xref: /openbmc/linux/fs/gfs2/lops.c (revision 568f4c96)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2005 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 v.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 <asm/semaphore.h>
16 
17 #include "gfs2.h"
18 #include "glock.h"
19 #include "log.h"
20 #include "lops.h"
21 #include "meta_io.h"
22 #include "recovery.h"
23 #include "rgrp.h"
24 #include "trans.h"
25 
26 static void glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
27 {
28 	struct gfs2_glock *gl;
29 
30 	get_transaction->tr_touched = 1;
31 
32 	if (!list_empty(&le->le_list))
33 		return;
34 
35 	gl = container_of(le, struct gfs2_glock, gl_le);
36 	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl)))
37 		return;
38 	gfs2_glock_hold(gl);
39 	set_bit(GLF_DIRTY, &gl->gl_flags);
40 
41 	gfs2_log_lock(sdp);
42 	sdp->sd_log_num_gl++;
43 	list_add(&le->le_list, &sdp->sd_log_le_gl);
44 	gfs2_log_unlock(sdp);
45 }
46 
47 static void glock_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
48 {
49 	struct list_head *head = &sdp->sd_log_le_gl;
50 	struct gfs2_glock *gl;
51 
52 	while (!list_empty(head)) {
53 		gl = list_entry(head->next, struct gfs2_glock, gl_le.le_list);
54 		list_del_init(&gl->gl_le.le_list);
55 		sdp->sd_log_num_gl--;
56 
57 		gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl));
58 		gfs2_glock_put(gl);
59 	}
60 	gfs2_assert_warn(sdp, !sdp->sd_log_num_gl);
61 }
62 
63 static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
64 {
65 	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
66 	struct gfs2_trans *tr;
67 
68 	if (!list_empty(&bd->bd_list_tr))
69 		return;
70 
71 	tr = get_transaction;
72 	tr->tr_touched = 1;
73 	tr->tr_num_buf++;
74 	list_add(&bd->bd_list_tr, &tr->tr_list_buf);
75 
76 	if (!list_empty(&le->le_list))
77 		return;
78 
79 	gfs2_trans_add_gl(bd->bd_gl);
80 
81 	gfs2_meta_check(sdp, bd->bd_bh);
82 	gfs2_pin(sdp, bd->bd_bh);
83 
84 	gfs2_log_lock(sdp);
85 	sdp->sd_log_num_buf++;
86 	list_add(&le->le_list, &sdp->sd_log_le_buf);
87 	gfs2_log_unlock(sdp);
88 
89 	tr->tr_num_buf_new++;
90 }
91 
92 static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
93 {
94 	struct list_head *head = &tr->tr_list_buf;
95 	struct gfs2_bufdata *bd;
96 
97 	while (!list_empty(head)) {
98 		bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
99 		list_del_init(&bd->bd_list_tr);
100 		tr->tr_num_buf--;
101 	}
102 	gfs2_assert_warn(sdp, !tr->tr_num_buf);
103 }
104 
105 static void buf_lo_before_commit(struct gfs2_sbd *sdp)
106 {
107 	struct buffer_head *bh;
108 	struct gfs2_log_descriptor *ld;
109 	struct gfs2_bufdata *bd1 = NULL, *bd2;
110 	unsigned int total = sdp->sd_log_num_buf;
111 	unsigned int offset = sizeof(struct gfs2_log_descriptor);
112 	unsigned int limit;
113 	unsigned int num;
114 	unsigned n;
115 	__be64 *ptr;
116 
117 	offset += (sizeof(__be64) - 1);
118 	offset &= ~(sizeof(__be64) - 1);
119 	limit = (sdp->sd_sb.sb_bsize - offset)/sizeof(__be64);
120 	/* for 4k blocks, limit = 503 */
121 
122 	bd1 = bd2 = list_prepare_entry(bd1, &sdp->sd_log_le_buf, bd_le.le_list);
123 	while(total) {
124 		num = total;
125 		if (total > limit)
126 			num = limit;
127 		bh = gfs2_log_get_buf(sdp);
128 		ld = (struct gfs2_log_descriptor *)bh->b_data;
129 		ptr = (__be64 *)(bh->b_data + offset);
130 		ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
131 		ld->ld_header.mh_type = cpu_to_be16(GFS2_METATYPE_LD);
132 		ld->ld_header.mh_format = cpu_to_be16(GFS2_FORMAT_LD);
133 		ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_METADATA);
134 		ld->ld_length = cpu_to_be32(num + 1);
