Loading...
1/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2007 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/crc32.h>
17#include <linux/delay.h>
18#include <linux/kthread.h>
19#include <linux/freezer.h>
20#include <linux/bio.h>
21#include <linux/writeback.h>
22
23#include "gfs2.h"
24#include "incore.h"
25#include "bmap.h"
26#include "glock.h"
27#include "log.h"
28#include "lops.h"
29#include "meta_io.h"
30#include "util.h"
31#include "dir.h"
32#include "trace_gfs2.h"
33
34#define PULL 1
35
36/**
37 * gfs2_struct2blk - compute stuff
38 * @sdp: the filesystem
39 * @nstruct: the number of structures
40 * @ssize: the size of the structures
41 *
42 * Compute the number of log descriptor blocks needed to hold a certain number
43 * of structures of a certain size.
44 *
45 * Returns: the number of blocks needed (minimum is always 1)
46 */
47
48unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
49 unsigned int ssize)
50{
51 unsigned int blks;
52 unsigned int first, second;
53
54 blks = 1;
55 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
56
57 if (nstruct > first) {
58 second = (sdp->sd_sb.sb_bsize -
59 sizeof(struct gfs2_meta_header)) / ssize;
60 blks += DIV_ROUND_UP(nstruct - first, second);
61 }
62
63 return blks;
64}
65
66/**
67 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
68 * @mapping: The associated mapping (maybe NULL)
69 * @bd: The gfs2_bufdata to remove
70 *
71 * The ail lock _must_ be held when calling this function
72 *
73 */
74
75void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
76{
77 bd->bd_ail = NULL;
78 list_del_init(&bd->bd_ail_st_list);
79 list_del_init(&bd->bd_ail_gl_list);
80 atomic_dec(&bd->bd_gl->gl_ail_count);
81 brelse(bd->bd_bh);
82}
83
84/**
85 * gfs2_ail1_start_one - Start I/O on a part of the AIL
86 * @sdp: the filesystem
87 * @wbc: The writeback control structure
88 * @ai: The ail structure
89 *
90 */
91
92static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
93 struct writeback_control *wbc,
94 struct gfs2_ail *ai)
95__releases(&sdp->sd_ail_lock)
96__acquires(&sdp->sd_ail_lock)
97{
98 struct gfs2_glock *gl = NULL;
99 struct address_space *mapping;
100 struct gfs2_bufdata *bd, *s;
101 struct buffer_head *bh;
102
103 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) {
104 bh = bd->bd_bh;
105
106 gfs2_assert(sdp, bd->bd_ail == ai);
107
108 if (!buffer_busy(bh)) {
109 if (!buffer_uptodate(bh))
110 gfs2_io_error_bh(sdp, bh);
111 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
112 continue;
113 }
114
115 if (!buffer_dirty(bh))
116 continue;
117 if (gl == bd->bd_gl)
118 continue;
119 gl = bd->bd_gl;
120 list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
121 mapping = bh->b_page->mapping;
122 if (!mapping)
123 continue;
124 spin_unlock(&sdp->sd_ail_lock);
125 generic_writepages(mapping, wbc);
126 spin_lock(&sdp->sd_ail_lock);
127 if (wbc->nr_to_write <= 0)
128 break;
129 return 1;
130 }
131
132 return 0;
133}
134
135
136/**
137 * gfs2_ail1_flush - start writeback of some ail1 entries
138 * @sdp: The super block
139 * @wbc: The writeback control structure
140 *
141 * Writes back some ail1 entries, according to the limits in the
142 * writeback control structure
143 */
144
145void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
146{
147 struct list_head *head = &sdp->sd_ail1_list;
148 struct gfs2_ail *ai;
149
150 trace_gfs2_ail_flush(sdp, wbc, 1);
151 spin_lock(&sdp->sd_ail_lock);
152restart:
153 list_for_each_entry_reverse(ai, head, ai_list) {
154 if (wbc->nr_to_write <= 0)
155 break;
156 if (gfs2_ail1_start_one(sdp, wbc, ai))
157 goto restart;
158 }
159 spin_unlock(&sdp->sd_ail_lock);
160 trace_gfs2_ail_flush(sdp, wbc, 0);
161}
162
163/**
164 * gfs2_ail1_start - start writeback of all ail1 entries
165 * @sdp: The superblock
166 */
167
168static void gfs2_ail1_start(struct gfs2_sbd *sdp)
169{
170 struct writeback_control wbc = {
171 .sync_mode = WB_SYNC_NONE,
172 .nr_to_write = LONG_MAX,
173 .range_start = 0,
174 .range_end = LLONG_MAX,
175 };
176
177 return gfs2_ail1_flush(sdp, &wbc);
178}
179
180/**
181 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
182 * @sdp: the filesystem
183 * @ai: the AIL entry
184 *
185 */
186
187static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
188{
189 struct gfs2_bufdata *bd, *s;
190 struct buffer_head *bh;
191
192 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
193 bd_ail_st_list) {
194 bh = bd->bd_bh;
195 gfs2_assert(sdp, bd->bd_ail == ai);
196 if (buffer_busy(bh))
197 continue;
198 if (!buffer_uptodate(bh))
199 gfs2_io_error_bh(sdp, bh);
200 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
201 }
202
203}
204
205/**
206 * gfs2_ail1_empty - Try to empty the ail1 lists
207 * @sdp: The superblock
208 *
209 * Tries to empty the ail1 lists, starting with the oldest first
210 */
211
212static int gfs2_ail1_empty(struct gfs2_sbd *sdp)
213{
214 struct gfs2_ail *ai, *s;
215 int ret;
216
217 spin_lock(&sdp->sd_ail_lock);
218 list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
219 gfs2_ail1_empty_one(sdp, ai);
220 if (list_empty(&ai->ai_ail1_list))
221 list_move(&ai->ai_list, &sdp->sd_ail2_list);
222 else
223 break;
224 }
225 ret = list_empty(&sdp->sd_ail1_list);
226 spin_unlock(&sdp->sd_ail_lock);
227
228 return ret;
229}
230
231static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
232{
233 struct gfs2_ail *ai;
234 struct gfs2_bufdata *bd;
235 struct buffer_head *bh;
236
237 spin_lock(&sdp->sd_ail_lock);
238 list_for_each_entry_reverse(ai, &sdp->sd_ail1_list, ai_list) {
239 list_for_each_entry(bd, &ai->ai_ail1_list, bd_ail_st_list) {
240 bh = bd->bd_bh;
241 if (!buffer_locked(bh))
242 continue;
243 get_bh(bh);
244 spin_unlock(&sdp->sd_ail_lock);
245 wait_on_buffer(bh);
246 brelse(bh);
247 return;
248 }
249 }
250 spin_unlock(&sdp->sd_ail_lock);
251}
252
253/**
254 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
255 * @sdp: the filesystem
256 * @ai: the AIL entry
257 *
258 */
259
260static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
261{
262 struct list_head *head = &ai->ai_ail2_list;
263 struct gfs2_bufdata *bd;
264
265 while (!list_empty(head)) {
266 bd = list_entry(head->prev, struct gfs2_bufdata,
267 bd_ail_st_list);
268 gfs2_assert(sdp, bd->bd_ail == ai);
269 gfs2_remove_from_ail(bd);
270 }
271}
272
273static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
274{
275 struct gfs2_ail *ai, *safe;
276 unsigned int old_tail = sdp->sd_log_tail;
277 int wrap = (new_tail < old_tail);
278 int a, b, rm;
279
280 spin_lock(&sdp->sd_ail_lock);
281
282 list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
283 a = (old_tail <= ai->ai_first);
284 b = (ai->ai_first < new_tail);
285 rm = (wrap) ? (a || b) : (a && b);
286 if (!rm)
287 continue;
288
289 gfs2_ail2_empty_one(sdp, ai);
290 list_del(&ai->ai_list);
291 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
292 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
293 kfree(ai);
294 }
295
296 spin_unlock(&sdp->sd_ail_lock);
297}
298
299/**
300 * gfs2_log_reserve - Make a log reservation
301 * @sdp: The GFS2 superblock
302 * @blks: The number of blocks to reserve
303 *
304 * Note that we never give out the last few blocks of the journal. Thats
305 * due to the fact that there is a small number of header blocks
306 * associated with each log flush. The exact number can't be known until
307 * flush time, so we ensure that we have just enough free blocks at all
308 * times to avoid running out during a log flush.
