xref: /openbmc/linux/fs/gfs2/lops.c (revision 9d56dd3b)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
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.
8  */
9 
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>
16 #include <linux/bio.h>
17 #include <linux/fs.h>
18 
19 #include "gfs2.h"
20 #include "incore.h"
21 #include "inode.h"
22 #include "glock.h"
23 #include "log.h"
24 #include "lops.h"
25 #include "meta_io.h"
26 #include "recovery.h"
27 #include "rgrp.h"
28 #include "trans.h"
29 #include "util.h"
30 #include "trace_gfs2.h"
31 
32 /**
33  * gfs2_pin - Pin a buffer in memory
34  * @sdp: The superblock
35  * @bh: The buffer to be pinned
36  *
37  * The log lock must be held when calling this function
38  */
39 static void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
40 {
41 	struct gfs2_bufdata *bd;
42 
43 	gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
44 
45 	clear_buffer_dirty(bh);
46 	if (test_set_buffer_pinned(bh))
47 		gfs2_assert_withdraw(sdp, 0);
48 	if (!buffer_uptodate(bh))
49 		gfs2_io_error_bh(sdp, bh);
50 	bd = bh->b_private;
51 	/* If this buffer is in the AIL and it has already been written
52 	 * to in-place disk block, remove it from the AIL.
53 	 */
54 	if (bd->bd_ail)
55 		list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
56 	get_bh(bh);
57 	trace_gfs2_pin(bd, 1);
58 }
59 
60 /**
61  * gfs2_unpin - Unpin a buffer
62  * @sdp: the filesystem the buffer belongs to
63  * @bh: The buffer to unpin
64  * @ai:
65  *
66  */
67 
68 static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
69 		       struct gfs2_ail *ai)
70 {
71 	struct gfs2_bufdata *bd = bh->b_private;
72 
73 	gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
74 
75 	if (!buffer_pinned(bh))
76 		gfs2_assert_withdraw(sdp, 0);
77 
78 	lock_buffer(bh);
79 	mark_buffer_dirty(bh);
80 	clear_buffer_pinned(bh);
81 
82 	gfs2_log_lock(sdp);
83 	if (bd->bd_ail) {
84 		list_del(&bd->bd_ail_st_list);
85 		brelse(bh);
86 	} else {
87 		struct gfs2_glock *gl = bd->bd_gl;
88 		list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
89 		atomic_inc(&gl->gl_ail_count);
90 	}
91 	bd->bd_ail = ai;
92 	list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
93 	clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
94 	trace_gfs2_pin(bd, 0);
95 	gfs2_log_unlock(sdp);
96 	unlock_buffer(bh);
97 }
98 
99 
100 static inline struct gfs2_log_descriptor *bh_log_desc(struct buffer_head *bh)
101 {
102 	return (struct gfs2_log_descriptor *)bh->b_data;
103 }
104 
105 static inline __be64 *bh_log_ptr(struct buffer_head *bh)
106 {
107 	struct gfs2_log_descriptor *ld = bh_log_desc(bh);
108 	return (__force __be64 *)(ld + 1);
109 }
110 
111 static inline __be64 *bh_ptr_end(struct buffer_head *bh)
112 {
113 	return (__force __be64 *)(bh->b_data + bh->b_size);
114 }
115 
116 
117 static struct buffer_head *gfs2_get_log_desc(struct gfs2_sbd *sdp, u32 ld_type)
118 {
119 	struct buffer_head *bh = gfs2_log_get_buf(sdp);
120 	struct gfs2_log_descriptor *ld = bh_log_desc(bh);
121 	ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
122 	ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
123 	ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
124 	ld->ld_type = cpu_to_be32(ld_type);
125 	ld->ld_length = 0;
126 	ld->ld_data1 = 0;
127 	ld->ld_data2 = 0;
128 	memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
129 	return bh;
130 }
131 
132 static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
133 {
134 	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
135 	struct gfs2_meta_header *mh;
136 	struct gfs2_trans *tr;
137 
138 	lock_buffer(bd->bd_bh);
139 	gfs2_log_lock(sdp);
140 	if (!list_empty(&bd->bd_list_tr))
