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) 2004-2006 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 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 <linux/crc32.h>
  16 #include <linux/gfs2_ondisk.h>
  17
  18 #include "gfs2.h"
  19 #include "lm_interface.h"
  20 #include "incore.h"
  21 #include "bmap.h"
  22 #include "dir.h"
  23 #include "format.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 /**
  37  * gfs2_tune_init - Fill a gfs2_tune structure with default values
  38  * @gt: tune
  39  *
  40  */
  41
  42 void gfs2_tune_init(struct gfs2_tune *gt)
  43 {
  44         spin_lock_init(&gt->gt_spin);
  45
  46         gt->gt_ilimit = 100;
  47         gt->gt_ilimit_tries = 3;
  48         gt->gt_ilimit_min = 1;
  49         gt->gt_demote_secs = 300;
  50         gt->gt_incore_log_blocks = 1024;
  51         gt->gt_log_flush_secs = 60;
  52         gt->gt_jindex_refresh_secs = 60;
  53         gt->gt_scand_secs = 15;
  54         gt->gt_recoverd_secs = 60;
  55         gt->gt_logd_secs = 1;
  56         gt->gt_quotad_secs = 5;
  57         gt->gt_quota_simul_sync = 64;
  58         gt->gt_quota_warn_period = 10;
  59         gt->gt_quota_scale_num = 1;
  60         gt->gt_quota_scale_den = 1;
  61         gt->gt_quota_cache_secs = 300;
  62         gt->gt_quota_quantum = 60;
  63         gt->gt_atime_quantum = 3600;
  64         gt->gt_new_files_jdata = 0;
  65         gt->gt_new_files_directio = 0;
  66         gt->gt_max_atomic_write = 4 << 20;
  67         gt->gt_max_readahead = 1 << 18;
  68         gt->gt_lockdump_size = 131072;
  69         gt->gt_stall_secs = 600;
  70         gt->gt_complain_secs = 10;
  71         gt->gt_reclaim_limit = 5000;
  72         gt->gt_entries_per_readdir = 32;
  73         gt->gt_prefetch_secs = 10;
  74         gt->gt_greedy_default = HZ / 10;
  75         gt->gt_greedy_quantum = HZ / 40;
  76         gt->gt_greedy_max = HZ / 4;
  77         gt->gt_statfs_quantum = 30;
  78         gt->gt_statfs_slow = 0;
  79 }
  80
  81 /**
  82  * gfs2_check_sb - Check superblock
  83  * @sdp: the filesystem
  84  * @sb: The superblock
  85  * @silent: Don't print a message if the check fails
  86  *
  87  * Checks the version code of the FS is one that we understand how to
  88  * read and that the sizes of the various on-disk structures have not
  89  * changed.
  90  */
  91
  92 int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb *sb, int silent)
  93 {
  94         unsigned int x;
  95
  96         if (sb->sb_header.mh_magic != GFS2_MAGIC ||
  97             sb->sb_header.mh_type != GFS2_METATYPE_SB) {
  98                 if (!silent)
  99                         printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
 100                 return -EINVAL;
 101         }
 102
 103         /*  If format numbers match exactly, we're done.  */
 104
 105         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
 106             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
 107                 return 0;
 108
 109         if (sb->sb_fs_format != GFS2_FORMAT_FS) {
 110                 for (x = 0; gfs2_old_fs_formats[x]; x++)
 111                         if (gfs2_old_fs_formats[x] == sb->sb_fs_format)
 112                                 break;
 113
 114                 if (!gfs2_old_fs_formats[x]) {
 115                         printk(KERN_WARNING
 116                                "GFS2: code version (%u, %u) is incompatible "
 117                                "with ondisk format (%u, %u)\n",
 118                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 119                                sb->sb_fs_format, sb->sb_multihost_format);
 120                         printk(KERN_WARNING
 121                                "GFS2: I don't know how to upgrade this FS\n");
 122                         return -EINVAL;
 123                 }
 124         }
 125
 126         if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
 127                 for (x = 0; gfs2_old_multihost_formats[x]; x++)
 128                         if (gfs2_old_multihost_formats[x] ==
 129                             sb->sb_multihost_format)
 130                                 break;
 131
 132                 if (!gfs2_old_multihost_formats[x]) {
 133                         printk(KERN_WARNING
 134                                "GFS2: code version (%u, %u) is incompatible "
 135                                "with ondisk format (%u, %u)\n",
 136                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 137                                sb->sb_fs_format, sb->sb_multihost_format);
 138                         printk(KERN_WARNING
 139                                "GFS2: I don't know how to upgrade this FS\n");
 140                         return -EINVAL;
 141                 }
 142         }
 143
 144         if (!sdp->sd_args.ar_upgrade) {
 145                 printk(KERN_WARNING
 146                        "GFS2: code version (%u, %u) is incompatible "
 147                        "with ondisk format (%u, %u)\n",
