xref: /openbmc/linux/fs/gfs2/lops.c (revision 171f1bc7)
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 	BUG_ON(!current->journal_info);
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 	spin_lock(&sdp->sd_ail_lock);
55 	if (bd->bd_ail)
56 		list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
57 	spin_unlock(&sdp->sd_ail_lock);
58 	get_bh(bh);
59 	atomic_inc(&sdp->sd_log_pinned);
60 	trace_gfs2_pin(bd, 1);
61 }
62 
63 static bool buffer_is_rgrp(const struct gfs2_bufdata *bd)
64 {
65 	return bd->bd_gl->gl_name.ln_type == LM_TYPE_RGRP;
66 }
67 
68 static void maybe_release_space(struct gfs2_bufdata *bd)
69 {
70 	struct gfs2_glock *gl = bd->bd_gl;
71 	struct gfs2_sbd *sdp = gl->gl_sbd;
72 	struct gfs2_rgrpd *rgd = gl->gl_object;
73 	unsigned int index = bd->bd_bh->b_blocknr - gl->gl_name.ln_number;
74 	struct gfs2_bitmap *bi = rgd->rd_bits + index;
75 
76 	if (bi->bi_clone == 0)
77 		return;
78 	if (sdp->sd_args.ar_discard)
79 		gfs2_rgrp_send_discards(sdp, rgd->rd_data0, bd->bd_bh, bi);
80 	memcpy(bi->bi_clone + bi->bi_offset,
81 	       bd->bd_bh->b_data + bi->bi_offset, bi->bi_len);
82 	clear_bit(GBF_FULL, &bi->bi_flags);
83 	rgd->rd_free_clone = rgd->rd_free;
84 }
85 
86 /**
87  * gfs2_unpin - Unpin a buffer
88  * @sdp: the filesystem the buffer belongs to
89  * @bh: The buffer to unpin
90  * @ai:
91  * @flags: The inode dirty flags
92  *
93  */
94 
95 static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
96 		       struct gfs2_ail *ai)
97 {
98 	struct gfs2_bufdata *bd = bh->b_private;
99 
100 	BUG_ON(!buffer_uptodate(bh));
101 	BUG_ON(!buffer_pinned(bh));
102 
103 	lock_buffer(bh);
104 	mark_buffer_dirty(bh);
105 	clear_buffer_pinned(bh);
106 
107 	if (buffer_is_rgrp(bd))
108 		maybe_release_space(bd);
109 
110 	spin_lock(&sdp->sd_ail_lock);
111 	if (bd->bd_ail) {
112 		list_del(&bd->bd_ail_st_list);
113 		brelse(bh);
114 	} else {
115 		struct gfs2_glock *gl = bd->bd_gl;
116 		list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
117 		atomic_inc(&gl->gl_ail_count);
118 	}
119 	bd->bd_ail = ai;
120 	list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
121 	spin_unlock(&sdp->sd_ail_lock);
122 
123 	clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
124 	trace_gfs2_pin(bd, 0);
125 	unlock_buffer(bh);
126 	atomic_dec(&sdp->sd_log_pinned);
127 }
128 
129 
130 static inline struct gfs2_log_descriptor *bh_log_desc(struct buffer_head *bh)
131 {
132 	return (struct gfs2_log_descriptor *)bh->b_data;
133 }
134 
135 static inline __be64 *bh_log_ptr(struct buffer_head *bh)
136 {
137 	struct gfs2_log_descriptor *ld = bh_log_desc(bh);
138 	return (__force __be64 *)(ld + 1);
139 }
140 
141 static inline __be64 *bh_ptr_end(struct buffer_head *bh)
142 {
143 	return (__force __be64 *)(bh->b_data + bh->b_size);
144 }
145 
146 
147 static struct buffer_head *gfs2_get_log_desc(struct gfs2_sbd *sdp, u32 ld_type)
148 {
149 	struct buffer_head *bh = gfs2_log_get_buf(sdp);
150 	struct gfs2_log_descriptor *ld = bh_log_desc(bh);
151 	ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
152 	ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
153 	ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
154 	ld->ld_type = cpu_to_be32(ld_type);
155 	ld->ld_length = 0;
156 	ld->ld_data1 = 0;
157 	ld->ld_data2 = 0;
158 	memset(ld->ld_reserved, 0, sizeof(ld->ld_reserved));
159 	return bh;
160 }
161 
162 static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
163 {
164 	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
165 	struct gfs2_meta_header *mh;
166 	struct gfs2_trans *tr;
167 
168 	lock_buffer(bd->bd_bh);
