/*
 *  dir.c
 *
 *  Copyright (C) 1995, 1996 by Volker Lendecke
 *  Modified for big endian by J.F. Chadima and David S. Miller
 *
 */

#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/kernel.h>
#include <linux/malloc.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/ncp_fs.h>
#include <asm/uaccess.h>
#include <asm/byteorder.h>
#include <linux/errno.h>
#include <linux/locks.h>
#include "ncplib_kernel.h"


struct ncp_dirent {
	struct nw_info_struct i;
	struct nw_search_sequence s;	/* given back for i */
	unsigned long f_pos;
};

static long
 ncp_dir_read(struct inode *inode, struct file *filp, char *buf, unsigned long count);

static int
 ncp_readdir(struct inode *inode, struct file *filp,
	     void *dirent, filldir_t filldir);

static int
 ncp_read_volume_list(struct ncp_server *server, int start_with,
		      int cache_size);

static int
 ncp_do_readdir(struct ncp_server *server, struct inode *dir, int fpos,
		int cache_size, struct ncp_dirent *entry);

static struct inode *
 ncp_iget(struct inode *dir, struct nw_file_info *finfo);

static struct ncp_inode_info *
 ncp_find_dir_inode(struct inode *dir, const char *name);

static int
 ncp_lookup(struct inode *dir, const char *__name,
	    int len, struct inode **result);

static int
 ncp_create(struct inode *dir, const char *name, int len, int mode,
	    struct inode **result);

static int
 ncp_mkdir(struct inode *dir, const char *name, int len, int mode);

static int
 ncp_rmdir(struct inode *dir, const char *name, int len);

static int
 ncp_unlink(struct inode *dir, const char *name, int len);

static int
 ncp_rename(struct inode *old_dir, const char *old_name, int old_len,
	    struct inode *new_dir, const char *new_name, int new_len,
	    int must_be_dir);

static inline void str_upper(char *name)
{
	while (*name) {
		if (*name >= 'a' && *name <= 'z') {
			*name -= ('a' - 'A');
		}
		name++;
	}
}

static inline void str_lower(char *name)
{
	while (*name) {
		if (*name >= 'A' && *name <= 'Z') {
			*name += ('a' - 'A');
		}
		name++;
	}
}

static inline int ncp_namespace(struct inode *i)
{
	struct ncp_server *server = NCP_SERVER(i);
	struct nw_info_struct *info = NCP_ISTRUCT(i);
	return server->name_space[info->volNumber];
}

static inline int ncp_preserve_case(struct inode *i)
{
	return (ncp_namespace(i) == NW_NS_OS2);
}

static struct file_operations ncp_dir_operations =
{
	NULL,			/* lseek - default */
	ncp_dir_read,		/* read - bad */
	NULL,			/* write - bad */
	ncp_readdir,		/* readdir */
	NULL,			/* poll - default */
	ncp_ioctl,		/* ioctl */
	NULL,			/* mmap */
	NULL,			/* no special open code */
	NULL,			/* no special release code */
	NULL			/* fsync */
};

struct inode_operations ncp_dir_inode_operations =
{
	&ncp_dir_operations,	/* default directory file ops */
	ncp_create,		/* create */
	ncp_lookup,		/* lookup */
	NULL,			/* link */
	ncp_unlink,		/* unlink */
	NULL,			/* symlink */
	ncp_mkdir,		/* mkdir */
	ncp_rmdir,		/* rmdir */
	NULL,			/* mknod */
	ncp_rename,		/* rename */
	NULL,			/* readlink */
	NULL,			/* follow_link */
	NULL,			/* bmap */
	NULL,			/* truncate */
	NULL,			/* permission */
	NULL			/* smap */
};


