2 * Copyright (c) 2007-2008 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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.
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
34 * $DragonFly: src/sys/vfs/hammer/hammer_ondisk.c,v 1.58 2008/06/17 04:02:38 dillon Exp $
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.
43 #include <sys/fcntl.h>
44 #include <sys/nlookup.h>
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_node_t node
, int isnew
);
54 * Red-Black tree support for various structures
57 hammer_ino_rb_compare(hammer_inode_t ip1
, hammer_inode_t ip2
)
59 if (ip1
->obj_id
< ip2
->obj_id
)
61 if (ip1
->obj_id
> ip2
->obj_id
)
63 if (ip1
->obj_asof
< ip2
->obj_asof
)
65 if (ip1
->obj_asof
> ip2
->obj_asof
)
71 hammer_inode_info_cmp(hammer_inode_info_t info
, hammer_inode_t ip
)
73 if (info
->obj_id
< ip
->obj_id
)
75 if (info
->obj_id
> ip
->obj_id
)
77 if (info
->obj_asof
< ip
->obj_asof
)
79 if (info
->obj_asof
> ip
->obj_asof
)
85 hammer_vol_rb_compare(hammer_volume_t vol1
, hammer_volume_t vol2
)
87 if (vol1
->vol_no
< vol2
->vol_no
)
89 if (vol1
->vol_no
> vol2
->vol_no
)
95 hammer_buf_rb_compare(hammer_buffer_t buf1
, hammer_buffer_t buf2
)
97 if (buf1
->zoneX_offset
< buf2
->zoneX_offset
)
99 if (buf1
->zoneX_offset
> buf2
->zoneX_offset
)
105 hammer_nod_rb_compare(hammer_node_t node1
, hammer_node_t node2
)
107 if (node1
->node_offset
< node2
->node_offset
)
109 if (node1
->node_offset
> node2
->node_offset
)
115 * Note: The lookup function for hammer_ino_rb_tree winds up being named
116 * hammer_ino_rb_tree_RB_LOOKUP_INFO(root, info). The other lookup
117 * functions are normal, e.g. hammer_buf_rb_tree_RB_LOOKUP(root, zone2_offset).
119 RB_GENERATE(hammer_ino_rb_tree
, hammer_inode
, rb_node
, hammer_ino_rb_compare
);
120 RB_GENERATE_XLOOKUP(hammer_ino_rb_tree
, INFO
, hammer_inode
, rb_node
,
121 hammer_inode_info_cmp
, hammer_inode_info_t
);
122 RB_GENERATE2(hammer_vol_rb_tree
, hammer_volume
, rb_node
,
123 hammer_vol_rb_compare
, int32_t, vol_no
);
124 RB_GENERATE2(hammer_buf_rb_tree
, hammer_buffer
, rb_node
,
125 hammer_buf_rb_compare
, hammer_off_t
, zoneX_offset
);
126 RB_GENERATE2(hammer_nod_rb_tree
, hammer_node
, rb_node
,
127 hammer_nod_rb_compare
, hammer_off_t
, node_offset
);
129 /************************************************************************
131 ************************************************************************
133 * Load a HAMMER volume by name. Returns 0 on success or a positive error
134 * code on failure. Volumes must be loaded at mount time, get_volume() will
135 * not load a new volume.
137 * Calls made to hammer_load_volume() or single-threaded
140 hammer_install_volume(struct hammer_mount
*hmp
, const char *volname
)
143 hammer_volume_t volume
;
144 struct hammer_volume_ondisk
*ondisk
;
145 struct nlookupdata nd
;
146 struct buf
*bp
= NULL
;
152 ronly
= ((mp
->mnt_flag
& MNT_RDONLY
) ? 1 : 0);
155 * Allocate a volume structure
157 ++hammer_count_volumes
;
158 volume
= kmalloc(sizeof(*volume
), M_HAMMER
, M_WAITOK
|M_ZERO
);
159 volume
->vol_name
= kstrdup(volname
, M_HAMMER
);
160 hammer_io_init(&volume
->io
, hmp
, HAMMER_STRUCTURE_VOLUME
);
161 volume
->io
.offset
= 0LL;
164 * Get the device vnode
166 error
= nlookup_init(&nd
, volume
->vol_name
, UIO_SYSSPACE
, NLC_FOLLOW
);
168 error
= nlookup(&nd
);
170 error
= cache_vref(&nd
.nl_nch
, nd
.nl_cred
, &volume
->devvp
);
173 if (vn_isdisk(volume
->devvp
, &error
)) {
174 error
= vfs_mountedon(volume
->devvp
);
178 count_udev(volume
->devvp
->v_umajor
, volume
->devvp
->v_uminor
) > 0) {
182 vn_lock(volume
->devvp
, LK_EXCLUSIVE
| LK_RETRY
);
183 error
= vinvalbuf(volume
->devvp
, V_SAVE
, 0, 0);
185 error
= VOP_OPEN(volume
->devvp
,
186 (ronly
? FREAD
: FREAD
|FWRITE
),
189 vn_unlock(volume
->devvp
);
192 hammer_free_volume(volume
);
195 volume
->devvp
->v_rdev
->si_mountpoint
= mp
;
199 * Extract the volume number from the volume header and do various