309 *
310 * We no longer flush the log here, instead we wake up logd to do that
311 * for us. To avoid the thundering herd and to ensure that we deal fairly
312 * with queued waiters, we use an exclusive wait. This means that when we
313 * get woken with enough journal space to get our reservation, we need to
314 * wake the next waiter on the list.
315 *
316 * Returns: errno
317 */
318
319int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
320{
321 unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
322 unsigned wanted = blks + reserved_blks;
323 DEFINE_WAIT(wait);
324 int did_wait = 0;
325 unsigned int free_blocks;
326
327 if (gfs2_assert_warn(sdp, blks) ||
328 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
329 return -EINVAL;
330retry:
331 free_blocks = atomic_read(&sdp->sd_log_blks_free);
332 if (unlikely(free_blocks <= wanted)) {
333 do {
334 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
335 TASK_UNINTERRUPTIBLE);
336 wake_up(&sdp->sd_logd_waitq);
337 did_wait = 1;
338 if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
339 io_schedule();
340 free_blocks = atomic_read(&sdp->sd_log_blks_free);
341 } while(free_blocks <= wanted);
342 finish_wait(&sdp->sd_log_waitq, &wait);
343 }
344 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
345 free_blocks - blks) != free_blocks)
346 goto retry;
347 trace_gfs2_log_blocks(sdp, -blks);
348
349 /*
350 * If we waited, then so might others, wake them up _after_ we get
351 * our share of the log.
352 */
353 if (unlikely(did_wait))
354 wake_up(&sdp->sd_log_waitq);
355
356 down_read(&sdp->sd_log_flush_lock);
357
358 return 0;
359}
360
361static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
362{
363 struct gfs2_journal_extent *je;
364
365 list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) {
366 if (lbn >= je->lblock && lbn < je->lblock + je->blocks)
367 return je->dblock + lbn - je->lblock;
368 }
369
370 return -1;
371}
372
373/**
374 * log_distance - Compute distance between two journal blocks
375 * @sdp: The GFS2 superblock
376 * @newer: The most recent journal block of the pair
377 * @older: The older journal block of the pair
378 *
379 * Compute the distance (in the journal direction) between two
380 * blocks in the journal
381 *
382 * Returns: the distance in blocks
383 */
384
385static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
386 unsigned int older)
387{
388 int dist;
389
390 dist = newer - older;
391 if (dist < 0)
392 dist += sdp->sd_jdesc->jd_blocks;
393
394 return dist;
395}
396
397/**
398 * calc_reserved - Calculate the number of blocks to reserve when
399 * refunding a transaction's unused buffers.
400 * @sdp: The GFS2 superblock
401 *
402 * This is complex. We need to reserve room for all our currently used
403 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
404 * all our journaled data buffers for journaled files (e.g. files in the
405 * meta_fs like rindex, or files for which chattr +j was done.)
406 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
407 * will count it as free space (sd_log_blks_free) and corruption will follow.
408 *
409 * We can have metadata bufs and jdata bufs in the same journal. So each
410 * type gets its own log header, for which we need to reserve a block.
411 * In fact, each type has the potential for needing more than one header
412 * in cases where we have more buffers than will fit on a journal page.
413 * Metadata journal entries take up half the space of journaled buffer entries.
414 * Thus, metadata entries have buf_limit (502) and journaled buffers have
415 * databuf_limit (251) before they cause a wrap around.
416 *
417 * Also, we need to reserve blocks for revoke journal entries and one for an
418 * overall header for the lot.
419 *
420 * Returns: the number of blocks reserved
421 */
422static unsigned int calc_reserved(struct gfs2_sbd *sdp)
423{
424 unsigned int reserved = 0;
425 unsigned int mbuf_limit, metabufhdrs_needed;
426 unsigned int dbuf_limit, databufhdrs_needed;
427 unsigned int revokes = 0;
428
429 mbuf_limit = buf_limit(sdp);
430 metabufhdrs_needed = (sdp->sd_log_commited_buf +
431 (mbuf_limit - 1)) / mbuf_limit;
432 dbuf_limit = databuf_limit(sdp);
433 databufhdrs_needed = (sdp->sd_log_commited_databuf +
434 (dbuf_limit - 1)) / dbuf_limit;
435
436 if (sdp->sd_log_commited_revoke > 0)
437 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
438 sizeof(u64));
439
440 reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
441 sdp->sd_log_commited_databuf + databufhdrs_needed +
442 revokes;
443 /* One for the overall header */
444 if (reserved)
445 reserved++;
446 return reserved;
447}
448
449static unsigned int current_tail(struct gfs2_sbd *sdp)
450{
451 struct gfs2_ail *ai;
452 unsigned int tail;
453
454 spin_lock(&sdp->sd_ail_lock);
455
456 if (list_empty(&sdp->sd_ail1_list)) {
457 tail = sdp->sd_log_head;
458 } else {
459 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
460 tail = ai->ai_first;
461 }
462
463 spin_unlock(&sdp->sd_ail_lock);
464
465 return tail;
466}
467
468void gfs2_log_incr_head(struct gfs2_sbd *sdp)
469{
470 if (sdp->sd_log_flush_head == sdp->sd_log_tail)
471 BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head);
472
473 if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
474 sdp->sd_log_flush_head = 0;
475 sdp->sd_log_flush_wrapped = 1;
476 }
477}
478
479/**
480 * gfs2_log_write_endio - End of I/O for a log buffer
481 * @bh: The buffer head
482 * @uptodate: I/O Status
483 *
484 */
485
486static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate)
487{
488 struct gfs2_sbd *sdp = bh->b_private;
489 bh->b_private = NULL;
490
491 end_buffer_write_sync(bh, uptodate);
492 if (atomic_dec_and_test(&sdp->sd_log_in_flight))
493 wake_up(&sdp->sd_log_flush_wait);
494}
495
496/**
497 * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
498 * @sdp: The GFS2 superblock
499 *
500 * Returns: the buffer_head
501 */
502
503struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
504{
505 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
506 struct buffer_head *bh;
507
508 bh = sb_getblk(sdp->sd_vfs, blkno);
509 lock_buffer(bh);
510 memset(bh->b_data, 0, bh->b_size);
511 set_buffer_uptodate(bh);
512 clear_buffer_dirty(bh);
513 gfs2_log_incr_head(sdp);
514 atomic_inc(&sdp->sd_log_in_flight);
515 bh->b_private = sdp;
516 bh->b_end_io = gfs2_log_write_endio;
517
518 return bh;
519}
520
521/**
522 * gfs2_fake_write_endio -
523 * @bh: The buffer head
524 * @uptodate: The I/O Status
525 *
526 */
527
528static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate)
529{
530 struct buffer_head *real_bh = bh->b_private;
531 struct gfs2_bufdata *bd = real_bh->b_private;
