/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#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/blkdev.h>
  16#include <linux/kthread.h>
  17#include <linux/export.h>
  18#include <linux/namei.h>
  19#include <linux/mount.h>
  20#include <linux/gfs2_ondisk.h>
  21#include <linux/quotaops.h>
  22#include <linux/lockdep.h>
  23
  24#include "gfs2.h"
  25#include "incore.h"
  26#include "bmap.h"
  27#include "glock.h"
  28#include "glops.h"
  29#include "inode.h"
  30#include "recovery.h"
  31#include "rgrp.h"
  32#include "super.h"
  33#include "sys.h"
  34#include "util.h"
  35#include "log.h"
  36#include "quota.h"
  37#include "dir.h"
  38#include "trace_gfs2.h"
  39
  40#define DO 0
  41#define UNDO 1
  42
  43/**
  44 * gfs2_tune_init - Fill a gfs2_tune structure with default values
  45 * @gt: tune
  46 *
  47 */
  48
  49static void gfs2_tune_init(struct gfs2_tune *gt)
  50{
  51	spin_lock_init(&gt->gt_spin);
  52
  53	gt->gt_quota_simul_sync = 64;
  54	gt->gt_quota_warn_period = 10;
  55	gt->gt_quota_scale_num = 1;
  56	gt->gt_quota_scale_den = 1;
  57	gt->gt_new_files_jdata = 0;
  58	gt->gt_max_readahead = 1 << 18;
  59	gt->gt_complain_secs = 10;
  60}
  61
  62static struct gfs2_sbd *init_sbd(struct super_block *sb)
  63{
  64	struct gfs2_sbd *sdp;
  65
  66	sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
  67	if (!sdp)
  68		return NULL;
  69
  70	sb->s_fs_info = sdp;
  71	sdp->sd_vfs = sb;
  72	sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats);
  73	if (!sdp->sd_lkstats) {
  74		kfree(sdp);
  75		return NULL;
  76	}
  77
  78	set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
  79	gfs2_tune_init(&sdp->sd_tune);
  80
  81	init_waitqueue_head(&sdp->sd_glock_wait);
  82	atomic_set(&sdp->sd_glock_disposal, 0);
  83	init_completion(&sdp->sd_locking_init);
  84	init_completion(&sdp->sd_wdack);
  85	spin_lock_init(&sdp->sd_statfs_spin);
  86
  87	spin_lock_init(&sdp->sd_rindex_spin);
  88	sdp->sd_rindex_tree.rb_node = NULL;
  89
  90	INIT_LIST_HEAD(&sdp->sd_jindex_list);
  91	spin_lock_init(&sdp->sd_jindex_spin);
  92	mutex_init(&sdp->sd_jindex_mutex);
  93
  94	INIT_LIST_HEAD(&sdp->sd_quota_list);
  95	mutex_init(&sdp->sd_quota_mutex);
  96	init_waitqueue_head(&sdp->sd_quota_wait);
  97	INIT_LIST_HEAD(&sdp->sd_trunc_list);
  98	spin_lock_init(&sdp->sd_trunc_lock);
  99
 100	spin_lock_init(&sdp->sd_log_lock);
 101	atomic_set(&sdp->sd_log_pinned, 0);
 102	INIT_LIST_HEAD(&sdp->sd_log_le_buf);
 103	INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
 104	INIT_LIST_HEAD(&sdp->sd_log_le_databuf);
 105	INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
 106	spin_lock_init(&sdp->sd_ordered_lock);
 107
 108	init_waitqueue_head(&sdp->sd_log_waitq);
 109	init_waitqueue_head(&sdp->sd_logd_waitq);
 110	spin_lock_init(&sdp->sd_ail_lock);
 111	INIT_LIST_HEAD(&sdp->sd_ail1_list);
 112	INIT_LIST_HEAD(&sdp->sd_ail2_list);
 113
 114	init_rwsem(&sdp->sd_log_flush_lock);
 115	atomic_set(&sdp->sd_log_in_flight, 0);
 116	init_waitqueue_head(&sdp->sd_log_flush_wait);
 117
 118	INIT_LIST_HEAD(&sdp->sd_revoke_list);
 119
 120	return sdp;
 121}
 122
 123
 124/**
 125 * gfs2_check_sb - Check superblock
 126 * @sdp: the filesystem
 127 * @sb: The superblock
 128 * @silent: Don't print a message if the check fails
 129 *
 130 * Checks the version code of the FS is one that we understand how to
 131 * read and that the sizes of the various on-disk structures have not
 132 * changed.
 133 */
 134
 135static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
 136{
 137	struct gfs2_sb_host *sb = &sdp->sd_sb;
 138
 139	if (sb->sb_magic != GFS2_MAGIC ||
 140	    sb->sb_type != GFS2_METATYPE_SB) {
 141		if (!silent)
 142			printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
 143		return -EINVAL;
 144	}
 145
 146	/*  If format numbers match exactly, we're done.  */
 147
 148	if (sb->sb_fs_format == GFS2_FORMAT_FS &&
 149	    sb->sb_multihost_format == GFS2_FORMAT_MULTI)
 150		return 0;
 151
 152	fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
 153
 154	return -EINVAL;
 155}
 156
 157static void end_bio_io_page(struct bio *bio, int error)
 158{
 159	struct page *page = bio->bi_private;
 160
 161	if (!error)
 162		SetPageUptodate(page);
 163	else
 164		printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
 165	unlock_page(page);
 166}
 167
 168static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
 169{
 170	struct gfs2_sb_host *sb = &sdp->sd_sb;
 171	struct super_block *s = sdp->sd_vfs;
 172	const struct gfs2_sb *str = buf;
 173
 174	sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
 175	sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
 176	sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
 177	sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
 178	sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
 179	sb->sb_bsize = be32_to_cpu(str->sb_bsize);
 180	sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
 181	sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
 182	sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
 183	sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
 184	sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
 185
 186	memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
 187	memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
 188	memcpy(s->s_uuid, str->sb_uuid, 16);
 189}
 190
 191/**
 192 * gfs2_read_super - Read the gfs2 super block from disk
 193 * @sdp: The GFS2 super block
 194 * @sector: The location of the super block
 195 * @error: The error code to return
 196 *
 197 * This uses the bio functions to read the super block from disk
 198 * because we want to be 100% sure that we never read cached data.
