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7 * it under the terms of the GNU General Public License version 2 only,
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13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
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17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
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21 * CA 95054 USA or visit www.sun.com if you need additional information or
27 * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
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31 * Copyright (c) 2012, 2013, Intel Corporation.
32 * Use is subject to license terms.
35 * This file is part of Lustre, http://www.lustre.org/
36 * Lustre is a trademark of Sun Microsystems, Inc.
38 * lustre/osd-zfs/osd_io.c
40 * Author: Alex Zhuravlev <bzzz@whamcloud.com>
41 * Author: Mike Pershin <tappro@whamcloud.com>
44 #define DEBUG_SUBSYSTEM S_OSD
46 #include <lustre_ver.h>
47 #include <libcfs/libcfs.h>
48 #include <obd_support.h>
49 #include <lustre_net.h>
51 #include <obd_class.h>
52 #include <lustre_disk.h>
53 #include <lustre_fid.h>
55 #include "osd_internal.h"
57 #include <sys/dnode.h>
62 #include <sys/spa_impl.h>
63 #include <sys/zfs_znode.h>
64 #include <sys/dmu_tx.h>
65 #include <sys/dmu_objset.h>
66 #include <sys/dsl_prop.h>
67 #include <sys/sa_impl.h>
70 static char *osd_zerocopy_tag = "zerocopy";
72 static ssize_t osd_read(const struct lu_env *env, struct dt_object *dt,
73 struct lu_buf *buf, loff_t *pos,
74 struct lustre_capa *capa)
76 struct osd_object *obj = osd_dt_obj(dt);
77 struct osd_device *osd = osd_obj2dev(obj);
79 int size = buf->lb_len;
82 LASSERT(dt_object_exists(dt));
85 read_lock(&obj->oo_attr_lock);
86 old_size = obj->oo_attr.la_size;
87 read_unlock(&obj->oo_attr_lock);
89 if (*pos + size > old_size) {
93 size = old_size - *pos;
96 rc = -dmu_read(osd->od_objset.os, obj->oo_db->db_object, *pos, size,
97 buf->lb_buf, DMU_READ_PREFETCH);
102 /* XXX: workaround for bug in HEAD: fsfilt_ldiskfs_read() returns
103 * requested number of bytes, not actually read ones */
104 if (S_ISLNK(obj->oo_dt.do_lu.lo_header->loh_attr))
110 static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
111 const loff_t size, loff_t pos,
114 struct osd_object *obj = osd_dt_obj(dt);
115 struct osd_device *osd = osd_obj2dev(obj);
116 struct osd_thandle *oh;
120 oh = container_of0(th, struct osd_thandle, ot_super);
122 /* in some cases declare can race with creation (e.g. llog)
123 * and we need to wait till object is initialized. notice
124 * LOHA_EXISTs is supposed to be the last step in the
127 /* declare possible size change. notice we can't check
128 * current size here as another thread can change it */
130 if (dt_object_exists(dt)) {
132 oid = obj->oo_db->db_object;
134 dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
136 oid = DMU_NEW_OBJECT;
137 dmu_tx_hold_sa_create(oh->ot_tx, ZFS_SA_BASE_ATTR_SIZE);
140 dmu_tx_hold_write(oh->ot_tx, oid, pos, size);
142 /* dt_declare_write() is usually called for system objects, such
143 * as llog or last_rcvd files. We needn't enforce quota on those
144 * objects, so always set the lqi_space as 0. */
145 RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
146 obj->oo_attr.la_gid, 0, oh, true, NULL,
150 static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
151 const struct lu_buf *buf, loff_t *pos,
152 struct thandle *th, struct lustre_capa *capa,
155 struct osd_object *obj = osd_dt_obj(dt);
156 struct osd_device *osd = osd_obj2dev(obj);
157 udmu_objset_t *uos = &osd->od_objset;
158 struct osd_thandle *oh;
159 uint64_t offset = *pos;
163 LASSERT(dt_object_exists(dt));
167 oh = container_of0(th, struct osd_thandle, ot_super);
169 dmu_write(osd->od_objset.os, obj->oo_db->db_object, offset,
170 (uint64_t)buf->lb_len, buf->lb_buf, oh->ot_tx);
171 write_lock(&obj->oo_attr_lock);
172 if (obj->oo_attr.la_size < offset + buf->lb_len) {
173 obj->oo_attr.la_size = offset + buf->lb_len;
174 write_unlock(&obj->oo_attr_lock);
175 /* osd_object_sa_update() will be copying directly from oo_attr
176 * into dbuf. any update within a single txg will copy the
178 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(uos),
179 &obj->oo_attr.la_size, 8, oh);
183 write_unlock(&obj->oo_attr_lock);
194 * XXX: for the moment I don't want to use lnb_flags for osd-internal
195 * purposes as it's not very well defined ...
