[GFS2] Remove all_list from lock_dlm
[linux-2.6.git] / fs / gfs2 / super.c
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/crc32.h>
16 #include <linux/gfs2_ondisk.h>
17 #include <linux/bio.h>
18 #include <linux/lm_interface.h>
19
20 #include "gfs2.h"
21 #include "incore.h"
22 #include "bmap.h"
23 #include "dir.h"
24 #include "glock.h"
25 #include "glops.h"
26 #include "inode.h"
27 #include "log.h"
28 #include "meta_io.h"
29 #include "quota.h"
30 #include "recovery.h"
31 #include "rgrp.h"
32 #include "super.h"
33 #include "trans.h"
34 #include "util.h"
35
36 static const u32 gfs2_old_fs_formats[] = {
37         0
38 };
39
40 static const u32 gfs2_old_multihost_formats[] = {
41         0
42 };
43
44 /**
45  * gfs2_tune_init - Fill a gfs2_tune structure with default values
46  * @gt: tune
47  *
48  */
49
50 void gfs2_tune_init(struct gfs2_tune *gt)
51 {
52         spin_lock_init(&gt->gt_spin);
53
54         gt->gt_demote_secs = 300;
55         gt->gt_incore_log_blocks = 1024;
56         gt->gt_log_flush_secs = 60;
57         gt->gt_recoverd_secs = 60;
58         gt->gt_logd_secs = 1;
59         gt->gt_quotad_secs = 5;
60         gt->gt_quota_simul_sync = 64;
61         gt->gt_quota_warn_period = 10;
62         gt->gt_quota_scale_num = 1;
63         gt->gt_quota_scale_den = 1;
64         gt->gt_quota_cache_secs = 300;
65         gt->gt_quota_quantum = 60;
66         gt->gt_atime_quantum = 3600;
67         gt->gt_new_files_jdata = 0;
68         gt->gt_new_files_directio = 0;
69         gt->gt_max_readahead = 1 << 18;
70         gt->gt_stall_secs = 600;
71         gt->gt_complain_secs = 10;
72         gt->gt_statfs_quantum = 30;
73         gt->gt_statfs_slow = 0;
74 }
75
76 /**
77  * gfs2_check_sb - Check superblock
78  * @sdp: the filesystem
79  * @sb: The superblock
80  * @silent: Don't print a message if the check fails
81  *
82  * Checks the version code of the FS is one that we understand how to
83  * read and that the sizes of the various on-disk structures have not
84  * changed.
85  */
86
87 int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb_host *sb, int silent)
88 {
89         unsigned int x;
90
91         if (sb->sb_magic != GFS2_MAGIC ||
92             sb->sb_type != GFS2_METATYPE_SB) {
93                 if (!silent)
94                         printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
95                 return -EINVAL;
96         }
97
98         /*  If format numbers match exactly, we're done.  */
99
100         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
101             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
102                 return 0;
103
104         if (sb->sb_fs_format != GFS2_FORMAT_FS) {
105                 for (x = 0; gfs2_old_fs_formats[x]; x++)
106                         if (gfs2_old_fs_formats[x] == sb->sb_fs_format)
107                                 break;
108
109                 if (!gfs2_old_fs_formats[x]) {
110                         printk(KERN_WARNING
111                                "GFS2: code version (%u, %u) is incompatible "
112                                "with ondisk format (%u, %u)\n",
113                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
114                                sb->sb_fs_format, sb->sb_multihost_format);
115                         printk(KERN_WARNING
116                                "GFS2: I don't know how to upgrade this FS\n");
117                         return -EINVAL;
118                 }
119         }
120
121         if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
122                 for (x = 0; gfs2_old_multihost_formats[x]; x++)
123                         if (gfs2_old_multihost_formats[x] ==
124                             sb->sb_multihost_format)
125                                 break;
126
127                 if (!gfs2_old_multihost_formats[x]) {
128                         printk(KERN_WARNING
129                                "GFS2: code version (%u, %u) is incompatible "
130                                "with ondisk format (%u, %u)\n",
131                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
132                                sb->sb_fs_format, sb->sb_multihost_format);
133                         printk(KERN_WARNING
134                                "GFS2: I don't know how to upgrade this FS\n");
135                         return -EINVAL;
136                 }
137         }
138
139         if (!sdp->sd_args.ar_upgrade) {
140                 printk(KERN_WARNING
141                        "GFS2: code version (%u, %u) is incompatible "
142                        "with ondisk format (%u, %u)\n",
143                        GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
144                        sb->sb_fs_format, sb->sb_multihost_format);
145                 printk(KERN_INFO
146                        "GFS2: Use the \"upgrade\" mount option to upgrade "
147                        "the FS\n");
148                 printk(KERN_INFO "GFS2: See the manual for more details\n");
149                 return -EINVAL;
150         }
151
152         return 0;
153 }
154
155
156 static void end_bio_io_page(struct bio *bio, int error)
157 {
158         struct page *page = bio->bi_private;
159
160         if (!error)
161                 SetPageUptodate(page);
162         else
163                 printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
164         unlock_page(page);
165 }
166
167 static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf)
168 {
169         const struct gfs2_sb *str = buf;
170
171         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
172         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
173         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
174         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
175         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
176         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
177         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
178         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
179         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
180         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
181         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
182
183         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
184         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
185 }
186
187 /**
188  * gfs2_read_super - Read the gfs2 super block from disk
189  * @sdp: The GFS2 super block
190  * @sector: The location of the super block
191  * @error: The error code to return
192  *
193  * This uses the bio functions to read the super block from disk
194  * because we want to be 100% sure that we never read cached data.
