[deliverable/linux.git] / fs / overlayfs / inode.c

/*
 *
 * Copyright (C) 2011 Novell Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/xattr.h>
#include "overlayfs.h"

static int ovl_copy_up_last(struct dentry *dentry, struct iattr *attr,
			    bool no_data)
{
	int err;
	struct dentry *parent;
	struct kstat stat;
	struct path lowerpath;

	parent = dget_parent(dentry);
	err = ovl_copy_up(parent);
	if (err)
		goto out_dput_parent;

	ovl_path_lower(dentry, &lowerpath);
	err = vfs_getattr(&lowerpath, &stat);
	if (err)
		goto out_dput_parent;

	if (no_data)
		stat.size = 0;

	err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat, attr);

out_dput_parent:
	dput(parent);
	return err;
}

int ovl_setattr(struct dentry *dentry, struct iattr *attr)
{
	int err;
	struct dentry *upperdentry;

	err = ovl_want_write(dentry);
	if (err)
		goto out;

	err = ovl_copy_up(dentry);
	if (!err) {
		upperdentry = ovl_dentry_upper(dentry);

		mutex_lock(&upperdentry->d_inode->i_mutex);
		err = notify_change(upperdentry, attr, NULL);
		mutex_unlock(&upperdentry->d_inode->i_mutex);
	}
	ovl_drop_write(dentry);
out:
	return err;
}

static int ovl_getattr(struct vfsmount *mnt, struct dentry *dentry,
			 struct kstat *stat)
{
	struct path realpath;

	ovl_path_real(dentry, &realpath);
	return vfs_getattr(&realpath, stat);
}

int ovl_permission(struct inode *inode, int mask)
{
	struct ovl_entry *oe;
	struct dentry *alias = NULL;
	struct inode *realinode;
	struct dentry *realdentry;
	bool is_upper;
	int err;

	if (S_ISDIR(inode->i_mode)) {
		oe = inode->i_private;
	} else if (mask & MAY_NOT_BLOCK) {
		return -ECHILD;
	} else {
		/*
		 * For non-directories find an alias and get the info
		 * from there.
		 */
		alias = d_find_any_alias(inode);
		if (WARN_ON(!alias))
			return -ENOENT;

		oe = alias->d_fsdata;
	}

	realdentry = ovl_entry_real(oe, &is_upper);

	/* Careful in RCU walk mode */
	realinode = ACCESS_ONCE(realdentry->d_inode);
	if (!realinode) {
		WARN_ON(!(mask & MAY_NOT_BLOCK));
		err = -ENOENT;
		goto out_dput;
	}

	if (mask & MAY_WRITE) {
		umode_t mode = realinode->i_mode;

		/*
		 * Writes will always be redirected to upper layer, so
		 * ignore lower layer being read-only.
		 *
		 * If the overlay itself is read-only then proceed
		 * with the permission check, don't return EROFS.
		 * This will only happen if this is the lower layer of
		 * another overlayfs.
		 *
		 * If upper fs becomes read-only after the overlay was
		 * constructed return EROFS to prevent modification of
		 * upper layer.
		 */
		err = -EROFS;
		if (is_upper && !IS_RDONLY(inode) && IS_RDONLY(realinode) &&
		    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
			goto out_dput;
	}

	err = __inode_permission(realinode, mask);
out_dput:
	dput(alias);
	return err;
}


struct ovl_link_data {
	struct dentry *realdentry;
	void *cookie;
};

static const char *ovl_follow_link(struct dentry *dentry, void **cookie)
{
	struct dentry *realdentry;
	struct inode *realinode;
	struct ovl_link_data *data = NULL;
	const char *ret;

	realdentry = ovl_dentry_real(dentry);
	realinode = realdentry->d_inode;

	if (WARN_ON(!realinode->i_op->follow_link))
		return ERR_PTR(-EPERM);

	if (realinode->i_op->put_link) {
		data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL);
		if (!data)
			return ERR_PTR(-ENOMEM);
		data->realdentry = realdentry;
	}

	ret = realinode->i_op->follow_link(realdentry, cookie);
	if (IS_ERR_OR_NULL(ret)) {
		kfree(data);
		return ret;
	}

	if (data)
		data->cookie = *cookie;