532 struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd;
533
534 end_buffer_write_sync(bh, uptodate);
535 free_buffer_head(bh);
536 unlock_buffer(real_bh);
537 brelse(real_bh);
538 if (atomic_dec_and_test(&sdp->sd_log_in_flight))
539 wake_up(&sdp->sd_log_flush_wait);
540}
541
542/**
543 * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
544 * @sdp: the filesystem
545 * @data: the data the buffer_head should point to
546 *
547 * Returns: the log buffer descriptor
548 */
549
550struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
551 struct buffer_head *real)
552{
553 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
554 struct buffer_head *bh;
555
556 bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
557 atomic_set(&bh->b_count, 1);
558 bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock);
559 set_bh_page(bh, real->b_page, bh_offset(real));
560 bh->b_blocknr = blkno;
561 bh->b_size = sdp->sd_sb.sb_bsize;
562 bh->b_bdev = sdp->sd_vfs->s_bdev;
563 bh->b_private = real;
564 bh->b_end_io = gfs2_fake_write_endio;
565
566 gfs2_log_incr_head(sdp);
567 atomic_inc(&sdp->sd_log_in_flight);
568
569 return bh;
570}
571
572static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
573{
574 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
575
576 ail2_empty(sdp, new_tail);
577
578 atomic_add(dist, &sdp->sd_log_blks_free);
579 trace_gfs2_log_blocks(sdp, dist);
580 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
581 sdp->sd_jdesc->jd_blocks);
582
583 sdp->sd_log_tail = new_tail;
584}
585
586/**
587 * log_write_header - Get and initialize a journal header buffer
588 * @sdp: The GFS2 superblock
589 *
590 * Returns: the initialized log buffer descriptor
591 */
592
593static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
594{
595 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
596 struct buffer_head *bh;
597 struct gfs2_log_header *lh;
598 unsigned int tail;
599 u32 hash;
600
601 bh = sb_getblk(sdp->sd_vfs, blkno);
602 lock_buffer(bh);
603 memset(bh->b_data, 0, bh->b_size);
604 set_buffer_uptodate(bh);
605 clear_buffer_dirty(bh);
606
607 gfs2_ail1_empty(sdp);
608 tail = current_tail(sdp);
609
610 lh = (struct gfs2_log_header *)bh->b_data;
611 memset(lh, 0, sizeof(struct gfs2_log_header));
612 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
613 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
614 lh->lh_header.__pad0 = cpu_to_be64(0);
615 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
616 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
617 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
618 lh->lh_flags = cpu_to_be32(flags);
619 lh->lh_tail = cpu_to_be32(tail);
620 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
621 hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
622 lh->lh_hash = cpu_to_be32(hash);
623
624 bh->b_end_io = end_buffer_write_sync;
625 get_bh(bh);
626 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
627 submit_bh(WRITE_SYNC | REQ_META | REQ_PRIO, bh);
628 else
629 submit_bh(WRITE_FLUSH_FUA | REQ_META | REQ_PRIO, bh);
630 wait_on_buffer(bh);
631
632 if (!buffer_uptodate(bh))
633 gfs2_io_error_bh(sdp, bh);
634 brelse(bh);
635
636 if (sdp->sd_log_tail != tail)
637 log_pull_tail(sdp, tail);
638 else
639 gfs2_assert_withdraw(sdp, !pull);
640
641 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
642 gfs2_log_incr_head(sdp);
643}
644
645static void log_flush_commit(struct gfs2_sbd *sdp)
646{
647 DEFINE_WAIT(wait);
648
649 if (atomic_read(&sdp->sd_log_in_flight)) {
650 do {
651 prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
652 TASK_UNINTERRUPTIBLE);
653 if (atomic_read(&sdp->sd_log_in_flight))
654 io_schedule();
655 } while(atomic_read(&sdp->sd_log_in_flight));
656 finish_wait(&sdp->sd_log_flush_wait, &wait);
657 }
658
659 log_write_header(sdp, 0, 0);
660}
661
662static void gfs2_ordered_write(struct gfs2_sbd *sdp)
663{
664 struct gfs2_bufdata *bd;
665 struct buffer_head *bh;
666 LIST_HEAD(written);
667
668 gfs2_log_lock(sdp);
669 while (!list_empty(&sdp->sd_log_le_ordered)) {
670 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list);
671 list_move(&bd->bd_le.le_list, &written);
672 bh = bd->bd_bh;
673 if (!buffer_dirty(bh))
674 continue;
675 get_bh(bh);
676 gfs2_log_unlock(sdp);
677 lock_buffer(bh);
678 if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) {
679 bh->b_end_io = end_buffer_write_sync;
680 submit_bh(WRITE_SYNC, bh);
681 } else {
682 unlock_buffer(bh);
683 brelse(bh);
684 }
685 gfs2_log_lock(sdp);
686 }
687 list_splice(&written, &sdp->sd_log_le_ordered);
688 gfs2_log_unlock(sdp);
689}
690
691static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
692{
693 struct gfs2_bufdata *bd;
694 struct buffer_head *bh;
695
696 gfs2_log_lock(sdp);
697 while (!list_empty(&sdp->sd_log_le_ordered)) {
698 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list);
699 bh = bd->bd_bh;
700 if (buffer_locked(bh)) {
701 get_bh(bh);
702 gfs2_log_unlock(sdp);
703 wait_on_buffer(bh);
704 brelse(bh);
705 gfs2_log_lock(sdp);
706 continue;
707 }
708 list_del_init(&bd->bd_le.le_list);
709 }
710 gfs2_log_unlock(sdp);
711}
712
713/**
714 * gfs2_log_flush - flush incore transaction(s)
715 * @sdp: the filesystem
716 * @gl: The glock structure to flush. If NULL, flush the whole incore log
717 *
718 */
719
720void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
721{
722 struct gfs2_ail *ai;
723
724 down_write(&sdp->sd_log_flush_lock);
725
726 /* Log might have been flushed while we waited for the flush lock */
727 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
728 up_write(&sdp->sd_log_flush_lock);
729 return;
730 }
731 trace_gfs2_log_flush(sdp, 1);
732
733 ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
734 INIT_LIST_HEAD(&ai->ai_ail1_list);
735 INIT_LIST_HEAD(&ai->ai_ail2_list);
736
737 if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
738 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
739 sdp->sd_log_commited_buf);
740 gfs2_assert_withdraw(sdp, 0);
741 }
742 if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
743 printk(KERN_INFO "GFS2: log databuf %u %u\n",
744 sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
745 gfs2_assert_withdraw(sdp, 0);
746 }
747 gfs2_assert_withdraw(sdp,
748 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
749
750 sdp->sd_log_flush_head = sdp->sd_log_head;
751 sdp->sd_log_flush_wrapped = 0;
752 ai->ai_first = sdp->sd_log_flush_head;
753
754 gfs2_ordered_write(sdp);
755 lops_before_commit(sdp);
756 gfs2_ordered_wait(sdp);
757
758 if (sdp->sd_log_head != sdp->sd_log_flush_head)
759 log_flush_commit(sdp);
760 else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
761 gfs2_log_lock(sdp);
