[deliverable/linux.git] / fs / xfs / linux-2.6 / xfs_acl.c

/*
 * Copyright (c) 2008, Christoph Hellwig
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_acl.h"
#include "xfs_attr.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_vnodeops.h"
#include "xfs_trace.h"
#include <linux/slab.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>


/*
 * Locking scheme:
 *  - all ACL updates are protected by inode->i_mutex, which is taken before
 *    calling into this file.
 */

STATIC struct posix_acl *
xfs_acl_from_disk(struct xfs_acl *aclp)
{
	struct posix_acl_entry *acl_e;
	struct posix_acl *acl;
	struct xfs_acl_entry *ace;
	int count, i;

	count = be32_to_cpu(aclp->acl_cnt);

	acl = posix_acl_alloc(count, GFP_KERNEL);
	if (!acl)
		return ERR_PTR(-ENOMEM);

	for (i = 0; i < count; i++) {
		acl_e = &acl->a_entries[i];
		ace = &aclp->acl_entry[i];

		/*
		 * The tag is 32 bits on disk and 16 bits in core.
		 *
		 * Because every access to it goes through the core
		 * format first this is not a problem.
		 */
		acl_e->e_tag = be32_to_cpu(ace->ae_tag);
		acl_e->e_perm = be16_to_cpu(ace->ae_perm);

		switch (acl_e->e_tag) {
		case ACL_USER:
		case ACL_GROUP:
			acl_e->e_id = be32_to_cpu(ace->ae_id);
			break;
		case ACL_USER_OBJ:
		case ACL_GROUP_OBJ:
		case ACL_MASK:
		case ACL_OTHER:
			acl_e->e_id = ACL_UNDEFINED_ID;
			break;
		default:
			goto fail;
		}
	}
	return acl;

fail:
	posix_acl_release(acl);
	return ERR_PTR(-EINVAL);
}

STATIC void
xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
{
	const struct posix_acl_entry *acl_e;
	struct xfs_acl_entry *ace;
	int i;

	aclp->acl_cnt = cpu_to_be32(acl->a_count);
	for (i = 0; i < acl->a_count; i++) {
		ace = &aclp->acl_entry[i];
		acl_e = &acl->a_entries[i];

		ace->ae_tag = cpu_to_be32(acl_e->e_tag);
		ace->ae_id = cpu_to_be32(acl_e->e_id);
		ace->ae_perm = cpu_to_be16(acl_e->e_perm);
	}
}

struct posix_acl *
xfs_get_acl(struct inode *inode, int type)
{
	struct xfs_inode *ip = XFS_I(inode);
	struct posix_acl *acl;
	struct xfs_acl *xfs_acl;
	int len = sizeof(struct xfs_acl);
	unsigned char *ea_name;
	int error;

	acl = get_cached_acl(inode, type);
	if (acl != ACL_NOT_CACHED)
		return acl;

	switch (type) {
	case ACL_TYPE_ACCESS:
		ea_name = SGI_ACL_FILE;
		break;
	case ACL_TYPE_DEFAULT:
		ea_name = SGI_ACL_DEFAULT;
		break;
	default:
		BUG();
	}

	/*
	 * If we have a cached ACLs value just return it, not need to
	 * go out to the disk.
	 */

	xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
	if (!xfs_acl)
		return ERR_PTR(-ENOMEM);

	error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
							&len, ATTR_ROOT);
	if (error) {
		/*
		 * If the attribute doesn't exist make sure we have a negative
		 * cache entry, for any other error assume it is transient and
		 * leave the cache entry as ACL_NOT_CACHED.
		 */
		if (error == -ENOATTR) {
			acl = NULL;
			goto out_update_cache;
		}
		goto out;
	}

	acl = xfs_acl_from_disk(xfs_acl);
	if (IS_ERR(acl))
		goto out;

 out_update_cache:
	set_cached_acl(inode, type, acl);
 out:
	kfree(xfs_acl);
	return acl;
}