	*cookie = data;

	return ret;
}

static void ovl_put_link(struct inode *unused, void *c)
{
	struct inode *realinode;
	struct ovl_link_data *data = c;

	if (!data)
		return;

	realinode = data->realdentry->d_inode;
	realinode->i_op->put_link(realinode, data->cookie);
	kfree(data);
}

static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
{
	struct path realpath;
	struct inode *realinode;

	ovl_path_real(dentry, &realpath);
	realinode = realpath.dentry->d_inode;

	if (!realinode->i_op->readlink)
		return -EINVAL;

	touch_atime(&realpath);

	return realinode->i_op->readlink(realpath.dentry, buf, bufsiz);
}


static bool ovl_is_private_xattr(const char *name)
{
	return strncmp(name, OVL_XATTR_PRE_NAME, OVL_XATTR_PRE_LEN) == 0;
}

int ovl_setxattr(struct dentry *dentry, const char *name,
		 const void *value, size_t size, int flags)
{
	int err;
	struct dentry *upperdentry;

	err = ovl_want_write(dentry);
	if (err)
		goto out;

	err = -EPERM;
	if (ovl_is_private_xattr(name))
		goto out_drop_write;

	err = ovl_copy_up(dentry);
	if (err)
		goto out_drop_write;

	upperdentry = ovl_dentry_upper(dentry);
	err = vfs_setxattr(upperdentry, name, value, size, flags);

out_drop_write:
	ovl_drop_write(dentry);
out:
	return err;
}

static bool ovl_need_xattr_filter(struct dentry *dentry,
				  enum ovl_path_type type)
{
	if ((type & (__OVL_PATH_PURE | __OVL_PATH_UPPER)) == __OVL_PATH_UPPER)
		return S_ISDIR(dentry->d_inode->i_mode);
	else
		return false;
}

ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
		     void *value, size_t size)
{
	struct path realpath;
	enum ovl_path_type type = ovl_path_real(dentry, &realpath);

	if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
		return -ENODATA;

	return vfs_getxattr(realpath.dentry, name, value, size);
}

ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
{
	struct path realpath;
	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
	ssize_t res;
	int off;

	res = vfs_listxattr(realpath.dentry, list, size);
	if (res <= 0 || size == 0)
		return res;

	if (!ovl_need_xattr_filter(dentry, type))
		return res;

	/* filter out private xattrs */
	for (off = 0; off < res;) {
		char *s = list + off;
		size_t slen = strlen(s) + 1;

		BUG_ON(off + slen > res);

		if (ovl_is_private_xattr(s)) {
			res -= slen;
			memmove(s, s + slen, res - off);
		} else {
			off += slen;
		}
	}

	return res;
}

int ovl_removexattr(struct dentry *dentry, const char *name)
{
	int err;
	struct path realpath;
	enum ovl_path_type type = ovl_path_real(dentry, &realpath);

	err = ovl_want_write(dentry);
	if (err)
		goto out;

	err = -ENODATA;
	if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
		goto out_drop_write;

	if (!OVL_TYPE_UPPER(type)) {
		err = vfs_getxattr(realpath.dentry, name, NULL, 0);
		if (err < 0)
			goto out_drop_write;

		err = ovl_copy_up(dentry);
		if (err)
			goto out_drop_write;

		ovl_path_upper(dentry, &realpath);
	}

	err = vfs_removexattr(realpath.dentry, name);
out_drop_write:
	ovl_drop_write(dentry);
out:
	return err;
}

static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,
				  struct dentry *realdentry)
{
	if (OVL_TYPE_UPPER(type))
		return false;

	if (special_file(realdentry->d_inode->i_mode))
		return false;

	if (!(OPEN_FMODE(flags) & FMODE_WRITE) && !(flags & O_TRUNC))
		return false;

	return true;
}

struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags)
{
	int err;
	struct path realpath;
	enum ovl_path_type type;

	if (d_is_dir(dentry))
		return d_backing_inode(dentry);

	type = ovl_path_real(dentry, &realpath);
	if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
		err = ovl_want_write(dentry);
		if (err)
			return ERR_PTR(err);

		if (file_flags & O_TRUNC)
			err = ovl_copy_up_last(dentry, NULL, true);
		else
			err = ovl_copy_up(dentry);
		ovl_drop_write(dentry);
		if (err)
			return ERR_PTR(err);

