/*
	Copyright 1999-2001, Be Incorporated.   All Rights Reserved.
	This file may be used under the terms of the Be Sample Code License.
*/

#include "dir.h"

#include "system_dependencies.h"

#include "iter.h"
#include "dosfs.h"
#include "attr.h"
#include "dlist.h"
#include "fat.h"
#include "util.h"
#include "vcache.h"
#include "file.h"

#include "encodings.h"

#define DPRINTF(a,b) if (debug_dir > (a)) dprintf b


typedef struct dircookie {
	uint32		current_index;
} dircookie;

static status_t	findfile(nspace *vol, vnode *dir, const char *file,
	ino_t *vnid, vnode **node, bool check_case, bool check_dups,
	bool *dups_exist);


// private structure for returning data from _next_dirent_()
struct _dirent_info_ {
	uint32 sindex;
	uint32 eindex;
	uint32 mode;
	uint32 cluster;
	uint32 size;
	uint32 time;
	uint32 creation_time;
};


//!	Scans dir for the next entry, using the state stored in a struct diri.
static status_t
_next_dirent_(struct diri *iter, struct _dirent_info_ *oinfo, char *filename,
	int len)
{
	uint8 *buffer;
	uint8 hash = 0;
	uchar uni[1024];
	uint16 *puni;
	uint32 i;

	// lfn state
	uint32 start_index = 0xffff, filename_len = 0;
	uint32 lfn_count = 0;

	if (iter->current_block == NULL)
		return ENOENT;

	if (len < 15) {
		DPRINTF(0, ("_next_dirent_: len too short (%x)\n", len));
		return ENOMEM;
	}

	buffer = iter->current_block + ((iter->current_index)
		% (iter->csi.vol->bytes_per_sector / 0x20)) * 0x20;

	for (; buffer != NULL; buffer = diri_next_entry(iter)) {
		DPRINTF(2, ("_next_dirent_: %" B_PRIu32 "/%" B_PRIu32 "/%" B_PRIu32
			"\n", iter->csi.cluster, iter->csi.sector, iter->current_index));
		if (buffer[0] == 0) { // quit if at end of table
			if (start_index != 0xffff)
				dprintf("lfn entry (%" B_PRIu32 ") with no alias\n", lfn_count);
			return ENOENT;
		}

		if (buffer[0] == 0xe5) { // skip erased entries
			if (start_index != 0xffff) {
				dprintf("lfn entry (%" B_PRIu32 ") with intervening erased "
					"entries\n", lfn_count);
				start_index = 0xffff;
			}
			DPRINTF(2, ("entry erased, skipping...\n"));
			continue;
		}

		if (buffer[0xb] == 0xf) { // long file name
			if ((buffer[0xc] != 0) ||
				(buffer[0x1a] != 0) || (buffer[0x1b] != 0)) {
				dprintf("invalid long file name: reserved fields munged\n");
				continue;
			}
			if (start_index == 0xffff) {
				if ((buffer[0] & 0x40) == 0) {
					dprintf("bad lfn start entry in directory\n");
					continue;
				}
				hash = buffer[0xd];
				lfn_count = buffer[0] & 0x1f;
				start_index = iter->current_index;
				puni = (uint16 *)(uni + 2*13*(lfn_count - 1));
				for (i = 1; i < 0x20; i += 2) {
					if (*(uint16 *)&buffer[i] == 0xffff)
						break;
					*puni++ = *(uint16 *)&buffer[i];
					if (i == 0x9) i+=3;
					if (i == 0x18) i+=2;
				}
				*puni++ = 0;
				filename_len = (uchar *)(puni) - uni;

				continue;
			} else {
				if (buffer[0xd] != hash) {
					dprintf("error in long file name: hash values don't match\n");
					start_index = 0xffff;
					continue;
				}
				if (buffer[0] != --lfn_count) {
					dprintf("bad lfn entry in directory\n");
					start_index = 0xffff;
					continue;
				}

				puni = (uint16 *)(uni + 2*13*(lfn_count - 1));
				for (i = 1; i < 0x20; i += 2) {
					if ((buffer[i] == 0xff) && (buffer[i+1] == 0xff)) {
						dprintf("bad lfn entry in directory\n");
						start_index = 0xffff;
						break;
					}
					*puni++ = *(uint16 *)&buffer[i];
					if (i == 0x9) i+=3;
					if (i == 0x18) i+=2;
				}
				continue;
			}
		}

		break;
	}

	// hit end of directory entries with no luck
	if (buffer == NULL)
		return ENOENT;

	// process long name
	if (start_index != 0xffff) {
		if (lfn_count != 1) {
			dprintf("unfinished lfn in directory\n");
			start_index = 0xffff;
		} else {
			if (unicode_to_utf8(uni, filename_len, (uint8*)filename, len)) {
				// rewind to beginning of call
				dprintf("error: long file name too long\n");

				diri_init(iter->csi.vol, iter->starting_cluster, start_index,
					iter);
				return ENAMETOOLONG;
			} else if (hash_msdos_name((const char *)buffer) != hash) {
				dprintf("error: long file name (%s) hash and short file name "
					"don't match\n", filename);
				start_index = 0xffff;
			}
		}
	}

