2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 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 version 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/mempool.h>
16 #include <linux/gfs2_ondisk.h>
17 #include <linux/bio.h>
31 #include "trace_gfs2.h"
34 * gfs2_pin - Pin a buffer in memory
35 * @sdp: The superblock
36 * @bh: The buffer to be pinned
38 * The log lock must be held when calling this function
40 void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
42 struct gfs2_bufdata *bd;
44 BUG_ON(!current->journal_info);
46 clear_buffer_dirty(bh);
47 if (test_set_buffer_pinned(bh))
48 gfs2_assert_withdraw(sdp, 0);
49 if (!buffer_uptodate(bh))
50 gfs2_io_error_bh(sdp, bh);
52 /* If this buffer is in the AIL and it has already been written
53 * to in-place disk block, remove it from the AIL.
55 spin_lock(&sdp->sd_ail_lock);
57 list_move(&bd->bd_ail_st_list, &bd->bd_tr->tr_ail2_list);
58 spin_unlock(&sdp->sd_ail_lock);
60 atomic_inc(&sdp->sd_log_pinned);
61 trace_gfs2_pin(bd, 1);
64 static bool buffer_is_rgrp(const struct gfs2_bufdata *bd)
66 return bd->bd_gl->gl_name.ln_type == LM_TYPE_RGRP;
69 static void maybe_release_space(struct gfs2_bufdata *bd)
71 struct gfs2_glock *gl = bd->bd_gl;
72 struct gfs2_sbd *sdp = gl->gl_sbd;
73 struct gfs2_rgrpd *rgd = gl->gl_object;
74 unsigned int index = bd->bd_bh->b_blocknr - gl->gl_name.ln_number;
75 struct gfs2_bitmap *bi = rgd->rd_bits + index;
77 if (bi->bi_clone == 0)
79 if (sdp->sd_args.ar_discard)
80 gfs2_rgrp_send_discards(sdp, rgd->rd_data0, bd->bd_bh, bi, 1, NULL);
81 memcpy(bi->bi_clone + bi->bi_offset,
82 bd->bd_bh->b_data + bi->bi_offset, bi->bi_len);
83 clear_bit(GBF_FULL, &bi->bi_flags);
84 rgd->rd_free_clone = rgd->rd_free;
88 * gfs2_unpin - Unpin a buffer
89 * @sdp: the filesystem the buffer belongs to
90 * @bh: The buffer to unpin
92 * @flags: The inode dirty flags
96 static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
97 struct gfs2_trans *tr)
99 struct gfs2_bufdata *bd = bh->b_private;
101 BUG_ON(!buffer_uptodate(bh));
102 BUG_ON(!buffer_pinned(bh));
105 mark_buffer_dirty(bh);
106 clear_buffer_pinned(bh);
108 if (buffer_is_rgrp(bd))
109 maybe_release_space(bd);
111 spin_lock(&sdp->sd_ail_lock);
113 list_del(&bd->bd_ail_st_list);
116 struct gfs2_glock *gl = bd->bd_gl;
117 list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
118 atomic_inc(&gl->gl_ail_count);
121 list_add(&bd->bd_ail_st_list, &tr->tr_ail1_list);
122 spin_unlock(&sdp->sd_ail_lock);
124 clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
125 trace_gfs2_pin(bd, 0);
127 atomic_dec(&sdp->sd_log_pinned);
130 static void gfs2_log_incr_head(struct gfs2_sbd *sdp)
132 BUG_ON((sdp->sd_log_flush_head == sdp->sd_log_tail) &&
133 (sdp->sd_log_flush_head != sdp->sd_log_head));
135 if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
136 sdp->sd_log_flush_head = 0;
137 sdp->sd_log_flush_wrapped = 1;
141 static u64 gfs2_log_bmap(struct gfs2_sbd *sdp)
143 unsigned int lbn = sdp->sd_log_flush_head;
144 struct gfs2_journal_extent *je;
147 list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) {
148 if (lbn >= je->lblock && lbn < je->lblock + je->blocks) {
149 block = je->dblock + lbn - je->lblock;
150 gfs2_log_incr_head(sdp);
159 * gfs2_end_log_write_bh - end log write of pagecache data with buffers
160 * @sdp: The superblock
162 * @error: The i/o status
164 * This finds the relavent buffers and unlocks then and sets the
165 * error flag according to the status of the i/o request. This is
166 * used when the log is writing data which has an in-place version
167 * that is pinned in the pagecache.