		ovl_path_upper(dentry, &realpath);
	}

	if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE)
		return realpath.dentry->d_op->d_select_inode(realpath.dentry, file_flags);

	return d_backing_inode(realpath.dentry);
}

static const struct inode_operations ovl_file_inode_operations = {
	.setattr	= ovl_setattr,
	.permission	= ovl_permission,
	.getattr	= ovl_getattr,
	.setxattr	= ovl_setxattr,
	.getxattr	= ovl_getxattr,
	.listxattr	= ovl_listxattr,
	.removexattr	= ovl_removexattr,
};

static const struct inode_operations ovl_symlink_inode_operations = {
	.setattr	= ovl_setattr,
	.follow_link	= ovl_follow_link,
	.put_link	= ovl_put_link,
	.readlink	= ovl_readlink,
	.getattr	= ovl_getattr,
	.setxattr	= ovl_setxattr,
	.getxattr	= ovl_getxattr,
	.listxattr	= ovl_listxattr,
	.removexattr	= ovl_removexattr,
};

struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
			    struct ovl_entry *oe)
{
	struct inode *inode;

	inode = new_inode(sb);
	if (!inode)
		return NULL;

	mode &= S_IFMT;

	inode->i_ino = get_next_ino();
	inode->i_mode = mode;
	inode->i_flags |= S_NOATIME | S_NOCMTIME;

	switch (mode) {
	case S_IFDIR:
		inode->i_private = oe;
		inode->i_op = &ovl_dir_inode_operations;
		inode->i_fop = &ovl_dir_operations;
		break;

	case S_IFLNK:
		inode->i_op = &ovl_symlink_inode_operations;
		break;

	case S_IFREG:
	case S_IFSOCK:
	case S_IFBLK:
	case S_IFCHR:
	case S_IFIFO:
		inode->i_op = &ovl_file_inode_operations;
		break;

	default:
		WARN(1, "illegal file type: %i\n", mode);
		iput(inode);
		inode = NULL;
	}