762 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
763 trace_gfs2_log_blocks(sdp, -1);
764 gfs2_log_unlock(sdp);
765 log_write_header(sdp, 0, PULL);
766 }
767 lops_after_commit(sdp, ai);
768
769 gfs2_log_lock(sdp);
770 sdp->sd_log_head = sdp->sd_log_flush_head;
771 sdp->sd_log_blks_reserved = 0;
772 sdp->sd_log_commited_buf = 0;
773 sdp->sd_log_commited_databuf = 0;
774 sdp->sd_log_commited_revoke = 0;
775
776 spin_lock(&sdp->sd_ail_lock);
777 if (!list_empty(&ai->ai_ail1_list)) {
778 list_add(&ai->ai_list, &sdp->sd_ail1_list);
779 ai = NULL;
780 }
781 spin_unlock(&sdp->sd_ail_lock);
782 gfs2_log_unlock(sdp);
783 trace_gfs2_log_flush(sdp, 0);
784 up_write(&sdp->sd_log_flush_lock);
785
786 kfree(ai);
787}
788
789static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
790{
791 unsigned int reserved;
792 unsigned int unused;
793
794 gfs2_log_lock(sdp);
795
796 sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
797 sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
798 tr->tr_num_databuf_rm;
799 gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
800 (((int)sdp->sd_log_commited_databuf) >= 0));
801 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
802 reserved = calc_reserved(sdp);
803 gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
804 unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
805 atomic_add(unused, &sdp->sd_log_blks_free);
806 trace_gfs2_log_blocks(sdp, unused);
807 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
808 sdp->sd_jdesc->jd_blocks);
809 sdp->sd_log_blks_reserved = reserved;
810
811 gfs2_log_unlock(sdp);
812}
813
814static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
815{
816 struct list_head *head = &tr->tr_list_buf;
817 struct gfs2_bufdata *bd;
818
819 gfs2_log_lock(sdp);
820 while (!list_empty(head)) {
821 bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
822 list_del_init(&bd->bd_list_tr);
823 tr->tr_num_buf--;
824 }
825 gfs2_log_unlock(sdp);
826 gfs2_assert_warn(sdp, !tr->tr_num_buf);
827}
828
829/**
830 * gfs2_log_commit - Commit a transaction to the log
831 * @sdp: the filesystem
832 * @tr: the transaction
833 *
834 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
835 * or the total number of used blocks (pinned blocks plus AIL blocks)
836 * is greater than thresh2.
837 *
838 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
839 * journal size.
840 *
841 * Returns: errno
842 */
843
844void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
845{
846 log_refund(sdp, tr);
847 buf_lo_incore_commit(sdp, tr);
848
849 up_read(&sdp->sd_log_flush_lock);
850
851 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
852 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
853 atomic_read(&sdp->sd_log_thresh2)))
854 wake_up(&sdp->sd_logd_waitq);
855}
856
857/**
858 * gfs2_log_shutdown - write a shutdown header into a journal
859 * @sdp: the filesystem
860 *
861 */
862
863void gfs2_log_shutdown(struct gfs2_sbd *sdp)
864{
865 down_write(&sdp->sd_log_flush_lock);
866
867 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
868 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
869 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
870 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
871 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
872 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
873
874 sdp->sd_log_flush_head = sdp->sd_log_head;
875 sdp->sd_log_flush_wrapped = 0;
876
877 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT,
878 (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
879
880 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
881 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
882 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
883
884 sdp->sd_log_head = sdp->sd_log_flush_head;
885 sdp->sd_log_tail = sdp->sd_log_head;
886
887 up_write(&sdp->sd_log_flush_lock);
888}
889
890
891/**
892 * gfs2_meta_syncfs - sync all the buffers in a filesystem
893 * @sdp: the filesystem
894 *
895 */
896
897void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
898{
899 gfs2_log_flush(sdp, NULL);
900 for (;;) {
901 gfs2_ail1_start(sdp);
902 gfs2_ail1_wait(sdp);
903 if (gfs2_ail1_empty(sdp))
904 break;
905 }
906 gfs2_log_flush(sdp, NULL);
907}
908
909static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
910{
911 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1));
912}
913
914static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
915{
916 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
917 return used_blocks >= atomic_read(&sdp->sd_log_thresh2);
918}
919
920/**
921 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
922 * @sdp: Pointer to GFS2 superblock
923 *
924 * Also, periodically check to make sure that we're using the most recent
925 * journal index.
926 */
927
928int gfs2_logd(void *data)
929{
930 struct gfs2_sbd *sdp = data;
931 unsigned long t = 1;
932 DEFINE_WAIT(wait);
933 unsigned preflush;
934
935 while (!kthread_should_stop()) {
936
937 preflush = atomic_read(&sdp->sd_log_pinned);
938 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
939 gfs2_ail1_empty(sdp);
940 gfs2_log_flush(sdp, NULL);
941 }
942
943 if (gfs2_ail_flush_reqd(sdp)) {
944 gfs2_ail1_start(sdp);
945 gfs2_ail1_wait(sdp);
946 gfs2_ail1_empty(sdp);
947 gfs2_log_flush(sdp, NULL);
948 }
949
950 if (!gfs2_ail_flush_reqd(sdp))
951 wake_up(&sdp->sd_log_waitq);
952
953 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
954 if (freezing(current))
955 refrigerator();
956
957 do {
958 prepare_to_wait(&sdp->sd_logd_waitq, &wait,
959 TASK_INTERRUPTIBLE);
960 if (!gfs2_ail_flush_reqd(sdp) &&
961 !gfs2_jrnl_flush_reqd(sdp) &&
962 !kthread_should_stop())
963 t = schedule_timeout(t);
964 } while(t && !gfs2_ail_flush_reqd(sdp) &&
965 !gfs2_jrnl_flush_reqd(sdp) &&
966 !kthread_should_stop());
967 finish_wait(&sdp->sd_logd_waitq, &wait);
968 }
969
970 return 0;
971}
972
1/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2007 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/crc32.h>
17#include <linux/delay.h>
18#include <linux/kthread.h>
19#include <linux/freezer.h>
20#include <linux/bio.h>
21#include <linux/blkdev.h>
22#include <linux/writeback.h>
23#include <linux/list_sort.h>
24
25#include "gfs2.h"
26#include "incore.h"
27#include "bmap.h"
28#include "glock.h"
29#include "log.h"
30#include "lops.h"
31#include "meta_io.h"
32#include "util.h"
33#include "dir.h"
34#include "trace_gfs2.h"
35
36/**
37 * gfs2_struct2blk - compute stuff
38 * @sdp: the filesystem
39 * @nstruct: the number of structures
40 * @ssize: the size of the structures
41 *
42 * Compute the number of log descriptor blocks needed to hold a certain number
43 * of structures of a certain size.
