AMD64 - Fix many compile-time warnings. int/ptr type mismatches, %llx, etc.
[dragonfly.git] / sys / vfs / hammer / hammer_ondisk.c
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 #include <sys/buf2.h>
47
48 static void hammer_free_volume(hammer_volume_t volume);
49 static int hammer_load_volume(hammer_volume_t volume);
50 static int hammer_load_buffer(hammer_buffer_t buffer, int isnew);
51 static int hammer_load_node(hammer_transaction_t trans,
52                                 hammer_node_t node, int isnew);
53
54 static int
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
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
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, get_volume() will
101  * not load a new volume.
102  *
103  * Calls made to hammer_load_volume() or single-threaded
104  */
105 int
106 hammer_install_volume(struct hammer_mount *hmp, const char *volname,
107                       struct vnode *devvp)
108 {
109         struct mount *mp;
110         hammer_volume_t volume;
111         struct hammer_volume_ondisk *ondisk;
112         struct nlookupdata nd;
113         struct buf *bp = NULL;
114         int error;
115         int ronly;
116         int setmp = 0;
117
118         mp = hmp->mp;
119         ronly = ((mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
120
121         /*
122          * Allocate a volume structure
123          */
124         ++hammer_count_volumes;
125         volume = kmalloc(sizeof(*volume), hmp->m_misc, M_WAITOK|M_ZERO);
126         volume->vol_name = kstrdup(volname, hmp->m_misc);
127         volume->io.hmp = hmp;   /* bootstrap */
128         hammer_io_init(&volume->io, volume, HAMMER_STRUCTURE_VOLUME);
129         volume->io.offset = 0LL;
130         volume->io.bytes = HAMMER_BUFSIZE;
131
132         /*
133          * Get the device vnode
134          */
135         if (devvp == NULL) {
136                 error = nlookup_init(&nd, volume->vol_name, UIO_SYSSPACE, NLC_FOLLOW);
137                 if (error == 0)
138                         error = nlookup(&nd);
139                 if (error == 0)
140                         error = cache_vref(&nd.nl_nch, nd.nl_cred, &volume->devvp);
141                 nlookup_done(&nd);
142         } else {
143                 error = 0;
144                 volume->devvp = devvp;
145         }
146
147         if (error == 0) {
148                 if (vn_isdisk(volume->devvp, &error)) {
149                         error = vfs_mountedon(volume->devvp);
150                 }
151         }
152         if (error == 0 &&
153             count_udev(volume->devvp->v_umajor, volume->devvp->v_uminor) > 0) {
154                 error = EBUSY;
155         }
156         if (error == 0) {
157                 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
158                 error = vinvalbuf(volume->devvp, V_SAVE, 0, 0);
159                 if (error == 0) {
160                         error = VOP_OPEN(volume->devvp, 
161                                          (ronly ? FREAD : FREAD|FWRITE),
162                                          FSCRED, NULL);
163                 }
164                 vn_unlock(volume->devvp);
165         }
166         if (error) {
167                 hammer_free_volume(volume);
168                 return(error);
169         }
170         volume->devvp->v_rdev->si_mountpoint = mp;
171         setmp = 1;
172
173         /*
174          * Extract the volume number from the volume header and do various
175          * sanity checks.
176          */
177         error = bread(volume->devvp, 0LL, HAMMER_BUFSIZE, &bp);
178         if (error)
179                 goto late_failure;
180         ondisk = (void *)bp->b_data;
181         if (ondisk->vol_signature != HAMMER_FSBUF_VOLUME) {
182                 kprintf("hammer_mount: volume %s has an invalid header\n",
183                         volume->vol_name);
184                 error = EFTYPE;
185                 goto late_failure;
186         }
187         volume->vol_no = ondisk->vol_no;
188         volume->buffer_base = ondisk->vol_buf_beg;
189         volume->vol_flags = ondisk->vol_flags;
190         volume->nblocks = ondisk->vol_nblocks; 
191         volume->maxbuf_off = HAMMER_ENCODE_RAW_BUFFER(volume->vol_no,
192                                     ondisk->vol_buf_end - ondisk->vol_buf_beg);
193         volume->maxraw_off = ondisk->vol_buf_end;
194
195         if (RB_EMPTY(&hmp->rb_vols_root)) {
196                 hmp->fsid = ondisk->vol_fsid;
197         } else if (bcmp(&hmp->fsid, &ondisk->vol_fsid, sizeof(uuid_t))) {
198                 kprintf("hammer_mount: volume %s's fsid does not match "
199                         "other volumes\n", volume->vol_name);
200                 error = EFTYPE;
201                 goto late_failure;
202         }
203
204         /*
205          * Insert the volume structure into the red-black tree.
206          */
207         if (RB_INSERT(hammer_vol_rb_tree, &hmp->rb_vols_root, volume)) {
208                 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n",
209                         volume->vol_name, volume->vol_no);
210                 error = EEXIST;
211         }
212
213         /*
214          * Set the root volume .  HAMMER special cases rootvol the structure.
215          * We do not hold a ref because this would prevent related I/O
216          * from being flushed.
217          */
218         if (error == 0 && ondisk->vol_rootvol == ondisk->vol_no) {
219                 hmp->rootvol = volume;
220                 hmp->nvolumes = ondisk->vol_count;
221                 if (bp) {
222                         brelse(bp);
223                         bp = NULL;
224                 }
225                 hmp->mp->mnt_stat.f_blocks += ondisk->vol0_stat_bigblocks *
226                         (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
227                 hmp->mp->mnt_vstat.f_blocks += ondisk->vol0_stat_bigblocks *
228                         (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
229         }
230 late_failure:
231         if (bp)
232                 brelse(bp);
233         if (error) {
234                 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/
235                 if (setmp)
236                         volume->devvp->v_rdev->si_mountpoint = NULL;
237                 VOP_CLOSE(volume->devvp, ronly ? FREAD : FREAD|FWRITE);
238                 hammer_free_volume(volume);
239         }
240         return (error);
241 }
242
243 /*
244  * This is called for each volume when updating the mount point from
245  * read-write to read-only or vise-versa.
246  */
247 int
248 hammer_adjust_volume_mode(hammer_volume_t volume, void *data __unused)
249 {
250         if (volume->devvp) {
251                 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
252                 if (volume->io.hmp->ronly) {
253                         /* do not call vinvalbuf */
254                         VOP_OPEN(volume->devvp, FREAD, FSCRED, NULL);
255                         VOP_CLOSE(volume->devvp, FREAD|FWRITE);
256                 } else {
257                         /* do not call vinvalbuf */
258                         VOP_OPEN(volume->devvp, FREAD|FWRITE, FSCRED, NULL);
259                         VOP_CLOSE(volume->devvp, FREAD);
260                 }
261                 vn_unlock(volume->devvp);
262         }
263         return(0);
264 }
265
266 /*
267  * Unload and free a HAMMER volume.  Must return >= 0 to continue scan
268  * so returns -1 on failure.