 148                        GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 149                        sb->sb_fs_format, sb->sb_multihost_format);
 150                 printk(KERN_INFO
 151                        "GFS2: Use the \"upgrade\" mount option to upgrade "
 152                        "the FS\n");
 153                 printk(KERN_INFO "GFS2: See the manual for more details\n");
 154                 return -EINVAL;
 155         }
 156
 157         return 0;
 158 }
 159
 160 /**
 161  * gfs2_read_sb - Read super block
 162  * @sdp: The GFS2 superblock
 163  * @gl: the glock for the superblock (assumed to be held)
 164  * @silent: Don't print message if mount fails
 165  *
 166  */
 167
 168 int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
 169 {
 170         struct buffer_head *bh;
 171         uint32_t hash_blocks, ind_blocks, leaf_blocks;
 172         uint32_t tmp_blocks;
 173         unsigned int x;
 174         int error;
 175
 176         error = gfs2_meta_read(gl, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift,
 177                                DIO_FORCE | DIO_START | DIO_WAIT, &bh);
 178         if (error) {
 179                 if (!silent)
 180                         fs_err(sdp, "can't read superblock\n");
 181                 return error;
 182         }
 183
 184         gfs2_assert(sdp, sizeof(struct gfs2_sb) <= bh->b_size);
 185         gfs2_sb_in(&sdp->sd_sb, bh->b_data);
 186         brelse(bh);
 187
 188         error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
 189         if (error)
 190                 return error;
 191
 192         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
 193                                GFS2_BASIC_BLOCK_SHIFT;
 194         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
 195         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
 196                           sizeof(struct gfs2_dinode)) / sizeof(uint64_t);
 197         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
 198                           sizeof(struct gfs2_meta_header)) / sizeof(uint64_t);
 199         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
 200         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
 201         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
 202         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(uint64_t);
 203         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
 204                                 sizeof(struct gfs2_meta_header)) /
 205                                sizeof(struct gfs2_quota_change);
 206
 207         /* Compute maximum reservation required to add a entry to a directory */
 208
 209         hash_blocks = DIV_ROUND_UP(sizeof(uint64_t) * (1 << GFS2_DIR_MAX_DEPTH),
 210                              sdp->sd_jbsize);
 211
 212         ind_blocks = 0;
 213         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
 214                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
 215                 ind_blocks += tmp_blocks;
 216         }
 217
 218         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
 219
 220         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
 221
 222         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
 223                                 sizeof(struct gfs2_dinode);
 224         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
 225         for (x = 2;; x++) {
 226                 uint64_t space, d;
 227                 uint32_t m;
 228
 229                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
 230                 d = space;
 231                 m = do_div(d, sdp->sd_inptrs);
 232
 233                 if (d != sdp->sd_heightsize[x - 1] || m)
 234                         break;
 235                 sdp->sd_heightsize[x] = space;
 236         }
 237         sdp->sd_max_height = x;
 238         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 239
 240         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
 241                                  sizeof(struct gfs2_dinode);
 242         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
 243         for (x = 2;; x++) {
 244                 uint64_t space, d;
 245                 uint32_t m;
 246
 247                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
 248                 d = space;
 249                 m = do_div(d, sdp->sd_inptrs);
 250
 251                 if (d != sdp->sd_jheightsize[x - 1] || m)
 252                         break;
 253                 sdp->sd_jheightsize[x] = space;
 254         }
 255         sdp->sd_max_jheight = x;
 256         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
 257
 258         return 0;
 259 }
 260
 261 /**
 262  * gfs2_jindex_hold - Grab a lock on the jindex
 263  * @sdp: The GFS2 superblock
 264  * @ji_gh: the holder for the jindex glock
 265  *
 266  * This is very similar to the gfs2_rindex_hold() function, except that
 267  * in general we hold the jindex lock for longer periods of time and
 268  * we grab it far less frequently (in general) then the rgrp lock.