STATIC int
xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
{
	struct xfs_inode *ip = XFS_I(inode);
	unsigned char *ea_name;
	int error;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	switch (type) {
	case ACL_TYPE_ACCESS:
		ea_name = SGI_ACL_FILE;
		break;
	case ACL_TYPE_DEFAULT:
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EACCES : 0;
		ea_name = SGI_ACL_DEFAULT;
		break;
	default:
		return -EINVAL;
	}

	if (acl) {
		struct xfs_acl *xfs_acl;
		int len;

		xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
		if (!xfs_acl)
			return -ENOMEM;

		xfs_acl_to_disk(xfs_acl, acl);
		len = sizeof(struct xfs_acl) -
			(sizeof(struct xfs_acl_entry) *
			 (XFS_ACL_MAX_ENTRIES - acl->a_count));

		error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
				len, ATTR_ROOT);

		kfree(xfs_acl);
	} else {
		/*
		 * A NULL ACL argument means we want to remove the ACL.
		 */
		error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);

		/*
		 * If the attribute didn't exist to start with that's fine.
		 */
		if (error == -ENOATTR)
			error = 0;
	}

	if (!error)
		set_cached_acl(inode, type, acl);
	return error;
}

int
xfs_check_acl(struct inode *inode, int mask, unsigned int flags)
{
	struct xfs_inode *ip;
	struct posix_acl *acl;
	int error = -EAGAIN;

	if (flags & IPERM_FLAG_RCU)
		return -ECHILD;

	ip = XFS_I(inode);
	trace_xfs_check_acl(ip);

	/*
	 * If there is no attribute fork no ACL exists on this inode and
	 * we can skip the whole exercise.
	 */
	if (!XFS_IFORK_Q(ip))
		return -EAGAIN;

	acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl) {
		error = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
	}

	return error;
}

static int
xfs_set_mode(struct inode *inode, mode_t mode)
{
	int error = 0;

	if (mode != inode->i_mode) {
		struct iattr iattr;

		iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
		iattr.ia_mode = mode;
		iattr.ia_ctime = current_fs_time(inode->i_sb);

		error = -xfs_setattr(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
	}

	return error;
}

static int
xfs_acl_exists(struct inode *inode, unsigned char *name)
{
	int len = sizeof(struct xfs_acl);

	return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
			    ATTR_ROOT|ATTR_KERNOVAL) == 0);
}

int
posix_acl_access_exists(struct inode *inode)
{
	return xfs_acl_exists(inode, SGI_ACL_FILE);
}

int
posix_acl_default_exists(struct inode *inode)
{
	if (!S_ISDIR(inode->i_mode))
		return 0;
	return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
}

/*
 * No need for i_mutex because the inode is not yet exposed to the VFS.
 */
int
xfs_inherit_acl(struct inode *inode, struct posix_acl *default_acl)
{
	struct posix_acl *clone;
	mode_t mode;
	int error = 0, inherit = 0;

	if (S_ISDIR(inode->i_mode)) {
		error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl);
		if (error)
			return error;
	}

	clone = posix_acl_clone(default_acl, GFP_KERNEL);
	if (!clone)
		return -ENOMEM;

	mode = inode->i_mode;
	error = posix_acl_create_masq(clone, &mode);
	if (error < 0)
		goto out_release_clone;

	/*
	 * If posix_acl_create_masq returns a positive value we need to
	 * inherit a permission that can't be represented using the Unix
	 * mode bits and we actually need to set an ACL.
	 */
	if (error > 0)
		inherit = 1;

	error = xfs_set_mode(inode, mode);
	if (error)
		goto out_release_clone;

	if (inherit)
		error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);

 out_release_clone:
	posix_acl_release(clone);
	return error;
}

int
xfs_acl_chmod(struct inode *inode)
{
	struct posix_acl *acl, *clone;
	int error;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl) || !acl)
		return PTR_ERR(acl);

	clone = posix_acl_clone(acl, GFP_KERNEL);
	posix_acl_release(acl);
	if (!clone)
		return -ENOMEM;

	error = posix_acl_chmod_masq(clone, inode->i_mode);
	if (!error)
		error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);

	posix_acl_release(clone);
	return error;
}

static int
xfs_xattr_acl_get(struct dentry *dentry, const char *name,
		void *value, size_t size, int type)
{
	struct posix_acl *acl;
	int error;

	acl = xfs_get_acl(dentry->d_inode, type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl == NULL)
		return -ENODATA;

	error = posix_acl_to_xattr(acl, value, size);
	posix_acl_release(acl);

	return error;
}

static int
xfs_xattr_acl_set(struct dentry *dentry, const char *name,
		const void *value, size_t size, int flags, int type)
{
	struct inode *inode = dentry->d_inode;
	struct posix_acl *acl = NULL;
	int error = 0;

