dir.c

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

	if (!newdent->d_inode) {
		entry->opened = 0;
		entry->ino = iunique(inode->i_sb, 2);
		newino = ncp_iget(inode->i_sb, entry);
		if (newino) {
			newdent->d_op = &ncp_dentry_operations;
			d_instantiate(newdent, newino);
			if (!hashed)
				d_rehash(newdent);
		}
	} else
		ncp_update_inode2(newdent->d_inode, entry);

	if (newdent->d_inode) {
		ino = newdent->d_inode->i_ino;
		newdent->d_fsdata = (void *) ctl.fpos;
		ncp_new_dentry(newdent);
	}

	if (ctl.idx >= NCP_DIRCACHE_SIZE) {
		if (ctl.page) {
			kunmap(ctl.page);
			SetPageUptodate(ctl.page);
			UnlockPage(ctl.page);
			page_cache_release(ctl.page);
		}
		ctl.cache = NULL;
		ctl.idx  -= NCP_DIRCACHE_SIZE;
		ctl.ofs  += 1;
		ctl.page  = grab_cache_page(&inode->i_data, ctl.ofs);
		if (ctl.page)
			ctl.cache = kmap(ctl.page);
	}
	if (ctl.cache) {
		ctl.cache->dentry[ctl.idx] = newdent;
		valid = 1;
	}
	dput(newdent);
end_advance:
	if (!valid)
		ctl.valid = 0;
	if (!ctl.filled && (ctl.fpos == filp->f_pos)) {
		if (!ino)
			ino = find_inode_number(dentry, &qname);
		if (!ino)
			ino = iunique(inode->i_sb, 2);
		ctl.filled = filldir(dirent, qname.name, qname.len,
				     filp->f_pos, ino, DT_UNKNOWN);
		if (!ctl.filled)
			filp->f_pos += 1;
	}
	ctl.fpos += 1;
	ctl.idx  += 1;
	*ctrl = ctl;
	return (ctl.valid || !ctl.filled);
}

static void
ncp_read_volume_list(struct file *filp, void *dirent, filldir_t filldir,
			struct ncp_cache_control *ctl)
{
	struct dentry *dentry = filp->f_dentry;
	struct inode *inode = dentry->d_inode;
	struct ncp_server *server = NCP_SERVER(inode);
	struct ncp_volume_info info;
	struct ncp_entry_info entry;
	int i;

	DPRINTK("ncp_read_volume_list: pos=%ld\n",
			(unsigned long) filp->f_pos);

	for (i = 0; i < NCP_NUMBER_OF_VOLUMES; i++) {

		if (ncp_get_volume_info_with_number(server, i, &info) != 0)
			return;
		if (!strlen(info.volume_name))
			continue;

		DPRINTK("ncp_read_volume_list: found vol: %s\n",
			info.volume_name);

		if (ncp_lookup_volume(server, info.volume_name,
					&entry.i)) {
			DPRINTK("ncpfs: could not lookup vol %s\n",
				info.volume_name);
			continue;
		}
		if (!ncp_fill_cache(filp, dirent, filldir, ctl, &entry))
			return;
	}
}

static void
ncp_do_readdir(struct file *filp, void *dirent, filldir_t filldir,
						struct ncp_cache_control *ctl)
{
	struct dentry *dentry = filp->f_dentry;
	struct inode *dir = dentry->d_inode;
	struct ncp_server *server = NCP_SERVER(dir);
	struct nw_search_sequence seq;
	struct ncp_entry_info entry;
	int err;

