fs/gfs2/ops_fstype.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2008 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/sched.h>
  13 #include <linux/slab.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/completion.h>
  16 #include <linux/buffer_head.h>
  17 #include <linux/blkdev.h>
  18 #include <linux/kthread.h>
  19 #include <linux/export.h>
  20 #include <linux/namei.h>
  21 #include <linux/mount.h>
  22 #include <linux/gfs2_ondisk.h>
  23 #include <linux/quotaops.h>
  24 #include <linux/lockdep.h>
  25 #include <linux/module.h>
  26 #include <linux/backing-dev.h>
  27
  28 #include "gfs2.h"
  29 #include "incore.h"
  30 #include "bmap.h"
  31 #include "glock.h"
  32 #include "glops.h"
  33 #include "inode.h"
  34 #include "recovery.h"
  35 #include "rgrp.h"
  36 #include "super.h"
  37 #include "sys.h"
  38 #include "util.h"
  39 #include "log.h"
  40 #include "quota.h"
  41 #include "dir.h"
  42 #include "meta_io.h"
  43 #include "trace_gfs2.h"
  44
  45 #define DO 0
  46 #define UNDO 1
  47
  48 /**
  49  * gfs2_tune_init - Fill a gfs2_tune structure with default values
  50  * @gt: tune
  51  *
  52  */
  53
  54 static void gfs2_tune_init(struct gfs2_tune *gt)
  55 {
  56         spin_lock_init(&gt->gt_spin);
  57
  58         gt->gt_quota_warn_period = 10;
  59         gt->gt_quota_scale_num = 1;
  60         gt->gt_quota_scale_den = 1;
  61         gt->gt_new_files_jdata = 0;
  62         gt->gt_max_readahead = BIT(18);
  63         gt->gt_complain_secs = 10;
  64 }
  65
  66 static struct gfs2_sbd *init_sbd(struct super_block *sb)
  67 {
  68         struct gfs2_sbd *sdp;
  69         struct address_space *mapping;
  70
  71         sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
  72         if (!sdp)
  73                 return NULL;
  74
  75         sdp->sd_vfs = sb;
  76         sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats);
  77         if (!sdp->sd_lkstats) {
  78                 kfree(sdp);
  79                 return NULL;
  80         }
  81         sb->s_fs_info = sdp;
  82
  83         set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
  84         gfs2_tune_init(&sdp->sd_tune);
  85
  86         init_waitqueue_head(&sdp->sd_glock_wait);
  87         atomic_set(&sdp->sd_glock_disposal, 0);
  88         init_completion(&sdp->sd_locking_init);
  89         init_completion(&sdp->sd_wdack);
  90         spin_lock_init(&sdp->sd_statfs_spin);
  91
  92         spin_lock_init(&sdp->sd_rindex_spin);
  93         sdp->sd_rindex_tree.rb_node = NULL;
  94
  95         INIT_LIST_HEAD(&sdp->sd_jindex_list);
  96         spin_lock_init(&sdp->sd_jindex_spin);
  97         mutex_init(&sdp->sd_jindex_mutex);
  98         init_completion(&sdp->sd_journal_ready);
  99
 100         INIT_LIST_HEAD(&sdp->sd_quota_list);
 101         mutex_init(&sdp->sd_quota_mutex);
 102         mutex_init(&sdp->sd_quota_sync_mutex);
 103         init_waitqueue_head(&sdp->sd_quota_wait);
 104         INIT_LIST_HEAD(&sdp->sd_trunc_list);
 105         spin_lock_init(&sdp->sd_trunc_lock);
 106         spin_lock_init(&sdp->sd_bitmap_lock);
 107
 108         mapping = &sdp->sd_aspace;
 109
 110         address_space_init_once(mapping);
 111         mapping->a_ops = &gfs2_rgrp_aops;
 112         mapping->host = sb->s_bdev->bd_inode;
 113         mapping->flags = 0;
 114         mapping_set_gfp_mask(mapping, GFP_NOFS);
 115         mapping->private_data = NULL;
 116         mapping->writeback_index = 0;
 117
 118         spin_lock_init(&sdp->sd_log_lock);
 119         atomic_set(&sdp->sd_log_pinned, 0);
 120         INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
 121         INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
 122         spin_lock_init(&sdp->sd_ordered_lock);
 123
 124         init_waitqueue_head(&sdp->sd_log_waitq);
 125         init_waitqueue_head(&sdp->sd_logd_waitq);
 126         spin_lock_init(&sdp->sd_ail_lock);
 127         INIT_LIST_HEAD(&sdp->sd_ail1_list);
 128         INIT_LIST_HEAD(&sdp->sd_ail2_list);
 129
 130         init_rwsem(&sdp->sd_log_flush_lock);
 131         atomic_set(&sdp->sd_log_in_flight, 0);
 132         atomic_set(&sdp->sd_reserving_log, 0);
 133         init_waitqueue_head(&sdp->sd_reserving_log_wait);
 134         init_waitqueue_head(&sdp->sd_log_flush_wait);
 135         atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
 136         mutex_init(&sdp->sd_freeze_mutex);
 137
 138         return sdp;
 139 }
 140
 141
 142 /**
 143  * gfs2_check_sb - Check superblock
 144  * @sdp: the filesystem
 145  * @sb: The superblock
 146  * @silent: Don't print a message if the check fails
 147  *
 148  * Checks the version code of the FS is one that we understand how to
 149  * read and that the sizes of the various on-disk structures have not
 150  * changed.
