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 1.76 2008/08/29 20:19:08 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_transaction_t trans,
52 hammer_node_t node, int isnew);
55 hammer_vol_rb_compare(hammer_volume_t vol1, hammer_volume_t vol2)
57 if (vol1->vol_no < vol2->vol_no)
59 if (vol1->vol_no > vol2->vol_no)
65 * hammer_buffer structures are indexed via their zoneX_offset, not
69 hammer_buf_rb_compare(hammer_buffer_t buf1, hammer_buffer_t buf2)
71 if (buf1->zoneX_offset < buf2->zoneX_offset)
73 if (buf1->zoneX_offset > buf2->zoneX_offset)
79 hammer_nod_rb_compare(hammer_node_t node1, hammer_node_t node2)
81 if (node1->node_offset < node2->node_offset)
83 if (node1->node_offset > node2->node_offset)
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);
95 /************************************************************************
97 ************************************************************************
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.
103 * Calls made to hammer_load_volume() or single-threaded
106 hammer_install_volume(struct hammer_mount *hmp, const char *volname,
110 hammer_volume_t volume;
111 struct hammer_volume_ondisk *ondisk;
112 struct nlookupdata nd;
113 struct buf *bp = NULL;
119 ronly = ((mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
122 * Allocate a volume structure
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;
133 * Get the device vnode
136 error = nlookup_init(&nd, volume->vol_name, UIO_SYSSPACE, NLC_FOLLOW);
138 error = nlookup(&nd);
140 error = cache_vref(&nd.nl_nch, nd.nl_cred, &volume->devvp);
144 volume->devvp = devvp;
148 if (vn_isdisk(volume->devvp, &error)) {
149 error = vfs_mountedon(volume->devvp);
152 if (error == 0 && vcount(volume->devvp) > 0)
155 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
156 error = vinvalbuf(volume->devvp, V_SAVE, 0, 0);
158 error = VOP_OPEN(volume->devvp,
159 (ronly ? FREAD : FREAD|FWRITE),
162 vn_unlock(volume->devvp);
165 hammer_free_volume(volume);
168 volume->devvp->v_rdev->si_mountpoint = mp;
172 * Extract the volume number from the volume header and do various
175 error = bread(volume->devvp, 0LL, HAMMER_BUFSIZE, &bp);
178 ondisk = (void *)bp->b_data;
179 if (ondisk->vol_signature != HAMMER_FSBUF_VOLUME) {
180 kprintf("hammer_mount: volume %s has an invalid header\n",
185 volume->vol_no = ondisk->vol_no;
186 volume->buffer_base = ondisk->vol_buf_beg;
187 volume->vol_flags = ondisk->vol_flags;
188 volume->nblocks = ondisk->vol_nblocks;
189 volume->maxbuf_off = HAMMER_ENCODE_RAW_BUFFER(volume->vol_no,
190 ondisk->vol_buf_end - ondisk->vol_buf_beg);
191 volume->maxraw_off = ondisk->vol_buf_end;
193 if (RB_EMPTY(&hmp->rb_vols_root)) {
194 hmp->fsid = ondisk->vol_fsid;
195 } else if (bcmp(&hmp->fsid, &ondisk->vol_fsid, sizeof(uuid_t))) {
196 kprintf("hammer_mount: volume %s's fsid does not match "
197 "other volumes\n", volume->vol_name);
203 * Insert the volume structure into the red-black tree.
205 if (RB_INSERT(hammer_vol_rb_tree, &hmp->rb_vols_root, volume)) {
206 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n",
207 volume->vol_name, volume->vol_no);
212 * Set the root volume . HAMMER special cases rootvol the structure.
213 * We do not hold a ref because this would prevent related I/O
214 * from being flushed.
216 if (error == 0 && ondisk->vol_rootvol == ondisk->vol_no) {
217 hmp->rootvol = volume;
218 hmp->nvolumes = ondisk->vol_count;
223 hmp->mp->mnt_stat.f_blocks += ondisk->vol0_stat_bigblocks *
224 (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
225 hmp->mp->mnt_vstat.f_blocks += ondisk->vol0_stat_bigblocks *
226 (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
232 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/
234 volume->devvp->v_rdev->si_mountpoint = NULL;
235 VOP_CLOSE(volume->devvp, ronly ? FREAD : FREAD|FWRITE);
236 hammer_free_volume(volume);
242 * This is called for each volume when updating the mount point from
243 * read-write to read-only or vise-versa.
246 hammer_adjust_volume_mode(hammer_volume_t volume, void *data __unused)
249 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
250 if (volume->io.hmp->ronly) {
251 /* do not call vinvalbuf */
252 VOP_OPEN(volume->devvp, FREAD, FSCRED, NULL);
253 VOP_CLOSE(volume->devvp, FREAD|FWRITE);
255 /* do not call vinvalbuf */
256 VOP_OPEN(volume->devvp, FREAD|FWRITE, FSCRED, NULL);
257 VOP_CLOSE(volume->devvp, FREAD);
259 vn_unlock(volume->devvp);
265 * Unload and free a HAMMER volume. Must return >= 0 to continue scan
266 * so returns -1 on failure.