	DPRINTK("ncp_do_readdir: %s/%s, fpos=%ld\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		(unsigned long) filp->f_pos);
	PPRINTK("ncp_do_readdir: init %s, volnum=%d, dirent=%u\n",
		dentry->d_name.name, NCP_FINFO(dir)->volNumber,
		NCP_FINFO(dir)->dirEntNum);

	err = ncp_initialize_search(server, dir, &seq);
	if (err) {
		DPRINTK("ncp_do_readdir: init failed, err=%d\n", err);
		return;
	}
	for (;;) {
		err = ncp_search_for_file_or_subdir(server, &seq, &entry.i);
		if (err) {
			DPRINTK("ncp_do_readdir: search failed, err=%d\n", err);
			return;
		}
		if (!ncp_fill_cache(filp, dirent, filldir, ctl, &entry))
			return;
	}
}

int ncp_conn_logged_in(struct super_block *sb)
{
	struct ncp_server* server = NCP_SBP(sb);
	struct nw_info_struct i;
	int result, len = strlen(server->m.mounted_vol) + 1;
	__u8 __name[len];

	if (ncp_single_volume(server)) {
		struct dentry* dent;

		result = -ENOENT;
		if (ncp_io2vol(server, __name, &len, server->m.mounted_vol,
								len-1, 1))
			goto out;
		if (ncp_lookup_volume(server, __name, &i)) {
			PPRINTK("ncp_conn_logged_in: %s not found\n",
				server->m.mounted_vol);
			goto out;
		}
		dent = sb->s_root;
		if (dent) {
			struct inode* ino = dent->d_inode;
			if (ino) {
				NCP_FINFO(ino)->volNumber = i.volNumber;
				NCP_FINFO(ino)->dirEntNum = i.dirEntNum;
				NCP_FINFO(ino)->DosDirNum = i.DosDirNum;
			} else {
				DPRINTK("ncpfs: sb->s_root->d_inode == NULL!\n");
			}
		} else {
			DPRINTK("ncpfs: sb->s_root == NULL!\n");
		}
	}
	result = 0;

out:
	return result;
}

static struct dentry *ncp_lookup(struct inode *dir, struct dentry *dentry)
{
	struct ncp_server *server = NCP_SERVER(dir);
	struct inode *inode = NULL;
	struct ncp_entry_info finfo;
	int error, res, len = dentry->d_name.len + 1;
	__u8 __name[len];

	error = -EIO;
	if (!ncp_conn_valid(server))
		goto finished;

	PPRINTK("ncp_lookup: server lookup for %s/%s\n",
		dentry->d_parent->d_name.name, dentry->d_name.name);

	if (ncp_is_server_root(dir)) {
		res = ncp_io2vol(server, __name, &len, dentry->d_name.name,
						len-1, 1);
		if (!res)
			res = ncp_lookup_volume(server, __name, &(finfo.i));
	} else {
		res = ncp_io2vol(server, __name, &len, dentry->d_name.name,
						len-1, !ncp_preserve_case(dir));
		if (!res)
			res = ncp_obtain_info(server, dir, __name, &(finfo.i));
	}
	PPRINTK("ncp_lookup: looked for %s/%s, res=%d\n",
		dentry->d_parent->d_name.name, __name, res);
	/*
	 * If we didn't find an entry, make a negative dentry.
	 */
	if (res)
		goto add_entry;

	/*
	 * Create an inode for the entry.
	 */
	finfo.opened = 0;
	finfo.ino = iunique(dir->i_sb, 2);
	error = -EACCES;
	inode = ncp_iget(dir->i_sb, &finfo);

	if (inode) {
		ncp_new_dentry(dentry);
add_entry:
		dentry->d_op = &ncp_dentry_operations;
		d_add(dentry, inode);
		error = 0;
	}

finished:
	PPRINTK("ncp_lookup: result=%d\n", error);
	return ERR_PTR(error);
}

/*
 * This code is common to create, mkdir, and mknod.
 */
static int ncp_instantiate(struct inode *dir, struct dentry *dentry,
			struct ncp_entry_info *finfo)
{
	struct inode *inode;
	int error = -EINVAL;

	finfo->ino = iunique(dir->i_sb, 2);
	inode = ncp_iget(dir->i_sb, finfo);
	if (!inode)
		goto out_close;
	d_instantiate(dentry,inode);
	error = 0;
out:
	return error;

out_close:
	PPRINTK("ncp_instantiate: %s/%s failed, closing file\n",
		dentry->d_parent->d_name.name, dentry->d_name.name);
	ncp_close_file(NCP_SERVER(dir), finfo->file_handle);
	goto out;
}

int ncp_create_new(struct inode *dir, struct dentry *dentry, int mode,
		int attributes)
{
	struct ncp_server *server = NCP_SERVER(dir);
	struct ncp_entry_info finfo;
	int error, result, len = dentry->d_name.len + 1;
	int opmode;
	__u8 __name[len];
	