135 		ld->ld_data1 = cpu_to_be32(num);
136 		ld->ld_data2 = cpu_to_be32(0);
137 		memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
138 
139 		n = 0;
140 		list_for_each_entry_continue(bd1, &sdp->sd_log_le_buf,
141 					     bd_le.le_list) {
142 			*ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
143 			if (++n >= num)
144 				break;
145 		}
146 
147 		set_buffer_dirty(bh);
148 		ll_rw_block(WRITE, 1, &bh);
149 
150 		n = 0;
151 		list_for_each_entry_continue(bd2, &sdp->sd_log_le_buf,
152 					     bd_le.le_list) {
153 			bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
154 			set_buffer_dirty(bh);
155 			ll_rw_block(WRITE, 1, &bh);
156 			if (++n >= num)
157 				break;
158 		}
159 
160 		total -= num;
161 	}
162 }
163 
164 static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
165 {
166 	struct list_head *head = &sdp->sd_log_le_buf;
167 	struct gfs2_bufdata *bd;
168 
169 	while (!list_empty(head)) {
170 		bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
171 		list_del_init(&bd->bd_le.le_list);
172 		sdp->sd_log_num_buf--;
173 
174 		gfs2_unpin(sdp, bd->bd_bh, ai);
175 	}
176 	gfs2_assert_warn(sdp, !sdp->sd_log_num_buf);
177 }
178 
179 static void buf_lo_before_scan(struct gfs2_jdesc *jd,
180 			       struct gfs2_log_header *head, int pass)
181 {
182 	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
183 
184 	if (pass != 0)
185 		return;
186 
187 	sdp->sd_found_blocks = 0;
188 	sdp->sd_replayed_blocks = 0;
189 }
190 
191 static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
192 				struct gfs2_log_descriptor *ld, __be64 *ptr,
193 				int pass)
194 {
195 	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
196 	struct gfs2_glock *gl = get_v2ip(jd->jd_inode)->i_gl;
197 	unsigned int blks = be32_to_cpu(ld->ld_data1);
198 	struct buffer_head *bh_log, *bh_ip;
199 	uint64_t blkno;
200 	int error = 0;
201 
202 	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_METADATA)
203 		return 0;
204 
205 	gfs2_replay_incr_blk(sdp, &start);
206 
207 	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
208 		blkno = be64_to_cpu(*ptr++);
209 
210 		sdp->sd_found_blocks++;
211 
212 		if (gfs2_revoke_check(sdp, blkno, start))
213 			continue;
214 
215 		error = gfs2_replay_read_block(jd, start, &bh_log);
216                 if (error)
217                         return error;
218 
219 		bh_ip = gfs2_meta_new(gl, blkno);
220 		memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
221 
222 		if (gfs2_meta_check(sdp, bh_ip))
223 			error = -EIO;
224 		else
225 			mark_buffer_dirty(bh_ip);
226 
227 		brelse(bh_log);
228 		brelse(bh_ip);
229 
230 		if (error)
231 			break;
232 
233 		sdp->sd_replayed_blocks++;
234 	}
235 
236 	return error;
237 }
238 
239 static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
240 {
241 	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
242 
243 	if (error) {
244 		gfs2_meta_sync(get_v2ip(jd->jd_inode)->i_gl,
245 			       DIO_START | DIO_WAIT);
246 		return;
247 	}
248 	if (pass != 1)
249 		return;
250 
251 	gfs2_meta_sync(get_v2ip(jd->jd_inode)->i_gl, DIO_START | DIO_WAIT);
252 
253 	fs_info(sdp, "jid=%u: Replayed %u of %u blocks\n",
254 	        jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
255 }
256 
257 static void revoke_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
258 {
259 	struct gfs2_trans *tr;
260 
261 	tr = get_transaction;
262 	tr->tr_touched = 1;
263 	tr->tr_num_revoke++;
264 
265 	gfs2_log_lock(sdp);
266 	sdp->sd_log_num_revoke++;
267 	list_add(&le->le_list, &sdp->sd_log_le_revoke);
268 	gfs2_log_unlock(sdp);
