[mirror_ubuntu-zesty-kernel.git] / fs / 9p / acl.c

/*
 * Copyright IBM Corporation, 2010
 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2.1 of the GNU Lesser General Public License
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/posix_acl_xattr.h>
#include "xattr.h"
#include "acl.h"
#include "v9fs_vfs.h"
#include "v9fs.h"

static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name)
{
	ssize_t size;
	void *value = NULL;
	struct posix_acl *acl = NULL;

	size = v9fs_fid_xattr_get(fid, name, NULL, 0);
	if (size > 0) {
		value = kzalloc(size, GFP_NOFS);
		if (!value)
			return ERR_PTR(-ENOMEM);
		size = v9fs_fid_xattr_get(fid, name, value, size);
		if (size > 0) {
			acl = posix_acl_from_xattr(value, size);
			if (IS_ERR(acl))
				goto err_out;
		}
	} else if (size == -ENODATA || size == 0 ||
		   size == -ENOSYS || size == -EOPNOTSUPP) {
		acl = NULL;
	} else
		acl = ERR_PTR(-EIO);

err_out:
	kfree(value);
	return acl;
}

int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
{
	int retval = 0;
	struct posix_acl *pacl, *dacl;
	struct v9fs_session_info *v9ses;

	v9ses = v9fs_inode2v9ses(inode);
	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
		set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
		set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
		return 0;
	}
	/* get the default/access acl values and cache them */
	dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT);
	pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS);

	if (!IS_ERR(dacl) && !IS_ERR(pacl)) {
		set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
		set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);
	} else
		retval = -EIO;

	if (!IS_ERR(dacl))
		posix_acl_release(dacl);

	if (!IS_ERR(pacl))
		posix_acl_release(pacl);

	return retval;
}

static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
{
	struct posix_acl *acl;
	/*
	 * 9p Always cache the acl value when
	 * instantiating the inode (v9fs_inode_from_fid)
	 */
	acl = get_cached_acl(inode, type);
	BUG_ON(acl == ACL_NOT_CACHED);
	return acl;
}

int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags)
{
	struct posix_acl *acl;
	struct v9fs_session_info *v9ses;

	if (flags & IPERM_FLAG_RCU)
		return -ECHILD;

	v9ses = v9fs_inode2v9ses(inode);
	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
		/*
		 * On access = client mode get the acl
		 * values from the server
		 */
		return 0;
	}
	acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);

	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl) {
		int error = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
		return error;
	}
	return -EAGAIN;
}

static int v9fs_set_acl(struct dentry *dentry, int type, struct posix_acl *acl)
{
	int retval;
	char *name;
	size_t size;
	void *buffer;
	struct inode *inode = dentry->d_inode;

	set_cached_acl(inode, type, acl);
	/* Set a setxattr request to server */
	size = posix_acl_xattr_size(acl->a_count);
	buffer = kmalloc(size, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;
	retval = posix_acl_to_xattr(acl, buffer, size);
	if (retval < 0)
		goto err_free_out;
	switch (type) {
	case ACL_TYPE_ACCESS:
		name = POSIX_ACL_XATTR_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		name = POSIX_ACL_XATTR_DEFAULT;
		break;
	default:
		BUG();
	}
	retval = v9fs_xattr_set(dentry, name, buffer, size, 0);
err_free_out:
	kfree(buffer);
	return retval;
}

int v9fs_acl_chmod(struct dentry *dentry)
{
	int retval = 0;
	struct posix_acl *acl, *clone;
	struct inode *inode = dentry->d_inode;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;
	acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
	if (acl) {
		clone = posix_acl_clone(acl, GFP_KERNEL);
		posix_acl_release(acl);
		if (!clone)
			return -ENOMEM;
		retval = posix_acl_chmod_masq(clone, inode->i_mode);
		if (!retval)
			retval = v9fs_set_acl(dentry, ACL_TYPE_ACCESS, clone);
		posix_acl_release(clone);
	}
	return retval;
}

