[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 <linux/posix_acl.h>
#include "overlayfs.h"

static int ovl_copy_up_truncate(struct dentry *dentry)
{
	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;

	stat.size = 0;
	err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat);

out_dput_parent:
	dput(parent);
	return err;
}

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

	/*
	 * Check for permissions before trying to copy-up.  This is redundant
	 * since it will be rechecked later by ->setattr() on upper dentry.  But
	 * without this, copy-up can be triggered by just about anybody.
	 *
	 * We don't initialize inode->size, which just means that
	 * inode_newsize_ok() will always check against MAX_LFS_FILESIZE and not
	 * check for a swapfile (which this won't be anyway).
	 */
	err = inode_change_ok(dentry->d_inode, attr);
	if (err)
		return err;

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

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

		if (attr->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
			attr->ia_valid &= ~ATTR_MODE;

		inode_lock(upperdentry->d_inode);
		old_cred = ovl_override_creds(dentry->d_sb);
		err = notify_change(upperdentry, attr, NULL);
		revert_creds(old_cred);
		if (!err)
			ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
		inode_unlock(upperdentry->d_inode);
	}
	ovl_drop_write(dentry);
out:
	return err;
}

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

	ovl_path_real(dentry, &realpath);
	old_cred = ovl_override_creds(dentry->d_sb);
	err = vfs_getattr(&realpath, stat);
	revert_creds(old_cred);
	return err;
}

int ovl_permission(struct inode *inode, int mask)
{
	bool is_upper;
	struct inode *realinode = ovl_inode_real(inode, &is_upper);
	const struct cred *old_cred;
	int err;

	/* Careful in RCU walk mode */
	if (!realinode) {
		WARN_ON(!(mask & MAY_NOT_BLOCK));
		return -ECHILD;
	}

	/*
	 * Check overlay inode with the creds of task and underlying inode
	 * with creds of mounter
	 */
	err = generic_permission(inode, mask);
	if (err)
		return err;

	old_cred = ovl_override_creds(inode->i_sb);
	if (!is_upper && !special_file(realinode->i_mode) && mask & MAY_WRITE) {
		mask &= ~(MAY_WRITE | MAY_APPEND);
		/* Make sure mounter can read file for copy up later */
		mask |= MAY_READ;
	}
	err = inode_permission(realinode, mask);
	revert_creds(old_cred);

	return err;
}

static const char *ovl_get_link(struct dentry *dentry,
				struct inode *inode,
				struct delayed_call *done)
{
	struct dentry *realdentry;
	struct inode *realinode;
	const struct cred *old_cred;
	const char *p;

	if (!dentry)
		return ERR_PTR(-ECHILD);

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

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

	old_cred = ovl_override_creds(dentry->d_sb);
	p = realinode->i_op->get_link(realdentry, realinode, done);
	revert_creds(old_cred);
	return p;
}

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

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

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

	old_cred = ovl_override_creds(dentry->d_sb);
	err = realinode->i_op->readlink(realpath.dentry, buf, bufsiz);
	revert_creds(old_cred);
	return err;
}

bool ovl_is_private_xattr(const char *name)
{
	return strncmp(name, OVL_XATTR_PREFIX,
		       sizeof(OVL_XATTR_PREFIX) - 1) == 0;
}

int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
		  size_t size, int flags)
{
	int err;
	struct path realpath;
	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
	const struct cred *old_cred;

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

	if (!value && !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;

	if (!OVL_TYPE_UPPER(type))
		ovl_path_upper(dentry, &realpath);

	old_cred = ovl_override_creds(dentry->d_sb);
	if (value)
		err = vfs_setxattr(realpath.dentry, name, value, size, flags);
	else {
		WARN_ON(flags != XATTR_REPLACE);
		err = vfs_removexattr(realpath.dentry, name);
	}
	revert_creds(old_cred);

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

int ovl_xattr_get(struct dentry *dentry, const char *name,
		  void *value, size_t size)
{
	struct dentry *realdentry = ovl_dentry_real(dentry);
	ssize_t res;
	const struct cred *old_cred;

	old_cred = ovl_override_creds(dentry->d_sb);
	res = vfs_getxattr(realdentry, name, value, size);
	revert_creds(old_cred);
	return res;
}

ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
{
	struct dentry *realdentry = ovl_dentry_real(dentry);
	ssize_t res;
	size_t len;
	char *s;
	const struct cred *old_cred;

	old_cred = ovl_override_creds(dentry->d_sb);
	res = vfs_listxattr(realdentry, list, size);
	revert_creds(old_cred);
	if (res <= 0 || size == 0)
		return res;

	/* filter out private xattrs */
	for (s = list, len = res; len;) {
		size_t slen = strnlen(s, len) + 1;

		/* underlying fs providing us with an broken xattr list? */
		if (WARN_ON(slen > len))
			return -EIO;

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

	return res;
}

struct posix_acl *ovl_get_acl(struct inode *inode, int type)
{
	struct inode *realinode = ovl_inode_real(inode, NULL);
	const struct cred *old_cred;
	struct posix_acl *acl;

	if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !IS_POSIXACL(realinode))
		return NULL;

	if (!realinode->i_op->get_acl)
		return NULL;

	old_cred = ovl_override_creds(inode->i_sb);
	acl = get_acl(realinode, type);
	revert_creds(old_cred);

	return acl;
}

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;
}

int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
{
	int err = 0;
	struct path realpath;
	enum ovl_path_type type;

	type = ovl_path_real(dentry, &realpath);
	if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
		err = ovl_want_write(dentry);
		if (!err) {
			if (file_flags & O_TRUNC)
				err = ovl_copy_up_truncate(dentry);
			else
				err = ovl_copy_up(dentry);
			ovl_drop_write(dentry);
		}
	}

	return err;
}

int ovl_update_time(struct inode *inode, struct timespec *ts, int flags)
{
	struct dentry *alias;
	struct path upperpath;

	if (!(flags & S_ATIME))
		return 0;

	alias = d_find_any_alias(inode);
	if (!alias)
		return 0;

	ovl_path_upper(alias, &upperpath);
	if (upperpath.dentry) {
		touch_atime(&upperpath);
		inode->i_atime = d_inode(upperpath.dentry)->i_atime;
	}

	dput(alias);

	return 0;
}

static const struct inode_operations ovl_file_inode_operations = {
	.setattr	= ovl_setattr,
	.permission	= ovl_permission,
	.getattr	= ovl_getattr,
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= ovl_listxattr,
	.removexattr	= generic_removexattr,
	.get_acl	= ovl_get_acl,
	.update_time	= ovl_update_time,
};

static const struct inode_operations ovl_symlink_inode_operations = {
	.setattr	= ovl_setattr,
	.get_link	= ovl_get_link,
	.readlink	= ovl_readlink,
	.getattr	= ovl_getattr,
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= ovl_listxattr,
	.removexattr	= generic_removexattr,
	.update_time	= ovl_update_time,
};

static void ovl_fill_inode(struct inode *inode, umode_t mode)
{
	inode->i_ino = get_next_ino();
	inode->i_mode = mode;
	inode->i_flags |= S_NOCMTIME;
#ifdef CONFIG_FS_POSIX_ACL
	inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE;
#endif

	mode &= S_IFMT;
	switch (mode) {
	case S_IFDIR:
		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;

	default:
		WARN(1, "illegal file type: %i\n", mode);
		/* Fall through */

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

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

	inode = new_inode(sb);
	if (inode)
		ovl_fill_inode(inode, mode);

	return inode;
}

static int ovl_inode_test(struct inode *inode, void *data)
{
	return ovl_inode_real(inode, NULL) == data;
}

static int ovl_inode_set(struct inode *inode, void *data)
{
	inode->i_private = (void *) (((unsigned long) data) | OVL_ISUPPER_MASK);
	return 0;
}

struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode)

{
	struct inode *inode;

	inode = iget5_locked(sb, (unsigned long) realinode,
			     ovl_inode_test, ovl_inode_set, realinode);
	if (inode && inode->i_state & I_NEW) {
		ovl_fill_inode(inode, realinode->i_mode);
		set_nlink(inode, realinode->i_nlink);
		unlock_new_inode(inode);
	}