	// process short name
	if (start_index == 0xffff) {
		start_index = iter->current_index;
		// korli : seen on FreeBSD /src/sys/fs/msdosfs/direntry.h
		msdos_to_utf8(buffer, (uchar *)filename, len, buffer[0xc] & 0x18);
	}

	if (oinfo) {
		oinfo->sindex = start_index;
		oinfo->eindex = iter->current_index;
		oinfo->mode = buffer[0xb];
		oinfo->cluster = read16(buffer, 0x1a);
		if (iter->csi.vol->fat_bits == 32)
			oinfo->cluster += 0x10000 * read16(buffer, 0x14);
		oinfo->size = read32(buffer, 0x1c);
		oinfo->time = read32(buffer, 0x16);
		oinfo->creation_time = read32(buffer, 0x0e);
	}

	diri_next_entry(iter);

	return B_NO_ERROR;
}


static status_t
get_next_dirent(nspace *vol, vnode *dir, struct diri *iter, ino_t *vnid,
	char *filename, int len)
{
	struct _dirent_info_ info;
	status_t result;

	do {
		result = _next_dirent_(iter, &info, filename, len);
		if (result < 0)
			return result;
		// only hide volume label entries in the root directory
	} while ((info.mode & FAT_VOLUME) && (dir->vnid == vol->root_vnode.vnid));

	if (!strcmp(filename, ".")) {
		// assign vnode based on parent
		if (vnid) *vnid = dir->vnid;
	} else if (!strcmp(filename, "..")) {
		// assign vnode based on parent of parent
		if (vnid) *vnid = dir->dir_vnid;
	} else {
		if (vnid) {
			ino_t loc = (IS_DATA_CLUSTER(info.cluster))
				? GENERATE_DIR_CLUSTER_VNID(dir->vnid, info.cluster)
				: GENERATE_DIR_INDEX_VNID(dir->vnid, info.sindex);
			bool added_to_vcache = false;

			/* if it matches a loc in the lookup table, we are done. */
			result = vcache_loc_to_vnid(vol, loc, vnid);
			if (result == ENOENT) {
				/* ...else check if it matches any vnid's in the lookup table */
				if (find_vnid_in_vcache(vol, loc) == B_OK) {
					/* if it does, create a random one since we can't reuse
					 * existing vnid's */
					*vnid = generate_unique_vnid(vol);
					/* and add it to the vcache */
					if ((result = add_to_vcache(vol, *vnid, loc)) < 0)
						return result;
					added_to_vcache = true;
				} else {
					/* otherwise we are free to use it */
					*vnid = loc;
				}
			} else if (result != B_OK) {
				dprintf("get_next_dirent: unknown error (%s)\n",
					strerror(result));
				return result;
			}

			if (info.mode & FAT_SUBDIR) {
				if (dlist_find(vol, info.cluster) == -1LL) {
					if ((result = dlist_add(vol, *vnid)) < 0) {
						if (added_to_vcache)
							remove_from_vcache(vol, *vnid);
						return result;
					}
				}
			}
		}
	}

	DPRINTF(2, ("get_next_dirent: found %s (vnid %" B_PRIdINO ")\n", filename,
		vnid != NULL ? *vnid : (ino_t)0));

	return B_NO_ERROR;
}


status_t
check_dir_empty(nspace *vol, vnode *dir)
{
	uint32 i;
	struct diri iter;
	status_t result = B_ERROR;

	if (diri_init(vol, dir->cluster, 0, &iter) == NULL) {
		dprintf("check_dir_empty: error opening directory\n");
		return B_ERROR;
	}

	i = (dir->vnid == vol->root_vnode.vnid) ? 2 : 0;

	for (; i < 3; i++) {
		char filename[512];
		result = _next_dirent_(&iter, NULL, filename, 512);
		if (result < 0) {
			if (i == 2 && result == ENOENT)
				result = B_OK;
			break;
		}

		if ((i == 0 && strcmp(filename, "."))
			|| (i == 1 && strcmp(filename, ".."))
			// weird case where ./.. are stored as long file names
			|| (i < 2 && iter.current_index != i + 1)) {
			dprintf("check_dir_empty: malformed directory\n");
			result = ENOTDIR;
			break;
		}

		result = ENOTEMPTY;
	}

	return result;
}


status_t
findfile_case(nspace *vol, vnode *dir, const char *file, ino_t *vnid,
	vnode **node)
{
	return findfile(vol, dir, file, vnid, node, true, false, NULL);
}


status_t
findfile_nocase(nspace *vol, vnode *dir, const char *file, ino_t *vnid,
	vnode **node)
{
	return findfile(vol, dir, file, vnid, node, false, false, NULL);
}


status_t
findfile_nocase_duplicates(nspace *vol, vnode *dir, const char *file,
	ino_t *vnid, vnode **node, bool *dups_exist)
{
	return findfile(vol, dir, file, vnid, node, false, true, dups_exist);
}


