2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License v.2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/gfs2_ondisk.h>
18 #include "lm_interface.h"
29 static void glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
31 struct gfs2_glock *gl;
32 struct gfs2_trans *tr = current->journal_info;
36 if (!list_empty(&le->le_list))
39 gl = container_of(le, struct gfs2_glock, gl_le);
40 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl)))
43 set_bit(GLF_DIRTY, &gl->gl_flags);
47 list_add(&le->le_list, &sdp->sd_log_le_gl);
51 static void glock_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
53 struct list_head *head = &sdp->sd_log_le_gl;
54 struct gfs2_glock *gl;
56 while (!list_empty(head)) {
57 gl = list_entry(head->next, struct gfs2_glock, gl_le.le_list);
58 list_del_init(&gl->gl_le.le_list);
61 gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl));
64 gfs2_assert_warn(sdp, !sdp->sd_log_num_gl);
67 static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
69 struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
70 struct gfs2_trans *tr;
72 if (!list_empty(&bd->bd_list_tr))
75 tr = current->journal_info;
78 list_add(&bd->bd_list_tr, &tr->tr_list_buf);
80 if (!list_empty(&le->le_list))
83 gfs2_trans_add_gl(bd->bd_gl);
85 gfs2_meta_check(sdp, bd->bd_bh);
86 gfs2_pin(sdp, bd->bd_bh);
89 sdp->sd_log_num_buf++;
90 list_add(&le->le_list, &sdp->sd_log_le_buf);
96 static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
98 struct list_head *head = &tr->tr_list_buf;
99 struct gfs2_bufdata *bd;
101 while (!list_empty(head)) {
102 bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
103 list_del_init(&bd->bd_list_tr);
106 gfs2_assert_warn(sdp, !tr->tr_num_buf);
109 static void buf_lo_before_commit(struct gfs2_sbd *sdp)
111 struct buffer_head *bh;
112 struct gfs2_log_descriptor *ld;
113 struct gfs2_bufdata *bd1 = NULL, *bd2;
114 unsigned int total = sdp->sd_log_num_buf;
115 unsigned int offset = sizeof(struct gfs2_log_descriptor);
121 offset += (sizeof(__be64) - 1);
122 offset &= ~(sizeof(__be64) - 1);
123 limit = (sdp->sd_sb.sb_bsize - offset)/sizeof(__be64);
124 /* for 4k blocks, limit = 503 */
126 bd1 = bd2 = list_prepare_entry(bd1, &sdp->sd_log_le_buf, bd_le.le_list);
131 bh = gfs2_log_get_buf(sdp);
132 sdp->sd_log_num_hdrs++;
133 ld = (struct gfs2_log_descriptor *)bh->b_data;
134 ptr = (__be64 *)(bh->b_data + offset);
135 ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
136 ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
137 ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
138 ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_METADATA);
139 ld->ld_length = cpu_to_be32(num + 1);
140 ld->ld_data1 = cpu_to_be32(num);
141 ld->ld_data2 = cpu_to_be32(0);
142 memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
145 list_for_each_entry_continue(bd1, &sdp->sd_log_le_buf,
147 *ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
152 set_buffer_dirty(bh);
153 ll_rw_block(WRITE, 1, &bh);
156 list_for_each_entry_continue(bd2, &sdp->sd_log_le_buf,
158 bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
159 set_buffer_dirty(bh);
160 ll_rw_block(WRITE, 1, &bh);
169 static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
171 struct list_head *head = &sdp->sd_log_le_buf;
172 struct gfs2_bufdata *bd;
174 while (!list_empty(head)) {
175 bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
176 list_del_init(&bd->bd_le.le_list);
177 sdp->sd_log_num_buf--;
179 gfs2_unpin(sdp, bd->bd_bh, ai);
181 gfs2_assert_warn(sdp, !sdp->sd_log_num_buf);
184 static void buf_lo_before_scan(struct gfs2_jdesc *jd,
185 struct gfs2_log_header *head, int pass)
187 struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
188 struct gfs2_sbd *sdp = ip->i_sbd;
193 sdp->sd_found_blocks = 0;
