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 1.47 2008/06/28 23:50:37 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
);
57 static int hammer_io_direct_uncache_callback(hammer_inode_t ip
, void *data
);
60 * Initialize a new, already-zero'd hammer_io structure, or reinitialize
61 * an existing hammer_io structure which may have switched to another type.
64 hammer_io_init(hammer_io_t io
, hammer_mount_t hmp
, enum hammer_io_type type
)
71 * Helper routine to disassociate a buffer cache buffer from an I/O
74 * The io may have 0 or 1 references depending on who called us. The
75 * caller is responsible for dealing with the refs.
77 * This call can only be made when no action is required on the buffer.
78 * HAMMER must own the buffer (released == 0) since we mess around with it.
81 hammer_io_disassociate(hammer_io_structure_t iou
, int elseit
)
83 struct buf
*bp
= iou
->io
.bp
;
85 KKASSERT(iou
->io
.modified
== 0);
86 KKASSERT(LIST_FIRST(&bp
->b_dep
) == (void *)iou
);
91 * If the buffer was locked someone wanted to get rid of it.
93 if (bp
->b_flags
& B_LOCKED
) {
94 --hammer_count_io_locked
;
95 bp
->b_flags
&= ~B_LOCKED
;
99 * elseit is 0 when called from the kernel path when the io
100 * might have no references.
103 KKASSERT(iou
->io
.released
== 0);
104 iou
->io
.released
= 1;
106 bp
->b_flags
|= B_NOCACHE
|B_RELBUF
;
109 KKASSERT(iou
->io
.released
);
113 switch(iou
->io
.type
) {
114 case HAMMER_STRUCTURE_VOLUME
:
115 iou
->volume
.ondisk
= NULL
;
117 case HAMMER_STRUCTURE_DATA_BUFFER
:
118 case HAMMER_STRUCTURE_META_BUFFER
:
119 case HAMMER_STRUCTURE_UNDO_BUFFER
:
120 iou
->buffer
.ondisk
= NULL
;
126 * Wait for any physical IO to complete
129 hammer_io_wait(hammer_io_t io
)
133 tsleep_interlock(io
);
136 tsleep(io
, 0, "hmrflw", 0);
137 if (io
->running
== 0)
139 tsleep_interlock(io
);
141 if (io
->running
== 0)
149 * Wait for all hammer_io-initated write I/O's to complete. This is not
150 * supposed to count direct I/O's but some can leak through (for
151 * non-full-sized direct I/Os).
154 hammer_io_wait_all(hammer_mount_t hmp
, const char *ident
)
157 while (hmp
->io_running_space
)
158 tsleep(&hmp
->io_running_space
, 0, ident
, 0);
162 #define HAMMER_MAXRA 4
165 * Load bp for a HAMMER structure. The io must be exclusively locked by
168 * This routine is mostly used on meta-data and small-data blocks. Generally
169 * speaking HAMMER assumes some locality of reference and will cluster
172 * Note that clustering occurs at the device layer, not the logical layer.
173 * If the buffers do not apply to the current operation they may apply to
177 hammer_io_read(struct vnode
*devvp
, struct hammer_io
*io
, hammer_off_t limit
)
182 if ((bp
= io
->bp
) == NULL
) {
183 hammer_count_io_running_read
+= io
->bytes
;
185 error
= cluster_read(devvp
, limit
, io
->offset
, io
->bytes
,
187 HAMMER_CLUSTER_BUFS
, &io
->bp
);
189 error
= bread(devvp
, io
->offset
, io
->bytes
, &io
->bp
);
191 hammer_count_io_running_read
-= io
->bytes
;
194 bp
->b_ops
= &hammer_bioops
;
195 KKASSERT(LIST_FIRST(&bp
->b_dep
) == NULL
);
196 LIST_INSERT_HEAD(&bp
->b_dep
, &io
->worklist
, node
);
199 KKASSERT(io
->modified
== 0);
200 KKASSERT(io
->running
== 0);
201 KKASSERT(io
->waiting
== 0);
202 io
->released
= 0; /* we hold an active lock on bp */
210 * Similar to hammer_io_read() but returns a zero'd out buffer instead.
