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
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31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * IO Primitives and buffer cache management
37 * All major data-tracking structures in HAMMER contain a struct hammer_io
38 * which is used to manage their backing store. We use filesystem buffers
39 * for backing store and we leave them passively associated with their
42 * If the kernel tries to destroy a passively associated buf which we cannot
43 * yet let go we set B_LOCKED in the buffer and then actively released it
46 * The io_token is required for anything which might race bioops and bio_done
47 * callbacks, with one exception: A successful hammer_try_interlock_norefs().
48 * the fs_token will be held in all other cases.
52 #include <sys/fcntl.h>
53 #include <sys/nlookup.h>
58 static void hammer_io_modify(hammer_io_t io, int count);
59 static void hammer_io_deallocate(struct buf *bp);
60 static void hammer_indirect_callback(struct bio *bio);
61 static void hammer_io_direct_write_complete(struct bio *nbio);
62 static int hammer_io_direct_uncache_callback(hammer_inode_t ip, void *data);
63 static void hammer_io_set_modlist(struct hammer_io *io);
64 static void hammer_io_flush_mark(hammer_volume_t volume);
67 hammer_mod_rb_compare(hammer_io_t io1, hammer_io_t io2)
69 hammer_off_t io1_offset;
70 hammer_off_t io2_offset;
72 io1_offset = ((io1->offset & HAMMER_OFF_SHORT_MASK) << 8) |
74 io2_offset = ((io2->offset & HAMMER_OFF_SHORT_MASK) << 8) |
77 if (io1_offset < io2_offset)
79 if (io1_offset > io2_offset)
84 RB_GENERATE(hammer_mod_rb_tree, hammer_io, rb_node, hammer_mod_rb_compare);
87 * Initialize a new, already-zero'd hammer_io structure, or reinitialize
88 * an existing hammer_io structure which may have switched to another type.
91 hammer_io_init(hammer_io_t io, hammer_volume_t volume, enum hammer_io_type type)
94 io->hmp = volume->io.hmp;
99 * Helper routine to disassociate a buffer cache buffer from an I/O
100 * structure. The io must be interlocked and marked appropriately for
103 * The io must be in a released state with the io->bp owned and
104 * locked by the caller of this function. When not called from an
105 * io_deallocate() this cannot race an io_deallocate() since the
106 * kernel would be unable to get the buffer lock in that case.
107 * (The released state in this case means we own the bp, not the
108 * hammer_io structure).
110 * The io may have 0 or 1 references depending on who called us. The
111 * caller is responsible for dealing with the refs.
113 * This call can only be made when no action is required on the buffer.
115 * This function is guaranteed not to race against anything because we
116 * own both the io lock and the bp lock and are interlocked with no
120 hammer_io_disassociate(hammer_io_structure_t iou)
122 struct buf *bp = iou->io.bp;
124 KKASSERT(iou->io.released);
125 KKASSERT(iou->io.modified == 0);
126 KKASSERT(LIST_FIRST(&bp->b_dep) == (void *)iou);
131 * If the buffer was locked someone wanted to get rid of it.
133 if (bp->b_flags & B_LOCKED) {
134 atomic_add_int(&hammer_count_io_locked, -1);
135 bp->b_flags &= ~B_LOCKED;
137 if (iou->io.reclaim) {
138 bp->b_flags |= B_NOCACHE|B_RELBUF;
142 switch(iou->io.type) {
143 case HAMMER_STRUCTURE_VOLUME:
144 iou->volume.ondisk = NULL;
146 case HAMMER_STRUCTURE_DATA_BUFFER:
147 case HAMMER_STRUCTURE_META_BUFFER:
148 case HAMMER_STRUCTURE_UNDO_BUFFER:
149 iou->buffer.ondisk = NULL;
151 case HAMMER_STRUCTURE_DUMMY:
152 panic("hammer_io_disassociate: bad io type");
158 * Wait for any physical IO to complete
160 * XXX we aren't interlocked against a spinlock or anything so there
161 * is a small window in the interlock / io->running == 0 test.
164 hammer_io_wait(hammer_io_t io)
167 hammer_mount_t hmp = io->hmp;
169 lwkt_gettoken(&hmp->io_token);
170 while (io->running) {
172 tsleep_interlock(io, 0);
174 tsleep(io, PINTERLOCKED, "hmrflw", hz);
176 lwkt_reltoken(&hmp->io_token);
181 * Wait for all currently queued HAMMER-initiated I/Os to complete.
183 * This is not supposed to count direct I/O's but some can leak
184 * through (for non-full-sized direct I/Os).
187 hammer_io_wait_all(hammer_mount_t hmp, const char *ident, int doflush)
189 struct hammer_io iodummy;
193 * Degenerate case, no I/O is running
195 lwkt_gettoken(&hmp->io_token);
196 if (TAILQ_EMPTY(&hmp->iorun_list)) {
197 lwkt_reltoken(&hmp->io_token);
199 hammer_io_flush_sync(hmp);
202 bzero(&iodummy, sizeof(iodummy));
203 iodummy.type = HAMMER_STRUCTURE_DUMMY;
206 * Add placemarker and then wait until it becomes the head of
209 TAILQ_INSERT_TAIL(&hmp->iorun_list, &iodummy, iorun_entry);
210 while (TAILQ_FIRST(&hmp->iorun_list) != &iodummy) {
211 tsleep(&iodummy, 0, ident, 0);
215 * Chain in case several placemarkers are present.
217 TAILQ_REMOVE(&hmp->iorun_list, &iodummy, iorun_entry);
218 io = TAILQ_FIRST(&hmp->iorun_list);
219 if (io && io->type == HAMMER_STRUCTURE_DUMMY)
221 lwkt_reltoken(&hmp->io_token);
224 hammer_io_flush_sync(hmp);
228 * Clear a flagged error condition on a I/O buffer. The caller must hold
229 * its own ref on the buffer.
232 hammer_io_clear_error(struct hammer_io *io)
234 hammer_mount_t hmp = io->hmp;
236 lwkt_gettoken(&hmp->io_token);
239 hammer_rel(&io->lock);
240 KKASSERT(hammer_isactive(&io->lock));
242 lwkt_reltoken(&hmp->io_token);
246 hammer_io_clear_error_noassert(struct hammer_io *io)
248 hammer_mount_t hmp = io->hmp;
250 lwkt_gettoken(&hmp->io_token);
253 hammer_rel(&io->lock);
255 lwkt_reltoken(&hmp->io_token);
259 * This is an advisory function only which tells the buffer cache
260 * the bp is not a meta-data buffer, even though it is backed by
263 * This is used by HAMMER's reblocking code to avoid trying to
264 * swapcache the filesystem's data when it is read or written
265 * by the reblocking code.
267 * The caller has a ref on the buffer preventing the bp from
268 * being disassociated from it.
