dir.c

linux 内核源代码

/*
 *  dir.c
 *
 *  Copyright (C) 1995, 1996 by Volker Lendecke
 *  Modified for big endian by J.F. Chadima and David S. Miller
 *  Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
 *  Modified 1998, 1999 Wolfram Pienkoss for NLS
 *  Modified 1999 Wolfram Pienkoss for directory caching
 *  Modified 2000 Ben Harris, University of Cambridge for NFS NS meta-info
 *
 */


#include <linux/time.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <asm/uaccess.h>
#include <asm/byteorder.h>
#include <linux/smp_lock.h>

#include <linux/ncp_fs.h>

#include "ncplib_kernel.h"

static void ncp_read_volume_list(struct file *, void *, filldir_t,
				struct ncp_cache_control *);
static void ncp_do_readdir(struct file *, void *, filldir_t,
				struct ncp_cache_control *);

static int ncp_readdir(struct file *, void *, filldir_t);

static int ncp_create(struct inode *, struct dentry *, int, struct nameidata *);
static struct dentry *ncp_lookup(struct inode *, struct dentry *, struct nameidata *);
static int ncp_unlink(struct inode *, struct dentry *);
static int ncp_mkdir(struct inode *, struct dentry *, int);
static int ncp_rmdir(struct inode *, struct dentry *);
static int ncp_rename(struct inode *, struct dentry *,
	  	      struct inode *, struct dentry *);
static int ncp_mknod(struct inode * dir, struct dentry *dentry,
		     int mode, dev_t rdev);
#if defined(CONFIG_NCPFS_EXTRAS) || defined(CONFIG_NCPFS_NFS_NS)
extern int ncp_symlink(struct inode *, struct dentry *, const char *);
#else
#define ncp_symlink NULL
#endif
		      
const struct file_operations ncp_dir_operations =
{
	.read		= generic_read_dir,
	.readdir	= ncp_readdir,
	.ioctl		= ncp_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= ncp_compat_ioctl,
#endif
};

const struct inode_operations ncp_dir_inode_operations =
{
	.create		= ncp_create,
	.lookup		= ncp_lookup,
	.unlink		= ncp_unlink,
	.symlink	= ncp_symlink,
	.mkdir		= ncp_mkdir,
	.rmdir		= ncp_rmdir,
	.mknod		= ncp_mknod,
	.rename		= ncp_rename,
	.setattr	= ncp_notify_change,
};

/*
 * Dentry operations routines
 */
static int ncp_lookup_validate(struct dentry *, struct nameidata *);
static int ncp_hash_dentry(struct dentry *, struct qstr *);
static int ncp_compare_dentry (struct dentry *, struct qstr *, struct qstr *);
static int ncp_delete_dentry(struct dentry *);

static struct dentry_operations ncp_dentry_operations =
{
	.d_revalidate	= ncp_lookup_validate,
	.d_hash		= ncp_hash_dentry,
	.d_compare	= ncp_compare_dentry,
	.d_delete	= ncp_delete_dentry,
};

struct dentry_operations ncp_root_dentry_operations =
{
	.d_hash		= ncp_hash_dentry,
	.d_compare	= ncp_compare_dentry,
	.d_delete	= ncp_delete_dentry,
};


/*
 * Note: leave the hash unchanged if the directory
 * is case-sensitive.
 */
static int 
ncp_hash_dentry(struct dentry *dentry, struct qstr *this)
{
	struct nls_table *t;
	unsigned long hash;
	int i;

	t = NCP_IO_TABLE(dentry);

	if (!ncp_case_sensitive(dentry->d_inode)) {
		hash = init_name_hash();
		for (i=0; i<this->len ; i++)
			hash = partial_name_hash(ncp_tolower(t, this->name[i]),
									hash);
		this->hash = end_name_hash(hash);
	}
	return 0;
}

static int
ncp_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
{
	if (a->len != b->len)
		return 1;

	if (ncp_case_sensitive(dentry->d_inode))
		return strncmp(a->name, b->name, a->len);

	return ncp_strnicmp(NCP_IO_TABLE(dentry), a->name, b->name, a->len);
}

/*
 * This is the callback from dput() when d_count is going to 0.
 * We use this to unhash dentries with bad inodes.
 * Closing files can be safely postponed until iput() - it's done there anyway.
 */
static int
ncp_delete_dentry(struct dentry * dentry)
{
	struct inode *inode = dentry->d_inode;

	if (inode) {
		if (is_bad_inode(inode))
			return 1;
	} else
	{
	/* N.B. Unhash negative dentries? */
	}
	return 0;
}