 269  *
 270  * Returns: errno
 271  */
 272
 273 int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 274 {
 275         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
 276         struct qstr name;
 277         char buf[20];
 278         struct gfs2_jdesc *jd;
 279         int error;
 280
 281         name.name = buf;
 282
 283         mutex_lock(&sdp->sd_jindex_mutex);
 284
 285         for (;;) {
 286                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED,
 287                                            GL_LOCAL_EXCL, ji_gh);
 288                 if (error)
 289                         break;
 290
 291                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
 292                 name.hash = gfs2_disk_hash(name.name, name.len);
 293
 294                 error = gfs2_dir_search(sdp->sd_jindex, &name, NULL, NULL);
 295                 if (error == -ENOENT) {
 296                         error = 0;
 297                         break;
 298                 }
 299
 300                 gfs2_glock_dq_uninit(ji_gh);
 301
 302                 if (error)
 303                         break;
 304
 305                 error = -ENOMEM;
 306                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
 307                 if (!jd)
 308                         break;
 309
 310                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1, NULL);
 311                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
 312                         if (!jd->jd_inode)
 313                                 error = -ENOENT;
 314                         else
 315                                 error = PTR_ERR(jd->jd_inode);
 316                         kfree(jd);
 317                         break;
 318                 }
 319
 320                 spin_lock(&sdp->sd_jindex_spin);
 321                 jd->jd_jid = sdp->sd_journals++;
 322                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
 323                 spin_unlock(&sdp->sd_jindex_spin);
 324         }
 325
 326         mutex_unlock(&sdp->sd_jindex_mutex);
 327
 328         return error;
 329 }
 330
 331 /**
 332  * gfs2_jindex_free - Clear all the journal index information
 333  * @sdp: The GFS2 superblock
 334  *
 335  */
 336
 337 void gfs2_jindex_free(struct gfs2_sbd *sdp)
 338 {
 339         struct list_head list;
 340         struct gfs2_jdesc *jd;
 341
 342         spin_lock(&sdp->sd_jindex_spin);
 343         list_add(&list, &sdp->sd_jindex_list);
 344         list_del_init(&sdp->sd_jindex_list);
 345         sdp->sd_journals = 0;
 346         spin_unlock(&sdp->sd_jindex_spin);
 347
 348         while (!list_empty(&list)) {
 349                 jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
 350                 list_del(&jd->jd_list);
 351                 iput(jd->jd_inode);
 352                 kfree(jd);
 353         }
 354 }
 355
 356 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
 357 {
 358         struct gfs2_jdesc *jd;
 359         int found = 0;
 360
 361         list_for_each_entry(jd, head, jd_list) {
 362                 if (jd->jd_jid == jid) {
 363                         found = 1;
 364                         break;
 365                 }
 366         }
 367
 368         if (!found)
 369                 jd = NULL;
 370
 371         return jd;
 372 }
 373
 374 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
 375 {
 376         struct gfs2_jdesc *jd;
 377
 378         spin_lock(&sdp->sd_jindex_spin);
 379         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 380         spin_unlock(&sdp->sd_jindex_spin);
 381
 382         return jd;
 383 }
 384
 385 void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid)
 386 {
 387         struct gfs2_jdesc *jd;
 388
 389         spin_lock(&sdp->sd_jindex_spin);
 390         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 391         if (jd)
 392                 jd->jd_dirty = 1;
 393         spin_unlock(&sdp->sd_jindex_spin);
 394 }
 395
 396 struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp)
 397 {
 398         struct gfs2_jdesc *jd;
 399         int found = 0;
 400
 401         spin_lock(&sdp->sd_jindex_spin);
 402
 403         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 404                 if (jd->jd_dirty) {
 405                         jd->jd_dirty = 0;
