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 <sys/nlookup.h>
43 #include <sys/buf2.h>
44
45 #include "hammer.h"
46
47 static void hammer_free_volume(hammer_volume_t volume);
48 static int hammer_load_volume(hammer_volume_t volume);
49 static int hammer_load_buffer(hammer_buffer_t buffer, int isnew);
50 static int hammer_load_node(hammer_transaction_t trans,
51 hammer_node_t node, int isnew);
52 static void _hammer_rel_node(hammer_node_t node, int locked);
53
54 static int
hammer_vol_rb_compare(hammer_volume_t vol1,hammer_volume_t vol2)55 hammer_vol_rb_compare(hammer_volume_t vol1, hammer_volume_t vol2)
56 {
57 if (vol1->vol_no < vol2->vol_no)
58 return(-1);
59 if (vol1->vol_no > vol2->vol_no)
60 return(1);
61 return(0);
62 }
63
64 /*
65 * hammer_buffer structures are indexed via their zoneX_offset, not
66 * their zone2_offset.
67 */
68 static int
hammer_buf_rb_compare(hammer_buffer_t buf1,hammer_buffer_t buf2)69 hammer_buf_rb_compare(hammer_buffer_t buf1, hammer_buffer_t buf2)
70 {
71 if (buf1->zoneX_offset < buf2->zoneX_offset)
72 return(-1);
73 if (buf1->zoneX_offset > buf2->zoneX_offset)
74 return(1);
75 return(0);
76 }
77
78 static int
hammer_nod_rb_compare(hammer_node_t node1,hammer_node_t node2)79 hammer_nod_rb_compare(hammer_node_t node1, hammer_node_t node2)
80 {
81 if (node1->node_offset < node2->node_offset)
82 return(-1);
83 if (node1->node_offset > node2->node_offset)
84 return(1);
85 return(0);
86 }
87
88 RB_GENERATE2(hammer_vol_rb_tree, hammer_volume, rb_node,
89 hammer_vol_rb_compare, int32_t, vol_no);
90 RB_GENERATE2(hammer_buf_rb_tree, hammer_buffer, rb_node,
91 hammer_buf_rb_compare, hammer_off_t, zoneX_offset);
92 RB_GENERATE2(hammer_nod_rb_tree, hammer_node, rb_node,
93 hammer_nod_rb_compare, hammer_off_t, node_offset);
94
95 /************************************************************************
96 * VOLUMES *
97 ************************************************************************
98 *
99 * Load a HAMMER volume by name. Returns 0 on success or a positive error
100 * code on failure. Volumes must be loaded at mount time or via hammer
101 * volume-add command, hammer_get_volume() will not load a new volume.
102 *
103 * The passed devvp is vref()'d but not locked. This function consumes the
104 * ref (typically by associating it with the volume structure).
105 *
106 * Calls made to hammer_load_volume() or single-threaded
107 */
108 int
hammer_install_volume(hammer_mount_t hmp,const char * volname,struct vnode * devvp,void * data)109 hammer_install_volume(hammer_mount_t hmp, const char *volname,
110 struct vnode *devvp, void *data)
111 {
112 struct mount *mp;
113 hammer_volume_t volume;
114 hammer_volume_ondisk_t ondisk;
115 hammer_volume_ondisk_t img;
116 struct nlookupdata nd;
117 struct buf *bp = NULL;
118 int error;
119 int ronly;
120 int setmp = 0;
121 int i;
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_IOTYPE_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
185 /*
186 * Initialize the volume header with data if the data is specified.
187 */
188 if (ronly == 0 && data) {
189 img = (hammer_volume_ondisk_t)data;
190 if (ondisk->vol_signature == HAMMER_FSBUF_VOLUME) {
191 hkprintf("Formatting of valid HAMMER volume %s denied. "
192 "Erase with hammer strip or dd!\n", volname);
193 error = EFTYPE;
194 goto late_failure;
195 }
196 bcopy(img, ondisk, sizeof(*img));
197 }
198
199 if (ondisk->vol_signature != HAMMER_FSBUF_VOLUME) {
200 hkprintf("volume %s has an invalid header\n", volume->vol_name);
201 for (i = 0; i < (int)sizeof(ondisk->vol_signature); i++) {
202 kprintf("%02x", ((char*)&ondisk->vol_signature)[i] & 0xFF);
203 if (i != (int)sizeof(ondisk->vol_signature) - 1)
204 kprintf(" ");
205 }
206 kprintf("\n");
207 error = EFTYPE;
208 goto late_failure;
209 }
210 volume->vol_no = ondisk->vol_no;
211 volume->vol_flags = ondisk->vol_flags;
212 volume->maxbuf_off = HAMMER_ENCODE_RAW_BUFFER(volume->vol_no,
213 HAMMER_VOL_BUF_SIZE(ondisk));
214
215 if (RB_EMPTY(&hmp->rb_vols_root)) {
216 hmp->fsid = ondisk->vol_fsid;
217 } else if (kuuid_compare(&hmp->fsid, &ondisk->vol_fsid)) {
218 hkprintf("volume %s's fsid does not match other volumes\n",
219 volume->vol_name);
220 error = EFTYPE;
221 goto late_failure;
222 }
223
224 /*
225 * Insert the volume structure into the red-black tree.
226 */
227 if (RB_INSERT(hammer_vol_rb_tree, &hmp->rb_vols_root, volume)) {
228 hkprintf("volume %s has a duplicate vol_no %d\n",
229 volume->vol_name, volume->vol_no);
230 error = EEXIST;
231 }
232
233 if (error == 0)
234 hammer_volume_number_add(hmp, volume);
235
236 /*
237 * Set the root volume . HAMMER special cases rootvol the structure.
238 * We do not hold a ref because this would prevent related I/O
239 * from being flushed.
240 */
241 if (error == 0 && ondisk->vol_rootvol == ondisk->vol_no) {
242 if (ondisk->vol_rootvol != HAMMER_ROOT_VOLNO) {
243 hkprintf("volume %s has invalid root vol_no %d\n",
244 volume->vol_name, ondisk->vol_rootvol);
245 error = EINVAL;
246 goto late_failure;
247 }
248 hmp->rootvol = volume;
249 hmp->nvolumes = ondisk->vol_count;
250 if (bp) {
251 brelse(bp);
252 bp = NULL;
253 }
254 hmp->mp->mnt_stat.f_blocks += ondisk->vol0_stat_bigblocks *
255 HAMMER_BUFFERS_PER_BIGBLOCK;
256 hmp->mp->mnt_vstat.f_blocks += ondisk->vol0_stat_bigblocks *
257 HAMMER_BUFFERS_PER_BIGBLOCK;
258 }
259 late_failure:
260 if (bp)
261 brelse(bp);
262 if (error) {
263 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/
264 if (setmp)
265 volume->devvp->v_rdev->si_mountpoint = NULL;
266 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
267 VOP_CLOSE(volume->devvp, ronly ? FREAD : FREAD|FWRITE, NULL);
268 vn_unlock(volume->devvp);
269 hammer_free_volume(volume);
270 }
271 return (error);
272 }
273
274 /*
275 * This is called for each volume when updating the mount point from
276 * read-write to read-only or vise-versa.
277 */
278 int
hammer_adjust_volume_mode(hammer_volume_t volume,void * data __unused)279 hammer_adjust_volume_mode(hammer_volume_t volume, void *data __unused)
280 {
281 if (volume->devvp) {
282 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
283 if (volume->io.hmp->ronly) {
284 /* do not call vinvalbuf */
285 VOP_OPEN(volume->devvp, FREAD, FSCRED, NULL);
286 VOP_CLOSE(volume->devvp, FREAD|FWRITE, NULL);
287 } else {
288 /* do not call vinvalbuf */
289 VOP_OPEN(volume->devvp, FREAD|FWRITE, FSCRED, NULL);
290 VOP_CLOSE(volume->devvp, FREAD, NULL);
291 }
292 vn_unlock(volume->devvp);
293 }
294 return(0);
295 }
296
297 /*
298 * Unload and free a HAMMER volume. Must return >= 0 to continue scan
299 * so returns -1 on failure.
