dir.c

linux 内核源代码

	DDPRINTK("ncp_readdir: reading %s/%s, pos=%d\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		(int) filp->f_pos);

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

	result = 0;
	if (filp->f_pos == 0) {
		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR))
			goto out;
		filp->f_pos = 1;
	}
	if (filp->f_pos == 1) {
		if (filldir(dirent, "..", 2, 1, parent_ino(dentry), DT_DIR))
			goto out;
		filp->f_pos = 2;
	}

	page = grab_cache_page(&inode->i_data, 0);
	if (!page)
		goto read_really;

	ctl.cache = cache = kmap(page);
	ctl.head  = cache->head;

	if (!PageUptodate(page) || !ctl.head.eof)
		goto init_cache;

	if (filp->f_pos == 2) {
		if (jiffies - ctl.head.time >= NCP_MAX_AGE(server))
			goto init_cache;

		mtime = ncp_obtain_mtime(dentry);
		mtime_valid = 1;
		if ((!mtime) || (mtime != ctl.head.mtime))
			goto init_cache;
	}

	if (filp->f_pos > ctl.head.end)
		goto finished;

	ctl.fpos = filp->f_pos + (NCP_DIRCACHE_START - 2);
	ctl.ofs  = ctl.fpos / NCP_DIRCACHE_SIZE;
	ctl.idx  = ctl.fpos % NCP_DIRCACHE_SIZE;

	for (;;) {
		if (ctl.ofs != 0) {
			ctl.page = find_lock_page(&inode->i_data, ctl.ofs);
			if (!ctl.page)
				goto invalid_cache;
			ctl.cache = kmap(ctl.page);
			if (!PageUptodate(ctl.page))
				goto invalid_cache;
		}
		while (ctl.idx < NCP_DIRCACHE_SIZE) {
			struct dentry *dent;
			int res;

			dent = ncp_dget_fpos(ctl.cache->dentry[ctl.idx],
						dentry, filp->f_pos);
			if (!dent)
				goto invalid_cache;
			res = filldir(dirent, dent->d_name.name,
					dent->d_name.len, filp->f_pos,
					dent->d_inode->i_ino, DT_UNKNOWN);
			dput(dent);
			if (res)
				goto finished;
			filp->f_pos += 1;
			ctl.idx += 1;
			if (filp->f_pos > ctl.head.end)
				goto finished;
		}
		if (ctl.page) {
			kunmap(ctl.page);
			SetPageUptodate(ctl.page);
			unlock_page(ctl.page);
			page_cache_release(ctl.page);
			ctl.page = NULL;
		}
		ctl.idx  = 0;
		ctl.ofs += 1;
	}
invalid_cache:
	if (ctl.page) {
		kunmap(ctl.page);
		unlock_page(ctl.page);
		page_cache_release(ctl.page);
		ctl.page = NULL;
	}
	ctl.cache = cache;
init_cache:
	ncp_invalidate_dircache_entries(dentry);
	if (!mtime_valid) {
		mtime = ncp_obtain_mtime(dentry);
		mtime_valid = 1;
	}
	ctl.head.mtime = mtime;
	ctl.head.time = jiffies;
	ctl.head.eof = 0;
	ctl.fpos = 2;
	ctl.ofs = 0;
	ctl.idx = NCP_DIRCACHE_START;
	ctl.filled = 0;
	ctl.valid  = 1;
read_really:
	if (ncp_is_server_root(inode)) {
		ncp_read_volume_list(filp, dirent, filldir, &ctl);
	} else {
		ncp_do_readdir(filp, dirent, filldir, &ctl);
	}
	ctl.head.end = ctl.fpos - 1;
	ctl.head.eof = ctl.valid;
finished:
	if (page) {
		cache->head = ctl.head;
		kunmap(page);
		SetPageUptodate(page);
		unlock_page(page);
		page_cache_release(page);
	}
	if (ctl.page) {
		kunmap(ctl.page);
		SetPageUptodate(ctl.page);
		unlock_page(ctl.page);
		page_cache_release(ctl.page);
	}
out:
	unlock_kernel();
	return result;
}