/* Here we encapsulate the inode number handling that depends upon the
 * mount mode: When we mount a complete server, the memory address of
 * the ncp_inode_info is used as the inode number. When only a single
 * volume is mounted, then the dirEntNum is used as the inode
 * number. As this is unique for the complete volume, this should
 * enable the NFS exportability of a ncpfs-mounted volume.
 */

static inline int ncp_single_volume(struct ncp_server *server)
{
	return (server->m.mounted_vol[0] != '\0');
}

inline ino_t
 ncp_info_ino(struct ncp_server * server, struct ncp_inode_info * info)
{
	return ncp_single_volume(server)
	    ? info->finfo.i.dirEntNum : (ino_t) info;
}

static inline int ncp_is_server_root(struct inode *inode)
{
	struct ncp_server *s = NCP_SERVER(inode);

	return ((!ncp_single_volume(s))
		&& (inode->i_ino == ncp_info_ino(s, &(s->root))));
}

struct ncp_inode_info *
 ncp_find_inode(struct inode *inode)
{
	struct ncp_server *server = NCP_SERVER(inode);
	struct ncp_inode_info *root = &(server->root);
	struct ncp_inode_info *this = root;

	ino_t ino = inode->i_ino;

	do {
		if (ino == ncp_info_ino(server, this)) {
			return this;
		}
		this = this->next;
	}
	while (this != root);

	return NULL;
}

static long ncp_dir_read(struct inode *inode, struct file *filp, char *buf, unsigned long count)
{
	return -EISDIR;
}

static kdev_t c_dev = 0;
static unsigned long c_ino = 0;
static int c_size;
static int c_seen_eof;
static int c_last_returned_index;
static struct ncp_dirent *c_entry = NULL;
static int c_lock = 0;
static struct wait_queue *c_wait = NULL;

static inline void ncp_lock_dircache(void)
{
	while (c_lock)
		sleep_on(&c_wait);
	c_lock = 1;
}

static inline void ncp_unlock_dircache(void)
{
	c_lock = 0;
	wake_up(&c_wait);
}

static int ncp_readdir(struct inode *inode, struct file *filp,
		       void *dirent, filldir_t filldir)
{
	int result = 0;
	int i = 0;
	int index = 0;
	struct ncp_dirent *entry = NULL;
	struct ncp_server *server = NCP_SERVER(inode);
	struct ncp_inode_info *dir = NCP_INOP(inode);

	DDPRINTK("ncp_readdir: filp->f_pos = %d\n", (int) filp->f_pos);
	DDPRINTK("ncp_readdir: inode->i_ino = %ld, c_ino = %ld\n",
		 inode->i_ino, c_ino);

	if (!inode || !S_ISDIR(inode->i_mode)) {
		printk("ncp_readdir: inode is NULL or not a directory\n");
		return -EBADF;
	}
	if (!ncp_conn_valid(server)) {
		return -EIO;
	}
	ncp_lock_dircache();

	if (c_entry == NULL) {
		i = sizeof(struct ncp_dirent) * NCP_READDIR_CACHE_SIZE;
		c_entry = (struct ncp_dirent *) vmalloc(i);
		if (c_entry == NULL) {
			printk("ncp_readdir: no MEMORY for cache\n");
			result = -ENOMEM;
			goto finished;
		}
	}
	if (filp->f_pos == 0) {
		ncp_invalid_dir_cache(inode);
		if (filldir(dirent, ".", 1, filp->f_pos,
			    ncp_info_ino(server, dir)) < 0) {
			goto finished;
		}
		filp->f_pos += 1;
	}
	if (filp->f_pos == 1) {
		if (filldir(dirent, "..", 2, filp->f_pos,
			    ncp_info_ino(server, dir->dir)) < 0) {
			goto finished;
		}
		filp->f_pos += 1;
	}
	if ((inode->i_dev == c_dev) && (inode->i_ino == c_ino)) {
		for (i = 0; i < c_size; i++) {
			if (filp->f_pos == c_entry[i].f_pos) {
				entry = &c_entry[i];
				c_last_returned_index = i;
				index = i;
				break;
			}
		}
		if ((entry == NULL) && c_seen_eof) {
			goto finished;
		}
	}
	if (entry == NULL) {
		int entries;
		DDPRINTK("ncp_readdir: Not found in cache.\n");

		if (ncp_is_server_root(inode)) {
			entries = ncp_read_volume_list(server, filp->f_pos,
						 NCP_READDIR_CACHE_SIZE);
			DPRINTK("ncp_read_volume_list returned %d\n", entries);

