dd3e737f528e0b111387b506608e63fc99ef5c0b
[linux-2.6.git] / fs / gfs2 / super.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/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_ilimit = 100;
55         gt->gt_ilimit_tries = 3;
56         gt->gt_ilimit_min = 1;
57         gt->gt_demote_secs = 300;
58         gt->gt_incore_log_blocks = 1024;
59         gt->gt_log_flush_secs = 60;
60         gt->gt_jindex_refresh_secs = 60;
61         gt->gt_recoverd_secs = 60;
62         gt->gt_logd_secs = 1;
63         gt->gt_quotad_secs = 5;
64         gt->gt_quota_simul_sync = 64;
65         gt->gt_quota_warn_period = 10;
66         gt->gt_quota_scale_num = 1;
67         gt->gt_quota_scale_den = 1;
68         gt->gt_quota_cache_secs = 300;
69         gt->gt_quota_quantum = 60;
70         gt->gt_atime_quantum = 3600;
71         gt->gt_new_files_jdata = 0;
72         gt->gt_new_files_directio = 0;
73         gt->gt_max_readahead = 1 << 18;
74         gt->gt_lockdump_size = 131072;
75         gt->gt_stall_secs = 600;
76         gt->gt_complain_secs = 10;
77         gt->gt_reclaim_limit = 5000;
78         gt->gt_statfs_quantum = 30;
79         gt->gt_statfs_slow = 0;
80 }
81
82 /**
83  * gfs2_check_sb - Check superblock
84  * @sdp: the filesystem
85  * @sb: The superblock
86  * @silent: Don't print a message if the check fails
87  *
88  * Checks the version code of the FS is one that we understand how to
89  * read and that the sizes of the various on-disk structures have not
90  * changed.
91  */
92
93 int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb_host *sb, int silent)
94 {
95         unsigned int x;
96
97         if (sb->sb_magic != GFS2_MAGIC ||
98             sb->sb_type != GFS2_METATYPE_SB) {
99                 if (!silent)
100                         printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
101                 return -EINVAL;
102         }
103
104         /*  If format numbers match exactly, we're done.  */
105
106         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
107             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
108                 return 0;
109
110         if (sb->sb_fs_format != GFS2_FORMAT_FS) {
111                 for (x = 0; gfs2_old_fs_formats[x]; x++)
112                         if (gfs2_old_fs_formats[x] == sb->sb_fs_format)
113                                 break;
114
115                 if (!gfs2_old_fs_formats[x]) {
116                         printk(KERN_WARNING
117                                "GFS2: code version (%u, %u) is incompatible "
118                                "with ondisk format (%u, %u)\n",
119                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
120                                sb->sb_fs_format, sb->sb_multihost_format);
121                         printk(KERN_WARNING
122                                "GFS2: I don't know how to upgrade this FS\n");
123                         return -EINVAL;
124                 }
125         }
126
127         if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
128                 for (x = 0; gfs2_old_multihost_formats[x]; x++)
129                         if (gfs2_old_multihost_formats[x] ==
130                             sb->sb_multihost_format)
131                                 break;
132
133                 if (!gfs2_old_multihost_formats[x]) {
134                         printk(KERN_WARNING
135                                "GFS2: code version (%u, %u) is incompatible "
136                                "with ondisk format (%u, %u)\n",
137                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
138                                sb->sb_fs_format, sb->sb_multihost_format);
139                         printk(KERN_WARNING
140                                "GFS2: I don't know how to upgrade this FS\n");
141                         return -EINVAL;
142                 }
143         }
144
145         if (!sdp->sd_args.ar_upgrade) {
146                 printk(KERN_WARNING
147                        "GFS2: code version (%u, %u) is incompatible "
148                        "with ondisk format (%u, %u)\n",
149                        GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
150                        sb->sb_fs_format, sb->sb_multihost_format);
151                 printk(KERN_INFO
152                        "GFS2: Use the \"upgrade\" mount option to upgrade "
153                        "the FS\n");
154                 printk(KERN_INFO "GFS2: See the manual for more details\n");
155                 return -EINVAL;
156         }
157
158         return 0;
159 }
160
161
162 static void end_bio_io_page(struct bio *bio, int error)
163 {
164         struct page *page = bio->bi_private;
165
166         if (!error)
167                 SetPageUptodate(page);
168         else
169                 printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
170         unlock_page(page);
171 }
172
173 static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf)
174 {
175         const struct gfs2_sb *str = buf;
176
177         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
178         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
179         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
180         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
181         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
182         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
183         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
184         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
185         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
186         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
187         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
188
189         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
190         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
191 }
192
193 /**
194  * gfs2_read_super - Read the gfs2 super block from disk
195  * @sdp: The GFS2 super block
196  * @sector: The location of the super block
197  * @error: The error code to return
198  *
199  * This uses the bio functions to read the super block from disk
200  * because we want to be 100% sure that we never read cached data.