300 */
301 int
hammer_unload_volume(hammer_volume_t volume,void * data)302 hammer_unload_volume(hammer_volume_t volume, void *data)
303 {
304 hammer_mount_t hmp = volume->io.hmp;
305 struct buf *bp = NULL;
306 hammer_volume_ondisk_t img;
307 int ronly = ((hmp->mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
308 int error;
309
310 /*
311 * Clear the volume header with data if the data is specified.
312 */
313 if (ronly == 0 && data && volume->devvp) {
314 img = (hammer_volume_ondisk_t)data;
315 error = bread(volume->devvp, 0LL, HAMMER_BUFSIZE, &bp);
316 if (error || bp->b_bcount < sizeof(*img)) {
317 hmkprintf(hmp, "Failed to read volume header: %d\n", error);
318 brelse(bp);
319 } else {
320 bcopy(img, bp->b_data, sizeof(*img));
321 error = bwrite(bp);
322 if (error)
323 hmkprintf(hmp, "Failed to clear volume header: %d\n",
324 error);
325 }
326 }
327
328 /*
329 * Clean up the root volume pointer, which is held unlocked in hmp.
330 */
331 if (hmp->rootvol == volume)
332 hmp->rootvol = NULL;
333
334 /*
335 * We must not flush a dirty buffer to disk on umount. It should
336 * have already been dealt with by the flusher, or we may be in
337 * catastrophic failure.
338 */
339 hammer_io_clear_modify(&volume->io, 1);
340 volume->io.waitdep = 1;
341
342 /*
343 * Clean up the persistent ref ioerror might have on the volume
344 */
345 if (volume->io.ioerror)
346 hammer_io_clear_error_noassert(&volume->io);
347
348 /*
349 * This should release the bp. Releasing the volume with flush set
350 * implies the interlock is set.
351 */
352 hammer_ref_interlock_true(&volume->io.lock);
353 hammer_rel_volume(volume, 1);
354 KKASSERT(volume->io.bp == NULL);
355
356 /*
357 * There should be no references on the volume.
358 */
359 KKASSERT(hammer_norefs(&volume->io.lock));
360
361 volume->ondisk = NULL;
362 if (volume->devvp) {
363 if (volume->devvp->v_rdev &&
364 volume->devvp->v_rdev->si_mountpoint == hmp->mp) {
365 volume->devvp->v_rdev->si_mountpoint = NULL;
366 }
367 if (ronly) {
368 /*
369 * Make sure we don't sync anything to disk if we
370 * are in read-only mode (1) or critically-errored
371 * (2). Note that there may be dirty buffers in
372 * normal read-only mode from crash recovery.
373 */
374 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
375 vinvalbuf(volume->devvp, 0, 0, 0);
376 VOP_CLOSE(volume->devvp, FREAD, NULL);
377 vn_unlock(volume->devvp);
378 } else {
379 /*
380 * Normal termination, save any dirty buffers
381 * (XXX there really shouldn't be any).
382 */
383 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
384 vinvalbuf(volume->devvp, V_SAVE, 0, 0);
385 VOP_CLOSE(volume->devvp, FREAD|FWRITE, NULL);
386 vn_unlock(volume->devvp);
387 }
388 }
389
390 /*
391 * Destroy the structure
392 */
393 RB_REMOVE(hammer_vol_rb_tree, &hmp->rb_vols_root, volume);
394 hammer_volume_number_del(hmp, volume);
395 hammer_free_volume(volume);
396 return(0);
397 }
398
399 static
400 void
hammer_free_volume(hammer_volume_t volume)401 hammer_free_volume(hammer_volume_t volume)
402 {
403 hammer_mount_t hmp = volume->io.hmp;
404
405 if (volume->vol_name) {
406 kfree(volume->vol_name, hmp->m_misc);
407 volume->vol_name = NULL;
408 }
409 if (volume->devvp) {
410 vrele(volume->devvp);
411 volume->devvp = NULL;
412 }
413 --hammer_count_volumes;
414 kfree(volume, hmp->m_misc);
415 }
416
417 /*
418 * Get a HAMMER volume. The volume must already exist.
419 */
420 hammer_volume_t
hammer_get_volume(hammer_mount_t hmp,int32_t vol_no,int * errorp)421 hammer_get_volume(hammer_mount_t hmp, int32_t vol_no, int *errorp)
422 {
423 hammer_volume_t volume;
424
425 /*
426 * Locate the volume structure
427 */
428 volume = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, vol_no);
429 if (volume == NULL) {
430 *errorp = ENOENT;
431 return(NULL);
432 }
433
434 /*
435 * Reference the volume, load/check the data on the 0->1 transition.
436 * hammer_load_volume() will dispose of the interlock on return,
437 * and also clean up the ref count on error.
438 */
439 if (hammer_ref_interlock(&volume->io.lock)) {
440 *errorp = hammer_load_volume(volume);
441 if (*errorp)
442 volume = NULL;
443 } else {
444 KKASSERT(volume->ondisk);
445 *errorp = 0;
446 }
447 return(volume);
448 }
449
450 int
hammer_ref_volume(hammer_volume_t volume)451 hammer_ref_volume(hammer_volume_t volume)
452 {
453 int error;
454
455 /*
456 * Reference the volume and deal with the check condition used to
457 * load its ondisk info.
458 */
459 if (hammer_ref_interlock(&volume->io.lock)) {
460 error = hammer_load_volume(volume);
461 } else {
462 KKASSERT(volume->ondisk);
463 error = 0;
464 }
465 return (error);
466 }
467
468 /*
469 * May be called without fs_token
470 */
471 hammer_volume_t
hammer_get_root_volume(hammer_mount_t hmp,int * errorp)472 hammer_get_root_volume(hammer_mount_t hmp, int *errorp)
473 {
474 hammer_volume_t volume;
475
476 volume = hmp->rootvol;
477 KKASSERT(volume != NULL);
478
479 /*
480 * Reference the volume and deal with the check condition used to
481 * load its ondisk info.
482 */
483 if (hammer_ref_interlock(&volume->io.lock)) {
484 lwkt_gettoken(&volume->io.hmp->fs_token);
485 *errorp = hammer_load_volume(volume);
486 lwkt_reltoken(&volume->io.hmp->fs_token);
487 if (*errorp)
488 volume = NULL;
489 } else {
490 KKASSERT(volume->ondisk);
491 *errorp = 0;
492 }
493 return (volume);
494 }
495
496 /*
497 * Load a volume's on-disk information. The volume must be referenced and
498 * the interlock is held on call. The interlock will be released on return.
499 * The reference will also be released on return if an error occurs.
500 */
501 static int
hammer_load_volume(hammer_volume_t volume)502 hammer_load_volume(hammer_volume_t volume)
503 {
504 int error;
505
506 if (volume->ondisk == NULL) {
507 error = hammer_io_read(volume->devvp, &volume->io,
508 HAMMER_BUFSIZE);
509 if (error == 0) {
510 volume->ondisk = (void *)volume->io.bp->b_data;
511 hammer_ref_interlock_done(&volume->io.lock);
512 } else {
513 hammer_rel_volume(volume, 1);
514 }
515 } else {
516 error = 0;
517 }
518 return(error);
519 }
520
521 /*
522 * Release a previously acquired reference on the volume.
523 *
524 * Volumes are not unloaded from memory during normal operation.
