[linux.git] / fs / xfs / 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;
	unsigned int count, i;

	count = be32_to_cpu(aclp->acl_cnt);
	if (count > XFS_ACL_MAX_ENTRIES)
		return ERR_PTR(-EFSCORRUPTED);

	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;

	trace_xfs_get_acl(ip);

	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;
}

static int
xfs_set_mode(struct inode *inode, umode_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_nonsize(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 *acl)
{
	umode_t mode = inode->i_mode;
	int error = 0, inherit = 0;

	if (S_ISDIR(inode->i_mode)) {
		error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
		if (error)
			goto out;
	}

	error = posix_acl_create(&acl, GFP_KERNEL, &mode);
	if (error < 0)
		return error;

	/*
	 * If posix_acl_create 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;

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

out:
	posix_acl_release(acl);
	return error;
}

int
xfs_acl_chmod(struct inode *inode)
{
	struct posix_acl *acl;
	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);

	error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
	if (error)
		return error;

	error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
	posix_acl_release(acl);
	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) {
		umode_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;
093019cf	42	unsigned int count, i;
ef14f0c1 CH	43
ef14f0c1 CH	44	count = be32_to_cpu(aclp->acl_cnt);
fa8b18ed CH	45	if (count > XFS_ACL_MAX_ENTRIES)
fa8b18ed CH	46	return ERR_PTR(-EFSCORRUPTED);
ef14f0c1 CH	47
	48	acl = posix_acl_alloc(count, GFP_KERNEL);
	49	if (!acl)
	50	return ERR_PTR(-ENOMEM);
	51
	52	for (i = 0; i < count; i++) {
	53	acl_e = &acl->a_entries[i];
	54	ace = &aclp->acl_entry[i];
	55
	56	/*
	57	* The tag is 32 bits on disk and 16 bits in core.
	58	*
	59	* Because every access to it goes through the core
	60	* format first this is not a problem.
	61	*/
	62	acl_e->e_tag = be32_to_cpu(ace->ae_tag);
	63	acl_e->e_perm = be16_to_cpu(ace->ae_perm);
	64
	65	switch (acl_e->e_tag) {
	66	case ACL_USER:
	67	case ACL_GROUP:
	68	acl_e->e_id = be32_to_cpu(ace->ae_id);
	69	break;
	70	case ACL_USER_OBJ:
	71	case ACL_GROUP_OBJ:
	72	case ACL_MASK:
	73	case ACL_OTHER:
	74	acl_e->e_id = ACL_UNDEFINED_ID;
	75	break;
	76	default:
	77	goto fail;
	78	}
	79	}
	80	return acl;
	81
	82	fail:
	83	posix_acl_release(acl);
	84	return ERR_PTR(-EINVAL);
	85	}
	86
	87	STATIC void
	88	xfs_acl_to_disk(struct xfs_acl aclp, const struct posix_acl acl)
	89	{
	90	const struct posix_acl_entry *acl_e;
	91	struct xfs_acl_entry *ace;
	92	int i;
	93
	94	aclp->acl_cnt = cpu_to_be32(acl->a_count);
	95	for (i = 0; i < acl->a_count; i++) {
	96	ace = &aclp->acl_entry[i];
	97	acl_e = &acl->a_entries[i];
	98
	99	ace->ae_tag = cpu_to_be32(acl_e->e_tag);
	100	ace->ae_id = cpu_to_be32(acl_e->e_id);
	101	ace->ae_perm = cpu_to_be16(acl_e->e_perm);
	102	}
	103	}
	104
ef14f0c1 CH	105	struct posix_acl *
	106	xfs_get_acl(struct inode *inode, int type)
	107	{
	108	struct xfs_inode *ip = XFS_I(inode);
1cbd20d8	109	struct posix_acl *acl;
ef14f0c1 CH	110	struct xfs_acl *xfs_acl;
ef14f0c1 CH	111	int len = sizeof(struct xfs_acl);
a9273ca5	112	unsigned char *ea_name;
ef14f0c1 CH	113	int error;
ef14f0c1 CH	114
1cbd20d8 AV	115	acl = get_cached_acl(inode, type);
	116	if (acl != ACL_NOT_CACHED)
	117	return acl;
	118
4e34e719 CH	119	trace_xfs_get_acl(ip);
4e34e719 CH	120
ef14f0c1 CH	121	switch (type) {
	122	case ACL_TYPE_ACCESS:
	123	ea_name = SGI_ACL_FILE;
ef14f0c1 CH	124	break;
	125	case ACL_TYPE_DEFAULT:
	126	ea_name = SGI_ACL_DEFAULT;
ef14f0c1 CH	127	break;
ef14f0c1 CH	128	default:
1cbd20d8	129	BUG();
ef14f0c1 CH	130	}
ef14f0c1 CH	131
ef14f0c1 CH	132	/*
	133	* If we have a cached ACLs value just return it, not need to
	134	* go out to the disk.
