1// SPDX-License-Identifier: GPL-2.0-only
   2/* * This file is part of UBIFS.
   3 *
   4 * Copyright (C) 2006-2008 Nokia Corporation.
   5 * Copyright (C) 2006, 2007 University of Szeged, Hungary
   6 *
 
 
 
 
 
 
 
 
 
 
 
 
 
   7 * Authors: Artem Bityutskiy (Битюцкий Артём)
   8 *          Adrian Hunter
   9 *          Zoltan Sogor
  10 */
  11
  12/*
  13 * This file implements directory operations.
  14 *
  15 * All FS operations in this file allocate budget before writing anything to the
  16 * media. If they fail to allocate it, the error is returned. The only
  17 * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even
  18 * if they unable to allocate the budget, because deletion %-ENOSPC failure is
  19 * not what users are usually ready to get. UBIFS budgeting subsystem has some
  20 * space reserved for these purposes.
  21 *
  22 * All operations in this file write all inodes which they change straight
  23 * away, instead of marking them dirty. For example, 'ubifs_link()' changes
  24 * @i_size of the parent inode and writes the parent inode together with the
  25 * target inode. This was done to simplify file-system recovery which would
  26 * otherwise be very difficult to do. The only exception is rename which marks
  27 * the re-named inode dirty (because its @i_ctime is updated) but does not
  28 * write it, but just marks it as dirty.
  29 */
  30
  31#include "ubifs.h"
  32
  33/**
  34 * inherit_flags - inherit flags of the parent inode.
  35 * @dir: parent inode
  36 * @mode: new inode mode flags
  37 *
  38 * This is a helper function for 'ubifs_new_inode()' which inherits flag of the
  39 * parent directory inode @dir. UBIFS inodes inherit the following flags:
  40 * o %UBIFS_COMPR_FL, which is useful to switch compression on/of on
  41 *   sub-directory basis;
  42 * o %UBIFS_SYNC_FL - useful for the same reasons;
  43 * o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories.
  44 *
  45 * This function returns the inherited flags.
  46 */
  47static int inherit_flags(const struct inode *dir, umode_t mode)
  48{
  49	int flags;
  50	const struct ubifs_inode *ui = ubifs_inode(dir);
  51
  52	if (!S_ISDIR(dir->i_mode))
  53		/*
  54		 * The parent is not a directory, which means that an extended
  55		 * attribute inode is being created. No flags.
  56		 */
  57		return 0;
  58
  59	flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL);
  60	if (!S_ISDIR(mode))
  61		/* The "DIRSYNC" flag only applies to directories */
  62		flags &= ~UBIFS_DIRSYNC_FL;
  63	return flags;
  64}
  65
  66/**
  67 * ubifs_new_inode - allocate new UBIFS inode object.
  68 * @c: UBIFS file-system description object
  69 * @dir: parent directory inode
  70 * @mode: inode mode flags
  71 *
  72 * This function finds an unused inode number, allocates new inode and
  73 * initializes it. Returns new inode in case of success and an error code in
  74 * case of failure.
  75 */
  76struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
  77			      umode_t mode)
  78{
  79	int err;
  80	struct inode *inode;
  81	struct ubifs_inode *ui;
  82	bool encrypted = false;
  83
  84	if (ubifs_crypt_is_encrypted(dir)) {
  85		err = fscrypt_get_encryption_info(dir);
  86		if (err) {
  87			ubifs_err(c, "fscrypt_get_encryption_info failed: %i", err);
  88			return ERR_PTR(err);
  89		}
  90
  91		if (!fscrypt_has_encryption_key(dir))
  92			return ERR_PTR(-EPERM);
  93
  94		encrypted = true;
  95	}
  96
  97	inode = new_inode(c->vfs_sb);
  98	ui = ubifs_inode(inode);
  99	if (!inode)
 100		return ERR_PTR(-ENOMEM);
 101
 102	/*
 103	 * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and
 104	 * marking them dirty in file write path (see 'file_update_time()').
 105	 * UBIFS has to fully control "clean <-> dirty" transitions of inodes
 106	 * to make budgeting work.
 107	 */
 108	inode->i_flags |= S_NOCMTIME;
 109
 110	inode_init_owner(inode, dir, mode);
 111	inode->i_mtime = inode->i_atime = inode->i_ctime =
 112			 current_time(inode);
 113	inode->i_mapping->nrpages = 0;
 114
 115	switch (mode & S_IFMT) {
 116	case S_IFREG:
 117		inode->i_mapping->a_ops = &ubifs_file_address_operations;
 118		inode->i_op = &ubifs_file_inode_operations;
 119		inode->i_fop = &ubifs_file_operations;
 120		break;
 121	case S_IFDIR:
 122		inode->i_op  = &ubifs_dir_inode_operations;
 123		inode->i_fop = &ubifs_dir_operations;
 124		inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ;
 125		break;
 126	case S_IFLNK:
 127		inode->i_op = &ubifs_symlink_inode_operations;
 128		break;
 129	case S_IFSOCK:
 130	case S_IFIFO:
 131	case S_IFBLK:
 132	case S_IFCHR:
 133		inode->i_op  = &ubifs_file_inode_operations;
 134		encrypted = false;
 135		break;
 136	default:
 137		BUG();
 138	}
 139
 140	ui->flags = inherit_flags(dir, mode);
 141	ubifs_set_inode_flags(inode);
 142	if (S_ISREG(mode))
 143		ui->compr_type = c->default_compr;
 144	else
 145		ui->compr_type = UBIFS_COMPR_NONE;
 146	ui->synced_i_size = 0;
 147
 148	spin_lock(&c->cnt_lock);
 149	/* Inode number overflow is currently not supported */
 150	if (c->highest_inum >= INUM_WARN_WATERMARK) {
 151		if (c->highest_inum >= INUM_WATERMARK) {
 152			spin_unlock(&c->cnt_lock);
 153			ubifs_err(c, "out of inode numbers");
 154			make_bad_inode(inode);
 155			iput(inode);
 156			return ERR_PTR(-EINVAL);
 157		}
 158		ubifs_warn(c, "running out of inode numbers (current %lu, max %u)",
 159			   (unsigned long)c->highest_inum, INUM_WATERMARK);
 160	}
 161
 162	inode->i_ino = ++c->highest_inum;
 163	/*
 164	 * The creation sequence number remains with this inode for its
 165	 * lifetime. All nodes for this inode have a greater sequence number,
 166	 * and so it is possible to distinguish obsolete nodes belonging to a
 167	 * previous incarnation of the same inode number - for example, for the
 168	 * purpose of rebuilding the index.
 169	 */
 170	ui->creat_sqnum = ++c->max_sqnum;
 171	spin_unlock(&c->cnt_lock);
 172
 173	if (encrypted) {
 174		err = fscrypt_inherit_context(dir, inode, &encrypted, true);
 175		if (err) {
 176			ubifs_err(c, "fscrypt_inherit_context failed: %i", err);
 177			make_bad_inode(inode);
 178			iput(inode);
 179			return ERR_PTR(err);
 180		}
 181	}
 182
 183	return inode;
 184}
 185
 186static int dbg_check_name(const struct ubifs_info *c,
 187			  const struct ubifs_dent_node *dent,
 188			  const struct fscrypt_name *nm)
 189{
 190	if (!dbg_is_chk_gen(c))
 191		return 0;
 192	if (le16_to_cpu(dent->nlen) != fname_len(nm))
 193		return -EINVAL;
 194	if (memcmp(dent->name, fname_name(nm), fname_len(nm)))
 195		return -EINVAL;
 196	return 0;
 197}
 198
 199static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
 200				   unsigned int flags)
 201{
 202	int err;
 203	union ubifs_key key;
 204	struct inode *inode = NULL;
 205	struct ubifs_dent_node *dent = NULL;
 206	struct ubifs_info *c = dir->i_sb->s_fs_info;
 207	struct fscrypt_name nm;
 208
 209	dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino);
 210
 211	err = fscrypt_prepare_lookup(dir, dentry, &nm);
 212	if (err == -ENOENT)
 213		return d_splice_alias(NULL, dentry);
 214	if (err)
 215		return ERR_PTR(err);
 216
 217	if (fname_len(&nm) > UBIFS_MAX_NLEN) {
 218		inode = ERR_PTR(-ENAMETOOLONG);
 219		goto done;
 220	}
 221
 222	dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
 223	if (!dent) {
 224		inode = ERR_PTR(-ENOMEM);
 225		goto done;
 226	}
 227
 228	if (nm.hash) {
 229		ubifs_assert(c, fname_len(&nm) == 0);
 230		ubifs_assert(c, fname_name(&nm) == NULL);
 231		dent_key_init_hash(c, &key, dir->i_ino, nm.hash);
 232		err = ubifs_tnc_lookup_dh(c, &key, dent, nm.minor_hash);
 233	} else {
 234		dent_key_init(c, &key, dir->i_ino, &nm);
 235		err = ubifs_tnc_lookup_nm(c, &key, dent, &nm);
 236	}
 237
 