141 		goto out;
142 	tr = current->journal_info;
143 	tr->tr_touched = 1;
144 	tr->tr_num_buf++;
145 	list_add(&bd->bd_list_tr, &tr->tr_list_buf);
146 	if (!list_empty(&le->le_list))
147 		goto out;
148 	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
149 	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
150 	gfs2_meta_check(sdp, bd->bd_bh);
151 	gfs2_pin(sdp, bd->bd_bh);
152 	mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
153 	mh->__pad0 = cpu_to_be64(0);
154 	mh->mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
155 	sdp->sd_log_num_buf++;
156 	list_add(&le->le_list, &sdp->sd_log_le_buf);
157 	tr->tr_num_buf_new++;
158 out:
159 	gfs2_log_unlock(sdp);
160 	unlock_buffer(bd->bd_bh);
161 }
162 
163 static void buf_lo_before_commit(struct gfs2_sbd *sdp)
164 {
165 	struct buffer_head *bh;
166 	struct gfs2_log_descriptor *ld;
167 	struct gfs2_bufdata *bd1 = NULL, *bd2;
168 	unsigned int total;
169 	unsigned int limit;
170 	unsigned int num;
171 	unsigned n;
172 	__be64 *ptr;
173 
174 	limit = buf_limit(sdp);
175 	/* for 4k blocks, limit = 503 */
176 
177 	gfs2_log_lock(sdp);
178 	total = sdp->sd_log_num_buf;
179 	bd1 = bd2 = list_prepare_entry(bd1, &sdp->sd_log_le_buf, bd_le.le_list);
180 	while(total) {
181 		num = total;
182 		if (total > limit)
183 			num = limit;
184 		gfs2_log_unlock(sdp);
185 		bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_METADATA);
186 		gfs2_log_lock(sdp);
187 		ld = bh_log_desc(bh);
188 		ptr = bh_log_ptr(bh);
189 		ld->ld_length = cpu_to_be32(num + 1);
190 		ld->ld_data1 = cpu_to_be32(num);
191 
192 		n = 0;
193 		list_for_each_entry_continue(bd1, &sdp->sd_log_le_buf,
194 					     bd_le.le_list) {
195 			*ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
196 			if (++n >= num)
197 				break;
198 		}
199 
200 		gfs2_log_unlock(sdp);
201 		submit_bh(WRITE_SYNC_PLUG, bh);
202 		gfs2_log_lock(sdp);
203 
204 		n = 0;
205 		list_for_each_entry_continue(bd2, &sdp->sd_log_le_buf,
206 					     bd_le.le_list) {
207 			get_bh(bd2->bd_bh);
208 			gfs2_log_unlock(sdp);
209 			lock_buffer(bd2->bd_bh);
210 			bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
211 			submit_bh(WRITE_SYNC_PLUG, bh);
212 			gfs2_log_lock(sdp);
213 			if (++n >= num)
214 				break;
215 		}
216 
217 		BUG_ON(total < num);
218 		total -= num;
219 	}
220 	gfs2_log_unlock(sdp);
221 }
222 
223 static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
224 {
225 	struct list_head *head = &sdp->sd_log_le_buf;
226 	struct gfs2_bufdata *bd;
227 
228 	while (!list_empty(head)) {
229 		bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
230 		list_del_init(&bd->bd_le.le_list);
231 		sdp->sd_log_num_buf--;
232 
233 		gfs2_unpin(sdp, bd->bd_bh, ai);
234 	}
235 	gfs2_assert_warn(sdp, !sdp->sd_log_num_buf);
236 }
237 
238 static void buf_lo_before_scan(struct gfs2_jdesc *jd,
239 			       struct gfs2_log_header_host *head, int pass)
240 {
241 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
242 
243 	if (pass != 0)
244 		return;
245 
246 	sdp->sd_found_blocks = 0;
247 	sdp->sd_replayed_blocks = 0;
248 }
249 
250 static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
251 				struct gfs2_log_descriptor *ld, __be64 *ptr,
252 				int pass)
253 {
254 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
255 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
256 	struct gfs2_glock *gl = ip->i_gl;
257 	unsigned int blks = be32_to_cpu(ld->ld_data1);
258 	struct buffer_head *bh_log, *bh_ip;
259 	u64 blkno;
260 	int error = 0;
261 
262 	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_METADATA)
263 		return 0;
264 
265 	gfs2_replay_incr_blk(sdp, &start);
266 
