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
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);
62 static void hammer_io_direct_read_complete(struct bio *nbio);
64 static void hammer_io_direct_write_complete(struct bio *nbio);
65 static int hammer_io_direct_uncache_callback(hammer_inode_t ip, void *data);
66 static void hammer_io_set_modlist(struct hammer_io *io);
67 static void hammer_io_flush_mark(hammer_volume_t volume);
70 hammer_mod_rb_compare(hammer_io_t io1, hammer_io_t io2)
72 hammer_off_t io1_offset;
73 hammer_off_t io2_offset;
75 io1_offset = ((io1->offset & HAMMER_OFF_SHORT_MASK) << 8) |
76 HAMMER_VOL_DECODE(io1->offset);
77 io2_offset = ((io2->offset & HAMMER_OFF_SHORT_MASK) << 8) |
78 HAMMER_VOL_DECODE(io2->offset);
80 if (io1_offset < io2_offset)
82 if (io1_offset > io2_offset)
87 RB_GENERATE(hammer_mod_rb_tree, hammer_io, rb_node, hammer_mod_rb_compare);
90 * Initialize a new, already-zero'd hammer_io structure, or reinitialize
91 * an existing hammer_io structure which may have switched to another type.
94 hammer_io_init(hammer_io_t io, hammer_volume_t volume, enum hammer_io_type type)
97 io->hmp = volume->io.hmp;
102 * Helper routine to disassociate a buffer cache buffer from an I/O
103 * structure. The io must be interlocked and marked appropriately for
106 * The io must be in a released state with the io->bp owned and
107 * locked by the caller of this function. When not called from an
108 * io_deallocate() this cannot race an io_deallocate() since the
109 * kernel would be unable to get the buffer lock in that case.
110 * (The released state in this case means we own the bp, not the
111 * hammer_io structure).
113 * The io may have 0 or 1 references depending on who called us. The
114 * caller is responsible for dealing with the refs.
116 * This call can only be made when no action is required on the buffer.
118 * This function is guaranteed not to race against anything because we
119 * own both the io lock and the bp lock and are interlocked with no
123 hammer_io_disassociate(hammer_io_structure_t iou)
125 struct buf *bp = iou->io.bp;
127 KKASSERT(iou->io.released);
128 KKASSERT(iou->io.modified == 0);
129 KKASSERT(LIST_FIRST(&bp->b_dep) == (void *)iou);
134 * If the buffer was locked someone wanted to get rid of it.
136 if (bp->b_flags & B_LOCKED) {
137 atomic_add_int(&hammer_count_io_locked, -1);
138 bp->b_flags &= ~B_LOCKED;
140 if (iou->io.reclaim) {
141 bp->b_flags |= B_NOCACHE|B_RELBUF;
145 switch(iou->io.type) {
146 case HAMMER_STRUCTURE_VOLUME:
147 iou->volume.ondisk = NULL;
149 case HAMMER_STRUCTURE_DATA_BUFFER:
150 case HAMMER_STRUCTURE_META_BUFFER:
151 case HAMMER_STRUCTURE_UNDO_BUFFER:
152 iou->buffer.ondisk = NULL;
154 case HAMMER_STRUCTURE_DUMMY:
155 panic("hammer_io_disassociate: bad io type");
161 * Wait for any physical IO to complete
163 * XXX we aren't interlocked against a spinlock or anything so there
164 * is a small window in the interlock / io->running == 0 test.
167 hammer_io_wait(hammer_io_t io)
170 hammer_mount_t hmp = io->hmp;
172 lwkt_gettoken(&hmp->io_token);
173 while (io->running) {
175 tsleep_interlock(io, 0);
177 tsleep(io, PINTERLOCKED, "hmrflw", hz);
179 lwkt_reltoken(&hmp->io_token);
184 * Wait for all currently queued HAMMER-initiated I/Os to complete.
186 * This is not supposed to count direct I/O's but some can leak
187 * through (for non-full-sized direct I/Os).
190 hammer_io_wait_all(hammer_mount_t hmp, const char *ident, int doflush)
192 struct hammer_io iodummy;
196 * Degenerate case, no I/O is running
198 lwkt_gettoken(&hmp->io_token);
199 if (TAILQ_EMPTY(&hmp->iorun_list)) {
200 lwkt_reltoken(&hmp->io_token);
202 hammer_io_flush_sync(hmp);
205 bzero(&iodummy, sizeof(iodummy));
206 iodummy.type = HAMMER_STRUCTURE_DUMMY;
209 * Add placemarker and then wait until it becomes the head of
212 TAILQ_INSERT_TAIL(&hmp->iorun_list, &iodummy, iorun_entry);
213 while (TAILQ_FIRST(&hmp->iorun_list) != &iodummy) {
214 tsleep(&iodummy, 0, ident, 0);
218 * Chain in case several placemarkers are present.
220 TAILQ_REMOVE(&hmp->iorun_list, &iodummy, iorun_entry);
221 io = TAILQ_FIRST(&hmp->iorun_list);
222 if (io && io->type == HAMMER_STRUCTURE_DUMMY)
224 lwkt_reltoken(&hmp->io_token);
227 hammer_io_flush_sync(hmp);
231 * Clear a flagged error condition on a I/O buffer. The caller must hold
232 * its own ref on the buffer.
235 hammer_io_clear_error(struct hammer_io *io)
237 hammer_mount_t hmp = io->hmp;
239 lwkt_gettoken(&hmp->io_token);
242 hammer_rel(&io->lock);
243 KKASSERT(hammer_isactive(&io->lock));
245 lwkt_reltoken(&hmp->io_token);
249 hammer_io_clear_error_noassert(struct hammer_io *io)
251 hammer_mount_t hmp = io->hmp;
253 lwkt_gettoken(&hmp->io_token);
256 hammer_rel(&io->lock);
258 lwkt_reltoken(&hmp->io_token);
262 * This is an advisory function only which tells the buffer cache
263 * the bp is not a meta-data buffer, even though it is backed by
266 * This is used by HAMMER's reblocking code to avoid trying to
267 * swapcache the filesystem's data when it is read or written
268 * by the reblocking code.
270 * The caller has a ref on the buffer preventing the bp from
271 * being disassociated from it.
274 hammer_io_notmeta(hammer_buffer_t buffer)
276 if ((buffer->io.bp->b_flags & B_NOTMETA) == 0) {
277 hammer_mount_t hmp = buffer->io.hmp;
279 lwkt_gettoken(&hmp->io_token);
280 buffer->io.bp->b_flags |= B_NOTMETA;
281 lwkt_reltoken(&hmp->io_token);
286 * Load bp for a HAMMER structure. The io must be exclusively locked by
289 * This routine is mostly used on meta-data and small-data blocks. Generally
290 * speaking HAMMER assumes some locality of reference and will cluster.
292 * Note that the caller (hammer_ondisk.c) may place further restrictions
293 * on clusterability via the limit (in bytes). Typically large-data
294 * zones cannot be clustered due to their mixed buffer sizes. This is
295 * not an issue since such clustering occurs in hammer_vnops at the
296 * regular file layer, whereas this is the buffered block device layer.
298 * No I/O callbacks can occur while we hold the buffer locked.
