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 1.67 2008/07/09 10:29:20 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 hammer_vol_rb_compare(hammer_volume_t vol1
, hammer_volume_t vol2
)
56 if (vol1
->vol_no
< vol2
->vol_no
)
58 if (vol1
->vol_no
> vol2
->vol_no
)
64 hammer_buf_rb_compare(hammer_buffer_t buf1
, hammer_buffer_t buf2
)
66 if (buf1
->zoneX_offset
< buf2
->zoneX_offset
)
68 if (buf1
->zoneX_offset
> buf2
->zoneX_offset
)
74 hammer_nod_rb_compare(hammer_node_t node1
, hammer_node_t node2
)
76 if (node1
->node_offset
< node2
->node_offset
)
78 if (node1
->node_offset
> node2
->node_offset
)
83 RB_GENERATE2(hammer_vol_rb_tree
, hammer_volume
, rb_node
,
84 hammer_vol_rb_compare
, int32_t, vol_no
);
85 RB_GENERATE2(hammer_buf_rb_tree
, hammer_buffer
, rb_node
,
86 hammer_buf_rb_compare
, hammer_off_t
, zoneX_offset
);
87 RB_GENERATE2(hammer_nod_rb_tree
, hammer_node
, rb_node
,
88 hammer_nod_rb_compare
, hammer_off_t
, node_offset
);
90 /************************************************************************
92 ************************************************************************
94 * Load a HAMMER volume by name. Returns 0 on success or a positive error
95 * code on failure. Volumes must be loaded at mount time, get_volume() will
96 * not load a new volume.
98 * Calls made to hammer_load_volume() or single-threaded
101 hammer_install_volume(struct hammer_mount
*hmp
, const char *volname
)
104 hammer_volume_t volume
;
105 struct hammer_volume_ondisk
*ondisk
;
106 struct nlookupdata nd
;
107 struct buf
*bp
= NULL
;
113 ronly
= ((mp
->mnt_flag
& MNT_RDONLY
) ? 1 : 0);
116 * Allocate a volume structure
118 ++hammer_count_volumes
;
119 volume
= kmalloc(sizeof(*volume
), M_HAMMER
, M_WAITOK
|M_ZERO
);
120 volume
->vol_name
= kstrdup(volname
, M_HAMMER
);
121 hammer_io_init(&volume
->io
, hmp
, HAMMER_STRUCTURE_VOLUME
);
122 volume
->io
.offset
= 0LL;
123 volume
->io
.bytes
= HAMMER_BUFSIZE
;
126 * Get the device vnode
128 error
= nlookup_init(&nd
, volume
->vol_name
, UIO_SYSSPACE
, NLC_FOLLOW
);
130 error
= nlookup(&nd
);
132 error
= cache_vref(&nd
.nl_nch
, nd
.nl_cred
, &volume
->devvp
);
135 if (vn_isdisk(volume
->devvp
, &error
)) {
136 error
= vfs_mountedon(volume
->devvp
);
140 count_udev(volume
->devvp
->v_umajor
, volume
->devvp
->v_uminor
) > 0) {
144 vn_lock(volume
->devvp
, LK_EXCLUSIVE
| LK_RETRY
);
145 error
= vinvalbuf(volume
->devvp
, V_SAVE
, 0, 0);
147 error
= VOP_OPEN(volume
->devvp
,
148 (ronly
? FREAD
: FREAD
|FWRITE
),
151 vn_unlock(volume
->devvp
);
154 hammer_free_volume(volume
);
157 volume
->devvp
->v_rdev
->si_mountpoint
= mp
;
161 * Extract the volume number from the volume header and do various
164 error
= bread(volume
->devvp
, 0LL, HAMMER_BUFSIZE
, &bp
);
167 ondisk
= (void *)bp
->b_data
;
168 if (ondisk
->vol_signature
!= HAMMER_FSBUF_VOLUME
) {
169 kprintf("hammer_mount: volume %s has an invalid header\n",
174 volume
->vol_no
= ondisk
->vol_no
;
175 volume
->buffer_base
= ondisk
->vol_buf_beg
;
176 volume
->vol_flags
= ondisk
->vol_flags
;
177 volume
->nblocks
= ondisk
->vol_nblocks
;
178 volume
->maxbuf_off
= HAMMER_ENCODE_RAW_BUFFER(volume
->vol_no
,
179 ondisk
->vol_buf_end
- ondisk
->vol_buf_beg
);
180 volume
->maxraw_off
= ondisk
->vol_buf_end
;
182 if (RB_EMPTY(&hmp
->rb_vols_root
)) {
183 hmp
->fsid
= ondisk
->vol_fsid
;
184 } else if (bcmp(&hmp
->fsid
, &ondisk
->vol_fsid
, sizeof(uuid_t
))) {
185 kprintf("hammer_mount: volume %s's fsid does not match "
186 "other volumes\n", volume
->vol_name
);
192 * Insert the volume structure into the red-black tree.