	return inode;
}
Commit	Line	Data
e9be9d5e MS	1	/*
	2	*
	3	* Copyright (C) 2011 Novell Inc.
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License version 2 as published by
	7	* the Free Software Foundation.
	8	*/
	9
	10	#include <linux/fs.h>
	11	#include <linux/slab.h>
	12	#include <linux/xattr.h>
	13	#include "overlayfs.h"
	14
	15	static int ovl_copy_up_last(struct dentry dentry, struct iattr attr,
	16	bool no_data)
	17	{
	18	int err;
	19	struct dentry *parent;
	20	struct kstat stat;
	21	struct path lowerpath;
	22
	23	parent = dget_parent(dentry);
	24	err = ovl_copy_up(parent);
	25	if (err)
	26	goto out_dput_parent;
	27
	28	ovl_path_lower(dentry, &lowerpath);
	29	err = vfs_getattr(&lowerpath, &stat);
	30	if (err)
	31	goto out_dput_parent;
	32
	33	if (no_data)
	34	stat.size = 0;
	35
	36	err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat, attr);
	37
	38	out_dput_parent:
	39	dput(parent);
	40	return err;
	41	}
	42
	43	int ovl_setattr(struct dentry dentry, struct iattr attr)
	44	{
	45	int err;
	46	struct dentry *upperdentry;
	47
	48	err = ovl_want_write(dentry);
	49	if (err)
	50	goto out;
	51
acff81ec MS	52	err = ovl_copy_up(dentry);
	53	if (!err) {
	54	upperdentry = ovl_dentry_upper(dentry);
	55
e9be9d5e MS	56	mutex_lock(&upperdentry->d_inode->i_mutex);
	57	err = notify_change(upperdentry, attr, NULL);
	58	mutex_unlock(&upperdentry->d_inode->i_mutex);
e9be9d5e MS	59	}
	60	ovl_drop_write(dentry);
	61	out:
	62	return err;
	63	}
	64
	65	static int ovl_getattr(struct vfsmount mnt, struct dentry dentry,
	66	struct kstat *stat)
	67	{
	68	struct path realpath;
	69
	70	ovl_path_real(dentry, &realpath);
	71	return vfs_getattr(&realpath, stat);
	72	}
	73
	74	int ovl_permission(struct inode *inode, int mask)
	75	{
	76	struct ovl_entry *oe;
	77	struct dentry *alias = NULL;
	78	struct inode *realinode;
	79	struct dentry *realdentry;
	80	bool is_upper;
	81	int err;
	82
	83	if (S_ISDIR(inode->i_mode)) {
	84	oe = inode->i_private;
	85	} else if (mask & MAY_NOT_BLOCK) {
	86	return -ECHILD;
	87	} else {
	88	/*
	89	* For non-directories find an alias and get the info
	90	* from there.
	91	*/
	92	alias = d_find_any_alias(inode);
	93	if (WARN_ON(!alias))
	94	return -ENOENT;
	95
	96	oe = alias->d_fsdata;
	97	}
	98
	99	realdentry = ovl_entry_real(oe, &is_upper);
	100
	101	/* Careful in RCU walk mode */
	102	realinode = ACCESS_ONCE(realdentry->d_inode);
	103	if (!realinode) {
	104	WARN_ON(!(mask & MAY_NOT_BLOCK));
	105	err = -ENOENT;
	106	goto out_dput;
	107	}
	108
	109	if (mask & MAY_WRITE) {
	110	umode_t mode = realinode->i_mode;
	111
	112	/*
	113	* Writes will always be redirected to upper layer, so
	114	* ignore lower layer being read-only.
	115	*
	116	* If the overlay itself is read-only then proceed
	117	* with the permission check, don't return EROFS.
	118	* This will only happen if this is the lower layer of
	119	* another overlayfs.
	120	*
	121	* If upper fs becomes read-only after the overlay was
	122	* constructed return EROFS to prevent modification of
123	* upper layer.
124	*/
125	err = -EROFS;
126	if (is_upper && !IS_RDONLY(inode) && IS_RDONLY(realinode) &&
127	(S_ISREG(mode) \|\| S_ISDIR(mode) \|\| S_ISLNK(mode)))
128	goto out_dput;
129	}
130
131	err = __inode_permission(realinode, mask);
132	out_dput:
133	dput(alias);
134	return err;
135	}
136
137
138	struct ovl_link_data {
139	struct dentry *realdentry;
140	void *cookie;
141	};
142
6e77137b	143	static const char ovl_follow_link(struct dentry dentry, void **cookie)
e9be9d5e	144	{
e9be9d5e MS	145	struct dentry *realdentry;
e9be9d5e MS	146	struct inode *realinode;
3188b295	147	struct ovl_link_data *data = NULL;
680baacb	148	const char *ret;
e9be9d5e MS	149
	150	realdentry = ovl_dentry_real(dentry);
	151	realinode = realdentry->d_inode;
	152
	153	if (WARN_ON(!realinode->i_op->follow_link))
