1/*
   2 * This file is part of UBIFS.
   3 *
   4 * Copyright (C) 2006-2008 Nokia Corporation.
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms of the GNU General Public License version 2 as published by
   8 * the Free Software Foundation.
   9 *
  10 * This program is distributed in the hope that it will be useful, but WITHOUT
  11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13 * more details.
  14 *
  15 * You should have received a copy of the GNU General Public License along with
  16 * this program; if not, write to the Free Software Foundation, Inc., 51
  17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18 *
  19 * Authors: Artem Bityutskiy (Битюцкий Артём)
  20 *          Adrian Hunter
  21 */
  22
  23/*
  24 * This file implements UBIFS initialization and VFS superblock operations. Some
  25 * initialization stuff which is rather large and complex is placed at
  26 * corresponding subsystems, but most of it is here.
  27 */
  28
  29#include <linux/init.h>
  30#include <linux/slab.h>
  31#include <linux/module.h>
  32#include <linux/ctype.h>
  33#include <linux/kthread.h>
  34#include <linux/parser.h>
  35#include <linux/seq_file.h>
  36#include <linux/mount.h>
  37#include <linux/math64.h>
  38#include <linux/writeback.h>
  39#include "ubifs.h"
  40
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  41/*
  42 * Maximum amount of memory we may 'kmalloc()' without worrying that we are
  43 * allocating too much.
  44 */
  45#define UBIFS_KMALLOC_OK (128*1024)
  46
  47/* Slab cache for UBIFS inodes */
  48struct kmem_cache *ubifs_inode_slab;
  49
  50/* UBIFS TNC shrinker description */
  51static struct shrinker ubifs_shrinker_info = {
  52	.scan_objects = ubifs_shrink_scan,
  53	.count_objects = ubifs_shrink_count,
  54	.seeks = DEFAULT_SEEKS,
  55};
  56
  57/**
  58 * validate_inode - validate inode.
  59 * @c: UBIFS file-system description object
  60 * @inode: the inode to validate
  61 *
  62 * This is a helper function for 'ubifs_iget()' which validates various fields
  63 * of a newly built inode to make sure they contain sane values and prevent
  64 * possible vulnerabilities. Returns zero if the inode is all right and
  65 * a non-zero error code if not.
  66 */
  67static int validate_inode(struct ubifs_info *c, const struct inode *inode)
  68{
  69	int err;
  70	const struct ubifs_inode *ui = ubifs_inode(inode);
  71
  72	if (inode->i_size > c->max_inode_sz) {
  73		ubifs_err(c, "inode is too large (%lld)",
  74			  (long long)inode->i_size);
  75		return 1;
  76	}
  77
  78	if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
  79		ubifs_err(c, "unknown compression type %d", ui->compr_type);
  80		return 2;
  81	}
  82
  83	if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
  84		return 3;
  85
  86	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
  87		return 4;
  88
  89	if (ui->xattr && !S_ISREG(inode->i_mode))
  90		return 5;
  91
  92	if (!ubifs_compr_present(ui->compr_type)) {
  93		ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",
  94			   inode->i_ino, ubifs_compr_name(ui->compr_type));
  95	}
  96
  97	err = dbg_check_dir(c, inode);
  98	return err;
  99}
 100
 101struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 102{
 103	int err;
 104	union ubifs_key key;
 105	struct ubifs_ino_node *ino;
 106	struct ubifs_info *c = sb->s_fs_info;
 107	struct inode *inode;
 108	struct ubifs_inode *ui;
 109
 110	dbg_gen("inode %lu", inum);
 111
 112	inode = iget_locked(sb, inum);
 113	if (!inode)
 114		return ERR_PTR(-ENOMEM);
 115	if (!(inode->i_state & I_NEW))
 116		return inode;
 117	ui = ubifs_inode(inode);
 118
 119	ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
 120	if (!ino) {
 121		err = -ENOMEM;
 122		goto out;
 123	}
 124
 125	ino_key_init(c, &key, inode->i_ino);
 126
 127	err = ubifs_tnc_lookup(c, &key, ino);
 128	if (err)
 129		goto out_ino;
 130
 131	inode->i_flags |= S_NOCMTIME;
 132#ifndef CONFIG_UBIFS_ATIME_SUPPORT
 133	inode->i_flags |= S_NOATIME;
 134#endif
 
 135	set_nlink(inode, le32_to_cpu(ino->nlink));
 136	i_uid_write(inode, le32_to_cpu(ino->uid));
 137	i_gid_write(inode, le32_to_cpu(ino->gid));
 138	inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
 139	inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
 140	inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
 141	inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
 142	inode->i_ctime.tv_sec  = (int64_t)le64_to_cpu(ino->ctime_sec);
 143	inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
 144	inode->i_mode = le32_to_cpu(ino->mode);
 145	inode->i_size = le64_to_cpu(ino->size);
 146
 147	ui->data_len    = le32_to_cpu(ino->data_len);
 148	ui->flags       = le32_to_cpu(ino->flags);
 149	ui->compr_type  = le16_to_cpu(ino->compr_type);
 150	ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
 151	ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
 152	ui->xattr_size  = le32_to_cpu(ino->xattr_size);
 153	ui->xattr_names = le32_to_cpu(ino->xattr_names);
 154	ui->synced_i_size = ui->ui_size = inode->i_size;
 155
 156	ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
 157
 158	err = validate_inode(c, inode);
 159	if (err)
 160		goto out_invalid;
 161
 162	switch (inode->i_mode & S_IFMT) {
 163	case S_IFREG:
 164		inode->i_mapping->a_ops = &ubifs_file_address_operations;
 165		inode->i_op = &ubifs_file_inode_operations;
 166		inode->i_fop = &ubifs_file_operations;
 167		if (ui->xattr) {
 168			ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
 169			if (!ui->data) {
 170				err = -ENOMEM;
 171				goto out_ino;
 172			}
 173			memcpy(ui->data, ino->data, ui->data_len);
 174			((char *)ui->data)[ui->data_len] = '\0';
 175		} else if (ui->data_len != 0) {
 176			err = 10;
 177			goto out_invalid;
 178		}
 179		break;
 180	case S_IFDIR:
 181		inode->i_op  = &ubifs_dir_inode_operations;
 182		inode->i_fop = &ubifs_dir_operations;
 183		if (ui->data_len != 0) {
 184			err = 11;
 185			goto out_invalid;
 186		}
 187		break;
 188	case S_IFLNK:
 189		inode->i_op = &ubifs_symlink_inode_operations;
 190		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
 191			err = 12;
 192			goto out_invalid;
 193		}
 194		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
 195		if (!ui->data) {
 196			err = -ENOMEM;
 197			goto out_ino;
 198		}
 199		memcpy(ui->data, ino->data, ui->data_len);
 200		((char *)ui->data)[ui->data_len] = '\0';
 201		inode->i_link = ui->data;
 202		break;
 203	case S_IFBLK:
 204	case S_IFCHR:
 205	{
 206		dev_t rdev;
 207		union ubifs_dev_desc *dev;
 208
 209		ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
 210		if (!ui->data) {
 211			err = -ENOMEM;
 212			goto out_ino;
 213		}
 214
 215		dev = (union ubifs_dev_desc *)ino->data;
 216		if (ui->data_len == sizeof(dev->new))
 217			rdev = new_decode_dev(le32_to_cpu(dev->new));
 218		else if (ui->data_len == sizeof(dev->huge))
 219			rdev = huge_decode_dev(le64_to_cpu(dev->huge));
 220		else {
 221			err = 13;
 222			goto out_invalid;
 223		}
 224		memcpy(ui->data, ino->data, ui->data_len);
 225		inode->i_op = &ubifs_file_inode_operations;
 226		init_special_inode(inode, inode->i_mode, rdev);
 227		break;
 228	}
 229	case S_IFSOCK:
 230	case S_IFIFO:
 231		inode->i_op = &ubifs_file_inode_operations;
 232		init_special_inode(inode, inode->i_mode, 0);
 233		if (ui->data_len != 0) {
 234			err = 14;
 235			goto out_invalid;
 236		}
 237		break;
 238	default:
 239		err = 15;
 240		goto out_invalid;
 241	}
 242
 243	kfree(ino);
 244	ubifs_set_inode_flags(inode);
 245	unlock_new_inode(inode);
 246	return inode;
 247
 248out_invalid:
 249	ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);
 250	ubifs_dump_node(c, ino);
 251	ubifs_dump_inode(c, inode);
 252	err = -EINVAL;
 253out_ino:
 254	kfree(ino);
 255out:
 256	ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);
 257	iget_failed(inode);
 258	return ERR_PTR(err);
 259}
 260
 261static struct inode *ubifs_alloc_inode(struct super_block *sb)
 262{
 263	struct ubifs_inode *ui;
 264
 265	ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
 266	if (!ui)
 267		return NULL;
 268
 269	memset((void *)ui + sizeof(struct inode), 0,
 270	       sizeof(struct ubifs_inode) - sizeof(struct inode));
 271	mutex_init(&ui->ui_mutex);
 
 272	spin_lock_init(&ui->ui_lock);
 273	return &ui->vfs_inode;
 274};
 275
 276static void ubifs_i_callback(struct rcu_head *head)
 277{
 278	struct inode *inode = container_of(head, struct inode, i_rcu);
 279	struct ubifs_inode *ui = ubifs_inode(inode);
 280	kmem_cache_free(ubifs_inode_slab, ui);
 281}
 282
 283static void ubifs_destroy_inode(struct inode *inode)
 284{
 285	struct ubifs_inode *ui = ubifs_inode(inode);
 286
 287	kfree(ui->data);
 288	call_rcu(&inode->i_rcu, ubifs_i_callback);
 
