1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * This file is part of UBIFS.
   4 *
   5 * Copyright (C) 2006-2008 Nokia Corporation.
   6 *
   7 * Authors: Artem Bityutskiy (Битюцкий Артём)
   8 *          Adrian Hunter
   9 */
  10
  11/*
  12 * This file implements UBIFS initialization and VFS superblock operations. Some
  13 * initialization stuff which is rather large and complex is placed at
  14 * corresponding subsystems, but most of it is here.
  15 */
  16
  17#include <linux/init.h>
  18#include <linux/slab.h>
  19#include <linux/module.h>
  20#include <linux/ctype.h>
  21#include <linux/kthread.h>
  22#include <linux/parser.h>
  23#include <linux/seq_file.h>
  24#include <linux/mount.h>
  25#include <linux/math64.h>
  26#include <linux/writeback.h>
  27#include "ubifs.h"
  28
  29static int ubifs_default_version_set(const char *val, const struct kernel_param *kp)
  30{
  31	int n = 0, ret;
  32
  33	ret = kstrtoint(val, 10, &n);
  34	if (ret != 0 || n < 4 || n > UBIFS_FORMAT_VERSION)
  35		return -EINVAL;
  36	return param_set_int(val, kp);
  37}
  38
  39static const struct kernel_param_ops ubifs_default_version_ops = {
  40	.set = ubifs_default_version_set,
  41	.get = param_get_int,
  42};
  43
  44int ubifs_default_version = UBIFS_FORMAT_VERSION;
  45module_param_cb(default_version, &ubifs_default_version_ops, &ubifs_default_version, 0600);
  46
  47/*
  48 * Maximum amount of memory we may 'kmalloc()' without worrying that we are
  49 * allocating too much.
  50 */
  51#define UBIFS_KMALLOC_OK (128*1024)
  52
  53/* Slab cache for UBIFS inodes */
  54static struct kmem_cache *ubifs_inode_slab;
  55
  56/* UBIFS TNC shrinker description */
  57static struct shrinker *ubifs_shrinker_info;
 
 
 
 
  58
  59/**
  60 * validate_inode - validate inode.
  61 * @c: UBIFS file-system description object
  62 * @inode: the inode to validate
  63 *
  64 * This is a helper function for 'ubifs_iget()' which validates various fields
  65 * of a newly built inode to make sure they contain sane values and prevent
  66 * possible vulnerabilities. Returns zero if the inode is all right and
  67 * a non-zero error code if not.
  68 */
  69static int validate_inode(struct ubifs_info *c, const struct inode *inode)
  70{
  71	int err;
  72	const struct ubifs_inode *ui = ubifs_inode(inode);
  73
  74	if (inode->i_size > c->max_inode_sz) {
  75		ubifs_err(c, "inode is too large (%lld)",
  76			  (long long)inode->i_size);
  77		return 1;
  78	}
  79
  80	if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
  81		ubifs_err(c, "unknown compression type %d", ui->compr_type);
  82		return 2;
  83	}
  84
  85	if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
  86		return 3;
  87
  88	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
  89		return 4;
  90
  91	if (ui->xattr && !S_ISREG(inode->i_mode))
  92		return 5;
  93
  94	if (!ubifs_compr_present(c, ui->compr_type)) {
  95		ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",
  96			   inode->i_ino, ubifs_compr_name(c, ui->compr_type));
  97	}
  98
  99	err = dbg_check_dir(c, inode);
 100	return err;
 101}
 102
 103struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 104{
 105	int err;
 106	union ubifs_key key;
 107	struct ubifs_ino_node *ino;
 108	struct ubifs_info *c = sb->s_fs_info;
 109	struct inode *inode;
 110	struct ubifs_inode *ui;
 111
 112	dbg_gen("inode %lu", inum);
 113
 114	inode = iget_locked(sb, inum);
 115	if (!inode)
 116		return ERR_PTR(-ENOMEM);
 117	if (!(inode->i_state & I_NEW))
 118		return inode;
 119	ui = ubifs_inode(inode);
 120
 121	ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
 122	if (!ino) {
 123		err = -ENOMEM;
 124		goto out;
 125	}
 126
 127	ino_key_init(c, &key, inode->i_ino);
 128
 129	err = ubifs_tnc_lookup(c, &key, ino);
 130	if (err)
 131		goto out_ino;
 132
 133	inode->i_flags |= S_NOCMTIME;
 134
 135	if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
 136		inode->i_flags |= S_NOATIME;
 137
 138	set_nlink(inode, le32_to_cpu(ino->nlink));
 139	i_uid_write(inode, le32_to_cpu(ino->uid));
 140	i_gid_write(inode, le32_to_cpu(ino->gid));
 141	inode_set_atime(inode, (int64_t)le64_to_cpu(ino->atime_sec),
 142			le32_to_cpu(ino->atime_nsec));
 143	inode_set_mtime(inode, (int64_t)le64_to_cpu(ino->mtime_sec),
 144			le32_to_cpu(ino->mtime_nsec));
 145	inode_set_ctime(inode, (int64_t)le64_to_cpu(ino->ctime_sec),
 146			le32_to_cpu(ino->ctime_nsec));
 147	inode->i_mode = le32_to_cpu(ino->mode);
 148	inode->i_size = le64_to_cpu(ino->size);
 149
 150	ui->data_len    = le32_to_cpu(ino->data_len);
 151	ui->flags       = le32_to_cpu(ino->flags);
 152	ui->compr_type  = le16_to_cpu(ino->compr_type);
 153	ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
 154	ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
 155	ui->xattr_size  = le32_to_cpu(ino->xattr_size);
 156	ui->xattr_names = le32_to_cpu(ino->xattr_names);
 157	ui->synced_i_size = ui->ui_size = inode->i_size;
 158
 159	ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
 160
 161	err = validate_inode(c, inode);
 162	if (err)
 163		goto out_invalid;
 164
 165	switch (inode->i_mode & S_IFMT) {
 166	case S_IFREG:
 167		inode->i_mapping->a_ops = &ubifs_file_address_operations;
 168		inode->i_op = &ubifs_file_inode_operations;
 169		inode->i_fop = &ubifs_file_operations;
 170		if (ui->xattr) {
 171			ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
 172			if (!ui->data) {
 173				err = -ENOMEM;
 174				goto out_ino;
 175			}
 176			memcpy(ui->data, ino->data, ui->data_len);
 177			((char *)ui->data)[ui->data_len] = '\0';
 178		} else if (ui->data_len != 0) {
 179			err = 10;
 180			goto out_invalid;
 181		}
 182		break;
 183	case S_IFDIR:
 184		inode->i_op  = &ubifs_dir_inode_operations;
 185		inode->i_fop = &ubifs_dir_operations;
 186		if (ui->data_len != 0) {
 187			err = 11;
 188			goto out_invalid;
 189		}
 190		break;
 191	case S_IFLNK:
 192		inode->i_op = &ubifs_symlink_inode_operations;
 193		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
 194			err = 12;
 195			goto out_invalid;
 196		}
 197		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
 198		if (!ui->data) {
 199			err = -ENOMEM;
 200			goto out_ino;
 201		}
 202		memcpy(ui->data, ino->data, ui->data_len);
 203		((char *)ui->data)[ui->data_len] = '\0';
 204		break;
 205	case S_IFBLK:
 206	case S_IFCHR:
 207	{
 208		dev_t rdev;
 209		union ubifs_dev_desc *dev;
 210
 211		ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
 212		if (!ui->data) {
 213			err = -ENOMEM;
 214			goto out_ino;
 215		}
 216
 217		dev = (union ubifs_dev_desc *)ino->data;
 218		if (ui->data_len == sizeof(dev->new))
 219			rdev = new_decode_dev(le32_to_cpu(dev->new));
 220		else if (ui->data_len == sizeof(dev->huge))
 221			rdev = huge_decode_dev(le64_to_cpu(dev->huge));
 222		else {
 223			err = 13;
 224			goto out_invalid;
 225		}
 226		memcpy(ui->data, ino->data, ui->data_len);
 227		inode->i_op = &ubifs_file_inode_operations;
 228		init_special_inode(inode, inode->i_mode, rdev);
 229		break;
 230	}
 231	case S_IFSOCK:
 232	case S_IFIFO:
 233		inode->i_op = &ubifs_file_inode_operations;
 234		init_special_inode(inode, inode->i_mode, 0);
 235		if (ui->data_len != 0) {
 236			err = 14;
 237			goto out_invalid;
 238		}
 239		break;
 240	default:
 241		err = 15;
 242		goto out_invalid;
 243	}
 244
 245	kfree(ino);
 246	ubifs_set_inode_flags(inode);
 247	unlock_new_inode(inode);
 248	return inode;
 249
 250out_invalid:
 251	ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);
 252	ubifs_dump_node(c, ino, UBIFS_MAX_INO_NODE_SZ);
 253	ubifs_dump_inode(c, inode);
 254	err = -EINVAL;
 255out_ino:
 256	kfree(ino);
 257out:
 258	ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);
 259	iget_failed(inode);
 260	return ERR_PTR(err);
 261}
 262
 263static struct inode *ubifs_alloc_inode(struct super_block *sb)
 264{
 265	struct ubifs_inode *ui;
 266
 267	ui = alloc_inode_sb(sb, ubifs_inode_slab, GFP_NOFS);
 268	if (!ui)
 269		return NULL;
 270
 271	memset((void *)ui + sizeof(struct inode), 0,
 272	       sizeof(struct ubifs_inode) - sizeof(struct inode));
 273	mutex_init(&ui->ui_mutex);
 274	init_rwsem(&ui->xattr_sem);
 275	spin_lock_init(&ui->ui_lock);
 276	return &ui->vfs_inode;
 277};
 278
 279static void ubifs_free_inode(struct inode *inode)
 280{
 281	struct ubifs_inode *ui = ubifs_inode(inode);
 282
 283	kfree(ui->data);
 284	fscrypt_free_inode(inode);
 285
 286	kmem_cache_free(ubifs_inode_slab, ui);
 287}
 288
 289/*
 290 * Note, Linux write-back code calls this without 'i_mutex'.
 291 */
 292static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
 293{
 294	int err = 0;
 295	struct ubifs_info *c = inode->i_sb->s_fs_info;
 296	struct ubifs_inode *ui = ubifs_inode(inode);
 297
 298	ubifs_assert(c, !ui->xattr);
 299	if (is_bad_inode(inode))
 300		return 0;
 301
 302	mutex_lock(&ui->ui_mutex);
 303	/*
 304	 * Due to races between write-back forced by budgeting
 305	 * (see 'sync_some_inodes()') and background write-back, the inode may
 306	 * have already been synchronized, do not do this again. This might
 307	 * also happen if it was synchronized in an VFS operation, e.g.
