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/fs/gfs2/ops_fstype.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 1408 lines | 1075 code | 202 blank | 131 comment | 164 complexity | c561b0b5efd93b3f2a5d51b0c8e40e34 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
   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/namei.h>
  18#include <linux/mount.h>
  19#include <linux/gfs2_ondisk.h>
  20#include <linux/quotaops.h>
  21
  22#include "gfs2.h"
  23#include "incore.h"
  24#include "bmap.h"
  25#include "glock.h"
  26#include "glops.h"
  27#include "inode.h"
  28#include "recovery.h"
  29#include "rgrp.h"
  30#include "super.h"
  31#include "sys.h"
  32#include "util.h"
  33#include "log.h"
  34#include "quota.h"
  35#include "dir.h"
  36#include "trace_gfs2.h"
  37
  38#define DO 0
  39#define UNDO 1
  40
  41/**
  42 * gfs2_tune_init - Fill a gfs2_tune structure with default values
  43 * @gt: tune
  44 *
  45 */
  46
  47static void gfs2_tune_init(struct gfs2_tune *gt)
  48{
  49	spin_lock_init(&gt->gt_spin);
  50
  51	gt->gt_quota_simul_sync = 64;
  52	gt->gt_quota_warn_period = 10;
  53	gt->gt_quota_scale_num = 1;
  54	gt->gt_quota_scale_den = 1;
  55	gt->gt_new_files_jdata = 0;
  56	gt->gt_max_readahead = 1 << 18;
  57	gt->gt_complain_secs = 10;
  58}
  59
  60static struct gfs2_sbd *init_sbd(struct super_block *sb)
  61{
  62	struct gfs2_sbd *sdp;
  63
  64	sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
  65	if (!sdp)
  66		return NULL;
  67
  68	sb->s_fs_info = sdp;
  69	sdp->sd_vfs = sb;
  70	set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
  71	gfs2_tune_init(&sdp->sd_tune);
  72
  73	init_waitqueue_head(&sdp->sd_glock_wait);
  74	atomic_set(&sdp->sd_glock_disposal, 0);
  75	init_completion(&sdp->sd_locking_init);
  76	spin_lock_init(&sdp->sd_statfs_spin);
  77
  78	spin_lock_init(&sdp->sd_rindex_spin);
  79	mutex_init(&sdp->sd_rindex_mutex);
  80	INIT_LIST_HEAD(&sdp->sd_rindex_list);
  81	INIT_LIST_HEAD(&sdp->sd_rindex_mru_list);
  82
  83	INIT_LIST_HEAD(&sdp->sd_jindex_list);
  84	spin_lock_init(&sdp->sd_jindex_spin);
  85	mutex_init(&sdp->sd_jindex_mutex);
  86
  87	INIT_LIST_HEAD(&sdp->sd_quota_list);
  88	mutex_init(&sdp->sd_quota_mutex);
  89	init_waitqueue_head(&sdp->sd_quota_wait);
  90	INIT_LIST_HEAD(&sdp->sd_trunc_list);
  91	spin_lock_init(&sdp->sd_trunc_lock);
  92
  93	spin_lock_init(&sdp->sd_log_lock);
  94	atomic_set(&sdp->sd_log_pinned, 0);
  95	INIT_LIST_HEAD(&sdp->sd_log_le_buf);
  96	INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
  97	INIT_LIST_HEAD(&sdp->sd_log_le_rg);
  98	INIT_LIST_HEAD(&sdp->sd_log_le_databuf);
  99	INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
 100
 101	init_waitqueue_head(&sdp->sd_log_waitq);
 102	init_waitqueue_head(&sdp->sd_logd_waitq);
 103	spin_lock_init(&sdp->sd_ail_lock);
 104	INIT_LIST_HEAD(&sdp->sd_ail1_list);
 105	INIT_LIST_HEAD(&sdp->sd_ail2_list);
 106
 107	init_rwsem(&sdp->sd_log_flush_lock);
 108	atomic_set(&sdp->sd_log_in_flight, 0);
 109	init_waitqueue_head(&sdp->sd_log_flush_wait);
 110
 111	INIT_LIST_HEAD(&sdp->sd_revoke_list);
 112
 113	mutex_init(&sdp->sd_freeze_lock);
 114
 115	return sdp;
 116}
 117
 118
 119/**
 120 * gfs2_check_sb - Check superblock
 121 * @sdp: the filesystem
 122 * @sb: The superblock
 123 * @silent: Don't print a message if the check fails
 124 *
 125 * Checks the version code of the FS is one that we understand how to
 126 * read and that the sizes of the various on-disk structures have not
 127 * changed.
 128 */
 129
 130static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
 131{
 132	struct gfs2_sb_host *sb = &sdp->sd_sb;
 133
 134	if (sb->sb_magic != GFS2_MAGIC ||
 135	    sb->sb_type != GFS2_METATYPE_SB) {
 136		if (!silent)
 137			printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
 138		return -EINVAL;
 139	}
 140
 141	/*  If format numbers match exactly, we're done.  */
 142
 143	if (sb->sb_fs_format == GFS2_FORMAT_FS &&
 144	    sb->sb_multihost_format == GFS2_FORMAT_MULTI)
 145		return 0;
 146
 147	fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
 148
 149	return -EINVAL;
 150}
 151
 152static void end_bio_io_page(struct bio *bio, int error)
 153{
 154	struct page *page = bio->bi_private;
 155
 156	if (!error)
 157		SetPageUptodate(page);
 158	else
 159		printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
 160	unlock_page(page);
 161}
 162
 163static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
 164{
 165	struct gfs2_sb_host *sb = &sdp->sd_sb;
 166	struct super_block *s = sdp->sd_vfs;
 167	const struct gfs2_sb *str = buf;
 168
 169	sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
 170	sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
 171	sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
 172	sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
 173	sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
 174	sb->sb_bsize = be32_to_cpu(str->sb_bsize);
 175	sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
 176	sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
 177	sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
 178	sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
 179	sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
 180
 181	memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
 182	memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
 183	memcpy(s->s_uuid, str->sb_uuid, 16);
 184}
 185
 186/**
 187 * gfs2_read_super - Read the gfs2 super block from disk
 188 * @sdp: The GFS2 super block
 189 * @sector: The location of the super block
 190 * @error: The error code to return
 191 *
 192 * This uses the bio functions to read the super block from disk
 193 * because we want to be 100% sure that we never read cached data.