269 hammer_unload_volume(hammer_volume_t volume, void *data __unused)
271 hammer_mount_t hmp = volume->io.hmp;
272 int ronly = ((hmp->mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
275 * Clean up the root volume pointer, which is held unlocked in hmp.
277 if (hmp->rootvol == volume)
281 * We must not flush a dirty buffer to disk on umount. It should
282 * have already been dealt with by the flusher, or we may be in
283 * catastrophic failure.
285 hammer_io_clear_modify(&volume->io, 1);
286 volume->io.waitdep = 1;
289 * Clean up the persistent ref ioerror might have on the volume
291 if (volume->io.ioerror) {
292 volume->io.ioerror = 0;
293 hammer_unref(&volume->io.lock);
297 * This should release the bp.
299 KKASSERT(volume->io.lock.refs == 0);
300 hammer_ref(&volume->io.lock);
301 hammer_rel_volume(volume, 1);
302 KKASSERT(volume->io.bp == NULL);
305 * There should be no references on the volume, no clusters, and
308 KKASSERT(volume->io.lock.refs == 0);
310 volume->ondisk = NULL;
312 if (volume->devvp->v_rdev &&
313 volume->devvp->v_rdev->si_mountpoint == hmp->mp
315 volume->devvp->v_rdev->si_mountpoint = NULL;
319 * Make sure we don't sync anything to disk if we
320 * are in read-only mode (1) or critically-errored
321 * (2). Note that there may be dirty buffers in
322 * normal read-only mode from crash recovery.
324 vinvalbuf(volume->devvp, 0, 0, 0);
325 VOP_CLOSE(volume->devvp, FREAD);
328 * Normal termination, save any dirty buffers
329 * (XXX there really shouldn't be any).
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 hammer_mount_t hmp = volume->io.hmp;
350 if (volume->vol_name) {
351 kfree(volume->vol_name, hmp->m_misc);
352 volume->vol_name = NULL;
355 vrele(volume->devvp);
356 volume->devvp = NULL;
358 --hammer_count_volumes;
359 kfree(volume, hmp->m_misc);
363 * Get a HAMMER volume. The volume must already exist.
366 hammer_get_volume(struct hammer_mount *hmp, int32_t vol_no, int *errorp)
368 struct hammer_volume *volume;
371 * Locate the volume structure
373 volume = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, vol_no);
374 if (volume == NULL) {
378 hammer_ref(&volume->io.lock);
381 * Deal with on-disk info
383 if (volume->ondisk == NULL || volume->io.loading) {
384 *errorp = hammer_load_volume(volume);
386 hammer_rel_volume(volume, 1);
396 hammer_ref_volume(hammer_volume_t volume)
400 hammer_ref(&volume->io.lock);
403 * Deal with on-disk info
405 if (volume->ondisk == NULL || volume->io.loading) {
406 error = hammer_load_volume(volume);
408 hammer_rel_volume(volume, 1);
416 hammer_get_root_volume(struct hammer_mount *hmp, int *errorp)
418 hammer_volume_t volume;
420 volume = hmp->rootvol;
421 KKASSERT(volume != NULL);
422 hammer_ref(&volume->io.lock);
425 * Deal with on-disk info
427 if (volume->ondisk == NULL || volume->io.loading) {
428 *errorp = hammer_load_volume(volume);
430 hammer_rel_volume(volume, 1);
440 * Load a volume's on-disk information. The volume must be referenced and
441 * not locked. We temporarily acquire an exclusive lock to interlock
442 * against releases or multiple get's.
445 hammer_load_volume(hammer_volume_t volume)
449 ++volume->io.loading;
450 hammer_lock_ex(&volume->io.lock);
452 if (volume->ondisk == NULL) {
453 error = hammer_io_read(volume->devvp, &volume->io,
456 volume->ondisk = (void *)volume->io.bp->b_data;
460 --volume->io.loading;
461 hammer_unlock(&volume->io.lock);
466 * Release a volume. Call hammer_io_release on the last reference. We have
467 * to acquire an exclusive lock to interlock against volume->ondisk tests
468 * in hammer_load_volume(), and hammer_io_release() also expects an exclusive
471 * Volumes are not unloaded from memory during normal operation.
474 hammer_rel_volume(hammer_volume_t volume, int flush)
476 struct buf *bp = NULL;
479 if (volume->io.lock.refs == 1) {
480 ++volume->io.loading;
481 hammer_lock_ex(&volume->io.lock);
482 if (volume->io.lock.refs == 1) {
483 volume->ondisk = NULL;
484 bp = hammer_io_release(&volume->io, flush);
486 --volume->io.loading;
487 hammer_unlock(&volume->io.lock);
489 hammer_unref(&volume->io.lock);
496 hammer_mountcheck_volumes(struct hammer_mount *hmp)
501 for (i = 0; i < hmp->nvolumes; ++i) {
502 vol = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, i);
509 /************************************************************************
511 ************************************************************************
513 * Manage buffers. Currently most blockmap-backed zones are direct-mapped
514 * to zone-2 buffer offsets, without a translation stage. However, the
515 * hammer_buffer structure is indexed by its zoneX_offset, not its
518 * The proper zone must be maintained throughout the code-base all the way
519 * through to the big-block allocator, or routines like hammer_del_buffers()
520 * will not be able to locate all potentially conflicting buffers.