44 *
45 * Returns: the number of blocks needed (minimum is always 1)
46 */
47
48unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
49 unsigned int ssize)
50{
51 unsigned int blks;
52 unsigned int first, second;
53
54 blks = 1;
55 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
56
57 if (nstruct > first) {
58 second = (sdp->sd_sb.sb_bsize -
59 sizeof(struct gfs2_meta_header)) / ssize;
60 blks += DIV_ROUND_UP(nstruct - first, second);
61 }
62
63 return blks;
64}
65
66/**
67 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
68 * @mapping: The associated mapping (maybe NULL)
69 * @bd: The gfs2_bufdata to remove
70 *
71 * The ail lock _must_ be held when calling this function
72 *
73 */
74
75void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
76{
77 bd->bd_tr = NULL;
78 list_del_init(&bd->bd_ail_st_list);
79 list_del_init(&bd->bd_ail_gl_list);
80 atomic_dec(&bd->bd_gl->gl_ail_count);
81 brelse(bd->bd_bh);
82}
83
84/**
85 * gfs2_ail1_start_one - Start I/O on a part of the AIL
86 * @sdp: the filesystem
87 * @wbc: The writeback control structure
88 * @ai: The ail structure
89 *
90 */
91
92static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
93 struct writeback_control *wbc,
94 struct gfs2_trans *tr)
95__releases(&sdp->sd_ail_lock)
96__acquires(&sdp->sd_ail_lock)
97{
98 struct gfs2_glock *gl = NULL;
99 struct address_space *mapping;
100 struct gfs2_bufdata *bd, *s;
101 struct buffer_head *bh;
102
103 list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) {
104 bh = bd->bd_bh;
105
106 gfs2_assert(sdp, bd->bd_tr == tr);
107
108 if (!buffer_busy(bh)) {
109 if (!buffer_uptodate(bh))
110 gfs2_io_error_bh(sdp, bh);
111 list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
112 continue;
113 }
114
115 if (!buffer_dirty(bh))
116 continue;
117 if (gl == bd->bd_gl)
118 continue;
119 gl = bd->bd_gl;
120 list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list);
121 mapping = bh->b_page->mapping;
122 if (!mapping)
123 continue;
124 spin_unlock(&sdp->sd_ail_lock);
125 generic_writepages(mapping, wbc);
126 spin_lock(&sdp->sd_ail_lock);
127 if (wbc->nr_to_write <= 0)
128 break;
129 return 1;
130 }
131
132 return 0;
133}
134
135
136/**
137 * gfs2_ail1_flush - start writeback of some ail1 entries
138 * @sdp: The super block
139 * @wbc: The writeback control structure
140 *
141 * Writes back some ail1 entries, according to the limits in the
142 * writeback control structure
143 */
144
145void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
146{
147 struct list_head *head = &sdp->sd_ail1_list;
148 struct gfs2_trans *tr;
149 struct blk_plug plug;
150
151 trace_gfs2_ail_flush(sdp, wbc, 1);
152 blk_start_plug(&plug);
153 spin_lock(&sdp->sd_ail_lock);
154restart:
155 list_for_each_entry_reverse(tr, head, tr_list) {
156 if (wbc->nr_to_write <= 0)
157 break;
158 if (gfs2_ail1_start_one(sdp, wbc, tr))
159 goto restart;
160 }
161 spin_unlock(&sdp->sd_ail_lock);
162 blk_finish_plug(&plug);
163 trace_gfs2_ail_flush(sdp, wbc, 0);
164}
165
166/**
167 * gfs2_ail1_start - start writeback of all ail1 entries
168 * @sdp: The superblock
169 */
170
171static void gfs2_ail1_start(struct gfs2_sbd *sdp)
172{
173 struct writeback_control wbc = {
174 .sync_mode = WB_SYNC_NONE,
175 .nr_to_write = LONG_MAX,
176 .range_start = 0,
177 .range_end = LLONG_MAX,
178 };
179
180 return gfs2_ail1_flush(sdp, &wbc);
181}
182
183/**
184 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
185 * @sdp: the filesystem
186 * @ai: the AIL entry
187 *
188 */
189
190static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
191{
192 struct gfs2_bufdata *bd, *s;
193 struct buffer_head *bh;
194
195 list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list,
196 bd_ail_st_list) {
197 bh = bd->bd_bh;
198 gfs2_assert(sdp, bd->bd_tr == tr);
199 if (buffer_busy(bh))
200 continue;
201 if (!buffer_uptodate(bh))
202 gfs2_io_error_bh(sdp, bh);
203 list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
204 }
205
206}
207
208/**
209 * gfs2_ail1_empty - Try to empty the ail1 lists
210 * @sdp: The superblock
211 *
212 * Tries to empty the ail1 lists, starting with the oldest first
213 */
214
215static int gfs2_ail1_empty(struct gfs2_sbd *sdp)
216{
217 struct gfs2_trans *tr, *s;
218 int oldest_tr = 1;
219 int ret;
220
221 spin_lock(&sdp->sd_ail_lock);
222 list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) {
223 gfs2_ail1_empty_one(sdp, tr);
224 if (list_empty(&tr->tr_ail1_list) && oldest_tr)
225 list_move(&tr->tr_list, &sdp->sd_ail2_list);
226 else
227 oldest_tr = 0;
228 }
229 ret = list_empty(&sdp->sd_ail1_list);
230 spin_unlock(&sdp->sd_ail_lock);
231
232 return ret;
233}
234
235static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
236{
237 struct gfs2_trans *tr;
238 struct gfs2_bufdata *bd;
239 struct buffer_head *bh;
240
241 spin_lock(&sdp->sd_ail_lock);
242 list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
243 list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) {
244 bh = bd->bd_bh;
245 if (!buffer_locked(bh))
246 continue;
247 get_bh(bh);
248 spin_unlock(&sdp->sd_ail_lock);
249 wait_on_buffer(bh);
250 brelse(bh);
251 return;
252 }
253 }
254 spin_unlock(&sdp->sd_ail_lock);
255}
256
257/**
258 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
259 * @sdp: the filesystem
260 * @ai: the AIL entry
261 *
262 */
263
264static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
265{
266 struct list_head *head = &tr->tr_ail2_list;
267 struct gfs2_bufdata *bd;
268
269 while (!list_empty(head)) {
270 bd = list_entry(head->prev, struct gfs2_bufdata,
271 bd_ail_st_list);
272 gfs2_assert(sdp, bd->bd_tr == tr);
273 gfs2_remove_from_ail(bd);
274 }
275}
276
277static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
278{
279 struct gfs2_trans *tr, *safe;
280 unsigned int old_tail = sdp->sd_log_tail;
281 int wrap = (new_tail < old_tail);
282 int a, b, rm;
283
284 spin_lock(&sdp->sd_ail_lock);
285
286 list_for_each_entry_safe(tr, safe, &sdp->sd_ail2_list, tr_list) {
287 a = (old_tail <= tr->tr_first);
288 b = (tr->tr_first < new_tail);
289 rm = (wrap) ? (a || b) : (a && b);
290 if (!rm)
291 continue;
292
293 gfs2_ail2_empty_one(sdp, tr);
294 list_del(&tr->tr_list);
295 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
296 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
297 kfree(tr);
298 }
299
300 spin_unlock(&sdp->sd_ail_lock);
301}
302
303/**
304 * gfs2_log_reserve - Make a log reservation
305 * @sdp: The GFS2 superblock
306 * @blks: The number of blocks to reserve
307 *
308 * Note that we never give out the last few blocks of the journal. Thats
309 * due to the fact that there is a small number of header blocks
310 * associated with each log flush. The exact number can't be known until
311 * flush time, so we ensure that we have just enough free blocks at all
312 * times to avoid running out during a log flush.