		} else {
			entries = ncp_do_readdir(server, inode, filp->f_pos,
						 NCP_READDIR_CACHE_SIZE,
						 c_entry);
			DPRINTK("ncp_readdir returned %d\n", entries);
		}

		if (entries < 0) {
			c_dev = 0;
			c_ino = 0;
			result = entries;
			goto finished;
		}
		if (entries > 0) {
			c_seen_eof = (entries < NCP_READDIR_CACHE_SIZE);
			c_dev = inode->i_dev;
			c_ino = inode->i_ino;
			c_size = entries;
			entry = c_entry;
			c_last_returned_index = 0;
			index = 0;

			if (!ncp_preserve_case(inode)) {
				for (i = 0; i < c_size; i++) {
					str_lower(c_entry[i].i.entryName);
				}
			}
		}
	}
	if (entry == NULL) {
		/* Nothing found, even from a ncp call */
		goto finished;
	}
	while (index < c_size) {
		ino_t ino;

		if (ncp_single_volume(server)) {
			ino = (ino_t) (entry->i.dirEntNum);
		} else {
			/* For getwd() we have to return the correct
			 * inode in d_ino if the inode is currently in
			 * use. Otherwise the inode number does not
			 * matter. (You can argue a lot about this..) */
			struct ncp_inode_info *ino_info;
			ino_info = ncp_find_dir_inode(inode,
						      entry->i.entryName);

			/* Some programs seem to be confused about a
			 * zero inode number, so we set it to one.
			 * Thanks to Gordon Chaffee for this one. */
			if (ino_info == NULL) {
				ino_info = (struct ncp_inode_info *) 1;
			}
			ino = (ino_t) (ino_info);
		}

		DDPRINTK("ncp_readdir: entry->path= %s\n", entry->i.entryName);
		DDPRINTK("ncp_readdir: entry->f_pos = %ld\n", entry->f_pos);

		if (filldir(dirent, entry->i.entryName, entry->i.nameLen,
			    entry->f_pos, ino) < 0) {
			break;
		}
		if ((inode->i_dev != c_dev)
		    || (inode->i_ino != c_ino)
		    || (entry->f_pos != filp->f_pos)) {
			/* Someone has destroyed the cache while we slept
			   in filldir */
			break;
		}
		filp->f_pos += 1;
		index += 1;
		entry += 1;
	}
      finished:
	ncp_unlock_dircache();
	return result;
}

static int ncp_read_volume_list(struct ncp_server *server, int fpos, int cache_size)
{
	struct ncp_dirent *entry = c_entry;

	int total_count = 2;
	int i;

#if 1
	if (fpos < 2) {
		printk("OOPS, we expect fpos >= 2");
		fpos = 2;
	}
#endif

	for (i = 0; i < NCP_NUMBER_OF_VOLUMES; i++) {
		struct ncp_volume_info info;

		if (ncp_get_volume_info_with_number(server, i, &info) != 0) {
			return (total_count - fpos);
		}
		if (strlen(info.volume_name) > 0) {
			if (total_count < fpos) {
				DPRINTK("ncp_read_volumes: skipped vol: %s\n",
					info.volume_name);
			} else if (total_count >= fpos + cache_size) {
				return (total_count - fpos);
			} else {
				DPRINTK("ncp_read_volumes: found vol: %s\n",
					info.volume_name);

				if (ncp_lookup_volume(server,
						      info.volume_name,
						      &(entry->i)) != 0) {
					DPRINTK("ncpfs: could not lookup vol "
						"%s\n", info.volume_name);
					continue;
				}
				entry->f_pos = total_count;
				entry += 1;
			}
			total_count += 1;
		}
	}
	return (total_count - fpos);
}

static int ncp_do_readdir(struct ncp_server *server, struct inode *dir, int fpos,
			  int cache_size, struct ncp_dirent *entry)
{
	static struct nw_search_sequence seq;
	static struct inode *last_dir;
	static int total_count;