status_t
findfile_case_duplicates(nspace *vol, vnode *dir, const char *file,
	ino_t *vnid, vnode **node, bool *dups_exist)
{
	return findfile(vol, dir, file, vnid, node, true, true, dups_exist);
}


static status_t
findfile(nspace *vol, vnode *dir, const char *file, ino_t *vnid,
	vnode **node, bool check_case, bool check_dups, bool *dups_exist)
{
	/* Starting at the base, find the file in the subdir
	   and return its vnode id */
	/* The check_case flags determines whether or not the search
	   is done for the exact case or not. If it is not, it will
	   return the first occurance of the match. */
	/* The check_dups flag instructs the function to find the
	   first filename match based on the case sensitivity in
	   check_case, but continue searching to see if there are
	   any other case-insensitive matches. If there are, the
	   dups_exist flag is set to true. */
	int		result = 0;
	ino_t	found_vnid = 0;
	bool found_file = false;

//	dprintf("findfile: %s in %Lx, case %d dups %d\n", file, dir->vnid, check_case, check_dups);

	DPRINTF(1, ("findfile: %s in %" B_PRIdINO "\n", file, dir->vnid));

	if (dups_exist != NULL)
		*dups_exist = false;
	else
		check_dups = false;

	if (strcmp(file,".") == 0 && dir->vnid == vol->root_vnode.vnid) {
		found_file = true;
		found_vnid = dir->vnid;
	} else if (strcmp(file, "..") == 0 && dir->vnid == vol->root_vnode.vnid) {
		found_file = true;
		found_vnid = dir->dir_vnid;
	} else {
		struct diri diri;

		// XXX: do it in a smarter way
		if (diri_init(vol, dir->cluster, 0, &diri) == NULL) {
			dprintf("findfile: error opening directory\n");
			return ENOENT;
		}

		while (1) {
			char filename[512];
			ino_t _vnid;

			result = get_next_dirent(vol, dir, &diri, &_vnid, filename, 512);
			if (result != B_NO_ERROR)
				break;

			if (check_case) {
				if (!found_file && !strcmp(filename, file)) {
					found_file = true;
					found_vnid = _vnid;
				} else if (check_dups && !strcasecmp(filename, file)) {
					*dups_exist = true;
				}
			} else {
				if (!strcasecmp(filename, file)) {
					if (check_dups && found_file)
						*dups_exist = true;

					found_file = true;
					found_vnid = _vnid;
				}
			}

			if (found_file && (!check_dups || (check_dups && *dups_exist)))
				break;
		}
	}
	if (found_file) {
		if (vnid)
			*vnid = found_vnid;
		if (node)
			result = get_vnode(vol->volume, found_vnid, (void **)node);
		result = B_OK;
	} else {
		result = ENOENT;
	}
#if 0
	dprintf("findfile: returning %d", result);
	if(dups_exist)
		dprintf(" dups_exist %d\n", *dups_exist);
	else
		dprintf("\n");
#endif
	return result;
}


status_t
erase_dir_entry(nspace *vol, vnode *node)
{
	status_t result;
	uint32 i;
	char filename[512];
	uint8 *buffer;
	struct _dirent_info_ info;
	struct diri diri;

	DPRINTF(0, ("erasing directory entries %" B_PRIu32 " through %" B_PRIu32
		"\n", node->sindex, node->eindex));
	buffer = diri_init(vol,VNODE_PARENT_DIR_CLUSTER(node), node->sindex, &diri);

	// first pass: check if the entry is still valid
	if (buffer == NULL) {
		dprintf("erase_dir_entry: error reading directory\n");
		return ENOENT;
	}

	result = _next_dirent_(&diri, &info, filename, 512);

	if (result < 0)
		return result;

	if (info.sindex != node->sindex || info.eindex != node->eindex) {
		// any other attributes may be in a state of flux due to wstat calls
		dprintf("erase_dir_entry: directory entry doesn't match\n");
		return B_ERROR;
	}

	// second pass: actually erase the entry
	buffer = diri_init(vol, VNODE_PARENT_DIR_CLUSTER(node), node->sindex, &diri);
	for (i = node->sindex; i <= node->eindex && buffer;
			buffer = diri_next_entry(&diri), i++) {
		diri_make_writable(&diri);
		buffer[0] = 0xe5; // mark entry erased
	}

	return 0;
}


/*!	shrink directory to the size needed
	errors here are neither likely nor problematic
	w95 doesn't seem to do this, so it's possible to create a
	really large directory that consumes all available space!
*/
status_t
compact_directory(nspace *vol, vnode *dir)
{
	uint32 last = 0;
	struct diri diri;
	status_t error = B_ERROR; /* quiet warning */

	DPRINTF(0, ("compacting directory with vnode id %" B_PRIdINO "\n",
		dir->vnid));