313 *
314 * We no longer flush the log here, instead we wake up logd to do that
315 * for us. To avoid the thundering herd and to ensure that we deal fairly
316 * with queued waiters, we use an exclusive wait. This means that when we
317 * get woken with enough journal space to get our reservation, we need to
318 * wake the next waiter on the list.
319 *
320 * Returns: errno
321 */
322
323int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
324{
325 unsigned reserved_blks = 7 * (4096 / sdp->sd_vfs->s_blocksize);
326 unsigned wanted = blks + reserved_blks;
327 DEFINE_WAIT(wait);
328 int did_wait = 0;
329 unsigned int free_blocks;
330
331 if (gfs2_assert_warn(sdp, blks) ||
332 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
333 return -EINVAL;
334retry:
335 free_blocks = atomic_read(&sdp->sd_log_blks_free);
336 if (unlikely(free_blocks <= wanted)) {
337 do {
338 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
339 TASK_UNINTERRUPTIBLE);
340 wake_up(&sdp->sd_logd_waitq);
341 did_wait = 1;
342 if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
343 io_schedule();
344 free_blocks = atomic_read(&sdp->sd_log_blks_free);
345 } while(free_blocks <= wanted);
346 finish_wait(&sdp->sd_log_waitq, &wait);
347 }
348 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
349 free_blocks - blks) != free_blocks)
350 goto retry;
351 trace_gfs2_log_blocks(sdp, -blks);
352
353 /*
354 * If we waited, then so might others, wake them up _after_ we get
355 * our share of the log.
356 */
357 if (unlikely(did_wait))
358 wake_up(&sdp->sd_log_waitq);
359
360 down_read(&sdp->sd_log_flush_lock);
361
362 return 0;
363}
364
365/**
366 * log_distance - Compute distance between two journal blocks
367 * @sdp: The GFS2 superblock
368 * @newer: The most recent journal block of the pair
369 * @older: The older journal block of the pair
370 *
371 * Compute the distance (in the journal direction) between two
372 * blocks in the journal
373 *
374 * Returns: the distance in blocks
375 */
376
377static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
378 unsigned int older)
379{
380 int dist;
381
382 dist = newer - older;
383 if (dist < 0)
384 dist += sdp->sd_jdesc->jd_blocks;
385
386 return dist;
387}
388
389/**
390 * calc_reserved - Calculate the number of blocks to reserve when
391 * refunding a transaction's unused buffers.
392 * @sdp: The GFS2 superblock
393 *
394 * This is complex. We need to reserve room for all our currently used
395 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
396 * all our journaled data buffers for journaled files (e.g. files in the
397 * meta_fs like rindex, or files for which chattr +j was done.)
398 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
399 * will count it as free space (sd_log_blks_free) and corruption will follow.
400 *
401 * We can have metadata bufs and jdata bufs in the same journal. So each
402 * type gets its own log header, for which we need to reserve a block.
403 * In fact, each type has the potential for needing more than one header
404 * in cases where we have more buffers than will fit on a journal page.
405 * Metadata journal entries take up half the space of journaled buffer entries.
406 * Thus, metadata entries have buf_limit (502) and journaled buffers have
407 * databuf_limit (251) before they cause a wrap around.
408 *
409 * Also, we need to reserve blocks for revoke journal entries and one for an
410 * overall header for the lot.
411 *
412 * Returns: the number of blocks reserved
413 */
414static unsigned int calc_reserved(struct gfs2_sbd *sdp)
415{
416 unsigned int reserved = 0;
417 unsigned int mbuf;
418 unsigned int dbuf;
419 struct gfs2_trans *tr = sdp->sd_log_tr;
420
421 if (tr) {
422 mbuf = tr->tr_num_buf_new - tr->tr_num_buf_rm;
423 dbuf = tr->tr_num_databuf_new - tr->tr_num_databuf_rm;
424 reserved = mbuf + dbuf;
425 /* Account for header blocks */
426 reserved += DIV_ROUND_UP(mbuf, buf_limit(sdp));
427 reserved += DIV_ROUND_UP(dbuf, databuf_limit(sdp));
428 }
429
430 if (sdp->sd_log_commited_revoke > 0)
431 reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
432 sizeof(u64));
433 /* One for the overall header */
434 if (reserved)
435 reserved++;
436 return reserved;
437}
438
439static unsigned int current_tail(struct gfs2_sbd *sdp)
440{
441 struct gfs2_trans *tr;
442 unsigned int tail;
443
444 spin_lock(&sdp->sd_ail_lock);
445
446 if (list_empty(&sdp->sd_ail1_list)) {
447 tail = sdp->sd_log_head;
448 } else {
449 tr = list_entry(sdp->sd_ail1_list.prev, struct gfs2_trans,
450 tr_list);
451 tail = tr->tr_first;
452 }
453
454 spin_unlock(&sdp->sd_ail_lock);
455
456 return tail;
457}
458
459static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
460{
461 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
462
463 ail2_empty(sdp, new_tail);
464
465 atomic_add(dist, &sdp->sd_log_blks_free);
466 trace_gfs2_log_blocks(sdp, dist);
467 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
468 sdp->sd_jdesc->jd_blocks);
469
470 sdp->sd_log_tail = new_tail;
471}
472
473
474static void log_flush_wait(struct gfs2_sbd *sdp)
475{
476 DEFINE_WAIT(wait);
477
478 if (atomic_read(&sdp->sd_log_in_flight)) {
479 do {
480 prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
481 TASK_UNINTERRUPTIBLE);
482 if (atomic_read(&sdp->sd_log_in_flight))
483 io_schedule();
484 } while(atomic_read(&sdp->sd_log_in_flight));
485 finish_wait(&sdp->sd_log_flush_wait, &wait);
486 }
487}
488
489static int ip_cmp(void *priv, struct list_head *a, struct list_head *b)
490{
491 struct gfs2_inode *ipa, *ipb;
492
493 ipa = list_entry(a, struct gfs2_inode, i_ordered);
494 ipb = list_entry(b, struct gfs2_inode, i_ordered);
495
496 if (ipa->i_no_addr < ipb->i_no_addr)
497 return -1;
498 if (ipa->i_no_addr > ipb->i_no_addr)
499 return 1;
500 return 0;
501}
502
503static void gfs2_ordered_write(struct gfs2_sbd *sdp)
504{
505 struct gfs2_inode *ip;
506 LIST_HEAD(written);
507
508 spin_lock(&sdp->sd_ordered_lock);