169 	gfs2_log_lock(sdp);
170 	if (!list_empty(&bd->bd_list_tr))
171 		goto out;
172 	tr = current->journal_info;
173 	tr->tr_touched = 1;
174 	tr->tr_num_buf++;
175 	list_add(&bd->bd_list_tr, &tr->tr_list_buf);
176 	if (!list_empty(&le->le_list))
177 		goto out;
178 	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
179 	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
180 	gfs2_meta_check(sdp, bd->bd_bh);
181 	gfs2_pin(sdp, bd->bd_bh);
182 	mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
183 	mh->__pad0 = cpu_to_be64(0);
184 	mh->mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
185 	sdp->sd_log_num_buf++;
186 	list_add(&le->le_list, &sdp->sd_log_le_buf);
187 	tr->tr_num_buf_new++;
188 out:
189 	gfs2_log_unlock(sdp);
190 	unlock_buffer(bd->bd_bh);
191 }
192 
193 static void buf_lo_before_commit(struct gfs2_sbd *sdp)
194 {
195 	struct buffer_head *bh;
196 	struct gfs2_log_descriptor *ld;
197 	struct gfs2_bufdata *bd1 = NULL, *bd2;
198 	unsigned int total;
199 	unsigned int limit;
200 	unsigned int num;
201 	unsigned n;
202 	__be64 *ptr;
203 
204 	limit = buf_limit(sdp);
205 	/* for 4k blocks, limit = 503 */
206 
207 	gfs2_log_lock(sdp);
208 	total = sdp->sd_log_num_buf;
209 	bd1 = bd2 = list_prepare_entry(bd1, &sdp->sd_log_le_buf, bd_le.le_list);
210 	while(total) {
211 		num = total;
212 		if (total > limit)
213 			num = limit;
214 		gfs2_log_unlock(sdp);
215 		bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_METADATA);
216 		gfs2_log_lock(sdp);
217 		ld = bh_log_desc(bh);
218 		ptr = bh_log_ptr(bh);
219 		ld->ld_length = cpu_to_be32(num + 1);
220 		ld->ld_data1 = cpu_to_be32(num);
221 
222 		n = 0;
223 		list_for_each_entry_continue(bd1, &sdp->sd_log_le_buf,
224 					     bd_le.le_list) {
225 			*ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
226 			if (++n >= num)
227 				break;
228 		}
229 
230 		gfs2_log_unlock(sdp);
231 		submit_bh(WRITE_SYNC, bh);
232 		gfs2_log_lock(sdp);
233 
234 		n = 0;
235 		list_for_each_entry_continue(bd2, &sdp->sd_log_le_buf,
236 					     bd_le.le_list) {
237 			get_bh(bd2->bd_bh);
238 			gfs2_log_unlock(sdp);
239 			lock_buffer(bd2->bd_bh);
240 			bh = gfs2_log_fake_buf(sdp, bd2->bd_bh);
241 			submit_bh(WRITE_SYNC, bh);
242 			gfs2_log_lock(sdp);
243 			if (++n >= num)
244 				break;
245 		}
246 
247 		BUG_ON(total < num);
248 		total -= num;
249 	}
250 	gfs2_log_unlock(sdp);
251 }
252 
253 static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
254 {
255 	struct list_head *head = &sdp->sd_log_le_buf;
256 	struct gfs2_bufdata *bd;
257 
258 	while (!list_empty(head)) {
259 		bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
260 		list_del_init(&bd->bd_le.le_list);
261 		sdp->sd_log_num_buf--;
262 
263 		gfs2_unpin(sdp, bd->bd_bh, ai);
264 	}
265 	gfs2_assert_warn(sdp, !sdp->sd_log_num_buf);
266 }
267 
268 static void buf_lo_before_scan(struct gfs2_jdesc *jd,
269 			       struct gfs2_log_header_host *head, int pass)
270 {
271 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
272 
273 	if (pass != 0)
274 		return;
275 
276 	sdp->sd_found_blocks = 0;
277 	sdp->sd_replayed_blocks = 0;
278 }
279 
280 static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
281 				struct gfs2_log_descriptor *ld, __be64 *ptr,
282 				int pass)
283 {
284 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
285 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
286 	struct gfs2_glock *gl = ip->i_gl;
287 	unsigned int blks = be32_to_cpu(ld->ld_data1);
288 	struct buffer_head *bh_log, *bh_ip;
289 	u64 blkno;
290 	int error = 0;
291 
