2 * Copyright (c) 2007-2008 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * $DragonFly: src/sys/vfs/hammer/hammer_io.c,v 1.44 2008/06/20 05:38:26 dillon Exp $
37 * IO Primitives and buffer cache management
39 * All major data-tracking structures in HAMMER contain a struct hammer_io
40 * which is used to manage their backing store. We use filesystem buffers
41 * for backing store and we leave them passively associated with their
44 * If the kernel tries to destroy a passively associated buf which we cannot
45 * yet let go we set B_LOCKED in the buffer and then actively released it
50 #include <sys/fcntl.h>
51 #include <sys/nlookup.h>
55 static void hammer_io_modify(hammer_io_t io
, int count
);
56 static void hammer_io_deallocate(struct buf
*bp
);
59 * Initialize a new, already-zero'd hammer_io structure, or reinitialize
60 * an existing hammer_io structure which may have switched to another type.
63 hammer_io_init(hammer_io_t io
, hammer_mount_t hmp
, enum hammer_io_type type
)
70 * Helper routine to disassociate a buffer cache buffer from an I/O
73 * The io may have 0 or 1 references depending on who called us. The
74 * caller is responsible for dealing with the refs.
76 * This call can only be made when no action is required on the buffer.
77 * HAMMER must own the buffer (released == 0) since we mess around with it.
80 hammer_io_disassociate(hammer_io_structure_t iou
, int elseit
)
82 struct buf
*bp
= iou
->io
.bp
;
84 KKASSERT(iou
->io
.modified
== 0);
85 KKASSERT(LIST_FIRST(&bp
->b_dep
) == (void *)iou
);
90 * If the buffer was locked someone wanted to get rid of it.
92 if (bp
->b_flags
& B_LOCKED
) {
93 --hammer_count_io_locked
;
94 bp
->b_flags
&= ~B_LOCKED
;
98 * elseit is 0 when called from the kernel path when the io
99 * might have no references.
102 KKASSERT(iou
->io
.released
== 0);
103 iou
->io
.released
= 1;
105 bp
->b_flags
|= B_NOCACHE
|B_RELBUF
;
108 KKASSERT(iou
->io
.released
);
112 switch(iou
->io
.type
) {
113 case HAMMER_STRUCTURE_VOLUME
:
114 iou
->volume
.ondisk
= NULL
;
116 case HAMMER_STRUCTURE_DATA_BUFFER
:
117 case HAMMER_STRUCTURE_META_BUFFER
:
118 case HAMMER_STRUCTURE_UNDO_BUFFER
:
119 iou
->buffer
.ondisk
= NULL
;
125 * Wait for any physical IO to complete
128 hammer_io_wait(hammer_io_t io
)
132 tsleep_interlock(io
);
135 tsleep(io
, 0, "hmrflw", 0);
136 if (io
->running
== 0)
138 tsleep_interlock(io
);
140 if (io
->running
== 0)
148 * Wait for all hammer_io-initated write I/O's to complete. This is not
149 * supposed to count direct I/O's but some can leak through (for
150 * non-full-sized direct I/Os).
153 hammer_io_wait_all(hammer_mount_t hmp
, const char *ident
)
156 while (hmp
->io_running_count
)
157 tsleep(&hmp
->io_running_count
, 0, ident
, 0);
161 #define HAMMER_MAXRA 4
164 * Load bp for a HAMMER structure. The io must be exclusively locked by
167 * This routine is mostly used on meta-data and small-data blocks. Generally
168 * speaking HAMMER assumes some locality of reference and will cluster
171 * Note that clustering occurs at the device layer, not the logical layer.