194 if (RB_INSERT(hammer_vol_rb_tree
, &hmp
->rb_vols_root
, volume
)) {
195 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n",
196 volume
->vol_name
, volume
->vol_no
);
201 * Set the root volume . HAMMER special cases rootvol the structure.
202 * We do not hold a ref because this would prevent related I/O
203 * from being flushed.
205 if (error
== 0 && ondisk
->vol_rootvol
== ondisk
->vol_no
) {
206 hmp
->rootvol
= volume
;
211 hmp
->mp
->mnt_stat
.f_blocks
+= ondisk
->vol0_stat_bigblocks
*
212 (HAMMER_LARGEBLOCK_SIZE
/ HAMMER_BUFSIZE
);
213 hmp
->mp
->mnt_vstat
.f_blocks
+= ondisk
->vol0_stat_bigblocks
*
214 (HAMMER_LARGEBLOCK_SIZE
/ HAMMER_BUFSIZE
);
220 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/
222 volume
->devvp
->v_rdev
->si_mountpoint
= NULL
;
223 VOP_CLOSE(volume
->devvp
, ronly
? FREAD
: FREAD
|FWRITE
);
224 hammer_free_volume(volume
);
230 * This is called for each volume when updating the mount point from
231 * read-write to read-only or vise-versa.
234 hammer_adjust_volume_mode(hammer_volume_t volume
, void *data __unused
)
237 vn_lock(volume
->devvp
, LK_EXCLUSIVE
| LK_RETRY
);
238 if (volume
->io
.hmp
->ronly
) {
239 /* do not call vinvalbuf */
240 VOP_OPEN(volume
->devvp
, FREAD
, FSCRED
, NULL
);
241 VOP_CLOSE(volume
->devvp
, FREAD
|FWRITE
);
243 /* do not call vinvalbuf */
244 VOP_OPEN(volume
->devvp
, FREAD
|FWRITE
, FSCRED
, NULL
);
245 VOP_CLOSE(volume
->devvp
, FREAD
);
247 vn_unlock(volume
->devvp
);
253 * Unload and free a HAMMER volume. Must return >= 0 to continue scan
254 * so returns -1 on failure.
257 hammer_unload_volume(hammer_volume_t volume
, void *data __unused
)
259 struct hammer_mount
*hmp
= volume
->io
.hmp
;
260 int ronly
= ((hmp
->mp
->mnt_flag
& MNT_RDONLY
) ? 1 : 0);
264 * Clean up the root volume pointer, which is held unlocked in hmp.
266 if (hmp
->rootvol
== volume
)
270 * Release our buffer and flush anything left in the buffer cache.
272 volume
->io
.waitdep
= 1;
273 bp
= hammer_io_release(&volume
->io
, 1);
274 hammer_io_clear_modlist(&volume
->io
);
277 * There should be no references on the volume, no clusters, and
280 KKASSERT(volume
->io
.lock
.refs
== 0);
284 volume
->ondisk
= NULL
;
286 if (volume
->devvp
->v_rdev
&&
287 volume
->devvp
->v_rdev
->si_mountpoint
== hmp
->mp
289 volume
->devvp
->v_rdev
->si_mountpoint
= NULL
;
292 vinvalbuf(volume
->devvp
, 0, 0, 0);
293 VOP_CLOSE(volume
->devvp
, FREAD
);
295 vinvalbuf(volume
->devvp
, V_SAVE
, 0, 0);
296 VOP_CLOSE(volume
->devvp
, FREAD
|FWRITE
);
301 * Destroy the structure
303 RB_REMOVE(hammer_vol_rb_tree
, &hmp
->rb_vols_root
, volume
);
304 hammer_free_volume(volume
);
310 hammer_free_volume(hammer_volume_t volume
)
312 if (volume
->vol_name
) {
313 kfree(volume
->vol_name
, M_HAMMER
);
314 volume
->vol_name
= NULL
;
317 vrele(volume
->devvp
);
318 volume
->devvp
= NULL
;
320 --hammer_count_volumes
;
321 kfree(volume
, M_HAMMER
);
325 * Get a HAMMER volume. The volume must already exist.
328 hammer_get_volume(struct hammer_mount
*hmp
, int32_t vol_no
, int *errorp
)
330 struct hammer_volume
*volume
;
333 * Locate the volume structure
335 volume
= RB_LOOKUP(hammer_vol_rb_tree
, &hmp
->rb_vols_root
, vol_no
);
336 if (volume
== NULL
) {
340 hammer_ref(&volume
->io
.lock
);
343 * Deal with on-disk info
345 if (volume
->ondisk
== NULL
|| volume
->io
.loading
) {
346 *errorp
= hammer_load_volume(volume
);
348 hammer_rel_volume(volume
, 1);
358 hammer_ref_volume(hammer_volume_t volume
)
362 hammer_ref(&volume
->io
.lock
);
365 * Deal with on-disk info
367 if (volume
->ondisk
== NULL
|| volume
->io
.loading
) {
368 error
= hammer_load_volume(volume
);
370 hammer_rel_volume(volume
, 1);
378 hammer_get_root_volume(struct hammer_mount
*hmp
, int *errorp
)
380 hammer_volume_t volume
;
382 volume
= hmp
->rootvol
;
383 KKASSERT(volume
!= NULL
);
384 hammer_ref(&volume
->io
.lock
);
387 * Deal with on-disk info
389 if (volume
->ondisk
== NULL
|| volume
->io
.loading
) {
390 *errorp
= hammer_load_volume(volume
);
392 hammer_rel_volume(volume
, 1);
402 * Load a volume's on-disk information. The volume must be referenced and
403 * not locked. We temporarily acquire an exclusive lock to interlock
404 * against releases or multiple get's.