202 error
= bread(volume
->devvp
, 0LL, HAMMER_BUFSIZE
, &bp
);
205 ondisk
= (void *)bp
->b_data
;
206 if (ondisk
->vol_signature
!= HAMMER_FSBUF_VOLUME
) {
207 kprintf("hammer_mount: volume %s has an invalid header\n",
212 volume
->vol_no
= ondisk
->vol_no
;
213 volume
->buffer_base
= ondisk
->vol_buf_beg
;
214 volume
->vol_flags
= ondisk
->vol_flags
;
215 volume
->nblocks
= ondisk
->vol_nblocks
;
216 volume
->maxbuf_off
= HAMMER_ENCODE_RAW_BUFFER(volume
->vol_no
,
217 ondisk
->vol_buf_end
- ondisk
->vol_buf_beg
);
218 volume
->maxraw_off
= ondisk
->vol_buf_end
;
220 if (RB_EMPTY(&hmp
->rb_vols_root
)) {
221 hmp
->fsid
= ondisk
->vol_fsid
;
222 } else if (bcmp(&hmp
->fsid
, &ondisk
->vol_fsid
, sizeof(uuid_t
))) {
223 kprintf("hammer_mount: volume %s's fsid does not match "
224 "other volumes\n", volume
->vol_name
);
230 * Insert the volume structure into the red-black tree.
232 if (RB_INSERT(hammer_vol_rb_tree
, &hmp
->rb_vols_root
, volume
)) {
233 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n",
234 volume
->vol_name
, volume
->vol_no
);
239 * Set the root volume . HAMMER special cases rootvol the structure.
240 * We do not hold a ref because this would prevent related I/O
241 * from being flushed.
243 if (error
== 0 && ondisk
->vol_rootvol
== ondisk
->vol_no
) {
244 hmp
->rootvol
= volume
;
249 hmp
->fsid_udev
= dev2udev(vn_todev(volume
->devvp
));
250 hmp
->mp
->mnt_stat
.f_blocks
+= ondisk
->vol0_stat_bigblocks
*
251 (HAMMER_LARGEBLOCK_SIZE
/ HAMMER_BUFSIZE
);
252 hmp
->mp
->mnt_vstat
.f_blocks
+= ondisk
->vol0_stat_bigblocks
*
253 (HAMMER_LARGEBLOCK_SIZE
/ HAMMER_BUFSIZE
);
259 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/
261 volume
->devvp
->v_rdev
->si_mountpoint
= NULL
;
262 VOP_CLOSE(volume
->devvp
, ronly
? FREAD
: FREAD
|FWRITE
);
263 hammer_free_volume(volume
);
269 * This is called for each volume when updating the mount point from
270 * read-write to read-only or vise-versa.
273 hammer_adjust_volume_mode(hammer_volume_t volume
, void *data __unused
)
276 vn_lock(volume
->devvp
, LK_EXCLUSIVE
| LK_RETRY
);
277 if (volume
->io
.hmp
->ronly
) {
278 /* do not call vinvalbuf */
279 VOP_OPEN(volume
->devvp
, FREAD
, FSCRED
, NULL
);
280 VOP_CLOSE(volume
->devvp
, FREAD
|FWRITE
);
282 /* do not call vinvalbuf */
283 VOP_OPEN(volume
->devvp
, FREAD
|FWRITE
, FSCRED
, NULL
);
284 VOP_CLOSE(volume
->devvp
, FREAD
);
286 vn_unlock(volume
->devvp
);
292 * Unload and free a HAMMER volume. Must return >= 0 to continue scan
293 * so returns -1 on failure.
296 hammer_unload_volume(hammer_volume_t volume
, void *data __unused
)
298 struct hammer_mount
*hmp
= volume
->io
.hmp
;
299 int ronly
= ((hmp
->mp
->mnt_flag
& MNT_RDONLY
) ? 1 : 0);
302 * Clean up the root volume pointer, which is held unlocked in hmp.
304 if (hmp
->rootvol
== volume
)
308 * Release our buffer and flush anything left in the buffer cache.
310 volume
->io
.waitdep
= 1;
311 hammer_io_release(&volume
->io
, 1);
312 hammer_io_clear_modlist(&volume
->io
);
315 * There should be no references on the volume, no clusters, and
318 KKASSERT(volume
->io
.lock
.refs
== 0);
320 volume
->ondisk
= NULL
;
322 if (volume
->devvp
->v_rdev
&&
323 volume
->devvp
->v_rdev
->si_mountpoint
== hmp
->mp
325 volume
->devvp
->v_rdev
->si_mountpoint
= NULL
;
328 vinvalbuf(volume
->devvp
, 0, 0, 0);
329 VOP_CLOSE(volume
->devvp
, FREAD
);
331 vinvalbuf(volume
->devvp
, V_SAVE
, 0, 0);
332 VOP_CLOSE(volume
->devvp
, FREAD
|FWRITE
);
337 * Destroy the structure
339 RB_REMOVE(hammer_vol_rb_tree
, &hmp
->rb_vols_root
, volume
);
340 hammer_free_volume(volume
);
346 hammer_free_volume(hammer_volume_t volume
)
348 if (volume
->vol_name
) {
349 kfree(volume
->vol_name
, M_HAMMER
);
350 volume
->vol_name
= NULL
;
353 vrele(volume
->devvp
);
354 volume
->devvp
= NULL
;
356 --hammer_count_volumes
;
357 kfree(volume
, M_HAMMER
);
361 * Get a HAMMER volume. The volume must already exist.
