[GFS2] Update copyright date to 2006
[linux-2.6.git] / fs / gfs2 / meta_io.c
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 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 <linux/mm.h>
16 #include <linux/pagemap.h>
17 #include <linux/writeback.h>
18 #include <linux/swap.h>
19 #include <linux/delay.h>
20 #include <linux/gfs2_ondisk.h>
21
22 #include "gfs2.h"
23 #include "lm_interface.h"
24 #include "incore.h"
25 #include "glock.h"
26 #include "glops.h"
27 #include "inode.h"
28 #include "log.h"
29 #include "lops.h"
30 #include "meta_io.h"
31 #include "rgrp.h"
32 #include "trans.h"
33 #include "util.h"
34
35 #define buffer_busy(bh) \
36 ((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock) | (1ul << BH_Pinned)))
37 #define buffer_in_io(bh) \
38 ((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock)))
39
40 static int aspace_get_block(struct inode *inode, sector_t lblock,
41                             struct buffer_head *bh_result, int create)
42 {
43         gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
44         return -EOPNOTSUPP;
45 }
46
47 static int gfs2_aspace_writepage(struct page *page,
48                                  struct writeback_control *wbc)
49 {
50         return block_write_full_page(page, aspace_get_block, wbc);
51 }
52
53 /**
54  * stuck_releasepage - We're stuck in gfs2_releasepage().  Print stuff out.
55  * @bh: the buffer we're stuck on
56  *
57  */
58
59 static void stuck_releasepage(struct buffer_head *bh)
60 {
61         struct inode *inode = bh->b_page->mapping->host;
62         struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
63         struct gfs2_bufdata *bd = bh->b_private;
64         struct gfs2_glock *gl;
65
66         fs_warn(sdp, "stuck in gfs2_releasepage() %p\n", inode);
67         fs_warn(sdp, "blkno = %llu, bh->b_count = %d\n",
68                 (uint64_t)bh->b_blocknr, atomic_read(&bh->b_count));
69         fs_warn(sdp, "pinned = %u\n", buffer_pinned(bh));
70         fs_warn(sdp, "bh->b_private = %s\n", (bd) ? "!NULL" : "NULL");
71
72         if (!bd)
73                 return;
74
75         gl = bd->bd_gl;
76
77         fs_warn(sdp, "gl = (%u, %llu)\n", 
78                 gl->gl_name.ln_type, gl->gl_name.ln_number);
79
80         fs_warn(sdp, "bd_list_tr = %s, bd_le.le_list = %s\n",
81                 (list_empty(&bd->bd_list_tr)) ? "no" : "yes",
82                 (list_empty(&bd->bd_le.le_list)) ? "no" : "yes");
83
84         if (gl->gl_ops == &gfs2_inode_glops) {
85                 struct gfs2_inode *ip = gl->gl_object;
86                 unsigned int x;
87
88                 if (!ip)
89                         return;
90
91                 fs_warn(sdp, "ip = %llu %llu\n",
92                         ip->i_num.no_formal_ino, ip->i_num.no_addr);
93                 fs_warn(sdp, "ip->i_count = %d, ip->i_vnode = %s\n",
94                         atomic_read(&ip->i_count),
95                         (ip->i_vnode) ? "!NULL" : "NULL");
96
97                 for (x = 0; x < GFS2_MAX_META_HEIGHT; x++)
98                         fs_warn(sdp, "ip->i_cache[%u] = %s\n",
99                                 x, (ip->i_cache[x]) ? "!NULL" : "NULL");
100         }
101 }
102
103 /**
104  * gfs2_aspace_releasepage - free the metadata associated with a page
105  * @page: the page that's being released
106  * @gfp_mask: passed from Linux VFS, ignored by us
107  *
108  * Call try_to_free_buffers() if the buffers in this page can be
109  * released.