196 * instead I use the lowest bit of the address so that:
197 * arc buffer: .lnb_obj = abuf (arc we loan for write)
198 * dbuf buffer: .lnb_obj = dbuf | 1 (dbuf we get for read)
199 * copy buffer: .lnb_page->mapping = obj (page we allocate for write)
203 static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
204 struct niobuf_local *lnb, int npages)
206 struct osd_object *obj = osd_dt_obj(dt);
207 struct osd_device *osd = osd_obj2dev(obj);
211 LASSERT(dt_object_exists(dt));
214 for (i = 0; i < npages; i++) {
215 if (lnb[i].page == NULL)
217 if (lnb[i].page->mapping == (void *)obj) {
218 /* this is anonymous page allocated for copy-write */
219 lnb[i].page->mapping = NULL;
220 __free_page(lnb[i].page);
221 cfs_atomic_dec(&osd->od_zerocopy_alloc);
223 /* see comment in osd_bufs_get_read() */
224 ptr = (unsigned long)lnb[i].dentry;
227 dmu_buf_rele((void *)ptr, osd_zerocopy_tag);
228 cfs_atomic_dec(&osd->od_zerocopy_pin);
229 } else if (lnb[i].dentry != NULL) {
230 dmu_return_arcbuf((void *)lnb[i].dentry);
231 cfs_atomic_dec(&osd->od_zerocopy_loan);
235 lnb[i].dentry = NULL;
241 static inline struct page *kmem_to_page(void *addr)
243 if (is_vmalloc_addr(addr))
244 return vmalloc_to_page(addr);
246 return virt_to_page(addr);
249 static int osd_bufs_get_read(const struct lu_env *env, struct osd_object *obj,
250 loff_t off, ssize_t len, struct niobuf_local *lnb)
252 struct osd_device *osd = osd_obj2dev(obj);
254 int rc, i, numbufs, npages = 0;
257 /* grab buffers for read:
258 * OSD API let us to grab buffers first, then initiate IO(s)
259 * so that all required IOs will be done in parallel, but at the
260 * moment DMU doesn't provide us with a method to grab buffers.
261 * If we discover this is a vital for good performance we
262 * can get own replacement for dmu_buf_hold_array_by_bonus().
