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 version 2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/crc32.h>
  16 #include <linux/gfs2_ondisk.h>
  17 #include <linux/bio.h>
  18 #include <linux/lm_interface.h>
  19
  20 #include "gfs2.h"
  21 #include "incore.h"
  22 #include "bmap.h"
  23 #include "dir.h"
  24 #include "glock.h"
  25 #include "glops.h"
  26 #include "inode.h"
  27 #include "log.h"
  28 #include "meta_io.h"
  29 #include "quota.h"
  30 #include "recovery.h"
  31 #include "rgrp.h"
  32 #include "super.h"
  33 #include "trans.h"
  34 #include "util.h"
  35
  36 static const u32 gfs2_old_fs_formats[] = {
  37         0
  38 };
  39
  40 static const u32 gfs2_old_multihost_formats[] = {
  41         0
  42 };
  43
  44 /**
  45  * gfs2_tune_init - Fill a gfs2_tune structure with default values
  46  * @gt: tune
  47  *
  48  */
  49
  50 void gfs2_tune_init(struct gfs2_tune *gt)
  51 {
  52         spin_lock_init(&gt->gt_spin);
  53
  54         gt->gt_ilimit = 100;
  55         gt->gt_ilimit_tries = 3;
  56         gt->gt_ilimit_min = 1;
  57         gt->gt_demote_secs = 300;
  58         gt->gt_incore_log_blocks = 1024;
  59         gt->gt_log_flush_secs = 60;
  60         gt->gt_jindex_refresh_secs = 60;
  61         gt->gt_scand_secs = 15;
  62         gt->gt_recoverd_secs = 60;
  63         gt->gt_logd_secs = 1;
  64         gt->gt_quotad_secs = 5;
  65         gt->gt_quota_simul_sync = 64;
  66         gt->gt_quota_warn_period = 10;
  67         gt->gt_quota_scale_num = 1;
  68         gt->gt_quota_scale_den = 1;
  69         gt->gt_quota_cache_secs = 300;
  70         gt->gt_quota_quantum = 60;
  71         gt->gt_atime_quantum = 3600;
  72         gt->gt_new_files_jdata = 0;
  73         gt->gt_new_files_directio = 0;
  74         gt->gt_max_readahead = 1 << 18;
  75         gt->gt_lockdump_size = 131072;
  76         gt->gt_stall_secs = 600;
  77         gt->gt_complain_secs = 10;
  78         gt->gt_reclaim_limit = 5000;
  79         gt->gt_statfs_quantum = 30;
  80         gt->gt_statfs_slow = 0;
  81 }
  82
  83 /**
  84  * gfs2_check_sb - Check superblock
  85  * @sdp: the filesystem
  86  * @sb: The superblock
  87  * @silent: Don't print a message if the check fails
  88  *
  89  * Checks the version code of the FS is one that we understand how to
  90  * read and that the sizes of the various on-disk structures have not
  91  * changed.