170 static void gfs2_end_log_write_bh(struct gfs2_sbd *sdp, struct bio_vec *bvec,
173 struct buffer_head *bh, *next;
174 struct page *page = bvec->bv_page;
177 bh = page_buffers(page);
179 while (bh_offset(bh) < bvec->bv_offset)
180 bh = bh->b_this_page;
183 set_buffer_write_io_error(bh);
185 next = bh->b_this_page;
193 * gfs2_end_log_write - end of i/o to the log
195 * @error: Status of i/o request
197 * Each bio_vec contains either data from the pagecache or data
198 * relating to the log itself. Here we iterate over the bio_vec
199 * array, processing both kinds of data.
203 static void gfs2_end_log_write(struct bio *bio, int error)
205 struct gfs2_sbd *sdp = bio->bi_private;
206 struct bio_vec *bvec;
211 sdp->sd_log_error = error;
212 fs_err(sdp, "Error %d writing to log\n", error);
215 bio_for_each_segment_all(bvec, bio, i) {
216 page = bvec->bv_page;
217 if (page_has_buffers(page))
218 gfs2_end_log_write_bh(sdp, bvec, error);
220 mempool_free(page, gfs2_page_pool);
224 if (atomic_dec_and_test(&sdp->sd_log_in_flight))
225 wake_up(&sdp->sd_log_flush_wait);
229 * gfs2_log_flush_bio - Submit any pending log bio
230 * @sdp: The superblock
233 * Submit any pending part-built or full bio to the block device. If
234 * there is no pending bio, then this is a no-op.
237 void gfs2_log_flush_bio(struct gfs2_sbd *sdp, int rw)
239 if (sdp->sd_log_bio) {
240 atomic_inc(&sdp->sd_log_in_flight);
241 submit_bio(rw, sdp->sd_log_bio);
242 sdp->sd_log_bio = NULL;
247 * gfs2_log_alloc_bio - Allocate a new bio for log writing
248 * @sdp: The superblock
249 * @blkno: The next device block number we want to write to
251 * This should never be called when there is a cached bio in the
252 * super block. When it returns, there will be a cached bio in the
253 * super block which will have as many bio_vecs as the device is
256 * Returns: Newly allocated bio
259 static struct bio *gfs2_log_alloc_bio(struct gfs2_sbd *sdp, u64 blkno)
261 struct super_block *sb = sdp->sd_vfs;
262 unsigned nrvecs = bio_get_nr_vecs(sb->s_bdev);
265 BUG_ON(sdp->sd_log_bio);
268 bio = bio_alloc(GFP_NOIO, nrvecs);
271 nrvecs = max(nrvecs/2, 1U);
274 bio->bi_sector = blkno * (sb->s_blocksize >> 9);
275 bio->bi_bdev = sb->s_bdev;
276 bio->bi_end_io = gfs2_end_log_write;
277 bio->bi_private = sdp;
279 sdp->sd_log_bio = bio;
285 * gfs2_log_get_bio - Get cached log bio, or allocate a new one
286 * @sdp: The superblock
287 * @blkno: The device block number we want to write to
289 * If there is a cached bio, then if the next block number is sequential
290 * with the previous one, return it, otherwise flush the bio to the
291 * device. If there is not a cached bio, or we just flushed it, then
292 * allocate a new one.
294 * Returns: The bio to use for log writes
297 static struct bio *gfs2_log_get_bio(struct gfs2_sbd *sdp, u64 blkno)
299 struct bio *bio = sdp->sd_log_bio;
303 nblk = bio_end_sector(bio);
304 nblk >>= sdp->sd_fsb2bb_shift;
307 gfs2_log_flush_bio(sdp, WRITE);
310 return gfs2_log_alloc_bio(sdp, blkno);
315 * gfs2_log_write - write to log
316 * @sdp: the filesystem
317 * @page: the page to write
318 * @size: the size of the data to write
319 * @offset: the offset within the page
321 * Try and add the page segment to the current bio. If that fails,
322 * submit the current bio to the device and create a new one, and
323 * then add the page segment to that.