195  * A super block is read twice only during each GFS2 mount and is
196  * never written to by the filesystem. The first time its read no
197  * locks are held, and the only details which are looked at are those
198  * relating to the locking protocol. Once locking is up and working,
199  * the sb is read again under the lock to establish the location of
200  * the master directory (contains pointers to journals etc) and the
201  * root directory.
202  *
203  * Returns: 0 on success or error
204  */
205
206 int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector)
207 {
208         struct super_block *sb = sdp->sd_vfs;
209         struct gfs2_sb *p;
210         struct page *page;
211         struct bio *bio;
212
213         page = alloc_page(GFP_NOFS);
214         if (unlikely(!page))
215                 return -ENOBUFS;
216
217         ClearPageUptodate(page);
218         ClearPageDirty(page);
219         lock_page(page);
220
221         bio = bio_alloc(GFP_NOFS, 1);
222         if (unlikely(!bio)) {
223                 __free_page(page);
224                 return -ENOBUFS;
225         }
226
227         bio->bi_sector = sector * (sb->s_blocksize >> 9);
228         bio->bi_bdev = sb->s_bdev;
229         bio_add_page(bio, page, PAGE_SIZE, 0);
230
231         bio->bi_end_io = end_bio_io_page;
232         bio->bi_private = page;
233         submit_bio(READ_SYNC | (1 << BIO_RW_META), bio);
234         wait_on_page_locked(page);
235         bio_put(bio);
236         if (!PageUptodate(page)) {
237                 __free_page(page);
238                 return -EIO;
239         }
240         p = kmap(page);
241         gfs2_sb_in(&sdp->sd_sb, p);
242         kunmap(page);
243         __free_page(page);
244         return 0;
245 }
246
247 /**
248  * gfs2_read_sb - Read super block
249  * @sdp: The GFS2 superblock
250  * @gl: the glock for the superblock (assumed to be held)
251  * @silent: Don't print message if mount fails
252  *
253  */
254
255 int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
256 {
257         u32 hash_blocks, ind_blocks, leaf_blocks;
258         u32 tmp_blocks;
259         unsigned int x;
260         int error;
261
262         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
263         if (error) {
264                 if (!silent)
265                         fs_err(sdp, "can't read superblock\n");
266                 return error;
267         }
268
269         error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
270         if (error)
271                 return error;
272
273         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
274                                GFS2_BASIC_BLOCK_SHIFT;
275         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
276         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
277                           sizeof(struct gfs2_dinode)) / sizeof(u64);
278         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
279                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
280         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
281         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
282         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
283         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
284         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
285                                 sizeof(struct gfs2_meta_header)) /
286                                 sizeof(struct gfs2_quota_change);
287
288         /* Compute maximum reservation required to add a entry to a directory */
289
290         hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
291                              sdp->sd_jbsize);
292
293         ind_blocks = 0;
294         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
295                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
296                 ind_blocks += tmp_blocks;
297         }
298
299         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
300
301         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
302
303         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
304                                 sizeof(struct gfs2_dinode);
305         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
306         for (x = 2;; x++) {
307                 u64 space, d;
308                 u32 m;
309
310                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
311                 d = space;
312                 m = do_div(d, sdp->sd_inptrs);
313
314                 if (d != sdp->sd_heightsize[x - 1] || m)
315                         break;
316                 sdp->sd_heightsize[x] = space;
317         }
318         sdp->sd_max_height = x;
319         sdp->sd_heightsize[x] = ~0;
320         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
321
322         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
323                                  sizeof(struct gfs2_dinode);
324         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
325         for (x = 2;; x++) {
326                 u64 space, d;
327                 u32 m;
328
329                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
330                 d = space;
331                 m = do_div(d, sdp->sd_inptrs);
332
333                 if (d != sdp->sd_jheightsize[x - 1] || m)
334                         break;
335                 sdp->sd_jheightsize[x] = space;
336         }
337         sdp->sd_max_jheight = x;
338         sdp->sd_jheightsize[x] = ~0;
339         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
340
341         return 0;
342 }
343
344 /**
345  * gfs2_jindex_hold - Grab a lock on the jindex
346  * @sdp: The GFS2 superblock
347  * @ji_gh: the holder for the jindex glock
348  *
349  * This is very similar to the gfs2_rindex_hold() function, except that
350  * in general we hold the jindex lock for longer periods of time and
351  * we grab it far less frequently (in general) then the rgrp lock.