301 hammer_io_read(struct vnode *devvp, struct hammer_io *io, int limit)
306 if ((bp = io->bp) == NULL) {
307 atomic_add_long(&hammer_count_io_running_read, io->bytes);
308 if (hammer_cluster_enable && limit > io->bytes) {
309 error = cluster_read(devvp, io->offset + limit,
310 io->offset, io->bytes,
315 error = bread(devvp, io->offset, io->bytes, &io->bp);
317 hammer_stats_disk_read += io->bytes;
318 atomic_add_long(&hammer_count_io_running_read, -io->bytes);
321 * The code generally assumes b_ops/b_dep has been set-up,
322 * even if we error out here.
325 if ((hammer_debug_io & 0x0001) && (bp->b_flags & B_IODEBUG)) {
326 const char *metatype;
329 case HAMMER_STRUCTURE_VOLUME:
332 case HAMMER_STRUCTURE_META_BUFFER:
333 switch(((struct hammer_buffer *)io)->
334 zoneX_offset & HAMMER_OFF_ZONE_MASK) {
335 case HAMMER_ZONE_BTREE:
338 case HAMMER_ZONE_META:
341 case HAMMER_ZONE_FREEMAP:
342 metatype = "freemap";
349 case HAMMER_STRUCTURE_DATA_BUFFER:
352 case HAMMER_STRUCTURE_UNDO_BUFFER:
356 metatype = "unknown";
359 kprintf("doff %016jx %s\n",
360 (intmax_t)bp->b_bio2.bio_offset,
363 bp->b_flags &= ~B_IODEBUG;
364 bp->b_ops = &hammer_bioops;
365 KKASSERT(LIST_FIRST(&bp->b_dep) == NULL);
367 /* io->worklist is locked by the io lock */
368 LIST_INSERT_HEAD(&bp->b_dep, &io->worklist, node);
370 KKASSERT(io->modified == 0);
371 KKASSERT(io->running == 0);
372 KKASSERT(io->waiting == 0);
373 io->released = 0; /* we hold an active lock on bp */
381 * Similar to hammer_io_read() but returns a zero'd out buffer instead.
382 * Must be called with the IO exclusively locked.
384 * vfs_bio_clrbuf() is kinda nasty, enforce serialization against background
385 * I/O by forcing the buffer to not be in a released state before calling
388 * This function will also mark the IO as modified but it will not
389 * increment the modify_refs count.
391 * No I/O callbacks can occur while we hold the buffer locked.
394 hammer_io_new(struct vnode *devvp, struct hammer_io *io)
398 if ((bp = io->bp) == NULL) {
399 io->bp = getblk(devvp, io->offset, io->bytes, 0, 0);
401 bp->b_ops = &hammer_bioops;
402 KKASSERT(LIST_FIRST(&bp->b_dep) == NULL);
404 /* io->worklist is locked by the io lock */
405 LIST_INSERT_HEAD(&bp->b_dep, &io->worklist, node);
407 KKASSERT(io->running == 0);
417 hammer_io_modify(io, 0);
423 * Advance the activity count on the underlying buffer because
424 * HAMMER does not getblk/brelse on every access.
426 * The io->bp cannot go away while the buffer is referenced.
429 hammer_io_advance(struct hammer_io *io)
432 buf_act_advance(io->bp);
436 * Remove potential device level aliases against buffers managed by high level
437 * vnodes. Aliases can also be created due to mixed buffer sizes or via
438 * direct access to the backing store device.
440 * This is nasty because the buffers are also VMIO-backed. Even if a buffer
441 * does not exist its backing VM pages might, and we have to invalidate
442 * those as well or a getblk() will reinstate them.
444 * Buffer cache buffers associated with hammer_buffers cannot be
448 hammer_io_inval(hammer_volume_t volume, hammer_off_t zone2_offset)
450 hammer_io_structure_t iou;
452 hammer_off_t phys_offset;
456 hmp = volume->io.hmp;
457 lwkt_gettoken(&hmp->io_token);
460 * If a device buffer already exists for the specified physical
461 * offset use that, otherwise instantiate a buffer to cover any
462 * related VM pages, set BNOCACHE, and brelse().
464 phys_offset = volume->ondisk->vol_buf_beg +
465 (zone2_offset & HAMMER_OFF_SHORT_MASK);
466 if ((bp = findblk(volume->devvp, phys_offset, 0)) != NULL)
469 bp = getblk(volume->devvp, phys_offset, HAMMER_BUFSIZE, 0, 0);
471 if ((iou = (void *)LIST_FIRST(&bp->b_dep)) != NULL) {
473 hammer_ref(&iou->io.lock);
474 hammer_io_clear_modify(&iou->io, 1);
476 iou->io.released = 0;
479 iou->io.waitdep = 1; /* XXX this is a fs_token field */
480 KKASSERT(hammer_isactive(&iou->io.lock) == 1);
481 hammer_rel_buffer(&iou->buffer, 0);
482 /*hammer_io_deallocate(bp);*/
487 KKASSERT((bp->b_flags & B_LOCKED) == 0);
489 bp->b_flags |= B_NOCACHE|B_RELBUF;
493 lwkt_reltoken(&hmp->io_token);
498 * This routine is called on the last reference to a hammer structure.
499 * The io must be interlocked with a refcount of zero. The hammer structure
500 * will remain interlocked on return.
502 * This routine may return a non-NULL bp to the caller for dispoal.
503 * The caller typically brelse()'s the bp.
505 * The bp may or may not still be passively associated with the IO. It
506 * will remain passively associated if it is unreleasable (e.g. a modified
509 * The only requirement here is that modified meta-data and volume-header
510 * buffer may NOT be disassociated from the IO structure, and consequently
511 * we also leave such buffers actively associated with the IO if they already
512 * are (since the kernel can't do anything with them anyway). Only the
513 * flusher is allowed to write such buffers out. Modified pure-data and
514 * undo buffers are returned to the kernel but left passively associated
515 * so we can track when the kernel writes the bp out.
518 hammer_io_release(struct hammer_io *io, int flush)
520 union hammer_io_structure *iou = (void *)io;
523 if ((bp = io->bp) == NULL)
527 * Try to flush a dirty IO to disk if asked to by the
528 * caller or if the kernel tried to flush the buffer in the past.
530 * Kernel-initiated flushes are only allowed for pure-data buffers.
531 * meta-data and volume buffers can only be flushed explicitly
536 hammer_io_flush(io, 0);
537 } else if (bp->b_flags & B_LOCKED) {
539 case HAMMER_STRUCTURE_DATA_BUFFER:
540 hammer_io_flush(io, 0);
542 case HAMMER_STRUCTURE_UNDO_BUFFER:
543 hammer_io_flush(io, hammer_undo_reclaim(io));
548 } /* else no explicit request to flush the buffer */
552 * Wait for the IO to complete if asked to. This occurs when
553 * the buffer must be disposed of definitively during an umount
554 * or buffer invalidation.
