[GFS2] Shrink gfs2_inode (4) - di_uid/di_gid
[linux-2.6.git] / fs / gfs2 / ops_address.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 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/pagemap.h>
16 #include <linux/pagevec.h>
17 #include <linux/mpage.h>
18 #include <linux/fs.h>
19 #include <linux/gfs2_ondisk.h>
20 #include <linux/lm_interface.h>
21
22 #include "gfs2.h"
23 #include "incore.h"
24 #include "bmap.h"
25 #include "glock.h"
26 #include "inode.h"
27 #include "log.h"
28 #include "meta_io.h"
29 #include "ops_address.h"
30 #include "quota.h"
31 #include "trans.h"
32 #include "rgrp.h"
33 #include "ops_file.h"
34 #include "util.h"
35 #include "glops.h"
36
37
38 static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
39                                    unsigned int from, unsigned int to)
40 {
41         struct buffer_head *head = page_buffers(page);
42         unsigned int bsize = head->b_size;
43         struct buffer_head *bh;
44         unsigned int start, end;
45
46         for (bh = head, start = 0; bh != head || !start;
47              bh = bh->b_this_page, start = end) {
48                 end = start + bsize;
49                 if (end <= from || start >= to)
50                         continue;
51                 gfs2_trans_add_bh(ip->i_gl, bh, 0);
52         }
53 }
54
55 /**
56  * gfs2_get_block - Fills in a buffer head with details about a block
57  * @inode: The inode
58  * @lblock: The block number to look up
59  * @bh_result: The buffer head to return the result in
60  * @create: Non-zero if we may add block to the file
61  *
62  * Returns: errno
63  */
64
65 int gfs2_get_block(struct inode *inode, sector_t lblock,
66                    struct buffer_head *bh_result, int create)
67 {
68         return gfs2_block_map(inode, lblock, create, bh_result);
69 }
70
71 /**
72  * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
73  * @inode: The inode
74  * @lblock: The block number to look up
75  * @bh_result: The buffer head to return the result in
76  * @create: Non-zero if we may add block to the file
77  *
78  * Returns: errno
79  */
80
81 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
82                                   struct buffer_head *bh_result, int create)
83 {
84         int error;
85
86         error = gfs2_block_map(inode, lblock, 0, bh_result);
87         if (error)
88                 return error;
89         if (bh_result->b_blocknr == 0)
90                 return -EIO;
91         return 0;
92 }
93
94 static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
95                                  struct buffer_head *bh_result, int create)
96 {
97         return gfs2_block_map(inode, lblock, 0, bh_result);
98 }
99
100 /**
101  * gfs2_writepage - Write complete page
102  * @page: Page to write
103  *
104  * Returns: errno
105  *
106  * Some of this is copied from block_write_full_page() although we still
107  * call it to do most of the work.
108  */
109
110 static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
111 {
112         struct inode *inode = page->mapping->host;
113         struct gfs2_inode *ip = GFS2_I(inode);
114         struct gfs2_sbd *sdp = GFS2_SB(inode);
115         loff_t i_size = i_size_read(inode);
116         pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
117         unsigned offset;
118         int error;
119         int done_trans = 0;
120
121         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
122                 unlock_page(page);
123                 return -EIO;
124         }
125         if (current->journal_info)
126                 goto out_ignore;
127
128         /* Is the page fully outside i_size? (truncate in progress) */
129         offset = i_size & (PAGE_CACHE_SIZE-1);
130         if (page->index > end_index || (page->index == end_index && !offset)) {
131                 page->mapping->a_ops->invalidatepage(page, 0);
132                 unlock_page(page);
133                 return 0; /* don't care */
134         }
135
136         if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) {
137                 error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
138                 if (error)
139                         goto out_ignore;
140                 if (!page_has_buffers(page)) {
141                         create_empty_buffers(page, inode->i_sb->s_blocksize,
142                                              (1 << BH_Dirty)|(1 << BH_Uptodate));
