git.oblomov.eu Git - linux-2.6/blob - 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(KERN_WARNING "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(KERN_WARNING
 114                                "GFS2: code version (%u, %u) is incompatible "
 115                                "with ondisk format (%u, %u)\n",
 116                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 117                                sb->sb_fs_format, sb->sb_multihost_format);
 118                         printk(KERN_WARNING
 119                                "GFS2: I don't know how to upgrade this FS\n");
 120                         return -EINVAL;
 121                 }
 122         }
 123
 124         if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
 125                 for (x = 0; gfs2_old_multihost_formats[x]; x++)
 126                         if (gfs2_old_multihost_formats[x] ==
 127                             sb->sb_multihost_format)
 128                                 break;
 129
 130                 if (!gfs2_old_multihost_formats[x]) {
 131                         printk(KERN_WARNING
 132                                "GFS2: code version (%u, %u) is incompatible "
 133                                "with ondisk format (%u, %u)\n",
 134                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 135                                sb->sb_fs_format, sb->sb_multihost_format);
 136                         printk(KERN_WARNING
 137                                "GFS2: I don't know how to upgrade this FS\n");
 138                         return -EINVAL;
 139                 }
 140         }
 141
 142         if (!sdp->sd_args.ar_upgrade) {
 143                 printk(KERN_WARNING
 144                        "GFS2: code version (%u, %u) is incompatible "
 145                        "with ondisk format (%u, %u)\n",
 146                        GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 147                        sb->sb_fs_format, sb->sb_multihost_format);
 148                 printk(KERN_INFO
 149                        "GFS2: Use the \"upgrade\" mount option to upgrade "
 150                        "the FS\n");
 151                 printk(KERN_INFO "GFS2: See the manual for more details\n");
 152                 return -EINVAL;
 153         }
 154
 155         return 0;
 156 }
 157
 158 /**
 159  * gfs2_read_sb - Read super block
 160  * @sdp: The GFS2 superblock
 161  * @gl: the glock for the superblock (assumed to be held)
 162  * @silent: Don't print message if mount fails
 163  *
 164  */
 165
 166 int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
 167 {
 168         struct buffer_head *bh;
 169         uint32_t hash_blocks, ind_blocks, leaf_blocks;
 170         uint32_t tmp_blocks;
 171         unsigned int x;
 172         int error;
 173
 174         error = gfs2_meta_read(gl, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift,
 175                                DIO_FORCE | DIO_START | DIO_WAIT, &bh);
 176         if (error) {
 177                 if (!silent)
 178                         fs_err(sdp, "can't read superblock\n");
 179                 return error;
 180         }
 181
 182         gfs2_assert(sdp, sizeof(struct gfs2_sb) <= bh->b_size);
 183         gfs2_sb_in(&sdp->sd_sb, bh->b_data);
 184         brelse(bh);
 185
 186         error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
 187         if (error)
 188                 return error;
 189
 190         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
 191                                GFS2_BASIC_BLOCK_SHIFT;
 192         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
 193         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
 194                           sizeof(struct gfs2_dinode)) / sizeof(uint64_t);
 195         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
 196                           sizeof(struct gfs2_meta_header)) / sizeof(uint64_t);
 197         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
 198         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
 199         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
 200         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(uint64_t);
 201         sdp->sd_ut_per_block = (sdp->sd_sb.sb_bsize -
 202                                 sizeof(struct gfs2_meta_header)) /
 203                                sizeof(struct gfs2_unlinked_tag);
 204         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
 205                                 sizeof(struct gfs2_meta_header)) /