509 list_sort(NULL, &sdp->sd_log_le_ordered, &ip_cmp);
510 while (!list_empty(&sdp->sd_log_le_ordered)) {
511 ip = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_inode, i_ordered);
512 list_move(&ip->i_ordered, &written);
513 if (ip->i_inode.i_mapping->nrpages == 0)
514 continue;
515 spin_unlock(&sdp->sd_ordered_lock);
516 filemap_fdatawrite(ip->i_inode.i_mapping);
517 spin_lock(&sdp->sd_ordered_lock);
518 }
519 list_splice(&written, &sdp->sd_log_le_ordered);
520 spin_unlock(&sdp->sd_ordered_lock);
521}
522
523static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
524{
525 struct gfs2_inode *ip;
526
527 spin_lock(&sdp->sd_ordered_lock);
528 while (!list_empty(&sdp->sd_log_le_ordered)) {
529 ip = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_inode, i_ordered);
530 list_del(&ip->i_ordered);
531 WARN_ON(!test_and_clear_bit(GIF_ORDERED, &ip->i_flags));
532 if (ip->i_inode.i_mapping->nrpages == 0)
533 continue;
534 spin_unlock(&sdp->sd_ordered_lock);
535 filemap_fdatawait(ip->i_inode.i_mapping);
536 spin_lock(&sdp->sd_ordered_lock);
537 }
538 spin_unlock(&sdp->sd_ordered_lock);
539}
540
541void gfs2_ordered_del_inode(struct gfs2_inode *ip)
542{
543 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
544
545 spin_lock(&sdp->sd_ordered_lock);
546 if (test_and_clear_bit(GIF_ORDERED, &ip->i_flags))
547 list_del(&ip->i_ordered);
548 spin_unlock(&sdp->sd_ordered_lock);
549}
550
551void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
552{
553 struct buffer_head *bh = bd->bd_bh;
554 struct gfs2_glock *gl = bd->bd_gl;
555
556 bh->b_private = NULL;
557 bd->bd_blkno = bh->b_blocknr;
558 gfs2_remove_from_ail(bd); /* drops ref on bh */
559 bd->bd_bh = NULL;
560 bd->bd_ops = &gfs2_revoke_lops;
561 sdp->sd_log_num_revoke++;
562 atomic_inc(&gl->gl_revokes);
563 set_bit(GLF_LFLUSH, &gl->gl_flags);
564 list_add(&bd->bd_list, &sdp->sd_log_le_revoke);
565}
566
567void gfs2_write_revokes(struct gfs2_sbd *sdp)
568{
569 struct gfs2_trans *tr;
570 struct gfs2_bufdata *bd, *tmp;
571 int have_revokes = 0;
572 int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64);
573
574 gfs2_ail1_empty(sdp);
575 spin_lock(&sdp->sd_ail_lock);
576 list_for_each_entry(tr, &sdp->sd_ail1_list, tr_list) {
577 list_for_each_entry(bd, &tr->tr_ail2_list, bd_ail_st_list) {
578 if (list_empty(&bd->bd_list)) {
579 have_revokes = 1;
580 goto done;
581 }
582 }
583 }
584done:
585 spin_unlock(&sdp->sd_ail_lock);
586 if (have_revokes == 0)
587 return;
588 while (sdp->sd_log_num_revoke > max_revokes)
589 max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64);
590 max_revokes -= sdp->sd_log_num_revoke;
591 if (!sdp->sd_log_num_revoke) {
592 atomic_dec(&sdp->sd_log_blks_free);
593 /* If no blocks have been reserved, we need to also
594 * reserve a block for the header */
595 if (!sdp->sd_log_blks_reserved)
596 atomic_dec(&sdp->sd_log_blks_free);
597 }
598 gfs2_log_lock(sdp);
599 spin_lock(&sdp->sd_ail_lock);
600 list_for_each_entry(tr, &sdp->sd_ail1_list, tr_list) {
601 list_for_each_entry_safe(bd, tmp, &tr->tr_ail2_list, bd_ail_st_list) {
602 if (max_revokes == 0)
603 goto out_of_blocks;
604 if (!list_empty(&bd->bd_list))
605 continue;
606 gfs2_add_revoke(sdp, bd);
607 max_revokes--;
608 }
609 }
610out_of_blocks:
611 spin_unlock(&sdp->sd_ail_lock);
612 gfs2_log_unlock(sdp);
613
614 if (!sdp->sd_log_num_revoke) {
615 atomic_inc(&sdp->sd_log_blks_free);
616 if (!sdp->sd_log_blks_reserved)
617 atomic_inc(&sdp->sd_log_blks_free);
618 }
619}
620
621/**
622 * log_write_header - Get and initialize a journal header buffer
623 * @sdp: The GFS2 superblock
624 *
625 * Returns: the initialized log buffer descriptor
626 */
627
628static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
629{
630 struct gfs2_log_header *lh;
631 unsigned int tail;
632 u32 hash;
633 int rw = WRITE_FLUSH_FUA | REQ_META;
634 struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
635 lh = page_address(page);
636 clear_page(lh);
637
638 tail = current_tail(sdp);
639
640 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
641 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
642 lh->lh_header.__pad0 = cpu_to_be64(0);
643 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
644 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
645 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
646 lh->lh_flags = cpu_to_be32(flags);
647 lh->lh_tail = cpu_to_be32(tail);
648 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
649 hash = gfs2_disk_hash(page_address(page), sizeof(struct gfs2_log_header));
650 lh->lh_hash = cpu_to_be32(hash);
651
652 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
653 gfs2_ordered_wait(sdp);
654 log_flush_wait(sdp);
655 rw = WRITE_SYNC | REQ_META | REQ_PRIO;
656 }
657
658 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
659 gfs2_log_write_page(sdp, page);
660 gfs2_log_flush_bio(sdp, rw);
661 log_flush_wait(sdp);
662
663 if (sdp->sd_log_tail != tail)
664 log_pull_tail(sdp, tail);
665}
666
667/**
668 * gfs2_log_flush - flush incore transaction(s)
669 * @sdp: the filesystem
670 * @gl: The glock structure to flush. If NULL, flush the whole incore log
671 *
672 */
673
674void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
675{
676 struct gfs2_trans *tr;
677
678 down_write(&sdp->sd_log_flush_lock);
679
680 /* Log might have been flushed while we waited for the flush lock */
681 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
682 up_write(&sdp->sd_log_flush_lock);
683 return;
684 }
685 trace_gfs2_log_flush(sdp, 1);
686
687 sdp->sd_log_flush_head = sdp->sd_log_head;
688 sdp->sd_log_flush_wrapped = 0;
689 tr = sdp->sd_log_tr;
690 if (tr) {
691 sdp->sd_log_tr = NULL;
692 INIT_LIST_HEAD(&tr->tr_ail1_list);
693 INIT_LIST_HEAD(&tr->tr_ail2_list);
694 tr->tr_first = sdp->sd_log_flush_head;
695 }
696
697 gfs2_assert_withdraw(sdp,
698 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
699
700 gfs2_ordered_write(sdp);
701 lops_before_commit(sdp, tr);
702 gfs2_log_flush_bio(sdp, WRITE);
