[linux-2.6-block.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_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_acl.h"
#include "xfs_attr.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_ag.h"
#include "xfs_sb.h"
#include "xfs_mount.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,
	int		max_entries)
{
	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 > 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:
			acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
			break;
		case ACL_GROUP:
			acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
			break;
		case ACL_USER_OBJ:
		case ACL_GROUP_OBJ:
		case ACL_MASK:
		case ACL_OTHER:
			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);
		switch (acl_e->e_tag) {
		case ACL_USER:
			ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
			break;
		case ACL_GROUP:
			ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
			break;
		default:
			ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
			break;
		}

		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;
	unsigned char *ea_name;
	int error;
	int len;

	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.
	 */
	len = XFS_ACL_MAX_SIZE(ip->i_mount);
	xfs_acl = kmem_zalloc(len, KM_SLEEP | KM_MAYFAIL);
	if (!xfs_acl) {
		xfs_acl = kmem_zalloc_large(len);
		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, XFS_ACL_MAX_ENTRIES(ip->i_mount));
	if (IS_ERR(acl))
		goto out;

out_update_cache:
	set_cached_acl(inode, type, acl);
out:
	if (is_vmalloc_addr(xfs_acl))
		kmem_free_large(xfs_acl);
	else
		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_MAX_SIZE(ip->i_mount);

		xfs_acl = kmem_zalloc(len, KM_SLEEP | KM_MAYFAIL);
		if (!xfs_acl) {
			xfs_acl = kmem_zalloc_large(len);
			if (!xfs_acl)
				return -ENOMEM;
		}

		xfs_acl_to_disk(xfs_acl, acl);

		/* subtract away the unused acl entries */
		len -= sizeof(struct xfs_acl_entry) *
			 (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);

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

		if (is_vmalloc_addr(xfs_acl))
			kmem_free_large(xfs_acl);
		else
			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 = XFS_ACL_MAX_SIZE(XFS_M(inode->i_sb));

	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(&init_user_ns, 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 (!inode_owner_or_capable(inode))
		return -EPERM;

	if (!value)
		goto set_acl;