 206                                sizeof(struct gfs2_quota_change);
 207
 208         /* Compute maximum reservation required to add a entry to a directory */
 209
 210         hash_blocks = DIV_RU(sizeof(uint64_t) * (1 << GFS2_DIR_MAX_DEPTH),
 211                              sdp->sd_jbsize);
 212
 213         ind_blocks = 0;
 214         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
 215                 tmp_blocks = DIV_RU(tmp_blocks, sdp->sd_inptrs);
 216                 ind_blocks += tmp_blocks;
 217         }
 218
 219         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
 220
 221         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
 222
 223         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
 224                                 sizeof(struct gfs2_dinode);
 225         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
 226         for (x = 2;; x++) {
 227                 uint64_t space, d;
 228                 uint32_t m;
 229
 230                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
 231                 d = space;
 232                 m = do_div(d, sdp->sd_inptrs);
 233
 234                 if (d != sdp->sd_heightsize[x - 1] || m)
 235                         break;
 236                 sdp->sd_heightsize[x] = space;
 237         }
 238         sdp->sd_max_height = x;
 239         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 240
 241         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
 242                                  sizeof(struct gfs2_dinode);
 243         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
 244         for (x = 2;; x++) {
 245                 uint64_t space, d;
 246                 uint32_t m;
 247
 248                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
 249                 d = space;
 250                 m = do_div(d, sdp->sd_inptrs);
 251
 252                 if (d != sdp->sd_jheightsize[x - 1] || m)
 253                         break;
 254                 sdp->sd_jheightsize[x] = space;
 255         }
 256         sdp->sd_max_jheight = x;
 257         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
 258
 259         return 0;
 260 }
 261
 262 int gfs2_do_upgrade(struct gfs2_sbd *sdp, struct gfs2_glock *sb_gl)
 263 {
 264         return 0;
 265 }
 266
 267 /**
 268  * gfs2_jindex_hold - Grab a lock on the jindex
 269  * @sdp: The GFS2 superblock
 270  * @ji_gh: the holder for the jindex glock
 271  *
 272  * This is very similar to the gfs2_rindex_hold() function, except that
 273  * in general we hold the jindex lock for longer periods of time and
 274  * we grab it far less frequently (in general) then the rgrp lock.
 275  *
 276  * Returns: errno
 277  */
 278
 279 int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 280 {
 281         struct gfs2_inode *dip = get_v2ip(sdp->sd_jindex);
 282         struct qstr name;
 283         char buf[20];
 284         struct gfs2_jdesc *jd;
 285         int error;
 286
 287         name.name = buf;
 288
 289         mutex_lock(&sdp->sd_jindex_mutex);
 290
 291         for (;;) {
 292                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED,
 293                                            GL_LOCAL_EXCL, ji_gh);
 294                 if (error)
 295                         break;
 296
 297                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
 298
 299                 error = gfs2_dir_search(get_v2ip(sdp->sd_jindex),
 300                                         &name, NULL, NULL);
 301                 if (error == -ENOENT) {
 302                         error = 0;
 303                         break;
 304                 }
 305
 306                 gfs2_glock_dq_uninit(ji_gh);
 307
 308                 if (error)
 309                         break;
 310
 311                 error = -ENOMEM;
 312                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
 313                 if (!jd)
 314                         break;
 315
 316                 error = gfs2_lookupi(sdp->sd_jindex, &name, 1, &jd->jd_inode);
 317                 if (error) {
 318                         kfree(jd);
 319                         break;
 320                 }
 321
 322                 spin_lock(&sdp->sd_jindex_spin);
 323                 jd->jd_jid = sdp->sd_journals++;
 324                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
 325                 spin_unlock(&sdp->sd_jindex_spin);
 326         }
 327
 328         mutex_unlock(&sdp->sd_jindex_mutex);
 329
 330         return error;
 331 }
 332
 333 /**
 334  * gfs2_jindex_free - Clear all the journal index information