556 if (io->waitdep && io->running) {
561 * Return control of the buffer to the kernel (with the provisio
562 * that our bioops can override kernel decisions with regards to
565 if ((flush || io->reclaim) && io->modified == 0 && io->running == 0) {
567 * Always disassociate the bp if an explicit flush
568 * was requested and the IO completed with no error
569 * (so unmount can really clean up the structure).
577 hammer_io_disassociate((hammer_io_structure_t)io);
579 } else if (io->modified) {
581 * Only certain IO types can be released to the kernel if
582 * the buffer has been modified.
584 * volume and meta-data IO types may only be explicitly
588 case HAMMER_STRUCTURE_DATA_BUFFER:
589 case HAMMER_STRUCTURE_UNDO_BUFFER:
590 if (io->released == 0) {
598 bp = NULL; /* bp left associated */
599 } else if (io->released == 0) {
601 * Clean buffers can be generally released to the kernel.
602 * We leave the bp passively associated with the HAMMER
603 * structure and use bioops to disconnect it later on
604 * if the kernel wants to discard the buffer.
606 * We can steal the structure's ownership of the bp.
609 if (bp->b_flags & B_LOCKED) {
610 hammer_io_disassociate(iou);
614 hammer_io_disassociate(iou);
617 /* return the bp (bp passively associated) */
622 * A released buffer is passively associate with our
623 * hammer_io structure. The kernel cannot destroy it
624 * without making a bioops call. If the kernel (B_LOCKED)
625 * or we (reclaim) requested that the buffer be destroyed
626 * we destroy it, otherwise we do a quick get/release to
627 * reset its position in the kernel's LRU list.
629 * Leaving the buffer passively associated allows us to
630 * use the kernel's LRU buffer flushing mechanisms rather
631 * then rolling our own.
633 * XXX there are two ways of doing this. We can re-acquire
634 * and passively release to reset the LRU, or not.
636 if (io->running == 0) {
638 if ((bp->b_flags & B_LOCKED) || io->reclaim) {
639 hammer_io_disassociate(iou);
642 /* return the bp (bp passively associated) */
646 * bp is left passively associated but we do not
647 * try to reacquire it. Interactions with the io
648 * structure will occur on completion of the bp's
658 * This routine is called with a locked IO when a flush is desired and
659 * no other references to the structure exists other then ours. This
660 * routine is ONLY called when HAMMER believes it is safe to flush a
661 * potentially modified buffer out.
663 * The locked io or io reference prevents a flush from being initiated
667 hammer_io_flush(struct hammer_io *io, int reclaim)
673 * Degenerate case - nothing to flush if nothing is dirty.
675 if (io->modified == 0)
679 KKASSERT(io->modify_refs <= 0);
682 * Acquire ownership of the bp, particularly before we clear our
685 * We are going to bawrite() this bp. Don't leave a window where
686 * io->released is set, we actually own the bp rather then our
689 * The io_token should not be required here as only
695 /* BUF_KERNPROC(io->bp); */
696 /* io->released = 0; */
697 KKASSERT(io->released);
698 KKASSERT(io->bp == bp);
705 if ((bp->b_flags & B_LOCKED) == 0) {
706 bp->b_flags |= B_LOCKED;
707 atomic_add_int(&hammer_count_io_locked, 1);
712 * Acquire exclusive access to the bp and then clear the modified
713 * state of the buffer prior to issuing I/O to interlock any
714 * modifications made while the I/O is in progress. This shouldn't
715 * happen anyway but losing data would be worse. The modified bit
716 * will be rechecked after the IO completes.
718 * NOTE: This call also finalizes the buffer's content (inval == 0).
720 * This is only legal when lock.refs == 1 (otherwise we might clear
721 * the modified bit while there are still users of the cluster
722 * modifying the data).
724 * Do this before potentially blocking so any attempt to modify the
725 * ondisk while we are blocked blocks waiting for us.
727 hammer_ref(&io->lock);
728 hammer_io_clear_modify(io, 0);
729 hammer_rel(&io->lock);
731 if (hammer_debug_io & 0x0002)
732 kprintf("hammer io_write %016jx\n", bp->b_bio1.bio_offset);
735 * Transfer ownership to the kernel and initiate I/O.
737 * NOTE: We do not hold io_token so an atomic op is required to
738 * update io_running_space.
741 atomic_add_long(&hmp->io_running_space, io->bytes);
742 atomic_add_long(&hammer_count_io_running_write, io->bytes);
743 lwkt_gettoken(&hmp->io_token);
744 TAILQ_INSERT_TAIL(&hmp->iorun_list, io, iorun_entry);
745 lwkt_reltoken(&hmp->io_token);
747 hammer_io_flush_mark(io->volume);
750 /************************************************************************
752 ************************************************************************
754 * These routines deal with dependancies created when IO buffers get
755 * modified. The caller must call hammer_modify_*() on a referenced
756 * HAMMER structure prior to modifying its on-disk data.
758 * Any intent to modify an IO buffer acquires the related bp and imposes
759 * various write ordering dependancies.
763 * Mark a HAMMER structure as undergoing modification. Meta-data buffers
764 * are locked until the flusher can deal with them, pure data buffers
765 * can be written out.
767 * The referenced io prevents races.
771 hammer_io_modify(hammer_io_t io, int count)
774 * io->modify_refs must be >= 0
776 while (io->modify_refs < 0) {
778 tsleep(io, 0, "hmrmod", 0);
782 * Shortcut if nothing to do.
784 KKASSERT(hammer_isactive(&io->lock) && io->bp != NULL);
785 io->modify_refs += count;
786 if (io->modified && io->released == 0)
790 * NOTE: It is important not to set the modified bit
791 * until after we have acquired the bp or we risk
792 * racing against checkwrite.
794 hammer_lock_ex(&io->lock);
797 BUF_KERNPROC(io->bp);
800 if (io->modified == 0) {
801 hammer_io_set_modlist(io);
804 hammer_unlock(&io->lock);
809 hammer_io_modify_done(hammer_io_t io)
811 KKASSERT(io->modify_refs > 0);
813 if (io->modify_refs == 0 && io->waitmod) {
820 * The write interlock blocks other threads trying to modify a buffer
821 * (they block in hammer_io_modify()) after us, or blocks us while other
822 * threads are in the middle of modifying a buffer.
824 * The caller also has a ref on the io, however if we are not careful
825 * we will race bioops callbacks (checkwrite). To deal with this
826 * we must at least acquire and release the io_token, and it is probably
827 * better to hold it through the setting of modify_refs.
830 hammer_io_write_interlock(hammer_io_t io)
832 hammer_mount_t hmp = io->hmp;
834 lwkt_gettoken(&hmp->io_token);
835 while (io->modify_refs != 0) {
837 tsleep(io, 0, "hmrmod", 0);
839 io->modify_refs = -1;
840 lwkt_reltoken(&hmp->io_token);
844 hammer_io_done_interlock(hammer_io_t io)
846 KKASSERT(io->modify_refs == -1);
855 * Caller intends to modify a volume's ondisk structure.