172 * If the buffers do not apply to the current operation they may apply to
176 hammer_io_read(struct vnode
*devvp
, struct hammer_io
*io
, hammer_off_t limit
)
181 if ((bp
= io
->bp
) == NULL
) {
182 ++hammer_count_io_running_read
;
184 error
= cluster_read(devvp
, limit
, io
->offset
, io
->bytes
,
186 HAMMER_CLUSTER_BUFS
, &io
->bp
);
188 error
= bread(devvp
, io
->offset
, io
->bytes
, &io
->bp
);
190 --hammer_count_io_running_read
;
193 bp
->b_ops
= &hammer_bioops
;
194 KKASSERT(LIST_FIRST(&bp
->b_dep
) == NULL
);
195 LIST_INSERT_HEAD(&bp
->b_dep
, &io
->worklist
, node
);
198 KKASSERT(io
->modified
== 0);
199 KKASSERT(io
->running
== 0);
200 KKASSERT(io
->waiting
== 0);
201 io
->released
= 0; /* we hold an active lock on bp */
209 * Similar to hammer_io_read() but returns a zero'd out buffer instead.
210 * Must be called with the IO exclusively locked.
212 * vfs_bio_clrbuf() is kinda nasty, enforce serialization against background
213 * I/O by forcing the buffer to not be in a released state before calling
216 * This function will also mark the IO as modified but it will not
217 * increment the modify_refs count.
220 hammer_io_new(struct vnode
*devvp
, struct hammer_io
*io
)
224 if ((bp
= io
->bp
) == NULL
) {
225 io
->bp
= getblk(devvp
, io
->offset
, io
->bytes
, 0, 0);
227 bp
->b_ops
= &hammer_bioops
;
228 KKASSERT(LIST_FIRST(&bp
->b_dep
) == NULL
);
229 LIST_INSERT_HEAD(&bp
->b_dep
, &io
->worklist
, node
);
231 KKASSERT(io
->running
== 0);
241 hammer_io_modify(io
, 0);
247 * Remove potential device level aliases against buffers managed by high level
251 hammer_io_inval(hammer_volume_t volume
, hammer_off_t zone2_offset
)
253 hammer_io_structure_t iou
;
254 hammer_off_t phys_offset
;
257 phys_offset
= volume
->ondisk
->vol_buf_beg
+
258 (zone2_offset
& HAMMER_OFF_SHORT_MASK
);
260 if ((bp
= findblk(volume
->devvp
, phys_offset
)) != NULL
) {
261 bp
= getblk(volume
->devvp
, phys_offset
, bp
->b_bufsize
, 0, 0);
262 if ((iou
= (void *)LIST_FIRST(&bp
->b_dep
)) != NULL
) {
263 hammer_io_clear_modify(&iou
->io
, 1);
266 hammer_io_deallocate(bp
);
268 KKASSERT((bp
->b_flags
& B_LOCKED
) == 0);
270 bp
->b_flags
|= B_NOCACHE
|B_RELBUF
;
278 * This routine is called on the last reference to a hammer structure.
279 * The io is usually locked exclusively (but may not be during unmount).
281 * This routine is responsible for the disposition of the buffer cache
282 * buffer backing the IO. Only pure-data and undo buffers can be handed
283 * back to the kernel. Volume and meta-data buffers must be retained
284 * by HAMMER until explicitly flushed by the backend.
287 hammer_io_release(struct hammer_io
*io
, int flush
)
289 union hammer_io_structure
*iou
= (void *)io
;
292 if ((bp
= io
->bp
) == NULL
)
296 * Try to flush a dirty IO to disk if asked to by the
297 * caller or if the kernel tried to flush the buffer in the past.
299 * Kernel-initiated flushes are only allowed for pure-data buffers.
300 * meta-data and volume buffers can only be flushed explicitly
306 } else if (bp
->b_flags
& B_LOCKED
) {
308 case HAMMER_STRUCTURE_DATA_BUFFER
:
309 case HAMMER_STRUCTURE_UNDO_BUFFER
:
315 } /* else no explicit request to flush the buffer */
319 * Wait for the IO to complete if asked to.
321 if (io
->waitdep
&& io
->running
) {
326 * Return control of the buffer to the kernel (with the provisio
327 * that our bioops can override kernel decisions with regards to
330 if ((flush
|| io
->reclaim
) && io
->modified
== 0 && io
->running
== 0) {
332 * Always disassociate the bp if an explicit flush
333 * was requested and the IO completed with no error
334 * (so unmount can really clean up the structure).