 308	 * 'ubifs_link()'.
 309	 */
 310	if (!ui->dirty) {
 311		mutex_unlock(&ui->ui_mutex);
 312		return 0;
 313	}
 314
 315	/*
 316	 * As an optimization, do not write orphan inodes to the media just
 317	 * because this is not needed.
 318	 */
 319	dbg_gen("inode %lu, mode %#x, nlink %u",
 320		inode->i_ino, (int)inode->i_mode, inode->i_nlink);
 321	if (inode->i_nlink) {
 322		err = ubifs_jnl_write_inode(c, inode);
 323		if (err)
 324			ubifs_err(c, "can't write inode %lu, error %d",
 325				  inode->i_ino, err);
 326		else
 327			err = dbg_check_inode_size(c, inode, ui->ui_size);
 328	}
 329
 330	ui->dirty = 0;
 331	mutex_unlock(&ui->ui_mutex);
 332	ubifs_release_dirty_inode_budget(c, ui);
 333	return err;
 334}
 335
 336static int ubifs_drop_inode(struct inode *inode)
 337{
 338	int drop = generic_drop_inode(inode);
 339
 340	if (!drop)
 341		drop = fscrypt_drop_inode(inode);
 342
 343	return drop;
 344}
 345
 346static void ubifs_evict_inode(struct inode *inode)
 347{
 348	int err;
 349	struct ubifs_info *c = inode->i_sb->s_fs_info;
 350	struct ubifs_inode *ui = ubifs_inode(inode);
 351
 352	if (ui->xattr)
 353		/*
 354		 * Extended attribute inode deletions are fully handled in
 355		 * 'ubifs_removexattr()'. These inodes are special and have
 356		 * limited usage, so there is nothing to do here.
 357		 */
 358		goto out;
 359
 360	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
 361	ubifs_assert(c, !atomic_read(&inode->i_count));
 362
 363	truncate_inode_pages_final(&inode->i_data);
 364
 365	if (inode->i_nlink)
 366		goto done;
 367
 368	if (is_bad_inode(inode))
 369		goto out;
 370
 371	ui->ui_size = inode->i_size = 0;
 372	err = ubifs_jnl_delete_inode(c, inode);
 373	if (err)
 374		/*
 375		 * Worst case we have a lost orphan inode wasting space, so a
 376		 * simple error message is OK here.
 377		 */
 378		ubifs_err(c, "can't delete inode %lu, error %d",
 379			  inode->i_ino, err);
 380
 381out:
 382	if (ui->dirty)
 383		ubifs_release_dirty_inode_budget(c, ui);
 384	else {
 385		/* We've deleted something - clean the "no space" flags */
 386		c->bi.nospace = c->bi.nospace_rp = 0;
 387		smp_wmb();
 388	}
 389done:
 390	clear_inode(inode);
 391	fscrypt_put_encryption_info(inode);
 392}
 393
 394static void ubifs_dirty_inode(struct inode *inode, int flags)
 395{
 396	struct ubifs_info *c = inode->i_sb->s_fs_info;
 397	struct ubifs_inode *ui = ubifs_inode(inode);
 398
 399	ubifs_assert(c, mutex_is_locked(&ui->ui_mutex));
 400	if (!ui->dirty) {
 401		ui->dirty = 1;
 402		dbg_gen("inode %lu",  inode->i_ino);
 403	}
 404}
 405
 406static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
 407{
 408	struct ubifs_info *c = dentry->d_sb->s_fs_info;
 409	unsigned long long free;
 410	__le32 *uuid = (__le32 *)c->uuid;
 411
 412	free = ubifs_get_free_space(c);
 413	dbg_gen("free space %lld bytes (%lld blocks)",
 414		free, free >> UBIFS_BLOCK_SHIFT);
 415
 416	buf->f_type = UBIFS_SUPER_MAGIC;
 417	buf->f_bsize = UBIFS_BLOCK_SIZE;
 418	buf->f_blocks = c->block_cnt;
 419	buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
 420	if (free > c->report_rp_size)
 421		buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
 422	else
 423		buf->f_bavail = 0;
 424	buf->f_files = 0;
 425	buf->f_ffree = 0;
 426	buf->f_namelen = UBIFS_MAX_NLEN;
 427	buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
 428	buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
 429	ubifs_assert(c, buf->f_bfree <= c->block_cnt);
 430	return 0;
 431}
 432
 433static int ubifs_show_options(struct seq_file *s, struct dentry *root)
 434{
 435	struct ubifs_info *c = root->d_sb->s_fs_info;
 436
 437	if (c->mount_opts.unmount_mode == 2)
 438		seq_puts(s, ",fast_unmount");
 439	else if (c->mount_opts.unmount_mode == 1)
 440		seq_puts(s, ",norm_unmount");
 441
 442	if (c->mount_opts.bulk_read == 2)
 443		seq_puts(s, ",bulk_read");
 444	else if (c->mount_opts.bulk_read == 1)
 445		seq_puts(s, ",no_bulk_read");
 446
 447	if (c->mount_opts.chk_data_crc == 2)
 448		seq_puts(s, ",chk_data_crc");
 449	else if (c->mount_opts.chk_data_crc == 1)
 450		seq_puts(s, ",no_chk_data_crc");
 451
 452	if (c->mount_opts.override_compr) {
 453		seq_printf(s, ",compr=%s",
 454			   ubifs_compr_name(c, c->mount_opts.compr_type));
 455	}
 456
 457	seq_printf(s, ",assert=%s", ubifs_assert_action_name(c));
 458	seq_printf(s, ",ubi=%d,vol=%d", c->vi.ubi_num, c->vi.vol_id);
 459
 460	return 0;
 461}
 462
 463static int ubifs_sync_fs(struct super_block *sb, int wait)
 464{
 465	int i, err;
 466	struct ubifs_info *c = sb->s_fs_info;
 467
 468	/*
 469	 * Zero @wait is just an advisory thing to help the file system shove
 470	 * lots of data into the queues, and there will be the second
 471	 * '->sync_fs()' call, with non-zero @wait.
 472	 */
 473	if (!wait)
 474		return 0;
 475
 476	/*
 477	 * Synchronize write buffers, because 'ubifs_run_commit()' does not
 478	 * do this if it waits for an already running commit.
 479	 */
 480	for (i = 0; i < c->jhead_cnt; i++) {
 481		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
 482		if (err)
 483			return err;
 484	}
 485
 486	/*
 487	 * Strictly speaking, it is not necessary to commit the journal here,
 488	 * synchronizing write-buffers would be enough. But committing makes
 489	 * UBIFS free space predictions much more accurate, so we want to let
 490	 * the user be able to get more accurate results of 'statfs()' after
 491	 * they synchronize the file system.
 492	 */
 493	err = ubifs_run_commit(c);
 494	if (err)
 495		return err;
 496
 497	return ubi_sync(c->vi.ubi_num);
 498}
 499
 500/**
 501 * init_constants_early - initialize UBIFS constants.
 502 * @c: UBIFS file-system description object
 503 *
 504 * This function initialize UBIFS constants which do not need the superblock to
 505 * be read. It also checks that the UBI volume satisfies basic UBIFS
 506 * requirements. Returns zero in case of success and a negative error code in
 507 * case of failure.
 508 */
 509static int init_constants_early(struct ubifs_info *c)
 510{
 511	if (c->vi.corrupted) {
 512		ubifs_warn(c, "UBI volume is corrupted - read-only mode");
 513		c->ro_media = 1;
 514	}
 515
 516	if (c->di.ro_mode) {
 517		ubifs_msg(c, "read-only UBI device");
 518		c->ro_media = 1;
 519	}
 520
 521	if (c->vi.vol_type == UBI_STATIC_VOLUME) {
 522		ubifs_msg(c, "static UBI volume - read-only mode");
 523		c->ro_media = 1;
 524	}
 525
 526	c->leb_cnt = c->vi.size;
 527	c->leb_size = c->vi.usable_leb_size;
 528	c->leb_start = c->di.leb_start;
 529	c->half_leb_size = c->leb_size / 2;
 530	c->min_io_size = c->di.min_io_size;
 531	c->min_io_shift = fls(c->min_io_size) - 1;
 532	c->max_write_size = c->di.max_write_size;
 533	c->max_write_shift = fls(c->max_write_size) - 1;
 534
 535	if (c->leb_size < UBIFS_MIN_LEB_SZ) {
 536		ubifs_errc(c, "too small LEBs (%d bytes), min. is %d bytes",
 537			   c->leb_size, UBIFS_MIN_LEB_SZ);
 538		return -EINVAL;
 539	}
 540
 541	if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
 542		ubifs_errc(c, "too few LEBs (%d), min. is %d",
 543			   c->leb_cnt, UBIFS_MIN_LEB_CNT);
 544		return -EINVAL;
 545	}
 546
 547	if (!is_power_of_2(c->min_io_size)) {
 548		ubifs_errc(c, "bad min. I/O size %d", c->min_io_size);
 549		return -EINVAL;
 550	}
 551
 552	/*
 553	 * Maximum write size has to be greater or equivalent to min. I/O
 554	 * size, and be multiple of min. I/O size.
 555	 */
 556	if (c->max_write_size < c->min_io_size ||
 557	    c->max_write_size % c->min_io_size ||
 558	    !is_power_of_2(c->max_write_size)) {
 559		ubifs_errc(c, "bad write buffer size %d for %d min. I/O unit",
 560			   c->max_write_size, c->min_io_size);
 561		return -EINVAL;
 562	}
 563
 564	/*
 565	 * UBIFS aligns all node to 8-byte boundary, so to make function in
 566	 * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
 567	 * less than 8.
 568	 */
 569	if (c->min_io_size < 8) {
 570		c->min_io_size = 8;
 571		c->min_io_shift = 3;
 572		if (c->max_write_size < c->min_io_size) {
 573			c->max_write_size = c->min_io_size;
 574			c->max_write_shift = c->min_io_shift;
 575		}
 576	}
 577
 578	c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
 579	c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
 580
 581	/*
 582	 * Initialize node length ranges which are mostly needed for node
 583	 * length validation.