857 * This is only allowed if we are the flusher or we have a ref on the
861 hammer_modify_volume(hammer_transaction_t trans, hammer_volume_t volume,
864 KKASSERT (trans == NULL || trans->sync_lock_refs > 0);
866 hammer_io_modify(&volume->io, 1);
868 intptr_t rel_offset = (intptr_t)base - (intptr_t)volume->ondisk;
869 KKASSERT((rel_offset & ~(intptr_t)HAMMER_BUFMASK) == 0);
870 hammer_generate_undo(trans,
871 HAMMER_ENCODE_RAW_VOLUME(volume->vol_no, rel_offset),
877 * Caller intends to modify a buffer's ondisk structure.
879 * This is only allowed if we are the flusher or we have a ref on the
883 hammer_modify_buffer(hammer_transaction_t trans, hammer_buffer_t buffer,
886 KKASSERT (trans == NULL || trans->sync_lock_refs > 0);
888 hammer_io_modify(&buffer->io, 1);
890 intptr_t rel_offset = (intptr_t)base - (intptr_t)buffer->ondisk;
891 KKASSERT((rel_offset & ~(intptr_t)HAMMER_BUFMASK) == 0);
892 hammer_generate_undo(trans,
893 buffer->zone2_offset + rel_offset,
899 hammer_modify_volume_done(hammer_volume_t volume)
901 hammer_io_modify_done(&volume->io);
905 hammer_modify_buffer_done(hammer_buffer_t buffer)
907 hammer_io_modify_done(&buffer->io);
911 * Mark an entity as not being dirty any more and finalize any
912 * delayed adjustments to the buffer.
914 * Delayed adjustments are an important performance enhancement, allowing
915 * us to avoid recalculating B-Tree node CRCs over and over again when
916 * making bulk-modifications to the B-Tree.
918 * If inval is non-zero delayed adjustments are ignored.
920 * This routine may dereference related btree nodes and cause the
921 * buffer to be dereferenced. The caller must own a reference on io.
924 hammer_io_clear_modify(struct hammer_io *io, int inval)
929 * io_token is needed to avoid races on mod_root
931 if (io->modified == 0)
934 lwkt_gettoken(&hmp->io_token);
935 if (io->modified == 0) {
936 lwkt_reltoken(&hmp->io_token);
941 * Take us off the mod-list and clear the modified bit.
943 KKASSERT(io->mod_root != NULL);
944 if (io->mod_root == &io->hmp->volu_root ||
945 io->mod_root == &io->hmp->meta_root) {
946 io->hmp->locked_dirty_space -= io->bytes;
947 atomic_add_long(&hammer_count_dirtybufspace, -io->bytes);
949 RB_REMOVE(hammer_mod_rb_tree, io->mod_root, io);
953 lwkt_reltoken(&hmp->io_token);
956 * If this bit is not set there are no delayed adjustments.
963 * Finalize requested CRCs. The NEEDSCRC flag also holds a reference
964 * on the node (& underlying buffer). Release the node after clearing
967 if (io->type == HAMMER_STRUCTURE_META_BUFFER) {
968 hammer_buffer_t buffer = (void *)io;
972 TAILQ_FOREACH(node, &buffer->clist, entry) {
973 if ((node->flags & HAMMER_NODE_NEEDSCRC) == 0)
975 node->flags &= ~HAMMER_NODE_NEEDSCRC;
976 KKASSERT(node->ondisk);
978 node->ondisk->crc = crc32(&node->ondisk->crc + 1, HAMMER_BTREE_CRCSIZE);
979 hammer_rel_node(node);
983 /* caller must still have ref on io */
984 KKASSERT(hammer_isactive(&io->lock));
988 * Clear the IO's modify list. Even though the IO is no longer modified
989 * it may still be on the lose_root. This routine is called just before
990 * the governing hammer_buffer is destroyed.
992 * mod_root requires io_token protection.
995 hammer_io_clear_modlist(struct hammer_io *io)
997 hammer_mount_t hmp = io->hmp;
999 KKASSERT(io->modified == 0);
1001 lwkt_gettoken(&hmp->io_token);
1003 KKASSERT(io->mod_root == &io->hmp->lose_root);
1004 RB_REMOVE(hammer_mod_rb_tree, io->mod_root, io);
1005 io->mod_root = NULL;
1007 lwkt_reltoken(&hmp->io_token);
1012 hammer_io_set_modlist(struct hammer_io *io)
1014 struct hammer_mount *hmp = io->hmp;
1016 lwkt_gettoken(&hmp->io_token);
1017 KKASSERT(io->mod_root == NULL);
1020 case HAMMER_STRUCTURE_VOLUME:
1021 io->mod_root = &hmp->volu_root;
1022 hmp->locked_dirty_space += io->bytes;
1023 atomic_add_long(&hammer_count_dirtybufspace, io->bytes);
1025 case HAMMER_STRUCTURE_META_BUFFER:
1026 io->mod_root = &hmp->meta_root;
1027 hmp->locked_dirty_space += io->bytes;
1028 atomic_add_long(&hammer_count_dirtybufspace, io->bytes);
1030 case HAMMER_STRUCTURE_UNDO_BUFFER:
1031 io->mod_root = &hmp->undo_root;
1033 case HAMMER_STRUCTURE_DATA_BUFFER:
1034 io->mod_root = &hmp->data_root;
1036 case HAMMER_STRUCTURE_DUMMY:
1037 panic("hammer_io_set_modlist: bad io type");
1038 break; /* NOT REACHED */
1040 if (RB_INSERT(hammer_mod_rb_tree, io->mod_root, io)) {
1041 panic("hammer_io_set_modlist: duplicate entry");
1044 lwkt_reltoken(&hmp->io_token);
1047 /************************************************************************
1049 ************************************************************************
1054 * Pre-IO initiation kernel callback - cluster build only
1056 * bioops callback - hold io_token
1059 hammer_io_start(struct buf *bp)
1061 /* nothing to do, so io_token not needed */
1065 * Post-IO completion kernel callback - MAY BE CALLED FROM INTERRUPT!
1067 * NOTE: HAMMER may modify a data buffer after we have initiated write
1070 * NOTE: MPSAFE callback
1072 * bioops callback - hold io_token
1075 hammer_io_complete(struct buf *bp)
1077 union hammer_io_structure *iou = (void *)LIST_FIRST(&bp->b_dep);
1078 struct hammer_mount *hmp = iou->io.hmp;
1079 struct hammer_io *ionext;
1081 lwkt_gettoken(&hmp->io_token);
1083 KKASSERT(iou->io.released == 1);
1086 * Deal with people waiting for I/O to drain
1088 if (iou->io.running) {
1090 * Deal with critical write errors. Once a critical error
1091 * has been flagged in hmp the UNDO FIFO will not be updated.