267 	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
268 		blkno = be64_to_cpu(*ptr++);
269 
270 		sdp->sd_found_blocks++;
271 
272 		if (gfs2_revoke_check(sdp, blkno, start))
273 			continue;
274 
275 		error = gfs2_replay_read_block(jd, start, &bh_log);
276 		if (error)
277 			return error;
278 
279 		bh_ip = gfs2_meta_new(gl, blkno);
280 		memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
281 
282 		if (gfs2_meta_check(sdp, bh_ip))
283 			error = -EIO;
284 		else
285 			mark_buffer_dirty(bh_ip);
286 
287 		brelse(bh_log);
288 		brelse(bh_ip);
289 
290 		if (error)
291 			break;
292 
293 		sdp->sd_replayed_blocks++;
294 	}
295 
296 	return error;
297 }
298 
299 static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
300 {
301 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
302 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
303 
304 	if (error) {
305 		gfs2_meta_sync(ip->i_gl);
306 		return;
307 	}
308 	if (pass != 1)
309 		return;
310 
311 	gfs2_meta_sync(ip->i_gl);
312 
313 	fs_info(sdp, "jid=%u: Replayed %u of %u blocks\n",
314 	        jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
315 }
316 
317 static void revoke_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
318 {
319 	struct gfs2_trans *tr;
320 
321 	tr = current->journal_info;
322 	tr->tr_touched = 1;
323 	tr->tr_num_revoke++;
324 	sdp->sd_log_num_revoke++;
325 	list_add(&le->le_list, &sdp->sd_log_le_revoke);
326 }
327 
328 static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
329 {
330 	struct gfs2_log_descriptor *ld;
331 	struct gfs2_meta_header *mh;
332 	struct buffer_head *bh;
333 	unsigned int offset;
334 	struct list_head *head = &sdp->sd_log_le_revoke;
335 	struct gfs2_bufdata *bd;
336 
337 	if (!sdp->sd_log_num_revoke)
338 		return;
339 
340 	bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_REVOKE);
341 	ld = bh_log_desc(bh);
342 	ld->ld_length = cpu_to_be32(gfs2_struct2blk(sdp, sdp->sd_log_num_revoke,
343 						    sizeof(u64)));
344 	ld->ld_data1 = cpu_to_be32(sdp->sd_log_num_revoke);
345 	offset = sizeof(struct gfs2_log_descriptor);
346 
347 	while (!list_empty(head)) {
348 		bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
349 		list_del_init(&bd->bd_le.le_list);
350 		sdp->sd_log_num_revoke--;
351 
352 		if (offset + sizeof(u64) > sdp->sd_sb.sb_bsize) {
353 			submit_bh(WRITE_SYNC_PLUG, bh);
354 
355 			bh = gfs2_log_get_buf(sdp);
356 			mh = (struct gfs2_meta_header *)bh->b_data;
357 			mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
358 			mh->mh_type = cpu_to_be32(GFS2_METATYPE_LB);
359 			mh->mh_format = cpu_to_be32(GFS2_FORMAT_LB);
360 			offset = sizeof(struct gfs2_meta_header);
361 		}
362 
363 		*(__be64 *)(bh->b_data + offset) = cpu_to_be64(bd->bd_blkno);
364 		kmem_cache_free(gfs2_bufdata_cachep, bd);
365 
366 		offset += sizeof(u64);
367 	}
368 	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
369 
370 	submit_bh(WRITE_SYNC_PLUG, bh);
371 }
372 
373 static void revoke_lo_before_scan(struct gfs2_jdesc *jd,
374 				  struct gfs2_log_header_host *head, int pass)
375 {
376 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
377 
378 	if (pass != 0)
379 		return;
380 
381 	sdp->sd_found_revokes = 0;
382 	sdp->sd_replay_tail = head->lh_tail;
383 }
384 
385 static int revoke_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
386 				   struct gfs2_log_descriptor *ld, __be64 *ptr,
387 				   int pass)
388 {
389 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
390 	unsigned int blks = be32_to_cpu(ld->ld_length);
391 	unsigned int revokes = be32_to_cpu(ld->ld_data1);
392 	struct buffer_head *bh;
393 	unsigned int offset;
394 	u64 blkno;
395 	int first = 1;