 584	 */
 585	c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
 586	c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
 587	c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
 588	c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
 589	c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
 590	c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
 591	c->ranges[UBIFS_AUTH_NODE].min_len = UBIFS_AUTH_NODE_SZ;
 592	c->ranges[UBIFS_AUTH_NODE].max_len = UBIFS_AUTH_NODE_SZ +
 593				UBIFS_MAX_HMAC_LEN;
 594	c->ranges[UBIFS_SIG_NODE].min_len = UBIFS_SIG_NODE_SZ;
 595	c->ranges[UBIFS_SIG_NODE].max_len = c->leb_size - UBIFS_SB_NODE_SZ;
 596
 597	c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
 598	c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
 599	c->ranges[UBIFS_ORPH_NODE].min_len =
 600				UBIFS_ORPH_NODE_SZ + sizeof(__le64);
 601	c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
 602	c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
 603	c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
 604	c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
 605	c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
 606	c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
 607	c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
 608	/*
 609	 * Minimum indexing node size is amended later when superblock is
 610	 * read and the key length is known.
 611	 */
 612	c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
 613	/*
 614	 * Maximum indexing node size is amended later when superblock is
 615	 * read and the fanout is known.
 616	 */
 617	c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
 618
 619	/*
 620	 * Initialize dead and dark LEB space watermarks. See gc.c for comments
 621	 * about these values.
 622	 */
 623	c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
 624	c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
 625
 626	/*
 627	 * Calculate how many bytes would be wasted at the end of LEB if it was
 628	 * fully filled with data nodes of maximum size. This is used in
 629	 * calculations when reporting free space.
 630	 */
 631	c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
 632
 633	/* Buffer size for bulk-reads */
 634	c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
 635	if (c->max_bu_buf_len > c->leb_size)
 636		c->max_bu_buf_len = c->leb_size;
 637
 638	/* Log is ready, preserve one LEB for commits. */
 639	c->min_log_bytes = c->leb_size;
 640
 641	return 0;
 642}
 643
 644/**
 645 * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
 646 * @c: UBIFS file-system description object
 647 * @lnum: LEB the write-buffer was synchronized to
 648 * @free: how many free bytes left in this LEB
 649 * @pad: how many bytes were padded
 650 *
 651 * This is a callback function which is called by the I/O unit when the
 652 * write-buffer is synchronized. We need this to correctly maintain space
 653 * accounting in bud logical eraseblocks. This function returns zero in case of
 654 * success and a negative error code in case of failure.
 655 *
 656 * This function actually belongs to the journal, but we keep it here because
 657 * we want to keep it static.
 658 */
 659static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
 660{
 661	return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
 662}
 663
 664/*
 665 * init_constants_sb - initialize UBIFS constants.
 666 * @c: UBIFS file-system description object
 667 *
 668 * This is a helper function which initializes various UBIFS constants after
 669 * the superblock has been read. It also checks various UBIFS parameters and
 670 * makes sure they are all right. Returns zero in case of success and a
 671 * negative error code in case of failure.
 672 */
 673static int init_constants_sb(struct ubifs_info *c)
 674{
 675	int tmp, err;
 676	long long tmp64;
 677
 678	c->main_bytes = (long long)c->main_lebs * c->leb_size;
 679	c->max_znode_sz = sizeof(struct ubifs_znode) +
 680				c->fanout * sizeof(struct ubifs_zbranch);
 681
 682	tmp = ubifs_idx_node_sz(c, 1);
 683	c->ranges[UBIFS_IDX_NODE].min_len = tmp;
 684	c->min_idx_node_sz = ALIGN(tmp, 8);
 685
 686	tmp = ubifs_idx_node_sz(c, c->fanout);
 687	c->ranges[UBIFS_IDX_NODE].max_len = tmp;
 688	c->max_idx_node_sz = ALIGN(tmp, 8);
 689
 690	/* Make sure LEB size is large enough to fit full commit */
 691	tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
 692	tmp = ALIGN(tmp, c->min_io_size);
 693	if (tmp > c->leb_size) {
 694		ubifs_err(c, "too small LEB size %d, at least %d needed",
 695			  c->leb_size, tmp);
 696		return -EINVAL;
 697	}
 698
 699	/*
 700	 * Make sure that the log is large enough to fit reference nodes for
 701	 * all buds plus one reserved LEB.
 702	 */
 703	tmp64 = c->max_bud_bytes + c->leb_size - 1;
 704	c->max_bud_cnt = div_u64(tmp64, c->leb_size);
 705	tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
 706	tmp /= c->leb_size;
 707	tmp += 1;
 708	if (c->log_lebs < tmp) {
 709		ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",
 710			  c->log_lebs, tmp);
 711		return -EINVAL;
 712	}
 713
 714	/*
 715	 * When budgeting we assume worst-case scenarios when the pages are not
 716	 * be compressed and direntries are of the maximum size.
 717	 *
 718	 * Note, data, which may be stored in inodes is budgeted separately, so
 719	 * it is not included into 'c->bi.inode_budget'.
 720	 */
 721	c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
 722	c->bi.inode_budget = UBIFS_INO_NODE_SZ;
 723	c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
 724
 725	/*
 726	 * When the amount of flash space used by buds becomes
 727	 * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
 728	 * The writers are unblocked when the commit is finished. To avoid
 729	 * writers to be blocked UBIFS initiates background commit in advance,
 730	 * when number of bud bytes becomes above the limit defined below.
 731	 */
 732	c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
 733
 734	/*
 735	 * Ensure minimum journal size. All the bytes in the journal heads are
 736	 * considered to be used, when calculating the current journal usage.
 737	 * Consequently, if the journal is too small, UBIFS will treat it as
 738	 * always full.
 739	 */
 740	tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
 741	if (c->bg_bud_bytes < tmp64)
 742		c->bg_bud_bytes = tmp64;
 743	if (c->max_bud_bytes < tmp64 + c->leb_size)
 744		c->max_bud_bytes = tmp64 + c->leb_size;
 745
 746	err = ubifs_calc_lpt_geom(c);
 747	if (err)
 748		return err;
 749
 750	/* Initialize effective LEB size used in budgeting calculations */
 751	c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
 752	return 0;
 753}
 754
 755/*
 756 * init_constants_master - initialize UBIFS constants.
 757 * @c: UBIFS file-system description object
 758 *
 759 * This is a helper function which initializes various UBIFS constants after
 760 * the master node has been read. It also checks various UBIFS parameters and
 761 * makes sure they are all right.
 762 */
 763static void init_constants_master(struct ubifs_info *c)
 764{
 765	long long tmp64;
 766
 767	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
 768	c->report_rp_size = ubifs_reported_space(c, c->rp_size);
 769
 770	/*
 771	 * Calculate total amount of FS blocks. This number is not used
 772	 * internally because it does not make much sense for UBIFS, but it is
 773	 * necessary to report something for the 'statfs()' call.
 774	 *
 775	 * Subtract the LEB reserved for GC, the LEB which is reserved for
 776	 * deletions, minimum LEBs for the index, and assume only one journal
 777	 * head is available.
 778	 */
 779	tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
 780	tmp64 *= (long long)c->leb_size - c->leb_overhead;
 781	tmp64 = ubifs_reported_space(c, tmp64);
 782	c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
 783}
 784
 785/**
 786 * take_gc_lnum - reserve GC LEB.
 787 * @c: UBIFS file-system description object
 788 *
 789 * This function ensures that the LEB reserved for garbage collection is marked
 790 * as "taken" in lprops. We also have to set free space to LEB size and dirty
 791 * space to zero, because lprops may contain out-of-date information if the
 792 * file-system was un-mounted before it has been committed. This function
 793 * returns zero in case of success and a negative error code in case of
 794 * failure.
 795 */
 796static int take_gc_lnum(struct ubifs_info *c)
 797{
 798	int err;
 799
 800	if (c->gc_lnum == -1) {
 801		ubifs_err(c, "no LEB for GC");
 802		return -EINVAL;
 803	}
 804
 805	/* And we have to tell lprops that this LEB is taken */
 806	err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
 807				  LPROPS_TAKEN, 0, 0);
 808	return err;
 809}
 810
 811/**
 812 * alloc_wbufs - allocate write-buffers.
 813 * @c: UBIFS file-system description object
 814 *
 815 * This helper function allocates and initializes UBIFS write-buffers. Returns
 816 * zero in case of success and %-ENOMEM in case of failure.
 817 */
 818static int alloc_wbufs(struct ubifs_info *c)
 819{
 820	int i, err;
 821
 822	c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),
 823			    GFP_KERNEL);
 824	if (!c->jheads)
 825		return -ENOMEM;
 826
 827	/* Initialize journal heads */
 828	for (i = 0; i < c->jhead_cnt; i++) {
 829		INIT_LIST_HEAD(&c->jheads[i].buds_list);
 830		err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
 831		if (err)
 832			goto out_wbuf;
 833
 834		c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
 835		c->jheads[i].wbuf.jhead = i;
 836		c->jheads[i].grouped = 1;
 837		c->jheads[i].log_hash = ubifs_hash_get_desc(c);
 838		if (IS_ERR(c->jheads[i].log_hash)) {
 839			err = PTR_ERR(c->jheads[i].log_hash);
 840			goto out_log_hash;
 841		}
 842	}
 843
 844	/*
 845	 * Garbage Collector head does not need to be synchronized by timer.
 846	 * Also GC head nodes are not grouped.
 847	 */
 848	c->jheads[GCHD].wbuf.no_timer = 1;
 849	c->jheads[GCHD].grouped = 0;
 850
 851	return 0;
 852
 853out_log_hash:
 854	kfree(c->jheads[i].wbuf.buf);
 855	kfree(c->jheads[i].wbuf.inodes);
 856
 857out_wbuf:
 858	while (i--) {
 859		kfree(c->jheads[i].wbuf.buf);
 860		kfree(c->jheads[i].wbuf.inodes);
 861		kfree(c->jheads[i].log_hash);
 862	}
 863	kfree(c->jheads);
 864	c->jheads = NULL;
 865
 866	return err;
 867}
 868
 869/**
 870 * free_wbufs - free write-buffers.
 871 * @c: UBIFS file-system description object
 872 */
 873static void free_wbufs(struct ubifs_info *c)
 874{
 875	int i;
 876
 877	if (c->jheads) {
 878		for (i = 0; i < c->jhead_cnt; i++) {
 879			kfree(c->jheads[i].wbuf.buf);
 880			kfree(c->jheads[i].wbuf.inodes);
 881			kfree(c->jheads[i].log_hash);
 882		}
 883		kfree(c->jheads);
 884		c->jheads = NULL;
 885	}
 886}
 887
 888/**
 889 * free_orphans - free orphans.
