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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * fs/f2fs/dir.c
   4 *
   5 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   6 *             http://www.samsung.com/
   7 */
   8#include <linux/fs.h>
   9#include <linux/f2fs_fs.h>
  10#include <linux/sched/signal.h>
  11#include <linux/unicode.h>
  12#include "f2fs.h"
  13#include "node.h"
  14#include "acl.h"
  15#include "xattr.h"
  16#include <trace/events/f2fs.h>
  17
  18static unsigned long dir_blocks(struct inode *inode)
  19{
  20	return ((unsigned long long) (i_size_read(inode) + PAGE_SIZE - 1))
  21							>> PAGE_SHIFT;
  22}
  23
  24static unsigned int dir_buckets(unsigned int level, int dir_level)
  25{
  26	if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
  27		return 1 << (level + dir_level);
  28	else
  29		return MAX_DIR_BUCKETS;
  30}
  31
  32static unsigned int bucket_blocks(unsigned int level)
  33{
  34	if (level < MAX_DIR_HASH_DEPTH / 2)
  35		return 2;
  36	else
  37		return 4;
  38}
  39
  40static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
  41	[F2FS_FT_UNKNOWN]	= DT_UNKNOWN,
  42	[F2FS_FT_REG_FILE]	= DT_REG,
  43	[F2FS_FT_DIR]		= DT_DIR,
  44	[F2FS_FT_CHRDEV]	= DT_CHR,
  45	[F2FS_FT_BLKDEV]	= DT_BLK,
  46	[F2FS_FT_FIFO]		= DT_FIFO,
  47	[F2FS_FT_SOCK]		= DT_SOCK,
  48	[F2FS_FT_SYMLINK]	= DT_LNK,
  49};
  50
  51static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
  52	[S_IFREG >> S_SHIFT]	= F2FS_FT_REG_FILE,
  53	[S_IFDIR >> S_SHIFT]	= F2FS_FT_DIR,
  54	[S_IFCHR >> S_SHIFT]	= F2FS_FT_CHRDEV,
  55	[S_IFBLK >> S_SHIFT]	= F2FS_FT_BLKDEV,
  56	[S_IFIFO >> S_SHIFT]	= F2FS_FT_FIFO,
  57	[S_IFSOCK >> S_SHIFT]	= F2FS_FT_SOCK,
  58	[S_IFLNK >> S_SHIFT]	= F2FS_FT_SYMLINK,
  59};
  60
  61static void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
  62{
  63	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
  64}
  65
  66unsigned char f2fs_get_de_type(struct f2fs_dir_entry *de)
  67{
  68	if (de->file_type < F2FS_FT_MAX)
  69		return f2fs_filetype_table[de->file_type];
  70	return DT_UNKNOWN;
  71}
  72
  73/* If @dir is casefolded, initialize @fname->cf_name from @fname->usr_fname. */
  74int f2fs_init_casefolded_name(const struct inode *dir,
  75			      struct f2fs_filename *fname)
  76{
  77#ifdef CONFIG_UNICODE
  78	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
  79
  80	if (IS_CASEFOLDED(dir)) {
  81		fname->cf_name.name = f2fs_kmalloc(sbi, F2FS_NAME_LEN,
  82						   GFP_NOFS);
  83		if (!fname->cf_name.name)
  84			return -ENOMEM;
  85		fname->cf_name.len = utf8_casefold(sbi->s_encoding,
  86						   fname->usr_fname,
  87						   fname->cf_name.name,
  88						   F2FS_NAME_LEN);
  89		if ((int)fname->cf_name.len <= 0) {
  90			kfree(fname->cf_name.name);
  91			fname->cf_name.name = NULL;
  92			if (f2fs_has_strict_mode(sbi))
  93				return -EINVAL;
  94			/* fall back to treating name as opaque byte sequence */
  95		}
  96	}
  97#endif
  98	return 0;
  99}
 100
 101static int __f2fs_setup_filename(const struct inode *dir,
 102				 const struct fscrypt_name *crypt_name,
 103				 struct f2fs_filename *fname)
 104{
 105	int err;
 106
 107	memset(fname, 0, sizeof(*fname));
 108
 109	fname->usr_fname = crypt_name->usr_fname;
 110	fname->disk_name = crypt_name->disk_name;
 111#ifdef CONFIG_FS_ENCRYPTION
 112	fname->crypto_buf = crypt_name->crypto_buf;
 113#endif
 114	if (crypt_name->is_ciphertext_name) {
 115		/* hash was decoded from the no-key name */
 116		fname->hash = cpu_to_le32(crypt_name->hash);
 117	} else {
 118		err = f2fs_init_casefolded_name(dir, fname);
 119		if (err) {
 120			f2fs_free_filename(fname);
 121			return err;
 122		}
 123		f2fs_hash_filename(dir, fname);
 124	}
 125	return 0;
 126}
 127
 128/*
 129 * Prepare to search for @iname in @dir.  This is similar to
 130 * fscrypt_setup_filename(), but this also handles computing the casefolded name
 131 * and the f2fs dirhash if needed, then packing all the information about this
 132 * filename up into a 'struct f2fs_filename'.