 199 * A super block is read twice only during each GFS2 mount and is
 200 * never written to by the filesystem. The first time its read no
 201 * locks are held, and the only details which are looked at are those
 202 * relating to the locking protocol. Once locking is up and working,
 203 * the sb is read again under the lock to establish the location of
 204 * the master directory (contains pointers to journals etc) and the
 205 * root directory.
 206 *
 207 * Returns: 0 on success or error
 208 */
 209
 210static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
 211{
 212	struct super_block *sb = sdp->sd_vfs;
 213	struct gfs2_sb *p;
 214	struct page *page;
 215	struct bio *bio;
 216
 217	page = alloc_page(GFP_NOFS);
 218	if (unlikely(!page))
 219		return -ENOBUFS;
 220
 221	ClearPageUptodate(page);
 222	ClearPageDirty(page);
 223	lock_page(page);
 224
 225	bio = bio_alloc(GFP_NOFS, 1);
 226	bio->bi_sector = sector * (sb->s_blocksize >> 9);
 227	bio->bi_bdev = sb->s_bdev;
 228	bio_add_page(bio, page, PAGE_SIZE, 0);
 229
 230	bio->bi_end_io = end_bio_io_page;
 231	bio->bi_private = page;
 232	submit_bio(READ_SYNC | REQ_META, bio);
 233	wait_on_page_locked(page);
 234	bio_put(bio);
 235	if (!PageUptodate(page)) {
 236		__free_page(page);
 237		return -EIO;
 238	}
 239	p = kmap(page);
 240	gfs2_sb_in(sdp, p);
 241	kunmap(page);
 242	__free_page(page);
 243	return gfs2_check_sb(sdp, silent);
 244}
 245
 246/**
 247 * gfs2_read_sb - Read super block
 248 * @sdp: The GFS2 superblock
 249 * @silent: Don't print message if mount fails
 250 *
 251 */
 252
 253static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
 254{
 255	u32 hash_blocks, ind_blocks, leaf_blocks;
 256	u32 tmp_blocks;
 257	unsigned int x;
 258	int error;
 259
 260	error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
 261	if (error) {
 262		if (!silent)
 263			fs_err(sdp, "can't read superblock\n");
 264		return error;
 265	}
 266
 267	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
 268			       GFS2_BASIC_BLOCK_SHIFT;
 269	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
 270	sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
 271			  sizeof(struct gfs2_dinode)) / sizeof(u64);
 272	sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
 273			  sizeof(struct gfs2_meta_header)) / sizeof(u64);
 274	sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
 275	sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
 276	sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
 277	sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
 278	sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
 279				sizeof(struct gfs2_meta_header)) /
 280			        sizeof(struct gfs2_quota_change);
 281	sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
 282				     sizeof(struct gfs2_meta_header))
 283		* GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
 284
 285	/* Compute maximum reservation required to add a entry to a directory */
 286
 287	hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
 288			     sdp->sd_jbsize);
 289
 290	ind_blocks = 0;
 291	for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
 292		tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
 293		ind_blocks += tmp_blocks;
 294	}
 295
 296	leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
 297
 298	sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
 299
 300	sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
 301				sizeof(struct gfs2_dinode);
 302	sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
 303	for (x = 2;; x++) {
 304		u64 space, d;
 305		u32 m;
 306
 307		space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
 308		d = space;
 309		m = do_div(d, sdp->sd_inptrs);
 310
 311		if (d != sdp->sd_heightsize[x - 1] || m)
 312			break;
 313		sdp->sd_heightsize[x] = space;
 314	}
 315	sdp->sd_max_height = x;
 316	sdp->sd_heightsize[x] = ~0;
 317	gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 318
 319	sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
 320				 sizeof(struct gfs2_dinode);
 321	sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
 322	for (x = 2;; x++) {
 323		u64 space, d;
 324		u32 m;
 325
 326		space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
 327		d = space;
 328		m = do_div(d, sdp->sd_inptrs);
 329
 330		if (d != sdp->sd_jheightsize[x - 1] || m)
 331			break;
 332		sdp->sd_jheightsize[x] = space;
 333	}
 334	sdp->sd_max_jheight = x;
 335	sdp->sd_jheightsize[x] = ~0;
 336	gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
 337
 338	return 0;
 339}
 340
 341static int init_names(struct gfs2_sbd *sdp, int silent)
 342{
 343	char *proto, *table;
 344	int error = 0;
 345
 346	proto = sdp->sd_args.ar_lockproto;
 347	table = sdp->sd_args.ar_locktable;
 348
 349	/*  Try to autodetect  */
 350
 351	if (!proto[0] || !table[0]) {
 352		error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
 353		if (error)
 354			return error;
 355
 356		if (!proto[0])
 357			proto = sdp->sd_sb.sb_lockproto;
 358		if (!table[0])
 359			table = sdp->sd_sb.sb_locktable;