523 hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset,
524 int bytes, int isnew, int *errorp)
526 hammer_buffer_t buffer;
527 hammer_volume_t volume;
528 hammer_off_t zone2_offset;
529 hammer_io_type_t iotype;
533 buf_offset &= ~HAMMER_BUFMASK64;
536 * Shortcut if the buffer is already cached
538 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, buf_offset);
540 if (buffer->io.lock.refs == 0)
541 ++hammer_count_refedbufs;
542 hammer_ref(&buffer->io.lock);
545 * Once refed the ondisk field will not be cleared by
548 if (buffer->ondisk && buffer->io.loading == 0) {
550 hammer_io_advance(&buffer->io);
555 * The buffer is no longer loose if it has a ref, and
556 * cannot become loose once it gains a ref. Loose
557 * buffers will never be in a modified state. This should
558 * only occur on the 0->1 transition of refs.
560 * lose_list can be modified via a biodone() interrupt.
562 if (buffer->io.mod_list == &hmp->lose_list) {
563 crit_enter(); /* biodone race against list */
564 TAILQ_REMOVE(buffer->io.mod_list, &buffer->io,
567 buffer->io.mod_list = NULL;
568 KKASSERT(buffer->io.modified == 0);
574 * What is the buffer class?
576 zone = HAMMER_ZONE_DECODE(buf_offset);
579 case HAMMER_ZONE_LARGE_DATA_INDEX:
580 case HAMMER_ZONE_SMALL_DATA_INDEX:
581 iotype = HAMMER_STRUCTURE_DATA_BUFFER;
583 case HAMMER_ZONE_UNDO_INDEX:
584 iotype = HAMMER_STRUCTURE_UNDO_BUFFER;
586 case HAMMER_ZONE_META_INDEX:
589 * NOTE: inode data and directory entries are placed in this
590 * zone. inode atime/mtime is updated in-place and thus
591 * buffers containing inodes must be synchronized as
592 * meta-buffers, same as buffers containing B-Tree info.
594 iotype = HAMMER_STRUCTURE_META_BUFFER;
599 * Handle blockmap offset translations
601 if (zone >= HAMMER_ZONE_BTREE_INDEX) {
602 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, errorp);
603 } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
604 zone2_offset = hammer_undo_lookup(hmp, buf_offset, errorp);
606 KKASSERT(zone == HAMMER_ZONE_RAW_BUFFER_INDEX);
607 zone2_offset = buf_offset;
614 * NOTE: zone2_offset and maxbuf_off are both full zone-2 offset
617 KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) ==
618 HAMMER_ZONE_RAW_BUFFER);
619 vol_no = HAMMER_VOL_DECODE(zone2_offset);
620 volume = hammer_get_volume(hmp, vol_no, errorp);
624 KKASSERT(zone2_offset < volume->maxbuf_off);
627 * Allocate a new buffer structure. We will check for races later.
629 ++hammer_count_buffers;
630 buffer = kmalloc(sizeof(*buffer), hmp->m_misc,
631 M_WAITOK|M_ZERO|M_USE_RESERVE);
632 buffer->zone2_offset = zone2_offset;
633 buffer->zoneX_offset = buf_offset;
635 hammer_io_init(&buffer->io, volume, iotype);
636 buffer->io.offset = volume->ondisk->vol_buf_beg +
637 (zone2_offset & HAMMER_OFF_SHORT_MASK);
638 buffer->io.bytes = bytes;
639 TAILQ_INIT(&buffer->clist);
640 hammer_ref(&buffer->io.lock);
643 * Insert the buffer into the RB tree and handle late collisions.
645 if (RB_INSERT(hammer_buf_rb_tree, &hmp->rb_bufs_root, buffer)) {
646 hammer_rel_volume(volume, 0);
647 buffer->io.volume = NULL; /* safety */
648 hammer_unref(&buffer->io.lock); /* safety */
649 --hammer_count_buffers;
650 kfree(buffer, hmp->m_misc);
653 ++hammer_count_refedbufs;
657 * Deal with on-disk info and loading races.