407 hammer_load_volume(hammer_volume_t volume
)
411 ++volume
->io
.loading
;
412 hammer_lock_ex(&volume
->io
.lock
);
414 if (volume
->ondisk
== NULL
) {
415 error
= hammer_io_read(volume
->devvp
, &volume
->io
,
418 volume
->ondisk
= (void *)volume
->io
.bp
->b_data
;
422 --volume
->io
.loading
;
423 hammer_unlock(&volume
->io
.lock
);
428 * Release a volume. Call hammer_io_release on the last reference. We have
429 * to acquire an exclusive lock to interlock against volume->ondisk tests
430 * in hammer_load_volume(), and hammer_io_release() also expects an exclusive
433 * Volumes are not unloaded from memory during normal operation.
436 hammer_rel_volume(hammer_volume_t volume
, int flush
)
438 struct buf
*bp
= NULL
;
441 if (volume
->io
.lock
.refs
== 1) {
442 ++volume
->io
.loading
;
443 hammer_lock_ex(&volume
->io
.lock
);
444 if (volume
->io
.lock
.refs
== 1) {
445 volume
->ondisk
= NULL
;
446 bp
= hammer_io_release(&volume
->io
, flush
);
448 --volume
->io
.loading
;
449 hammer_unlock(&volume
->io
.lock
);
451 hammer_unref(&volume
->io
.lock
);
457 /************************************************************************
459 ************************************************************************
461 * Manage buffers. Currently all blockmap-backed zones are translated
462 * to zone-2 buffer offsets.
465 hammer_get_buffer(hammer_mount_t hmp
, hammer_off_t buf_offset
,
466 int bytes
, int isnew
, int *errorp
)
468 hammer_buffer_t buffer
;
469 hammer_volume_t volume
;
470 hammer_off_t zone2_offset
;
471 hammer_io_type_t iotype
;
475 buf_offset
&= ~HAMMER_BUFMASK64
;
478 * Shortcut if the buffer is already cached
480 buffer
= RB_LOOKUP(hammer_buf_rb_tree
, &hmp
->rb_bufs_root
, buf_offset
);
482 if (buffer
->io
.lock
.refs
== 0)
483 ++hammer_count_refedbufs
;
484 hammer_ref(&buffer
->io
.lock
);
487 * Onced refed the ondisk field will not be cleared by
490 if (buffer
->ondisk
&& buffer
->io
.loading
== 0) {
496 * The buffer is no longer loose if it has a ref, and
497 * cannot become loose once it gains a ref. Loose
498 * buffers will never be in a modified state. This should
499 * only occur on the 0->1 transition of refs.
501 * lose_list can be modified via a biodone() interrupt.
503 if (buffer
->io
.mod_list
== &hmp
->lose_list
) {
504 crit_enter(); /* biodone race against list */
505 TAILQ_REMOVE(buffer
->io
.mod_list
, &buffer
->io
,
508 buffer
->io
.mod_list
= NULL
;
509 KKASSERT(buffer
->io
.modified
== 0);
515 * What is the buffer class?
517 zone
= HAMMER_ZONE_DECODE(buf_offset
);
520 case HAMMER_ZONE_LARGE_DATA_INDEX
:
521 case HAMMER_ZONE_SMALL_DATA_INDEX
:
522 iotype
= HAMMER_STRUCTURE_DATA_BUFFER
;
524 case HAMMER_ZONE_UNDO_INDEX
:
525 iotype
= HAMMER_STRUCTURE_UNDO_BUFFER
;
527 case HAMMER_ZONE_META_INDEX
:
530 * NOTE: inode data and directory entries are placed in this
531 * zone. inode atime/mtime is updated in-place and thus
532 * buffers containing inodes must be synchronized as
533 * meta-buffers, same as buffers containing B-Tree info.
535 iotype
= HAMMER_STRUCTURE_META_BUFFER
;
540 * Handle blockmap offset translations
542 if (zone
>= HAMMER_ZONE_BTREE_INDEX
) {
543 zone2_offset
= hammer_blockmap_lookup(hmp
, buf_offset
, errorp
);
544 } else if (zone
== HAMMER_ZONE_UNDO_INDEX
) {
545 zone2_offset
= hammer_undo_lookup(hmp
, buf_offset
, errorp
);
547 KKASSERT(zone
== HAMMER_ZONE_RAW_BUFFER_INDEX
);
548 zone2_offset
= buf_offset
;
555 * NOTE: zone2_offset and maxbuf_off are both full zone-2 offset
558 KKASSERT((zone2_offset
& HAMMER_OFF_ZONE_MASK
) ==
559 HAMMER_ZONE_RAW_BUFFER
);
560 vol_no
= HAMMER_VOL_DECODE(zone2_offset
);
561 volume
= hammer_get_volume(hmp
, vol_no
, errorp
);
565 KKASSERT(zone2_offset
< volume
->maxbuf_off
);
568 * Allocate a new buffer structure. We will check for races later.