 133 */
 134int f2fs_setup_filename(struct inode *dir, const struct qstr *iname,
 135			int lookup, struct f2fs_filename *fname)
 136{
 137	struct fscrypt_name crypt_name;
 138	int err;
 139
 140	err = fscrypt_setup_filename(dir, iname, lookup, &crypt_name);
 141	if (err)
 142		return err;
 143
 144	return __f2fs_setup_filename(dir, &crypt_name, fname);
 145}
 146
 147/*
 148 * Prepare to look up @dentry in @dir.  This is similar to
 149 * fscrypt_prepare_lookup(), but this also handles computing the casefolded name
 150 * and the f2fs dirhash if needed, then packing all the information about this
 151 * filename up into a 'struct f2fs_filename'.
 152 */
 153int f2fs_prepare_lookup(struct inode *dir, struct dentry *dentry,
 154			struct f2fs_filename *fname)
 155{
 156	struct fscrypt_name crypt_name;
 157	int err;
 158
 159	err = fscrypt_prepare_lookup(dir, dentry, &crypt_name);
 160	if (err)
 161		return err;
 162
 163	return __f2fs_setup_filename(dir, &crypt_name, fname);
 164}
 165
 166void f2fs_free_filename(struct f2fs_filename *fname)
 167{
 168#ifdef CONFIG_FS_ENCRYPTION
 169	kfree(fname->crypto_buf.name);
 170	fname->crypto_buf.name = NULL;
 171#endif
 172#ifdef CONFIG_UNICODE
 173	kfree(fname->cf_name.name);
 174	fname->cf_name.name = NULL;
 175#endif
 176}
 177
 178static unsigned long dir_block_index(unsigned int level,
 179				int dir_level, unsigned int idx)
 180{
 181	unsigned long i;
 182	unsigned long bidx = 0;
 183
 184	for (i = 0; i < level; i++)
 185		bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
 186	bidx += idx * bucket_blocks(level);
 187	return bidx;
 188}
 189
 190static struct f2fs_dir_entry *find_in_block(struct inode *dir,
 191				struct page *dentry_page,
 192				const struct f2fs_filename *fname,
 193				int *max_slots,
 194				struct page **res_page)
 195{
 196	struct f2fs_dentry_block *dentry_blk;
 197	struct f2fs_dir_entry *de;
 198	struct f2fs_dentry_ptr d;
 199
 200	dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page);
 201
 202	make_dentry_ptr_block(dir, &d, dentry_blk);
 203	de = f2fs_find_target_dentry(&d, fname, max_slots);
 204	if (de)
 205		*res_page = dentry_page;
 206
 207	return de;
 208}
 209
 210#ifdef CONFIG_UNICODE
 211/*
 212 * Test whether a case-insensitive directory entry matches the filename
 213 * being searched for.
 214 */
 215static bool f2fs_match_ci_name(const struct inode *dir, const struct qstr *name,
 216			       const u8 *de_name, u32 de_name_len)
 217{
 218	const struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
 219	const struct unicode_map *um = sbi->s_encoding;
 220	struct qstr entry = QSTR_INIT(de_name, de_name_len);
 221	int res;
 222
 223	res = utf8_strncasecmp_folded(um, name, &entry);
 224	if (res < 0) {
 225		/*
 226		 * In strict mode, ignore invalid names.  In non-strict mode,
 227		 * fall back to treating them as opaque byte sequences.
 228		 */
 229		if (f2fs_has_strict_mode(sbi) || name->len != entry.len)
 230			return false;
 231		return !memcmp(name->name, entry.name, name->len);
 232	}
 233	return res == 0;
 234}
 235#endif /* CONFIG_UNICODE */
 236
 237static inline bool f2fs_match_name(const struct inode *dir,
 238				   const struct f2fs_filename *fname,
 239				   const u8 *de_name, u32 de_name_len)
 240{
 241	struct fscrypt_name f;
 242
 243#ifdef CONFIG_UNICODE
 244	if (fname->cf_name.name) {
 245		struct qstr cf = FSTR_TO_QSTR(&fname->cf_name);
 246
 247		return f2fs_match_ci_name(dir, &cf, de_name, de_name_len);
 248	}
 249#endif
 250	f.usr_fname = fname->usr_fname;
 251	f.disk_name = fname->disk_name;
 252#ifdef CONFIG_FS_ENCRYPTION
 253	f.crypto_buf = fname->crypto_buf;
 254#endif
 255	return fscrypt_match_name(&f, de_name, de_name_len);
 256}
 257
 258struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d,
 259			const struct f2fs_filename *fname, int *max_slots)
 260{
 261	struct f2fs_dir_entry *de;
 262	unsigned long bit_pos = 0;
 263	int max_len = 0;
 264
 265	if (max_slots)
 266		*max_slots = 0;
 267	while (bit_pos < d->max) {
 268		if (!test_bit_le(bit_pos, d->bitmap)) {