364 hammer_get_volume(struct hammer_mount
*hmp
, int32_t vol_no
, int *errorp
)
366 struct hammer_volume
*volume
;
369 * Locate the volume structure
371 volume
= RB_LOOKUP(hammer_vol_rb_tree
, &hmp
->rb_vols_root
, vol_no
);
372 if (volume
== NULL
) {
376 hammer_ref(&volume
->io
.lock
);
379 * Deal with on-disk info
381 if (volume
->ondisk
== NULL
|| volume
->io
.loading
) {
382 *errorp
= hammer_load_volume(volume
);
384 hammer_rel_volume(volume
, 1);
394 hammer_ref_volume(hammer_volume_t volume
)
398 hammer_ref(&volume
->io
.lock
);
401 * Deal with on-disk info
403 if (volume
->ondisk
== NULL
|| volume
->io
.loading
) {
404 error
= hammer_load_volume(volume
);
406 hammer_rel_volume(volume
, 1);
414 hammer_get_root_volume(struct hammer_mount
*hmp
, int *errorp
)
416 hammer_volume_t volume
;
418 volume
= hmp
->rootvol
;
419 KKASSERT(volume
!= NULL
);
420 hammer_ref(&volume
->io
.lock
);
423 * Deal with on-disk info
425 if (volume
->ondisk
== NULL
|| volume
->io
.loading
) {
426 *errorp
= hammer_load_volume(volume
);
428 hammer_rel_volume(volume
, 1);
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.
443 hammer_load_volume(hammer_volume_t volume
)
447 ++volume
->io
.loading
;
448 hammer_lock_ex(&volume
->io
.lock
);
450 if (volume
->ondisk
== NULL
) {
451 error
= hammer_io_read(volume
->devvp
, &volume
->io
,
454 volume
->ondisk
= (void *)volume
->io
.bp
->b_data
;
458 --volume
->io
.loading
;
459 hammer_unlock(&volume
->io
.lock
);
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
469 * Volumes are not unloaded from memory during normal operation.
472 hammer_rel_volume(hammer_volume_t volume
, int flush
)
475 if (volume
->io
.lock
.refs
== 1) {
476 ++volume
->io
.loading
;
477 hammer_lock_ex(&volume
->io
.lock
);
478 if (volume
->io
.lock
.refs
== 1) {
479 volume
->ondisk
= NULL
;
480 hammer_io_release(&volume
->io
, flush
);
482 --volume
->io
.loading
;
483 hammer_unlock(&volume
->io
.lock
);
485 hammer_unref(&volume
->io
.lock
);
489 /************************************************************************
491 ************************************************************************
493 * Manage buffers. Currently all blockmap-backed zones are translated
494 * to zone-2 buffer offsets.
497 hammer_get_buffer(hammer_mount_t hmp
, hammer_off_t buf_offset
,
498 int isnew
, int *errorp
)
500 hammer_buffer_t buffer
;
501 hammer_volume_t volume
;
502 hammer_off_t zone2_offset
;
503 hammer_io_type_t iotype
;
509 * Shortcut if the buffer is already cached
511 buffer
= RB_LOOKUP(hammer_buf_rb_tree
, &hmp
->rb_bufs_root
,
512 buf_offset
& ~HAMMER_BUFMASK64
);
514 if (buffer
->io
.lock
.refs
== 0)
515 ++hammer_count_refedbufs
;
516 hammer_ref(&buffer
->io
.lock
);
519 * Onced refed the ondisk field will not be cleared by
522 if (buffer
->ondisk
&& buffer
->io
.loading
== 0) {
528 * The buffer is no longer loose if it has a ref, and
529 * cannot become loose once it gains a ref. Loose
530 * buffers will never be in a modified state. This should
531 * only occur on the 0->1 transition of refs.
533 * lose_list can be modified via a biodone() interrupt.
535 if (buffer
->io
.mod_list
== &hmp
->lose_list
) {
536 crit_enter(); /* biodone race against list */
537 TAILQ_REMOVE(buffer
->io
.mod_list
, &buffer
->io
,
540 buffer
->io
.mod_list
= NULL
;
541 KKASSERT(buffer
->io
.modified
== 0);
547 * What is the buffer class?