525 *
526 * May be called without fs_token
527 */
528 void
hammer_rel_volume(hammer_volume_t volume,int locked)529 hammer_rel_volume(hammer_volume_t volume, int locked)
530 {
531 struct buf *bp;
532
533 if (hammer_rel_interlock(&volume->io.lock, locked)) {
534 lwkt_gettoken(&volume->io.hmp->fs_token);
535 volume->ondisk = NULL;
536 bp = hammer_io_release(&volume->io, locked);
537 lwkt_reltoken(&volume->io.hmp->fs_token);
538 hammer_rel_interlock_done(&volume->io.lock, locked);
539 if (bp)
540 brelse(bp);
541 }
542 }
543
544 int
hammer_mountcheck_volumes(hammer_mount_t hmp)545 hammer_mountcheck_volumes(hammer_mount_t hmp)
546 {
547 hammer_volume_t vol;
548 int i;
549
550 HAMMER_VOLUME_NUMBER_FOREACH(hmp, i) {
551 vol = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, i);
552 if (vol == NULL)
553 return(EINVAL);
554 }
555 return(0);
556 }
557
558 int
hammer_get_installed_volumes(hammer_mount_t hmp)559 hammer_get_installed_volumes(hammer_mount_t hmp)
560 {
561 int i, ret = 0;
562
563 HAMMER_VOLUME_NUMBER_FOREACH(hmp, i)
564 ret++;
565 return(ret);
566 }
567
568 /************************************************************************
569 * BUFFERS *
570 ************************************************************************
571 *
572 * Manage buffers. Currently most blockmap-backed zones are direct-mapped
573 * to zone-2 buffer offsets, without a translation stage. However, the
574 * hammer_buffer structure is indexed by its zoneX_offset, not its
575 * zone2_offset.
576 *
577 * The proper zone must be maintained throughout the code-base all the way
578 * through to the big-block allocator, or routines like hammer_del_buffers()
579 * will not be able to locate all potentially conflicting buffers.
580 */
581
582 /*
583 * Helper function returns whether a zone offset can be directly translated
584 * to a raw buffer index or not. Really only the volume and undo zones
585 * can't be directly translated. Volumes are special-cased and undo zones
586 * shouldn't be aliased accessed in read-only mode.
587 *
588 * This function is ONLY used to detect aliased zones during a read-only
589 * mount.
590 */
591 static __inline int
hammer_direct_zone(hammer_off_t buf_offset)592 hammer_direct_zone(hammer_off_t buf_offset)
593 {
594 return(hammer_is_zone_direct_xlated(buf_offset));
595 }
596
597 hammer_buffer_t
hammer_get_buffer(hammer_mount_t hmp,hammer_off_t buf_offset,int bytes,int isnew,int * errorp)598 hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset,
599 int bytes, int isnew, int *errorp)
600 {
601 hammer_buffer_t buffer;
602 hammer_volume_t volume;
603 hammer_off_t zone2_offset;
604 int vol_no;
605 int zone;
606
607 buf_offset &= ~HAMMER_BUFMASK64;
608 again:
609 /*
610 * Shortcut if the buffer is already cached
611 */
612 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, buf_offset);
613 if (buffer) {
614 /*
615 * Once refed the ondisk field will not be cleared by
616 * any other action. Shortcut the operation if the
617 * ondisk structure is valid.
618 */
619 found_aliased:
620 if (hammer_ref_interlock(&buffer->io.lock) == 0) {
621 hammer_io_advance(&buffer->io);
622 KKASSERT(buffer->ondisk);
623 *errorp = 0;
624 return(buffer);
625 }
626
627 /*
628 * 0->1 transition or defered 0->1 transition (CHECK),
629 * interlock now held. Shortcut if ondisk is already
630 * assigned.
631 */
632 atomic_add_int(&hammer_count_refedbufs, 1);
633 if (buffer->ondisk) {
634 hammer_io_advance(&buffer->io);
635 hammer_ref_interlock_done(&buffer->io.lock);
636 *errorp = 0;
637 return(buffer);
638 }
639
640 /*
641 * The buffer is no longer loose if it has a ref, and
642 * cannot become loose once it gains a ref. Loose
643 * buffers will never be in a modified state. This should
644 * only occur on the 0->1 transition of refs.
645 *
646 * lose_root can be modified via a biodone() interrupt
647 * so the io_token must be held.
648 */
649 if (buffer->io.mod_root == &hmp->lose_root) {
650 lwkt_gettoken(&hmp->io_token);
651 if (buffer->io.mod_root == &hmp->lose_root) {
652 RB_REMOVE(hammer_mod_rb_tree,
653 buffer->io.mod_root, &buffer->io);
654 buffer->io.mod_root = NULL;
655 KKASSERT(buffer->io.modified == 0);
656 }
657 lwkt_reltoken(&hmp->io_token);
658 }
659 goto found;
660 } else if (hmp->ronly && hammer_direct_zone(buf_offset)) {
661 /*
662 * If this is a read-only mount there could be an alias
663 * in the raw-zone. If there is we use that buffer instead.
664 *
665 * rw mounts will not have aliases. Also note when going
666 * from ro -> rw the recovered raw buffers are flushed and
667 * reclaimed, so again there will not be any aliases once
668 * the mount is rw.
669 */
670 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
671 hammer_xlate_to_zone2(buf_offset));
672 if (buffer) {
673 if (hammer_debug_general & 0x0001) {
674 hkrateprintf(&hmp->kdiag,
675 "recovered aliased %016jx\n",
676 (intmax_t)buf_offset);
677 }
678 goto found_aliased;
679 }
680 }
681
682 /*
683 * Handle blockmap offset translations
684 */
685 zone = HAMMER_ZONE_DECODE(buf_offset);
686 if (hammer_is_index_record(zone)) {
687 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, errorp);
688 } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
689 zone2_offset = hammer_undo_lookup(hmp, buf_offset, errorp);
690 } else {
691 /* Must be zone-2 (not 1 or 4 or 15) */
692 KKASSERT(zone == HAMMER_ZONE_RAW_BUFFER_INDEX);
693 zone2_offset = buf_offset;
694 *errorp = 0;
695 }
696 if (*errorp)
697 return(NULL);
698
699 /*
700 * NOTE: zone2_offset and maxbuf_off are both full zone-2 offset
701 * specifications.
702 */
703 KKASSERT(hammer_is_zone_raw_buffer(zone2_offset));
704 vol_no = HAMMER_VOL_DECODE(zone2_offset);
705 volume = hammer_get_volume(hmp, vol_no, errorp);
706 if (volume == NULL)
707 return(NULL);
708
709 KKASSERT(zone2_offset < volume->maxbuf_off);
710
711 /*
712 * Allocate a new buffer structure. We will check for races later.
713 */
714 ++hammer_count_buffers;
715 buffer = kmalloc(sizeof(*buffer), hmp->m_misc,
716 M_WAITOK|M_ZERO|M_USE_RESERVE);
717 buffer->zone2_offset = zone2_offset;
718 buffer->zoneX_offset = buf_offset;
719
720 hammer_io_init(&buffer->io, volume, hammer_zone_to_iotype(zone));
721 buffer->io.offset = hammer_xlate_to_phys(volume->ondisk, zone2_offset);
722 buffer->io.bytes = bytes;
723 TAILQ_INIT(&buffer->node_list);
724 hammer_ref_interlock_true(&buffer->io.lock);
725
726 /*
727 * Insert the buffer into the RB tree and handle late collisions.
728 */
729 if (RB_INSERT(hammer_buf_rb_tree, &hmp->rb_bufs_root, buffer)) {
730 hammer_rel_volume(volume, 0);
731 buffer->io.volume = NULL; /* safety */
732 if (hammer_rel_interlock(&buffer->io.lock, 1)) /* safety */
733 hammer_rel_interlock_done(&buffer->io.lock, 1);
734 --hammer_count_buffers;
735 kfree(buffer, hmp->m_misc);
736 goto again;
737 }
738 atomic_add_int(&hammer_count_refedbufs, 1);
739 found:
740
741 /*
742 * The buffer is referenced and interlocked. Load the buffer
743 * if necessary. hammer_load_buffer() deals with the interlock
744 * and, if an error is returned, also deals with the ref.