 194 * A super block is read twice only during each GFS2 mount and is
 195 * never written to by the filesystem. The first time its read no
 196 * locks are held, and the only details which are looked at are those
 197 * relating to the locking protocol. Once locking is up and working,
 198 * the sb is read again under the lock to establish the location of
 199 * the master directory (contains pointers to journals etc) and the
 200 * root directory.
 201 *
 202 * Returns: 0 on success or error
 203 */
 204
 205static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
 206{
 207	struct super_block *sb = sdp->sd_vfs;
 208	struct gfs2_sb *p;
 209	struct page *page;
 210	struct bio *bio;
 211
 212	page = alloc_page(GFP_NOFS);
 213	if (unlikely(!page))
 214		return -ENOBUFS;
 215
 216	ClearPageUptodate(page);
 217	ClearPageDirty(page);
 218	lock_page(page);
 219
 220	bio = bio_alloc(GFP_NOFS, 1);
 221	bio->bi_sector = sector * (sb->s_blocksize >> 9);
 222	bio->bi_bdev = sb->s_bdev;
 223	bio_add_page(bio, page, PAGE_SIZE, 0);
 224
 225	bio->bi_end_io = end_bio_io_page;
 226	bio->bi_private = page;
 227	submit_bio(READ_SYNC | REQ_META | REQ_PRIO, bio);
 228	wait_on_page_locked(page);
 229	bio_put(bio);
 230	if (!PageUptodate(page)) {
 231		__free_page(page);
 232		return -EIO;
 233	}
 234	p = kmap(page);
 235	gfs2_sb_in(sdp, p);
 236	kunmap(page);
 237	__free_page(page);
 238	return gfs2_check_sb(sdp, silent);
 239}
 240
 241/**
 242 * gfs2_read_sb - Read super block
 243 * @sdp: The GFS2 superblock
 244 * @silent: Don't print message if mount fails
 245 *
 246 */
 247
 248static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
 249{
 250	u32 hash_blocks, ind_blocks, leaf_blocks;
 251	u32 tmp_blocks;
 252	unsigned int x;
 253	int error;
 254
 255	error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
 256	if (error) {
 257		if (!silent)
 258			fs_err(sdp, "can't read superblock\n");
 259		return error;
 260	}
 261
 262	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
 263			       GFS2_BASIC_BLOCK_SHIFT;
 264	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
 265	sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
 266			  sizeof(struct gfs2_dinode)) / sizeof(u64);
 267	sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
 268			  sizeof(struct gfs2_meta_header)) / sizeof(u64);
 269	sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
 270	sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
 271	sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
 272	sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
 273	sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
 274				sizeof(struct gfs2_meta_header)) /
 275			        sizeof(struct gfs2_quota_change);
 276
 277	/* Compute maximum reservation required to add a entry to a directory */
 278
 279	hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
 280			     sdp->sd_jbsize);
 281
 282	ind_blocks = 0;
 283	for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
 284		tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
 285		ind_blocks += tmp_blocks;
 286	}
 287
 288	leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
 289
 290	sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
 291
 292	sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
 293				sizeof(struct gfs2_dinode);
 294	sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
 295	for (x = 2;; x++) {
 296		u64 space, d;
 297		u32 m;
 298
 299		space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
 300		d = space;
 301		m = do_div(d, sdp->sd_inptrs);
 302
 303		if (d != sdp->sd_heightsize[x - 1] || m)
 304			break;
 305		sdp->sd_heightsize[x] = space;
 306	}
 307	sdp->sd_max_height = x;
 308	sdp->sd_heightsize[x] = ~0;
 309	gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 310
 311	sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
 312				 sizeof(struct gfs2_dinode);
 313	sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
 314	for (x = 2;; x++) {
 315		u64 space, d;
 316		u32 m;
 317
 318		space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
 319		d = space;
 320		m = do_div(d, sdp->sd_inptrs);
 321
 322		if (d != sdp->sd_jheightsize[x - 1] || m)
 323			break;
 324		sdp->sd_jheightsize[x] = space;
 325	}
 326	sdp->sd_max_jheight = x;
 327	sdp->sd_jheightsize[x] = ~0;
 328	gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
 329
 330	return 0;
 331}
 332
 333static int init_names(struct gfs2_sbd *sdp, int silent)
 334{
 335	char *proto, *table;
 336	int error = 0;
 337
 338	proto = sdp->sd_args.ar_lockproto;
 339	table = sdp->sd_args.ar_locktable;
 340
 341	/*  Try to autodetect  */
 342
 343	if (!proto[0] || !table[0]) {
 344		error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
 345		if (error)
 346			return error;
 347
 348		if (!proto[0])
 349			proto = sdp->sd_sb.sb_lockproto;
 350		if (!table[0])
 351			table = sdp->sd_sb.sb_locktable;
 352	}
 353
 354	if (!table[0])
 355		table = sdp->sd_vfs->s_id;
 356