549 zone
= HAMMER_ZONE_DECODE(buf_offset
);
552 case HAMMER_ZONE_LARGE_DATA_INDEX
:
553 case HAMMER_ZONE_SMALL_DATA_INDEX
:
554 case HAMMER_ZONE_META_INDEX
: /* meta-data isn't a meta-buffer */
555 iotype
= HAMMER_STRUCTURE_DATA_BUFFER
;
557 case HAMMER_ZONE_UNDO_INDEX
:
558 iotype
= HAMMER_STRUCTURE_UNDO_BUFFER
;
561 iotype
= HAMMER_STRUCTURE_META_BUFFER
;
566 * Handle blockmap offset translations
568 if (zone
>= HAMMER_ZONE_BTREE_INDEX
) {
569 zone2_offset
= hammer_blockmap_lookup(hmp
, buf_offset
, errorp
);
570 } else if (zone
== HAMMER_ZONE_UNDO_INDEX
) {
571 zone2_offset
= hammer_undo_lookup(hmp
, buf_offset
, errorp
);
573 KKASSERT(zone
== HAMMER_ZONE_RAW_BUFFER_INDEX
);
574 zone2_offset
= buf_offset
;
581 * Calculate the base zone2-offset and acquire the volume
583 * NOTE: zone2_offset and maxbuf_off are both full zone-2 offset
586 zone2_offset
&= ~HAMMER_BUFMASK64
;
587 KKASSERT((zone2_offset
& HAMMER_OFF_ZONE_MASK
) ==
588 HAMMER_ZONE_RAW_BUFFER
);
589 vol_no
= HAMMER_VOL_DECODE(zone2_offset
);
590 volume
= hammer_get_volume(hmp
, vol_no
, errorp
);
594 KKASSERT(zone2_offset
< volume
->maxbuf_off
);
597 * Allocate a new buffer structure. We will check for races later.
599 ++hammer_count_buffers
;
600 buffer
= kmalloc(sizeof(*buffer
), M_HAMMER
, M_WAITOK
|M_ZERO
);
601 buffer
->zone2_offset
= zone2_offset
;
602 buffer
->zoneX_offset
= buf_offset
;
603 buffer
->volume
= volume
;
605 hammer_io_init(&buffer
->io
, hmp
, iotype
);
606 buffer
->io
.offset
= volume
->ondisk
->vol_buf_beg
+
607 (zone2_offset
& HAMMER_OFF_SHORT_MASK
);
608 TAILQ_INIT(&buffer
->clist
);
609 hammer_ref(&buffer
->io
.lock
);
612 * Insert the buffer into the RB tree and handle late collisions.
614 if (RB_INSERT(hammer_buf_rb_tree
, &hmp
->rb_bufs_root
, buffer
)) {
615 hammer_unref(&buffer
->io
.lock
);
616 --hammer_count_buffers
;
617 kfree(buffer
, M_HAMMER
);
620 ++hammer_count_refedbufs
;
624 * Deal with on-disk info and loading races.
626 if (buffer
->ondisk
== NULL
|| buffer
->io
.loading
) {
627 *errorp
= hammer_load_buffer(buffer
, isnew
);
629 hammer_rel_buffer(buffer
, 1);
639 * Destroy all buffers covering the specified zoneX offset range. This
640 * is called when the related blockmap layer2 entry is freed or when
641 * a direct write bypasses our buffer/buffer-cache subsystem.
643 * The buffers may be referenced by the caller itself. Setting reclaim
644 * will cause the buffer to be destroyed when it's ref count reaches zero.
647 hammer_del_buffers(hammer_mount_t hmp
, hammer_off_t base_offset
,
648 hammer_off_t zone2_offset
, int bytes
)
650 hammer_buffer_t buffer
;
651 hammer_volume_t volume
;
655 vol_no
= HAMMER_VOL_DECODE(zone2_offset
);
656 volume
= hammer_get_volume(hmp
, vol_no
, &error
);
657 KKASSERT(error
== 0);
660 buffer
= RB_LOOKUP(hammer_buf_rb_tree
, &hmp
->rb_bufs_root
,
663 KKASSERT(buffer
->zone2_offset
== zone2_offset
);
664 hammer_io_clear_modify(&buffer
->io
);
665 buffer
->io
.reclaim
= 1;
666 KKASSERT(buffer
->volume
== volume
);
667 if (buffer
->io
.lock
.refs
== 0)
668 hammer_unload_buffer(buffer
, NULL
);
670 hammer_io_inval(volume
, zone2_offset
);
672 base_offset
+= HAMMER_BUFSIZE
;
673 zone2_offset
+= HAMMER_BUFSIZE
;
674 bytes
-= HAMMER_BUFSIZE
;
676 hammer_rel_volume(volume
, 0);
680 hammer_load_buffer(hammer_buffer_t buffer
, int isnew
)
682 hammer_volume_t volume
;
686 * Load the buffer's on-disk info
688 volume
= buffer
->volume
;
689 ++buffer
->io
.loading
;
690 hammer_lock_ex(&buffer
->io
.lock
);
692 if (hammer_debug_io
& 0x0001) {
693 kprintf("load_buffer %016llx %016llx isnew=%d od=%p\n",
694 buffer
->zoneX_offset
, buffer
->zone2_offset
, isnew
,
698 if (buffer
->ondisk
== NULL
) {
700 error
= hammer_io_new(volume
->devvp
, &buffer
->io
);
702 error
= hammer_io_read(volume
->devvp
, &buffer
->io
,
706 buffer
->ondisk
= (void *)buffer
->io
.bp
->b_data
;
708 error
= hammer_io_new(volume
->devvp
, &buffer
->io
);
712 --buffer
->io
.loading
;
713 hammer_unlock(&buffer
->io
.lock
);
718 * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
721 hammer_unload_buffer(hammer_buffer_t buffer
, void *data __unused
)
723 ++hammer_count_refedbufs
;
724 hammer_ref(&buffer
->io
.lock
);
725 hammer_flush_buffer_nodes(buffer
);
726 KKASSERT(buffer
->io
.lock
.refs
== 1);
727 hammer_rel_buffer(buffer
, 2);
732 * Reference a buffer that is either already referenced or via a specially
733 * handled pointer (aka cursor->buffer).