 890 * @c: UBIFS file-system description object
 891 */
 892static void free_orphans(struct ubifs_info *c)
 893{
 894	struct ubifs_orphan *orph;
 895
 896	while (c->orph_dnext) {
 897		orph = c->orph_dnext;
 898		c->orph_dnext = orph->dnext;
 899		list_del(&orph->list);
 900		kfree(orph);
 901	}
 902
 903	while (!list_empty(&c->orph_list)) {
 904		orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
 905		list_del(&orph->list);
 906		kfree(orph);
 907		ubifs_err(c, "orphan list not empty at unmount");
 908	}
 909
 910	vfree(c->orph_buf);
 911	c->orph_buf = NULL;
 912}
 913
 914/**
 915 * free_buds - free per-bud objects.
 916 * @c: UBIFS file-system description object
 917 */
 918static void free_buds(struct ubifs_info *c)
 919{
 920	struct ubifs_bud *bud, *n;
 921
 922	rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb) {
 923		kfree(bud->log_hash);
 924		kfree(bud);
 925	}
 926}
 927
 928/**
 929 * check_volume_empty - check if the UBI volume is empty.
 930 * @c: UBIFS file-system description object
 931 *
 932 * This function checks if the UBIFS volume is empty by looking if its LEBs are
 933 * mapped or not. The result of checking is stored in the @c->empty variable.
 934 * Returns zero in case of success and a negative error code in case of
 935 * failure.
 936 */
 937static int check_volume_empty(struct ubifs_info *c)
 938{
 939	int lnum, err;
 940
 941	c->empty = 1;
 942	for (lnum = 0; lnum < c->leb_cnt; lnum++) {
 943		err = ubifs_is_mapped(c, lnum);
 944		if (unlikely(err < 0))
 945			return err;
 946		if (err == 1) {
 947			c->empty = 0;
 948			break;
 949		}
 950
 951		cond_resched();
 952	}
 953
 954	return 0;
 955}
 956
 957/*
 958 * UBIFS mount options.
 959 *
 960 * Opt_fast_unmount: do not run a journal commit before un-mounting
 961 * Opt_norm_unmount: run a journal commit before un-mounting
 962 * Opt_bulk_read: enable bulk-reads
 963 * Opt_no_bulk_read: disable bulk-reads
 964 * Opt_chk_data_crc: check CRCs when reading data nodes
 965 * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
 966 * Opt_override_compr: override default compressor
 967 * Opt_assert: set ubifs_assert() action
 968 * Opt_auth_key: The key name used for authentication
 969 * Opt_auth_hash_name: The hash type used for authentication
 970 * Opt_err: just end of array marker
 971 */
 972enum {
 973	Opt_fast_unmount,
 974	Opt_norm_unmount,
 975	Opt_bulk_read,
 976	Opt_no_bulk_read,
 977	Opt_chk_data_crc,
 978	Opt_no_chk_data_crc,
 979	Opt_override_compr,
 980	Opt_assert,
 981	Opt_auth_key,
 982	Opt_auth_hash_name,
 983	Opt_ignore,
 984	Opt_err,
 985};
 986
 987static const match_table_t tokens = {
 988	{Opt_fast_unmount, "fast_unmount"},
 989	{Opt_norm_unmount, "norm_unmount"},
 990	{Opt_bulk_read, "bulk_read"},
 991	{Opt_no_bulk_read, "no_bulk_read"},
 992	{Opt_chk_data_crc, "chk_data_crc"},
 993	{Opt_no_chk_data_crc, "no_chk_data_crc"},
 994	{Opt_override_compr, "compr=%s"},
 995	{Opt_auth_key, "auth_key=%s"},
 996	{Opt_auth_hash_name, "auth_hash_name=%s"},
 997	{Opt_ignore, "ubi=%s"},
 998	{Opt_ignore, "vol=%s"},
 999	{Opt_assert, "assert=%s"},
1000	{Opt_err, NULL},
1001};
1002
1003/**
1004 * parse_standard_option - parse a standard mount option.
1005 * @option: the option to parse
1006 *
1007 * Normally, standard mount options like "sync" are passed to file-systems as
1008 * flags. However, when a "rootflags=" kernel boot parameter is used, they may
1009 * be present in the options string. This function tries to deal with this
1010 * situation and parse standard options. Returns 0 if the option was not
1011 * recognized, and the corresponding integer flag if it was.
1012 *
1013 * UBIFS is only interested in the "sync" option, so do not check for anything
1014 * else.
1015 */
1016static int parse_standard_option(const char *option)
1017{
1018
1019	pr_notice("UBIFS: parse %s\n", option);
1020	if (!strcmp(option, "sync"))
1021		return SB_SYNCHRONOUS;
1022	return 0;
1023}
1024
1025/**
1026 * ubifs_parse_options - parse mount parameters.
1027 * @c: UBIFS file-system description object
1028 * @options: parameters to parse
1029 * @is_remount: non-zero if this is FS re-mount
1030 *
1031 * This function parses UBIFS mount options and returns zero in case success
1032 * and a negative error code in case of failure.
1033 */
1034static int ubifs_parse_options(struct ubifs_info *c, char *options,
1035			       int is_remount)
1036{
1037	char *p;
1038	substring_t args[MAX_OPT_ARGS];
1039
1040	if (!options)
1041		return 0;
1042
1043	while ((p = strsep(&options, ","))) {
1044		int token;
1045
1046		if (!*p)
1047			continue;
1048
1049		token = match_token(p, tokens, args);
1050		switch (token) {
1051		/*
1052		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
1053		 * We accept them in order to be backward-compatible. But this
1054		 * should be removed at some point.
1055		 */
1056		case Opt_fast_unmount:
1057			c->mount_opts.unmount_mode = 2;
1058			break;
1059		case Opt_norm_unmount:
1060			c->mount_opts.unmount_mode = 1;
1061			break;
1062		case Opt_bulk_read:
1063			c->mount_opts.bulk_read = 2;
1064			c->bulk_read = 1;
1065			break;
1066		case Opt_no_bulk_read:
1067			c->mount_opts.bulk_read = 1;
1068			c->bulk_read = 0;
1069			break;
1070		case Opt_chk_data_crc:
1071			c->mount_opts.chk_data_crc = 2;
1072			c->no_chk_data_crc = 0;
1073			break;
1074		case Opt_no_chk_data_crc:
1075			c->mount_opts.chk_data_crc = 1;
1076			c->no_chk_data_crc = 1;
1077			break;
1078		case Opt_override_compr:
1079		{
1080			char *name = match_strdup(&args[0]);
1081
1082			if (!name)
1083				return -ENOMEM;
1084			if (!strcmp(name, "none"))
1085				c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1086			else if (!strcmp(name, "lzo"))
1087				c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1088			else if (!strcmp(name, "zlib"))
1089				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1090			else if (!strcmp(name, "zstd"))
1091				c->mount_opts.compr_type = UBIFS_COMPR_ZSTD;
1092			else {
1093				ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
1094				kfree(name);
1095				return -EINVAL;
1096			}
1097			kfree(name);
1098			c->mount_opts.override_compr = 1;
1099			c->default_compr = c->mount_opts.compr_type;
1100			break;
1101		}
1102		case Opt_assert:
1103		{
1104			char *act = match_strdup(&args[0]);
1105
1106			if (!act)
1107				return -ENOMEM;
1108			if (!strcmp(act, "report"))
1109				c->assert_action = ASSACT_REPORT;
1110			else if (!strcmp(act, "read-only"))
1111				c->assert_action = ASSACT_RO;
1112			else if (!strcmp(act, "panic"))
1113				c->assert_action = ASSACT_PANIC;
1114			else {
1115				ubifs_err(c, "unknown assert action \"%s\"", act);
1116				kfree(act);
1117				return -EINVAL;
1118			}
1119			kfree(act);
1120			break;
1121		}
1122		case Opt_auth_key:
1123			if (!is_remount) {
1124				c->auth_key_name = kstrdup(args[0].from,
1125								GFP_KERNEL);
1126				if (!c->auth_key_name)
1127					return -ENOMEM;
1128			}
1129			break;
1130		case Opt_auth_hash_name:
1131			if (!is_remount) {
1132				c->auth_hash_name = kstrdup(args[0].from,
1133								GFP_KERNEL);
1134				if (!c->auth_hash_name)
1135					return -ENOMEM;
1136			}
1137			break;
1138		case Opt_ignore:
1139			break;
1140		default:
1141		{
1142			unsigned long flag;
1143			struct super_block *sb = c->vfs_sb;
1144
1145			flag = parse_standard_option(p);
1146			if (!flag) {
1147				ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
1148					  p);
1149				return -EINVAL;
1150			}
1151			sb->s_flags |= flag;
1152			break;
1153		}
1154		}
1155	}
1156
1157	return 0;
1158}
1159
1160/*
1161 * ubifs_release_options - release mount parameters which have been dumped.
1162 * @c: UBIFS file-system description object
1163 */
1164static void ubifs_release_options(struct ubifs_info *c)
1165{
1166	kfree(c->auth_key_name);
1167	c->auth_key_name = NULL;
1168	kfree(c->auth_hash_name);
1169	c->auth_hash_name = NULL;
1170}
1171
1172/**
1173 * destroy_journal - destroy journal data structures.
1174 * @c: UBIFS file-system description object
1175 *
1176 * This function destroys journal data structures including those that may have
1177 * been created by recovery functions.
1178 */
1179static void destroy_journal(struct ubifs_info *c)
1180{
1181	while (!list_empty(&c->unclean_leb_list)) {
1182		struct ubifs_unclean_leb *ucleb;
1183
1184		ucleb = list_entry(c->unclean_leb_list.next,
1185				   struct ubifs_unclean_leb, list);
1186		list_del(&ucleb->list);
1187		kfree(ucleb);
1188	}
1189	while (!list_empty(&c->old_buds)) {
1190		struct ubifs_bud *bud;
1191
1192		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1193		list_del(&bud->list);
1194		kfree(bud->log_hash);
1195		kfree(bud);
1196	}
1197	ubifs_destroy_idx_gc(c);
1198	ubifs_destroy_size_tree(c);
1199	ubifs_tnc_close(c);
1200	free_buds(c);
1201}
1202
1203/**
1204 * bu_init - initialize bulk-read information.
1205 * @c: UBIFS file-system description object
1206 */
1207static void bu_init(struct ubifs_info *c)
1208{
1209	ubifs_assert(c, c->bulk_read == 1);
1210
1211	if (c->bu.buf)
1212		return; /* Already initialized */
1213
1214again:
1215	c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1216	if (!c->bu.buf) {
1217		if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1218			c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1219			goto again;
1220		}
1221
1222		/* Just disable bulk-read */
1223		ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
1224			   c->max_bu_buf_len);
1225		c->mount_opts.bulk_read = 1;
1226		c->bulk_read = 0;
1227		return;
1228	}
1229}
1230
1231/**
1232 * check_free_space - check if there is enough free space to mount.