271 hammer_io_notmeta(hammer_buffer_t buffer)
273 if ((buffer->io.bp->b_flags & B_NOTMETA) == 0) {
274 hammer_mount_t hmp = buffer->io.hmp;
276 lwkt_gettoken(&hmp->io_token);
277 buffer->io.bp->b_flags |= B_NOTMETA;
278 lwkt_reltoken(&hmp->io_token);
283 * Load bp for a HAMMER structure. The io must be exclusively locked by
286 * This routine is mostly used on meta-data and small-data blocks. Generally
287 * speaking HAMMER assumes some locality of reference and will cluster.
289 * Note that the caller (hammer_ondisk.c) may place further restrictions
290 * on clusterability via the limit (in bytes). Typically large-data
291 * zones cannot be clustered due to their mixed buffer sizes. This is
292 * not an issue since such clustering occurs in hammer_vnops at the
293 * regular file layer, whereas this is the buffered block device layer.
295 * No I/O callbacks can occur while we hold the buffer locked.
298 hammer_io_read(struct vnode *devvp, struct hammer_io *io, int limit)
303 if ((bp = io->bp) == NULL) {
304 atomic_add_long(&hammer_count_io_running_read, io->bytes);
305 if (hammer_cluster_enable && limit > io->bytes) {
306 error = cluster_read(devvp, io->offset + limit,
307 io->offset, io->bytes,
312 error = bread(devvp, io->offset, io->bytes, &io->bp);
314 hammer_stats_disk_read += io->bytes;
315 atomic_add_long(&hammer_count_io_running_read, -io->bytes);
318 * The code generally assumes b_ops/b_dep has been set-up,
319 * even if we error out here.
322 if ((hammer_debug_io & 0x0001) && (bp->b_flags & B_IODEBUG)) {
323 const char *metatype;
326 case HAMMER_STRUCTURE_VOLUME:
329 case HAMMER_STRUCTURE_META_BUFFER:
330 switch(((struct hammer_buffer *)io)->
331 zoneX_offset & HAMMER_OFF_ZONE_MASK) {
332 case HAMMER_ZONE_BTREE:
335 case HAMMER_ZONE_META:
338 case HAMMER_ZONE_FREEMAP:
339 metatype = "freemap";
346 case HAMMER_STRUCTURE_DATA_BUFFER:
349 case HAMMER_STRUCTURE_UNDO_BUFFER:
353 metatype = "unknown";
356 kprintf("doff %016jx %s\n",
357 (intmax_t)bp->b_bio2.bio_offset,
360 bp->b_flags &= ~B_IODEBUG;
361 bp->b_ops = &hammer_bioops;
362 KKASSERT(LIST_FIRST(&bp->b_dep) == NULL);
364 /* io->worklist is locked by the io lock */
365 LIST_INSERT_HEAD(&bp->b_dep, &io->worklist, node);
367 KKASSERT(io->modified == 0);
368 KKASSERT(io->running == 0);
369 KKASSERT(io->waiting == 0);
370 io->released = 0; /* we hold an active lock on bp */
378 * Similar to hammer_io_read() but returns a zero'd out buffer instead.
379 * Must be called with the IO exclusively locked.
381 * vfs_bio_clrbuf() is kinda nasty, enforce serialization against background
382 * I/O by forcing the buffer to not be in a released state before calling
385 * This function will also mark the IO as modified but it will not
386 * increment the modify_refs count.
388 * No I/O callbacks can occur while we hold the buffer locked.
391 hammer_io_new(struct vnode *devvp, struct hammer_io *io)
395 if ((bp = io->bp) == NULL) {
396 io->bp = getblk(devvp, io->offset, io->bytes, 0, 0);
398 bp->b_ops = &hammer_bioops;
399 KKASSERT(LIST_FIRST(&bp->b_dep) == NULL);
401 /* io->worklist is locked by the io lock */
402 LIST_INSERT_HEAD(&bp->b_dep, &io->worklist, node);
404 KKASSERT(io->running == 0);
414 hammer_io_modify(io, 0);
420 * Advance the activity count on the underlying buffer because
421 * HAMMER does not getblk/brelse on every access.
423 * The io->bp cannot go away while the buffer is referenced.
426 hammer_io_advance(struct hammer_io *io)
429 buf_act_advance(io->bp);
433 * Remove potential device level aliases against buffers managed by high level
434 * vnodes. Aliases can also be created due to mixed buffer sizes or via
435 * direct access to the backing store device.
437 * This is nasty because the buffers are also VMIO-backed. Even if a buffer
438 * does not exist its backing VM pages might, and we have to invalidate
439 * those as well or a getblk() will reinstate them.
441 * Buffer cache buffers associated with hammer_buffers cannot be
445 hammer_io_inval(hammer_volume_t volume, hammer_off_t zone2_offset)
447 hammer_io_structure_t iou;
449 hammer_off_t phys_offset;
453 hmp = volume->io.hmp;
454 lwkt_gettoken(&hmp->io_token);
457 * If a device buffer already exists for the specified physical
458 * offset use that, otherwise instantiate a buffer to cover any
459 * related VM pages, set BNOCACHE, and brelse().
461 phys_offset = volume->ondisk->vol_buf_beg +
462 (zone2_offset & HAMMER_OFF_SHORT_MASK);
463 if ((bp = findblk(volume->devvp, phys_offset, 0)) != NULL)
466 bp = getblk(volume->devvp, phys_offset, HAMMER_BUFSIZE, 0, 0);
468 if ((iou = (void *)LIST_FIRST(&bp->b_dep)) != NULL) {
470 hammer_ref(&iou->io.lock);
471 hammer_io_clear_modify(&iou->io, 1);
473 iou->io.released = 0;
476 iou->io.waitdep = 1; /* XXX this is a fs_token field */
477 KKASSERT(hammer_isactive(&iou->io.lock) == 1);
478 hammer_rel_buffer(&iou->buffer, 0);
479 /*hammer_io_deallocate(bp);*/
484 KKASSERT((bp->b_flags & B_LOCKED) == 0);
486 bp->b_flags |= B_NOCACHE|B_RELBUF;
490 lwkt_reltoken(&hmp->io_token);
495 * This routine is called on the last reference to a hammer structure.
496 * The io must be interlocked with a refcount of zero. The hammer structure
497 * will remain interlocked on return.
499 * This routine may return a non-NULL bp to the caller for dispoal.
500 * The caller typically brelse()'s the bp.
502 * The bp may or may not still be passively associated with the IO. It
503 * will remain passively associated if it is unreleasable (e.g. a modified
506 * The only requirement here is that modified meta-data and volume-header
507 * buffer may NOT be disassociated from the IO structure, and consequently
508 * we also leave such buffers actively associated with the IO if they already
509 * are (since the kernel can't do anything with them anyway). Only the
510 * flusher is allowed to write such buffers out. Modified pure-data and
511 * undo buffers are returned to the kernel but left passively associated
512 * so we can track when the kernel writes the bp out.
515 hammer_io_release(struct hammer_io *io, int flush)
517 union hammer_io_structure *iou = (void *)io;
520 if ((bp = io->bp) == NULL)
524 * Try to flush a dirty IO to disk if asked to by the
525 * caller or if the kernel tried to flush the buffer in the past.
527 * Kernel-initiated flushes are only allowed for pure-data buffers.