	PPRINTK("ncp_create_new: creating %s/%s, mode=%x\n",
		dentry->d_parent->d_name.name, dentry->d_name.name, mode);
	error = -EIO;
	if (!ncp_conn_valid(server))
		goto out;

	ncp_age_dentry(server, dentry);
	error = ncp_io2vol(server, __name, &len, dentry->d_name.name,
						len-1, !ncp_preserve_case(dir));
	if (error)
		goto out;

	error = -EACCES;
	
	if (S_ISREG(mode) && 
	    (server->m.flags & NCP_MOUNT_EXTRAS) && 
	    (mode & S_IXUGO))
		attributes |= aSYSTEM;
	
	result = ncp_open_create_file_or_subdir(server, dir, __name,
				OC_MODE_CREATE | OC_MODE_OPEN | OC_MODE_REPLACE,
				attributes, AR_READ | AR_WRITE, &finfo);
	opmode = O_RDWR;
	if (result) {
		result = ncp_open_create_file_or_subdir(server, dir, __name,
				OC_MODE_CREATE | OC_MODE_OPEN | OC_MODE_REPLACE,
				attributes, AR_WRITE, &finfo);
		if (result) {
			if (result == 0x87)
				error = -ENAMETOOLONG;
			DPRINTK("ncp_create: %s/%s failed\n",
				dentry->d_parent->d_name.name, dentry->d_name.name);
			goto out;
		}
		opmode = O_WRONLY;
	}
	finfo.access = opmode;
	error = ncp_instantiate(dir, dentry, &finfo);
out:
	return error;
}

static int ncp_create(struct inode *dir, struct dentry *dentry, int mode)
{
	return ncp_create_new(dir, dentry, mode, 0);
}

static int ncp_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	struct ncp_entry_info finfo;
	struct ncp_server *server = NCP_SERVER(dir);
	int error, len = dentry->d_name.len + 1;
	__u8 __name[len];

	DPRINTK("ncp_mkdir: making %s/%s\n",
		dentry->d_parent->d_name.name, dentry->d_name.name);
	error = -EIO;
	if (!ncp_conn_valid(server))
		goto out;

	ncp_age_dentry(server, dentry);
	error = ncp_io2vol(server, __name, &len, dentry->d_name.name,
						len-1, !ncp_preserve_case(dir));
	if (error)
		goto out;

	error = -EACCES;
	if (ncp_open_create_file_or_subdir(server, dir, __name,
					   OC_MODE_CREATE, aDIR, 0xffff,
					   &finfo) == 0)
	{
		error = ncp_instantiate(dir, dentry, &finfo);
	}
out:
	return error;
}

static int ncp_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct ncp_server *server = NCP_SERVER(dir);
	int error, result, len = dentry->d_name.len + 1;
	__u8 __name[len];

	DPRINTK("ncp_rmdir: removing %s/%s\n",
		dentry->d_parent->d_name.name, dentry->d_name.name);

	error = -EIO;
	if (!ncp_conn_valid(server))
		goto out;

	error = -EBUSY;
	if (!d_unhashed(dentry))
		goto out;

	error = ncp_io2vol(server, __name, &len, dentry->d_name.name,
						len-1, !ncp_preserve_case(dir));
	if (error)
		goto out;

	result = ncp_del_file_or_subdir(server, dir, __name);
	switch (result) {
		case 0x00:
			error = 0;
			break;
		case 0x85:	/* unauthorized to delete file */
		case 0x8A:	/* unauthorized to delete file */
			error = -EACCES;
			break;
		case 0x8F:
		case 0x90:	/* read only */
			error = -EPERM;
			break;
		case 0x9F:	/* in use by another client */
			error = -EBUSY;
			break;
		case 0xA0:	/* directory not empty */
			error = -ENOTEMPTY;
			break;
		case 0xFF:	/* someone deleted file */
			error = -ENOENT;
			break;
		default:
			error = -EACCES;
			break;
       	}
out:
	return error;
}

static int ncp_unlink(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	struct ncp_server *server = NCP_SERVER(dir);
	int error;