 
 289}
 290
 291/*
 292 * Note, Linux write-back code calls this without 'i_mutex'.
 293 */
 294static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
 295{
 296	int err = 0;
 297	struct ubifs_info *c = inode->i_sb->s_fs_info;
 298	struct ubifs_inode *ui = ubifs_inode(inode);
 299
 300	ubifs_assert(!ui->xattr);
 301	if (is_bad_inode(inode))
 302		return 0;
 303
 304	mutex_lock(&ui->ui_mutex);
 305	/*
 306	 * Due to races between write-back forced by budgeting
 307	 * (see 'sync_some_inodes()') and background write-back, the inode may
 308	 * have already been synchronized, do not do this again. This might
 309	 * also happen if it was synchronized in an VFS operation, e.g.
 310	 * 'ubifs_link()'.
 311	 */
 312	if (!ui->dirty) {
 313		mutex_unlock(&ui->ui_mutex);
 314		return 0;
 315	}
 316
 317	/*
 318	 * As an optimization, do not write orphan inodes to the media just
 319	 * because this is not needed.
 320	 */
 321	dbg_gen("inode %lu, mode %#x, nlink %u",
 322		inode->i_ino, (int)inode->i_mode, inode->i_nlink);
 323	if (inode->i_nlink) {
 324		err = ubifs_jnl_write_inode(c, inode);
 325		if (err)
 326			ubifs_err(c, "can't write inode %lu, error %d",
 327				  inode->i_ino, err);
 328		else
 329			err = dbg_check_inode_size(c, inode, ui->ui_size);
 330	}
 331
 332	ui->dirty = 0;
 333	mutex_unlock(&ui->ui_mutex);
 334	ubifs_release_dirty_inode_budget(c, ui);
 335	return err;
 336}
 337
 
 
 
 
 
 
 
 
 
 
 338static void ubifs_evict_inode(struct inode *inode)
 339{
 340	int err;
 341	struct ubifs_info *c = inode->i_sb->s_fs_info;
 342	struct ubifs_inode *ui = ubifs_inode(inode);
 343
 344	if (ui->xattr)
 345		/*
 346		 * Extended attribute inode deletions are fully handled in
 347		 * 'ubifs_removexattr()'. These inodes are special and have
 348		 * limited usage, so there is nothing to do here.
 349		 */
 350		goto out;
 351
 352	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
 353	ubifs_assert(!atomic_read(&inode->i_count));
 354
 355	truncate_inode_pages_final(&inode->i_data);
 356
 357	if (inode->i_nlink)
 358		goto done;
 359
 360	if (is_bad_inode(inode))
 361		goto out;
 362
 363	ui->ui_size = inode->i_size = 0;
 364	err = ubifs_jnl_delete_inode(c, inode);
 365	if (err)
 366		/*
 367		 * Worst case we have a lost orphan inode wasting space, so a
 368		 * simple error message is OK here.
 369		 */
 370		ubifs_err(c, "can't delete inode %lu, error %d",
 371			  inode->i_ino, err);
 372
 373out:
 374	if (ui->dirty)
 375		ubifs_release_dirty_inode_budget(c, ui);
 376	else {
 377		/* We've deleted something - clean the "no space" flags */
 378		c->bi.nospace = c->bi.nospace_rp = 0;
 379		smp_wmb();
 380	}
 381done:
 382	clear_inode(inode);
 
 383}
 384
 385static void ubifs_dirty_inode(struct inode *inode, int flags)
 386{
 
 387	struct ubifs_inode *ui = ubifs_inode(inode);
 388
 389	ubifs_assert(mutex_is_locked(&ui->ui_mutex));
 390	if (!ui->dirty) {
 391		ui->dirty = 1;
 392		dbg_gen("inode %lu",  inode->i_ino);
 393	}
 394}
 395
 396static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
 397{
 398	struct ubifs_info *c = dentry->d_sb->s_fs_info;
 399	unsigned long long free;
 400	__le32 *uuid = (__le32 *)c->uuid;
 401
 402	free = ubifs_get_free_space(c);
 403	dbg_gen("free space %lld bytes (%lld blocks)",
 404		free, free >> UBIFS_BLOCK_SHIFT);
 405
 406	buf->f_type = UBIFS_SUPER_MAGIC;
 407	buf->f_bsize = UBIFS_BLOCK_SIZE;
 408	buf->f_blocks = c->block_cnt;
 409	buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
 410	if (free > c->report_rp_size)
 411		buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
 412	else
 413		buf->f_bavail = 0;
 414	buf->f_files = 0;
 415	buf->f_ffree = 0;
 416	buf->f_namelen = UBIFS_MAX_NLEN;
 417	buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
 418	buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
 419	ubifs_assert(buf->f_bfree <= c->block_cnt);
 420	return 0;
 421}
 422
 423static int ubifs_show_options(struct seq_file *s, struct dentry *root)
 424{
 425	struct ubifs_info *c = root->d_sb->s_fs_info;
 426
 427	if (c->mount_opts.unmount_mode == 2)
 428		seq_puts(s, ",fast_unmount");
 429	else if (c->mount_opts.unmount_mode == 1)
 430		seq_puts(s, ",norm_unmount");
 431
 432	if (c->mount_opts.bulk_read == 2)
 433		seq_puts(s, ",bulk_read");
 434	else if (c->mount_opts.bulk_read == 1)
 435		seq_puts(s, ",no_bulk_read");
 436
 437	if (c->mount_opts.chk_data_crc == 2)
 438		seq_puts(s, ",chk_data_crc");
 439	else if (c->mount_opts.chk_data_crc == 1)
 440		seq_puts(s, ",no_chk_data_crc");
 441
 442	if (c->mount_opts.override_compr) {
 443		seq_printf(s, ",compr=%s",
 444			   ubifs_compr_name(c->mount_opts.compr_type));
 445	}
 446
 
 
 
 447	return 0;
 448}
 449
 450static int ubifs_sync_fs(struct super_block *sb, int wait)
 451{
 452	int i, err;
 453	struct ubifs_info *c = sb->s_fs_info;
 454
 455	/*
 456	 * Zero @wait is just an advisory thing to help the file system shove
 457	 * lots of data into the queues, and there will be the second
 458	 * '->sync_fs()' call, with non-zero @wait.
 459	 */
 460	if (!wait)
 461		return 0;
 462
 463	/*
 464	 * Synchronize write buffers, because 'ubifs_run_commit()' does not
 465	 * do this if it waits for an already running commit.
 466	 */
 467	for (i = 0; i < c->jhead_cnt; i++) {
 468		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
 469		if (err)
 470			return err;
 471	}
 472
 473	/*
 474	 * Strictly speaking, it is not necessary to commit the journal here,
 475	 * synchronizing write-buffers would be enough. But committing makes
 476	 * UBIFS free space predictions much more accurate, so we want to let
 477	 * the user be able to get more accurate results of 'statfs()' after
 478	 * they synchronize the file system.
 479	 */
 480	err = ubifs_run_commit(c);
 481	if (err)
 482		return err;
 483
 484	return ubi_sync(c->vi.ubi_num);
 485}
 486
 487/**
 488 * init_constants_early - initialize UBIFS constants.
 489 * @c: UBIFS file-system description object
 490 *
 491 * This function initialize UBIFS constants which do not need the superblock to
 492 * be read. It also checks that the UBI volume satisfies basic UBIFS
 493 * requirements. Returns zero in case of success and a negative error code in
 494 * case of failure.
 495 */
 496static int init_constants_early(struct ubifs_info *c)
 497{
 498	if (c->vi.corrupted) {
 499		ubifs_warn(c, "UBI volume is corrupted - read-only mode");
 500		c->ro_media = 1;
 501	}
 502
 503	if (c->di.ro_mode) {
 504		ubifs_msg(c, "read-only UBI device");
 505		c->ro_media = 1;
 506	}
 507
 508	if (c->vi.vol_type == UBI_STATIC_VOLUME) {
 509		ubifs_msg(c, "static UBI volume - read-only mode");
 510		c->ro_media = 1;
 511	}
 512
 513	c->leb_cnt = c->vi.size;
 514	c->leb_size = c->vi.usable_leb_size;
 515	c->leb_start = c->di.leb_start;
 516	c->half_leb_size = c->leb_size / 2;
 517	c->min_io_size = c->di.min_io_size;
 518	c->min_io_shift = fls(c->min_io_size) - 1;
 519	c->max_write_size = c->di.max_write_size;
 520	c->max_write_shift = fls(c->max_write_size) - 1;
 521
 522	if (c->leb_size < UBIFS_MIN_LEB_SZ) {
 523		ubifs_err(c, "too small LEBs (%d bytes), min. is %d bytes",
 524			  c->leb_size, UBIFS_MIN_LEB_SZ);
 525		return -EINVAL;
 526	}
 527
 528	if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
 529		ubifs_err(c, "too few LEBs (%d), min. is %d",
 530			  c->leb_cnt, UBIFS_MIN_LEB_CNT);
 531		return -EINVAL;
 532	}
 533
 534	if (!is_power_of_2(c->min_io_size)) {
 535		ubifs_err(c, "bad min. I/O size %d", c->min_io_size);
 536		return -EINVAL;
 537	}
 538
 539	/*
 540	 * Maximum write size has to be greater or equivalent to min. I/O
 541	 * size, and be multiple of min. I/O size.
 542	 */
 543	if (c->max_write_size < c->min_io_size ||
 544	    c->max_write_size % c->min_io_size ||
 545	    !is_power_of_2(c->max_write_size)) {
 546		ubifs_err(c, "bad write buffer size %d for %d min. I/O unit",
 547			  c->max_write_size, c->min_io_size);
 548		return -EINVAL;
 549	}
 550
 551	/*
 552	 * UBIFS aligns all node to 8-byte boundary, so to make function in
 553	 * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
 554	 * less than 8.
 555	 */
 556	if (c->min_io_size < 8) {
 557		c->min_io_size = 8;
 558		c->min_io_shift = 3;
 559		if (c->max_write_size < c->min_io_size) {
 560			c->max_write_size = c->min_io_size;
 561			c->max_write_shift = c->min_io_shift;
 562		}
 563	}
 564
 565	c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
 566	c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
 567
 568	/*
 569	 * Initialize node length ranges which are mostly needed for node
 570	 * length validation.
 571	 */
 572	c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
 573	c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
 574	c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
 575	c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
 576	c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
 577	c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
 