  92  */
  93
  94 int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb_host *sb, int silent)
  95 {
  96         unsigned int x;
  97
  98         if (sb->sb_header.mh_magic != GFS2_MAGIC ||
  99             sb->sb_header.mh_type != GFS2_METATYPE_SB) {
 100                 if (!silent)
 101                         printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
 102                 return -EINVAL;
 103         }
 104
 105         /*  If format numbers match exactly, we're done.  */
 106
 107         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
 108             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
 109                 return 0;
 110
 111         if (sb->sb_fs_format != GFS2_FORMAT_FS) {
 112                 for (x = 0; gfs2_old_fs_formats[x]; x++)
 113                         if (gfs2_old_fs_formats[x] == sb->sb_fs_format)
 114                                 break;
 115
 116                 if (!gfs2_old_fs_formats[x]) {
 117                         printk(KERN_WARNING
 118                                "GFS2: code version (%u, %u) is incompatible "
 119                                "with ondisk format (%u, %u)\n",
 120                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 121                                sb->sb_fs_format, sb->sb_multihost_format);
 122                         printk(KERN_WARNING
 123                                "GFS2: I don't know how to upgrade this FS\n");
 124                         return -EINVAL;
 125                 }
 126         }
 127
 128         if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
 129                 for (x = 0; gfs2_old_multihost_formats[x]; x++)
 130                         if (gfs2_old_multihost_formats[x] ==
 131                             sb->sb_multihost_format)
 132                                 break;
 133
 134                 if (!gfs2_old_multihost_formats[x]) {
 135                         printk(KERN_WARNING
 136                                "GFS2: code version (%u, %u) is incompatible "
 137                                "with ondisk format (%u, %u)\n",
 138                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 139                                sb->sb_fs_format, sb->sb_multihost_format);
 140                         printk(KERN_WARNING
 141                                "GFS2: I don't know how to upgrade this FS\n");
 142                         return -EINVAL;
 143                 }
 144         }
 145
 146         if (!sdp->sd_args.ar_upgrade) {
 147                 printk(KERN_WARNING
 148                        "GFS2: code version (%u, %u) is incompatible "
 149                        "with ondisk format (%u, %u)\n",
 150                        GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 151                        sb->sb_fs_format, sb->sb_multihost_format);
 152                 printk(KERN_INFO
 153                        "GFS2: Use the \"upgrade\" mount option to upgrade "
 154                        "the FS\n");
 155                 printk(KERN_INFO "GFS2: See the manual for more details\n");
 156                 return -EINVAL;
 157         }
 158
 159         return 0;
 160 }
 161
 162
 163 static int end_bio_io_page(struct bio *bio, unsigned int bytes_done, int error)
 164 {
 165         struct page *page = bio->bi_private;
 166         if (bio->bi_size)
 167                 return 1;
 168
 169         if (!error)
 170                 SetPageUptodate(page);
 171         else
 172                 printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
 173         unlock_page(page);
 174         return 0;
 175 }
 176
 177 /**
 178  * gfs2_read_super - Read the gfs2 super block from disk
 179  * @sb: The VFS super block
 180  * @sector: The location of the super block
 181  *
 182  * This uses the bio functions to read the super block from disk
 183  * because we want to be 100% sure that we never read cached data.
 184  * A super block is read twice only during each GFS2 mount and is
 185  * never written to by the filesystem. The first time its read no
 186  * locks are held, and the only details which are looked at are those
 187  * relating to the locking protocol. Once locking is up and working,
 188  * the sb is read again under the lock to establish the location of
 189  * the master directory (contains pointers to journals etc) and the
 190  * root directory.
 191  *
 192  * Returns: A page containing the sb or NULL
 193  */
 194
 195 struct page *gfs2_read_super(struct super_block *sb, sector_t sector)
 196 {
 197         struct page *page;
 198         struct bio *bio;
 199
 200         page = alloc_page(GFP_KERNEL);
 201         if (unlikely(!page))
 202                 return NULL;
 203
 204         ClearPageUptodate(page);
 205         ClearPageDirty(page);
 206         lock_page(page);
 207
 208         bio = bio_alloc(GFP_KERNEL, 1);
 209         if (unlikely(!bio)) {
 210                 __free_page(page);
 211                 return NULL;
 212         }
 213
 214         bio->bi_sector = sector * (sb->s_blocksize >> 9);
 215         bio->bi_bdev = sb->s_bdev;
 216         bio_add_page(bio, page, PAGE_SIZE, 0);