	// root directory can't shrink in fat12 and fat16
	if (IS_FIXED_ROOT(dir->cluster))
		return 0;

	if (diri_init(vol, dir->cluster, 0, &diri) == NULL) {
		dprintf("compact_directory: cannot open dir at cluster (%" B_PRIu32
			")\n", dir->cluster);
		return EIO;
	}
	while (diri.current_block) {
		char filename[512];
		struct _dirent_info_ info;

		error = _next_dirent_(&diri, &info, filename, 512);

		if (error == B_OK) {
			// don't compact away volume labels in the root dir
			if (!(info.mode & FAT_VOLUME) || (dir->vnid != vol->root_vnode.vnid))
				last = diri.current_index;
		} else if (error == ENOENT) {
			uint32 clusters = (last + vol->bytes_per_sector / 0x20
				* vol->sectors_per_cluster - 1) / (vol->bytes_per_sector / 0x20)
				/ vol->sectors_per_cluster;
			error = 0;

			// special case for fat32 root directory; we don't want
			// it to disappear
			if (clusters == 0)
				clusters = 1;

			if (clusters * vol->bytes_per_sector * vol->sectors_per_cluster
					< dir->st_size) {
				DPRINTF(0, ("shrinking directory to %" B_PRIu32 " clusters\n",
					clusters));
				error = set_fat_chain_length(vol, dir, clusters, true);
				dir->st_size = clusters * vol->bytes_per_sector
					* vol->sectors_per_cluster;
				dir->iteration++;
			}
			break;
		} else {
			dprintf("compact_directory: unknown error from _next_dirent_ (%s)\n",
				strerror(error));
			break;
		}
	}

	return error;
}


//! name is array of char[11] as returned by findfile
static status_t
find_short_name(nspace *vol, vnode *dir, const uchar *name)
{
	struct diri diri;
	uint8 *buffer;
	status_t result = ENOENT;

	buffer = diri_init(vol, dir->cluster, 0, &diri);
	while (buffer) {
		if (buffer[0] == 0)
			break;

		if (buffer[0xb] != 0xf) { // not long file name
			if (!memcmp(name, buffer, 11)) {
				result = B_OK;
				break;
			}
		}

		buffer = diri_next_entry(&diri);
	}

	return result;
}


struct _entry_info_ {
	uint32 mode;
	uint32 cluster;
	uint32 size;
	time_t time;
	time_t creation_time;
};


static status_t
_create_dir_entry_(nspace *vol, vnode *dir, struct _entry_info_ *info,
	const char nshort[11], const char *nlong, uint32 len, uint32 *ns,
	uint32 *ne)
{
	status_t error = B_ERROR; /* quiet warning */
	uint32 required_entries, i;
	uint8 *buffer, hash;
	bool last_entry;
	struct diri diri;

	// short name cannot be the same as that of a device
	// this list was created by running strings on io.sys
	const char *device_names[] = {
		"CON        ",
		"AUX        ",
		"PRN        ",
		"CLOCK$     ",
		"COM1       ",
		"LPT1       ",
		"LPT2       ",
		"LPT3       ",
		"COM2       ",
		"COM3       ",
		"COM4       ",
		"CONFIG$    ",
		NULL
	};

	// check short name against device names
	for (i = 0; device_names[i]; i++) {
		// only first 8 characters seem to matter
		if (!memcmp(nshort, device_names[i], 8))
			return EPERM;
	}

	if (info->cluster != 0 && !IS_DATA_CLUSTER(info->cluster)) {
		dprintf("_create_dir_entry_ for bad cluster (%" B_PRIu32 ")\n",
			info->cluster);
		return EINVAL;
	}

	/* convert byte length of unicode name to directory entries */
	required_entries = (len + 24) / 26 + 1;

	// find a place to put the entries
	*ns = 0;
	last_entry = true;
	if (diri_init(vol, dir->cluster, 0, &diri) == NULL) {
		dprintf("_create_dir_entry_: cannot open dir at cluster (%" B_PRIu32
			")\n", dir->cluster);
		return EIO;
	}

	while (diri.current_block) {
		char filename[512];
		struct _dirent_info_ info;
		error = _next_dirent_(&diri, &info, filename, 512);
		if (error == B_OK) {
			if (info.sindex - *ns >= required_entries) {
				last_entry = false;
				break;
			}
			*ns = diri.current_index;
		} else if (error == ENOENT) {
			// hit end of directory marker
			break;
		} else {
			dprintf("_create_dir_entry_: unknown error from _next_dirent_ (%s)\n",
				strerror(error));
			break;
		}
	}

	// if at end of directory, last_entry flag will be true as it should be

	if (error != B_OK && error != ENOENT)
		return error;

	*ne = *ns + required_entries - 1;

	for (i = *ns; i <= *ne; i++) {
		ASSERT(find_loc_in_vcache(vol,
			GENERATE_DIR_INDEX_VNID(dir->cluster, i)) == ENOENT);
	}

	DPRINTF(0, ("directory entry runs from %" B_PRIu32 " to %" B_PRIu32
		" (dirsize = %" B_PRIdOFF ") (is%s last entry)\n", *ns, *ne,
		dir->st_size, last_entry ? "" : "n't"));