396 	int error;
397 
398 	if (pass != 0 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_REVOKE)
399 		return 0;
400 
401 	offset = sizeof(struct gfs2_log_descriptor);
402 
403 	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
404 		error = gfs2_replay_read_block(jd, start, &bh);
405 		if (error)
406 			return error;
407 
408 		if (!first)
409 			gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LB);
410 
411 		while (offset + sizeof(u64) <= sdp->sd_sb.sb_bsize) {
412 			blkno = be64_to_cpu(*(__be64 *)(bh->b_data + offset));
413 
414 			error = gfs2_revoke_add(sdp, blkno, start);
415 			if (error < 0) {
416 				brelse(bh);
417 				return error;
418 			}
419 			else if (error)
420 				sdp->sd_found_revokes++;
421 
422 			if (!--revokes)
423 				break;
424 			offset += sizeof(u64);
425 		}
426 
427 		brelse(bh);
428 		offset = sizeof(struct gfs2_meta_header);
429 		first = 0;
430 	}
431 
432 	return 0;
433 }
434 
435 static void revoke_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
436 {
437 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
438 
439 	if (error) {
440 		gfs2_revoke_clean(sdp);
441 		return;
442 	}
443 	if (pass != 1)
444 		return;
445 
446 	fs_info(sdp, "jid=%u: Found %u revoke tags\n",
447 	        jd->jd_jid, sdp->sd_found_revokes);
448 
449 	gfs2_revoke_clean(sdp);
450 }
451 
452 static void rg_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
453 {
454 	struct gfs2_rgrpd *rgd;
455 	struct gfs2_trans *tr = current->journal_info;
456 
457 	tr->tr_touched = 1;
458 
459 	rgd = container_of(le, struct gfs2_rgrpd, rd_le);
460 
461 	gfs2_log_lock(sdp);
462 	if (!list_empty(&le->le_list)){
463 		gfs2_log_unlock(sdp);
464 		return;
465 	}
466 	gfs2_rgrp_bh_hold(rgd);
467 	sdp->sd_log_num_rg++;
468 	list_add(&le->le_list, &sdp->sd_log_le_rg);
469 	gfs2_log_unlock(sdp);
470 }
471 
472 static void rg_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
473 {
474 	struct list_head *head = &sdp->sd_log_le_rg;
475 	struct gfs2_rgrpd *rgd;
476 
477 	while (!list_empty(head)) {
478 		rgd = list_entry(head->next, struct gfs2_rgrpd, rd_le.le_list);
479 		list_del_init(&rgd->rd_le.le_list);
480 		sdp->sd_log_num_rg--;
481 
482 		gfs2_rgrp_repolish_clones(rgd);
483 		gfs2_rgrp_bh_put(rgd);
484 	}
485 	gfs2_assert_warn(sdp, !sdp->sd_log_num_rg);
486 }
487 
488 /**
489  * databuf_lo_add - Add a databuf to the transaction.
490  *
491  * This is used in two distinct cases:
492  * i) In ordered write mode
493  *    We put the data buffer on a list so that we can ensure that its
494  *    synced to disk at the right time
495  * ii) In journaled data mode
496  *    We need to journal the data block in the same way as metadata in
497  *    the functions above. The difference is that here we have a tag
498  *    which is two __be64's being the block number (as per meta data)
499  *    and a flag which says whether the data block needs escaping or
500  *    not. This means we need a new log entry for each 251 or so data
501  *    blocks, which isn't an enormous overhead but twice as much as
502  *    for normal metadata blocks.
503  */
504 static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
505 {
506 	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
507 	struct gfs2_trans *tr = current->journal_info;
508 	struct address_space *mapping = bd->bd_bh->b_page->mapping;
509 	struct gfs2_inode *ip = GFS2_I(mapping->host);
510 
511 	lock_buffer(bd->bd_bh);
512 	gfs2_log_lock(sdp);
513 	if (tr) {
514 		if (!list_empty(&bd->bd_list_tr))
515 			goto out;
516 		tr->tr_touched = 1;
517 		if (gfs2_is_jdata(ip)) {
518 			tr->tr_num_buf++;
519 			list_add(&bd->bd_list_tr, &tr->tr_list_buf);