 217
 218         bio->bi_end_io = end_bio_io_page;
 219         bio->bi_private = page;
 220         submit_bio(READ_SYNC | (1 << BIO_RW_META), bio);
 221         wait_on_page_locked(page);
 222         bio_put(bio);
 223         if (!PageUptodate(page)) {
 224                 __free_page(page);
 225                 return NULL;
 226         }
 227         return page;
 228 }
 229
 230 /**
 231  * gfs2_read_sb - Read super block
 232  * @sdp: The GFS2 superblock
 233  * @gl: the glock for the superblock (assumed to be held)
 234  * @silent: Don't print message if mount fails
 235  *
 236  */
 237
 238 int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
 239 {
 240         u32 hash_blocks, ind_blocks, leaf_blocks;
 241         u32 tmp_blocks;
 242         unsigned int x;
 243         int error;
 244         struct page *page;
 245         char *sb;
 246
 247         page = gfs2_read_super(sdp->sd_vfs, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
 248         if (!page) {
 249                 if (!silent)
 250                         fs_err(sdp, "can't read superblock\n");
 251                 return -EIO;
 252         }
 253         sb = kmap(page);
 254         gfs2_sb_in(&sdp->sd_sb, sb);
 255         kunmap(page);
 256         __free_page(page);
 257
 258         error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
 259         if (error)
 260                 return error;
 261
 262         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
 263                                GFS2_BASIC_BLOCK_SHIFT;
 264         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
 265         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
 266                           sizeof(struct gfs2_dinode)) / sizeof(u64);
 267         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
 268                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
 269         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
 270         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
 271         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
 272         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
 273         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
 274                                 sizeof(struct gfs2_meta_header)) /
 275                                 sizeof(struct gfs2_quota_change);
 276
 277         /* Compute maximum reservation required to add a entry to a directory */
 278
 279         hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
 280                              sdp->sd_jbsize);
 281
 282         ind_blocks = 0;
 283         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
 284                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
 285                 ind_blocks += tmp_blocks;
 286         }
 287
 288         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
 289
 290         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
 291
 292         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
 293                                 sizeof(struct gfs2_dinode);
 294         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
 295         for (x = 2;; x++) {
 296                 u64 space, d;
 297                 u32 m;
 298
 299                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
 300                 d = space;
 301                 m = do_div(d, sdp->sd_inptrs);
 302
 303                 if (d != sdp->sd_heightsize[x - 1] || m)
 304                         break;
 305                 sdp->sd_heightsize[x] = space;
 306         }
 307         sdp->sd_max_height = x;
 308         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 309
 310         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
 311                                  sizeof(struct gfs2_dinode);
 312         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
 313         for (x = 2;; x++) {
 314                 u64 space, d;
 315                 u32 m;
 316
 317                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
 318                 d = space;
 319                 m = do_div(d, sdp->sd_inptrs);
 320
 321                 if (d != sdp->sd_jheightsize[x - 1] || m)
 322                         break;
 323                 sdp->sd_jheightsize[x] = space;
 324         }
 325         sdp->sd_max_jheight = x;
 326         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
 327
 328         return 0;
 329 }
 330
 331 /**
 332  * gfs2_jindex_hold - Grab a lock on the jindex
 333  * @sdp: The GFS2 superblock
 334  * @ji_gh: the holder for the jindex glock
 335  *
 336  * This is very similar to the gfs2_rindex_hold() function, except that
 337  * in general we hold the jindex lock for longer periods of time and
 338  * we grab it far less frequently (in general) then the rgrp lock.
 339  *
 340  * Returns: errno
 341  */
 342
 343 int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 344 {
 345         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
 346         struct qstr name;
 347         char buf[20];
 348         struct gfs2_jdesc *jd;
 349         int error;
 350
 351         name.name = buf;