201  * A super block is read twice only during each GFS2 mount and is
202  * never written to by the filesystem. The first time its read no
203  * locks are held, and the only details which are looked at are those
204  * relating to the locking protocol. Once locking is up and working,
205  * the sb is read again under the lock to establish the location of
206  * the master directory (contains pointers to journals etc) and the
207  * root directory.
208  *
209  * Returns: 0 on success or error
210  */
211
212 int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector)
213 {
214         struct super_block *sb = sdp->sd_vfs;
215         struct gfs2_sb *p;
216         struct page *page;
217         struct bio *bio;
218
219         page = alloc_page(GFP_KERNEL);
220         if (unlikely(!page))
221                 return -ENOBUFS;
222
223         ClearPageUptodate(page);
224         ClearPageDirty(page);
225         lock_page(page);
226
227         bio = bio_alloc(GFP_KERNEL, 1);
228         if (unlikely(!bio)) {
229                 __free_page(page);
230                 return -ENOBUFS;
231         }
232
233         bio->bi_sector = sector * (sb->s_blocksize >> 9);
234         bio->bi_bdev = sb->s_bdev;
235         bio_add_page(bio, page, PAGE_SIZE, 0);
236
237         bio->bi_end_io = end_bio_io_page;
238         bio->bi_private = page;
239         submit_bio(READ_SYNC | (1 << BIO_RW_META), bio);
240         wait_on_page_locked(page);
241         bio_put(bio);
242         if (!PageUptodate(page)) {
243                 __free_page(page);
244                 return -EIO;
245         }
246         p = kmap(page);
247         gfs2_sb_in(&sdp->sd_sb, p);
248         kunmap(page);
249         __free_page(page);
250         return 0;
251 }
252
253 /**
254  * gfs2_read_sb - Read super block
255  * @sdp: The GFS2 superblock
256  * @gl: the glock for the superblock (assumed to be held)
257  * @silent: Don't print message if mount fails
258  *
259  */
260
261 int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
262 {
263         u32 hash_blocks, ind_blocks, leaf_blocks;
264         u32 tmp_blocks;
265         unsigned int x;
266         int error;
267
268         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
269         if (error) {
270                 if (!silent)
271                         fs_err(sdp, "can't read superblock\n");
272                 return error;
273         }
274
275         error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
276         if (error)
277                 return error;
278
279         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
280                                GFS2_BASIC_BLOCK_SHIFT;
281         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
282         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
283                           sizeof(struct gfs2_dinode)) / sizeof(u64);
284         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
285                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
286         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
287         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
288         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
289         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
290         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
291                                 sizeof(struct gfs2_meta_header)) /
292                                 sizeof(struct gfs2_quota_change);
293
294         /* Compute maximum reservation required to add a entry to a directory */
295
296         hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
297                              sdp->sd_jbsize);
298
299         ind_blocks = 0;
300         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
301                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
302                 ind_blocks += tmp_blocks;
303         }
304
305         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
306
307         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
308
309         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
310                                 sizeof(struct gfs2_dinode);
311         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
312         for (x = 2;; x++) {
313                 u64 space, d;
314                 u32 m;
315
316                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
317                 d = space;
318                 m = do_div(d, sdp->sd_inptrs);
319
320                 if (d != sdp->sd_heightsize[x - 1] || m)
321                         break;
322                 sdp->sd_heightsize[x] = space;
323         }
324         sdp->sd_max_height = x;
325         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
326
327         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
328                                  sizeof(struct gfs2_dinode);
329         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
330         for (x = 2;; x++) {
331                 u64 space, d;
332                 u32 m;
333
334                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
335                 d = space;
336                 m = do_div(d, sdp->sd_inptrs);
337
338                 if (d != sdp->sd_jheightsize[x - 1] || m)
339                         break;
340                 sdp->sd_jheightsize[x] = space;
341         }
342         sdp->sd_max_jheight = x;
343         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
344
345         return 0;
346 }
347
348 /**
349  * gfs2_jindex_hold - Grab a lock on the jindex
350  * @sdp: The GFS2 superblock
351  * @ji_gh: the holder for the jindex glock
352  *
353  * This is very similar to the gfs2_rindex_hold() function, except that
354  * in general we hold the jindex lock for longer periods of time and
355  * we grab it far less frequently (in general) then the rgrp lock.