	if (flags & XATTR_CREATE)
		return -EINVAL;
	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
		return value ? -EACCES : 0;
	if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
		return -EPERM;

	if (!value)
		goto set_acl;

	acl = posix_acl_from_xattr(value, size);
	if (!acl) {
		/*
		 * acl_set_file(3) may request that we set default ACLs with
		 * zero length -- defend (gracefully) against that here.
		 */
		goto out;
	}
	if (IS_ERR(acl)) {
		error = PTR_ERR(acl);
		goto out;
	}

	error = posix_acl_valid(acl);
	if (error)
		goto out_release;

	error = -EINVAL;
	if (acl->a_count > XFS_ACL_MAX_ENTRIES)
		goto out_release;

	if (type == ACL_TYPE_ACCESS) {
		mode_t mode = inode->i_mode;
		error = posix_acl_equiv_mode(acl, &mode);

		if (error <= 0) {
			posix_acl_release(acl);
			acl = NULL;

			if (error < 0)
				return error;
		}

		error = xfs_set_mode(inode, mode);
		if (error)
			goto out_release;
	}

 set_acl:
	error = xfs_set_acl(inode, type, acl);
 out_release:
	posix_acl_release(acl);
 out:
	return error;
}

const struct xattr_handler xfs_xattr_acl_access_handler = {
	.prefix	= POSIX_ACL_XATTR_ACCESS,
	.flags	= ACL_TYPE_ACCESS,
	.get	= xfs_xattr_acl_get,
	.set	= xfs_xattr_acl_set,
};