292 	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_METADATA)
293 		return 0;
294 
295 	gfs2_replay_incr_blk(sdp, &start);
296 
297 	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
298 		blkno = be64_to_cpu(*ptr++);
299 
300 		sdp->sd_found_blocks++;
301 
302 		if (gfs2_revoke_check(sdp, blkno, start))
303 			continue;
304 
305 		error = gfs2_replay_read_block(jd, start, &bh_log);
306 		if (error)
307 			return error;
308 
309 		bh_ip = gfs2_meta_new(gl, blkno);
310 		memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
311 
312 		if (gfs2_meta_check(sdp, bh_ip))
313 			error = -EIO;
314 		else
315 			mark_buffer_dirty(bh_ip);
316 
317 		brelse(bh_log);
318 		brelse(bh_ip);
319 
320 		if (error)
321 			break;
322 
323 		sdp->sd_replayed_blocks++;
324 	}
325 
326 	return error;
327 }
328 
329 static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
330 {
331 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
332 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
333 
334 	if (error) {
335 		gfs2_meta_sync(ip->i_gl);
336 		return;
337 	}
338 	if (pass != 1)
339 		return;
340 
341 	gfs2_meta_sync(ip->i_gl);
342 
343 	fs_info(sdp, "jid=%u: Replayed %u of %u blocks\n",
344 	        jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
345 }
346 
347 static void revoke_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
348 {
349 	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
350 	struct gfs2_glock *gl = bd->bd_gl;
351 	struct gfs2_trans *tr;
352 
353 	tr = current->journal_info;
354 	tr->tr_touched = 1;
355 	tr->tr_num_revoke++;
356 	sdp->sd_log_num_revoke++;
357 	atomic_inc(&gl->gl_revokes);
358 	set_bit(GLF_LFLUSH, &gl->gl_flags);
359 	list_add(&le->le_list, &sdp->sd_log_le_revoke);
360 }
361 
362 static void revoke_lo_before_commit(struct gfs2_sbd *sdp)
363 {
364 	struct gfs2_log_descriptor *ld;
365 	struct gfs2_meta_header *mh;
366 	struct buffer_head *bh;
367 	unsigned int offset;
368 	struct list_head *head = &sdp->sd_log_le_revoke;
369 	struct gfs2_bufdata *bd;
370 
371 	if (!sdp->sd_log_num_revoke)
372 		return;
373 
374 	bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_REVOKE);
375 	ld = bh_log_desc(bh);
376 	ld->ld_length = cpu_to_be32(gfs2_struct2blk(sdp, sdp->sd_log_num_revoke,
377 						    sizeof(u64)));
378 	ld->ld_data1 = cpu_to_be32(sdp->sd_log_num_revoke);
379 	offset = sizeof(struct gfs2_log_descriptor);
380 
381 	list_for_each_entry(bd, head, bd_le.le_list) {
382 		sdp->sd_log_num_revoke--;
383 
384 		if (offset + sizeof(u64) > sdp->sd_sb.sb_bsize) {
385 			submit_bh(WRITE_SYNC, bh);
386 
387 			bh = gfs2_log_get_buf(sdp);
388 			mh = (struct gfs2_meta_header *)bh->b_data;
389 			mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
390 			mh->mh_type = cpu_to_be32(GFS2_METATYPE_LB);
391 			mh->mh_format = cpu_to_be32(GFS2_FORMAT_LB);
392 			offset = sizeof(struct gfs2_meta_header);
393 		}
394 
395 		*(__be64 *)(bh->b_data + offset) = cpu_to_be64(bd->bd_blkno);
396 		offset += sizeof(u64);
397 	}
398 	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
399 
400 	submit_bh(WRITE_SYNC, bh);
401 }
402 
403 static void revoke_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
404 {
405 	struct list_head *head = &sdp->sd_log_le_revoke;
406 	struct gfs2_bufdata *bd;
407 	struct gfs2_glock *gl;
408 
409 	while (!list_empty(head)) {
410 		bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
411 		list_del_init(&bd->bd_le.le_list);
412 		gl = bd->bd_gl;
413 		atomic_dec(&gl->gl_revokes);
414 		clear_bit(GLF_LFLUSH, &gl->gl_flags);
415 		kmem_cache_free(gfs2_bufdata_cachep, bd);