745 */
746 if (buffer->ondisk == NULL) {
747 *errorp = hammer_load_buffer(buffer, isnew);
748 if (*errorp)
749 buffer = NULL;
750 } else {
751 hammer_io_advance(&buffer->io);
752 hammer_ref_interlock_done(&buffer->io.lock);
753 *errorp = 0;
754 }
755 return(buffer);
756 }
757
758 /*
759 * This is used by the direct-read code to deal with large-data buffers
760 * created by the reblocker and mirror-write code. The direct-read code
761 * bypasses the HAMMER buffer subsystem and so any aliased dirty or write-
762 * running hammer buffers must be fully synced to disk before we can issue
763 * the direct-read.
764 *
765 * This code path is not considered critical as only the rebocker and
766 * mirror-write code will create large-data buffers via the HAMMER buffer
767 * subsystem. They do that because they operate at the B-Tree level and
768 * do not access the vnode/inode structures.
769 */
770 void
hammer_sync_buffers(hammer_mount_t hmp,hammer_off_t base_offset,int bytes)771 hammer_sync_buffers(hammer_mount_t hmp, hammer_off_t base_offset, int bytes)
772 {
773 hammer_buffer_t buffer;
774 int error;
775
776 KKASSERT(hammer_is_zone_large_data(base_offset));
777
778 while (bytes > 0) {
779 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
780 base_offset);
781 if (buffer && (buffer->io.modified || buffer->io.running)) {
782 error = hammer_ref_buffer(buffer);
783 if (error == 0) {
784 hammer_io_wait(&buffer->io);
785 if (buffer->io.modified) {
786 hammer_io_write_interlock(&buffer->io);
787 hammer_io_flush(&buffer->io, 0);
788 hammer_io_done_interlock(&buffer->io);
789 hammer_io_wait(&buffer->io);
790 }
791 hammer_rel_buffer(buffer, 0);
792 }
793 }
794 base_offset += HAMMER_BUFSIZE;
795 bytes -= HAMMER_BUFSIZE;
796 }
797 }
798
799 /*
800 * Destroy all buffers covering the specified zoneX offset range. This
801 * is called when the related blockmap layer2 entry is freed or when
802 * a direct write bypasses our buffer/buffer-cache subsystem.
803 *
804 * The buffers may be referenced by the caller itself. Setting reclaim
805 * will cause the buffer to be destroyed when it's ref count reaches zero.
806 *
807 * Return 0 on success, EAGAIN if some buffers could not be destroyed due
808 * to additional references held by other threads, or some other (typically
809 * fatal) error.
810 */
811 int
hammer_del_buffers(hammer_mount_t hmp,hammer_off_t base_offset,hammer_off_t zone2_offset,int bytes,int report_conflicts)812 hammer_del_buffers(hammer_mount_t hmp, hammer_off_t base_offset,
813 hammer_off_t zone2_offset, int bytes,
814 int report_conflicts)
815 {
816 hammer_buffer_t buffer;
817 hammer_volume_t volume;
818 int vol_no;
819 int error;
820 int ret_error;
821
822 vol_no = HAMMER_VOL_DECODE(zone2_offset);
823 volume = hammer_get_volume(hmp, vol_no, &ret_error);
824 KKASSERT(ret_error == 0);
825
826 while (bytes > 0) {
827 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
828 base_offset);
829 if (buffer) {
830 error = hammer_ref_buffer(buffer);
831 if (hammer_debug_general & 0x20000) {
832 hkprintf("delbufr %016jx rerr=%d 1ref=%d\n",
833 (intmax_t)buffer->zoneX_offset,
834 error,
835 hammer_oneref(&buffer->io.lock));
836 }
837 if (error == 0 && !hammer_oneref(&buffer->io.lock)) {
838 error = EAGAIN;
839 hammer_rel_buffer(buffer, 0);
840 }
841 if (error == 0) {
842 KKASSERT(buffer->zone2_offset == zone2_offset);
843 hammer_io_clear_modify(&buffer->io, 1);
844 buffer->io.reclaim = 1;
845 buffer->io.waitdep = 1;
846 KKASSERT(buffer->io.volume == volume);
847 hammer_rel_buffer(buffer, 0);
848 }
849 } else {
850 error = hammer_io_inval(volume, zone2_offset);
851 }
852 if (error) {
853 ret_error = error;
854 if (report_conflicts ||
855 (hammer_debug_general & 0x8000)) {
856 krateprintf(&hmp->kdiag,
857 "hammer_del_buffers: unable to "
858 "invalidate %016jx buffer=%p "
859 "rep=%d lkrefs=%08x\n",
860 (intmax_t)base_offset,
861 buffer, report_conflicts,
862 (buffer ? buffer->io.lock.refs : -1));
863 }
864 }
865 base_offset += HAMMER_BUFSIZE;
866 zone2_offset += HAMMER_BUFSIZE;
867 bytes -= HAMMER_BUFSIZE;
868 }
869 hammer_rel_volume(volume, 0);
870 return (ret_error);
871 }
872
873 /*
874 * Given a referenced and interlocked buffer load/validate the data.
875 *
876 * The buffer interlock will be released on return. If an error is
877 * returned the buffer reference will also be released (and the buffer
878 * pointer will thus be stale).
879 */
880 static int
hammer_load_buffer(hammer_buffer_t buffer,int isnew)881 hammer_load_buffer(hammer_buffer_t buffer, int isnew)
882 {
883 hammer_volume_t volume;
884 int error;
885
886 /*
887 * Load the buffer's on-disk info
888 */
889 volume = buffer->io.volume;
890
891 if (hammer_debug_io & 0x0004) {
892 hdkprintf("load_buffer %016jx %016jx isnew=%d od=%p\n",
893 (intmax_t)buffer->zoneX_offset,
894 (intmax_t)buffer->zone2_offset,
895 isnew, buffer->ondisk);
896 }
897
898 if (buffer->ondisk == NULL) {
899 /*
900 * Issue the read or generate a new buffer. When reading
901 * the limit argument controls any read-ahead clustering
902 * hammer_io_read() is allowed to do.
903 *
904 * We cannot read-ahead in the large-data zone and we cannot
905 * cross a big-block boundary as the next big-block might
906 * use a different buffer size.
907 */
908 if (isnew) {
909 error = hammer_io_new(volume->devvp, &buffer->io);
910 } else if (hammer_is_zone_large_data(buffer->zoneX_offset)) {
911 error = hammer_io_read(volume->devvp, &buffer->io,
912 buffer->io.bytes);
913 } else {
914 hammer_off_t limit;
915
916 limit = HAMMER_BIGBLOCK_DOALIGN(buffer->zone2_offset);
917 limit -= buffer->zone2_offset;
918 error = hammer_io_read(volume->devvp, &buffer->io,
919 limit);
920 }
921 if (error == 0)
922 buffer->ondisk = (void *)buffer->io.bp->b_data;
923 } else if (isnew) {
924 error = hammer_io_new(volume->devvp, &buffer->io);
925 } else {
926 error = 0;
927 }
928 if (error == 0) {
929 hammer_io_advance(&buffer->io);
930 hammer_ref_interlock_done(&buffer->io.lock);
931 } else {
932 hammer_rel_buffer(buffer, 1);
933 }
934 return (error);
935 }
936
937 /*
938 * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
939 * This routine is only called during unmount or when a volume is
940 * removed.
941 *
942 * If data != NULL, it specifies a volume whoose buffers should
943 * be unloaded.
944 */
945 int
hammer_unload_buffer(hammer_buffer_t buffer,void * data)946 hammer_unload_buffer(hammer_buffer_t buffer, void *data)
947 {
948 hammer_volume_t volume = (hammer_volume_t)data;
949
950 /*
951 * If volume != NULL we are only interested in unloading buffers
952 * associated with a particular volume.
953 */
954 if (volume != NULL && volume != buffer->io.volume)
955 return 0;
956
957 /*
958 * Clean up the persistent ref ioerror might have on the buffer
959 * and acquire a ref. Expect a 0->1 transition.
