fs/gfs2/super.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License v.2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <asm/semaphore.h>
  16
  17 #include "gfs2.h"
  18 #include "bmap.h"
  19 #include "dir.h"
  20 #include "format.h"
  21 #include "glock.h"
  22 #include "glops.h"
  23 #include "inode.h"
  24 #include "log.h"
  25 #include "meta_io.h"
  26 #include "quota.h"
  27 #include "recovery.h"
  28 #include "rgrp.h"
  29 #include "super.h"
  30 #include "trans.h"
  31 #include "unlinked.h"
  32
  33 /**
  34  * gfs2_tune_init - Fill a gfs2_tune structure with default values
  35  * @gt: tune
  36  *
  37  */
  38
  39 void gfs2_tune_init(struct gfs2_tune *gt)
  40 {
  41         spin_lock_init(&gt->gt_spin);
  42
  43         gt->gt_ilimit = 100;
  44         gt->gt_ilimit_tries = 3;
  45         gt->gt_ilimit_min = 1;
  46         gt->gt_demote_secs = 300;
  47         gt->gt_incore_log_blocks = 1024;
  48         gt->gt_log_flush_secs = 60;
  49         gt->gt_jindex_refresh_secs = 60;
  50         gt->gt_scand_secs = 15;
  51         gt->gt_recoverd_secs = 60;
  52         gt->gt_logd_secs = 1;
  53         gt->gt_quotad_secs = 5;
  54         gt->gt_inoded_secs = 15;
  55         gt->gt_quota_simul_sync = 64;
  56         gt->gt_quota_warn_period = 10;
  57         gt->gt_quota_scale_num = 1;
  58         gt->gt_quota_scale_den = 1;
  59         gt->gt_quota_cache_secs = 300;
  60         gt->gt_quota_quantum = 60;
  61         gt->gt_atime_quantum = 3600;
  62         gt->gt_new_files_jdata = 0;
  63         gt->gt_new_files_directio = 0;
  64         gt->gt_max_atomic_write = 4 << 20;
  65         gt->gt_max_readahead = 1 << 18;
  66         gt->gt_lockdump_size = 131072;
  67         gt->gt_stall_secs = 600;
  68         gt->gt_complain_secs = 10;
  69         gt->gt_reclaim_limit = 5000;
  70         gt->gt_entries_per_readdir = 32;
  71         gt->gt_prefetch_secs = 10;
  72         gt->gt_greedy_default = HZ / 10;
  73         gt->gt_greedy_quantum = HZ / 40;
  74         gt->gt_greedy_max = HZ / 4;
  75         gt->gt_statfs_quantum = 30;
  76         gt->gt_statfs_slow = 0;
  77 }
  78
  79 /**
  80  * gfs2_check_sb - Check superblock
  81  * @sdp: the filesystem
  82  * @sb: The superblock
  83  * @silent: Don't print a message if the check fails
  84  *
  85  * Checks the version code of the FS is one that we understand how to
  86  * read and that the sizes of the various on-disk structures have not
  87  * changed.