 335  * @sdp: The GFS2 superblock
 336  *
 337  */
 338
 339 void gfs2_jindex_free(struct gfs2_sbd *sdp)
 340 {
 341         struct list_head list;
 342         struct gfs2_jdesc *jd;
 343
 344         spin_lock(&sdp->sd_jindex_spin);
 345         list_add(&list, &sdp->sd_jindex_list);
 346         list_del_init(&sdp->sd_jindex_list);
 347         sdp->sd_journals = 0;
 348         spin_unlock(&sdp->sd_jindex_spin);
 349
 350         while (!list_empty(&list)) {
 351                 jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
 352                 list_del(&jd->jd_list);
 353                 iput(jd->jd_inode);
 354                 kfree(jd);
 355         }
 356 }
 357
 358 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
 359 {
 360         struct gfs2_jdesc *jd;
 361         int found = 0;
 362
 363         list_for_each_entry(jd, head, jd_list) {
 364                 if (jd->jd_jid == jid) {
 365                         found = 1;
 366                         break;
 367                 }
 368         }
 369
 370         if (!found)
 371                 jd = NULL;
 372
 373         return jd;
 374 }
 375
 376 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
 377 {
 378         struct gfs2_jdesc *jd;
 379
 380         spin_lock(&sdp->sd_jindex_spin);
 381         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 382         spin_unlock(&sdp->sd_jindex_spin);
 383
 384         return jd;
 385 }
 386
 387 void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid)
 388 {
 389         struct gfs2_jdesc *jd;
 390
 391         spin_lock(&sdp->sd_jindex_spin);
 392         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 393         if (jd)
 394                 jd->jd_dirty = 1;
 395         spin_unlock(&sdp->sd_jindex_spin);
 396 }
 397
 398 struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp)
 399 {
 400         struct gfs2_jdesc *jd;
 401         int found = 0;
 402
 403         spin_lock(&sdp->sd_jindex_spin);
 404
 405         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 406                 if (jd->jd_dirty) {
 407                         jd->jd_dirty = 0;
 408                         found = 1;
 409                         break;
 410                 }
 411         }
 412         spin_unlock(&sdp->sd_jindex_spin);
 413
 414         if (!found)
 415                 jd = NULL;
 416
 417         return jd;
 418 }
 419
 420 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
 421 {
 422         struct gfs2_inode *ip = get_v2ip(jd->jd_inode);
 423         struct gfs2_sbd *sdp = ip->i_sbd;
 424         int ar;
 425         int error;
 426
 427         if (ip->i_di.di_size < (8 << 20) ||
 428             ip->i_di.di_size > (1 << 30) ||
 429             (ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) {
 430                 gfs2_consist_inode(ip);
 431                 return -EIO;
 432         }
 433         jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
 434
 435         error = gfs2_write_alloc_required(ip,
 436                                           0, ip->i_di.di_size,
 437                                           &ar);
 438         if (!error && ar) {
 439                 gfs2_consist_inode(ip);
 440                 error = -EIO;
 441         }
 442
 443         return error;
 444 }
 445
 446 int gfs2_lookup_master_dir(struct gfs2_sbd *sdp)
 447 {
 448         struct inode *inode = NULL;
 449         struct gfs2_glock *gl;
 450         int error;
 451
 452         error = gfs2_glock_get(sdp,
 453                                sdp->sd_sb.sb_master_dir.no_addr,
 454                                &gfs2_inode_glops, CREATE, &gl);
 455         if (!error) {
 456                 error = gfs2_lookup_simple(sdp->sd_root_dir, ".gfs2_admin",
 457                                            &inode);
 458                 sdp->sd_master_dir = inode;
 459                 gfs2_glock_put(gl);
 460         }
 461
 462         return error;
 463 }
 464
 465 /**
 466  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
 467  * @sdp: the filesystem
 468  *
 469  * Returns: errno
 470  */
 471
 472 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 473 {
 474         struct gfs2_glock *j_gl = get_v2ip(sdp->sd_jdesc->jd_inode)->i_gl;
 475         struct gfs2_holder t_gh;
 476         struct gfs2_log_header head;
 477         int error;
 478
 479         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
 480                                    GL_LOCAL_EXCL | GL_NEVER_RECURSE, &t_gh);
 481         if (error)
 482                 return error;
 483