 151  */
 152
 153 static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
 154 {
 155         struct gfs2_sb_host *sb = &sdp->sd_sb;
 156
 157         if (sb->sb_magic != GFS2_MAGIC ||
 158             sb->sb_type != GFS2_METATYPE_SB) {
 159                 if (!silent)
 160                         pr_warn("not a GFS2 filesystem\n");
 161                 return -EINVAL;
 162         }
 163
 164         if (sb->sb_fs_format != GFS2_FORMAT_FS ||
 165             sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
 166                 fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
 167                 return -EINVAL;
 168         }
 169
 170         if (sb->sb_bsize < 512 || sb->sb_bsize > PAGE_SIZE ||
 171             (sb->sb_bsize & (sb->sb_bsize - 1))) {
 172                 pr_warn("Invalid superblock size\n");
 173                 return -EINVAL;
 174         }
 175         if (sb->sb_bsize_shift != ffs(sb->sb_bsize) - 1) {
 176                 pr_warn("Invalid block size shift\n");
 177                 return -EINVAL;
 178         }
 179         return 0;
 180 }
 181
 182 static void end_bio_io_page(struct bio *bio)
 183 {
 184         struct page *page = bio->bi_private;
 185
 186         if (!bio->bi_status)
 187                 SetPageUptodate(page);
 188         else
 189                 pr_warn("error %d reading superblock\n", bio->bi_status);
 190         unlock_page(page);
 191 }
 192
 193 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
 194 {
 195         struct gfs2_sb_host *sb = &sdp->sd_sb;
 196         struct super_block *s = sdp->sd_vfs;
 197         const struct gfs2_sb *str = buf;
 198
 199         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
 200         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
 201         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
 202         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
 203         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
 204         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
 205         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
 206         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
 207         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
 208         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
 209         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
 210
 211         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
 212         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
 213         memcpy(&s->s_uuid, str->sb_uuid, 16);
 214 }
 215
 216 /**
 217  * gfs2_read_super - Read the gfs2 super block from disk
 218  * @sdp: The GFS2 super block
 219  * @sector: The location of the super block
 220  * @error: The error code to return
 221  *
 222  * This uses the bio functions to read the super block from disk
 223  * because we want to be 100% sure that we never read cached data.
 224  * A super block is read twice only during each GFS2 mount and is
 225  * never written to by the filesystem. The first time its read no
 226  * locks are held, and the only details which are looked at are those
 227  * relating to the locking protocol. Once locking is up and working,
 228  * the sb is read again under the lock to establish the location of
 229  * the master directory (contains pointers to journals etc) and the
 230  * root directory.
 231  *
 232  * Returns: 0 on success or error
 233  */
 234
 235 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
 236 {
 237         struct super_block *sb = sdp->sd_vfs;
 238         struct gfs2_sb *p;
 239         struct page *page;
 240         struct bio *bio;
 241
 242         page = alloc_page(GFP_NOFS);
 243         if (unlikely(!page))
 244                 return -ENOMEM;
 245
 246         ClearPageUptodate(page);
 247         ClearPageDirty(page);
 248         lock_page(page);
 249
 250         bio = bio_alloc(GFP_NOFS, 1);
 251         bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
 252         bio_set_dev(bio, sb->s_bdev);
 253         bio_add_page(bio, page, PAGE_SIZE, 0);
 254
 255         bio->bi_end_io = end_bio_io_page;
 256         bio->bi_private = page;
 257         bio_set_op_attrs(bio, REQ_OP_READ, REQ_META);
 258         submit_bio(bio);
 259         wait_on_page_locked(page);
 260         bio_put(bio);
 261         if (!PageUptodate(page)) {
 262                 __free_page(page);
 263                 return -EIO;
 264         }
 265         p = kmap(page);
 266         gfs2_sb_in(sdp, p);
 267         kunmap(page);
 268         __free_page(page);
 269         return gfs2_check_sb(sdp, silent);
 270 }
 271
 272 /**
 273  * gfs2_read_sb - Read super block
 274  * @sdp: The GFS2 superblock
 275  * @silent: Don't print message if mount fails
 276  *
 277  */
 278
 279 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
 280 {
 281         u32 hash_blocks, ind_blocks, leaf_blocks;
 282         u32 tmp_blocks;
 283         unsigned int x;
 284         int error;
 285
 286         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
 287         if (error) {
 288                 if (!silent)
 289                         fs_err(sdp, "can't read superblock\n");
 290                 return error;
 291         }
 292
 293         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
 294                                GFS2_BASIC_BLOCK_SHIFT;
 295         sdp->sd_fsb2bb = BIT(sdp->sd_fsb2bb_shift);
 296         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
 297                           sizeof(struct gfs2_dinode)) / sizeof(u64);
 298         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
 299                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
 300         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
 301         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
 302         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
 303         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
 304         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
 305                                 sizeof(struct gfs2_meta_header)) /
 306                                 sizeof(struct gfs2_quota_change);
 307         sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
 308                                      sizeof(struct gfs2_meta_header))
 309                 * GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
 310
 311         /* Compute maximum reservation required to add a entry to a directory */
 312
 313         hash_blocks = DIV_ROUND_UP(sizeof(u64) * BIT(GFS2_DIR_MAX_DEPTH),
 314                              sdp->sd_jbsize);
 315
 316         ind_blocks = 0;
 317         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
 318                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
 319                 ind_blocks += tmp_blocks;
 320         }
 321
 322         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
 323
 324         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
 325
 326         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
 327                                 sizeof(struct gfs2_dinode);
 328         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
 329         for (x = 2;; x++) {
 330                 u64 space, d;
 331                 u32 m;
 332
 333                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
 334                 d = space;