269 }
270 
271 static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
272 {
273 	struct gfs2_log_descriptor *ld;
274 	struct gfs2_meta_header *mh;
275 	struct buffer_head *bh;
276 	unsigned int offset;
277 	struct list_head *head = &sdp->sd_log_le_revoke;
278 	struct gfs2_revoke *rv;
279 
280 	if (!sdp->sd_log_num_revoke)
281 		return;
282 
283 	bh = gfs2_log_get_buf(sdp);
284 	ld = (struct gfs2_log_descriptor *)bh->b_data;
285 	ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
286 	ld->ld_header.mh_type = cpu_to_be16(GFS2_METATYPE_LD);
287 	ld->ld_header.mh_format = cpu_to_be16(GFS2_FORMAT_LD);
288 	ld->ld_type = cpu_to_be32(GFS2_LOG_DESC_REVOKE);
289 	ld->ld_length = cpu_to_be32(gfs2_struct2blk(sdp, sdp->sd_log_num_revoke,
290 						    sizeof(uint64_t)));
291 	ld->ld_data1 = cpu_to_be32(sdp->sd_log_num_revoke);
292 	ld->ld_data2 = cpu_to_be32(0);
293 	memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
294 	offset = sizeof(struct gfs2_log_descriptor);
295 
296 	while (!list_empty(head)) {
297 		rv = list_entry(head->next, struct gfs2_revoke, rv_le.le_list);
298 		list_del_init(&rv->rv_le.le_list);
299 		sdp->sd_log_num_revoke--;
300 
301 		if (offset + sizeof(uint64_t) > sdp->sd_sb.sb_bsize) {
302 			set_buffer_dirty(bh);
303 			ll_rw_block(WRITE, 1, &bh);
304 
305 			bh = gfs2_log_get_buf(sdp);
306 			mh = (struct gfs2_meta_header *)bh->b_data;
307 			mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
308 			mh->mh_type = cpu_to_be16(GFS2_METATYPE_LB);
309 			mh->mh_format = cpu_to_be16(GFS2_FORMAT_LB);
310 			offset = sizeof(struct gfs2_meta_header);
311 		}
312 
313 		*(__be64 *)(bh->b_data + offset) = cpu_to_be64(rv->rv_blkno);
314 		kfree(rv);
315 
316 		offset += sizeof(uint64_t);
317 	}
318 	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
319 
320 	set_buffer_dirty(bh);
321 	ll_rw_block(WRITE, 1, &bh);
322 }
323 
324 static void revoke_lo_before_scan(struct gfs2_jdesc *jd,
325 				  struct gfs2_log_header *head, int pass)
326 {
327 	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
328 
329 	if (pass != 0)
330 		return;
331 
332 	sdp->sd_found_revokes = 0;
333 	sdp->sd_replay_tail = head->lh_tail;
334 }
335 
336 static int revoke_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
337 				   struct gfs2_log_descriptor *ld, __be64 *ptr,
338 				   int pass)
339 {
340 	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
341 	unsigned int blks = be32_to_cpu(ld->ld_length);
342 	unsigned int revokes = be32_to_cpu(ld->ld_data1);
343 	struct buffer_head *bh;
344 	unsigned int offset;
345 	uint64_t blkno;
346 	int first = 1;
347 	int error;
348 
349 	if (pass != 0 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_REVOKE)
350 		return 0;
351 
352 	offset = sizeof(struct gfs2_log_descriptor);
353 
354 	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
355 		error = gfs2_replay_read_block(jd, start, &bh);
356 		if (error)
357 			return error;
358 
359 		if (!first)
360 			gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LB);
361 
362 		while (offset + sizeof(uint64_t) <= sdp->sd_sb.sb_bsize) {
363 			blkno = be64_to_cpu(*(__be64 *)(bh->b_data + offset));
364 
365 			error = gfs2_revoke_add(sdp, blkno, start);
366 			if (error < 0)
367 				return error;
368 			else if (error)
369 				sdp->sd_found_revokes++;
370 
371 			if (!--revokes)
372 				break;
373 			offset += sizeof(uint64_t);
374 		}
375 
376 		brelse(bh);
377 		offset = sizeof(struct gfs2_meta_header);
378 		first = 0;
379 	}
380 
381 	return 0;
382 }
383 
384 static void revoke_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