	acl = posix_acl_from_xattr(&init_user_ns, 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(XFS_M(inode->i_sb)))
		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"
69432832	19	#include "xfs_log_format.h"
7fd36c44	20	#include "xfs_trans_resv.h"
ef14f0c1 CH	21	#include "xfs_acl.h"
	22	#include "xfs_attr.h"
	23	#include "xfs_bmap_btree.h"
	24	#include "xfs_inode.h"
9356fe22	25	#include "xfs_ag.h"
0a8aa193 DC	26	#include "xfs_sb.h"
0a8aa193 DC	27	#include "xfs_mount.h"
0b1b213f	28	#include "xfs_trace.h"
5a0e3ad6	29	#include <linux/slab.h>
ef14f0c1 CH	30	#include <linux/xattr.h>
	31	#include <linux/posix_acl_xattr.h>
	32
	33
ef14f0c1 CH	34	/*
	35	* Locking scheme:
	36	* - all ACL updates are protected by inode->i_mutex, which is taken before
	37	* calling into this file.
ef14f0c1 CH	38	*/
	39
	40	STATIC struct posix_acl *
0a8aa193 DC	41	xfs_acl_from_disk(
	42	struct xfs_acl *aclp,
	43	int max_entries)
ef14f0c1 CH	44	{
	45	struct posix_acl_entry *acl_e;
	46	struct posix_acl *acl;
	47	struct xfs_acl_entry *ace;
093019cf	48	unsigned int count, i;
ef14f0c1 CH	49
ef14f0c1 CH	50	count = be32_to_cpu(aclp->acl_cnt);
0a8aa193	51	if (count > max_entries)
fa8b18ed	52	return ERR_PTR(-EFSCORRUPTED);
ef14f0c1 CH	53
	54	acl = posix_acl_alloc(count, GFP_KERNEL);
	55	if (!acl)
	56	return ERR_PTR(-ENOMEM);
	57
	58	for (i = 0; i < count; i++) {
	59	acl_e = &acl->a_entries[i];
	60	ace = &aclp->acl_entry[i];
	61
	62	/*
	63	* The tag is 32 bits on disk and 16 bits in core.
	64	*
	65	* Because every access to it goes through the core
	66	* format first this is not a problem.
	67	*/
	68	acl_e->e_tag = be32_to_cpu(ace->ae_tag);
	69	acl_e->e_perm = be16_to_cpu(ace->ae_perm);
	70
	71	switch (acl_e->e_tag) {
	72	case ACL_USER:
288bbe0e DE	73	acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id));
288bbe0e DE	74	break;
ef14f0c1	75	case ACL_GROUP:
288bbe0e	76	acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id));
ef14f0c1 CH	77	break;
	78	case ACL_USER_OBJ:
	79	case ACL_GROUP_OBJ:
	80	case ACL_MASK:
	81	case ACL_OTHER:
ef14f0c1 CH	82	break;
	83	default:
	84	goto fail;
	85	}
	86	}
	87	return acl;
	88
	89	fail:
	90	posix_acl_release(acl);
	91	return ERR_PTR(-EINVAL);
	92	}
	93
	94	STATIC void
	95	xfs_acl_to_disk(struct xfs_acl aclp, const struct posix_acl acl)
	96	{
	97	const struct posix_acl_entry *acl_e;
	98	struct xfs_acl_entry *ace;
	99	int i;
	100
	101	aclp->acl_cnt = cpu_to_be32(acl->a_count);
	102	for (i = 0; i < acl->a_count; i++) {
	103	ace = &aclp->acl_entry[i];
	104	acl_e = &acl->a_entries[i];
	105
	106	ace->ae_tag = cpu_to_be32(acl_e->e_tag);
288bbe0e DE	107	switch (acl_e->e_tag) {
	108	case ACL_USER:
	109	ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid));
	110	break;
	111	case ACL_GROUP:
	112	ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid));
	113	break;
	114	default:
	115	ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID);
	116	break;
	117	}
	118
ef14f0c1 CH	119	ace->ae_perm = cpu_to_be16(acl_e->e_perm);
	120	}
	121	}
	122
ef14f0c1 CH	123	struct posix_acl *
	124	xfs_get_acl(struct inode *inode, int type)
	125	{
	126	struct xfs_inode *ip = XFS_I(inode);
1cbd20d8	127	struct posix_acl *acl;
ef14f0c1	128	struct xfs_acl *xfs_acl;
a9273ca5	129	unsigned char *ea_name;
ef14f0c1	130	int error;
0a8aa193	131	int len;
ef14f0c1	132
1cbd20d8 AV	133	acl = get_cached_acl(inode, type);
	134	if (acl != ACL_NOT_CACHED)
	135	return acl;
	136
4e34e719 CH	137	trace_xfs_get_acl(ip);
4e34e719 CH	138
ef14f0c1 CH	139	switch (type) {
	140	case ACL_TYPE_ACCESS:
	141	ea_name = SGI_ACL_FILE;
ef14f0c1 CH	142	break;
	143	case ACL_TYPE_DEFAULT:
	144	ea_name = SGI_ACL_DEFAULT;
ef14f0c1 CH	145	break;
ef14f0c1 CH	146	default:
1cbd20d8	147	BUG();
ef14f0c1 CH	148	}
ef14f0c1 CH	149
ef14f0c1 CH	150	/*
	151	* If we have a cached ACLs value just return it, not need to
	152	* go out to the disk.
	153	*/
0a8aa193	154	len = XFS_ACL_MAX_SIZE(ip->i_mount);
2dc164f2 DC	155	xfs_acl = kmem_zalloc(len, KM_SLEEP \| KM_MAYFAIL);
	156	if (!xfs_acl) {
	157	xfs_acl = kmem_zalloc_large(len);
	158	if (!xfs_acl)
	159	return ERR_PTR(-ENOMEM);
	160	}
ef14f0c1	161
a9273ca5 DC	162	error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
a9273ca5 DC	163	&len, ATTR_ROOT);
ef14f0c1 CH	164	if (error) {
	165	/*
	166	* If the attribute doesn't exist make sure we have a negative
	167	* cache entry, for any other error assume it is transient and
1cbd20d8	168	* leave the cache entry as ACL_NOT_CACHED.
ef14f0c1 CH	169	*/
	170	if (error == -ENOATTR) {
	171	acl = NULL;
	172	goto out_update_cache;
	173	}
	174	goto out;
	175	}
	176
0a8aa193	177	acl = xfs_acl_from_disk(xfs_acl, XFS_ACL_MAX_ENTRIES(ip->i_mount));