#if 1
	if (fpos < 2) {
		printk("OOPS, we expect fpos >= 2");
		fpos = 2;
	}
#endif
	DPRINTK("ncp_do_readdir: fpos = %d\n", fpos);

	if (fpos == 2) {
		last_dir = NULL;
		total_count = 2;
	}
	if ((fpos != total_count) || (dir != last_dir)) {
		total_count = 2;
		last_dir = dir;

		DPRINTK("ncp_do_readdir: re-used seq for %s\n",
			NCP_ISTRUCT(dir)->entryName);

		if (ncp_initialize_search(server, NCP_ISTRUCT(dir), &seq) != 0) {
			DPRINTK("ncp_init_search failed\n");
			return total_count - fpos;
		}
	}
	while (total_count < fpos + cache_size) {
		if (ncp_search_for_file_or_subdir(server, &seq,
						  &(entry->i)) != 0) {
			return total_count - fpos;
		}
		if (total_count < fpos) {
			DPRINTK("ncp_do_readdir: skipped file: %s\n",
				entry->i.entryName);
		} else {
			DDPRINTK("ncp_do_r: file: %s, f_pos=%d,total_count=%d",
				 entry->i.entryName, fpos, total_count);
			entry->s = seq;
			entry->f_pos = total_count;
			entry += 1;
		}
		total_count += 1;
	}
	return (total_count - fpos);
}

void ncp_init_dir_cache(void)
{
	c_dev = 0;
	c_ino = 0;
	c_entry = NULL;
}

void ncp_invalid_dir_cache(struct inode *ino)
{
	if ((ino->i_dev == c_dev) && (ino->i_ino == c_ino)) {
		c_dev = 0;
		c_ino = 0;
		c_seen_eof = 0;
	}
}

void ncp_free_dir_cache(void)
{
	DPRINTK("ncp_free_dir_cache: enter\n");

	if (c_entry == NULL) {
		return;
	}
	vfree(c_entry);
	c_entry = NULL;

	DPRINTK("ncp_free_dir_cache: exit\n");
}


static struct inode *
 ncp_iget(struct inode *dir, struct nw_file_info *finfo)
{
	struct inode *inode;
	struct ncp_inode_info *new_inode_info;
	struct ncp_inode_info *root;

	if (dir == NULL) {
		printk("ncp_iget: dir is NULL\n");
		return NULL;
	}
	if (finfo == NULL) {
		printk("ncp_iget: finfo is NULL\n");
		return NULL;
	}
	new_inode_info = ncp_kmalloc(sizeof(struct ncp_inode_info),
				     GFP_KERNEL);

	if (new_inode_info == NULL) {
		printk("ncp_iget: could not alloc mem for %s\n",
		       finfo->i.entryName);
		return NULL;
	}
	new_inode_info->state = NCP_INODE_LOOKED_UP;
	new_inode_info->nused = 0;
	new_inode_info->dir = NCP_INOP(dir);
	new_inode_info->finfo = *finfo;

	NCP_INOP(dir)->nused += 1;

	/* We have to link the new inode_info into the doubly linked
	   list of inode_infos to make a complete linear search
	   possible. */

	root = &(NCP_SERVER(dir)->root);

	new_inode_info->prev = root;
	new_inode_info->next = root->next;
	root->next->prev = new_inode_info;
	root->next = new_inode_info;

	if (!(inode = iget(dir->i_sb, ncp_info_ino(NCP_SERVER(dir),
						   new_inode_info)))) {
		printk("ncp_iget: iget failed!");
		return NULL;
	}
	return inode;
}

void ncp_free_inode_info(struct ncp_inode_info *i)
{
	if (i == NULL) {
		printk("ncp_free_inode: i == NULL\n");
		return;
	}
	i->state = NCP_INODE_CACHED;
	while ((i->nused == 0) && (i->state == NCP_INODE_CACHED)) {
		struct ncp_inode_info *dir = i->dir;

		i->next->prev = i->prev;
		i->prev->next = i->next;