143                 }
144                 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
145                 done_trans = 1;
146         }
147         error = block_write_full_page(page, gfs2_get_block_noalloc, wbc);
148         if (done_trans)
149                 gfs2_trans_end(sdp);
150         gfs2_meta_cache_flush(ip);
151         return error;
152
153 out_ignore:
154         redirty_page_for_writepage(wbc, page);
155         unlock_page(page);
156         return 0;
157 }
158
159 static int zero_readpage(struct page *page)
160 {
161         void *kaddr;
162
163         kaddr = kmap_atomic(page, KM_USER0);
164         memset(kaddr, 0, PAGE_CACHE_SIZE);
165         kunmap_atomic(kaddr, KM_USER0);
166
167         SetPageUptodate(page);
168
169         return 0;
170 }
171
172 /**
173  * stuffed_readpage - Fill in a Linux page with stuffed file data
174  * @ip: the inode
175  * @page: the page
176  *
177  * Returns: errno
178  */
179
180 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
181 {
182         struct buffer_head *dibh;
183         void *kaddr;
184         int error;
185
186         /* Only the first page of a stuffed file might contain data */
187         if (unlikely(page->index))
188                 return zero_readpage(page);
189
190         error = gfs2_meta_inode_buffer(ip, &dibh);
191         if (error)
192                 return error;
193
194         kaddr = kmap_atomic(page, KM_USER0);
195         memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode),
196                ip->i_di.di_size);
197         memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size);
198         kunmap_atomic(kaddr, KM_USER0);
199
200         brelse(dibh);
201
202         SetPageUptodate(page);
203
204         return 0;
205 }
206
207
208 /**
209  * gfs2_readpage - readpage with locking
210  * @file: The file to read a page for. N.B. This may be NULL if we are
211  * reading an internal file.
212  * @page: The page to read
213  *
214  * Returns: errno
215  */
216
217 static int gfs2_readpage(struct file *file, struct page *page)
218 {
219         struct gfs2_inode *ip = GFS2_I(page->mapping->host);
220         struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
221         struct gfs2_file *gf = NULL;
222         struct gfs2_holder gh;
223         int error;
224         int do_unlock = 0;
225
226         if (likely(file != &gfs2_internal_file_sentinel)) {
227                 if (file) {
228                         gf = file->private_data;
229                         if (test_bit(GFF_EXLOCK, &gf->f_flags))
230                                 /* gfs2_sharewrite_nopage has grabbed the ip->i_gl already */
231                                 goto skip_lock;
232                 }
233                 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|GL_AOP, &gh);
234                 do_unlock = 1;
235                 error = gfs2_glock_nq_m_atime(1, &gh);
236                 if (unlikely(error))
237                         goto out_unlock;
238         }
239
240 skip_lock:
241         if (gfs2_is_stuffed(ip)) {
242                 error = stuffed_readpage(ip, page);
243                 unlock_page(page);
244         } else
245                 error = mpage_readpage(page, gfs2_get_block);
246
247         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
248                 error = -EIO;
249
250         if (do_unlock) {
251                 gfs2_glock_dq_m(1, &gh);
252                 gfs2_holder_uninit(&gh);
253         }
254 out:
255         return error;
256 out_unlock:
257         unlock_page(page);
258         if (do_unlock)
259                 gfs2_holder_uninit(&gh);
260         goto out;
261 }
262
263 /**
264  * gfs2_readpages - Read a bunch of pages at once
265  *
266  * Some notes:
267  * 1. This is only for readahead, so we can simply ignore any things
268  *    which are slightly inconvenient (such as locking conflicts between
269  *    the page lock and the glock) and return having done no I/O. Its
270  *    obviously not something we'd want to do on too regular a basis.
271  *    Any I/O we ignore at this time will be done via readpage later.
272  * 2. We have to handle stuffed files here too.
273  * 3. mpage_readpages() does most of the heavy lifting in the common case.
274  * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places.
275  * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as
276  *    well as read-ahead.