 
 
 
 
 578
 579	c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
 580	c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
 581	c->ranges[UBIFS_ORPH_NODE].min_len =
 582				UBIFS_ORPH_NODE_SZ + sizeof(__le64);
 583	c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
 584	c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
 585	c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
 586	c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
 587	c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
 588	c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
 589	c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
 590	/*
 591	 * Minimum indexing node size is amended later when superblock is
 592	 * read and the key length is known.
 593	 */
 594	c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
 595	/*
 596	 * Maximum indexing node size is amended later when superblock is
 597	 * read and the fanout is known.
 598	 */
 599	c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
 600
 601	/*
 602	 * Initialize dead and dark LEB space watermarks. See gc.c for comments
 603	 * about these values.
 604	 */
 605	c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
 606	c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
 607
 608	/*
 609	 * Calculate how many bytes would be wasted at the end of LEB if it was
 610	 * fully filled with data nodes of maximum size. This is used in
 611	 * calculations when reporting free space.
 612	 */
 613	c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
 614
 615	/* Buffer size for bulk-reads */
 616	c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
 617	if (c->max_bu_buf_len > c->leb_size)
 618		c->max_bu_buf_len = c->leb_size;
 
 
 
 
 619	return 0;
 620}
 621
 622/**
 623 * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
 624 * @c: UBIFS file-system description object
 625 * @lnum: LEB the write-buffer was synchronized to
 626 * @free: how many free bytes left in this LEB
 627 * @pad: how many bytes were padded
 628 *
 629 * This is a callback function which is called by the I/O unit when the
 630 * write-buffer is synchronized. We need this to correctly maintain space
 631 * accounting in bud logical eraseblocks. This function returns zero in case of
 632 * success and a negative error code in case of failure.
 633 *
 634 * This function actually belongs to the journal, but we keep it here because
 635 * we want to keep it static.
 636 */
 637static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
 638{
 639	return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
 640}
 641
 642/*
 643 * init_constants_sb - initialize UBIFS constants.
 644 * @c: UBIFS file-system description object
 645 *
 646 * This is a helper function which initializes various UBIFS constants after
 647 * the superblock has been read. It also checks various UBIFS parameters and
 648 * makes sure they are all right. Returns zero in case of success and a
 649 * negative error code in case of failure.
 650 */
 651static int init_constants_sb(struct ubifs_info *c)
 652{
 653	int tmp, err;
 654	long long tmp64;
 655
 656	c->main_bytes = (long long)c->main_lebs * c->leb_size;
 657	c->max_znode_sz = sizeof(struct ubifs_znode) +
 658				c->fanout * sizeof(struct ubifs_zbranch);
 659
 660	tmp = ubifs_idx_node_sz(c, 1);
 661	c->ranges[UBIFS_IDX_NODE].min_len = tmp;
 662	c->min_idx_node_sz = ALIGN(tmp, 8);
 663
 664	tmp = ubifs_idx_node_sz(c, c->fanout);
 665	c->ranges[UBIFS_IDX_NODE].max_len = tmp;
 666	c->max_idx_node_sz = ALIGN(tmp, 8);
 667
 668	/* Make sure LEB size is large enough to fit full commit */
 669	tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
 670	tmp = ALIGN(tmp, c->min_io_size);
 671	if (tmp > c->leb_size) {
 672		ubifs_err(c, "too small LEB size %d, at least %d needed",
 673			  c->leb_size, tmp);
 674		return -EINVAL;
 675	}
 676
 677	/*
 678	 * Make sure that the log is large enough to fit reference nodes for
 679	 * all buds plus one reserved LEB.
 680	 */
 681	tmp64 = c->max_bud_bytes + c->leb_size - 1;
 682	c->max_bud_cnt = div_u64(tmp64, c->leb_size);
 683	tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
 684	tmp /= c->leb_size;
 685	tmp += 1;
 686	if (c->log_lebs < tmp) {
 687		ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",
 688			  c->log_lebs, tmp);
 689		return -EINVAL;
 690	}
 691
 692	/*
 693	 * When budgeting we assume worst-case scenarios when the pages are not
 694	 * be compressed and direntries are of the maximum size.
 695	 *
 696	 * Note, data, which may be stored in inodes is budgeted separately, so
 697	 * it is not included into 'c->bi.inode_budget'.
 698	 */
 699	c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
 700	c->bi.inode_budget = UBIFS_INO_NODE_SZ;
 701	c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
 702
 703	/*
 704	 * When the amount of flash space used by buds becomes
 705	 * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
 706	 * The writers are unblocked when the commit is finished. To avoid
 707	 * writers to be blocked UBIFS initiates background commit in advance,
 708	 * when number of bud bytes becomes above the limit defined below.
 709	 */
 710	c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
 711
 712	/*
 713	 * Ensure minimum journal size. All the bytes in the journal heads are
 714	 * considered to be used, when calculating the current journal usage.
 715	 * Consequently, if the journal is too small, UBIFS will treat it as
 716	 * always full.
 717	 */
 718	tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
 719	if (c->bg_bud_bytes < tmp64)
 720		c->bg_bud_bytes = tmp64;
 721	if (c->max_bud_bytes < tmp64 + c->leb_size)
 722		c->max_bud_bytes = tmp64 + c->leb_size;
 723
 724	err = ubifs_calc_lpt_geom(c);
 725	if (err)
 726		return err;
 727
 728	/* Initialize effective LEB size used in budgeting calculations */
 729	c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
 730	return 0;
 731}
 732
 733/*
 734 * init_constants_master - initialize UBIFS constants.
 735 * @c: UBIFS file-system description object
 736 *
 737 * This is a helper function which initializes various UBIFS constants after
 738 * the master node has been read. It also checks various UBIFS parameters and
 739 * makes sure they are all right.
 740 */
 741static void init_constants_master(struct ubifs_info *c)
 742{
 743	long long tmp64;
 744
 745	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
 746	c->report_rp_size = ubifs_reported_space(c, c->rp_size);
 747
 748	/*
 749	 * Calculate total amount of FS blocks. This number is not used
 750	 * internally because it does not make much sense for UBIFS, but it is
 751	 * necessary to report something for the 'statfs()' call.
 752	 *
 753	 * Subtract the LEB reserved for GC, the LEB which is reserved for
 754	 * deletions, minimum LEBs for the index, and assume only one journal
 755	 * head is available.
 756	 */
 757	tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
 758	tmp64 *= (long long)c->leb_size - c->leb_overhead;
 759	tmp64 = ubifs_reported_space(c, tmp64);
 760	c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
 761}
 762
 763/**
 764 * take_gc_lnum - reserve GC LEB.
 765 * @c: UBIFS file-system description object
 766 *
 767 * This function ensures that the LEB reserved for garbage collection is marked
 768 * as "taken" in lprops. We also have to set free space to LEB size and dirty
 769 * space to zero, because lprops may contain out-of-date information if the
 770 * file-system was un-mounted before it has been committed. This function
 771 * returns zero in case of success and a negative error code in case of
 772 * failure.
 773 */
 774static int take_gc_lnum(struct ubifs_info *c)
 775{
 776	int err;
 777
 778	if (c->gc_lnum == -1) {
 779		ubifs_err(c, "no LEB for GC");
 780		return -EINVAL;
 781	}
 782
 783	/* And we have to tell lprops that this LEB is taken */
 784	err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
 785				  LPROPS_TAKEN, 0, 0);
 786	return err;
 787}
 788
 789/**
 790 * alloc_wbufs - allocate write-buffers.
 791 * @c: UBIFS file-system description object
 792 *
 793 * This helper function allocates and initializes UBIFS write-buffers. Returns
 794 * zero in case of success and %-ENOMEM in case of failure.
 795 */
 796static int alloc_wbufs(struct ubifs_info *c)
 797{
 798	int i, err;
 799
 800	c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),
 801			    GFP_KERNEL);
 802	if (!c->jheads)
 803		return -ENOMEM;
 804
 805	/* Initialize journal heads */
 806	for (i = 0; i < c->jhead_cnt; i++) {
 807		INIT_LIST_HEAD(&c->jheads[i].buds_list);
 808		err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
 809		if (err)
 810			return err;
 811
 812		c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
 813		c->jheads[i].wbuf.jhead = i;
 814		c->jheads[i].grouped = 1;
 
 
 
 
 
 815	}
 816
 817	/*
 818	 * Garbage Collector head does not need to be synchronized by timer.
 819	 * Also GC head nodes are not grouped.
 820	 */
 821	c->jheads[GCHD].wbuf.no_timer = 1;
 822	c->jheads[GCHD].grouped = 0;
 823
 824	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 825}
 826
 827/**
 828 * free_wbufs - free write-buffers.
 829 * @c: UBIFS file-system description object
 830 */
 831static void free_wbufs(struct ubifs_info *c)
 832{
 833	int i;
 834
 835	if (c->jheads) {
 836		for (i = 0; i < c->jhead_cnt; i++) {
 837			kfree(c->jheads[i].wbuf.buf);
 838			kfree(c->jheads[i].wbuf.inodes);
 