194 sdp->sd_replayed_blocks = 0;
197 static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
198 struct gfs2_log_descriptor *ld, __be64 *ptr,
201 struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
202 struct gfs2_sbd *sdp = ip->i_sbd;
203 struct gfs2_glock *gl = ip->i_gl;
204 unsigned int blks = be32_to_cpu(ld->ld_data1);
205 struct buffer_head *bh_log, *bh_ip;
209 if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_METADATA)
212 gfs2_replay_incr_blk(sdp, &start);
214 for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
215 blkno = be64_to_cpu(*ptr++);
217 sdp->sd_found_blocks++;
219 if (gfs2_revoke_check(sdp, blkno, start))
222 error = gfs2_replay_read_block(jd, start, &bh_log);
226 bh_ip = gfs2_meta_new(gl, blkno);
227 memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
229 if (gfs2_meta_check(sdp, bh_ip))
232 mark_buffer_dirty(bh_ip);
240 sdp->sd_replayed_blocks++;
246 static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
248 struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
249 struct gfs2_sbd *sdp = ip->i_sbd;
252 gfs2_meta_sync(ip->i_gl,
253 DIO_START | DIO_WAIT);
259 gfs2_meta_sync(ip->i_gl, DIO_START | DIO_WAIT);
261 fs_info(sdp, "jid=%u: Replayed %u of %u blocks\n",
262 jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
265 static void revoke_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
267 struct gfs2_trans *tr;
269 tr = current->journal_info;
274 sdp->sd_log_num_revoke++;
275 list_add(&le->le_list, &sdp->sd_log_le_revoke);
276 gfs2_log_unlock(sdp);
279 static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
281 struct gfs2_log_descriptor *ld;
282 struct gfs2_meta_header *mh;
283 struct buffer_head *bh;
285 struct list_head *head = &sdp->sd_log_le_revoke;
286 struct gfs2_revoke *rv;
288 if (!sdp->sd_log_num_revoke)
291 bh = gfs2_log_get_buf(sdp);
292 ld = (struct gfs2_log_descriptor *)bh->b_data;
293 ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
294 ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
295 ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
296 ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_REVOKE);
297 ld->ld_length = cpu_to_be32(gfs2_struct2blk(sdp, sdp->sd_log_num_revoke,
299 ld->ld_data1 = cpu_to_be32(sdp->sd_log_num_revoke);
300 ld->ld_data2 = cpu_to_be32(0);
301 memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
302 offset = sizeof(struct gfs2_log_descriptor);
304 while (!list_empty(head)) {
305 rv = list_entry(head->next, struct gfs2_revoke, rv_le.le_list);
306 list_del_init(&rv->rv_le.le_list);
307 sdp->sd_log_num_revoke--;
309 if (offset + sizeof(uint64_t) > sdp->sd_sb.sb_bsize) {
310 set_buffer_dirty(bh);
311 ll_rw_block(WRITE, 1, &bh);
313 bh = gfs2_log_get_buf(sdp);
314 mh = (struct gfs2_meta_header *)bh->b_data;
315 mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
316 mh->mh_type = cpu_to_be32(GFS2_METATYPE_LB);
317 mh->mh_format = cpu_to_be32(GFS2_FORMAT_LB);
318 offset = sizeof(struct gfs2_meta_header);
321 *(__be64 *)(bh->b_data + offset) = cpu_to_be64(rv->rv_blkno);
324 offset += sizeof(uint64_t);
326 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
328 set_buffer_dirty(bh);
329 ll_rw_block(WRITE, 1, &bh);
332 static void revoke_lo_before_scan(struct gfs2_jdesc *jd,
333 struct gfs2_log_header *head, int pass)
335 struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
336 struct gfs2_sbd *sdp = ip->i_sbd;
341 sdp->sd_found_revokes = 0;
342 sdp->sd_replay_tail = head->lh_tail;
345 static int revoke_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
346 struct gfs2_log_descriptor *ld, __be64 *ptr,
349 struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
350 struct gfs2_sbd *sdp = ip->i_sbd;
351 unsigned int blks = be32_to_cpu(ld->ld_length);
352 unsigned int revokes = be32_to_cpu(ld->ld_data1);