 406                         found = 1;
 407                         break;
 408                 }
 409         }
 410         spin_unlock(&sdp->sd_jindex_spin);
 411
 412         if (!found)
 413                 jd = NULL;
 414
 415         return jd;
 416 }
 417
 418 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
 419 {
 420         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 421         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 422         int ar;
 423         int error;
 424
 425         if (ip->i_di.di_size < (8 << 20) || ip->i_di.di_size > (1 << 30) ||
 426             (ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) {
 427                 gfs2_consist_inode(ip);
 428                 return -EIO;
 429         }
 430         jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
 431
 432         error = gfs2_write_alloc_required(ip, 0, ip->i_di.di_size, &ar);
 433         if (!error && ar) {
 434                 gfs2_consist_inode(ip);
 435                 error = -EIO;
 436         }
 437
 438         return error;
 439 }
 440
 441 /**
 442  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
 443  * @sdp: the filesystem
 444  *
 445  * Returns: errno
 446  */
 447
 448 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 449 {
 450         struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 451         struct gfs2_glock *j_gl = ip->i_gl;
 452         struct gfs2_holder t_gh;
 453         struct gfs2_log_header head;
 454         int error;
 455
 456         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
 457                                    GL_LOCAL_EXCL, &t_gh);
 458         if (error)
 459                 return error;
 460
 461         gfs2_meta_cache_flush(ip);
 462         j_gl->gl_ops->go_inval(j_gl, DIO_METADATA | DIO_DATA);
 463
 464         error = gfs2_find_jhead(sdp->sd_jdesc, &head);
 465         if (error)
 466                 goto fail;
 467
 468         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 469                 gfs2_consist(sdp);
 470                 error = -EIO;
 471                 goto fail;
 472         }
 473
 474         /*  Initialize some head of the log stuff  */
 475         sdp->sd_log_sequence = head.lh_sequence + 1;
 476         gfs2_log_pointers_init(sdp, head.lh_blkno);
 477
 478         error = gfs2_quota_init(sdp);
 479         if (error)
 480                 goto fail_unlinked;
 481
 482         set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 483
 484         gfs2_glock_dq_uninit(&t_gh);
 485
 486         return 0;
 487
 488  fail_unlinked:
 489
 490  fail:
 491         t_gh.gh_flags |= GL_NOCACHE;
 492         gfs2_glock_dq_uninit(&t_gh);
 493
 494         return error;
 495 }
 496
 497 /**
 498  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
 499  * @sdp: the filesystem
 500  *
 501  * Returns: errno
 502  */
 503
 504 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
 505 {
 506         struct gfs2_holder t_gh;
 507         int error;
 508
 509         gfs2_quota_sync(sdp);
 510         gfs2_statfs_sync(sdp);
 511
 512         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED,
 513                                 GL_LOCAL_EXCL | GL_NOCACHE,
 514                                 &t_gh);
 515         if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
 516                 return error;
 517
 518         gfs2_meta_syncfs(sdp);
 519         gfs2_log_shutdown(sdp);
 520
 521         clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 522
 523         if (t_gh.gh_gl)
 524                 gfs2_glock_dq_uninit(&t_gh);
 525
 526         gfs2_quota_cleanup(sdp);
 527
 528         return error;
 529 }
 530
 531 int gfs2_statfs_init(struct gfs2_sbd *sdp)
 532 {
 533         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 534         struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
 535         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 536         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 537         struct buffer_head *m_bh, *l_bh;
 538         struct gfs2_holder gh;
 539         int error;
 540
 541         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 542                                    &gh);
 543         if (error)
 544                 return error;
 545