659 if (buffer->ondisk == NULL || buffer->io.loading) {
660 *errorp = hammer_load_buffer(buffer, isnew);
662 hammer_rel_buffer(buffer, 1);
665 hammer_io_advance(&buffer->io);
669 hammer_io_advance(&buffer->io);
675 * This is used by the direct-read code to deal with large-data buffers
676 * created by the reblocker and mirror-write code. The direct-read code
677 * bypasses the HAMMER buffer subsystem and so any aliased dirty or write-
678 * running hammer buffers must be fully synced to disk before we can issue
681 * This code path is not considered critical as only the rebocker and
682 * mirror-write code will create large-data buffers via the HAMMER buffer
683 * subsystem. They do that because they operate at the B-Tree level and
684 * do not access the vnode/inode structures.
687 hammer_sync_buffers(hammer_mount_t hmp, hammer_off_t base_offset, int bytes)
689 hammer_buffer_t buffer;
692 KKASSERT((base_offset & HAMMER_OFF_ZONE_MASK) ==
693 HAMMER_ZONE_LARGE_DATA);
696 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
698 if (buffer && (buffer->io.modified || buffer->io.running)) {
699 error = hammer_ref_buffer(buffer);
701 hammer_io_wait(&buffer->io);
702 if (buffer->io.modified) {
703 hammer_io_write_interlock(&buffer->io);
704 hammer_io_flush(&buffer->io, 0);
705 hammer_io_done_interlock(&buffer->io);
706 hammer_io_wait(&buffer->io);
708 hammer_rel_buffer(buffer, 0);
711 base_offset += HAMMER_BUFSIZE;
712 bytes -= HAMMER_BUFSIZE;
717 * Destroy all buffers covering the specified zoneX offset range. This
718 * is called when the related blockmap layer2 entry is freed or when
719 * a direct write bypasses our buffer/buffer-cache subsystem.
721 * The buffers may be referenced by the caller itself. Setting reclaim
722 * will cause the buffer to be destroyed when it's ref count reaches zero.
724 * Return 0 on success, EAGAIN if some buffers could not be destroyed due
725 * to additional references held by other threads, or some other (typically
729 hammer_del_buffers(hammer_mount_t hmp, hammer_off_t base_offset,
730 hammer_off_t zone2_offset, int bytes,
731 int report_conflicts)
733 hammer_buffer_t buffer;
734 hammer_volume_t volume;
739 vol_no = HAMMER_VOL_DECODE(zone2_offset);
740 volume = hammer_get_volume(hmp, vol_no, &ret_error);
741 KKASSERT(ret_error == 0);
744 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
747 error = hammer_ref_buffer(buffer);
748 if (error == 0 && buffer->io.lock.refs != 1) {
750 hammer_rel_buffer(buffer, 0);
753 KKASSERT(buffer->zone2_offset == zone2_offset);
754 hammer_io_clear_modify(&buffer->io, 1);
755 buffer->io.reclaim = 1;
756 buffer->io.waitdep = 1;
757 KKASSERT(buffer->io.volume == volume);
758 hammer_rel_buffer(buffer, 0);
761 error = hammer_io_inval(volume, zone2_offset);
765 if (report_conflicts ||
766 (hammer_debug_general & 0x8000)) {
767 kprintf("hammer_del_buffers: unable to "
768 "invalidate %016llx buffer=%p rep=%d\n",
769 (long long)base_offset,
770 buffer, report_conflicts);
773 base_offset += HAMMER_BUFSIZE;
774 zone2_offset += HAMMER_BUFSIZE;
775 bytes -= HAMMER_BUFSIZE;
777 hammer_rel_volume(volume, 0);
782 hammer_load_buffer(hammer_buffer_t buffer, int isnew)
784 hammer_volume_t volume;
788 * Load the buffer's on-disk info
790 volume = buffer->io.volume;
791 ++buffer->io.loading;
792 hammer_lock_ex(&buffer->io.lock);
794 if (hammer_debug_io & 0x0001) {
795 kprintf("load_buffer %016llx %016llx isnew=%d od=%p\n",
796 (long long)buffer->zoneX_offset,
797 (long long)buffer->zone2_offset,
798 isnew, buffer->ondisk);
801 if (buffer->ondisk == NULL) {
803 error = hammer_io_new(volume->devvp, &buffer->io);
805 error = hammer_io_read(volume->devvp, &buffer->io,
809 buffer->ondisk = (void *)buffer->io.bp->b_data;
811 error = hammer_io_new(volume->devvp, &buffer->io);
815 --buffer->io.loading;
816 hammer_unlock(&buffer->io.lock);
821 * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
822 * This routine is only called during unmount or when a volume is
825 * If data != NULL, it specifies a volume whoose buffers should
829 hammer_unload_buffer(hammer_buffer_t buffer, void *data)
831 struct hammer_volume *volume = (struct hammer_volume *) data;
833 if (volume != NULL && volume != buffer->io.volume) {
835 * We are only interested in unloading buffers of volume,
842 * Clean up the persistent ref ioerror might have on the buffer
843 * and acquire a ref (steal ioerror's if we can).
845 if (buffer->io.ioerror) {
846 buffer->io.ioerror = 0;
848 if (buffer->io.lock.refs == 0)
849 ++hammer_count_refedbufs;
850 hammer_ref(&buffer->io.lock);
854 * We must not flush a dirty buffer to disk on umount. It should
855 * have already been dealt with by the flusher, or we may be in
856 * catastrophic failure.