416 	}
417 }
418 
419 static void revoke_lo_before_scan(struct gfs2_jdesc *jd,
420 				  struct gfs2_log_header_host *head, int pass)
421 {
422 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
423 
424 	if (pass != 0)
425 		return;
426 
427 	sdp->sd_found_revokes = 0;
428 	sdp->sd_replay_tail = head->lh_tail;
429 }
430 
431 static int revoke_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
432 				   struct gfs2_log_descriptor *ld, __be64 *ptr,
433 				   int pass)
434 {
435 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
436 	unsigned int blks = be32_to_cpu(ld->ld_length);
437 	unsigned int revokes = be32_to_cpu(ld->ld_data1);
438 	struct buffer_head *bh;
439 	unsigned int offset;
440 	u64 blkno;
441 	int first = 1;
442 	int error;
443 
444 	if (pass != 0 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_REVOKE)
445 		return 0;
446 
447 	offset = sizeof(struct gfs2_log_descriptor);
448 
449 	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
450 		error = gfs2_replay_read_block(jd, start, &bh);
451 		if (error)
452 			return error;
453 
454 		if (!first)
455 			gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LB);
456 
457 		while (offset + sizeof(u64) <= sdp->sd_sb.sb_bsize) {
458 			blkno = be64_to_cpu(*(__be64 *)(bh->b_data + offset));
459 
460 			error = gfs2_revoke_add(sdp, blkno, start);
461 			if (error < 0) {
462 				brelse(bh);
463 				return error;
464 			}
465 			else if (error)
466 				sdp->sd_found_revokes++;
467 
468 			if (!--revokes)
469 				break;
470 			offset += sizeof(u64);
471 		}
472 
473 		brelse(bh);
474 		offset = sizeof(struct gfs2_meta_header);
475 		first = 0;
476 	}
477 
478 	return 0;
479 }
480 
481 static void revoke_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
482 {
483 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
484 
485 	if (error) {
486 		gfs2_revoke_clean(sdp);
487 		return;
488 	}
489 	if (pass != 1)
490 		return;
491 
492 	fs_info(sdp, "jid=%u: Found %u revoke tags\n",
493 	        jd->jd_jid, sdp->sd_found_revokes);
494 
495 	gfs2_revoke_clean(sdp);
496 }
497 
498 /**
499  * databuf_lo_add - Add a databuf to the transaction.
500  *
501  * This is used in two distinct cases:
502  * i) In ordered write mode
503  *    We put the data buffer on a list so that we can ensure that its
504  *    synced to disk at the right time
505  * ii) In journaled data mode
506  *    We need to journal the data block in the same way as metadata in
507  *    the functions above. The difference is that here we have a tag
508  *    which is two __be64's being the block number (as per meta data)
509  *    and a flag which says whether the data block needs escaping or
510  *    not. This means we need a new log entry for each 251 or so data
511  *    blocks, which isn't an enormous overhead but twice as much as
512  *    for normal metadata blocks.
513  */
514 static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
515 {
516 	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);
517 	struct gfs2_trans *tr = current->journal_info;
518 	struct address_space *mapping = bd->bd_bh->b_page->mapping;
519 	struct gfs2_inode *ip = GFS2_I(mapping->host);
520 
521 	lock_buffer(bd->bd_bh);
522 	gfs2_log_lock(sdp);
523 	if (tr) {
524 		if (!list_empty(&bd->bd_list_tr))
525 			goto out;
526 		tr->tr_touched = 1;
527 		if (gfs2_is_jdata(ip)) {
528 			tr->tr_num_buf++;
529 			list_add(&bd->bd_list_tr, &tr->tr_list_buf);
530 		}
531 	}
532 	if (!list_empty(&le->le_list))
533 		goto out;
534 
535 	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