	// check if the directory needs to be expanded
	if (*ne * 0x20 >= dir->st_size) {
		uint32 clusters_needed;

		// can't expand fat12 and fat16 root directories :(
		if (IS_FIXED_ROOT(dir->cluster)) {
			DPRINTF(0, ("_create_dir_entry_: out of space in root directory\n"));
			return ENOSPC;
		}

		// otherwise grow directory to fit
		clusters_needed = ((*ne + 1) * 0x20 +
			vol->bytes_per_sector*vol->sectors_per_cluster - 1) /
			vol->bytes_per_sector / vol->sectors_per_cluster;

		DPRINTF(0, ("expanding directory from %" B_PRIdOFF " to %" B_PRIu32
			" clusters\n", dir->st_size / vol->bytes_per_sector
				/ vol->sectors_per_cluster, clusters_needed));
		if ((error = set_fat_chain_length(vol, dir, clusters_needed, false))
				< 0) {
			return error;
		}

		dir->st_size = vol->bytes_per_sector*vol->sectors_per_cluster*clusters_needed;
		dir->iteration++;
	}

	// starting blitting entries
	buffer = diri_init(vol,dir->cluster, *ns, &diri);
	if (buffer == NULL) {
		dprintf("_create_dir_entry_: cannot open dir at (%" B_PRIu32 ", %"
			B_PRIu32 ")\n", dir->cluster, *ns);
		return EIO;
	}
	hash = hash_msdos_name(nshort);

	// write lfn entries
	for (i = 1; i < required_entries && buffer; i++) {
		const char *p = nlong + (required_entries - i - 1) * 26;
			// go to unicode offset
		diri_make_writable(&diri);
		memset(buffer, 0, 0x20);
		buffer[0] = required_entries - i + ((i == 1) ? 0x40 : 0);
		buffer[0x0b] = 0x0f;
		buffer[0x0d] = hash;
		memcpy(buffer+1,p,10);
		memcpy(buffer+0x0e,p+10,12);
		memcpy(buffer+0x1c,p+22,4);
		buffer = diri_next_entry(&diri);
	}

	ASSERT(buffer != NULL);
	if (buffer == NULL)	{	// this should never happen...
		DPRINTF(0, ("_create_dir_entry_: the unthinkable has occured\n"));
		return B_ERROR;
	}

	// write directory entry
	diri_make_writable(&diri);
	memcpy(buffer, nshort, 11);
	buffer[0x0b] = info->mode;
	memset(buffer+0xc, 0, 0x16-0xc);
	i = time_t2dos(info->creation_time);
	buffer[0x0e] = i & 0xff;
	buffer[0x0f] = (i >> 8) & 0xff;
	buffer[0x10] = (i >> 16) & 0xff;
	buffer[0x11] = (i >> 24) & 0xff;
	i = time_t2dos(info->time);
	buffer[0x16] = i & 0xff;
	buffer[0x17] = (i >> 8) & 0xff;
	buffer[0x18] = (i >> 16) & 0xff;
	buffer[0x19] = (i >> 24) & 0xff;
	i = info->cluster;
	if (info->size == 0) i = 0;		// cluster = 0 for 0 byte files
	buffer[0x1a] = i & 0xff;
	buffer[0x1b] = (i >> 8) & 0xff;
	if (vol->fat_bits == 32) {
		buffer[0x14] = (i >> 16) & 0xff;
		buffer[0x15] = (i >> 24) & 0xff;
	}
	i = (info->mode & FAT_SUBDIR) ? 0 : info->size;
	buffer[0x1c] = i & 0xff;
	buffer[0x1d] = (i >> 8) & 0xff;
	buffer[0x1e] = (i >> 16) & 0xff;
	buffer[0x1f] = (i >> 24) & 0xff;

	if (last_entry) {
		// add end of directory markers to the rest of the
		// cluster; need to clear all the other entries or else
		// scandisk will complain.
		while ((buffer = diri_next_entry(&diri)) != NULL) {
			diri_make_writable(&diri);
			memset(buffer, 0, 0x20);
		}
	}

	return 0;
}


//! doesn't do any name checking
status_t
create_volume_label(nspace *vol, const char name[11], uint32 *index)
{
	status_t err;
	uint32 dummy;
	struct _entry_info_ info = {
		FAT_ARCHIVE | FAT_VOLUME, 0, 0, 0
	};
	time(&info.time);

	// check if name already exists
	err = find_short_name(vol, &(vol->root_vnode), (uchar *)name);
	if (err == B_OK)
		return EEXIST;
	if (err != ENOENT)
		return err;

	return _create_dir_entry_(vol, &(vol->root_vnode), &info, name, NULL,
		0, index, &dummy);
}


bool
is_filename_legal(const char *name)
{
	unsigned int i;
	unsigned int len = strlen(name);

	if (len <= 0)
		return false;

	// names ending with a dot are not allowed
	if (name[len - 1] == '.')
		return false;
	// names ending with a space are not allowed
	if (name[len - 1] == ' ')
		return false;