353 struct buffer_head *bh;
359 if (pass != 0 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_REVOKE)
362 offset = sizeof(struct gfs2_log_descriptor);
364 for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
365 error = gfs2_replay_read_block(jd, start, &bh);
370 gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LB);
372 while (offset + sizeof(uint64_t) <= sdp->sd_sb.sb_bsize) {
373 blkno = be64_to_cpu(*(__be64 *)(bh->b_data + offset));
375 error = gfs2_revoke_add(sdp, blkno, start);
379 sdp->sd_found_revokes++;
383 offset += sizeof(uint64_t);
387 offset = sizeof(struct gfs2_meta_header);
394 static void revoke_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
396 struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
397 struct gfs2_sbd *sdp = ip->i_sbd;
400 gfs2_revoke_clean(sdp);
406 fs_info(sdp, "jid=%u: Found %u revoke tags\n",
407 jd->jd_jid, sdp->sd_found_revokes);
409 gfs2_revoke_clean(sdp);
412 static void rg_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
414 struct gfs2_rgrpd *rgd;
415 struct gfs2_trans *tr = current->journal_info;
419 if (!list_empty(&le->le_list))
422 rgd = container_of(le, struct gfs2_rgrpd, rd_le);
423 gfs2_rgrp_bh_hold(rgd);
426 sdp->sd_log_num_rg++;
427 list_add(&le->le_list, &sdp->sd_log_le_rg);
428 gfs2_log_unlock(sdp);
431 static void rg_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
433 struct list_head *head = &sdp->sd_log_le_rg;
434 struct gfs2_rgrpd *rgd;
436 while (!list_empty(head)) {
437 rgd = list_entry(head->next, struct gfs2_rgrpd, rd_le.le_list);
438 list_del_init(&rgd->rd_le.le_list);
439 sdp->sd_log_num_rg--;
441 gfs2_rgrp_repolish_clones(rgd);
442 gfs2_rgrp_bh_put(rgd);
444 gfs2_assert_warn(sdp, !sdp->sd_log_num_rg);
448 * databuf_lo_add - Add a databuf to the transaction.
450 * This is used in two distinct cases:
451 * i) In ordered write mode
452 * We put the data buffer on a list so that we can ensure that its
453 * synced to disk at the right time
454 * ii) In journaled data mode
455 * We need to journal the data block in the same way as metadata in
456 * the functions above. The difference is that here we have a tag
457 * which is two __be64's being the block number (as per meta data)
458 * and a flag which says whether the data block needs escaping or
459 * not. This means we need a new log entry for each 251 or so data
460 * blocks, which isn't an enormous overhead but twice as much as
461 * for normal metadata blocks.
463 static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
465 struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
466 struct gfs2_trans *tr = current->journal_info;
467 struct address_space *mapping = bd->bd_bh->b_page->mapping;
468 struct gfs2_inode *ip = mapping->host->u.generic_ip;
471 if (!list_empty(&bd->bd_list_tr) &&
472 (ip->i_di.di_flags & GFS2_DIF_JDATA)) {
474 gfs2_trans_add_gl(bd->bd_gl);
475 list_add(&bd->bd_list_tr, &tr->tr_list_buf);
476 gfs2_pin(sdp, bd->bd_bh);
477 tr->tr_num_buf_new++;
480 if (!list_empty(&le->le_list)) {
481 if (ip->i_di.di_flags & GFS2_DIF_JDATA)
482 sdp->sd_log_num_jdata++;
483 sdp->sd_log_num_databuf++;
484 list_add(&le->le_list, &sdp->sd_log_le_databuf);
486 gfs2_log_unlock(sdp);
489 static int gfs2_check_magic(struct buffer_head *bh)
491 struct page *page = bh->b_page;
496 kaddr = kmap_atomic(page, KM_USER0);
497 ptr = kaddr + bh_offset(bh);
498 if (*ptr == cpu_to_be32(GFS2_MAGIC))
500 kunmap_atomic(page, KM_USER0);
506 * databuf_lo_before_commit - Scan the data buffers, writing as we go
508 * Here we scan through the lists of buffers and make the assumption
509 * that any buffer thats been pinned is being journaled, and that
510 * any unpinned buffer is an ordered write data buffer and therefore
511 * will be written back rather than journaled.