269  */
270 int
271 hammer_unload_volume(hammer_volume_t volume, void *data __unused)
272 {
273         hammer_mount_t hmp = volume->io.hmp;
274         int ronly = ((hmp->mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
275         struct buf *bp;
276
277         /*
278          * Clean up the root volume pointer, which is held unlocked in hmp.
279          */
280         if (hmp->rootvol == volume)
281                 hmp->rootvol = NULL;
282
283         /*
284          * We must not flush a dirty buffer to disk on umount.  It should
285          * have already been dealt with by the flusher, or we may be in
286          * catastrophic failure.
287          */
288         hammer_io_clear_modify(&volume->io, 1);
289         volume->io.waitdep = 1;
290         bp = hammer_io_release(&volume->io, 1);
291
292         /*
293          * Clean up the persistent ref ioerror might have on the volume
294          */
295         if (volume->io.ioerror) {
296                 volume->io.ioerror = 0;
297                 hammer_unref(&volume->io.lock);
298         }
299
300         /*
301          * There should be no references on the volume, no clusters, and
302          * no super-clusters.
303          */
304         KKASSERT(volume->io.lock.refs == 0);
305         if (bp)
306                 brelse(bp);
307
308         volume->ondisk = NULL;
309         if (volume->devvp) {
310                 if (volume->devvp->v_rdev &&
311                     volume->devvp->v_rdev->si_mountpoint == hmp->mp
312                 ) {
313                         volume->devvp->v_rdev->si_mountpoint = NULL;
314                 }
315                 if (ronly) {
316                         /*
317                          * Make sure we don't sync anything to disk if we
318                          * are in read-only mode (1) or critically-errored
319                          * (2).  Note that there may be dirty buffers in
320                          * normal read-only mode from crash recovery.
321                          */
322                         vinvalbuf(volume->devvp, 0, 0, 0);
323                         VOP_CLOSE(volume->devvp, FREAD);
324                 } else {
325                         /*
326                          * Normal termination, save any dirty buffers
327                          * (XXX there really shouldn't be any).
328                          */
329                         vinvalbuf(volume->devvp, V_SAVE, 0, 0);
330                         VOP_CLOSE(volume->devvp, FREAD|FWRITE);
331                 }
332         }
333
334         /*
335          * Destroy the structure
336          */
337         RB_REMOVE(hammer_vol_rb_tree, &hmp->rb_vols_root, volume);
338         hammer_free_volume(volume);
339         return(0);
340 }
341
342 static
343 void
344 hammer_free_volume(hammer_volume_t volume)
345 {
346         hammer_mount_t hmp = volume->io.hmp;
347
348         if (volume->vol_name) {
349                 kfree(volume->vol_name, hmp->m_misc);
350                 volume->vol_name = NULL;
351         }
352         if (volume->devvp) {
353                 vrele(volume->devvp);
354                 volume->devvp = NULL;
355         }
356         --hammer_count_volumes;
357         kfree(volume, hmp->m_misc);
358 }
359
360 /*
361  * Get a HAMMER volume.  The volume must already exist.
362  */
363 hammer_volume_t
364 hammer_get_volume(struct hammer_mount *hmp, int32_t vol_no, int *errorp)
365 {
366         struct hammer_volume *volume;
367
368         /*
369          * Locate the volume structure
370          */
371         volume = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, vol_no);
372         if (volume == NULL) {
373                 *errorp = ENOENT;
374                 return(NULL);
375         }
376         hammer_ref(&volume->io.lock);
377
378         /*
379          * Deal with on-disk info
380          */
381         if (volume->ondisk == NULL || volume->io.loading) {
382                 *errorp = hammer_load_volume(volume);
383                 if (*errorp) {
384                         hammer_rel_volume(volume, 1);
385                         volume = NULL;
386                 }
387         } else {
388                 *errorp = 0;
389         }
390         return(volume);
391 }
392
393 int
394 hammer_ref_volume(hammer_volume_t volume)
395 {
396         int error;
397
398         hammer_ref(&volume->io.lock);
399
400         /*
401          * Deal with on-disk info
402          */
403         if (volume->ondisk == NULL || volume->io.loading) {
404                 error = hammer_load_volume(volume);
405                 if (error)
406                         hammer_rel_volume(volume, 1);
407         } else {
408                 error = 0;
409         }
410         return (error);
411 }
412
413 hammer_volume_t
414 hammer_get_root_volume(struct hammer_mount *hmp, int *errorp)
415 {
416         hammer_volume_t volume;
417
418         volume = hmp->rootvol;
419         KKASSERT(volume != NULL);
420         hammer_ref(&volume->io.lock);
421
422         /*
423          * Deal with on-disk info
424          */
425         if (volume->ondisk == NULL || volume->io.loading) {
426                 *errorp = hammer_load_volume(volume);
427                 if (*errorp) {
428                         hammer_rel_volume(volume, 1);
429                         volume = NULL;
430                 }
431         } else {
432                 *errorp = 0;
433         }
434         return (volume);
435 }
436
437 /*
438  * Load a volume's on-disk information.  The volume must be referenced and
439  * not locked.  We temporarily acquire an exclusive lock to interlock
440  * against releases or multiple get's.
441  */
442 static int
443 hammer_load_volume(hammer_volume_t volume)
444 {
445         int error;
446
447         ++volume->io.loading;
448         hammer_lock_ex(&volume->io.lock);
449
450         if (volume->ondisk == NULL) {
451                 error = hammer_io_read(volume->devvp, &volume->io,
452                                        volume->maxraw_off);
453                 if (error == 0)
454                         volume->ondisk = (void *)volume->io.bp->b_data;
455         } else {
456                 error = 0;
457         }
458         --volume->io.loading;
459         hammer_unlock(&volume->io.lock);
460         return(error);
461 }
462
463 /*
464  * Release a volume.  Call hammer_io_release on the last reference.  We have
465  * to acquire an exclusive lock to interlock against volume->ondisk tests
466  * in hammer_load_volume(), and hammer_io_release() also expects an exclusive
467  * lock to be held.
468  *
469  * Volumes are not unloaded from memory during normal operation.