 839		}
 840		kfree(c->jheads);
 841		c->jheads = NULL;
 842	}
 843}
 844
 845/**
 846 * free_orphans - free orphans.
 847 * @c: UBIFS file-system description object
 848 */
 849static void free_orphans(struct ubifs_info *c)
 850{
 851	struct ubifs_orphan *orph;
 852
 853	while (c->orph_dnext) {
 854		orph = c->orph_dnext;
 855		c->orph_dnext = orph->dnext;
 856		list_del(&orph->list);
 857		kfree(orph);
 858	}
 859
 860	while (!list_empty(&c->orph_list)) {
 861		orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
 862		list_del(&orph->list);
 863		kfree(orph);
 864		ubifs_err(c, "orphan list not empty at unmount");
 865	}
 866
 867	vfree(c->orph_buf);
 868	c->orph_buf = NULL;
 869}
 870
 871/**
 872 * free_buds - free per-bud objects.
 873 * @c: UBIFS file-system description object
 874 */
 875static void free_buds(struct ubifs_info *c)
 876{
 877	struct ubifs_bud *bud, *n;
 878
 879	rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
 
 880		kfree(bud);
 
 881}
 882
 883/**
 884 * check_volume_empty - check if the UBI volume is empty.
 885 * @c: UBIFS file-system description object
 886 *
 887 * This function checks if the UBIFS volume is empty by looking if its LEBs are
 888 * mapped or not. The result of checking is stored in the @c->empty variable.
 889 * Returns zero in case of success and a negative error code in case of
 890 * failure.
 891 */
 892static int check_volume_empty(struct ubifs_info *c)
 893{
 894	int lnum, err;
 895
 896	c->empty = 1;
 897	for (lnum = 0; lnum < c->leb_cnt; lnum++) {
 898		err = ubifs_is_mapped(c, lnum);
 899		if (unlikely(err < 0))
 900			return err;
 901		if (err == 1) {
 902			c->empty = 0;
 903			break;
 904		}
 905
 906		cond_resched();
 907	}
 908
 909	return 0;
 910}
 911
 912/*
 913 * UBIFS mount options.
 914 *
 915 * Opt_fast_unmount: do not run a journal commit before un-mounting
 916 * Opt_norm_unmount: run a journal commit before un-mounting
 917 * Opt_bulk_read: enable bulk-reads
 918 * Opt_no_bulk_read: disable bulk-reads
 919 * Opt_chk_data_crc: check CRCs when reading data nodes
 920 * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
 921 * Opt_override_compr: override default compressor
 
 
 
 922 * Opt_err: just end of array marker
 923 */
 924enum {
 925	Opt_fast_unmount,
 926	Opt_norm_unmount,
 927	Opt_bulk_read,
 928	Opt_no_bulk_read,
 929	Opt_chk_data_crc,
 930	Opt_no_chk_data_crc,
 931	Opt_override_compr,
 
 
 
 
 932	Opt_err,
 933};
 934
 935static const match_table_t tokens = {
 936	{Opt_fast_unmount, "fast_unmount"},
 937	{Opt_norm_unmount, "norm_unmount"},
 938	{Opt_bulk_read, "bulk_read"},
 939	{Opt_no_bulk_read, "no_bulk_read"},
 940	{Opt_chk_data_crc, "chk_data_crc"},
 941	{Opt_no_chk_data_crc, "no_chk_data_crc"},
 942	{Opt_override_compr, "compr=%s"},
 
 
 
 
 
 943	{Opt_err, NULL},
 944};
 945
 946/**
 947 * parse_standard_option - parse a standard mount option.
 948 * @option: the option to parse
 949 *
 950 * Normally, standard mount options like "sync" are passed to file-systems as
 951 * flags. However, when a "rootflags=" kernel boot parameter is used, they may
 952 * be present in the options string. This function tries to deal with this
 953 * situation and parse standard options. Returns 0 if the option was not
 954 * recognized, and the corresponding integer flag if it was.
 955 *
 956 * UBIFS is only interested in the "sync" option, so do not check for anything
 957 * else.
 958 */
 959static int parse_standard_option(const char *option)
 960{
 961
 962	pr_notice("UBIFS: parse %s\n", option);
 963	if (!strcmp(option, "sync"))
 964		return MS_SYNCHRONOUS;
 965	return 0;
 966}
 967
 968/**
 969 * ubifs_parse_options - parse mount parameters.
 970 * @c: UBIFS file-system description object
 971 * @options: parameters to parse
 972 * @is_remount: non-zero if this is FS re-mount
 973 *
 974 * This function parses UBIFS mount options and returns zero in case success
 975 * and a negative error code in case of failure.
 976 */
 977static int ubifs_parse_options(struct ubifs_info *c, char *options,
 978			       int is_remount)
 979{
 980	char *p;
 981	substring_t args[MAX_OPT_ARGS];
 982
 983	if (!options)
 984		return 0;
 985
 986	while ((p = strsep(&options, ","))) {
 987		int token;
 988
 989		if (!*p)
 990			continue;
 991
 992		token = match_token(p, tokens, args);
 993		switch (token) {
 994		/*
 995		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
 996		 * We accept them in order to be backward-compatible. But this
 997		 * should be removed at some point.
 998		 */
 999		case Opt_fast_unmount:
1000			c->mount_opts.unmount_mode = 2;
1001			break;
1002		case Opt_norm_unmount:
1003			c->mount_opts.unmount_mode = 1;
1004			break;
1005		case Opt_bulk_read:
1006			c->mount_opts.bulk_read = 2;
1007			c->bulk_read = 1;
1008			break;
1009		case Opt_no_bulk_read:
1010			c->mount_opts.bulk_read = 1;
1011			c->bulk_read = 0;
1012			break;
1013		case Opt_chk_data_crc:
1014			c->mount_opts.chk_data_crc = 2;
1015			c->no_chk_data_crc = 0;
1016			break;
1017		case Opt_no_chk_data_crc:
1018			c->mount_opts.chk_data_crc = 1;
1019			c->no_chk_data_crc = 1;
1020			break;
1021		case Opt_override_compr:
1022		{
1023			char *name = match_strdup(&args[0]);
1024
1025			if (!name)
1026				return -ENOMEM;
1027			if (!strcmp(name, "none"))
1028				c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1029			else if (!strcmp(name, "lzo"))
1030				c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1031			else if (!strcmp(name, "zlib"))
1032				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
 
 
1033			else {
1034				ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
1035				kfree(name);
1036				return -EINVAL;
1037			}
1038			kfree(name);
1039			c->mount_opts.override_compr = 1;
1040			c->default_compr = c->mount_opts.compr_type;
1041			break;
1042		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1043		default:
1044		{
1045			unsigned long flag;
1046			struct super_block *sb = c->vfs_sb;
1047
1048			flag = parse_standard_option(p);
1049			if (!flag) {
1050				ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
1051					  p);
1052				return -EINVAL;
1053			}
1054			sb->s_flags |= flag;
1055			break;
1056		}
1057		}
1058	}
1059
1060	return 0;
1061}
1062
 
 
 
 
 
 
 
 
 
 
 
 
1063/**
1064 * destroy_journal - destroy journal data structures.
1065 * @c: UBIFS file-system description object
1066 *
1067 * This function destroys journal data structures including those that may have
1068 * been created by recovery functions.
1069 */
1070static void destroy_journal(struct ubifs_info *c)
1071{
1072	while (!list_empty(&c->unclean_leb_list)) {
1073		struct ubifs_unclean_leb *ucleb;
1074
1075		ucleb = list_entry(c->unclean_leb_list.next,
1076				   struct ubifs_unclean_leb, list);
1077		list_del(&ucleb->list);
1078		kfree(ucleb);
1079	}
1080	while (!list_empty(&c->old_buds)) {
1081		struct ubifs_bud *bud;
1082
1083		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1084		list_del(&bud->list);
 
1085		kfree(bud);
1086	}
1087	ubifs_destroy_idx_gc(c);
1088	ubifs_destroy_size_tree(c);
1089	ubifs_tnc_close(c);
1090	free_buds(c);
1091}
1092
1093/**
1094 * bu_init - initialize bulk-read information.
1095 * @c: UBIFS file-system description object
1096 */
1097static void bu_init(struct ubifs_info *c)
1098{
1099	ubifs_assert(c->bulk_read == 1);
1100
1101	if (c->bu.buf)
1102		return; /* Already initialized */
1103
1104again:
1105	c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1106	if (!c->bu.buf) {
1107		if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1108			c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1109			goto again;
1110		}
1111
1112		/* Just disable bulk-read */
1113		ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
1114			   c->max_bu_buf_len);
1115		c->mount_opts.bulk_read = 1;
1116		c->bulk_read = 0;
1117		return;
1118	}
1119}
1120
1121/**
1122 * check_free_space - check if there is enough free space to mount.
1123 * @c: UBIFS file-system description object
1124 *
1125 * This function makes sure UBIFS has enough free space to be mounted in
1126 * read/write mode. UBIFS must always have some free space to allow deletions.
1127 */
1128static int check_free_space(struct ubifs_info *c)
1129{
1130	ubifs_assert(c->dark_wm > 0);
1131	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1132		ubifs_err(c, "insufficient free space to mount in R/W mode");
1133		ubifs_dump_budg(c, &c->bi);
1134		ubifs_dump_lprops(c);
1135		return -ENOSPC;
1136	}
1137	return 0;
1138}
1139
1140/**
1141 * mount_ubifs - mount UBIFS file-system.
1142 * @c: UBIFS file-system description object
1143 *
1144 * This function mounts UBIFS file system. Returns zero in case of success and
1145 * a negative error code in case of failure.
1146 */
1147static int mount_ubifs(struct ubifs_info *c)
1148{
1149	int err;
1150	long long x, y;
1151	size_t sz;
1152
1153	c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
1154	/* Suppress error messages while probing if MS_SILENT is set */
1155	c->probing = !!(c->vfs_sb->s_flags & MS_SILENT);
1156
1157	err = init_constants_early(c);
1158	if (err)
1159		return err;
1160
1161	err = ubifs_debugging_init(c);
1162	if (err)
1163		return err;
1164
 