110  *
111  * Returns: 0
112  */
113
114 static int gfs2_aspace_releasepage(struct page *page, gfp_t gfp_mask)
115 {
116         struct inode *aspace = page->mapping->host;
117         struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info;
118         struct buffer_head *bh, *head;
119         struct gfs2_bufdata *bd;
120         unsigned long t;
121
122         if (!page_has_buffers(page))
123                 goto out;
124
125         head = bh = page_buffers(page);
126         do {
127                 t = jiffies;
128
129                 while (atomic_read(&bh->b_count)) {
130                         if (atomic_read(&aspace->i_writecount)) {
131                                 if (time_after_eq(jiffies, t +
132                                     gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
133                                         stuck_releasepage(bh);
134                                         t = jiffies;
135                                 }
136
137                                 yield();
138                                 continue;
139                         }
140
141                         return 0;
142                 }
143
144                 gfs2_assert_warn(sdp, !buffer_pinned(bh));
145
146                 bd = bh->b_private;
147                 if (bd) {
148                         gfs2_assert_warn(sdp, bd->bd_bh == bh);
149                         gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
150                         gfs2_assert_warn(sdp, list_empty(&bd->bd_le.le_list));
151                         gfs2_assert_warn(sdp, !bd->bd_ail);
152                         kmem_cache_free(gfs2_bufdata_cachep, bd);
153                         bh->b_private = NULL;
154                 }
155
156                 bh = bh->b_this_page;
157         }
158         while (bh != head);
159
160  out:
161         return try_to_free_buffers(page);
162 }
163
164 static struct address_space_operations aspace_aops = {
165         .writepage = gfs2_aspace_writepage,
166         .releasepage = gfs2_aspace_releasepage,
167 };
168
169 /**
170  * gfs2_aspace_get - Create and initialize a struct inode structure
171  * @sdp: the filesystem the aspace is in
172  *
173  * Right now a struct inode is just a struct inode.  Maybe Linux
174  * will supply a more lightweight address space construct (that works)
175  * in the future.
176  *
177  * Make sure pages/buffers in this aspace aren't in high memory.
178  *
179  * Returns: the aspace
180  */
181
182 struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
183 {
184         struct inode *aspace;
185
186         aspace = new_inode(sdp->sd_vfs);
187         if (aspace) {
188                 mapping_set_gfp_mask(aspace->i_mapping, GFP_KERNEL);
189                 aspace->i_mapping->a_ops = &aspace_aops;
190                 aspace->i_size = ~0ULL;
191                 aspace->u.generic_ip = NULL;
192                 insert_inode_hash(aspace);
193         }
194         return aspace;
195 }
196
197 void gfs2_aspace_put(struct inode *aspace)
198 {
199         remove_inode_hash(aspace);
200         iput(aspace);
201 }
202
203 /**
204  * gfs2_ail1_start_one - Start I/O on a part of the AIL
205  * @sdp: the filesystem
206  * @tr: the part of the AIL
207  *
208  */
209
210 void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
211 {
212         struct gfs2_bufdata *bd, *s;
213         struct buffer_head *bh;
214         int retry;
215
216         BUG_ON(!spin_is_locked(&sdp->sd_log_lock));
217
218         do {
219                 retry = 0;
220
221                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
222                                                  bd_ail_st_list) {
223                         bh = bd->bd_bh;
224
225                         gfs2_assert(sdp, bd->bd_ail == ai);
226
227                         if (!buffer_busy(bh)) {
228                                 if (!buffer_uptodate(bh)) {
229                                         gfs2_log_unlock(sdp);
230                                         gfs2_io_error_bh(sdp, bh);
231                                         gfs2_log_lock(sdp);
232                                 }
233                                 list_move(&bd->bd_ail_st_list,
234                                           &ai->ai_ail2_list);
235                                 continue;
236                         }
237
238                         if (!buffer_dirty(bh))
239                                 continue;
240
241                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
242
243                         gfs2_log_unlock(sdp);
244                         wait_on_buffer(bh);
245                         ll_rw_block(WRITE, 1, &bh);
246                         gfs2_log_lock(sdp);
247
248                         retry = 1;
249                         break;
250                 }
251         } while (retry);
252 }
253
254 /**
255  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
256  * @sdp: the filesystem
257  * @ai: the AIL entry
258  *
259  */
260
261 int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
262 {
263         struct gfs2_bufdata *bd, *s;
264         struct buffer_head *bh;
265
266         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
267                                          bd_ail_st_list) {
268                 bh = bd->bd_bh;
269
270                 gfs2_assert(sdp, bd->bd_ail == ai);
271
272                 if (buffer_busy(bh)) {
273                         if (flags & DIO_ALL)
274                                 continue;
275                         else
276                                 break;
277                 }
278
279                 if (!buffer_uptodate(bh))
280                         gfs2_io_error_bh(sdp, bh);
281
282                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
283         }
284
285         return list_empty(&ai->ai_ail1_list);
286 }
287
288 /**
289  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
290  * @sdp: the filesystem
291  * @ai: the AIL entry
292  *
293  */
294
295 void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
296 {
297         struct list_head *head = &ai->ai_ail2_list;
298         struct gfs2_bufdata *bd;
299
300         while (!list_empty(head)) {
301                 bd = list_entry(head->prev, struct gfs2_bufdata,
302                                 bd_ail_st_list);
303                 gfs2_assert(sdp, bd->bd_ail == ai);
304                 bd->bd_ail = NULL;
305                 list_del(&bd->bd_ail_st_list);
306                 list_del(&bd->bd_ail_gl_list);
307                 atomic_dec(&bd->bd_gl->gl_ail_count);
308                 brelse(bd->bd_bh);
309         }
310 }
311
312 /**
313  * ail_empty_gl - remove all buffers for a given lock from the AIL
314  * @gl: the glock
315  *
316  * None of the buffers should be dirty, locked, or pinned.
