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_recoverd_secs = 60;
  62         gt->gt_logd_secs = 1;
  63         gt->gt_quotad_secs = 5;
  64         gt->gt_quota_simul_sync = 64;
  65         gt->gt_quota_warn_period = 10;
  66         gt->gt_quota_scale_num = 1;
  67         gt->gt_quota_scale_den = 1;
  68         gt->gt_quota_cache_secs = 300;
  69         gt->gt_quota_quantum = 60;
  70         gt->gt_atime_quantum = 3600;
  71         gt->gt_new_files_jdata = 0;
  72         gt->gt_new_files_directio = 0;
  73         gt->gt_max_readahead = 1 << 18;
  74         gt->gt_lockdump_size = 131072;
  75         gt->gt_stall_secs = 600;
  76         gt->gt_complain_secs = 10;
  77         gt->gt_reclaim_limit = 5000;
  78         gt->gt_statfs_quantum = 30;
  79         gt->gt_statfs_slow = 0;
  80 }
  81
  82 /**
  83  * gfs2_check_sb - Check superblock
  84  * @sdp: the filesystem
  85  * @sb: The superblock
  86  * @silent: Don't print a message if the check fails
  87  *
  88  * Checks the version code of the FS is one that we understand how to
  89  * read and that the sizes of the various on-disk structures have not
  90  * changed.
  91  */
  92
  93 int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb_host *sb, int silent)
  94 {
  95         unsigned int x;
  96
  97         if (sb->sb_magic != GFS2_MAGIC ||
  98             sb->sb_type != GFS2_METATYPE_SB) {
  99                 if (!silent)
 100                         printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
 101                 return -EINVAL;
 102         }
 103
 104         /*  If format numbers match exactly, we're done.  */
 105
 106         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
 107             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
 108                 return 0;
 109
 110         if (sb->sb_fs_format != GFS2_FORMAT_FS) {
 111                 for (x = 0; gfs2_old_fs_formats[x]; x++)
 112                         if (gfs2_old_fs_formats[x] == sb->sb_fs_format)
 113                                 break;
 114
 115                 if (!gfs2_old_fs_formats[x]) {
 116                         printk(KERN_WARNING
 117                                "GFS2: code version (%u, %u) is incompatible "
 118                                "with ondisk format (%u, %u)\n",
 119                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 120                                sb->sb_fs_format, sb->sb_multihost_format);
 121                         printk(KERN_WARNING
 122                                "GFS2: I don't know how to upgrade this FS\n");
 123                         return -EINVAL;
 124                 }
 125         }
 126
 127         if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
 128                 for (x = 0; gfs2_old_multihost_formats[x]; x++)
 129                         if (gfs2_old_multihost_formats[x] ==
 130                             sb->sb_multihost_format)
 131                                 break;
 132
 133                 if (!gfs2_old_multihost_formats[x]) {
 134                         printk(KERN_WARNING
 135                                "GFS2: code version (%u, %u) is incompatible "
 136                                "with ondisk format (%u, %u)\n",
 137                                GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 138                                sb->sb_fs_format, sb->sb_multihost_format);
 139                         printk(KERN_WARNING
 140                                "GFS2: I don't know how to upgrade this FS\n");
 141                         return -EINVAL;
 142                 }
 143         }
 144
 145         if (!sdp->sd_args.ar_upgrade) {
 146                 printk(KERN_WARNING
 147                        "GFS2: code version (%u, %u) is incompatible "
 148                        "with ondisk format (%u, %u)\n",
 149                        GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
 150                        sb->sb_fs_format, sb->sb_multihost_format);
 151                 printk(KERN_INFO
 152                        "GFS2: Use the \"upgrade\" mount option to upgrade "
 153                        "the FS\n");
 154                 printk(KERN_INFO "GFS2: See the manual for more details\n");
 155                 return -EINVAL;
 156         }
 157
 158         return 0;
 159 }
 160
 161
 162 static void end_bio_io_page(struct bio *bio, int error)
 163 {
 164         struct page *page = bio->bi_private;
 165
 166         if (!error)
 167                 SetPageUptodate(page);
 168         else
 169                 printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
 170         unlock_page(page);
 171 }
 172
 173 static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf)
 174 {
 175         const struct gfs2_sb *str = buf;
 176
 177         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
 178         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
 179         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
 180         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
 181         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
 182         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
 183         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
 184         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
 185         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
 186         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
 187         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
 188
 189         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
 190         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
 191 }
 192
 193 /**
 194  * gfs2_read_super - Read the gfs2 super block from disk
 195  * @sdp: The GFS2 super block
 196  * @sector: The location of the super block
 197  * @error: The error code to return
 198  *
 199  * This uses the bio functions to read the super block from disk
 200  * because we want to be 100% sure that we never read cached data.