277  */
278 static int gfs2_readpages(struct file *file, struct address_space *mapping,
279                           struct list_head *pages, unsigned nr_pages)
280 {
281         struct inode *inode = mapping->host;
282         struct gfs2_inode *ip = GFS2_I(inode);
283         struct gfs2_sbd *sdp = GFS2_SB(inode);
284         struct gfs2_holder gh;
285         unsigned page_idx;
286         int ret;
287         int do_unlock = 0;
288
289         if (likely(file != &gfs2_internal_file_sentinel)) {
290                 if (file) {
291                         struct gfs2_file *gf = file->private_data;
292                         if (test_bit(GFF_EXLOCK, &gf->f_flags))
293                                 goto skip_lock;
294                 }
295                 gfs2_holder_init(ip->i_gl, LM_ST_SHARED,
296                                  LM_FLAG_TRY_1CB|GL_ATIME|GL_AOP, &gh);
297                 do_unlock = 1;
298                 ret = gfs2_glock_nq_m_atime(1, &gh);
299                 if (ret == GLR_TRYFAILED)
300                         goto out_noerror;
301                 if (unlikely(ret))
302                         goto out_unlock;
303         }
304 skip_lock:
305         if (gfs2_is_stuffed(ip)) {
306                 struct pagevec lru_pvec;
307                 pagevec_init(&lru_pvec, 0);
308                 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
309                         struct page *page = list_entry(pages->prev, struct page, lru);
310                         prefetchw(&page->flags);
311                         list_del(&page->lru);
312                         if (!add_to_page_cache(page, mapping,
313                                                page->index, GFP_KERNEL)) {
314                                 ret = stuffed_readpage(ip, page);
315                                 unlock_page(page);
316                                 if (!pagevec_add(&lru_pvec, page))
317                                          __pagevec_lru_add(&lru_pvec);
318                         } else {
319                                 page_cache_release(page);
320                         }
321                 }
322                 pagevec_lru_add(&lru_pvec);
323                 ret = 0;
324         } else {
325                 /* What we really want to do .... */
326                 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block);
327         }
328
329         if (do_unlock) {
330                 gfs2_glock_dq_m(1, &gh);
331                 gfs2_holder_uninit(&gh);
332         }
333 out:
334         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
335                 ret = -EIO;
336         return ret;
337 out_noerror:
338         ret = 0;
339 out_unlock:
340         if (do_unlock)
341                 gfs2_holder_uninit(&gh);
342         goto out;
343 }
344
345 /**
346  * gfs2_prepare_write - Prepare to write a page to a file
347  * @file: The file to write to
348  * @page: The page which is to be prepared for writing
349  * @from: From (byte range within page)
350  * @to: To (byte range within page)
351  *
352  * Returns: errno
353  */
354
355 static int gfs2_prepare_write(struct file *file, struct page *page,
356                               unsigned from, unsigned to)
357 {
358         struct gfs2_inode *ip = GFS2_I(page->mapping->host);
359         struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
360         unsigned int data_blocks, ind_blocks, rblocks;
361         int alloc_required;
362         int error = 0;
363         loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
364         loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
365         struct gfs2_alloc *al;
366         unsigned int write_len = to - from;
367
368
369         gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|GL_AOP, &ip->i_gh);
370         error = gfs2_glock_nq_m_atime(1, &ip->i_gh);
371         if (error)
372                 goto out_uninit;
373
374         gfs2_write_calc_reserv(ip, write_len, &data_blocks, &ind_blocks);
375
376         error = gfs2_write_alloc_required(ip, pos, write_len, &alloc_required);
377         if (error)
378                 goto out_unlock;
379
380
381         ip->i_alloc.al_requested = 0;
382         if (alloc_required) {
383                 al = gfs2_alloc_get(ip);
384
385                 error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
386                 if (error)
387                         goto out_alloc_put;
388
389                 error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid);