341 hammer_io_disassociate((hammer_io_structure_t
)io
, 1);
342 } else if (io
->modified
) {
344 * Only certain IO types can be released to the kernel.
345 * volume and meta-data IO types must be explicitly flushed
349 case HAMMER_STRUCTURE_DATA_BUFFER
:
350 case HAMMER_STRUCTURE_UNDO_BUFFER
:
351 if (io
->released
== 0) {
359 } else if (io
->released
== 0) {
361 * Clean buffers can be generally released to the kernel.
362 * We leave the bp passively associated with the HAMMER
363 * structure and use bioops to disconnect it later on
364 * if the kernel wants to discard the buffer.
366 if (bp
->b_flags
& B_LOCKED
) {
367 hammer_io_disassociate(iou
, 1);
370 hammer_io_disassociate(iou
, 1);
378 * A released buffer is passively associate with our
379 * hammer_io structure. The kernel cannot destroy it
380 * without making a bioops call. If the kernel (B_LOCKED)
381 * or we (reclaim) requested that the buffer be destroyed
382 * we destroy it, otherwise we do a quick get/release to
383 * reset its position in the kernel's LRU list.
385 * Leaving the buffer passively associated allows us to
386 * use the kernel's LRU buffer flushing mechanisms rather
387 * then rolling our own.
389 * XXX there are two ways of doing this. We can re-acquire
390 * and passively release to reset the LRU, or not.
393 if (io
->running
== 0) {
395 if ((bp
->b_flags
& B_LOCKED
) || io
->reclaim
) {
398 hammer_io_disassociate(iou
, 1);
408 * This routine is called with a locked IO when a flush is desired and
409 * no other references to the structure exists other then ours. This
410 * routine is ONLY called when HAMMER believes it is safe to flush a
411 * potentially modified buffer out.
414 hammer_io_flush(struct hammer_io
*io
)
419 * Degenerate case - nothing to flush if nothing is dirty.
421 if (io
->modified
== 0) {
426 KKASSERT(io
->modify_refs
<= 0);
429 * Acquire ownership of the bp, particularly before we clear our
432 * We are going to bawrite() this bp. Don't leave a window where
433 * io->released is set, we actually own the bp rather then our
439 /* BUF_KERNPROC(io->bp); */
440 /* io->released = 0; */
441 KKASSERT(io
->released
);
442 KKASSERT(io
->bp
== bp
);
447 * Acquire exclusive access to the bp and then clear the modified
448 * state of the buffer prior to issuing I/O to interlock any
449 * modifications made while the I/O is in progress. This shouldn't
450 * happen anyway but losing data would be worse. The modified bit
451 * will be rechecked after the IO completes.
453 * NOTE: This call also finalizes the buffer's content (inval == 0).
455 * This is only legal when lock.refs == 1 (otherwise we might clear
456 * the modified bit while there are still users of the cluster
457 * modifying the data).
459 * Do this before potentially blocking so any attempt to modify the
460 * ondisk while we are blocked blocks waiting for us.
462 hammer_io_clear_modify(io
, 0);
465 * Transfer ownership to the kernel and initiate I/O.
468 ++io
->hmp
->io_running_count
;
469 ++hammer_count_io_running_write
;
473 /************************************************************************
475 ************************************************************************
477 * These routines deal with dependancies created when IO buffers get
478 * modified. The caller must call hammer_modify_*() on a referenced
479 * HAMMER structure prior to modifying its on-disk data.
481 * Any intent to modify an IO buffer acquires the related bp and imposes
482 * various write ordering dependancies.
486 * Mark a HAMMER structure as undergoing modification. Meta-data buffers
487 * are locked until the flusher can deal with them, pure data buffers
488 * can be written out.
492 hammer_io_modify(hammer_io_t io
, int count
)
494 struct hammer_mount
*hmp
= io
->hmp
;
497 * io->modify_refs must be >= 0
499 while (io
->modify_refs
< 0) {
501 tsleep(io
, 0, "hmrmod", 0);
505 * Shortcut if nothing to do.