470  */
471 void
472 hammer_rel_volume(hammer_volume_t volume, int flush)
473 {
474         struct buf *bp = NULL;
475
476         crit_enter();
477         if (volume->io.lock.refs == 1) {
478                 ++volume->io.loading;
479                 hammer_lock_ex(&volume->io.lock);
480                 if (volume->io.lock.refs == 1) {
481                         volume->ondisk = NULL;
482                         bp = hammer_io_release(&volume->io, flush);
483                 }
484                 --volume->io.loading;
485                 hammer_unlock(&volume->io.lock);
486         }
487         hammer_unref(&volume->io.lock);
488         if (bp)
489                 brelse(bp);
490         crit_exit();
491 }
492
493 int
494 hammer_mountcheck_volumes(struct hammer_mount *hmp)
495 {
496         hammer_volume_t vol;
497         int i;
498
499         for (i = 0; i < hmp->nvolumes; ++i) {
500                 vol = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, i);
501                 if (vol == NULL)
502                         return(EINVAL);
503         }
504         return(0);
505 }
506
507 /************************************************************************
508  *                              BUFFERS                                 *
509  ************************************************************************
510  *
511  * Manage buffers.  Currently all blockmap-backed zones are direct-mapped
512  * to zone-2 buffer offsets, without a translation stage.  However, the
513  * hammer_buffer structure is indexed by its zoneX_offset, not its
514  * zone2_offset.
515  *
516  * The proper zone must be maintained throughout the code-base all the way
517  * through to the big-block allocator, or routines like hammer_del_buffers()
518  * will not be able to locate all potentially conflicting buffers.
519  */
520 hammer_buffer_t
521 hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset,
522                   int bytes, int isnew, int *errorp)
523 {
524         hammer_buffer_t buffer;
525         hammer_volume_t volume;
526         hammer_off_t    zone2_offset;
527         hammer_io_type_t iotype;
528         int vol_no;
529         int zone;
530
531         buf_offset &= ~HAMMER_BUFMASK64;
532 again:
533         /*
534          * Shortcut if the buffer is already cached
535          */
536         buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, buf_offset);
537         if (buffer) {
538                 if (buffer->io.lock.refs == 0)
539                         ++hammer_count_refedbufs;
540                 hammer_ref(&buffer->io.lock);
541
542                 /*
543                  * Once refed the ondisk field will not be cleared by
544                  * any other action.
545                  */
546                 if (buffer->ondisk && buffer->io.loading == 0) {
547                         *errorp = 0;
548                         return(buffer);
549                 }
550
551                 /*
552                  * The buffer is no longer loose if it has a ref, and
553                  * cannot become loose once it gains a ref.  Loose
554                  * buffers will never be in a modified state.  This should
555                  * only occur on the 0->1 transition of refs.
556                  *
557                  * lose_list can be modified via a biodone() interrupt.
558                  */
559                 if (buffer->io.mod_list == &hmp->lose_list) {
560                         crit_enter();   /* biodone race against list */
561                         TAILQ_REMOVE(buffer->io.mod_list, &buffer->io,
562                                      mod_entry);
563                         crit_exit();
564                         buffer->io.mod_list = NULL;
565                         KKASSERT(buffer->io.modified == 0);
566                 }
567                 goto found;
568         }
569
570         /*
571          * What is the buffer class?
572          */
573         zone = HAMMER_ZONE_DECODE(buf_offset);
574
575         switch(zone) {
576         case HAMMER_ZONE_LARGE_DATA_INDEX:
577         case HAMMER_ZONE_SMALL_DATA_INDEX:
578                 iotype = HAMMER_STRUCTURE_DATA_BUFFER;
579                 break;
580         case HAMMER_ZONE_UNDO_INDEX:
581                 iotype = HAMMER_STRUCTURE_UNDO_BUFFER;
582                 break;
583         case HAMMER_ZONE_META_INDEX:
584         default:
585                 /*
586                  * NOTE: inode data and directory entries are placed in this
587                  * zone.  inode atime/mtime is updated in-place and thus
588                  * buffers containing inodes must be synchronized as
589                  * meta-buffers, same as buffers containing B-Tree info.
590                  */
591                 iotype = HAMMER_STRUCTURE_META_BUFFER;
592                 break;
593         }
594
595         /*
596          * Handle blockmap offset translations
597          */
598         if (zone >= HAMMER_ZONE_BTREE_INDEX) {
599                 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, errorp);
600         } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
601                 zone2_offset = hammer_undo_lookup(hmp, buf_offset, errorp);
602         } else {
603                 KKASSERT(zone == HAMMER_ZONE_RAW_BUFFER_INDEX);
604                 zone2_offset = buf_offset;
605                 *errorp = 0;
606         }
607         if (*errorp)
608                 return(NULL);
609
610         /*
611          * NOTE: zone2_offset and maxbuf_off are both full zone-2 offset
612          * specifications.
613          */
614         KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) ==
615                  HAMMER_ZONE_RAW_BUFFER);
616         vol_no = HAMMER_VOL_DECODE(zone2_offset);
617         volume = hammer_get_volume(hmp, vol_no, errorp);
618         if (volume == NULL)
619                 return(NULL);
620
621         KKASSERT(zone2_offset < volume->maxbuf_off);
622
623         /*
624          * Allocate a new buffer structure.  We will check for races later.
625          */
626         ++hammer_count_buffers;
627         buffer = kmalloc(sizeof(*buffer), hmp->m_misc,
628                          M_WAITOK|M_ZERO|M_USE_RESERVE);
629         buffer->zone2_offset = zone2_offset;
630         buffer->zoneX_offset = buf_offset;
631
632         hammer_io_init(&buffer->io, volume, iotype);
633         buffer->io.offset = volume->ondisk->vol_buf_beg +
634                             (zone2_offset & HAMMER_OFF_SHORT_MASK);
635         buffer->io.bytes = bytes;
636         TAILQ_INIT(&buffer->clist);
637         hammer_ref(&buffer->io.lock);
638
639         /*
640          * Insert the buffer into the RB tree and handle late collisions.
641          */
642         if (RB_INSERT(hammer_buf_rb_tree, &hmp->rb_bufs_root, buffer)) {
643                 hammer_unref(&buffer->io.lock); /* safety */
644                 --hammer_count_buffers;
645                 hammer_rel_volume(volume, 0);
646                 buffer->io.volume = NULL;       /* safety */
647                 kfree(buffer, hmp->m_misc);
648                 goto again;
649         }
650         ++hammer_count_refedbufs;
651 found:
652
653         /*
654          * Deal with on-disk info and loading races.