	135	*/
ef14f0c1 CH	136
	137	xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
	138	if (!xfs_acl)
	139	return ERR_PTR(-ENOMEM);
	140
a9273ca5 DC	141	error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
a9273ca5 DC	142	&len, ATTR_ROOT);
ef14f0c1 CH	143	if (error) {
	144	/*
	145	* If the attribute doesn't exist make sure we have a negative
	146	* cache entry, for any other error assume it is transient and
1cbd20d8	147	* leave the cache entry as ACL_NOT_CACHED.
ef14f0c1 CH	148	*/
	149	if (error == -ENOATTR) {
	150	acl = NULL;
	151	goto out_update_cache;
	152	}
	153	goto out;
	154	}
	155
	156	acl = xfs_acl_from_disk(xfs_acl);
	157	if (IS_ERR(acl))
	158	goto out;
	159
	160	out_update_cache:
1cbd20d8	161	set_cached_acl(inode, type, acl);
ef14f0c1 CH	162	out:
	163	kfree(xfs_acl);
	164	return acl;
	165	}
	166
	167	STATIC int
	168	xfs_set_acl(struct inode inode, int type, struct posix_acl acl)
	169	{
	170	struct xfs_inode *ip = XFS_I(inode);
a9273ca5	171	unsigned char *ea_name;
ef14f0c1 CH	172	int error;
	173
	174	if (S_ISLNK(inode->i_mode))
	175	return -EOPNOTSUPP;
	176
	177	switch (type) {
	178	case ACL_TYPE_ACCESS:
	179	ea_name = SGI_ACL_FILE;
ef14f0c1 CH	180	break;
	181	case ACL_TYPE_DEFAULT:
	182	if (!S_ISDIR(inode->i_mode))
	183	return acl ? -EACCES : 0;
	184	ea_name = SGI_ACL_DEFAULT;
ef14f0c1 CH	185	break;
	186	default:
	187	return -EINVAL;
	188	}
	189
	190	if (acl) {
	191	struct xfs_acl *xfs_acl;
	192	int len;
	193
	194	xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
	195	if (!xfs_acl)
	196	return -ENOMEM;
	197
	198	xfs_acl_to_disk(xfs_acl, acl);
	199	len = sizeof(struct xfs_acl) -
	200	(sizeof(struct xfs_acl_entry) *
	201	(XFS_ACL_MAX_ENTRIES - acl->a_count));
	202
a9273ca5	203	error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
ef14f0c1 CH	204	len, ATTR_ROOT);
	205
	206	kfree(xfs_acl);
	207	} else {
	208	/*
	209	* A NULL ACL argument means we want to remove the ACL.
	210	*/
	211	error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
	212
	213	/*
	214	* If the attribute didn't exist to start with that's fine.
	215	*/
	216	if (error == -ENOATTR)
	217	error = 0;
	218	}
	219
	220	if (!error)
1cbd20d8	221	set_cached_acl(inode, type, acl);
ef14f0c1 CH	222	return error;
	223	}
	224
ef14f0c1	225	static int
d3fb6120	226	xfs_set_mode(struct inode *inode, umode_t mode)
ef14f0c1 CH	227	{
	228	int error = 0;
	229
	230	if (mode != inode->i_mode) {
	231	struct iattr iattr;
	232
d6d59bad	233	iattr.ia_valid = ATTR_MODE \| ATTR_CTIME;
ef14f0c1	234	iattr.ia_mode = mode;
d6d59bad	235	iattr.ia_ctime = current_fs_time(inode->i_sb);
ef14f0c1	236
c4ed4243	237	error = -xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
ef14f0c1 CH	238	}
	239
	240	return error;
	241	}
	242
	243	static int
a9273ca5	244	xfs_acl_exists(struct inode inode, unsigned char name)
ef14f0c1 CH	245	{
	246	int len = sizeof(struct xfs_acl);
	247
	248	return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
	249	ATTR_ROOT\|ATTR_KERNOVAL) == 0);
	250	}
	251
	252	int
	253	posix_acl_access_exists(struct inode *inode)
	254	{
	255	return xfs_acl_exists(inode, SGI_ACL_FILE);
	256	}
	257
	258	int
	259	posix_acl_default_exists(struct inode *inode)
	260	{
	261	if (!S_ISDIR(inode->i_mode))
	262	return 0;
	263	return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
	264	}
	265
	266	/*
	267	* No need for i_mutex because the inode is not yet exposed to the VFS.
	268	*/
	269	int
826cae2f	270	xfs_inherit_acl(struct inode inode, struct posix_acl acl)
ef14f0c1	271	{
d3fb6120	272	umode_t mode = inode->i_mode;
ef14f0c1 CH	273	int error = 0, inherit = 0;
	274
	275	if (S_ISDIR(inode->i_mode)) {
826cae2f	276	error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
ef14f0c1	277	if (error)
826cae2f	278	goto out;
ef14f0c1 CH	279	}
ef14f0c1 CH	280
826cae2f	281	error = posix_acl_create(&acl, GFP_KERNEL, &mode);