520 		}
521 	}
522 	if (!list_empty(&le->le_list))
523 		goto out;
524 
525 	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
526 	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
527 	if (gfs2_is_jdata(ip)) {
528 		gfs2_pin(sdp, bd->bd_bh);
529 		tr->tr_num_databuf_new++;
530 		sdp->sd_log_num_databuf++;
531 		list_add(&le->le_list, &sdp->sd_log_le_databuf);
532 	} else {
533 		list_add(&le->le_list, &sdp->sd_log_le_ordered);
534 	}
535 out:
536 	gfs2_log_unlock(sdp);
537 	unlock_buffer(bd->bd_bh);
538 }
539 
540 static void gfs2_check_magic(struct buffer_head *bh)
541 {
542 	void *kaddr;
543 	__be32 *ptr;
544 
545 	clear_buffer_escaped(bh);
546 	kaddr = kmap_atomic(bh->b_page, KM_USER0);
547 	ptr = kaddr + bh_offset(bh);
548 	if (*ptr == cpu_to_be32(GFS2_MAGIC))
549 		set_buffer_escaped(bh);
550 	kunmap_atomic(kaddr, KM_USER0);
551 }
552 
553 static void gfs2_write_blocks(struct gfs2_sbd *sdp, struct buffer_head *bh,
554 			      struct list_head *list, struct list_head *done,
555 			      unsigned int n)
556 {
557 	struct buffer_head *bh1;
558 	struct gfs2_log_descriptor *ld;
559 	struct gfs2_bufdata *bd;
560 	__be64 *ptr;
561 
562 	if (!bh)
563 		return;
564 
565 	ld = bh_log_desc(bh);
566 	ld->ld_length = cpu_to_be32(n + 1);
567 	ld->ld_data1 = cpu_to_be32(n);
568 
569 	ptr = bh_log_ptr(bh);
570 
571 	get_bh(bh);
572 	submit_bh(WRITE_SYNC_PLUG, bh);
573 	gfs2_log_lock(sdp);
574 	while(!list_empty(list)) {
575 		bd = list_entry(list->next, struct gfs2_bufdata, bd_le.le_list);
576 		list_move_tail(&bd->bd_le.le_list, done);
577 		get_bh(bd->bd_bh);
578 		while (be64_to_cpu(*ptr) != bd->bd_bh->b_blocknr) {
579 			gfs2_log_incr_head(sdp);
580 			ptr += 2;
581 		}
582 		gfs2_log_unlock(sdp);
583 		lock_buffer(bd->bd_bh);
584 		if (buffer_escaped(bd->bd_bh)) {
585 			void *kaddr;
586 			bh1 = gfs2_log_get_buf(sdp);
587 			kaddr = kmap_atomic(bd->bd_bh->b_page, KM_USER0);
588 			memcpy(bh1->b_data, kaddr + bh_offset(bd->bd_bh),
589 			       bh1->b_size);
590 			kunmap_atomic(kaddr, KM_USER0);
591 			*(__be32 *)bh1->b_data = 0;
592 			clear_buffer_escaped(bd->bd_bh);
593 			unlock_buffer(bd->bd_bh);
594 			brelse(bd->bd_bh);
595 		} else {
596 			bh1 = gfs2_log_fake_buf(sdp, bd->bd_bh);
597 		}
598 		submit_bh(WRITE_SYNC_PLUG, bh1);
599 		gfs2_log_lock(sdp);
600 		ptr += 2;
601 	}
602 	gfs2_log_unlock(sdp);
603 	brelse(bh);
604 }
605 
606 /**
607  * databuf_lo_before_commit - Scan the data buffers, writing as we go
608  *
609  */
610 
611 static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
612 {
613 	struct gfs2_bufdata *bd = NULL;
614 	struct buffer_head *bh = NULL;
615 	unsigned int n = 0;
616 	__be64 *ptr = NULL, *end = NULL;
617 	LIST_HEAD(processed);
618 	LIST_HEAD(in_progress);
619 
620 	gfs2_log_lock(sdp);
621 	while (!list_empty(&sdp->sd_log_le_databuf)) {
622 		if (ptr == end) {
623 			gfs2_log_unlock(sdp);
624 			gfs2_write_blocks(sdp, bh, &in_progress, &processed, n);
625 			n = 0;
626 			bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_JDATA);
627 			ptr = bh_log_ptr(bh);
628 			end = bh_ptr_end(bh) - 1;
629 			gfs2_log_lock(sdp);
630 			continue;
631 		}
632 		bd = list_entry(sdp->sd_log_le_databuf.next, struct gfs2_bufdata, bd_le.le_list);
633 		list_move_tail(&bd->bd_le.le_list, &in_progress);
634 		gfs2_check_magic(bd->bd_bh);
635 		*ptr++ = cpu_to_be64(bd->bd_bh->b_blocknr);
636 		*ptr++ = cpu_to_be64(buffer_escaped(bh) ? 1 : 0);
637 		n++;
638 	}
639 	gfs2_log_unlock(sdp);
640 	gfs2_write_blocks(sdp, bh, &in_progress, &processed, n);
641 	gfs2_log_lock(sdp);
642 	list_splice(&processed, &sdp->sd_log_le_databuf);
643 	gfs2_log_unlock(sdp);
644 }
645 