655          */
656         if (buffer->ondisk == NULL || buffer->io.loading) {
657                 *errorp = hammer_load_buffer(buffer, isnew);
658                 if (*errorp) {
659                         hammer_rel_buffer(buffer, 1);
660                         buffer = NULL;
661                 }
662         } else {
663                 *errorp = 0;
664         }
665         return(buffer);
666 }
667
668 /*
669  * This is used by the direct-read code to deal with large-data buffers
670  * created by the reblocker and mirror-write code.  The direct-read code
671  * bypasses the HAMMER buffer subsystem and so any aliased dirty or write-
672  * running hammer buffers must be fully synced to disk before we can issue
673  * the direct-read.
674  *
675  * This code path is not considered critical as only the rebocker and
676  * mirror-write code will create large-data buffers via the HAMMER buffer
677  * subsystem.  They do that because they operate at the B-Tree level and
678  * do not access the vnode/inode structures.
679  */
680 void
681 hammer_sync_buffers(hammer_mount_t hmp, hammer_off_t base_offset, int bytes)
682 {
683         hammer_buffer_t buffer;
684         int error;
685
686         KKASSERT((base_offset & HAMMER_OFF_ZONE_MASK) ==
687                  HAMMER_ZONE_LARGE_DATA);
688
689         while (bytes > 0) {
690                 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
691                                    base_offset);
692                 if (buffer && (buffer->io.modified || buffer->io.running)) {
693                         error = hammer_ref_buffer(buffer);
694                         if (error == 0) {
695                                 hammer_io_wait(&buffer->io);
696                                 if (buffer->io.modified) {
697                                         hammer_io_write_interlock(&buffer->io);
698                                         hammer_io_flush(&buffer->io);
699                                         hammer_io_done_interlock(&buffer->io);
700                                         hammer_io_wait(&buffer->io);
701                                 }
702                                 hammer_rel_buffer(buffer, 0);
703                         }
704                 }
705                 base_offset += HAMMER_BUFSIZE;
706                 bytes -= HAMMER_BUFSIZE;
707         }
708 }
709
710 /*
711  * Destroy all buffers covering the specified zoneX offset range.  This
712  * is called when the related blockmap layer2 entry is freed or when
713  * a direct write bypasses our buffer/buffer-cache subsystem.
714  *
715  * The buffers may be referenced by the caller itself.  Setting reclaim
716  * will cause the buffer to be destroyed when it's ref count reaches zero.
717  *
718  * Return 0 on success, EAGAIN if some buffers could not be destroyed due
719  * to additional references held by other threads, or some other (typically
720  * fatal) error.
721  */
722 int
723 hammer_del_buffers(hammer_mount_t hmp, hammer_off_t base_offset,
724                    hammer_off_t zone2_offset, int bytes,
725                    int report_conflicts)
726 {
727         hammer_buffer_t buffer;
728         hammer_volume_t volume;
729         int vol_no;
730         int error;
731         int ret_error;
732
733         vol_no = HAMMER_VOL_DECODE(zone2_offset);
734         volume = hammer_get_volume(hmp, vol_no, &ret_error);
735         KKASSERT(ret_error == 0);
736
737         while (bytes > 0) {
738                 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
739                                    base_offset);
740                 if (buffer) {
741                         error = hammer_ref_buffer(buffer);
742                         if (error == 0 && buffer->io.lock.refs != 1) {
743                                 error = EAGAIN;
744                                 hammer_rel_buffer(buffer, 0);
745                         }
746                         if (error == 0) {
747                                 KKASSERT(buffer->zone2_offset == zone2_offset);
748                                 hammer_io_clear_modify(&buffer->io, 1);
749                                 buffer->io.reclaim = 1;
750                                 buffer->io.waitdep = 1;
751                                 KKASSERT(buffer->io.volume == volume);
752                                 hammer_rel_buffer(buffer, 0);
753                         }
754                 } else {
755                         error = hammer_io_inval(volume, zone2_offset);
756                 }
757                 if (error) {
758                         ret_error = error;
759                         if (report_conflicts ||
760                             (hammer_debug_general & 0x8000)) {
761                                 kprintf("hammer_del_buffers: unable to "
762                                         "invalidate %016llx buffer=%p rep=%d\n",
763                                         (long long)base_offset,
764                                         buffer, report_conflicts);
765                         }
766                 }
767                 base_offset += HAMMER_BUFSIZE;
768                 zone2_offset += HAMMER_BUFSIZE;
769                 bytes -= HAMMER_BUFSIZE;
770         }
771         hammer_rel_volume(volume, 0);
772         return (ret_error);
773 }
774
775 static int
776 hammer_load_buffer(hammer_buffer_t buffer, int isnew)
777 {
778         hammer_volume_t volume;
779         int error;
780
781         /*
782          * Load the buffer's on-disk info
783          */
784         volume = buffer->io.volume;
785         ++buffer->io.loading;
786         hammer_lock_ex(&buffer->io.lock);
787
788         if (hammer_debug_io & 0x0001) {
789                 kprintf("load_buffer %016llx %016llx isnew=%d od=%p\n",
790                         (long long)buffer->zoneX_offset,
791                         (long long)buffer->zone2_offset,
792                         isnew, buffer->ondisk);
793         }
794
795         if (buffer->ondisk == NULL) {
796                 if (isnew) {
797                         error = hammer_io_new(volume->devvp, &buffer->io);
798                 } else {
799                         error = hammer_io_read(volume->devvp, &buffer->io,
800                                                volume->maxraw_off);
801                 }
802                 if (error == 0)
803                         buffer->ondisk = (void *)buffer->io.bp->b_data;
804         } else if (isnew) {
805                 error = hammer_io_new(volume->devvp, &buffer->io);
806         } else {
807                 error = 0;
808         }
809         --buffer->io.loading;
810         hammer_unlock(&buffer->io.lock);
811         return (error);
812 }
813
814 /*
815  * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
816  * This routine is only called during unmount.
817  */
818 int
819 hammer_unload_buffer(hammer_buffer_t buffer, void *data __unused)
820 {
821         /*
822          * Clean up the persistent ref ioerror might have on the buffer
823          * and acquire a ref (steal ioerror's if we can).
824          */
825         if (buffer->io.ioerror) {
826                 buffer->io.ioerror = 0;
827         } else {
828                 if (buffer->io.lock.refs == 0)
829                         ++hammer_count_refedbufs;
830                 hammer_ref(&buffer->io.lock);
831         }
832
833         /*
834          * We must not flush a dirty buffer to disk on umount.  It should
835          * have already been dealt with by the flusher, or we may be in
836          * catastrophic failure.