 484         gfs2_meta_cache_flush(get_v2ip(sdp->sd_jdesc->jd_inode));
 485         j_gl->gl_ops->go_inval(j_gl, DIO_METADATA | DIO_DATA);
 486
 487         error = gfs2_find_jhead(sdp->sd_jdesc, &head);
 488         if (error)
 489                 goto fail;
 490
 491         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 492                 gfs2_consist(sdp);
 493                 error = -EIO;
 494                 goto fail;
 495         }
 496
 497         /*  Initialize some head of the log stuff  */
 498         sdp->sd_log_sequence = head.lh_sequence + 1;
 499         gfs2_log_pointers_init(sdp, head.lh_blkno);
 500
 501         error = gfs2_unlinked_init(sdp);
 502         if (error)
 503                 goto fail;
 504         error = gfs2_quota_init(sdp);
 505         if (error)
 506                 goto fail_unlinked;
 507
 508         set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 509
 510         gfs2_glock_dq_uninit(&t_gh);
 511
 512         return 0;
 513
 514  fail_unlinked:
 515         gfs2_unlinked_cleanup(sdp);
 516
 517  fail:
 518         t_gh.gh_flags |= GL_NOCACHE;
 519         gfs2_glock_dq_uninit(&t_gh);
 520
 521         return error;
 522 }
 523
 524 /**
 525  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
 526  * @sdp: the filesystem
 527  *
 528  * Returns: errno
 529  */
 530
 531 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
 532 {
 533         struct gfs2_holder t_gh;
 534         int error;
 535
 536         gfs2_unlinked_dealloc(sdp);
 537         gfs2_quota_sync(sdp);
 538         gfs2_statfs_sync(sdp);
 539
 540         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
 541                                 GL_LOCAL_EXCL | GL_NEVER_RECURSE | GL_NOCACHE,
 542                                 &t_gh);
 543         if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
 544                 return error;
 545
 546         gfs2_meta_syncfs(sdp);
 547         gfs2_log_shutdown(sdp);
 548
 549         clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 550
 551         if (t_gh.gh_gl)
 552                 gfs2_glock_dq_uninit(&t_gh);
 553
 554         gfs2_unlinked_cleanup(sdp);
 555         gfs2_quota_cleanup(sdp);
 556
 557         return error;
 558 }
 559
 560 int gfs2_statfs_init(struct gfs2_sbd *sdp)
 561 {
 562         struct gfs2_inode *m_ip = get_v2ip(sdp->sd_statfs_inode);
 563         struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
 564         struct gfs2_inode *l_ip = get_v2ip(sdp->sd_sc_inode);
 565         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 566         struct buffer_head *m_bh, *l_bh;
 567         struct gfs2_holder gh;
 568         int error;
 569
 570         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 571                                    &gh);
 572         if (error)
 573                 return error;
 574
 575         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 576         if (error)
 577                 goto out;
 578
 579         if (sdp->sd_args.ar_spectator) {
 580                 spin_lock(&sdp->sd_statfs_spin);
 581                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 582                                       sizeof(struct gfs2_dinode));
 583                 spin_unlock(&sdp->sd_statfs_spin);
 584         } else {
 585                 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 586                 if (error)
 587                         goto out_m_bh;
 588
 589                 spin_lock(&sdp->sd_statfs_spin);
 590                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 591                                       sizeof(struct gfs2_dinode));
 592                 gfs2_statfs_change_in(l_sc, l_bh->b_data +
 593                                       sizeof(struct gfs2_dinode));
 594                 spin_unlock(&sdp->sd_statfs_spin);
 595
 596                 brelse(l_bh);
 597         }
 598
 599  out_m_bh:
 600         brelse(m_bh);
 601
 602  out:
 603         gfs2_glock_dq_uninit(&gh);
 604
 605         return 0;
 606 }
 607
 608 void gfs2_statfs_change(struct gfs2_sbd *sdp, int64_t total, int64_t free,
 609                         int64_t dinodes)
 610 {
 611         struct gfs2_inode *l_ip = get_v2ip(sdp->sd_sc_inode);
 612         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 613         struct buffer_head *l_bh;
 614         int error;
 615
 616         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 617         if (error)
 618                 return;
 619
 620         mutex_lock(&sdp->sd_statfs_mutex);