536 	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
537 	if (gfs2_is_jdata(ip)) {
538 		gfs2_pin(sdp, bd->bd_bh);
539 		tr->tr_num_databuf_new++;
540 		sdp->sd_log_num_databuf++;
541 		list_add_tail(&le->le_list, &sdp->sd_log_le_databuf);
542 	} else {
543 		list_add_tail(&le->le_list, &sdp->sd_log_le_ordered);
544 	}
545 out:
546 	gfs2_log_unlock(sdp);
547 	unlock_buffer(bd->bd_bh);
548 }
549 
550 static void gfs2_check_magic(struct buffer_head *bh)
551 {
552 	void *kaddr;
553 	__be32 *ptr;
554 
555 	clear_buffer_escaped(bh);
556 	kaddr = kmap_atomic(bh->b_page, KM_USER0);
557 	ptr = kaddr + bh_offset(bh);
558 	if (*ptr == cpu_to_be32(GFS2_MAGIC))
559 		set_buffer_escaped(bh);
560 	kunmap_atomic(kaddr, KM_USER0);
561 }
562 
563 static void gfs2_write_blocks(struct gfs2_sbd *sdp, struct buffer_head *bh,
564 			      struct list_head *list, struct list_head *done,
565 			      unsigned int n)
566 {
567 	struct buffer_head *bh1;
568 	struct gfs2_log_descriptor *ld;
569 	struct gfs2_bufdata *bd;
570 	__be64 *ptr;
571 
572 	if (!bh)
573 		return;
574 
575 	ld = bh_log_desc(bh);
576 	ld->ld_length = cpu_to_be32(n + 1);
577 	ld->ld_data1 = cpu_to_be32(n);
578 
579 	ptr = bh_log_ptr(bh);
580 
581 	get_bh(bh);
582 	submit_bh(WRITE_SYNC, bh);
583 	gfs2_log_lock(sdp);
584 	while(!list_empty(list)) {
585 		bd = list_entry(list->next, struct gfs2_bufdata, bd_le.le_list);
586 		list_move_tail(&bd->bd_le.le_list, done);
587 		get_bh(bd->bd_bh);
588 		while (be64_to_cpu(*ptr) != bd->bd_bh->b_blocknr) {
589 			gfs2_log_incr_head(sdp);
590 			ptr += 2;
591 		}
592 		gfs2_log_unlock(sdp);
593 		lock_buffer(bd->bd_bh);
594 		if (buffer_escaped(bd->bd_bh)) {
595 			void *kaddr;
596 			bh1 = gfs2_log_get_buf(sdp);
597 			kaddr = kmap_atomic(bd->bd_bh->b_page, KM_USER0);
598 			memcpy(bh1->b_data, kaddr + bh_offset(bd->bd_bh),
599 			       bh1->b_size);
600 			kunmap_atomic(kaddr, KM_USER0);
601 			*(__be32 *)bh1->b_data = 0;
602 			clear_buffer_escaped(bd->bd_bh);
603 			unlock_buffer(bd->bd_bh);
604 			brelse(bd->bd_bh);
605 		} else {
606 			bh1 = gfs2_log_fake_buf(sdp, bd->bd_bh);
607 		}
608 		submit_bh(WRITE_SYNC, bh1);
609 		gfs2_log_lock(sdp);
610 		ptr += 2;
611 	}
612 	gfs2_log_unlock(sdp);
613 	brelse(bh);
614 }
615 
616 /**
617  * databuf_lo_before_commit - Scan the data buffers, writing as we go
618  *
619  */
620 
621 static void databuf_lo_before_commit(struct gfs2_sbd *sdp)
622 {
623 	struct gfs2_bufdata *bd = NULL;
624 	struct buffer_head *bh = NULL;
625 	unsigned int n = 0;
626 	__be64 *ptr = NULL, *end = NULL;
627 	LIST_HEAD(processed);
628 	LIST_HEAD(in_progress);
629 
630 	gfs2_log_lock(sdp);
631 	while (!list_empty(&sdp->sd_log_le_databuf)) {
632 		if (ptr == end) {
633 			gfs2_log_unlock(sdp);
634 			gfs2_write_blocks(sdp, bh, &in_progress, &processed, n);
635 			n = 0;
636 			bh = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_JDATA);
637 			ptr = bh_log_ptr(bh);
638 			end = bh_ptr_end(bh) - 1;
639 			gfs2_log_lock(sdp);
640 			continue;
641 		}
642 		bd = list_entry(sdp->sd_log_le_databuf.next, struct gfs2_bufdata, bd_le.le_list);
643 		list_move_tail(&bd->bd_le.le_list, &in_progress);
644 		gfs2_check_magic(bd->bd_bh);
645 		*ptr++ = cpu_to_be64(bd->bd_bh->b_blocknr);
646 		*ptr++ = cpu_to_be64(buffer_escaped(bh) ? 1 : 0);
647 		n++;
648 	}
649 	gfs2_log_unlock(sdp);
650 	gfs2_write_blocks(sdp, bh, &in_progress, &processed, n);
651 	gfs2_log_lock(sdp);
652 	list_splice(&processed, &sdp->sd_log_le_databuf);
653 	gfs2_log_unlock(sdp);
654 }
655 
656 static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