528 * meta-data and volume buffers can only be flushed explicitly
533 hammer_io_flush(io, 0);
534 } else if (bp->b_flags & B_LOCKED) {
536 case HAMMER_STRUCTURE_DATA_BUFFER:
537 hammer_io_flush(io, 0);
539 case HAMMER_STRUCTURE_UNDO_BUFFER:
540 hammer_io_flush(io, hammer_undo_reclaim(io));
545 } /* else no explicit request to flush the buffer */
549 * Wait for the IO to complete if asked to. This occurs when
550 * the buffer must be disposed of definitively during an umount
551 * or buffer invalidation.
553 if (io->waitdep && io->running) {
558 * Return control of the buffer to the kernel (with the provisio
559 * that our bioops can override kernel decisions with regards to
562 if ((flush || io->reclaim) && io->modified == 0 && io->running == 0) {
564 * Always disassociate the bp if an explicit flush
565 * was requested and the IO completed with no error
566 * (so unmount can really clean up the structure).
574 hammer_io_disassociate((hammer_io_structure_t)io);
576 } else if (io->modified) {
578 * Only certain IO types can be released to the kernel if
579 * the buffer has been modified.
581 * volume and meta-data IO types may only be explicitly
585 case HAMMER_STRUCTURE_DATA_BUFFER:
586 case HAMMER_STRUCTURE_UNDO_BUFFER:
587 if (io->released == 0) {
589 bp->b_flags |= B_CLUSTEROK;
596 bp = NULL; /* bp left associated */
597 } else if (io->released == 0) {
599 * Clean buffers can be generally released to the kernel.
600 * We leave the bp passively associated with the HAMMER
601 * structure and use bioops to disconnect it later on
602 * if the kernel wants to discard the buffer.
604 * We can steal the structure's ownership of the bp.
607 if (bp->b_flags & B_LOCKED) {
608 hammer_io_disassociate(iou);
612 hammer_io_disassociate(iou);
615 /* return the bp (bp passively associated) */
620 * A released buffer is passively associate with our
621 * hammer_io structure. The kernel cannot destroy it
622 * without making a bioops call. If the kernel (B_LOCKED)
623 * or we (reclaim) requested that the buffer be destroyed
624 * we destroy it, otherwise we do a quick get/release to
625 * reset its position in the kernel's LRU list.
627 * Leaving the buffer passively associated allows us to
628 * use the kernel's LRU buffer flushing mechanisms rather
629 * then rolling our own.
631 * XXX there are two ways of doing this. We can re-acquire
632 * and passively release to reset the LRU, or not.
634 if (io->running == 0) {
636 if ((bp->b_flags & B_LOCKED) || io->reclaim) {
637 hammer_io_disassociate(iou);
640 /* return the bp (bp passively associated) */
644 * bp is left passively associated but we do not
645 * try to reacquire it. Interactions with the io
646 * structure will occur on completion of the bp's
656 * This routine is called with a locked IO when a flush is desired and
657 * no other references to the structure exists other then ours. This
658 * routine is ONLY called when HAMMER believes it is safe to flush a
659 * potentially modified buffer out.
661 * The locked io or io reference prevents a flush from being initiated
665 hammer_io_flush(struct hammer_io *io, int reclaim)
671 * Degenerate case - nothing to flush if nothing is dirty.
673 if (io->modified == 0)
677 KKASSERT(io->modify_refs <= 0);
680 * Acquire ownership of the bp, particularly before we clear our
683 * We are going to bawrite() this bp. Don't leave a window where
684 * io->released is set, we actually own the bp rather then our
687 * The io_token should not be required here as only
693 /* BUF_KERNPROC(io->bp); */
694 /* io->released = 0; */
695 KKASSERT(io->released);
696 KKASSERT(io->bp == bp);
703 if ((bp->b_flags & B_LOCKED) == 0) {
704 bp->b_flags |= B_LOCKED;
705 atomic_add_int(&hammer_count_io_locked, 1);
710 * Acquire exclusive access to the bp and then clear the modified
711 * state of the buffer prior to issuing I/O to interlock any
712 * modifications made while the I/O is in progress. This shouldn't
713 * happen anyway but losing data would be worse. The modified bit
714 * will be rechecked after the IO completes.
716 * NOTE: This call also finalizes the buffer's content (inval == 0).
718 * This is only legal when lock.refs == 1 (otherwise we might clear
719 * the modified bit while there are still users of the cluster
720 * modifying the data).
722 * Do this before potentially blocking so any attempt to modify the
723 * ondisk while we are blocked blocks waiting for us.
725 hammer_ref(&io->lock);
726 hammer_io_clear_modify(io, 0);
727 hammer_rel(&io->lock);
729 if (hammer_debug_io & 0x0002)
730 kprintf("hammer io_write %016jx\n", bp->b_bio1.bio_offset);
733 * Transfer ownership to the kernel and initiate I/O.
735 * NOTE: We do not hold io_token so an atomic op is required to
736 * update io_running_space.
739 atomic_add_long(&hmp->io_running_space, io->bytes);
740 atomic_add_long(&hammer_count_io_running_write, io->bytes);
741 lwkt_gettoken(&hmp->io_token);
742 TAILQ_INSERT_TAIL(&hmp->iorun_list, io, iorun_entry);
743 lwkt_reltoken(&hmp->io_token);
745 hammer_io_flush_mark(io->volume);
748 /************************************************************************
750 ************************************************************************
752 * These routines deal with dependancies created when IO buffers get
753 * modified. The caller must call hammer_modify_*() on a referenced
754 * HAMMER structure prior to modifying its on-disk data.
756 * Any intent to modify an IO buffer acquires the related bp and imposes
757 * various write ordering dependancies.
761 * Mark a HAMMER structure as undergoing modification. Meta-data buffers
762 * are locked until the flusher can deal with them, pure data buffers
763 * can be written out.
765 * The referenced io prevents races.
769 hammer_io_modify(hammer_io_t io, int count)
772 * io->modify_refs must be >= 0
774 while (io->modify_refs < 0) {
776 tsleep(io, 0, "hmrmod", 0);
780 * Shortcut if nothing to do.
782 KKASSERT(hammer_isactive(&io->lock) && io->bp != NULL);
783 io->modify_refs += count;
784 if (io->modified && io->released == 0)
788 * NOTE: It is important not to set the modified bit
789 * until after we have acquired the bp or we risk
790 * racing against checkwrite.
792 hammer_lock_ex(&io->lock);
795 BUF_KERNPROC(io->bp);
798 if (io->modified == 0) {
799 hammer_io_set_modlist(io);
802 hammer_unlock(&io->lock);
807 hammer_io_modify_done(hammer_io_t io)
809 KKASSERT(io->modify_refs > 0);
811 if (io->modify_refs == 0 && io->waitmod) {
818 * The write interlock blocks other threads trying to modify a buffer
819 * (they block in hammer_io_modify()) after us, or blocks us while other
820 * threads are in the middle of modifying a buffer.
822 * The caller also has a ref on the io, however if we are not careful
823 * we will race bioops callbacks (checkwrite). To deal with this
824 * we must at least acquire and release the io_token, and it is probably
825 * better to hold it through the setting of modify_refs.