 201  * A super block is read twice only during each GFS2 mount and is
 202  * never written to by the filesystem. The first time its read no
 203  * locks are held, and the only details which are looked at are those
 204  * relating to the locking protocol. Once locking is up and working,
 205  * the sb is read again under the lock to establish the location of
 206  * the master directory (contains pointers to journals etc) and the
 207  * root directory.
 208  *
 209  * Returns: 0 on success or error
 210  */
 211
 212 int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector)
 213 {
 214         struct super_block *sb = sdp->sd_vfs;
 215         struct gfs2_sb *p;
 216         struct page *page;
 217         struct bio *bio;
 218
 219         page = alloc_page(GFP_KERNEL);
 220         if (unlikely(!page))
 221                 return -ENOBUFS;
 222
 223         ClearPageUptodate(page);
 224         ClearPageDirty(page);
 225         lock_page(page);
 226
 227         bio = bio_alloc(GFP_KERNEL, 1);
 228         if (unlikely(!bio)) {
 229                 __free_page(page);
 230                 return -ENOBUFS;
 231         }
 232
 233         bio->bi_sector = sector * (sb->s_blocksize >> 9);
 234         bio->bi_bdev = sb->s_bdev;
 235         bio_add_page(bio, page, PAGE_SIZE, 0);
 236
 237         bio->bi_end_io = end_bio_io_page;
 238         bio->bi_private = page;
 239         submit_bio(READ_SYNC | (1 << BIO_RW_META), bio);
 240         wait_on_page_locked(page);
 241         bio_put(bio);
 242         if (!PageUptodate(page)) {
 243                 __free_page(page);
 244                 return -EIO;
 245         }
 246         p = kmap(page);
 247         gfs2_sb_in(&sdp->sd_sb, p);
 248         kunmap(page);
 249         __free_page(page);
 250         return 0;
 251 }
 252
 253 /**
 254  * gfs2_read_sb - Read super block
 255  * @sdp: The GFS2 superblock
 256  * @gl: the glock for the superblock (assumed to be held)
 257  * @silent: Don't print message if mount fails
 258  *
 259  */
 260
 261 int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
 262 {
 263         u32 hash_blocks, ind_blocks, leaf_blocks;
 264         u32 tmp_blocks;
 265         unsigned int x;
 266         int error;
 267
 268         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
 269         if (error) {
 270                 if (!silent)
 271                         fs_err(sdp, "can't read superblock\n");
 272                 return error;
 273         }
 274
 275         error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
 276         if (error)
 277                 return error;
 278
 279         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
 280                                GFS2_BASIC_BLOCK_SHIFT;
 281         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
 282         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
 283                           sizeof(struct gfs2_dinode)) / sizeof(u64);
 284         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
 285                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
 286         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
 287         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
 288         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
 289         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
 290         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
 291                                 sizeof(struct gfs2_meta_header)) /
 292                                 sizeof(struct gfs2_quota_change);
 293
 294         /* Compute maximum reservation required to add a entry to a directory */
 295
 296         hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
 297                              sdp->sd_jbsize);
 298
 299         ind_blocks = 0;
 300         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
 301                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
 302                 ind_blocks += tmp_blocks;
 303         }
 304
 305         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
 306
 307         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
 308
 309         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
 310                                 sizeof(struct gfs2_dinode);
 311         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
 312         for (x = 2;; x++) {
 313                 u64 space, d;
 314                 u32 m;
 315
 316                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
 317                 d = space;
 318                 m = do_div(d, sdp->sd_inptrs);
 319
 320                 if (d != sdp->sd_heightsize[x - 1] || m)