 269			bit_pos++;
 270			max_len++;
 271			continue;
 272		}
 273
 274		de = &d->dentry[bit_pos];
 275
 276		if (unlikely(!de->name_len)) {
 277			bit_pos++;
 278			continue;
 279		}
 280
 281		if (de->hash_code == fname->hash &&
 282		    f2fs_match_name(d->inode, fname, d->filename[bit_pos],
 283				    le16_to_cpu(de->name_len)))
 284			goto found;
 285
 286		if (max_slots && max_len > *max_slots)
 287			*max_slots = max_len;
 288		max_len = 0;
 289
 290		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
 291	}
 292
 293	de = NULL;
 294found:
 295	if (max_slots && max_len > *max_slots)
 296		*max_slots = max_len;
 297	return de;
 298}
 299
 300static struct f2fs_dir_entry *find_in_level(struct inode *dir,
 301					unsigned int level,
 302					const struct f2fs_filename *fname,
 303					struct page **res_page)
 304{
 305	int s = GET_DENTRY_SLOTS(fname->disk_name.len);
 306	unsigned int nbucket, nblock;
 307	unsigned int bidx, end_block;
 308	struct page *dentry_page;
 309	struct f2fs_dir_entry *de = NULL;
 310	bool room = false;
 311	int max_slots;
 312
 313	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 314	nblock = bucket_blocks(level);
 315
 316	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
 317			       le32_to_cpu(fname->hash) % nbucket);
 318	end_block = bidx + nblock;
 319
 320	for (; bidx < end_block; bidx++) {
 321		/* no need to allocate new dentry pages to all the indices */
 322		dentry_page = f2fs_find_data_page(dir, bidx);
 323		if (IS_ERR(dentry_page)) {
 324			if (PTR_ERR(dentry_page) == -ENOENT) {
 325				room = true;
 326				continue;
 327			} else {
 328				*res_page = dentry_page;
 329				break;
 330			}
 331		}
 332
 333		de = find_in_block(dir, dentry_page, fname, &max_slots,
 334				   res_page);
 335		if (de)
 336			break;
 337
 338		if (max_slots >= s)
 339			room = true;
 340		f2fs_put_page(dentry_page, 0);
 341	}
 342
 343	if (!de && room && F2FS_I(dir)->chash != fname->hash) {
 344		F2FS_I(dir)->chash = fname->hash;
 345		F2FS_I(dir)->clevel = level;
 346	}
 347
 348	return de;
 349}
 350
 351struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
 352					 const struct f2fs_filename *fname,
 353					 struct page **res_page)
 354{
 355	unsigned long npages = dir_blocks(dir);
 356	struct f2fs_dir_entry *de = NULL;
 357	unsigned int max_depth;
 358	unsigned int level;
 359
 360	if (f2fs_has_inline_dentry(dir)) {
 361		*res_page = NULL;
 362		de = f2fs_find_in_inline_dir(dir, fname, res_page);
 363		goto out;
 364	}
 365
 366	if (npages == 0) {
 367		*res_page = NULL;
 368		goto out;
 369	}
 370
 371	max_depth = F2FS_I(dir)->i_current_depth;
 372	if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
 373		f2fs_warn(F2FS_I_SB(dir), "Corrupted max_depth of %lu: %u",
 374			  dir->i_ino, max_depth);
 375		max_depth = MAX_DIR_HASH_DEPTH;
 376		f2fs_i_depth_write(dir, max_depth);
 377	}
 378
 379	for (level = 0; level < max_depth; level++) {
 380		*res_page = NULL;
 381		de = find_in_level(dir, level, fname, res_page);
 382		if (de || IS_ERR(*res_page))
 383			break;
 384	}
 385out:
 386	/* This is to increase the speed of f2fs_create */
 387	if (!de)
 388		F2FS_I(dir)->task = current;
 389	return de;
 390}
 391
 392/*
 393 * Find an entry in the specified directory with the wanted name.
 394 * It returns the page where the entry was found (as a parameter - res_page),
 395 * and the entry itself. Page is returned mapped and unlocked.
 396 * Entry is guaranteed to be valid.
 397 */
 398struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
 399			const struct qstr *child, struct page **res_page)
 400{
 401	struct f2fs_dir_entry *de = NULL;
 402	struct f2fs_filename fname;
 403	int err;
 404
 405	err = f2fs_setup_filename(dir, child, 1, &fname);
 406	if (err) {
 407		if (err == -ENOENT)
 408			*res_page = NULL;
 409		else
 410			*res_page = ERR_PTR(err);
 411		return NULL;
 412	}
 413
 414	de = __f2fs_find_entry(dir, &fname, res_page);
 415
 416	f2fs_free_filename(&fname);
 417	return de;
 418}
 419
 420struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