 357	strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
 358	strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
 359
 360	table = sdp->sd_table_name;
 361	while ((table = strchr(table, '/')))
 362		*table = '_';
 363
 364	return error;
 365}
 366
 367static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
 368			int undo)
 369{
 370	int error = 0;
 371
 372	if (undo)
 373		goto fail_trans;
 374
 375	error = gfs2_glock_nq_num(sdp,
 376				  GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
 377				  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
 378				  mount_gh);
 379	if (error) {
 380		fs_err(sdp, "can't acquire mount glock: %d\n", error);
 381		goto fail;
 382	}
 383
 384	error = gfs2_glock_nq_num(sdp,
 385				  GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
 386				  LM_ST_SHARED,
 387				  LM_FLAG_NOEXP | GL_EXACT,
 388				  &sdp->sd_live_gh);
 389	if (error) {
 390		fs_err(sdp, "can't acquire live glock: %d\n", error);
 391		goto fail_mount;
 392	}
 393
 394	error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
 395			       CREATE, &sdp->sd_rename_gl);
 396	if (error) {
 397		fs_err(sdp, "can't create rename glock: %d\n", error);
 398		goto fail_live;
 399	}
 400
 401	error = gfs2_glock_get(sdp, GFS2_TRANS_LOCK, &gfs2_trans_glops,
 402			       CREATE, &sdp->sd_trans_gl);
 403	if (error) {
 404		fs_err(sdp, "can't create transaction glock: %d\n", error);
 405		goto fail_rename;
 406	}
 407
 408	return 0;
 409
 410fail_trans:
 411	gfs2_glock_put(sdp->sd_trans_gl);
 412fail_rename:
 413	gfs2_glock_put(sdp->sd_rename_gl);
 414fail_live:
 415	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
 416fail_mount:
 417	gfs2_glock_dq_uninit(mount_gh);
 418fail:
 419	return error;
 420}
 421
 422static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
 423			    u64 no_addr, const char *name)
 424{
 425	struct gfs2_sbd *sdp = sb->s_fs_info;
 426	struct dentry *dentry;
 427	struct inode *inode;
 428
 429	inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
 430	if (IS_ERR(inode)) {
 431		fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
 432		return PTR_ERR(inode);
 433	}
 434	dentry = d_alloc_root(inode);
 435	if (!dentry) {
 436		fs_err(sdp, "can't alloc %s dentry\n", name);
 437		iput(inode);
 438		return -ENOMEM;
 439	}
 440	*dptr = dentry;
 441	return 0;
 442}
 443
 444static int init_sb(struct gfs2_sbd *sdp, int silent)
 445{
 446	struct super_block *sb = sdp->sd_vfs;
 447	struct gfs2_holder sb_gh;
 448	u64 no_addr;
 449	int ret;
 450
 451	ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
 452				LM_ST_SHARED, 0, &sb_gh);
 453	if (ret) {
 454		fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
 455		return ret;
 456	}
 457
 458	ret = gfs2_read_sb(sdp, silent);
 459	if (ret) {
 460		fs_err(sdp, "can't read superblock: %d\n", ret);
 461		goto out;
 462	}
 463
 464	/* Set up the buffer cache and SB for real */
 465	if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
 466		ret = -EINVAL;
 467		fs_err(sdp, "FS block size (%u) is too small for device "
 468		       "block size (%u)\n",
 469		       sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
 470		goto out;
 471	}
 472	if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
 473		ret = -EINVAL;
 474		fs_err(sdp, "FS block size (%u) is too big for machine "
 475		       "page size (%u)\n",
 476		       sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
 477		goto out;
 478	}
 479	sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
 480
 481	/* Get the root inode */
 482	no_addr = sdp->sd_sb.sb_root_dir.no_addr;
 483	ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
 484	if (ret)
 485		goto out;
 486
 487	/* Get the master inode */
 488	no_addr = sdp->sd_sb.sb_master_dir.no_addr;
 489	ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
 490	if (ret) {
 491		dput(sdp->sd_root_dir);
 492		goto out;
 493	}
 494	sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
 495out:
 496	gfs2_glock_dq_uninit(&sb_gh);
 497	return ret;
 498}
 499
 500/**
 501 * map_journal_extents - create a reusable "extent" mapping from all logical
 502 * blocks to all physical blocks for the given journal.  This will save
 503 * us time when writing journal blocks.  Most journals will have only one
 504 * extent that maps all their logical blocks.  That's because gfs2.mkfs
 505 * arranges the journal blocks sequentially to maximize performance.
 506 * So the extent would map the first block for the entire file length.
 507 * However, gfs2_jadd can happen while file activity is happening, so
 508 * those journals may not be sequential.  Less likely is the case where
 509 * the users created their own journals by mounting the metafs and
 510 * laying it out.  But it's still possible.  These journals might have
 511 * several extents.
 512 *
 513 * TODO: This should be done in bigger chunks rather than one block at a time,
 514 *       but since it's only done at mount time, I'm not worried about the
 515 *       time it takes.