 352
 353         mutex_lock(&sdp->sd_jindex_mutex);
 354
 355         for (;;) {
 356                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
 357                 if (error)
 358                         break;
 359
 360                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
 361                 name.hash = gfs2_disk_hash(name.name, name.len);
 362
 363                 error = gfs2_dir_search(sdp->sd_jindex, &name, NULL, NULL);
 364                 if (error == -ENOENT) {
 365                         error = 0;
 366                         break;
 367                 }
 368
 369                 gfs2_glock_dq_uninit(ji_gh);
 370
 371                 if (error)
 372                         break;
 373
 374                 error = -ENOMEM;
 375                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
 376                 if (!jd)
 377                         break;
 378
 379                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1, NULL);
 380                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
 381                         if (!jd->jd_inode)
 382                                 error = -ENOENT;
 383                         else
 384                                 error = PTR_ERR(jd->jd_inode);
 385                         kfree(jd);
 386                         break;
 387                 }
 388
 389                 spin_lock(&sdp->sd_jindex_spin);
 390                 jd->jd_jid = sdp->sd_journals++;
 391                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
 392                 spin_unlock(&sdp->sd_jindex_spin);
 393         }
 394
 395         mutex_unlock(&sdp->sd_jindex_mutex);
 396
 397         return error;
 398 }
 399
 400 /**
 401  * gfs2_jindex_free - Clear all the journal index information
 402  * @sdp: The GFS2 superblock
 403  *
 404  */
 405
 406 void gfs2_jindex_free(struct gfs2_sbd *sdp)
 407 {
 408         struct list_head list;
 409         struct gfs2_jdesc *jd;
 410
 411         spin_lock(&sdp->sd_jindex_spin);
 412         list_add(&list, &sdp->sd_jindex_list);
 413         list_del_init(&sdp->sd_jindex_list);
 414         sdp->sd_journals = 0;
 415         spin_unlock(&sdp->sd_jindex_spin);
 416
 417         while (!list_empty(&list)) {
 418                 jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
 419                 list_del(&jd->jd_list);
 420                 iput(jd->jd_inode);
 421                 kfree(jd);
 422         }
 423 }
 424
 425 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
 426 {
 427         struct gfs2_jdesc *jd;
 428         int found = 0;
 429
 430         list_for_each_entry(jd, head, jd_list) {
 431                 if (jd->jd_jid == jid) {
 432                         found = 1;
 433                         break;
 434                 }
 435         }
 436
 437         if (!found)
 438                 jd = NULL;
 439
 440         return jd;
 441 }
 442
 443 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
 444 {
 445         struct gfs2_jdesc *jd;
 446
 447         spin_lock(&sdp->sd_jindex_spin);
 448         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 449         spin_unlock(&sdp->sd_jindex_spin);
 450
 451         return jd;
 452 }
 453
 454 void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid)
 455 {
 456         struct gfs2_jdesc *jd;
 457
 458         spin_lock(&sdp->sd_jindex_spin);
 459         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 460         if (jd)
 461                 jd->jd_dirty = 1;
 462         spin_unlock(&sdp->sd_jindex_spin);
 463 }
 464
 465 struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp)
 466 {
 467         struct gfs2_jdesc *jd;
 468         int found = 0;
 469
 470         spin_lock(&sdp->sd_jindex_spin);
 471
 472         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 473                 if (jd->jd_dirty) {
 474                         jd->jd_dirty = 0;
 475                         found = 1;
 476                         break;
 477                 }
 478         }
 479         spin_unlock(&sdp->sd_jindex_spin);
 480
 481         if (!found)
 482                 jd = NULL;
 483
 484         return jd;
 485 }
 486
 487 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
 488 {
 489         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 490         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 491         int ar;
 492         int error;
 493
 494         if (ip->i_di.di_size < (8 << 20) || ip->i_di.di_size > (1 << 30) ||
 495             (ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) {
 496                 gfs2_consist_inode(ip);
 497                 return -EIO;
 498         }
 499         jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
 500
 501         error = gfs2_write_alloc_required(ip, 0, ip->i_di.di_size, &ar);
 502         if (!error && ar) {
 503                 gfs2_consist_inode(ip);
 504                 error = -EIO;
 505         }
 506
 507         return error;
 508 }
 509
 510 /**
 511  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
 512  * @sdp: the filesystem
 513  *
 514  * Returns: errno
 515  */