828 hammer_io_write_interlock(hammer_io_t io)
830 hammer_mount_t hmp = io->hmp;
832 lwkt_gettoken(&hmp->io_token);
833 while (io->modify_refs != 0) {
835 tsleep(io, 0, "hmrmod", 0);
837 io->modify_refs = -1;
838 lwkt_reltoken(&hmp->io_token);
842 hammer_io_done_interlock(hammer_io_t io)
844 KKASSERT(io->modify_refs == -1);
853 * Caller intends to modify a volume's ondisk structure.
855 * This is only allowed if we are the flusher or we have a ref on the
859 hammer_modify_volume(hammer_transaction_t trans, hammer_volume_t volume,
862 KKASSERT (trans == NULL || trans->sync_lock_refs > 0);
864 hammer_io_modify(&volume->io, 1);
866 intptr_t rel_offset = (intptr_t)base - (intptr_t)volume->ondisk;
867 KKASSERT((rel_offset & ~(intptr_t)HAMMER_BUFMASK) == 0);
868 hammer_generate_undo(trans,
869 HAMMER_ENCODE_RAW_VOLUME(volume->vol_no, rel_offset),
875 * Caller intends to modify a buffer's ondisk structure.
877 * This is only allowed if we are the flusher or we have a ref on the
881 hammer_modify_buffer(hammer_transaction_t trans, hammer_buffer_t buffer,
884 KKASSERT (trans == NULL || trans->sync_lock_refs > 0);
886 hammer_io_modify(&buffer->io, 1);
888 intptr_t rel_offset = (intptr_t)base - (intptr_t)buffer->ondisk;
889 KKASSERT((rel_offset & ~(intptr_t)HAMMER_BUFMASK) == 0);
890 hammer_generate_undo(trans,
891 buffer->zone2_offset + rel_offset,
897 hammer_modify_volume_done(hammer_volume_t volume)
899 hammer_io_modify_done(&volume->io);
903 hammer_modify_buffer_done(hammer_buffer_t buffer)
905 hammer_io_modify_done(&buffer->io);
909 * Mark an entity as not being dirty any more and finalize any
910 * delayed adjustments to the buffer.
912 * Delayed adjustments are an important performance enhancement, allowing
913 * us to avoid recalculating B-Tree node CRCs over and over again when
914 * making bulk-modifications to the B-Tree.
916 * If inval is non-zero delayed adjustments are ignored.
918 * This routine may dereference related btree nodes and cause the
919 * buffer to be dereferenced. The caller must own a reference on io.
922 hammer_io_clear_modify(struct hammer_io *io, int inval)
927 * io_token is needed to avoid races on mod_root
929 if (io->modified == 0)
932 lwkt_gettoken(&hmp->io_token);
933 if (io->modified == 0) {
934 lwkt_reltoken(&hmp->io_token);
939 * Take us off the mod-list and clear the modified bit.
941 KKASSERT(io->mod_root != NULL);
942 if (io->mod_root == &io->hmp->volu_root ||
943 io->mod_root == &io->hmp->meta_root) {
944 io->hmp->locked_dirty_space -= io->bytes;
945 atomic_add_long(&hammer_count_dirtybufspace, -io->bytes);
947 RB_REMOVE(hammer_mod_rb_tree, io->mod_root, io);
951 lwkt_reltoken(&hmp->io_token);
954 * If this bit is not set there are no delayed adjustments.
961 * Finalize requested CRCs. The NEEDSCRC flag also holds a reference
962 * on the node (& underlying buffer). Release the node after clearing
965 if (io->type == HAMMER_STRUCTURE_META_BUFFER) {
966 hammer_buffer_t buffer = (void *)io;
970 TAILQ_FOREACH(node, &buffer->clist, entry) {
971 if ((node->flags & HAMMER_NODE_NEEDSCRC) == 0)
973 node->flags &= ~HAMMER_NODE_NEEDSCRC;
974 KKASSERT(node->ondisk);
976 node->ondisk->crc = crc32(&node->ondisk->crc + 1, HAMMER_BTREE_CRCSIZE);
977 hammer_rel_node(node);
981 /* caller must still have ref on io */
982 KKASSERT(hammer_isactive(&io->lock));
986 * Clear the IO's modify list. Even though the IO is no longer modified
987 * it may still be on the lose_root. This routine is called just before
988 * the governing hammer_buffer is destroyed.
990 * mod_root requires io_token protection.
993 hammer_io_clear_modlist(struct hammer_io *io)
995 hammer_mount_t hmp = io->hmp;
997 KKASSERT(io->modified == 0);
999 lwkt_gettoken(&hmp->io_token);
1001 KKASSERT(io->mod_root == &io->hmp->lose_root);
1002 RB_REMOVE(hammer_mod_rb_tree, io->mod_root, io);
1003 io->mod_root = NULL;
1005 lwkt_reltoken(&hmp->io_token);
1010 hammer_io_set_modlist(struct hammer_io *io)
1012 struct hammer_mount *hmp = io->hmp;
1014 lwkt_gettoken(&hmp->io_token);
1015 KKASSERT(io->mod_root == NULL);
1018 case HAMMER_STRUCTURE_VOLUME:
1019 io->mod_root = &hmp->volu_root;
1020 hmp->locked_dirty_space += io->bytes;
1021 atomic_add_long(&hammer_count_dirtybufspace, io->bytes);
1023 case HAMMER_STRUCTURE_META_BUFFER:
1024 io->mod_root = &hmp->meta_root;
1025 hmp->locked_dirty_space += io->bytes;
1026 atomic_add_long(&hammer_count_dirtybufspace, io->bytes);
1028 case HAMMER_STRUCTURE_UNDO_BUFFER:
1029 io->mod_root = &hmp->undo_root;
1031 case HAMMER_STRUCTURE_DATA_BUFFER:
1032 io->mod_root = &hmp->data_root;
1034 case HAMMER_STRUCTURE_DUMMY:
1035 panic("hammer_io_set_modlist: bad io type");
1036 break; /* NOT REACHED */
1038 if (RB_INSERT(hammer_mod_rb_tree, io->mod_root, io)) {
1039 panic("hammer_io_set_modlist: duplicate entry");
1042 lwkt_reltoken(&hmp->io_token);
1045 /************************************************************************
1047 ************************************************************************
1052 * Pre-IO initiation kernel callback - cluster build only
1054 * bioops callback - hold io_token
1057 hammer_io_start(struct buf *bp)
1059 /* nothing to do, so io_token not needed */
1063 * Post-IO completion kernel callback - MAY BE CALLED FROM INTERRUPT!
1065 * NOTE: HAMMER may modify a data buffer after we have initiated write
1068 * NOTE: MPSAFE callback
1070 * bioops callback - hold io_token
1073 hammer_io_complete(struct buf *bp)
1075 union hammer_io_structure *iou = (void *)LIST_FIRST(&bp->b_dep);
1076 struct hammer_mount *hmp = iou->io.hmp;
1077 struct hammer_io *ionext;
1079 lwkt_gettoken(&hmp->io_token);
1081 KKASSERT(iou->io.released == 1);
1084 * Deal with people waiting for I/O to drain
1086 if (iou->io.running) {
1088 * Deal with critical write errors. Once a critical error
1089 * has been flagged in hmp the UNDO FIFO will not be updated.