 
 
 
1165	err = check_volume_empty(c);
1166	if (err)
1167		goto out_free;
1168
1169	if (c->empty && (c->ro_mount || c->ro_media)) {
1170		/*
1171		 * This UBI volume is empty, and read-only, or the file system
1172		 * is mounted read-only - we cannot format it.
1173		 */
1174		ubifs_err(c, "can't format empty UBI volume: read-only %s",
1175			  c->ro_media ? "UBI volume" : "mount");
1176		err = -EROFS;
1177		goto out_free;
1178	}
1179
1180	if (c->ro_media && !c->ro_mount) {
1181		ubifs_err(c, "cannot mount read-write - read-only media");
1182		err = -EROFS;
1183		goto out_free;
1184	}
1185
1186	/*
1187	 * The requirement for the buffer is that it should fit indexing B-tree
1188	 * height amount of integers. We assume the height if the TNC tree will
1189	 * never exceed 64.
1190	 */
1191	err = -ENOMEM;
1192	c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
 
1193	if (!c->bottom_up_buf)
1194		goto out_free;
1195
1196	c->sbuf = vmalloc(c->leb_size);
1197	if (!c->sbuf)
1198		goto out_free;
1199
1200	if (!c->ro_mount) {
1201		c->ileb_buf = vmalloc(c->leb_size);
1202		if (!c->ileb_buf)
1203			goto out_free;
1204	}
1205
1206	if (c->bulk_read == 1)
1207		bu_init(c);
1208
1209	if (!c->ro_mount) {
1210		c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
 
1211					       GFP_KERNEL);
1212		if (!c->write_reserve_buf)
1213			goto out_free;
1214	}
1215
1216	c->mounting = 1;
1217
 
 
 
 
 
 
 
 
 
 
 
 
 
1218	err = ubifs_read_superblock(c);
1219	if (err)
1220		goto out_free;
1221
1222	c->probing = 0;
1223
1224	/*
1225	 * Make sure the compressor which is set as default in the superblock
1226	 * or overridden by mount options is actually compiled in.
1227	 */
1228	if (!ubifs_compr_present(c->default_compr)) {
1229		ubifs_err(c, "'compressor \"%s\" is not compiled in",
1230			  ubifs_compr_name(c->default_compr));
1231		err = -ENOTSUPP;
1232		goto out_free;
1233	}
1234
1235	err = init_constants_sb(c);
1236	if (err)
1237		goto out_free;
1238
1239	sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
1240	sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
1241	c->cbuf = kmalloc(sz, GFP_NOFS);
1242	if (!c->cbuf) {
1243		err = -ENOMEM;
1244		goto out_free;
1245	}
1246
1247	err = alloc_wbufs(c);
1248	if (err)
1249		goto out_cbuf;
1250
1251	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1252	if (!c->ro_mount) {
1253		/* Create background thread */
1254		c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1255		if (IS_ERR(c->bgt)) {
1256			err = PTR_ERR(c->bgt);
1257			c->bgt = NULL;
1258			ubifs_err(c, "cannot spawn \"%s\", error %d",
1259				  c->bgt_name, err);
1260			goto out_wbufs;
1261		}
1262		wake_up_process(c->bgt);
1263	}
1264
1265	err = ubifs_read_master(c);
1266	if (err)
1267		goto out_master;
1268
1269	init_constants_master(c);
1270
1271	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1272		ubifs_msg(c, "recovery needed");
1273		c->need_recovery = 1;
1274	}
1275
1276	if (c->need_recovery && !c->ro_mount) {
1277		err = ubifs_recover_inl_heads(c, c->sbuf);
1278		if (err)
1279			goto out_master;
1280	}
1281
1282	err = ubifs_lpt_init(c, 1, !c->ro_mount);
1283	if (err)
1284		goto out_master;
1285
1286	if (!c->ro_mount && c->space_fixup) {
1287		err = ubifs_fixup_free_space(c);
1288		if (err)
1289			goto out_lpt;
1290	}
1291
1292	if (!c->ro_mount && !c->need_recovery) {
1293		/*
1294		 * Set the "dirty" flag so that if we reboot uncleanly we
1295		 * will notice this immediately on the next mount.
1296		 */
1297		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1298		err = ubifs_write_master(c);
1299		if (err)
1300			goto out_lpt;
1301	}
1302
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1303	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1304	if (err)
1305		goto out_lpt;
1306
1307	err = ubifs_replay_journal(c);
1308	if (err)
1309		goto out_journal;
1310
1311	/* Calculate 'min_idx_lebs' after journal replay */
1312	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1313
1314	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1315	if (err)
1316		goto out_orphans;
1317
1318	if (!c->ro_mount) {
1319		int lnum;
1320
1321		err = check_free_space(c);
1322		if (err)
1323			goto out_orphans;
1324
1325		/* Check for enough log space */
1326		lnum = c->lhead_lnum + 1;
1327		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1328			lnum = UBIFS_LOG_LNUM;
1329		if (lnum == c->ltail_lnum) {
1330			err = ubifs_consolidate_log(c);
1331			if (err)
1332				goto out_orphans;
1333		}
1334
1335		if (c->need_recovery) {
1336			err = ubifs_recover_size(c);
1337			if (err)
1338				goto out_orphans;
 
 
 
1339			err = ubifs_rcvry_gc_commit(c);
1340			if (err)
1341				goto out_orphans;
 
 
 
 
 
 
1342		} else {
1343			err = take_gc_lnum(c);
1344			if (err)
1345				goto out_orphans;
1346
1347			/*
1348			 * GC LEB may contain garbage if there was an unclean
1349			 * reboot, and it should be un-mapped.
1350			 */
1351			err = ubifs_leb_unmap(c, c->gc_lnum);
1352			if (err)
1353				goto out_orphans;
1354		}
1355
1356		err = dbg_check_lprops(c);
1357		if (err)
1358			goto out_orphans;
1359	} else if (c->need_recovery) {
1360		err = ubifs_recover_size(c);
1361		if (err)
1362			goto out_orphans;
1363	} else {
1364		/*
1365		 * Even if we mount read-only, we have to set space in GC LEB
1366		 * to proper value because this affects UBIFS free space
1367		 * reporting. We do not want to have a situation when
1368		 * re-mounting from R/O to R/W changes amount of free space.
1369		 */
1370		err = take_gc_lnum(c);
1371		if (err)
1372			goto out_orphans;
1373	}
1374
1375	spin_lock(&ubifs_infos_lock);
1376	list_add_tail(&c->infos_list, &ubifs_infos);
1377	spin_unlock(&ubifs_infos_lock);
1378
1379	if (c->need_recovery) {
1380		if (c->ro_mount)
1381			ubifs_msg(c, "recovery deferred");
1382		else {
1383			c->need_recovery = 0;
1384			ubifs_msg(c, "recovery completed");
1385			/*
1386			 * GC LEB has to be empty and taken at this point. But
1387			 * the journal head LEBs may also be accounted as
1388			 * "empty taken" if they are empty.
1389			 */
1390			ubifs_assert(c->lst.taken_empty_lebs > 0);
1391		}
1392	} else
1393		ubifs_assert(c->lst.taken_empty_lebs > 0);
1394
1395	err = dbg_check_filesystem(c);
1396	if (err)
1397		goto out_infos;
1398
1399	err = dbg_debugfs_init_fs(c);
1400	if (err)
1401		goto out_infos;
1402
1403	c->mounting = 0;
1404
1405	ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
1406		  c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1407		  c->ro_mount ? ", R/O mode" : "");
1408	x = (long long)c->main_lebs * c->leb_size;
1409	y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1410	ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1411		  c->leb_size, c->leb_size >> 10, c->min_io_size,
1412		  c->max_write_size);
1413	ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), journal size %lld bytes (%lld MiB, %d LEBs)",
1414		  x, x >> 20, c->main_lebs,
1415		  y, y >> 20, c->log_lebs + c->max_bud_cnt);
1416	ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
1417		  c->report_rp_size, c->report_rp_size >> 10);
1418	ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1419		  c->fmt_version, c->ro_compat_version,
1420		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1421		  c->big_lpt ? ", big LPT model" : ", small LPT model");
1422
1423	dbg_gen("default compressor:  %s", ubifs_compr_name(c->default_compr));
1424	dbg_gen("data journal heads:  %d",
1425		c->jhead_cnt - NONDATA_JHEADS_CNT);
1426	dbg_gen("log LEBs:            %d (%d - %d)",
1427		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1428	dbg_gen("LPT area LEBs:       %d (%d - %d)",
1429		c->lpt_lebs, c->lpt_first, c->lpt_last);
1430	dbg_gen("orphan area LEBs:    %d (%d - %d)",
1431		c->orph_lebs, c->orph_first, c->orph_last);
1432	dbg_gen("main area LEBs:      %d (%d - %d)",
1433		c->main_lebs, c->main_first, c->leb_cnt - 1);
1434	dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1435	dbg_gen("total index bytes:   %lld (%lld KiB, %lld MiB)",
1436		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1437		c->bi.old_idx_sz >> 20);
1438	dbg_gen("key hash type:       %d", c->key_hash_type);
1439	dbg_gen("tree fanout:         %d", c->fanout);
1440	dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1441	dbg_gen("max. znode size      %d", c->max_znode_sz);
1442	dbg_gen("max. index node size %d", c->max_idx_node_sz);
1443	dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1444		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1445	dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1446		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1447	dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1448		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1449	dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1450		UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1451		UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1452	dbg_gen("dead watermark:      %d", c->dead_wm);
1453	dbg_gen("dark watermark:      %d", c->dark_wm);
1454	dbg_gen("LEB overhead:        %d", c->leb_overhead);
1455	x = (long long)c->main_lebs * c->dark_wm;
1456	dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1457		x, x >> 10, x >> 20);
1458	dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1459		c->max_bud_bytes, c->max_bud_bytes >> 10,
1460		c->max_bud_bytes >> 20);
1461	dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1462		c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1463		c->bg_bud_bytes >> 20);
1464	dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1465		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1466	dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1467	dbg_gen("commit number:       %llu", c->cmt_no);
 