858 * We must set waitdep to ensure that a running buffer is waited
859 * on and released prior to us trying to unload the volume.
861 hammer_io_clear_modify(&buffer->io, 1);
862 hammer_flush_buffer_nodes(buffer);
863 KKASSERT(buffer->io.lock.refs == 1);
864 buffer->io.waitdep = 1;
865 hammer_rel_buffer(buffer, 2);
870 * Reference a buffer that is either already referenced or via a specially
871 * handled pointer (aka cursor->buffer).
874 hammer_ref_buffer(hammer_buffer_t buffer)
878 if (buffer->io.lock.refs == 0)
879 ++hammer_count_refedbufs;
880 hammer_ref(&buffer->io.lock);
883 * At this point a biodone() will not touch the buffer other then
884 * incidental bits. However, lose_list can be modified via
885 * a biodone() interrupt.
889 if (buffer->io.mod_list == &buffer->io.hmp->lose_list) {
891 TAILQ_REMOVE(buffer->io.mod_list, &buffer->io, mod_entry);
892 buffer->io.mod_list = NULL;
896 if (buffer->ondisk == NULL || buffer->io.loading) {
897 error = hammer_load_buffer(buffer, 0);
899 hammer_rel_buffer(buffer, 1);
901 * NOTE: buffer pointer can become stale after
912 * Release a buffer. We have to deal with several places where
913 * another thread can ref the buffer.
915 * Only destroy the structure itself if the related buffer cache buffer
916 * was disassociated from it. This ties the management of the structure
917 * to the buffer cache subsystem. buffer->ondisk determines whether the
918 * embedded io is referenced or not.
921 hammer_rel_buffer(hammer_buffer_t buffer, int flush)
923 hammer_volume_t volume;
925 struct buf *bp = NULL;
928 hmp = buffer->io.hmp;
931 if (buffer->io.lock.refs == 1) {
932 ++buffer->io.loading; /* force interlock check */
933 hammer_lock_ex(&buffer->io.lock);
934 if (buffer->io.lock.refs == 1) {
935 bp = hammer_io_release(&buffer->io, flush);
937 if (buffer->io.lock.refs == 1)
938 --hammer_count_refedbufs;
940 if (buffer->io.bp == NULL &&
941 buffer->io.lock.refs == 1) {
945 * NOTE: It is impossible for any associated
946 * B-Tree nodes to have refs if the buffer
947 * has no additional refs.
949 RB_REMOVE(hammer_buf_rb_tree,
950 &buffer->io.hmp->rb_bufs_root,
952 volume = buffer->io.volume;
953 buffer->io.volume = NULL; /* sanity */
954 hammer_rel_volume(volume, 0);
955 hammer_io_clear_modlist(&buffer->io);
956 hammer_flush_buffer_nodes(buffer);
957 KKASSERT(TAILQ_EMPTY(&buffer->clist));
961 --buffer->io.loading;
962 hammer_unlock(&buffer->io.lock);
964 hammer_unref(&buffer->io.lock);
969 --hammer_count_buffers;
970 kfree(buffer, hmp->m_misc);
975 * Access the filesystem buffer containing the specified hammer offset.
976 * buf_offset is a conglomeration of the volume number and vol_buf_beg
977 * relative buffer offset. It must also have bit 55 set to be valid.
978 * (see hammer_off_t in hammer_disk.h).
980 * Any prior buffer in *bufferp will be released and replaced by the
983 * NOTE: The buffer is indexed via its zoneX_offset but we allow the
984 * passed cached *bufferp to match against either zoneX or zone2.
988 _hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
989 int *errorp, struct hammer_buffer **bufferp)
991 hammer_buffer_t buffer;
992 int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
994 buf_offset &= ~HAMMER_BUFMASK64;
995 KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) != 0);
998 if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
999 buffer->zoneX_offset != buf_offset)) {
1001 hammer_rel_buffer(buffer, 0);
1002 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 0, errorp);
1009 * Return a pointer to the buffer data.
1014 return((char *)buffer->ondisk + xoff);
1018 hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset,
1019 int *errorp, struct hammer_buffer **bufferp)
1021 return(_hammer_bread(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp));
1025 hammer_bread_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1026 int *errorp, struct hammer_buffer **bufferp)
1028 bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK;
1029 return(_hammer_bread(hmp, buf_offset, bytes, errorp, bufferp));
1033 * Access the filesystem buffer containing the specified hammer offset.
1034 * No disk read operation occurs. The result buffer may contain garbage.
1036 * Any prior buffer in *bufferp will be released and replaced by the
1039 * This function marks the buffer dirty but does not increment its
1040 * modify_refs count.