 360	}
 361
 362	if (!table[0])
 363		table = sdp->sd_vfs->s_id;
 364
 365	strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
 366	strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
 367
 368	table = sdp->sd_table_name;
 369	while ((table = strchr(table, '/')))
 370		*table = '_';
 371
 372	return error;
 373}
 374
 375static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
 376			int undo)
 377{
 378	int error = 0;
 379
 380	if (undo)
 381		goto fail_trans;
 382
 383	error = gfs2_glock_nq_num(sdp,
 384				  GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
 385				  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
 386				  mount_gh);
 387	if (error) {
 388		fs_err(sdp, "can't acquire mount glock: %d\n", error);
 389		goto fail;
 390	}
 391
 392	error = gfs2_glock_nq_num(sdp,
 393				  GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
 394				  LM_ST_SHARED,
 395				  LM_FLAG_NOEXP | GL_EXACT,
 396				  &sdp->sd_live_gh);
 397	if (error) {
 398		fs_err(sdp, "can't acquire live glock: %d\n", error);
 399		goto fail_mount;
 400	}
 401
 402	error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
 403			       CREATE, &sdp->sd_rename_gl);
 404	if (error) {
 405		fs_err(sdp, "can't create rename glock: %d\n", error);
 406		goto fail_live;
 407	}
 408
 409	error = gfs2_glock_get(sdp, GFS2_TRANS_LOCK, &gfs2_trans_glops,
 410			       CREATE, &sdp->sd_trans_gl);
 411	if (error) {
 412		fs_err(sdp, "can't create transaction glock: %d\n", error);
 413		goto fail_rename;
 414	}
 415
 416	return 0;
 417
 418fail_trans:
 419	gfs2_glock_put(sdp->sd_trans_gl);
 420fail_rename:
 421	gfs2_glock_put(sdp->sd_rename_gl);
 422fail_live:
 423	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
 424fail_mount:
 425	gfs2_glock_dq_uninit(mount_gh);
 426fail:
 427	return error;
 428}
 429
 430static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
 431			    u64 no_addr, const char *name)
 432{
 433	struct gfs2_sbd *sdp = sb->s_fs_info;
 434	struct dentry *dentry;
 435	struct inode *inode;
 436
 437	inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
 438	if (IS_ERR(inode)) {
 439		fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
 440		return PTR_ERR(inode);
 441	}
 442	dentry = d_make_root(inode);
 443	if (!dentry) {
 444		fs_err(sdp, "can't alloc %s dentry\n", name);
 445		return -ENOMEM;
 446	}
 447	*dptr = dentry;
 448	return 0;
 449}
 450
 451static int init_sb(struct gfs2_sbd *sdp, int silent)
 452{
 453	struct super_block *sb = sdp->sd_vfs;
 454	struct gfs2_holder sb_gh;
 455	u64 no_addr;
 456	int ret;
 457
 458	ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
 459				LM_ST_SHARED, 0, &sb_gh);
 460	if (ret) {
 461		fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
 462		return ret;
 463	}
 464
 465	ret = gfs2_read_sb(sdp, silent);
 466	if (ret) {
 467		fs_err(sdp, "can't read superblock: %d\n", ret);
 468		goto out;
 469	}
 470
 471	/* Set up the buffer cache and SB for real */
 472	if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
 473		ret = -EINVAL;
 474		fs_err(sdp, "FS block size (%u) is too small for device "
 475		       "block size (%u)\n",
 476		       sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
 477		goto out;
 478	}
 479	if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
 480		ret = -EINVAL;
 481		fs_err(sdp, "FS block size (%u) is too big for machine "
 482		       "page size (%u)\n",
 483		       sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
 484		goto out;
 485	}
 486	sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
 487
 488	/* Get the root inode */
 489	no_addr = sdp->sd_sb.sb_root_dir.no_addr;
 490	ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
 491	if (ret)
 492		goto out;
 493
 494	/* Get the master inode */
 495	no_addr = sdp->sd_sb.sb_master_dir.no_addr;
 496	ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
 497	if (ret) {
 498		dput(sdp->sd_root_dir);
 499		goto out;
 500	}
 501	sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
 502out:
 503	gfs2_glock_dq_uninit(&sb_gh);
 504	return ret;
 505}
 506
 507/**
 508 * map_journal_extents - create a reusable "extent" mapping from all logical
 509 * blocks to all physical blocks for the given journal.  This will save
 510 * us time when writing journal blocks.  Most journals will have only one
 511 * extent that maps all their logical blocks.  That's because gfs2.mkfs
 512 * arranges the journal blocks sequentially to maximize performance.
 513 * So the extent would map the first block for the entire file length.
 514 * However, gfs2_jadd can happen while file activity is happening, so
 515 * those journals may not be sequential.  Less likely is the case where
 516 * the users created their own journals by mounting the metafs and
 517 * laying it out.  But it's still possible.  These journals might have
 518 * several extents.
 519 *
 520 * TODO: This should be done in bigger chunks rather than one block at a time,
 521 *       but since it's only done at mount time, I'm not worried about the
 522 *       time it takes.