 238	if (err) {
 239		if (err == -ENOENT)
 240			dbg_gen("not found");
 241		else
 242			inode = ERR_PTR(err);
 243		goto done;
 244	}
 245
 246	if (dbg_check_name(c, dent, &nm)) {
 247		inode = ERR_PTR(-EINVAL);
 248		goto done;
 249	}
 250
 251	inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
 252	if (IS_ERR(inode)) {
 253		/*
 254		 * This should not happen. Probably the file-system needs
 255		 * checking.
 256		 */
 257		err = PTR_ERR(inode);
 258		ubifs_err(c, "dead directory entry '%pd', error %d",
 259			  dentry, err);
 260		ubifs_ro_mode(c, err);
 261		goto done;
 262	}
 263
 264	if (ubifs_crypt_is_encrypted(dir) &&
 265	    (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
 266	    !fscrypt_has_permitted_context(dir, inode)) {
 267		ubifs_warn(c, "Inconsistent encryption contexts: %lu/%lu",
 268			   dir->i_ino, inode->i_ino);
 269		iput(inode);
 270		inode = ERR_PTR(-EPERM);
 271	}
 272
 273done:
 274	kfree(dent);
 275	fscrypt_free_filename(&nm);
 276	return d_splice_alias(inode, dentry);
 
 
 
 
 
 
 
 
 277}
 278
 279static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 280			bool excl)
 281{
 282	struct inode *inode;
 283	struct ubifs_info *c = dir->i_sb->s_fs_info;
 