211 * Must be called with the IO exclusively locked.
213 * vfs_bio_clrbuf() is kinda nasty, enforce serialization against background
214 * I/O by forcing the buffer to not be in a released state before calling
217 * This function will also mark the IO as modified but it will not
218 * increment the modify_refs count.
221 hammer_io_new(struct vnode
*devvp
, struct hammer_io
*io
)
225 if ((bp
= io
->bp
) == NULL
) {
226 io
->bp
= getblk(devvp
, io
->offset
, io
->bytes
, 0, 0);
228 bp
->b_ops
= &hammer_bioops
;
229 KKASSERT(LIST_FIRST(&bp
->b_dep
) == NULL
);
230 LIST_INSERT_HEAD(&bp
->b_dep
, &io
->worklist
, node
);
232 KKASSERT(io
->running
== 0);
242 hammer_io_modify(io
, 0);
248 * Remove potential device level aliases against buffers managed by high level
252 hammer_io_inval(hammer_volume_t volume
, hammer_off_t zone2_offset
)
254 hammer_io_structure_t iou
;
255 hammer_off_t phys_offset
;
258 phys_offset
= volume
->ondisk
->vol_buf_beg
+
259 (zone2_offset
& HAMMER_OFF_SHORT_MASK
);
261 if ((bp
= findblk(volume
->devvp
, phys_offset
)) != NULL
) {
262 bp
= getblk(volume
->devvp
, phys_offset
, bp
->b_bufsize
, 0, 0);
263 if ((iou
= (void *)LIST_FIRST(&bp
->b_dep
)) != NULL
) {
264 hammer_io_clear_modify(&iou
->io
, 1);
267 hammer_io_deallocate(bp
);
269 KKASSERT((bp
->b_flags
& B_LOCKED
) == 0);
271 bp
->b_flags
|= B_NOCACHE
|B_RELBUF
;
279 * This routine is called on the last reference to a hammer structure.
280 * The io is usually locked exclusively (but may not be during unmount).
282 * This routine is responsible for the disposition of the buffer cache
283 * buffer backing the IO. Only pure-data and undo buffers can be handed
284 * back to the kernel. Volume and meta-data buffers must be retained
285 * by HAMMER until explicitly flushed by the backend.
288 hammer_io_release(struct hammer_io
*io
, int flush
)
290 union hammer_io_structure
*iou
= (void *)io
;
293 if ((bp
= io
->bp
) == NULL
)
297 * Try to flush a dirty IO to disk if asked to by the
298 * caller or if the kernel tried to flush the buffer in the past.
300 * Kernel-initiated flushes are only allowed for pure-data buffers.
301 * meta-data and volume buffers can only be flushed explicitly
307 } else if (bp
->b_flags
& B_LOCKED
) {
309 case HAMMER_STRUCTURE_DATA_BUFFER
:
310 case HAMMER_STRUCTURE_UNDO_BUFFER
:
316 } /* else no explicit request to flush the buffer */
320 * Wait for the IO to complete if asked to.
322 if (io
->waitdep
&& io
->running
) {
327 * Return control of the buffer to the kernel (with the provisio
328 * that our bioops can override kernel decisions with regards to
331 if ((flush
|| io
->reclaim
) && io
->modified
== 0 && io
->running
== 0) {
333 * Always disassociate the bp if an explicit flush
334 * was requested and the IO completed with no error
335 * (so unmount can really clean up the structure).
342 hammer_io_disassociate((hammer_io_structure_t
)io
, 1);
343 } else if (io
->modified
) {
345 * Only certain IO types can be released to the kernel.
346 * volume and meta-data IO types must be explicitly flushed
350 case HAMMER_STRUCTURE_DATA_BUFFER
:
351 case HAMMER_STRUCTURE_UNDO_BUFFER
:
352 if (io
->released
== 0) {
360 } else if (io
->released
== 0) {
362 * Clean buffers can be generally released to the kernel.
363 * We leave the bp passively associated with the HAMMER
364 * structure and use bioops to disconnect it later on
365 * if the kernel wants to discard the buffer.
