path: root/fs/f2fs/dir.c

// SPDX-License-Identifier: GPL-2.0
/*
 * fs/f2fs/dir.c
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 */
#include <linux/fs.h>
#include <linux/f2fs_fs.h>
#include <linux/sched/signal.h>
#include <linux/unicode.h>
#include "f2fs.h"
#include "node.h"
#include "acl.h"
#include "xattr.h"
#include <trace/events/f2fs.h>

static unsigned long dir_blocks(struct inode *inode)
{
	return ((unsigned long long) (i_size_read(inode) + PAGE_SIZE - 1))
							>> PAGE_SHIFT;
}

static unsigned int dir_buckets(unsigned int level, int dir_level)
{
	if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
		return 1 << (level + dir_level);
	else
		return MAX_DIR_BUCKETS;
}

static unsigned int bucket_blocks(unsigned int level)
{
	if (level < MAX_DIR_HASH_DEPTH / 2)
		return 2;
	else
		return 4;
}

static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
	[F2FS_FT_UNKNOWN]	= DT_UNKNOWN,
	[F2FS_FT_REG_FILE]	= DT_REG,
	[F2FS_FT_DIR]		= DT_DIR,
	[F2FS_FT_CHRDEV]	= DT_CHR,
	[F2FS_FT_BLKDEV]	= DT_BLK,
	[F2FS_FT_FIFO]		= DT_FIFO,
	[F2FS_FT_SOCK]		= DT_SOCK,
	[F2FS_FT_SYMLINK]	= DT_LNK,
};

static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
	[S_IFREG >> S_SHIFT]	= F2FS_FT_REG_FILE,
	[S_IFDIR >> S_SHIFT]	= F2FS_FT_DIR,
	[S_IFCHR >> S_SHIFT]	= F2FS_FT_CHRDEV,
	[S_IFBLK >> S_SHIFT]	= F2FS_FT_BLKDEV,
	[S_IFIFO >> S_SHIFT]	= F2FS_FT_FIFO,
	[S_IFSOCK >> S_SHIFT]	= F2FS_FT_SOCK,
	[S_IFLNK >> S_SHIFT]	= F2FS_FT_SYMLINK,
};

static void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
{
	de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
}

unsigned char f2fs_get_de_type(struct f2fs_dir_entry *de)
{
	if (de->file_type < F2FS_FT_MAX)
		return f2fs_filetype_table[de->file_type];
	return DT_UNKNOWN;
}

/* If @dir is casefolded, initialize @fname->cf_name from @fname->usr_fname. */
int f2fs_init_casefolded_name(const struct inode *dir,
			      struct f2fs_filename *fname)
{
#ifdef CONFIG_UNICODE
	struct super_block *sb = dir->i_sb;
	struct f2fs_sb_info *sbi = F2FS_SB(sb);

	if (IS_CASEFOLDED(dir)) {
		fname->cf_name.name = f2fs_kmalloc(sbi, F2FS_NAME_LEN,
						   GFP_NOFS);
		if (!fname->cf_name.name)
			return -ENOMEM;
		fname->cf_name.len = utf8_casefold(sb->s_encoding,
						   fname->usr_fname,
						   fname->cf_name.name,
						   F2FS_NAME_LEN);
		if ((int)fname->cf_name.len <= 0) {
			kfree(fname->cf_name.name);
			fname->cf_name.name = NULL;
			if (sb_has_strict_encoding(sb))
				return -EINVAL;
			/* fall back to treating name as opaque byte sequence */
		}
	}
#endif
	return 0;
}

static int __f2fs_setup_filename(const struct inode *dir,
				 const struct fscrypt_name *crypt_name,
				 struct f2fs_filename *fname)
{
	int err;

	memset(fname, 0, sizeof(*fname));

	fname->usr_fname = crypt_name->usr_fname;
	fname->disk_name = crypt_name->disk_name;
#ifdef CONFIG_FS_ENCRYPTION
	fname->crypto_buf = crypt_name->crypto_buf;
#endif
	if (crypt_name->is_nokey_name) {
		/* hash was decoded from the no-key name */
		fname->hash = cpu_to_le32(crypt_name->hash);
	} else {
		err = f2fs_init_casefolded_name(dir, fname);
		if (err) {
			f2fs_free_filename(fname);
			return err;
		}
		f2fs_hash_filename(dir, fname);
	}
	return 0;
}

/*
 * Prepare to search for @iname in @dir.  This is similar to
 * fscrypt_setup_filename(), but this also handles computing the casefolded name
 * and the f2fs dirhash if needed, then packing all the information about this
 * filename up into a 'struct f2fs_filename'.
 */
int f2fs_setup_filename(struct inode *dir, const struct qstr *iname,
			int lookup, struct f2fs_filename *fname)
{
	struct fscrypt_name crypt_name;
	int err;

	err = fscrypt_setup_filename(dir, iname, lookup, &crypt_name);
	if (err)
		return err;

	return __f2fs_setup_filename(dir, &crypt_name, fname);
}

/*
 * Prepare to look up @dentry in @dir.  This is similar to
 * fscrypt_prepare_lookup(), but this also handles computing the casefolded name
 * and the f2fs dirhash if needed, then packing all the information about this
 * filename up into a 'struct f2fs_filename'.
 */
int f2fs_prepare_lookup(struct inode