317  */
318
319 void gfs2_ail_empty_gl(struct gfs2_glock *gl)
320 {
321         struct gfs2_sbd *sdp = gl->gl_sbd;
322         unsigned int blocks;
323         struct list_head *head = &gl->gl_ail_list;
324         struct gfs2_bufdata *bd;
325         struct buffer_head *bh;
326         uint64_t blkno;
327         int error;
328
329         blocks = atomic_read(&gl->gl_ail_count);
330         if (!blocks)
331                 return;
332
333         error = gfs2_trans_begin(sdp, 0, blocks);
334         if (gfs2_assert_withdraw(sdp, !error))
335                 return;
336
337         gfs2_log_lock(sdp);
338         while (!list_empty(head)) {
339                 bd = list_entry(head->next, struct gfs2_bufdata,
340                                 bd_ail_gl_list);
341                 bh = bd->bd_bh;
342                 blkno = bh->b_blocknr;
343                 gfs2_assert_withdraw(sdp, !buffer_busy(bh));
344
345                 bd->bd_ail = NULL;
346                 list_del(&bd->bd_ail_st_list);
347                 list_del(&bd->bd_ail_gl_list);
348                 atomic_dec(&gl->gl_ail_count);
349                 brelse(bh);
350                 gfs2_log_unlock(sdp);
351
352                 gfs2_trans_add_revoke(sdp, blkno);
353
354                 gfs2_log_lock(sdp);
355         }
356         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
357         gfs2_log_unlock(sdp);
358
359         gfs2_trans_end(sdp);
360         gfs2_log_flush(sdp, NULL);
361 }
362
363 /**
364  * gfs2_meta_inval - Invalidate all buffers associated with a glock
365  * @gl: the glock
366  *
367  */
368
369 void gfs2_meta_inval(struct gfs2_glock *gl)
370 {
371         struct gfs2_sbd *sdp = gl->gl_sbd;
372         struct inode *aspace = gl->gl_aspace;
373         struct address_space *mapping = gl->gl_aspace->i_mapping;
374
375         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
376
377         atomic_inc(&aspace->i_writecount);
378         truncate_inode_pages(mapping, 0);
379         atomic_dec(&aspace->i_writecount);
380
381         gfs2_assert_withdraw(sdp, !mapping->nrpages);
382 }
383
384 /**
385  * gfs2_meta_sync - Sync all buffers associated with a glock
386  * @gl: The glock
387  * @flags: DIO_START | DIO_WAIT
388  *
389  */
390
391 void gfs2_meta_sync(struct gfs2_glock *gl, int flags)
392 {
393         struct address_space *mapping = gl->gl_aspace->i_mapping;
394         int error = 0;
395
396         if (flags & DIO_START)
397                 filemap_fdatawrite(mapping);
398         if (!error && (flags & DIO_WAIT))
399                 error = filemap_fdatawait(mapping);
400
401         if (error)
402                 gfs2_io_error(gl->gl_sbd);
403 }
404
405 /**
406  * getbuf - Get a buffer with a given address space
407  * @sdp: the filesystem
408  * @aspace: the address space
409  * @blkno: the block number (filesystem scope)
410  * @create: 1 if the buffer should be created
411  *
412  * Returns: the buffer
413  */
414
415 static struct buffer_head *getbuf(struct gfs2_sbd *sdp, struct inode *aspace,
416                                   uint64_t blkno, int create)
417 {
418         struct page *page;
419         struct buffer_head *bh;
420         unsigned int shift;
421         unsigned long index;
422         unsigned int bufnum;
423
424         shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
425         index = blkno >> shift;             /* convert block to page */
426         bufnum = blkno - (index << shift);  /* block buf index within page */
427
428         if (create) {
429                 for (;;) {
430                         page = grab_cache_page(aspace->i_mapping, index);
431                         if (page)
432                                 break;
433                         yield();
434                 }
435         } else {
436                 page = find_lock_page(aspace->i_mapping, index);
437                 if (!page)
438                         return NULL;
439         }
440
441         if (!page_has_buffers(page))
442                 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
443
444         /* Locate header for our buffer within our page */
445         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
446                 /* Do nothing */;
447         get_bh(bh);
448
449         if (!buffer_mapped(bh))
450                 map_bh(bh, sdp->sd_vfs, blkno);
451
452         unlock_page(page);
453         mark_page_accessed(page);
454         page_cache_release(page);
455
456         return bh;
457 }
458
459 static void meta_prep_new(struct buffer_head *bh)
460 {
461         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
462