	154	return ERR_PTR(-EPERM);
	155
e9be9d5e	156	if (realinode->i_op->put_link) {
e9be9d5e	157	data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL);
3188b295	158	if (!data)
e9be9d5e	159	return ERR_PTR(-ENOMEM);
e9be9d5e	160	data->realdentry = realdentry;
3188b295	161	}
e9be9d5e	162
6e77137b	163	ret = realinode->i_op->follow_link(realdentry, cookie);
680baacb	164	if (IS_ERR_OR_NULL(ret)) {
3188b295 N	165	kfree(data);
3188b295 N	166	return ret;
e9be9d5e	167	}
3188b295 N	168
3188b295 N	169	if (data)
680baacb	170	data->cookie = *cookie;
3188b295	171
680baacb AV	172	*cookie = data;
	173
	174	return ret;
e9be9d5e MS	175	}
e9be9d5e MS	176
5f2c4179	177	static void ovl_put_link(struct inode unused, void c)
e9be9d5e MS	178	{
	179	struct inode *realinode;
	180	struct ovl_link_data *data = c;
	181
	182	if (!data)
	183	return;
	184
	185	realinode = data->realdentry->d_inode;
5f2c4179	186	realinode->i_op->put_link(realinode, data->cookie);
e9be9d5e MS	187	kfree(data);
	188	}
	189
	190	static int ovl_readlink(struct dentry dentry, char __user buf, int bufsiz)
	191	{
	192	struct path realpath;
	193	struct inode *realinode;
	194
	195	ovl_path_real(dentry, &realpath);
	196	realinode = realpath.dentry->d_inode;
	197
	198	if (!realinode->i_op->readlink)
	199	return -EINVAL;
	200
	201	touch_atime(&realpath);
	202
	203	return realinode->i_op->readlink(realpath.dentry, buf, bufsiz);
	204	}
	205
	206
	207	static bool ovl_is_private_xattr(const char *name)
	208	{
cead89bb	209	return strncmp(name, OVL_XATTR_PRE_NAME, OVL_XATTR_PRE_LEN) == 0;
e9be9d5e MS	210	}
	211
	212	int ovl_setxattr(struct dentry dentry, const char name,
	213	const void *value, size_t size, int flags)
	214	{
	215	int err;
	216	struct dentry *upperdentry;
	217
	218	err = ovl_want_write(dentry);
	219	if (err)
	220	goto out;
	221
	222	err = -EPERM;
	223	if (ovl_is_private_xattr(name))
	224	goto out_drop_write;
	225
	226	err = ovl_copy_up(dentry);
	227	if (err)
	228	goto out_drop_write;
	229
	230	upperdentry = ovl_dentry_upper(dentry);
	231	err = vfs_setxattr(upperdentry, name, value, size, flags);
	232
	233	out_drop_write:
	234	ovl_drop_write(dentry);
	235	out:
	236	return err;
	237	}
	238
52148463 MS	239	static bool ovl_need_xattr_filter(struct dentry *dentry,
	240	enum ovl_path_type type)
	241	{
1afaba1e MS	242	if ((type & (__OVL_PATH_PURE \| __OVL_PATH_UPPER)) == __OVL_PATH_UPPER)
	243	return S_ISDIR(dentry->d_inode->i_mode);
	244	else
	245	return false;
52148463 MS	246	}
52148463 MS	247
e9be9d5e MS	248	ssize_t ovl_getxattr(struct dentry dentry, const char name,
	249	void *value, size_t size)
	250	{
52148463 MS	251	struct path realpath;
	252	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
	253
	254	if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
e9be9d5e MS	255	return -ENODATA;
e9be9d5e MS	256
52148463	257	return vfs_getxattr(realpath.dentry, name, value, size);
e9be9d5e MS	258	}
	259
	260	ssize_t ovl_listxattr(struct dentry dentry, char list, size_t size)
	261	{
52148463 MS	262	struct path realpath;
52148463 MS	263	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
e9be9d5e MS	264	ssize_t res;
	265	int off;
	266
52148463	267	res = vfs_listxattr(realpath.dentry, list, size);
e9be9d5e MS	268	if (res <= 0 \|\| size == 0)
	269	return res;
	270
52148463	271	if (!ovl_need_xattr_filter(dentry, type))
e9be9d5e MS	272	return res;
	273
	274	/* filter out private xattrs */
	275	for (off = 0; off < res;) {
	276	char *s = list + off;
	277	size_t slen = strlen(s) + 1;
	278
	279	BUG_ON(off + slen > res);
	280
	281	if (ovl_is_private_xattr(s)) {
	282	res -= slen;
	283	memmove(s, s + slen, res - off);
	284	} else {
	285	off += slen;
	286	}
	287	}
	288
	289	return res;
	290	}
	291
	292	int ovl_removexattr(struct dentry dentry, const char name)
	293	{
	294	int err;
