[linux-2.6-block.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;

	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, 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_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)
{
	mode_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) {
		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
4e34e719 CH	117	trace_xfs_get_acl(ip);
4e34e719 CH	118
ef14f0c1 CH	119	switch (type) {
	120	case ACL_TYPE_ACCESS:
	121	ea_name = SGI_ACL_FILE;
ef14f0c1 CH	122	break;
	123	case ACL_TYPE_DEFAULT:
	124	ea_name = SGI_ACL_DEFAULT;
ef14f0c1 CH	125	break;
ef14f0c1 CH	126	default:
1cbd20d8	127	BUG();
ef14f0c1 CH	128	}
ef14f0c1 CH	129
ef14f0c1 CH	130	/*
	131	* If we have a cached ACLs value just return it, not need to
	132	* go out to the disk.
	133	*/
ef14f0c1 CH	134
	135	xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
	136	if (!xfs_acl)
	137	return ERR_PTR(-ENOMEM);
	138
a9273ca5 DC	139	error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
a9273ca5 DC	140	&len, ATTR_ROOT);
ef14f0c1 CH	141	if (error) {
	142	/*
	143	* If the attribute doesn't exist make sure we have a negative
	144	* cache entry, for any other error assume it is transient and
1cbd20d8	145	* leave the cache entry as ACL_NOT_CACHED.
ef14f0c1 CH	146	*/
	147	if (error == -ENOATTR) {
	148	acl = NULL;
	149	goto out_update_cache;
	150	}
	151	goto out;
	152	}
	153
	154	acl = xfs_acl_from_disk(xfs_acl);
	155	if (IS_ERR(acl))
	156	goto out;
	157
	158	out_update_cache:
1cbd20d8	159	set_cached_acl(inode, type, acl);
ef14f0c1 CH	160	out:
	161	kfree(xfs_acl);
	162	return acl;
	163	}
	164
	165	STATIC int
	166	xfs_set_acl(struct inode inode, int type, struct posix_acl acl)
	167	{
	168	struct xfs_inode *ip = XFS_I(inode);
a9273ca5	169	unsigned char *ea_name;
ef14f0c1 CH	170	int error;
	171
	172	if (S_ISLNK(inode->i_mode))
	173	return -EOPNOTSUPP;
	174
	175	switch (type) {
	176	case ACL_TYPE_ACCESS:
	177	ea_name = SGI_ACL_FILE;
ef14f0c1 CH	178	break;
	179	case ACL_TYPE_DEFAULT:
	180	if (!S_ISDIR(inode->i_mode))
	181	return acl ? -EACCES : 0;
	182	ea_name = SGI_ACL_DEFAULT;
ef14f0c1 CH	183	break;
	184	default:
	185	return -EINVAL;
	186	}
	187
	188	if (acl) {
	189	struct xfs_acl *xfs_acl;
	190	int len;
	191
	192	xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
	193	if (!xfs_acl)
	194	return -ENOMEM;
	195
	196	xfs_acl_to_disk(xfs_acl, acl);
	197	len = sizeof(struct xfs_acl) -
	198	(sizeof(struct xfs_acl_entry) *
	199	(XFS_ACL_MAX_ENTRIES - acl->a_count));
	200
a9273ca5	201	error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
ef14f0c1 CH	202	len, ATTR_ROOT);
	203
	204	kfree(xfs_acl);
	205	} else {
	206	/*
	207	* A NULL ACL argument means we want to remove the ACL.
	208	*/
	209	error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
	210
	211	/*
	212	* If the attribute didn't exist to start with that's fine.
	213	*/
	214	if (error == -ENOATTR)
	215	error = 0;
	216	}
	217
	218	if (!error)
1cbd20d8	219	set_cached_acl(inode, type, acl);
ef14f0c1 CH	220	return error;
	221	}
	222
ef14f0c1 CH	223	static int
	224	xfs_set_mode(struct inode *inode, mode_t mode)
	225	{
	226	int error = 0;
	227
	228	if (mode != inode->i_mode) {
	229	struct iattr iattr;
	230
d6d59bad	231	iattr.ia_valid = ATTR_MODE \| ATTR_CTIME;
ef14f0c1	232	iattr.ia_mode = mode;
d6d59bad	233	iattr.ia_ctime = current_fs_time(inode->i_sb);
ef14f0c1	234
c4ed4243	235	error = -xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
ef14f0c1 CH	236	}
	237
	238	return error;
	239	}
	240
	241	static int
a9273ca5	242	xfs_acl_exists(struct inode inode, unsigned char name)
ef14f0c1 CH	243	{
	244	int len = sizeof(struct xfs_acl);
	245
	246	return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
	247	ATTR_ROOT\|ATTR_KERNOVAL) == 0);
	248	}
	249
	250	int
	251	posix_acl_access_exists(struct inode *inode)
	252	{
	253	return xfs_acl_exists(inode, SGI_ACL_FILE);
	254	}
	255
	256	int
	257	posix_acl_default_exists(struct inode *inode)
	258	{
	259	if (!S_ISDIR(inode->i_mode))
	260	return 0;
	261	return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
	262	}
	263
	264	/*
	265	* No need for i_mutex because the inode is not yet exposed to the VFS.