  88  */
  89
  90 int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb *sb, int silent)
  91 {
  92         unsigned int x;
  93
  94         if (sb->sb_header.mh_magic != GFS2_MAGIC ||
  95             sb->sb_header.mh_type != GFS2_METATYPE_SB) {
  96                 if (!silent)
  97                         printk("GFS2: not a GFS2 filesystem\n");
  98                 return -EINVAL;
  99         }
 100
 101         /*  If format numbers match exactly, we're done.  */
 102
 103         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
 104             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
 105                 return 0;
 106
 107         if (sb->sb_fs_format != GFS2_FORMAT_FS) {
 108                 for (x = 0; gfs2_old_fs_formats[x]; x++)
 109                         if (gfs2_old_fs_formats[x] == sb->sb_fs_format)
 110                                 break;
 111
 112                 if (!gfs2_old_fs_formats[x]) {
 113                         printk("GFS2: code version (%u, %u) is incompatible "
 114                                "with ondisk format (%u, %u)\n",
 115                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 116                                sb->sb_fs_format, sb->sb_multihost_format);
 117                         printk("GFS2: I don't know how to upgrade this FS\n");
 118                         return -EINVAL;
 119                 }
 120         }
 121
 122         if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
 123                 for (x = 0; gfs2_old_multihost_formats[x]; x++)
 124                         if (gfs2_old_multihost_formats[x] == sb->sb_multihost_format)
 125                                 break;
 126
 127                 if (!gfs2_old_multihost_formats[x]) {
 128                         printk("GFS2: code version (%u, %u) is incompatible "
 129                                "with ondisk format (%u, %u)\n",
 130                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 131                                sb->sb_fs_format, sb->sb_multihost_format);
 132                         printk("GFS2: I don't know how to upgrade this FS\n");
 133                         return -EINVAL;
 134                 }
 135         }
 136
 137         if (!sdp->sd_args.ar_upgrade) {
 138                 printk("GFS2: code version (%u, %u) is incompatible "
 139                        "with ondisk format (%u, %u)\n",
 140                        GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 141                        sb->sb_fs_format, sb->sb_multihost_format);
 142                 printk("GFS2: Use the \"upgrade\" mount option to upgrade "
 143                        "the FS\n");
 144                 printk("GFS2: See the manual for more details\n");
 145                 return -EINVAL;
 146         }
 147
 148         return 0;
 149 }
 150
 151 /**
 152  * gfs2_read_sb - Read super block
 153  * @sdp: The GFS2 superblock
 154  * @gl: the glock for the superblock (assumed to be held)
 155  * @silent: Don't print message if mount fails
 156  *
 157  */
 158
 159 int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
 160 {
 161         struct buffer_head *bh;
 162         uint32_t hash_blocks, ind_blocks, leaf_blocks;
 163         uint32_t tmp_blocks;
 164         unsigned int x;
 165         int error;
 166
 167         error = gfs2_meta_read(gl, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift,
 168                                DIO_FORCE | DIO_START | DIO_WAIT, &bh);
 169         if (error) {
 170                 if (!silent)
 171                         fs_err(sdp, "can't read superblock\n");
 172                 return error;
 173         }
 174
 175         gfs2_assert(sdp, sizeof(struct gfs2_sb) <= bh->b_size);
 176         gfs2_sb_in(&sdp->sd_sb, bh->b_data);
 177         brelse(bh);
 178
 179         error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
 180         if (error)
 181                 return error;
 182
 183         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
 184                                GFS2_BASIC_BLOCK_SHIFT;
 185         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
 186         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
 187                           sizeof(struct gfs2_dinode)) / sizeof(uint64_t);
 188         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
 189                           sizeof(struct gfs2_meta_header)) / sizeof(uint64_t);
 190         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
 191         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
 192         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
 193         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(uint64_t);
 194         sdp->sd_ut_per_block = (sdp->sd_sb.sb_bsize -
 195                                 sizeof(struct gfs2_meta_header)) /
 196                                sizeof(struct gfs2_unlinked_tag);
 197         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
 198                                 sizeof(struct gfs2_meta_header)) /
 199                                sizeof(struct gfs2_quota_change);
 200
 201         /* Compute maximum reservation required to add a entry to a directory */
 202
 203         hash_blocks = DIV_RU(sizeof(uint64_t) * (1 << GFS2_DIR_MAX_DEPTH),
 204                              sdp->sd_jbsize);
 205
 206         ind_blocks = 0;
 207         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
 208                 tmp_blocks = DIV_RU(tmp_blocks, sdp->sd_inptrs);
 209                 ind_blocks += tmp_blocks;
 210         }
 211
 212         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
 213
 214         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
 215
 216         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
 217                                 sizeof(struct gfs2_dinode);
 218         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
 219         for (x = 2;; x++) {
 220                 uint64_t space, d;
 221                 uint32_t m;
 222
 223                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
 224                 d = space;
 225                 m = do_div(d, sdp->sd_inptrs);
 226
 227                 if (d != sdp->sd_heightsize[x - 1] || m)
 228                         break;
 229                 sdp->sd_heightsize[x] = space;
 230         }
 231         sdp->sd_max_height = x;
 232         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 233
 234         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
 235                                  sizeof(struct gfs2_dinode);
 236         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
 237         for (x = 2;; x++) {
 238                 uint64_t space, d;
 239                 uint32_t m;
 240
 241                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
 242                 d = space;
 243                 m = do_div(d, sdp->sd_inptrs);
 244
 245                 if (d != sdp->sd_jheightsize[x - 1] || m)
 246                         break;
 247                 sdp->sd_jheightsize[x] = space;
 248         }
 249         sdp->sd_max_jheight = x;
 250         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
 251
 252         return 0;
 253 }
 254
 255 int gfs2_do_upgrade(struct gfs2_sbd *sdp, struct gfs2_glock *sb_gl)
 256 {
 257         return 0;
 258 }
 259
 260 /**
 261  * gfs2_jindex_hold - Grab a lock on the jindex
 262  * @sdp: The GFS2 superblock
 263  * @ji_gh: the holder for the jindex glock
 264  *
 265  * This is very similar to the gfs2_rindex_hold() function, except that
 266  * in general we hold the jindex lock for longer periods of time and
 267  * we grab it far less frequently (in general) then the rgrp lock.