960 */
961 if (buffer->io.ioerror) {
962 hammer_io_clear_error_noassert(&buffer->io);
963 atomic_add_int(&hammer_count_refedbufs, -1);
964 }
965 hammer_ref_interlock_true(&buffer->io.lock);
966 atomic_add_int(&hammer_count_refedbufs, 1);
967
968 /*
969 * We must not flush a dirty buffer to disk on umount. It should
970 * have already been dealt with by the flusher, or we may be in
971 * catastrophic failure.
972 *
973 * We must set waitdep to ensure that a running buffer is waited
974 * on and released prior to us trying to unload the volume.
975 */
976 hammer_io_clear_modify(&buffer->io, 1);
977 hammer_flush_buffer_nodes(buffer);
978 buffer->io.waitdep = 1;
979 hammer_rel_buffer(buffer, 1);
980 return(0);
981 }
982
983 /*
984 * Reference a buffer that is either already referenced or via a specially
985 * handled pointer (aka cursor->buffer).
986 */
987 int
hammer_ref_buffer(hammer_buffer_t buffer)988 hammer_ref_buffer(hammer_buffer_t buffer)
989 {
990 hammer_mount_t hmp;
991 int error;
992 int locked;
993
994 /*
995 * Acquire a ref, plus the buffer will be interlocked on the
996 * 0->1 transition.
997 */
998 locked = hammer_ref_interlock(&buffer->io.lock);
999 hmp = buffer->io.hmp;
1000
1001 /*
1002 * At this point a biodone() will not touch the buffer other then
1003 * incidental bits. However, lose_root can be modified via
1004 * a biodone() interrupt.
1005 *
1006 * No longer loose. lose_root requires the io_token.
1007 */
1008 if (buffer->io.mod_root == &hmp->lose_root) {
1009 lwkt_gettoken(&hmp->io_token);
1010 if (buffer->io.mod_root == &hmp->lose_root) {
1011 RB_REMOVE(hammer_mod_rb_tree,
1012 buffer->io.mod_root, &buffer->io);
1013 buffer->io.mod_root = NULL;
1014 }
1015 lwkt_reltoken(&hmp->io_token);
1016 }
1017
1018 if (locked) {
1019 atomic_add_int(&hammer_count_refedbufs, 1);
1020 error = hammer_load_buffer(buffer, 0);
1021 /* NOTE: on error the buffer pointer is stale */
1022 } else {
1023 error = 0;
1024 }
1025 return(error);
1026 }
1027
1028 /*
1029 * Release a reference on the buffer. On the 1->0 transition the
1030 * underlying IO will be released but the data reference is left
1031 * cached.
1032 *
1033 * Only destroy the structure itself if the related buffer cache buffer
1034 * was disassociated from it. This ties the management of the structure
1035 * to the buffer cache subsystem. buffer->ondisk determines whether the
1036 * embedded io is referenced or not.
1037 */
1038 void
hammer_rel_buffer(hammer_buffer_t buffer,int locked)1039 hammer_rel_buffer(hammer_buffer_t buffer, int locked)
1040 {
1041 hammer_volume_t volume;
1042 hammer_mount_t hmp;
1043 struct buf *bp = NULL;
1044 int freeme = 0;
1045
1046 hmp = buffer->io.hmp;
1047
1048 if (hammer_rel_interlock(&buffer->io.lock, locked) == 0)
1049 return;
1050
1051 /*
1052 * hammer_count_refedbufs accounting. Decrement if we are in
1053 * the error path or if CHECK is clear.
1054 *
1055 * If we are not in the error path and CHECK is set the caller
1056 * probably just did a hammer_ref() and didn't account for it,
1057 * so we don't account for the loss here.
1058 */
1059 if (locked || (buffer->io.lock.refs & HAMMER_REFS_CHECK) == 0)
1060 atomic_add_int(&hammer_count_refedbufs, -1);
1061
1062 /*
1063 * If the caller locked us or the normal released transitions
1064 * from 1->0 (and acquired the lock) attempt to release the
1065 * io. If the called locked us we tell hammer_io_release()
1066 * to flush (which would be the unload or failure path).
1067 */
1068 bp = hammer_io_release(&buffer->io, locked);
1069
1070 /*
1071 * If the buffer has no bp association and no refs we can destroy
1072 * it.
1073 *
1074 * NOTE: It is impossible for any associated B-Tree nodes to have
1075 * refs if the buffer has no additional refs.
1076 */
1077 if (buffer->io.bp == NULL && hammer_norefs(&buffer->io.lock)) {
1078 RB_REMOVE(hammer_buf_rb_tree,
1079 &buffer->io.hmp->rb_bufs_root,
1080 buffer);
1081 volume = buffer->io.volume;
1082 buffer->io.volume = NULL; /* sanity */
1083 hammer_rel_volume(volume, 0);
1084 hammer_io_clear_modlist(&buffer->io);
1085 hammer_flush_buffer_nodes(buffer);
1086 KKASSERT(TAILQ_EMPTY(&buffer->node_list));
1087 freeme = 1;
1088 }
1089
1090 /*
1091 * Cleanup
1092 */
1093 hammer_rel_interlock_done(&buffer->io.lock, locked);
1094 if (bp)
1095 brelse(bp);
1096 if (freeme) {
1097 --hammer_count_buffers;
1098 kfree(buffer, hmp->m_misc);
1099 }
1100 }
1101
1102 /*
1103 * Access the filesystem buffer containing the specified hammer offset.
1104 * buf_offset is a conglomeration of the volume number and vol_buf_beg
1105 * relative buffer offset. It must also have bit 55 set to be valid.
1106 * (see hammer_off_t in hammer_disk.h).
1107 *
1108 * Any prior buffer in *bufferp will be released and replaced by the
1109 * requested buffer.
1110 *
1111 * NOTE: The buffer is indexed via its zoneX_offset but we allow the
1112 * passed cached *bufferp to match against either zoneX or zone2.
1113 */
1114 static __inline
1115 void *
_hammer_bread(hammer_mount_t hmp,hammer_off_t buf_offset,int bytes,int isnew,int * errorp,hammer_buffer_t * bufferp)1116 _hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1117 int isnew, int *errorp, hammer_buffer_t *bufferp)
1118 {
1119 hammer_buffer_t buffer;
1120 int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
1121
1122 buf_offset &= ~HAMMER_BUFMASK64;
1123 KKASSERT(HAMMER_ZONE(buf_offset) != 0);
1124
1125 buffer = *bufferp;
1126 if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
1127 buffer->zoneX_offset != buf_offset)) {
1128 if (buffer)
1129 hammer_rel_buffer(buffer, 0);
1130 buffer = hammer_get_buffer(hmp, buf_offset, bytes, isnew, errorp);
1131 *bufferp = buffer;
1132 } else {
1133 *errorp = 0;
1134 }
1135
1136 /*
1137 * Return a pointer to the buffer data.
1138 */
1139 if (buffer == NULL)
1140 return(NULL);
1141 else
1142 return((char *)buffer->ondisk + xoff);
1143 }
1144
1145 void *
hammer_bread(hammer_mount_t hmp,hammer_off_t buf_offset,int * errorp,hammer_buffer_t * bufferp)1146 hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset,
1147 int *errorp, hammer_buffer_t *bufferp)
1148 {
1149 return(_hammer_bread(hmp, buf_offset, HAMMER_BUFSIZE, 0, errorp, bufferp));
1150 }
1151
1152 void *
hammer_bread_ext(hammer_mount_t hmp,hammer_off_t buf_offset,int bytes,int * errorp,hammer_buffer_t * bufferp)1153 hammer_bread_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1154 int *errorp, hammer_buffer_t *bufferp)
1155 {
1156 bytes = HAMMER_BUFSIZE_DOALIGN(bytes);
1157 return(_hammer_bread(hmp, buf_offset, bytes, 0, errorp, bufferp));
1158 }
1159
1160 /*
1161 * Access the filesystem buffer containing the specified hammer offset.