463         lock_buffer(bh);
464         clear_buffer_dirty(bh);
465         set_buffer_uptodate(bh);
466         unlock_buffer(bh);
467
468         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
469 }
470
471 /**
472  * gfs2_meta_new - Get a block
473  * @gl: The glock associated with this block
474  * @blkno: The block number
475  *
476  * Returns: The buffer
477  */
478
479 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, uint64_t blkno)
480 {
481         struct buffer_head *bh;
482         bh = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
483         meta_prep_new(bh);
484         return bh;
485 }
486
487 /**
488  * gfs2_meta_read - Read a block from disk
489  * @gl: The glock covering the block
490  * @blkno: The block number
491  * @flags: flags to gfs2_dreread()
492  * @bhp: the place where the buffer is returned (NULL on failure)
493  *
494  * Returns: errno
495  */
496
497 int gfs2_meta_read(struct gfs2_glock *gl, uint64_t blkno, int flags,
498                    struct buffer_head **bhp)
499 {
500         int error;
501
502         *bhp = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
503         error = gfs2_meta_reread(gl->gl_sbd, *bhp, flags);
504         if (error)
505                 brelse(*bhp);
506
507         return error;
508 }
509
510 /**
511  * gfs2_meta_reread - Reread a block from disk
512  * @sdp: the filesystem
513  * @bh: The block to read
514  * @flags: Flags that control the read
515  *
516  * Returns: errno
517  */
518
519 int gfs2_meta_reread(struct gfs2_sbd *sdp, struct buffer_head *bh, int flags)
520 {
521         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
522                 return -EIO;
523
524         if (flags & DIO_FORCE)
525                 clear_buffer_uptodate(bh);
526
527         if ((flags & DIO_START) && !buffer_uptodate(bh))
528                 ll_rw_block(READ, 1, &bh);
529
530         if (flags & DIO_WAIT) {
531                 wait_on_buffer(bh);
532
533                 if (!buffer_uptodate(bh)) {
534                         struct gfs2_trans *tr = current->journal_info;
535                         if (tr && tr->tr_touched)
536                                 gfs2_io_error_bh(sdp, bh);
537                         return -EIO;
538                 }
539                 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
540                         return -EIO;
541         }
542
543         return 0;
544 }
545
546 /**
547  * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
548  * @gl: the glock the buffer belongs to
549  * @bh: The buffer to be attached to
550  * @meta: Flag to indicate whether its metadata or not
551  */
552
553 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
554                          int meta)
555 {
556         struct gfs2_bufdata *bd;
557
558         if (meta)
559                 lock_page(bh->b_page);
560
561         if (bh->b_private) {
562                 if (meta)
563                         unlock_page(bh->b_page);
564                 return;
565         }
566
567         bd = kmem_cache_alloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL),
568         memset(bd, 0, sizeof(struct gfs2_bufdata));
569
570         bd->bd_bh = bh;
571         bd->bd_gl = gl;
572
573         INIT_LIST_HEAD(&bd->bd_list_tr);
574         if (meta) {
575                 lops_init_le(&bd->bd_le, &gfs2_buf_lops);
576         } else {
577                 lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
578                 get_bh(bh);
579         }
580         bh->b_private = bd;
581
582         if (meta)
583                 unlock_page(bh->b_page);
584 }
585
586 /**
587  * gfs2_pin - Pin a buffer in memory
588  * @sdp: the filesystem the buffer belongs to
589  * @bh: The buffer to be pinned
590  *
591  */
592
593 void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
594 {
595         struct gfs2_bufdata *bd = bh->b_private;
596
597         gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
598
599         if (test_set_buffer_pinned(bh))
600                 gfs2_assert_withdraw(sdp, 0);
601
602         wait_on_buffer(bh);
603
604         /* If this buffer is in the AIL and it has already been written
605            to in-place disk block, remove it from the AIL. */
606
607         gfs2_log_lock(sdp);
608         if (bd->bd_ail && !buffer_in_io(bh))
609                 list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
610         gfs2_log_unlock(sdp);
611
612         clear_buffer_dirty(bh);
613         wait_on_buffer(bh);
614
615         if (!buffer_uptodate(bh))
616                 gfs2_io_error_bh(sdp, bh);
617
618         get_bh(bh);
619 }
620
621 /**
622  * gfs2_unpin - Unpin a buffer