352  *
353  * Returns: errno
354  */
355
356 int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
357 {
358         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
359         struct qstr name;
360         char buf[20];
361         struct gfs2_jdesc *jd;
362         int error;
363
364         name.name = buf;
365
366         mutex_lock(&sdp->sd_jindex_mutex);
367
368         for (;;) {
369                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
370                 if (error)
371                         break;
372
373                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
374                 name.hash = gfs2_disk_hash(name.name, name.len);
375
376                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
377                 if (error == -ENOENT) {
378                         error = 0;
379                         break;
380                 }
381
382                 gfs2_glock_dq_uninit(ji_gh);
383
384                 if (error)
385                         break;
386
387                 error = -ENOMEM;
388                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
389                 if (!jd)
390                         break;
391
392                 INIT_LIST_HEAD(&jd->extent_list);
393                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1, NULL);
394                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
395                         if (!jd->jd_inode)
396                                 error = -ENOENT;
397                         else
398                                 error = PTR_ERR(jd->jd_inode);
399                         kfree(jd);
400                         break;
401                 }
402
403                 spin_lock(&sdp->sd_jindex_spin);
404                 jd->jd_jid = sdp->sd_journals++;
405                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
406                 spin_unlock(&sdp->sd_jindex_spin);
407         }
408
409         mutex_unlock(&sdp->sd_jindex_mutex);
410
411         return error;
412 }
413
414 /**
415  * gfs2_jindex_free - Clear all the journal index information
416  * @sdp: The GFS2 superblock
417  *
418  */
419
420 void gfs2_jindex_free(struct gfs2_sbd *sdp)
421 {
422         struct list_head list, *head;
423         struct gfs2_jdesc *jd;
424         struct gfs2_journal_extent *jext;
425
426         spin_lock(&sdp->sd_jindex_spin);
427         list_add(&list, &sdp->sd_jindex_list);
428         list_del_init(&sdp->sd_jindex_list);
429         sdp->sd_journals = 0;
430         spin_unlock(&sdp->sd_jindex_spin);
431
432         while (!list_empty(&list)) {
433                 jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
434                 head = &jd->extent_list;
435                 while (!list_empty(head)) {
436                         jext = list_entry(head->next,
437                                           struct gfs2_journal_extent,
438                                           extent_list);
439                         list_del(&jext->extent_list);
440                         kfree(jext);
441                 }
442                 list_del(&jd->jd_list);
443                 iput(jd->jd_inode);
444                 kfree(jd);
445         }
446 }
447
448 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
449 {
450         struct gfs2_jdesc *jd;
451         int found = 0;
452
453         list_for_each_entry(jd, head, jd_list) {
454                 if (jd->jd_jid == jid) {
455                         found = 1;
456                         break;
457                 }
458         }
459
460         if (!found)
461                 jd = NULL;
462
463         return jd;
464 }
465
466 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
467 {
468         struct gfs2_jdesc *jd;
469
470         spin_lock(&sdp->sd_jindex_spin);
471         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
472         spin_unlock(&sdp->sd_jindex_spin);
473
474         return jd;
475 }
476
477 void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid)
478 {
479         struct gfs2_jdesc *jd;
480
481         spin_lock(&sdp->sd_jindex_spin);
482         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
483         if (jd)
484                 jd->jd_dirty = 1;
485         spin_unlock(&sdp->sd_jindex_spin);
486 }
487
488 struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp)
489 {
490         struct gfs2_jdesc *jd;
491         int found = 0;
492
493         spin_lock(&sdp->sd_jindex_spin);
494
495         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
496                 if (jd->jd_dirty) {
497                         jd->jd_dirty = 0;
498                         found = 1;
499                         break;
500                 }
501         }
502         spin_unlock(&sdp->sd_jindex_spin);
503
504         if (!found)
505                 jd = NULL;
506
507         return jd;
508 }
509
510 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
511 {
512         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