1092 * That way crash recover will give us a consistent
1095 * Because of this we can throw away failed UNDO buffers. If
1096 * we throw away META or DATA buffers we risk corrupting
1097 * the now read-only version of the filesystem visible to
1098 * the user. Clear B_ERROR so the buffer is not re-dirtied
1099 * by the kernel and ref the io so it doesn't get thrown
1102 if (bp->b_flags & B_ERROR) {
1103 lwkt_gettoken(&hmp->fs_token);
1104 hammer_critical_error(hmp, NULL, bp->b_error,
1105 "while flushing meta-data");
1106 lwkt_reltoken(&hmp->fs_token);
1108 switch(iou->io.type) {
1109 case HAMMER_STRUCTURE_UNDO_BUFFER:
1112 if (iou->io.ioerror == 0) {
1113 iou->io.ioerror = 1;
1114 hammer_ref(&iou->io.lock);
1118 bp->b_flags &= ~B_ERROR;
1121 hammer_io_set_modlist(&iou->io);
1122 iou->io.modified = 1;
1125 hammer_stats_disk_write += iou->io.bytes;
1126 atomic_add_long(&hammer_count_io_running_write, -iou->io.bytes);
1127 atomic_add_long(&hmp->io_running_space, -iou->io.bytes);
1128 KKASSERT(hmp->io_running_space >= 0);
1129 iou->io.running = 0;
1132 * Remove from iorun list and wakeup any multi-io waiter(s).
1134 if (TAILQ_FIRST(&hmp->iorun_list) == &iou->io) {
1135 ionext = TAILQ_NEXT(&iou->io, iorun_entry);
1136 if (ionext && ionext->type == HAMMER_STRUCTURE_DUMMY)
1139 TAILQ_REMOVE(&hmp->iorun_list, &iou->io, iorun_entry);
1141 hammer_stats_disk_read += iou->io.bytes;
1144 if (iou->io.waiting) {
1145 iou->io.waiting = 0;
1150 * If B_LOCKED is set someone wanted to deallocate the bp at some
1151 * point, try to do it now. The operation will fail if there are
1152 * refs or if hammer_io_deallocate() is unable to gain the
1155 if (bp->b_flags & B_LOCKED) {
1156 atomic_add_int(&hammer_count_io_locked, -1);
1157 bp->b_flags &= ~B_LOCKED;
1158 hammer_io_deallocate(bp);
1159 /* structure may be dead now */
1161 lwkt_reltoken(&hmp->io_token);
1165 * Callback from kernel when it wishes to deallocate a passively
1166 * associated structure. This mostly occurs with clean buffers
1167 * but it may be possible for a holding structure to be marked dirty
1168 * while its buffer is passively associated. The caller owns the bp.
1170 * If we cannot disassociate we set B_LOCKED to prevent the buffer
1171 * from getting reused.
1173 * WARNING: Because this can be called directly by getnewbuf we cannot
1174 * recurse into the tree. If a bp cannot be immediately disassociated
1175 * our only recourse is to set B_LOCKED.
1177 * WARNING: This may be called from an interrupt via hammer_io_complete()
1179 * bioops callback - hold io_token
1182 hammer_io_deallocate(struct buf *bp)
1184 hammer_io_structure_t iou = (void *)LIST_FIRST(&bp->b_dep);
1189 lwkt_gettoken(&hmp->io_token);
1191 KKASSERT((bp->b_flags & B_LOCKED) == 0 && iou->io.running == 0);
1192 if (hammer_try_interlock_norefs(&iou->io.lock) == 0) {
1194 * We cannot safely disassociate a bp from a referenced
1195 * or interlocked HAMMER structure.
1197 bp->b_flags |= B_LOCKED;
1198 atomic_add_int(&hammer_count_io_locked, 1);
1199 } else if (iou->io.modified) {
1201 * It is not legal to disassociate a modified buffer. This
1202 * case really shouldn't ever occur.
1204 bp->b_flags |= B_LOCKED;
1205 atomic_add_int(&hammer_count_io_locked, 1);
1206 hammer_put_interlock(&iou->io.lock, 0);
1209 * Disassociate the BP. If the io has no refs left we
1210 * have to add it to the loose list. The kernel has
1211 * locked the buffer and therefore our io must be
1212 * in a released state.
1214 hammer_io_disassociate(iou);
1215 if (iou->io.type != HAMMER_STRUCTURE_VOLUME) {
1216 KKASSERT(iou->io.bp == NULL);
1217 KKASSERT(iou->io.mod_root == NULL);
1218 iou->io.mod_root = &hmp->lose_root;
1219 if (RB_INSERT(hammer_mod_rb_tree, iou->io.mod_root,
1221 panic("hammer_io_deallocate: duplicate entry");
1224 hammer_put_interlock(&iou->io.lock, 1);
1226 lwkt_reltoken(&hmp->io_token);
1230 * bioops callback - hold io_token
1233 hammer_io_fsync(struct vnode *vp)
1235 /* nothing to do, so io_token not needed */
1240 * NOTE: will not be called unless we tell the kernel about the
1241 * bioops. Unused... we use the mount's VFS_SYNC instead.
1243 * bioops callback - hold io_token
1246 hammer_io_sync(struct mount *mp)
1248 /* nothing to do, so io_token not needed */
1253 * bioops callback - hold io_token
1256 hammer_io_movedeps(struct buf *bp1, struct buf *bp2)
1258 /* nothing to do, so io_token not needed */
1262 * I/O pre-check for reading and writing. HAMMER only uses this for
1263 * B_CACHE buffers so checkread just shouldn't happen, but if it does
1266 * Writing is a different case. We don't want the kernel to try to write
1267 * out a buffer that HAMMER may be modifying passively or which has a
1268 * dependancy. In addition, kernel-demanded writes can only proceed for
1269 * certain types of buffers (i.e. UNDO and DATA types). Other dirty
1270 * buffer types can only be explicitly written by the flusher.
1272 * checkwrite will only be called for bdwrite()n buffers. If we return
1273 * success the kernel is guaranteed to initiate the buffer write.
1275 * bioops callback - hold io_token
1278 hammer_io_checkread(struct buf *bp)
1280 /* nothing to do, so io_token not needed */
1285 * The kernel is asking us whether it can write out a dirty buffer or not.
1287 * bioops callback - hold io_token
1290 hammer_io_checkwrite(struct buf *bp)
1292 hammer_io_t io = (void *)LIST_FIRST(&bp->b_dep);
1293 hammer_mount_t hmp = io->hmp;
1296 * This shouldn't happen under normal operation.
1298 lwkt_gettoken(&hmp->io_token);
1299 if (io->type == HAMMER_STRUCTURE_VOLUME ||
1300 io->type == HAMMER_STRUCTURE_META_BUFFER) {
1302 panic("hammer_io_checkwrite: illegal buffer");
1303 if ((bp->b_flags & B_LOCKED) == 0) {
1304 bp->b_flags |= B_LOCKED;
1305 atomic_add_int(&hammer_count_io_locked, 1);
1307 lwkt_reltoken(&hmp->io_token);
1312 * We have to be able to interlock the IO to safely modify any
1313 * of its fields without holding the fs_token. If we can't lock
1314 * it then we are racing someone.
1316 * Our ownership of the bp lock prevents the io from being ripped
1317 * out from under us.
1319 if (hammer_try_interlock_norefs(&io->lock) == 0) {
1320 bp->b_flags |= B_LOCKED;
1321 atomic_add_int(&hammer_count_io_locked, 1);
1322 lwkt_reltoken(&hmp->io_token);
1327 * The modified bit must be cleared prior to the initiation of
1328 * any IO (returning 0 initiates the IO). Because this is a
1329 * normal data buffer hammer_io_clear_modify() runs through a
1330 * simple degenerate case.