1162 * No disk read operation occurs. The result buffer may contain garbage.
1163 *
1164 * Any prior buffer in *bufferp will be released and replaced by the
1165 * requested buffer.
1166 *
1167 * This function marks the buffer dirty but does not increment its
1168 * modify_refs count.
1169 */
1170 void *
hammer_bnew(hammer_mount_t hmp,hammer_off_t buf_offset,int * errorp,hammer_buffer_t * bufferp)1171 hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset,
1172 int *errorp, hammer_buffer_t *bufferp)
1173 {
1174 return(_hammer_bread(hmp, buf_offset, HAMMER_BUFSIZE, 1, errorp, bufferp));
1175 }
1176
1177 void *
hammer_bnew_ext(hammer_mount_t hmp,hammer_off_t buf_offset,int bytes,int * errorp,hammer_buffer_t * bufferp)1178 hammer_bnew_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1179 int *errorp, hammer_buffer_t *bufferp)
1180 {
1181 bytes = HAMMER_BUFSIZE_DOALIGN(bytes);
1182 return(_hammer_bread(hmp, buf_offset, bytes, 1, errorp, bufferp));
1183 }
1184
1185 /************************************************************************
1186 * NODES *
1187 ************************************************************************
1188 *
1189 * Manage B-Tree nodes. B-Tree nodes represent the primary indexing
1190 * method used by the HAMMER filesystem.
1191 *
1192 * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
1193 * associated with its buffer, and will only referenced the buffer while
1194 * the node itself is referenced.
1195 *
1196 * A hammer_node can also be passively associated with other HAMMER
1197 * structures, such as inodes, while retaining 0 references. These
1198 * associations can be cleared backwards using a pointer-to-pointer in
1199 * the hammer_node.
1200 *
1201 * This allows the HAMMER implementation to cache hammer_nodes long-term
1202 * and short-cut a great deal of the infrastructure's complexity. In
1203 * most cases a cached node can be reacquired without having to dip into
1204 * the B-Tree.
1205 */
1206 hammer_node_t
hammer_get_node(hammer_transaction_t trans,hammer_off_t node_offset,int isnew,int * errorp)1207 hammer_get_node(hammer_transaction_t trans, hammer_off_t node_offset,
1208 int isnew, int *errorp)
1209 {
1210 hammer_mount_t hmp = trans->hmp;
1211 hammer_node_t node;
1212 int doload;
1213
1214 KKASSERT(hammer_is_zone_btree(node_offset));
1215
1216 /*
1217 * Locate the structure, allocating one if necessary.
1218 */
1219 again:
1220 node = RB_LOOKUP(hammer_nod_rb_tree, &hmp->rb_nods_root, node_offset);
1221 if (node == NULL) {
1222 ++hammer_count_nodes;
1223 node = kmalloc(sizeof(*node), hmp->m_misc, M_WAITOK|M_ZERO|M_USE_RESERVE);
1224 node->node_offset = node_offset;
1225 node->hmp = hmp;
1226 TAILQ_INIT(&node->cursor_list);
1227 TAILQ_INIT(&node->cache_list);
1228 if (RB_INSERT(hammer_nod_rb_tree, &hmp->rb_nods_root, node)) {
1229 --hammer_count_nodes;
1230 kfree(node, hmp->m_misc);
1231 goto again;
1232 }
1233 doload = hammer_ref_interlock_true(&node->lock);
1234 } else {
1235 doload = hammer_ref_interlock(&node->lock);
1236 }
1237 if (doload) {
1238 *errorp = hammer_load_node(trans, node, isnew);
1239 if (*errorp)
1240 node = NULL;
1241 } else {
1242 KKASSERT(node->ondisk);
1243 *errorp = 0;
1244 hammer_io_advance(&node->buffer->io);
1245 }
1246 return(node);
1247 }
1248
1249 /*
1250 * Reference an already-referenced node. 0->1 transitions should assert
1251 * so we do not have to deal with hammer_ref() setting CHECK.
1252 */
1253 void
hammer_ref_node(hammer_node_t node)1254 hammer_ref_node(hammer_node_t node)
1255 {
1256 KKASSERT(hammer_isactive(&node->lock) && node->ondisk != NULL);
1257 hammer_ref(&node->lock);
1258 }
1259
1260 /*
1261 * Load a node's on-disk data reference. Called with the node referenced
1262 * and interlocked.
1263 *
1264 * On return the node interlock will be unlocked. If a non-zero error code
1265 * is returned the node will also be dereferenced (and the caller's pointer
1266 * will be stale).
1267 */
1268 static int
hammer_load_node(hammer_transaction_t trans,hammer_node_t node,int isnew)1269 hammer_load_node(hammer_transaction_t trans, hammer_node_t node, int isnew)
1270 {
1271 hammer_buffer_t buffer;
1272 hammer_off_t buf_offset;
1273 hammer_mount_t hmp = trans->hmp;
1274 int error;
1275
1276 error = 0;
1277 if (node->ondisk == NULL) {
1278 /*
1279 * This is a little confusing but the jist is that
1280 * node->buffer determines whether the node is on
1281 * the buffer's node_list and node->ondisk determines
1282 * whether the buffer is referenced.
1283 *
1284 * We could be racing a buffer release, in which case
1285 * node->buffer may become NULL while we are blocked
1286 * referencing the buffer.
1287 */
1288 if ((buffer = node->buffer) != NULL) {
1289 error = hammer_ref_buffer(buffer);
1290 if (error == 0 && node->buffer == NULL) {
1291 TAILQ_INSERT_TAIL(&buffer->node_list, node, entry);
1292 node->buffer = buffer;
1293 }
1294 } else {
1295 buf_offset = node->node_offset & ~HAMMER_BUFMASK64;
1296 buffer = hammer_get_buffer(node->hmp, buf_offset,
1297 HAMMER_BUFSIZE, 0, &error);
1298 if (buffer) {
1299 KKASSERT(error == 0);
1300 TAILQ_INSERT_TAIL(&buffer->node_list, node, entry);
1301 node->buffer = buffer;
1302 }
1303 }
1304 if (error)
1305 goto failed;
1306 node->ondisk = (void *)((char *)buffer->ondisk +
1307 (node->node_offset & HAMMER_BUFMASK));
1308
1309 /*
1310 * Check CRC. NOTE: Neither flag is set and the CRC is not
1311 * generated on new B-Tree nodes.
1312 */
1313 if (isnew == 0 &&
1314 (node->flags & HAMMER_NODE_CRCANY) == 0) {
1315 if (hammer_crc_test_btree(hmp->version, node->ondisk) == 0) {
1316 hdkprintf("CRC B-TREE NODE @ %016jx/%lu FAILED\n",
1317 (intmax_t)node->node_offset,
1318 sizeof(*node->ondisk));
1319 if (hammer_debug_critical)
1320 Debugger("CRC FAILED: B-TREE NODE");
1321 node->flags |= HAMMER_NODE_CRCBAD;
1322 } else {
1323 node->flags |= HAMMER_NODE_CRCGOOD;
1324 }
1325 }
1326 }
1327 if (node->flags & HAMMER_NODE_CRCBAD) {
1328 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1329 error = EDOM;
1330 else
1331 error = EIO;
1332 }
1333 failed:
1334 if (error) {
1335 _hammer_rel_node(node, 1);
1336 } else {
1337 hammer_ref_interlock_done(&node->lock);
1338 }
1339 return (error);
1340 }
1341
1342 /*
1343 * Safely reference a node, interlock against flushes via the IO subsystem.