513 static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
516 struct gfs2_bufdata *bd1 = NULL, *bd2, *bdt;
517 struct buffer_head *bh = NULL;
518 unsigned int offset = sizeof(struct gfs2_log_descriptor);
519 struct gfs2_log_descriptor *ld;
521 unsigned int total_dbuf = sdp->sd_log_num_databuf;
522 unsigned int total_jdata = sdp->sd_log_num_jdata;
526 offset += (2*sizeof(__be64) - 1);
527 offset &= ~(2*sizeof(__be64) - 1);
528 limit = (sdp->sd_sb.sb_bsize - offset)/sizeof(__be64);
531 * Start writing ordered buffers, write journaled buffers
532 * into the log along with a header
535 bd2 = bd1 = list_prepare_entry(bd1, &sdp->sd_log_le_databuf,
542 list_for_each_entry_safe_continue(bd1, bdt,
543 &sdp->sd_log_le_databuf,
545 /* An ordered write buffer */
546 if (bd1->bd_bh && !buffer_pinned(bd1->bd_bh)) {
547 list_move(&bd1->bd_le.le_list, &started);
550 bd2 = list_prepare_entry(bd2,
551 &sdp->sd_log_le_databuf,
557 if (buffer_dirty(bd1->bd_bh)) {
558 gfs2_log_unlock(sdp);
559 wait_on_buffer(bd1->bd_bh);
560 ll_rw_block(WRITE, 1,
568 } else if (bd1->bd_bh) { /* A journaled buffer */
570 gfs2_log_unlock(sdp);
572 bh = gfs2_log_get_buf(sdp);
573 sdp->sd_log_num_hdrs++;
574 ld = (struct gfs2_log_descriptor *)
576 ptr = (__be64 *)(bh->b_data + offset);
577 ld->ld_header.mh_magic =
578 cpu_to_be32(GFS2_MAGIC);
579 ld->ld_header.mh_type =
580 cpu_to_be32(GFS2_METATYPE_LD);
581 ld->ld_header.mh_format =
582 cpu_to_be32(GFS2_FORMAT_LD);
584 cpu_to_be32(GFS2_LOG_DESC_JDATA);
585 ld->ld_length = cpu_to_be32(num + 1);
586 ld->ld_data1 = cpu_to_be32(num);
587 ld->ld_data2 = cpu_to_be32(0);
588 memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
590 magic = gfs2_check_magic(bd1->bd_bh);
591 *ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
592 *ptr++ = cpu_to_be64((__u64)magic);
593 clear_buffer_escaped(bd1->bd_bh);
594 if (unlikely(magic != 0))
595 set_buffer_escaped(bd1->bd_bh);
601 gfs2_log_unlock(sdp);
603 set_buffer_dirty(bh);
604 ll_rw_block(WRITE, 1, &bh);
609 list_for_each_entry_continue(bd2, &sdp->sd_log_le_databuf,
613 /* copy buffer if it needs escaping */
614 gfs2_log_unlock(sdp);
615 if (unlikely(buffer_escaped(bd2->bd_bh))) {
617 struct page *page = bd2->bd_bh->b_page;
618 bh = gfs2_log_get_buf(sdp);
619 kaddr = kmap_atomic(page, KM_USER0);
621 kaddr + bh_offset(bd2->bd_bh),
622 sdp->sd_sb.sb_bsize);
623 kunmap_atomic(page, KM_USER0);
624 *(__be32 *)bh->b_data = 0;
626 bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
628 set_buffer_dirty(bh);
629 ll_rw_block(WRITE, 1, &bh);
638 gfs2_log_unlock(sdp);
640 /* Wait on all ordered buffers */
641 while (!list_empty(&started)) {
643 bd1 = list_entry(started.next, struct gfs2_bufdata,
645 list_del(&bd1->bd_le.le_list);
646 sdp->sd_log_num_databuf--;
650 bh->b_private = NULL;
651 gfs2_log_unlock(sdp);
655 gfs2_log_unlock(sdp);
660 /* We've removed all the ordered write bufs here, so only jdata left */
661 gfs2_assert_warn(sdp, sdp->sd_log_num_databuf == sdp->sd_log_num_jdata);
664 static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