int v9fs_set_create_acl(struct dentry *dentry,
			struct posix_acl *dpacl, struct posix_acl *pacl)
{
	if (dpacl)
		v9fs_set_acl(dentry, ACL_TYPE_DEFAULT, dpacl);
	if (pacl)
		v9fs_set_acl(dentry, ACL_TYPE_ACCESS, pacl);
	posix_acl_release(dpacl);
	posix_acl_release(pacl);
	return 0;
}

int v9fs_acl_mode(struct inode *dir, mode_t *modep,
		  struct posix_acl **dpacl, struct posix_acl **pacl)
{
	int retval = 0;
	mode_t mode = *modep;
	struct posix_acl *acl = NULL;

	if (!S_ISLNK(mode)) {
		acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		if (!acl)
			mode &= ~current_umask();
	}
	if (acl) {
		struct posix_acl *clone;

		if (S_ISDIR(mode))
			*dpacl = acl;
		clone = posix_acl_clone(acl, GFP_NOFS);
		retval = -ENOMEM;
		if (!clone)
			goto cleanup;

		retval = posix_acl_create_masq(clone, &mode);
		if (retval < 0) {
			posix_acl_release(clone);
			goto cleanup;
		}
		if (retval > 0)
			*pacl = clone;
	}
	*modep  = mode;
	return 0;
cleanup:
	posix_acl_release(acl);
	return retval;

}

static int v9fs_remote_get_acl(struct dentry *dentry, const char *name,
			       void *buffer, size_t size, int type)
{
	char *full_name;

	switch (type) {
	case ACL_TYPE_ACCESS:
		full_name =  POSIX_ACL_XATTR_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		full_name = POSIX_ACL_XATTR_DEFAULT;
		break;
	default:
		BUG();
	}
	return v9fs_xattr_get(dentry, full_name, buffer, size);
}

static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
			      void *buffer, size_t size, int type)
{
	struct v9fs_session_info *v9ses;
	struct posix_acl *acl;
	int error;

	if (strcmp(name, "") != 0)
		return -EINVAL;

	v9ses = v9fs_inode2v9ses(dentry->d_inode);
	/*
	 * We allow set/get/list of acl when access=client is not specified
	 */
	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
		return v9fs_remote_get_acl(dentry, name, buffer, size, type);

	acl = v9fs_get_cached_acl(dentry->d_inode, type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl == NULL)
		return -ENODATA;
	error = posix_acl_to_xattr(acl, buffer, size);
	posix_acl_release(acl);

	return error;
}

static int v9fs_remote_set_acl(struct dentry *dentry, const char *name,
			      const void *value, size_t size,
			      int flags, int type)
{
	char *full_name;

	switch (type) {
	case ACL_TYPE_ACCESS:
		full_name =  POSIX_ACL_XATTR_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		full_name = POSIX_ACL_XATTR_DEFAULT;
		break;
	default:
		BUG();
	}
	return v9fs_xattr_set(dentry, full_name, value, size, flags);
}


static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
			      const void *value, size_t size,
			      int flags, int type)
{
	int retval;
	struct posix_acl *acl;
	struct v9fs_session_info *v9ses;
	struct inode *inode = dentry->d_inode;

	if (strcmp(name, "") != 0)
		return -EINVAL;

	v9ses = v9fs_inode2v9ses(dentry->d_inode);
	/*
	 * set the attribute on the remote. Without even looking at the
	 * xattr value. We leave it to the server to validate
	 */
	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
		return v9fs_remote_set_acl(dentry, name,
					   value, size, flags, type);