 335                 m = do_div(d, sdp->sd_inptrs);
 336
 337                 if (d != sdp->sd_heightsize[x - 1] || m)
 338                         break;
 339                 sdp->sd_heightsize[x] = space;
 340         }
 341         sdp->sd_max_height = x;
 342         sdp->sd_heightsize[x] = ~0;
 343         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 344
 345         sdp->sd_max_dents_per_leaf = (sdp->sd_sb.sb_bsize -
 346                                       sizeof(struct gfs2_leaf)) /
 347                                      GFS2_MIN_DIRENT_SIZE;
 348         return 0;
 349 }
 350
 351 static int init_names(struct gfs2_sbd *sdp, int silent)
 352 {
 353         char *proto, *table;
 354         int error = 0;
 355
 356         proto = sdp->sd_args.ar_lockproto;
 357         table = sdp->sd_args.ar_locktable;
 358
 359         /*  Try to autodetect  */
 360
 361         if (!proto[0] || !table[0]) {
 362                 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
 363                 if (error)
 364                         return error;
 365
 366                 if (!proto[0])
 367                         proto = sdp->sd_sb.sb_lockproto;
 368                 if (!table[0])
 369                         table = sdp->sd_sb.sb_locktable;
 370         }
 371
 372         if (!table[0])
 373                 table = sdp->sd_vfs->s_id;
 374
 375         BUILD_BUG_ON(GFS2_LOCKNAME_LEN > GFS2_FSNAME_LEN);
 376
 377         strscpy(sdp->sd_proto_name, proto, GFS2_LOCKNAME_LEN);
 378         strscpy(sdp->sd_table_name, table, GFS2_LOCKNAME_LEN);
 379
 380         table = sdp->sd_table_name;
 381         while ((table = strchr(table, '/')))
 382                 *table = '_';
 383
 384         return error;
 385 }
 386
 387 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
 388                         int undo)
 389 {
 390         int error = 0;
 391
 392         if (undo)
 393                 goto fail_trans;
 394
 395         error = gfs2_glock_nq_num(sdp,
 396                                   GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
 397                                   LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
 398                                   mount_gh);
 399         if (error) {
 400                 fs_err(sdp, "can't acquire mount glock: %d\n", error);
 401                 goto fail;
 402         }
 403
 404         error = gfs2_glock_nq_num(sdp,
 405                                   GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
 406                                   LM_ST_SHARED,
 407                                   LM_FLAG_NOEXP | GL_EXACT,
 408                                   &sdp->sd_live_gh);
 409         if (error) {
 410                 fs_err(sdp, "can't acquire live glock: %d\n", error);
 411                 goto fail_mount;
 412         }
 413
 414         error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
 415                                CREATE, &sdp->sd_rename_gl);
 416         if (error) {
 417                 fs_err(sdp, "can't create rename glock: %d\n", error);
 418                 goto fail_live;
 419         }
 420
 421         error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
 422                                CREATE, &sdp->sd_freeze_gl);
 423         if (error) {
 424                 fs_err(sdp, "can't create transaction glock: %d\n", error);
 425                 goto fail_rename;
 426         }
 427
 428         return 0;
 429
 430 fail_trans:
 431         gfs2_glock_put(sdp->sd_freeze_gl);
 432 fail_rename:
 433         gfs2_glock_put(sdp->sd_rename_gl);
 434 fail_live:
 435         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
 436 fail_mount:
 437         gfs2_glock_dq_uninit(mount_gh);
 438 fail:
 439         return error;
 440 }
 441
 442 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
 443                             u64 no_addr, const char *name)
 444 {
 445         struct gfs2_sbd *sdp = sb->s_fs_info;
 446         struct dentry *dentry;
 447         struct inode *inode;
 448
 449         inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0,
 450                                   GFS2_BLKST_FREE /* ignore */);
 451         if (IS_ERR(inode)) {
 452                 fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
 453                 return PTR_ERR(inode);
 454         }
 455         dentry = d_make_root(inode);
 456         if (!dentry) {
 457                 fs_err(sdp, "can't alloc %s dentry\n", name);
 458                 return -ENOMEM;
 459         }
 460         *dptr = dentry;
 461         return 0;
 462 }
 463
 464 static int init_sb(struct gfs2_sbd *sdp, int silent)
 465 {
 466         struct super_block *sb = sdp->sd_vfs;
 467         struct gfs2_holder sb_gh;
 468         u64 no_addr;
 469         int ret;
 470
 471         ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
 472                                 LM_ST_SHARED, 0, &sb_gh);
 473         if (ret) {
 474                 fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
 475                 return ret;
 476         }
 477
 478         ret = gfs2_read_sb(sdp, silent);
 479         if (ret) {
 480                 fs_err(sdp, "can't read superblock: %d\n", ret);
 481                 goto out;
 482         }
 483
 484         /* Set up the buffer cache and SB for real */
 485         if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
 486                 ret = -EINVAL;
 487                 fs_err(sdp, "FS block size (%u) is too small for device "
 488                        "block size (%u)\n",
 489                        sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
 490                 goto out;
 491         }
 492         if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
 493                 ret = -EINVAL;
 494                 fs_err(sdp, "FS block size (%u) is too big for machine "
 495                        "page size (%u)\n",
 496                        sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
 497                 goto out;
 498         }
 499         sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
 500
 501         /* Get the root inode */
 502         no_addr = sdp->sd_sb.sb_root_dir.no_addr;
 503         ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
 504         if (ret)
 505                 goto out;
 506
 507         /* Get the master inode */
 508         no_addr = sdp->sd_sb.sb_master_dir.no_addr;
 509         ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
 510         if (ret) {
 511                 dput(sdp->sd_root_dir);
 512                 goto out;
 513         }
 514         sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
 515 out:
 516         gfs2_glock_dq_uninit(&sb_gh);
 517         return ret;
 518 }
 519
 520 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
 521 {
 522         char *message = "FIRSTMOUNT=Done";
 523         char *envp[] = { message, NULL };
 524
 525         fs_info(sdp, "first mount done, others may mount\n");
 526
 527         if (sdp->sd_lockstruct.ls_ops->lm_first_done)
 528                 sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
 529
 530         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
 531 }
 532
 533 /**
 534  * gfs2_jindex_hold - Grab a lock on the jindex
 535  * @sdp: The GFS2 superblock
 536  * @ji_gh: the holder for the jindex glock
 537  *
 538  * Returns: errno
 539  */
 540