 516
 517 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 518 {
 519         struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 520         struct gfs2_glock *j_gl = ip->i_gl;
 521         struct gfs2_holder t_gh;
 522         struct gfs2_log_header_host head;
 523         int error;
 524
 525         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &t_gh);
 526         if (error)
 527                 return error;
 528
 529         gfs2_meta_cache_flush(ip);
 530         j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
 531
 532         error = gfs2_find_jhead(sdp->sd_jdesc, &head);
 533         if (error)
 534                 goto fail;
 535
 536         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 537                 gfs2_consist(sdp);
 538                 error = -EIO;
 539                 goto fail;
 540         }
 541
 542         /*  Initialize some head of the log stuff  */
 543         sdp->sd_log_sequence = head.lh_sequence + 1;
 544         gfs2_log_pointers_init(sdp, head.lh_blkno);
 545
 546         error = gfs2_quota_init(sdp);
 547         if (error)
 548                 goto fail;
 549
 550         set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 551
 552         gfs2_glock_dq_uninit(&t_gh);
 553
 554         return 0;
 555
 556 fail:
 557         t_gh.gh_flags |= GL_NOCACHE;
 558         gfs2_glock_dq_uninit(&t_gh);
 559
 560         return error;
 561 }
 562
 563 /**
 564  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
 565  * @sdp: the filesystem
 566  *
 567  * Returns: errno
 568  */
 569
 570 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
 571 {
 572         struct gfs2_holder t_gh;
 573         int error;
 574
 575         gfs2_quota_sync(sdp);
 576         gfs2_statfs_sync(sdp);
 577
 578         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, GL_NOCACHE,
 579                                    &t_gh);
 580         if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
 581                 return error;
 582
 583         gfs2_meta_syncfs(sdp);
 584         gfs2_log_shutdown(sdp);
 585
 586         clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 587
 588         if (t_gh.gh_gl)
 589                 gfs2_glock_dq_uninit(&t_gh);
 590
 591         gfs2_quota_cleanup(sdp);
 592
 593         return error;
 594 }
 595
 596 int gfs2_statfs_init(struct gfs2_sbd *sdp)
 597 {
 598         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 599         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 600         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 601         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 602         struct buffer_head *m_bh, *l_bh;
 603         struct gfs2_holder gh;
 604         int error;
 605
 606         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 607                                    &gh);
 608         if (error)
 609                 return error;
 610
 611         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 612         if (error)
 613                 goto out;
 614
 615         if (sdp->sd_args.ar_spectator) {
 616                 spin_lock(&sdp->sd_statfs_spin);
 617                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 618                                       sizeof(struct gfs2_dinode));
 619                 spin_unlock(&sdp->sd_statfs_spin);
 620         } else {
 621                 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 622                 if (error)
 623                         goto out_m_bh;
 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                 gfs2_statfs_change_in(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 out_m_bh:
 636         brelse(m_bh);
 637 out:
 638         gfs2_glock_dq_uninit(&gh);
 639         return 0;
 640 }
 641
 642 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
 643                         s64 dinodes)
 644 {
 645         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 646         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 647         struct buffer_head *l_bh;
 648         int error;
 649
 650         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 651         if (error)
 652                 return;
 653
 654         mutex_lock(&sdp->sd_statfs_mutex);
 655         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 656         mutex_unlock(&sdp->sd_statfs_mutex);
 657
 658         spin_lock(&sdp->sd_statfs_spin);
 659         l_sc->sc_total += total;
 660         l_sc->sc_free += free;
 661         l_sc->sc_dinodes += dinodes;
 662         gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
 663         spin_unlock(&sdp->sd_statfs_spin);
 664
 665         brelse(l_bh);
 666 }
 667
 668 int gfs2_statfs_sync(struct gfs2_sbd *sdp)
 669 {
 670         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 671         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 672         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 673         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 674         struct gfs2_holder gh;
 675         struct buffer_head *m_bh, *l_bh;
 676         int error;
 677