570 ++hammer_count_buffers
;
571 buffer
= kmalloc(sizeof(*buffer
), M_HAMMER
,
572 M_WAITOK
|M_ZERO
|M_USE_RESERVE
);
573 buffer
->zone2_offset
= zone2_offset
;
574 buffer
->zoneX_offset
= buf_offset
;
575 buffer
->volume
= volume
;
577 hammer_io_init(&buffer
->io
, hmp
, iotype
);
578 buffer
->io
.offset
= volume
->ondisk
->vol_buf_beg
+
579 (zone2_offset
& HAMMER_OFF_SHORT_MASK
);
580 buffer
->io
.bytes
= bytes
;
581 TAILQ_INIT(&buffer
->clist
);
582 hammer_ref(&buffer
->io
.lock
);
585 * Insert the buffer into the RB tree and handle late collisions.
587 if (RB_INSERT(hammer_buf_rb_tree
, &hmp
->rb_bufs_root
, buffer
)) {
588 hammer_unref(&buffer
->io
.lock
);
589 --hammer_count_buffers
;
590 kfree(buffer
, M_HAMMER
);
593 ++hammer_count_refedbufs
;
597 * Deal with on-disk info and loading races.
599 if (buffer
->ondisk
== NULL
|| buffer
->io
.loading
) {
600 *errorp
= hammer_load_buffer(buffer
, isnew
);
602 hammer_rel_buffer(buffer
, 1);
612 * Destroy all buffers covering the specified zoneX offset range. This
613 * is called when the related blockmap layer2 entry is freed or when
614 * a direct write bypasses our buffer/buffer-cache subsystem.
616 * The buffers may be referenced by the caller itself. Setting reclaim
617 * will cause the buffer to be destroyed when it's ref count reaches zero.
620 hammer_del_buffers(hammer_mount_t hmp
, hammer_off_t base_offset
,
621 hammer_off_t zone2_offset
, int bytes
)
623 hammer_buffer_t buffer
;
624 hammer_volume_t volume
;
628 vol_no
= HAMMER_VOL_DECODE(zone2_offset
);
629 volume
= hammer_get_volume(hmp
, vol_no
, &error
);
630 KKASSERT(error
== 0);
633 buffer
= RB_LOOKUP(hammer_buf_rb_tree
, &hmp
->rb_bufs_root
,
636 KKASSERT(buffer
->zone2_offset
== zone2_offset
);
637 hammer_io_clear_modify(&buffer
->io
, 1);
638 buffer
->io
.reclaim
= 1;
639 KKASSERT(buffer
->volume
== volume
);
640 if (buffer
->io
.lock
.refs
== 0)
641 hammer_unload_buffer(buffer
, NULL
);
643 hammer_io_inval(volume
, zone2_offset
);
645 base_offset
+= HAMMER_BUFSIZE
;
646 zone2_offset
+= HAMMER_BUFSIZE
;
647 bytes
-= HAMMER_BUFSIZE
;
649 hammer_rel_volume(volume
, 0);
653 hammer_load_buffer(hammer_buffer_t buffer
, int isnew
)
655 hammer_volume_t volume
;
659 * Load the buffer's on-disk info
661 volume
= buffer
->volume
;
662 ++buffer
->io
.loading
;
663 hammer_lock_ex(&buffer
->io
.lock
);
665 if (hammer_debug_io
& 0x0001) {
666 kprintf("load_buffer %016llx %016llx isnew=%d od=%p\n",
667 buffer
->zoneX_offset
, buffer
->zone2_offset
, isnew
,
671 if (buffer
->ondisk
== NULL
) {
673 error
= hammer_io_new(volume
->devvp
, &buffer
->io
);
675 error
= hammer_io_read(volume
->devvp
, &buffer
->io
,
679 buffer
->ondisk
= (void *)buffer
->io
.bp
->b_data
;
681 error
= hammer_io_new(volume
->devvp
, &buffer
->io
);
685 --buffer
->io
.loading
;
686 hammer_unlock(&buffer
->io
.lock
);
691 * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
694 hammer_unload_buffer(hammer_buffer_t buffer
, void *data __unused
)
696 ++hammer_count_refedbufs
;
697 hammer_ref(&buffer
->io
.lock
);
698 hammer_flush_buffer_nodes(buffer
);
699 KKASSERT(buffer
->io
.lock
.refs
== 1);
700 hammer_rel_buffer(buffer
, 2);
705 * Reference a buffer that is either already referenced or via a specially
706 * handled pointer (aka cursor->buffer).