 523 */
 524static int map_journal_extents(struct gfs2_sbd *sdp)
 525{
 526	struct gfs2_jdesc *jd = sdp->sd_jdesc;
 527	unsigned int lb;
 528	u64 db, prev_db; /* logical block, disk block, prev disk block */
 529	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 530	struct gfs2_journal_extent *jext = NULL;
 531	struct buffer_head bh;
 532	int rc = 0;
 533
 534	prev_db = 0;
 535
 536	for (lb = 0; lb < i_size_read(jd->jd_inode) >> sdp->sd_sb.sb_bsize_shift; lb++) {
 537		bh.b_state = 0;
 538		bh.b_blocknr = 0;
 539		bh.b_size = 1 << ip->i_inode.i_blkbits;
 540		rc = gfs2_block_map(jd->jd_inode, lb, &bh, 0);
 541		db = bh.b_blocknr;
 542		if (rc || !db) {
 543			printk(KERN_INFO "GFS2 journal mapping error %d: lb="
 544			       "%u db=%llu\n", rc, lb, (unsigned long long)db);
 545			break;
 546		}
 547		if (!prev_db || db != prev_db + 1) {
 548			jext = kzalloc(sizeof(struct gfs2_journal_extent),
 549				       GFP_KERNEL);
 550			if (!jext) {
 551				printk(KERN_INFO "GFS2 error: out of memory "
 552				       "mapping journal extents.\n");
 553				rc = -ENOMEM;
 554				break;
 555			}
 556			jext->dblock = db;
 557			jext->lblock = lb;
 558			jext->blocks = 1;
 559			list_add_tail(&jext->extent_list, &jd->extent_list);
 560		} else {
 561			jext->blocks++;
 562		}
 563		prev_db = db;
 564	}
 565	return rc;
 566}
 567
 568static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
 569{
 570	char *message = "FIRSTMOUNT=Done";
 571	char *envp[] = { message, NULL };
 572
 573	fs_info(sdp, "first mount done, others may mount\n");
 574
 575	if (sdp->sd_lockstruct.ls_ops->lm_first_done)
 576		sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
 577
 578	kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
 579}
 580
 581/**
 582 * gfs2_jindex_hold - Grab a lock on the jindex
 583 * @sdp: The GFS2 superblock
 584 * @ji_gh: the holder for the jindex glock
 585 *
 586 * Returns: errno
 587 */
 588
 589static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 590{
 591	struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
 592	struct qstr name;
 593	char buf[20];
 594	struct gfs2_jdesc *jd;
 595	int error;
 596
 597	name.name = buf;
 598
 599	mutex_lock(&sdp->sd_jindex_mutex);
 600
 601	for (;;) {
 602		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
 603		if (error)
 604			break;
 605
 606		name.len = sprintf(buf, "journal%u", sdp->sd_journals);
 607		name.hash = gfs2_disk_hash(name.name, name.len);
 608
 609		error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
 610		if (error == -ENOENT) {
 611			error = 0;
 612			break;
 613		}
 614
 615		gfs2_glock_dq_uninit(ji_gh);
 616
 617		if (error)
 618			break;
 619
 620		error = -ENOMEM;
 621		jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
 622		if (!jd)
 623			break;
 624
 625		INIT_LIST_HEAD(&jd->extent_list);
 626		INIT_WORK(&jd->jd_work, gfs2_recover_func);
 627		jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
 628		if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
 629			if (!jd->jd_inode)
 630				error = -ENOENT;
 631			else
 632				error = PTR_ERR(jd->jd_inode);
 633			kfree(jd);
 634			break;
 635		}
 636
 637		spin_lock(&sdp->sd_jindex_spin);
 638		jd->jd_jid = sdp->sd_journals++;
 639		list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
 640		spin_unlock(&sdp->sd_jindex_spin);
 641	}
 642
 643	mutex_unlock(&sdp->sd_jindex_mutex);
 644
 645	return error;
 646}
 647
 648static int init_journal(struct gfs2_sbd *sdp, int undo)
 649{
 650	struct inode *master = sdp->sd_master_dir->d_inode;
 651	struct gfs2_holder ji_gh;
 652	struct gfs2_inode *ip;
 653	int jindex = 1;
 654	int error = 0;
 655
 656	if (undo) {
 657		jindex = 0;
 658		goto fail_jinode_gh;
 659	}
 660
 661	sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
 662	if (IS_ERR(sdp->sd_jindex)) {
 663		fs_err(sdp, "can't lookup journal index: %d\n", error);
 664		return PTR_ERR(sdp->sd_jindex);
 665	}
 666
 667	/* Load in the journal index special file */
 668
 669	error = gfs2_jindex_hold(sdp, &ji_gh);
 670	if (error) {
 671		fs_err(sdp, "can't read journal index: %d\n", error);
 672		goto fail;
 673	}
 674
 675	error = -EUSERS;
 676	if (!gfs2_jindex_size(sdp)) {
 677		fs_err(sdp, "no journals!\n");
 678		goto fail_jindex;
 679	}
 680
 681	if (sdp->sd_args.ar_spectator) {
 682		sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
 683		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
 684		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
 685		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
 686	} else {
 687		if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
 688			fs_err(sdp, "can't mount journal #%u\n",
 689			       sdp->sd_lockstruct.ls_jid);
 690			fs_err(sdp, "there are only %u journals (0 - %u)\n",
 691			       gfs2_jindex_size(sdp),
 692			       gfs2_jindex_size(sdp) - 1);
 693			goto fail_jindex;
 694		}
 695		sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
 696
 697		error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
 698					  &gfs2_journal_glops,
 699					  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
 700					  &sdp->sd_journal_gh);
 701		if (error) {
 702			fs_err(sdp, "can't acquire journal glock: %d\n", error);
 703			goto fail_jindex;
 704		}
 705
 706		ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 707		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 708					   LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