507 KKASSERT(io
->lock
.refs
!= 0 && io
->bp
!= NULL
);
508 io
->modify_refs
+= count
;
509 if (io
->modified
&& io
->released
== 0)
512 hammer_lock_ex(&io
->lock
);
513 if (io
->modified
== 0) {
514 KKASSERT(io
->mod_list
== NULL
);
516 case HAMMER_STRUCTURE_VOLUME
:
517 io
->mod_list
= &hmp
->volu_list
;
518 ++hmp
->locked_dirty_count
;
519 ++hammer_count_dirtybufs
;
521 case HAMMER_STRUCTURE_META_BUFFER
:
522 io
->mod_list
= &hmp
->meta_list
;
523 ++hmp
->locked_dirty_count
;
524 ++hammer_count_dirtybufs
;
526 case HAMMER_STRUCTURE_UNDO_BUFFER
:
527 io
->mod_list
= &hmp
->undo_list
;
529 case HAMMER_STRUCTURE_DATA_BUFFER
:
530 io
->mod_list
= &hmp
->data_list
;
533 TAILQ_INSERT_TAIL(io
->mod_list
, io
, mod_entry
);
538 BUF_KERNPROC(io
->bp
);
540 KKASSERT(io
->modified
!= 0);
542 hammer_unlock(&io
->lock
);
547 hammer_io_modify_done(hammer_io_t io
)
549 KKASSERT(io
->modify_refs
> 0);
551 if (io
->modify_refs
== 0 && io
->waitmod
) {
558 hammer_io_write_interlock(hammer_io_t io
)
560 while (io
->modify_refs
!= 0) {
562 tsleep(io
, 0, "hmrmod", 0);
564 io
->modify_refs
= -1;
568 hammer_io_done_interlock(hammer_io_t io
)
570 KKASSERT(io
->modify_refs
== -1);
579 * Caller intends to modify a volume's ondisk structure.
581 * This is only allowed if we are the flusher or we have a ref on the
585 hammer_modify_volume(hammer_transaction_t trans
, hammer_volume_t volume
,
588 KKASSERT (trans
== NULL
|| trans
->sync_lock_refs
> 0);
590 hammer_io_modify(&volume
->io
, 1);
592 intptr_t rel_offset
= (intptr_t)base
- (intptr_t)volume
->ondisk
;
593 KKASSERT((rel_offset
& ~(intptr_t)HAMMER_BUFMASK
) == 0);
594 hammer_generate_undo(trans
, &volume
->io
,
595 HAMMER_ENCODE_RAW_VOLUME(volume
->vol_no
, rel_offset
),
601 * Caller intends to modify a buffer's ondisk structure.
603 * This is only allowed if we are the flusher or we have a ref on the
607 hammer_modify_buffer(hammer_transaction_t trans
, hammer_buffer_t buffer
,
610 KKASSERT (trans
== NULL
|| trans
->sync_lock_refs
> 0);
612 hammer_io_modify(&buffer
->io
, 1);
614 intptr_t rel_offset
= (intptr_t)base
- (intptr_t)buffer
->ondisk
;
615 KKASSERT((rel_offset
& ~(intptr_t)HAMMER_BUFMASK
) == 0);
616 hammer_generate_undo(trans
, &buffer
->io
,
617 buffer
->zone2_offset
+ rel_offset
,
623 hammer_modify_volume_done(hammer_volume_t volume
)
625 hammer_io_modify_done(&volume
->io
);
629 hammer_modify_buffer_done(hammer_buffer_t buffer
)
631 hammer_io_modify_done(&buffer
->io
);
635 * Mark an entity as not being dirty any more and finalize any
636 * delayed adjustments to the buffer.
638 * Delayed adjustments are an important performance enhancement, allowing
639 * us to avoid recalculating B-Tree node CRCs over and over again when
640 * making bulk-modifications to the B-Tree.
642 * If inval is non-zero delayed adjustments are ignored.
645 hammer_io_clear_modify(struct hammer_io
*io
, int inval
)
647 if (io
->modified
== 0)
651 * Take us off the mod-list and clear the modified bit.