 546         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 547         if (error)
 548                 goto out;
 549
 550         if (sdp->sd_args.ar_spectator) {
 551                 spin_lock(&sdp->sd_statfs_spin);
 552                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 553                                       sizeof(struct gfs2_dinode));
 554                 spin_unlock(&sdp->sd_statfs_spin);
 555         } else {
 556                 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 557                 if (error)
 558                         goto out_m_bh;
 559
 560                 spin_lock(&sdp->sd_statfs_spin);
 561                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 562                                       sizeof(struct gfs2_dinode));
 563                 gfs2_statfs_change_in(l_sc, l_bh->b_data +
 564                                       sizeof(struct gfs2_dinode));
 565                 spin_unlock(&sdp->sd_statfs_spin);
 566
 567                 brelse(l_bh);
 568         }
 569
 570  out_m_bh:
 571         brelse(m_bh);
 572
 573  out:
 574         gfs2_glock_dq_uninit(&gh);
 575
 576         return 0;
 577 }
 578
 579 void gfs2_statfs_change(struct gfs2_sbd *sdp, int64_t total, int64_t free,
 580                         int64_t dinodes)
 581 {
 582         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 583         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 584         struct buffer_head *l_bh;
 585         int error;
 586
 587         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 588         if (error)
 589                 return;
 590
 591         mutex_lock(&sdp->sd_statfs_mutex);
 592         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 593         mutex_unlock(&sdp->sd_statfs_mutex);
 594
 595         spin_lock(&sdp->sd_statfs_spin);
 596         l_sc->sc_total += total;
 597         l_sc->sc_free += free;
 598         l_sc->sc_dinodes += dinodes;
 599         gfs2_statfs_change_out(l_sc, l_bh->b_data +
 600                                sizeof(struct gfs2_dinode));
 601         spin_unlock(&sdp->sd_statfs_spin);
 602
 603         brelse(l_bh);
 604 }
 605
 606 int gfs2_statfs_sync(struct gfs2_sbd *sdp)
 607 {
 608         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 609         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 610         struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
 611         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 612         struct gfs2_holder gh;
 613         struct buffer_head *m_bh, *l_bh;
 614         int error;
 615
 616         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 617                                    &gh);
 618         if (error)
 619                 return error;
 620
 621         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 622         if (error)
 623                 goto out;
 624
 625         spin_lock(&sdp->sd_statfs_spin);
 626         gfs2_statfs_change_in(m_sc, m_bh->b_data +
 627                               sizeof(struct gfs2_dinode));
 628         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
 629                 spin_unlock(&sdp->sd_statfs_spin);
 630                 goto out_bh;
 631         }
 632         spin_unlock(&sdp->sd_statfs_spin);
 633
 634         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 635         if (error)
 636                 goto out_bh;
 637
 638         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
 639         if (error)
 640                 goto out_bh2;
 641
 642         mutex_lock(&sdp->sd_statfs_mutex);
 643         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 644         mutex_unlock(&sdp->sd_statfs_mutex);
 645
 646         spin_lock(&sdp->sd_statfs_spin);
 647         m_sc->sc_total += l_sc->sc_total;
 648         m_sc->sc_free += l_sc->sc_free;
 649         m_sc->sc_dinodes += l_sc->sc_dinodes;
 650         memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
 651         memset(l_bh->b_data + sizeof(struct gfs2_dinode),
 652                0, sizeof(struct gfs2_statfs_change));
 653         spin_unlock(&sdp->sd_statfs_spin);
 654
 655         gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
 656         gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
 657
 658         gfs2_trans_end(sdp);
 659