390                 if (error)
391                         goto out_qunlock;
392
393                 al->al_requested = data_blocks + ind_blocks;
394                 error = gfs2_inplace_reserve(ip);
395                 if (error)
396                         goto out_qunlock;
397         }
398
399         rblocks = RES_DINODE + ind_blocks;
400         if (gfs2_is_jdata(ip))
401                 rblocks += data_blocks ? data_blocks : 1;
402         if (ind_blocks || data_blocks)
403                 rblocks += RES_STATFS + RES_QUOTA;
404
405         error = gfs2_trans_begin(sdp, rblocks, 0);
406         if (error)
407                 goto out;
408
409         if (gfs2_is_stuffed(ip)) {
410                 if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
411                         error = gfs2_unstuff_dinode(ip, page);
412                         if (error == 0)
413                                 goto prepare_write;
414                 } else if (!PageUptodate(page))
415                         error = stuffed_readpage(ip, page);
416                 goto out;
417         }
418
419 prepare_write:
420         error = block_prepare_write(page, from, to, gfs2_get_block);
421
422 out:
423         if (error) {
424                 gfs2_trans_end(sdp);
425                 if (alloc_required) {
426                         gfs2_inplace_release(ip);
427 out_qunlock:
428                         gfs2_quota_unlock(ip);
429 out_alloc_put:
430                         gfs2_alloc_put(ip);
431                 }
432 out_unlock:
433                 gfs2_glock_dq_m(1, &ip->i_gh);
434 out_uninit:
435                 gfs2_holder_uninit(&ip->i_gh);
436         }
437
438         return error;
439 }
440
441 /**
442  * gfs2_commit_write - Commit write to a file
443  * @file: The file to write to
444  * @page: The page containing the data
445  * @from: From (byte range within page)
446  * @to: To (byte range within page)
447  *
448  * Returns: errno
449  */
450
451 static int gfs2_commit_write(struct file *file, struct page *page,
452                              unsigned from, unsigned to)
453 {
454         struct inode *inode = page->mapping->host;
455         struct gfs2_inode *ip = GFS2_I(inode);
456         struct gfs2_sbd *sdp = GFS2_SB(inode);
457         int error = -EOPNOTSUPP;
458         struct buffer_head *dibh;
459         struct gfs2_alloc *al = &ip->i_alloc;
460         struct gfs2_dinode *di;
461
462         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
463                 goto fail_nounlock;
464
465         error = gfs2_meta_inode_buffer(ip, &dibh);
466         if (error)
467                 goto fail_endtrans;
468
469         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
470         di = (struct gfs2_dinode *)dibh->b_data;
471
472         if (gfs2_is_stuffed(ip)) {
473                 u64 file_size;
474                 void *kaddr;
475
476                 file_size = ((u64)page->index << PAGE_CACHE_SHIFT) + to;
477
478                 kaddr = kmap_atomic(page, KM_USER0);
479                 memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
480                        kaddr + from, to - from);
481                 kunmap_atomic(kaddr, KM_USER0);
482
483                 SetPageUptodate(page);
484
485                 if (inode->i_size < file_size)
486                         i_size_write(inode, file_size);
487         } else {
488                 if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED ||
489                     gfs2_is_jdata(ip))
490                         gfs2_page_add_databufs(ip, page, from, to);
491                 error = generic_commit_write(file, page, from, to);
492                 if (error)
493                         goto fail;
494         }
495
496         if (ip->i_di.di_size < inode->i_size) {
497                 ip->i_di.di_size = inode->i_size;
498                 di->di_size = cpu_to_be64(inode->i_size);
499         }
500
501         di->di_atime = cpu_to_be64(inode->i_atime.tv_sec);
502         di->di_mtime = cpu_to_be64(inode->i_mtime.tv_sec);
503         di->di_ctime = cpu_to_be64(inode->i_ctime.tv_sec);
504
505         brelse(dibh);
506         gfs2_trans_end(sdp);
507         if (al->al_requested) {
508                 gfs2_inplace_release(ip);
509                 gfs2_quota_unlock(ip);
510                 gfs2_alloc_put(ip);
511         }
512         gfs2_glock_dq_m(1, &ip->i_gh);
513         gfs2_holder_uninit(&ip->i_gh);
514         return 0;
515
516 fail:
517         brelse(dibh);
518 fail_endtrans:
519         gfs2_trans_end(sdp);
520         if (al->al_requested) {
521                 gfs2_inplace_release(ip);
522                 gfs2_quota_unlock(ip);
523                 gfs2_alloc_put(ip);
524         }
525         gfs2_glock_dq_m(1, &ip->i_gh);
526         gfs2_holder_uninit(&ip->i_gh);
527 fail_nounlock:
528         ClearPageUptodate(page);
529         return error;
530 }
531
532 /**
533  * gfs2_bmap - Block map function
534  * @mapping: Address space info
535  * @lblock: The block to map
536  *
537  * Returns: The disk address for the block or 0 on hole or error
538  */
539
540 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
541 {
542         struct gfs2_inode *ip = GFS2_I(mapping->host);
543         struct gfs2_holder i_gh;
544         sector_t dblock = 0;
545         int error;
546
547         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
548         if (error)
549                 return 0;
550
551         if (!gfs2_is_stuffed(ip))
552                 dblock = generic_block_bmap(mapping, lblock, gfs2_get_block);
553
554         gfs2_glock_dq_uninit(&i_gh);
555
556         return dblock;
557 }
558
559 static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
560 {
561         struct gfs2_bufdata *bd;
562
563         gfs2_log_lock(sdp);
564         bd = bh->b_private;
565         if (bd) {
566                 bd->bd_bh = NULL;
567                 bh->b_private = NULL;
568         }
569         gfs2_log_unlock(sdp);
570
571         lock_buffer(bh);
572         clear_buffer_dirty(bh);
573         bh->b_bdev = NULL;
574         clear_buffer_mapped(bh);
575         clear_buffer_req(bh);
576         clear_buffer_new(bh);
577         clear_buffer_delay(bh);
578         unlock_buffer(bh);
579 }
580
581 static void gfs2_invalidatepage(struct page *page, unsigned long offset)
582 {
583         struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
584         struct buffer_head *head, *bh, *next;
585         unsigned int curr_off = 0;
586
587         BUG_ON(!PageLocked(page));
588         if (!page_has_buffers(page))
589                 return;
590
591         bh = head = page_buffers(page);
592         do {
593                 unsigned int next_off = curr_off + bh->b_size;
594                 next = bh->b_this_page;
595
596                 if (offset <= curr_off)
597                         discard_buffer(sdp, bh);
598
599                 curr_off = next_off;
600                 bh = next;
601         } while (bh != head);
602
603         if (!offset)
604                 try_to_release_page(page, 0);
605
606         return;
607 }
608
609 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
610                               const struct iovec *iov, loff_t offset,
611                               unsigned long nr_segs)
612 {
613         struct file *file = iocb->ki_filp;
614         struct inode *inode = file->f_mapping->host;
615         struct gfs2_inode *ip = GFS2_I(inode);
616         struct gfs2_holder gh;
617         int rv;
618
619         if (rw == READ)
620                 mutex_lock(&inode->i_mutex);
621         /*
622          * Shared lock, even if its a write, since we do no allocation
623          * on this path. All we need change is atime.
624          */
625         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
626         rv = gfs2_glock_nq_m_atime(1, &gh);
627         if (rv)
628                 goto out;
629
630         if (offset > i_size_read(inode))
631                 goto out;
632
633         /*
634          * Should we return an error here? I can't see that O_DIRECT for
635          * a journaled file makes any sense. For now we'll silently fall
636          * back to buffered I/O, likewise we do the same for stuffed
637          * files since they are (a) small and (b) unaligned.
638          */
639         if (gfs2_is_jdata(ip))
640                 goto out;
641
642         if (gfs2_is_stuffed(ip))
643                 goto out;
644
645         rv = blockdev_direct_IO_own_locking(rw, iocb, inode,
646                                             inode->i_sb->s_bdev,
647                                             iov, offset, nr_segs,
648                                             gfs2_get_block_direct, NULL);
649 out:
650         gfs2_glock_dq_m(1, &gh);
651         gfs2_holder_uninit(&gh);
652         if (rw == READ)
653                 mutex_unlock(&inode->i_mutex);
654
655         return rv;
656 }
657
658 /**
659  * stuck_releasepage - We're stuck in gfs2_releasepage().  Print stuff out.