513         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
514         int ar;
515         int error;
516
517         if (ip->i_di.di_size < (8 << 20) || ip->i_di.di_size > (1 << 30) ||
518             (ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) {
519                 gfs2_consist_inode(ip);
520                 return -EIO;
521         }
522         jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
523
524         error = gfs2_write_alloc_required(ip, 0, ip->i_di.di_size, &ar);
525         if (!error && ar) {
526                 gfs2_consist_inode(ip);
527                 error = -EIO;
528         }
529
530         return error;
531 }
532
533 /**
534  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
535  * @sdp: the filesystem
536  *
537  * Returns: errno
538  */
539
540 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
541 {
542         struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
543         struct gfs2_glock *j_gl = ip->i_gl;
544         struct gfs2_holder t_gh;
545         struct gfs2_log_header_host head;
546         int error;
547
548         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &t_gh);
549         if (error)
550                 return error;
551
552         j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
553
554         error = gfs2_find_jhead(sdp->sd_jdesc, &head);
555         if (error)
556                 goto fail;
557
558         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
559                 gfs2_consist(sdp);
560                 error = -EIO;
561                 goto fail;
562         }
563
564         /*  Initialize some head of the log stuff  */
565         sdp->sd_log_sequence = head.lh_sequence + 1;
566         gfs2_log_pointers_init(sdp, head.lh_blkno);
567
568         error = gfs2_quota_init(sdp);
569         if (error)
570                 goto fail;
571
572         set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
573
574         gfs2_glock_dq_uninit(&t_gh);
575
576         return 0;
577
578 fail:
579         t_gh.gh_flags |= GL_NOCACHE;
580         gfs2_glock_dq_uninit(&t_gh);
581
582         return error;
583 }
584
585 /**
586  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
587  * @sdp: the filesystem
588  *
589  * Returns: errno
590  */
591
592 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
593 {
594         struct gfs2_holder t_gh;
595         int error;
596
597         gfs2_quota_sync(sdp);
598         gfs2_statfs_sync(sdp);
599
600         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, GL_NOCACHE,
601                                    &t_gh);
602         if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
603                 return error;
604
605         gfs2_meta_syncfs(sdp);
606         gfs2_log_shutdown(sdp);
607
608         clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
609
610         if (t_gh.gh_gl)
611                 gfs2_glock_dq_uninit(&t_gh);
612
613         gfs2_quota_cleanup(sdp);
614
615         return error;
616 }
617
618 static void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
619 {
620         const struct gfs2_statfs_change *str = buf;
621
622         sc->sc_total = be64_to_cpu(str->sc_total);
623         sc->sc_free = be64_to_cpu(str->sc_free);
624         sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
625 }
626
627 static void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
628 {
629         struct gfs2_statfs_change *str = buf;
630
631         str->sc_total = cpu_to_be64(sc->sc_total);
632         str->sc_free = cpu_to_be64(sc->sc_free);
633         str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
634 }
635
636 int gfs2_statfs_init(struct gfs2_sbd *sdp)
637 {
638         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
639         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
640         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
641         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
642         struct buffer_head *m_bh, *l_bh;
643         struct gfs2_holder gh;
644         int error;
645
646         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
647                                    &gh);
648         if (error)
649                 return error;
650
651         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
652         if (error)
653                 goto out;
654
655         if (sdp->sd_args.ar_spectator) {
656                 spin_lock(&sdp->sd_statfs_spin);
657                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
658                                       sizeof(struct gfs2_dinode));
659                 spin_unlock(&sdp->sd_statfs_spin);
660         } else {
661                 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
662                 if (error)
663                         goto out_m_bh;
664
665                 spin_lock(&sdp->sd_statfs_spin);
666                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
667                                       sizeof(struct gfs2_dinode));