 660  out_bh2:
 661         brelse(l_bh);
 662
 663  out_bh:
 664         brelse(m_bh);
 665
 666  out:
 667         gfs2_glock_dq_uninit(&gh);
 668
 669         return error;
 670 }
 671
 672 /**
 673  * gfs2_statfs_i - Do a statfs
 674  * @sdp: the filesystem
 675  * @sg: the sg structure
 676  *
 677  * Returns: errno
 678  */
 679
 680 int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc)
 681 {
 682         struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master;
 683         struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local;
 684
 685         spin_lock(&sdp->sd_statfs_spin);
 686
 687         *sc = *m_sc;
 688         sc->sc_total += l_sc->sc_total;
 689         sc->sc_free += l_sc->sc_free;
 690         sc->sc_dinodes += l_sc->sc_dinodes;
 691
 692         spin_unlock(&sdp->sd_statfs_spin);
 693
 694         if (sc->sc_free < 0)
 695                 sc->sc_free = 0;
 696         if (sc->sc_free > sc->sc_total)
 697                 sc->sc_free = sc->sc_total;
 698         if (sc->sc_dinodes < 0)
 699                 sc->sc_dinodes = 0;
 700
 701         return 0;
 702 }
 703
 704 /**
 705  * statfs_fill - fill in the sg for a given RG
 706  * @rgd: the RG
 707  * @sc: the sc structure
 708  *
 709  * Returns: 0 on success, -ESTALE if the LVB is invalid
 710  */
 711
 712 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
 713                             struct gfs2_statfs_change *sc)
 714 {
 715         gfs2_rgrp_verify(rgd);
 716         sc->sc_total += rgd->rd_ri.ri_data;
 717         sc->sc_free += rgd->rd_rg.rg_free;
 718         sc->sc_dinodes += rgd->rd_rg.rg_dinodes;
 719         return 0;
 720 }
 721
 722 /**
 723  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
 724  * @sdp: the filesystem
 725  * @sc: the sc info that will be returned
 726  *
 727  * Any error (other than a signal) will cause this routine to fall back
 728  * to the synchronous version.
 729  *
 730  * FIXME: This really shouldn't busy wait like this.
 731  *
 732  * Returns: errno
 733  */
 734
 735 int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc)
 736 {
 737         struct gfs2_holder ri_gh;
 738         struct gfs2_rgrpd *rgd_next;
 739         struct gfs2_holder *gha, *gh;
 740         unsigned int slots = 64;
 741         unsigned int x;
 742         int done;
 743         int error = 0, err;
 744
 745         memset(sc, 0, sizeof(struct gfs2_statfs_change));
 746         gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
 747         if (!gha)
 748                 return -ENOMEM;
 749
 750         error = gfs2_rindex_hold(sdp, &ri_gh);
 751         if (error)
 752                 goto out;
 753
 754         rgd_next = gfs2_rgrpd_get_first(sdp);
 755
 756         for (;;) {
 757                 done = 1;
 758
 759                 for (x = 0; x < slots; x++) {
 760                         gh = gha + x;
 761
 762                         if (gh->gh_gl && gfs2_glock_poll(gh)) {
 763                                 err = gfs2_glock_wait(gh);
 764                                 if (err) {
 765                                         gfs2_holder_uninit(gh);
 766                                         error = err;
 767                                 } else {
 768                                         if (!error)
 769                                                 error = statfs_slow_fill(
 770                                                         gh->gh_gl->gl_object, sc);
 771                                         gfs2_glock_dq_uninit(gh);
 772                                 }
 773                         }
 774
 775                         if (gh->gh_gl)
 776                                 done = 0;
 777                         else if (rgd_next && !error) {
 778                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
 779                                                            LM_ST_SHARED,
 780                                                            GL_ASYNC,
 781                                                            gh);
 782                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
 783                                 done = 0;
 784                         }
 785
 786                         if (signal_pending(current))
 787                                 error = -ERESTARTSYS;
 788                 }