385 {
386 	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
387 
388 	if (error) {
389 		gfs2_revoke_clean(sdp);
390 		return;
391 	}
392 	if (pass != 1)
393 		return;
394 
395 	fs_info(sdp, "jid=%u: Found %u revoke tags\n",
396 	        jd->jd_jid, sdp->sd_found_revokes);
397 
398 	gfs2_revoke_clean(sdp);
399 }
400 
401 static void rg_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
402 {
403 	struct gfs2_rgrpd *rgd;
404 
405 	get_transaction->tr_touched = 1;
406 
407 	if (!list_empty(&le->le_list))
408 		return;
409 
410 	rgd = container_of(le, struct gfs2_rgrpd, rd_le);
411 	gfs2_rgrp_bh_hold(rgd);
412 
413 	gfs2_log_lock(sdp);
414 	sdp->sd_log_num_rg++;
415 	list_add(&le->le_list, &sdp->sd_log_le_rg);
416 	gfs2_log_unlock(sdp);
417 }
418 
419 static void rg_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
420 {
421 	struct list_head *head = &sdp->sd_log_le_rg;
422 	struct gfs2_rgrpd *rgd;
423 
424 	while (!list_empty(head)) {
425 		rgd = list_entry(head->next, struct gfs2_rgrpd, rd_le.le_list);
426 		list_del_init(&rgd->rd_le.le_list);
427 		sdp->sd_log_num_rg--;
428 
429 		gfs2_rgrp_repolish_clones(rgd);
430 		gfs2_rgrp_bh_put(rgd);
431 	}
432 	gfs2_assert_warn(sdp, !sdp->sd_log_num_rg);
433 }
434 
435 /**
436  * databuf_lo_add - Add a databuf to the transaction.
437  *
438  * This is used in two distinct cases:
439  * i) In ordered write mode
440  *    We put the data buffer on a list so that we can ensure that its
441  *    synced to disk at the right time
442  * ii) In journaled data mode
443  *    We need to journal the data block in the same way as metadata in
444  *    the functions above. The difference is that here we have a tag
445  *    which is two __be64's being the block number (as per meta data)
446  *    and a flag which says whether the data block needs escaping or
447  *    not. This means we need a new log entry for each 251 or so data
448  *    blocks, which isn't an enormous overhead but twice as much as
449  *    for normal metadata blocks.
450  */
451 static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
452 {
453 	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
454 	struct gfs2_trans *tr = get_transaction;
455 	struct address_space *mapping = bd->bd_bh->b_page->mapping;
456 	struct gfs2_inode *ip = get_v2ip(mapping->host);
457 
458 	tr->tr_touched = 1;
459 	if (!list_empty(&bd->bd_list_tr) &&
460 	    (ip->i_di.di_flags & GFS2_DIF_JDATA)) {
461 		tr->tr_num_buf++;
462 		gfs2_trans_add_gl(bd->bd_gl);
463 		list_add(&bd->bd_list_tr, &tr->tr_list_buf);
464 		gfs2_pin(sdp, bd->bd_bh);
465 	}
466 	gfs2_log_lock(sdp);
467 	if (!list_empty(&le->le_list)) {
468 		if (ip->i_di.di_flags & GFS2_DIF_JDATA)
469 			sdp->sd_log_num_jdata++;
470 		sdp->sd_log_num_databuf++;
471 		list_add(&le->le_list, &sdp->sd_log_le_databuf);
472 	}
473 	gfs2_log_unlock(sdp);
474 }
475 
476 static int gfs2_check_magic(struct buffer_head *bh)
477 {
478 	struct page *page = bh->b_page;
479 	void *kaddr;
480 	__be32 *ptr;
481 	int rv = 0;
482 
483 	kaddr = kmap_atomic(page, KM_USER0);
484 	ptr = kaddr + bh_offset(bh);
485 	if (*ptr == cpu_to_be32(GFS2_MAGIC))
486 		rv = 1;
487 	kunmap_atomic(page, KM_USER0);
488 
489 	return rv;
490 }
491 
492 /**
493  * databuf_lo_before_commit - Scan the data buffers, writing as we go
494  *
495  * Here we scan through the lists of buffers and make the assumption
496  * that any buffer thats been pinned is being journaled, and that
497  * any unpinned buffer is an ordered write data buffer and therefore
498  * will be written back rather than journaled.