1090 * That way crash recover will give us a consistent
1093 * Because of this we can throw away failed UNDO buffers. If
1094 * we throw away META or DATA buffers we risk corrupting
1095 * the now read-only version of the filesystem visible to
1096 * the user. Clear B_ERROR so the buffer is not re-dirtied
1097 * by the kernel and ref the io so it doesn't get thrown
1100 if (bp->b_flags & B_ERROR) {
1101 lwkt_gettoken(&hmp->fs_token);
1102 hammer_critical_error(hmp, NULL, bp->b_error,
1103 "while flushing meta-data");
1104 lwkt_reltoken(&hmp->fs_token);
1106 switch(iou->io.type) {
1107 case HAMMER_STRUCTURE_UNDO_BUFFER:
1110 if (iou->io.ioerror == 0) {
1111 iou->io.ioerror = 1;
1112 hammer_ref(&iou->io.lock);
1116 bp->b_flags &= ~B_ERROR;
1119 hammer_io_set_modlist(&iou->io);
1120 iou->io.modified = 1;
1123 hammer_stats_disk_write += iou->io.bytes;
1124 atomic_add_long(&hammer_count_io_running_write, -iou->io.bytes);
1125 atomic_add_long(&hmp->io_running_space, -iou->io.bytes);
1126 KKASSERT(hmp->io_running_space >= 0);
1127 iou->io.running = 0;
1130 * Remove from iorun list and wakeup any multi-io waiter(s).
1132 if (TAILQ_FIRST(&hmp->iorun_list) == &iou->io) {
1133 ionext = TAILQ_NEXT(&iou->io, iorun_entry);
1134 if (ionext && ionext->type == HAMMER_STRUCTURE_DUMMY)
1137 TAILQ_REMOVE(&hmp->iorun_list, &iou->io, iorun_entry);
1139 hammer_stats_disk_read += iou->io.bytes;
1142 if (iou->io.waiting) {
1143 iou->io.waiting = 0;
1148 * If B_LOCKED is set someone wanted to deallocate the bp at some
1149 * point, try to do it now. The operation will fail if there are
1150 * refs or if hammer_io_deallocate() is unable to gain the
1153 if (bp->b_flags & B_LOCKED) {
1154 atomic_add_int(&hammer_count_io_locked, -1);
1155 bp->b_flags &= ~B_LOCKED;
1156 hammer_io_deallocate(bp);
1157 /* structure may be dead now */
1159 lwkt_reltoken(&hmp->io_token);
1163 * Callback from kernel when it wishes to deallocate a passively
1164 * associated structure. This mostly occurs with clean buffers
1165 * but it may be possible for a holding structure to be marked dirty
1166 * while its buffer is passively associated. The caller owns the bp.
1168 * If we cannot disassociate we set B_LOCKED to prevent the buffer
1169 * from getting reused.
1171 * WARNING: Because this can be called directly by getnewbuf we cannot
1172 * recurse into the tree. If a bp cannot be immediately disassociated
1173 * our only recourse is to set B_LOCKED.
1175 * WARNING: This may be called from an interrupt via hammer_io_complete()
1177 * bioops callback - hold io_token
1180 hammer_io_deallocate(struct buf *bp)
1182 hammer_io_structure_t iou = (void *)LIST_FIRST(&bp->b_dep);
1187 lwkt_gettoken(&hmp->io_token);
1189 KKASSERT((bp->b_flags & B_LOCKED) == 0 && iou->io.running == 0);
1190 if (hammer_try_interlock_norefs(&iou->io.lock) == 0) {
1192 * We cannot safely disassociate a bp from a referenced
1193 * or interlocked HAMMER structure.
1195 bp->b_flags |= B_LOCKED;
1196 atomic_add_int(&hammer_count_io_locked, 1);
1197 } else if (iou->io.modified) {
1199 * It is not legal to disassociate a modified buffer. This
1200 * case really shouldn't ever occur.
1202 bp->b_flags |= B_LOCKED;
1203 atomic_add_int(&hammer_count_io_locked, 1);
1204 hammer_put_interlock(&iou->io.lock, 0);
1207 * Disassociate the BP. If the io has no refs left we
1208 * have to add it to the loose list. The kernel has
1209 * locked the buffer and therefore our io must be
1210 * in a released state.
1212 hammer_io_disassociate(iou);
1213 if (iou->io.type != HAMMER_STRUCTURE_VOLUME) {
1214 KKASSERT(iou->io.bp == NULL);
1215 KKASSERT(iou->io.mod_root == NULL);
1216 iou->io.mod_root = &hmp->lose_root;
1217 if (RB_INSERT(hammer_mod_rb_tree, iou->io.mod_root,
1219 panic("hammer_io_deallocate: duplicate entry");
1222 hammer_put_interlock(&iou->io.lock, 1);
1224 lwkt_reltoken(&hmp->io_token);
1228 * bioops callback - hold io_token
1231 hammer_io_fsync(struct vnode *vp)
1233 /* nothing to do, so io_token not needed */
1238 * NOTE: will not be called unless we tell the kernel about the
1239 * bioops. Unused... we use the mount's VFS_SYNC instead.
1241 * bioops callback - hold io_token
1244 hammer_io_sync(struct mount *mp)
1246 /* nothing to do, so io_token not needed */
1251 * bioops callback - hold io_token
1254 hammer_io_movedeps(struct buf *bp1, struct buf *bp2)
1256 /* nothing to do, so io_token not needed */
1260 * I/O pre-check for reading and writing. HAMMER only uses this for
1261 * B_CACHE buffers so checkread just shouldn't happen, but if it does
1264 * Writing is a different case. We don't want the kernel to try to write
1265 * out a buffer that HAMMER may be modifying passively or which has a
1266 * dependancy. In addition, kernel-demanded writes can only proceed for
1267 * certain types of buffers (i.e. UNDO and DATA types). Other dirty
1268 * buffer types can only be explicitly written by the flusher.
1270 * checkwrite will only be called for bdwrite()n buffers. If we return
1271 * success the kernel is guaranteed to initiate the buffer write.
1273 * bioops callback - hold io_token
1276 hammer_io_checkread(struct buf *bp)
1278 /* nothing to do, so io_token not needed */
1283 * The kernel is asking us whether it can write out a dirty buffer or not.
1285 * bioops callback - hold io_token
1288 hammer_io_checkwrite(struct buf *bp)
1290 hammer_io_t io = (void *)LIST_FIRST(&bp->b_dep);
1291 hammer_mount_t hmp = io->hmp;
1294 * This shouldn't happen under normal operation.