367 if (bp
->b_flags
& B_LOCKED
) {
368 hammer_io_disassociate(iou
, 1);
371 hammer_io_disassociate(iou
, 1);
379 * A released buffer is passively associate with our
380 * hammer_io structure. The kernel cannot destroy it
381 * without making a bioops call. If the kernel (B_LOCKED)
382 * or we (reclaim) requested that the buffer be destroyed
383 * we destroy it, otherwise we do a quick get/release to
384 * reset its position in the kernel's LRU list.
386 * Leaving the buffer passively associated allows us to
387 * use the kernel's LRU buffer flushing mechanisms rather
388 * then rolling our own.
390 * XXX there are two ways of doing this. We can re-acquire
391 * and passively release to reset the LRU, or not.
394 if (io
->running
== 0) {
396 if ((bp
->b_flags
& B_LOCKED
) || io
->reclaim
) {
399 hammer_io_disassociate(iou
, 1);
409 * This routine is called with a locked IO when a flush is desired and
410 * no other references to the structure exists other then ours. This
411 * routine is ONLY called when HAMMER believes it is safe to flush a
412 * potentially modified buffer out.
415 hammer_io_flush(struct hammer_io
*io
)
420 * Degenerate case - nothing to flush if nothing is dirty.
422 if (io
->modified
== 0) {
427 KKASSERT(io
->modify_refs
<= 0);
430 * Acquire ownership of the bp, particularly before we clear our
433 * We are going to bawrite() this bp. Don't leave a window where
434 * io->released is set, we actually own the bp rather then our
440 /* BUF_KERNPROC(io->bp); */
441 /* io->released = 0; */
442 KKASSERT(io
->released
);
443 KKASSERT(io
->bp
== bp
);
448 * Acquire exclusive access to the bp and then clear the modified
449 * state of the buffer prior to issuing I/O to interlock any
450 * modifications made while the I/O is in progress. This shouldn't
451 * happen anyway but losing data would be worse. The modified bit
452 * will be rechecked after the IO completes.
454 * NOTE: This call also finalizes the buffer's content (inval == 0).
456 * This is only legal when lock.refs == 1 (otherwise we might clear
457 * the modified bit while there are still users of the cluster
458 * modifying the data).
460 * Do this before potentially blocking so any attempt to modify the
461 * ondisk while we are blocked blocks waiting for us.
463 hammer_io_clear_modify(io
, 0);
466 * Transfer ownership to the kernel and initiate I/O.
469 io
->hmp
->io_running_space
+= io
->bytes
;
470 hammer_count_io_running_write
+= io
->bytes
;
474 /************************************************************************
476 ************************************************************************
478 * These routines deal with dependancies created when IO buffers get
479 * modified. The caller must call hammer_modify_*() on a referenced
480 * HAMMER structure prior to modifying its on-disk data.
482 * Any intent to modify an IO buffer acquires the related bp and imposes
483 * various write ordering dependancies.
487 * Mark a HAMMER structure as undergoing modification. Meta-data buffers
488 * are locked until the flusher can deal with them, pure data buffers
489 * can be written out.
493 hammer_io_modify(hammer_io_t io
, int count
)
495 struct hammer_mount
*hmp
= io
->hmp
;
498 * io->modify_refs must be >= 0
500 while (io
->modify_refs
< 0) {
502 tsleep(io
, 0, "hmrmod", 0);
506 * Shortcut if nothing to do.