1233 * @c: UBIFS file-system description object
1234 *
1235 * This function makes sure UBIFS has enough free space to be mounted in
1236 * read/write mode. UBIFS must always have some free space to allow deletions.
1237 */
1238static int check_free_space(struct ubifs_info *c)
1239{
1240	ubifs_assert(c, c->dark_wm > 0);
1241	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1242		ubifs_err(c, "insufficient free space to mount in R/W mode");
1243		ubifs_dump_budg(c, &c->bi);
1244		ubifs_dump_lprops(c);
1245		return -ENOSPC;
1246	}
1247	return 0;
1248}
1249
1250/**
1251 * mount_ubifs - mount UBIFS file-system.
1252 * @c: UBIFS file-system description object
1253 *
1254 * This function mounts UBIFS file system. Returns zero in case of success and
1255 * a negative error code in case of failure.
1256 */
1257static int mount_ubifs(struct ubifs_info *c)
1258{
1259	int err;
1260	long long x, y;
1261	size_t sz;
1262
1263	c->ro_mount = !!sb_rdonly(c->vfs_sb);
1264	/* Suppress error messages while probing if SB_SILENT is set */
1265	c->probing = !!(c->vfs_sb->s_flags & SB_SILENT);
1266
1267	err = init_constants_early(c);
1268	if (err)
1269		return err;
1270
1271	err = ubifs_debugging_init(c);
1272	if (err)
1273		return err;
1274
1275	err = ubifs_sysfs_register(c);
1276	if (err)
1277		goto out_debugging;
1278
1279	err = check_volume_empty(c);
1280	if (err)
1281		goto out_free;
1282
1283	if (c->empty && (c->ro_mount || c->ro_media)) {
1284		/*
1285		 * This UBI volume is empty, and read-only, or the file system
1286		 * is mounted read-only - we cannot format it.
1287		 */
1288		ubifs_err(c, "can't format empty UBI volume: read-only %s",
1289			  c->ro_media ? "UBI volume" : "mount");
1290		err = -EROFS;
1291		goto out_free;
1292	}
1293
1294	if (c->ro_media && !c->ro_mount) {
1295		ubifs_err(c, "cannot mount read-write - read-only media");
1296		err = -EROFS;
1297		goto out_free;
1298	}
1299
1300	/*
1301	 * The requirement for the buffer is that it should fit indexing B-tree
1302	 * height amount of integers. We assume the height if the TNC tree will
1303	 * never exceed 64.
1304	 */
1305	err = -ENOMEM;
1306	c->bottom_up_buf = kmalloc_array(BOTTOM_UP_HEIGHT, sizeof(int),
1307					 GFP_KERNEL);
1308	if (!c->bottom_up_buf)
1309		goto out_free;
1310
1311	c->sbuf = vmalloc(c->leb_size);
1312	if (!c->sbuf)
1313		goto out_free;
1314
1315	if (!c->ro_mount) {
1316		c->ileb_buf = vmalloc(c->leb_size);
1317		if (!c->ileb_buf)
1318			goto out_free;
1319	}
1320
1321	if (c->bulk_read == 1)
1322		bu_init(c);
1323
1324	if (!c->ro_mount) {
1325		c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1326					       UBIFS_CIPHER_BLOCK_SIZE,
1327					       GFP_KERNEL);
1328		if (!c->write_reserve_buf)
1329			goto out_free;
1330	}
1331
1332	c->mounting = 1;
1333
1334	if (c->auth_key_name) {
1335		if (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) {
1336			err = ubifs_init_authentication(c);
1337			if (err)
1338				goto out_free;
1339		} else {
1340			ubifs_err(c, "auth_key_name, but UBIFS is built without"
1341				  " authentication support");
1342			err = -EINVAL;
1343			goto out_free;
1344		}
1345	}
1346
1347	err = ubifs_read_superblock(c);
1348	if (err)
1349		goto out_auth;
1350
1351	c->probing = 0;
1352
1353	/*
1354	 * Make sure the compressor which is set as default in the superblock
1355	 * or overridden by mount options is actually compiled in.
1356	 */
1357	if (!ubifs_compr_present(c, c->default_compr)) {
1358		ubifs_err(c, "'compressor \"%s\" is not compiled in",
1359			  ubifs_compr_name(c, c->default_compr));
1360		err = -ENOTSUPP;
1361		goto out_auth;
1362	}
1363
1364	err = init_constants_sb(c);
1365	if (err)
1366		goto out_auth;
1367
1368	sz = ALIGN(c->max_idx_node_sz, c->min_io_size) * 2;
1369	c->cbuf = kmalloc(sz, GFP_NOFS);
1370	if (!c->cbuf) {
1371		err = -ENOMEM;
1372		goto out_auth;
1373	}
1374
1375	err = alloc_wbufs(c);
1376	if (err)
1377		goto out_cbuf;
1378
1379	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1380	if (!c->ro_mount) {
1381		/* Create background thread */
1382		c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
1383		if (IS_ERR(c->bgt)) {
1384			err = PTR_ERR(c->bgt);
1385			c->bgt = NULL;
1386			ubifs_err(c, "cannot spawn \"%s\", error %d",
1387				  c->bgt_name, err);
1388			goto out_wbufs;
1389		}
1390	}
1391
1392	err = ubifs_read_master(c);
1393	if (err)
1394		goto out_master;
1395
1396	init_constants_master(c);
1397
1398	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1399		ubifs_msg(c, "recovery needed");
1400		c->need_recovery = 1;
1401	}
1402
1403	if (c->need_recovery && !c->ro_mount) {
1404		err = ubifs_recover_inl_heads(c, c->sbuf);
1405		if (err)
1406			goto out_master;
1407	}
1408
1409	err = ubifs_lpt_init(c, 1, !c->ro_mount);
1410	if (err)
1411		goto out_master;
1412
1413	if (!c->ro_mount && c->space_fixup) {
1414		err = ubifs_fixup_free_space(c);
1415		if (err)
1416			goto out_lpt;
1417	}
1418
1419	if (!c->ro_mount && !c->need_recovery) {
1420		/*
1421		 * Set the "dirty" flag so that if we reboot uncleanly we
1422		 * will notice this immediately on the next mount.
1423		 */
1424		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1425		err = ubifs_write_master(c);
1426		if (err)
1427			goto out_lpt;
1428	}
1429
1430	/*
1431	 * Handle offline signed images: Now that the master node is
1432	 * written and its validation no longer depends on the hash
1433	 * in the superblock, we can update the offline signed
1434	 * superblock with a HMAC version,
1435	 */
1436	if (ubifs_authenticated(c) && ubifs_hmac_zero(c, c->sup_node->hmac)) {
1437		err = ubifs_hmac_wkm(c, c->sup_node->hmac_wkm);
1438		if (err)
1439			goto out_lpt;
1440		c->superblock_need_write = 1;
1441	}
1442
1443	if (!c->ro_mount && c->superblock_need_write) {
1444		err = ubifs_write_sb_node(c, c->sup_node);
1445		if (err)
1446			goto out_lpt;
1447		c->superblock_need_write = 0;
1448	}
1449
1450	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1451	if (err)
1452		goto out_lpt;
1453
1454	err = ubifs_replay_journal(c);
1455	if (err)
1456		goto out_journal;
1457
1458	/* Calculate 'min_idx_lebs' after journal replay */
1459	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1460
1461	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1462	if (err)
1463		goto out_orphans;
1464
1465	if (!c->ro_mount) {
1466		int lnum;
1467
1468		err = check_free_space(c);
1469		if (err)
1470			goto out_orphans;
1471
1472		/* Check for enough log space */
1473		lnum = c->lhead_lnum + 1;
1474		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1475			lnum = UBIFS_LOG_LNUM;
1476		if (lnum == c->ltail_lnum) {
1477			err = ubifs_consolidate_log(c);
1478			if (err)
1479				goto out_orphans;
1480		}
1481
1482		if (c->need_recovery) {
1483			if (!ubifs_authenticated(c)) {
1484				err = ubifs_recover_size(c, true);
1485				if (err)
1486					goto out_orphans;
1487			}
1488
1489			err = ubifs_rcvry_gc_commit(c);
1490			if (err)
1491				goto out_orphans;
1492
1493			if (ubifs_authenticated(c)) {
1494				err = ubifs_recover_size(c, false);
1495				if (err)
1496					goto out_orphans;
1497			}
1498		} else {
1499			err = take_gc_lnum(c);
1500			if (err)
1501				goto out_orphans;
1502
1503			/*
1504			 * GC LEB may contain garbage if there was an unclean
1505			 * reboot, and it should be un-mapped.
1506			 */
1507			err = ubifs_leb_unmap(c, c->gc_lnum);
1508			if (err)
1509				goto out_orphans;
1510		}
1511
1512		err = dbg_check_lprops(c);
1513		if (err)
1514			goto out_orphans;
1515	} else if (c->need_recovery) {
1516		err = ubifs_recover_size(c, false);
1517		if (err)
1518			goto out_orphans;
1519	} else {
1520		/*
1521		 * Even if we mount read-only, we have to set space in GC LEB
1522		 * to proper value because this affects UBIFS free space
1523		 * reporting. We do not want to have a situation when
1524		 * re-mounting from R/O to R/W changes amount of free space.
1525		 */
1526		err = take_gc_lnum(c);
1527		if (err)
1528			goto out_orphans;
1529	}
1530
1531	spin_lock(&ubifs_infos_lock);
1532	list_add_tail(&c->infos_list, &ubifs_infos);
1533	spin_unlock(&ubifs_infos_lock);
1534
1535	if (c->need_recovery) {
1536		if (c->ro_mount)
1537			ubifs_msg(c, "recovery deferred");
1538		else {
1539			c->need_recovery = 0;
1540			ubifs_msg(c, "recovery completed");
1541			/*
1542			 * GC LEB has to be empty and taken at this point. But
1543			 * the journal head LEBs may also be accounted as
1544			 * "empty taken" if they are empty.