const struct xattr_handler xfs_xattr_acl_default_handler = {
	.prefix	= POSIX_ACL_XATTR_DEFAULT,
	.flags	= ACL_TYPE_DEFAULT,
	.get	= xfs_xattr_acl_get,
	.set	= xfs_xattr_acl_set,
};
Commit	Line	Data
ef14f0c1 CH	1	/*
	2	* Copyright (c) 2008, Christoph Hellwig
	3	* All Rights Reserved.
	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public License as
	7	* published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it would be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write the Free Software Foundation,
	16	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	17	*/
	18	#include "xfs.h"
	19	#include "xfs_acl.h"
	20	#include "xfs_attr.h"
	21	#include "xfs_bmap_btree.h"
	22	#include "xfs_inode.h"
	23	#include "xfs_vnodeops.h"
0b1b213f	24	#include "xfs_trace.h"
5a0e3ad6	25	#include <linux/slab.h>
ef14f0c1 CH	26	#include <linux/xattr.h>
	27	#include <linux/posix_acl_xattr.h>
	28
	29
ef14f0c1 CH	30	/*
	31	* Locking scheme:
	32	* - all ACL updates are protected by inode->i_mutex, which is taken before
	33	* calling into this file.
ef14f0c1 CH	34	*/
	35
	36	STATIC struct posix_acl *
	37	xfs_acl_from_disk(struct xfs_acl *aclp)
	38	{
	39	struct posix_acl_entry *acl_e;
	40	struct posix_acl *acl;
	41	struct xfs_acl_entry *ace;
	42	int count, i;
	43
	44	count = be32_to_cpu(aclp->acl_cnt);
	45
	46	acl = posix_acl_alloc(count, GFP_KERNEL);
	47	if (!acl)
	48	return ERR_PTR(-ENOMEM);
	49
	50	for (i = 0; i < count; i++) {
	51	acl_e = &acl->a_entries[i];
	52	ace = &aclp->acl_entry[i];
	53
	54	/*
	55	* The tag is 32 bits on disk and 16 bits in core.
	56	*
	57	* Because every access to it goes through the core
	58	* format first this is not a problem.
	59	*/
	60	acl_e->e_tag = be32_to_cpu(ace->ae_tag);
	61	acl_e->e_perm = be16_to_cpu(ace->ae_perm);
	62
	63	switch (acl_e->e_tag) {
	64	case ACL_USER:
	65	case ACL_GROUP:
	66	acl_e->e_id = be32_to_cpu(ace->ae_id);
	67	break;
	68	case ACL_USER_OBJ:
	69	case ACL_GROUP_OBJ:
	70	case ACL_MASK:
	71	case ACL_OTHER:
	72	acl_e->e_id = ACL_UNDEFINED_ID;
	73	break;
	74	default:
	75	goto fail;
	76	}
	77	}
	78	return acl;
	79
	80	fail:
	81	posix_acl_release(acl);
	82	return ERR_PTR(-EINVAL);
	83	}
	84
	85	STATIC void
	86	xfs_acl_to_disk(struct xfs_acl aclp, const struct posix_acl acl)
	87	{
	88	const struct posix_acl_entry *acl_e;
	89	struct xfs_acl_entry *ace;
	90	int i;
	91
	92	aclp->acl_cnt = cpu_to_be32(acl->a_count);
	93	for (i = 0; i < acl->a_count; i++) {
	94	ace = &aclp->acl_entry[i];
	95	acl_e = &acl->a_entries[i];
	96
	97	ace->ae_tag = cpu_to_be32(acl_e->e_tag);
98	ace->ae_id = cpu_to_be32(acl_e->e_id);
99	ace->ae_perm = cpu_to_be16(acl_e->e_perm);
100	}
101	}
102
ef14f0c1 CH	103	struct posix_acl *
	104	xfs_get_acl(struct inode *inode, int type)
	105	{
	106	struct xfs_inode *ip = XFS_I(inode);
1cbd20d8	107	struct posix_acl *acl;
ef14f0c1 CH	108	struct xfs_acl *xfs_acl;
ef14f0c1 CH	109	int len = sizeof(struct xfs_acl);
a9273ca5	110	unsigned char *ea_name;
ef14f0c1 CH	111	int error;
ef14f0c1 CH	112
1cbd20d8 AV	113	acl = get_cached_acl(inode, type);
	114	if (acl != ACL_NOT_CACHED)
	115	return acl;
	116
ef14f0c1 CH	117	switch (type) {
	118	case ACL_TYPE_ACCESS:
	119	ea_name = SGI_ACL_FILE;
ef14f0c1 CH	120	break;
	121	case ACL_TYPE_DEFAULT:
	122	ea_name = SGI_ACL_DEFAULT;
ef14f0c1 CH	123	break;
ef14f0c1 CH	124	default:
1cbd20d8	125	BUG();
ef14f0c1 CH	126	}
ef14f0c1 CH	127
ef14f0c1 CH	128	/*
	129	* If we have a cached ACLs value just return it, not need to
	130	* go out to the disk.
	131	*/
ef14f0c1 CH	132
	133	xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
	134	if (!xfs_acl)
	135	return ERR_PTR(-ENOMEM);
	136
a9273ca5 DC	137	error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
a9273ca5 DC	138	&len, ATTR_ROOT);
ef14f0c1 CH	139	if (error) {
	140	/*
	141	* If the attribute doesn't exist make sure we have a negative
	142	* cache entry, for any other error assume it is transient and
1cbd20d8	143	* leave the cache entry as ACL_NOT_CACHED.