 709					   &sdp->sd_jinode_gh);
 710		if (error) {
 711			fs_err(sdp, "can't acquire journal inode glock: %d\n",
 712			       error);
 713			goto fail_journal_gh;
 714		}
 715
 716		error = gfs2_jdesc_check(sdp->sd_jdesc);
 717		if (error) {
 718			fs_err(sdp, "my journal (%u) is bad: %d\n",
 719			       sdp->sd_jdesc->jd_jid, error);
 720			goto fail_jinode_gh;
 721		}
 722		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
 723		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
 724		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
 725
 726		/* Map the extents for this journal's blocks */
 727		map_journal_extents(sdp);
 728	}
 729	trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
 730
 731	if (sdp->sd_lockstruct.ls_first) {
 732		unsigned int x;
 733		for (x = 0; x < sdp->sd_journals; x++) {
 734			error = gfs2_recover_journal(gfs2_jdesc_find(sdp, x),
 735						     true);
 736			if (error) {
 737				fs_err(sdp, "error recovering journal %u: %d\n",
 738				       x, error);
 739				goto fail_jinode_gh;
 740			}
 741		}
 742
 743		gfs2_others_may_mount(sdp);
 744	} else if (!sdp->sd_args.ar_spectator) {
 745		error = gfs2_recover_journal(sdp->sd_jdesc, true);
 746		if (error) {
 747			fs_err(sdp, "error recovering my journal: %d\n", error);
 748			goto fail_jinode_gh;
 749		}
 750	}
 751
 752	set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
 753	gfs2_glock_dq_uninit(&ji_gh);
 754	jindex = 0;
 755
 756	return 0;
 757
 758fail_jinode_gh:
 759	if (!sdp->sd_args.ar_spectator)
 760		gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
 761fail_journal_gh:
 762	if (!sdp->sd_args.ar_spectator)
 763		gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
 764fail_jindex:
 765	gfs2_jindex_free(sdp);
 766	if (jindex)
 767		gfs2_glock_dq_uninit(&ji_gh);
 768fail:
 769	iput(sdp->sd_jindex);
 770	return error;
 771}
 772
 773static struct lock_class_key gfs2_quota_imutex_key;
 774
 775static int init_inodes(struct gfs2_sbd *sdp, int undo)
 776{
 777	int error = 0;
 778	struct inode *master = sdp->sd_master_dir->d_inode;
 779
 780	if (undo)
 781		goto fail_qinode;
 782
 783	error = init_journal(sdp, undo);
 784	if (error)
 785		goto fail;
 786
 787	/* Read in the master statfs inode */
 788	sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
 789	if (IS_ERR(sdp->sd_statfs_inode)) {
 790		error = PTR_ERR(sdp->sd_statfs_inode);
 791		fs_err(sdp, "can't read in statfs inode: %d\n", error);
 792		goto fail_journal;
 793	}
 794
 795	/* Read in the resource index inode */
 796	sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
 797	if (IS_ERR(sdp->sd_rindex)) {
 798		error = PTR_ERR(sdp->sd_rindex);
 799		fs_err(sdp, "can't get resource index inode: %d\n", error);
 800		goto fail_statfs;
 801	}
 802	sdp->sd_rindex_uptodate = 0;
 803
 804	/* Read in the quota inode */
 805	sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
 806	if (IS_ERR(sdp->sd_quota_inode)) {
 807		error = PTR_ERR(sdp->sd_quota_inode);
 808		fs_err(sdp, "can't get quota file inode: %d\n", error);
 809		goto fail_rindex;
 810	}
 811	/*
 812	 * i_mutex on quota files is special. Since this inode is hidden system
 813	 * file, we are safe to define locking ourselves.
 814	 */
 815	lockdep_set_class(&sdp->sd_quota_inode->i_mutex,
 816			  &gfs2_quota_imutex_key);
 817
 818	error = gfs2_rindex_update(sdp);
 819	if (error)
 820		goto fail_qinode;
 821
 822	return 0;
 823
 824fail_qinode:
 825	iput(sdp->sd_quota_inode);
 826fail_rindex:
 827	gfs2_clear_rgrpd(sdp);
 828	iput(sdp->sd_rindex);
 829fail_statfs:
 830	iput(sdp->sd_statfs_inode);
 831fail_journal:
 832	init_journal(sdp, UNDO);
 833fail:
 834	return error;
 835}
 836
 837static int init_per_node(struct gfs2_sbd *sdp, int undo)
 838{
 839	struct inode *pn = NULL;
 840	char buf[30];
 841	int error = 0;
 842	struct gfs2_inode *ip;
 843	struct inode *master = sdp->sd_master_dir->d_inode;
 844
 845	if (sdp->sd_args.ar_spectator)
 846		return 0;
 847
 848	if (undo)
 849		goto fail_qc_gh;
 850
 851	pn = gfs2_lookup_simple(master, "per_node");
 852	if (IS_ERR(pn)) {
 853		error = PTR_ERR(pn);
 854		fs_err(sdp, "can't find per_node directory: %d\n", error);
 855		return error;
 856	}
 857
 858	sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
 859	sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
 860	if (IS_ERR(sdp->sd_sc_inode)) {
 861		error = PTR_ERR(sdp->sd_sc_inode);
 862		fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
 863		goto fail;
 864	}
 865
 866	sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
 867	sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
 868	if (IS_ERR(sdp->sd_qc_inode)) {
 869		error = PTR_ERR(sdp->sd_qc_inode);
 870		fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
 871		goto fail_ut_i;
 872	}
 873
 874	iput(pn);
 875	pn = NULL;
 876
 877	ip = GFS2_I(sdp->sd_sc_inode);
 878	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
 879				   &sdp->sd_sc_gh);
 880	if (error) {
 881		fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
 882		goto fail_qc_i;
 883	}
 884
 885	ip = GFS2_I(sdp->sd_qc_inode);
 886	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
 887				   &sdp->sd_qc_gh);
 888	if (error) {
 889		fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
 890		goto fail_ut_gh;
 891	}
 892
 893	return 0;
 894
 895fail_qc_gh:
 896	gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
 897fail_ut_gh:
 898	gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
 899fail_qc_i:
 900	iput(sdp->sd_qc_inode);
 901fail_ut_i:
 902	iput(sdp->sd_sc_inode);
 903fail:
 904	if (pn)
 905		iput(pn);
 906	return error;
 907}
 908
 909static int init_threads(struct gfs2_sbd *sdp, int undo)
 910{
 911	struct task_struct *p;
 912	int error = 0;
 913
 914	if (undo)
 915		goto fail_quotad;
 916
 917	p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
 918	error = IS_ERR(p);
 919	if (error) {
 920		fs_err(sdp, "can't start logd thread: %d\n", error);
 921		return error;
 922	}
 923	sdp->sd_logd_process = p;
 924
 925	p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
 926	error = IS_ERR(p);
 927	if (error) {
 928		fs_err(sdp, "can't start quotad thread: %d\n", error);
 929		goto fail;
 930	}
 931	sdp->sd_quotad_process = p;
 932
 933	return 0;
 934
 935
 936fail_quotad:
 937	kthread_stop(sdp->sd_quotad_process);
 938fail:
 939	kthread_stop(sdp->sd_logd_process);
 940	return error;
 941}
 942
 943static const match_table_t nolock_tokens = {
 944	{ Opt_jid, "jid=%d\n", },
 945	{ Opt_err, NULL },
 946};
 947
 948static const struct lm_lockops nolock_ops = {
 949	.lm_proto_name = "lock_nolock",
 950	.lm_put_lock = gfs2_glock_free,
 951	.lm_tokens = &nolock_tokens,
 952};
 953
 954/**
 955 * gfs2_lm_mount - mount a locking protocol
 956 * @sdp: the filesystem
 957 * @args: mount arguments
 958 * @silent: if 1, don't complain if the FS isn't a GFS2 fs
 959 *
 960 * Returns: errno
 961 */
 962
 963static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
 964{
 965	const struct lm_lockops *lm;
 966	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 967	struct gfs2_args *args = &sdp->sd_args;
 968	const char *proto = sdp->sd_proto_name;
 969	const char *table = sdp->sd_table_name;
 970	char *o, *options;
 971	int ret;
 972
 973	if (!strcmp("lock_nolock", proto)) {
 974		lm = &nolock_ops;
 975		sdp->sd_args.ar_localflocks = 1;
 976#ifdef CONFIG_GFS2_FS_LOCKING_DLM
 977	} else if (!strcmp("lock_dlm", proto)) {
 978		lm = &gfs2_dlm_ops;
 979#endif
 980	} else {
 981		printk(KERN_INFO "GFS2: can't find protocol %s\n", proto);
 982		return -ENOENT;
 983	}
 984
 985	fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
 986
 987	ls->ls_ops = lm;
 988	ls->ls_first = 1;
 989
 990	for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
 991		substring_t tmp[MAX_OPT_ARGS];
 992		int token, option;
 993
 994		if (!o || !*o)
 995			continue;
 996
 997		token = match_token(o, *lm->lm_tokens, tmp);
 998		switch (token) {
 999		case Opt_jid:
1000			ret = match_int(&tmp[0], &option);
1001			if (ret || option < 0) 
1002				goto hostdata_error;
1003			if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
1004				ls->ls_jid = option;
1005			break;
1006		case Opt_id:
1007		case Opt_nodir:
1008			/* Obsolete, but left for backward compat purposes */
1009			break;
1010		case Opt_first:
1011			ret = match_int(&tmp[0], &option);
1012			if (ret || (option != 0 && option != 1))
1013				goto hostdata_error;
1014			ls->ls_first = option;
1015			break;
1016		case Opt_err:
1017		default:
1018hostdata_error:
1019			fs_info(sdp, "unknown hostdata (%s)\n", o);
1020			return -EINVAL;
1021		}
1022	}
1023
1024	if (lm->lm_mount == NULL) {
1025		fs_info(sdp, "Now mounting FS...\n");
1026		complete_all(&sdp->sd_locking_init);
1027		return 0;
1028	}
1029	ret = lm->lm_mount(sdp, table);
1030	if (ret == 0)
1031		fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1032	complete_all(&sdp->sd_locking_init);
1033	return ret;
1034}
1035
1036void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1037{
1038	const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1039	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1040	    lm->lm_unmount)
1041		lm->lm_unmount(sdp);
1042}
1043
1044static int gfs2_journalid_wait(void *word)
1045{
1046	if (signal_pending(current))
1047		return -EINTR;
1048	schedule();
1049	return 0;
1050}
1051
1052static int wait_on_journal(struct gfs2_sbd *sdp)
1053{
1054	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1055		return 0;
1056
1057	return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, gfs2_journalid_wait, TASK_INTERRUPTIBLE);
1058}
1059
1060void gfs2_online_uevent(struct gfs2_sbd *sdp)
1061{
1062	struct super_block *sb = sdp->sd_vfs;
1063	char ro[20];
1064	char spectator[20];
1065	char *envp[] = { ro, spectator, NULL };
1066	sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1067	sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1068	kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1069}
1070
1071/**
1072 * fill_super - Read in superblock
1073 * @sb: The VFS superblock
1074 * @data: Mount options
1075 * @silent: Don't complain if it's not a GFS2 filesystem
1076 *
1077 * Returns: errno
1078 */
1079
1080static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1081{
1082	struct gfs2_sbd *sdp;
1083	struct gfs2_holder mount_gh;
1084	int error;
1085
1086	sdp = init_sbd(sb);
1087	if (!sdp) {
1088		printk(KERN_WARNING "GFS2: can't alloc struct gfs2_sbd\n");
1089		return -ENOMEM;
1090	}
1091	sdp->sd_args = *args;
1092
1093	if (sdp->sd_args.ar_spectator) {
1094                sb->s_flags |= MS_RDONLY;
1095		set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1096	}
1097	if (sdp->sd_args.ar_posix_acl)
1098		sb->s_flags |= MS_POSIXACL;