1344 */
1345 hammer_node_t
hammer_ref_node_safe(hammer_transaction_t trans,hammer_node_cache_t cache,int * errorp)1346 hammer_ref_node_safe(hammer_transaction_t trans, hammer_node_cache_t cache,
1347 int *errorp)
1348 {
1349 hammer_node_t node;
1350 int doload;
1351
1352 node = cache->node;
1353 if (node != NULL) {
1354 doload = hammer_ref_interlock(&node->lock);
1355 if (doload) {
1356 *errorp = hammer_load_node(trans, node, 0);
1357 if (*errorp)
1358 node = NULL;
1359 } else {
1360 KKASSERT(node->ondisk);
1361 if (node->flags & HAMMER_NODE_CRCBAD) {
1362 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1363 *errorp = EDOM;
1364 else
1365 *errorp = EIO;
1366 _hammer_rel_node(node, 0);
1367 node = NULL;
1368 } else {
1369 *errorp = 0;
1370 }
1371 }
1372 } else {
1373 *errorp = ENOENT;
1374 }
1375 return(node);
1376 }
1377
1378 /*
1379 * Release a hammer_node. On the last release the node dereferences
1380 * its underlying buffer and may or may not be destroyed.
1381 *
1382 * If locked is non-zero the passed node has been interlocked by the
1383 * caller and we are in the failure/unload path, otherwise it has not and
1384 * we are doing a normal release.
1385 *
1386 * This function will dispose of the interlock and the reference.
1387 * On return the node pointer is stale.
1388 */
1389 void
_hammer_rel_node(hammer_node_t node,int locked)1390 _hammer_rel_node(hammer_node_t node, int locked)
1391 {
1392 hammer_buffer_t buffer;
1393
1394 /*
1395 * Deref the node. If this isn't the 1->0 transition we're basically
1396 * done. If locked is non-zero this function will just deref the
1397 * locked node and return 1, otherwise it will deref the locked
1398 * node and either lock and return 1 on the 1->0 transition or
1399 * not lock and return 0.
1400 */
1401 if (hammer_rel_interlock(&node->lock, locked) == 0)
1402 return;
1403
1404 /*
1405 * Either locked was non-zero and we are interlocked, or the
1406 * hammer_rel_interlock() call returned non-zero and we are
1407 * interlocked.
1408 *
1409 * The ref-count must still be decremented if locked != 0 so
1410 * the cleanup required still varies a bit.
1411 *
1412 * hammer_flush_node() when called with 1 or 2 will dispose of
1413 * the lock and possible ref-count.
1414 */
1415 if (node->ondisk == NULL) {
1416 hammer_flush_node(node, locked + 1);
1417 /* node is stale now */
1418 return;
1419 }
1420
1421 /*
1422 * Do not disassociate the node from the buffer if it represents
1423 * a modified B-Tree node that still needs its crc to be generated.
1424 */
1425 if (node->flags & HAMMER_NODE_NEEDSCRC) {
1426 hammer_rel_interlock_done(&node->lock, locked);
1427 return;
1428 }
1429
1430 /*
1431 * Do final cleanups and then either destroy the node and leave it
1432 * passively cached. The buffer reference is removed regardless.
1433 */
1434 buffer = node->buffer;
1435 node->ondisk = NULL;
1436
1437 if ((node->flags & HAMMER_NODE_FLUSH) == 0) {
1438 /*
1439 * Normal release.
1440 */
1441 hammer_rel_interlock_done(&node->lock, locked);
1442 } else {
1443 /*
1444 * Destroy the node.
1445 */
1446 hammer_flush_node(node, locked + 1);
1447 /* node is stale */
1448
1449 }
1450 hammer_rel_buffer(buffer, 0);
1451 }
1452
1453 void
hammer_rel_node(hammer_node_t node)1454 hammer_rel_node(hammer_node_t node)
1455 {
1456 _hammer_rel_node(node, 0);
1457 }
1458
1459 /*
1460 * Free space on-media associated with a B-Tree node.
1461 */
1462 void
hammer_delete_node(hammer_transaction_t trans,hammer_node_t node)1463 hammer_delete_node(hammer_transaction_t trans, hammer_node_t node)
1464 {
1465 KKASSERT((node->flags & HAMMER_NODE_DELETED) == 0);
1466 node->flags |= HAMMER_NODE_DELETED;
1467 hammer_blockmap_free(trans, node->node_offset, sizeof(*node->ondisk));
1468 }
1469
1470 /*
1471 * Passively cache a referenced hammer_node. The caller may release
1472 * the node on return.
1473 */
1474 void
hammer_cache_node(hammer_node_cache_t cache,hammer_node_t node)1475 hammer_cache_node(hammer_node_cache_t cache, hammer_node_t node)
1476 {
1477 /*
1478 * If the node doesn't exist, or is being deleted, don't cache it!
1479 *
1480 * The node can only ever be NULL in the I/O failure path.
1481 */
1482 if (node == NULL || (node->flags & HAMMER_NODE_DELETED))
1483 return;
1484 if (cache->node == node)
1485 return;
1486 while (cache->node)
1487 hammer_uncache_node(cache);
1488 if (node->flags & HAMMER_NODE_DELETED)
1489 return;
1490 cache->node = node;
1491 TAILQ_INSERT_TAIL(&node->cache_list, cache, entry);
1492 }
1493
1494 void
hammer_uncache_node(hammer_node_cache_t cache)1495 hammer_uncache_node(hammer_node_cache_t cache)
1496 {
1497 hammer_node_t node;
1498
1499 if ((node = cache->node) != NULL) {
1500 TAILQ_REMOVE(&node->cache_list, cache, entry);
1501 cache->node = NULL;
1502 if (TAILQ_EMPTY(&node->cache_list))
1503 hammer_flush_node(node, 0);
1504 }
1505 }
1506
1507 /*
1508 * Remove a node's cache references and destroy the node if it has no
1509 * other references or backing store.
1510 *
1511 * locked == 0 Normal unlocked operation
1512 * locked == 1 Call hammer_rel_interlock_done(..., 0);
1513 * locked == 2 Call hammer_rel_interlock_done(..., 1);
1514 *
1515 * XXX for now this isn't even close to being MPSAFE so the refs check
1516 * is sufficient.
1517 */
1518 void
hammer_flush_node(hammer_node_t node,int locked)1519 hammer_flush_node(hammer_node_t node, int locked)
1520 {
1521 hammer_node_cache_t cache;
1522 hammer_buffer_t buffer;
1523 hammer_mount_t hmp = node->hmp;
1524 int dofree;
1525
1526 while ((cache = TAILQ_FIRST(&node->cache_list)) != NULL) {
1527 TAILQ_REMOVE(&node->cache_list, cache, entry);
1528 cache->node = NULL;
1529 }
1530
1531 /*
1532 * NOTE: refs is predisposed if another thread is blocking and
1533 * will be larger than 0 in that case. We aren't MPSAFE
1534 * here.
1535 */
1536 if (node->ondisk == NULL && hammer_norefs(&node->lock)) {
1537 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1538 RB_REMOVE(hammer_nod_rb_tree, &node->hmp->rb_nods_root, node);
1539 if ((buffer = node->buffer) != NULL) {
1540 node->buffer = NULL;
1541 TAILQ_REMOVE(&buffer->node_list, node, entry);
1542 /* buffer is unreferenced because ondisk is NULL */
1543 }
1544 dofree = 1;
1545 } else {
1546 dofree = 0;
1547 }
1548
1549 /*
1550 * Deal with the interlock if locked == 1 or locked == 2.
1551 */
1552 if (locked)
1553 hammer_rel_interlock_done(&node->lock, locked - 1);
1554
1555 /*
1556 * Destroy if requested
1557 */
1558 if (dofree) {
1559 --hammer_count_nodes;
1560 kfree(node, hmp->m_misc);
1561 }
1562 }
1563
1564 /*
1565 * Flush passively cached B-Tree nodes associated with this buffer.
1566 * This is only called when the buffer is about to be destroyed, so
1567 * none of the nodes should have any references. The buffer is locked.
1568 *
1569 * We may be interlocked with the buffer.