	266	*/
	267	int
826cae2f	268	xfs_inherit_acl(struct inode inode, struct posix_acl acl)
ef14f0c1	269	{
826cae2f	270	mode_t mode = inode->i_mode;
ef14f0c1 CH	271	int error = 0, inherit = 0;
	272
	273	if (S_ISDIR(inode->i_mode)) {
826cae2f	274	error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
ef14f0c1	275	if (error)
826cae2f	276	goto out;
ef14f0c1 CH	277	}
ef14f0c1 CH	278
826cae2f	279	error = posix_acl_create(&acl, GFP_KERNEL, &mode);
ef14f0c1	280	if (error < 0)
826cae2f	281	return error;
ef14f0c1 CH	282
ef14f0c1 CH	283	/*
826cae2f	284	* If posix_acl_create returns a positive value we need to
ef14f0c1 CH	285	* inherit a permission that can't be represented using the Unix
	286	* mode bits and we actually need to set an ACL.
	287	*/
	288	if (error > 0)
	289	inherit = 1;
	290
	291	error = xfs_set_mode(inode, mode);
	292	if (error)
826cae2f	293	goto out;
ef14f0c1 CH	294
ef14f0c1 CH	295	if (inherit)
826cae2f	296	error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
ef14f0c1	297
826cae2f AV	298	out:
826cae2f AV	299	posix_acl_release(acl);
ef14f0c1 CH	300	return error;
	301	}
	302
	303	int
	304	xfs_acl_chmod(struct inode *inode)
	305	{
bc26ab5f	306	struct posix_acl *acl;
ef14f0c1 CH	307	int error;
	308
	309	if (S_ISLNK(inode->i_mode))
	310	return -EOPNOTSUPP;
	311
	312	acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
	313	if (IS_ERR(acl) \|\| !acl)
	314	return PTR_ERR(acl);
	315
bc26ab5f AV	316	error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
	317	if (error)
	318	return error;
ef14f0c1	319
bc26ab5f AV	320	error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
bc26ab5f AV	321	posix_acl_release(acl);
ef14f0c1 CH	322	return error;
	323	}
	324
ef14f0c1	325	static int
431547b3 CH	326	xfs_xattr_acl_get(struct dentry dentry, const char name,
431547b3 CH	327	void *value, size_t size, int type)
ef14f0c1 CH	328	{
ef14f0c1 CH	329	struct posix_acl *acl;
431547b3	330	int error;
ef14f0c1	331
431547b3	332	acl = xfs_get_acl(dentry->d_inode, type);
ef14f0c1 CH	333	if (IS_ERR(acl))
	334	return PTR_ERR(acl);
	335	if (acl == NULL)
	336	return -ENODATA;
	337
	338	error = posix_acl_to_xattr(acl, value, size);
	339	posix_acl_release(acl);
	340
	341	return error;
	342	}
	343
	344	static int
431547b3 CH	345	xfs_xattr_acl_set(struct dentry dentry, const char name,
431547b3 CH	346	const void *value, size_t size, int flags, int type)
ef14f0c1	347	{
431547b3	348	struct inode *inode = dentry->d_inode;
ef14f0c1	349	struct posix_acl *acl = NULL;
431547b3	350	int error = 0;
ef14f0c1	351
ef14f0c1 CH	352	if (flags & XATTR_CREATE)
	353	return -EINVAL;
	354	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
	355	return value ? -EACCES : 0;
	356	if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
	357	return -EPERM;
	358
	359	if (!value)
	360	goto set_acl;
	361
	362	acl = posix_acl_from_xattr(value, size);
	363	if (!acl) {
	364	/*
	365	* acl_set_file(3) may request that we set default ACLs with
	366	* zero length -- defend (gracefully) against that here.
	367	*/
	368	goto out;
	369	}
	370	if (IS_ERR(acl)) {
	371	error = PTR_ERR(acl);
	372	goto out;
	373	}
	374
	375	error = posix_acl_valid(acl);
	376	if (error)
	377	goto out_release;
	378
	379	error = -EINVAL;
	380	if (acl->a_count > XFS_ACL_MAX_ENTRIES)
	381	goto out_release;
	382
	383	if (type == ACL_TYPE_ACCESS) {
	384	mode_t mode = inode->i_mode;
	385	error = posix_acl_equiv_mode(acl, &mode);
	386
	387	if (error <= 0) {
	388	posix_acl_release(acl);
	389	acl = NULL;
	390
	391	if (error < 0)
	392	return error;
	393	}
	394
	395	error = xfs_set_mode(inode, mode);
	396	if (error)
	397	goto out_release;
	398	}
	399
	400	set_acl:
	401	error = xfs_set_acl(inode, type, acl);
	402	out_release:
	403	posix_acl_release(acl);
	404	out:
	405	return error;
	406	}
	407
46e58764	408	const struct xattr_handler xfs_xattr_acl_access_handler = {
431547b3 CH	409	.prefix = POSIX_ACL_XATTR_ACCESS,
	410	.flags = ACL_TYPE_ACCESS,
	411	.get = xfs_xattr_acl_get,
	412	.set = xfs_xattr_acl_set,
	413	};
	414
46e58764	415	const struct xattr_handler xfs_xattr_acl_default_handler = {
431547b3 CH	416	.prefix = POSIX_ACL_XATTR_DEFAULT,
	417	.flags = ACL_TYPE_DEFAULT,
	418	.get = xfs_xattr_acl_get,
	419	.set = xfs_xattr_acl_set,
ef14f0c1	420	};