 268  *
 269  * Returns: errno
 270  */
 271
 272 int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 273 {
 274         struct gfs2_inode *dip = get_v2ip(sdp->sd_jindex);
 275         struct qstr name;
 276         char buf[20];
 277         struct gfs2_jdesc *jd;
 278         int error;
 279
 280         name.name = buf;
 281
 282         mutex_lock(&sdp->sd_jindex_mutex);
 283
 284         for (;;) {
 285                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED,
 286                                            GL_LOCAL_EXCL, ji_gh);
 287                 if (error)
 288                         break;
 289
 290                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
 291
 292                 error = gfs2_dir_search(get_v2ip(sdp->sd_jindex), &name, NULL, NULL);
 293                 if (error == -ENOENT) {
 294                         error = 0;
 295                         break;
 296                 }
 297
 298                 gfs2_glock_dq_uninit(ji_gh);
 299
 300                 if (error)
 301                         break;
 302
 303                 error = -ENOMEM;
 304                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
 305                 if (!jd)
 306                         break;
 307
 308                 error = gfs2_lookupi(sdp->sd_jindex, &name, 1, &jd->jd_inode);
 309                 if (error) {
 310                         kfree(jd);
 311                         break;
 312                 }
 313
 314                 spin_lock(&sdp->sd_jindex_spin);
 315                 jd->jd_jid = sdp->sd_journals++;
 316                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
 317                 spin_unlock(&sdp->sd_jindex_spin);
 318         }
 319
 320         mutex_unlock(&sdp->sd_jindex_mutex);
 321
 322         return error;
 323 }
 324
 325 /**
 326  * gfs2_jindex_free - Clear all the journal index information
 327  * @sdp: The GFS2 superblock
 328  *
 329  */
 330
 331 void gfs2_jindex_free(struct gfs2_sbd *sdp)
 332 {
 333         struct list_head list;
 334         struct gfs2_jdesc *jd;
 335
 336         spin_lock(&sdp->sd_jindex_spin);
 337         list_add(&list, &sdp->sd_jindex_list);
 338         list_del_init(&sdp->sd_jindex_list);
 339         sdp->sd_journals = 0;
 340         spin_unlock(&sdp->sd_jindex_spin);
 341
 342         while (!list_empty(&list)) {
 343                 jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
 344                 list_del(&jd->jd_list);
 345                 iput(jd->jd_inode);
 346                 kfree(jd);
 347         }
 348 }
 349
 350 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
 351 {
 352         struct gfs2_jdesc *jd;
 353         int found = 0;
 354
 355         list_for_each_entry(jd, head, jd_list) {
 356                 if (jd->jd_jid == jid) {
 357                         found = 1;
 358                         break;
 359                 }
 360         }
 361
 362         if (!found)
 363                 jd = NULL;
 364
 365         return jd;
 366 }
 367
 368 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
 369 {
 370         struct gfs2_jdesc *jd;
 371
 372         spin_lock(&sdp->sd_jindex_spin);
 373         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 374         spin_unlock(&sdp->sd_jindex_spin);
 375
 376         return jd;
 377 }
 378
 379 void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid)
 380 {
 381         struct gfs2_jdesc *jd;
 382
 383         spin_lock(&sdp->sd_jindex_spin);
 384         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 385         if (jd)
 386                 jd->jd_dirty = 1;
 387         spin_unlock(&sdp->sd_jindex_spin);
 388 }
 389
 390 struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp)
 391 {
 392         struct gfs2_jdesc *jd;
 393         int found = 0;
 394
 395         spin_lock(&sdp->sd_jindex_spin);
 396
 397         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 398                 if (jd->jd_dirty) {
 399                         jd->jd_dirty = 0;
 400                         found = 1;
 401                         break;
 402                 }
 403         }
 404         spin_unlock(&sdp->sd_jindex_spin);
 405
 406         if (!found)
 407                 jd = NULL;
 408
 409         return jd;
 410 }
 411
 412 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
 413 {
 414         struct gfs2_inode *ip = get_v2ip(jd->jd_inode);