703
704 if (sdp->sd_log_head != sdp->sd_log_flush_head) {
705 log_flush_wait(sdp);
706 log_write_header(sdp, 0);
707 } else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
708 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
709 trace_gfs2_log_blocks(sdp, -1);
710 log_write_header(sdp, 0);
711 }
712 lops_after_commit(sdp, tr);
713
714 gfs2_log_lock(sdp);
715 sdp->sd_log_head = sdp->sd_log_flush_head;
716 sdp->sd_log_blks_reserved = 0;
717 sdp->sd_log_commited_revoke = 0;
718
719 spin_lock(&sdp->sd_ail_lock);
720 if (tr && !list_empty(&tr->tr_ail1_list)) {
721 list_add(&tr->tr_list, &sdp->sd_ail1_list);
722 tr = NULL;
723 }
724 spin_unlock(&sdp->sd_ail_lock);
725 gfs2_log_unlock(sdp);
726 trace_gfs2_log_flush(sdp, 0);
727 up_write(&sdp->sd_log_flush_lock);
728
729 kfree(tr);
730}
731
732/**
733 * gfs2_merge_trans - Merge a new transaction into a cached transaction
734 * @old: Original transaction to be expanded
735 * @new: New transaction to be merged
736 */
737
738static void gfs2_merge_trans(struct gfs2_trans *old, struct gfs2_trans *new)
739{
740 WARN_ON_ONCE(old->tr_attached != 1);
741
742 old->tr_num_buf_new += new->tr_num_buf_new;
743 old->tr_num_databuf_new += new->tr_num_databuf_new;
744 old->tr_num_buf_rm += new->tr_num_buf_rm;
745 old->tr_num_databuf_rm += new->tr_num_databuf_rm;
746 old->tr_num_revoke += new->tr_num_revoke;
747 old->tr_num_revoke_rm += new->tr_num_revoke_rm;
748
749 list_splice_tail_init(&new->tr_databuf, &old->tr_databuf);
750 list_splice_tail_init(&new->tr_buf, &old->tr_buf);
751}
752
753static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
754{
755 unsigned int reserved;
756 unsigned int unused;
757 unsigned int maxres;
758
759 gfs2_log_lock(sdp);
760
761 if (sdp->sd_log_tr) {
762 gfs2_merge_trans(sdp->sd_log_tr, tr);
763 } else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) {
764 gfs2_assert_withdraw(sdp, tr->tr_t_gh.gh_gl);
765 sdp->sd_log_tr = tr;
766 tr->tr_attached = 1;
767 }
768
769 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
770 reserved = calc_reserved(sdp);
771 maxres = sdp->sd_log_blks_reserved + tr->tr_reserved;
772 gfs2_assert_withdraw(sdp, maxres >= reserved);
773 unused = maxres - reserved;
774 atomic_add(unused, &sdp->sd_log_blks_free);
775 trace_gfs2_log_blocks(sdp, unused);
776 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
777 sdp->sd_jdesc->jd_blocks);
778 sdp->sd_log_blks_reserved = reserved;
779
780 gfs2_log_unlock(sdp);
781}
782
783/**
784 * gfs2_log_commit - Commit a transaction to the log
785 * @sdp: the filesystem
786 * @tr: the transaction
787 *
788 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
789 * or the total number of used blocks (pinned blocks plus AIL blocks)
790 * is greater than thresh2.
791 *
792 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
793 * journal size.
794 *
795 * Returns: errno
796 */
797
798void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
799{
800 log_refund(sdp, tr);
801
802 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
803 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
804 atomic_read(&sdp->sd_log_thresh2)))
805 wake_up(&sdp->sd_logd_waitq);
806}
807
808/**
809 * gfs2_log_shutdown - write a shutdown header into a journal
810 * @sdp: the filesystem
811 *
812 */
813
814void gfs2_log_shutdown(struct gfs2_sbd *sdp)
815{
816 down_write(&sdp->sd_log_flush_lock);
817
818 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
819 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
820 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
821
822 sdp->sd_log_flush_head = sdp->sd_log_head;
823 sdp->sd_log_flush_wrapped = 0;
824
825 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT);
826
827 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
828 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
829 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
830
831 sdp->sd_log_head = sdp->sd_log_flush_head;
832 sdp->sd_log_tail = sdp->sd_log_head;
833
834 up_write(&sdp->sd_log_flush_lock);
835}
836
837
838/**
839 * gfs2_meta_syncfs - sync all the buffers in a filesystem
840 * @sdp: the filesystem
841 *
842 */
843
844void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
845{
846 gfs2_log_flush(sdp, NULL);
847 for (;;) {
848 gfs2_ail1_start(sdp);
849 gfs2_ail1_wait(sdp);
850 if (gfs2_ail1_empty(sdp))
851 break;
852 }
853 gfs2_log_flush(sdp, NULL);
854}
855
856static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
857{
858 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1));
859}
860
861static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
862{
863 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
864 return used_blocks >= atomic_read(&sdp->sd_log_thresh2);
865}
866
867/**
868 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
869 * @sdp: Pointer to GFS2 superblock
870 *
871 * Also, periodically check to make sure that we're using the most recent
872 * journal index.
873 */
874
875int gfs2_logd(void *data)
876{
877 struct gfs2_sbd *sdp = data;
878 unsigned long t = 1;
879 DEFINE_WAIT(wait);
880
881 while (!kthread_should_stop()) {
882
883 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
884 gfs2_ail1_empty(sdp);
885 gfs2_log_flush(sdp, NULL);
886 }
887
888 if (gfs2_ail_flush_reqd(sdp)) {
889 gfs2_ail1_start(sdp);
890 gfs2_ail1_wait(sdp);
891 gfs2_ail1_empty(sdp);
892 gfs2_log_flush(sdp, NULL);
893 }
894
895 if (!gfs2_ail_flush_reqd(sdp))
896 wake_up(&sdp->sd_log_waitq);
897
898 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
899
900 try_to_freeze();
901
902 do {
903 prepare_to_wait(&sdp->sd_logd_waitq, &wait,
904 TASK_INTERRUPTIBLE);
905 if (!gfs2_ail_flush_reqd(sdp) &&
906 !gfs2_jrnl_flush_reqd(sdp) &&
907 !kthread_should_stop())
908 t = schedule_timeout(t);
909 } while(t && !gfs2_ail_flush_reqd(sdp) &&
910 !gfs2_jrnl_flush_reqd(sdp) &&
911 !kthread_should_stop());
912 finish_wait(&sdp->sd_logd_waitq, &wait);
913 }
914
915 return 0;
916}
917