668                 gfs2_statfs_change_in(l_sc, l_bh->b_data +
669                                       sizeof(struct gfs2_dinode));
670                 spin_unlock(&sdp->sd_statfs_spin);
671
672                 brelse(l_bh);
673         }
674
675 out_m_bh:
676         brelse(m_bh);
677 out:
678         gfs2_glock_dq_uninit(&gh);
679         return 0;
680 }
681
682 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
683                         s64 dinodes)
684 {
685         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
686         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
687         struct buffer_head *l_bh;
688         int error;
689
690         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
691         if (error)
692                 return;
693
694         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
695
696         spin_lock(&sdp->sd_statfs_spin);
697         l_sc->sc_total += total;
698         l_sc->sc_free += free;
699         l_sc->sc_dinodes += dinodes;
700         gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
701         spin_unlock(&sdp->sd_statfs_spin);
702
703         brelse(l_bh);
704 }
705
706 int gfs2_statfs_sync(struct gfs2_sbd *sdp)
707 {
708         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
709         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
710         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
711         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
712         struct gfs2_holder gh;
713         struct buffer_head *m_bh, *l_bh;
714         int error;
715
716         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
717                                    &gh);
718         if (error)
719                 return error;
720
721         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
722         if (error)
723                 goto out;
724
725         spin_lock(&sdp->sd_statfs_spin);
726         gfs2_statfs_change_in(m_sc, m_bh->b_data +
727                               sizeof(struct gfs2_dinode));
728         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
729                 spin_unlock(&sdp->sd_statfs_spin);
730                 goto out_bh;
731         }
732         spin_unlock(&sdp->sd_statfs_spin);
733
734         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
735         if (error)
736                 goto out_bh;
737
738         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
739         if (error)
740                 goto out_bh2;
741
742         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
743
744         spin_lock(&sdp->sd_statfs_spin);
745         m_sc->sc_total += l_sc->sc_total;
746         m_sc->sc_free += l_sc->sc_free;
747         m_sc->sc_dinodes += l_sc->sc_dinodes;
748         memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
749         memset(l_bh->b_data + sizeof(struct gfs2_dinode),
750                0, sizeof(struct gfs2_statfs_change));
751         spin_unlock(&sdp->sd_statfs_spin);
752
753         gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
754         gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
755
756         gfs2_trans_end(sdp);
757
758 out_bh2:
759         brelse(l_bh);
760 out_bh:
761         brelse(m_bh);
762 out:
763         gfs2_glock_dq_uninit(&gh);
764         return error;
765 }
766
767 /**
768  * gfs2_statfs_i - Do a statfs
769  * @sdp: the filesystem
770  * @sg: the sg structure
771  *
772  * Returns: errno
773  */
774
775 int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
776 {
777         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
778         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
779
780         spin_lock(&sdp->sd_statfs_spin);
781
782         *sc = *m_sc;
783         sc->sc_total += l_sc->sc_total;
784         sc->sc_free += l_sc->sc_free;
785         sc->sc_dinodes += l_sc->sc_dinodes;
786
787         spin_unlock(&sdp->sd_statfs_spin);
788
789         if (sc->sc_free < 0)
790                 sc->sc_free = 0;
791         if (sc->sc_free > sc->sc_total)
792                 sc->sc_free = sc->sc_total;
793         if (sc->sc_dinodes < 0)
794                 sc->sc_dinodes = 0;
795
796         return 0;
797 }
798
799 /**
800  * statfs_fill - fill in the sg for a given RG
801  * @rgd: the RG
802  * @sc: the sc structure
803  *
804  * Returns: 0 on success, -ESTALE if the LVB is invalid
805  */
806
807 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
808                             struct gfs2_statfs_change_host *sc)
809 {
810         gfs2_rgrp_verify(rgd);
811         sc->sc_total += rgd->rd_data;
812         sc->sc_free += rgd->rd_rg.rg_free;
813         sc->sc_dinodes += rgd->rd_rg.rg_dinodes;
814         return 0;
815 }
816
817 /**
818  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
819  * @sdp: the filesystem
820  * @sc: the sc info that will be returned
821  *
822  * Any error (other than a signal) will cause this routine to fall back
823  * to the synchronous version.
824  *
825  * FIXME: This really shouldn't busy wait like this.
