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