 516 */
 517static int map_journal_extents(struct gfs2_sbd *sdp)
 518{
 519	struct gfs2_jdesc *jd = sdp->sd_jdesc;
 520	unsigned int lb;
 521	u64 db, prev_db; /* logical block, disk block, prev disk block */
 522	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
 523	struct gfs2_journal_extent *jext = NULL;
 524	struct buffer_head bh;
 525	int rc = 0;
 526
 527	prev_db = 0;
 528
 529	for (lb = 0; lb < i_size_read(jd->jd_inode) >> sdp->sd_sb.sb_bsize_shift; lb++) {
 530		bh.b_state = 0;
 531		bh.b_blocknr = 0;
 532		bh.b_size = 1 << ip->i_inode.i_blkbits;
 533		rc = gfs2_block_map(jd->jd_inode, lb, &bh, 0);
 534		db = bh.b_blocknr;
 535		if (rc || !db) {
 536			printk(KERN_INFO "GFS2 journal mapping error %d: lb="
 537			       "%u db=%llu\n", rc, lb, (unsigned long long)db);
 538			break;
 539		}
 540		if (!prev_db || db != prev_db + 1) {
 541			jext = kzalloc(sizeof(struct gfs2_journal_extent),
 542				       GFP_KERNEL);
 543			if (!jext) {
 544				printk(KERN_INFO "GFS2 error: out of memory "
 545				       "mapping journal extents.\n");
 546				rc = -ENOMEM;
 547				break;
 548			}
 549			jext->dblock = db;
 550			jext->lblock = lb;
 551			jext->blocks = 1;
 552			list_add_tail(&jext->extent_list, &jd->extent_list);
 553		} else {
 554			jext->blocks++;
 555		}
 556		prev_db = db;
 557	}
 558	return rc;
 559}
 560
 561static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
 562{
 563	char *message = "FIRSTMOUNT=Done";
 564	char *envp[] = { message, NULL };
 565	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 566	ls->ls_first_done = 1;
 567	kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
 568}
 569
 570/**
 571 * gfs2_jindex_hold - Grab a lock on the jindex
 572 * @sdp: The GFS2 superblock
 573 * @ji_gh: the holder for the jindex glock
 574 *
 575 * Returns: errno
 576 */
 577
 578static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 579{
 580	struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
 581	struct qstr name;
 582	char buf[20];
 583	struct gfs2_jdesc *jd;
 584	int error;
 585
 586	name.name = buf;
 587
 588	mutex_lock(&sdp->sd_jindex_mutex);
 589
 590	for (;;) {
 591		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
 592		if (error)
 593			break;
 594
 595		name.len = sprintf(buf, "journal%u", sdp->sd_journals);
 596		name.hash = gfs2_disk_hash(name.name, name.len);
 597
 598		error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
 599		if (error == -ENOENT) {
 600			error = 0;
 601			break;
 602		}
 603
 604		gfs2_glock_dq_uninit(ji_gh);
 605
 606		if (error)
 607			break;
 608
 609		error = -ENOMEM;
 610		jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
 611		if (!jd)
 612			break;
 613
 614		INIT_LIST_HEAD(&jd->extent_list);
 615		INIT_WORK(&jd->jd_work, gfs2_recover_func);
 616		jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
 617		if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
 618			if (!jd->jd_inode)
 619				error = -ENOENT;
 620			else
 621				error = PTR_ERR(jd->jd_inode);
 622			kfree(jd);
 623			break;
 624		}
 625
 626		spin_lock(&sdp->sd_jindex_spin);
 627		jd->jd_jid = sdp->sd_journals++;
 628		list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
 629		spin_unlock(&sdp->sd_jindex_spin);
 630	}
 631
 632	mutex_unlock(&sdp->sd_jindex_mutex);
 633
 634	return error;
 635}
 636
 637static int init_journal(struct gfs2_sbd *sdp, int undo)
 638{
 639	struct inode *master = sdp->sd_master_dir->d_inode;
 640	struct gfs2_holder ji_gh;
 641	struct gfs2_inode *ip;
 642	int jindex = 1;
 643	int error = 0;
 644
 645	if (undo) {
 646		jindex = 0;
 647		goto fail_jinode_gh;
 648	}
 649
 650	sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
 651	if (IS_ERR(sdp->sd_jindex)) {
 652		fs_err(sdp, "can't lookup journal index: %d\n", error);
 653		return PTR_ERR(sdp->sd_jindex);
 654	}
 655	ip = GFS2_I(sdp->sd_jindex);
 656
 657	/* Load in the journal index special file */
 658
 659	error = gfs2_jindex_hold(sdp, &ji_gh);
 660	if (error) {
 661		fs_err(sdp, "can't read journal index: %d\n", error);
 662		goto fail;
 663	}
 664
 665	error = -EUSERS;
 666	if (!gfs2_jindex_size(sdp)) {
 667		fs_err(sdp, "no journals!\n");
 668		goto fail_jindex;
 669	}
 670
 671	if (sdp->sd_args.ar_spectator) {
 672		sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
 673		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
 674		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
 675		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
 676	} else {
 677		if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
 678			fs_err(sdp, "can't mount journal #%u\n",
 679			       sdp->sd_lockstruct.ls_jid);
 680			fs_err(sdp, "there are only %u journals (0 - %u)\n",
 681			       gfs2_jindex_size(sdp),
 682			       gfs2_jindex_size(sdp) - 1);
 683			goto fail_jindex;
 684		}
 685		sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
 686
 687		error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
 688					  &gfs2_journal_glops,
 689					  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
 690					  &sdp->sd_journal_gh);
 691		if (error) {
 692			fs_err(sdp, "can't acquire journal glock: %d\n", error);