837          */
838         hammer_io_clear_modify(&buffer->io, 1);
839         hammer_flush_buffer_nodes(buffer);
840         KKASSERT(buffer->io.lock.refs == 1);
841         hammer_rel_buffer(buffer, 2);
842         return(0);
843 }
844
845 /*
846  * Reference a buffer that is either already referenced or via a specially
847  * handled pointer (aka cursor->buffer).
848  */
849 int
850 hammer_ref_buffer(hammer_buffer_t buffer)
851 {
852         int error;
853
854         if (buffer->io.lock.refs == 0)
855                 ++hammer_count_refedbufs;
856         hammer_ref(&buffer->io.lock);
857
858         /*
859          * At this point a biodone() will not touch the buffer other then
860          * incidental bits.  However, lose_list can be modified via
861          * a biodone() interrupt.
862          *
863          * No longer loose
864          */
865         if (buffer->io.mod_list == &buffer->io.hmp->lose_list) {
866                 crit_enter();
867                 TAILQ_REMOVE(buffer->io.mod_list, &buffer->io, mod_entry);
868                 buffer->io.mod_list = NULL;
869                 crit_exit();
870         }
871
872         if (buffer->ondisk == NULL || buffer->io.loading) {
873                 error = hammer_load_buffer(buffer, 0);
874                 if (error) {
875                         hammer_rel_buffer(buffer, 1);
876                         /*
877                          * NOTE: buffer pointer can become stale after
878                          * the above release.
879                          */
880                 }
881         } else {
882                 error = 0;
883         }
884         return(error);
885 }
886
887 /*
888  * Release a buffer.  We have to deal with several places where
889  * another thread can ref the buffer.
890  *
891  * Only destroy the structure itself if the related buffer cache buffer
892  * was disassociated from it.  This ties the management of the structure
893  * to the buffer cache subsystem.  buffer->ondisk determines whether the
894  * embedded io is referenced or not.
895  */
896 void
897 hammer_rel_buffer(hammer_buffer_t buffer, int flush)
898 {
899         hammer_volume_t volume;
900         hammer_mount_t hmp;
901         struct buf *bp = NULL;
902         int freeme = 0;
903
904         hmp = buffer->io.hmp;
905
906         crit_enter();
907         if (buffer->io.lock.refs == 1) {
908                 ++buffer->io.loading;   /* force interlock check */
909                 hammer_lock_ex(&buffer->io.lock);
910                 if (buffer->io.lock.refs == 1) {
911                         bp = hammer_io_release(&buffer->io, flush);
912
913                         if (buffer->io.lock.refs == 1)
914                                 --hammer_count_refedbufs;
915
916                         if (buffer->io.bp == NULL &&
917                             buffer->io.lock.refs == 1) {
918                                 /*
919                                  * Final cleanup
920                                  *
921                                  * NOTE: It is impossible for any associated
922                                  * B-Tree nodes to have refs if the buffer
923                                  * has no additional refs.
924                                  */
925                                 RB_REMOVE(hammer_buf_rb_tree,
926                                           &buffer->io.hmp->rb_bufs_root,
927                                           buffer);
928                                 volume = buffer->io.volume;
929                                 buffer->io.volume = NULL; /* sanity */
930                                 hammer_rel_volume(volume, 0);
931                                 hammer_io_clear_modlist(&buffer->io);
932                                 hammer_flush_buffer_nodes(buffer);
933                                 KKASSERT(TAILQ_EMPTY(&buffer->clist));
934                                 freeme = 1;
935                         }
936                 }
937                 --buffer->io.loading;
938                 hammer_unlock(&buffer->io.lock);
939         }
940         hammer_unref(&buffer->io.lock);
941         crit_exit();
942         if (bp)
943                 brelse(bp);
944         if (freeme) {
945                 --hammer_count_buffers;
946                 kfree(buffer, hmp->m_misc);
947         }
948 }
949
950 /*
951  * Access the filesystem buffer containing the specified hammer offset.
952  * buf_offset is a conglomeration of the volume number and vol_buf_beg
953  * relative buffer offset.  It must also have bit 55 set to be valid.
954  * (see hammer_off_t in hammer_disk.h).
955  *
956  * Any prior buffer in *bufferp will be released and replaced by the
957  * requested buffer.
958  *
959  * NOTE: The buffer is indexed via its zoneX_offset but we allow the
960  * passed cached *bufferp to match against either zoneX or zone2.
961  */
962 static __inline
963 void *
964 _hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
965              int *errorp, struct hammer_buffer **bufferp)
966 {
967         hammer_buffer_t buffer;
968         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
969
970         buf_offset &= ~HAMMER_BUFMASK64;
971         KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) != 0);
972
973         buffer = *bufferp;
974         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
975                                buffer->zoneX_offset != buf_offset)) {
976                 if (buffer)
977                         hammer_rel_buffer(buffer, 0);
978                 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 0, errorp);
979                 *bufferp = buffer;
980         } else {
981                 *errorp = 0;
982         }
983
984         /*
985          * Return a pointer to the buffer data.
986          */
987         if (buffer == NULL)
988                 return(NULL);
989         else
990                 return((char *)buffer->ondisk + xoff);
991 }
992
993 void *
994 hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset,
995              int *errorp, struct hammer_buffer **bufferp)
996 {
997         return(_hammer_bread(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp));
998 }
999
1000 void *
1001 hammer_bread_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1002                  int *errorp, struct hammer_buffer **bufferp)
1003 {
1004         bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK;
1005         return(_hammer_bread(hmp, buf_offset, bytes, errorp, bufferp));
1006 }
1007
1008 /*
1009  * Access the filesystem buffer containing the specified hammer offset.
1010  * No disk read operation occurs.  The result buffer may contain garbage.
1011  *
1012  * Any prior buffer in *bufferp will be released and replaced by the
1013  * requested buffer.
1014  *
1015  * This function marks the buffer dirty but does not increment its
1016  * modify_refs count.
1017  */
1018 static __inline
1019 void *
1020 _hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1021              int *errorp, struct hammer_buffer **bufferp)
1022 {
1023         hammer_buffer_t buffer;
1024         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
1025
1026         buf_offset &= ~HAMMER_BUFMASK64;
1027
1028         buffer = *bufferp;
1029         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
1030                                buffer->zoneX_offset != buf_offset)) {
1031                 if (buffer)
1032                         hammer_rel_buffer(buffer, 0);
1033                 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 1, errorp);
1034                 *bufferp = buffer;
1035         } else {
1036                 *errorp = 0;
1037         }
1038
1039         /*
1040          * Return a pointer to the buffer data.