 678         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 679                                    &gh);
 680         if (error)
 681                 return error;
 682
 683         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 684         if (error)
 685                 goto out;
 686
 687         spin_lock(&sdp->sd_statfs_spin);
 688         gfs2_statfs_change_in(m_sc, m_bh->b_data +
 689                               sizeof(struct gfs2_dinode));
 690         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
 691                 spin_unlock(&sdp->sd_statfs_spin);
 692                 goto out_bh;
 693         }
 694         spin_unlock(&sdp->sd_statfs_spin);
 695
 696         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 697         if (error)
 698                 goto out_bh;
 699
 700         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
 701         if (error)
 702                 goto out_bh2;
 703
 704         mutex_lock(&sdp->sd_statfs_mutex);
 705         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 706         mutex_unlock(&sdp->sd_statfs_mutex);
 707
 708         spin_lock(&sdp->sd_statfs_spin);
 709         m_sc->sc_total += l_sc->sc_total;
 710         m_sc->sc_free += l_sc->sc_free;
 711         m_sc->sc_dinodes += l_sc->sc_dinodes;
 712         memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
 713         memset(l_bh->b_data + sizeof(struct gfs2_dinode),
 714                0, sizeof(struct gfs2_statfs_change));
 715         spin_unlock(&sdp->sd_statfs_spin);
 716
 717         gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
 718         gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
 719
 720         gfs2_trans_end(sdp);
 721
 722 out_bh2:
 723         brelse(l_bh);
 724 out_bh:
 725         brelse(m_bh);
 726 out:
 727         gfs2_glock_dq_uninit(&gh);
 728         return error;
 729 }
 730
 731 /**
 732  * gfs2_statfs_i - Do a statfs
 733  * @sdp: the filesystem
 734  * @sg: the sg structure
 735  *
 736  * Returns: errno
 737  */
 738
 739 int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
 740 {
 741         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 742         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 743
 744         spin_lock(&sdp->sd_statfs_spin);
 745
 746         *sc = *m_sc;
 747         sc->sc_total += l_sc->sc_total;
 748         sc->sc_free += l_sc->sc_free;
 749         sc->sc_dinodes += l_sc->sc_dinodes;
 750
 751         spin_unlock(&sdp->sd_statfs_spin);
 752
 753         if (sc->sc_free < 0)
 754                 sc->sc_free = 0;
 755         if (sc->sc_free > sc->sc_total)
 756                 sc->sc_free = sc->sc_total;
 757         if (sc->sc_dinodes < 0)
 758                 sc->sc_dinodes = 0;
 759
 760         return 0;
 761 }
 762
 763 /**
 764  * statfs_fill - fill in the sg for a given RG
 765  * @rgd: the RG
 766  * @sc: the sc structure
 767  *
 768  * Returns: 0 on success, -ESTALE if the LVB is invalid
 769  */
 770
 771 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
 772                             struct gfs2_statfs_change_host *sc)
 773 {
 774         gfs2_rgrp_verify(rgd);
 775         sc->sc_total += rgd->rd_ri.ri_data;
 776         sc->sc_free += rgd->rd_rg.rg_free;
 777         sc->sc_dinodes += rgd->rd_rg.rg_dinodes;
 778         return 0;
 779 }
 780
 781 /**
 782  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
 783  * @sdp: the filesystem
 784  * @sc: the sc info that will be returned
 785  *
 786  * Any error (other than a signal) will cause this routine to fall back
 787  * to the synchronous version.
 788  *
 789  * FIXME: This really shouldn't busy wait like this.
 790  *
 791  * Returns: errno
 792  */
 793
 794 int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
 795 {
 796         struct gfs2_holder ri_gh;
 797         struct gfs2_rgrpd *rgd_next;
 798         struct gfs2_holder *gha, *gh;
 799         unsigned int slots = 64;
 800         unsigned int x;
 801         int done;
 802         int error = 0, err;
 803
 804         memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
 805         gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
 806         if (!gha)
 807                 return -ENOMEM;
 808
 809         error = gfs2_rindex_hold(sdp, &ri_gh);
 810         if (error)
 811                 goto out;
 812
 813         rgd_next = gfs2_rgrpd_get_first(sdp);
 814
 815         for (;;) {
 816                 done = 1;
 817
 818                 for (x = 0; x < slots; x++) {
 819                         gh = gha + x;
 820
 821                         if (gh->gh_gl && gfs2_glock_poll(gh)) {
 822                                 err = gfs2_glock_wait(gh);
 823                                 if (err) {
 824                                         gfs2_holder_uninit(gh);
 825                                         error = err;
 826                                 } else {
 827                                         if (!error)
 828                                                 error = statfs_slow_fill(
 829                                                         gh->gh_gl->gl_object, sc);