 693			goto fail_jindex;
 694		}
 695
 696		ip = GFS2_I(sdp->sd_jdesc->jd_inode);
 697		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 698					   LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
 699					   &sdp->sd_jinode_gh);
 700		if (error) {
 701			fs_err(sdp, "can't acquire journal inode glock: %d\n",
 702			       error);
 703			goto fail_journal_gh;
 704		}
 705
 706		error = gfs2_jdesc_check(sdp->sd_jdesc);
 707		if (error) {
 708			fs_err(sdp, "my journal (%u) is bad: %d\n",
 709			       sdp->sd_jdesc->jd_jid, error);
 710			goto fail_jinode_gh;
 711		}
 712		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
 713		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
 714		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
 715
 716		/* Map the extents for this journal's blocks */
 717		map_journal_extents(sdp);
 718	}
 719	trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
 720
 721	if (sdp->sd_lockstruct.ls_first) {
 722		unsigned int x;
 723		for (x = 0; x < sdp->sd_journals; x++) {
 724			error = gfs2_recover_journal(gfs2_jdesc_find(sdp, x),
 725						     true);
 726			if (error) {
 727				fs_err(sdp, "error recovering journal %u: %d\n",
 728				       x, error);
 729				goto fail_jinode_gh;
 730			}
 731		}
 732
 733		gfs2_others_may_mount(sdp);
 734	} else if (!sdp->sd_args.ar_spectator) {
 735		error = gfs2_recover_journal(sdp->sd_jdesc, true);
 736		if (error) {
 737			fs_err(sdp, "error recovering my journal: %d\n", error);
 738			goto fail_jinode_gh;
 739		}
 740	}
 741
 742	set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
 743	gfs2_glock_dq_uninit(&ji_gh);
 744	jindex = 0;
 745
 746	return 0;
 747
 748fail_jinode_gh:
 749	if (!sdp->sd_args.ar_spectator)
 750		gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
 751fail_journal_gh:
 752	if (!sdp->sd_args.ar_spectator)
 753		gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
 754fail_jindex:
 755	gfs2_jindex_free(sdp);
 756	if (jindex)
 757		gfs2_glock_dq_uninit(&ji_gh);
 758fail:
 759	iput(sdp->sd_jindex);
 760	return error;
 761}
 762
 763
 764static int init_inodes(struct gfs2_sbd *sdp, int undo)
 765{
 766	int error = 0;
 767	struct gfs2_inode *ip;
 768	struct inode *master = sdp->sd_master_dir->d_inode;
 769
 770	if (undo)
 771		goto fail_qinode;
 772
 773	error = init_journal(sdp, undo);
 774	if (error)
 775		goto fail;
 776
 777	/* Read in the master statfs inode */
 778	sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
 779	if (IS_ERR(sdp->sd_statfs_inode)) {
 780		error = PTR_ERR(sdp->sd_statfs_inode);
 781		fs_err(sdp, "can't read in statfs inode: %d\n", error);
 782		goto fail_journal;
 783	}
 784
 785	/* Read in the resource index inode */
 786	sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
 787	if (IS_ERR(sdp->sd_rindex)) {
 788		error = PTR_ERR(sdp->sd_rindex);
 789		fs_err(sdp, "can't get resource index inode: %d\n", error);
 790		goto fail_statfs;
 791	}
 792	ip = GFS2_I(sdp->sd_rindex);
 793	sdp->sd_rindex_uptodate = 0;
 794
 795	/* Read in the quota inode */
 796	sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
 797	if (IS_ERR(sdp->sd_quota_inode)) {
 798		error = PTR_ERR(sdp->sd_quota_inode);
 799		fs_err(sdp, "can't get quota file inode: %d\n", error);
 800		goto fail_rindex;
 801	}
 802	return 0;
 803
 804fail_qinode:
 805	iput(sdp->sd_quota_inode);
 806fail_rindex:
 807	gfs2_clear_rgrpd(sdp);
 808	iput(sdp->sd_rindex);
 809fail_statfs:
 810	iput(sdp->sd_statfs_inode);
 811fail_journal:
 812	init_journal(sdp, UNDO);
 813fail:
 814	return error;
 815}
 816
 817static int init_per_node(struct gfs2_sbd *sdp, int undo)
 818{
 819	struct inode *pn = NULL;
 820	char buf[30];
 821	int error = 0;
 822	struct gfs2_inode *ip;
 823	struct inode *master = sdp->sd_master_dir->d_inode;
 824
 825	if (sdp->sd_args.ar_spectator)
 826		return 0;
 827
 828	if (undo)
 829		goto fail_qc_gh;
 830
 831	pn = gfs2_lookup_simple(master, "per_node");
 832	if (IS_ERR(pn)) {
 833		error = PTR_ERR(pn);
 834		fs_err(sdp, "can't find per_node directory: %d\n", error);
 835		return error;
 836	}
 837
 838	sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
 839	sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
 840	if (IS_ERR(sdp->sd_sc_inode)) {
 841		error = PTR_ERR(sdp->sd_sc_inode);
 842		fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
 843		goto fail;
 844	}
 845
 846	sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
 847	sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
 848	if (IS_ERR(sdp->sd_qc_inode)) {
 849		error = PTR_ERR(sdp->sd_qc_inode);
 850		fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
 851		goto fail_ut_i;
 852	}
 853
 854	iput(pn);
 855	pn = NULL;
 856
 857	ip = GFS2_I(sdp->sd_sc_inode);
 858	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
 859				   &sdp->sd_sc_gh);
 860	if (error) {
 861		fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
 862		goto fail_qc_i;
 863	}
 864
 865	ip = GFS2_I(sdp->sd_qc_inode);
 866	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
 867				   &sdp->sd_qc_gh);
 868	if (error) {
 869		fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
 870		goto fail_ut_gh;