1041          */
1042         if (buffer == NULL)
1043                 return(NULL);
1044         else
1045                 return((char *)buffer->ondisk + xoff);
1046 }
1047
1048 void *
1049 hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset,
1050              int *errorp, struct hammer_buffer **bufferp)
1051 {
1052         return(_hammer_bnew(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp));
1053 }
1054
1055 void *
1056 hammer_bnew_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1057                 int *errorp, struct hammer_buffer **bufferp)
1058 {
1059         bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK;
1060         return(_hammer_bnew(hmp, buf_offset, bytes, errorp, bufferp));
1061 }
1062
1063 /************************************************************************
1064  *                              NODES                                   *
1065  ************************************************************************
1066  *
1067  * Manage B-Tree nodes.  B-Tree nodes represent the primary indexing
1068  * method used by the HAMMER filesystem.
1069  *
1070  * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
1071  * associated with its buffer, and will only referenced the buffer while
1072  * the node itself is referenced.
1073  *
1074  * A hammer_node can also be passively associated with other HAMMER
1075  * structures, such as inodes, while retaining 0 references.  These
1076  * associations can be cleared backwards using a pointer-to-pointer in
1077  * the hammer_node.
1078  *
1079  * This allows the HAMMER implementation to cache hammer_nodes long-term
1080  * and short-cut a great deal of the infrastructure's complexity.  In
1081  * most cases a cached node can be reacquired without having to dip into
1082  * either the buffer or cluster management code.
1083  *
1084  * The caller must pass a referenced cluster on call and will retain
1085  * ownership of the reference on return.  The node will acquire its own
1086  * additional references, if necessary.
1087  */
1088 hammer_node_t
1089 hammer_get_node(hammer_transaction_t trans, hammer_off_t node_offset,
1090                 int isnew, int *errorp)
1091 {
1092         hammer_mount_t hmp = trans->hmp;
1093         hammer_node_t node;
1094
1095         KKASSERT((node_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_BTREE);
1096
1097         /*
1098          * Locate the structure, allocating one if necessary.
1099          */
1100 again:
1101         node = RB_LOOKUP(hammer_nod_rb_tree, &hmp->rb_nods_root, node_offset);
1102         if (node == NULL) {
1103                 ++hammer_count_nodes;
1104                 node = kmalloc(sizeof(*node), hmp->m_misc, M_WAITOK|M_ZERO|M_USE_RESERVE);
1105                 node->node_offset = node_offset;
1106                 node->hmp = hmp;
1107                 TAILQ_INIT(&node->cursor_list);
1108                 TAILQ_INIT(&node->cache_list);
1109                 if (RB_INSERT(hammer_nod_rb_tree, &hmp->rb_nods_root, node)) {
1110                         --hammer_count_nodes;
1111                         kfree(node, hmp->m_misc);
1112                         goto again;
1113                 }
1114         }
1115         hammer_ref(&node->lock);
1116         if (node->ondisk) {
1117                 *errorp = 0;
1118         } else {
1119                 *errorp = hammer_load_node(trans, node, isnew);
1120                 trans->flags |= HAMMER_TRANSF_DIDIO;
1121         }
1122         if (*errorp) {
1123                 hammer_rel_node(node);
1124                 node = NULL;
1125         }
1126         return(node);
1127 }
1128
1129 /*
1130  * Reference an already-referenced node.
1131  */
1132 void
1133 hammer_ref_node(hammer_node_t node)
1134 {
1135         KKASSERT(node->lock.refs > 0 && node->ondisk != NULL);
1136         hammer_ref(&node->lock);
1137 }
1138
1139 /*
1140  * Load a node's on-disk data reference.
1141  */
1142 static int
1143 hammer_load_node(hammer_transaction_t trans, hammer_node_t node, int isnew)
1144 {
1145         hammer_buffer_t buffer;
1146         hammer_off_t buf_offset;
1147         int error;
1148
1149         error = 0;
1150         ++node->loading;
1151         hammer_lock_ex(&node->lock);
1152         if (node->ondisk == NULL) {
1153                 /*
1154                  * This is a little confusing but the jist is that
1155                  * node->buffer determines whether the node is on
1156                  * the buffer's clist and node->ondisk determines
1157                  * whether the buffer is referenced.
1158                  *
1159                  * We could be racing a buffer release, in which case
1160                  * node->buffer may become NULL while we are blocked
1161                  * referencing the buffer.
1162                  */
1163                 if ((buffer = node->buffer) != NULL) {
1164                         error = hammer_ref_buffer(buffer);
1165                         if (error == 0 && node->buffer == NULL) {
1166                                 TAILQ_INSERT_TAIL(&buffer->clist,
1167                                                   node, entry);
1168                                 node->buffer = buffer;
1169                         }
1170                 } else {
1171                         buf_offset = node->node_offset & ~HAMMER_BUFMASK64;
1172                         buffer = hammer_get_buffer(node->hmp, buf_offset,
1173                                                    HAMMER_BUFSIZE, 0, &error);
1174                         if (buffer) {
1175                                 KKASSERT(error == 0);
1176                                 TAILQ_INSERT_TAIL(&buffer->clist,
1177                                                   node, entry);
1178                                 node->buffer = buffer;
1179                         }
1180                 }
1181                 if (error)
1182                         goto failed;
1183                 node->ondisk = (void *)((char *)buffer->ondisk +
1184                                         (node->node_offset & HAMMER_BUFMASK));
1185
1186                 /*
1187                  * Check CRC.  NOTE: Neither flag is set and the CRC is not
1188                  * generated on new B-Tree nodes.
1189                  */
1190                 if (isnew == 0 && 
1191                     (node->flags & HAMMER_NODE_CRCANY) == 0) {
1192                         if (hammer_crc_test_btree(node->ondisk) == 0) {
1193                                 if (hammer_debug_debug & 0x0002)
1194                                         Debugger("CRC FAILED: B-TREE NODE");
1195                                 node->flags |= HAMMER_NODE_CRCBAD;
1196                         } else {
1197                                 node->flags |= HAMMER_NODE_CRCGOOD;
1198                         }
1199                 }
1200         }
1201         if (node->flags & HAMMER_NODE_CRCBAD) {
1202                 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1203                         error = EDOM;
1204                 else
1205                         error = EIO;
1206         }
1207 failed:
1208         --node->loading;
1209         hammer_unlock(&node->lock);
1210         return (error);
1211 }
1212
1213 /*
1214  * Safely reference a node, interlock against flushes via the IO subsystem.