265 rc = -dmu_buf_hold_array_by_bonus(obj->oo_db, off, len, TRUE,
266 osd_zerocopy_tag, &numbufs,
271 for (i = 0; i < numbufs; i++) {
272 int bufoff, tocpy, thispage;
277 cfs_atomic_inc(&osd->od_zerocopy_pin);
279 bufoff = off - dbp[i]->db_offset;
280 tocpy = min_t(int, dbp[i]->db_size - bufoff, len);
282 /* kind of trick to differentiate dbuf vs. arcbuf */
283 LASSERT(((unsigned long)dbp[i] & 1) == 0);
284 dbf = (void *) ((unsigned long)dbp[i] | 1);
287 thispage = PAGE_CACHE_SIZE;
288 thispage -= bufoff & (PAGE_CACHE_SIZE - 1);
289 thispage = min(tocpy, thispage);
292 lnb->lnb_file_offset = off;
293 lnb->lnb_page_offset = bufoff & ~CFS_PAGE_MASK;
295 lnb->page = kmem_to_page(dbp[i]->db_data +
297 /* mark just a single slot: we need this
298 * reference to dbuf to be release once */
311 /* steal dbuf so dmu_buf_rele_array() cant release it */
315 dmu_buf_rele_array(dbp, numbufs, osd_zerocopy_tag);
322 osd_bufs_put(env, &obj->oo_dt, lnb - npages, npages);
326 static int osd_bufs_get_write(const struct lu_env *env, struct osd_object *obj,
327 loff_t off, ssize_t len, struct niobuf_local *lnb)
329 struct osd_device *osd = osd_obj2dev(obj);
330 int plen, off_in_block, sz_in_block;
331 int i = 0, npages = 0;
337 dmu_object_size_from_db(obj->oo_db, &bs, &dummy);
340 * currently only full blocks are subject to zerocopy approach:
341 * so that we're sure nobody is trying to update the same block
344 LASSERT(npages < PTLRPC_MAX_BRW_PAGES);
346 off_in_block = off & (bs - 1);
347 sz_in_block = min_t(int, bs - off_in_block, len);
349 if (sz_in_block == bs) {
350 /* full block, try to use zerocopy */
352 abuf = dmu_request_arcbuf(obj->oo_db, bs);
353 if (unlikely(abuf == NULL))
354 GOTO(out_err, -ENOMEM);
356 cfs_atomic_inc(&osd->od_zerocopy_loan);
358 /* go over pages arcbuf contains, put them as
359 * local niobufs for ptlrpc's bulks */
360 while (sz_in_block > 0) {
361 plen = min_t(int, sz_in_block, PAGE_CACHE_SIZE);
363 lnb[i].lnb_file_offset = off;
364 lnb[i].lnb_page_offset = 0;
367 if (sz_in_block == bs)
368 lnb[i].dentry = (void *)abuf;
370 lnb[i].dentry = NULL;
372 /* this one is not supposed to fail */
373 lnb[i].page = kmem_to_page(abuf->b_data +
375 LASSERT(lnb[i].page);
377 lprocfs_counter_add(osd->od_stats,
378 LPROC_OSD_ZEROCOPY_IO, 1);
383 off_in_block += plen;
388 if (off_in_block == 0 && len < bs &&
389 off + len >= obj->oo_attr.la_size)
390 lprocfs_counter_add(osd->od_stats,
391 LPROC_OSD_TAIL_IO, 1);
393 /* can't use zerocopy, allocate temp. buffers */
394 while (sz_in_block > 0) {
395 plen = min_t(int, sz_in_block, PAGE_CACHE_SIZE);
397 lnb[i].lnb_file_offset = off;
398 lnb[i].lnb_page_offset = 0;
401 lnb[i].dentry = NULL;
403 lnb[i].page = alloc_page(OSD_GFP_IO);
404 if (unlikely(lnb[i].page == NULL))
405 GOTO(out_err, -ENOMEM);
407 LASSERT(lnb[i].page->mapping == NULL);
408 lnb[i].page->mapping = (void *)obj;
410 cfs_atomic_inc(&osd->od_zerocopy_alloc);
411 lprocfs_counter_add(osd->od_stats,
412 LPROC_OSD_COPY_IO, 1);
426 osd_bufs_put(env, &obj->oo_dt, lnb, npages);
430 static int osd_bufs_get(const struct lu_env *env, struct dt_object *dt,
431 loff_t offset, ssize_t len, struct niobuf_local *lnb,
432 int rw, struct lustre_capa *capa)
434 struct osd_object *obj = osd_dt_obj(dt);
437 LASSERT(dt_object_exists(dt));
441 rc = osd_bufs_get_read(env, obj, offset, len, lnb);
443 rc = osd_bufs_get_write(env, obj, offset, len, lnb);
448 static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
449 struct niobuf_local *lnb, int npages)