356  *
357  * Returns: errno
358  */
359
360 int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
361 {
362         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
363         struct qstr name;
364         char buf[20];
365         struct gfs2_jdesc *jd;
366         int error;
367
368         name.name = buf;
369
370         mutex_lock(&sdp->sd_jindex_mutex);
371
372         for (;;) {
373                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
374                 if (error)
375                         break;
376
377                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
378                 name.hash = gfs2_disk_hash(name.name, name.len);
379
380                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
381                 if (error == -ENOENT) {
382                         error = 0;
383                         break;
384                 }
385
386                 gfs2_glock_dq_uninit(ji_gh);
387
388                 if (error)
389                         break;
390
391                 error = -ENOMEM;
392                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
393                 if (!jd)
394                         break;
395
396                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1, NULL);
397                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
398                         if (!jd->jd_inode)
399                                 error = -ENOENT;
400                         else
401                                 error = PTR_ERR(jd->jd_inode);
402                         kfree(jd);
403                         break;
404                 }
405
406                 spin_lock(&sdp->sd_jindex_spin);
407                 jd->jd_jid = sdp->sd_journals++;
408                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
409                 spin_unlock(&sdp->sd_jindex_spin);
410         }
411
412         mutex_unlock(&sdp->sd_jindex_mutex);
413
414         return error;
415 }
416
417 /**
418  * gfs2_jindex_free - Clear all the journal index information
419  * @sdp: The GFS2 superblock
420  *
421  */
422
423 void gfs2_jindex_free(struct gfs2_sbd *sdp)
424 {
425         struct list_head list;
426         struct gfs2_jdesc *jd;
427
428         spin_lock(&sdp->sd_jindex_spin);
429         list_add(&list, &sdp->sd_jindex_list);
430         list_del_init(&sdp->sd_jindex_list);
431         sdp->sd_journals = 0;
432         spin_unlock(&sdp->sd_jindex_spin);
433
434         while (!list_empty(&list)) {
435                 jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
436                 list_del(&jd->jd_list);
437                 iput(jd->jd_inode);
438                 kfree(jd);
439         }
440 }
441
442 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
443 {
444         struct gfs2_jdesc *jd;
445         int found = 0;
446
447         list_for_each_entry(jd, head, jd_list) {
448                 if (jd->jd_jid == jid) {
449                         found = 1;
450                         break;
451                 }
452         }
453
454         if (!found)
455                 jd = NULL;
456
457         return jd;
458 }
459
460 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
461 {
462         struct gfs2_jdesc *jd;
463
464         spin_lock(&sdp->sd_jindex_spin);
465         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
466         spin_unlock(&sdp->sd_jindex_spin);
467
468         return jd;
469 }
470
471 void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid)
472 {
473         struct gfs2_jdesc *jd;
474
475         spin_lock(&sdp->sd_jindex_spin);
476         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
477         if (jd)
478                 jd->jd_dirty = 1;
479         spin_unlock(&sdp->sd_jindex_spin);
480 }
481
482 struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp)
483 {
484         struct gfs2_jdesc *jd;
485         int found = 0;
486
487         spin_lock(&sdp->sd_jindex_spin);
488
489         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
490                 if (jd->jd_dirty) {
491                         jd->jd_dirty = 0;
492                         found = 1;
493                         break;
494                 }
495         }
496         spin_unlock(&sdp->sd_jindex_spin);
497
498         if (!found)
499                 jd = NULL;
500
501         return jd;
502 }
503
504 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
505 {
506         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
507         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
508         int ar;
509         int error;
510
511         if (ip->i_di.di_size < (8 << 20) || ip->i_di.di_size > (1 << 30) ||
512             (ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) {
513                 gfs2_consist_inode(ip);
514                 return -EIO;
515         }
516         jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
