linux/fs/hpfs/dnode.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hpfs/dnode.c
 *
 *  Mikulas Patocka ([email protected]), 1998-1999
 *
 *  handling directory dnode tree - adding, deleteing & searching for dirents
 */

#include "hpfs_fn.h"

static loff_t get_pos(struct dnode *d, struct hpfs_dirent *fde)
{ … }

int hpfs_add_pos(struct inode *inode, loff_t *pos)
{ … }

void hpfs_del_pos(struct inode *inode, loff_t *pos)
{ … }

static void for_all_poss(struct inode *inode, void (*f)(loff_t *, loff_t, loff_t),
			 loff_t p1, loff_t p2)
{ … }

static void hpfs_pos_subst(loff_t *p, loff_t f, loff_t t)
{ … }

/*void hpfs_hpfs_pos_substd(loff_t *p, loff_t f, loff_t t)
{
	if ((*p & ~0x3f) == (f & ~0x3f)) *p = (t & ~0x3f) | (*p & 0x3f);
}*/

static void hpfs_pos_ins(loff_t *p, loff_t d, loff_t c)
{ … }

static void hpfs_pos_del(loff_t *p, loff_t d, loff_t c)
{ … }

static struct hpfs_dirent *dnode_pre_last_de(struct dnode *d)
{ … }

static struct hpfs_dirent *dnode_last_de(struct dnode *d)
{ … }

static void set_last_pointer(struct super_block *s, struct dnode *d, dnode_secno ptr)
{ … }

/* Add an entry to dnode and don't care if it grows over 2048 bytes */

struct hpfs_dirent *hpfs_add_de(struct super_block *s, struct dnode *d,
				const unsigned char *name,
				unsigned namelen, secno down_ptr)
{ … }

/* Delete dirent and don't care about its subtree */

static void hpfs_delete_de(struct super_block *s, struct dnode *d,
			   struct hpfs_dirent *de)
{ … }

static void fix_up_ptrs(struct super_block *s, struct dnode *d)
{ … }

/* Add an entry to dnode and do dnode splitting if required */

static int hpfs_add_to_dnode(struct inode *i, dnode_secno dno,
			     const unsigned char *name, unsigned namelen,
			     struct hpfs_dirent *new_de, dnode_secno down_ptr)
{ … }

/*
 * Add an entry to directory btree.
 * I hate such crazy directory structure.
 * It's easy to read but terrible to write.
 * I wrote this directory code 4 times.
 * I hope, now it's finally bug-free.
 */

int hpfs_add_dirent(struct inode *i,
		    const unsigned char *name, unsigned namelen,
		    struct hpfs_dirent *new_de)
{ … }

/* 
 * Find dirent with higher name in 'from' subtree and move it to 'to' dnode.
 * Return the dnode we moved from (to be checked later if it's empty)
 */

static secno move_to_top(struct inode *i, dnode_secno from, dnode_secno to)
{ … }

/* 
 * Check if a dnode is empty and delete it from the tree
 * (chkdsk doesn't like empty dnodes)
 */

static void delete_empty_dnode(struct inode *i, dnode_secno dno)
{ … }


/* Delete dirent from directory */

int hpfs_remove_dirent(struct inode *i, dnode_secno dno, struct hpfs_dirent *de,
		       struct quad_buffer_head *qbh, int depth)
{ … }

void hpfs_count_dnodes(struct super_block *s, dnode_secno dno, int *n_dnodes,
		       int *n_subdirs, int *n_items)
{ … }

static struct hpfs_dirent *map_nth_dirent(struct super_block *s, dnode_secno dno, int n,
					  struct quad_buffer_head *qbh, struct dnode **dn)
{ … }

dnode_secno hpfs_de_as_down_as_possible(struct super_block *s, dnode_secno dno)
{ … }

struct hpfs_dirent *map_pos_dirent(struct inode *inode, loff_t *posp,
				   struct quad_buffer_head *qbh)
{ … }

/* Find a dirent in tree */

struct hpfs_dirent *map_dirent(struct inode *inode, dnode_secno dno,
			       const unsigned char *name, unsigned len,
			       dnode_secno *dd, struct quad_buffer_head *qbh)
{ … }

/*
 * Remove empty directory. In normal cases it is only one dnode with two
 * entries, but we must handle also such obscure cases when it's a tree
 * of empty dnodes.
 */

void hpfs_remove_dtree(struct super_block *s, dnode_secno dno)
{ … }

/* 
 * Find dirent for specified fnode. Use truncated 15-char name in fnode as
 * a help for searching.
 */

struct hpfs_dirent *map_fnode_dirent(struct super_block *s, fnode_secno fno,
				     struct fnode *f, struct quad_buffer_head *qbh)
{ … }