		DDPRINTK("ncp_free_inode_info: freeing %s\n",
			 i->finfo.i.entryName);

		ncp_kfree_s(i, sizeof(struct ncp_inode_info));

		if (dir == i)
			return;

		(dir->nused)--;
		i = dir;
	}
}

void ncp_init_root(struct ncp_server *server)
{
	struct ncp_inode_info *root = &(server->root);
	struct nw_info_struct *i = &(root->finfo.i);
	unsigned short dummy;

	DPRINTK("ncp_init_root: i = %x\n", (int) i);

	root->finfo.opened = 0;
	i->attributes = aDIR;
	i->dataStreamSize = 1024;
	i->dirEntNum = i->DosDirNum = 0;
	i->volNumber = NCP_NUMBER_OF_VOLUMES + 1;	/* illegal volnum */
	ncp_date_unix2dos(0, &(i->creationTime), &(i->creationDate));
	ncp_date_unix2dos(0, &(i->modifyTime), &(i->modifyDate));
	ncp_date_unix2dos(0, &dummy, &(i->lastAccessDate));
	i->creationTime = le16_to_cpu(i->creationTime);
	i->creationDate = le16_to_cpu(i->creationDate);
	i->modifyTime = le16_to_cpu(i->modifyTime);
	i->modifyDate = le16_to_cpu(i->modifyDate);
	i->lastAccessDate = le16_to_cpu(i->lastAccessDate);
	i->nameLen = 0;
	i->entryName[0] = '\0';

	root->state = NCP_INODE_LOOKED_UP;
	root->nused = 1;
	root->dir = root;
	root->next = root->prev = root;
	return;
}

int ncp_conn_logged_in(struct ncp_server *server)
{
	if (server->m.mounted_vol[0] == '\0') {
		return 0;
	}
	str_upper(server->m.mounted_vol);
	if (ncp_lookup_volume(server, server->m.mounted_vol,
			      &(server->root.finfo.i)) != 0) {
		return -ENOENT;
	}
	str_lower(server->root.finfo.i.entryName);

	return 0;
}

void ncp_free_all_inodes(struct ncp_server *server)
{
	/* Here nothing should be to do. I do not know whether it's
	   better to leave some memory allocated or be stuck in an
	   endless loop */
#if 1
	struct ncp_inode_info *root = &(server->root);

	if (root->next != root) {
		printk("ncp_free_all_inodes: INODES LEFT!!!\n");
	}
	while (root->next != root) {
		printk("ncp_free_all_inodes: freeing inode\n");
		ncp_free_inode_info(root->next);
		/* In case we have an endless loop.. */
		schedule();
	}
#endif

	return;
}

/* We will search the inode that belongs to this name, currently by a
   complete linear search through the inodes belonging to this
   filesystem. This has to be fixed. */
static struct ncp_inode_info *
 ncp_find_dir_inode(struct inode *dir, const char *name)
{
	struct ncp_server *server = NCP_SERVER(dir);
	struct nw_info_struct *dir_info = NCP_ISTRUCT(dir);
	struct ncp_inode_info *result = &(server->root);

	if (name == NULL) {
		return NULL;
	}
	do {
		if ((result->dir->finfo.i.dirEntNum == dir_info->dirEntNum)
		&& (result->dir->finfo.i.volNumber == dir_info->volNumber)
		    && (strcmp(result->finfo.i.entryName, name) == 0)
		/* The root dir is never looked up using this
		 * routine.  Without the following test a root
		 * directory 'sys' in a volume named 'sys' could
		 * never be looked up, because
		 * server->root->dir==server->root. */
		    && (result != &(server->root))) {
			return result;
		}
		result = result->next;