 871	}
 872
 873	return 0;
 874
 875fail_qc_gh:
 876	gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
 877fail_ut_gh:
 878	gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
 879fail_qc_i:
 880	iput(sdp->sd_qc_inode);
 881fail_ut_i:
 882	iput(sdp->sd_sc_inode);
 883fail:
 884	if (pn)
 885		iput(pn);
 886	return error;
 887}
 888
 889static int init_threads(struct gfs2_sbd *sdp, int undo)
 890{
 891	struct task_struct *p;
 892	int error = 0;
 893
 894	if (undo)
 895		goto fail_quotad;
 896
 897	p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
 898	error = IS_ERR(p);
 899	if (error) {
 900		fs_err(sdp, "can't start logd thread: %d\n", error);
 901		return error;
 902	}
 903	sdp->sd_logd_process = p;
 904
 905	p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
 906	error = IS_ERR(p);
 907	if (error) {
 908		fs_err(sdp, "can't start quotad thread: %d\n", error);
 909		goto fail;
 910	}
 911	sdp->sd_quotad_process = p;
 912
 913	return 0;
 914
 915
 916fail_quotad:
 917	kthread_stop(sdp->sd_quotad_process);
 918fail:
 919	kthread_stop(sdp->sd_logd_process);
 920	return error;
 921}
 922
 923static const match_table_t nolock_tokens = {
 924	{ Opt_jid, "jid=%d\n", },
 925	{ Opt_err, NULL },
 926};
 927
 928static const struct lm_lockops nolock_ops = {
 929	.lm_proto_name = "lock_nolock",
 930	.lm_put_lock = gfs2_glock_free,
 931	.lm_tokens = &nolock_tokens,
 932};
 933
 934/**
 935 * gfs2_lm_mount - mount a locking protocol
 936 * @sdp: the filesystem
 937 * @args: mount arguments
 938 * @silent: if 1, don't complain if the FS isn't a GFS2 fs
 939 *
 940 * Returns: errno
 941 */
 942
 943static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
 944{
 945	const struct lm_lockops *lm;
 946	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 947	struct gfs2_args *args = &sdp->sd_args;
 948	const char *proto = sdp->sd_proto_name;
 949	const char *table = sdp->sd_table_name;
 950	const char *fsname;
 951	char *o, *options;
 952	int ret;
 953
 954	if (!strcmp("lock_nolock", proto)) {
 955		lm = &nolock_ops;
 956		sdp->sd_args.ar_localflocks = 1;
 957#ifdef CONFIG_GFS2_FS_LOCKING_DLM
 958	} else if (!strcmp("lock_dlm", proto)) {
 959		lm = &gfs2_dlm_ops;
 960#endif
 961	} else {
 962		printk(KERN_INFO "GFS2: can't find protocol %s\n", proto);
 963		return -ENOENT;
 964	}
 965
 966	fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
 967
 968	ls->ls_ops = lm;
 969	ls->ls_first = 1;
 970
 971	for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
 972		substring_t tmp[MAX_OPT_ARGS];
 973		int token, option;
 974
 975		if (!o || !*o)
 976			continue;
 977
 978		token = match_token(o, *lm->lm_tokens, tmp);
 979		switch (token) {
 980		case Opt_jid:
 981			ret = match_int(&tmp[0], &option);
 982			if (ret || option < 0) 
 983				goto hostdata_error;
 984			if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
 985				ls->ls_jid = option;
 986			break;
 987		case Opt_id:
 988			/* Obsolete, but left for backward compat purposes */
 989			break;
 990		case Opt_first:
 991			ret = match_int(&tmp[0], &option);
 992			if (ret || (option != 0 && option != 1))
 993				goto hostdata_error;
 994			ls->ls_first = option;
 995			break;
 996		case Opt_nodir:
 997			ret = match_int(&tmp[0], &option);
 998			if (ret || (option != 0 && option != 1))
 999				goto hostdata_error;
1000			ls->ls_nodir = option;
1001			break;
1002		case Opt_err:
1003		default:
1004hostdata_error:
1005			fs_info(sdp, "unknown hostdata (%s)\n", o);
1006			return -EINVAL;
1007		}
1008	}
1009
1010	if (sdp->sd_args.ar_spectator)
1011		snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s", table);
1012	else
1013		snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u", table,
1014			 sdp->sd_lockstruct.ls_jid);
1015
1016	fsname = strchr(table, ':');
1017	if (fsname)
1018		fsname++;
1019	if (lm->lm_mount == NULL) {
1020		fs_info(sdp, "Now mounting FS...\n");
1021		complete_all(&sdp->sd_locking_init);
1022		return 0;
1023	}
1024	ret = lm->lm_mount(sdp, fsname);
1025	if (ret == 0)
1026		fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1027	complete_all(&sdp->sd_locking_init);
1028	return ret;
1029}
1030
1031void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1032{
1033	const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1034	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1035	    lm->lm_unmount)
1036		lm->lm_unmount(sdp);
1037}
1038
1039static int gfs2_journalid_wait(void *word)
1040{
1041	if (signal_pending(current))
1042		return -EINTR;
1043	schedule();
1044	return 0;
1045}
1046
1047static int wait_on_journal(struct gfs2_sbd *sdp)
1048{
1049	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1050		return 0;
1051
1052	return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, gfs2_journalid_wait, TASK_INTERRUPTIBLE);
1053}
1054
1055void gfs2_online_uevent(struct gfs2_sbd *sdp)
1056{
1057	struct super_block *sb = sdp->sd_vfs;
1058	char ro[20];
1059	char spectator[20];
1060	char *envp[] = { ro, spectator, NULL };
1061	sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1062	sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1063	kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1064}
