
1713 hammer_queue_inodes_flusher(hammer_mount_t hmp, int waitfor)
1714 {
1715 struct hammer_sync_info info;
1716
1717 info.error = 0;
1718 info.waitfor = waitfor;
1719 if (waitfor == MNT_WAIT) {
1720 vsyncscan(hmp->mp, VMSC_GETVP | VMSC_ONEPASS,
1721 hammer_sync_scan2, &info);
1722 } else {
1723 vsyncscan(hmp->mp, VMSC_GETVP | VMSC_ONEPASS | VMSC_NOWAIT,
1724 hammer_sync_scan2, &info);
1725 }
1726 return(info.error);
1727 }
1728
1729 /*
1730 * Filesystem sync. If doing a synchronous sync make a second pass on
1731 * the vnodes in case any were already flushing during the first pass,
1732 * and activate the flusher twice (the second time brings the UNDO FIFO's
1733 * start position up to the end position after the first call).
1734 *
1735 * If doing a lazy sync make just one pass on the vnode list, ignoring
1736 * any new vnodes added to the list while the sync is in progress.
1737 */
1738 int
1739 hammer_sync_hmp(hammer_mount_t hmp, int waitfor)
1740 {
1741 struct hammer_sync_info info;
1742 int flags;
1743
1744 flags = VMSC_GETVP;
1745 if (waitfor & MNT_LAZY)
1746 flags |= VMSC_ONEPASS;
1747
1748 info.error = 0;
1749 info.waitfor = MNT_NOWAIT;
1750 vsyncscan(hmp->mp, flags | VMSC_NOWAIT, hammer_sync_scan2, &info);
1751
1752 if (info.error == 0 && (waitfor & MNT_WAIT)) {
1753 info.waitfor = waitfor;
1754 vsyncscan(hmp->mp, flags, hammer_sync_scan2, &info);
1755 }
1756 if (waitfor == MNT_WAIT) {
1757 hammer_flusher_sync(hmp);
1758 hammer_flusher_sync(hmp);
1759 } else {
1760 hammer_flusher_async(hmp, NULL);
1761 hammer_flusher_async(hmp, NULL);
1762 }
1763 return(info.error);
1764 }
1765
1766 static int
1767 hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1768 {
1769 struct hammer_sync_info *info = data;
1770 struct hammer_inode *ip;
1771 int error;
1772
1773 ip = VTOI(vp);
1774 if (ip == NULL)
1775 return(0);
1776 if (vp->v_type == VNON || vp->v_type == VBAD) {
1777 vclrisdirty(vp);
1778 return(0);
1779 }
1780 if ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1781 RB_EMPTY(&vp->v_rbdirty_tree)) {
1782 vclrisdirty(vp);
1783 return(0);
1784 }
1785 error = VOP_FSYNC(vp, MNT_NOWAIT, 0);
1786 if (error)
1787 info->error = error;
1788 return(0);
1789 }
Cache object: ecee01cb75458808ec1259c7d924148e
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