	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>
5201dc44	13	#include <linux/posix_acl.h>
e9be9d5e MS	14	#include "overlayfs.h"
e9be9d5e MS	15
0f7ff2da	16	static int ovl_copy_up_truncate(struct dentry *dentry)
e9be9d5e MS	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
0f7ff2da AV	33	stat.size = 0;
0f7ff2da AV	34	err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat);
e9be9d5e MS	35
	36	out_dput_parent:
	37	dput(parent);
	38	return err;
	39	}
	40
	41	int ovl_setattr(struct dentry dentry, struct iattr attr)
	42	{
	43	int err;
	44	struct dentry *upperdentry;
1175b6b8	45	const struct cred *old_cred;
e9be9d5e	46
cf9a6784 MS	47	/*
	48	* Check for permissions before trying to copy-up. This is redundant
	49	* since it will be rechecked later by ->setattr() on upper dentry. But
	50	* without this, copy-up can be triggered by just about anybody.
	51	*
	52	* We don't initialize inode->size, which just means that
	53	* inode_newsize_ok() will always check against MAX_LFS_FILESIZE and not
	54	* check for a swapfile (which this won't be anyway).
	55	*/
	56	err = inode_change_ok(dentry->d_inode, attr);
	57	if (err)
	58	return err;
	59
e9be9d5e MS	60	err = ovl_want_write(dentry);
	61	if (err)
	62	goto out;
	63
acff81ec MS	64	err = ovl_copy_up(dentry);
	65	if (!err) {
	66	upperdentry = ovl_dentry_upper(dentry);
	67
b99c2d91 MS	68	if (attr->ia_valid & (ATTR_KILL_SUID\|ATTR_KILL_SGID))
	69	attr->ia_valid &= ~ATTR_MODE;
	70
5955102c	71	inode_lock(upperdentry->d_inode);
1175b6b8	72	old_cred = ovl_override_creds(dentry->d_sb);
e9be9d5e	73	err = notify_change(upperdentry, attr, NULL);
1175b6b8	74	revert_creds(old_cred);
b81de061 KK	75	if (!err)
b81de061 KK	76	ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
5955102c	77	inode_unlock(upperdentry->d_inode);
e9be9d5e MS	78	}
	79	ovl_drop_write(dentry);
	80	out:
	81	return err;
	82	}
	83
	84	static int ovl_getattr(struct vfsmount mnt, struct dentry dentry,
	85	struct kstat *stat)
	86	{
	87	struct path realpath;
1175b6b8 VG	88	const struct cred *old_cred;
1175b6b8 VG	89	int err;
e9be9d5e MS	90
e9be9d5e MS	91	ovl_path_real(dentry, &realpath);
1175b6b8 VG	92	old_cred = ovl_override_creds(dentry->d_sb);
	93	err = vfs_getattr(&realpath, stat);
	94	revert_creds(old_cred);
	95	return err;
e9be9d5e MS	96	}
	97
	98	int ovl_permission(struct inode *inode, int mask)
	99	{
e9be9d5e	100	bool is_upper;
39b681f8	101	struct inode *realinode = ovl_inode_real(inode, &is_upper);
c0ca3d70	102	const struct cred *old_cred;
e9be9d5e MS	103	int err;
e9be9d5e MS	104
e9be9d5e	105	/* Careful in RCU walk mode */
e9be9d5e MS	106	if (!realinode) {
e9be9d5e MS	107	WARN_ON(!(mask & MAY_NOT_BLOCK));
a999d7e1	108	return -ECHILD;
e9be9d5e MS	109	}
e9be9d5e MS	110
c0ca3d70 VG	111	/*
	112	* Check overlay inode with the creds of task and underlying inode
	113	* with creds of mounter
	114	*/
	115	err = generic_permission(inode, mask);
	116	if (err)
	117	return err;
	118
	119	old_cred = ovl_override_creds(inode->i_sb);
500cac3c	120	if (!is_upper && !special_file(realinode->i_mode) && mask & MAY_WRITE) {
754f8cb7	121	mask &= ~(MAY_WRITE \| MAY_APPEND);
500cac3c VG	122	/* Make sure mounter can read file for copy up later */