 
1468
1469	return 0;
1470
1471out_infos:
1472	spin_lock(&ubifs_infos_lock);
1473	list_del(&c->infos_list);
1474	spin_unlock(&ubifs_infos_lock);
1475out_orphans:
1476	free_orphans(c);
1477out_journal:
1478	destroy_journal(c);
1479out_lpt:
1480	ubifs_lpt_free(c, 0);
1481out_master:
1482	kfree(c->mst_node);
1483	kfree(c->rcvrd_mst_node);
1484	if (c->bgt)
1485		kthread_stop(c->bgt);
1486out_wbufs:
1487	free_wbufs(c);
1488out_cbuf:
1489	kfree(c->cbuf);
 
 
1490out_free:
1491	kfree(c->write_reserve_buf);
1492	kfree(c->bu.buf);
1493	vfree(c->ileb_buf);
1494	vfree(c->sbuf);
1495	kfree(c->bottom_up_buf);
 
 
 
1496	ubifs_debugging_exit(c);
1497	return err;
1498}
1499
1500/**
1501 * ubifs_umount - un-mount UBIFS file-system.
1502 * @c: UBIFS file-system description object
1503 *
1504 * Note, this function is called to free allocated resourced when un-mounting,
1505 * as well as free resources when an error occurred while we were half way
1506 * through mounting (error path cleanup function). So it has to make sure the
1507 * resource was actually allocated before freeing it.
1508 */
1509static void ubifs_umount(struct ubifs_info *c)
1510{
1511	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1512		c->vi.vol_id);
1513
1514	dbg_debugfs_exit_fs(c);
1515	spin_lock(&ubifs_infos_lock);
1516	list_del(&c->infos_list);
1517	spin_unlock(&ubifs_infos_lock);
1518
1519	if (c->bgt)
1520		kthread_stop(c->bgt);
1521
1522	destroy_journal(c);
1523	free_wbufs(c);
1524	free_orphans(c);
1525	ubifs_lpt_free(c, 0);
 
1526
 
1527	kfree(c->cbuf);
1528	kfree(c->rcvrd_mst_node);
1529	kfree(c->mst_node);
1530	kfree(c->write_reserve_buf);
1531	kfree(c->bu.buf);
1532	vfree(c->ileb_buf);
1533	vfree(c->sbuf);
1534	kfree(c->bottom_up_buf);
 
1535	ubifs_debugging_exit(c);
 
1536}
1537
1538/**
1539 * ubifs_remount_rw - re-mount in read-write mode.
1540 * @c: UBIFS file-system description object
1541 *
1542 * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1543 * mode. This function allocates the needed resources and re-mounts UBIFS in
1544 * read-write mode.
1545 */
1546static int ubifs_remount_rw(struct ubifs_info *c)
1547{
1548	int err, lnum;
1549
1550	if (c->rw_incompat) {
1551		ubifs_err(c, "the file-system is not R/W-compatible");
1552		ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1553			  c->fmt_version, c->ro_compat_version,
1554			  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1555		return -EROFS;
1556	}
1557
1558	mutex_lock(&c->umount_mutex);
1559	dbg_save_space_info(c);
1560	c->remounting_rw = 1;
1561	c->ro_mount = 0;
1562
1563	if (c->space_fixup) {
1564		err = ubifs_fixup_free_space(c);
1565		if (err)
1566			goto out;
1567	}
1568
1569	err = check_free_space(c);
1570	if (err)
1571		goto out;
1572
1573	if (c->old_leb_cnt != c->leb_cnt) {
1574		struct ubifs_sb_node *sup;
1575
1576		sup = ubifs_read_sb_node(c);
1577		if (IS_ERR(sup)) {
1578			err = PTR_ERR(sup);
1579			goto out;
1580		}
1581		sup->leb_cnt = cpu_to_le32(c->leb_cnt);
1582		err = ubifs_write_sb_node(c, sup);
1583		kfree(sup);
1584		if (err)
1585			goto out;
1586	}
1587
1588	if (c->need_recovery) {
1589		ubifs_msg(c, "completing deferred recovery");
1590		err = ubifs_write_rcvrd_mst_node(c);
1591		if (err)
1592			goto out;
1593		err = ubifs_recover_size(c);
1594		if (err)
1595			goto out;
 
 
1596		err = ubifs_clean_lebs(c, c->sbuf);
1597		if (err)
1598			goto out;
1599		err = ubifs_recover_inl_heads(c, c->sbuf);
1600		if (err)
1601			goto out;
1602	} else {
1603		/* A readonly mount is not allowed to have orphans */
1604		ubifs_assert(c->tot_orphans == 0);
1605		err = ubifs_clear_orphans(c);
1606		if (err)
1607			goto out;
1608	}
1609
1610	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1611		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1612		err = ubifs_write_master(c);
1613		if (err)
1614			goto out;
1615	}
1616
 
 
 
 
 
 
 
 
 
 
1617	c->ileb_buf = vmalloc(c->leb_size);
1618	if (!c->ileb_buf) {
1619		err = -ENOMEM;
1620		goto out;
1621	}
1622
1623	c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
 
1624	if (!c->write_reserve_buf) {
1625		err = -ENOMEM;
1626		goto out;
1627	}
1628
1629	err = ubifs_lpt_init(c, 0, 1);
1630	if (err)
1631		goto out;
1632
1633	/* Create background thread */
1634	c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1635	if (IS_ERR(c->bgt)) {
1636		err = PTR_ERR(c->bgt);
1637		c->bgt = NULL;
1638		ubifs_err(c, "cannot spawn \"%s\", error %d",
1639			  c->bgt_name, err);
1640		goto out;
1641	}
1642	wake_up_process(c->bgt);
1643
1644	c->orph_buf = vmalloc(c->leb_size);
1645	if (!c->orph_buf) {
1646		err = -ENOMEM;
1647		goto out;
1648	}
1649
1650	/* Check for enough log space */
1651	lnum = c->lhead_lnum + 1;
1652	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1653		lnum = UBIFS_LOG_LNUM;
1654	if (lnum == c->ltail_lnum) {
1655		err = ubifs_consolidate_log(c);
1656		if (err)
1657			goto out;
1658	}
1659
1660	if (c->need_recovery)
1661		err = ubifs_rcvry_gc_commit(c);
1662	else
 
 
 
 
 
 
 
 
1663		err = ubifs_leb_unmap(c, c->gc_lnum);
 
1664	if (err)
1665		goto out;
1666
1667	dbg_gen("re-mounted read-write");
1668	c->remounting_rw = 0;
1669
1670	if (c->need_recovery) {
1671		c->need_recovery = 0;
1672		ubifs_msg(c, "deferred recovery completed");
1673	} else {
1674		/*
1675		 * Do not run the debugging space check if the were doing
1676		 * recovery, because when we saved the information we had the
1677		 * file-system in a state where the TNC and lprops has been
1678		 * modified in memory, but all the I/O operations (including a
1679		 * commit) were deferred. So the file-system was in
1680		 * "non-committed" state. Now the file-system is in committed
1681		 * state, and of course the amount of free space will change
1682		 * because, for example, the old index size was imprecise.
1683		 */
1684		err = dbg_check_space_info(c);
1685	}
1686
1687	mutex_unlock(&c->umount_mutex);
1688	return err;
1689
1690out:
1691	c->ro_mount = 1;
1692	vfree(c->orph_buf);
1693	c->orph_buf = NULL;
1694	if (c->bgt) {
1695		kthread_stop(c->bgt);
1696		c->bgt = NULL;
1697	}
1698	free_wbufs(c);
1699	kfree(c->write_reserve_buf);
1700	c->write_reserve_buf = NULL;
1701	vfree(c->ileb_buf);
1702	c->ileb_buf = NULL;
1703	ubifs_lpt_free(c, 1);
1704	c->remounting_rw = 0;
1705	mutex_unlock(&c->umount_mutex);
1706	return err;
1707}
1708
1709/**
1710 * ubifs_remount_ro - re-mount in read-only mode.
1711 * @c: UBIFS file-system description object
1712 *
1713 * We assume VFS has stopped writing. Possibly the background thread could be
1714 * running a commit, however kthread_stop will wait in that case.
1715 */
1716static void ubifs_remount_ro(struct ubifs_info *c)
1717{
1718	int i, err;
1719
1720	ubifs_assert(!c->need_recovery);
1721	ubifs_assert(!c->ro_mount);
1722
1723	mutex_lock(&c->umount_mutex);
1724	if (c->bgt) {
1725		kthread_stop(c->bgt);
1726		c->bgt = NULL;
1727	}
1728
1729	dbg_save_space_info(c);
1730
1731	for (i = 0; i < c->jhead_cnt; i++)
1732		ubifs_wbuf_sync(&c->jheads[i].wbuf);
 