	}
	while (result != &(server->root));

	return NULL;
}

static int ncp_lookup(struct inode *dir, const char *__name, int len,
		      struct inode **result)
{
	struct nw_file_info finfo;
	struct ncp_server *server;
	struct ncp_inode_info *result_info;
	int found_in_cache;
	int down_case = 0;
	char name[len + 1];

	*result = NULL;

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("ncp_lookup: inode is NULL or not a directory.\n");
		iput(dir);
		return -ENOENT;
	}
	server = NCP_SERVER(dir);

	if (!ncp_conn_valid(server)) {
		iput(dir);
		return -EIO;
	}
	DPRINTK("ncp_lookup: %s, len %d\n", __name, len);

	/* Fast cheat for . */
	if (len == 0 || (len == 1 && __name[0] == '.')) {
		*result = dir;
		return 0;
	}
	/* ..and for .. */
	if (len == 2 && __name[0] == '.' && __name[1] == '.') {
		struct ncp_inode_info *parent = NCP_INOP(dir)->dir;

		if (parent->state == NCP_INODE_CACHED) {
			parent->state = NCP_INODE_LOOKED_UP;
		}
		*result = iget(dir->i_sb, ncp_info_ino(server, parent));
		iput(dir);
		if (*result == 0) {
			return -EACCES;
		} else {
			return 0;
		}
	}
	memcpy(name, __name, len);
	name[len] = 0;
	lock_super(dir->i_sb);
	result_info = ncp_find_dir_inode(dir, name);

	if (result_info != 0) {
		if (result_info->state == NCP_INODE_CACHED) {
			result_info->state = NCP_INODE_LOOKED_UP;
		}
		/* Here we convert the inode_info address into an
		   inode number */

		*result = iget(dir->i_sb, ncp_info_ino(server, result_info));
		unlock_super(dir->i_sb);
		iput(dir);

		if (*result == NULL) {
			return -EACCES;
		}
		return 0;
	}
	/* If the file is in the dir cache, we do not have to ask the
	   server. */

	found_in_cache = 0;
	ncp_lock_dircache();

	if ((dir->i_dev == c_dev) && (dir->i_ino == c_ino)) {
		int first = c_last_returned_index;
		int i;

		i = first;
		do {
			DDPRINTK("ncp_lookup: trying index: %d, name: %s\n",
				 i, c_entry[i].i.entryName);

			if (strcmp(c_entry[i].i.entryName, name) == 0) {
				DPRINTK("ncp_lookup: found in cache!\n");
				finfo.i = c_entry[i].i;
				found_in_cache = 1;
				break;
			}
			i = (i + 1) % c_size;
		}
		while (i != first);
	}
	ncp_unlock_dircache();

	if (found_in_cache == 0) {
		int res;

		DDPRINTK("ncp_lookup: do_lookup on %s/%s\n",
			 NCP_ISTRUCT(dir)->entryName, name);

		if (ncp_is_server_root(dir)) {
			str_upper(name);
			down_case = 1;
			res = ncp_lookup_volume(server, name, &(finfo.i));
		} else {
			if (!ncp_preserve_case(dir)) {
				str_upper(name);
				down_case = 1;
			}
			res = ncp_obtain_info(server,
					      NCP_ISTRUCT(dir)->volNumber,
					      NCP_ISTRUCT(dir)->dirEntNum,
					      name, &(finfo.i));
		}
		if (res != 0) {
			unlock_super(dir->i_sb);
			iput(dir);
			return -ENOENT;
		}
	}
	finfo.opened = 0;

	if (down_case != 0) {
		str_lower(finfo.i.entryName);
	}
	if (!(*result = ncp_iget(dir, &finfo))) {
		unlock_super(dir->i_sb);
		iput(dir);
		return -EACCES;
	}
	unlock_super(dir->i_sb);
	iput(dir);
	return 0;
}

static int ncp_create(struct inode *dir, const char *name, int len, int mode,
		      struct inode **result)
{
	struct nw_file_info finfo;
	__u8 _name[len + 1];

	*result = NULL;