 621         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 622         mutex_unlock(&sdp->sd_statfs_mutex);
 623
 624         spin_lock(&sdp->sd_statfs_spin);
 625         l_sc->sc_total += total;
 626         l_sc->sc_free += free;
 627         l_sc->sc_dinodes += dinodes;
 628         gfs2_statfs_change_out(l_sc, l_bh->b_data +
 629                                sizeof(struct gfs2_dinode));
 630         spin_unlock(&sdp->sd_statfs_spin);
 631
 632         brelse(l_bh);
 633 }
 634
 635 int gfs2_statfs_sync(struct gfs2_sbd *sdp)
 636 {
 637         struct gfs2_inode *m_ip = get_v2ip(sdp->sd_statfs_inode);
 638         struct gfs2_inode *l_ip = get_v2ip(sdp->sd_sc_inode);
 639         struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
 640         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 641         struct gfs2_holder gh;
 642         struct buffer_head *m_bh, *l_bh;
 643         int error;
 644
 645         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 646                                    &gh);
 647         if (error)
 648                 return error;
 649
 650         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 651         if (error)
 652                 goto out;
 653
 654         spin_lock(&sdp->sd_statfs_spin);
 655         gfs2_statfs_change_in(m_sc, m_bh->b_data +
 656                               sizeof(struct gfs2_dinode));
 657         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
 658                 spin_unlock(&sdp->sd_statfs_spin);
 659                 goto out_bh;
 660         }
 661         spin_unlock(&sdp->sd_statfs_spin);
 662
 663         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 664         if (error)
 665                 goto out_bh;
 666
 667         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
 668         if (error)
 669                 goto out_bh2;
 670
 671         mutex_lock(&sdp->sd_statfs_mutex);
 672         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 673         mutex_unlock(&sdp->sd_statfs_mutex);
 674
 675         spin_lock(&sdp->sd_statfs_spin);
 676         m_sc->sc_total += l_sc->sc_total;
 677         m_sc->sc_free += l_sc->sc_free;
 678         m_sc->sc_dinodes += l_sc->sc_dinodes;
 679         memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
 680         memset(l_bh->b_data + sizeof(struct gfs2_dinode),
 681                0, sizeof(struct gfs2_statfs_change));
 682         spin_unlock(&sdp->sd_statfs_spin);
 683
 684         gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
 685         gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
 686
 687         gfs2_trans_end(sdp);
 688
 689  out_bh2:
 690         brelse(l_bh);
 691
 692  out_bh:
 693         brelse(m_bh);
 694
 695  out:
 696         gfs2_glock_dq_uninit(&gh);
 697
 698         return error;
 699 }
 700
 701 /**
 702  * gfs2_statfs_i - Do a statfs
 703  * @sdp: the filesystem
 704  * @sg: the sg structure
 705  *
 706  * Returns: errno
 707  */
 708
 709 int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc)
 710 {
 711         struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
 712         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 713
 714         spin_lock(&sdp->sd_statfs_spin);
 715
 716         *sc = *m_sc;
 717         sc->sc_total += l_sc->sc_total;
 718         sc->sc_free += l_sc->sc_free;
 719         sc->sc_dinodes += l_sc->sc_dinodes;
 720
 721         spin_unlock(&sdp->sd_statfs_spin);
 722
 723         if (sc->sc_free < 0)
 724                 sc->sc_free = 0;
 725         if (sc->sc_free > sc->sc_total)
 726                 sc->sc_free = sc->sc_total;
 727         if (sc->sc_dinodes < 0)
 728                 sc->sc_dinodes = 0;
 729
 730         return 0;
 731 }
 732
 733 /**
 734  * statfs_fill - fill in the sg for a given RG
 735  * @rgd: the RG
 736  * @sc: the sc structure
 737  *
 738  * Returns: 0 on success, -ESTALE if the LVB is invalid
 739  */
 740
 741 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
 742                             struct gfs2_statfs_change *sc)
 743 {
 744         gfs2_rgrp_verify(rgd);
 745         sc->sc_total += rgd->rd_ri.ri_data;
 746         sc->sc_free += rgd->rd_rg.rg_free;
 747         sc->sc_dinodes += rgd->rd_rg.rg_dinodes;
 748         return 0;
 749 }
 750
 751 /**
 752  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
 753  * @sdp: the filesystem
 754  * @sc: the sc info that will be returned
 755  *
 756  * Any error (other than a signal) will cause this routine to fall back
 757  * to the synchronous version.
 758  *
 759  * FIXME: This really shouldn't busy wait like this.