736 hammer_ref_buffer(hammer_buffer_t buffer
)
740 if (buffer
->io
.lock
.refs
== 0)
741 ++hammer_count_refedbufs
;
742 hammer_ref(&buffer
->io
.lock
);
745 * At this point a biodone() will not touch the buffer other then
746 * incidental bits. However, lose_list can be modified via
747 * a biodone() interrupt.
751 if (buffer
->io
.mod_list
== &buffer
->io
.hmp
->lose_list
) {
753 TAILQ_REMOVE(buffer
->io
.mod_list
, &buffer
->io
, mod_entry
);
754 buffer
->io
.mod_list
= NULL
;
758 if (buffer
->ondisk
== NULL
|| buffer
->io
.loading
) {
759 error
= hammer_load_buffer(buffer
, 0);
761 hammer_rel_buffer(buffer
, 1);
763 * NOTE: buffer pointer can become stale after
774 * Release a buffer. We have to deal with several places where
775 * another thread can ref the buffer.
777 * Only destroy the structure itself if the related buffer cache buffer
778 * was disassociated from it. This ties the management of the structure
779 * to the buffer cache subsystem. buffer->ondisk determines whether the
780 * embedded io is referenced or not.
783 hammer_rel_buffer(hammer_buffer_t buffer
, int flush
)
785 hammer_volume_t volume
;
789 if (buffer
->io
.lock
.refs
== 1) {
790 ++buffer
->io
.loading
; /* force interlock check */
791 hammer_lock_ex(&buffer
->io
.lock
);
792 if (buffer
->io
.lock
.refs
== 1) {
793 hammer_io_release(&buffer
->io
, flush
);
795 if (buffer
->io
.bp
== NULL
&&
796 buffer
->io
.lock
.refs
== 1) {
800 * NOTE: It is impossible for any associated
801 * B-Tree nodes to have refs if the buffer
802 * has no additional refs.
804 RB_REMOVE(hammer_buf_rb_tree
,
805 &buffer
->io
.hmp
->rb_bufs_root
,
807 volume
= buffer
->volume
;
808 buffer
->volume
= NULL
; /* sanity */
809 hammer_rel_volume(volume
, 0);
810 hammer_io_clear_modlist(&buffer
->io
);
811 hammer_flush_buffer_nodes(buffer
);
812 KKASSERT(TAILQ_EMPTY(&buffer
->clist
));
813 if (buffer
->io
.lock
.refs
== 1)
814 --hammer_count_refedbufs
;
818 --buffer
->io
.loading
;
819 hammer_unlock(&buffer
->io
.lock
);
821 hammer_unref(&buffer
->io
.lock
);
824 --hammer_count_buffers
;
825 kfree(buffer
, M_HAMMER
);
830 * Access the filesystem buffer containing the specified hammer offset.
831 * buf_offset is a conglomeration of the volume number and vol_buf_beg
832 * relative buffer offset. It must also have bit 55 set to be valid.
833 * (see hammer_off_t in hammer_disk.h).
835 * Any prior buffer in *bufferp will be released and replaced by the
839 hammer_bread(hammer_mount_t hmp
, hammer_off_t buf_offset
, int *errorp
,
840 struct hammer_buffer
**bufferp
)
842 hammer_buffer_t buffer
;
843 int32_t xoff
= (int32_t)buf_offset
& HAMMER_BUFMASK
;
845 buf_offset
&= ~HAMMER_BUFMASK64
;
846 KKASSERT((buf_offset
& HAMMER_OFF_ZONE_MASK
) != 0);
849 if (buffer
== NULL
|| (buffer
->zone2_offset
!= buf_offset
&&
850 buffer
->zoneX_offset
!= buf_offset
)) {
852 hammer_rel_buffer(buffer
, 0);
853 buffer
= hammer_get_buffer(hmp
, buf_offset
, 0, errorp
);
860 * Return a pointer to the buffer data.
865 return((char *)buffer
->ondisk
+ xoff
);
869 * Access the filesystem buffer containing the specified hammer offset.