1215  */
1216 hammer_node_t
1217 hammer_ref_node_safe(hammer_transaction_t trans, hammer_node_cache_t cache,
1218                      int *errorp)
1219 {
1220         hammer_node_t node;
1221
1222         node = cache->node;
1223         if (node != NULL) {
1224                 hammer_ref(&node->lock);
1225                 if (node->ondisk) {
1226                         if (node->flags & HAMMER_NODE_CRCBAD) {
1227                                 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1228                                         *errorp = EDOM;
1229                                 else
1230                                         *errorp = EIO;
1231                         } else {
1232                                 *errorp = 0;
1233                         }
1234                 } else {
1235                         *errorp = hammer_load_node(trans, node, 0);
1236                 }
1237                 if (*errorp) {
1238                         hammer_rel_node(node);
1239                         node = NULL;
1240                 }
1241         } else {
1242                 *errorp = ENOENT;
1243         }
1244         return(node);
1245 }
1246
1247 /*
1248  * Release a hammer_node.  On the last release the node dereferences
1249  * its underlying buffer and may or may not be destroyed.
1250  */
1251 void
1252 hammer_rel_node(hammer_node_t node)
1253 {
1254         hammer_buffer_t buffer;
1255
1256         /*
1257          * If this isn't the last ref just decrement the ref count and
1258          * return.
1259          */
1260         if (node->lock.refs > 1) {
1261                 hammer_unref(&node->lock);
1262                 return;
1263         }
1264
1265         /*
1266          * If there is no ondisk info or no buffer the node failed to load,
1267          * remove the last reference and destroy the node.
1268          */
1269         if (node->ondisk == NULL) {
1270                 hammer_unref(&node->lock);
1271                 hammer_flush_node(node);
1272                 /* node is stale now */
1273                 return;
1274         }
1275
1276         /*
1277          * Do not disassociate the node from the buffer if it represents
1278          * a modified B-Tree node that still needs its crc to be generated.
1279          */
1280         if (node->flags & HAMMER_NODE_NEEDSCRC)
1281                 return;
1282
1283         /*
1284          * Do final cleanups and then either destroy the node and leave it
1285          * passively cached.  The buffer reference is removed regardless.
1286          */
1287         buffer = node->buffer;
1288         node->ondisk = NULL;
1289
1290         if ((node->flags & HAMMER_NODE_FLUSH) == 0) {
1291                 hammer_unref(&node->lock);
1292                 hammer_rel_buffer(buffer, 0);
1293                 return;
1294         }
1295
1296         /*
1297          * Destroy the node.
1298          */
1299         hammer_unref(&node->lock);
1300         hammer_flush_node(node);
1301         /* node is stale */
1302         hammer_rel_buffer(buffer, 0);
1303 }
1304
1305 /*
1306  * Free space on-media associated with a B-Tree node.
1307  */
1308 void
1309 hammer_delete_node(hammer_transaction_t trans, hammer_node_t node)
1310 {
1311         KKASSERT((node->flags & HAMMER_NODE_DELETED) == 0);
1312         node->flags |= HAMMER_NODE_DELETED;
1313         hammer_blockmap_free(trans, node->node_offset, sizeof(*node->ondisk));
1314 }
1315
1316 /*
1317  * Passively cache a referenced hammer_node.  The caller may release
1318  * the node on return.
1319  */
1320 void
1321 hammer_cache_node(hammer_node_cache_t cache, hammer_node_t node)
1322 {
1323         /*
1324          * If the node doesn't exist, or is being deleted, don't cache it!
1325          *
1326          * The node can only ever be NULL in the I/O failure path.
1327          */
1328         if (node == NULL || (node->flags & HAMMER_NODE_DELETED))
1329                 return;
1330         if (cache->node == node)
1331                 return;
1332         while (cache->node)
1333                 hammer_uncache_node(cache);
1334         if (node->flags & HAMMER_NODE_DELETED)
1335                 return;
1336         cache->node = node;
1337         TAILQ_INSERT_TAIL(&node->cache_list, cache, entry);
1338 }
1339
1340 void
1341 hammer_uncache_node(hammer_node_cache_t cache)
1342 {
1343         hammer_node_t node;
1344
1345         if ((node = cache->node) != NULL) {
1346                 TAILQ_REMOVE(&node->cache_list, cache, entry);
1347                 cache->node = NULL;
1348                 if (TAILQ_EMPTY(&node->cache_list))
1349                         hammer_flush_node(node);
1350         }
1351 }
1352
1353 /*
1354  * Remove a node's cache references and destroy the node if it has no
1355  * other references or backing store.
1356  */
1357 void
1358 hammer_flush_node(hammer_node_t node)
1359 {
1360         hammer_node_cache_t cache;
1361         hammer_buffer_t buffer;
1362         hammer_mount_t hmp = node->hmp;
1363
1364         while ((cache = TAILQ_FIRST(&node->cache_list)) != NULL) {
1365                 TAILQ_REMOVE(&node->cache_list, cache, entry);
1366                 cache->node = NULL;
1367         }
1368         if (node->lock.refs == 0 && node->ondisk == NULL) {
1369                 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1370                 RB_REMOVE(hammer_nod_rb_tree, &node->hmp->rb_nods_root, node);
1371                 if ((buffer = node->buffer) != NULL) {
1372                         node->buffer = NULL;
1373                         TAILQ_REMOVE(&buffer->clist, node, entry);
1374                         /* buffer is unreferenced because ondisk is NULL */
1375                 }
1376                 --hammer_count_nodes;
1377                 kfree(node, hmp->m_misc);
1378         }
1379 }
1380
1381 /*
1382  * Flush passively cached B-Tree nodes associated with this buffer.
1383  * This is only called when the buffer is about to be destroyed, so
1384  * none of the nodes should have any references.  The buffer is locked.
1385  *
1386  * We may be interlocked with the buffer.
1387  */
1388 void
1389 hammer_flush_buffer_nodes(hammer_buffer_t buffer)
1390 {
1391         hammer_node_t node;
1392
1393         while ((node = TAILQ_FIRST(&buffer->clist)) != NULL) {
1394                 KKASSERT(node->ondisk == NULL);
1395                 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1396
1397                 if (node->lock.refs == 0) {
1398                         hammer_ref(&node->lock);
1399                         node->flags |= HAMMER_NODE_FLUSH;
1400                         hammer_rel_node(node);
1401                 } else {
1402                         KKASSERT(node->loading != 0);
1403                         KKASSERT(node->buffer != NULL);
1404                         buffer = node->buffer;
1405                         node->buffer = NULL;
1406                         TAILQ_REMOVE(&buffer->clist, node, entry);
1407                         /* buffer is unreferenced because ondisk is NULL */
1408                 }
1409         }
1410 }
1411
1412
1413 /************************************************************************
1414  *                              ALLOCATORS                              *
1415  ************************************************************************/
1416
1417 /*
1418  * Allocate a B-Tree node.