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("ncp_create: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (!ncp_conn_valid(NCP_SERVER(dir))) {
		iput(dir);
		return -EIO;
	}
	strncpy(_name, name, len);
	_name[len] = '\0';

	if (!ncp_preserve_case(dir)) {
		str_upper(_name);
	}
	lock_super(dir->i_sb);
	if (ncp_open_create_file_or_subdir(NCP_SERVER(dir),
					   NCP_ISTRUCT(dir), _name,
					   OC_MODE_CREATE | OC_MODE_OPEN |
					   OC_MODE_REPLACE,
					   0, AR_READ | AR_WRITE,
					   &finfo) != 0) {
		unlock_super(dir->i_sb);
		iput(dir);
		return -EACCES;
	}
	ncp_invalid_dir_cache(dir);

	if (!ncp_preserve_case(dir)) {
		str_lower(finfo.i.entryName);
	}
	finfo.access = O_RDWR;

	if (!(*result = ncp_iget(dir, &finfo)) < 0) {
		ncp_close_file(NCP_SERVER(dir), finfo.file_handle);
		unlock_super(dir->i_sb);
		iput(dir);
		return -EINVAL;
	}
	unlock_super(dir->i_sb);
	iput(dir);
	return 0;
}

static int ncp_mkdir(struct inode *dir, const char *name, int len, int mode)
{
	int error;
	struct nw_file_info new_dir;
	__u8 _name[len + 1];

	if ((name[0] == '.')
	    && ((len == 1)
		|| ((len == 2)
		    && (name[1] == '.')))) {
		iput(dir);
		return -EEXIST;
	}
	strncpy(_name, name, len);
	_name[len] = '\0';

	if (!ncp_preserve_case(dir)) {
		str_upper(_name);
	}
	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("ncp_mkdir: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (!ncp_conn_valid(NCP_SERVER(dir))) {
		iput(dir);
		return -EIO;
	}
	if (ncp_open_create_file_or_subdir(NCP_SERVER(dir),
					   NCP_ISTRUCT(dir), _name,
					   OC_MODE_CREATE, aDIR, 0xffff,
					   &new_dir) != 0) {
		error = -EACCES;
	} else {
		error = 0;
		ncp_invalid_dir_cache(dir);
	}

	iput(dir);
	return error;
}

static int ncp_rmdir(struct inode *dir, const char *name, int len)
{
	int error;
	__u8 _name[len + 1];

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("ncp_rmdir: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (!ncp_conn_valid(NCP_SERVER(dir))) {
		iput(dir);
		return -EIO;
	}
	if (ncp_find_dir_inode(dir, name) != NULL) {
		iput(dir);
		error = -EBUSY;
	} else {

		strncpy(_name, name, len);
		_name[len] = '\0';

		if (!ncp_preserve_case(dir)) {
			str_upper(_name);
		}
		if ((error = ncp_del_file_or_subdir(NCP_SERVER(dir),
						    NCP_ISTRUCT(dir),
						    _name)) == 0) {
			ncp_invalid_dir_cache(dir);
		} else {
			error = -EACCES;
		}
	}
	iput(dir);
	return error;
}

static int ncp_unlink(struct inode *dir, const char *name, int len)
{
	int error;
	__u8 _name[len + 1];

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("ncp_unlink: inode is NULL or not a directory\n");
		iput(dir);
		return -ENOENT;
	}
	if (!ncp_conn_valid(NCP_SERVER(dir))) {
		iput(dir);
		return -EIO;
	}
	if (ncp_find_dir_inode(dir, name) != NULL) {
		iput(dir);
		error = -EBUSY;
	} else {
		strncpy(_name, name, len);
		_name[len] = '\0';

		if (!ncp_preserve_case(dir)) {
			str_upper(_name);
		}
		if ((error = ncp_del_file_or_subdir(NCP_SERVER(dir),
						    NCP_ISTRUCT(dir),
						    _name)) == 0) {
			ncp_invalid_dir_cache(dir);
		} else {
			error = -EACCES;
		}
	}
	iput(dir);
	return error;
}