 415         struct gfs2_sbd *sdp = ip->i_sbd;
 416         int ar;
 417         int error;
 418
 419         if (ip->i_di.di_size < (8 << 20) ||
 420             ip->i_di.di_size > (1 << 30) ||
 421             (ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) {
 422                 gfs2_consist_inode(ip);
 423                 return -EIO;
 424         }
 425         jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
 426
 427         error = gfs2_write_alloc_required(ip,
 428                                           0, ip->i_di.di_size,
 429                                           &ar);
 430         if (!error && ar) {
 431                 gfs2_consist_inode(ip);
 432                 error = -EIO;
 433         }
 434
 435         return error;
 436 }
 437
 438 int gfs2_lookup_master_dir(struct gfs2_sbd *sdp)
 439 {
 440         struct inode *inode = NULL;
 441         struct gfs2_glock *gl;
 442         int error;
 443
 444         error = gfs2_glock_get(sdp,
 445                                sdp->sd_sb.sb_master_dir.no_addr,
 446                                &gfs2_inode_glops, CREATE, &gl);
 447         if (!error) {
 448                 error = gfs2_lookup_simple(sdp->sd_root_dir, ".gfs2_admin", &inode);
 449                 sdp->sd_master_dir = inode;
 450                 gfs2_glock_put(gl);
 451         }
 452
 453         return error;
 454 }
 455
 456 /**
 457  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
 458  * @sdp: the filesystem
 459  *
 460  * Returns: errno
 461  */
 462
 463 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 464 {
 465         struct gfs2_glock *j_gl = get_v2ip(sdp->sd_jdesc->jd_inode)->i_gl;
 466         struct gfs2_holder t_gh;
 467         struct gfs2_log_header head;
 468         int error;
 469
 470         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
 471                                    GL_LOCAL_EXCL | GL_NEVER_RECURSE, &t_gh);
 472         if (error)
 473                 return error;
 474
 475         gfs2_meta_cache_flush(get_v2ip(sdp->sd_jdesc->jd_inode));
 476         j_gl->gl_ops->go_inval(j_gl, DIO_METADATA | DIO_DATA);
 477
 478         error = gfs2_find_jhead(sdp->sd_jdesc, &head);
 479         if (error)
 480                 goto fail;
 481
 482         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 483                 gfs2_consist(sdp);
 484                 error = -EIO;
 485                 goto fail;
 486         }
 487
 488         /*  Initialize some head of the log stuff  */
 489         sdp->sd_log_sequence = head.lh_sequence + 1;
 490         gfs2_log_pointers_init(sdp, head.lh_blkno);
 491
 492         error = gfs2_unlinked_init(sdp);
 493         if (error)
 494                 goto fail;
 495         error = gfs2_quota_init(sdp);
 496         if (error)
 497                 goto fail_unlinked;
 498
 499         set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 500
 501         gfs2_glock_dq_uninit(&t_gh);
 502
 503         return 0;
 504
 505  fail_unlinked:
 506         gfs2_unlinked_cleanup(sdp);
 507
 508  fail:
 509         t_gh.gh_flags |= GL_NOCACHE;
 510         gfs2_glock_dq_uninit(&t_gh);
 511
 512         return error;
 513 }
 514
 515 /**
 516  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
 517  * @sdp: the filesystem
 518  *
 519  * Returns: errno
 520  */
 521
 522 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
 523 {
 524         struct gfs2_holder t_gh;
 525         int error;
 526
 527         gfs2_unlinked_dealloc(sdp);
 528         gfs2_quota_sync(sdp);
 529         gfs2_statfs_sync(sdp);
 530
 531         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
 532                                 GL_LOCAL_EXCL | GL_NEVER_RECURSE | GL_NOCACHE,
 533                                 &t_gh);
 534         if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
 535                 return error;
 536
 537         gfs2_meta_syncfs(sdp);
 538         gfs2_log_shutdown(sdp);
 539
 540         clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 541
 542         if (t_gh.gh_gl)
 543                 gfs2_glock_dq_uninit(&t_gh);
 544
 545         gfs2_unlinked_cleanup(sdp);
 546         gfs2_quota_cleanup(sdp);
 547
 548         return error;
 549 }
 550
 551 int gfs2_statfs_init(struct gfs2_sbd *sdp)
 552 {
 553         struct gfs2_inode *m_ip = get_v2ip(sdp->sd_statfs_inode);
 554         struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