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

static inline int ncp_is_server_root(struct inode *inode)
{
	return (!ncp_single_volume(NCP_SERVER(inode)) &&
		inode == inode->i_sb->s_root->d_inode);
}


/*
 * This is the callback when the dcache has a lookup hit.
 */


#ifdef CONFIG_NCPFS_STRONG
/* try to delete a readonly file (NW R bit set) */

static int
ncp_force_unlink(struct inode *dir, struct dentry* dentry)
{
        int res=0x9c,res2;
	struct nw_modify_dos_info info;
	__le32 old_nwattr;
	struct inode *inode;

	memset(&info, 0, sizeof(info));
	
        /* remove the Read-Only flag on the NW server */
	inode = dentry->d_inode;

	old_nwattr = NCP_FINFO(inode)->nwattr;
	info.attributes = old_nwattr & ~(aRONLY|aDELETEINHIBIT|aRENAMEINHIBIT);
	res2 = ncp_modify_file_or_subdir_dos_info_path(NCP_SERVER(inode), inode, NULL, DM_ATTRIBUTES, &info);
	if (res2)
		goto leave_me;

        /* now try again the delete operation */
        res = ncp_del_file_or_subdir2(NCP_SERVER(dir), dentry);

        if (res)  /* delete failed, set R bit again */
        {
		info.attributes = old_nwattr;
		res2 = ncp_modify_file_or_subdir_dos_info_path(NCP_SERVER(inode), inode, NULL, DM_ATTRIBUTES, &info);
		if (res2)
                        goto leave_me;
        }
leave_me:
        return(res);
}
#endif	/* CONFIG_NCPFS_STRONG */

#ifdef CONFIG_NCPFS_STRONG
static int
ncp_force_rename(struct inode *old_dir, struct dentry* old_dentry, char *_old_name,
                 struct inode *new_dir, struct dentry* new_dentry, char *_new_name)
{
	struct nw_modify_dos_info info;
        int res=0x90,res2;
	struct inode *old_inode = old_dentry->d_inode;
	__le32 old_nwattr = NCP_FINFO(old_inode)->nwattr;
	__le32 new_nwattr = 0; /* shut compiler warning */
	int old_nwattr_changed = 0;
	int new_nwattr_changed = 0;

	memset(&info, 0, sizeof(info));
	
        /* remove the Read-Only flag on the NW server */

	info.attributes = old_nwattr & ~(aRONLY|aRENAMEINHIBIT|aDELETEINHIBIT);
	res2 = ncp_modify_file_or_subdir_dos_info_path(NCP_SERVER(old_inode), old_inode, NULL, DM_ATTRIBUTES, &info);
	if (!res2)
		old_nwattr_changed = 1;
	if (new_dentry && new_dentry->d_inode) {
		new_nwattr = NCP_FINFO(new_dentry->d_inode)->nwattr;
		info.attributes = new_nwattr & ~(aRONLY|aRENAMEINHIBIT|aDELETEINHIBIT);
		res2 = ncp_modify_file_or_subdir_dos_info_path(NCP_SERVER(new_dir), new_dir, _new_name, DM_ATTRIBUTES, &info);
		if (!res2)
			new_nwattr_changed = 1;
	}
        /* now try again the rename operation */
	/* but only if something really happened */
	if (new_nwattr_changed || old_nwattr_changed) {
	        res = ncp_ren_or_mov_file_or_subdir(NCP_SERVER(old_dir),
        	                                    old_dir, _old_name,
                	                            new_dir, _new_name);
	} 
	if (res)
		goto leave_me;
	/* file was successfully renamed, so:
	   do not set attributes on old file - it no longer exists
	   copy attributes from old file to new */
	new_nwattr_changed = old_nwattr_changed;
	new_nwattr = old_nwattr;
	old_nwattr_changed = 0;
	