static int ncp_rename(struct inode *old_dir, const char *old_name, int old_len,
		struct inode *new_dir, const char *new_name, int new_len,
		      int must_be_dir)
{
	int res;
	char _old_name[old_len + 1];
	char _new_name[new_len + 1];

	if (!old_dir || !S_ISDIR(old_dir->i_mode)) {
		printk("ncp_rename: old inode is NULL or not a directory\n");
		res = -ENOENT;
		goto finished;
	}
	if (!ncp_conn_valid(NCP_SERVER(old_dir))) {
		res = -EIO;
		goto finished;
	}
	if (!new_dir || !S_ISDIR(new_dir->i_mode)) {
		printk("ncp_rename: new inode is NULL or not a directory\n");
		res = -ENOENT;
		goto finished;
	}
	if ((ncp_find_dir_inode(old_dir, old_name) != NULL)
	    || (ncp_find_dir_inode(new_dir, new_name) != NULL)) {
		res = -EBUSY;
		goto finished;
	}
	strncpy(_old_name, old_name, old_len);
	_old_name[old_len] = '\0';

	if (!ncp_preserve_case(old_dir)) {
		str_upper(_old_name);
	}
	strncpy(_new_name, new_name, new_len);
	_new_name[new_len] = '\0';

	if (!ncp_preserve_case(new_dir)) {
		str_upper(_new_name);
	}
	res = ncp_ren_or_mov_file_or_subdir(NCP_SERVER(old_dir),
					 NCP_ISTRUCT(old_dir), _old_name,
					NCP_ISTRUCT(new_dir), _new_name);

	if (res == 0) {
		ncp_invalid_dir_cache(old_dir);
		ncp_invalid_dir_cache(new_dir);
	} else {
		res = -EACCES;
	}

      finished:
	iput(old_dir);
	iput(new_dir);
	return res;
}

/* The following routines are taken directly from msdos-fs */

/* Linear day numbers of the respective 1sts in non-leap years. */

static int day_n[] =
{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, 0};
		  /* JanFebMarApr May Jun Jul Aug Sep Oct Nov Dec */


extern struct timezone sys_tz;

static int utc2local(int time)
{
	return time - sys_tz.tz_minuteswest * 60 +
	    (sys_tz.tz_dsttime ? 3600 : 0);
}

static int local2utc(int time)
{
	return time + sys_tz.tz_minuteswest * 60 -
	    (sys_tz.tz_dsttime ? 3600 : 0);
}

/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */

int ncp_date_dos2unix(unsigned short time, unsigned short date)
{
	int month, year, secs;

	month = ((date >> 5) & 15) - 1;
	year = date >> 9;
	secs = (time & 31) * 2 + 60 * ((time >> 5) & 63) + (time >> 11) * 3600 + 86400 *
	    ((date & 31) - 1 + day_n[month] + (year / 4) + year * 365 - ((year & 3) == 0 &&
					      month < 2 ? 1 : 0) + 3653);
	/* days since 1.1.70 plus 80's leap day */
	return local2utc(secs);
}


/* Convert linear UNIX date to a MS-DOS time/date pair. */
void ncp_date_unix2dos(int unix_date, unsigned short *time, unsigned short *date)
{
	int day, year, nl_day, month;

	unix_date = utc2local(unix_date);
	*time = (unix_date % 60) / 2 + (((unix_date / 60) % 60) << 5) +
	    (((unix_date / 3600) % 24) << 11);
	day = unix_date / 86400 - 3652;
	year = day / 365;
	if ((year + 3) / 4 + 365 * year > day)
		year--;
	day -= (year + 3) / 4 + 365 * year;
	if (day == 59 && !(year & 3)) {
		nl_day = day;
		month = 2;
	} else {
		nl_day = (year & 3) || day <= 59 ? day : day - 1;
		for (month = 0; month < 12; month++)
			if (day_n[month] > nl_day)
				break;
	}
	*date = nl_day - day_n[month - 1] + 1 + (month << 5) + (year << 9);
}