870 * No disk read operation occurs. The result buffer may contain garbage.
872 * Any prior buffer in *bufferp will be released and replaced by the
875 * This function marks the buffer dirty but does not increment its
879 hammer_bnew(hammer_mount_t hmp
, hammer_off_t buf_offset
, int *errorp
,
880 struct hammer_buffer
**bufferp
)
882 hammer_buffer_t buffer
;
883 int32_t xoff
= (int32_t)buf_offset
& HAMMER_BUFMASK
;
885 buf_offset
&= ~HAMMER_BUFMASK64
;
888 if (buffer
== NULL
|| (buffer
->zone2_offset
!= buf_offset
&&
889 buffer
->zoneX_offset
!= buf_offset
)) {
891 hammer_rel_buffer(buffer
, 0);
892 buffer
= hammer_get_buffer(hmp
, buf_offset
, 1, errorp
);
899 * Return a pointer to the buffer data.
904 return((char *)buffer
->ondisk
+ xoff
);
907 /************************************************************************
909 ************************************************************************
911 * Manage B-Tree nodes. B-Tree nodes represent the primary indexing
912 * method used by the HAMMER filesystem.
914 * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
915 * associated with its buffer, and will only referenced the buffer while
916 * the node itself is referenced.
918 * A hammer_node can also be passively associated with other HAMMER
919 * structures, such as inodes, while retaining 0 references. These
920 * associations can be cleared backwards using a pointer-to-pointer in
923 * This allows the HAMMER implementation to cache hammer_nodes long-term
924 * and short-cut a great deal of the infrastructure's complexity. In
925 * most cases a cached node can be reacquired without having to dip into
926 * either the buffer or cluster management code.
928 * The caller must pass a referenced cluster on call and will retain
929 * ownership of the reference on return. The node will acquire its own
930 * additional references, if necessary.
933 hammer_get_node(hammer_mount_t hmp
, hammer_off_t node_offset
,
934 int isnew
, int *errorp
)
938 KKASSERT((node_offset
& HAMMER_OFF_ZONE_MASK
) == HAMMER_ZONE_BTREE
);
941 * Locate the structure, allocating one if necessary.
944 node
= RB_LOOKUP(hammer_nod_rb_tree
, &hmp
->rb_nods_root
, node_offset
);
946 ++hammer_count_nodes
;
947 node
= kmalloc(sizeof(*node
), M_HAMMER
, M_WAITOK
|M_ZERO
);
948 node
->node_offset
= node_offset
;
950 if (RB_INSERT(hammer_nod_rb_tree
, &hmp
->rb_nods_root
, node
)) {
951 --hammer_count_nodes
;
952 kfree(node
, M_HAMMER
);
956 hammer_ref(&node
->lock
);
960 *errorp
= hammer_load_node(node
, isnew
);
962 hammer_rel_node(node
);
969 * Reference an already-referenced node.
972 hammer_ref_node(hammer_node_t node
)
974 KKASSERT(node
->lock
.refs
> 0 && node
->ondisk
!= NULL
);
975 hammer_ref(&node
->lock
);
979 * Load a node's on-disk data reference.
982 hammer_load_node(hammer_node_t node
, int isnew
)
984 hammer_buffer_t buffer
;
985 hammer_off_t buf_offset
;
990 hammer_lock_ex(&node
->lock
);
991 if (node
->ondisk
== NULL
) {
993 * This is a little confusing but the jist is that
994 * node->buffer determines whether the node is on
995 * the buffer's clist and node->ondisk determines
996 * whether the buffer is referenced.
998 * We could be racing a buffer release, in which case
999 * node->buffer may become NULL while we are blocked
1000 * referencing the buffer.
1002 if ((buffer
= node
->buffer
) != NULL
) {
1003 error
= hammer_ref_buffer(buffer
);
1004 if (error
== 0 && node
->buffer
== NULL
) {
1005 TAILQ_INSERT_TAIL(&buffer
->clist
,
1007 node
->buffer
= buffer
;
1010 buf_offset
= node
->node_offset
& ~HAMMER_BUFMASK64
;
1011 buffer
= hammer_get_buffer(node
->hmp
, buf_offset
,
1014 KKASSERT(error
== 0);
1015 TAILQ_INSERT_TAIL(&buffer
->clist
,
1017 node
->buffer
= buffer
;
1021 node
->ondisk
= (void *)((char *)buffer
->ondisk
+
1022 (node
->node_offset
& HAMMER_BUFMASK
));
1024 hammer_crc_test_btree(node
->ondisk
) == 0) {
1025 Debugger("CRC FAILED: B-TREE NODE");
1030 hammer_unlock(&node
->lock
);
1035 * Safely reference a node, interlock against flushes via the IO subsystem.
1038 hammer_ref_node_safe(struct hammer_mount
*hmp
, struct hammer_node
**cache
,
1045 hammer_ref(&node
->lock
);
1049 *errorp
= hammer_load_node(node
, 0);
1051 hammer_rel_node(node
);
1061 * Release a hammer_node. On the last release the node dereferences
1062 * its underlying buffer and may or may not be destroyed.