	DPRINTK("ncp_unlink: unlinking %s/%s\n",
		dentry->d_parent->d_name.name, dentry->d_name.name);
	
	error = -EIO;
	if (!ncp_conn_valid(server))
		goto out;

	/*
	 * Check whether to close the file ...
	 */
	if (inode) {
		PPRINTK("ncp_unlink: closing file\n");
		ncp_make_closed(inode);
	}

	error = ncp_del_file_or_subdir2(server, dentry);
#ifdef CONFIG_NCPFS_STRONG
	/* 9C is Invalid path.. It should be 8F, 90 - read only, but
	   it is not :-( */
	if ((error == 0x9C || error == 0x90) && server->m.flags & NCP_MOUNT_STRONG) { /* R/O */
		error = ncp_force_unlink(dir, dentry);
	}
#endif
	switch (error) {
		case 0x00:
			DPRINTK("ncp: removed %s/%s\n",
				dentry->d_parent->d_name.name, dentry->d_name.name);
			break;
		case 0x85:
		case 0x8A:
			error = -EACCES;
			break;
		case 0x8D:	/* some files in use */
		case 0x8E:	/* all files in use */
			error = -EBUSY;
			break;
		case 0x8F:	/* some read only */
		case 0x90:	/* all read only */
		case 0x9C:	/* !!! returned when in-use or read-only by NW4 */
			error = -EPERM;
			break;
		case 0xFF:
			error = -ENOENT;
			break;
		default:
			error = -EACCES;
			break;
	}
		
out:
	return error;
}

static int ncp_rename(struct inode *old_dir, struct dentry *old_dentry,
		      struct inode *new_dir, struct dentry *new_dentry)
{
	struct ncp_server *server = NCP_SERVER(old_dir);
	int error;
	int old_len = old_dentry->d_name.len + 1;
	int new_len = new_dentry->d_name.len + 1;
	__u8 __old_name[old_len], __new_name[new_len];

	DPRINTK("ncp_rename: %s/%s to %s/%s\n",
		old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
		new_dentry->d_parent->d_name.name, new_dentry->d_name.name);

	error = -EIO;
	if (!ncp_conn_valid(server))
		goto out;

	ncp_age_dentry(server, old_dentry);
	ncp_age_dentry(server, new_dentry);

	error = ncp_io2vol(server, __old_name, &old_len,
					old_dentry->d_name.name, old_len-1,
					!ncp_preserve_case(old_dir));
	if (error)
		goto out;

	error = ncp_io2vol(server, __new_name, &new_len,
					new_dentry->d_name.name, new_len-1,
					!ncp_preserve_case(new_dir));
	if (error)
		goto out;

	error = ncp_ren_or_mov_file_or_subdir(server, old_dir, __old_name,
						      new_dir, __new_name);
#ifdef CONFIG_NCPFS_STRONG
	if ((error == 0x90 || error == 0x8B || error == -EACCES) &&
			server->m.flags & NCP_MOUNT_STRONG) {	/* RO */
		error = ncp_force_rename(old_dir, old_dentry, __old_name,
					 new_dir, new_dentry, __new_name);
	}
#endif
	switch (error) {
		case 0x00:
               	        DPRINTK("ncp renamed %s -> %s.\n",
                                old_dentry->d_name.name,new_dentry->d_name.name);
			break;
		case 0x9E:
			error = -ENAMETOOLONG;
			break;
		case 0xFF:
			error = -ENOENT;
			break;
		default:
			error = -EACCES;
			break;
	}
out:
	return error;
}

/* 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};
/* Jan Feb Mar Apr 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;
}

static int local2utc(int time)
{
	return time + sys_tz.tz_minuteswest * 60;
}

/* 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;

	/* first subtract and mask after that... Otherwise, if
	   date == 0, bad things happen */
	month = ((date >> 5) - 1) & 15;
	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);
}