 284	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
 285					.dirtied_ino = 1 };
 286	struct ubifs_inode *dir_ui = ubifs_inode(dir);
 287	struct fscrypt_name nm;
 288	int err, sz_change;
 289
 290	/*
 291	 * Budget request settings: new inode, new direntry, changing the
 292	 * parent directory inode.
 293	 */
 294
 295	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
 296		dentry, mode, dir->i_ino);
 297
 298	err = ubifs_budget_space(c, &req);
 299	if (err)
 300		return err;
 301
 302	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
 303	if (err)
 304		goto out_budg;
 305
 306	sz_change = CALC_DENT_SIZE(fname_len(&nm));
 307
 308	inode = ubifs_new_inode(c, dir, mode);
 309	if (IS_ERR(inode)) {
 310		err = PTR_ERR(inode);
 311		goto out_fname;
 312	}
 313
 314	err = ubifs_init_security(dir, inode, &dentry->d_name);
 315	if (err)
 316		goto out_inode;
 317
 318	mutex_lock(&dir_ui->ui_mutex);
 319	dir->i_size += sz_change;
 320	dir_ui->ui_size = dir->i_size;
 321	dir->i_mtime = dir->i_ctime = inode->i_ctime;
 322	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
 323	if (err)
 324		goto out_cancel;
 325	mutex_unlock(&dir_ui->ui_mutex);
 326
 327	ubifs_release_budget(c, &req);
 328	fscrypt_free_filename(&nm);
 329	insert_inode_hash(inode);
 330	d_instantiate(dentry, inode);
 331	return 0;
 332
 333out_cancel:
 334	dir->i_size -= sz_change;
 335	dir_ui->ui_size = dir->i_size;
 336	mutex_unlock(&dir_ui->ui_mutex);
 337out_inode:
 338	make_bad_inode(inode);
 339	iput(inode);
 340out_fname:
 341	fscrypt_free_filename(&nm);
 342out_budg:
 343	ubifs_release_budget(c, &req);
 344	ubifs_err(c, "cannot create regular file, error %d", err);
 345	return err;
 346}
 347
 348static int do_tmpfile(struct inode *dir, struct dentry *dentry,
 349		      umode_t mode, struct inode **whiteout)
 350{
 351	struct inode *inode;
 352	struct ubifs_info *c = dir->i_sb->s_fs_info;
 353	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1};
 354	struct ubifs_budget_req ino_req = { .dirtied_ino = 1 };
 355	struct ubifs_inode *ui, *dir_ui = ubifs_inode(dir);
 356	int err, instantiated = 0;
 357	struct fscrypt_name nm;
 358
 359	/*
 360	 * Budget request settings: new dirty inode, new direntry,
 361	 * budget for dirtied inode will be released via writeback.
 362	 */
 363
 364	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
 365		dentry, mode, dir->i_ino);
 366
 367	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
 368	if (err)
 369		return err;
 370
 371	err = ubifs_budget_space(c, &req);
 372	if (err) {
 373		fscrypt_free_filename(&nm);
 374		return err;
 375	}
 376
 377	err = ubifs_budget_space(c, &ino_req);
 378	if (err) {
 379		ubifs_release_budget(c, &req);
 380		fscrypt_free_filename(&nm);
 381		return err;
 382	}
 383
 384	inode = ubifs_new_inode(c, dir, mode);
 385	if (IS_ERR(inode)) {
 386		err = PTR_ERR(inode);
 387		goto out_budg;
 388	}
 389	ui = ubifs_inode(inode);
 390
 391	if (whiteout) {
 392		init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
 393		ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations);
 394	}
 395
 396	err = ubifs_init_security(dir, inode, &dentry->d_name);
 397	if (err)
 398		goto out_inode;
 399
 400	mutex_lock(&ui->ui_mutex);
 401	insert_inode_hash(inode);
 402
 403	if (whiteout) {
 404		mark_inode_dirty(inode);
 405		drop_nlink(inode);
 406		*whiteout = inode;
 407	} else {
 408		d_tmpfile(dentry, inode);
 409	}
 410	ubifs_assert(c, ui->dirty);
 411
 412	instantiated = 1;
 413	mutex_unlock(&ui->ui_mutex);
 414
 415	mutex_lock(&dir_ui->ui_mutex);
 416	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
 417	if (err)
 418		goto out_cancel;
 419	mutex_unlock(&dir_ui->ui_mutex);
 420
 421	ubifs_release_budget(c, &req);
 422
 423	return 0;
 424
 425out_cancel:
 426	mutex_unlock(&dir_ui->ui_mutex);
 427out_inode:
 428	make_bad_inode(inode);
 429	if (!instantiated)
 430		iput(inode);
 431out_budg:
 432	ubifs_release_budget(c, &req);
 433	if (!instantiated)
 434		ubifs_release_budget(c, &ino_req);
 435	fscrypt_free_filename(&nm);
 436	ubifs_err(c, "cannot create temporary file, error %d", err);
 437	return err;
 438}
 439
 440static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry,
 441			 umode_t mode)
 442{
 443	return do_tmpfile(dir, dentry, mode, NULL);
 444}
 445
 446/**
 447 * vfs_dent_type - get VFS directory entry type.
 448 * @type: UBIFS directory entry type
 449 *
 450 * This function converts UBIFS directory entry type into VFS directory entry
 451 * type.
 452 */
 453static unsigned int vfs_dent_type(uint8_t type)
 454{
 455	switch (type) {
 456	case UBIFS_ITYPE_REG:
 457		return DT_REG;
 458	case UBIFS_ITYPE_DIR:
 459		return DT_DIR;
 460	case UBIFS_ITYPE_LNK:
 461		return DT_LNK;
 462	case UBIFS_ITYPE_BLK:
 463		return DT_BLK;
 464	case UBIFS_ITYPE_CHR:
 465		return DT_CHR;
 466	case UBIFS_ITYPE_FIFO:
 467		return DT_FIFO;
 468	case UBIFS_ITYPE_SOCK:
 469		return DT_SOCK;
 470	default:
 471		BUG();
 472	}
 473	return 0;
 474}
 475
 476/*
 477 * The classical Unix view for directory is that it is a linear array of
 478 * (name, inode number) entries. Linux/VFS assumes this model as well.
 479 * Particularly, 'readdir()' call wants us to return a directory entry offset
 480 * which later may be used to continue 'readdir()'ing the directory or to
 481 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
 482 * model because directory entries are identified by keys, which may collide.
 483 *
 484 * UBIFS uses directory entry hash value for directory offsets, so
 485 * 'seekdir()'/'telldir()' may not always work because of possible key
 486 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
 487 * properly by means of saving full directory entry name in the private field
 488 * of the file description object.
 489 *
 490 * This means that UBIFS cannot support NFS which requires full
 491 * 'seekdir()'/'telldir()' support.
 492 */
 493static int ubifs_readdir(struct file *file, struct dir_context *ctx)
 494{
 495	int fstr_real_len = 0, err = 0;
 496	struct fscrypt_name nm;
 497	struct fscrypt_str fstr = {0};
 498	union ubifs_key key;
 499	struct ubifs_dent_node *dent;
 500	struct inode *dir = file_inode(file);
 501	struct ubifs_info *c = dir->i_sb->s_fs_info;
 502	bool encrypted = ubifs_crypt_is_encrypted(dir);
 503
 504	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos);
 505
 506	if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2)
 507		/*
 508		 * The directory was seek'ed to a senseless position or there
 509		 * are no more entries.
 510		 */
 511		return 0;
 512
 513	if (encrypted) {
 514		err = fscrypt_get_encryption_info(dir);
 515		if (err && err != -ENOKEY)
 516			return err;
 517
 518		err = fscrypt_fname_alloc_buffer(dir, UBIFS_MAX_NLEN, &fstr);
 519		if (err)
 520			return err;
 521
 522		fstr_real_len = fstr.len;
 523	}
 524
 525	if (file->f_version == 0) {
 526		/*
 527		 * The file was seek'ed, which means that @file->private_data
 528		 * is now invalid. This may also be just the first
 529		 * 'ubifs_readdir()' invocation, in which case
 530		 * @file->private_data is NULL, and the below code is
 531		 * basically a no-op.
 532		 */
 533		kfree(file->private_data);
 534		file->private_data = NULL;
 535	}
 536
 537	/*
 538	 * 'generic_file_llseek()' unconditionally sets @file->f_version to
 539	 * zero, and we use this for detecting whether the file was seek'ed.
 540	 */
 541	file->f_version = 1;
 542
 543	/* File positions 0 and 1 correspond to "." and ".." */
 544	if (ctx->pos < 2) {
 545		ubifs_assert(c, !file->private_data);
 546		if (!dir_emit_dots(file, ctx)) {
 547			if (encrypted)
 548				fscrypt_fname_free_buffer(&fstr);
 549			return 0;
 550		}
 551
 552		/* Find the first entry in TNC and save it */
 553		lowest_dent_key(c, &key, dir->i_ino);
 554		fname_len(&nm) = 0;
 555		dent = ubifs_tnc_next_ent(c, &key, &nm);
 556		if (IS_ERR(dent)) {
 557			err = PTR_ERR(dent);
 558			goto out;
 559		}
 560
 561		ctx->pos = key_hash_flash(c, &dent->key);
 562		file->private_data = dent;
 563	}
 564
 565	dent = file->private_data;
 566	if (!dent) {
 567		/*
 568		 * The directory was seek'ed to and is now readdir'ed.
 569		 * Find the entry corresponding to @ctx->pos or the closest one.
 570		 */
 571		dent_key_init_hash(c, &key, dir->i_ino, ctx->pos);
 572		fname_len(&nm) = 0;
 573		dent = ubifs_tnc_next_ent(c, &key, &nm);
 574		if (IS_ERR(dent)) {
 575			err = PTR_ERR(dent);
 576			goto out;
 577		}
 578		ctx->pos = key_hash_flash(c, &dent->key);
 579		file->private_data = dent;
 580	}
 581
 582	while (1) {
 583		dbg_gen("ino %llu, new f_pos %#x",
 584			(unsigned long long)le64_to_cpu(dent->inum),
 585			key_hash_flash(c, &dent->key));
 586		ubifs_assert(c, le64_to_cpu(dent->ch.sqnum) >
 587			     ubifs_inode(dir)->creat_sqnum);
 588
 589		fname_len(&nm) = le16_to_cpu(dent->nlen);
 590		fname_name(&nm) = dent->name;
 591
 592		if (encrypted) {
 593			fstr.len = fstr_real_len;
 594
 595			err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c,
 596							&dent->key),
 597							le32_to_cpu(dent->cookie),
 598							&nm.disk_name, &fstr);
 599			if (err)
 600				goto out;
 601		} else {
 602			fstr.len = fname_len(&nm);
 603			fstr.name = fname_name(&nm);
 604		}
 605
 606		if (!dir_emit(ctx, fstr.name, fstr.len,
 607			       le64_to_cpu(dent->inum),
 608			       vfs_dent_type(dent->type))) {
 609			if (encrypted)
 610				fscrypt_fname_free_buffer(&fstr);
 611			return 0;
 612		}
 613
 614		/* Switch to the next entry */
 615		key_read(c, &dent->key, &key);
 