326 static void gfs2_log_write(struct gfs2_sbd *sdp, struct page *page,
327 unsigned size, unsigned offset)
329 u64 blkno = gfs2_log_bmap(sdp);
333 bio = gfs2_log_get_bio(sdp, blkno);
334 ret = bio_add_page(bio, page, size, offset);
336 gfs2_log_flush_bio(sdp, WRITE);
337 bio = gfs2_log_alloc_bio(sdp, blkno);
338 ret = bio_add_page(bio, page, size, offset);
344 * gfs2_log_write_bh - write a buffer's content to the log
345 * @sdp: The super block
346 * @bh: The buffer pointing to the in-place location
348 * This writes the content of the buffer to the next available location
349 * in the log. The buffer will be unlocked once the i/o to the log has
353 static void gfs2_log_write_bh(struct gfs2_sbd *sdp, struct buffer_head *bh)
355 gfs2_log_write(sdp, bh->b_page, bh->b_size, bh_offset(bh));
359 * gfs2_log_write_page - write one block stored in a page, into the log
360 * @sdp: The superblock
361 * @page: The struct page
363 * This writes the first block-sized part of the page into the log. Note
364 * that the page must have been allocated from the gfs2_page_pool mempool
365 * and that after this has been called, ownership has been transferred and
366 * the page may be freed at any time.
369 void gfs2_log_write_page(struct gfs2_sbd *sdp, struct page *page)
371 struct super_block *sb = sdp->sd_vfs;
372 gfs2_log_write(sdp, page, sb->s_blocksize, 0);
375 static struct page *gfs2_get_log_desc(struct gfs2_sbd *sdp, u32 ld_type,
376 u32 ld_length, u32 ld_data1)
378 struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
379 struct gfs2_log_descriptor *ld = page_address(page);
381 ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
382 ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
383 ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
384 ld->ld_type = cpu_to_be32(ld_type);
385 ld->ld_length = cpu_to_be32(ld_length);
386 ld->ld_data1 = cpu_to_be32(ld_data1);
391 static void gfs2_check_magic(struct buffer_head *bh)
396 clear_buffer_escaped(bh);
397 kaddr = kmap_atomic(bh->b_page);
398 ptr = kaddr + bh_offset(bh);
399 if (*ptr == cpu_to_be32(GFS2_MAGIC))
400 set_buffer_escaped(bh);
401 kunmap_atomic(kaddr);
404 static void gfs2_before_commit(struct gfs2_sbd *sdp, unsigned int limit,
405 unsigned int total, struct list_head *blist,
408 struct gfs2_log_descriptor *ld;
409 struct gfs2_bufdata *bd1 = NULL, *bd2;
416 bd1 = bd2 = list_prepare_entry(bd1, blist, bd_list);
421 gfs2_log_unlock(sdp);
422 page = gfs2_get_log_desc(sdp,
423 is_databuf ? GFS2_LOG_DESC_JDATA :
424 GFS2_LOG_DESC_METADATA, num + 1, num);
425 ld = page_address(page);
427 ptr = (__be64 *)(ld + 1);
430 list_for_each_entry_continue(bd1, blist, bd_list) {
431 *ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
433 gfs2_check_magic(bd1->bd_bh);
434 *ptr++ = cpu_to_be64(buffer_escaped(bd1->bd_bh) ? 1 : 0);
440 gfs2_log_unlock(sdp);
441 gfs2_log_write_page(sdp, page);
445 list_for_each_entry_continue(bd2, blist, bd_list) {
447 gfs2_log_unlock(sdp);
448 lock_buffer(bd2->bd_bh);
450 if (buffer_escaped(bd2->bd_bh)) {
452 page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
453 ptr = page_address(page);
454 kaddr = kmap_atomic(bd2->bd_bh->b_page);
455 memcpy(ptr, kaddr + bh_offset(bd2->bd_bh),
457 kunmap_atomic(kaddr);
459 clear_buffer_escaped(bd2->bd_bh);
460 unlock_buffer(bd2->bd_bh);
462 gfs2_log_write_page(sdp, page);
464 gfs2_log_write_bh(sdp, bd2->bd_bh);
474 gfs2_log_unlock(sdp);
477 static void buf_lo_before_commit(struct gfs2_sbd *sdp)
479 unsigned int limit = buf_limit(sdp); /* 503 for 4k blocks */
481 gfs2_before_commit(sdp, limit, sdp->sd_log_num_buf,
482 &sdp->sd_log_le_buf, 0);
485 static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
487 struct list_head *head = &sdp->sd_log_le_buf;
488 struct gfs2_bufdata *bd;
491 gfs2_assert(sdp, list_empty(head));
495 while (!list_empty(head)) {