	// XXX illegal character search can be made faster
	for (i = 0; i < len; i++) {
		if (name[i] & 0x80)
			continue; //belongs to an utf8 char
		if (strchr(sIllegal, name[i]))
			return false;
		if ((unsigned char)name[i] < 32)
			return false;
	}
	return true;
}


status_t
create_dir_entry(nspace *vol, vnode *dir, vnode *node, const char *name,
	uint32 *ns, uint32 *ne)
{
	status_t error;
	int32 len;
	unsigned char nlong[512], nshort[11];
	int encoding;
	struct _entry_info_ info;

	// check name legality before doing anything
	if (!is_filename_legal(name))
		return EINVAL;

	// check if name already exists
	error = findfile_nocase(vol, dir, name, NULL, NULL);
	if (error == B_OK) {
		DPRINTF(0, ("%s already found in directory %" B_PRIdINO "\n", name,
			dir->vnid));
		return EEXIST;
	}
	if (error != ENOENT)
		return error;

	// check name legality while converting. we ignore the case conversion
	// flag, i.e. (filename "blah" will always have a patched short name),
	// because the whole case conversion system in dos is brain damaged;
	// remanants of CP/M no less.

	// existing names pose a problem; in these cases, we'll just live with
	// two identical short names. not a great solution, but there's little
	// we can do about it.
	len = utf8_to_unicode(name, nlong, 512);
	if (len <= 0) {
		DPRINTF(0, ("Error converting utf8 name '%s' to unicode\n", name));
		return len ? len : B_ERROR;
	}
	memset(nlong + len, 0xff, 512 - len); /* pad with 0xff */

	error = generate_short_name((uchar *)name, nlong, len, nshort, &encoding);
	if (error) {
		DPRINTF(0, ("Error generating short name for '%s'\n", name));
		return error;
	}

	// if there is a long name, patch short name if necessary and check for duplication
	if (requires_long_name(name, nlong)) {
		char tshort[11]; // temporary short name
		int iter = 1;

		memcpy(tshort, nshort, 11);

		if (requires_munged_short_name((uchar *)name, nshort, encoding))
			error = B_OK;
		else
			error = find_short_name(vol, dir, nshort);

		if (error == B_OK) {
			do {
				memcpy(nshort, tshort, 11);
				DPRINTF(0, ("trying short name %11.11s\n", nshort));
				munge_short_name1(nshort, iter, encoding);
			} while ((error = find_short_name(vol, dir, nshort)) == B_OK && ++iter < 10);
		}

		if (error != B_OK && error != ENOENT)
			return error;

		if (error == B_OK) {
			// XXX: possible infinite loop here
			do {
				memcpy(nshort, tshort, 11);
				DPRINTF(0, ("trying short name %11.11s\n", nshort));
				munge_short_name2(nshort, encoding);
			} while ((error = find_short_name(vol, dir, nshort)) == B_OK);

			if (error != ENOENT)
				return error;
		}
	} else {
		len = 0; /* entry doesn't need a long name */
	}

	DPRINTF(0, ("creating directory entry (%11.11s)\n", nshort));

	info.mode = node->mode;
	if ((node->mode & FAT_SUBDIR) == 0)
		info.mode |= FAT_ARCHIVE;
	info.cluster = node->cluster;
	info.size = node->st_size;
	info.time = node->st_time;
	info.creation_time = node->st_crtim;

	return _create_dir_entry_(vol, dir, &info, (char *)nshort,
		(char *)nlong, len, ns, ne);
}


status_t
dosfs_read_vnode(fs_volume *_vol, ino_t vnid, fs_vnode *_node, int *_type,
	uint32 *_flags, bool reenter)
{
	nspace *vol = (nspace *)_vol->private_volume;
	int result = B_NO_ERROR;
	ino_t loc, dir_vnid;
	vnode *entry;
	struct _dirent_info_ info;
	struct diri iter;
	char filename[512]; /* need this for setting mime type */

	RecursiveLocker lock(vol->vlock);

	_node->private_node = NULL;
	_node->ops = &gFATVnodeOps;
	*_flags = 0;

	DPRINTF(0, ("dosfs_read_vnode (vnode id %" B_PRIdINO ")\n", vnid));

	if (vnid == vol->root_vnode.vnid) {
		dprintf("??? dosfs_read_vnode called on root node ???\n");
		_node->private_node = (void *)&(vol->root_vnode);
		*_type = make_mode(vol, &vol->root_vnode);
		return result;
	}

	if (vcache_vnid_to_loc(vol, vnid, &loc) != B_OK)
		loc = vnid;

	if (IS_ARTIFICIAL_VNID(loc) || IS_INVALID_VNID(loc)) {
		DPRINTF(0, ("dosfs_read_vnode: unknown vnid %" B_PRIdINO " (loc %"
			B_PRIdINO ")\n", vnid, loc));
		return ENOENT;
	}

	if ((dir_vnid = dlist_find(vol, DIR_OF_VNID(loc))) == -1LL) {
		DPRINTF(0, ("dosfs_read_vnode: unknown directory at cluster %" B_PRIu32
			"\n", DIR_OF_VNID(loc)));
		return ENOENT;
	}