826  *
827  * Returns: errno
828  */
829
830 int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
831 {
832         struct gfs2_holder ri_gh;
833         struct gfs2_rgrpd *rgd_next;
834         struct gfs2_holder *gha, *gh;
835         unsigned int slots = 64;
836         unsigned int x;
837         int done;
838         int error = 0, err;
839
840         memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
841         gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
842         if (!gha)
843                 return -ENOMEM;
844
845         error = gfs2_rindex_hold(sdp, &ri_gh);
846         if (error)
847                 goto out;
848
849         rgd_next = gfs2_rgrpd_get_first(sdp);
850
851         for (;;) {
852                 done = 1;
853
854                 for (x = 0; x < slots; x++) {
855                         gh = gha + x;
856
857                         if (gh->gh_gl && gfs2_glock_poll(gh)) {
858                                 err = gfs2_glock_wait(gh);
859                                 if (err) {
860                                         gfs2_holder_uninit(gh);
861                                         error = err;
862                                 } else {
863                                         if (!error)
864                                                 error = statfs_slow_fill(
865                                                         gh->gh_gl->gl_object, sc);
866                                         gfs2_glock_dq_uninit(gh);
867                                 }
868                         }
869
870                         if (gh->gh_gl)
871                                 done = 0;
872                         else if (rgd_next && !error) {
873                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
874                                                            LM_ST_SHARED,
875                                                            GL_ASYNC,
876                                                            gh);
877                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
878                                 done = 0;
879                         }
880
881                         if (signal_pending(current))
882                                 error = -ERESTARTSYS;
883                 }
884
885                 if (done)
886                         break;
887
888                 yield();
889         }
890
891         gfs2_glock_dq_uninit(&ri_gh);
892
893 out:
894         kfree(gha);
895         return error;
896 }
897
898 struct lfcc {
899         struct list_head list;
900         struct gfs2_holder gh;
901 };
902
903 /**
904  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
905  *                            journals are clean
906  * @sdp: the file system
907  * @state: the state to put the transaction lock into
908  * @t_gh: the hold on the transaction lock
909  *
910  * Returns: errno
911  */
912
913 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
914                                     struct gfs2_holder *t_gh)
915 {
916         struct gfs2_inode *ip;
917         struct gfs2_holder ji_gh;
918         struct gfs2_jdesc *jd;
919         struct lfcc *lfcc;
920         LIST_HEAD(list);
921         struct gfs2_log_header_host lh;
922         int error;
923
924         error = gfs2_jindex_hold(sdp, &ji_gh);
925         if (error)
926                 return error;
927
928         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
929                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
930                 if (!lfcc) {
931                         error = -ENOMEM;
932                         goto out;
933                 }
934                 ip = GFS2_I(jd->jd_inode);
935                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
936                 if (error) {
937                         kfree(lfcc);
938                         goto out;
939                 }
940                 list_add(&lfcc->list, &list);
941         }
942
943         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
944                                    GL_NOCACHE, t_gh);
945
946         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
947                 error = gfs2_jdesc_check(jd);
948                 if (error)
949                         break;
950                 error = gfs2_find_jhead(jd, &lh);
951                 if (error)
952                         break;
953                 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
954                         error = -EBUSY;
955                         break;
956                 }
957         }
958
959         if (error)
960                 gfs2_glock_dq_uninit(t_gh);
961
962 out:
963         while (!list_empty(&list)) {
964                 lfcc = list_entry(list.next, struct lfcc, list);
965                 list_del(&lfcc->list);
966                 gfs2_glock_dq_uninit(&lfcc->gh);
967                 kfree(lfcc);
968         }
969         gfs2_glock_dq_uninit(&ji_gh);
970         return error;
971 }
972
973 /**
974  * gfs2_freeze_fs - freezes the file system
975  * @sdp: the file system
976  *
977  * This function flushes data and meta data for all machines by
978  * aquiring the transaction log exclusively.  All journals are
979  * ensured to be in a clean state as well.
980  *
981  * Returns: errno
982  */
983
984 int gfs2_freeze_fs(struct gfs2_sbd *sdp)
985 {
986         int error = 0;
987
988         mutex_lock(&sdp->sd_freeze_lock);
989
990         if (!sdp->sd_freeze_count++) {
991                 error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
992                 if (error)
993                         sdp->sd_freeze_count--;
994         }
995
996         mutex_unlock(&sdp->sd_freeze_lock);
997
998         return error;
999 }
1000
1001 /**
1002  * gfs2_unfreeze_fs - unfreezes the file system
1003  * @sdp: the file system
1004  *
1005  * This function allows the file system to proceed by unlocking
1006  * the exclusively held transaction lock.  Other GFS2 nodes are
1007  * now free to acquire the lock shared and go on with their lives.
1008  *
1009  */
1010
1011 void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
1012 {
1013         mutex_lock(&sdp->sd_freeze_lock);
1014
1015         if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
1016                 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
1017
1018         mutex_unlock(&sdp->sd_freeze_lock);
1019 }
1020