496 bd = list_entry(head->next, struct gfs2_bufdata, bd_list);
497 list_del_init(&bd->bd_list);
498 sdp->sd_log_num_buf--;
500 gfs2_unpin(sdp, bd->bd_bh, tr);
502 gfs2_assert_warn(sdp, !sdp->sd_log_num_buf);
505 static void buf_lo_before_scan(struct gfs2_jdesc *jd,
506 struct gfs2_log_header_host *head, int pass)
508 struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
513 sdp->sd_found_blocks = 0;
514 sdp->sd_replayed_blocks = 0;
517 static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
518 struct gfs2_log_descriptor *ld, __be64 *ptr,
521 struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
522 struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
523 struct gfs2_glock *gl = ip->i_gl;
524 unsigned int blks = be32_to_cpu(ld->ld_data1);
525 struct buffer_head *bh_log, *bh_ip;
529 if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_METADATA)
532 gfs2_replay_incr_blk(sdp, &start);
534 for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
535 blkno = be64_to_cpu(*ptr++);
537 sdp->sd_found_blocks++;
539 if (gfs2_revoke_check(sdp, blkno, start))
542 error = gfs2_replay_read_block(jd, start, &bh_log);
546 bh_ip = gfs2_meta_new(gl, blkno);
547 memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
549 if (gfs2_meta_check(sdp, bh_ip))
552 mark_buffer_dirty(bh_ip);
560 sdp->sd_replayed_blocks++;
566 static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
568 struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
569 struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
572 gfs2_meta_sync(ip->i_gl);
578 gfs2_meta_sync(ip->i_gl);
580 fs_info(sdp, "jid=%u: Replayed %u of %u blocks\n",
581 jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
584 static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
586 struct gfs2_meta_header *mh;
588 struct list_head *head = &sdp->sd_log_le_revoke;
589 struct gfs2_bufdata *bd;
593 if (!sdp->sd_log_num_revoke)
596 length = gfs2_struct2blk(sdp, sdp->sd_log_num_revoke, sizeof(u64));
597 page = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_REVOKE, length, sdp->sd_log_num_revoke);
598 offset = sizeof(struct gfs2_log_descriptor);
600 list_for_each_entry(bd, head, bd_list) {
601 sdp->sd_log_num_revoke--;
603 if (offset + sizeof(u64) > sdp->sd_sb.sb_bsize) {
605 gfs2_log_write_page(sdp, page);
606 page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
607 mh = page_address(page);
609 mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
610 mh->mh_type = cpu_to_be32(GFS2_METATYPE_LB);
611 mh->mh_format = cpu_to_be32(GFS2_FORMAT_LB);
612 offset = sizeof(struct gfs2_meta_header);
615 *(__be64 *)(page_address(page) + offset) = cpu_to_be64(bd->bd_blkno);
616 offset += sizeof(u64);
618 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
620 gfs2_log_write_page(sdp, page);
623 static void revoke_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
625 struct list_head *head = &sdp->sd_log_le_revoke;
626 struct gfs2_bufdata *bd;
627 struct gfs2_glock *gl;
629 while (!list_empty(head)) {
630 bd = list_entry(head->next, struct gfs2_bufdata, bd_list);
631 list_del_init(&bd->bd_list);
633 atomic_dec(&gl->gl_revokes);
634 clear_bit(GLF_LFLUSH, &gl->gl_flags);
635 kmem_cache_free(gfs2_bufdata_cachep, bd);
639 static void revoke_lo_before_scan(struct gfs2_jdesc *jd,
640 struct gfs2_log_header_host *head, int pass)
642 struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
647 sdp->sd_found_revokes = 0;
648 sdp->sd_replay_tail = head->lh_tail;
651 static int revoke_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
652 struct gfs2_log_descriptor *ld, __be64 *ptr,
655 struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
656 unsigned int blks = be32_to_cpu(ld->ld_length);
657 unsigned int revokes = be32_to_cpu(ld->ld_data1);
658 struct buffer_head *bh;
664 if (pass != 0 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_REVOKE)