 760  *
 761  * Returns: errno
 762  */
 763
 764 int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc)
 765 {
 766         struct gfs2_holder ri_gh;
 767         struct gfs2_rgrpd *rgd_next;
 768         struct gfs2_holder *gha, *gh;
 769         unsigned int slots = 64;
 770         unsigned int x;
 771         int done;
 772         int error = 0, err;
 773
 774         memset(sc, 0, sizeof(struct gfs2_statfs_change));
 775         gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
 776         if (!gha)
 777                 return -ENOMEM;
 778
 779         error = gfs2_rindex_hold(sdp, &ri_gh);
 780         if (error)
 781                 goto out;
 782
 783         rgd_next = gfs2_rgrpd_get_first(sdp);
 784
 785         for (;;) {
 786                 done = 1;
 787
 788                 for (x = 0; x < slots; x++) {
 789                         gh = gha + x;
 790
 791                         if (gh->gh_gl && gfs2_glock_poll(gh)) {
 792                                 err = gfs2_glock_wait(gh);
 793                                 if (err) {
 794                                         gfs2_holder_uninit(gh);
 795                                         error = err;
 796                                 } else {
 797                                         if (!error)
 798                                                 error = statfs_slow_fill(get_gl2rgd(gh->gh_gl), sc);
 799                                         gfs2_glock_dq_uninit(gh);
 800                                 }
 801                         }
 802
 803                         if (gh->gh_gl)
 804                                 done = 0;
 805                         else if (rgd_next && !error) {
 806                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
 807                                                            LM_ST_SHARED,
 808                                                            GL_ASYNC,
 809                                                            gh);
 810                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
 811                                 done = 0;
 812                         }
 813
 814                         if (signal_pending(current))
 815                                 error = -ERESTARTSYS;
 816                 }
 817
 818                 if (done)
 819                         break;
 820
 821                 yield();
 822         }
 823
 824         gfs2_glock_dq_uninit(&ri_gh);
 825
 826  out:
 827         kfree(gha);
 828
 829         return error;
 830 }
 831
 832 struct lfcc {
 833         struct list_head list;
 834         struct gfs2_holder gh;
 835 };
 836
 837 /**
 838  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
 839  *                            journals are clean
 840  * @sdp: the file system
 841  * @state: the state to put the transaction lock into
 842  * @t_gh: the hold on the transaction lock
 843  *
 844  * Returns: errno
 845  */
 846
 847 int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp, struct gfs2_holder *t_gh)
 848 {
 849         struct gfs2_holder ji_gh;
 850         struct gfs2_jdesc *jd;
 851         struct lfcc *lfcc;
 852         LIST_HEAD(list);
 853         struct gfs2_log_header lh;
 854         int error;
 855
 856         error = gfs2_jindex_hold(sdp, &ji_gh);
 857         if (error)
 858                 return error;
 859
 860         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 861                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
 862                 if (!lfcc) {
 863                         error = -ENOMEM;
 864                         goto out;
 865                 }
 866                 error = gfs2_glock_nq_init(get_v2ip(jd->jd_inode)->i_gl,
 867                                            LM_ST_SHARED, 0,
 868                                            &lfcc->gh);
 869                 if (error) {
 870                         kfree(lfcc);
 871                         goto out;
 872                 }
 873                 list_add(&lfcc->list, &list);
 874         }
 875
 876         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
 877                                LM_FLAG_PRIORITY | GL_NEVER_RECURSE | GL_NOCACHE,
 878                                t_gh);
 879
 880         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 881                 error = gfs2_jdesc_check(jd);
 882                 if (error)
 883                         break;
 884                 error = gfs2_find_jhead(jd, &lh);
 885                 if (error)
 886                         break;
 887                 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 888                         error = -EBUSY;
 889                         break;
 890                 }
 891         }
 892
 893         if (error)
 894                 gfs2_glock_dq_uninit(t_gh);
 895
 896  out:
 897         while (!list_empty(&list)) {
 898                 lfcc = list_entry(list.next, struct lfcc, list);
 899                 list_del(&lfcc->list);
 900                 gfs2_glock_dq_uninit(&lfcc->gh);
 901                 kfree(lfcc);
 902         }
 903         gfs2_glock_dq_uninit(&ji_gh);
 904
 905         return error;
 906 }
 907
 908 /**
 909  * gfs2_freeze_fs - freezes the file system
 910  * @sdp: the file system
 911  *
 912  * This function flushes data and meta data for all machines by
 913  * aquiring the transaction log exclusively.  All journals are
 914  * ensured to be in a clean state as well.
 915  *
 916  * Returns: errno
 917  */
 918
 919 int gfs2_freeze_fs(struct gfs2_sbd *sdp)
 920 {
 921         int error = 0;
 922
 923         mutex_lock(&sdp->sd_freeze_lock);
 924
 925         if (!sdp->sd_freeze_count++) {
 926                 error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
 927                 if (error)
 928                         sdp->sd_freeze_count--;
 929         }
 930
 931         mutex_unlock(&sdp->sd_freeze_lock);
 932
 933         return error;
 934 }
 935
 936 /**
 937  * gfs2_unfreeze_fs - unfreezes the file system
 938  * @sdp: the file system
 939  *
 940  * This function allows the file system to proceed by unlocking
 941  * the exclusively held transaction lock.  Other GFS2 nodes are
 942  * now free to acquire the lock shared and go on with their lives.
 943  *
 944  */
 945
 946 void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
 947 {
 948         mutex_lock(&sdp->sd_freeze_lock);
 949
 950         if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
 951                 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
 952
 953         mutex_unlock(&sdp->sd_freeze_lock);
 954 }
 955