623  * @sdp: the filesystem the buffer belongs to
624  * @bh: The buffer to unpin
625  * @ai:
626  *
627  */
628
629 void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
630                 struct gfs2_ail *ai)
631 {
632         struct gfs2_bufdata *bd = bh->b_private;
633
634         gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
635
636         if (!buffer_pinned(bh))
637                 gfs2_assert_withdraw(sdp, 0);
638
639         mark_buffer_dirty(bh);
640         clear_buffer_pinned(bh);
641
642         gfs2_log_lock(sdp);
643         if (bd->bd_ail) {
644                 list_del(&bd->bd_ail_st_list);
645                 brelse(bh);
646         } else {
647                 struct gfs2_glock *gl = bd->bd_gl;
648                 list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
649                 atomic_inc(&gl->gl_ail_count);
650         }
651         bd->bd_ail = ai;
652         list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
653         gfs2_log_unlock(sdp);
654 }
655
656 /**
657  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
658  * @ip: the inode who owns the buffers
659  * @bstart: the first buffer in the run
660  * @blen: the number of buffers in the run
661  *
662  */
663
664 void gfs2_meta_wipe(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
665 {
666         struct gfs2_sbd *sdp = ip->i_sbd;
667         struct inode *aspace = ip->i_gl->gl_aspace;
668         struct buffer_head *bh;
669
670         while (blen) {
671                 bh = getbuf(sdp, aspace, bstart, NO_CREATE);
672                 if (bh) {
673                         struct gfs2_bufdata *bd = bh->b_private;
674
675                         if (test_clear_buffer_pinned(bh)) {
676                                 struct gfs2_trans *tr = current->journal_info;
677                                 gfs2_log_lock(sdp);
678                                 list_del_init(&bd->bd_le.le_list);
679                                 gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
680                                 sdp->sd_log_num_buf--;
681                                 gfs2_log_unlock(sdp);
682                                 tr->tr_num_buf_rm++;
683                                 brelse(bh);
684                         }
685                         if (bd) {
686                                 gfs2_log_lock(sdp);
687                                 if (bd->bd_ail) {
688                                         uint64_t blkno = bh->b_blocknr;
689                                         bd->bd_ail = NULL;
690                                         list_del(&bd->bd_ail_st_list);
691                                         list_del(&bd->bd_ail_gl_list);
692                                         atomic_dec(&bd->bd_gl->gl_ail_count);
693                                         brelse(bh);
694                                         gfs2_log_unlock(sdp);
695                                         gfs2_trans_add_revoke(sdp, blkno);
696                                 } else
697                                         gfs2_log_unlock(sdp);
698                         }
699
700                         lock_buffer(bh);
701                         clear_buffer_dirty(bh);
702                         clear_buffer_uptodate(bh);
703                         unlock_buffer(bh);
704
705                         brelse(bh);
706                 }
707
708                 bstart++;
709                 blen--;
710         }
711 }
712
713 /**
714  * gfs2_meta_cache_flush - get rid of any references on buffers for this inode
715  * @ip: The GFS2 inode
716  *
717  * This releases buffers that are in the most-recently-used array of
718  * blocks used for indirect block addressing for this inode.
719  */
720
721 void gfs2_meta_cache_flush(struct gfs2_inode *ip)
722 {
723         struct buffer_head **bh_slot;
724         unsigned int x;
725
726         spin_lock(&ip->i_spin);
727
728         for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) {
729                 bh_slot = &ip->i_cache[x];
730                 if (!*bh_slot)
731                         break;
732                 brelse(*bh_slot);
733                 *bh_slot = NULL;
734         }
735
736         spin_unlock(&ip->i_spin);
737 }
738
739 /**
740  * gfs2_meta_indirect_buffer - Get a metadata buffer
741  * @ip: The GFS2 inode
742  * @height: The level of this buf in the metadata (indir addr) tree (if any)
743  * @num: The block number (device relative) of the buffer
744  * @new: Non-zero if we may create a new buffer
745  * @bhp: the buffer is returned here
746  *
747  * Try to use the gfs2_inode's MRU metadata tree cache.