709 hammer_ref_buffer(hammer_buffer_t buffer
)
713 if (buffer
->io
.lock
.refs
== 0)
714 ++hammer_count_refedbufs
;
715 hammer_ref(&buffer
->io
.lock
);
718 * At this point a biodone() will not touch the buffer other then
719 * incidental bits. However, lose_list can be modified via
720 * a biodone() interrupt.
724 if (buffer
->io
.mod_list
== &buffer
->io
.hmp
->lose_list
) {
726 TAILQ_REMOVE(buffer
->io
.mod_list
, &buffer
->io
, mod_entry
);
727 buffer
->io
.mod_list
= NULL
;
731 if (buffer
->ondisk
== NULL
|| buffer
->io
.loading
) {
732 error
= hammer_load_buffer(buffer
, 0);
734 hammer_rel_buffer(buffer
, 1);
736 * NOTE: buffer pointer can become stale after
747 * Release a buffer. We have to deal with several places where
748 * another thread can ref the buffer.
750 * Only destroy the structure itself if the related buffer cache buffer
751 * was disassociated from it. This ties the management of the structure
752 * to the buffer cache subsystem. buffer->ondisk determines whether the
753 * embedded io is referenced or not.
756 hammer_rel_buffer(hammer_buffer_t buffer
, int flush
)
758 hammer_volume_t volume
;
759 struct buf
*bp
= NULL
;
763 if (buffer
->io
.lock
.refs
== 1) {
764 ++buffer
->io
.loading
; /* force interlock check */
765 hammer_lock_ex(&buffer
->io
.lock
);
766 if (buffer
->io
.lock
.refs
== 1) {
767 bp
= hammer_io_release(&buffer
->io
, flush
);
769 if (buffer
->io
.lock
.refs
== 1)
770 --hammer_count_refedbufs
;
772 if (buffer
->io
.bp
== NULL
&&
773 buffer
->io
.lock
.refs
== 1) {
777 * NOTE: It is impossible for any associated
778 * B-Tree nodes to have refs if the buffer
779 * has no additional refs.
781 RB_REMOVE(hammer_buf_rb_tree
,
782 &buffer
->io
.hmp
->rb_bufs_root
,
784 volume
= buffer
->volume
;
785 buffer
->volume
= NULL
; /* sanity */
786 hammer_rel_volume(volume
, 0);
787 hammer_io_clear_modlist(&buffer
->io
);
788 hammer_flush_buffer_nodes(buffer
);
789 KKASSERT(TAILQ_EMPTY(&buffer
->clist
));
793 --buffer
->io
.loading
;
794 hammer_unlock(&buffer
->io
.lock
);
796 hammer_unref(&buffer
->io
.lock
);
801 --hammer_count_buffers
;
802 kfree(buffer
, M_HAMMER
);
807 * Access the filesystem buffer containing the specified hammer offset.
808 * buf_offset is a conglomeration of the volume number and vol_buf_beg
809 * relative buffer offset. It must also have bit 55 set to be valid.
810 * (see hammer_off_t in hammer_disk.h).
812 * Any prior buffer in *bufferp will be released and replaced by the
817 _hammer_bread(hammer_mount_t hmp
, hammer_off_t buf_offset
, int bytes
,
818 int *errorp
, struct hammer_buffer
**bufferp
)
820 hammer_buffer_t buffer
;
821 int32_t xoff
= (int32_t)buf_offset
& HAMMER_BUFMASK
;
823 buf_offset
&= ~HAMMER_BUFMASK64
;
824 KKASSERT((buf_offset
& HAMMER_OFF_ZONE_MASK
) != 0);
827 if (buffer
== NULL
|| (buffer
->zone2_offset
!= buf_offset
&&
828 buffer
->zoneX_offset
!= buf_offset
)) {
830 hammer_rel_buffer(buffer
, 0);
831 buffer
= hammer_get_buffer(hmp
, buf_offset
, bytes
, 0, errorp
);
838 * Return a pointer to the buffer data.
843 return((char *)buffer
->ondisk
+ xoff
);
847 hammer_bread(hammer_mount_t hmp
, hammer_off_t buf_offset
,
848 int *errorp
, struct hammer_buffer
**bufferp
)
850 return(_hammer_bread(hmp
, buf_offset
, HAMMER_BUFSIZE
, errorp
, bufferp
));
854 hammer_bread_ext(hammer_mount_t hmp
, hammer_off_t buf_offset
, int bytes
,
855 int *errorp
, struct hammer_buffer
**bufferp
)
857 bytes
= (bytes
+ HAMMER_BUFMASK
) & ~HAMMER_BUFMASK
;
858 return(_hammer_bread(hmp
, buf_offset
, bytes
, errorp
, bufferp
));
862 * Access the filesystem buffer containing the specified hammer offset.
863 * No disk read operation occurs. The result buffer may contain garbage.