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;
	if (!is_owner_or_cap(inode))
		return -EPERM;
	if (value) {
		/* update the cached acl value */
		acl = posix_acl_from_xattr(value, size);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		else if (acl) {
			retval = posix_acl_valid(acl);
			if (retval)
				goto err_out;
		}
	} else
		acl = NULL;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name = POSIX_ACL_XATTR_ACCESS;
		if (acl) {
			mode_t mode = inode->i_mode;
			retval = posix_acl_equiv_mode(acl, &mode);
			if (retval < 0)
				goto err_out;
			else {
				struct iattr iattr;
				if (retval == 0) {
					/*
					 * ACL can be represented
					 * by the mode bits. So don't
					 * update ACL.
					 */
					acl = NULL;
					value = NULL;
					size = 0;
				}
				/* Updte the mode bits */
				iattr.ia_mode = ((mode & S_IALLUGO) |
						 (inode->i_mode & ~S_IALLUGO));
				iattr.ia_valid = ATTR_MODE;
				/* FIXME should we update ctime ?
				 * What is the following setxattr update the
				 * mode ?
				 */
				v9fs_vfs_setattr_dotl(dentry, &iattr);
			}
		}
		break;
	case ACL_TYPE_DEFAULT:
		name = POSIX_ACL_XATTR_DEFAULT;
		if (!S_ISDIR(inode->i_mode)) {
			retval = acl ? -EINVAL : 0;
			goto err_out;
		}
		break;
	default:
		BUG();
	}
	retval = v9fs_xattr_set(dentry, name, value, size, flags);
	if (!retval)
		set_cached_acl(inode, type, acl);
err_out:
	posix_acl_release(acl);
	return retval;
}

const struct xattr_handler v9fs_xattr_acl_access_handler = {
	.prefix	= POSIX_ACL_XATTR_ACCESS,
	.flags	= ACL_TYPE_ACCESS,
	.get	= v9fs_xattr_get_acl,
	.set	= v9fs_xattr_set_acl,
};