 616		dent = ubifs_tnc_next_ent(c, &key, &nm);
 617		if (IS_ERR(dent)) {
 618			err = PTR_ERR(dent);
 619			goto out;
 620		}
 621
 622		kfree(file->private_data);
 623		ctx->pos = key_hash_flash(c, &dent->key);
 624		file->private_data = dent;
 625		cond_resched();
 626	}
 627
 628out:
 629	kfree(file->private_data);
 630	file->private_data = NULL;
 631
 632	if (encrypted)
 633		fscrypt_fname_free_buffer(&fstr);
 634
 635	if (err != -ENOENT)
 636		ubifs_err(c, "cannot find next direntry, error %d", err);
 637	else
 638		/*
 639		 * -ENOENT is a non-fatal error in this context, the TNC uses
 640		 * it to indicate that the cursor moved past the current directory
 641		 * and readdir() has to stop.
 642		 */
 643		err = 0;
 644
 645
 646	/* 2 is a special value indicating that there are no more direntries */
 647	ctx->pos = 2;
 648	return err;
 649}
 650
 651/* Free saved readdir() state when the directory is closed */
 652static int ubifs_dir_release(struct inode *dir, struct file *file)
 653{
 654	kfree(file->private_data);
 655	file->private_data = NULL;
 656	return 0;
 657}
 658
 659/**
 660 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
 661 * @inode1: first inode
 662 * @inode2: second inode
 663 *
 664 * We do not implement any tricks to guarantee strict lock ordering, because
 665 * VFS has already done it for us on the @i_mutex. So this is just a simple
 666 * wrapper function.
 667 */
 668static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
 669{
 670	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
 671	mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
 672}
 673
 674/**
 675 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
 676 * @inode1: first inode
 677 * @inode2: second inode
 678 */
 679static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
 680{
 681	mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
 682	mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
 683}
 684
 685static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
 686		      struct dentry *dentry)
 687{
 688	struct ubifs_info *c = dir->i_sb->s_fs_info;
 689	struct inode *inode = d_inode(old_dentry);
 690	struct ubifs_inode *ui = ubifs_inode(inode);
 691	struct ubifs_inode *dir_ui = ubifs_inode(dir);
 692	int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
 693	struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
 694				.dirtied_ino_d = ALIGN(ui->data_len, 8) };
 695	struct fscrypt_name nm;
 696
 697	/*
 698	 * Budget request settings: new direntry, changing the target inode,
 699	 * changing the parent inode.
 700	 */
 701
 702	dbg_gen("dent '%pd' to ino %lu (nlink %d) in dir ino %lu",
 703		dentry, inode->i_ino,
 704		inode->i_nlink, dir->i_ino);
 705	ubifs_assert(c, inode_is_locked(dir));
 706	ubifs_assert(c, inode_is_locked(inode));
 707
 708	err = fscrypt_prepare_link(old_dentry, dir, dentry);
 709	if (err)
 710		return err;
 711
 712	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
 713	if (err)
 714		return err;
 715
 716	err = dbg_check_synced_i_size(c, inode);
 717	if (err)
 718		goto out_fname;
 719
 720	err = ubifs_budget_space(c, &req);
 721	if (err)
 722		goto out_fname;
 723
 724	lock_2_inodes(dir, inode);
 725
 726	/* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */
 727	if (inode->i_nlink == 0)
 728		ubifs_delete_orphan(c, inode->i_ino);
 729
 730	inc_nlink(inode);
 731	ihold(inode);
 732	inode->i_ctime = current_time(inode);
 733	dir->i_size += sz_change;
 734	dir_ui->ui_size = dir->i_size;
 735	dir->i_mtime = dir->i_ctime = inode->i_ctime;
 736	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
 737	if (err)
 738		goto out_cancel;
 739	unlock_2_inodes(dir, inode);
 740
 741	ubifs_release_budget(c, &req);
 742	d_instantiate(dentry, inode);
 743	fscrypt_free_filename(&nm);
 744	return 0;
 745
 746out_cancel:
 747	dir->i_size -= sz_change;
 748	dir_ui->ui_size = dir->i_size;
 749	drop_nlink(inode);
 750	if (inode->i_nlink == 0)
 751		ubifs_add_orphan(c, inode->i_ino);
 752	unlock_2_inodes(dir, inode);
 753	ubifs_release_budget(c, &req);
 754	iput(inode);
 755out_fname:
 756	fscrypt_free_filename(&nm);
 757	return err;
 758}
 759
 760static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
 761{
 762	struct ubifs_info *c = dir->i_sb->s_fs_info;
 763	struct inode *inode = d_inode(dentry);
 764	struct ubifs_inode *dir_ui = ubifs_inode(dir);
 765	int err, sz_change, budgeted = 1;
 
 766	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
 767	unsigned int saved_nlink = inode->i_nlink;
 768	struct fscrypt_name nm;
 769
 770	/*
 771	 * Budget request settings: deletion direntry, deletion inode (+1 for
 772	 * @dirtied_ino), changing the parent directory inode. If budgeting
 773	 * fails, go ahead anyway because we have extra space reserved for
 774	 * deletions.
 775	 */
 776
 777	dbg_gen("dent '%pd' from ino %lu (nlink %d) in dir ino %lu",
 778		dentry, inode->i_ino,
 779		inode->i_nlink, dir->i_ino);
 780
 781	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
 782	if (err)
 783		return err;
 784
 785	err = ubifs_purge_xattrs(inode);
 786	if (err)
 787		return err;
 788
 789	sz_change = CALC_DENT_SIZE(fname_len(&nm));
 790
 791	ubifs_assert(c, inode_is_locked(dir));
 792	ubifs_assert(c, inode_is_locked(inode));
 793	err = dbg_check_synced_i_size(c, inode);
 794	if (err)
 795		goto out_fname;
 796
 797	err = ubifs_budget_space(c, &req);
 798	if (err) {
 799		if (err != -ENOSPC)
 800			goto out_fname;
 801		budgeted = 0;
 802	}
 803
 804	lock_2_inodes(dir, inode);
 805	inode->i_ctime = current_time(dir);
 806	drop_nlink(inode);
 807	dir->i_size -= sz_change;
 808	dir_ui->ui_size = dir->i_size;
 809	dir->i_mtime = dir->i_ctime = inode->i_ctime;
 810	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
 811	if (err)
 812		goto out_cancel;
 813	unlock_2_inodes(dir, inode);
 814
 815	if (budgeted)
 816		ubifs_release_budget(c, &req);
 817	else {
 818		/* We've deleted something - clean the "no space" flags */
 819		c->bi.nospace = c->bi.nospace_rp = 0;
 820		smp_wmb();
 821	}
 822	fscrypt_free_filename(&nm);
 823	return 0;
 824
 825out_cancel:
 826	dir->i_size += sz_change;
 827	dir_ui->ui_size = dir->i_size;
 828	set_nlink(inode, saved_nlink);
 829	unlock_2_inodes(dir, inode);
 830	if (budgeted)
 831		ubifs_release_budget(c, &req);
 832out_fname:
 833	fscrypt_free_filename(&nm);
 834	return err;
 835}
 836
 837/**
 838 * check_dir_empty - check if a directory is empty or not.
 