 541 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 542 {
 543         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
 544         struct qstr name;
 545         char buf[20];
 546         struct gfs2_jdesc *jd;
 547         int error;
 548
 549         name.name = buf;
 550
 551         mutex_lock(&sdp->sd_jindex_mutex);
 552
 553         for (;;) {
 554                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
 555                 if (error)
 556                         break;
 557
 558                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
 559                 name.hash = gfs2_disk_hash(name.name, name.len);
 560
 561                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
 562                 if (error == -ENOENT) {
 563                         error = 0;
 564                         break;
 565                 }
 566
 567                 gfs2_glock_dq_uninit(ji_gh);
 568
 569                 if (error)
 570                         break;
 571
 572                 error = -ENOMEM;
 573                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
 574                 if (!jd)
 575                         break;
 576
 577                 INIT_LIST_HEAD(&jd->extent_list);
 578                 INIT_LIST_HEAD(&jd->jd_revoke_list);
 579
 580                 INIT_WORK(&jd->jd_work, gfs2_recover_func);
 581                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
 582                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
 583                         if (!jd->jd_inode)
 584                                 error = -ENOENT;
 585                         else
 586                                 error = PTR_ERR(jd->jd_inode);
 587                         kfree(jd);
 588                         break;
 589                 }
 590
 591                 spin_lock(&sdp->sd_jindex_spin);
 592                 jd->jd_jid = sdp->sd_journals++;
 593                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
 594                 spin_unlock(&sdp->sd_jindex_spin);
 595         }
 596
 597         mutex_unlock(&sdp->sd_jindex_mutex);
 598
 599         return error;
 600 }
 601
 602 /**
 603  * check_journal_clean - Make sure a journal is clean for a spectator mount
 604  * @sdp: The GFS2 superblock
 605  * @jd: The journal descriptor
 606  *
 607  * Returns: 0 if the journal is clean or locked, else an error
 608  */
 609 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
 610 {
 611         int error;
 612         struct gfs2_holder j_gh;
 613         struct gfs2_log_header_host head;
 614         struct gfs2_inode *ip;
 615
 616         ip = GFS2_I(jd->jd_inode);
 617         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
 618                                    GL_EXACT | GL_NOCACHE, &j_gh);
 619         if (error) {
 620                 fs_err(sdp, "Error locking journal for spectator mount.\n");
 621                 return -EPERM;
 622         }
 623         error = gfs2_jdesc_check(jd);
 624         if (error) {
 625                 fs_err(sdp, "Error checking journal for spectator mount.\n");
 626                 goto out_unlock;
 627         }
 628         error = gfs2_find_jhead(jd, &head);
 629         if (error) {
 630                 fs_err(sdp, "Error parsing journal for spectator mount.\n");
 631                 goto out_unlock;
 632         }
 633         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
 634                 error = -EPERM;
 635                 fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
 636                        "must not be a spectator.\n", jd->jd_jid);
 637         }
 638
 639 out_unlock:
 640         gfs2_glock_dq_uninit(&j_gh);
 641         return error;
 642 }
 643
 644 static int init_journal(struct gfs2_sbd *sdp, int undo)
 645 {
 646         struct inode *master = d_inode(sdp->sd_master_dir);
 647         struct gfs2_holder ji_gh;
 648         struct gfs2_inode *ip;
 649         int jindex = 1;
 650         int error = 0;
 651
 652         if (undo) {
 653                 jindex = 0;
 654                 goto fail_jinode_gh;
 655         }
 656
 657         sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
 658         if (IS_ERR(sdp->sd_jindex)) {
 659                 fs_err(sdp, "can't lookup journal index: %d\n", error);
 660                 return PTR_ERR(sdp->sd_jindex);
 661         }
 662
 663         /* Load in the journal index special file */
 664
 665         error = gfs2_jindex_hold(sdp, &ji_gh);
 666         if (error) {
 667                 fs_err(sdp, "can't read journal index: %d\n", error);
 668                 goto fail;
 669         }
 670
 671         error = -EUSERS;
 672         if (!gfs2_jindex_size(sdp)) {
 673                 fs_err(sdp, "no journals!\n");
 674                 goto fail_jindex;
 675         }
 676
 677         atomic_set(&sdp->sd_log_blks_needed, 0);
 678         if (sdp->sd_args.ar_spectator) {
 679                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
 680                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
 681                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
 682                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
 683         } else {
 684                 if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
 685                         fs_err(sdp, "can't mount journal #%u\n",
 686                                sdp->sd_lockstruct.ls_jid);
 687                         fs_err(sdp, "there are only %u journals (0 - %u)\n",
 688                                gfs2_jindex_size(sdp),
 689                                gfs2_jindex_size(sdp) - 1);
 690                         goto fail_jindex;
 691                 }
 692                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
 693
 694                 error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
 695                                           &gfs2_journal_glops,
 696                                           LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
 697                                           &sdp->sd_journal_gh);
 698                 if (error) {
 699                         fs_err(sdp, "can't acquire journal glock: %d\n", error);
 700                         goto fail_jindex;
 701                 }
 702
 703                 ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 704                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 705                                            LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
 706                                            &sdp->sd_jinode_gh);
 707                 if (error) {
 708                         fs_err(sdp, "can't acquire journal inode glock: %d\n",
 709                                error);
 710                         goto fail_journal_gh;
 711                 }
 712
 713                 error = gfs2_jdesc_check(sdp->sd_jdesc);
 714                 if (error) {
 715                         fs_err(sdp, "my journal (%u) is bad: %d\n",
 716                                sdp->sd_jdesc->jd_jid, error);
 717                         goto fail_jinode_gh;
 718                 }
 719                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
 720                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
 721                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
 722