748  *
749  * Returns: errno
750  */
751
752 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, uint64_t num,
753                               int new, struct buffer_head **bhp)
754 {
755         struct buffer_head *bh, **bh_slot = ip->i_cache + height;
756         int error;
757
758         spin_lock(&ip->i_spin);
759         bh = *bh_slot;
760         if (bh) {
761                 if (bh->b_blocknr == num)
762                         get_bh(bh);
763                 else
764                         bh = NULL;
765         }
766         spin_unlock(&ip->i_spin);
767
768         if (bh) {
769                 if (new)
770                         meta_prep_new(bh);
771                 else {
772                         error = gfs2_meta_reread(ip->i_sbd, bh,
773                                                  DIO_START | DIO_WAIT);
774                         if (error) {
775                                 brelse(bh);
776                                 return error;
777                         }
778                 }
779         } else {
780                 if (new)
781                         bh = gfs2_meta_new(ip->i_gl, num);
782                 else {
783                         error = gfs2_meta_read(ip->i_gl, num,
784                                                DIO_START | DIO_WAIT, &bh);
785                         if (error)
786                                 return error;
787                 }
788
789                 spin_lock(&ip->i_spin);
790                 if (*bh_slot != bh) {
791                         brelse(*bh_slot);
792                         *bh_slot = bh;
793                         get_bh(bh);
794                 }
795                 spin_unlock(&ip->i_spin);
796         }
797
798         if (new) {
799                 if (gfs2_assert_warn(ip->i_sbd, height)) {
800                         brelse(bh);
801                         return -EIO;
802                 }
803                 gfs2_trans_add_bh(ip->i_gl, bh, 1);
804                 gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
805                 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
806
807         } else if (gfs2_metatype_check(ip->i_sbd, bh,
808                              (height) ? GFS2_METATYPE_IN : GFS2_METATYPE_DI)) {
809                 brelse(bh);
810                 return -EIO;
811         }
812
813         *bhp = bh;
814
815         return 0;
816 }
817
818 /**
819  * gfs2_meta_ra - start readahead on an extent of a file
820  * @gl: the glock the blocks belong to
821  * @dblock: the starting disk block
822  * @extlen: the number of blocks in the extent
823  *
824  */
825
826 void gfs2_meta_ra(struct gfs2_glock *gl, uint64_t dblock, uint32_t extlen)
827 {
828         struct gfs2_sbd *sdp = gl->gl_sbd;
829         struct inode *aspace = gl->gl_aspace;
830         struct buffer_head *first_bh, *bh;
831         uint32_t max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
832                           sdp->sd_sb.sb_bsize_shift;
833         int error;
834
835         if (!extlen || !max_ra)
836                 return;
837         if (extlen > max_ra)
838                 extlen = max_ra;
839
840         first_bh = getbuf(sdp, aspace, dblock, CREATE);
841
842         if (buffer_uptodate(first_bh))
843                 goto out;
844         if (!buffer_locked(first_bh)) {
845                 error = gfs2_meta_reread(sdp, first_bh, DIO_START);
846                 if (error)
847                         goto out;
848         }
849
850         dblock++;
851         extlen--;
852
853         while (extlen) {
854                 bh = getbuf(sdp, aspace, dblock, CREATE);
855
856                 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
857                         error = gfs2_meta_reread(sdp, bh, DIO_START);
858                         brelse(bh);
859                         if (error)
860                                 goto out;
861                 } else
862                         brelse(bh);
863
864                 dblock++;
865                 extlen--;
866
867                 if (buffer_uptodate(first_bh))
868                         break;
869         }
870
871  out:
872         brelse(first_bh);
873 }
874
875 /**
876  * gfs2_meta_syncfs - sync all the buffers in a filesystem
877  * @sdp: the filesystem
878  *
879  */
880
881 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
882 {
883         gfs2_log_flush(sdp, NULL);
884         for (;;) {
885                 gfs2_ail1_start(sdp, DIO_ALL);
886                 if (gfs2_ail1_empty(sdp, DIO_ALL))
887                         break;
888                 msleep(10);
889         }
890 }
891