 839 * @dir: VFS inode object of the directory to check
 840 *
 841 * This function checks if directory @dir is empty. Returns zero if the
 842 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
 843 * in case of of errors.
 844 */
 845int ubifs_check_dir_empty(struct inode *dir)
 846{
 847	struct ubifs_info *c = dir->i_sb->s_fs_info;
 848	struct fscrypt_name nm = { 0 };
 849	struct ubifs_dent_node *dent;
 850	union ubifs_key key;
 851	int err;
 852
 853	lowest_dent_key(c, &key, dir->i_ino);
 854	dent = ubifs_tnc_next_ent(c, &key, &nm);
 855	if (IS_ERR(dent)) {
 856		err = PTR_ERR(dent);
 857		if (err == -ENOENT)
 858			err = 0;
 859	} else {
 860		kfree(dent);
 861		err = -ENOTEMPTY;
 862	}
 863	return err;
 864}
 865
 866static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
 867{
 868	struct ubifs_info *c = dir->i_sb->s_fs_info;
 869	struct inode *inode = d_inode(dentry);
 870	int err, sz_change, budgeted = 1;
 
 871	struct ubifs_inode *dir_ui = ubifs_inode(dir);
 872	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
 873	struct fscrypt_name nm;
 874
 875	/*
 876	 * Budget request settings: deletion direntry, deletion inode and
 877	 * changing the parent inode. If budgeting fails, go ahead anyway
 878	 * because we have extra space reserved for deletions.
 879	 */
 880
 881	dbg_gen("directory '%pd', ino %lu in dir ino %lu", dentry,
 882		inode->i_ino, dir->i_ino);
 883	ubifs_assert(c, inode_is_locked(dir));
 884	ubifs_assert(c, inode_is_locked(inode));
 885	err = ubifs_check_dir_empty(d_inode(dentry));
 886	if (err)
 887		return err;
 888
 889	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
 890	if (err)
 891		return err;
 892
 893	err = ubifs_purge_xattrs(inode);
 894	if (err)
 895		return err;
 896
 897	sz_change = CALC_DENT_SIZE(fname_len(&nm));
 898
 899	err = ubifs_budget_space(c, &req);
 900	if (err) {
 901		if (err != -ENOSPC)
 902			goto out_fname;
 903		budgeted = 0;
 904	}
 905
 906	lock_2_inodes(dir, inode);
 907	inode->i_ctime = current_time(dir);
 908	clear_nlink(inode);
 909	drop_nlink(dir);
 910	dir->i_size -= sz_change;
 911	dir_ui->ui_size = dir->i_size;
 912	dir->i_mtime = dir->i_ctime = inode->i_ctime;
 913	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
 914	if (err)
 915		goto out_cancel;
 916	unlock_2_inodes(dir, inode);
 917
 918	if (budgeted)
 919		ubifs_release_budget(c, &req);
 920	else {
 921		/* We've deleted something - clean the "no space" flags */
 922		c->bi.nospace = c->bi.nospace_rp = 0;
 923		smp_wmb();
 924	}
 925	fscrypt_free_filename(&nm);
 926	return 0;
 927
 928out_cancel:
 929	dir->i_size += sz_change;
 930	dir_ui->ui_size = dir->i_size;
 931	inc_nlink(dir);
 932	set_nlink(inode, 2);
 933	unlock_2_inodes(dir, inode);
 934	if (budgeted)
 935		ubifs_release_budget(c, &req);
 936out_fname:
 937	fscrypt_free_filename(&nm);
 938	return err;
 939}
 940
 941static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 942{
 943	struct inode *inode;
 944	struct ubifs_inode *dir_ui = ubifs_inode(dir);
 945	struct ubifs_info *c = dir->i_sb->s_fs_info;
 946	int err, sz_change;
 947	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
 948	struct fscrypt_name nm;
 949
 950	/*
 951	 * Budget request settings: new inode, new direntry and changing parent
 952	 * directory inode.
 953	 */
 954
 955	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
 956		dentry, mode, dir->i_ino);
 957
 958	err = ubifs_budget_space(c, &req);
 959	if (err)
 960		return err;
 961
 962	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
 963	if (err)
 964		goto out_budg;
 965
 966	sz_change = CALC_DENT_SIZE(fname_len(&nm));
 967
 968	inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
 969	if (IS_ERR(inode)) {
 970		err = PTR_ERR(inode);
 971		goto out_fname;
 972	}
 973
 974	err = ubifs_init_security(dir, inode, &dentry->d_name);
 975	if (err)
 976		goto out_inode;
 977
 978	mutex_lock(&dir_ui->ui_mutex);
 979	insert_inode_hash(inode);
 980	inc_nlink(inode);
 981	inc_nlink(dir);
 982	dir->i_size += sz_change;
 983	dir_ui->ui_size = dir->i_size;
 984	dir->i_mtime = dir->i_ctime = inode->i_ctime;
 985	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
 986	if (err) {
 987		ubifs_err(c, "cannot create directory, error %d", err);
 988		goto out_cancel;
 989	}
 990	mutex_unlock(&dir_ui->ui_mutex);
 991
 992	ubifs_release_budget(c, &req);
 993	d_instantiate(dentry, inode);
 994	fscrypt_free_filename(&nm);
 995	return 0;
 996
 997out_cancel:
 998	dir->i_size -= sz_change;
 999	dir_ui->ui_size = dir->i_size;
1000	drop_nlink(dir);
1001	mutex_unlock(&dir_ui->ui_mutex);
1002out_inode:
1003	make_bad_inode(inode);
1004	iput(inode);
1005out_fname:
1006	fscrypt_free_filename(&nm);
1007out_budg:
1008	ubifs_release_budget(c, &req);
1009	return err;
1010}
1011
1012static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
1013		       umode_t mode, dev_t rdev)
1014{
1015	struct inode *inode;
1016	struct ubifs_inode *ui;
1017	struct ubifs_inode *dir_ui = ubifs_inode(dir);
1018	struct ubifs_info *c = dir->i_sb->s_fs_info;
1019	union ubifs_dev_desc *dev = NULL;
1020	int sz_change;
1021	int err, devlen = 0;
1022	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
 