 723                 /* Map the extents for this journal's blocks */
 724                 gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
 725         }
 726         trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
 727
 728         if (sdp->sd_lockstruct.ls_first) {
 729                 unsigned int x;
 730                 for (x = 0; x < sdp->sd_journals; x++) {
 731                         struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
 732
 733                         if (sdp->sd_args.ar_spectator) {
 734                                 error = check_journal_clean(sdp, jd);
 735                                 if (error)
 736                                         goto fail_jinode_gh;
 737                                 continue;
 738                         }
 739                         error = gfs2_recover_journal(jd, true);
 740                         if (error) {
 741                                 fs_err(sdp, "error recovering journal %u: %d\n",
 742                                        x, error);
 743                                 goto fail_jinode_gh;
 744                         }
 745                 }
 746
 747                 gfs2_others_may_mount(sdp);
 748         } else if (!sdp->sd_args.ar_spectator) {
 749                 error = gfs2_recover_journal(sdp->sd_jdesc, true);
 750                 if (error) {
 751                         fs_err(sdp, "error recovering my journal: %d\n", error);
 752                         goto fail_jinode_gh;
 753                 }
 754         }
 755
 756         sdp->sd_log_idle = 1;
 757         set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
 758         gfs2_glock_dq_uninit(&ji_gh);
 759         jindex = 0;
 760         INIT_WORK(&sdp->sd_freeze_work, gfs2_freeze_func);
 761         return 0;
 762
 763 fail_jinode_gh:
 764         if (!sdp->sd_args.ar_spectator)
 765                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
 766 fail_journal_gh:
 767         if (!sdp->sd_args.ar_spectator)
 768                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
 769 fail_jindex:
 770         gfs2_jindex_free(sdp);
 771         if (jindex)
 772                 gfs2_glock_dq_uninit(&ji_gh);
 773 fail:
 774         iput(sdp->sd_jindex);
 775         return error;
 776 }
 777
 778 static struct lock_class_key gfs2_quota_imutex_key;
 779
 780 static int init_inodes(struct gfs2_sbd *sdp, int undo)
 781 {
 782         int error = 0;
 783         struct inode *master = d_inode(sdp->sd_master_dir);
 784
 785         if (undo)
 786                 goto fail_qinode;
 787
 788         error = init_journal(sdp, undo);
 789         complete_all(&sdp->sd_journal_ready);
 790         if (error)
 791                 goto fail;
 792
 793         /* Read in the master statfs inode */
 794         sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
 795         if (IS_ERR(sdp->sd_statfs_inode)) {
 796                 error = PTR_ERR(sdp->sd_statfs_inode);
 797                 fs_err(sdp, "can't read in statfs inode: %d\n", error);
 798                 goto fail_journal;
 799         }
 800
 801         /* Read in the resource index inode */
 802         sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
 803         if (IS_ERR(sdp->sd_rindex)) {
 804                 error = PTR_ERR(sdp->sd_rindex);
 805                 fs_err(sdp, "can't get resource index inode: %d\n", error);
 806                 goto fail_statfs;
 807         }
 808         sdp->sd_rindex_uptodate = 0;
 809
 810         /* Read in the quota inode */
 811         sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
 812         if (IS_ERR(sdp->sd_quota_inode)) {
 813                 error = PTR_ERR(sdp->sd_quota_inode);
 814                 fs_err(sdp, "can't get quota file inode: %d\n", error);
 815                 goto fail_rindex;
 816         }
 817         /*
 818          * i_rwsem on quota files is special. Since this inode is hidden system
 819          * file, we are safe to define locking ourselves.
 820          */
 821         lockdep_set_class(&sdp->sd_quota_inode->i_rwsem,
 822                           &gfs2_quota_imutex_key);
 823
 824         error = gfs2_rindex_update(sdp);
 825         if (error)
 826                 goto fail_qinode;
 827
 828         return 0;
 829
 830 fail_qinode:
 831         iput(sdp->sd_quota_inode);
 832 fail_rindex:
 833         gfs2_clear_rgrpd(sdp);
 834         iput(sdp->sd_rindex);
 835 fail_statfs:
 836         iput(sdp->sd_statfs_inode);
 837 fail_journal:
 838         init_journal(sdp, UNDO);
 839 fail:
 840         return error;
 841 }
 842
 843 static int init_per_node(struct gfs2_sbd *sdp, int undo)
 844 {
 845         struct inode *pn = NULL;
 846         char buf[30];
 847         int error = 0;
 848         struct gfs2_inode *ip;
 849         struct inode *master = d_inode(sdp->sd_master_dir);
 850
 851         if (sdp->sd_args.ar_spectator)
 852                 return 0;
 853
 854         if (undo)
 855                 goto fail_qc_gh;
 856
 857         pn = gfs2_lookup_simple(master, "per_node");
 858         if (IS_ERR(pn)) {
 859                 error = PTR_ERR(pn);
 860                 fs_err(sdp, "can't find per_node directory: %d\n", error);
 861                 return error;
 862         }
 863
 864         sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
 865         sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
 866         if (IS_ERR(sdp->sd_sc_inode)) {
 867                 error = PTR_ERR(sdp->sd_sc_inode);
 868                 fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
 869                 goto fail;
 870         }
 871
 872         sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
 873         sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
 874         if (IS_ERR(sdp->sd_qc_inode)) {
 875                 error = PTR_ERR(sdp->sd_qc_inode);
 876                 fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
 877                 goto fail_ut_i;
 878         }
 879
 880         iput(pn);
 881         pn = NULL;
 882
 883         ip = GFS2_I(sdp->sd_sc_inode);
 884         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
 885                                    &sdp->sd_sc_gh);
 886         if (error) {
 887                 fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
 888                 goto fail_qc_i;
 889         }
 890
 891         ip = GFS2_I(sdp->sd_qc_inode);
 892         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
 893                                    &sdp->sd_qc_gh);
 894         if (error) {
 895                 fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
 896                 goto fail_ut_gh;
 897         }
 898
 899         return 0;
 900
 901 fail_qc_gh:
 902         gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
 903 fail_ut_gh:
 904         gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
 905 fail_qc_i:
 906         iput(sdp->sd_qc_inode);
 907 fail_ut_i:
 908         iput(sdp->sd_sc_inode);
 909 fail:
 910         iput(pn);
 911         return error;
 912 }
 913
 914 static const match_table_t nolock_tokens = {
 915         { Opt_jid, "jid=%d", },
 916         { Opt_err, NULL },
 917 };
 918
 919 static const struct lm_lockops nolock_ops = {
 920         .lm_proto_name = "lock_nolock",
 921         .lm_put_lock = gfs2_glock_free,
 922         .lm_tokens = &nolock_tokens,
 923 };
 924
 925 /**