499  */
500 static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
501 {
502 	LIST_HEAD(started);
503 	struct gfs2_bufdata *bd1 = NULL, *bd2, *bdt;
504 	struct buffer_head *bh = NULL;
505 	unsigned int offset = sizeof(struct gfs2_log_descriptor);
506 	struct gfs2_log_descriptor *ld;
507 	unsigned int limit;
508 	unsigned int total_dbuf = sdp->sd_log_num_databuf;
509 	unsigned int total_jdata = sdp->sd_log_num_jdata;
510 	unsigned int num, n;
511 	__be64 *ptr = NULL;
512 
513 	offset += (2*sizeof(__be64) - 1);
514 	offset &= ~(2*sizeof(__be64) - 1);
515 	limit = (sdp->sd_sb.sb_bsize - offset)/sizeof(__be64);
516 
517 	/*
518 	 * Start writing ordered buffers, write journaled buffers
519 	 * into the log along with a header
520 	 */
521 	gfs2_log_lock(sdp);
522 	bd2 = bd1 = list_prepare_entry(bd1, &sdp->sd_log_le_databuf,
523 				       bd_le.le_list);
524 	while(total_dbuf) {
525 		num = total_jdata;
526 		if (num > limit)
527 			num = limit;
528 		n = 0;
529 		list_for_each_entry_safe_continue(bd1, bdt,
530 						  &sdp->sd_log_le_databuf,
531 						  bd_le.le_list) {
532 			/* An ordered write buffer */
533 			if (bd1->bd_bh && !buffer_pinned(bd1->bd_bh)) {
534 				list_move(&bd1->bd_le.le_list, &started);
535 				if (bd1 == bd2) {
536 					bd2 = NULL;
537 					bd2 = list_prepare_entry(bd2,
538 							&sdp->sd_log_le_databuf,
539 							bd_le.le_list);
540 				}
541 				total_dbuf--;
542 				if (bd1->bd_bh) {
543 					get_bh(bd1->bd_bh);
544 					if (buffer_dirty(bd1->bd_bh)) {
545 						gfs2_log_unlock(sdp);
546 						wait_on_buffer(bd1->bd_bh);
547 						ll_rw_block(WRITE, 1,
548 							    &bd1->bd_bh);
549 						gfs2_log_lock(sdp);
550 					}
551 					brelse(bd1->bd_bh);
552 					continue;
553 				}
554 				continue;
555 			} else if (bd1->bd_bh) { /* A journaled buffer */
556 				int magic;
557 				gfs2_log_unlock(sdp);
558 				if (!bh) {
559 					bh = gfs2_log_get_buf(sdp);
560 					ld = (struct gfs2_log_descriptor *)
561 					     bh->b_data;
562 					ptr = (__be64 *)(bh->b_data + offset);
563 					ld->ld_header.mh_magic =
564 						cpu_to_be32(GFS2_MAGIC);
565 					ld->ld_header.mh_type =
566 						cpu_to_be16(GFS2_METATYPE_LD);
567 					ld->ld_header.mh_format =
568 						cpu_to_be16(GFS2_FORMAT_LD);
569 					ld->ld_type =
570 						cpu_to_be32(GFS2_LOG_DESC_JDATA);
571 					ld->ld_length = cpu_to_be32(num + 1);
572 					ld->ld_data1 = cpu_to_be32(num);
573 					ld->ld_data2 = cpu_to_be32(0);
574 					memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
575 				}
576 				magic = gfs2_check_magic(bd1->bd_bh);
577 				*ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
578 				*ptr++ = cpu_to_be64((__u64)magic);
579 				clear_buffer_escaped(bd1->bd_bh);
580 				if (unlikely(magic != 0))
581 					set_buffer_escaped(bd1->bd_bh);
582 				gfs2_log_lock(sdp);
583 				if (n++ > num)
584 					break;
585 			}
586 		}