1332 * Return 0 will cause the kernel to initiate the IO, and we
1333 * must normally clear the modified bit before we begin. If
1334 * the io has modify_refs we do not clear the modified bit,
1335 * otherwise we may miss changes.
1337 * Only data and undo buffers can reach here. These buffers do
1338 * not have terminal crc functions but we temporarily reference
1339 * the IO anyway, just in case.
1341 if (io->modify_refs == 0 && io->modified) {
1342 hammer_ref(&io->lock);
1343 hammer_io_clear_modify(io, 0);
1344 hammer_rel(&io->lock);
1345 } else if (io->modified) {
1346 KKASSERT(io->type == HAMMER_STRUCTURE_DATA_BUFFER);
1350 * The kernel is going to start the IO, set io->running.
1352 KKASSERT(io->running == 0);
1354 atomic_add_long(&io->hmp->io_running_space, io->bytes);
1355 atomic_add_long(&hammer_count_io_running_write, io->bytes);
1356 TAILQ_INSERT_TAIL(&io->hmp->iorun_list, io, iorun_entry);
1358 hammer_put_interlock(&io->lock, 1);
1359 lwkt_reltoken(&hmp->io_token);
1365 * Return non-zero if we wish to delay the kernel's attempt to flush
1366 * this buffer to disk.
1368 * bioops callback - hold io_token
1371 hammer_io_countdeps(struct buf *bp, int n)
1373 /* nothing to do, so io_token not needed */
1377 struct bio_ops hammer_bioops = {
1378 .io_start = hammer_io_start,
1379 .io_complete = hammer_io_complete,
1380 .io_deallocate = hammer_io_deallocate,
1381 .io_fsync = hammer_io_fsync,
1382 .io_sync = hammer_io_sync,
1383 .io_movedeps = hammer_io_movedeps,
1384 .io_countdeps = hammer_io_countdeps,
1385 .io_checkread = hammer_io_checkread,
1386 .io_checkwrite = hammer_io_checkwrite,
1389 /************************************************************************
1391 ************************************************************************
1393 * These functions operate directly on the buffer cache buffer associated
1394 * with a front-end vnode rather then a back-end device vnode.
1398 * Read a buffer associated with a front-end vnode directly from the
1399 * disk media. The bio may be issued asynchronously. If leaf is non-NULL
1400 * we validate the CRC.
1402 * We must check for the presence of a HAMMER buffer to handle the case
1403 * where the reblocker has rewritten the data (which it does via the HAMMER
1404 * buffer system, not via the high-level vnode buffer cache), but not yet
1405 * committed the buffer to the media.
1408 hammer_io_direct_read(hammer_mount_t hmp, struct bio *bio,
1409 hammer_btree_leaf_elm_t leaf)
1411 hammer_off_t buf_offset;
1412 hammer_off_t zone2_offset;
1413 hammer_volume_t volume;
1419 buf_offset = bio->bio_offset;
1420 KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) ==
1421 HAMMER_ZONE_LARGE_DATA);
1424 * The buffer cache may have an aliased buffer (the reblocker can
1425 * write them). If it does we have to sync any dirty data before
1426 * we can build our direct-read. This is a non-critical code path.
1429 hammer_sync_buffers(hmp, buf_offset, bp->b_bufsize);
1432 * Resolve to a zone-2 offset. The conversion just requires
1433 * munging the top 4 bits but we want to abstract it anyway
1434 * so the blockmap code can verify the zone assignment.
1436 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, &error);
1439 KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) ==
1440 HAMMER_ZONE_RAW_BUFFER);
1443 * Resolve volume and raw-offset for 3rd level bio. The
1444 * offset will be specific to the volume.
1446 vol_no = HAMMER_VOL_DECODE(zone2_offset);
1447 volume = hammer_get_volume(hmp, vol_no, &error);
1448 if (error == 0 && zone2_offset >= volume->maxbuf_off)
1455 nbio = push_bio(bio);
1456 nbio->bio_offset = volume->ondisk->vol_buf_beg +
1457 (zone2_offset & HAMMER_OFF_SHORT_MASK);
1460 * XXX disabled - our CRC check doesn't work if the OS
1461 * does bogus_page replacement on the direct-read.
1463 if (leaf && hammer_verify_data) {
1464 nbio->bio_done = hammer_io_direct_read_complete;
1465 nbio->bio_caller_info1.uvalue32 = leaf->data_crc;
1468 hammer_stats_disk_read += bp->b_bufsize;
1469 vn_strategy(volume->devvp, nbio);
1471 hammer_rel_volume(volume, 0);
1474 kprintf("hammer_direct_read: failed @ %016llx\n",
1475 (long long)zone2_offset);
1476 bp->b_error = error;
1477 bp->b_flags |= B_ERROR;
1484 * This works similarly to hammer_io_direct_read() except instead of
1485 * directly reading from the device into the bio we instead indirectly
1486 * read through the device's buffer cache and then copy the data into
1489 * If leaf is non-NULL and validation is enabled, the CRC will be checked.
1491 * This routine also executes asynchronously. It allows hammer strategy
1492 * calls to operate asynchronously when in double_buffer mode (in addition
1493 * to operating asynchronously when in normal mode).
1496 hammer_io_indirect_read(hammer_mount_t hmp, struct bio *bio,
1497 hammer_btree_leaf_elm_t leaf)
1499 hammer_off_t buf_offset;
1500 hammer_off_t zone2_offset;
1501 hammer_volume_t volume;
1506 buf_offset = bio->bio_offset;
1507 KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) ==
1508 HAMMER_ZONE_LARGE_DATA);
1511 * The buffer cache may have an aliased buffer (the reblocker can
1512 * write them). If it does we have to sync any dirty data before
1513 * we can build our direct-read. This is a non-critical code path.
1516 hammer_sync_buffers(hmp, buf_offset, bp->b_bufsize);
1519 * Resolve to a zone-2 offset. The conversion just requires
1520 * munging the top 4 bits but we want to abstract it anyway
1521 * so the blockmap code can verify the zone assignment.
1523 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, &error);
1526 KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) ==
1527 HAMMER_ZONE_RAW_BUFFER);
1530 * Resolve volume and raw-offset for 3rd level bio. The
1531 * offset will be specific to the volume.
1533 vol_no = HAMMER_VOL_DECODE(zone2_offset);
1534 volume = hammer_get_volume(hmp, vol_no, &error);
1535 if (error == 0 && zone2_offset >= volume->maxbuf_off)
1540 * Convert to the raw volume->devvp offset and acquire
1541 * the buf, issuing async I/O if necessary.
1543 buf_offset = volume->ondisk->vol_buf_beg +
1544 (zone2_offset & HAMMER_OFF_SHORT_MASK);
1546 if (leaf && hammer_verify_data) {
1547 bio->bio_caller_info1.uvalue32 = leaf->data_crc;
1548 bio->bio_caller_info2.index = 1;
1550 bio->bio_caller_info2.index = 0;
1552 breadcb(volume->devvp, buf_offset, bp->b_bufsize,
1553 hammer_indirect_callback, bio);
1555 hammer_rel_volume(volume, 0);
1558 kprintf("hammer_direct_read: failed @ %016llx\n",
1559 (long long)zone2_offset);
1560 bp->b_error = error;
1561 bp->b_flags |= B_ERROR;
1568 * Indirect callback on completion. bio/bp specify the device-backed
1569 * buffer. bio->bio_caller_info1.ptr holds obio.