leave_me:;
	if (old_nwattr_changed) {
		info.attributes = old_nwattr;
		res2 = ncp_modify_file_or_subdir_dos_info_path(NCP_SERVER(old_inode), old_inode, NULL, DM_ATTRIBUTES, &info);
		/* ignore errors */
	}
	if (new_nwattr_changed)	{
		info.attributes = new_nwattr;
		res2 = ncp_modify_file_or_subdir_dos_info_path(NCP_SERVER(new_dir), new_dir, _new_name, DM_ATTRIBUTES, &info);
		/* ignore errors */
	}
        return(res);
}
#endif	/* CONFIG_NCPFS_STRONG */


static int
__ncp_lookup_validate(struct dentry * dentry, struct nameidata *nd)
{
	struct ncp_server *server;
	struct dentry *parent;
	struct inode *dir;
	struct ncp_entry_info finfo;
	int res, val = 0, len;
	__u8 __name[NCP_MAXPATHLEN + 1];

	parent = dget_parent(dentry);
	dir = parent->d_inode;

	if (!dentry->d_inode)
		goto finished;

	server = NCP_SERVER(dir);

	if (!ncp_conn_valid(server))
		goto finished;

	/*
	 * Inspired by smbfs:
	 * The default validation is based on dentry age:
	 * We set the max age at mount time.  (But each
	 * successful server lookup renews the timestamp.)
	 */
	val = NCP_TEST_AGE(server, dentry);
	if (val)
		goto finished;

	DDPRINTK("ncp_lookup_validate: %s/%s not valid, age=%ld, server lookup\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		NCP_GET_AGE(dentry));

	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));
	}
	finfo.volume = finfo.i.volNumber;
	DDPRINTK("ncp_lookup_validate: looked for %s/%s, res=%d\n",
		dentry->d_parent->d_name.name, __name, res);
	/*
	 * If we didn't find it, or if it has a different dirEntNum to
	 * what we remember, it's not valid any more.
	 */
	if (!res) {
		if (finfo.i.dirEntNum == NCP_FINFO(dentry->d_inode)->dirEntNum) {
			ncp_new_dentry(dentry);
			val=1;
		} else
			DDPRINTK("ncp_lookup_validate: found, but dirEntNum changed\n");

		ncp_update_inode2(dentry->d_inode, &finfo);
	}

finished:
	DDPRINTK("ncp_lookup_validate: result=%d\n", val);
	dput(parent);
	return val;
}

static int
ncp_lookup_validate(struct dentry * dentry, struct nameidata *nd)
{
	int res;
	lock_kernel();
	res = __ncp_lookup_validate(dentry, nd);
	unlock_kernel();
	return res;
}

static struct dentry *
ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
{
	struct dentry *dent = dentry;
	struct list_head *next;

	if (d_validate(dent, parent)) {
		if (dent->d_name.len <= NCP_MAXPATHLEN &&
		    (unsigned long)dent->d_fsdata == fpos) {
			if (!dent->d_inode) {
				dput(dent);
				dent = NULL;
			}
			return dent;
		}
		dput(dent);
	}

	/* If a pointer is invalid, we search the dentry. */
	spin_lock(&dcache_lock);
	next = parent->d_subdirs.next;
	while (next != &parent->d_subdirs) {
		dent = list_entry(next, struct dentry, d_u.d_child);
		if ((unsigned long)dent->d_fsdata == fpos) {
			if (dent->d_inode)
				dget_locked(dent);
			else
				dent = NULL;
			spin_unlock(&dcache_lock);
			goto out;
		}
		next = next->next;
	}
	spin_unlock(&dcache_lock);
	return NULL;

out:
	return dent;
}

static time_t ncp_obtain_mtime(struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	struct ncp_server *server = NCP_SERVER(inode);
	struct nw_info_struct i;

	if (!ncp_conn_valid(server) || ncp_is_server_root(inode))
		return 0;

	if (ncp_obtain_info(server, inode, NULL, &i))
		return 0;

	return ncp_date_dos2unix(i.modifyTime, i.modifyDate);
}

static int ncp_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct dentry *dentry = filp->f_path.dentry;
	struct inode *inode = dentry->d_inode;
	struct page *page = NULL;
	struct ncp_server *server = NCP_SERVER(inode);
	union  ncp_dir_cache *cache = NULL;
	struct ncp_cache_control ctl;
	int result, mtime_valid = 0;
	time_t mtime = 0;

	lock_kernel();

	ctl.page  = NULL;
	ctl.cache = NULL;