	if (diri_init(vol, DIR_OF_VNID(loc),
			IS_DIR_CLUSTER_VNID(loc) ? 0 : INDEX_OF_DIR_INDEX_VNID(loc),
			&iter) == NULL) {
		dprintf("dosfs_read_vnode: error initializing directory for vnid %"
			B_PRIdINO " (loc %" B_PRIdINO ")\n", vnid, loc);
		return ENOENT;
	}

	while (1) {
		result = _next_dirent_(&iter, &info, filename, 512);
		if (result < 0) {
			dprintf("dosfs_read_vnode: error finding vnid %" B_PRIdINO
				" (loc %" B_PRIdINO ") (%s)\n", vnid, loc, strerror(result));
			return result;
		}

		if (IS_DIR_CLUSTER_VNID(loc)) {
			if (info.cluster == CLUSTER_OF_DIR_CLUSTER_VNID(loc))
				break;
		} else {
			if (info.sindex == INDEX_OF_DIR_INDEX_VNID(loc))
				break;
			dprintf("dosfs_read_vnode: error finding vnid %" B_PRIdINO
				" (loc %" B_PRIdINO ") (%s)\n", vnid, loc, strerror(result));
			return ENOENT;
		}
	}

	if ((entry = (vnode *)calloc(sizeof(struct vnode), 1)) == NULL) {
		DPRINTF(0, ("dosfs_read_vnode: out of memory\n"));
		return ENOMEM;
	}

	entry->vnid = vnid;
	entry->dir_vnid = dir_vnid;
	entry->disk_image = 0;
	if (vol->respect_disk_image) {
		if ((dir_vnid == vol->root_vnode.vnid) && !strcmp(filename, "BEOS")) {
			vol->beos_vnid = vnid;
			entry->disk_image = 1;
		}
		if ((dir_vnid == vol->beos_vnid) && !strcmp(filename, "IMAGE.BE")) {
			entry->disk_image = 2;
		}
	}
	entry->iteration = 0;
	entry->sindex = info.sindex;
	entry->eindex = info.eindex;
	entry->cluster = info.cluster;
	entry->mode = info.mode;
	entry->st_size = info.size;
	entry->dirty = false;
	if (info.mode & FAT_SUBDIR) {
		entry->st_size = count_clusters(vol,entry->cluster)
			* vol->sectors_per_cluster * vol->bytes_per_sector;
	}
	if (entry->cluster) {
		entry->end_cluster = get_nth_fat_entry(vol, info.cluster,
			(entry->st_size + vol->bytes_per_sector * vol->sectors_per_cluster - 1) /
			vol->bytes_per_sector / vol->sectors_per_cluster - 1);
	} else
		entry->end_cluster = 0;
	entry->st_time = dos2time_t(info.time);
	entry->st_crtim = dos2time_t(info.creation_time);

	entry->filename = (char *)malloc(sizeof(filename) + 1);
	if (entry->filename) strcpy(entry->filename, filename);

	entry->cache = file_cache_create(vol->id, vnid, entry->st_size);
	entry->file_map = file_map_create(vol->id, vnid, entry->st_size);
	if (!(entry->mode & FAT_SUBDIR))
		set_mime_type(entry, filename);

	_node->private_node = entry;
	*_type = make_mode(vol, entry);

	return B_OK;
}


status_t
dosfs_walk(fs_volume *_vol, fs_vnode *_dir, const char *file, ino_t *_vnid)
{
	/* Starting at the base, find file in the subdir, and return path
		string and vnode id of file. */
	nspace	*vol = (nspace *)_vol->private_volume;
	vnode	*dir = (vnode *)_dir->private_node;
	vnode	*vnode = NULL;
	status_t result = ENOENT;

	RecursiveLocker lock(vol->vlock);

	DPRINTF(0, ("dosfs_walk: find %" B_PRIdINO "/%s\n", dir->vnid, file));

	result = findfile_case(vol, dir, file, _vnid, &vnode);
	if (result != B_OK) {
		DPRINTF(0, ("dosfs_walk (%s)\n", strerror(result)));
	} else {
		DPRINTF(0, ("dosfs_walk: found vnid %" B_PRIdINO "\n", *_vnid));
	}

	return result;
}


status_t
dosfs_access(fs_volume *_vol, fs_vnode *_node, int mode)
{
	status_t result = B_OK;
	nspace *vol = (nspace *)_vol->private_volume;
	vnode *node = (vnode *)_node->private_node;

	RecursiveLocker lock(vol->vlock);

	DPRINTF(0, ("dosfs_access (vnode id %" B_PRIdINO ", mode %o)\n", node->vnid,
		mode));

	if (mode & W_OK) {
		if (vol->flags & B_FS_IS_READONLY) {
			DPRINTF(0, ("dosfs_access: can't write on read-only volume\n"));
			result = EROFS;
		} else if (node->mode & FAT_READ_ONLY) {
			DPRINTF(0, ("can't open read-only file for writing\n"));
			result = EPERM;
		} else if (node->disk_image != 0) {
			DPRINTF(0, ("can't open disk image file for writing\n"));
			result = EPERM;
		}
	}

	return result;
}


status_t
dosfs_opendir(fs_volume *_vol, fs_vnode *_node, void **_cookie)
{
	nspace *vol = (nspace *)_vol->private_volume;
	vnode *node = (vnode *)_node->private_node;