1571 * obio/obp is the original regular file buffer. obio->bio_caller_info*
1572 * contains the crc specification.
1574 * We are responsible for calling bpdone() and bqrelse() on bio/bp, and
1575 * for calling biodone() on obio.
1578 hammer_indirect_callback(struct bio *bio)
1580 struct buf *bp = bio->bio_buf;
1585 * If BIO_DONE is already set the device buffer was already
1586 * fully valid (B_CACHE). If it is not set then I/O was issued
1587 * and we have to run I/O completion as the last bio.
1589 * Nobody is waiting for our device I/O to complete, we are
1590 * responsible for bqrelse()ing it which means we also have to do
1591 * the equivalent of biowait() and clear BIO_DONE (which breadcb()
1594 * Any preexisting device buffer should match the requested size,
1595 * but due to bigblock recycling and other factors there is some
1596 * fragility there, so we assert that the device buffer covers
1599 if ((bio->bio_flags & BIO_DONE) == 0)
1601 bio->bio_flags &= ~(BIO_DONE | BIO_SYNC);
1603 obio = bio->bio_caller_info1.ptr;
1604 obp = obio->bio_buf;
1606 if (bp->b_flags & B_ERROR) {
1607 obp->b_flags |= B_ERROR;
1608 obp->b_error = bp->b_error;
1609 } else if (obio->bio_caller_info2.index &&
1610 obio->bio_caller_info1.uvalue32 !=
1611 crc32(bp->b_data, bp->b_bufsize)) {
1612 obp->b_flags |= B_ERROR;
1615 KKASSERT(bp->b_bufsize >= obp->b_bufsize);
1616 bcopy(bp->b_data, obp->b_data, obp->b_bufsize);
1618 obp->b_flags |= B_AGE;
1626 * On completion of the BIO this callback must check the data CRC
1627 * and chain to the previous bio.
1629 * MPSAFE - since we do not modify and hammer_records we do not need
1632 * NOTE: MPSAFE callback
1636 hammer_io_direct_read_complete(struct bio *nbio)
1640 u_int32_t rec_crc = nbio->bio_caller_info1.uvalue32;
1643 if (crc32(bp->b_data, bp->b_bufsize) != rec_crc) {
1644 kprintf("HAMMER: data_crc error @%016llx/%d\n",
1645 nbio->bio_offset, bp->b_bufsize);
1646 if (hammer_debug_critical)
1647 Debugger("data_crc on read");
1648 bp->b_flags |= B_ERROR;
1651 obio = pop_bio(nbio);
1657 * Write a buffer associated with a front-end vnode directly to the
1658 * disk media. The bio may be issued asynchronously.
1660 * The BIO is associated with the specified record and RECG_DIRECT_IO
1661 * is set. The recorded is added to its object.
1664 hammer_io_direct_write(hammer_mount_t hmp, struct bio *bio,
1665 hammer_record_t record)
1667 hammer_btree_leaf_elm_t leaf = &record->leaf;
1668 hammer_off_t buf_offset;
1669 hammer_off_t zone2_offset;
1670 hammer_volume_t volume;
1671 hammer_buffer_t buffer;
1678 buf_offset = leaf->data_offset;
1680 KKASSERT(buf_offset > HAMMER_ZONE_BTREE);
1681 KKASSERT(bio->bio_buf->b_cmd == BUF_CMD_WRITE);
1684 * Issue or execute the I/O. The new memory record must replace
1685 * the old one before the I/O completes, otherwise a reaquisition of
1686 * the buffer will load the old media data instead of the new.
1688 if ((buf_offset & HAMMER_BUFMASK) == 0 &&
1689 leaf->data_len >= HAMMER_BUFSIZE) {
1691 * We are using the vnode's bio to write directly to the
1692 * media, any hammer_buffer at the same zone-X offset will
1693 * now have stale data.
1695 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, &error);
1696 vol_no = HAMMER_VOL_DECODE(zone2_offset);
1697 volume = hammer_get_volume(hmp, vol_no, &error);
1699 if (error == 0 && zone2_offset >= volume->maxbuf_off)
1703 KKASSERT((bp->b_bufsize & HAMMER_BUFMASK) == 0);
1705 hammer_del_buffers(hmp, buf_offset,
1706 zone2_offset, bp->b_bufsize);
1710 * Second level bio - cached zone2 offset.
1712 * (We can put our bio_done function in either the
1713 * 2nd or 3rd level).
1715 nbio = push_bio(bio);
1716 nbio->bio_offset = zone2_offset;
1717 nbio->bio_done = hammer_io_direct_write_complete;
1718 nbio->bio_caller_info1.ptr = record;
1719 record->zone2_offset = zone2_offset;
1720 record->gflags |= HAMMER_RECG_DIRECT_IO |
1721 HAMMER_RECG_DIRECT_INVAL;
1724 * Third level bio - raw offset specific to the
1727 zone2_offset &= HAMMER_OFF_SHORT_MASK;
1728 nbio = push_bio(nbio);
1729 nbio->bio_offset = volume->ondisk->vol_buf_beg +
1731 hammer_stats_disk_write += bp->b_bufsize;
1732 hammer_ip_replace_bulk(hmp, record);
1733 vn_strategy(volume->devvp, nbio);
1734 hammer_io_flush_mark(volume);
1736 hammer_rel_volume(volume, 0);
1739 * Must fit in a standard HAMMER buffer. In this case all
1740 * consumers use the HAMMER buffer system and RECG_DIRECT_IO
1741 * does not need to be set-up.
1743 KKASSERT(((buf_offset ^ (buf_offset + leaf->data_len - 1)) & ~HAMMER_BUFMASK64) == 0);
1745 ptr = hammer_bread(hmp, buf_offset, &error, &buffer);
1748 bp->b_flags |= B_AGE;
1749 hammer_io_modify(&buffer->io, 1);
1750 bcopy(bp->b_data, ptr, leaf->data_len);
1751 hammer_io_modify_done(&buffer->io);
1752 hammer_rel_buffer(buffer, 0);
1754 hammer_ip_replace_bulk(hmp, record);
1760 * Major suckage occured. Also note: The record was
1761 * never added to the tree so we do not have to worry
1762 * about the backend.
1764 kprintf("hammer_direct_write: failed @ %016llx\n",
1765 (long long)leaf->data_offset);
1769 bp->b_flags |= B_ERROR;
1771 record->flags |= HAMMER_RECF_DELETED_FE;
1772 hammer_rel_mem_record(record);
1778 * On completion of the BIO this callback must disconnect
1779 * it from the hammer_record and chain to the previous bio.
1781 * An I/O error forces the mount to read-only. Data buffers
1782 * are not B_LOCKED like meta-data buffers are, so we have to
1783 * throw the buffer away to prevent the kernel from retrying.
1785 * NOTE: MPSAFE callback, only modify fields we have explicit
1786 * access to (the bp and the record->gflags).