 926  * gfs2_lm_mount - mount a locking protocol
 927  * @sdp: the filesystem
 928  * @args: mount arguments
 929  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
 930  *
 931  * Returns: errno
 932  */
 933
 934 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
 935 {
 936         const struct lm_lockops *lm;
 937         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 938         struct gfs2_args *args = &sdp->sd_args;
 939         const char *proto = sdp->sd_proto_name;
 940         const char *table = sdp->sd_table_name;
 941         char *o, *options;
 942         int ret;
 943
 944         if (!strcmp("lock_nolock", proto)) {
 945                 lm = &nolock_ops;
 946                 sdp->sd_args.ar_localflocks = 1;
 947 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
 948         } else if (!strcmp("lock_dlm", proto)) {
 949                 lm = &gfs2_dlm_ops;
 950 #endif
 951         } else {
 952                 pr_info("can't find protocol %s\n", proto);
 953                 return -ENOENT;
 954         }
 955
 956         fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
 957
 958         ls->ls_ops = lm;
 959         ls->ls_first = 1;
 960
 961         for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
 962                 substring_t tmp[MAX_OPT_ARGS];
 963                 int token, option;
 964
 965                 if (!o || !*o)
 966                         continue;
 967
 968                 token = match_token(o, *lm->lm_tokens, tmp);
 969                 switch (token) {
 970                 case Opt_jid:
 971                         ret = match_int(&tmp[0], &option);
 972                         if (ret || option < 0)
 973                                 goto hostdata_error;
 974                         if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
 975                                 ls->ls_jid = option;
 976                         break;
 977                 case Opt_id:
 978                 case Opt_nodir:
 979                         /* Obsolete, but left for backward compat purposes */
 980                         break;
 981                 case Opt_first:
 982                         ret = match_int(&tmp[0], &option);
 983                         if (ret || (option != 0 && option != 1))
 984                                 goto hostdata_error;
 985                         ls->ls_first = option;
 986                         break;
 987                 case Opt_err:
 988                 default:
 989 hostdata_error:
 990                         fs_info(sdp, "unknown hostdata (%s)\n", o);
 991                         return -EINVAL;
 992                 }
 993         }
 994
 995         if (lm->lm_mount == NULL) {
 996                 fs_info(sdp, "Now mounting FS...\n");
 997                 complete_all(&sdp->sd_locking_init);
 998                 return 0;
 999         }
1000         ret = lm->lm_mount(sdp, table);
1001         if (ret == 0)
1002                 fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1003         complete_all(&sdp->sd_locking_init);
1004         return ret;
1005 }
1006
1007 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1008 {
1009         const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1010         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1011             lm->lm_unmount)
1012                 lm->lm_unmount(sdp);
1013 }
1014
1015 static int wait_on_journal(struct gfs2_sbd *sdp)
1016 {
1017         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1018                 return 0;
1019
1020         return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1021                 ? -EINTR : 0;
1022 }
1023
1024 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1025 {
1026         struct super_block *sb = sdp->sd_vfs;
1027         char ro[20];
1028         char spectator[20];
1029         char *envp[] = { ro, spectator, NULL };
1030         sprintf(ro, "RDONLY=%d", sb_rdonly(sb));
1031         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1032         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1033 }
1034
1035 /**
1036  * fill_super - Read in superblock
1037  * @sb: The VFS superblock
1038  * @data: Mount options
1039  * @silent: Don't complain if it's not a GFS2 filesystem
1040  *
1041  * Returns: errno
1042  */
1043
1044 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1045 {
1046         struct gfs2_sbd *sdp;
1047         struct gfs2_holder mount_gh;
1048         int error;
1049
1050         sdp = init_sbd(sb);
1051         if (!sdp) {
1052                 pr_warn("can't alloc struct gfs2_sbd\n");
1053                 return -ENOMEM;
1054         }
1055         sdp->sd_args = *args;
1056
1057         if (sdp->sd_args.ar_spectator) {
1058                 sb->s_flags |= SB_RDONLY;
1059                 set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1060         }
1061         if (sdp->sd_args.ar_posix_acl)
1062                 sb->s_flags |= SB_POSIXACL;
1063         if (sdp->sd_args.ar_nobarrier)
1064                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1065
1066         sb->s_flags |= SB_NOSEC;
1067         sb->s_magic = GFS2_MAGIC;
1068         sb->s_op = &gfs2_super_ops;
1069         sb->s_d_op = &gfs2_dops;
1070         sb->s_export_op = &gfs2_export_ops;
1071         sb->s_xattr = gfs2_xattr_handlers;
1072         sb->s_qcop = &gfs2_quotactl_ops;
1073         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1074         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1075         sb->s_time_gran = 1;
1076         sb->s_maxbytes = MAX_LFS_FILESIZE;
1077
1078         /* Set up the buffer cache and fill in some fake block size values
1079            to allow us to read-in the on-disk superblock. */
1080         sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1081         sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1082         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1083                                GFS2_BASIC_BLOCK_SHIFT;
1084         sdp->sd_fsb2bb = BIT(sdp->sd_fsb2bb_shift);
1085
1086         sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1087         sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1088         if (sdp->sd_args.ar_statfs_quantum) {
1089                 sdp->sd_tune.gt_statfs_slow = 0;
1090                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1091         } else {
1092                 sdp->sd_tune.gt_statfs_slow = 1;
1093                 sdp->sd_tune.gt_statfs_quantum = 30;
1094         }
1095
1096         error = init_names(sdp, silent);
1097         if (error) {
1098                 /* In this case, we haven't initialized sysfs, so we have to
1099                    manually free the sdp. */
1100                 free_percpu(sdp->sd_lkstats);
1101                 kfree(sdp);
1102                 sb->s_fs_info = NULL;
1103                 return error;
1104         }
1105
1106         snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s", sdp->sd_table_name);
1107
1108         error = gfs2_sys_fs_add(sdp);
1109         /*
1110          * If we hit an error here, gfs2_sys_fs_add will have called function
1111          * kobject_put which causes the sysfs usage count to go to zero, which
1112          * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1113          * Subsequent error paths here will call gfs2_sys_fs_del, which also
1114          * kobject_put to free sdp.