 421{
 422	struct qstr dotdot = QSTR_INIT("..", 2);
 423
 424	return f2fs_find_entry(dir, &dotdot, p);
 425}
 426
 427ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
 428							struct page **page)
 429{
 430	ino_t res = 0;
 431	struct f2fs_dir_entry *de;
 432
 433	de = f2fs_find_entry(dir, qstr, page);
 434	if (de) {
 435		res = le32_to_cpu(de->ino);
 436		f2fs_put_page(*page, 0);
 437	}
 438
 439	return res;
 440}
 441
 442void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
 443		struct page *page, struct inode *inode)
 444{
 445	enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
 446	lock_page(page);
 447	f2fs_wait_on_page_writeback(page, type, true, true);
 448	de->ino = cpu_to_le32(inode->i_ino);
 449	set_de_type(de, inode->i_mode);
 450	set_page_dirty(page);
 451
 452	dir->i_mtime = dir->i_ctime = current_time(dir);
 453	f2fs_mark_inode_dirty_sync(dir, false);
 454	f2fs_put_page(page, 1);
 455}
 456
 457static void init_dent_inode(const struct f2fs_filename *fname,
 458			    struct page *ipage)
 459{
 460	struct f2fs_inode *ri;
 461
 462	f2fs_wait_on_page_writeback(ipage, NODE, true, true);
 463
 464	/* copy name info. to this inode page */
 465	ri = F2FS_INODE(ipage);
 466	ri->i_namelen = cpu_to_le32(fname->disk_name.len);
 467	memcpy(ri->i_name, fname->disk_name.name, fname->disk_name.len);
 468	set_page_dirty(ipage);
 469}
 470
 471void f2fs_do_make_empty_dir(struct inode *inode, struct inode *parent,
 472					struct f2fs_dentry_ptr *d)
 473{
 474	struct fscrypt_str dot = FSTR_INIT(".", 1);
 475	struct fscrypt_str dotdot = FSTR_INIT("..", 2);
 476
 477	/* update dirent of "." */
 478	f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0);
 479
 480	/* update dirent of ".." */
 481	f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1);
 482}
 483
 484static int make_empty_dir(struct inode *inode,
 485		struct inode *parent, struct page *page)
 486{
 487	struct page *dentry_page;
 488	struct f2fs_dentry_block *dentry_blk;
 489	struct f2fs_dentry_ptr d;
 490
 491	if (f2fs_has_inline_dentry(inode))
 492		return f2fs_make_empty_inline_dir(inode, parent, page);
 493
 494	dentry_page = f2fs_get_new_data_page(inode, page, 0, true);
 495	if (IS_ERR(dentry_page))
 496		return PTR_ERR(dentry_page);
 497
 498	dentry_blk = page_address(dentry_page);
 499
 500	make_dentry_ptr_block(NULL, &d, dentry_blk);
 501	f2fs_do_make_empty_dir(inode, parent, &d);
 502
 503	set_page_dirty(dentry_page);
 504	f2fs_put_page(dentry_page, 1);
 505	return 0;
 506}
 507
 508struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir,
 509			const struct f2fs_filename *fname, struct page *dpage)
 510{
 511	struct page *page;
 512	int err;
 513
 514	if (is_inode_flag_set(inode, FI_NEW_INODE)) {
 515		page = f2fs_new_inode_page(inode);
 516		if (IS_ERR(page))
 517			return page;
 518
 519		if (S_ISDIR(inode->i_mode)) {
 520			/* in order to handle error case */
 521			get_page(page);
 522			err = make_empty_dir(inode, dir, page);
 523			if (err) {
 524				lock_page(page);
 525				goto put_error;
 526			}
 527			put_page(page);
 528		}
 529
 530		err = f2fs_init_acl(inode, dir, page, dpage);
 531		if (err)
 532			goto put_error;
 533
 534		err = f2fs_init_security(inode, dir,
 535					 fname ? fname->usr_fname : NULL, page);
 536		if (err)
 537			goto put_error;
 538
 539		if (IS_ENCRYPTED(inode)) {
 540			err = fscrypt_inherit_context(dir, inode, page, false);
 541			if (err)
 542				goto put_error;
 543		}
 544	} else {
 545		page = f2fs_get_node_page(F2FS_I_SB(dir), inode->i_ino);
 546		if (IS_ERR(page))
 547			return page;
 548	}
 549
 550	if (fname) {
 551		init_dent_inode(fname, page);
 552		if (IS_ENCRYPTED(dir))
 553			file_set_enc_name(inode);
 554	}
 555
 556	/*
 557	 * This file should be checkpointed during fsync.
 558	 * We lost i_pino from now on.
 559	 */
 560	if (is_inode_flag_set(inode, FI_INC_LINK)) {
 561		if (!S_ISDIR(inode->i_mode))
 562			file_lost_pino(inode);
 563		/*
 564		 * If link the tmpfile to alias through linkat path,
 565		 * we should remove this inode from orphan list.