const struct xattr_handler v9fs_xattr_acl_default_handler = {
	.prefix	= POSIX_ACL_XATTR_DEFAULT,
	.flags	= ACL_TYPE_DEFAULT,
	.get	= v9fs_xattr_get_acl,
	.set	= v9fs_xattr_set_acl,
};
Commit	Line	Data
85ff872d AK	1	/*
	2	* Copyright IBM Corporation, 2010
	3	* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of version 2.1 of the GNU Lesser General Public License
	7	* as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it would be useful, but
	10	* WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	12	*
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/fs.h>
	17	#include <net/9p/9p.h>
	18	#include <net/9p/client.h>
	19	#include <linux/slab.h>
22d8dcdf	20	#include <linux/sched.h>
85ff872d AK	21	#include <linux/posix_acl_xattr.h>
	22	#include "xattr.h"
	23	#include "acl.h"
22d8dcdf	24	#include "v9fs_vfs.h"
76381a42	25	#include "v9fs.h"
85ff872d AK	26
	27	static struct posix_acl __v9fs_get_acl(struct p9_fid fid, char *name)
	28	{
	29	ssize_t size;
	30	void *value = NULL;
009ca389	31	struct posix_acl *acl = NULL;
85ff872d AK	32
	33	size = v9fs_fid_xattr_get(fid, name, NULL, 0);
	34	if (size > 0) {
	35	value = kzalloc(size, GFP_NOFS);
	36	if (!value)
	37	return ERR_PTR(-ENOMEM);
	38	size = v9fs_fid_xattr_get(fid, name, value, size);
	39	if (size > 0) {
	40	acl = posix_acl_from_xattr(value, size);
	41	if (IS_ERR(acl))
	42	goto err_out;
	43	}
	44	} else if (size == -ENODATA \|\| size == 0 \|\|
	45	size == -ENOSYS \|\| size == -EOPNOTSUPP) {
	46	acl = NULL;
	47	} else
	48	acl = ERR_PTR(-EIO);
	49
	50	err_out:
	51	kfree(value);
	52	return acl;
	53	}
	54
	55	int v9fs_get_acl(struct inode inode, struct p9_fid fid)
	56	{
	57	int retval = 0;
	58	struct posix_acl pacl, dacl;
76381a42	59	struct v9fs_session_info *v9ses;
85ff872d	60
76381a42 AK	61	v9ses = v9fs_inode2v9ses(inode);
	62	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
	63	set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
	64	set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
	65	return 0;
	66	}
85ff872d AK	67	/* get the default/access acl values and cache them */
	68	dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT);
	69	pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS);
	70
	71	if (!IS_ERR(dacl) && !IS_ERR(pacl)) {
	72	set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
	73	set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);
85ff872d AK	74	} else
	75	retval = -EIO;
	76
c61fa0d6 VJJ	77	if (!IS_ERR(dacl))
	78	posix_acl_release(dacl);
	79
	80	if (!IS_ERR(pacl))
	81	posix_acl_release(pacl);
	82
85ff872d AK	83	return retval;
	84	}
	85
	86	static struct posix_acl v9fs_get_cached_acl(struct inode inode, int type)
	87	{
	88	struct posix_acl *acl;
	89	/*
	90	* 9p Always cache the acl value when
	91	* instantiating the inode (v9fs_inode_from_fid)
	92	*/
	93	acl = get_cached_acl(inode, type);
	94	BUG_ON(acl == ACL_NOT_CACHED);
	95	return acl;
	96	}
	97
b74c79e9	98	int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags)
85ff872d	99	{
76381a42 AK	100	struct posix_acl *acl;
	101	struct v9fs_session_info *v9ses;
	102
b74c79e9 NP	103	if (flags & IPERM_FLAG_RCU)
	104	return -ECHILD;
	105
76381a42 AK	106	v9ses = v9fs_inode2v9ses(inode);
	107	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) {
	108	/*
	109	* On access = client mode get the acl
	110	* values from the server
	111	*/
	112	return 0;
	113	}
	114	acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
85ff872d AK	115
	116	if (IS_ERR(acl))
	117	return PTR_ERR(acl);
	118	if (acl) {
	119	int error = posix_acl_permission(inode, acl, mask);
	120	posix_acl_release(acl);
	121	return error;
	122	}
	123	return -EAGAIN;