1044 _hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1045 int *errorp, struct hammer_buffer **bufferp)
1047 hammer_buffer_t buffer;
1048 int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
1050 buf_offset &= ~HAMMER_BUFMASK64;
1053 if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
1054 buffer->zoneX_offset != buf_offset)) {
1056 hammer_rel_buffer(buffer, 0);
1057 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 1, errorp);
1064 * Return a pointer to the buffer data.
1069 return((char *)buffer->ondisk + xoff);
1073 hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset,
1074 int *errorp, struct hammer_buffer **bufferp)
1076 return(_hammer_bnew(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp));
1080 hammer_bnew_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1081 int *errorp, struct hammer_buffer **bufferp)
1083 bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK;
1084 return(_hammer_bnew(hmp, buf_offset, bytes, errorp, bufferp));
1087 /************************************************************************
1089 ************************************************************************
1091 * Manage B-Tree nodes. B-Tree nodes represent the primary indexing
1092 * method used by the HAMMER filesystem.
1094 * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
1095 * associated with its buffer, and will only referenced the buffer while
1096 * the node itself is referenced.
1098 * A hammer_node can also be passively associated with other HAMMER
1099 * structures, such as inodes, while retaining 0 references. These
1100 * associations can be cleared backwards using a pointer-to-pointer in
1103 * This allows the HAMMER implementation to cache hammer_nodes long-term
1104 * and short-cut a great deal of the infrastructure's complexity. In
1105 * most cases a cached node can be reacquired without having to dip into
1106 * either the buffer or cluster management code.
1108 * The caller must pass a referenced cluster on call and will retain
1109 * ownership of the reference on return. The node will acquire its own
1110 * additional references, if necessary.
1113 hammer_get_node(hammer_transaction_t trans, hammer_off_t node_offset,
1114 int isnew, int *errorp)
1116 hammer_mount_t hmp = trans->hmp;
1119 KKASSERT((node_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_BTREE);
1122 * Locate the structure, allocating one if necessary.
1125 node = RB_LOOKUP(hammer_nod_rb_tree, &hmp->rb_nods_root, node_offset);
1127 ++hammer_count_nodes;
1128 node = kmalloc(sizeof(*node), hmp->m_misc, M_WAITOK|M_ZERO|M_USE_RESERVE);
1129 node->node_offset = node_offset;
1131 TAILQ_INIT(&node->cursor_list);
1132 TAILQ_INIT(&node->cache_list);
1133 if (RB_INSERT(hammer_nod_rb_tree, &hmp->rb_nods_root, node)) {
1134 --hammer_count_nodes;
1135 kfree(node, hmp->m_misc);
1139 hammer_ref(&node->lock);
1142 hammer_io_advance(&node->buffer->io);
1144 *errorp = hammer_load_node(trans, node, isnew);
1145 trans->flags |= HAMMER_TRANSF_DIDIO;
1148 hammer_rel_node(node);
1155 * Reference an already-referenced node.
1158 hammer_ref_node(hammer_node_t node)
1160 KKASSERT(node->lock.refs > 0 && node->ondisk != NULL);
1161 hammer_ref(&node->lock);
1165 * Load a node's on-disk data reference.
1168 hammer_load_node(hammer_transaction_t trans, hammer_node_t node, int isnew)
1170 hammer_buffer_t buffer;
1171 hammer_off_t buf_offset;
1176 hammer_lock_ex(&node->lock);
1177 if (node->ondisk == NULL) {
1179 * This is a little confusing but the jist is that
1180 * node->buffer determines whether the node is on
1181 * the buffer's clist and node->ondisk determines
1182 * whether the buffer is referenced.
1184 * We could be racing a buffer release, in which case
1185 * node->buffer may become NULL while we are blocked
1186 * referencing the buffer.
1188 if ((buffer = node->buffer) != NULL) {
1189 error = hammer_ref_buffer(buffer);
1190 if (error == 0 && node->buffer == NULL) {
1191 TAILQ_INSERT_TAIL(&buffer->clist,
1193 node->buffer = buffer;
1196 buf_offset = node->node_offset & ~HAMMER_BUFMASK64;
1197 buffer = hammer_get_buffer(node->hmp, buf_offset,
1198 HAMMER_BUFSIZE, 0, &error);
1200 KKASSERT(error == 0);
1201 TAILQ_INSERT_TAIL(&buffer->clist,
1203 node->buffer = buffer;
1208 node->ondisk = (void *)((char *)buffer->ondisk +
1209 (node->node_offset & HAMMER_BUFMASK));
1212 * Check CRC. NOTE: Neither flag is set and the CRC is not
1213 * generated on new B-Tree nodes.
1216 (node->flags & HAMMER_NODE_CRCANY) == 0) {
1217 if (hammer_crc_test_btree(node->ondisk) == 0) {
1218 if (hammer_debug_critical)
1219 Debugger("CRC FAILED: B-TREE NODE");
1220 node->flags |= HAMMER_NODE_CRCBAD;
1222 node->flags |= HAMMER_NODE_CRCGOOD;
1226 if (node->flags & HAMMER_NODE_CRCBAD) {
1227 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1234 hammer_unlock(&node->lock);
1239 * Safely reference a node, interlock against flushes via the IO subsystem.