 566		 */
 567		if (inode->i_nlink == 0)
 568			f2fs_remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
 569		f2fs_i_links_write(inode, true);
 570	}
 571	return page;
 572
 573put_error:
 574	clear_nlink(inode);
 575	f2fs_update_inode(inode, page);
 576	f2fs_put_page(page, 1);
 577	return ERR_PTR(err);
 578}
 579
 580void f2fs_update_parent_metadata(struct inode *dir, struct inode *inode,
 581						unsigned int current_depth)
 582{
 583	if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) {
 584		if (S_ISDIR(inode->i_mode))
 585			f2fs_i_links_write(dir, true);
 586		clear_inode_flag(inode, FI_NEW_INODE);
 587	}
 588	dir->i_mtime = dir->i_ctime = current_time(dir);
 589	f2fs_mark_inode_dirty_sync(dir, false);
 590
 591	if (F2FS_I(dir)->i_current_depth != current_depth)
 592		f2fs_i_depth_write(dir, current_depth);
 593
 594	if (inode && is_inode_flag_set(inode, FI_INC_LINK))
 595		clear_inode_flag(inode, FI_INC_LINK);
 596}
 597
 598int f2fs_room_for_filename(const void *bitmap, int slots, int max_slots)
 599{
 600	int bit_start = 0;
 601	int zero_start, zero_end;
 602next:
 603	zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
 604	if (zero_start >= max_slots)
 605		return max_slots;
 606
 607	zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
 608	if (zero_end - zero_start >= slots)
 609		return zero_start;
 610
 611	bit_start = zero_end + 1;
 612
 613	if (zero_end + 1 >= max_slots)
 614		return max_slots;
 615	goto next;
 616}
 617
 618bool f2fs_has_enough_room(struct inode *dir, struct page *ipage,
 619			  const struct f2fs_filename *fname)
 620{
 621	struct f2fs_dentry_ptr d;
 622	unsigned int bit_pos;
 623	int slots = GET_DENTRY_SLOTS(fname->disk_name.len);
 624
 625	make_dentry_ptr_inline(dir, &d, inline_data_addr(dir, ipage));
 626
 627	bit_pos = f2fs_room_for_filename(d.bitmap, slots, d.max);
 628
 629	return bit_pos < d.max;
 630}
 631
 632void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
 633			const struct fscrypt_str *name, f2fs_hash_t name_hash,
 634			unsigned int bit_pos)
 635{
 636	struct f2fs_dir_entry *de;
 637	int slots = GET_DENTRY_SLOTS(name->len);
 638	int i;
 639
 640	de = &d->dentry[bit_pos];
 641	de->hash_code = name_hash;
 642	de->name_len = cpu_to_le16(name->len);
 643	memcpy(d->filename[bit_pos], name->name, name->len);
 644	de->ino = cpu_to_le32(ino);
 645	set_de_type(de, mode);
 646	for (i = 0; i < slots; i++) {
 647		__set_bit_le(bit_pos + i, (void *)d->bitmap);
 648		/* avoid wrong garbage data for readdir */
 649		if (i)
 650			(de + i)->name_len = 0;
 651	}
 652}
 653
 654int f2fs_add_regular_entry(struct inode *dir, const struct f2fs_filename *fname,
 655			   struct inode *inode, nid_t ino, umode_t mode)
 656{
 657	unsigned int bit_pos;
 658	unsigned int level;
 659	unsigned int current_depth;
 660	unsigned long bidx, block;
 661	unsigned int nbucket, nblock;
 662	struct page *dentry_page = NULL;
 663	struct f2fs_dentry_block *dentry_blk = NULL;
 664	struct f2fs_dentry_ptr d;
 665	struct page *page = NULL;
 666	int slots, err = 0;
 667
 668	level = 0;
 669	slots = GET_DENTRY_SLOTS(fname->disk_name.len);
 670
 671	current_depth = F2FS_I(dir)->i_current_depth;
 672	if (F2FS_I(dir)->chash == fname->hash) {
 673		level = F2FS_I(dir)->clevel;
 674		F2FS_I(dir)->chash = 0;
 675	}
 676
 677start:
 678	if (time_to_inject(F2FS_I_SB(dir), FAULT_DIR_DEPTH)) {
 679		f2fs_show_injection_info(F2FS_I_SB(dir), FAULT_DIR_DEPTH);
 680		return -ENOSPC;
 681	}
 682
 683	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
 684		return -ENOSPC;
 685
 686	/* Increase the depth, if required */
 687	if (level == current_depth)
 688		++current_depth;
 689
 690	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 691	nblock = bucket_blocks(level);
 692
 693	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
 694				(le32_to_cpu(fname->hash) % nbucket));
 695
 696	for (block = bidx; block <= (bidx + nblock - 1); block++) {
 697		dentry_page = f2fs_get_new_data_page(dir, NULL, block, true);
 698		if (IS_ERR(dentry_page))
 699			return PTR_ERR(dentry_page);
 700
 701		dentry_blk = page_address(dentry_page);
 702		bit_pos = f2fs_room_for_filename(&dentry_blk->dentry_bitmap,
 703						slots, NR_DENTRY_IN_BLOCK);
 704		if (bit_pos < NR_DENTRY_IN_BLOCK)
 705			goto add_dentry;
 706
 707		f2fs_put_page(dentry_page, 1);
 708	}
 709
 710	/* Move to next level to find the empty slot for new dentry */
 711	++level;
 712	goto start;
 713add_dentry:
 714	f2fs_wait_on_page_writeback(dentry_page, DATA, true, true);
 715
 716	if (inode) {
 717		down_write(&F2FS_I(inode)->i_sem);
 718		page = f2fs_init_inode_metadata(inode, dir, fname, NULL);
 719		if (IS_ERR(page)) {
 720			err = PTR_ERR(page);
 721			goto fail;
 722		}
 723	}
 724
 725	make_dentry_ptr_block(NULL, &d, dentry_blk);
 726	f2fs_update_dentry(ino, mode, &d, &fname->disk_name, fname->hash,
 727			   bit_pos);
 728
 729	set_page_dirty(dentry_page);
 730
 731	if (inode) {
 732		f2fs_i_pino_write(inode, dir->i_ino);
 733
 734		/* synchronize inode page's data from inode cache */
 735		if (is_inode_flag_set(inode, FI_NEW_INODE))
 736			f2fs_update_inode(inode, page);
 737
 738		f2fs_put_page(page, 1);
 739	}
 740
 741	f2fs_update_parent_metadata(dir, inode, current_depth);
 742fail:
 743	if (inode)
 744		up_write(&F2FS_I(inode)->i_sem);
 745
 746	f2fs_put_page(dentry_page, 1);
 747
 748	return err;
 749}
 750
 751int f2fs_add_dentry(struct inode *dir, const struct f2fs_filename *fname,
 752		    struct inode *inode, nid_t ino, umode_t mode)
 753{
 754	int err = -EAGAIN;
 755
 756	if (f2fs_has_inline_dentry(dir))
 757		err = f2fs_add_inline_entry(dir, fname, inode, ino, mode);
 758	if (err == -EAGAIN)
 759		err = f2fs_add_regular_entry(dir, fname, inode, ino, mode);
 760
 761	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
 762	return err;
 763}
 764
 765/*
 766 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
 767 * f2fs_unlock_op().