653 KKASSERT(io
->mod_list
!= NULL
);
654 if (io
->mod_list
== &io
->hmp
->volu_list
||
655 io
->mod_list
== &io
->hmp
->meta_list
) {
656 --io
->hmp
->locked_dirty_count
;
657 --hammer_count_dirtybufs
;
659 TAILQ_REMOVE(io
->mod_list
, io
, mod_entry
);
664 * If this bit is not set there are no delayed adjustments.
671 * Finalize requested CRCs. The NEEDSCRC flag also holds a reference
672 * on the node (& underlying buffer). Release the node after clearing
675 if (io
->type
== HAMMER_STRUCTURE_META_BUFFER
) {
676 hammer_buffer_t buffer
= (void *)io
;
680 TAILQ_FOREACH(node
, &buffer
->clist
, entry
) {
681 if ((node
->flags
& HAMMER_NODE_NEEDSCRC
) == 0)
683 node
->flags
&= ~HAMMER_NODE_NEEDSCRC
;
684 KKASSERT(node
->ondisk
);
686 node
->ondisk
->crc
= crc32(&node
->ondisk
->crc
+ 1, HAMMER_BTREE_CRCSIZE
);
687 hammer_rel_node(node
);
695 * Clear the IO's modify list. Even though the IO is no longer modified
696 * it may still be on the lose_list. This routine is called just before
697 * the governing hammer_buffer is destroyed.
700 hammer_io_clear_modlist(struct hammer_io
*io
)
702 KKASSERT(io
->modified
== 0);
704 crit_enter(); /* biodone race against list */
705 KKASSERT(io
->mod_list
== &io
->hmp
->lose_list
);
706 TAILQ_REMOVE(io
->mod_list
, io
, mod_entry
);
712 /************************************************************************
714 ************************************************************************
719 * Pre-IO initiation kernel callback - cluster build only
722 hammer_io_start(struct buf
*bp
)
727 * Post-IO completion kernel callback - MAY BE CALLED FROM INTERRUPT!
729 * NOTE: HAMMER may modify a buffer after initiating I/O. The modified bit
730 * may also be set if we were marking a cluster header open. Only remove
731 * our dependancy if the modified bit is clear.
734 hammer_io_complete(struct buf
*bp
)
736 union hammer_io_structure
*iou
= (void *)LIST_FIRST(&bp
->b_dep
);
738 KKASSERT(iou
->io
.released
== 1);
741 * Deal with people waiting for I/O to drain
743 if (iou
->io
.running
) {
744 --hammer_count_io_running_write
;
745 if (--iou
->io
.hmp
->io_running_count
== 0)
746 wakeup(&iou
->io
.hmp
->io_running_count
);
747 KKASSERT(iou
->io
.hmp
->io_running_count
>= 0);
751 if (iou
->io
.waiting
) {
757 * If B_LOCKED is set someone wanted to deallocate the bp at some
758 * point, do it now if refs has become zero.
760 if ((bp
->b_flags
& B_LOCKED
) && iou
->io
.lock
.refs
== 0) {
761 KKASSERT(iou
->io
.modified
== 0);
762 --hammer_count_io_locked
;
763 bp
->b_flags
&= ~B_LOCKED
;
764 hammer_io_deallocate(bp
);
765 /* structure may be dead now */
770 * Callback from kernel when it wishes to deallocate a passively
771 * associated structure. This mostly occurs with clean buffers
772 * but it may be possible for a holding structure to be marked dirty
773 * while its buffer is passively associated. The caller owns the bp.
775 * If we cannot disassociate we set B_LOCKED to prevent the buffer
776 * from getting reused.
778 * WARNING: Because this can be called directly by getnewbuf we cannot
779 * recurse into the tree. If a bp cannot be immediately disassociated
780 * our only recourse is to set B_LOCKED.
782 * WARNING: This may be called from an interrupt via hammer_io_complete()
785 hammer_io_deallocate(struct buf
*bp
)
787 hammer_io_structure_t iou
= (void *)LIST_FIRST(&bp
->b_dep
);
789 KKASSERT((bp
->b_flags
& B_LOCKED
) == 0 && iou
->io
.running
== 0);
790 if (iou
->io
.lock
.refs
> 0 || iou
->io
.modified
) {
792 * It is not legal to disassociate a modified buffer. This
793 * case really shouldn't ever occur.