1115          */
1116         if (error)
1117                 return error;
1118
1119         gfs2_create_debugfs_file(sdp);
1120
1121         error = gfs2_lm_mount(sdp, silent);
1122         if (error)
1123                 goto fail_debug;
1124
1125         error = init_locking(sdp, &mount_gh, DO);
1126         if (error)
1127                 goto fail_lm;
1128
1129         error = init_sb(sdp, silent);
1130         if (error)
1131                 goto fail_locking;
1132
1133         error = wait_on_journal(sdp);
1134         if (error)
1135                 goto fail_sb;
1136
1137         /*
1138          * If user space has failed to join the cluster or some similar
1139          * failure has occurred, then the journal id will contain a
1140          * negative (error) number. This will then be returned to the
1141          * caller (of the mount syscall). We do this even for spectator
1142          * mounts (which just write a jid of 0 to indicate "ok" even though
1143          * the jid is unused in the spectator case)
1144          */
1145         if (sdp->sd_lockstruct.ls_jid < 0) {
1146                 error = sdp->sd_lockstruct.ls_jid;
1147                 sdp->sd_lockstruct.ls_jid = 0;
1148                 goto fail_sb;
1149         }
1150
1151         if (sdp->sd_args.ar_spectator)
1152                 snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s.s",
1153                          sdp->sd_table_name);
1154         else
1155                 snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s.%u",
1156                          sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1157
1158         error = init_inodes(sdp, DO);
1159         if (error)
1160                 goto fail_sb;
1161
1162         error = init_per_node(sdp, DO);
1163         if (error)
1164                 goto fail_inodes;
1165
1166         error = gfs2_statfs_init(sdp);
1167         if (error) {
1168                 fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1169                 goto fail_per_node;
1170         }
1171
1172         if (sb_rdonly(sb)) {
1173                 struct gfs2_holder freeze_gh;
1174
1175                 error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
1176                                            GL_EXACT, &freeze_gh);
1177                 if (error) {
1178                         fs_err(sdp, "can't make FS RO: %d\n", error);
1179                         goto fail_per_node;
1180                 }
1181                 gfs2_glock_dq_uninit(&freeze_gh);
1182         } else {
1183                 error = gfs2_make_fs_rw(sdp);
1184                 if (error) {
1185                         fs_err(sdp, "can't make FS RW: %d\n", error);
1186                         goto fail_per_node;
1187                 }
1188         }
1189
1190         gfs2_glock_dq_uninit(&mount_gh);
1191         gfs2_online_uevent(sdp);
1192         return 0;
1193
1194 fail_per_node:
1195         init_per_node(sdp, UNDO);
1196 fail_inodes:
1197         init_inodes(sdp, UNDO);
1198 fail_sb:
1199         if (sdp->sd_root_dir)
1200                 dput(sdp->sd_root_dir);
1201         if (sdp->sd_master_dir)
1202                 dput(sdp->sd_master_dir);
1203         if (sb->s_root)
1204                 dput(sb->s_root);
1205         sb->s_root = NULL;
1206 fail_locking:
1207         init_locking(sdp, &mount_gh, UNDO);
1208 fail_lm:
1209         complete_all(&sdp->sd_journal_ready);
1210         gfs2_gl_hash_clear(sdp);
1211         gfs2_lm_unmount(sdp);
1212 fail_debug:
1213         gfs2_delete_debugfs_file(sdp);
1214         free_percpu(sdp->sd_lkstats);
1215         /* gfs2_sys_fs_del must be the last thing we do, since it causes
1216          * sysfs to call function gfs2_sbd_release, which frees sdp. */
1217         gfs2_sys_fs_del(sdp);
1218         sb->s_fs_info = NULL;
1219         return error;
1220 }
1221
1222 static int set_gfs2_super(struct super_block *s, void *data)
1223 {
1224         s->s_bdev = data;
1225         s->s_dev = s->s_bdev->bd_dev;
1226         s->s_bdi = bdi_get(s->s_bdev->bd_bdi);
1227         return 0;
1228 }
1229
1230 static int test_gfs2_super(struct super_block *s, void *ptr)
1231 {
1232         struct block_device *bdev = ptr;
1233         return (bdev == s->s_bdev);
1234 }
1235
1236 /**
1237  * gfs2_mount - Get the GFS2 superblock
1238  * @fs_type: The GFS2 filesystem type
1239  * @flags: Mount flags
1240  * @dev_name: The name of the device
1241  * @data: The mount arguments
1242  *
1243  * Q. Why not use get_sb_bdev() ?