 768 */
 769int f2fs_do_add_link(struct inode *dir, const struct qstr *name,
 770				struct inode *inode, nid_t ino, umode_t mode)
 771{
 772	struct f2fs_filename fname;
 773	struct page *page = NULL;
 774	struct f2fs_dir_entry *de = NULL;
 775	int err;
 776
 777	err = f2fs_setup_filename(dir, name, 0, &fname);
 778	if (err)
 779		return err;
 780
 781	/*
 782	 * An immature stackable filesystem shows a race condition between lookup
 783	 * and create. If we have same task when doing lookup and create, it's
 784	 * definitely fine as expected by VFS normally. Otherwise, let's just
 785	 * verify on-disk dentry one more time, which guarantees filesystem
 786	 * consistency more.
 787	 */
 788	if (current != F2FS_I(dir)->task) {
 789		de = __f2fs_find_entry(dir, &fname, &page);
 790		F2FS_I(dir)->task = NULL;
 791	}
 792	if (de) {
 793		f2fs_put_page(page, 0);
 794		err = -EEXIST;
 795	} else if (IS_ERR(page)) {
 796		err = PTR_ERR(page);
 797	} else {
 798		err = f2fs_add_dentry(dir, &fname, inode, ino, mode);
 799	}
 800	f2fs_free_filename(&fname);
 801	return err;
 802}
 803
 804int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
 805{
 806	struct page *page;
 807	int err = 0;
 808
 809	down_write(&F2FS_I(inode)->i_sem);
 810	page = f2fs_init_inode_metadata(inode, dir, NULL, NULL);
 811	if (IS_ERR(page)) {
 812		err = PTR_ERR(page);
 813		goto fail;
 814	}
 815	f2fs_put_page(page, 1);
 816
 817	clear_inode_flag(inode, FI_NEW_INODE);
 818	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 819fail:
 820	up_write(&F2FS_I(inode)->i_sem);
 821	return err;
 822}
 823
 824void f2fs_drop_nlink(struct inode *dir, struct inode *inode)
 825{
 826	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 827
 828	down_write(&F2FS_I(inode)->i_sem);
 829
 830	if (S_ISDIR(inode->i_mode))
 831		f2fs_i_links_write(dir, false);
 832	inode->i_ctime = current_time(inode);
 833
 834	f2fs_i_links_write(inode, false);
 835	if (S_ISDIR(inode->i_mode)) {
 836		f2fs_i_links_write(inode, false);
 837		f2fs_i_size_write(inode, 0);
 838	}
 839	up_write(&F2FS_I(inode)->i_sem);
 840
 841	if (inode->i_nlink == 0)
 842		f2fs_add_orphan_inode(inode);
 843	else
 844		f2fs_release_orphan_inode(sbi);
 845}
 846
 847/*
 848 * It only removes the dentry from the dentry page, corresponding name
 849 * entry in name page does not need to be touched during deletion.