	123	mask \|= MAY_READ;
	124	}
9c630ebe	125	err = inode_permission(realinode, mask);
c0ca3d70 VG	126	revert_creds(old_cred);
	127
	128	return err;
e9be9d5e MS	129	}
e9be9d5e MS	130
6b255391	131	static const char ovl_get_link(struct dentry dentry,
fceef393 AV	132	struct inode *inode,
fceef393 AV	133	struct delayed_call *done)
e9be9d5e	134	{
e9be9d5e MS	135	struct dentry *realdentry;
e9be9d5e MS	136	struct inode *realinode;
1175b6b8 VG	137	const struct cred *old_cred;
1175b6b8 VG	138	const char *p;
e9be9d5e	139
6b255391 AV	140	if (!dentry)
	141	return ERR_PTR(-ECHILD);
	142
e9be9d5e MS	143	realdentry = ovl_dentry_real(dentry);
	144	realinode = realdentry->d_inode;
	145
6b255391	146	if (WARN_ON(!realinode->i_op->get_link))
e9be9d5e MS	147	return ERR_PTR(-EPERM);
e9be9d5e MS	148
1175b6b8 VG	149	old_cred = ovl_override_creds(dentry->d_sb);
	150	p = realinode->i_op->get_link(realdentry, realinode, done);
	151	revert_creds(old_cred);
	152	return p;
e9be9d5e MS	153	}
	154
	155	static int ovl_readlink(struct dentry dentry, char __user buf, int bufsiz)
	156	{
	157	struct path realpath;
	158	struct inode *realinode;
1175b6b8 VG	159	const struct cred *old_cred;
1175b6b8 VG	160	int err;
e9be9d5e MS	161
	162	ovl_path_real(dentry, &realpath);
	163	realinode = realpath.dentry->d_inode;
	164
	165	if (!realinode->i_op->readlink)
	166	return -EINVAL;
	167
1175b6b8 VG	168	old_cred = ovl_override_creds(dentry->d_sb);
	169	err = realinode->i_op->readlink(realpath.dentry, buf, bufsiz);
	170	revert_creds(old_cred);
	171	return err;
e9be9d5e MS	172	}
e9be9d5e MS	173
0956254a	174	bool ovl_is_private_xattr(const char *name)
e9be9d5e	175	{
fe2b7595 AG	176	return strncmp(name, OVL_XATTR_PREFIX,
fe2b7595 AG	177	sizeof(OVL_XATTR_PREFIX) - 1) == 0;
e9be9d5e MS	178	}
e9be9d5e MS	179
0e585ccc AG	180	int ovl_xattr_set(struct dentry dentry, const char name, const void *value,
0e585ccc AG	181	size_t size, int flags)
e9be9d5e MS	182	{
e9be9d5e MS	183	int err;
0e585ccc AG	184	struct path realpath;
0e585ccc AG	185	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
1175b6b8	186	const struct cred *old_cred;
e9be9d5e MS	187
	188	err = ovl_want_write(dentry);
	189	if (err)
	190	goto out;
	191
0e585ccc AG	192	if (!value && !OVL_TYPE_UPPER(type)) {
	193	err = vfs_getxattr(realpath.dentry, name, NULL, 0);
	194	if (err < 0)
	195	goto out_drop_write;
	196	}
	197
e9be9d5e MS	198	err = ovl_copy_up(dentry);
	199	if (err)
	200	goto out_drop_write;
	201
0e585ccc AG	202	if (!OVL_TYPE_UPPER(type))
	203	ovl_path_upper(dentry, &realpath);
	204
1175b6b8	205	old_cred = ovl_override_creds(dentry->d_sb);
0e585ccc AG	206	if (value)
	207	err = vfs_setxattr(realpath.dentry, name, value, size, flags);
	208	else {
	209	WARN_ON(flags != XATTR_REPLACE);
	210	err = vfs_removexattr(realpath.dentry, name);
	211	}
1175b6b8	212	revert_creds(old_cred);
e9be9d5e MS	213
	214	out_drop_write:
	215	ovl_drop_write(dentry);
	216	out:
	217	return err;
	218	}
	219
0eb45fc3 AG	220	int ovl_xattr_get(struct dentry dentry, const char name,
0eb45fc3 AG	221	void *value, size_t size)
e9be9d5e	222	{
b581755b	223	struct dentry *realdentry = ovl_dentry_real(dentry);
1175b6b8 VG	224	ssize_t res;