 
 
1733
1734	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1735	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1736	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1737	err = ubifs_write_master(c);
1738	if (err)
1739		ubifs_ro_mode(c, err);
1740
1741	vfree(c->orph_buf);
1742	c->orph_buf = NULL;
1743	kfree(c->write_reserve_buf);
1744	c->write_reserve_buf = NULL;
1745	vfree(c->ileb_buf);
1746	c->ileb_buf = NULL;
1747	ubifs_lpt_free(c, 1);
1748	c->ro_mount = 1;
1749	err = dbg_check_space_info(c);
1750	if (err)
1751		ubifs_ro_mode(c, err);
1752	mutex_unlock(&c->umount_mutex);
1753}
1754
1755static void ubifs_put_super(struct super_block *sb)
1756{
1757	int i;
1758	struct ubifs_info *c = sb->s_fs_info;
1759
1760	ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
1761
1762	/*
1763	 * The following asserts are only valid if there has not been a failure
1764	 * of the media. For example, there will be dirty inodes if we failed
1765	 * to write them back because of I/O errors.
1766	 */
1767	if (!c->ro_error) {
1768		ubifs_assert(c->bi.idx_growth == 0);
1769		ubifs_assert(c->bi.dd_growth == 0);
1770		ubifs_assert(c->bi.data_growth == 0);
1771	}
1772
1773	/*
1774	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1775	 * and file system un-mount. Namely, it prevents the shrinker from
1776	 * picking this superblock for shrinking - it will be just skipped if
1777	 * the mutex is locked.
1778	 */
1779	mutex_lock(&c->umount_mutex);
1780	if (!c->ro_mount) {
1781		/*
1782		 * First of all kill the background thread to make sure it does
1783		 * not interfere with un-mounting and freeing resources.
1784		 */
1785		if (c->bgt) {
1786			kthread_stop(c->bgt);
1787			c->bgt = NULL;
1788		}
1789
1790		/*
1791		 * On fatal errors c->ro_error is set to 1, in which case we do
1792		 * not write the master node.
1793		 */
1794		if (!c->ro_error) {
1795			int err;
1796
1797			/* Synchronize write-buffers */
1798			for (i = 0; i < c->jhead_cnt; i++)
1799				ubifs_wbuf_sync(&c->jheads[i].wbuf);
 
 
 
1800
1801			/*
1802			 * We are being cleanly unmounted which means the
1803			 * orphans were killed - indicate this in the master
1804			 * node. Also save the reserved GC LEB number.
1805			 */
1806			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1807			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1808			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1809			err = ubifs_write_master(c);
1810			if (err)
1811				/*
1812				 * Recovery will attempt to fix the master area
1813				 * next mount, so we just print a message and
1814				 * continue to unmount normally.
1815				 */
1816				ubifs_err(c, "failed to write master node, error %d",
1817					  err);
1818		} else {
1819			for (i = 0; i < c->jhead_cnt; i++)
1820				/* Make sure write-buffer timers are canceled */
1821				hrtimer_cancel(&c->jheads[i].wbuf.timer);
1822		}
1823	}
1824
1825	ubifs_umount(c);
1826	bdi_destroy(&c->bdi);
1827	ubi_close_volume(c->ubi);
1828	mutex_unlock(&c->umount_mutex);
1829}
1830
1831static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
1832{
1833	int err;
1834	struct ubifs_info *c = sb->s_fs_info;
1835
1836	sync_filesystem(sb);
1837	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
1838
1839	err = ubifs_parse_options(c, data, 1);
1840	if (err) {
1841		ubifs_err(c, "invalid or unknown remount parameter");
1842		return err;
1843	}
1844
1845	if (c->ro_mount && !(*flags & MS_RDONLY)) {
1846		if (c->ro_error) {
1847			ubifs_msg(c, "cannot re-mount R/W due to prior errors");
1848			return -EROFS;
1849		}
1850		if (c->ro_media) {
1851			ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
1852			return -EROFS;
1853		}
1854		err = ubifs_remount_rw(c);
1855		if (err)
1856			return err;
1857	} else if (!c->ro_mount && (*flags & MS_RDONLY)) {
1858		if (c->ro_error) {
1859			ubifs_msg(c, "cannot re-mount R/O due to prior errors");
1860			return -EROFS;
1861		}
1862		ubifs_remount_ro(c);
1863	}
1864
1865	if (c->bulk_read == 1)
1866		bu_init(c);
1867	else {
1868		dbg_gen("disable bulk-read");
 
1869		kfree(c->bu.buf);
1870		c->bu.buf = NULL;
 
1871	}
1872
1873	ubifs_assert(c->lst.taken_empty_lebs > 0);
 
 
1874	return 0;
1875}
1876
1877const struct super_operations ubifs_super_operations = {
1878	.alloc_inode   = ubifs_alloc_inode,
1879	.destroy_inode = ubifs_destroy_inode,
1880	.put_super     = ubifs_put_super,
1881	.write_inode   = ubifs_write_inode,
 
1882	.evict_inode   = ubifs_evict_inode,
1883	.statfs        = ubifs_statfs,
1884	.dirty_inode   = ubifs_dirty_inode,
1885	.remount_fs    = ubifs_remount_fs,
1886	.show_options  = ubifs_show_options,
1887	.sync_fs       = ubifs_sync_fs,
1888};
1889
1890/**
1891 * open_ubi - parse UBI device name string and open the UBI device.
1892 * @name: UBI volume name
1893 * @mode: UBI volume open mode
1894 *
1895 * The primary method of mounting UBIFS is by specifying the UBI volume
1896 * character device node path. However, UBIFS may also be mounted withoug any
1897 * character device node using one of the following methods:
1898 *
1899 * o ubiX_Y    - mount UBI device number X, volume Y;
1900 * o ubiY      - mount UBI device number 0, volume Y;
1901 * o ubiX:NAME - mount UBI device X, volume with name NAME;
1902 * o ubi:NAME  - mount UBI device 0, volume with name NAME.
1903 *
1904 * Alternative '!' separator may be used instead of ':' (because some shells
1905 * like busybox may interpret ':' as an NFS host name separator). This function
1906 * returns UBI volume description object in case of success and a negative
1907 * error code in case of failure.
1908 */
1909static struct ubi_volume_desc *open_ubi(const char *name, int mode)
1910{
1911	struct ubi_volume_desc *ubi;
1912	int dev, vol;
1913	char *endptr;
1914
 
 
 
1915	/* First, try to open using the device node path method */
1916	ubi = ubi_open_volume_path(name, mode);
1917	if (!IS_ERR(ubi))
1918		return ubi;
1919
1920	/* Try the "nodev" method */
1921	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
1922		return ERR_PTR(-EINVAL);
1923
1924	/* ubi:NAME method */
1925	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
1926		return ubi_open_volume_nm(0, name + 4, mode);
1927
1928	if (!isdigit(name[3]))
1929		return ERR_PTR(-EINVAL);
1930
1931	dev = simple_strtoul(name + 3, &endptr, 0);
1932
1933	/* ubiY method */
1934	if (*endptr == '\0')
1935		return ubi_open_volume(0, dev, mode);
1936
1937	/* ubiX_Y method */
1938	if (*endptr == '_' && isdigit(endptr[1])) {
1939		vol = simple_strtoul(endptr + 1, &endptr, 0);
1940		if (*endptr != '\0')
1941			return ERR_PTR(-EINVAL);
1942		return ubi_open_volume(dev, vol, mode);
1943	}
1944
1945	/* ubiX:NAME method */
1946	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
1947		return ubi_open_volume_nm(dev, ++endptr, mode);
1948
1949	return ERR_PTR(-EINVAL);
1950}
1951
1952static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
1953{
1954	struct ubifs_info *c;
1955
1956	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
1957	if (c) {
1958		spin_lock_init(&c->cnt_lock);
1959		spin_lock_init(&c->cs_lock);
1960		spin_lock_init(&c->buds_lock);
1961		spin_lock_init(&c->space_lock);
1962		spin_lock_init(&c->orphan_lock);
1963		init_rwsem(&c->commit_sem);
1964		mutex_init(&c->lp_mutex);
1965		mutex_init(&c->tnc_mutex);
1966		mutex_init(&c->log_mutex);
1967		mutex_init(&c->umount_mutex);
1968		mutex_init(&c->bu_mutex);
1969		mutex_init(&c->write_reserve_mutex);
1970		init_waitqueue_head(&c->cmt_wq);
 
 
1971		c->buds = RB_ROOT;
1972		c->old_idx = RB_ROOT;
1973		c->size_tree = RB_ROOT;
1974		c->orph_tree = RB_ROOT;
1975		INIT_LIST_HEAD(&c->infos_list);
1976		INIT_LIST_HEAD(&c->idx_gc);
1977		INIT_LIST_HEAD(&c->replay_list);
1978		INIT_LIST_HEAD(&c->replay_buds);
1979		INIT_LIST_HEAD(&c->uncat_list);
1980		INIT_LIST_HEAD(&c->empty_list);
1981		INIT_LIST_HEAD(&c->freeable_list);
1982		INIT_LIST_HEAD(&c->frdi_idx_list);
1983		INIT_LIST_HEAD(&c->unclean_leb_list);
1984		INIT_LIST_HEAD(&c->old_buds);
1985		INIT_LIST_HEAD(&c->orph_list);
1986		INIT_LIST_HEAD(&c->orph_new);
1987		c->no_chk_data_crc = 1;
 