517
518         error = gfs2_write_alloc_required(ip, 0, ip->i_di.di_size, &ar);
519         if (!error && ar) {
520                 gfs2_consist_inode(ip);
521                 error = -EIO;
522         }
523
524         return error;
525 }
526
527 /**
528  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
529  * @sdp: the filesystem
530  *
531  * Returns: errno
532  */
533
534 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
535 {
536         struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
537         struct gfs2_glock *j_gl = ip->i_gl;
538         struct gfs2_holder t_gh;
539         struct gfs2_log_header_host head;
540         int error;
541
542         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &t_gh);
543         if (error)
544                 return error;
545
546         gfs2_meta_cache_flush(ip);
547         j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
548
549         error = gfs2_find_jhead(sdp->sd_jdesc, &head);
550         if (error)
551                 goto fail;
552
553         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
554                 gfs2_consist(sdp);
555                 error = -EIO;
556                 goto fail;
557         }
558
559         /*  Initialize some head of the log stuff  */
560         sdp->sd_log_sequence = head.lh_sequence + 1;
561         gfs2_log_pointers_init(sdp, head.lh_blkno);
562
563         error = gfs2_quota_init(sdp);
564         if (error)
565                 goto fail;
566
567         set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
568
569         gfs2_glock_dq_uninit(&t_gh);
570
571         return 0;
572
573 fail:
574         t_gh.gh_flags |= GL_NOCACHE;
575         gfs2_glock_dq_uninit(&t_gh);
576
577         return error;
578 }
579
580 /**
581  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
582  * @sdp: the filesystem
583  *
584  * Returns: errno
585  */
586
587 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
588 {
589         struct gfs2_holder t_gh;
590         int error;
591
592         gfs2_quota_sync(sdp);
593         gfs2_statfs_sync(sdp);
594
595         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, GL_NOCACHE,
596                                    &t_gh);
597         if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
598                 return error;
599
600         gfs2_meta_syncfs(sdp);
601         gfs2_log_shutdown(sdp);
602
603         clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
604
605         if (t_gh.gh_gl)
606                 gfs2_glock_dq_uninit(&t_gh);
607
608         gfs2_quota_cleanup(sdp);
609
610         return error;
611 }
612
613 static void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
614 {
615         const struct gfs2_statfs_change *str = buf;
616
617         sc->sc_total = be64_to_cpu(str->sc_total);
618         sc->sc_free = be64_to_cpu(str->sc_free);
619         sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
620 }
621
622 static void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
623 {
624         struct gfs2_statfs_change *str = buf;
625
626         str->sc_total = cpu_to_be64(sc->sc_total);
627         str->sc_free = cpu_to_be64(sc->sc_free);
628         str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
629 }
630
631 int gfs2_statfs_init(struct gfs2_sbd *sdp)
632 {
633         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
634         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
635         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
636         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
637         struct buffer_head *m_bh, *l_bh;
638         struct gfs2_holder gh;
639         int error;
640
641         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
642                                    &gh);
643         if (error)
644                 return error;
645
646         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
647         if (error)
648                 goto out;
649
650         if (sdp->sd_args.ar_spectator) {
651                 spin_lock(&sdp->sd_statfs_spin);
652                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
653                                       sizeof(struct gfs2_dinode));
654                 spin_unlock(&sdp->sd_statfs_spin);
655         } else {
656                 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
657                 if (error)
658                         goto out_m_bh;
659
660                 spin_lock(&sdp->sd_statfs_spin);
661                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
662                                       sizeof(struct gfs2_dinode));
663                 gfs2_statfs_change_in(l_sc, l_bh->b_data +
664                                       sizeof(struct gfs2_dinode));
665                 spin_unlock(&sdp->sd_statfs_spin);
666
667                 brelse(l_bh);
668         }
669
670 out_m_bh:
671         brelse(m_bh);
672 out:
673         gfs2_glock_dq_uninit(&gh);
674         return 0;
675 }
676
677 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
678                         s64 dinodes)
679 {
680         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
681         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
682         struct buffer_head *l_bh;
683         int error;
684
685         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
686         if (error)
687                 return;
688
689         mutex_lock(&sdp->sd_statfs_mutex);
690         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
691         mutex_unlock(&sdp->sd_statfs_mutex);
692
693         spin_lock(&sdp->sd_statfs_spin);
694         l_sc->sc_total += total;
695         l_sc->sc_free += free;
696         l_sc->sc_dinodes += dinodes;
697         gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
698         spin_unlock(&sdp->sd_statfs_spin);
699
700         brelse(l_bh);
701 }
702
703 int gfs2_statfs_sync(struct gfs2_sbd *sdp)
704 {
705         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
706         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
707         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
708         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
709         struct gfs2_holder gh;
710         struct buffer_head *m_bh, *l_bh;
711         int error;
712
713         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
714                                    &gh);
715         if (error)
716                 return error;
717
718         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
719         if (error)
720                 goto out;
721
722         spin_lock(&sdp->sd_statfs_spin);
723         gfs2_statfs_change_in(m_sc, m_bh->b_data +
724                               sizeof(struct gfs2_dinode));
725         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
726                 spin_unlock(&sdp->sd_statfs_spin);
727                 goto out_bh;
728         }
729         spin_unlock(&sdp->sd_statfs_spin);
730
731         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
732         if (error)
733                 goto out_bh;
734
735         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
736         if (error)
737                 goto out_bh2;
738
739         mutex_lock(&sdp->sd_statfs_mutex);
740         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
741         mutex_unlock(&sdp->sd_statfs_mutex);
742
743         spin_lock(&sdp->sd_statfs_spin);
744         m_sc->sc_total += l_sc->sc_total;
745         m_sc->sc_free += l_sc->sc_free;
746         m_sc->sc_dinodes += l_sc->sc_dinodes;
747         memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
748         memset(l_bh->b_data + sizeof(struct gfs2_dinode),
749                0, sizeof(struct gfs2_statfs_change));
750         spin_unlock(&sdp->sd_statfs_spin);
751
752         gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
753         gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
754
755         gfs2_trans_end(sdp);
756
757 out_bh2:
758         brelse(l_bh);
759 out_bh:
760         brelse(m_bh);
761 out:
762         gfs2_glock_dq_uninit(&gh);
763         return error;
764 }
765
766 /**
767  * gfs2_statfs_i - Do a statfs
768  * @sdp: the filesystem
769  * @sg: the sg structure
770  *
771  * Returns: errno
772  */
773
774 int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
775 {
776         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
777         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
778
779         spin_lock(&sdp->sd_statfs_spin);
780
781         *sc = *m_sc;
782         sc->sc_total += l_sc->sc_total;
783         sc->sc_free += l_sc->sc_free;
784         sc->sc_dinodes += l_sc->sc_dinodes;
785
786         spin_unlock(&sdp->sd_statfs_spin);
787
788         if (sc->sc_free < 0)
789                 sc->sc_free = 0;
790         if (sc->sc_free > sc->sc_total)
791                 sc->sc_free = sc->sc_total;
792         if (sc->sc_dinodes < 0)
793                 sc->sc_dinodes = 0;
794
795         return 0;
796 }
797
798 /**
799  * statfs_fill - fill in the sg for a given RG
800  * @rgd: the RG
801  * @sc: the sc structure
802  *
803  * Returns: 0 on success, -ESTALE if the LVB is invalid
804  */
805
806 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
807                             struct gfs2_statfs_change_host *sc)
808 {
809         gfs2_rgrp_verify(rgd);
810         sc->sc_total += rgd->rd_data;
811         sc->sc_free += rgd->rd_rg.rg_free;
812         sc->sc_dinodes += rgd->rd_rg.rg_dinodes;
813         return 0;
814 }
815
816 /**
817  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
818  * @sdp: the filesystem
819  * @sc: the sc info that will be returned
820  *
821  * Any error (other than a signal) will cause this routine to fall back
822  * to the synchronous version.