 789
 790                 if (done)
 791                         break;
 792
 793                 yield();
 794         }
 795
 796         gfs2_glock_dq_uninit(&ri_gh);
 797
 798  out:
 799         kfree(gha);
 800
 801         return error;
 802 }
 803
 804 struct lfcc {
 805         struct list_head list;
 806         struct gfs2_holder gh;
 807 };
 808
 809 /**
 810  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
 811  *                            journals are clean
 812  * @sdp: the file system
 813  * @state: the state to put the transaction lock into
 814  * @t_gh: the hold on the transaction lock
 815  *
 816  * Returns: errno
 817  */
 818
 819 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
 820                                     struct gfs2_holder *t_gh)
 821 {
 822         struct gfs2_inode *ip;
 823         struct gfs2_holder ji_gh;
 824         struct gfs2_jdesc *jd;
 825         struct lfcc *lfcc;
 826         LIST_HEAD(list);
 827         struct gfs2_log_header lh;
 828         int error;
 829
 830         error = gfs2_jindex_hold(sdp, &ji_gh);
 831         if (error)
 832                 return error;
 833
 834         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 835                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
 836                 if (!lfcc) {
 837                         error = -ENOMEM;
 838                         goto out;
 839                 }
 840                 ip = GFS2_I(jd->jd_inode);
 841                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
 842                 if (error) {
 843                         kfree(lfcc);
 844                         goto out;
 845                 }
 846                 list_add(&lfcc->list, &list);
 847         }
 848
 849         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
 850                                LM_FLAG_PRIORITY | GL_NOCACHE,
 851                                t_gh);
 852
 853         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 854                 error = gfs2_jdesc_check(jd);
 855                 if (error)
 856                         break;
 857                 error = gfs2_find_jhead(jd, &lh);
 858                 if (error)
 859                         break;
 860                 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 861                         error = -EBUSY;
 862                         break;
 863                 }
 864         }
 865
 866         if (error)
 867                 gfs2_glock_dq_uninit(t_gh);
 868
 869  out:
 870         while (!list_empty(&list)) {
 871                 lfcc = list_entry(list.next, struct lfcc, list);
 872                 list_del(&lfcc->list);
 873                 gfs2_glock_dq_uninit(&lfcc->gh);
 874                 kfree(lfcc);
 875         }
 876         gfs2_glock_dq_uninit(&ji_gh);
 877
 878         return error;
 879 }
 880
 881 /**
 882  * gfs2_freeze_fs - freezes the file system
 883  * @sdp: the file system
 884  *
 885  * This function flushes data and meta data for all machines by
 886  * aquiring the transaction log exclusively.  All journals are
 887  * ensured to be in a clean state as well.
 888  *
 889  * Returns: errno
 890  */
 891
 892 int gfs2_freeze_fs(struct gfs2_sbd *sdp)
 893 {
 894         int error = 0;
 895
 896         mutex_lock(&sdp->sd_freeze_lock);
 897
 898         if (!sdp->sd_freeze_count++) {
 899                 error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
 900                 if (error)
 901                         sdp->sd_freeze_count--;
 902         }
 903
 904         mutex_unlock(&sdp->sd_freeze_lock);
 905
 906         return error;
 907 }
 908
 909 /**
 910  * gfs2_unfreeze_fs - unfreezes the file system
 911  * @sdp: the file system
 912  *
 913  * This function allows the file system to proceed by unlocking
 914  * the exclusively held transaction lock.  Other GFS2 nodes are
 915  * now free to acquire the lock shared and go on with their lives.
 916  *
 917  */
 918
 919 void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
 920 {
 921         mutex_lock(&sdp->sd_freeze_lock);
 922
 923         if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
 924                 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
 925
 926         mutex_unlock(&sdp->sd_freeze_lock);
 927 }
 928