 555         struct gfs2_inode *l_ip = get_v2ip(sdp->sd_sc_inode);
 556         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 557         struct buffer_head *m_bh, *l_bh;
 558         struct gfs2_holder gh;
 559         int error;
 560
 561         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 562                                    &gh);
 563         if (error)
 564                 return error;
 565
 566         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 567         if (error)
 568                 goto out;
 569
 570         if (sdp->sd_args.ar_spectator) {
 571                 spin_lock(&sdp->sd_statfs_spin);
 572                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 573                                       sizeof(struct gfs2_dinode));
 574                 spin_unlock(&sdp->sd_statfs_spin);
 575         } else {
 576                 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 577                 if (error)
 578                         goto out_m_bh;
 579
 580                 spin_lock(&sdp->sd_statfs_spin);
 581                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 582                                       sizeof(struct gfs2_dinode));
 583                 gfs2_statfs_change_in(l_sc, l_bh->b_data +
 584                                       sizeof(struct gfs2_dinode));
 585                 spin_unlock(&sdp->sd_statfs_spin);
 586
 587                 brelse(l_bh);
 588         }
 589
 590  out_m_bh:
 591         brelse(m_bh);
 592
 593  out:
 594         gfs2_glock_dq_uninit(&gh);
 595
 596         return 0;
 597 }
 598
 599 void gfs2_statfs_change(struct gfs2_sbd *sdp, int64_t total, int64_t free,
 600                         int64_t dinodes)
 601 {
 602         struct gfs2_inode *l_ip = get_v2ip(sdp->sd_sc_inode);
 603         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 604         struct buffer_head *l_bh;
 605         int error;
 606
 607         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 608         if (error)
 609                 return;
 610
 611         mutex_lock(&sdp->sd_statfs_mutex);
 612         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 613         mutex_unlock(&sdp->sd_statfs_mutex);
 614
 615         spin_lock(&sdp->sd_statfs_spin);
 616         l_sc->sc_total += total;
 617         l_sc->sc_free += free;
 618         l_sc->sc_dinodes += dinodes;
 619         gfs2_statfs_change_out(l_sc, l_bh->b_data +
 620                                sizeof(struct gfs2_dinode));
 621         spin_unlock(&sdp->sd_statfs_spin);
 622
 623         brelse(l_bh);
 624 }
 625
 626 int gfs2_statfs_sync(struct gfs2_sbd *sdp)
 627 {
 628         struct gfs2_inode *m_ip = get_v2ip(sdp->sd_statfs_inode);
 629         struct gfs2_inode *l_ip = get_v2ip(sdp->sd_sc_inode);
 630         struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
 631         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 632         struct gfs2_holder gh;
 633         struct buffer_head *m_bh, *l_bh;
 634         int error;
 635
 636         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 637                                    &gh);
 638         if (error)
 639                 return error;
 640
 641         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 642         if (error)
 643                 goto out;
 644
 645         spin_lock(&sdp->sd_statfs_spin);
 646         gfs2_statfs_change_in(m_sc, m_bh->b_data +
 647                               sizeof(struct gfs2_dinode));
 648         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
 649                 spin_unlock(&sdp->sd_statfs_spin);
 650                 goto out_bh;
 651         }
 652         spin_unlock(&sdp->sd_statfs_spin);
 653
 654         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 655         if (error)
 656                 goto out_bh;
 657
 658         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
 659         if (error)
 660                 goto out_bh2;
 661
 662         mutex_lock(&sdp->sd_statfs_mutex);
 663         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 664         mutex_unlock(&sdp->sd_statfs_mutex);
 665
 666         spin_lock(&sdp->sd_statfs_spin);
 667         m_sc->sc_total += l_sc->sc_total;
 668         m_sc->sc_free += l_sc->sc_free;
 669         m_sc->sc_dinodes += l_sc->sc_dinodes;
 670         memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
 671         memset(l_bh->b_data + sizeof(struct gfs2_dinode),