1988
1989		c->highest_inum = UBIFS_FIRST_INO;
1990		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
1991
1992		ubi_get_volume_info(ubi, &c->vi);
1993		ubi_get_device_info(c->vi.ubi_num, &c->di);
1994	}
1995	return c;
1996}
1997
1998static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
1999{
2000	struct ubifs_info *c = sb->s_fs_info;
2001	struct inode *root;
2002	int err;
2003
2004	c->vfs_sb = sb;
2005	/* Re-open the UBI device in read-write mode */
2006	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2007	if (IS_ERR(c->ubi)) {
2008		err = PTR_ERR(c->ubi);
2009		goto out;
2010	}
2011
 
 
 
 
2012	/*
2013	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2014	 * UBIFS, I/O is not deferred, it is done immediately in readpage,
2015	 * which means the user would have to wait not just for their own I/O
2016	 * but the read-ahead I/O as well i.e. completely pointless.
2017	 *
2018	 * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
 
 
2019	 */
2020	c->bdi.name = "ubifs",
2021	c->bdi.capabilities = 0;
2022	err  = bdi_init(&c->bdi);
2023	if (err)
2024		goto out_close;
2025	err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d",
2026			   c->vi.ubi_num, c->vi.vol_id);
2027	if (err)
2028		goto out_bdi;
2029
2030	err = ubifs_parse_options(c, data, 0);
2031	if (err)
2032		goto out_bdi;
2033
2034	sb->s_bdi = &c->bdi;
2035	sb->s_fs_info = c;
2036	sb->s_magic = UBIFS_SUPER_MAGIC;
2037	sb->s_blocksize = UBIFS_BLOCK_SIZE;
2038	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2039	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2040	if (c->max_inode_sz > MAX_LFS_FILESIZE)
2041		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2042	sb->s_op = &ubifs_super_operations;
 
 
2043
2044	mutex_lock(&c->umount_mutex);
2045	err = mount_ubifs(c);
2046	if (err) {
2047		ubifs_assert(err < 0);
2048		goto out_unlock;
2049	}
2050
2051	/* Read the root inode */
2052	root = ubifs_iget(sb, UBIFS_ROOT_INO);
2053	if (IS_ERR(root)) {
2054		err = PTR_ERR(root);
2055		goto out_umount;
2056	}
2057
 
2058	sb->s_root = d_make_root(root);
2059	if (!sb->s_root) {
2060		err = -ENOMEM;
2061		goto out_umount;
2062	}
2063
 
 
2064	mutex_unlock(&c->umount_mutex);
2065	return 0;
2066
2067out_umount:
2068	ubifs_umount(c);
2069out_unlock:
2070	mutex_unlock(&c->umount_mutex);
2071out_bdi:
2072	bdi_destroy(&c->bdi);
2073out_close:
 
2074	ubi_close_volume(c->ubi);
2075out:
2076	return err;
2077}
2078
2079static int sb_test(struct super_block *sb, void *data)
2080{
2081	struct ubifs_info *c1 = data;
2082	struct ubifs_info *c = sb->s_fs_info;
2083
2084	return c->vi.cdev == c1->vi.cdev;
2085}
2086
2087static int sb_set(struct super_block *sb, void *data)
2088{
2089	sb->s_fs_info = data;
2090	return set_anon_super(sb, NULL);
2091}
2092
2093static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2094			const char *name, void *data)
2095{
2096	struct ubi_volume_desc *ubi;
2097	struct ubifs_info *c;
2098	struct super_block *sb;
2099	int err;
2100
2101	dbg_gen("name %s, flags %#x", name, flags);
2102
2103	/*
2104	 * Get UBI device number and volume ID. Mount it read-only so far
2105	 * because this might be a new mount point, and UBI allows only one
2106	 * read-write user at a time.
2107	 */
2108	ubi = open_ubi(name, UBI_READONLY);
2109	if (IS_ERR(ubi)) {
2110		pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
2111		       current->pid, name, (int)PTR_ERR(ubi));
 
2112		return ERR_CAST(ubi);
2113	}
2114
2115	c = alloc_ubifs_info(ubi);
2116	if (!c) {
2117		err = -ENOMEM;
2118		goto out_close;
2119	}
2120
2121	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2122
2123	sb = sget(fs_type, sb_test, sb_set, flags, c);
2124	if (IS_ERR(sb)) {
2125		err = PTR_ERR(sb);
2126		kfree(c);
2127		goto out_close;
2128	}
2129
2130	if (sb->s_root) {
2131		struct ubifs_info *c1 = sb->s_fs_info;
2132		kfree(c);
2133		/* A new mount point for already mounted UBIFS */
2134		dbg_gen("this ubi volume is already mounted");
2135		if (!!(flags & MS_RDONLY) != c1->ro_mount) {
2136			err = -EBUSY;
2137			goto out_deact;
2138		}
2139	} else {
2140		err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
2141		if (err)
2142			goto out_deact;
2143		/* We do not support atime */
2144		sb->s_flags |= MS_ACTIVE;
2145#ifndef CONFIG_UBIFS_ATIME_SUPPORT
2146		sb->s_flags |= MS_NOATIME;
2147#else
2148		ubifs_msg(c, "full atime support is enabled.");
2149#endif
2150	}
2151
2152	/* 'fill_super()' opens ubi again so we must close it here */
2153	ubi_close_volume(ubi);
2154
2155	return dget(sb->s_root);
2156
2157out_deact:
2158	deactivate_locked_super(sb);
2159out_close:
2160	ubi_close_volume(ubi);
2161	return ERR_PTR(err);
2162}
2163
2164static void kill_ubifs_super(struct super_block *s)
2165{
2166	struct ubifs_info *c = s->s_fs_info;
2167	kill_anon_super(s);
2168	kfree(c);
2169}
2170
2171static struct file_system_type ubifs_fs_type = {
2172	.name    = "ubifs",
2173	.owner   = THIS_MODULE,
2174	.mount   = ubifs_mount,
2175	.kill_sb = kill_ubifs_super,
2176};
2177MODULE_ALIAS_FS("ubifs");
2178
2179/*
2180 * Inode slab cache constructor.
2181 */
2182static void inode_slab_ctor(void *obj)
2183{
2184	struct ubifs_inode *ui = obj;
2185	inode_init_once(&ui->vfs_inode);
2186}
2187
2188static int __init ubifs_init(void)
2189{
2190	int err;
2191
2192	BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2193
2194	/* Make sure node sizes are 8-byte aligned */
2195	BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2196	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2197	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2198	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2199	BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2200	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2201	BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2202	BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2203	BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2204	BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2205	BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2206
2207	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2208	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2209	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2210	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2211	BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2212	BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2213
2214	/* Check min. node size */
2215	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2216	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2217	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2218	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2219
2220	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2221	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2222	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2223	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2224
2225	/* Defined node sizes */
2226	BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2227	BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2228	BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2229	BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2230
2231	/*
2232	 * We use 2 bit wide bit-fields to store compression type, which should
2233	 * be amended if more compressors are added. The bit-fields are:
2234	 * @compr_type in 'struct ubifs_inode', @default_compr in
2235	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2236	 */
2237	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2238
2239	/*
2240	 * We require that PAGE_SIZE is greater-than-or-equal-to
2241	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2242	 */
2243	if (PAGE_SIZE < UBIFS_BLOCK_SIZE) {
2244		pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2245		       current->pid, (unsigned int)PAGE_SIZE);
2246		return -EINVAL;
2247	}
2248
2249	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2250				sizeof(struct ubifs_inode), 0,
2251				SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT |
2252				SLAB_ACCOUNT, &inode_slab_ctor);
2253	if (!ubifs_inode_slab)
2254		return -ENOMEM;
2255
2256	err = register_shrinker(&ubifs_shrinker_info);
2257	if (err)
2258		goto out_slab;
2259
 
 
 
 
 
2260	err = ubifs_compressors_init();
2261	if (err)
2262		goto out_shrinker;
2263
2264	err = dbg_debugfs_init();
 
 
2265	if (err)
2266		goto out_compr;
2267
2268	err = register_filesystem(&ubifs_fs_type);
2269	if (err) {
2270		pr_err("UBIFS error (pid %d): cannot register file system, error %d",
2271		       current->pid, err);
2272		goto out_dbg;
2273	}
2274	return 0;
2275
 
 
2276out_dbg:
2277	dbg_debugfs_exit();
2278out_compr:
2279	ubifs_compressors_exit();
2280out_shrinker:
2281	unregister_shrinker(&ubifs_shrinker_info);
2282out_slab:
2283	kmem_cache_destroy(ubifs_inode_slab);
2284	return err;
2285}
2286/* late_initcall to let compressors initialize first */
2287late_initcall(ubifs_init);
2288
2289static void __exit ubifs_exit(void)
2290{
2291	ubifs_assert(list_empty(&ubifs_infos));
2292	ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
2293
2294	dbg_debugfs_exit();
 
2295	ubifs_compressors_exit();
2296	unregister_shrinker(&ubifs_shrinker_info);
2297
2298	/*
2299	 * Make sure all delayed rcu free inodes are flushed before we
2300	 * destroy cache.
2301	 */
2302	rcu_barrier();
2303	kmem_cache_destroy(ubifs_inode_slab);
2304	unregister_filesystem(&ubifs_fs_type);
2305}
2306module_exit(ubifs_exit);
2307
2308MODULE_LICENSE("GPL");
2309MODULE_VERSION(__stringify(UBIFS_VERSION));
2310MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2311MODULE_DESCRIPTION("UBIFS - UBI File System");