1065
1066/**
1067 * fill_super - Read in superblock
1068 * @sb: The VFS superblock
1069 * @data: Mount options
1070 * @silent: Don't complain if it's not a GFS2 filesystem
1071 *
1072 * Returns: errno
1073 */
1074
1075static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1076{
1077	struct gfs2_sbd *sdp;
1078	struct gfs2_holder mount_gh;
1079	int error;
1080
1081	sdp = init_sbd(sb);
1082	if (!sdp) {
1083		printk(KERN_WARNING "GFS2: can't alloc struct gfs2_sbd\n");
1084		return -ENOMEM;
1085	}
1086	sdp->sd_args = *args;
1087
1088	if (sdp->sd_args.ar_spectator) {
1089                sb->s_flags |= MS_RDONLY;
1090		set_bit(SDF_NORECOVERY, &sdp->sd_flags);
1091	}
1092	if (sdp->sd_args.ar_posix_acl)
1093		sb->s_flags |= MS_POSIXACL;
1094	if (sdp->sd_args.ar_nobarrier)
1095		set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1096
1097	sb->s_flags |= MS_NOSEC;
1098	sb->s_magic = GFS2_MAGIC;
1099	sb->s_op = &gfs2_super_ops;
1100	sb->s_d_op = &gfs2_dops;
1101	sb->s_export_op = &gfs2_export_ops;
1102	sb->s_xattr = gfs2_xattr_handlers;
1103	sb->s_qcop = &gfs2_quotactl_ops;
1104	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1105	sb->s_time_gran = 1;
1106	sb->s_maxbytes = MAX_LFS_FILESIZE;
1107
1108	/* Set up the buffer cache and fill in some fake block size values
1109	   to allow us to read-in the on-disk superblock. */
1110	sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1111	sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1112	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1113                               GFS2_BASIC_BLOCK_SHIFT;
1114	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1115
1116	sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1117	sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1118	if (sdp->sd_args.ar_statfs_quantum) {
1119		sdp->sd_tune.gt_statfs_slow = 0;
1120		sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1121	} else {
1122		sdp->sd_tune.gt_statfs_slow = 1;
1123		sdp->sd_tune.gt_statfs_quantum = 30;
1124	}
1125
1126	error = init_names(sdp, silent);
1127	if (error)
1128		goto fail;
1129
1130	gfs2_create_debugfs_file(sdp);
1131
1132	error = gfs2_sys_fs_add(sdp);
1133	if (error)
1134		goto fail;
1135
1136	error = gfs2_lm_mount(sdp, silent);
1137	if (error)
1138		goto fail_sys;
1139
1140	error = init_locking(sdp, &mount_gh, DO);
1141	if (error)
1142		goto fail_lm;
1143
1144	error = init_sb(sdp, silent);
1145	if (error)
1146		goto fail_locking;
1147
1148	error = wait_on_journal(sdp);
1149	if (error)
1150		goto fail_sb;
1151
1152	/*
1153	 * If user space has failed to join the cluster or some similar
1154	 * failure has occurred, then the journal id will contain a
1155	 * negative (error) number. This will then be returned to the
1156	 * caller (of the mount syscall). We do this even for spectator
1157	 * mounts (which just write a jid of 0 to indicate "ok" even though
1158	 * the jid is unused in the spectator case)
1159	 */
1160	if (sdp->sd_lockstruct.ls_jid < 0) {
1161		error = sdp->sd_lockstruct.ls_jid;
1162		sdp->sd_lockstruct.ls_jid = 0;
1163		goto fail_sb;
1164	}
1165
1166	error = init_inodes(sdp, DO);
1167	if (error)
1168		goto fail_sb;
1169
1170	error = init_per_node(sdp, DO);
1171	if (error)
1172		goto fail_inodes;
1173
1174	error = gfs2_statfs_init(sdp);
1175	if (error) {
1176		fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1177		goto fail_per_node;
1178	}
1179
1180	error = init_threads(sdp, DO);
1181	if (error)
1182		goto fail_per_node;
1183
1184	if (!(sb->s_flags & MS_RDONLY)) {
1185		error = gfs2_make_fs_rw(sdp);
1186		if (error) {
1187			fs_err(sdp, "can't make FS RW: %d\n", error);
1188			goto fail_threads;
1189		}
1190	}
1191
1192	gfs2_glock_dq_uninit(&mount_gh);
1193	gfs2_online_uevent(sdp);
1194	return 0;
1195
1196fail_threads:
1197	init_threads(sdp, UNDO);
1198fail_per_node:
1199	init_per_node(sdp, UNDO);
1200fail_inodes:
1201	init_inodes(sdp, UNDO);
1202fail_sb:
1203	if (sdp->sd_root_dir)
1204		dput(sdp->sd_root_dir);
1205	if (sdp->sd_master_dir)
1206		dput(sdp->sd_master_dir);
1207	if (sb->s_root)
1208		dput(sb->s_root);
1209	sb->s_root = NULL;
1210fail_locking:
1211	init_locking(sdp, &mount_gh, UNDO);
1212fail_lm:
1213	gfs2_gl_hash_clear(sdp);
1214	gfs2_lm_unmount(sdp);
1215fail_sys:
1216	gfs2_sys_fs_del(sdp);
1217fail:
1218	gfs2_delete_debugfs_file(sdp);
1219	kfree(sdp);
1220	sb->s_fs_info = NULL;
1221	return error;
1222}
1223
1224static int set_gfs2_super(struct super_block *s, void *data)
1225{
1226	s->s_bdev = data;
1227	s->s_dev = s->s_bdev->bd_dev;
1228
1229	/*
1230	 * We set the bdi here to the queue backing, file systems can
1231	 * overwrite this in ->fill_super()
1232	 */
1233	s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1234	return 0;
1235}
1236
1237static int test_gfs2_super(struct super_block *s, void *ptr)
1238{
1239	struct block_device *bdev = ptr;
1240	return (bdev == s->s_bdev);
1241}
1242
1243/**
1244 * gfs2_mount - Get the GFS2 superblock
1245 * @fs_type: The GFS2 filesystem type
1246 * @flags: Mount flags
1247 * @dev_name: The name of the device
1248 * @data: The mount arguments
1249 *
1250 * Q. Why not use get_sb_bdev() ?