1023					.dirtied_ino = 1 };
1024	struct fscrypt_name nm;
1025
1026	/*
1027	 * Budget request settings: new inode, new direntry and changing parent
1028	 * directory inode.
1029	 */
1030
1031	dbg_gen("dent '%pd' in dir ino %lu", dentry, dir->i_ino);
1032
1033	if (S_ISBLK(mode) || S_ISCHR(mode)) {
1034		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
1035		if (!dev)
1036			return -ENOMEM;
1037		devlen = ubifs_encode_dev(dev, rdev);
1038	}
1039
1040	req.new_ino_d = ALIGN(devlen, 8);
1041	err = ubifs_budget_space(c, &req);
1042	if (err) {
1043		kfree(dev);
1044		return err;
1045	}
1046
1047	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
1048	if (err) {
1049		kfree(dev);
1050		goto out_budg;
1051	}
1052
1053	sz_change = CALC_DENT_SIZE(fname_len(&nm));
1054
1055	inode = ubifs_new_inode(c, dir, mode);
1056	if (IS_ERR(inode)) {
1057		kfree(dev);
1058		err = PTR_ERR(inode);
1059		goto out_fname;
1060	}
1061
1062	init_special_inode(inode, inode->i_mode, rdev);
1063	inode->i_size = ubifs_inode(inode)->ui_size = devlen;
1064	ui = ubifs_inode(inode);
1065	ui->data = dev;
1066	ui->data_len = devlen;
1067
1068	err = ubifs_init_security(dir, inode, &dentry->d_name);
1069	if (err)
1070		goto out_inode;
1071
1072	mutex_lock(&dir_ui->ui_mutex);
1073	dir->i_size += sz_change;
1074	dir_ui->ui_size = dir->i_size;
1075	dir->i_mtime = dir->i_ctime = inode->i_ctime;
1076	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
1077	if (err)
1078		goto out_cancel;
1079	mutex_unlock(&dir_ui->ui_mutex);
1080
1081	ubifs_release_budget(c, &req);
1082	insert_inode_hash(inode);
1083	d_instantiate(dentry, inode);
1084	fscrypt_free_filename(&nm);
1085	return 0;
1086
1087out_cancel:
1088	dir->i_size -= sz_change;
1089	dir_ui->ui_size = dir->i_size;
1090	mutex_unlock(&dir_ui->ui_mutex);
1091out_inode:
1092	make_bad_inode(inode);
1093	iput(inode);
1094out_fname:
1095	fscrypt_free_filename(&nm);
1096out_budg:
1097	ubifs_release_budget(c, &req);
1098	return err;
1099}
1100
1101static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
1102			 const char *symname)
1103{
1104	struct inode *inode;
1105	struct ubifs_inode *ui;
1106	struct ubifs_inode *dir_ui = ubifs_inode(dir);
1107	struct ubifs_info *c = dir->i_sb->s_fs_info;
1108	int err, sz_change, len = strlen(symname);
1109	struct fscrypt_str disk_link;
1110	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
1111					.new_ino_d = ALIGN(len, 8),
1112					.dirtied_ino = 1 };
1113	struct fscrypt_name nm;
1114
1115	dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry,
1116		symname, dir->i_ino);
1117
1118	err = fscrypt_prepare_symlink(dir, symname, len, UBIFS_MAX_INO_DATA,
1119				      &disk_link);
1120	if (err)
1121		return err;
1122
1123	/*
1124	 * Budget request settings: new inode, new direntry and changing parent
1125	 * directory inode.
1126	 */
 
 
 
 
 
 
 
1127	err = ubifs_budget_space(c, &req);
1128	if (err)
1129		return err;
1130
1131	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
1132	if (err)
1133		goto out_budg;
1134
1135	sz_change = CALC_DENT_SIZE(fname_len(&nm));
1136
1137	inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
1138	if (IS_ERR(inode)) {
1139		err = PTR_ERR(inode);
1140		goto out_fname;
1141	}
1142
1143	ui = ubifs_inode(inode);
1144	ui->data = kmalloc(disk_link.len, GFP_NOFS);
1145	if (!ui->data) {
1146		err = -ENOMEM;
1147		goto out_inode;
1148	}
1149
1150	if (IS_ENCRYPTED(inode)) {
1151		disk_link.name = ui->data; /* encrypt directly into ui->data */
1152		err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
1153		if (err)
1154			goto out_inode;
1155	} else {
1156		memcpy(ui->data, disk_link.name, disk_link.len);
1157		inode->i_link = ui->data;
1158	}
1159
1160	/*
1161	 * The terminating zero byte is not written to the flash media and it
1162	 * is put just to make later in-memory string processing simpler. Thus,
1163	 * data length is @disk_link.len - 1, not @disk_link.len.
1164	 */
1165	ui->data_len = disk_link.len - 1;
1166	inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1;
1167
1168	err = ubifs_init_security(dir, inode, &dentry->d_name);
1169	if (err)
1170		goto out_inode;
1171
1172	mutex_lock(&dir_ui->ui_mutex);
1173	dir->i_size += sz_change;
1174	dir_ui->ui_size = dir->i_size;
1175	dir->i_mtime = dir->i_ctime = inode->i_ctime;
1176	err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
1177	if (err)
1178		goto out_cancel;
1179	mutex_unlock(&dir_ui->ui_mutex);
1180
 
1181	insert_inode_hash(inode);
1182	d_instantiate(dentry, inode);
1183	err = 0;
1184	goto out_fname;
1185
1186out_cancel:
1187	dir->i_size -= sz_change;
1188	dir_ui->ui_size = dir->i_size;
1189	mutex_unlock(&dir_ui->ui_mutex);
1190out_inode:
1191	make_bad_inode(inode);
1192	iput(inode);
1193out_fname:
1194	fscrypt_free_filename(&nm);
1195out_budg:
1196	ubifs_release_budget(c, &req);
1197	return err;
1198}
1199
1200/**
1201 * lock_4_inodes - a wrapper for locking three UBIFS inodes.
1202 * @inode1: first inode
1203 * @inode2: second inode
1204 * @inode3: third inode
1205 * @inode4: fouth inode
1206 *
1207 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
1208 * @inode2 whereas @inode3 and @inode4 may be %NULL.
1209 *
1210 * We do not implement any tricks to guarantee strict lock ordering, because
1211 * VFS has already done it for us on the @i_mutex. So this is just a simple
1212 * wrapper function.
1213 */
1214static void lock_4_inodes(struct inode *inode1, struct inode *inode2,
1215			  struct inode *inode3, struct inode *inode4)
1216{
1217	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
1218	if (inode2 != inode1)
1219		mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
1220	if (inode3)
1221		mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
1222	if (inode4)
1223		mutex_lock_nested(&ubifs_inode(inode4)->ui_mutex, WB_MUTEX_4);
1224}
1225
1226/**
1227 * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename.
1228 * @inode1: first inode
1229 * @inode2: second inode
1230 * @inode3: third inode
1231 * @inode4: fouth inode
1232 */
1233static void unlock_4_inodes(struct inode *inode1, struct inode *inode2,
1234			    struct inode *inode3, struct inode *inode4)
1235{
1236	if (inode4)
1237		mutex_unlock(&ubifs_inode(inode4)->ui_mutex);
1238	if (inode3)
1239		mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
1240	if (inode1 != inode2)
1241		mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
1242	mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
1243}
1244
1245static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
1246		     struct inode *new_dir, struct dentry *new_dentry,
1247		     unsigned int flags)
1248{
1249	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1250	struct inode *old_inode = d_inode(old_dentry);
1251	struct inode *new_inode = d_inode(new_dentry);
1252	struct inode *whiteout = NULL;
1253	struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
1254	struct ubifs_inode *whiteout_ui = NULL;
1255	int err, release, sync = 0, move = (new_dir != old_dir);
1256	int is_dir = S_ISDIR(old_inode->i_mode);
1257	int unlink = !!new_inode, new_sz, old_sz;
 