508 KKASSERT(io
->lock
.refs
!= 0 && io
->bp
!= NULL
);
509 io
->modify_refs
+= count
;
510 if (io
->modified
&& io
->released
== 0)
513 hammer_lock_ex(&io
->lock
);
514 if (io
->modified
== 0) {
515 KKASSERT(io
->mod_list
== NULL
);
517 case HAMMER_STRUCTURE_VOLUME
:
518 io
->mod_list
= &hmp
->volu_list
;
519 hmp
->locked_dirty_space
+= io
->bytes
;
520 hammer_count_dirtybufspace
+= io
->bytes
;
522 case HAMMER_STRUCTURE_META_BUFFER
:
523 io
->mod_list
= &hmp
->meta_list
;
524 hmp
->locked_dirty_space
+= io
->bytes
;
525 hammer_count_dirtybufspace
+= io
->bytes
;
527 case HAMMER_STRUCTURE_UNDO_BUFFER
:
528 io
->mod_list
= &hmp
->undo_list
;
530 case HAMMER_STRUCTURE_DATA_BUFFER
:
531 io
->mod_list
= &hmp
->data_list
;
534 TAILQ_INSERT_TAIL(io
->mod_list
, io
, mod_entry
);
539 BUF_KERNPROC(io
->bp
);
541 KKASSERT(io
->modified
!= 0);
543 hammer_unlock(&io
->lock
);
548 hammer_io_modify_done(hammer_io_t io
)
550 KKASSERT(io
->modify_refs
> 0);
552 if (io
->modify_refs
== 0 && io
->waitmod
) {
559 hammer_io_write_interlock(hammer_io_t io
)
561 while (io
->modify_refs
!= 0) {
563 tsleep(io
, 0, "hmrmod", 0);
565 io
->modify_refs
= -1;
569 hammer_io_done_interlock(hammer_io_t io
)
571 KKASSERT(io
->modify_refs
== -1);
580 * Caller intends to modify a volume's ondisk structure.
582 * This is only allowed if we are the flusher or we have a ref on the
586 hammer_modify_volume(hammer_transaction_t trans
, hammer_volume_t volume
,
589 KKASSERT (trans
== NULL
|| trans
->sync_lock_refs
> 0);
591 hammer_io_modify(&volume
->io
, 1);
593 intptr_t rel_offset
= (intptr_t)base
- (intptr_t)volume
->ondisk
;
594 KKASSERT((rel_offset
& ~(intptr_t)HAMMER_BUFMASK
) == 0);
595 hammer_generate_undo(trans
, &volume
->io
,
596 HAMMER_ENCODE_RAW_VOLUME(volume
->vol_no
, rel_offset
),
602 * Caller intends to modify a buffer's ondisk structure.
604 * This is only allowed if we are the flusher or we have a ref on the
608 hammer_modify_buffer(hammer_transaction_t trans
, hammer_buffer_t buffer
,
611 KKASSERT (trans
== NULL
|| trans
->sync_lock_refs
> 0);
613 hammer_io_modify(&buffer
->io
, 1);
615 intptr_t rel_offset
= (intptr_t)base
- (intptr_t)buffer
->ondisk
;
616 KKASSERT((rel_offset
& ~(intptr_t)HAMMER_BUFMASK
) == 0);
617 hammer_generate_undo(trans
, &buffer
->io
,
618 buffer
->zone2_offset
+ rel_offset
,
624 hammer_modify_volume_done(hammer_volume_t volume
)
626 hammer_io_modify_done(&volume
->io
);
630 hammer_modify_buffer_done(hammer_buffer_t buffer
)
632 hammer_io_modify_done(&buffer
->io
);
636 * Mark an entity as not being dirty any more and finalize any
637 * delayed adjustments to the buffer.
639 * Delayed adjustments are an important performance enhancement, allowing
640 * us to avoid recalculating B-Tree node CRCs over and over again when
641 * making bulk-modifications to the B-Tree.
643 * If inval is non-zero delayed adjustments are ignored.
646 hammer_io_clear_modify(struct hammer_io
*io
, int inval
)
648 if (io
->modified
== 0)
652 * Take us off the mod-list and clear the modified bit.
654 KKASSERT(io
->mod_list
!= NULL
);
655 if (io
->mod_list
== &io
->hmp
->volu_list
||
656 io
->mod_list
== &io
->hmp
->meta_list
) {
657 io
->hmp
->locked_dirty_space
-= io
->bytes
;
658 hammer_count_dirtybufspace
-= io
->bytes
;
660 TAILQ_REMOVE(io
->mod_list
, io
, mod_entry
);
665 * If this bit is not set there are no delayed adjustments.