1099	if (sdp->sd_args.ar_nobarrier)
1100		set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1101
1102	sb->s_flags |= MS_NOSEC;
1103	sb->s_magic = GFS2_MAGIC;
1104	sb->s_op = &gfs2_super_ops;
1105	sb->s_d_op = &gfs2_dops;
1106	sb->s_export_op = &gfs2_export_ops;
1107	sb->s_xattr = gfs2_xattr_handlers;
1108	sb->s_qcop = &gfs2_quotactl_ops;
1109	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1110	sb->s_time_gran = 1;
1111	sb->s_maxbytes = MAX_LFS_FILESIZE;
1112
1113	/* Set up the buffer cache and fill in some fake block size values
1114	   to allow us to read-in the on-disk superblock. */
1115	sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1116	sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1117	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1118                               GFS2_BASIC_BLOCK_SHIFT;
1119	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1120
1121	sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1122	sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1123	if (sdp->sd_args.ar_statfs_quantum) {
1124		sdp->sd_tune.gt_statfs_slow = 0;
1125		sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1126	} else {
1127		sdp->sd_tune.gt_statfs_slow = 1;
1128		sdp->sd_tune.gt_statfs_quantum = 30;
1129	}
1130
1131	error = init_names(sdp, silent);
1132	if (error) {
1133		/* In this case, we haven't initialized sysfs, so we have to
1134		   manually free the sdp. */
1135		free_percpu(sdp->sd_lkstats);
1136		kfree(sdp);
1137		sb->s_fs_info = NULL;
1138		return error;
1139	}
1140
1141	snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);
1142
1143	error = gfs2_sys_fs_add(sdp);
1144	/*
1145	 * If we hit an error here, gfs2_sys_fs_add will have called function
1146	 * kobject_put which causes the sysfs usage count to go to zero, which
1147	 * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1148	 * Subsequent error paths here will call gfs2_sys_fs_del, which also
1149	 * kobject_put to free sdp.
1150	 */
1151	if (error)
1152		return error;
1153
1154	gfs2_create_debugfs_file(sdp);
1155
1156	error = gfs2_lm_mount(sdp, silent);
1157	if (error)
1158		goto fail_debug;
1159
1160	error = init_locking(sdp, &mount_gh, DO);
1161	if (error)
1162		goto fail_lm;
1163
1164	error = init_sb(sdp, silent);
1165	if (error)
1166		goto fail_locking;
1167
1168	error = wait_on_journal(sdp);
1169	if (error)
1170		goto fail_sb;
1171
1172	/*
1173	 * If user space has failed to join the cluster or some similar
1174	 * failure has occurred, then the journal id will contain a
1175	 * negative (error) number. This will then be returned to the
1176	 * caller (of the mount syscall). We do this even for spectator
1177	 * mounts (which just write a jid of 0 to indicate "ok" even though
1178	 * the jid is unused in the spectator case)
1179	 */
1180	if (sdp->sd_lockstruct.ls_jid < 0) {
1181		error = sdp->sd_lockstruct.ls_jid;
1182		sdp->sd_lockstruct.ls_jid = 0;
1183		goto fail_sb;
1184	}
1185
1186	if (sdp->sd_args.ar_spectator)
1187		snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
1188			 sdp->sd_table_name);
1189	else
1190		snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
1191			 sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1192
1193	error = init_inodes(sdp, DO);
1194	if (error)
1195		goto fail_sb;
1196
1197	error = init_per_node(sdp, DO);
1198	if (error)
1199		goto fail_inodes;
1200
1201	error = gfs2_statfs_init(sdp);
1202	if (error) {
1203		fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1204		goto fail_per_node;
1205	}
1206
1207	error = init_threads(sdp, DO);
1208	if (error)
1209		goto fail_per_node;
1210
1211	if (!(sb->s_flags & MS_RDONLY)) {
1212		error = gfs2_make_fs_rw(sdp);
1213		if (error) {
1214			fs_err(sdp, "can't make FS RW: %d\n", error);
1215			goto fail_threads;
1216		}
1217	}
1218
1219	gfs2_glock_dq_uninit(&mount_gh);
1220	gfs2_online_uevent(sdp);
1221	return 0;
1222
1223fail_threads:
1224	init_threads(sdp, UNDO);
1225fail_per_node:
1226	init_per_node(sdp, UNDO);
1227fail_inodes:
1228	init_inodes(sdp, UNDO);
1229fail_sb:
1230	if (sdp->sd_root_dir)
1231		dput(sdp->sd_root_dir);
1232	if (sdp->sd_master_dir)
1233		dput(sdp->sd_master_dir);
1234	if (sb->s_root)
1235		dput(sb->s_root);
1236	sb->s_root = NULL;
1237fail_locking:
1238	init_locking(sdp, &mount_gh, UNDO);
1239fail_lm:
1240	gfs2_gl_hash_clear(sdp);
1241	gfs2_lm_unmount(sdp);
1242fail_debug:
1243	gfs2_delete_debugfs_file(sdp);
1244	free_percpu(sdp->sd_lkstats);
1245	/* gfs2_sys_fs_del must be the last thing we do, since it causes
1246	 * sysfs to call function gfs2_sbd_release, which frees sdp. */
1247	gfs2_sys_fs_del(sdp);
1248	sb->s_fs_info = NULL;
1249	return error;
1250}
1251
1252static int set_gfs2_super(struct super_block *s, void *data)
1253{
1254	s->s_bdev = data;
1255	s->s_dev = s->s_bdev->bd_dev;
1256
1257	/*
1258	 * We set the bdi here to the queue backing, file systems can
1259	 * overwrite this in ->fill_super()
1260	 */
1261	s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1262	return 0;
1263}
1264
1265static int test_gfs2_super(struct super_block *s, void *ptr)
1266{
1267	struct block_device *bdev = ptr;
1268	return (bdev == s->s_bdev);
1269}
1270
1271/**
1272 * gfs2_mount - Get the GFS2 superblock
1273 * @fs_type: The GFS2 filesystem type
1274 * @flags: Mount flags
1275 * @dev_name: The name of the device
1276 * @data: The mount arguments
1277 *
1278 * Q. Why not use get_sb_bdev() ?