1545			 */
1546			ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1547		}
1548	} else
1549		ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1550
1551	err = dbg_check_filesystem(c);
1552	if (err)
1553		goto out_infos;
1554
1555	dbg_debugfs_init_fs(c);
1556
1557	c->mounting = 0;
1558
1559	ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
1560		  c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1561		  c->ro_mount ? ", R/O mode" : "");
1562	x = (long long)c->main_lebs * c->leb_size;
1563	y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1564	ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1565		  c->leb_size, c->leb_size >> 10, c->min_io_size,
1566		  c->max_write_size);
1567	ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), max %d LEBs, journal size %lld bytes (%lld MiB, %d LEBs)",
1568		  x, x >> 20, c->main_lebs, c->max_leb_cnt,
1569		  y, y >> 20, c->log_lebs + c->max_bud_cnt);
1570	ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
1571		  c->report_rp_size, c->report_rp_size >> 10);
1572	ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1573		  c->fmt_version, c->ro_compat_version,
1574		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1575		  c->big_lpt ? ", big LPT model" : ", small LPT model");
1576
1577	dbg_gen("default compressor:  %s", ubifs_compr_name(c, c->default_compr));
1578	dbg_gen("data journal heads:  %d",
1579		c->jhead_cnt - NONDATA_JHEADS_CNT);
1580	dbg_gen("log LEBs:            %d (%d - %d)",
1581		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1582	dbg_gen("LPT area LEBs:       %d (%d - %d)",
1583		c->lpt_lebs, c->lpt_first, c->lpt_last);
1584	dbg_gen("orphan area LEBs:    %d (%d - %d)",
1585		c->orph_lebs, c->orph_first, c->orph_last);
1586	dbg_gen("main area LEBs:      %d (%d - %d)",
1587		c->main_lebs, c->main_first, c->leb_cnt - 1);
1588	dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1589	dbg_gen("total index bytes:   %llu (%llu KiB, %llu MiB)",
1590		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1591		c->bi.old_idx_sz >> 20);
1592	dbg_gen("key hash type:       %d", c->key_hash_type);
1593	dbg_gen("tree fanout:         %d", c->fanout);
1594	dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1595	dbg_gen("max. znode size      %d", c->max_znode_sz);
1596	dbg_gen("max. index node size %d", c->max_idx_node_sz);
1597	dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1598		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1599	dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1600		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1601	dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1602		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1603	dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1604		UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1605		UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1606	dbg_gen("dead watermark:      %d", c->dead_wm);
1607	dbg_gen("dark watermark:      %d", c->dark_wm);
1608	dbg_gen("LEB overhead:        %d", c->leb_overhead);
1609	x = (long long)c->main_lebs * c->dark_wm;
1610	dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1611		x, x >> 10, x >> 20);
1612	dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1613		c->max_bud_bytes, c->max_bud_bytes >> 10,
1614		c->max_bud_bytes >> 20);
1615	dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1616		c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1617		c->bg_bud_bytes >> 20);
1618	dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1619		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1620	dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1621	dbg_gen("commit number:       %llu", c->cmt_no);
1622	dbg_gen("max. xattrs per inode: %d", ubifs_xattr_max_cnt(c));
1623	dbg_gen("max orphans:           %d", c->max_orphans);
1624
1625	return 0;
1626
1627out_infos:
1628	spin_lock(&ubifs_infos_lock);
1629	list_del(&c->infos_list);
1630	spin_unlock(&ubifs_infos_lock);
1631out_orphans:
1632	free_orphans(c);
1633out_journal:
1634	destroy_journal(c);
1635out_lpt:
1636	ubifs_lpt_free(c, 0);
1637out_master:
1638	kfree(c->mst_node);
1639	kfree(c->rcvrd_mst_node);
1640	if (c->bgt)
1641		kthread_stop(c->bgt);
1642out_wbufs:
1643	free_wbufs(c);
1644out_cbuf:
1645	kfree(c->cbuf);
1646out_auth:
1647	ubifs_exit_authentication(c);
1648out_free:
1649	kfree(c->write_reserve_buf);
1650	kfree(c->bu.buf);
1651	vfree(c->ileb_buf);
1652	vfree(c->sbuf);
1653	kfree(c->bottom_up_buf);
1654	kfree(c->sup_node);
1655	ubifs_sysfs_unregister(c);
1656out_debugging:
1657	ubifs_debugging_exit(c);
1658	return err;
1659}
1660
1661/**
1662 * ubifs_umount - un-mount UBIFS file-system.
1663 * @c: UBIFS file-system description object
1664 *
1665 * Note, this function is called to free allocated resourced when un-mounting,
1666 * as well as free resources when an error occurred while we were half way
1667 * through mounting (error path cleanup function). So it has to make sure the
1668 * resource was actually allocated before freeing it.
1669 */
1670static void ubifs_umount(struct ubifs_info *c)
1671{
1672	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1673		c->vi.vol_id);
1674
1675	dbg_debugfs_exit_fs(c);
1676	spin_lock(&ubifs_infos_lock);
1677	list_del(&c->infos_list);
1678	spin_unlock(&ubifs_infos_lock);
1679
1680	if (c->bgt)
1681		kthread_stop(c->bgt);
1682
1683	destroy_journal(c);
1684	free_wbufs(c);
1685	free_orphans(c);
1686	ubifs_lpt_free(c, 0);
1687	ubifs_exit_authentication(c);
1688
1689	ubifs_release_options(c);
1690	kfree(c->cbuf);
1691	kfree(c->rcvrd_mst_node);
1692	kfree(c->mst_node);
1693	kfree(c->write_reserve_buf);
1694	kfree(c->bu.buf);
1695	vfree(c->ileb_buf);
1696	vfree(c->sbuf);
1697	kfree(c->bottom_up_buf);
1698	kfree(c->sup_node);
1699	ubifs_debugging_exit(c);
1700	ubifs_sysfs_unregister(c);
1701}
1702
1703/**
1704 * ubifs_remount_rw - re-mount in read-write mode.
1705 * @c: UBIFS file-system description object
1706 *
1707 * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1708 * mode. This function allocates the needed resources and re-mounts UBIFS in
1709 * read-write mode.
1710 */
1711static int ubifs_remount_rw(struct ubifs_info *c)
1712{
1713	int err, lnum;
1714
1715	if (c->rw_incompat) {
1716		ubifs_err(c, "the file-system is not R/W-compatible");
1717		ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1718			  c->fmt_version, c->ro_compat_version,
1719			  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1720		return -EROFS;
1721	}
1722
1723	mutex_lock(&c->umount_mutex);
1724	dbg_save_space_info(c);
1725	c->remounting_rw = 1;
1726	c->ro_mount = 0;
1727
1728	if (c->space_fixup) {
1729		err = ubifs_fixup_free_space(c);
1730		if (err)
1731			goto out;
1732	}
1733
1734	err = check_free_space(c);
1735	if (err)
1736		goto out;
1737
1738	if (c->need_recovery) {
1739		ubifs_msg(c, "completing deferred recovery");
1740		err = ubifs_write_rcvrd_mst_node(c);
1741		if (err)
1742			goto out;
1743		if (!ubifs_authenticated(c)) {
1744			err = ubifs_recover_size(c, true);
1745			if (err)
1746				goto out;
1747		}
1748		err = ubifs_clean_lebs(c, c->sbuf);
1749		if (err)
1750			goto out;
1751		err = ubifs_recover_inl_heads(c, c->sbuf);
1752		if (err)
1753			goto out;
1754	} else {
1755		/* A readonly mount is not allowed to have orphans */
1756		ubifs_assert(c, c->tot_orphans == 0);
1757		err = ubifs_clear_orphans(c);
1758		if (err)
1759			goto out;
1760	}
1761
1762	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1763		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1764		err = ubifs_write_master(c);
1765		if (err)
1766			goto out;
1767	}
1768
1769	if (c->superblock_need_write) {
1770		struct ubifs_sb_node *sup = c->sup_node;
1771
1772		err = ubifs_write_sb_node(c, sup);
1773		if (err)
1774			goto out;
1775
1776		c->superblock_need_write = 0;
1777	}
1778
1779	c->ileb_buf = vmalloc(c->leb_size);
1780	if (!c->ileb_buf) {
1781		err = -ENOMEM;
1782		goto out;
1783	}
1784
1785	c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1786				       UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);
1787	if (!c->write_reserve_buf) {
1788		err = -ENOMEM;
1789		goto out;
1790	}
1791
1792	err = ubifs_lpt_init(c, 0, 1);
1793	if (err)
1794		goto out;
1795
1796	/* Create background thread */
1797	c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
1798	if (IS_ERR(c->bgt)) {
1799		err = PTR_ERR(c->bgt);
1800		c->bgt = NULL;
1801		ubifs_err(c, "cannot spawn \"%s\", error %d",
1802			  c->bgt_name, err);
1803		goto out;
1804	}
1805
1806	c->orph_buf = vmalloc(c->leb_size);
1807	if (!c->orph_buf) {
1808		err = -ENOMEM;
1809		goto out;
1810	}
1811
1812	/* Check for enough log space */
1813	lnum = c->lhead_lnum + 1;
1814	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1815		lnum = UBIFS_LOG_LNUM;
1816	if (lnum == c->ltail_lnum) {
1817		err = ubifs_consolidate_log(c);
1818		if (err)
1819			goto out;
1820	}
1821
1822	if (c->need_recovery) {
1823		err = ubifs_rcvry_gc_commit(c);
1824		if (err)
1825			goto out;
1826
1827		if (ubifs_authenticated(c)) {
1828			err = ubifs_recover_size(c, false);
1829			if (err)
1830				goto out;
1831		}
1832	} else {
1833		err = ubifs_leb_unmap(c, c->gc_lnum);
1834	}
1835	if (err)
1836		goto out;
1837
1838	dbg_gen("re-mounted read-write");
1839	c->remounting_rw = 0;
1840
1841	if (c->need_recovery) {
1842		c->need_recovery = 0;
1843		ubifs_msg(c, "deferred recovery completed");
1844	} else {
1845		/*
1846		 * Do not run the debugging space check if the were doing
1847		 * recovery, because when we saved the information we had the
1848		 * file-system in a state where the TNC and lprops has been
1849		 * modified in memory, but all the I/O operations (including a
1850		 * commit) were deferred. So the file-system was in
1851		 * "non-committed" state. Now the file-system is in committed
1852		 * state, and of course the amount of free space will change
1853		 * because, for example, the old index size was imprecise.