 850 */
 851void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
 852					struct inode *dir, struct inode *inode)
 853{
 854	struct	f2fs_dentry_block *dentry_blk;
 855	unsigned int bit_pos;
 856	int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
 857	int i;
 858
 859	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
 860
 861	if (F2FS_OPTION(F2FS_I_SB(dir)).fsync_mode == FSYNC_MODE_STRICT)
 862		f2fs_add_ino_entry(F2FS_I_SB(dir), dir->i_ino, TRANS_DIR_INO);
 863
 864	if (f2fs_has_inline_dentry(dir))
 865		return f2fs_delete_inline_entry(dentry, page, dir, inode);
 866
 867	lock_page(page);
 868	f2fs_wait_on_page_writeback(page, DATA, true, true);
 869
 870	dentry_blk = page_address(page);
 871	bit_pos = dentry - dentry_blk->dentry;
 872	for (i = 0; i < slots; i++)
 873		__clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
 874
 875	/* Let's check and deallocate this dentry page */
 876	bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
 877			NR_DENTRY_IN_BLOCK,
 878			0);
 879	set_page_dirty(page);
 880
 881	if (bit_pos == NR_DENTRY_IN_BLOCK &&
 882		!f2fs_truncate_hole(dir, page->index, page->index + 1)) {
 883		f2fs_clear_page_cache_dirty_tag(page);
 884		clear_page_dirty_for_io(page);
 885		f2fs_clear_page_private(page);
 886		ClearPageUptodate(page);
 887		clear_cold_data(page);
 888		inode_dec_dirty_pages(dir);
 889		f2fs_remove_dirty_inode(dir);
 890	}
 891	f2fs_put_page(page, 1);
 892
 893	dir->i_ctime = dir->i_mtime = current_time(dir);
 894	f2fs_mark_inode_dirty_sync(dir, false);
 895
 896	if (inode)
 897		f2fs_drop_nlink(dir, inode);
 898}
 899
 900bool f2fs_empty_dir(struct inode *dir)
 901{
 902	unsigned long bidx;
 903	struct page *dentry_page;
 904	unsigned int bit_pos;
 905	struct f2fs_dentry_block *dentry_blk;
 906	unsigned long nblock = dir_blocks(dir);
 907
 908	if (f2fs_has_inline_dentry(dir))
 909		return f2fs_empty_inline_dir(dir);
 910
 911	for (bidx = 0; bidx < nblock; bidx++) {
 912		dentry_page = f2fs_get_lock_data_page(dir, bidx, false);
 913		if (IS_ERR(dentry_page)) {
 914			if (PTR_ERR(dentry_page) == -ENOENT)
 915				continue;
 916			else
 917				return false;
 918		}
 919
 920		dentry_blk = page_address(dentry_page);
 921		if (bidx == 0)
 922			bit_pos = 2;
 923		else
 924			bit_pos = 0;
 925		bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
 926						NR_DENTRY_IN_BLOCK,
 927						bit_pos);
 928
 929		f2fs_put_page(dentry_page, 1);
 930
 931		if (bit_pos < NR_DENTRY_IN_BLOCK)
 932			return false;
 933	}
 934	return true;
 935}
 936
 937int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
 938			unsigned int start_pos, struct fscrypt_str *fstr)
 939{
 940	unsigned char d_type = DT_UNKNOWN;
 941	unsigned int bit_pos;
 942	struct f2fs_dir_entry *de = NULL;
 943	struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
 944	struct f2fs_sb_info *sbi = F2FS_I_SB(d->inode);
 945	struct blk_plug plug;
 946	bool readdir_ra = sbi->readdir_ra == 1;
 947	int err = 0;
 948
 949	bit_pos = ((unsigned long)ctx->pos % d->max);
 950
 951	if (readdir_ra)
 952		blk_start_plug(&plug);
 953
 954	while (bit_pos < d->max) {
 955		bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
 956		if (bit_pos >= d->max)
 957			break;
 958
 959		de = &d->dentry[bit_pos];
 960		if (de->name_len == 0) {
 961			bit_pos++;
 962			ctx->pos = start_pos + bit_pos;
 963			printk_ratelimited(
 964				"%sF2FS-fs (%s): invalid namelen(0), ino:%u, run fsck to fix.",
 965				KERN_WARNING, sbi->sb->s_id,
 966				le32_to_cpu(de->ino));
 967			set_sbi_flag(sbi, SBI_NEED_FSCK);
 968			continue;
 969		}
 970
 971		d_type = f2fs_get_de_type(de);
 972
 973		de_name.name = d->filename[bit_pos];
 974		de_name.len = le16_to_cpu(de->name_len);
 975
 976		/* check memory boundary before moving forward */
 977		bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
 978		if (unlikely(bit_pos > d->max ||
 979				le16_to_cpu(de->name_len) > F2FS_NAME_LEN)) {
 980			f2fs_warn(sbi, "%s: corrupted namelen=%d, run fsck to fix.",
 981				  __func__, le16_to_cpu(de->name_len));
 982			set_sbi_flag(sbi, SBI_NEED_FSCK);
 983			err = -EFSCORRUPTED;
 984			goto out;
 985		}
 986
 987		if (IS_ENCRYPTED(d->inode)) {
 988			int save_len = fstr->len;
 989
 990			err = fscrypt_fname_disk_to_usr(d->inode,
 991						(u32)le32_to_cpu(de->hash_code),
 992						0, &de_name, fstr);
 993			if (err)
 994				goto out;
 995
 996			de_name = *fstr;
 997			fstr->len = save_len;
 998		}
 999
1000		if (!dir_emit(ctx, de_name.name, de_name.len,
1001					le32_to_cpu(de->ino), d_type)) {
1002			err = 1;
1003			goto out;
1004		}
1005
1006		if (readdir_ra)
1007			f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
1008
1009		ctx->pos = start_pos + bit_pos;
1010	}
1011out:
1012	if (readdir_ra)
1013		blk_finish_plug(&plug);
1014	return err;
1015}
1016