 
1258	struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1259					.dirtied_ino = 3 };
1260	struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
1261			.dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
1262	struct timespec64 time;
1263	unsigned int uninitialized_var(saved_nlink);
1264	struct fscrypt_name old_nm, new_nm;
1265
1266	/*
1267	 * Budget request settings: deletion direntry, new direntry, removing
1268	 * the old inode, and changing old and new parent directory inodes.
1269	 *
1270	 * However, this operation also marks the target inode as dirty and
1271	 * does not write it, so we allocate budget for the target inode
1272	 * separately.
1273	 */
1274
1275	dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x",
1276		old_dentry, old_inode->i_ino, old_dir->i_ino,
1277		new_dentry, new_dir->i_ino, flags);
 
 
 
 
1278
1279	if (unlink) {
1280		ubifs_assert(c, inode_is_locked(new_inode));
1281
1282		err = ubifs_purge_xattrs(new_inode);
1283		if (err)
1284			return err;
1285	}
1286
1287	if (unlink && is_dir) {
1288		err = ubifs_check_dir_empty(new_inode);
1289		if (err)
1290			return err;
1291	}
1292
1293	err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_nm);
1294	if (err)
1295		return err;
1296
1297	err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_nm);
1298	if (err) {
1299		fscrypt_free_filename(&old_nm);
1300		return err;
1301	}
1302
1303	new_sz = CALC_DENT_SIZE(fname_len(&new_nm));
1304	old_sz = CALC_DENT_SIZE(fname_len(&old_nm));
1305
1306	err = ubifs_budget_space(c, &req);
1307	if (err) {
1308		fscrypt_free_filename(&old_nm);
1309		fscrypt_free_filename(&new_nm);
1310		return err;
1311	}
1312	err = ubifs_budget_space(c, &ino_req);
1313	if (err) {
1314		fscrypt_free_filename(&old_nm);
1315		fscrypt_free_filename(&new_nm);
1316		ubifs_release_budget(c, &req);
1317		return err;
1318	}
1319
1320	if (flags & RENAME_WHITEOUT) {
1321		union ubifs_dev_desc *dev = NULL;
1322
1323		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
1324		if (!dev) {
1325			err = -ENOMEM;
1326			goto out_release;
1327		}
1328
1329		err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout);
1330		if (err) {
1331			kfree(dev);
1332			goto out_release;
1333		}
1334
1335		whiteout->i_state |= I_LINKABLE;
1336		whiteout_ui = ubifs_inode(whiteout);
1337		whiteout_ui->data = dev;
1338		whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
1339		ubifs_assert(c, !whiteout_ui->dirty);
1340	}
1341
1342	lock_4_inodes(old_dir, new_dir, new_inode, whiteout);
1343
1344	/*
1345	 * Like most other Unix systems, set the @i_ctime for inodes on a
1346	 * rename.
1347	 */
1348	time = current_time(old_dir);
1349	old_inode->i_ctime = time;
1350
1351	/* We must adjust parent link count when renaming directories */
1352	if (is_dir) {
1353		if (move) {
1354			/*
1355			 * @old_dir loses a link because we are moving
1356			 * @old_inode to a different directory.
1357			 */
1358			drop_nlink(old_dir);
1359			/*
1360			 * @new_dir only gains a link if we are not also
1361			 * overwriting an existing directory.
1362			 */
1363			if (!unlink)
1364				inc_nlink(new_dir);
1365		} else {
1366			/*
1367			 * @old_inode is not moving to a different directory,
1368			 * but @old_dir still loses a link if we are
1369			 * overwriting an existing directory.
1370			 */
1371			if (unlink)
1372				drop_nlink(old_dir);
1373		}
1374	}
1375
1376	old_dir->i_size -= old_sz;
1377	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1378	old_dir->i_mtime = old_dir->i_ctime = time;
1379	new_dir->i_mtime = new_dir->i_ctime = time;
1380
1381	/*
1382	 * And finally, if we unlinked a direntry which happened to have the
1383	 * same name as the moved direntry, we have to decrement @i_nlink of
1384	 * the unlinked inode and change its ctime.
1385	 */
1386	if (unlink) {
1387		/*
1388		 * Directories cannot have hard-links, so if this is a
1389		 * directory, just clear @i_nlink.
1390		 */
1391		saved_nlink = new_inode->i_nlink;
1392		if (is_dir)
1393			clear_nlink(new_inode);
1394		else
1395			drop_nlink(new_inode);
1396		new_inode->i_ctime = time;
1397	} else {
1398		new_dir->i_size += new_sz;
1399		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1400	}
1401
1402	/*
1403	 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1404	 * is dirty, because this will be done later on at the end of
1405	 * 'ubifs_rename()'.
1406	 */
1407	if (IS_SYNC(old_inode)) {
1408		sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1409		if (unlink && IS_SYNC(new_inode))
1410			sync = 1;
1411	}
1412
1413	if (whiteout) {
1414		struct ubifs_budget_req wht_req = { .dirtied_ino = 1,
1415				.dirtied_ino_d = \
1416				ALIGN(ubifs_inode(whiteout)->data_len, 8) };
1417
1418		err = ubifs_budget_space(c, &wht_req);
1419		if (err) {
1420			kfree(whiteout_ui->data);
1421			whiteout_ui->data_len = 0;
1422			iput(whiteout);
1423			goto out_release;
1424		}
1425
1426		inc_nlink(whiteout);
1427		mark_inode_dirty(whiteout);
1428		whiteout->i_state &= ~I_LINKABLE;
1429		iput(whiteout);
1430	}
1431
1432	err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir,
1433			       new_inode, &new_nm, whiteout, sync);
1434	if (err)
1435		goto out_cancel;
1436
1437	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
1438	ubifs_release_budget(c, &req);
1439
1440	mutex_lock(&old_inode_ui->ui_mutex);
1441	release = old_inode_ui->dirty;
1442	mark_inode_dirty_sync(old_inode);
1443	mutex_unlock(&old_inode_ui->ui_mutex);
1444
1445	if (release)
1446		ubifs_release_budget(c, &ino_req);
1447	if (IS_SYNC(old_inode))
1448		err = old_inode->i_sb->s_op->write_inode(old_inode, NULL);
1449
1450	fscrypt_free_filename(&old_nm);
1451	fscrypt_free_filename(&new_nm);
1452	return err;
1453
1454out_cancel:
1455	if (unlink) {
1456		set_nlink(new_inode, saved_nlink);
1457	} else {
1458		new_dir->i_size -= new_sz;
1459		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1460	}
1461	old_dir->i_size += old_sz;
1462	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1463	if (is_dir) {
1464		if (move) {
1465			inc_nlink(old_dir);
1466			if (!unlink)