 321                         break;
 322                 sdp->sd_heightsize[x] = space;
 323         }
 324         sdp->sd_max_height = x;
 325         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 326
 327         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
 328                                  sizeof(struct gfs2_dinode);
 329         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
 330         for (x = 2;; x++) {
 331                 u64 space, d;
 332                 u32 m;
 333
 334                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
 335                 d = space;
 336                 m = do_div(d, sdp->sd_inptrs);
 337
 338                 if (d != sdp->sd_jheightsize[x - 1] || m)
 339                         break;
 340                 sdp->sd_jheightsize[x] = space;
 341         }
 342         sdp->sd_max_jheight = x;
 343         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
 344
 345         return 0;
 346 }
 347
 348 /**
 349  * gfs2_jindex_hold - Grab a lock on the jindex
 350  * @sdp: The GFS2 superblock
 351  * @ji_gh: the holder for the jindex glock
 352  *
 353  * This is very similar to the gfs2_rindex_hold() function, except that
 354  * in general we hold the jindex lock for longer periods of time and
 355  * we grab it far less frequently (in general) then the rgrp lock.
 356  *
 357  * Returns: errno
 358  */
 359
 360 int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 361 {
 362         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
 363         struct qstr name;
 364         char buf[20];
 365         struct gfs2_jdesc *jd;
 366         int error;
 367
 368         name.name = buf;
 369
 370         mutex_lock(&sdp->sd_jindex_mutex);
 371
 372         for (;;) {
 373                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
 374                 if (error)
 375                         break;
 376
 377                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
 378                 name.hash = gfs2_disk_hash(name.name, name.len);
 379
 380                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
 381                 if (error == -ENOENT) {
 382                         error = 0;
 383                         break;
 384                 }
 385
 386                 gfs2_glock_dq_uninit(ji_gh);
 387
 388                 if (error)
 389                         break;
 390
 391                 error = -ENOMEM;
 392                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
 393                 if (!jd)
 394                         break;
 395
 396                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1, NULL);
 397                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
 398                         if (!jd->jd_inode)
 399                                 error = -ENOENT;
 400                         else
 401                                 error = PTR_ERR(jd->jd_inode);
 402                         kfree(jd);
 403                         break;
 404                 }
 405
 406                 spin_lock(&sdp->sd_jindex_spin);
 407                 jd->jd_jid = sdp->sd_journals++;
 408                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
 409                 spin_unlock(&sdp->sd_jindex_spin);
 410         }
 411
 412         mutex_unlock(&sdp->sd_jindex_mutex);
 413
 414         return error;
 415 }
 416
 417 /**
 418  * gfs2_jindex_free - Clear all the journal index information
 419  * @sdp: The GFS2 superblock
 420  *
 421  */
 422
 423 void gfs2_jindex_free(struct gfs2_sbd *sdp)
 424 {
 425         struct list_head list;
 426         struct gfs2_jdesc *jd;
 427
 428         spin_lock(&sdp->sd_jindex_spin);
 429         list_add(&list, &sdp->sd_jindex_list);
 430         list_del_init(&sdp->sd_jindex_list);
 431         sdp->sd_journals = 0;
 432         spin_unlock(&sdp->sd_jindex_spin);
 433
 434         while (!list_empty(&list)) {
 435                 jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
 436                 list_del(&jd->jd_list);
 437                 iput(jd->jd_inode);
 438                 kfree(jd);
 439         }
 440 }
 441
 442 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
 443 {
 444         struct gfs2_jdesc *jd;
 445         int found = 0;
 446
 447         list_for_each_entry(jd, head, jd_list) {
 448                 if (jd->jd_jid == jid) {
 449                         found = 1;
 450                         break;
 451                 }
 452         }
 453
 454         if (!found)
 455                 jd = NULL;
 456
 457         return jd;
 458 }
 459