1017static int f2fs_readdir(struct file *file, struct dir_context *ctx)
1018{
1019	struct inode *inode = file_inode(file);
1020	unsigned long npages = dir_blocks(inode);
1021	struct f2fs_dentry_block *dentry_blk = NULL;
1022	struct page *dentry_page = NULL;
1023	struct file_ra_state *ra = &file->f_ra;
1024	loff_t start_pos = ctx->pos;
1025	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
1026	struct f2fs_dentry_ptr d;
1027	struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
1028	int err = 0;
1029
1030	if (IS_ENCRYPTED(inode)) {
1031		err = fscrypt_get_encryption_info(inode);
1032		if (err)
1033			goto out;
1034
1035		err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
1036		if (err < 0)
1037			goto out;
1038	}
1039
1040	if (f2fs_has_inline_dentry(inode)) {
1041		err = f2fs_read_inline_dir(file, ctx, &fstr);
1042		goto out_free;
1043	}
1044
1045	for (; n < npages; n++, ctx->pos = n * NR_DENTRY_IN_BLOCK) {
1046
1047		/* allow readdir() to be interrupted */
1048		if (fatal_signal_pending(current)) {
1049			err = -ERESTARTSYS;
1050			goto out_free;
1051		}
1052		cond_resched();
1053
1054		/* readahead for multi pages of dir */
1055		if (npages - n > 1 && !ra_has_index(ra, n))
1056			page_cache_sync_readahead(inode->i_mapping, ra, file, n,
1057				min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
1058
1059		dentry_page = f2fs_find_data_page(inode, n);
1060		if (IS_ERR(dentry_page)) {
1061			err = PTR_ERR(dentry_page);
1062			if (err == -ENOENT) {
1063				err = 0;
1064				continue;
1065			} else {
1066				goto out_free;
1067			}
1068		}
1069
1070		dentry_blk = page_address(dentry_page);
1071
1072		make_dentry_ptr_block(inode, &d, dentry_blk);
1073
1074		err = f2fs_fill_dentries(ctx, &d,
1075				n * NR_DENTRY_IN_BLOCK, &fstr);
1076		if (err) {
1077			f2fs_put_page(dentry_page, 0);
1078			break;
1079		}
1080
1081		f2fs_put_page(dentry_page, 0);
1082	}
1083out_free:
1084	fscrypt_fname_free_buffer(&fstr);
1085out:
1086	trace_f2fs_readdir(inode, start_pos, ctx->pos, err);
1087	return err < 0 ? err : 0;
1088}
1089
1090static int f2fs_dir_open(struct inode *inode, struct file *filp)
1091{
1092	if (IS_ENCRYPTED(inode))
1093		return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
1094	return 0;
1095}
1096
1097const struct file_operations f2fs_dir_operations = {
1098	.llseek		= generic_file_llseek,
1099	.read		= generic_read_dir,
1100	.iterate_shared	= f2fs_readdir,
1101	.fsync		= f2fs_sync_file,
1102	.open		= f2fs_dir_open,
1103	.unlocked_ioctl	= f2fs_ioctl,
1104#ifdef CONFIG_COMPAT
1105	.compat_ioctl   = f2fs_compat_ioctl,
1106#endif
1107};
1108
1109#ifdef CONFIG_UNICODE
1110static int f2fs_d_compare(const struct dentry *dentry, unsigned int len,
1111			  const char *str, const struct qstr *name)
1112{
1113	const struct dentry *parent = READ_ONCE(dentry->d_parent);
1114	const struct inode *dir = READ_ONCE(parent->d_inode);
1115	const struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
1116	struct qstr entry = QSTR_INIT(str, len);
1117	char strbuf[DNAME_INLINE_LEN];
1118	int res;
1119
1120	if (!dir || !IS_CASEFOLDED(dir))
1121		goto fallback;
1122
1123	/*
1124	 * If the dentry name is stored in-line, then it may be concurrently
1125	 * modified by a rename.  If this happens, the VFS will eventually retry
1126	 * the lookup, so it doesn't matter what ->d_compare() returns.
1127	 * However, it's unsafe to call utf8_strncasecmp() with an unstable
1128	 * string.  Therefore, we have to copy the name into a temporary buffer.
1129	 */
1130	if (len <= DNAME_INLINE_LEN - 1) {
1131		memcpy(strbuf, str, len);
1132		strbuf[len] = 0;
1133		entry.name = strbuf;
1134		/* prevent compiler from optimizing out the temporary buffer */
1135		barrier();
1136	}
1137
1138	res = utf8_strncasecmp(sbi->s_encoding, name, &entry);
1139	if (res >= 0)
1140		return res;
1141
1142	if (f2fs_has_strict_mode(sbi))
1143		return -EINVAL;
1144fallback:
1145	if (len != name->len)
1146		return 1;
1147	return !!memcmp(str, name->name, len);
1148}
1149
1150static int f2fs_d_hash(const struct dentry *dentry, struct qstr *str)
1151{
1152	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
1153	const struct unicode_map *um = sbi->s_encoding;
1154	const struct inode *inode = READ_ONCE(dentry->d_inode);
1155	unsigned char *norm;
1156	int len, ret = 0;
1157
1158	if (!inode || !IS_CASEFOLDED(inode))
1159		return 0;
1160
1161	norm = f2fs_kmalloc(sbi, PATH_MAX, GFP_ATOMIC);
1162	if (!norm)
1163		return -ENOMEM;
1164
1165	len = utf8_casefold(um, str, norm, PATH_MAX);
1166	if (len < 0) {
1167		if (f2fs_has_strict_mode(sbi))
1168			ret = -EINVAL;
1169		goto out;
1170	}
1171	str->hash = full_name_hash(dentry, norm, len);
1172out:
1173	kvfree(norm);
1174	return ret;
1175}
1176
1177const struct dentry_operations f2fs_dentry_ops = {
1178	.d_hash = f2fs_d_hash,
1179	.d_compare = f2fs_d_compare,
1180};
1181#endif