667 offset = sizeof(struct gfs2_log_descriptor);
669 for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
670 error = gfs2_replay_read_block(jd, start, &bh);
675 gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LB);
677 while (offset + sizeof(u64) <= sdp->sd_sb.sb_bsize) {
678 blkno = be64_to_cpu(*(__be64 *)(bh->b_data + offset));
680 error = gfs2_revoke_add(sdp, blkno, start);
686 sdp->sd_found_revokes++;
690 offset += sizeof(u64);
694 offset = sizeof(struct gfs2_meta_header);
701 static void revoke_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
703 struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
706 gfs2_revoke_clean(sdp);
712 fs_info(sdp, "jid=%u: Found %u revoke tags\n",
713 jd->jd_jid, sdp->sd_found_revokes);
715 gfs2_revoke_clean(sdp);
719 * databuf_lo_before_commit - Scan the data buffers, writing as we go
723 static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
725 unsigned int limit = buf_limit(sdp) / 2;
727 gfs2_before_commit(sdp, limit, sdp->sd_log_num_databuf,
728 &sdp->sd_log_le_databuf, 1);
731 static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
732 struct gfs2_log_descriptor *ld,
733 __be64 *ptr, int pass)
735 struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
736 struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
737 struct gfs2_glock *gl = ip->i_gl;
738 unsigned int blks = be32_to_cpu(ld->ld_data1);
739 struct buffer_head *bh_log, *bh_ip;
744 if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_JDATA)
747 gfs2_replay_incr_blk(sdp, &start);
748 for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
749 blkno = be64_to_cpu(*ptr++);
750 esc = be64_to_cpu(*ptr++);
752 sdp->sd_found_blocks++;
754 if (gfs2_revoke_check(sdp, blkno, start))
757 error = gfs2_replay_read_block(jd, start, &bh_log);
761 bh_ip = gfs2_meta_new(gl, blkno);
762 memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
766 __be32 *eptr = (__be32 *)bh_ip->b_data;
767 *eptr = cpu_to_be32(GFS2_MAGIC);
769 mark_buffer_dirty(bh_ip);
774 sdp->sd_replayed_blocks++;
780 /* FIXME: sort out accounting for log blocks etc. */
782 static void databuf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
784 struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
785 struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
788 gfs2_meta_sync(ip->i_gl);
795 gfs2_meta_sync(ip->i_gl);
797 fs_info(sdp, "jid=%u: Replayed %u of %u data blocks\n",
798 jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
801 static void databuf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
803 struct list_head *head = &sdp->sd_log_le_databuf;
804 struct gfs2_bufdata *bd;
807 gfs2_assert(sdp, list_empty(head));
811 while (!list_empty(head)) {
812 bd = list_entry(head->next, struct gfs2_bufdata, bd_list);
813 list_del_init(&bd->bd_list);
814 sdp->sd_log_num_databuf--;
815 gfs2_unpin(sdp, bd->bd_bh, tr);
817 gfs2_assert_warn(sdp, !sdp->sd_log_num_databuf);
821 const struct gfs2_log_operations gfs2_buf_lops = {
822 .lo_before_commit = buf_lo_before_commit,
823 .lo_after_commit = buf_lo_after_commit,
824 .lo_before_scan = buf_lo_before_scan,
825 .lo_scan_elements = buf_lo_scan_elements,
826 .lo_after_scan = buf_lo_after_scan,
830 const struct gfs2_log_operations gfs2_revoke_lops = {
831 .lo_before_commit = revoke_lo_before_commit,
832 .lo_after_commit = revoke_lo_after_commit,
833 .lo_before_scan = revoke_lo_before_scan,
834 .lo_scan_elements = revoke_lo_scan_elements,
835 .lo_after_scan = revoke_lo_after_scan,
839 const struct gfs2_log_operations gfs2_rg_lops = {
843 const struct gfs2_log_operations gfs2_databuf_lops = {
844 .lo_before_commit = databuf_lo_before_commit,
845 .lo_after_commit = databuf_lo_after_commit,
846 .lo_scan_elements = databuf_lo_scan_elements,
847 .lo_after_scan = databuf_lo_after_scan,
848 .lo_name = "databuf",
851 const struct gfs2_log_operations *gfs2_log_ops[] = {