 460 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
 461 {
 462         struct gfs2_jdesc *jd;
 463
 464         spin_lock(&sdp->sd_jindex_spin);
 465         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 466         spin_unlock(&sdp->sd_jindex_spin);
 467
 468         return jd;
 469 }
 470
 471 void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid)
 472 {
 473         struct gfs2_jdesc *jd;
 474
 475         spin_lock(&sdp->sd_jindex_spin);
 476         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
 477         if (jd)
 478                 jd->jd_dirty = 1;
 479         spin_unlock(&sdp->sd_jindex_spin);
 480 }
 481
 482 struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp)
 483 {
 484         struct gfs2_jdesc *jd;
 485         int found = 0;
 486
 487         spin_lock(&sdp->sd_jindex_spin);
 488
 489         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 490                 if (jd->jd_dirty) {
 491                         jd->jd_dirty = 0;
 492                         found = 1;
 493                         break;
 494                 }
 495         }
 496         spin_unlock(&sdp->sd_jindex_spin);
 497
 498         if (!found)
 499                 jd = NULL;
 500
 501         return jd;
 502 }
 503
 504 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
 505 {
 506         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 507         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
 508         int ar;
 509         int error;
 510
 511         if (ip->i_di.di_size < (8 << 20) || ip->i_di.di_size > (1 << 30) ||
 512             (ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) {
 513                 gfs2_consist_inode(ip);
 514                 return -EIO;
 515         }
 516         jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
 517
 518         error = gfs2_write_alloc_required(ip, 0, ip->i_di.di_size, &ar);
 519         if (!error && ar) {
 520                 gfs2_consist_inode(ip);
 521                 error = -EIO;
 522         }
 523
 524         return error;
 525 }
 526
 527 /**
 528  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
 529  * @sdp: the filesystem
 530  *
 531  * Returns: errno
 532  */
 533
 534 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
 535 {
 536         struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 537         struct gfs2_glock *j_gl = ip->i_gl;
 538         struct gfs2_holder t_gh;
 539         struct gfs2_log_header_host head;
 540         int error;
 541
 542         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &t_gh);
 543         if (error)
 544                 return error;
 545
 546         gfs2_meta_cache_flush(ip);
 547         j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
 548
 549         error = gfs2_find_jhead(sdp->sd_jdesc, &head);
 550         if (error)
 551                 goto fail;
 552
 553         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 554                 gfs2_consist(sdp);
 555                 error = -EIO;
 556                 goto fail;
 557         }
 558
 559         /*  Initialize some head of the log stuff  */
 560         sdp->sd_log_sequence = head.lh_sequence + 1;
 561         gfs2_log_pointers_init(sdp, head.lh_blkno);
 562
 563         error = gfs2_quota_init(sdp);
 564         if (error)
 565                 goto fail;
 566
 567         set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 568
 569         gfs2_glock_dq_uninit(&t_gh);
 570
 571         return 0;
 572
 573 fail:
 574         t_gh.gh_flags |= GL_NOCACHE;
 575         gfs2_glock_dq_uninit(&t_gh);
 576
 577         return error;
 578 }
 579
 580 /**
 581  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
 582  * @sdp: the filesystem
 583  *
 584  * Returns: errno
 585  */
 586
 587 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
 588 {
 589         struct gfs2_holder t_gh;
 590         int error;
 591
 592         gfs2_quota_sync(sdp);
 593         gfs2_statfs_sync(sdp);
 594
 595         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, GL_NOCACHE,
 596                                    &t_gh);
 597         if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
 598                 return error;
 599
 600         gfs2_meta_syncfs(sdp);
 601         gfs2_log_shutdown(sdp);
 602
 603         clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 604
 605         if (t_gh.gh_gl)
 606                 gfs2_glock_dq_uninit(&t_gh);
 607
 608         gfs2_quota_cleanup(sdp);
 609
 610         return error;
 611 }
 612
 613 static void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
 614 {
 615         const struct gfs2_statfs_change *str = buf;