	124	}
7a4566b0	125
6e8dc555 AK	126	static int v9fs_set_acl(struct dentry dentry, int type, struct posix_acl acl)
	127	{
	128	int retval;
	129	char *name;
	130	size_t size;
	131	void *buffer;
	132	struct inode *inode = dentry->d_inode;
	133
	134	set_cached_acl(inode, type, acl);
	135	/* Set a setxattr request to server */
	136	size = posix_acl_xattr_size(acl->a_count);
	137	buffer = kmalloc(size, GFP_KERNEL);
	138	if (!buffer)
	139	return -ENOMEM;
	140	retval = posix_acl_to_xattr(acl, buffer, size);
	141	if (retval < 0)
	142	goto err_free_out;
	143	switch (type) {
	144	case ACL_TYPE_ACCESS:
	145	name = POSIX_ACL_XATTR_ACCESS;
	146	break;
	147	case ACL_TYPE_DEFAULT:
	148	name = POSIX_ACL_XATTR_DEFAULT;
	149	break;
	150	default:
	151	BUG();
	152	}
	153	retval = v9fs_xattr_set(dentry, name, buffer, size, 0);
	154	err_free_out:
	155	kfree(buffer);
	156	return retval;
	157	}
	158
	159	int v9fs_acl_chmod(struct dentry *dentry)
	160	{
	161	int retval = 0;
	162	struct posix_acl acl, clone;
	163	struct inode *inode = dentry->d_inode;
	164
	165	if (S_ISLNK(inode->i_mode))
	166	return -EOPNOTSUPP;
	167	acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
	168	if (acl) {
	169	clone = posix_acl_clone(acl, GFP_KERNEL);
	170	posix_acl_release(acl);
	171	if (!clone)
	172	return -ENOMEM;
	173	retval = posix_acl_chmod_masq(clone, inode->i_mode);
	174	if (!retval)
	175	retval = v9fs_set_acl(dentry, ACL_TYPE_ACCESS, clone);
	176	posix_acl_release(clone);
	177	}
	178	return retval;
	179	}
	180
ad77dbce AK	181	int v9fs_set_create_acl(struct dentry *dentry,
	182	struct posix_acl dpacl, struct posix_acl pacl)
	183	{
	184	if (dpacl)
	185	v9fs_set_acl(dentry, ACL_TYPE_DEFAULT, dpacl);
	186	if (pacl)
	187	v9fs_set_acl(dentry, ACL_TYPE_ACCESS, pacl);
	188	posix_acl_release(dpacl);
	189	posix_acl_release(pacl);
	190	return 0;
	191	}
	192
	193	int v9fs_acl_mode(struct inode dir, mode_t modep,
	194	struct posix_acl dpacl, struct posix_acl pacl)
	195	{
	196	int retval = 0;
	197	mode_t mode = *modep;
	198	struct posix_acl *acl = NULL;
	199
	200	if (!S_ISLNK(mode)) {
	201	acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
	202	if (IS_ERR(acl))
	203	return PTR_ERR(acl);
	204	if (!acl)
	205	mode &= ~current_umask();
	206	}
	207	if (acl) {
	208	struct posix_acl *clone;
	209
	210	if (S_ISDIR(mode))
	211	*dpacl = acl;
	212	clone = posix_acl_clone(acl, GFP_NOFS);
	213	retval = -ENOMEM;
	214	if (!clone)
	215	goto cleanup;
	216
	217	retval = posix_acl_create_masq(clone, &mode);
	218	if (retval < 0) {
	219	posix_acl_release(clone);
	220	goto cleanup;
	221	}
	222	if (retval > 0)
	223	*pacl = clone;
	224	}
	225	*modep = mode;
	226	return 0;
	227	cleanup:
	228	posix_acl_release(acl);
	229	return retval;
	230
	231	}
	232
76381a42 AK	233	static int v9fs_remote_get_acl(struct dentry dentry, const char name,
	234	void *buffer, size_t size, int type)
	235	{
	236	char *full_name;
	237
	238	switch (type) {
	239	case ACL_TYPE_ACCESS:
	240	full_name = POSIX_ACL_XATTR_ACCESS;
	241	break;
	242	case ACL_TYPE_DEFAULT:
	243	full_name = POSIX_ACL_XATTR_DEFAULT;
	244	break;
	245	default:
	246	BUG();
	247	}
	248	return v9fs_xattr_get(dentry, full_name, buffer, size);
	249	}
	250
7a4566b0 AK	251	static int v9fs_xattr_get_acl(struct dentry dentry, const char name,
	252	void *buffer, size_t size, int type)
	253	{
76381a42	254	struct v9fs_session_info *v9ses;
7a4566b0 AK	255	struct posix_acl *acl;
	256	int error;
	257
	258	if (strcmp(name, "") != 0)
	259	return -EINVAL;
	260
76381a42 AK	261	v9ses = v9fs_inode2v9ses(dentry->d_inode);
	262	/*
	263	* We allow set/get/list of acl when access=client is not specified
	264	*/