1175b6b8 VG	225	const struct cred *old_cred;
52148463	226
1175b6b8 VG	227	old_cred = ovl_override_creds(dentry->d_sb);
	228	res = vfs_getxattr(realdentry, name, value, size);
	229	revert_creds(old_cred);
	230	return res;
e9be9d5e MS	231	}
	232
	233	ssize_t ovl_listxattr(struct dentry dentry, char list, size_t size)
	234	{
b581755b	235	struct dentry *realdentry = ovl_dentry_real(dentry);
e9be9d5e	236	ssize_t res;
7cb35119 MS	237	size_t len;
7cb35119 MS	238	char *s;
1175b6b8	239	const struct cred *old_cred;
e9be9d5e	240
1175b6b8	241	old_cred = ovl_override_creds(dentry->d_sb);
b581755b	242	res = vfs_listxattr(realdentry, list, size);
1175b6b8	243	revert_creds(old_cred);
e9be9d5e MS	244	if (res <= 0 \|\| size == 0)
	245	return res;
	246
e9be9d5e	247	/* filter out private xattrs */
7cb35119 MS	248	for (s = list, len = res; len;) {
7cb35119 MS	249	size_t slen = strnlen(s, len) + 1;
e9be9d5e	250
7cb35119 MS	251	/* underlying fs providing us with an broken xattr list? */
	252	if (WARN_ON(slen > len))
	253	return -EIO;
e9be9d5e	254
7cb35119	255	len -= slen;
e9be9d5e MS	256	if (ovl_is_private_xattr(s)) {
e9be9d5e MS	257	res -= slen;
7cb35119	258	memmove(s, s + slen, len);
e9be9d5e	259	} else {
7cb35119	260	s += slen;
e9be9d5e MS	261	}
	262	}
	263
	264	return res;
	265	}
	266
39a25b2b VG	267	struct posix_acl ovl_get_acl(struct inode inode, int type)
39a25b2b VG	268	{
39b681f8	269	struct inode *realinode = ovl_inode_real(inode, NULL);
1175b6b8 VG	270	const struct cred *old_cred;
1175b6b8 VG	271	struct posix_acl *acl;
39a25b2b	272
5201dc44	273	if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) \|\| !IS_POSIXACL(realinode))
39a25b2b VG	274	return NULL;
	275
	276	if (!realinode->i_op->get_acl)
	277	return NULL;
	278
1175b6b8	279	old_cred = ovl_override_creds(inode->i_sb);
5201dc44	280	acl = get_acl(realinode, type);
1175b6b8 VG	281	revert_creds(old_cred);
	282
	283	return acl;
39a25b2b VG	284	}
39a25b2b VG	285
e9be9d5e MS	286	static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,
	287	struct dentry *realdentry)
	288	{
1afaba1e	289	if (OVL_TYPE_UPPER(type))
e9be9d5e MS	290	return false;
	291
	292	if (special_file(realdentry->d_inode->i_mode))
	293	return false;
	294
	295	if (!(OPEN_FMODE(flags) & FMODE_WRITE) && !(flags & O_TRUNC))
	296	return false;
	297
	298	return true;
	299	}
	300
2d902671	301	int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
e9be9d5e	302	{
2d902671	303	int err = 0;
e9be9d5e MS	304	struct path realpath;
e9be9d5e MS	305	enum ovl_path_type type;
e9be9d5e MS	306
e9be9d5e MS	307	type = ovl_path_real(dentry, &realpath);
4bacc9c9	308	if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
e9be9d5e	309	err = ovl_want_write(dentry);
2d902671 MS	310	if (!err) {
	311	if (file_flags & O_TRUNC)
	312	err = ovl_copy_up_truncate(dentry);
	313	else
	314	err = ovl_copy_up(dentry);
	315	ovl_drop_write(dentry);
	316	}
e9be9d5e MS	317	}
e9be9d5e MS	318
2d902671	319	return err;
e9be9d5e MS	320	}
e9be9d5e MS	321
d719e8f2 MS	322	int ovl_update_time(struct inode inode, struct timespec ts, int flags)
	323	{
	324	struct dentry *alias;
	325	struct path upperpath;
	326
	327	if (!(flags & S_ATIME))
	328	return 0;
	329