 616
 617         sc->sc_total = be64_to_cpu(str->sc_total);
 618         sc->sc_free = be64_to_cpu(str->sc_free);
 619         sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
 620 }
 621
 622 static void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
 623 {
 624         struct gfs2_statfs_change *str = buf;
 625
 626         str->sc_total = cpu_to_be64(sc->sc_total);
 627         str->sc_free = cpu_to_be64(sc->sc_free);
 628         str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
 629 }
 630
 631 int gfs2_statfs_init(struct gfs2_sbd *sdp)
 632 {
 633         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 634         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 635         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 636         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 637         struct buffer_head *m_bh, *l_bh;
 638         struct gfs2_holder gh;
 639         int error;
 640
 641         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 642                                    &gh);
 643         if (error)
 644                 return error;
 645
 646         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 647         if (error)
 648                 goto out;
 649
 650         if (sdp->sd_args.ar_spectator) {
 651                 spin_lock(&sdp->sd_statfs_spin);
 652                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 653                                       sizeof(struct gfs2_dinode));
 654                 spin_unlock(&sdp->sd_statfs_spin);
 655         } else {
 656                 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 657                 if (error)
 658                         goto out_m_bh;
 659
 660                 spin_lock(&sdp->sd_statfs_spin);
 661                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
 662                                       sizeof(struct gfs2_dinode));
 663                 gfs2_statfs_change_in(l_sc, l_bh->b_data +
 664                                       sizeof(struct gfs2_dinode));
 665                 spin_unlock(&sdp->sd_statfs_spin);
 666
 667                 brelse(l_bh);
 668         }
 669
 670 out_m_bh:
 671         brelse(m_bh);
 672 out:
 673         gfs2_glock_dq_uninit(&gh);
 674         return 0;
 675 }
 676
 677 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
 678                         s64 dinodes)
 679 {
 680         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 681         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 682         struct buffer_head *l_bh;
 683         int error;
 684
 685         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 686         if (error)
 687                 return;
 688
 689         mutex_lock(&sdp->sd_statfs_mutex);
 690         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 691         mutex_unlock(&sdp->sd_statfs_mutex);
 692
 693         spin_lock(&sdp->sd_statfs_spin);
 694         l_sc->sc_total += total;
 695         l_sc->sc_free += free;
 696         l_sc->sc_dinodes += dinodes;
 697         gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
 698         spin_unlock(&sdp->sd_statfs_spin);
 699
 700         brelse(l_bh);
 701 }
 702
 703 int gfs2_statfs_sync(struct gfs2_sbd *sdp)
 704 {
 705         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
 706         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 707         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 708         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 709         struct gfs2_holder gh;
 710         struct buffer_head *m_bh, *l_bh;
 711         int error;
 712
 713         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
 714                                    &gh);
 715         if (error)
 716                 return error;
 717
 718         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
 719         if (error)
 720                 goto out;
 721
 722         spin_lock(&sdp->sd_statfs_spin);
 723         gfs2_statfs_change_in(m_sc, m_bh->b_data +
 724                               sizeof(struct gfs2_dinode));
 725         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
 726                 spin_unlock(&sdp->sd_statfs_spin);
 727                 goto out_bh;
 728         }
 729         spin_unlock(&sdp->sd_statfs_spin);
 730
 731         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
 732         if (error)
 733                 goto out_bh;
 734
 735         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
 736         if (error)
 737                 goto out_bh2;
 738
 739         mutex_lock(&sdp->sd_statfs_mutex);