657 				    struct gfs2_log_descriptor *ld,
658 				    __be64 *ptr, int pass)
659 {
660 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
661 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
662 	struct gfs2_glock *gl = ip->i_gl;
663 	unsigned int blks = be32_to_cpu(ld->ld_data1);
664 	struct buffer_head *bh_log, *bh_ip;
665 	u64 blkno;
666 	u64 esc;
667 	int error = 0;
668 
669 	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_JDATA)
670 		return 0;
671 
672 	gfs2_replay_incr_blk(sdp, &start);
673 	for (; blks; gfs2_replay_incr_blk(sdp, &start), blks--) {
674 		blkno = be64_to_cpu(*ptr++);
675 		esc = be64_to_cpu(*ptr++);
676 
677 		sdp->sd_found_blocks++;
678 
679 		if (gfs2_revoke_check(sdp, blkno, start))
680 			continue;
681 
682 		error = gfs2_replay_read_block(jd, start, &bh_log);
683 		if (error)
684 			return error;
685 
686 		bh_ip = gfs2_meta_new(gl, blkno);
687 		memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
688 
689 		/* Unescape */
690 		if (esc) {
691 			__be32 *eptr = (__be32 *)bh_ip->b_data;
692 			*eptr = cpu_to_be32(GFS2_MAGIC);
693 		}
694 		mark_buffer_dirty(bh_ip);
695 
696 		brelse(bh_log);
697 		brelse(bh_ip);
698 
699 		sdp->sd_replayed_blocks++;
700 	}
701 
702 	return error;
703 }
704 
705 /* FIXME: sort out accounting for log blocks etc. */
706 
707 static void databuf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
708 {
709 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
710 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
711 
712 	if (error) {
713 		gfs2_meta_sync(ip->i_gl);
714 		return;
715 	}
716 	if (pass != 1)
717 		return;
718 
719 	/* data sync? */
720 	gfs2_meta_sync(ip->i_gl);
721 
722 	fs_info(sdp, "jid=%u: Replayed %u of %u data blocks\n",
723 		jd->jd_jid, sdp->sd_replayed_blocks, sdp->sd_found_blocks);
724 }
725 
726 static void databuf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
727 {
728 	struct list_head *head = &sdp->sd_log_le_databuf;
729 	struct gfs2_bufdata *bd;
730 
731 	while (!list_empty(head)) {
732 		bd = list_entry(head->next, struct gfs2_bufdata, bd_le.le_list);
733 		list_del_init(&bd->bd_le.le_list);
734 		sdp->sd_log_num_databuf--;
735 		gfs2_unpin(sdp, bd->bd_bh, ai);
736 	}
737 	gfs2_assert_warn(sdp, !sdp->sd_log_num_databuf);
738 }
739 
740 
741 const struct gfs2_log_operations gfs2_buf_lops = {
742 	.lo_add = buf_lo_add,
743 	.lo_before_commit = buf_lo_before_commit,
744 	.lo_after_commit = buf_lo_after_commit,
745 	.lo_before_scan = buf_lo_before_scan,
746 	.lo_scan_elements = buf_lo_scan_elements,
747 	.lo_after_scan = buf_lo_after_scan,
748 	.lo_name = "buf",
749 };
750 
751 const struct gfs2_log_operations gfs2_revoke_lops = {
752 	.lo_add = revoke_lo_add,
753 	.lo_before_commit = revoke_lo_before_commit,
754 	.lo_after_commit = revoke_lo_after_commit,
755 	.lo_before_scan = revoke_lo_before_scan,
756 	.lo_scan_elements = revoke_lo_scan_elements,
757 	.lo_after_scan = revoke_lo_after_scan,
758 	.lo_name = "revoke",
759 };
760 
761 const struct gfs2_log_operations gfs2_rg_lops = {
762 	.lo_name = "rg",
763 };
764 
765 const struct gfs2_log_operations gfs2_databuf_lops = {
766 	.lo_add = databuf_lo_add,
767 	.lo_before_commit = databuf_lo_before_commit,
768 	.lo_after_commit = databuf_lo_after_commit,
769 	.lo_scan_elements = databuf_lo_scan_elements,
770 	.lo_after_scan = databuf_lo_after_scan,
771 	.lo_name = "databuf",
772 };
773 
774 const struct gfs2_log_operations *gfs2_log_ops[] = {
775 	&gfs2_databuf_lops,
776 	&gfs2_buf_lops,
777 	&gfs2_rg_lops,
778 	&gfs2_revoke_lops,
779 	NULL,
780 };
781 
782