ef14f0c1	282	if (error < 0)
826cae2f	283	return error;
ef14f0c1 CH	284
ef14f0c1 CH	285	/*
826cae2f	286	* If posix_acl_create returns a positive value we need to
ef14f0c1 CH	287	* inherit a permission that can't be represented using the Unix
	288	* mode bits and we actually need to set an ACL.
	289	*/
	290	if (error > 0)
	291	inherit = 1;
	292
	293	error = xfs_set_mode(inode, mode);
	294	if (error)
826cae2f	295	goto out;
ef14f0c1 CH	296
ef14f0c1 CH	297	if (inherit)
826cae2f	298	error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
ef14f0c1	299
826cae2f AV	300	out:
826cae2f AV	301	posix_acl_release(acl);
ef14f0c1 CH	302	return error;
	303	}
	304
	305	int
	306	xfs_acl_chmod(struct inode *inode)
	307	{
bc26ab5f	308	struct posix_acl *acl;
ef14f0c1 CH	309	int error;
	310
	311	if (S_ISLNK(inode->i_mode))
	312	return -EOPNOTSUPP;
	313
	314	acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
	315	if (IS_ERR(acl) \|\| !acl)
	316	return PTR_ERR(acl);
	317
bc26ab5f AV	318	error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
	319	if (error)
	320	return error;
ef14f0c1	321
bc26ab5f AV	322	error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
bc26ab5f AV	323	posix_acl_release(acl);
ef14f0c1 CH	324	return error;
	325	}
	326
ef14f0c1	327	static int
431547b3 CH	328	xfs_xattr_acl_get(struct dentry dentry, const char name,
431547b3 CH	329	void *value, size_t size, int type)
ef14f0c1 CH	330	{
ef14f0c1 CH	331	struct posix_acl *acl;
431547b3	332	int error;
ef14f0c1	333
431547b3	334	acl = xfs_get_acl(dentry->d_inode, type);
ef14f0c1 CH	335	if (IS_ERR(acl))
	336	return PTR_ERR(acl);
	337	if (acl == NULL)
	338	return -ENODATA;
	339
	340	error = posix_acl_to_xattr(acl, value, size);
	341	posix_acl_release(acl);
	342
	343	return error;
	344	}
	345
	346	static int
431547b3 CH	347	xfs_xattr_acl_set(struct dentry dentry, const char name,
431547b3 CH	348	const void *value, size_t size, int flags, int type)
ef14f0c1	349	{
431547b3	350	struct inode *inode = dentry->d_inode;
ef14f0c1	351	struct posix_acl *acl = NULL;
431547b3	352	int error = 0;
ef14f0c1	353
ef14f0c1 CH	354	if (flags & XATTR_CREATE)
	355	return -EINVAL;
	356	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
	357	return value ? -EACCES : 0;
	358	if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
	359	return -EPERM;
	360
	361	if (!value)
	362	goto set_acl;
	363
	364	acl = posix_acl_from_xattr(value, size);
	365	if (!acl) {
	366	/*
	367	* acl_set_file(3) may request that we set default ACLs with
	368	* zero length -- defend (gracefully) against that here.
	369	*/
	370	goto out;
	371	}
	372	if (IS_ERR(acl)) {
	373	error = PTR_ERR(acl);
	374	goto out;
	375	}
	376
	377	error = posix_acl_valid(acl);
	378	if (error)
	379	goto out_release;
	380
	381	error = -EINVAL;
	382	if (acl->a_count > XFS_ACL_MAX_ENTRIES)
	383	goto out_release;
	384
	385	if (type == ACL_TYPE_ACCESS) {
d6952123	386	umode_t mode = inode->i_mode;
ef14f0c1 CH	387	error = posix_acl_equiv_mode(acl, &mode);
	388
	389	if (error <= 0) {
	390	posix_acl_release(acl);
	391	acl = NULL;
	392
	393	if (error < 0)
	394	return error;
	395	}
	396
	397	error = xfs_set_mode(inode, mode);
	398	if (error)
	399	goto out_release;
	400	}
	401
	402	set_acl:
	403	error = xfs_set_acl(inode, type, acl);
	404	out_release:
	405	posix_acl_release(acl);
	406	out:
	407	return error;
	408	}
	409
46e58764	410	const struct xattr_handler xfs_xattr_acl_access_handler = {
431547b3 CH	411	.prefix = POSIX_ACL_XATTR_ACCESS,
	412	.flags = ACL_TYPE_ACCESS,
	413	.get = xfs_xattr_acl_get,
	414	.set = xfs_xattr_acl_set,
	415	};
	416
46e58764	417	const struct xattr_handler xfs_xattr_acl_default_handler = {
431547b3 CH	418	.prefix = POSIX_ACL_XATTR_DEFAULT,
	419	.flags = ACL_TYPE_DEFAULT,
	420	.get = xfs_xattr_acl_get,
	421	.set = xfs_xattr_acl_set,
ef14f0c1	422	};