451 struct osd_object *obj = osd_dt_obj(dt);
453 LASSERT(dt_object_exists(dt));
459 /* Return number of blocks that aren't mapped in the [start, start + size]
461 static int osd_count_not_mapped(struct osd_object *obj, uint64_t start,
464 dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)obj->oo_db;
475 if (dn->dn_maxblkid == 0) {
476 if (start + size <= dn->dn_datablksz)
478 if (start < dn->dn_datablksz)
479 start = dn->dn_datablksz;
480 /* assume largest block size */
481 blkshift = SPA_MAXBLOCKSHIFT;
483 /* blocksize can't change */
484 blkshift = dn->dn_datablkshift;
487 /* compute address of last block */
488 end = (start + size - 1) >> blkshift;
489 /* align start on block boundaries */
492 /* size is null, can't be mapped */
493 if (obj->oo_attr.la_size == 0 || dn->dn_maxblkid == 0)
494 GOTO(out, size = (end - start + 1) << blkshift);
496 /* beyond EOF, can't be mapped */
497 if (start > dn->dn_maxblkid)
498 GOTO(out, size = (end - start + 1) << blkshift);
501 for (blkid = start; blkid <= end; blkid++) {
502 if (blkid == dn->dn_maxblkid)
503 /* this one is mapped for sure */
505 if (blkid > dn->dn_maxblkid) {
506 size += (end - blkid + 1) << blkshift;
510 rc = dbuf_hold_impl(dn, 0, blkid, TRUE, FTAG, &db);
512 /* for ENOENT (block not mapped) and any other errors,
513 * assume the block isn't mapped */
514 size += 1 << blkshift;
526 static int osd_declare_write_commit(const struct lu_env *env,
527 struct dt_object *dt,
528 struct niobuf_local *lnb, int npages,
531 struct osd_object *obj = osd_dt_obj(dt);
532 struct osd_device *osd = osd_obj2dev(obj);
533 struct osd_thandle *oh;
536 int i, rc, flags = 0;
537 bool ignore_quota = false, synced = false;
541 LASSERT(dt_object_exists(dt));
547 oh = container_of0(th, struct osd_thandle, ot_super);
549 for (i = 0; i < npages; i++) {
551 /* ENOSPC, network RPC error, etc.
552 * We don't want to book space for pages which will be
553 * skipped in osd_write_commit(). Hence we skip pages
554 * with lnb_rc != 0 here too */
556 /* ignore quota for the whole request if any page is from
557 * client cache or written by root.
559 * XXX once we drop the 1.8 client support, the checking
560 * for whether page is from cache can be simplified as:
561 * !(lnb[i].flags & OBD_BRW_SYNC)
563 * XXX we could handle this on per-lnb basis as done by
565 if ((lnb[i].flags & OBD_BRW_NOQUOTA) ||
566 (lnb[i].flags & (OBD_BRW_FROM_GRANT | OBD_BRW_SYNC)) ==
570 /* first valid lnb */
571 offset = lnb[i].lnb_file_offset;
575 if (offset + size == lnb[i].lnb_file_offset) {
576 /* this lnb is contiguous to the previous one */
581 dmu_tx_hold_write(oh->ot_tx, obj->oo_db->db_object, offset,size);
583 /* estimating space that will be consumed by a write is rather
584 * complicated with ZFS. As a consequence, we don't account for
585 * indirect blocks and quota overrun will be adjusted once the
586 * operation is committed, if required. */
587 space += osd_count_not_mapped(obj, offset, size);
589 offset = lnb->lnb_file_offset;
594 dmu_tx_hold_write(oh->ot_tx, obj->oo_db->db_object, offset,size);
595 space += osd_count_not_mapped(obj, offset, size);
598 dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
600 oh->ot_write_commit = 1; /* used in osd_trans_start() for fail_loc */
602 /* backend zfs filesystem might be configured to store multiple data
604 space *= osd->od_objset.os->os_copies;
606 CDEBUG(D_QUOTA, "writting %d pages, reserving "LPD64"K of quota "
607 "space\n", npages, space);