646 static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
647 				    struct gfs2_log_descriptor *ld,
648 				    __be64 *ptr, int pass)
649 {
650 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
651 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
652 	struct gfs2_glock *gl = ip->i_gl;
653 	unsigned int blks = be32_to_cpu(ld->ld_data1);
654 	struct buffer_head *bh_log, *bh_ip;
655 	u64 blkno;
656 	u64 esc;
657 	int error = 0;
658 
659 	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_JDATA)
660 		return 0;
661 
662 	gfs2_replay_incr_blk(sdp, &start);
663 	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
664 		blkno = be64_to_cpu(*ptr++);
665 		esc = be64_to_cpu(*ptr++);
666 
667 		sdp->sd_found_blocks++;
668 
669 		if (gfs2_revoke_check(sdp, blkno, start))
670 			continue;
671 
672 		error = gfs2_replay_read_block(jd, start, &bh_log);
673 		if (error)
674 			return error;
675 
676 		bh_ip = gfs2_meta_new(gl, blkno);
677 		memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
678 
679 		/* Unescape */
680 		if (esc) {
681 			__be32 *eptr = (__be32 *)bh_ip->b_data;
682 			*eptr = cpu_to_be32(GFS2_MAGIC);
683 		}
684 		mark_buffer_dirty(bh_ip);
685 
686 		brelse(bh_log);
687 		brelse(bh_ip);
688 		if (error)
689 			break;
690 
691 		sdp->sd_replayed_blocks++;
692 	}
693 
694 	return error;
695 }
696 
697 /* FIXME: sort out accounting for log blocks etc. */
698 
699 static void databuf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
700 {
701 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
702 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
703 
704 	if (error) {
705 		gfs2_meta_sync(ip->i_gl);
706 		return;
707 	}
708 	if (pass != 1)
709 		return;
710 
711 	/* data sync? */
712 	gfs2_meta_sync(ip->i_gl);
713 
714 	fs_info(sdp, "jid=%u: Replayed %u of %u data blocks\n",
715 		jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
716 }
717 
718 static void databuf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
719 {
720 	struct list_head *head = &sdp->sd_log_le_databuf;
721 	struct gfs2_bufdata *bd;
722 
723 	while (!list_empty(head)) {
724 		bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
725 		list_del_init(&bd->bd_le.le_list);
726 		sdp->sd_log_num_databuf--;
727 		gfs2_unpin(sdp, bd->bd_bh, ai);
728 	}
729 	gfs2_assert_warn(sdp, !sdp->sd_log_num_databuf);
730 }
731 
732 
733 const struct gfs2_log_operations gfs2_buf_lops = {
734 	.lo_add = buf_lo_add,
735 	.lo_before_commit = buf_lo_before_commit,
736 	.lo_after_commit = buf_lo_after_commit,
737 	.lo_before_scan = buf_lo_before_scan,
738 	.lo_scan_elements = buf_lo_scan_elements,
739 	.lo_after_scan = buf_lo_after_scan,
740 	.lo_name = "buf",
741 };
742 
743 const struct gfs2_log_operations gfs2_revoke_lops = {
744 	.lo_add = revoke_lo_add,
745 	.lo_before_commit = revoke_lo_before_commit,
746 	.lo_before_scan = revoke_lo_before_scan,
747 	.lo_scan_elements = revoke_lo_scan_elements,
748 	.lo_after_scan = revoke_lo_after_scan,
749 	.lo_name = "revoke",
750 };
751 
752 const struct gfs2_log_operations gfs2_rg_lops = {
753 	.lo_add = rg_lo_add,
754 	.lo_after_commit = rg_lo_after_commit,
755 	.lo_name = "rg",
756 };
757 
758 const struct gfs2_log_operations gfs2_databuf_lops = {
759 	.lo_add = databuf_lo_add,
760 	.lo_before_commit = databuf_lo_before_commit,
761 	.lo_after_commit = databuf_lo_after_commit,
762 	.lo_scan_elements = databuf_lo_scan_elements,
763 	.lo_after_scan = databuf_lo_after_scan,
764 	.lo_name = "databuf",
765 };
766 
767 const struct gfs2_log_operations *gfs2_log_ops[] = {
768 	&gfs2_databuf_lops,
769 	&gfs2_buf_lops,
770 	&gfs2_rg_lops,
771 	&gfs2_revoke_lops,
772 	NULL,
773 };
774 
775