 740         gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
 741         mutex_unlock(&sdp->sd_statfs_mutex);
 742
 743         spin_lock(&sdp->sd_statfs_spin);
 744         m_sc->sc_total += l_sc->sc_total;
 745         m_sc->sc_free += l_sc->sc_free;
 746         m_sc->sc_dinodes += l_sc->sc_dinodes;
 747         memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
 748         memset(l_bh->b_data + sizeof(struct gfs2_dinode),
 749                0, sizeof(struct gfs2_statfs_change));
 750         spin_unlock(&sdp->sd_statfs_spin);
 751
 752         gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
 753         gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
 754
 755         gfs2_trans_end(sdp);
 756
 757 out_bh2:
 758         brelse(l_bh);
 759 out_bh:
 760         brelse(m_bh);
 761 out:
 762         gfs2_glock_dq_uninit(&gh);
 763         return error;
 764 }
 765
 766 /**
 767  * gfs2_statfs_i - Do a statfs
 768  * @sdp: the filesystem
 769  * @sg: the sg structure
 770  *
 771  * Returns: errno
 772  */
 773
 774 int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
 775 {
 776         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 777         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 778
 779         spin_lock(&sdp->sd_statfs_spin);
 780
 781         *sc = *m_sc;
 782         sc->sc_total += l_sc->sc_total;
 783         sc->sc_free += l_sc->sc_free;
 784         sc->sc_dinodes += l_sc->sc_dinodes;
 785
 786         spin_unlock(&sdp->sd_statfs_spin);
 787
 788         if (sc->sc_free < 0)
 789                 sc->sc_free = 0;
 790         if (sc->sc_free > sc->sc_total)
 791                 sc->sc_free = sc->sc_total;
 792         if (sc->sc_dinodes < 0)
 793                 sc->sc_dinodes = 0;
 794
 795         return 0;
 796 }
 797
 798 /**
 799  * statfs_fill - fill in the sg for a given RG
 800  * @rgd: the RG
 801  * @sc: the sc structure
 802  *
 803  * Returns: 0 on success, -ESTALE if the LVB is invalid
 804  */
 805
 806 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
 807                             struct gfs2_statfs_change_host *sc)
 808 {
 809         gfs2_rgrp_verify(rgd);
 810         sc->sc_total += rgd->rd_data;
 811         sc->sc_free += rgd->rd_rg.rg_free;
 812         sc->sc_dinodes += rgd->rd_rg.rg_dinodes;
 813         return 0;
 814 }
 815
 816 /**
 817  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
 818  * @sdp: the filesystem
 819  * @sc: the sc info that will be returned
 820  *
 821  * Any error (other than a signal) will cause this routine to fall back
 822  * to the synchronous version.
 823  *
 824  * FIXME: This really shouldn't busy wait like this.
 825  *
 826  * Returns: errno
 827  */
 828
 829 int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
 830 {
 831         struct gfs2_holder ri_gh;
 832         struct gfs2_rgrpd *rgd_next;
 833         struct gfs2_holder *gha, *gh;
 834         unsigned int slots = 64;
 835         unsigned int x;
 836         int done;
 837         int error = 0, err;
 838
 839         memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
 840         gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
 841         if (!gha)
 842                 return -ENOMEM;
 843
 844         error = gfs2_rindex_hold(sdp, &ri_gh);
 845         if (error)
 846                 goto out;
 847
 848         rgd_next = gfs2_rgrpd_get_first(sdp);
 849
 850         for (;;) {
 851                 done = 1;
 852
 853                 for (x = 0; x < slots; x++) {
 854                         gh = gha + x;
 855
 856                         if (gh->gh_gl && gfs2_glock_poll(gh)) {
 857                                 err = gfs2_glock_wait(gh);
 858                                 if (err) {
 859                                         gfs2_holder_uninit(gh);
 860                                         error = err;
 861                                 } else {
 862                                         if (!error)
 863                                                 error = statfs_slow_fill(
 864                                                         gh->gh_gl->gl_object, sc);
 865                                         gfs2_glock_dq_uninit(gh);
 866                                 }
 867                         }
 868
 869                         if (gh->gh_gl)
 870                                 done = 0;
 871                         else if (rgd_next && !error) {
 872                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
 873                                                            LM_ST_SHARED,
 874                                                            GL_ASYNC,