1467				drop_nlink(new_dir);
1468		} else {
1469			if (unlink)
1470				inc_nlink(old_dir);
1471		}
1472	}
1473	if (whiteout) {
1474		drop_nlink(whiteout);
1475		iput(whiteout);
1476	}
1477	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
1478out_release:
1479	ubifs_release_budget(c, &ino_req);
1480	ubifs_release_budget(c, &req);
1481	fscrypt_free_filename(&old_nm);
1482	fscrypt_free_filename(&new_nm);
1483	return err;
1484}
1485
1486static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
1487			struct inode *new_dir, struct dentry *new_dentry)
1488{
1489	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1490	struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1491				.dirtied_ino = 2 };
1492	int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1493	struct inode *fst_inode = d_inode(old_dentry);
1494	struct inode *snd_inode = d_inode(new_dentry);
1495	struct timespec64 time;
1496	int err;
1497	struct fscrypt_name fst_nm, snd_nm;
1498
1499	ubifs_assert(c, fst_inode && snd_inode);
1500
1501	err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &fst_nm);
1502	if (err)
1503		return err;
1504
1505	err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &snd_nm);
1506	if (err) {
1507		fscrypt_free_filename(&fst_nm);
1508		return err;
1509	}
1510
1511	lock_4_inodes(old_dir, new_dir, NULL, NULL);
1512
1513	time = current_time(old_dir);
1514	fst_inode->i_ctime = time;
1515	snd_inode->i_ctime = time;
1516	old_dir->i_mtime = old_dir->i_ctime = time;
1517	new_dir->i_mtime = new_dir->i_ctime = time;
1518
1519	if (old_dir != new_dir) {
1520		if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
1521			inc_nlink(new_dir);
1522			drop_nlink(old_dir);
1523		}
1524		else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
1525			drop_nlink(new_dir);
1526			inc_nlink(old_dir);
1527		}
1528	}
1529
1530	err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir,
1531				snd_inode, &snd_nm, sync);
1532
1533	unlock_4_inodes(old_dir, new_dir, NULL, NULL);
1534	ubifs_release_budget(c, &req);
1535
1536	fscrypt_free_filename(&fst_nm);
1537	fscrypt_free_filename(&snd_nm);
1538	return err;
1539}
1540
1541static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
1542			struct inode *new_dir, struct dentry *new_dentry,
1543			unsigned int flags)
1544{
1545	int err;
1546	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1547
1548	if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
1549		return -EINVAL;
1550
1551	ubifs_assert(c, inode_is_locked(old_dir));
1552	ubifs_assert(c, inode_is_locked(new_dir));
1553
1554	err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
1555				     flags);
1556	if (err)
1557		return err;
1558
1559	if (flags & RENAME_EXCHANGE)
1560		return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);
1561
1562	return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
1563}
1564
1565int ubifs_getattr(const struct path *path, struct kstat *stat,
1566		  u32 request_mask, unsigned int flags)
1567{
1568	loff_t size;
1569	struct inode *inode = d_inode(path->dentry);
1570	struct ubifs_inode *ui = ubifs_inode(inode);
1571
1572	mutex_lock(&ui->ui_mutex);
1573
1574	if (ui->flags & UBIFS_APPEND_FL)
1575		stat->attributes |= STATX_ATTR_APPEND;
1576	if (ui->flags & UBIFS_COMPR_FL)
1577		stat->attributes |= STATX_ATTR_COMPRESSED;
1578	if (ui->flags & UBIFS_CRYPT_FL)
1579		stat->attributes |= STATX_ATTR_ENCRYPTED;
1580	if (ui->flags & UBIFS_IMMUTABLE_FL)
1581		stat->attributes |= STATX_ATTR_IMMUTABLE;
1582
1583	stat->attributes_mask |= (STATX_ATTR_APPEND |
1584				STATX_ATTR_COMPRESSED |
1585				STATX_ATTR_ENCRYPTED |
1586				STATX_ATTR_IMMUTABLE);
1587
1588	generic_fillattr(inode, stat);
1589	stat->blksize = UBIFS_BLOCK_SIZE;
1590	stat->size = ui->ui_size;
1591
1592	/*
1593	 * Unfortunately, the 'stat()' system call was designed for block
1594	 * device based file systems, and it is not appropriate for UBIFS,
1595	 * because UBIFS does not have notion of "block". For example, it is
1596	 * difficult to tell how many block a directory takes - it actually
1597	 * takes less than 300 bytes, but we have to round it to block size,
1598	 * which introduces large mistake. This makes utilities like 'du' to
1599	 * report completely senseless numbers. This is the reason why UBIFS
1600	 * goes the same way as JFFS2 - it reports zero blocks for everything
1601	 * but regular files, which makes more sense than reporting completely
1602	 * wrong sizes.
1603	 */
1604	if (S_ISREG(inode->i_mode)) {
1605		size = ui->xattr_size;
1606		size += stat->size;
1607		size = ALIGN(size, UBIFS_BLOCK_SIZE);
1608		/*
1609		 * Note, user-space expects 512-byte blocks count irrespectively
1610		 * of what was reported in @stat->size.
1611		 */
1612		stat->blocks = size >> 9;
1613	} else
1614		stat->blocks = 0;
1615	mutex_unlock(&ui->ui_mutex);
1616	return 0;
1617}
1618
1619static int ubifs_dir_open(struct inode *dir, struct file *file)
1620{
1621	if (ubifs_crypt_is_encrypted(dir))
1622		return fscrypt_get_encryption_info(dir) ? -EACCES : 0;
1623
1624	return 0;
1625}
1626
1627const struct inode_operations ubifs_dir_inode_operations = {
1628	.lookup      = ubifs_lookup,
1629	.create      = ubifs_create,
1630	.link        = ubifs_link,
1631	.symlink     = ubifs_symlink,
1632	.unlink      = ubifs_unlink,
1633	.mkdir       = ubifs_mkdir,
1634	.rmdir       = ubifs_rmdir,
1635	.mknod       = ubifs_mknod,
1636	.rename      = ubifs_rename,
1637	.setattr     = ubifs_setattr,
1638	.getattr     = ubifs_getattr,
1639#ifdef CONFIG_UBIFS_FS_XATTR
 
1640	.listxattr   = ubifs_listxattr,
1641#endif
 
1642	.update_time = ubifs_update_time,
1643	.tmpfile     = ubifs_tmpfile,
1644};
1645
1646const struct file_operations ubifs_dir_operations = {
1647	.llseek         = generic_file_llseek,
1648	.release        = ubifs_dir_release,
1649	.read           = generic_read_dir,
1650	.iterate_shared = ubifs_readdir,
1651	.fsync          = ubifs_fsync,
1652	.unlocked_ioctl = ubifs_ioctl,
1653	.open		= ubifs_dir_open,
1654#ifdef CONFIG_COMPAT
1655	.compat_ioctl   = ubifs_compat_ioctl,
1656#endif
1657};