665 struct gfs2_log_descriptor *ld,
666 __be64 *ptr, int pass)
668 struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
669 struct gfs2_sbd *sdp = ip->i_sbd;
670 struct gfs2_glock *gl = ip->i_gl;
671 unsigned int blks = be32_to_cpu(ld->ld_data1);
672 struct buffer_head *bh_log, *bh_ip;
677 if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_JDATA)
680 gfs2_replay_incr_blk(sdp, &start);
681 for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
682 blkno = be64_to_cpu(*ptr++);
683 esc = be64_to_cpu(*ptr++);
685 sdp->sd_found_blocks++;
687 if (gfs2_revoke_check(sdp, blkno, start))
690 error = gfs2_replay_read_block(jd, start, &bh_log);
694 bh_ip = gfs2_meta_new(gl, blkno);
695 memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
699 __be32 *eptr = (__be32 *)bh_ip->b_data;
700 *eptr = cpu_to_be32(GFS2_MAGIC);
702 mark_buffer_dirty(bh_ip);
709 sdp->sd_replayed_blocks++;
715 /* FIXME: sort out accounting for log blocks etc. */
717 static void databuf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
719 struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
720 struct gfs2_sbd *sdp = ip->i_sbd;
723 gfs2_meta_sync(ip->i_gl,
724 DIO_START | DIO_WAIT);
731 gfs2_meta_sync(ip->i_gl, DIO_START | DIO_WAIT);
733 fs_info(sdp, "jid=%u: Replayed %u of %u data blocks\n",
734 jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
737 static void databuf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
739 struct list_head *head = &sdp->sd_log_le_databuf;
740 struct gfs2_bufdata *bd;
742 while (!list_empty(head)) {
743 bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
744 list_del(&bd->bd_le.le_list);
745 sdp->sd_log_num_databuf--;
746 sdp->sd_log_num_jdata--;
747 gfs2_unpin(sdp, bd->bd_bh, ai);
749 gfs2_assert_warn(sdp, !sdp->sd_log_num_databuf);
750 gfs2_assert_warn(sdp, !sdp->sd_log_num_jdata);
754 const struct gfs2_log_operations gfs2_glock_lops = {
755 .lo_add = glock_lo_add,
756 .lo_after_commit = glock_lo_after_commit,
760 const struct gfs2_log_operations gfs2_buf_lops = {
761 .lo_add = buf_lo_add,
762 .lo_incore_commit = buf_lo_incore_commit,
763 .lo_before_commit = buf_lo_before_commit,
764 .lo_after_commit = buf_lo_after_commit,
765 .lo_before_scan = buf_lo_before_scan,
766 .lo_scan_elements = buf_lo_scan_elements,
767 .lo_after_scan = buf_lo_after_scan,
771 const struct gfs2_log_operations gfs2_revoke_lops = {
772 .lo_add = revoke_lo_add,
773 .lo_before_commit = revoke_lo_before_commit,
774 .lo_before_scan = revoke_lo_before_scan,
775 .lo_scan_elements = revoke_lo_scan_elements,
776 .lo_after_scan = revoke_lo_after_scan,
780 const struct gfs2_log_operations gfs2_rg_lops = {
782 .lo_after_commit = rg_lo_after_commit,
786 const struct gfs2_log_operations gfs2_databuf_lops = {
787 .lo_add = databuf_lo_add,
788 .lo_incore_commit = buf_lo_incore_commit,
789 .lo_before_commit = databuf_lo_before_commit,
790 .lo_after_commit = databuf_lo_after_commit,
791 .lo_scan_elements = databuf_lo_scan_elements,
792 .lo_after_scan = databuf_lo_after_scan,
796 const struct gfs2_log_operations *gfs2_log_ops[] = {