ef14f0c1 CH	144	*/
	145	if (error == -ENOATTR) {
	146	acl = NULL;
	147	goto out_update_cache;
	148	}
	149	goto out;
	150	}
	151
	152	acl = xfs_acl_from_disk(xfs_acl);
	153	if (IS_ERR(acl))
	154	goto out;
	155
	156	out_update_cache:
1cbd20d8	157	set_cached_acl(inode, type, acl);
ef14f0c1 CH	158	out:
	159	kfree(xfs_acl);
	160	return acl;
	161	}
	162
	163	STATIC int
	164	xfs_set_acl(struct inode inode, int type, struct posix_acl acl)
	165	{
	166	struct xfs_inode *ip = XFS_I(inode);
a9273ca5	167	unsigned char *ea_name;
ef14f0c1 CH	168	int error;
	169
	170	if (S_ISLNK(inode->i_mode))
	171	return -EOPNOTSUPP;
	172
	173	switch (type) {
	174	case ACL_TYPE_ACCESS:
	175	ea_name = SGI_ACL_FILE;
ef14f0c1 CH	176	break;
	177	case ACL_TYPE_DEFAULT:
	178	if (!S_ISDIR(inode->i_mode))
	179	return acl ? -EACCES : 0;
	180	ea_name = SGI_ACL_DEFAULT;
ef14f0c1 CH	181	break;
	182	default:
	183	return -EINVAL;
	184	}
	185
	186	if (acl) {
	187	struct xfs_acl *xfs_acl;
	188	int len;
	189
	190	xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
	191	if (!xfs_acl)
	192	return -ENOMEM;
	193
	194	xfs_acl_to_disk(xfs_acl, acl);
	195	len = sizeof(struct xfs_acl) -
	196	(sizeof(struct xfs_acl_entry) *
	197	(XFS_ACL_MAX_ENTRIES - acl->a_count));
	198
a9273ca5	199	error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
ef14f0c1 CH	200	len, ATTR_ROOT);
	201
	202	kfree(xfs_acl);
	203	} else {
	204	/*
	205	* A NULL ACL argument means we want to remove the ACL.
	206	*/
	207	error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
	208
	209	/*
	210	* If the attribute didn't exist to start with that's fine.
	211	*/
	212	if (error == -ENOATTR)
	213	error = 0;
	214	}
	215
	216	if (!error)
1cbd20d8	217	set_cached_acl(inode, type, acl);
ef14f0c1 CH	218	return error;
	219	}
	220
	221	int
b74c79e9	222	xfs_check_acl(struct inode *inode, int mask, unsigned int flags)
ef14f0c1	223	{
b74c79e9	224	struct xfs_inode *ip;
ef14f0c1 CH	225	struct posix_acl *acl;
	226	int error = -EAGAIN;
	227
b74c79e9 NP	228	if (flags & IPERM_FLAG_RCU)
	229	return -ECHILD;
	230
	231	ip = XFS_I(inode);
cca28fb8	232	trace_xfs_check_acl(ip);
ef14f0c1 CH	233
	234	/*
	235	* If there is no attribute fork no ACL exists on this inode and
	236	* we can skip the whole exercise.
	237	*/
	238	if (!XFS_IFORK_Q(ip))
	239	return -EAGAIN;
	240
	241	acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
	242	if (IS_ERR(acl))
	243	return PTR_ERR(acl);
	244	if (acl) {
	245	error = posix_acl_permission(inode, acl, mask);
	246	posix_acl_release(acl);
	247	}
	248
	249	return error;
	250	}
	251
	252	static int
	253	xfs_set_mode(struct inode *inode, mode_t mode)
	254	{
	255	int error = 0;
	256
	257	if (mode != inode->i_mode) {
	258	struct iattr iattr;
	259
d6d59bad	260	iattr.ia_valid = ATTR_MODE \| ATTR_CTIME;
ef14f0c1	261	iattr.ia_mode = mode;
d6d59bad	262	iattr.ia_ctime = current_fs_time(inode->i_sb);
ef14f0c1 CH	263
	264	error = -xfs_setattr(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
	265	}
	266
	267	return error;
	268	}
	269
	270	static int
a9273ca5	271	xfs_acl_exists(struct inode inode, unsigned char name)
ef14f0c1 CH	272	{
	273	int len = sizeof(struct xfs_acl);
	274
	275	return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
	276	ATTR_ROOT\|ATTR_KERNOVAL) == 0);
	277	}
	278
	279	int
	280	posix_acl_access_exists(struct inode *inode)
	281	{
	282	return xfs_acl_exists(inode, SGI_ACL_FILE);
	283	}
	284
	285	int
	286	posix_acl_default_exists(struct inode *inode)
	287	{
	288	if (!S_ISDIR(inode->i_mode))
	289	return 0;
	290	return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
	291	}
	292
	293	/*
	294	* No need for i_mutex because the inode is not yet exposed to the VFS.
	295	*/
	296	int
	297	xfs_inherit_acl(struct inode inode, struct posix_acl default_acl)
	298	{
	299	struct posix_acl *clone;
	300	mode_t mode;
	301	int error = 0, inherit = 0;
	302
	303	if (S_ISDIR(inode->i_mode)) {
	304	error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl);