 672                0, sizeof(struct gfs2_statfs_change));
 673         spin_unlock(&sdp->sd_statfs_spin);
 674
 675         gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
 676         gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
 677
 678         gfs2_trans_end(sdp);
 679
 680  out_bh2:
 681         brelse(l_bh);
 682
 683  out_bh:
 684         brelse(m_bh);
 685
 686  out:
 687         gfs2_glock_dq_uninit(&gh);
 688
 689         return error;
 690 }
 691
 692 /**
 693  * gfs2_statfs_i - Do a statfs
 694  * @sdp: the filesystem
 695  * @sg: the sg structure
 696  *
 697  * Returns: errno
 698  */
 699
 700 int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc)
 701 {
 702         struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
 703         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 704
 705         spin_lock(&sdp->sd_statfs_spin);
 706
 707         *sc = *m_sc;
 708         sc->sc_total += l_sc->sc_total;
 709         sc->sc_free += l_sc->sc_free;
 710         sc->sc_dinodes += l_sc->sc_dinodes;
 711
 712         spin_unlock(&sdp->sd_statfs_spin);
 713
 714         if (sc->sc_free < 0)
 715                 sc->sc_free = 0;
 716         if (sc->sc_free > sc->sc_total)
 717                 sc->sc_free = sc->sc_total;
 718         if (sc->sc_dinodes < 0)
 719                 sc->sc_dinodes = 0;
 720
 721         return 0;
 722 }
 723
 724 /**
 725  * statfs_fill - fill in the sg for a given RG
 726  * @rgd: the RG
 727  * @sc: the sc structure
 728  *
 729  * Returns: 0 on success, -ESTALE if the LVB is invalid
 730  */
 731
 732 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
 733                             struct gfs2_statfs_change *sc)
 734 {
 735         gfs2_rgrp_verify(rgd);
 736         sc->sc_total += rgd->rd_ri.ri_data;
 737         sc->sc_free += rgd->rd_rg.rg_free;
 738         sc->sc_dinodes += rgd->rd_rg.rg_dinodes;
 739         return 0;
 740 }
 741
 742 /**
 743  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
 744  * @sdp: the filesystem
 745  * @sc: the sc info that will be returned
 746  *
 747  * Any error (other than a signal) will cause this routine to fall back
 748  * to the synchronous version.
 749  *
 750  * FIXME: This really shouldn't busy wait like this.
 751  *
 752  * Returns: errno
 753  */
 754
 755 int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc)
 756 {
 757         struct gfs2_holder ri_gh;
 758         struct gfs2_rgrpd *rgd_next;
 759         struct gfs2_holder *gha, *gh;
 760         unsigned int slots = 64;
 761         unsigned int x;
 762         int done;
 763         int error = 0, err;
 764
 765         memset(sc, 0, sizeof(struct gfs2_statfs_change));
 766         gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
 767         if (!gha)
 768                 return -ENOMEM;
 769
 770         error = gfs2_rindex_hold(sdp, &ri_gh);
 771         if (error)
 772                 goto out;
 773
 774         rgd_next = gfs2_rgrpd_get_first(sdp);
 775
 776         for (;;) {
 777                 done = 1;
 778
 779                 for (x = 0; x < slots; x++) {
 780                         gh = gha + x;
 781
 782                         if (gh->gh_gl && gfs2_glock_poll(gh)) {
 783                                 err = gfs2_glock_wait(gh);
 784                                 if (err) {
 785                                         gfs2_holder_uninit(gh);
 786                                         error = err;
 787                                 } else {
 788                                         if (!error)
 789                                                 error = statfs_slow_fill(get_gl2rgd(gh->gh_gl), sc);
 790                                         gfs2_glock_dq_uninit(gh);
 791                                 }
 792                         }
 793
 794                         if (gh->gh_gl)
 795                                 done = 0;
 796                         else if (rgd_next && !error) {
 797                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
 798                                                            LM_ST_SHARED,
 799                                                            GL_ASYNC,
 800                                                            gh);
 801                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
 802                                 done = 0;
 803                         }
 804