823  *
824  * FIXME: This really shouldn't busy wait like this.
825  *
826  * Returns: errno
827  */
828
829 int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
830 {
831         struct gfs2_holder ri_gh;
832         struct gfs2_rgrpd *rgd_next;
833         struct gfs2_holder *gha, *gh;
834         unsigned int slots = 64;
835         unsigned int x;
836         int done;
837         int error = 0, err;
838
839         memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
840         gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
841         if (!gha)
842                 return -ENOMEM;
843
844         error = gfs2_rindex_hold(sdp, &ri_gh);
845         if (error)
846                 goto out;
847
848         rgd_next = gfs2_rgrpd_get_first(sdp);
849
850         for (;;) {
851                 done = 1;
852
853                 for (x = 0; x < slots; x++) {
854                         gh = gha + x;
855
856                         if (gh->gh_gl && gfs2_glock_poll(gh)) {
857                                 err = gfs2_glock_wait(gh);
858                                 if (err) {
859                                         gfs2_holder_uninit(gh);
860                                         error = err;
861                                 } else {
862                                         if (!error)
863                                                 error = statfs_slow_fill(
864                                                         gh->gh_gl->gl_object, sc);
865                                         gfs2_glock_dq_uninit(gh);
866                                 }
867                         }
868
869                         if (gh->gh_gl)
870                                 done = 0;
871                         else if (rgd_next && !error) {
872                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
873                                                            LM_ST_SHARED,
874                                                            GL_ASYNC,
875                                                            gh);
876                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
877                                 done = 0;
878                         }
879
880                         if (signal_pending(current))
881                                 error = -ERESTARTSYS;
882                 }
883
884                 if (done)
885                         break;
886
887                 yield();
888         }
889
890         gfs2_glock_dq_uninit(&ri_gh);
891
892 out:
893         kfree(gha);
894         return error;
895 }
896
897 struct lfcc {
898         struct list_head list;
899         struct gfs2_holder gh;
900 };
901
902 /**
903  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
904  *                            journals are clean
905  * @sdp: the file system
906  * @state: the state to put the transaction lock into
907  * @t_gh: the hold on the transaction lock
908  *
909  * Returns: errno
910  */
911
912 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
913                                     struct gfs2_holder *t_gh)
914 {
915         struct gfs2_inode *ip;
916         struct gfs2_holder ji_gh;
917         struct gfs2_jdesc *jd;
918         struct lfcc *lfcc;
919         LIST_HEAD(list);
920         struct gfs2_log_header_host lh;
921         int error;
922
923         error = gfs2_jindex_hold(sdp, &ji_gh);
924         if (error)
925                 return error;
926
927         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
928                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
929                 if (!lfcc) {
930                         error = -ENOMEM;
931                         goto out;
932                 }
933                 ip = GFS2_I(jd->jd_inode);
934                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
935                 if (error) {
936                         kfree(lfcc);
937                         goto out;
938                 }
939                 list_add(&lfcc->list, &list);
940         }
941
942         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
943                                LM_FLAG_PRIORITY | GL_NOCACHE,
944                                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