865 * Any prior buffer in *bufferp will be released and replaced by the
868 * This function marks the buffer dirty but does not increment its
873 _hammer_bnew(hammer_mount_t hmp
, hammer_off_t buf_offset
, int bytes
,
874 int *errorp
, struct hammer_buffer
**bufferp
)
876 hammer_buffer_t buffer
;
877 int32_t xoff
= (int32_t)buf_offset
& HAMMER_BUFMASK
;
879 buf_offset
&= ~HAMMER_BUFMASK64
;
882 if (buffer
== NULL
|| (buffer
->zone2_offset
!= buf_offset
&&
883 buffer
->zoneX_offset
!= buf_offset
)) {
885 hammer_rel_buffer(buffer
, 0);
886 buffer
= hammer_get_buffer(hmp
, buf_offset
, bytes
, 1, errorp
);
893 * Return a pointer to the buffer data.
898 return((char *)buffer
->ondisk
+ xoff
);
902 hammer_bnew(hammer_mount_t hmp
, hammer_off_t buf_offset
,
903 int *errorp
, struct hammer_buffer
**bufferp
)
905 return(_hammer_bnew(hmp
, buf_offset
, HAMMER_BUFSIZE
, errorp
, bufferp
));
909 hammer_bnew_ext(hammer_mount_t hmp
, hammer_off_t buf_offset
, int bytes
,
910 int *errorp
, struct hammer_buffer
**bufferp
)
912 bytes
= (bytes
+ HAMMER_BUFMASK
) & ~HAMMER_BUFMASK
;
913 return(_hammer_bnew(hmp
, buf_offset
, bytes
, errorp
, bufferp
));
916 /************************************************************************
918 ************************************************************************
920 * Manage B-Tree nodes. B-Tree nodes represent the primary indexing
921 * method used by the HAMMER filesystem.
923 * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
924 * associated with its buffer, and will only referenced the buffer while
925 * the node itself is referenced.
927 * A hammer_node can also be passively associated with other HAMMER
928 * structures, such as inodes, while retaining 0 references. These
929 * associations can be cleared backwards using a pointer-to-pointer in
932 * This allows the HAMMER implementation to cache hammer_nodes long-term
933 * and short-cut a great deal of the infrastructure's complexity. In
934 * most cases a cached node can be reacquired without having to dip into
935 * either the buffer or cluster management code.
937 * The caller must pass a referenced cluster on call and will retain
938 * ownership of the reference on return. The node will acquire its own
939 * additional references, if necessary.
942 hammer_get_node(hammer_mount_t hmp
, hammer_off_t node_offset
,
943 int isnew
, int *errorp
)
947 KKASSERT((node_offset
& HAMMER_OFF_ZONE_MASK
) == HAMMER_ZONE_BTREE
);
950 * Locate the structure, allocating one if necessary.
953 node
= RB_LOOKUP(hammer_nod_rb_tree
, &hmp
->rb_nods_root
, node_offset
);
955 ++hammer_count_nodes
;
956 node
= kmalloc(sizeof(*node
), M_HAMMER
, M_WAITOK
|M_ZERO
|M_USE_RESERVE
);
957 node
->node_offset
= node_offset
;
959 TAILQ_INIT(&node
->cursor_list
);
960 TAILQ_INIT(&node
->cache_list
);
961 if (RB_INSERT(hammer_nod_rb_tree
, &hmp
->rb_nods_root
, node
)) {
962 --hammer_count_nodes
;
963 kfree(node
, M_HAMMER
);
967 hammer_ref(&node
->lock
);
971 *errorp
= hammer_load_node(node
, isnew
);
973 hammer_rel_node(node
);
980 * Reference an already-referenced node.
983 hammer_ref_node(hammer_node_t node
)
985 KKASSERT(node
->lock
.refs
> 0 && node
->ondisk
!= NULL
);
986 hammer_ref(&node
->lock
);
990 * Load a node's on-disk data reference.
993 hammer_load_node(hammer_node_t node
, int isnew
)
995 hammer_buffer_t buffer
;
996 hammer_off_t buf_offset
;
1001 hammer_lock_ex(&node
->lock
);
1002 if (node
->ondisk
== NULL
) {
1004 * This is a little confusing but the jist is that
1005 * node->buffer determines whether the node is on
1006 * the buffer's clist and node->ondisk determines
1007 * whether the buffer is referenced.
1009 * We could be racing a buffer release, in which case
1010 * node->buffer may become NULL while we are blocked
1011 * referencing the buffer.
1013 if ((buffer
= node
->buffer
) != NULL
) {
1014 error
= hammer_ref_buffer(buffer
);
1015 if (error
== 0 && node
->buffer
== NULL
) {
1016 TAILQ_INSERT_TAIL(&buffer
->clist
,
1018 node
->buffer
= buffer
;
1021 buf_offset
= node
->node_offset
& ~HAMMER_BUFMASK64
;
1022 buffer
= hammer_get_buffer(node
->hmp
, buf_offset
,
1023 HAMMER_BUFSIZE
, 0, &error
);
1025 KKASSERT(error
== 0);
1026 TAILQ_INSERT_TAIL(&buffer
->clist
,
1028 node
->buffer
= buffer
;
1033 node
->ondisk
= (void *)((char *)buffer
->ondisk
+
1034 (node
->node_offset
& HAMMER_BUFMASK
));
1036 (node
->flags
& HAMMER_NODE_CRCGOOD
) == 0) {
1037 if (hammer_crc_test_btree(node
->ondisk
) == 0)
1038 Debugger("CRC FAILED: B-TREE NODE");
1039 node
->flags
|= HAMMER_NODE_CRCGOOD
;
1044 hammer_unlock(&node
->lock
);
1049 * Safely reference a node, interlock against flushes via the IO subsystem.