795 bp
->b_flags
|= B_LOCKED
;
796 ++hammer_count_io_locked
;
799 * Disassociate the BP. If the io has no refs left we
800 * have to add it to the loose list.
802 hammer_io_disassociate(iou
, 0);
803 if (iou
->io
.bp
== NULL
&&
804 iou
->io
.type
!= HAMMER_STRUCTURE_VOLUME
) {
805 KKASSERT(iou
->io
.mod_list
== NULL
);
806 crit_enter(); /* biodone race against list */
807 iou
->io
.mod_list
= &iou
->io
.hmp
->lose_list
;
808 TAILQ_INSERT_TAIL(iou
->io
.mod_list
, &iou
->io
, mod_entry
);
815 hammer_io_fsync(struct vnode
*vp
)
821 * NOTE: will not be called unless we tell the kernel about the
822 * bioops. Unused... we use the mount's VFS_SYNC instead.
825 hammer_io_sync(struct mount
*mp
)
831 hammer_io_movedeps(struct buf
*bp1
, struct buf
*bp2
)
836 * I/O pre-check for reading and writing. HAMMER only uses this for
837 * B_CACHE buffers so checkread just shouldn't happen, but if it does
840 * Writing is a different case. We don't want the kernel to try to write
841 * out a buffer that HAMMER may be modifying passively or which has a
842 * dependancy. In addition, kernel-demanded writes can only proceed for
843 * certain types of buffers (i.e. UNDO and DATA types). Other dirty
844 * buffer types can only be explicitly written by the flusher.
846 * checkwrite will only be called for bdwrite()n buffers. If we return
847 * success the kernel is guaranteed to initiate the buffer write.
850 hammer_io_checkread(struct buf
*bp
)
856 hammer_io_checkwrite(struct buf
*bp
)
858 hammer_io_t io
= (void *)LIST_FIRST(&bp
->b_dep
);
861 * This shouldn't happen under normal operation.
863 if (io
->type
== HAMMER_STRUCTURE_VOLUME
||
864 io
->type
== HAMMER_STRUCTURE_META_BUFFER
) {
866 panic("hammer_io_checkwrite: illegal buffer");
867 if ((bp
->b_flags
& B_LOCKED
) == 0) {
868 bp
->b_flags
|= B_LOCKED
;
869 ++hammer_count_io_locked
;
875 * We can only clear the modified bit if the IO is not currently
876 * undergoing modification. Otherwise we may miss changes.
878 if (io
->modify_refs
== 0 && io
->modified
)
879 hammer_io_clear_modify(io
, 0);
882 * The kernel is going to start the IO, set io->running.
884 KKASSERT(io
->running
== 0);
886 ++io
->hmp
->io_running_count
;
887 ++hammer_count_io_running_write
;
892 * Return non-zero if we wish to delay the kernel's attempt to flush
893 * this buffer to disk.
896 hammer_io_countdeps(struct buf
*bp
, int n
)
901 struct bio_ops hammer_bioops
= {
902 .io_start
= hammer_io_start
,
903 .io_complete
= hammer_io_complete
,
904 .io_deallocate
= hammer_io_deallocate
,
905 .io_fsync
= hammer_io_fsync
,
906 .io_sync
= hammer_io_sync
,
907 .io_movedeps
= hammer_io_movedeps
,
908 .io_countdeps
= hammer_io_countdeps
,
909 .io_checkread
= hammer_io_checkread
,
910 .io_checkwrite
= hammer_io_checkwrite
,
913 /************************************************************************
915 ************************************************************************
917 * These functions operate directly on the buffer cache buffer associated
918 * with a front-end vnode rather then a back-end device vnode.
922 * Read a buffer associated with a front-end vnode directly from the
923 * disk media. The bio may be issued asynchronously.
925 * This function can takes a zone-2 or zone-X blockmap offset.