static int
ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
		struct ncp_cache_control *ctrl, struct ncp_entry_info *entry)
{
	struct dentry *newdent, *dentry = filp->f_path.dentry;
	struct inode *newino, *inode = dentry->d_inode;
	struct ncp_cache_control ctl = *ctrl;
	struct qstr qname;
	int valid = 0;
	int hashed = 0;
	ino_t ino = 0;
	__u8 __name[NCP_MAXPATHLEN + 1];

	qname.len = sizeof(__name);
	if (ncp_vol2io(NCP_SERVER(inode), __name, &qname.len,
			entry->i.entryName, entry->i.nameLen,
			!ncp_preserve_entry_case(inode, entry->i.NSCreator)))
		return 1; /* I'm not sure */

	qname.name = __name;
	qname.hash = full_name_hash(qname.name, qname.len);

	if (dentry->d_op && dentry->d_op->d_hash)
		if (dentry->d_op->d_hash(dentry, &qname) != 0)
			goto end_advance;

	newdent = d_lookup(dentry, &qname);

	if (!newdent) {
		newdent = d_alloc(dentry, &qname);
		if (!newdent)
			goto end_advance;
	} else {
		hashed = 1;
		memcpy((char *) newdent->d_name.name, qname.name,
							newdent->d_name.len);
	}

	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);
			unlock_page(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_path.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;
		}
		entry.volume = entry.i.volNumber;
		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_path.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;
	void* buf;
	int more;
	size_t bufsize;

	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;
	}
	/* We MUST NOT use server->buffer_size handshaked with server if we are
	   using UDP, as for UDP server uses max. buffer size determined by
	   MTU, and for TCP server uses hardwired value 65KB (== 66560 bytes). 
	   So we use 128KB, just to be sure, as there is no way how to know
	   this value in advance. */
	bufsize = 131072;
	buf = vmalloc(bufsize);
	if (!buf)
		return;
	do {
		int cnt;
		char* rpl;
		size_t rpls;

		err = ncp_search_for_fileset(server, &seq, &more, &cnt, buf, bufsize, &rpl, &rpls);
		if (err)		/* Error */
			break;
		if (!cnt)		/* prevent endless loop */
			break;
		while (cnt--) {
			size_t onerpl;
			
			if (rpls < offsetof(struct nw_info_struct, entryName))
				break;	/* short packet */
			ncp_extract_file_info(rpl, &entry.i);
			onerpl = offsetof(struct nw_info_struct, entryName) + entry.i.nameLen;
			if (rpls < onerpl)
				break;	/* short packet */
			(void)ncp_obtain_nfs_info(server, &entry.i);
			rpl += onerpl;
			rpls -= onerpl;
			entry.volume = entry.i.volNumber;
			if (!ncp_fill_cache(filp, dirent, filldir, ctl, &entry))
				break;
		}
	} while (more);
	vfree(buf);
	return;
}

int ncp_conn_logged_in(struct super_block *sb)
{
	struct ncp_server* server = NCP_SBP(sb);
	int result;

	if (ncp_single_volume(server)) {
		int len;
		struct dentry* dent;
		__u32 volNumber;
		__le32 dirEntNum;
		__le32 DosDirNum;
		__u8 __name[NCP_MAXPATHLEN + 1];

		len = sizeof(__name);
		result = ncp_io2vol(server, __name, &len, server->m.mounted_vol,
				    strlen(server->m.mounted_vol), 1);
		if (result)
			goto out;
		result = -ENOENT;
		if (ncp_get_volume_root(server, __name, &volNumber, &dirEntNum, &DosDirNum)) {
			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 = volNumber;
				NCP_FINFO(ino)->dirEntNum = dirEntNum;
				NCP_FINFO(ino)->DosDirNum = 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 nameidata *nd)
{
	struct ncp_server *server = NCP_SERVER(dir);
	struct inode *inode = NULL;
	struct ncp_entry_info finfo;
	int error, res, len;
	__u8 __name[NCP_MAXPATHLEN + 1];

	lock_kernel();
	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);

	len = sizeof(__name);
	if (ncp_is_server_root(dir)) {
		res = ncp_io2vol(server, __name, &len, dentry->d_name.name,
				 dentry->d_name.len, 1);
		if (!res)
			res = ncp_lookup_volume(server, __name, &(finfo.i));
	} else {
		res = ncp_io2vol(server, __name, &len, dentry->d_name.name,
				 dentry->d_name.len, !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);