1854		 */
1855		err = dbg_check_space_info(c);
1856	}
1857
1858	mutex_unlock(&c->umount_mutex);
1859	return err;
1860
1861out:
1862	c->ro_mount = 1;
1863	vfree(c->orph_buf);
1864	c->orph_buf = NULL;
1865	if (c->bgt) {
1866		kthread_stop(c->bgt);
1867		c->bgt = NULL;
1868	}
1869	kfree(c->write_reserve_buf);
1870	c->write_reserve_buf = NULL;
1871	vfree(c->ileb_buf);
1872	c->ileb_buf = NULL;
1873	ubifs_lpt_free(c, 1);
1874	c->remounting_rw = 0;
1875	mutex_unlock(&c->umount_mutex);
1876	return err;
1877}
1878
1879/**
1880 * ubifs_remount_ro - re-mount in read-only mode.
1881 * @c: UBIFS file-system description object
1882 *
1883 * We assume VFS has stopped writing. Possibly the background thread could be
1884 * running a commit, however kthread_stop will wait in that case.
1885 */
1886static void ubifs_remount_ro(struct ubifs_info *c)
1887{
1888	int i, err;
1889
1890	ubifs_assert(c, !c->need_recovery);
1891	ubifs_assert(c, !c->ro_mount);
1892
1893	mutex_lock(&c->umount_mutex);
1894	if (c->bgt) {
1895		kthread_stop(c->bgt);
1896		c->bgt = NULL;
1897	}
1898
1899	dbg_save_space_info(c);
1900
1901	for (i = 0; i < c->jhead_cnt; i++) {
1902		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1903		if (err)
1904			ubifs_ro_mode(c, err);
1905	}
1906
1907	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1908	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1909	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1910	err = ubifs_write_master(c);
1911	if (err)
1912		ubifs_ro_mode(c, err);
1913
1914	vfree(c->orph_buf);
1915	c->orph_buf = NULL;
1916	kfree(c->write_reserve_buf);
1917	c->write_reserve_buf = NULL;
1918	vfree(c->ileb_buf);
1919	c->ileb_buf = NULL;
1920	ubifs_lpt_free(c, 1);
1921	c->ro_mount = 1;
1922	err = dbg_check_space_info(c);
1923	if (err)
1924		ubifs_ro_mode(c, err);
1925	mutex_unlock(&c->umount_mutex);
1926}
1927
1928static void ubifs_put_super(struct super_block *sb)
1929{
1930	int i;
1931	struct ubifs_info *c = sb->s_fs_info;
1932
1933	ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
1934
1935	/*
1936	 * The following asserts are only valid if there has not been a failure
1937	 * of the media. For example, there will be dirty inodes if we failed
1938	 * to write them back because of I/O errors.
1939	 */
1940	if (!c->ro_error) {
1941		ubifs_assert(c, c->bi.idx_growth == 0);
1942		ubifs_assert(c, c->bi.dd_growth == 0);
1943		ubifs_assert(c, c->bi.data_growth == 0);
1944	}
1945
1946	/*
1947	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1948	 * and file system un-mount. Namely, it prevents the shrinker from
1949	 * picking this superblock for shrinking - it will be just skipped if
1950	 * the mutex is locked.
1951	 */
1952	mutex_lock(&c->umount_mutex);
1953	if (!c->ro_mount) {
1954		/*
1955		 * First of all kill the background thread to make sure it does
1956		 * not interfere with un-mounting and freeing resources.
1957		 */
1958		if (c->bgt) {
1959			kthread_stop(c->bgt);
1960			c->bgt = NULL;
1961		}
1962
1963		/*
1964		 * On fatal errors c->ro_error is set to 1, in which case we do
1965		 * not write the master node.
1966		 */
1967		if (!c->ro_error) {
1968			int err;
1969
1970			/* Synchronize write-buffers */
1971			for (i = 0; i < c->jhead_cnt; i++) {
1972				err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1973				if (err)
1974					ubifs_ro_mode(c, err);
1975			}
1976
1977			/*
1978			 * We are being cleanly unmounted which means the
1979			 * orphans were killed - indicate this in the master
1980			 * node. Also save the reserved GC LEB number.
1981			 */
1982			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1983			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1984			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1985			err = ubifs_write_master(c);
1986			if (err)
1987				/*
1988				 * Recovery will attempt to fix the master area
1989				 * next mount, so we just print a message and
1990				 * continue to unmount normally.
1991				 */
1992				ubifs_err(c, "failed to write master node, error %d",
1993					  err);
1994		} else {
1995			for (i = 0; i < c->jhead_cnt; i++)
1996				/* Make sure write-buffer timers are canceled */
1997				hrtimer_cancel(&c->jheads[i].wbuf.timer);
1998		}
1999	}
2000
2001	ubifs_umount(c);
2002	ubi_close_volume(c->ubi);
2003	mutex_unlock(&c->umount_mutex);
2004}
2005
2006static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
2007{
2008	int err;
2009	struct ubifs_info *c = sb->s_fs_info;
2010
2011	sync_filesystem(sb);
2012	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
2013
2014	err = ubifs_parse_options(c, data, 1);
2015	if (err) {
2016		ubifs_err(c, "invalid or unknown remount parameter");
2017		return err;
2018	}
2019
2020	if (c->ro_mount && !(*flags & SB_RDONLY)) {
2021		if (c->ro_error) {
2022			ubifs_msg(c, "cannot re-mount R/W due to prior errors");
2023			return -EROFS;
2024		}
2025		if (c->ro_media) {
2026			ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
2027			return -EROFS;
2028		}
2029		err = ubifs_remount_rw(c);
2030		if (err)
2031			return err;
2032	} else if (!c->ro_mount && (*flags & SB_RDONLY)) {
2033		if (c->ro_error) {
2034			ubifs_msg(c, "cannot re-mount R/O due to prior errors");
2035			return -EROFS;
2036		}
2037		ubifs_remount_ro(c);
2038	}
2039
2040	if (c->bulk_read == 1)
2041		bu_init(c);
2042	else {
2043		dbg_gen("disable bulk-read");
2044		mutex_lock(&c->bu_mutex);
2045		kfree(c->bu.buf);
2046		c->bu.buf = NULL;
2047		mutex_unlock(&c->bu_mutex);
2048	}
2049
2050	if (!c->need_recovery)
2051		ubifs_assert(c, c->lst.taken_empty_lebs > 0);
2052
2053	return 0;
2054}
2055
2056const struct super_operations ubifs_super_operations = {
2057	.alloc_inode   = ubifs_alloc_inode,
2058	.free_inode    = ubifs_free_inode,
2059	.put_super     = ubifs_put_super,
2060	.write_inode   = ubifs_write_inode,
2061	.drop_inode    = ubifs_drop_inode,
2062	.evict_inode   = ubifs_evict_inode,
2063	.statfs        = ubifs_statfs,
2064	.dirty_inode   = ubifs_dirty_inode,
2065	.remount_fs    = ubifs_remount_fs,
2066	.show_options  = ubifs_show_options,
2067	.sync_fs       = ubifs_sync_fs,
2068};
2069
2070/**
2071 * open_ubi - parse UBI device name string and open the UBI device.
2072 * @name: UBI volume name
2073 * @mode: UBI volume open mode
2074 *
2075 * The primary method of mounting UBIFS is by specifying the UBI volume
2076 * character device node path. However, UBIFS may also be mounted without any
2077 * character device node using one of the following methods:
2078 *
2079 * o ubiX_Y    - mount UBI device number X, volume Y;
2080 * o ubiY      - mount UBI device number 0, volume Y;
2081 * o ubiX:NAME - mount UBI device X, volume with name NAME;
2082 * o ubi:NAME  - mount UBI device 0, volume with name NAME.
2083 *
2084 * Alternative '!' separator may be used instead of ':' (because some shells
2085 * like busybox may interpret ':' as an NFS host name separator). This function
2086 * returns UBI volume description object in case of success and a negative
2087 * error code in case of failure.
2088 */
2089static struct ubi_volume_desc *open_ubi(const char *name, int mode)
2090{
2091	struct ubi_volume_desc *ubi;
2092	int dev, vol;
2093	char *endptr;
2094
2095	if (!name || !*name)
2096		return ERR_PTR(-EINVAL);
2097
2098	/* First, try to open using the device node path method */
2099	ubi = ubi_open_volume_path(name, mode);
2100	if (!IS_ERR(ubi))
2101		return ubi;
2102
2103	/* Try the "nodev" method */
2104	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
2105		return ERR_PTR(-EINVAL);
2106
2107	/* ubi:NAME method */
2108	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
2109		return ubi_open_volume_nm(0, name + 4, mode);
2110
2111	if (!isdigit(name[3]))
2112		return ERR_PTR(-EINVAL);
2113
2114	dev = simple_strtoul(name + 3, &endptr, 0);
2115
2116	/* ubiY method */
2117	if (*endptr == '\0')
2118		return ubi_open_volume(0, dev, mode);
2119
2120	/* ubiX_Y method */
2121	if (*endptr == '_' && isdigit(endptr[1])) {
2122		vol = simple_strtoul(endptr + 1, &endptr, 0);
2123		if (*endptr != '\0')
2124			return ERR_PTR(-EINVAL);
2125		return ubi_open_volume(dev, vol, mode);
2126	}
2127
2128	/* ubiX:NAME method */
2129	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
2130		return ubi_open_volume_nm(dev, ++endptr, mode);
2131
2132	return ERR_PTR(-EINVAL);
2133}
2134
2135static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
2136{
2137	struct ubifs_info *c;
2138
2139	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
2140	if (c) {
2141		spin_lock_init(&c->cnt_lock);
2142		spin_lock_init(&c->cs_lock);
2143		spin_lock_init(&c->buds_lock);
2144		spin_lock_init(&c->space_lock);
2145		spin_lock_init(&c->orphan_lock);
2146		init_rwsem(&c->commit_sem);
2147		mutex_init(&c->lp_mutex);
2148		mutex_init(&c->tnc_mutex);
2149		mutex_init(&c->log_mutex);
2150		mutex_init(&c->umount_mutex);
2151		mutex_init(&c->bu_mutex);
2152		mutex_init(&c->write_reserve_mutex);
2153		init_waitqueue_head(&c->cmt_wq);
2154		c->buds = RB_ROOT;
2155		c->old_idx = RB_ROOT;
2156		c->size_tree = RB_ROOT;
2157		c->orph_tree = RB_ROOT;
2158		INIT_LIST_HEAD(&c->infos_list);
2159		INIT_LIST_HEAD(&c->idx_gc);
2160		INIT_LIST_HEAD(&c->replay_list);
2161		INIT_LIST_HEAD(&c->replay_buds);
2162		INIT_LIST_HEAD(&c->uncat_list);
2163		INIT_LIST_HEAD(&c->empty_list);
2164		INIT_LIST_HEAD(&c->freeable_list);
2165		INIT_LIST_HEAD(&c->frdi_idx_list);
2166		INIT_LIST_HEAD(&c->unclean_leb_list);
2167		INIT_LIST_HEAD(&c->old_buds);
2168		INIT_LIST_HEAD(&c->orph_list);
2169		INIT_LIST_HEAD(&c->orph_new);
2170		c->no_chk_data_crc = 1;
2171		c->assert_action = ASSACT_RO;
2172
2173		c->highest_inum = UBIFS_FIRST_INO;
2174		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2175
2176		ubi_get_volume_info(ubi, &c->vi);
2177		ubi_get_device_info(c->vi.ubi_num, &c->di);
2178	}
2179	return c;
2180}
2181
2182static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2183{
2184	struct ubifs_info *c = sb->s_fs_info;
2185	struct inode *root;
2186	int err;
2187
2188	c->vfs_sb = sb;
2189	/* Re-open the UBI device in read-write mode */
2190	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2191	if (IS_ERR(c->ubi)) {
2192		err = PTR_ERR(c->ubi);
2193		goto out;
2194	}
2195
2196	err = ubifs_parse_options(c, data, 0);
2197	if (err)
2198		goto out_close;
2199
2200	/*
2201	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2202	 * UBIFS, I/O is not deferred, it is done immediately in read_folio,
2203	 * which means the user would have to wait not just for their own I/O
2204	 * but the read-ahead I/O as well i.e. completely pointless.