	330	alias = d_find_any_alias(inode);
	331	if (!alias)
	332	return 0;
	333
	334	ovl_path_upper(alias, &upperpath);
	335	if (upperpath.dentry) {
	336	touch_atime(&upperpath);
	337	inode->i_atime = d_inode(upperpath.dentry)->i_atime;
	338	}
	339
	340	dput(alias);
	341
	342	return 0;
	343	}
	344
e9be9d5e MS	345	static const struct inode_operations ovl_file_inode_operations = {
	346	.setattr = ovl_setattr,
	347	.permission = ovl_permission,
	348	.getattr = ovl_getattr,
d837a49b	349	.setxattr = generic_setxattr,
0eb45fc3	350	.getxattr = generic_getxattr,
e9be9d5e	351	.listxattr = ovl_listxattr,
0e585ccc	352	.removexattr = generic_removexattr,
39a25b2b	353	.get_acl = ovl_get_acl,
d719e8f2	354	.update_time = ovl_update_time,
e9be9d5e MS	355	};
	356
	357	static const struct inode_operations ovl_symlink_inode_operations = {
	358	.setattr = ovl_setattr,
6b255391	359	.get_link = ovl_get_link,
e9be9d5e MS	360	.readlink = ovl_readlink,
e9be9d5e MS	361	.getattr = ovl_getattr,
d837a49b	362	.setxattr = generic_setxattr,
0eb45fc3	363	.getxattr = generic_getxattr,
e9be9d5e	364	.listxattr = ovl_listxattr,
0e585ccc	365	.removexattr = generic_removexattr,
d719e8f2	366	.update_time = ovl_update_time,
e9be9d5e MS	367	};
e9be9d5e MS	368
51f7e52d	369	static void ovl_fill_inode(struct inode *inode, umode_t mode)
e9be9d5e	370	{
e9be9d5e MS	371	inode->i_ino = get_next_ino();
e9be9d5e MS	372	inode->i_mode = mode;
d719e8f2	373	inode->i_flags \|= S_NOCMTIME;
2a3a2a3f MS	374	#ifdef CONFIG_FS_POSIX_ACL
	375	inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE;
	376	#endif
e9be9d5e	377
07a2daab	378	mode &= S_IFMT;
e9be9d5e MS	379	switch (mode) {
e9be9d5e MS	380	case S_IFDIR:
e9be9d5e MS	381	inode->i_op = &ovl_dir_inode_operations;
	382	inode->i_fop = &ovl_dir_operations;
	383	break;
	384
	385	case S_IFLNK:
	386	inode->i_op = &ovl_symlink_inode_operations;
	387	break;
	388
51f7e52d MS	389	default:
	390	WARN(1, "illegal file type: %i\n", mode);
	391	/* Fall through */
	392
e9be9d5e MS	393	case S_IFREG:
	394	case S_IFSOCK:
	395	case S_IFBLK:
	396	case S_IFCHR:
	397	case S_IFIFO:
	398	inode->i_op = &ovl_file_inode_operations;
	399	break;
51f7e52d MS	400	}
51f7e52d MS	401	}
e9be9d5e	402
51f7e52d MS	403	struct inode ovl_new_inode(struct super_block sb, umode_t mode)
	404	{
	405	struct inode *inode;
	406
	407	inode = new_inode(sb);
	408	if (inode)
	409	ovl_fill_inode(inode, mode);
	410
	411	return inode;
	412	}
	413
	414	static int ovl_inode_test(struct inode inode, void data)
	415	{
	416	return ovl_inode_real(inode, NULL) == data;
	417	}
	418
	419	static int ovl_inode_set(struct inode inode, void data)
	420	{
	421	inode->i_private = (void *) (((unsigned long) data) \| OVL_ISUPPER_MASK);
	422	return 0;
	423	}
	424
	425	struct inode ovl_get_inode(struct super_block sb, struct inode *realinode)
	426
	427	{
	428	struct inode *inode;
	429
	430	inode = iget5_locked(sb, (unsigned long) realinode,
	431	ovl_inode_test, ovl_inode_set, realinode);
	432	if (inode && inode->i_state & I_NEW) {
	433	ovl_fill_inode(inode, realinode->i_mode);
	434	set_nlink(inode, realinode->i_nlink);
	435	unlock_new_inode(inode);
e9be9d5e MS	436	}
	437
	438	return inode;
e9be9d5e	439	}