1419  */
1420 hammer_node_t
1421 hammer_alloc_btree(hammer_transaction_t trans, hammer_off_t hint, int *errorp)
1422 {
1423         hammer_buffer_t buffer = NULL;
1424         hammer_node_t node = NULL;
1425         hammer_off_t node_offset;
1426
1427         node_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_BTREE_INDEX,
1428                                             sizeof(struct hammer_node_ondisk),
1429                                             hint, errorp);
1430         if (*errorp == 0) {
1431                 node = hammer_get_node(trans, node_offset, 1, errorp);
1432                 hammer_modify_node_noundo(trans, node);
1433                 bzero(node->ondisk, sizeof(*node->ondisk));
1434                 hammer_modify_node_done(node);
1435         }
1436         if (buffer)
1437                 hammer_rel_buffer(buffer, 0);
1438         return(node);
1439 }
1440
1441 /*
1442  * Allocate data.  If the address of a data buffer is supplied then
1443  * any prior non-NULL *data_bufferp will be released and *data_bufferp
1444  * will be set to the related buffer.  The caller must release it when
1445  * finally done.  The initial *data_bufferp should be set to NULL by
1446  * the caller.
1447  *
1448  * The caller is responsible for making hammer_modify*() calls on the
1449  * *data_bufferp.
1450  */
1451 void *
1452 hammer_alloc_data(hammer_transaction_t trans, int32_t data_len, 
1453                   u_int16_t rec_type, hammer_off_t *data_offsetp,
1454                   struct hammer_buffer **data_bufferp,
1455                   hammer_off_t hint, int *errorp)
1456 {
1457         void *data;
1458         int zone;
1459
1460         /*
1461          * Allocate data
1462          */
1463         if (data_len) {
1464                 switch(rec_type) {
1465                 case HAMMER_RECTYPE_INODE:
1466                 case HAMMER_RECTYPE_DIRENTRY:
1467                 case HAMMER_RECTYPE_EXT:
1468                 case HAMMER_RECTYPE_FIX:
1469                 case HAMMER_RECTYPE_PFS:
1470                         zone = HAMMER_ZONE_META_INDEX;
1471                         break;
1472                 case HAMMER_RECTYPE_DATA:
1473                 case HAMMER_RECTYPE_DB:
1474                         if (data_len <= HAMMER_BUFSIZE / 2) {
1475                                 zone = HAMMER_ZONE_SMALL_DATA_INDEX;
1476                         } else {
1477                                 data_len = (data_len + HAMMER_BUFMASK) &
1478                                            ~HAMMER_BUFMASK;
1479                                 zone = HAMMER_ZONE_LARGE_DATA_INDEX;
1480                         }
1481                         break;
1482                 default:
1483                         panic("hammer_alloc_data: rec_type %04x unknown",
1484                               rec_type);
1485                         zone = 0;       /* NOT REACHED */
1486                         break;
1487                 }
1488                 *data_offsetp = hammer_blockmap_alloc(trans, zone, data_len,
1489                                                       hint, errorp);
1490         } else {
1491                 *data_offsetp = 0;
1492         }
1493         if (*errorp == 0 && data_bufferp) {
1494                 if (data_len) {
1495                         data = hammer_bread_ext(trans->hmp, *data_offsetp,
1496                                                 data_len, errorp, data_bufferp);
1497                 } else {
1498                         data = NULL;
1499                 }
1500         } else {
1501                 data = NULL;
1502         }
1503         return(data);
1504 }
1505
1506 /*
1507  * Sync dirty buffers to the media and clean-up any loose ends.
1508  *
1509  * These functions do not start the flusher going, they simply
1510  * queue everything up to the flusher.
1511  */
1512 static int hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data);
1513 static int hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1514
1515 int
1516 hammer_queue_inodes_flusher(hammer_mount_t hmp, int waitfor)
1517 {
1518         struct hammer_sync_info info;
1519
1520         info.error = 0;
1521         info.waitfor = waitfor;
1522         if (waitfor == MNT_WAIT) {
1523                 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_ONEPASS,
1524                               hammer_sync_scan1, hammer_sync_scan2, &info);
1525         } else {
1526                 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_ONEPASS|VMSC_NOWAIT,
1527                               hammer_sync_scan1, hammer_sync_scan2, &info);
1528         }
1529         return(info.error);
1530 }
1531
1532 /*
1533  * Filesystem sync.  If doing a synchronous sync make a second pass on
1534  * the vnodes in case any were already flushing during the first pass,
1535  * and activate the flusher twice (the second time brings the UNDO FIFO's
1536  * start position up to the end position after the first call).
1537  */
1538 int
1539 hammer_sync_hmp(hammer_mount_t hmp, int waitfor)
1540 {
1541         struct hammer_sync_info info;
1542
1543         info.error = 0;
1544         info.waitfor = MNT_NOWAIT;
1545         vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_NOWAIT,
1546                       hammer_sync_scan1, hammer_sync_scan2, &info);
1547         if (info.error == 0 && waitfor == MNT_WAIT) {
1548                 info.waitfor = waitfor;
1549                 vmntvnodescan(hmp->mp, VMSC_GETVP,
1550                               hammer_sync_scan1, hammer_sync_scan2, &info);
1551         }
1552         if (waitfor == MNT_WAIT) {
1553                 hammer_flusher_sync(hmp);
1554                 hammer_flusher_sync(hmp);
1555         } else {
1556                 hammer_flusher_async(hmp, NULL);
1557                 hammer_flusher_async(hmp, NULL);
1558         }
1559         return(info.error);
1560 }
1561
1562 static int
1563 hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data)
1564 {
1565         struct hammer_inode *ip;
1566
1567         ip = VTOI(vp);
1568         if (vp->v_type == VNON || ip == NULL ||
1569             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1570              RB_EMPTY(&vp->v_rbdirty_tree))) {
1571                 return(-1);
1572         }
1573         return(0);
1574 }
1575
1576 static int
1577 hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1578 {
1579         struct hammer_sync_info *info = data;
1580         struct hammer_inode *ip;
1581         int error;
1582
1583         ip = VTOI(vp);
1584         if (vp->v_type == VNON || vp->v_type == VBAD ||
1585             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1586              RB_EMPTY(&vp->v_rbdirty_tree))) {
1587                 return(0);
1588         }
1589         error = VOP_FSYNC(vp, MNT_NOWAIT);
1590         if (error)
1591                 info->error = error;
1592         return(0);
1593 }
1594