1790 hammer_io_direct_write_complete(struct bio *nbio)
1794 hammer_record_t record;
1797 record = nbio->bio_caller_info1.ptr;
1798 KKASSERT(record != NULL);
1799 hmp = record->ip->hmp;
1801 lwkt_gettoken(&hmp->io_token);
1804 obio = pop_bio(nbio);
1805 if (bp->b_flags & B_ERROR) {
1806 lwkt_gettoken(&hmp->fs_token);
1807 hammer_critical_error(hmp, record->ip,
1809 "while writing bulk data");
1810 lwkt_reltoken(&hmp->fs_token);
1811 bp->b_flags |= B_INVAL;
1815 KKASSERT(record->gflags & HAMMER_RECG_DIRECT_IO);
1816 if (record->gflags & HAMMER_RECG_DIRECT_WAIT) {
1817 record->gflags &= ~(HAMMER_RECG_DIRECT_IO |
1818 HAMMER_RECG_DIRECT_WAIT);
1819 /* record can disappear once DIRECT_IO flag is cleared */
1820 wakeup(&record->flags);
1822 record->gflags &= ~HAMMER_RECG_DIRECT_IO;
1823 /* record can disappear once DIRECT_IO flag is cleared */
1825 lwkt_reltoken(&hmp->io_token);
1830 * This is called before a record is either committed to the B-Tree
1831 * or destroyed, to resolve any associated direct-IO.
1833 * (1) We must wait for any direct-IO related to the record to complete.
1835 * (2) We must remove any buffer cache aliases for data accessed via
1836 * leaf->data_offset or zone2_offset so non-direct-IO consumers
1837 * (the mirroring and reblocking code) do not see stale data.
1840 hammer_io_direct_wait(hammer_record_t record)
1842 hammer_mount_t hmp = record->ip->hmp;
1845 * Wait for I/O to complete
1847 if (record->gflags & HAMMER_RECG_DIRECT_IO) {
1848 lwkt_gettoken(&hmp->io_token);
1849 while (record->gflags & HAMMER_RECG_DIRECT_IO) {
1850 record->gflags |= HAMMER_RECG_DIRECT_WAIT;
1851 tsleep(&record->flags, 0, "hmdiow", 0);
1853 lwkt_reltoken(&hmp->io_token);
1857 * Invalidate any related buffer cache aliases associated with the
1858 * backing device. This is needed because the buffer cache buffer
1859 * for file data is associated with the file vnode, not the backing
1862 * XXX I do not think this case can occur any more now that
1863 * reservations ensure that all such buffers are removed before
1864 * an area can be reused.
1866 if (record->gflags & HAMMER_RECG_DIRECT_INVAL) {
1867 KKASSERT(record->leaf.data_offset);
1868 hammer_del_buffers(hmp, record->leaf.data_offset,
1869 record->zone2_offset, record->leaf.data_len,
1871 record->gflags &= ~HAMMER_RECG_DIRECT_INVAL;
1876 * This is called to remove the second-level cached zone-2 offset from
1877 * frontend buffer cache buffers, now stale due to a data relocation.
1878 * These offsets are generated by cluster_read() via VOP_BMAP, or directly
1879 * by hammer_vop_strategy_read().
1881 * This is rather nasty because here we have something like the reblocker
1882 * scanning the raw B-Tree with no held references on anything, really,
1883 * other then a shared lock on the B-Tree node, and we have to access the
1884 * frontend's buffer cache to check for and clean out the association.
1885 * Specifically, if the reblocker is moving data on the disk, these cached
1886 * offsets will become invalid.
1888 * Only data record types associated with the large-data zone are subject
1889 * to direct-io and need to be checked.
1893 hammer_io_direct_uncache(hammer_mount_t hmp, hammer_btree_leaf_elm_t leaf)
1895 struct hammer_inode_info iinfo;
1898 if (leaf->base.rec_type != HAMMER_RECTYPE_DATA)
1900 zone = HAMMER_ZONE_DECODE(leaf->data_offset);
1901 if (zone != HAMMER_ZONE_LARGE_DATA_INDEX)
1903 iinfo.obj_id = leaf->base.obj_id;
1904 iinfo.obj_asof = 0; /* unused */
1905 iinfo.obj_localization = leaf->base.localization &
1906 HAMMER_LOCALIZE_PSEUDOFS_MASK;
1907 iinfo.u.leaf = leaf;
1908 hammer_scan_inode_snapshots(hmp, &iinfo,
1909 hammer_io_direct_uncache_callback,
1914 hammer_io_direct_uncache_callback(hammer_inode_t ip, void *data)
1916 hammer_inode_info_t iinfo = data;
1917 hammer_off_t data_offset;
1918 hammer_off_t file_offset;
1925 data_offset = iinfo->u.leaf->data_offset;
1926 file_offset = iinfo->u.leaf->base.key - iinfo->u.leaf->data_len;
1927 blksize = iinfo->u.leaf->data_len;
1928 KKASSERT((blksize & HAMMER_BUFMASK) == 0);
1931 * Warning: FINDBLK_TEST return stable storage but not stable
1932 * contents. It happens to be ok in this case.
1934 hammer_ref(&ip->lock);
1935 if (hammer_get_vnode(ip, &vp) == 0) {
1936 if ((bp = findblk(ip->vp, file_offset, FINDBLK_TEST)) != NULL &&
1937 bp->b_bio2.bio_offset != NOOFFSET) {
1938 bp = getblk(ip->vp, file_offset, blksize, 0, 0);
1939 bp->b_bio2.bio_offset = NOOFFSET;
1944 hammer_rel_inode(ip, 0);
1950 * This function is called when writes may have occured on the volume,
1951 * indicating that the device may be holding cached writes.
1954 hammer_io_flush_mark(hammer_volume_t volume)
1956 atomic_set_int(&volume->vol_flags, HAMMER_VOLF_NEEDFLUSH);
1960 * This function ensures that the device has flushed any cached writes out.
1963 hammer_io_flush_sync(hammer_mount_t hmp)
1965 hammer_volume_t volume;
1966 struct buf *bp_base = NULL;
1969 RB_FOREACH(volume, hammer_vol_rb_tree, &hmp->rb_vols_root) {
1970 if (volume->vol_flags & HAMMER_VOLF_NEEDFLUSH) {
1971 atomic_clear_int(&volume->vol_flags,
1972 HAMMER_VOLF_NEEDFLUSH);
1974 bp->b_bio1.bio_offset = 0;
1977 bp->b_cmd = BUF_CMD_FLUSH;
1978 bp->b_bio1.bio_caller_info1.cluster_head = bp_base;
1979 bp->b_bio1.bio_done = biodone_sync;
1980 bp->b_bio1.bio_flags |= BIO_SYNC;
1982 vn_strategy(volume->devvp, &bp->b_bio1);
1985 while ((bp = bp_base) != NULL) {
1986 bp_base = bp->b_bio1.bio_caller_info1.cluster_head;
1987 biowait(&bp->b_bio1, "hmrFLS");
1993 * Limit the amount of backlog which we allow to build up
1996 hammer_io_limit_backlog(hammer_mount_t hmp)
1998 waitrunningbufspace();