672 * Finalize requested CRCs. The NEEDSCRC flag also holds a reference
673 * on the node (& underlying buffer). Release the node after clearing
676 if (io
->type
== HAMMER_STRUCTURE_META_BUFFER
) {
677 hammer_buffer_t buffer
= (void *)io
;
681 TAILQ_FOREACH(node
, &buffer
->clist
, entry
) {
682 if ((node
->flags
& HAMMER_NODE_NEEDSCRC
) == 0)
684 node
->flags
&= ~HAMMER_NODE_NEEDSCRC
;
685 KKASSERT(node
->ondisk
);
687 node
->ondisk
->crc
= crc32(&node
->ondisk
->crc
+ 1, HAMMER_BTREE_CRCSIZE
);
688 hammer_rel_node(node
);
696 * Clear the IO's modify list. Even though the IO is no longer modified
697 * it may still be on the lose_list. This routine is called just before
698 * the governing hammer_buffer is destroyed.
701 hammer_io_clear_modlist(struct hammer_io
*io
)
703 KKASSERT(io
->modified
== 0);
705 crit_enter(); /* biodone race against list */
706 KKASSERT(io
->mod_list
== &io
->hmp
->lose_list
);
707 TAILQ_REMOVE(io
->mod_list
, io
, mod_entry
);
713 /************************************************************************
715 ************************************************************************
720 * Pre-IO initiation kernel callback - cluster build only
723 hammer_io_start(struct buf
*bp
)
728 * Post-IO completion kernel callback - MAY BE CALLED FROM INTERRUPT!
730 * NOTE: HAMMER may modify a buffer after initiating I/O. The modified bit
731 * may also be set if we were marking a cluster header open. Only remove
732 * our dependancy if the modified bit is clear.
735 hammer_io_complete(struct buf
*bp
)
737 union hammer_io_structure
*iou
= (void *)LIST_FIRST(&bp
->b_dep
);
739 KKASSERT(iou
->io
.released
== 1);
742 * Deal with people waiting for I/O to drain
744 if (iou
->io
.running
) {
745 hammer_count_io_running_write
-= iou
->io
.bytes
;
746 iou
->io
.hmp
->io_running_space
-= iou
->io
.bytes
;
747 if (iou
->io
.hmp
->io_running_space
== 0)
748 wakeup(&iou
->io
.hmp
->io_running_space
);
749 KKASSERT(iou
->io
.hmp
->io_running_space
>= 0);
753 if (iou
->io
.waiting
) {
759 * If B_LOCKED is set someone wanted to deallocate the bp at some
760 * point, do it now if refs has become zero.
762 if ((bp
->b_flags
& B_LOCKED
) && iou
->io
.lock
.refs
== 0) {
763 KKASSERT(iou
->io
.modified
== 0);
764 --hammer_count_io_locked
;
765 bp
->b_flags
&= ~B_LOCKED
;
766 hammer_io_deallocate(bp
);
767 /* structure may be dead now */
772 * Callback from kernel when it wishes to deallocate a passively
773 * associated structure. This mostly occurs with clean buffers
774 * but it may be possible for a holding structure to be marked dirty
775 * while its buffer is passively associated. The caller owns the bp.
777 * If we cannot disassociate we set B_LOCKED to prevent the buffer
778 * from getting reused.
780 * WARNING: Because this can be called directly by getnewbuf we cannot
781 * recurse into the tree. If a bp cannot be immediately disassociated
782 * our only recourse is to set B_LOCKED.
784 * WARNING: This may be called from an interrupt via hammer_io_complete()
787 hammer_io_deallocate(struct buf
*bp
)
789 hammer_io_structure_t iou
= (void *)LIST_FIRST(&bp
->b_dep
);
791 KKASSERT((bp
->b_flags
& B_LOCKED
) == 0 && iou
->io
.running
== 0);
792 if (iou
->io
.lock
.refs
> 0 || iou
->io
.modified
) {
794 * It is not legal to disassociate a modified buffer. This
795 * case really shouldn't ever occur.
797 bp
->b_flags
|= B_LOCKED
;
798 ++hammer_count_io_locked
;
801 * Disassociate the BP. If the io has no refs left we
802 * have to add it to the loose list.