1242 hammer_ref_node_safe(hammer_transaction_t trans, hammer_node_cache_t cache,
1249 hammer_ref(&node->lock);
1251 if (node->flags & HAMMER_NODE_CRCBAD) {
1252 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1260 *errorp = hammer_load_node(trans, node, 0);
1263 hammer_rel_node(node);
1273 * Release a hammer_node. On the last release the node dereferences
1274 * its underlying buffer and may or may not be destroyed.
1277 hammer_rel_node(hammer_node_t node)
1279 hammer_buffer_t buffer;
1282 * If this isn't the last ref just decrement the ref count and
1285 if (node->lock.refs > 1) {
1286 hammer_unref(&node->lock);
1291 * If there is no ondisk info or no buffer the node failed to load,
1292 * remove the last reference and destroy the node.
1294 if (node->ondisk == NULL) {
1295 hammer_unref(&node->lock);
1296 hammer_flush_node(node);
1297 /* node is stale now */
1302 * Do not disassociate the node from the buffer if it represents
1303 * a modified B-Tree node that still needs its crc to be generated.
1305 if (node->flags & HAMMER_NODE_NEEDSCRC)
1309 * Do final cleanups and then either destroy the node and leave it
1310 * passively cached. The buffer reference is removed regardless.
1312 buffer = node->buffer;
1313 node->ondisk = NULL;
1315 if ((node->flags & HAMMER_NODE_FLUSH) == 0) {
1316 hammer_unref(&node->lock);
1317 hammer_rel_buffer(buffer, 0);
1324 hammer_unref(&node->lock);
1325 hammer_flush_node(node);
1327 hammer_rel_buffer(buffer, 0);
1331 * Free space on-media associated with a B-Tree node.
1334 hammer_delete_node(hammer_transaction_t trans, hammer_node_t node)
1336 KKASSERT((node->flags & HAMMER_NODE_DELETED) == 0);
1337 node->flags |= HAMMER_NODE_DELETED;
1338 hammer_blockmap_free(trans, node->node_offset, sizeof(*node->ondisk));
1342 * Passively cache a referenced hammer_node. The caller may release
1343 * the node on return.
1346 hammer_cache_node(hammer_node_cache_t cache, hammer_node_t node)
1349 * If the node doesn't exist, or is being deleted, don't cache it!
1351 * The node can only ever be NULL in the I/O failure path.
1353 if (node == NULL || (node->flags & HAMMER_NODE_DELETED))
1355 if (cache->node == node)
1358 hammer_uncache_node(cache);
1359 if (node->flags & HAMMER_NODE_DELETED)
1362 TAILQ_INSERT_TAIL(&node->cache_list, cache, entry);
1366 hammer_uncache_node(hammer_node_cache_t cache)
1370 if ((node = cache->node) != NULL) {
1371 TAILQ_REMOVE(&node->cache_list, cache, entry);
1373 if (TAILQ_EMPTY(&node->cache_list))
1374 hammer_flush_node(node);
1379 * Remove a node's cache references and destroy the node if it has no
1380 * other references or backing store.
1383 hammer_flush_node(hammer_node_t node)
1385 hammer_node_cache_t cache;
1386 hammer_buffer_t buffer;
1387 hammer_mount_t hmp = node->hmp;
1389 while ((cache = TAILQ_FIRST(&node->cache_list)) != NULL) {
1390 TAILQ_REMOVE(&node->cache_list, cache, entry);
1393 if (node->lock.refs == 0 && node->ondisk == NULL) {
1394 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1395 RB_REMOVE(hammer_nod_rb_tree, &node->hmp->rb_nods_root, node);
1396 if ((buffer = node->buffer) != NULL) {
1397 node->buffer = NULL;
1398 TAILQ_REMOVE(&buffer->clist, node, entry);
1399 /* buffer is unreferenced because ondisk is NULL */
1401 --hammer_count_nodes;
1402 kfree(node, hmp->m_misc);
1407 * Flush passively cached B-Tree nodes associated with this buffer.
1408 * This is only called when the buffer is about to be destroyed, so
1409 * none of the nodes should have any references. The buffer is locked.
1411 * We may be interlocked with the buffer.
1414 hammer_flush_buffer_nodes(hammer_buffer_t buffer)
1418 while ((node = TAILQ_FIRST(&buffer->clist)) != NULL) {
1419 KKASSERT(node->ondisk == NULL);
1420 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1422 if (node->lock.refs == 0) {
1423 hammer_ref(&node->lock);
1424 node->flags |= HAMMER_NODE_FLUSH;
1425 hammer_rel_node(node);
1427 KKASSERT(node->loading != 0);
1428 KKASSERT(node->buffer != NULL);
1429 buffer = node->buffer;
1430 node->buffer = NULL;
1431 TAILQ_REMOVE(&buffer->clist, node, entry);
1432 /* buffer is unreferenced because ondisk is NULL */
1438 /************************************************************************
1440 ************************************************************************/
1443 * Allocate a B-Tree node.