1296 lwkt_gettoken(&hmp->io_token);
1297 if (io->type == HAMMER_STRUCTURE_VOLUME ||
1298 io->type == HAMMER_STRUCTURE_META_BUFFER) {
1300 panic("hammer_io_checkwrite: illegal buffer");
1301 if ((bp->b_flags & B_LOCKED) == 0) {
1302 bp->b_flags |= B_LOCKED;
1303 atomic_add_int(&hammer_count_io_locked, 1);
1305 lwkt_reltoken(&hmp->io_token);
1310 * We have to be able to interlock the IO to safely modify any
1311 * of its fields without holding the fs_token. If we can't lock
1312 * it then we are racing someone.
1314 * Our ownership of the bp lock prevents the io from being ripped
1315 * out from under us.
1317 if (hammer_try_interlock_norefs(&io->lock) == 0) {
1318 bp->b_flags |= B_LOCKED;
1319 atomic_add_int(&hammer_count_io_locked, 1);
1320 lwkt_reltoken(&hmp->io_token);
1325 * The modified bit must be cleared prior to the initiation of
1326 * any IO (returning 0 initiates the IO). Because this is a
1327 * normal data buffer hammer_io_clear_modify() runs through a
1328 * simple degenerate case.
1330 * Return 0 will cause the kernel to initiate the IO, and we
1331 * must normally clear the modified bit before we begin. If
1332 * the io has modify_refs we do not clear the modified bit,
1333 * otherwise we may miss changes.
1335 * Only data and undo buffers can reach here. These buffers do
1336 * not have terminal crc functions but we temporarily reference
1337 * the IO anyway, just in case.
1339 if (io->modify_refs == 0 && io->modified) {
1340 hammer_ref(&io->lock);
1341 hammer_io_clear_modify(io, 0);
1342 hammer_rel(&io->lock);
1343 } else if (io->modified) {
1344 KKASSERT(io->type == HAMMER_STRUCTURE_DATA_BUFFER);
1348 * The kernel is going to start the IO, set io->running.
1350 KKASSERT(io->running == 0);
1352 atomic_add_long(&io->hmp->io_running_space, io->bytes);
1353 atomic_add_long(&hammer_count_io_running_write, io->bytes);
1354 TAILQ_INSERT_TAIL(&io->hmp->iorun_list, io, iorun_entry);
1356 hammer_put_interlock(&io->lock, 1);
1357 lwkt_reltoken(&hmp->io_token);
1363 * Return non-zero if we wish to delay the kernel's attempt to flush
1364 * this buffer to disk.
1366 * bioops callback - hold io_token
1369 hammer_io_countdeps(struct buf *bp, int n)
1371 /* nothing to do, so io_token not needed */
1375 struct bio_ops hammer_bioops = {
1376 .io_start = hammer_io_start,
1377 .io_complete = hammer_io_complete,
1378 .io_deallocate = hammer_io_deallocate,
1379 .io_fsync = hammer_io_fsync,
1380 .io_sync = hammer_io_sync,
1381 .io_movedeps = hammer_io_movedeps,
1382 .io_countdeps = hammer_io_countdeps,
1383 .io_checkread = hammer_io_checkread,
1384 .io_checkwrite = hammer_io_checkwrite,
1387 /************************************************************************
1389 ************************************************************************
1391 * These functions operate directly on the buffer cache buffer associated
1392 * with a front-end vnode rather then a back-end device vnode.
1396 * Read a buffer associated with a front-end vnode directly from the
1397 * disk media. The bio may be issued asynchronously. If leaf is non-NULL
1398 * we validate the CRC.
1400 * We must check for the presence of a HAMMER buffer to handle the case
1401 * where the reblocker has rewritten the data (which it does via the HAMMER
1402 * buffer system, not via the high-level vnode buffer cache), but not yet
1403 * committed the buffer to the media.
1406 hammer_io_direct_read(hammer_mount_t hmp, struct bio *bio,
1407 hammer_btree_leaf_elm_t leaf)
1409 hammer_off_t buf_offset;
1410 hammer_off_t zone2_offset;
1411 hammer_volume_t volume;
1417 buf_offset = bio->bio_offset;
1418 KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) ==
1419 HAMMER_ZONE_LARGE_DATA);
1422 * The buffer cache may have an aliased buffer (the reblocker can
1423 * write them). If it does we have to sync any dirty data before
1424 * we can build our direct-read. This is a non-critical code path.
1427 hammer_sync_buffers(hmp, buf_offset, bp->b_bufsize);
1430 * Resolve to a zone-2 offset. The conversion just requires
1431 * munging the top 4 bits but we want to abstract it anyway
1432 * so the blockmap code can verify the zone assignment.
1434 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, &error);
1437 KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) ==
1438 HAMMER_ZONE_RAW_BUFFER);
1441 * Resolve volume and raw-offset for 3rd level bio. The
1442 * offset will be specific to the volume.
1444 vol_no = HAMMER_VOL_DECODE(zone2_offset);
1445 volume = hammer_get_volume(hmp, vol_no, &error);
1446 if (error == 0 && zone2_offset >= volume->maxbuf_off)
1453 nbio = push_bio(bio);
1454 nbio->bio_offset = volume->ondisk->vol_buf_beg +
1455 (zone2_offset & HAMMER_OFF_SHORT_MASK);
1456 hammer_stats_disk_read += bp->b_bufsize;
1457 vn_strategy(volume->devvp, nbio);
1459 hammer_rel_volume(volume, 0);
1462 kprintf("hammer_direct_read: failed @ %016llx\n",
1463 (long long)zone2_offset);
1464 bp->b_error = error;
1465 bp->b_flags |= B_ERROR;
1472 * This works similarly to hammer_io_direct_read() except instead of
1473 * directly reading from the device into the bio we instead indirectly
1474 * read through the device's buffer cache and then copy the data into
1477 * If leaf is non-NULL and validation is enabled, the CRC will be checked.
1479 * This routine also executes asynchronously. It allows hammer strategy
1480 * calls to operate asynchronously when in double_buffer mode (in addition
1481 * to operating asynchronously when in normal mode).
1484 hammer_io_indirect_read(hammer_mount_t hmp, struct bio *bio,
1485 hammer_btree_leaf_elm_t leaf)
1487 hammer_off_t buf_offset;
1488 hammer_off_t zone2_offset;
1489 hammer_volume_t volume;
1494 buf_offset = bio->bio_offset;
1495 KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) ==
1496 HAMMER_ZONE_LARGE_DATA);
1499 * The buffer cache may have an aliased buffer (the reblocker can
1500 * write them). If it does we have to sync any dirty data before
1501 * we can build our direct-read. This is a non-critical code path.
1504 hammer_sync_buffers(hmp, buf_offset, bp->b_bufsize);
1507 * Resolve to a zone-2 offset. The conversion just requires
1508 * munging the top 4 bits but we want to abstract it anyway
1509 * so the blockmap code can verify the zone assignment.
1511 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, &error);
1514 KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) ==
1515 HAMMER_ZONE_RAW_BUFFER);
1518 * Resolve volume and raw-offset for 3rd level bio. The
1519 * offset will be specific to the volume.
1521 vol_no = HAMMER_VOL_DECODE(zone2_offset);
1522 volume = hammer_get_volume(hmp, vol_no, &error);
1523 if (error == 0 && zone2_offset >= volume->maxbuf_off)
1528 * Convert to the raw volume->devvp offset and acquire
1529 * the buf, issuing async I/O if necessary.