1065 hammer_rel_node(hammer_node_t node
)
1067 hammer_buffer_t buffer
;
1070 * If this isn't the last ref just decrement the ref count and
1073 if (node
->lock
.refs
> 1) {
1074 hammer_unref(&node
->lock
);
1079 * If there is no ondisk info or no buffer the node failed to load,
1080 * remove the last reference and destroy the node.
1082 if (node
->ondisk
== NULL
) {
1083 hammer_unref(&node
->lock
);
1084 hammer_flush_node(node
);
1085 /* node is stale now */
1090 * Do final cleanups and then either destroy the node and leave it
1091 * passively cached. The buffer reference is removed regardless.
1093 buffer
= node
->buffer
;
1094 node
->ondisk
= NULL
;
1096 if ((node
->flags
& HAMMER_NODE_FLUSH
) == 0) {
1097 hammer_unref(&node
->lock
);
1098 hammer_rel_buffer(buffer
, 0);
1105 hammer_unref(&node
->lock
);
1106 hammer_flush_node(node
);
1108 hammer_rel_buffer(buffer
, 0);
1112 * Free space on-media associated with a B-Tree node.
1115 hammer_delete_node(hammer_transaction_t trans
, hammer_node_t node
)
1117 KKASSERT((node
->flags
& HAMMER_NODE_DELETED
) == 0);
1118 node
->flags
|= HAMMER_NODE_DELETED
;
1119 hammer_blockmap_free(trans
, node
->node_offset
, sizeof(*node
->ondisk
));
1123 * Passively cache a referenced hammer_node in *cache. The caller may
1124 * release the node on return.
1127 hammer_cache_node(hammer_node_t node
, struct hammer_node
**cache
)
1132 * If the node is being deleted, don't cache it!
1134 if (node
->flags
& HAMMER_NODE_DELETED
)
1138 * Cache the node. If we previously cached a different node we
1139 * have to give HAMMER a chance to destroy it.
1142 if (node
->cache1
!= cache
) {
1143 if (node
->cache2
!= cache
) {
1144 if ((old
= *cache
) != NULL
) {
1145 KKASSERT(node
->lock
.refs
!= 0);
1146 hammer_uncache_node(cache
);
1150 *node
->cache2
= NULL
;
1151 node
->cache2
= node
->cache1
;
1152 node
->cache1
= cache
;
1155 struct hammer_node
**tmp
;
1157 node
->cache1
= node
->cache2
;
1164 hammer_uncache_node(struct hammer_node
**cache
)
1168 if ((node
= *cache
) != NULL
) {
1170 if (node
->cache1
== cache
) {
1171 node
->cache1
= node
->cache2
;
1172 node
->cache2
= NULL
;
1173 } else if (node
->cache2
== cache
) {
1174 node
->cache2
= NULL
;
1176 panic("hammer_uncache_node: missing cache linkage");
1178 if (node
->cache1
== NULL
&& node
->cache2
== NULL
) {
1179 hammer_flush_node(node
);
1185 * Remove a node's cache references and destroy the node if it has no
1186 * other references or backing store.
1189 hammer_flush_node(hammer_node_t node
)
1191 hammer_buffer_t buffer
;
1194 *node
->cache1
= NULL
;
1196 *node
->cache2
= NULL
;
1197 if (node
->lock
.refs
== 0 && node
->ondisk
== NULL
) {
1198 RB_REMOVE(hammer_nod_rb_tree
, &node
->hmp
->rb_nods_root
, node
);
1199 if ((buffer
= node
->buffer
) != NULL
) {
1200 node
->buffer
= NULL
;
1201 TAILQ_REMOVE(&buffer
->clist
, node
, entry
);
1202 /* buffer is unreferenced because ondisk is NULL */
1204 --hammer_count_nodes
;
1205 kfree(node
, M_HAMMER
);
1210 * Flush passively cached B-Tree nodes associated with this buffer.
1211 * This is only called when the buffer is about to be destroyed, so
1212 * none of the nodes should have any references. The buffer is locked.
1214 * We may be interlocked with the buffer.
1217 hammer_flush_buffer_nodes(hammer_buffer_t buffer
)
1221 while ((node
= TAILQ_FIRST(&buffer
->clist
)) != NULL
) {
1222 KKASSERT(node
->ondisk
== NULL
);
1224 if (node
->lock
.refs
== 0) {
1225 hammer_ref(&node
->lock
);
1226 node
->flags
|= HAMMER_NODE_FLUSH
;
1227 hammer_rel_node(node
);
1229 KKASSERT(node
->loading
!= 0);
1230 KKASSERT(node
->buffer
!= NULL
);
1231 buffer
= node
->buffer
;
1232 node
->buffer
= NULL
;
1233 TAILQ_REMOVE(&buffer
->clist
, node
, entry
);
1234 /* buffer is unreferenced because ondisk is NULL */
1240 /************************************************************************
1242 ************************************************************************/
1245 * Allocate a B-Tree node.