587 		gfs2_log_unlock(sdp);
588 		if (bh) {
589 			set_buffer_dirty(bh);
590 			ll_rw_block(WRITE, 1, &bh);
591 			bh = NULL;
592 		}
593 		n = 0;
594 		gfs2_log_lock(sdp);
595 		list_for_each_entry_continue(bd2, &sdp->sd_log_le_databuf,
596 					     bd_le.le_list) {
597 			if (!bd2->bd_bh)
598 				continue;
599 			/* copy buffer if it needs escaping */
600 			gfs2_log_unlock(sdp);
601 			if (unlikely(buffer_escaped(bd2->bd_bh))) {
602 				void *kaddr;
603 				struct page *page = bd2->bd_bh->b_page;
604 				bh = gfs2_log_get_buf(sdp);
605 				kaddr = kmap_atomic(page, KM_USER0);
606 				memcpy(bh->b_data,
607 				       kaddr + bh_offset(bd2->bd_bh),
608 				       sdp->sd_sb.sb_bsize);
609 				kunmap_atomic(page, KM_USER0);
610 				*(__be32 *)bh->b_data = 0;
611 			} else {
612 				bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
613 			}
614 			set_buffer_dirty(bh);
615 			ll_rw_block(WRITE, 1, &bh);
616 			gfs2_log_lock(sdp);
617 			if (++n >= num)
618 				break;
619 		}
620 		bh = NULL;
621 		total_dbuf -= num;
622 		total_jdata -= num;
623 	}
624 	gfs2_log_unlock(sdp);
625 
626 	/* Wait on all ordered buffers */
627 	while (!list_empty(&started)) {
628 		gfs2_log_lock(sdp);
629 		bd1 = list_entry(started.next, struct gfs2_bufdata,
630 				 bd_le.le_list);
631 		list_del(&bd1->bd_le.le_list);
632 		sdp->sd_log_num_databuf--;
633 
634 		bh = bd1->bd_bh;
635 		if (bh) {
636 			set_v2bd(bh, NULL);
637 			gfs2_log_unlock(sdp);
638 			wait_on_buffer(bh);
639 			brelse(bh);
640 		} else
641 			gfs2_log_unlock(sdp);
642 
643 		kfree(bd1);
644 	}
645 
646 	/* We've removed all the ordered write bufs here, so only jdata left */
647 	gfs2_assert_warn(sdp, sdp->sd_log_num_databuf == sdp->sd_log_num_jdata);
648 }
649 
650 static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
651 				    struct gfs2_log_descriptor *ld,
652 				    __be64 *ptr, int pass)
653 {
654 	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
655 	struct gfs2_glock *gl = get_v2ip(jd->jd_inode)->i_gl;
656 	unsigned int blks = be32_to_cpu(ld->ld_data1);
657 	struct buffer_head *bh_log, *bh_ip;
658 	uint64_t blkno;
659 	uint64_t esc;
660 	int error = 0;
661 
662 	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_JDATA)
663 		return 0;
664 
665 	gfs2_replay_incr_blk(sdp, &start);
666 	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
667 		blkno = be64_to_cpu(*ptr++);
668 		esc = be64_to_cpu(*ptr++);
669 
670 		sdp->sd_found_blocks++;
671 
672 		if (gfs2_revoke_check(sdp, blkno, start))
673 			continue;
674 
675 		error = gfs2_replay_read_block(jd, start, &bh_log);
676 		if (error)
677 			return error;
678 
679 		bh_ip = gfs2_meta_new(gl, blkno);
680 		memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
681 
682 		/* Unescape */
683 		if (esc) {
684 			__be32 *eptr = (__be32 *)bh_ip->b_data;
685 			*eptr = cpu_to_be32(GFS2_MAGIC);
686 		}