 875                                                            gh);
 876                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
 877                                 done = 0;
 878                         }
 879
 880                         if (signal_pending(current))
 881                                 error = -ERESTARTSYS;
 882                 }
 883
 884                 if (done)
 885                         break;
 886
 887                 yield();
 888         }
 889
 890         gfs2_glock_dq_uninit(&ri_gh);
 891
 892 out:
 893         kfree(gha);
 894         return error;
 895 }
 896
 897 struct lfcc {
 898         struct list_head list;
 899         struct gfs2_holder gh;
 900 };
 901
 902 /**
 903  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
 904  *                            journals are clean
 905  * @sdp: the file system
 906  * @state: the state to put the transaction lock into
 907  * @t_gh: the hold on the transaction lock
 908  *
 909  * Returns: errno
 910  */
 911
 912 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
 913                                     struct gfs2_holder *t_gh)
 914 {
 915         struct gfs2_inode *ip;
 916         struct gfs2_holder ji_gh;
 917         struct gfs2_jdesc *jd;
 918         struct lfcc *lfcc;
 919         LIST_HEAD(list);
 920         struct gfs2_log_header_host lh;
 921         int error;
 922
 923         error = gfs2_jindex_hold(sdp, &ji_gh);
 924         if (error)
 925                 return error;
 926
 927         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 928                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
 929                 if (!lfcc) {
 930                         error = -ENOMEM;
 931                         goto out;
 932                 }
 933                 ip = GFS2_I(jd->jd_inode);
 934                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
 935                 if (error) {
 936                         kfree(lfcc);
 937                         goto out;
 938                 }
 939                 list_add(&lfcc->list, &list);
 940         }
 941
 942         error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
 943                                LM_FLAG_PRIORITY | GL_NOCACHE,
 944                                t_gh);
 945
 946         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 947                 error = gfs2_jdesc_check(jd);
 948                 if (error)
 949                         break;
 950                 error = gfs2_find_jhead(jd, &lh);
 951                 if (error)
 952                         break;
 953                 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 954                         error = -EBUSY;
 955                         break;
 956                 }
 957         }
 958
 959         if (error)
 960                 gfs2_glock_dq_uninit(t_gh);
 961
 962 out:
 963         while (!list_empty(&list)) {
 964                 lfcc = list_entry(list.next, struct lfcc, list);
 965                 list_del(&lfcc->list);
 966                 gfs2_glock_dq_uninit(&lfcc->gh);
 967                 kfree(lfcc);
 968         }
 969         gfs2_glock_dq_uninit(&ji_gh);
 970         return error;
 971 }
 972
 973 /**
 974  * gfs2_freeze_fs - freezes the file system
 975  * @sdp: the file system
 976  *
 977  * This function flushes data and meta data for all machines by
 978  * aquiring the transaction log exclusively.  All journals are
 979  * ensured to be in a clean state as well.
 980  *
 981  * Returns: errno
 982  */
 983
 984 int gfs2_freeze_fs(struct gfs2_sbd *sdp)
 985 {
 986         int error = 0;
 987
 988         mutex_lock(&sdp->sd_freeze_lock);
 989
 990         if (!sdp->sd_freeze_count++) {
 991                 error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
 992                 if (error)
 993                         sdp->sd_freeze_count--;
 994         }
 995
 996         mutex_unlock(&sdp->sd_freeze_lock);
 997
 998         return error;
 999 }
1000
1001 /**
1002  * gfs2_unfreeze_fs - unfreezes the file system
1003  * @sdp: the file system
1004  *
1005  * This function allows the file system to proceed by unlocking
1006  * the exclusively held transaction lock.  Other GFS2 nodes are
1007  * now free to acquire the lock shared and go on with their lives.
1008  *
1009  */
1010
1011 void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
1012 {
1013         mutex_lock(&sdp->sd_freeze_lock);
1014
1015         if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
1016                 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
1017
1018         mutex_unlock(&sdp->sd_freeze_lock);
1019 }
1020