1531 buf_offset = volume->ondisk->vol_buf_beg +
1532 (zone2_offset & HAMMER_OFF_SHORT_MASK);
1534 if (leaf && hammer_verify_data) {
1535 bio->bio_caller_info1.uvalue32 = leaf->data_crc;
1536 bio->bio_caller_info2.index = 1;
1538 bio->bio_caller_info2.index = 0;
1540 breadcb(volume->devvp, buf_offset, bp->b_bufsize,
1541 hammer_indirect_callback, bio);
1543 hammer_rel_volume(volume, 0);
1546 kprintf("hammer_direct_read: failed @ %016llx\n",
1547 (long long)zone2_offset);
1548 bp->b_error = error;
1549 bp->b_flags |= B_ERROR;
1556 * Indirect callback on completion. bio/bp specify the device-backed
1557 * buffer. bio->bio_caller_info1.ptr holds obio.
1559 * obio/obp is the original regular file buffer. obio->bio_caller_info*
1560 * contains the crc specification.
1562 * We are responsible for calling bpdone() and bqrelse() on bio/bp, and
1563 * for calling biodone() on obio.
1566 hammer_indirect_callback(struct bio *bio)
1568 struct buf *bp = bio->bio_buf;
1573 * If BIO_DONE is already set the device buffer was already
1574 * fully valid (B_CACHE). If it is not set then I/O was issued
1575 * and we have to run I/O completion as the last bio.
1577 * Nobody is waiting for our device I/O to complete, we are
1578 * responsible for bqrelse()ing it which means we also have to do
1579 * the equivalent of biowait() and clear BIO_DONE (which breadcb()
1582 * Any preexisting device buffer should match the requested size,
1583 * but due to bigblock recycling and other factors there is some
1584 * fragility there, so we assert that the device buffer covers
1587 if ((bio->bio_flags & BIO_DONE) == 0)
1589 bio->bio_flags &= ~(BIO_DONE | BIO_SYNC);
1591 obio = bio->bio_caller_info1.ptr;
1592 obp = obio->bio_buf;
1594 if (bp->b_flags & B_ERROR) {
1595 obp->b_flags |= B_ERROR;
1596 obp->b_error = bp->b_error;
1597 } else if (obio->bio_caller_info2.index &&
1598 obio->bio_caller_info1.uvalue32 !=
1599 crc32(bp->b_data, bp->b_bufsize)) {
1600 obp->b_flags |= B_ERROR;
1603 KKASSERT(bp->b_bufsize >= obp->b_bufsize);
1604 bcopy(bp->b_data, obp->b_data, obp->b_bufsize);
1606 obp->b_flags |= B_AGE;
1613 * Write a buffer associated with a front-end vnode directly to the
1614 * disk media. The bio may be issued asynchronously.
1616 * The BIO is associated with the specified record and RECG_DIRECT_IO
1617 * is set. The recorded is added to its object.
1620 hammer_io_direct_write(hammer_mount_t hmp, struct bio *bio,
1621 hammer_record_t record)
1623 hammer_btree_leaf_elm_t leaf = &record->leaf;
1624 hammer_off_t buf_offset;
1625 hammer_off_t zone2_offset;
1626 hammer_volume_t volume;
1627 hammer_buffer_t buffer;
1634 buf_offset = leaf->data_offset;
1636 KKASSERT(buf_offset > HAMMER_ZONE_BTREE);
1637 KKASSERT(bio->bio_buf->b_cmd == BUF_CMD_WRITE);
1640 * Issue or execute the I/O. The new memory record must replace
1641 * the old one before the I/O completes, otherwise a reaquisition of
1642 * the buffer will load the old media data instead of the new.
1644 if ((buf_offset & HAMMER_BUFMASK) == 0 &&
1645 leaf->data_len >= HAMMER_BUFSIZE) {
1647 * We are using the vnode's bio to write directly to the
1648 * media, any hammer_buffer at the same zone-X offset will
1649 * now have stale data.
1651 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, &error);
1652 vol_no = HAMMER_VOL_DECODE(zone2_offset);
1653 volume = hammer_get_volume(hmp, vol_no, &error);
1655 if (error == 0 && zone2_offset >= volume->maxbuf_off)
1659 KKASSERT((bp->b_bufsize & HAMMER_BUFMASK) == 0);
1661 hammer_del_buffers(hmp, buf_offset,
1662 zone2_offset, bp->b_bufsize);
1666 * Second level bio - cached zone2 offset.
1668 * (We can put our bio_done function in either the
1669 * 2nd or 3rd level).
1671 nbio = push_bio(bio);
1672 nbio->bio_offset = zone2_offset;
1673 nbio->bio_done = hammer_io_direct_write_complete;
1674 nbio->bio_caller_info1.ptr = record;
1675 record->zone2_offset = zone2_offset;
1676 record->gflags |= HAMMER_RECG_DIRECT_IO |
1677 HAMMER_RECG_DIRECT_INVAL;
1680 * Third level bio - raw offset specific to the
1683 zone2_offset &= HAMMER_OFF_SHORT_MASK;
1684 nbio = push_bio(nbio);
1685 nbio->bio_offset = volume->ondisk->vol_buf_beg +
1687 hammer_stats_disk_write += bp->b_bufsize;
1688 hammer_ip_replace_bulk(hmp, record);
1689 vn_strategy(volume->devvp, nbio);
1690 hammer_io_flush_mark(volume);
1692 hammer_rel_volume(volume, 0);
1695 * Must fit in a standard HAMMER buffer. In this case all
1696 * consumers use the HAMMER buffer system and RECG_DIRECT_IO
1697 * does not need to be set-up.
1699 KKASSERT(((buf_offset ^ (buf_offset + leaf->data_len - 1)) & ~HAMMER_BUFMASK64) == 0);
1701 ptr = hammer_bread(hmp, buf_offset, &error, &buffer);
1704 bp->b_flags |= B_AGE;
1705 hammer_io_modify(&buffer->io, 1);
1706 bcopy(bp->b_data, ptr, leaf->data_len);
1707 hammer_io_modify_done(&buffer->io);
1708 hammer_rel_buffer(buffer, 0);
1710 hammer_ip_replace_bulk(hmp, record);
1716 * Major suckage occured. Also note: The record was
1717 * never added to the tree so we do not have to worry
1718 * about the backend.
1720 kprintf("hammer_direct_write: failed @ %016llx\n",
1721 (long long)leaf->data_offset);
1725 bp->b_flags |= B_ERROR;
1727 record->flags |= HAMMER_RECF_DELETED_FE;
1728 hammer_rel_mem_record(record);
1734 * On completion of the BIO this callback must disconnect
1735 * it from the hammer_record and chain to the previous bio.
1737 * An I/O error forces the mount to read-only. Data buffers
1738 * are not B_LOCKED like meta-data buffers are, so we have to
1739 * throw the buffer away to prevent the kernel from retrying.
1741 * NOTE: MPSAFE callback, only modify fields we have explicit
1742 * access to (the bp and the record->gflags).