	265	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
	266	return v9fs_remote_get_acl(dentry, name, buffer, size, type);
	267
7a4566b0 AK	268	acl = v9fs_get_cached_acl(dentry->d_inode, type);
	269	if (IS_ERR(acl))
	270	return PTR_ERR(acl);
	271	if (acl == NULL)
	272	return -ENODATA;
	273	error = posix_acl_to_xattr(acl, buffer, size);
	274	posix_acl_release(acl);
	275
	276	return error;
	277	}
	278
76381a42 AK	279	static int v9fs_remote_set_acl(struct dentry dentry, const char name,
	280	const void *value, size_t size,
	281	int flags, int type)
	282	{
	283	char *full_name;
	284
	285	switch (type) {
	286	case ACL_TYPE_ACCESS:
	287	full_name = POSIX_ACL_XATTR_ACCESS;
	288	break;
	289	case ACL_TYPE_DEFAULT:
	290	full_name = POSIX_ACL_XATTR_DEFAULT;
	291	break;
	292	default:
	293	BUG();
	294	}
	295	return v9fs_xattr_set(dentry, full_name, value, size, flags);
	296	}
	297
	298
7a4566b0 AK	299	static int v9fs_xattr_set_acl(struct dentry dentry, const char name,
	300	const void *value, size_t size,
	301	int flags, int type)
	302	{
22d8dcdf AK	303	int retval;
22d8dcdf AK	304	struct posix_acl *acl;
76381a42	305	struct v9fs_session_info *v9ses;
22d8dcdf AK	306	struct inode *inode = dentry->d_inode;
	307
	308	if (strcmp(name, "") != 0)
	309	return -EINVAL;
76381a42 AK	310
	311	v9ses = v9fs_inode2v9ses(dentry->d_inode);
	312	/*
	313	* set the attribute on the remote. Without even looking at the
	314	* xattr value. We leave it to the server to validate
	315	*/
	316	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
	317	return v9fs_remote_set_acl(dentry, name,
	318	value, size, flags, type);
	319
22d8dcdf AK	320	if (S_ISLNK(inode->i_mode))
	321	return -EOPNOTSUPP;
	322	if (!is_owner_or_cap(inode))
	323	return -EPERM;
	324	if (value) {
	325	/* update the cached acl value */
	326	acl = posix_acl_from_xattr(value, size);
	327	if (IS_ERR(acl))
	328	return PTR_ERR(acl);
	329	else if (acl) {
	330	retval = posix_acl_valid(acl);
	331	if (retval)
	332	goto err_out;
	333	}
	334	} else
	335	acl = NULL;
	336
	337	switch (type) {
	338	case ACL_TYPE_ACCESS:
	339	name = POSIX_ACL_XATTR_ACCESS;
	340	if (acl) {
	341	mode_t mode = inode->i_mode;
	342	retval = posix_acl_equiv_mode(acl, &mode);
	343	if (retval < 0)
	344	goto err_out;
	345	else {
	346	struct iattr iattr;
	347	if (retval == 0) {
	348	/*
	349	* ACL can be represented
	350	* by the mode bits. So don't
	351	* update ACL.
	352	*/
	353	acl = NULL;
	354	value = NULL;
	355	size = 0;
	356	}
	357	/* Updte the mode bits */
	358	iattr.ia_mode = ((mode & S_IALLUGO) \|
	359	(inode->i_mode & ~S_IALLUGO));
	360	iattr.ia_valid = ATTR_MODE;
	361	/* FIXME should we update ctime ?
	362	* What is the following setxattr update the
	363	* mode ?
	364	*/
	365	v9fs_vfs_setattr_dotl(dentry, &iattr);
	366	}
	367	}
	368	break;
	369	case ACL_TYPE_DEFAULT:
	370	name = POSIX_ACL_XATTR_DEFAULT;
	371	if (!S_ISDIR(inode->i_mode)) {
6f81c115	372	retval = acl ? -EINVAL : 0;
22d8dcdf AK	373	goto err_out;
	374	}
	375	break;
	376	default:
	377	BUG();
	378	}
	379	retval = v9fs_xattr_set(dentry, name, value, size, flags);
	380	if (!retval)
	381	set_cached_acl(inode, type, acl);
	382	err_out:
	383	posix_acl_release(acl);
	384	return retval;
7a4566b0 AK	385	}
	386
	387	const struct xattr_handler v9fs_xattr_acl_access_handler = {
	388	.prefix = POSIX_ACL_XATTR_ACCESS,
	389	.flags = ACL_TYPE_ACCESS,
	390	.get = v9fs_xattr_get_acl,
	391	.set = v9fs_xattr_set_acl,
	392	};
	393
	394	const struct xattr_handler v9fs_xattr_acl_default_handler = {
	395	.prefix = POSIX_ACL_XATTR_DEFAULT,
	396	.flags = ACL_TYPE_DEFAULT,
	397	.get = v9fs_xattr_get_acl,
	398	.set = v9fs_xattr_set_acl,
	399	};