1446 hammer_alloc_btree(hammer_transaction_t trans, hammer_off_t hint, int *errorp)
1448 hammer_buffer_t buffer = NULL;
1449 hammer_node_t node = NULL;
1450 hammer_off_t node_offset;
1452 node_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_BTREE_INDEX,
1453 sizeof(struct hammer_node_ondisk),
1456 node = hammer_get_node(trans, node_offset, 1, errorp);
1457 hammer_modify_node_noundo(trans, node);
1458 bzero(node->ondisk, sizeof(*node->ondisk));
1459 hammer_modify_node_done(node);
1462 hammer_rel_buffer(buffer, 0);
1467 * Allocate data. If the address of a data buffer is supplied then
1468 * any prior non-NULL *data_bufferp will be released and *data_bufferp
1469 * will be set to the related buffer. The caller must release it when
1470 * finally done. The initial *data_bufferp should be set to NULL by
1473 * The caller is responsible for making hammer_modify*() calls on the
1477 hammer_alloc_data(hammer_transaction_t trans, int32_t data_len,
1478 u_int16_t rec_type, hammer_off_t *data_offsetp,
1479 struct hammer_buffer **data_bufferp,
1480 hammer_off_t hint, int *errorp)
1490 case HAMMER_RECTYPE_INODE:
1491 case HAMMER_RECTYPE_DIRENTRY:
1492 case HAMMER_RECTYPE_EXT:
1493 case HAMMER_RECTYPE_FIX:
1494 case HAMMER_RECTYPE_PFS:
1495 case HAMMER_RECTYPE_SNAPSHOT:
1496 case HAMMER_RECTYPE_CONFIG:
1497 zone = HAMMER_ZONE_META_INDEX;
1499 case HAMMER_RECTYPE_DATA:
1500 case HAMMER_RECTYPE_DB:
1501 if (data_len <= HAMMER_BUFSIZE / 2) {
1502 zone = HAMMER_ZONE_SMALL_DATA_INDEX;
1504 data_len = (data_len + HAMMER_BUFMASK) &
1506 zone = HAMMER_ZONE_LARGE_DATA_INDEX;
1510 panic("hammer_alloc_data: rec_type %04x unknown",
1512 zone = 0; /* NOT REACHED */
1515 *data_offsetp = hammer_blockmap_alloc(trans, zone, data_len,
1520 if (*errorp == 0 && data_bufferp) {
1522 data = hammer_bread_ext(trans->hmp, *data_offsetp,
1523 data_len, errorp, data_bufferp);
1534 * Sync dirty buffers to the media and clean-up any loose ends.
1536 * These functions do not start the flusher going, they simply
1537 * queue everything up to the flusher.
1539 static int hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data);
1540 static int hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1543 hammer_queue_inodes_flusher(hammer_mount_t hmp, int waitfor)
1545 struct hammer_sync_info info;
1548 info.waitfor = waitfor;
1549 if (waitfor == MNT_WAIT) {
1550 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_ONEPASS,
1551 hammer_sync_scan1, hammer_sync_scan2, &info);
1553 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_ONEPASS|VMSC_NOWAIT,
1554 hammer_sync_scan1, hammer_sync_scan2, &info);
1560 * Filesystem sync. If doing a synchronous sync make a second pass on
1561 * the vnodes in case any were already flushing during the first pass,
1562 * and activate the flusher twice (the second time brings the UNDO FIFO's
1563 * start position up to the end position after the first call).
1566 hammer_sync_hmp(hammer_mount_t hmp, int waitfor)
1568 struct hammer_sync_info info;
1571 info.waitfor = MNT_NOWAIT;
1572 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_NOWAIT,
1573 hammer_sync_scan1, hammer_sync_scan2, &info);
1574 if (info.error == 0 && waitfor == MNT_WAIT) {
1575 info.waitfor = waitfor;
1576 vmntvnodescan(hmp->mp, VMSC_GETVP,
1577 hammer_sync_scan1, hammer_sync_scan2, &info);
1579 if (waitfor == MNT_WAIT) {
1580 hammer_flusher_sync(hmp);
1581 hammer_flusher_sync(hmp);
1583 hammer_flusher_async(hmp, NULL);
1584 hammer_flusher_async(hmp, NULL);
1590 hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data)
1592 struct hammer_inode *ip;
1595 if (vp->v_type == VNON || ip == NULL ||
1596 ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1597 RB_EMPTY(&vp->v_rbdirty_tree))) {
1604 hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1606 struct hammer_sync_info *info = data;
1607 struct hammer_inode *ip;
1611 if (vp->v_type == VNON || vp->v_type == VBAD ||
1612 ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1613 RB_EMPTY(&vp->v_rbdirty_tree))) {
1616 error = VOP_FSYNC(vp, MNT_NOWAIT, 0);
1618 info->error = error;