	305	if (error)
	306	return error;
	307	}
	308
	309	clone = posix_acl_clone(default_acl, GFP_KERNEL);
	310	if (!clone)
	311	return -ENOMEM;
	312
	313	mode = inode->i_mode;
	314	error = posix_acl_create_masq(clone, &mode);
	315	if (error < 0)
	316	goto out_release_clone;
	317
	318	/*
	319	* If posix_acl_create_masq returns a positive value we need to
	320	* inherit a permission that can't be represented using the Unix
	321	* mode bits and we actually need to set an ACL.
	322	*/
	323	if (error > 0)
	324	inherit = 1;
	325
	326	error = xfs_set_mode(inode, mode);
	327	if (error)
	328	goto out_release_clone;
	329
	330	if (inherit)
	331	error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
	332
	333	out_release_clone:
	334	posix_acl_release(clone);
	335	return error;
336	}
337
338	int
339	xfs_acl_chmod(struct inode *inode)
340	{
341	struct posix_acl acl, clone;
342	int error;
343
344	if (S_ISLNK(inode->i_mode))
345	return -EOPNOTSUPP;
346
347	acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
348	if (IS_ERR(acl) \|\| !acl)
349	return PTR_ERR(acl);
350
351	clone = posix_acl_clone(acl, GFP_KERNEL);
352	posix_acl_release(acl);
353	if (!clone)
354	return -ENOMEM;
355
356	error = posix_acl_chmod_masq(clone, inode->i_mode);
357	if (!error)
358	error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
359
360	posix_acl_release(clone);
361	return error;
362	}
363
ef14f0c1	364	static int
431547b3 CH	365	xfs_xattr_acl_get(struct dentry dentry, const char name,
431547b3 CH	366	void *value, size_t size, int type)
ef14f0c1 CH	367	{
ef14f0c1 CH	368	struct posix_acl *acl;
431547b3	369	int error;
ef14f0c1	370
431547b3	371	acl = xfs_get_acl(dentry->d_inode, type);
ef14f0c1 CH	372	if (IS_ERR(acl))
	373	return PTR_ERR(acl);
	374	if (acl == NULL)
	375	return -ENODATA;
	376
	377	error = posix_acl_to_xattr(acl, value, size);
	378	posix_acl_release(acl);
	379
	380	return error;
	381	}
	382
	383	static int
431547b3 CH	384	xfs_xattr_acl_set(struct dentry dentry, const char name,
431547b3 CH	385	const void *value, size_t size, int flags, int type)
ef14f0c1	386	{
431547b3	387	struct inode *inode = dentry->d_inode;
ef14f0c1	388	struct posix_acl *acl = NULL;
431547b3	389	int error = 0;
ef14f0c1	390
ef14f0c1 CH	391	if (flags & XATTR_CREATE)
	392	return -EINVAL;
	393	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
	394	return value ? -EACCES : 0;
	395	if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
	396	return -EPERM;
	397
	398	if (!value)
	399	goto set_acl;
	400
	401	acl = posix_acl_from_xattr(value, size);
	402	if (!acl) {
	403	/*
	404	* acl_set_file(3) may request that we set default ACLs with
	405	* zero length -- defend (gracefully) against that here.
	406	*/
	407	goto out;
	408	}
	409	if (IS_ERR(acl)) {
	410	error = PTR_ERR(acl);
	411	goto out;
	412	}
	413
	414	error = posix_acl_valid(acl);
	415	if (error)
	416	goto out_release;
	417
	418	error = -EINVAL;
	419	if (acl->a_count > XFS_ACL_MAX_ENTRIES)
	420	goto out_release;
	421
	422	if (type == ACL_TYPE_ACCESS) {
	423	mode_t mode = inode->i_mode;
	424	error = posix_acl_equiv_mode(acl, &mode);
	425
	426	if (error <= 0) {
	427	posix_acl_release(acl);
	428	acl = NULL;
	429
	430	if (error < 0)
	431	return error;
	432	}
	433
	434	error = xfs_set_mode(inode, mode);
	435	if (error)
	436	goto out_release;
	437	}
	438
	439	set_acl:
	440	error = xfs_set_acl(inode, type, acl);
	441	out_release:
	442	posix_acl_release(acl);
	443	out:
	444	return error;
	445	}
	446
46e58764	447	const struct xattr_handler xfs_xattr_acl_access_handler = {
431547b3 CH	448	.prefix = POSIX_ACL_XATTR_ACCESS,
	449	.flags = ACL_TYPE_ACCESS,
	450	.get = xfs_xattr_acl_get,
	451	.set = xfs_xattr_acl_set,
	452	};
	453
46e58764	454	const struct xattr_handler xfs_xattr_acl_default_handler = {
431547b3 CH	455	.prefix = POSIX_ACL_XATTR_DEFAULT,
	456	.flags = ACL_TYPE_DEFAULT,
	457	.get = xfs_xattr_acl_get,
	458	.set = xfs_xattr_acl_set,
ef14f0c1	459	};