804 hammer_io_disassociate(iou
, 0);
805 if (iou
->io
.bp
== NULL
&&
806 iou
->io
.type
!= HAMMER_STRUCTURE_VOLUME
) {
807 KKASSERT(iou
->io
.mod_list
== NULL
);
808 crit_enter(); /* biodone race against list */
809 iou
->io
.mod_list
= &iou
->io
.hmp
->lose_list
;
810 TAILQ_INSERT_TAIL(iou
->io
.mod_list
, &iou
->io
, mod_entry
);
817 hammer_io_fsync(struct vnode
*vp
)
823 * NOTE: will not be called unless we tell the kernel about the
824 * bioops. Unused... we use the mount's VFS_SYNC instead.
827 hammer_io_sync(struct mount
*mp
)
833 hammer_io_movedeps(struct buf
*bp1
, struct buf
*bp2
)
838 * I/O pre-check for reading and writing. HAMMER only uses this for
839 * B_CACHE buffers so checkread just shouldn't happen, but if it does
842 * Writing is a different case. We don't want the kernel to try to write
843 * out a buffer that HAMMER may be modifying passively or which has a
844 * dependancy. In addition, kernel-demanded writes can only proceed for
845 * certain types of buffers (i.e. UNDO and DATA types). Other dirty
846 * buffer types can only be explicitly written by the flusher.
848 * checkwrite will only be called for bdwrite()n buffers. If we return
849 * success the kernel is guaranteed to initiate the buffer write.
852 hammer_io_checkread(struct buf
*bp
)
858 hammer_io_checkwrite(struct buf
*bp
)
860 hammer_io_t io
= (void *)LIST_FIRST(&bp
->b_dep
);
863 * This shouldn't happen under normal operation.
865 if (io
->type
== HAMMER_STRUCTURE_VOLUME
||
866 io
->type
== HAMMER_STRUCTURE_META_BUFFER
) {
868 panic("hammer_io_checkwrite: illegal buffer");
869 if ((bp
->b_flags
& B_LOCKED
) == 0) {
870 bp
->b_flags
|= B_LOCKED
;
871 ++hammer_count_io_locked
;
877 * We can only clear the modified bit if the IO is not currently
878 * undergoing modification. Otherwise we may miss changes.
880 if (io
->modify_refs
== 0 && io
->modified
)
881 hammer_io_clear_modify(io
, 0);
884 * The kernel is going to start the IO, set io->running.
886 KKASSERT(io
->running
== 0);
888 io
->hmp
->io_running_space
+= io
->bytes
;
889 hammer_count_io_running_write
+= io
->bytes
;
894 * Return non-zero if we wish to delay the kernel's attempt to flush
895 * this buffer to disk.
898 hammer_io_countdeps(struct buf
*bp
, int n
)
903 struct bio_ops hammer_bioops
= {
904 .io_start
= hammer_io_start
,
905 .io_complete
= hammer_io_complete
,
906 .io_deallocate
= hammer_io_deallocate
,
907 .io_fsync
= hammer_io_fsync
,
908 .io_sync
= hammer_io_sync
,
909 .io_movedeps
= hammer_io_movedeps
,
910 .io_countdeps
= hammer_io_countdeps
,
911 .io_checkread
= hammer_io_checkread
,
912 .io_checkwrite
= hammer_io_checkwrite
,
915 /************************************************************************
917 ************************************************************************
919 * These functions operate directly on the buffer cache buffer associated
920 * with a front-end vnode rather then a back-end device vnode.
924 * Read a buffer associated with a front-end vnode directly from the
925 * disk media. The bio may be issued asynchronously.
927 * A second-level bio already resolved to a zone-2 offset (typically by
928 * the BMAP code, or by a previous hammer_io_direct_write()), is passed.
931 hammer_io_direct_read(hammer_mount_t hmp
, struct bio
*bio
)
933 hammer_off_t zone2_offset
;
934 hammer_volume_t volume
;
940 zone2_offset
= bio
->bio_offset
;
942 KKASSERT((zone2_offset
& HAMMER_OFF_ZONE_MASK
) ==
943 HAMMER_ZONE_RAW_BUFFER
);
945 vol_no
= HAMMER_VOL_DECODE(zone2_offset
);
946 volume
= hammer_get_volume(hmp
, vol_no
, &error
);
947 if (error
== 0 && zone2_offset
>= volume
->maxbuf_off
)
951 * Third level bio - raw offset specific to the
955 zone2_offset
&= HAMMER_OFF_SHORT_MASK
;
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
);
1017 * Second level bio - cached zone2 offset.