 830                                         gfs2_glock_dq_uninit(gh);
 831                                 }
 832                         }
 833
 834                         if (gh->gh_gl)
 835                                 done = 0;
 836                         else if (rgd_next && !error) {
 837                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
 838                                                            LM_ST_SHARED,
 839                                                            GL_ASYNC,
 840                                                            gh);
 841                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
 842                                 done = 0;
 843                         }
 844
 845                         if (signal_pending(current))
 846                                 error = -ERESTARTSYS;
 847                 }
 848
 849                 if (done)
 850                         break;
 851
 852                 yield();
 853         }
 854
 855         gfs2_glock_dq_uninit(&ri_gh);
 856
 857 out:
 858         kfree(gha);
 859         return error;
 860 }
 861
 862 struct lfcc {
 863         struct list_head list;
 864         struct gfs2_holder gh;
 865 };
 866
 867 /**
 868  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
 869  *                            journals are clean
 870  * @sdp: the file system
 871  * @state: the state to put the transaction lock into
 872  * @t_gh: the hold on the transaction lock
 873  *
 874  * Returns: errno
 875  */
 876
 877 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
 878                                     struct gfs2_holder *t_gh)
 879 {
 880         struct gfs2_inode *ip;
 881         struct gfs2_holder ji_gh;
 882         struct gfs2_jdesc *jd;
 883         struct lfcc *lfcc;
 884         LIST_HEAD(list);
 885         struct gfs2_log_header_host lh;
 886         int error;
 887
 888         error = gfs2_jindex_hold(sdp, &ji_gh);
 889         if (error)
 890                 return error;
 891
 892         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 893                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
 894                 if (!lfcc) {
 895                         error = -ENOMEM;
 896                         goto out;
 897                 }
 898                 ip = GFS2_I(jd->jd_inode);
 899                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
 900                 if (error) {
 901                         kfree(lfcc);
 902                         goto out;
 903                 }
 904                 list_add(&lfcc->list, &list);
 905         }
 906
 907         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
 908                                LM_FLAG_PRIORITY | GL_NOCACHE,
 909                                t_gh);
 910
 911         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 912                 error = gfs2_jdesc_check(jd);
 913                 if (error)
 914                         break;
 915                 error = gfs2_find_jhead(jd, &lh);
 916                 if (error)
 917                         break;
 918                 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 919                         error = -EBUSY;
 920                         break;
 921                 }
 922         }
 923
 924         if (error)
 925                 gfs2_glock_dq_uninit(t_gh);
 926
 927 out:
 928         while (!list_empty(&list)) {
 929                 lfcc = list_entry(list.next, struct lfcc, list);
 930                 list_del(&lfcc->list);
 931                 gfs2_glock_dq_uninit(&lfcc->gh);
 932                 kfree(lfcc);
 933         }
 934         gfs2_glock_dq_uninit(&ji_gh);
 935         return error;
 936 }
 937
 938 /**
 939  * gfs2_freeze_fs - freezes the file system
 940  * @sdp: the file system
 941  *
 942  * This function flushes data and meta data for all machines by
 943  * aquiring the transaction log exclusively.  All journals are
 944  * ensured to be in a clean state as well.
 945  *
 946  * Returns: errno
 947  */
 948
 949 int gfs2_freeze_fs(struct gfs2_sbd *sdp)
 950 {
 951         int error = 0;
 952
 953         mutex_lock(&sdp->sd_freeze_lock);
 954
 955         if (!sdp->sd_freeze_count++) {
 956                 error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
 957                 if (error)
 958                         sdp->sd_freeze_count--;
 959         }
 960
 961         mutex_unlock(&sdp->sd_freeze_lock);
 962
 963         return error;
 964 }
 965
 966 /**
 967  * gfs2_unfreeze_fs - unfreezes the file system
 968  * @sdp: the file system
 969  *
 970  * This function allows the file system to proceed by unlocking
 971  * the exclusively held transaction lock.  Other GFS2 nodes are
 972  * now free to acquire the lock shared and go on with their lives.
 973  *
 974  */
 975
 976 void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
 977 {
 978         mutex_lock(&sdp->sd_freeze_lock);
 979
 980         if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
 981                 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
 982
 983         mutex_unlock(&sdp->sd_freeze_lock);
 984 }
 985