1052 hammer_ref_node_safe(struct hammer_mount
*hmp
, hammer_node_cache_t cache
,
1059 hammer_ref(&node
->lock
);
1063 *errorp
= hammer_load_node(node
, 0);
1065 hammer_rel_node(node
);
1075 * Release a hammer_node. On the last release the node dereferences
1076 * its underlying buffer and may or may not be destroyed.
1079 hammer_rel_node(hammer_node_t node
)
1081 hammer_buffer_t buffer
;
1084 * If this isn't the last ref just decrement the ref count and
1087 if (node
->lock
.refs
> 1) {
1088 hammer_unref(&node
->lock
);
1093 * If there is no ondisk info or no buffer the node failed to load,
1094 * remove the last reference and destroy the node.
1096 if (node
->ondisk
== NULL
) {
1097 hammer_unref(&node
->lock
);
1098 hammer_flush_node(node
);
1099 /* node is stale now */
1104 * Do not disassociate the node from the buffer if it represents
1105 * a modified B-Tree node that still needs its crc to be generated.
1107 if (node
->flags
& HAMMER_NODE_NEEDSCRC
)
1111 * Do final cleanups and then either destroy the node and leave it
1112 * passively cached. The buffer reference is removed regardless.
1114 buffer
= node
->buffer
;
1115 node
->ondisk
= NULL
;
1117 if ((node
->flags
& HAMMER_NODE_FLUSH
) == 0) {
1118 hammer_unref(&node
->lock
);
1119 hammer_rel_buffer(buffer
, 0);
1126 hammer_unref(&node
->lock
);
1127 hammer_flush_node(node
);
1129 hammer_rel_buffer(buffer
, 0);
1133 * Free space on-media associated with a B-Tree node.
1136 hammer_delete_node(hammer_transaction_t trans
, hammer_node_t node
)
1138 KKASSERT((node
->flags
& HAMMER_NODE_DELETED
) == 0);
1139 node
->flags
|= HAMMER_NODE_DELETED
;
1140 hammer_blockmap_free(trans
, node
->node_offset
, sizeof(*node
->ondisk
));
1144 * Passively cache a referenced hammer_node. The caller may release
1145 * the node on return.
1148 hammer_cache_node(hammer_node_cache_t cache
, hammer_node_t node
)
1151 * If the node is being deleted, don't cache it!
1153 if (node
->flags
& HAMMER_NODE_DELETED
)
1155 if (cache
->node
== node
)
1158 hammer_uncache_node(cache
);
1159 if (node
->flags
& HAMMER_NODE_DELETED
)
1162 TAILQ_INSERT_TAIL(&node
->cache_list
, cache
, entry
);
1166 hammer_uncache_node(hammer_node_cache_t cache
)
1170 if ((node
= cache
->node
) != NULL
) {
1171 TAILQ_REMOVE(&node
->cache_list
, cache
, entry
);
1173 if (TAILQ_EMPTY(&node
->cache_list
))
1174 hammer_flush_node(node
);
1179 * Remove a node's cache references and destroy the node if it has no
1180 * other references or backing store.
1183 hammer_flush_node(hammer_node_t node
)
1185 hammer_node_cache_t cache
;
1186 hammer_buffer_t buffer
;
1188 while ((cache
= TAILQ_FIRST(&node
->cache_list
)) != NULL
) {
1189 TAILQ_REMOVE(&node
->cache_list
, cache
, entry
);
1192 if (node
->lock
.refs
== 0 && node
->ondisk
== NULL
) {
1193 KKASSERT((node
->flags
& HAMMER_NODE_NEEDSCRC
) == 0);
1194 RB_REMOVE(hammer_nod_rb_tree
, &node
->hmp
->rb_nods_root
, node
);
1195 if ((buffer
= node
->buffer
) != NULL
) {
1196 node
->buffer
= NULL
;
1197 TAILQ_REMOVE(&buffer
->clist
, node
, entry
);
1198 /* buffer is unreferenced because ondisk is NULL */
1200 --hammer_count_nodes
;
1201 kfree(node
, M_HAMMER
);
1206 * Flush passively cached B-Tree nodes associated with this buffer.
1207 * This is only called when the buffer is about to be destroyed, so
1208 * none of the nodes should have any references. The buffer is locked.
1210 * We may be interlocked with the buffer.