	295	struct path realpath;
52148463	296	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
e9be9d5e MS	297
	298	err = ovl_want_write(dentry);
	299	if (err)
	300	goto out;
	301
52148463 MS	302	err = -ENODATA;
52148463 MS	303	if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
e9be9d5e MS	304	goto out_drop_write;
e9be9d5e MS	305
1afaba1e	306	if (!OVL_TYPE_UPPER(type)) {
e9be9d5e MS	307	err = vfs_getxattr(realpath.dentry, name, NULL, 0);
	308	if (err < 0)
	309	goto out_drop_write;
	310
	311	err = ovl_copy_up(dentry);
	312	if (err)
	313	goto out_drop_write;
	314
	315	ovl_path_upper(dentry, &realpath);
	316	}
	317
	318	err = vfs_removexattr(realpath.dentry, name);
	319	out_drop_write:
	320	ovl_drop_write(dentry);
	321	out:
	322	return err;
	323	}
	324
	325	static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,
	326	struct dentry *realdentry)
	327	{
1afaba1e	328	if (OVL_TYPE_UPPER(type))
e9be9d5e MS	329	return false;
	330
	331	if (special_file(realdentry->d_inode->i_mode))
	332	return false;
	333
	334	if (!(OPEN_FMODE(flags) & FMODE_WRITE) && !(flags & O_TRUNC))
	335	return false;
	336
	337	return true;
	338	}
	339
4bacc9c9	340	struct inode ovl_d_select_inode(struct dentry dentry, unsigned file_flags)
e9be9d5e MS	341	{
	342	int err;
	343	struct path realpath;
	344	enum ovl_path_type type;
e9be9d5e	345
9391dd00 AV	346	if (d_is_dir(dentry))
	347	return d_backing_inode(dentry);
	348
e9be9d5e	349	type = ovl_path_real(dentry, &realpath);
4bacc9c9	350	if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
e9be9d5e MS	351	err = ovl_want_write(dentry);
e9be9d5e MS	352	if (err)
4bacc9c9	353	return ERR_PTR(err);
e9be9d5e	354
4bacc9c9	355	if (file_flags & O_TRUNC)
e9be9d5e MS	356	err = ovl_copy_up_last(dentry, NULL, true);
	357	else
	358	err = ovl_copy_up(dentry);
f25801ee	359	ovl_drop_write(dentry);
e9be9d5e	360	if (err)
4bacc9c9	361	return ERR_PTR(err);
e9be9d5e MS	362
	363	ovl_path_upper(dentry, &realpath);
	364	}
	365
1c8a47df MS	366	if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE)
	367	return realpath.dentry->d_op->d_select_inode(realpath.dentry, file_flags);
	368
4bacc9c9	369	return d_backing_inode(realpath.dentry);
e9be9d5e MS	370	}
	371
	372	static const struct inode_operations ovl_file_inode_operations = {
	373	.setattr = ovl_setattr,
	374	.permission = ovl_permission,
	375	.getattr = ovl_getattr,
	376	.setxattr = ovl_setxattr,
	377	.getxattr = ovl_getxattr,
	378	.listxattr = ovl_listxattr,
	379	.removexattr = ovl_removexattr,
e9be9d5e MS	380	};
	381
	382	static const struct inode_operations ovl_symlink_inode_operations = {
	383	.setattr = ovl_setattr,
	384	.follow_link = ovl_follow_link,
	385	.put_link = ovl_put_link,
	386	.readlink = ovl_readlink,
	387	.getattr = ovl_getattr,
	388	.setxattr = ovl_setxattr,
	389	.getxattr = ovl_getxattr,
	390	.listxattr = ovl_listxattr,
	391	.removexattr = ovl_removexattr,
	392	};
	393
	394	struct inode ovl_new_inode(struct super_block sb, umode_t mode,
	395	struct ovl_entry *oe)
	396	{
	397	struct inode *inode;
	398
	399	inode = new_inode(sb);
	400	if (!inode)
	401	return NULL;
	402
	403	mode &= S_IFMT;
	404
	405	inode->i_ino = get_next_ino();
	406	inode->i_mode = mode;
	407	inode->i_flags \|= S_NOATIME \| S_NOCMTIME;
	408
	409	switch (mode) {
	410	case S_IFDIR:
	411	inode->i_private = oe;
	412	inode->i_op = &ovl_dir_inode_operations;
	413	inode->i_fop = &ovl_dir_operations;
	414	break;
	415
	416	case S_IFLNK:
	417	inode->i_op = &ovl_symlink_inode_operations;
	418	break;
	419
	420	case S_IFREG:
	421	case S_IFSOCK:
	422	case S_IFBLK:
	423	case S_IFCHR:
	424	case S_IFIFO:
	425	inode->i_op = &ovl_file_inode_operations;
	426	break;
	427
	428	default:
	429	WARN(1, "illegal file type: %i\n", mode);
	430	iput(inode);
	431	inode = NULL;
	432	}
	433
	434	return inode;
e9be9d5e	435	}