1019 nbio
= push_bio(bio
);
1020 nbio
->bio_offset
= zone2_offset
;
1023 * Third level bio - raw offset specific to the
1026 zone2_offset
&= HAMMER_OFF_SHORT_MASK
;
1027 nbio
= push_bio(nbio
);
1028 nbio
->bio_offset
= volume
->ondisk
->vol_buf_beg
+
1030 vn_strategy(volume
->devvp
, nbio
);
1032 hammer_rel_volume(volume
, 0);
1034 /* must fit in a standard HAMMER buffer */
1035 KKASSERT(((buf_offset
^ (buf_offset
+ leaf
->data_len
- 1)) & ~HAMMER_BUFMASK64
) == 0);
1037 ptr
= hammer_bread(hmp
, buf_offset
, &error
, &buffer
);
1040 bp
->b_flags
|= B_AGE
;
1041 hammer_io_modify(&buffer
->io
, 1);
1042 bcopy(bp
->b_data
, ptr
, leaf
->data_len
);
1043 hammer_io_modify_done(&buffer
->io
);
1044 hammer_rel_buffer(buffer
, 0);
1050 kprintf("hammer_direct_write: failed @ %016llx\n",
1055 bp
->b_flags
|= B_ERROR
;
1062 * This is called to remove the second-level cached zone-2 offset from
1063 * frontend buffer cache buffers, now stale due to a data relocation.
1064 * These offsets are generated by cluster_read() via VOP_BMAP, or directly
1065 * by hammer_vop_strategy_read().
1067 * This is rather nasty because here we have something like the reblocker
1068 * scanning the raw B-Tree with no held references on anything, really,
1069 * other then a shared lock on the B-Tree node, and we have to access the
1070 * frontend's buffer cache to check for and clean out the association.
1071 * Specifically, if the reblocker is moving data on the disk, these cached
1072 * offsets will become invalid.
1074 * Only data record types associated with the large-data zone are subject
1075 * to direct-io and need to be checked.
1079 hammer_io_direct_uncache(hammer_mount_t hmp
, hammer_btree_leaf_elm_t leaf
)
1081 struct hammer_inode_info iinfo
;
1084 if (leaf
->base
.rec_type
!= HAMMER_RECTYPE_DATA
)
1086 zone
= HAMMER_ZONE_DECODE(leaf
->data_offset
);
1087 if (zone
!= HAMMER_ZONE_LARGE_DATA_INDEX
)
1089 iinfo
.obj_id
= leaf
->base
.obj_id
;
1090 iinfo
.obj_asof
= 0; /* unused */
1091 iinfo
.obj_localization
= leaf
->base
.localization
&
1092 HAMMER_LOCALIZE_PSEUDOFS_MASK
;
1093 iinfo
.u
.leaf
= leaf
;
1094 hammer_scan_inode_snapshots(hmp
, &iinfo
,
1095 hammer_io_direct_uncache_callback
,
1100 hammer_io_direct_uncache_callback(hammer_inode_t ip
, void *data
)
1102 hammer_inode_info_t iinfo
= data
;
1103 hammer_off_t data_offset
;
1104 hammer_off_t file_offset
;
1111 data_offset
= iinfo
->u
.leaf
->data_offset
;
1112 file_offset
= iinfo
->u
.leaf
->base
.key
- iinfo
->u
.leaf
->data_len
;
1113 blksize
= iinfo
->u
.leaf
->data_len
;
1114 KKASSERT((blksize
& HAMMER_BUFMASK
) == 0);
1116 hammer_ref(&ip
->lock
);
1117 if (hammer_get_vnode(ip
, &vp
) == 0) {
1118 if ((bp
= findblk(ip
->vp
, file_offset
)) != NULL
&&
1119 bp
->b_bio2
.bio_offset
!= NOOFFSET
) {
1120 bp
= getblk(ip
->vp
, file_offset
, blksize
, 0, 0);
1121 bp
->b_bio2
.bio_offset
= NOOFFSET
;
1126 hammer_rel_inode(ip
, 0);