/*
* fs/f2fs/dir.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/fs.h>
#include <linux/f2fs_fs.h>
#include "f2fs.h"
#include "node.h"
#include "acl.h"
#include "xattr.h"
static unsigned long dir_blocks(struct inode *inode)
{
return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1))
>> PAGE_CACHE_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;
}
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,
};
#define S_SHIFT 12
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,
};
void set_de_type(struct f2fs_dir_entry *de, struct inode *inode)
{
umode_t mode = inode->i_mode;
de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
}
static unsigned long dir_block_index(unsigned int level,
int dir_level, unsigned int idx)
{
unsigned long i;
unsigned long bidx = 0;
for (i = 0; i < level; i++)
bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
bidx += idx * bucket_blocks(level);
return bidx;
}
static bool early_match_name(size_t namelen, f2fs_hash_t namehash,
struct f2fs_dir_entry *de)
{
if (le16_to_cpu(de->name_len) != namelen)
return false;
if (de->hash_code != namehash)
return false;
return true;
}
static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
struct qstr *name, int *max_slots,
struct page **res_page)
{
struct f2fs_dentry_block *dentry_blk;
struct f2fs_dir_entry *de;
struct f2fs_dentry_ptr d;
dentry_blk = (struct f2fs_dentry_block *)kmap(dentry_page);
make_dentry_ptr(&d, (void *)dentry_blk, 1);
de = find_target_dentry(name, max_slots, &d);
if (de)
*res_page = dentry_page;
else
kunmap(dentry_page);
/*
* For the most part, it should be a bug when name_len is zero.
* We stop here for figuring out where the bugs has occurred.
*/
f2fs_bug_on(F2FS_P_SB(dentry_page), d.max < 0);
return de;
}
struct f2fs_dir_entry *find_target_dentry(struct qstr *name, int *max_slots,
struct f2fs_dentry_ptr *d)
{
struct f2fs_dir_entry *de;
unsigned long bit_pos = 0;
f2fs_hash_t namehash = f2fs_dentry_hash(name);
int max_len = 0;
if (max_slots)
*max_slots = 0;
while (bit_pos < d->max) {
if (!test_bit_le(bit_pos, d->bitmap)) {
if (bit_pos == 0)
max_len = 1;
else if (!test_bit_le(bit_pos - 1, d->bitmap))
max_len++;
bit_pos++;
continue;
}
de = &d->dentry[bit_pos];
if (early_match_name(name->len, namehash, de) &&
!memcmp(d->filename[bit_pos], name->name, name->len))
goto found;
if (max_slots && *max_slots >= 0 && max_len > *max_slots) {
*max_slots = max_len;
max_len = 0;
}
/* remain bug on condition */
if (unlikely(!de->name_len))
d->max = -1;
bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
}
de = NULL;
found:
if (max_slots && max_len > *max_slots)
*max_slots = max_len;
return de;
}
static struct f2fs_dir_entry *find_in_level(struct inode *dir,
unsigned int level, struct qstr *name,
f