610 /* acquire quota space if needed */
611 rc = osd_declare_quota(env, osd, obj->oo_attr.la_uid,
612 obj->oo_attr.la_gid, space, oh, true, &flags,
615 if (!synced && rc == -EDQUOT && (flags & QUOTA_FL_SYNC) != 0) {
616 dt_sync(env, th->th_dev);
618 CDEBUG(D_QUOTA, "retry after sync\n");
623 /* we need only to store the overquota flags in the first lnb for
624 * now, once we support multiple objects BRW, this code needs be
626 if (flags & QUOTA_FL_OVER_USRQUOTA)
627 lnb[0].flags |= OBD_BRW_OVER_USRQUOTA;
628 if (flags & QUOTA_FL_OVER_GRPQUOTA)
629 lnb[0].flags |= OBD_BRW_OVER_GRPQUOTA;
634 static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
635 struct niobuf_local *lnb, int npages,
638 struct osd_object *obj = osd_dt_obj(dt);
639 struct osd_device *osd = osd_obj2dev(obj);
640 udmu_objset_t *uos = &osd->od_objset;
641 struct osd_thandle *oh;
642 uint64_t new_size = 0;
646 LASSERT(dt_object_exists(dt));
650 oh = container_of0(th, struct osd_thandle, ot_super);
652 for (i = 0; i < npages; i++) {
653 CDEBUG(D_INODE, "write %u bytes at %u\n",
654 (unsigned) lnb[i].len,
655 (unsigned) lnb[i].lnb_file_offset);
658 /* ENOSPC, network RPC error, etc.
659 * Unlike ldiskfs, zfs allocates new blocks on rewrite,
660 * so we skip this page if lnb_rc is set to -ENOSPC */
661 CDEBUG(D_INODE, "obj "DFID": skipping lnb[%u]: rc=%d\n",
662 PFID(lu_object_fid(&dt->do_lu)), i,
667 if (lnb[i].page->mapping == (void *)obj) {
668 dmu_write(osd->od_objset.os, obj->oo_db->db_object,
669 lnb[i].lnb_file_offset, lnb[i].len,
670 kmap(lnb[i].page), oh->ot_tx);
672 } else if (lnb[i].dentry) {
673 LASSERT(((unsigned long)lnb[i].dentry & 1) == 0);
674 /* buffer loaned for zerocopy, try to use it.
675 * notice that dmu_assign_arcbuf() is smart
676 * enough to recognize changed blocksize
677 * in this case it fallbacks to dmu_write() */
678 dmu_assign_arcbuf(obj->oo_db, lnb[i].lnb_file_offset,
679 (void *)lnb[i].dentry, oh->ot_tx);
680 /* drop the reference, otherwise osd_put_bufs()
681 * will be releasing it - bad! */
682 lnb[i].dentry = NULL;
683 cfs_atomic_dec(&osd->od_zerocopy_loan);
686 if (new_size < lnb[i].lnb_file_offset + lnb[i].len)
687 new_size = lnb[i].lnb_file_offset + lnb[i].len;
690 if (unlikely(new_size == 0)) {
691 /* no pages to write, no transno is needed */
693 /* it is important to return 0 even when all lnb_rc == -ENOSPC
694 * since ofd_commitrw_write() retries several times on ENOSPC */
698 write_lock(&obj->oo_attr_lock);
699 if (obj->oo_attr.la_size < new_size) {
700 obj->oo_attr.la_size = new_size;
701 write_unlock(&obj->oo_attr_lock);
702 /* osd_object_sa_update() will be copying directly from
703 * oo_attr into dbuf. any update within a single txg will copy
705 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(uos),
706 &obj->oo_attr.la_size, 8, oh);
708 write_unlock(&obj->oo_attr_lock);
714 static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
715 struct niobuf_local *lnb, int npages)
717 struct osd_object *obj = osd_dt_obj(dt);
722 LASSERT(dt_object_exists(dt));
725 for (i = 0; i < npages; i++) {
726 buf.lb_buf = kmap(lnb[i].page);
727 buf.lb_len = lnb[i].len;
728 offset = lnb[i].lnb_file_offset;
730 CDEBUG(D_OTHER, "read %u bytes at %u\n",
731 (unsigned) lnb[i].len,
732 (unsigned) lnb[i].lnb_file_offset);
733 lnb[i].rc = osd_read(env, dt, &buf, &offset, NULL);
736 if (lnb[i].rc < buf.lb_len) {
737 /* all subsequent rc should be 0 */
748 * Punch/truncate an object
750 * IN: db - dmu_buf of the object to free data in.