2205	 *
2206	 * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also
2207	 * @sb->s_bdi->capabilities are initialized to 0 so there won't be any
2208	 * writeback happening.
2209	 */
2210	err = super_setup_bdi_name(sb, "ubifs_%d_%d", c->vi.ubi_num,
2211				   c->vi.vol_id);
2212	if (err)
2213		goto out_close;
2214	sb->s_bdi->ra_pages = 0;
2215	sb->s_bdi->io_pages = 0;
2216
2217	sb->s_fs_info = c;
2218	sb->s_magic = UBIFS_SUPER_MAGIC;
2219	sb->s_blocksize = UBIFS_BLOCK_SIZE;
2220	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2221	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2222	if (c->max_inode_sz > MAX_LFS_FILESIZE)
2223		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2224	sb->s_op = &ubifs_super_operations;
2225	sb->s_xattr = ubifs_xattr_handlers;
2226	fscrypt_set_ops(sb, &ubifs_crypt_operations);
2227
2228	mutex_lock(&c->umount_mutex);
2229	err = mount_ubifs(c);
2230	if (err) {
2231		ubifs_assert(c, err < 0);
2232		goto out_unlock;
2233	}
2234
2235	/* Read the root inode */
2236	root = ubifs_iget(sb, UBIFS_ROOT_INO);
2237	if (IS_ERR(root)) {
2238		err = PTR_ERR(root);
2239		goto out_umount;
2240	}
2241
2242	sb->s_root = d_make_root(root);
2243	if (!sb->s_root) {
2244		err = -ENOMEM;
2245		goto out_umount;
2246	}
2247
2248	import_uuid(&sb->s_uuid, c->uuid);
2249
2250	mutex_unlock(&c->umount_mutex);
2251	return 0;
2252
2253out_umount:
2254	ubifs_umount(c);
2255out_unlock:
2256	mutex_unlock(&c->umount_mutex);
2257out_close:
2258	ubifs_release_options(c);
2259	ubi_close_volume(c->ubi);
2260out:
2261	return err;
2262}
2263
2264static int sb_test(struct super_block *sb, void *data)
2265{
2266	struct ubifs_info *c1 = data;
2267	struct ubifs_info *c = sb->s_fs_info;
2268
2269	return c->vi.cdev == c1->vi.cdev;
2270}
2271
2272static int sb_set(struct super_block *sb, void *data)
2273{
2274	sb->s_fs_info = data;
2275	return set_anon_super(sb, NULL);
2276}
2277
2278static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2279			const char *name, void *data)
2280{
2281	struct ubi_volume_desc *ubi;
2282	struct ubifs_info *c;
2283	struct super_block *sb;
2284	int err;
2285
2286	dbg_gen("name %s, flags %#x", name, flags);
2287
2288	/*
2289	 * Get UBI device number and volume ID. Mount it read-only so far
2290	 * because this might be a new mount point, and UBI allows only one
2291	 * read-write user at a time.
2292	 */
2293	ubi = open_ubi(name, UBI_READONLY);
2294	if (IS_ERR(ubi)) {
2295		if (!(flags & SB_SILENT))
2296			pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
2297			       current->pid, name, (int)PTR_ERR(ubi));
2298		return ERR_CAST(ubi);
2299	}
2300
2301	c = alloc_ubifs_info(ubi);
2302	if (!c) {
2303		err = -ENOMEM;
2304		goto out_close;
2305	}
2306
2307	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2308
2309	sb = sget(fs_type, sb_test, sb_set, flags, c);
2310	if (IS_ERR(sb)) {
2311		err = PTR_ERR(sb);
2312		kfree(c);
2313		goto out_close;
2314	}
2315
2316	if (sb->s_root) {
2317		struct ubifs_info *c1 = sb->s_fs_info;
2318		kfree(c);
2319		/* A new mount point for already mounted UBIFS */
2320		dbg_gen("this ubi volume is already mounted");
2321		if (!!(flags & SB_RDONLY) != c1->ro_mount) {
2322			err = -EBUSY;
2323			goto out_deact;
2324		}
2325	} else {
2326		err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
2327		if (err)
2328			goto out_deact;
2329		/* We do not support atime */
2330		sb->s_flags |= SB_ACTIVE;
2331		if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
2332			ubifs_msg(c, "full atime support is enabled.");
2333		else
2334			sb->s_flags |= SB_NOATIME;
2335	}
2336
2337	/* 'fill_super()' opens ubi again so we must close it here */
2338	ubi_close_volume(ubi);
2339
2340	return dget(sb->s_root);
2341
2342out_deact:
2343	deactivate_locked_super(sb);
2344out_close:
2345	ubi_close_volume(ubi);
2346	return ERR_PTR(err);
2347}
2348
2349static void kill_ubifs_super(struct super_block *s)
2350{
2351	struct ubifs_info *c = s->s_fs_info;
2352	kill_anon_super(s);
2353	kfree(c);
2354}
2355
2356static struct file_system_type ubifs_fs_type = {
2357	.name    = "ubifs",
2358	.owner   = THIS_MODULE,
2359	.mount   = ubifs_mount,
2360	.kill_sb = kill_ubifs_super,
2361};
2362MODULE_ALIAS_FS("ubifs");
2363
2364/*
2365 * Inode slab cache constructor.
2366 */
2367static void inode_slab_ctor(void *obj)
2368{
2369	struct ubifs_inode *ui = obj;
2370	inode_init_once(&ui->vfs_inode);
2371}
2372
2373static int __init ubifs_init(void)
2374{
2375	int err = -ENOMEM;
2376
2377	BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2378
2379	/* Make sure node sizes are 8-byte aligned */
2380	BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2381	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2382	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2383	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2384	BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2385	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2386	BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2387	BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2388	BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2389	BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2390	BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2391
2392	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2393	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2394	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2395	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2396	BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2397	BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2398
2399	/* Check min. node size */
2400	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2401	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2402	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2403	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2404
2405	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2406	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2407	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2408	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2409
2410	/* Defined node sizes */
2411	BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2412	BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2413	BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2414	BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2415
2416	/*
2417	 * We use 2 bit wide bit-fields to store compression type, which should
2418	 * be amended if more compressors are added. The bit-fields are:
2419	 * @compr_type in 'struct ubifs_inode', @default_compr in
2420	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2421	 */
2422	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2423
2424	/*
2425	 * We require that PAGE_SIZE is greater-than-or-equal-to
2426	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2427	 */
2428	if (PAGE_SIZE < UBIFS_BLOCK_SIZE) {
2429		pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2430		       current->pid, (unsigned int)PAGE_SIZE);
2431		return -EINVAL;
2432	}
2433
2434	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2435				sizeof(struct ubifs_inode), 0,
2436				SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT |
2437				SLAB_ACCOUNT, &inode_slab_ctor);
2438	if (!ubifs_inode_slab)
2439		return -ENOMEM;
2440
2441	ubifs_shrinker_info = shrinker_alloc(0, "ubifs-slab");
2442	if (!ubifs_shrinker_info)
2443		goto out_slab;
2444
2445	ubifs_shrinker_info->count_objects = ubifs_shrink_count;
2446	ubifs_shrinker_info->scan_objects = ubifs_shrink_scan;
2447
2448	shrinker_register(ubifs_shrinker_info);
2449
2450	err = ubifs_compressors_init();
2451	if (err)
2452		goto out_shrinker;
2453
2454	dbg_debugfs_init();
2455
2456	err = ubifs_sysfs_init();
2457	if (err)
2458		goto out_dbg;
2459
2460	err = register_filesystem(&ubifs_fs_type);
2461	if (err) {
2462		pr_err("UBIFS error (pid %d): cannot register file system, error %d",
2463		       current->pid, err);
2464		goto out_sysfs;
2465	}
2466	return 0;
2467
2468out_sysfs:
2469	ubifs_sysfs_exit();
2470out_dbg:
2471	dbg_debugfs_exit();
2472	ubifs_compressors_exit();
2473out_shrinker:
2474	shrinker_free(ubifs_shrinker_info);
2475out_slab:
2476	kmem_cache_destroy(ubifs_inode_slab);
2477	return err;
2478}
2479/* late_initcall to let compressors initialize first */
2480late_initcall(ubifs_init);
2481
2482static void __exit ubifs_exit(void)
2483{
2484	WARN_ON(!list_empty(&ubifs_infos));
2485	WARN_ON(atomic_long_read(&ubifs_clean_zn_cnt) != 0);
2486
2487	dbg_debugfs_exit();
2488	ubifs_sysfs_exit();
2489	ubifs_compressors_exit();
2490	shrinker_free(ubifs_shrinker_info);
2491
2492	/*
2493	 * Make sure all delayed rcu free inodes are flushed before we
2494	 * destroy cache.
2495	 */
2496	rcu_barrier();
2497	kmem_cache_destroy(ubifs_inode_slab);
2498	unregister_filesystem(&ubifs_fs_type);
2499}
2500module_exit(ubifs_exit);
2501
2502MODULE_LICENSE("GPL");
2503MODULE_VERSION(__stringify(UBIFS_VERSION));
2504MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2505MODULE_DESCRIPTION("UBIFS - UBI File System");