1279 * A. We need to select one of two root directories to mount, independent
1280 *    of whether this is the initial, or subsequent, mount of this sb
1281 *
1282 * Returns: 0 or -ve on error
1283 */
1284
1285static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1286		       const char *dev_name, void *data)
1287{
1288	struct block_device *bdev;
1289	struct super_block *s;
1290	fmode_t mode = FMODE_READ | FMODE_EXCL;
1291	int error;
1292	struct gfs2_args args;
1293	struct gfs2_sbd *sdp;
1294
1295	if (!(flags & MS_RDONLY))
1296		mode |= FMODE_WRITE;
1297
1298	bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1299	if (IS_ERR(bdev))
1300		return ERR_CAST(bdev);
1301
1302	/*
1303	 * once the super is inserted into the list by sget, s_umount
1304	 * will protect the lockfs code from trying to start a snapshot
1305	 * while we are mounting
1306	 */
1307	mutex_lock(&bdev->bd_fsfreeze_mutex);
1308	if (bdev->bd_fsfreeze_count > 0) {
1309		mutex_unlock(&bdev->bd_fsfreeze_mutex);
1310		error = -EBUSY;
1311		goto error_bdev;
1312	}
1313	s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1314	mutex_unlock(&bdev->bd_fsfreeze_mutex);
1315	error = PTR_ERR(s);
1316	if (IS_ERR(s))
1317		goto error_bdev;
1318
1319	if (s->s_root)
1320		blkdev_put(bdev, mode);
1321
1322	memset(&args, 0, sizeof(args));
1323	args.ar_quota = GFS2_QUOTA_DEFAULT;
1324	args.ar_data = GFS2_DATA_DEFAULT;
1325	args.ar_commit = 30;
1326	args.ar_statfs_quantum = 30;
1327	args.ar_quota_quantum = 60;
1328	args.ar_errors = GFS2_ERRORS_DEFAULT;
1329
1330	error = gfs2_mount_args(&args, data);
1331	if (error) {
1332		printk(KERN_WARNING "GFS2: can't parse mount arguments\n");
1333		goto error_super;
1334	}
1335
1336	if (s->s_root) {
1337		error = -EBUSY;
1338		if ((flags ^ s->s_flags) & MS_RDONLY)
1339			goto error_super;
1340	} else {
1341		char b[BDEVNAME_SIZE];
1342
1343		s->s_mode = mode;
1344		strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1345		sb_set_blocksize(s, block_size(bdev));
1346		error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1347		if (error)
1348			goto error_super;
1349		s->s_flags |= MS_ACTIVE;
1350		bdev->bd_super = s;
1351	}
1352
1353	sdp = s->s_fs_info;
1354	if (args.ar_meta)
1355		return dget(sdp->sd_master_dir);
1356	else
1357		return dget(sdp->sd_root_dir);
1358
1359error_super:
1360	deactivate_locked_super(s);
1361	return ERR_PTR(error);
1362error_bdev:
1363	blkdev_put(bdev, mode);
1364	return ERR_PTR(error);
1365}
1366
1367static int set_meta_super(struct super_block *s, void *ptr)
1368{
1369	return -EINVAL;
1370}
1371
1372static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1373			int flags, const char *dev_name, void *data)
1374{
1375	struct super_block *s;
1376	struct gfs2_sbd *sdp;
1377	struct path path;
1378	int error;
1379
1380	error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1381	if (error) {
1382		printk(KERN_WARNING "GFS2: path_lookup on %s returned error %d\n",
1383		       dev_name, error);
1384		return ERR_PTR(error);
1385	}
1386	s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1387		 path.dentry->d_inode->i_sb->s_bdev);
1388	path_put(&path);
1389	if (IS_ERR(s)) {
1390		printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n");
1391		return ERR_CAST(s);
1392	}
1393	if ((flags ^ s->s_flags) & MS_RDONLY) {
1394		deactivate_locked_super(s);
1395		return ERR_PTR(-EBUSY);
1396	}
1397	sdp = s->s_fs_info;
1398	return dget(sdp->sd_master_dir);
1399}
1400
1401static void gfs2_kill_sb(struct super_block *sb)
1402{
1403	struct gfs2_sbd *sdp = sb->s_fs_info;
1404
1405	if (sdp == NULL) {
1406		kill_block_super(sb);
1407		return;
1408	}
1409
1410	gfs2_meta_syncfs(sdp);
1411	dput(sdp->sd_root_dir);
1412	dput(sdp->sd_master_dir);
1413	sdp->sd_root_dir = NULL;
1414	sdp->sd_master_dir = NULL;
1415	shrink_dcache_sb(sb);
1416	gfs2_delete_debugfs_file(sdp);
1417	free_percpu(sdp->sd_lkstats);
1418	kill_block_super(sb);
1419}
1420
1421struct file_system_type gfs2_fs_type = {
1422	.name = "gfs2",
1423	.fs_flags = FS_REQUIRES_DEV,
1424	.mount = gfs2_mount,
1425	.kill_sb = gfs2_kill_sb,
1426	.owner = THIS_MODULE,
1427};
1428
1429struct file_system_type gfs2meta_fs_type = {
1430	.name = "gfs2meta",
1431	.fs_flags = FS_REQUIRES_DEV,
1432	.mount = gfs2_mount_meta,
1433	.owner = THIS_MODULE,
1434};
1435