1746 hammer_io_direct_write_complete(struct bio *nbio)
1750 hammer_record_t record;
1753 record = nbio->bio_caller_info1.ptr;
1754 KKASSERT(record != NULL);
1755 hmp = record->ip->hmp;
1757 lwkt_gettoken(&hmp->io_token);
1760 obio = pop_bio(nbio);
1761 if (bp->b_flags & B_ERROR) {
1762 lwkt_gettoken(&hmp->fs_token);
1763 hammer_critical_error(hmp, record->ip,
1765 "while writing bulk data");
1766 lwkt_reltoken(&hmp->fs_token);
1767 bp->b_flags |= B_INVAL;
1771 KKASSERT(record->gflags & HAMMER_RECG_DIRECT_IO);
1772 if (record->gflags & HAMMER_RECG_DIRECT_WAIT) {
1773 record->gflags &= ~(HAMMER_RECG_DIRECT_IO |
1774 HAMMER_RECG_DIRECT_WAIT);
1775 /* record can disappear once DIRECT_IO flag is cleared */
1776 wakeup(&record->flags);
1778 record->gflags &= ~HAMMER_RECG_DIRECT_IO;
1779 /* record can disappear once DIRECT_IO flag is cleared */
1781 lwkt_reltoken(&hmp->io_token);
1786 * This is called before a record is either committed to the B-Tree
1787 * or destroyed, to resolve any associated direct-IO.
1789 * (1) We must wait for any direct-IO related to the record to complete.
1791 * (2) We must remove any buffer cache aliases for data accessed via
1792 * leaf->data_offset or zone2_offset so non-direct-IO consumers
1793 * (the mirroring and reblocking code) do not see stale data.
1796 hammer_io_direct_wait(hammer_record_t record)
1798 hammer_mount_t hmp = record->ip->hmp;
1801 * Wait for I/O to complete
1803 if (record->gflags & HAMMER_RECG_DIRECT_IO) {
1804 lwkt_gettoken(&hmp->io_token);
1805 while (record->gflags & HAMMER_RECG_DIRECT_IO) {
1806 record->gflags |= HAMMER_RECG_DIRECT_WAIT;
1807 tsleep(&record->flags, 0, "hmdiow", 0);
1809 lwkt_reltoken(&hmp->io_token);
1813 * Invalidate any related buffer cache aliases associated with the
1814 * backing device. This is needed because the buffer cache buffer
1815 * for file data is associated with the file vnode, not the backing
1818 * XXX I do not think this case can occur any more now that
1819 * reservations ensure that all such buffers are removed before
1820 * an area can be reused.
1822 if (record->gflags & HAMMER_RECG_DIRECT_INVAL) {
1823 KKASSERT(record->leaf.data_offset);
1824 hammer_del_buffers(hmp, record->leaf.data_offset,
1825 record->zone2_offset, record->leaf.data_len,
1827 record->gflags &= ~HAMMER_RECG_DIRECT_INVAL;
1832 * This is called to remove the second-level cached zone-2 offset from
1833 * frontend buffer cache buffers, now stale due to a data relocation.
1834 * These offsets are generated by cluster_read() via VOP_BMAP, or directly
1835 * by hammer_vop_strategy_read().
1837 * This is rather nasty because here we have something like the reblocker
1838 * scanning the raw B-Tree with no held references on anything, really,
1839 * other then a shared lock on the B-Tree node, and we have to access the
1840 * frontend's buffer cache to check for and clean out the association.
1841 * Specifically, if the reblocker is moving data on the disk, these cached
1842 * offsets will become invalid.
1844 * Only data record types associated with the large-data zone are subject
1845 * to direct-io and need to be checked.
1849 hammer_io_direct_uncache(hammer_mount_t hmp, hammer_btree_leaf_elm_t leaf)
1851 struct hammer_inode_info iinfo;
1854 if (leaf->base.rec_type != HAMMER_RECTYPE_DATA)
1856 zone = HAMMER_ZONE_DECODE(leaf->data_offset);
1857 if (zone != HAMMER_ZONE_LARGE_DATA_INDEX)
1859 iinfo.obj_id = leaf->base.obj_id;
1860 iinfo.obj_asof = 0; /* unused */
1861 iinfo.obj_localization = leaf->base.localization &
1862 HAMMER_LOCALIZE_PSEUDOFS_MASK;
1863 iinfo.u.leaf = leaf;
1864 hammer_scan_inode_snapshots(hmp, &iinfo,
1865 hammer_io_direct_uncache_callback,
1870 hammer_io_direct_uncache_callback(hammer_inode_t ip, void *data)
1872 hammer_inode_info_t iinfo = data;
1873 hammer_off_t file_offset;
1880 file_offset = iinfo->u.leaf->base.key - iinfo->u.leaf->data_len;
1881 blksize = iinfo->u.leaf->data_len;
1882 KKASSERT((blksize & HAMMER_BUFMASK) == 0);
1885 * Warning: FINDBLK_TEST return stable storage but not stable
1886 * contents. It happens to be ok in this case.
1888 hammer_ref(&ip->lock);
1889 if (hammer_get_vnode(ip, &vp) == 0) {
1890 if ((bp = findblk(ip->vp, file_offset, FINDBLK_TEST)) != NULL &&
1891 bp->b_bio2.bio_offset != NOOFFSET) {
1892 bp = getblk(ip->vp, file_offset, blksize, 0, 0);
1893 bp->b_bio2.bio_offset = NOOFFSET;
1898 hammer_rel_inode(ip, 0);
1904 * This function is called when writes may have occured on the volume,
1905 * indicating that the device may be holding cached writes.
1908 hammer_io_flush_mark(hammer_volume_t volume)
1910 atomic_set_int(&volume->vol_flags, HAMMER_VOLF_NEEDFLUSH);
1914 * This function ensures that the device has flushed any cached writes out.
1917 hammer_io_flush_sync(hammer_mount_t hmp)
1919 hammer_volume_t volume;
1920 struct buf *bp_base = NULL;
1923 RB_FOREACH(volume, hammer_vol_rb_tree, &hmp->rb_vols_root) {
1924 if (volume->vol_flags & HAMMER_VOLF_NEEDFLUSH) {
1925 atomic_clear_int(&volume->vol_flags,
1926 HAMMER_VOLF_NEEDFLUSH);
1928 bp->b_bio1.bio_offset = 0;
1931 bp->b_cmd = BUF_CMD_FLUSH;
1932 bp->b_bio1.bio_caller_info1.cluster_head = bp_base;
1933 bp->b_bio1.bio_done = biodone_sync;
1934 bp->b_bio1.bio_flags |= BIO_SYNC;
1936 vn_strategy(volume->devvp, &bp->b_bio1);
1939 while ((bp = bp_base) != NULL) {
1940 bp_base = bp->b_bio1.bio_caller_info1.cluster_head;
1941 biowait(&bp->b_bio1, "hmrFLS");
1947 * Limit the amount of backlog which we allow to build up
1950 hammer_io_limit_backlog(hammer_mount_t hmp)
1952 waitrunningbufspace();