1570 */
1571 void
hammer_flush_buffer_nodes(hammer_buffer_t buffer)1572 hammer_flush_buffer_nodes(hammer_buffer_t buffer)
1573 {
1574 hammer_node_t node;
1575
1576 while ((node = TAILQ_FIRST(&buffer->node_list)) != NULL) {
1577 KKASSERT(node->ondisk == NULL);
1578 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1579
1580 if (hammer_try_interlock_norefs(&node->lock)) {
1581 hammer_ref(&node->lock);
1582 node->flags |= HAMMER_NODE_FLUSH;
1583 _hammer_rel_node(node, 1);
1584 } else {
1585 KKASSERT(node->buffer != NULL);
1586 buffer = node->buffer;
1587 node->buffer = NULL;
1588 TAILQ_REMOVE(&buffer->node_list, node, entry);
1589 /* buffer is unreferenced because ondisk is NULL */
1590 }
1591 }
1592 }
1593
1594
1595 /************************************************************************
1596 * ALLOCATORS *
1597 ************************************************************************/
1598
1599 /*
1600 * Allocate a B-Tree node.
1601 */
1602 hammer_node_t
hammer_alloc_btree(hammer_transaction_t trans,hammer_off_t hint,int * errorp)1603 hammer_alloc_btree(hammer_transaction_t trans, hammer_off_t hint, int *errorp)
1604 {
1605 hammer_buffer_t buffer = NULL;
1606 hammer_node_t node = NULL;
1607 hammer_off_t node_offset;
1608
1609 node_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_BTREE_INDEX,
1610 sizeof(struct hammer_node_ondisk),
1611 hint, errorp);
1612 if (*errorp == 0) {
1613 node = hammer_get_node(trans, node_offset, 1, errorp);
1614 hammer_modify_node_noundo(trans, node);
1615 bzero(node->ondisk, sizeof(*node->ondisk));
1616 hammer_modify_node_done(node);
1617 }
1618 if (buffer)
1619 hammer_rel_buffer(buffer, 0);
1620 return(node);
1621 }
1622
1623 /*
1624 * Allocate data. If the address of a data buffer is supplied then
1625 * any prior non-NULL *data_bufferp will be released and *data_bufferp
1626 * will be set to the related buffer. The caller must release it when
1627 * finally done. The initial *data_bufferp should be set to NULL by
1628 * the caller.
1629 *
1630 * The caller is responsible for making hammer_modify*() calls on the
1631 * *data_bufferp.
1632 */
1633 void *
hammer_alloc_data(hammer_transaction_t trans,int32_t data_len,uint16_t rec_type,hammer_off_t * data_offsetp,hammer_buffer_t * data_bufferp,hammer_off_t hint,int * errorp)1634 hammer_alloc_data(hammer_transaction_t trans, int32_t data_len,
1635 uint16_t rec_type, hammer_off_t *data_offsetp,
1636 hammer_buffer_t *data_bufferp,
1637 hammer_off_t hint, int *errorp)
1638 {
1639 void *data;
1640 int zone;
1641
1642 /*
1643 * Allocate data directly from blockmap.
1644 */
1645 if (data_len) {
1646 switch(rec_type) {
1647 case HAMMER_RECTYPE_INODE:
1648 case HAMMER_RECTYPE_DIRENTRY:
1649 case HAMMER_RECTYPE_EXT:
1650 case HAMMER_RECTYPE_FIX:
1651 case HAMMER_RECTYPE_PFS:
1652 case HAMMER_RECTYPE_SNAPSHOT:
1653 case HAMMER_RECTYPE_CONFIG:
1654 zone = HAMMER_ZONE_META_INDEX;
1655 break;
1656 case HAMMER_RECTYPE_DATA:
1657 case HAMMER_RECTYPE_DB:
1658 /*
1659 * Only mirror-write comes here.
1660 * Regular allocation path uses blockmap reservation.
1661 */
1662 zone = hammer_data_zone_index(data_len);
1663 if (zone == HAMMER_ZONE_LARGE_DATA_INDEX) {
1664 /* round up */
1665 data_len = HAMMER_BUFSIZE_DOALIGN(data_len);
1666 }
1667 break;
1668 default:
1669 hpanic("rec_type %04x unknown", rec_type);
1670 zone = HAMMER_ZONE_UNAVAIL_INDEX; /* NOT REACHED */
1671 break;
1672 }
1673 *data_offsetp = hammer_blockmap_alloc(trans, zone, data_len,
1674 hint, errorp);
1675 } else {
1676 *data_offsetp = 0;
1677 }
1678
1679 data = NULL;
1680 if (*errorp == 0 && data_bufferp && data_len)
1681 data = hammer_bread_ext(trans->hmp, *data_offsetp, data_len,
1682 errorp, data_bufferp);
1683 return(data);
1684 }
1685
1686 /*
1687 * Sync dirty buffers to the media and clean-up any loose ends.
1688 *
1689 * These functions do not start the flusher going, they simply
1690 * queue everything up to the flusher.
1691 */
1692 static int hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1693
1694 struct hammer_sync_info {
1695 int error;
1696 };
1697
1698 int
hammer_queue_inodes_flusher(hammer_mount_t hmp,int waitfor)1699 hammer_queue_inodes_flusher(hammer_mount_t hmp, int waitfor)
1700 {
1701 struct hammer_sync_info info;
1702
1703 info.error = 0;
1704 if (waitfor == MNT_WAIT) {
1705 vsyncscan(hmp->mp, VMSC_GETVP | VMSC_ONEPASS,
1706 hammer_sync_scan2, &info);
1707 } else {
1708 vsyncscan(hmp->mp, VMSC_GETVP | VMSC_ONEPASS | VMSC_NOWAIT,
1709 hammer_sync_scan2, &info);
1710 }
1711 return(info.error);
1712 }
1713
1714 /*
1715 * Filesystem sync. If doing a synchronous sync make a second pass on
1716 * the vnodes in case any were already flushing during the first pass,
1717 * and activate the flusher twice (the second time brings the UNDO FIFO's
1718 * start position up to the end position after the first call).
1719 *
1720 * If doing a lazy sync make just one pass on the vnode list, ignoring
1721 * any new vnodes added to the list while the sync is in progress.
1722 */
1723 int
hammer_sync_hmp(hammer_mount_t hmp,int waitfor)1724 hammer_sync_hmp(hammer_mount_t hmp, int waitfor)
1725 {
1726 struct hammer_sync_info info;
1727 int flags;
1728
1729 flags = VMSC_GETVP;
1730 if (waitfor & MNT_LAZY)
1731 flags |= VMSC_ONEPASS;
1732
1733 info.error = 0;
1734 vsyncscan(hmp->mp, flags | VMSC_NOWAIT, hammer_sync_scan2, &info);
1735
1736 if (info.error == 0 && (waitfor & MNT_WAIT)) {
1737 vsyncscan(hmp->mp, flags, hammer_sync_scan2, &info);
1738 }
1739 if (waitfor == MNT_WAIT) {
1740 hammer_flusher_sync(hmp);
1741 hammer_flusher_sync(hmp);
1742 } else {
1743 hammer_flusher_async(hmp, NULL);
1744 hammer_flusher_async(hmp, NULL);
1745 }
1746 return(info.error);
1747 }
1748
1749 static int
hammer_sync_scan2(struct mount * mp,struct vnode * vp,void * data)1750 hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1751 {
1752 struct hammer_sync_info *info = data;
1753 hammer_inode_t ip;
1754 int error;
1755
1756 ip = VTOI(vp);
1757 if (ip == NULL)
1758 return(0);
1759 if (vp->v_type == VNON || vp->v_type == VBAD) {
1760 vclrisdirty(vp);
1761 return(0);
1762 }
1763 if ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1764 RB_EMPTY(&vp->v_rbdirty_tree)) {
1765 vclrisdirty(vp);
1766 return(0);
1767 }
1768 error = VOP_FSYNC(vp, MNT_NOWAIT, 0);
1769 if (error)
1770 info->error = error;
1771 return(0);
1772 }
1773