 805                         if (signal_pending(current))
 806                                 error = -ERESTARTSYS;
 807                 }
 808
 809                 if (done)
 810                         break;
 811
 812                 yield();
 813         }
 814
 815         gfs2_glock_dq_uninit(&ri_gh);
 816
 817  out:
 818         kfree(gha);
 819
 820         return error;
 821 }
 822
 823 struct lfcc {
 824         struct list_head list;
 825         struct gfs2_holder gh;
 826 };
 827
 828 /**
 829  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
 830  *                            journals are clean
 831  * @sdp: the file system
 832  * @state: the state to put the transaction lock into
 833  * @t_gh: the hold on the transaction lock
 834  *
 835  * Returns: errno
 836  */
 837
 838 int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp, struct gfs2_holder *t_gh)
 839 {
 840         struct gfs2_holder ji_gh;
 841         struct gfs2_jdesc *jd;
 842         struct lfcc *lfcc;
 843         LIST_HEAD(list);
 844         struct gfs2_log_header lh;
 845         int error;
 846
 847         error = gfs2_jindex_hold(sdp, &ji_gh);
 848         if (error)
 849                 return error;
 850
 851         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 852                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
 853                 if (!lfcc) {
 854                         error = -ENOMEM;
 855                         goto out;
 856                 }
 857                 error = gfs2_glock_nq_init(get_v2ip(jd->jd_inode)->i_gl, LM_ST_SHARED, 0,
 858                                            &lfcc->gh);
 859                 if (error) {
 860                         kfree(lfcc);
 861                         goto out;
 862                 }
 863                 list_add(&lfcc->list, &list);
 864         }
 865
 866         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
 867                                LM_FLAG_PRIORITY | GL_NEVER_RECURSE | GL_NOCACHE,
 868                                t_gh);
 869
 870         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 871                 error = gfs2_jdesc_check(jd);
 872                 if (error)
 873                         break;
 874                 error = gfs2_find_jhead(jd, &lh);
 875                 if (error)
 876                         break;
 877                 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 878                         error = -EBUSY;
 879                         break;
 880                 }
 881         }
 882
 883         if (error)
 884                 gfs2_glock_dq_uninit(t_gh);
 885
 886  out:
 887         while (!list_empty(&list)) {
 888                 lfcc = list_entry(list.next, struct lfcc, list);
 889                 list_del(&lfcc->list);
 890                 gfs2_glock_dq_uninit(&lfcc->gh);
 891                 kfree(lfcc);
 892         }
 893         gfs2_glock_dq_uninit(&ji_gh);
 894
 895         return error;
 896 }
 897
 898 /**
 899  * gfs2_freeze_fs - freezes the file system
 900  * @sdp: the file system
 901  *
 902  * This function flushes data and meta data for all machines by
 903  * aquiring the transaction log exclusively.  All journals are
 904  * ensured to be in a clean state as well.
 905  *
 906  * Returns: errno
 907  */
 908
 909 int gfs2_freeze_fs(struct gfs2_sbd *sdp)
 910 {
 911         int error = 0;
 912
 913         mutex_lock(&sdp->sd_freeze_lock);
 914
 915         if (!sdp->sd_freeze_count++) {
 916                 error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
 917                 if (error)
 918                         sdp->sd_freeze_count--;
 919         }
 920
 921         mutex_unlock(&sdp->sd_freeze_lock);
 922
 923         return error;
 924 }
 925
 926 /**
 927  * gfs2_unfreeze_fs - unfreezes the file system
 928  * @sdp: the file system
 929  *
 930  * This function allows the file system to proceed by unlocking
 931  * the exclusively held transaction lock.  Other GFS2 nodes are
 932  * now free to acquire the lock shared and go on with their lives.
 933  *
 934  */
 935
 936 void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
 937 {
 938         mutex_lock(&sdp->sd_freeze_lock);
 939
 940         if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
 941                 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
 942
 943         mutex_unlock(&sdp->sd_freeze_lock);
 944 }
 945