1251 * A. We need to select one of two root directories to mount, independent
1252 *    of whether this is the initial, or subsequent, mount of this sb
1253 *
1254 * Returns: 0 or -ve on error
1255 */
1256
1257static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1258		       const char *dev_name, void *data)
1259{
1260	struct block_device *bdev;
1261	struct super_block *s;
1262	fmode_t mode = FMODE_READ | FMODE_EXCL;
1263	int error;
1264	struct gfs2_args args;
1265	struct gfs2_sbd *sdp;
1266
1267	if (!(flags & MS_RDONLY))
1268		mode |= FMODE_WRITE;
1269
1270	bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1271	if (IS_ERR(bdev))
1272		return ERR_CAST(bdev);
1273
1274	/*
1275	 * once the super is inserted into the list by sget, s_umount
1276	 * will protect the lockfs code from trying to start a snapshot
1277	 * while we are mounting
1278	 */
1279	mutex_lock(&bdev->bd_fsfreeze_mutex);
1280	if (bdev->bd_fsfreeze_count > 0) {
1281		mutex_unlock(&bdev->bd_fsfreeze_mutex);
1282		error = -EBUSY;
1283		goto error_bdev;
1284	}
1285	s = sget(fs_type, test_gfs2_super, set_gfs2_super, bdev);
1286	mutex_unlock(&bdev->bd_fsfreeze_mutex);
1287	error = PTR_ERR(s);
1288	if (IS_ERR(s))
1289		goto error_bdev;
1290
1291	if (s->s_root)
1292		blkdev_put(bdev, mode);
1293
1294	memset(&args, 0, sizeof(args));
1295	args.ar_quota = GFS2_QUOTA_DEFAULT;
1296	args.ar_data = GFS2_DATA_DEFAULT;
1297	args.ar_commit = 30;
1298	args.ar_statfs_quantum = 30;
1299	args.ar_quota_quantum = 60;
1300	args.ar_errors = GFS2_ERRORS_DEFAULT;
1301
1302	error = gfs2_mount_args(&args, data);
1303	if (error) {
1304		printk(KERN_WARNING "GFS2: can't parse mount arguments\n");
1305		goto error_super;
1306	}
1307
1308	if (s->s_root) {
1309		error = -EBUSY;
1310		if ((flags ^ s->s_flags) & MS_RDONLY)
1311			goto error_super;
1312	} else {
1313		char b[BDEVNAME_SIZE];
1314
1315		s->s_flags = flags;
1316		s->s_mode = mode;
1317		strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1318		sb_set_blocksize(s, block_size(bdev));
1319		error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1320		if (error)
1321			goto error_super;
1322		s->s_flags |= MS_ACTIVE;
1323		bdev->bd_super = s;
1324	}
1325
1326	sdp = s->s_fs_info;
1327	if (args.ar_meta)
1328		return dget(sdp->sd_master_dir);
1329	else
1330		return dget(sdp->sd_root_dir);
1331
1332error_super:
1333	deactivate_locked_super(s);
1334	return ERR_PTR(error);
1335error_bdev:
1336	blkdev_put(bdev, mode);
1337	return ERR_PTR(error);
1338}
1339
1340static int set_meta_super(struct super_block *s, void *ptr)
1341{
1342	return -EINVAL;
1343}
1344
1345static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1346			int flags, const char *dev_name, void *data)
1347{
1348	struct super_block *s;
1349	struct gfs2_sbd *sdp;
1350	struct path path;
1351	int error;
1352
1353	error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1354	if (error) {
1355		printk(KERN_WARNING "GFS2: path_lookup on %s returned error %d\n",
1356		       dev_name, error);
1357		return ERR_PTR(error);
1358	}
1359	s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super,
1360		 path.dentry->d_inode->i_sb->s_bdev);
1361	path_put(&path);
1362	if (IS_ERR(s)) {
1363		printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n");
1364		return ERR_CAST(s);
1365	}
1366	if ((flags ^ s->s_flags) & MS_RDONLY) {
1367		deactivate_locked_super(s);
1368		return ERR_PTR(-EBUSY);
1369	}
1370	sdp = s->s_fs_info;
1371	return dget(sdp->sd_master_dir);
1372}
1373
1374static void gfs2_kill_sb(struct super_block *sb)
1375{
1376	struct gfs2_sbd *sdp = sb->s_fs_info;
1377
1378	if (sdp == NULL) {
1379		kill_block_super(sb);
1380		return;
1381	}
1382
1383	gfs2_meta_syncfs(sdp);
1384	dput(sdp->sd_root_dir);
1385	dput(sdp->sd_master_dir);
1386	sdp->sd_root_dir = NULL;
1387	sdp->sd_master_dir = NULL;
1388	shrink_dcache_sb(sb);
1389	kill_block_super(sb);
1390	gfs2_delete_debugfs_file(sdp);
1391	kfree(sdp);
1392}
1393
1394struct file_system_type gfs2_fs_type = {
1395	.name = "gfs2",
1396	.fs_flags = FS_REQUIRES_DEV,
1397	.mount = gfs2_mount,
1398	.kill_sb = gfs2_kill_sb,
1399	.owner = THIS_MODULE,
1400};
1401
1402struct file_system_type gfs2meta_fs_type = {
1403	.name = "gfs2meta",
1404	.fs_flags = FS_REQUIRES_DEV,
1405	.mount = gfs2_mount_meta,
1406	.owner = THIS_MODULE,
1407};
1408