751 * off - start of section to free.
752 * len - length of section to free (DMU_OBJECT_END => to EOF).
754 * RETURN: 0 if success
755 * error code if failure
757 * The transaction passed to this routine must have
758 * dmu_tx_hold_sa() and if off < size, dmu_tx_hold_free()
759 * called and then assigned to a transaction group.
761 static int __osd_object_punch(objset_t *os, dmu_buf_t *db, dmu_tx_t *tx,
762 uint64_t size, uint64_t off, uint64_t len)
766 /* Assert that the transaction has been assigned to a
767 transaction group. */
768 LASSERT(tx->tx_txg != 0);
770 * Nothing to do if file already at desired length.
772 if (len == DMU_OBJECT_END && size == off)
776 rc = -dmu_free_range(os, db->db_object, off, len, tx);
781 static int osd_punch(const struct lu_env *env, struct dt_object *dt,
782 __u64 start, __u64 end, struct thandle *th,
783 struct lustre_capa *capa)
785 struct osd_object *obj = osd_dt_obj(dt);
786 struct osd_device *osd = osd_obj2dev(obj);
787 udmu_objset_t *uos = &osd->od_objset;
788 struct osd_thandle *oh;
793 LASSERT(dt_object_exists(dt));
794 LASSERT(osd_invariant(obj));
797 oh = container_of0(th, struct osd_thandle, ot_super);
799 write_lock(&obj->oo_attr_lock);
801 if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
802 len = DMU_OBJECT_END;
805 write_unlock(&obj->oo_attr_lock);
807 rc = __osd_object_punch(osd->od_objset.os, obj->oo_db, oh->ot_tx,
808 obj->oo_attr.la_size, start, len);
810 if (len == DMU_OBJECT_END) {
811 write_lock(&obj->oo_attr_lock);
812 obj->oo_attr.la_size = start;
813 write_unlock(&obj->oo_attr_lock);
814 rc = osd_object_sa_update(obj, SA_ZPL_SIZE(uos),
815 &obj->oo_attr.la_size, 8, oh);
820 static int osd_declare_punch(const struct lu_env *env, struct dt_object *dt,
821 __u64 start, __u64 end, struct thandle *handle)
823 struct osd_object *obj = osd_dt_obj(dt);
824 struct osd_device *osd = osd_obj2dev(obj);
825 struct osd_thandle *oh;
829 oh = container_of0(handle, struct osd_thandle, ot_super);
831 read_lock(&obj->oo_attr_lock);
832 if (end == OBD_OBJECT_EOF || end >= obj->oo_attr.la_size)
833 len = DMU_OBJECT_END;
837 /* declare we'll free some blocks ... */
838 if (start < obj->oo_attr.la_size) {
839 read_unlock(&obj->oo_attr_lock);
840 dmu_tx_hold_free(oh->ot_tx, obj->oo_db->db_object, start, len);
842 read_unlock(&obj->oo_attr_lock);
845 /* ... and we'll modify size attribute */
846 dmu_tx_hold_sa(oh->ot_tx, obj->oo_sa_hdl, 0);
848 RETURN(osd_declare_quota(env, osd, obj->oo_attr.la_uid,
849 obj->oo_attr.la_gid, 0, oh, true, NULL,
854 struct dt_body_operations osd_body_ops = {
855 .dbo_read = osd_read,
856 .dbo_declare_write = osd_declare_write,
857 .dbo_write = osd_write,
858 .dbo_bufs_get = osd_bufs_get,
859 .dbo_bufs_put = osd_bufs_put,
860 .dbo_write_prep = osd_write_prep,
861 .dbo_declare_write_commit = osd_declare_write_commit,
862 .dbo_write_commit = osd_write_commit,
863 .dbo_read_prep = osd_read_prep,
864 .dbo_declare_punch = osd_declare_punch,
865 .dbo_punch = osd_punch,