928 hammer_io_direct_read(hammer_mount_t hmp
, struct bio
*bio
)
930 hammer_off_t data_offset
;
931 hammer_off_t zone2_offset
;
932 hammer_volume_t volume
;
938 data_offset
= bio
->bio_offset
;
940 if ((data_offset
& HAMMER_OFF_ZONE_MASK
) == HAMMER_ZONE_RAW_BUFFER
) {
941 zone2_offset
= data_offset
;
944 KKASSERT(data_offset
>= HAMMER_ZONE_BTREE
);
945 KKASSERT((data_offset
& HAMMER_BUFMASK
) == 0);
946 zone2_offset
= hammer_blockmap_lookup(hmp
, data_offset
, &error
);
949 vol_no
= HAMMER_VOL_DECODE(zone2_offset
);
950 volume
= hammer_get_volume(hmp
, vol_no
, &error
);
951 if (error
== 0 && zone2_offset
>= volume
->maxbuf_off
)
954 zone2_offset
&= HAMMER_OFF_SHORT_MASK
;
956 /* NOTE: third-level push */
957 nbio
= push_bio(bio
);
958 nbio
->bio_offset
= volume
->ondisk
->vol_buf_beg
+
960 vn_strategy(volume
->devvp
, nbio
);
962 hammer_rel_volume(volume
, 0);
965 kprintf("hammer_direct_read: failed @ %016llx\n",
969 bp
->b_flags
|= B_ERROR
;
976 * Write a buffer associated with a front-end vnode directly to the
977 * disk media. The bio may be issued asynchronously.
980 hammer_io_direct_write(hammer_mount_t hmp
, hammer_btree_leaf_elm_t leaf
,
983 hammer_off_t buf_offset
;
984 hammer_off_t zone2_offset
;
985 hammer_volume_t volume
;
986 hammer_buffer_t buffer
;
993 buf_offset
= leaf
->data_offset
;
995 KKASSERT(buf_offset
> HAMMER_ZONE_BTREE
);
996 KKASSERT(bio
->bio_buf
->b_cmd
== BUF_CMD_WRITE
);
998 if ((buf_offset
& HAMMER_BUFMASK
) == 0 &&
999 leaf
->data_len
>= HAMMER_BUFSIZE
) {
1001 * We are using the vnode's bio to write directly to the
1002 * media, any hammer_buffer at the same zone-X offset will
1003 * now have stale data.
1005 zone2_offset
= hammer_blockmap_lookup(hmp
, buf_offset
, &error
);
1006 vol_no
= HAMMER_VOL_DECODE(zone2_offset
);
1007 volume
= hammer_get_volume(hmp
, vol_no
, &error
);
1009 if (error
== 0 && zone2_offset
>= volume
->maxbuf_off
)
1013 KKASSERT((bp
->b_bufsize
& HAMMER_BUFMASK
) == 0);
1014 hammer_del_buffers(hmp
, buf_offset
,
1015 zone2_offset
, bp
->b_bufsize
);
1016 zone2_offset
&= HAMMER_OFF_SHORT_MASK
;
1018 nbio
= push_bio(bio
);
1019 nbio
->bio_offset
= volume
->ondisk
->vol_buf_beg
+
1021 vn_strategy(volume
->devvp
, nbio
);
1023 hammer_rel_volume(volume
, 0);
1025 /* must fit in a standard HAMMER buffer */
1026 KKASSERT(((buf_offset
^ (buf_offset
+ leaf
->data_len
- 1)) & ~HAMMER_BUFMASK64
) == 0);
1028 ptr
= hammer_bread(hmp
, buf_offset
, &error
, &buffer
);
1031 bp
->b_flags
|= B_AGE
;
1032 hammer_io_modify(&buffer
->io
, 1);
1033 bcopy(bp
->b_data
, ptr
, leaf
->data_len
);
1034 hammer_io_modify_done(&buffer
->io
);
1035 hammer_rel_buffer(buffer
, 0);
1041 kprintf("hammer_direct_write: failed @ %016llx\n",
1046 bp
->b_flags
|= B_ERROR
;