687 		mark_buffer_dirty(bh_ip);
688 
689 		brelse(bh_log);
690 		brelse(bh_ip);
691 		if (error)
692 			break;
693 
694 		sdp->sd_replayed_blocks++;
695 	}
696 
697 	return error;
698 }
699 
700 /* FIXME: sort out accounting for log blocks etc. */
701 
702 static void databuf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
703 {
704 	struct gfs2_sbd *sdp = get_v2ip(jd->jd_inode)->i_sbd;
705 
706 	if (error) {
707 		gfs2_meta_sync(get_v2ip(jd->jd_inode)->i_gl,
708 			       DIO_START | DIO_WAIT);
709 		return;
710 	}
711 	if (pass != 1)
712 		return;
713 
714 	/* data sync? */
715 	gfs2_meta_sync(get_v2ip(jd->jd_inode)->i_gl, DIO_START | DIO_WAIT);
716 
717 	fs_info(sdp, "jid=%u: Replayed %u of %u data blocks\n",
718 		jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
719 }
720 
721 static void databuf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
722 {
723 	struct list_head *head = &sdp->sd_log_le_databuf;
724 	struct gfs2_bufdata *bd;
725 
726 	while (!list_empty(head)) {
727 		bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
728 		list_del(&bd->bd_le.le_list);
729 		sdp->sd_log_num_databuf--;
730 		sdp->sd_log_num_jdata--;
731 		gfs2_unpin(sdp, bd->bd_bh, ai);
732 	}
733 	gfs2_assert_warn(sdp, !sdp->sd_log_num_databuf);
734 	gfs2_assert_warn(sdp, !sdp->sd_log_num_jdata);
735 }
736 
737 
738 struct gfs2_log_operations gfs2_glock_lops = {
739 	.lo_add = glock_lo_add,
740 	.lo_after_commit = glock_lo_after_commit,
741 	.lo_name = "glock"
742 };
743 
744 struct gfs2_log_operations gfs2_buf_lops = {
745 	.lo_add = buf_lo_add,
746 	.lo_incore_commit = buf_lo_incore_commit,
747 	.lo_before_commit = buf_lo_before_commit,
748 	.lo_after_commit = buf_lo_after_commit,
749 	.lo_before_scan = buf_lo_before_scan,
750 	.lo_scan_elements = buf_lo_scan_elements,
751 	.lo_after_scan = buf_lo_after_scan,
752 	.lo_name = "buf"
753 };
754 
755 struct gfs2_log_operations gfs2_revoke_lops = {
756 	.lo_add = revoke_lo_add,
757 	.lo_before_commit = revoke_lo_before_commit,
758 	.lo_before_scan = revoke_lo_before_scan,
759 	.lo_scan_elements = revoke_lo_scan_elements,
760 	.lo_after_scan = revoke_lo_after_scan,
761 	.lo_name = "revoke"
762 };
763 
764 struct gfs2_log_operations gfs2_rg_lops = {
765 	.lo_add = rg_lo_add,
766 	.lo_after_commit = rg_lo_after_commit,
767 	.lo_name = "rg"
768 };
769 
770 struct gfs2_log_operations gfs2_databuf_lops = {
771 	.lo_add = databuf_lo_add,
772 	.lo_incore_commit = buf_lo_incore_commit,
773 	.lo_before_commit = databuf_lo_before_commit,
774 	.lo_after_commit = databuf_lo_after_commit,
775 	.lo_scan_elements = databuf_lo_scan_elements,
776 	.lo_after_scan = databuf_lo_after_scan,
777 	.lo_name = "databuf"
778 };
779 
780 struct gfs2_log_operations *gfs2_log_ops[] = {
781 	&gfs2_glock_lops,
782 	&gfs2_buf_lops,
783 	&gfs2_revoke_lops,
784 	&gfs2_rg_lops,
785 	&gfs2_databuf_lops,
786 	NULL
787 };
788 
789