	RecursiveLocker lock(vol->vlock);

	DPRINTF(0, ("dosfs_opendir (vnode id %" B_PRIdINO ")\n", node->vnid));

	*_cookie = NULL;

	if (!(node->mode & FAT_SUBDIR)) {
		/* bash will try to opendir files unless OPENDIR_NOT_ROBUST is
		 * defined, so we'll suppress this message; it's more of a problem
		 * with the application than with the file system, anyway
		 */
		DPRINTF(0, ("dosfs_opendir error: vnode not a directory\n"));
		return ENOTDIR;
	}

	dircookie *cookie = (dircookie *)malloc(sizeof(dircookie));
	if (cookie == NULL) {
		DPRINTF(0, ("dosfs_opendir: out of memory error\n"));
		return ENOMEM;
	}

	cookie->current_index = 0;
	*_cookie = (void *)cookie;
	return B_OK;
}


status_t
dosfs_readdir(fs_volume *_vol, fs_vnode *_dir, void *_cookie,
	struct dirent *entry, size_t bufsize, uint32 *num)
{
	int 		result = ENOENT;
	nspace* 	vol = (nspace *)_vol->private_volume;
	vnode		*dir = (vnode *)_dir->private_node;
	dircookie* 	cookie = (dircookie *)_cookie;
	struct		diri diri;

	RecursiveLocker lock(vol->vlock);

	DPRINTF(0, ("dosfs_readdir: vnode id %" B_PRIdINO ", index %" B_PRIu32 "\n",
		dir->vnid, cookie->current_index));

	// simulate '.' and '..' entries for root directory
	if (dir->vnid == vol->root_vnode.vnid) {
		if (cookie->current_index >= 2) {
			cookie->current_index -= 2;
		} else {
			if (cookie->current_index++ == 0) {
				strcpy(entry->d_name, ".");
				entry->d_reclen = offsetof(struct dirent, d_name) + 2;
			} else {
				strcpy(entry->d_name, "..");
				entry->d_reclen = offsetof(struct dirent, d_name) + 3;
			}
			*num = 1;
			entry->d_ino = vol->root_vnode.vnid;
			entry->d_dev = vol->id;
			return B_NO_ERROR;
		}
	}

	if (diri_init(vol, dir->cluster, cookie->current_index, &diri) == NULL) {
		DPRINTF(0, ("dosfs_readdir: no more entries!\n"));
		// When you get to the end, don't return an error, just return 0
		// in *num.
		*num = 0;
		return B_NO_ERROR;
	}

	result = get_next_dirent(vol, dir, &diri, &entry->d_ino, entry->d_name,
		bufsize - offsetof(struct dirent, d_name) - 1);

	cookie->current_index = diri.current_index;

	if (dir->vnid == vol->root_vnode.vnid)
		cookie->current_index += 2;

	if (result == B_NO_ERROR) {
		*num = 1;
		entry->d_dev = vol->id;
		entry->d_reclen = offsetof(struct dirent, d_name) + strlen(entry->d_name) + 1;
		DPRINTF(0, ("dosfs_readdir: found file %s\n", entry->d_name));
	} else if (result == ENOENT) {
		// When you get to the end, don't return an error, just return 0
		// in *num.
		*num = 0;
		return B_OK;
	} else {
		dprintf("dosfs_readdir: error returned by get_next_dirent (%s)\n",
			strerror(result));
	}

	return B_OK;
}


status_t
dosfs_rewinddir(fs_volume *_vol, fs_vnode *_node, void* _cookie)
{
	nspace		*vol = (nspace *)_vol->private_volume;
	vnode		*node = (vnode *)_node->private_node;
	dircookie	*cookie = (dircookie *)_cookie;

	RecursiveLocker lock(vol->vlock);

	DPRINTF(0, ("dosfs_rewinddir (vnode id %" B_PRIdINO ")\n", node->vnid));

	cookie->current_index = 0;

	return B_OK;
}


status_t
dosfs_closedir(fs_volume *_vol, fs_vnode *_node, void *_cookie)
{
	DPRINTF(0, ("dosfs_closedir called\n"));

	return B_OK;
}


status_t
dosfs_free_dircookie(fs_volume *_vol, fs_vnode *_node, void *_cookie)
{
	nspace *vol = (nspace *)_vol->private_volume;
	vnode *node = (vnode *)_node->private_node;
	dircookie *cookie = (dircookie *)_cookie;

	RecursiveLocker lock(vol->vlock);

	DPRINTF(0, ("dosfs_free_dircookie (vnode id %" B_PRIdINO ")\n",
		node->vnid));

	free(cookie);

	return 0;
}