1248 hammer_alloc_btree(hammer_transaction_t trans
, int *errorp
)
1250 hammer_buffer_t buffer
= NULL
;
1251 hammer_node_t node
= NULL
;
1252 hammer_off_t node_offset
;
1254 node_offset
= hammer_blockmap_alloc(trans
, HAMMER_ZONE_BTREE_INDEX
,
1255 sizeof(struct hammer_node_ondisk
),
1258 node
= hammer_get_node(trans
->hmp
, node_offset
, 1, errorp
);
1259 hammer_modify_node_noundo(trans
, node
);
1260 bzero(node
->ondisk
, sizeof(*node
->ondisk
));
1261 hammer_modify_node_done(node
);
1264 hammer_rel_buffer(buffer
, 0);
1269 * Allocate data. If the address of a data buffer is supplied then
1270 * any prior non-NULL *data_bufferp will be released and *data_bufferp
1271 * will be set to the related buffer. The caller must release it when
1272 * finally done. The initial *data_bufferp should be set to NULL by
1275 * The caller is responsible for making hammer_modify*() calls on the
1279 hammer_alloc_data(hammer_transaction_t trans
, int32_t data_len
,
1280 u_int16_t rec_type
, hammer_off_t
*data_offsetp
,
1281 struct hammer_buffer
**data_bufferp
, int *errorp
)
1291 case HAMMER_RECTYPE_INODE
:
1292 case HAMMER_RECTYPE_PSEUDO_INODE
:
1293 case HAMMER_RECTYPE_DIRENTRY
:
1294 case HAMMER_RECTYPE_EXT
:
1295 case HAMMER_RECTYPE_FIX
:
1296 zone
= HAMMER_ZONE_META_INDEX
;
1298 case HAMMER_RECTYPE_DATA
:
1299 case HAMMER_RECTYPE_DB
:
1300 if (data_len
<= HAMMER_BUFSIZE
/ 2)
1301 zone
= HAMMER_ZONE_SMALL_DATA_INDEX
;
1303 zone
= HAMMER_ZONE_LARGE_DATA_INDEX
;
1306 panic("hammer_alloc_data: rec_type %04x unknown",
1308 zone
= 0; /* NOT REACHED */
1311 *data_offsetp
= hammer_blockmap_alloc(trans
, zone
,
1316 if (*errorp
== 0 && data_bufferp
) {
1318 data
= hammer_bread(trans
->hmp
, *data_offsetp
, errorp
,
1320 KKASSERT(*errorp
== 0);
1327 KKASSERT(*errorp
== 0);
1332 * Sync dirty buffers to the media and clean-up any loose ends.
1334 static int hammer_sync_scan1(struct mount
*mp
, struct vnode
*vp
, void *data
);
1335 static int hammer_sync_scan2(struct mount
*mp
, struct vnode
*vp
, void *data
);
1338 hammer_queue_inodes_flusher(hammer_mount_t hmp
, int waitfor
)
1340 struct hammer_sync_info info
;
1343 info
.waitfor
= waitfor
;
1344 if (waitfor
== MNT_WAIT
) {
1345 vmntvnodescan(hmp
->mp
, VMSC_GETVP
|VMSC_ONEPASS
,
1346 hammer_sync_scan1
, hammer_sync_scan2
, &info
);
1348 vmntvnodescan(hmp
->mp
, VMSC_GETVP
|VMSC_ONEPASS
|VMSC_NOWAIT
,
1349 hammer_sync_scan1
, hammer_sync_scan2
, &info
);
1355 hammer_sync_hmp(hammer_mount_t hmp
, int waitfor
)
1357 struct hammer_sync_info info
;
1360 info
.waitfor
= waitfor
;
1362 vmntvnodescan(hmp
->mp
, VMSC_GETVP
|VMSC_NOWAIT
,
1363 hammer_sync_scan1
, hammer_sync_scan2
, &info
);
1364 if (waitfor
== MNT_WAIT
)
1365 hammer_flusher_sync(hmp
);
1367 hammer_flusher_async(hmp
);
1373 hammer_sync_scan1(struct mount
*mp
, struct vnode
*vp
, void *data
)
1375 struct hammer_inode
*ip
;
1378 if (vp
->v_type
== VNON
|| ip
== NULL
||
1379 ((ip
->flags
& HAMMER_INODE_MODMASK
) == 0 &&
1380 RB_EMPTY(&vp
->v_rbdirty_tree
))) {
1387 hammer_sync_scan2(struct mount
*mp
, struct vnode
*vp
, void *data
)
1389 struct hammer_sync_info
*info
= data
;
1390 struct hammer_inode
*ip
;
1394 if (vp
->v_type
== VNON
|| vp
->v_type
== VBAD
||
1395 ((ip
->flags
& HAMMER_INODE_MODMASK
) == 0 &&
1396 RB_EMPTY(&vp
->v_rbdirty_tree
))) {
1399 error
= VOP_FSYNC(vp
, info
->waitfor
);
1401 info
->error
= error
;