1213 hammer_flush_buffer_nodes(hammer_buffer_t buffer
)
1217 while ((node
= TAILQ_FIRST(&buffer
->clist
)) != NULL
) {
1218 KKASSERT(node
->ondisk
== NULL
);
1219 KKASSERT((node
->flags
& HAMMER_NODE_NEEDSCRC
) == 0);
1221 if (node
->lock
.refs
== 0) {
1222 hammer_ref(&node
->lock
);
1223 node
->flags
|= HAMMER_NODE_FLUSH
;
1224 hammer_rel_node(node
);
1226 KKASSERT(node
->loading
!= 0);
1227 KKASSERT(node
->buffer
!= NULL
);
1228 buffer
= node
->buffer
;
1229 node
->buffer
= NULL
;
1230 TAILQ_REMOVE(&buffer
->clist
, node
, entry
);
1231 /* buffer is unreferenced because ondisk is NULL */
1237 /************************************************************************
1239 ************************************************************************/
1242 * Allocate a B-Tree node.
1245 hammer_alloc_btree(hammer_transaction_t trans
, int *errorp
)
1247 hammer_buffer_t buffer
= NULL
;
1248 hammer_node_t node
= NULL
;
1249 hammer_off_t node_offset
;
1251 node_offset
= hammer_blockmap_alloc(trans
, HAMMER_ZONE_BTREE_INDEX
,
1252 sizeof(struct hammer_node_ondisk
),
1255 node
= hammer_get_node(trans
->hmp
, node_offset
, 1, errorp
);
1256 hammer_modify_node_noundo(trans
, node
);
1257 bzero(node
->ondisk
, sizeof(*node
->ondisk
));
1258 hammer_modify_node_done(node
);
1261 hammer_rel_buffer(buffer
, 0);
1266 * Allocate data. If the address of a data buffer is supplied then
1267 * any prior non-NULL *data_bufferp will be released and *data_bufferp
1268 * will be set to the related buffer. The caller must release it when
1269 * finally done. The initial *data_bufferp should be set to NULL by
1272 * The caller is responsible for making hammer_modify*() calls on the
1276 hammer_alloc_data(hammer_transaction_t trans
, int32_t data_len
,
1277 u_int16_t rec_type
, hammer_off_t
*data_offsetp
,
1278 struct hammer_buffer
**data_bufferp
, int *errorp
)
1288 case HAMMER_RECTYPE_INODE
:
1289 case HAMMER_RECTYPE_DIRENTRY
:
1290 case HAMMER_RECTYPE_EXT
:
1291 case HAMMER_RECTYPE_FIX
:
1292 case HAMMER_RECTYPE_PFS
:
1293 zone
= HAMMER_ZONE_META_INDEX
;
1295 case HAMMER_RECTYPE_DATA
:
1296 case HAMMER_RECTYPE_DB
:
1297 if (data_len
<= HAMMER_BUFSIZE
/ 2) {
1298 zone
= HAMMER_ZONE_SMALL_DATA_INDEX
;
1300 data_len
= (data_len
+ HAMMER_BUFMASK
) &
1302 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_ext(trans
->hmp
, *data_offsetp
,
1319 data_len
, errorp
, data_bufferp
);
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 * Filesystem sync. If doing a synchronous sync make a second pass on
1356 * the vnodes in case any were already flushing during the first pass,
1357 * and activate the flusher twice (the second time brings the UNDO FIFO's
1358 * start position up to the end position after the first call).
1361 hammer_sync_hmp(hammer_mount_t hmp
, int waitfor
)
1363 struct hammer_sync_info info
;
1366 info
.waitfor
= MNT_NOWAIT
;
1367 vmntvnodescan(hmp
->mp
, VMSC_GETVP
|VMSC_NOWAIT
,
1368 hammer_sync_scan1
, hammer_sync_scan2
, &info
);
1369 if (info
.error
== 0 && waitfor
== MNT_WAIT
) {
1370 info
.waitfor
= waitfor
;
1371 vmntvnodescan(hmp
->mp
, VMSC_GETVP
,
1372 hammer_sync_scan1
, hammer_sync_scan2
, &info
);
1374 if (waitfor
== MNT_WAIT
) {
1375 hammer_flusher_sync(hmp
);
1376 hammer_flusher_sync(hmp
);
1378 hammer_flusher_async(hmp
);
1384 hammer_sync_scan1(struct mount
*mp
, struct vnode
*vp
, void *data
)
1386 struct hammer_inode
*ip
;
1389 if (vp
->v_type
== VNON
|| ip
== NULL
||
1390 ((ip
->flags
& HAMMER_INODE_MODMASK
) == 0 &&
1391 RB_EMPTY(&vp
->v_rbdirty_tree
))) {
1398 hammer_sync_scan2(struct mount
*mp
, struct vnode
*vp
, void *data
)
1400 struct hammer_sync_info
*info
= data
;
1401 struct hammer_inode
*ip
;
1405 if (vp
->v_type
== VNON
|| vp
->v_type
== VBAD
||
1406 ((ip
->flags
& HAMMER_INODE_MODMASK
) == 0 &&
1407 RB_EMPTY(&vp
->v_rbdirty_tree
))) {
1410 error
= VOP_FSYNC(vp
, info
->waitfor
);
1412 info
->error
= error
;