660  * @bh: the buffer we're stuck on
661  *
662  */
663
664 static void stuck_releasepage(struct buffer_head *bh)
665 {
666         struct inode *inode = bh->b_page->mapping->host;
667         struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
668         struct gfs2_bufdata *bd = bh->b_private;
669         struct gfs2_glock *gl;
670 static unsigned limit = 0;
671
672         if (limit > 3)
673                 return;
674         limit++;
675
676         fs_warn(sdp, "stuck in gfs2_releasepage() %p\n", inode);
677         fs_warn(sdp, "blkno = %llu, bh->b_count = %d\n",
678                 (unsigned long long)bh->b_blocknr, atomic_read(&bh->b_count));
679         fs_warn(sdp, "pinned = %u\n", buffer_pinned(bh));
680         fs_warn(sdp, "bh->b_private = %s\n", (bd) ? "!NULL" : "NULL");
681
682         if (!bd)
683                 return;
684
685         gl = bd->bd_gl;
686
687         fs_warn(sdp, "gl = (%u, %llu)\n",
688                 gl->gl_name.ln_type, (unsigned long long)gl->gl_name.ln_number);
689
690         fs_warn(sdp, "bd_list_tr = %s, bd_le.le_list = %s\n",
691                 (list_empty(&bd->bd_list_tr)) ? "no" : "yes",
692                 (list_empty(&bd->bd_le.le_list)) ? "no" : "yes");
693
694         if (gl->gl_ops == &gfs2_inode_glops) {
695                 struct gfs2_inode *ip = gl->gl_object;
696                 unsigned int x;
697
698                 if (!ip)
699                         return;
700
701                 fs_warn(sdp, "ip = %llu %llu\n",
702                         (unsigned long long)ip->i_num.no_formal_ino,
703                         (unsigned long long)ip->i_num.no_addr);
704
705                 for (x = 0; x < GFS2_MAX_META_HEIGHT; x++)
706                         fs_warn(sdp, "ip->i_cache[%u] = %s\n",
707                                 x, (ip->i_cache[x]) ? "!NULL" : "NULL");
708         }
709 }
710
711 /**
712  * gfs2_releasepage - free the metadata associated with a page
713  * @page: the page that's being released
714  * @gfp_mask: passed from Linux VFS, ignored by us
715  *
716  * Call try_to_free_buffers() if the buffers in this page can be
717  * released.
718  *
719  * Returns: 0
720  */
721
722 int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
723 {
724         struct inode *aspace = page->mapping->host;
725         struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info;
726         struct buffer_head *bh, *head;
727         struct gfs2_bufdata *bd;
728         unsigned long t = jiffies + gfs2_tune_get(sdp, gt_stall_secs) * HZ;
729
730         if (!page_has_buffers(page))
731                 goto out;
732
733         head = bh = page_buffers(page);
734         do {
735                 while (atomic_read(&bh->b_count)) {
736                         if (!atomic_read(&aspace->i_writecount))
737                                 return 0;
738
739                         if (time_after_eq(jiffies, t)) {
740                                 stuck_releasepage(bh);
741                                 /* should we withdraw here? */
742                                 return 0;
743                         }
744
745                         yield();
746                 }
747
748                 gfs2_assert_warn(sdp, !buffer_pinned(bh));
749                 gfs2_assert_warn(sdp, !buffer_dirty(bh));
750
751                 gfs2_log_lock(sdp);
752                 bd = bh->b_private;
753                 if (bd) {
754                         gfs2_assert_warn(sdp, bd->bd_bh == bh);
755                         gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
756                         gfs2_assert_warn(sdp, !bd->bd_ail);
757                         bd->bd_bh = NULL;
758                         if (!list_empty(&bd->bd_le.le_list))
759                                 bd = NULL;
760                         bh->b_private = NULL;
761                 }
762                 gfs2_log_unlock(sdp);
763                 if (bd)
764                         kmem_cache_free(gfs2_bufdata_cachep, bd);
765
766                 bh = bh->b_this_page;
767         } while (bh != head);
768
769 out:
770         return try_to_free_buffers(page);
771 }
772
773 const struct address_space_operations gfs2_file_aops = {
774         .writepage = gfs2_writepage,
775         .readpage = gfs2_readpage,
776         .readpages = gfs2_readpages,
777         .sync_page = block_sync_page,
778         .prepare_write = gfs2_prepare_write,
779         .commit_write = gfs2_commit_write,
780         .bmap = gfs2_bmap,
781         .invalidatepage = gfs2_invalidatepage,
782         .releasepage = gfs2_releasepage,
783         .direct_IO = gfs2_direct_IO,
784 };
785