1244  * A. We need to select one of two root directories to mount, independent
1245  *    of whether this is the initial, or subsequent, mount of this sb
1246  *
1247  * Returns: 0 or -ve on error
1248  */
1249
1250 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1251                        const char *dev_name, void *data)
1252 {
1253         struct block_device *bdev;
1254         struct super_block *s;
1255         fmode_t mode = FMODE_READ | FMODE_EXCL;
1256         int error;
1257         struct gfs2_args args;
1258         struct gfs2_sbd *sdp;
1259
1260         if (!(flags & SB_RDONLY))
1261                 mode |= FMODE_WRITE;
1262
1263         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1264         if (IS_ERR(bdev))
1265                 return ERR_CAST(bdev);
1266
1267         /*
1268          * once the super is inserted into the list by sget, s_umount
1269          * will protect the lockfs code from trying to start a snapshot
1270          * while we are mounting
1271          */
1272         mutex_lock(&bdev->bd_fsfreeze_mutex);
1273         if (bdev->bd_fsfreeze_count > 0) {
1274                 mutex_unlock(&bdev->bd_fsfreeze_mutex);
1275                 error = -EBUSY;
1276                 goto error_bdev;
1277         }
1278         s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1279         mutex_unlock(&bdev->bd_fsfreeze_mutex);
1280         error = PTR_ERR(s);
1281         if (IS_ERR(s))
1282                 goto error_bdev;
1283
1284         if (s->s_root) {
1285                 /*
1286                  * s_umount nests inside bd_mutex during
1287                  * __invalidate_device().  blkdev_put() acquires
1288                  * bd_mutex and can't be called under s_umount.  Drop
1289                  * s_umount temporarily.  This is safe as we're
1290                  * holding an active reference.
1291                  */
1292                 up_write(&s->s_umount);
1293                 blkdev_put(bdev, mode);
1294                 down_write(&s->s_umount);
1295         } else {
1296                 /* s_mode must be set before deactivate_locked_super calls */
1297                 s->s_mode = mode;
1298         }
1299
1300         memset(&args, 0, sizeof(args));
1301         args.ar_quota = GFS2_QUOTA_DEFAULT;
1302         args.ar_data = GFS2_DATA_DEFAULT;
1303         args.ar_commit = 30;
1304         args.ar_statfs_quantum = 30;
1305         args.ar_quota_quantum = 60;
1306         args.ar_errors = GFS2_ERRORS_DEFAULT;
1307
1308         error = gfs2_mount_args(&args, data);
1309         if (error) {
1310                 pr_warn("can't parse mount arguments\n");
1311                 goto error_super;
1312         }
1313
1314         if (s->s_root) {
1315                 error = -EBUSY;
1316                 if ((flags ^ s->s_flags) & SB_RDONLY)
1317                         goto error_super;
1318         } else {
1319                 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1320                 sb_set_blocksize(s, block_size(bdev));
1321                 error = fill_super(s, &args, flags & SB_SILENT ? 1 : 0);
1322                 if (error)
1323                         goto error_super;
1324                 s->s_flags |= SB_ACTIVE;
1325                 bdev->bd_super = s;
1326         }
1327
1328         sdp = s->s_fs_info;
1329         if (args.ar_meta)
1330                 return dget(sdp->sd_master_dir);
1331         else
1332                 return dget(sdp->sd_root_dir);
1333
1334 error_super:
1335         deactivate_locked_super(s);
1336         return ERR_PTR(error);
1337 error_bdev:
1338         blkdev_put(bdev, mode);
1339         return ERR_PTR(error);
1340 }
1341
1342 static int set_meta_super(struct super_block *s, void *ptr)
1343 {
1344         return -EINVAL;
1345 }
1346
1347 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1348                         int flags, const char *dev_name, void *data)
1349 {
1350         struct super_block *s;
1351         struct gfs2_sbd *sdp;
1352         struct path path;
1353         int error;
1354
1355         if (!dev_name || !*dev_name)
1356                 return ERR_PTR(-EINVAL);
1357
1358         error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1359         if (error) {
1360                 pr_warn("path_lookup on %s returned error %d\n",
1361                         dev_name, error);
1362                 return ERR_PTR(error);
1363         }
1364         s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1365                  path.dentry->d_sb->s_bdev);
1366         path_put(&path);
1367         if (IS_ERR(s)) {
1368                 pr_warn("gfs2 mount does not exist\n");
1369                 return ERR_CAST(s);
1370         }
1371         if ((flags ^ s->s_flags) & SB_RDONLY) {
1372                 deactivate_locked_super(s);
1373                 return ERR_PTR(-EBUSY);
1374         }
1375         sdp = s->s_fs_info;
1376         return dget(sdp->sd_master_dir);
1377 }
1378
1379 static void gfs2_kill_sb(struct super_block *sb)
1380 {
1381         struct gfs2_sbd *sdp = sb->s_fs_info;
1382
1383         if (sdp == NULL) {
1384                 kill_block_super(sb);
1385                 return;
1386         }
1387
1388         gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_SYNC | GFS2_LFC_KILL_SB);
1389         dput(sdp->sd_root_dir);
1390         dput(sdp->sd_master_dir);
1391         sdp->sd_root_dir = NULL;
1392         sdp->sd_master_dir = NULL;
1393         shrink_dcache_sb(sb);
1394         free_percpu(sdp->sd_lkstats);
1395         kill_block_super(sb);
1396 }
1397
1398 struct file_system_type gfs2_fs_type = {
1399         .name = "gfs2",
1400         .fs_flags = FS_REQUIRES_DEV,
1401         .mount = gfs2_mount,
1402         .kill_sb = gfs2_kill_sb,
1403         .owner = THIS_MODULE,
1404 };
1405 MODULE_ALIAS_FS("gfs2");
1406
1407 struct file_system_type gfs2meta_fs_type = {
1408         .name = "gfs2meta",
1409         .fs_flags = FS_REQUIRES_DEV,
1410         .mount = gfs2_mount_meta,
1411         .owner = THIS_MODULE,
1412 };
1413 MODULE_ALIAS_FS("gfs2meta");