ef14f0c1 CH	178	if (IS_ERR(acl))
	179	goto out;
	180
2dc164f2	181	out_update_cache:
1cbd20d8	182	set_cached_acl(inode, type, acl);
2dc164f2 DC	183	out:
	184	if (is_vmalloc_addr(xfs_acl))
	185	kmem_free_large(xfs_acl);
	186	else
	187	kfree(xfs_acl);
ef14f0c1 CH	188	return acl;
	189	}
	190
	191	STATIC int
	192	xfs_set_acl(struct inode inode, int type, struct posix_acl acl)
	193	{
	194	struct xfs_inode *ip = XFS_I(inode);
a9273ca5	195	unsigned char *ea_name;
ef14f0c1 CH	196	int error;
	197
	198	if (S_ISLNK(inode->i_mode))
	199	return -EOPNOTSUPP;
	200
	201	switch (type) {
	202	case ACL_TYPE_ACCESS:
	203	ea_name = SGI_ACL_FILE;
ef14f0c1 CH	204	break;
	205	case ACL_TYPE_DEFAULT:
	206	if (!S_ISDIR(inode->i_mode))
	207	return acl ? -EACCES : 0;
	208	ea_name = SGI_ACL_DEFAULT;
ef14f0c1 CH	209	break;
	210	default:
	211	return -EINVAL;
	212	}
	213
	214	if (acl) {
	215	struct xfs_acl *xfs_acl;
0a8aa193	216	int len = XFS_ACL_MAX_SIZE(ip->i_mount);
ef14f0c1	217
2dc164f2 DC	218	xfs_acl = kmem_zalloc(len, KM_SLEEP \| KM_MAYFAIL);
	219	if (!xfs_acl) {
	220	xfs_acl = kmem_zalloc_large(len);
	221	if (!xfs_acl)
	222	return -ENOMEM;
	223	}
ef14f0c1 CH	224
ef14f0c1 CH	225	xfs_acl_to_disk(xfs_acl, acl);
0a8aa193 DC	226
	227	/* subtract away the unused acl entries */
	228	len -= sizeof(struct xfs_acl_entry) *
	229	(XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count);
ef14f0c1	230
a9273ca5	231	error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
ef14f0c1 CH	232	len, ATTR_ROOT);
ef14f0c1 CH	233
2dc164f2 DC	234	if (is_vmalloc_addr(xfs_acl))
	235	kmem_free_large(xfs_acl);
	236	else
	237	kfree(xfs_acl);
ef14f0c1 CH	238	} else {
	239	/*
	240	* A NULL ACL argument means we want to remove the ACL.
	241	*/
	242	error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
	243
	244	/*
	245	* If the attribute didn't exist to start with that's fine.
	246	*/
	247	if (error == -ENOATTR)
	248	error = 0;
	249	}
	250
	251	if (!error)
1cbd20d8	252	set_cached_acl(inode, type, acl);
ef14f0c1 CH	253	return error;
	254	}
	255
ef14f0c1	256	static int
d3fb6120	257	xfs_set_mode(struct inode *inode, umode_t mode)
ef14f0c1 CH	258	{
	259	int error = 0;
	260
	261	if (mode != inode->i_mode) {
	262	struct iattr iattr;
	263
d6d59bad	264	iattr.ia_valid = ATTR_MODE \| ATTR_CTIME;
ef14f0c1	265	iattr.ia_mode = mode;
d6d59bad	266	iattr.ia_ctime = current_fs_time(inode->i_sb);
ef14f0c1	267
c4ed4243	268	error = -xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
ef14f0c1 CH	269	}
	270
	271	return error;
	272	}
	273
	274	static int
a9273ca5	275	xfs_acl_exists(struct inode inode, unsigned char name)
ef14f0c1	276	{
0a8aa193	277	int len = XFS_ACL_MAX_SIZE(XFS_M(inode->i_sb));
ef14f0c1 CH	278
	279	return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
	280	ATTR_ROOT\|ATTR_KERNOVAL) == 0);
	281	}
	282
	283	int
	284	posix_acl_access_exists(struct inode *inode)
	285	{
	286	return xfs_acl_exists(inode, SGI_ACL_FILE);
	287	}
	288
	289	int
	290	posix_acl_default_exists(struct inode *inode)
	291	{
	292	if (!S_ISDIR(inode->i_mode))
	293	return 0;
	294	return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
	295	}
	296
	297	/*
	298	* No need for i_mutex because the inode is not yet exposed to the VFS.
	299	*/
	300	int
826cae2f	301	xfs_inherit_acl(struct inode inode, struct posix_acl acl)
ef14f0c1	302	{
d3fb6120	303	umode_t mode = inode->i_mode;
ef14f0c1 CH	304	int error = 0, inherit = 0;
	305
	306	if (S_ISDIR(inode->i_mode)) {
826cae2f	307	error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
ef14f0c1	308	if (error)
826cae2f	309	goto out;
ef14f0c1 CH	310	}
ef14f0c1 CH	311
826cae2f	312	error = posix_acl_create(&acl, GFP_KERNEL, &mode);
ef14f0c1	313	if (error < 0)
826cae2f	314	return error;
ef14f0c1 CH	315
ef14f0c1 CH	316	/*
826cae2f	317	* If posix_acl_create returns a positive value we need to
ef14f0c1 CH	318	* inherit a permission that can't be represented using the Unix
	319	* mode bits and we actually need to set an ACL.
	320	*/
	321	if (error > 0)
	322	inherit = 1;
	323
	324	error = xfs_set_mode(inode, mode);
	325	if (error)
826cae2f	326	goto out;
ef14f0c1 CH	327
ef14f0c1 CH	328	if (inherit)
826cae2f	329	error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
ef14f0c1	330
826cae2f AV	331	out:
826cae2f AV	332	posix_acl_release(acl);
ef14f0c1 CH	333	return error;
	334	}
	335
	336	int
	337	xfs_acl_chmod(struct inode *inode)
	338	{
bc26ab5f	339	struct posix_acl *acl;
ef14f0c1 CH	340	int error;
	341
	342	if (S_ISLNK(inode->i_mode))
	343	return -EOPNOTSUPP;
	344
	345	acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
	346	if (IS_ERR(acl) \|\| !acl)
	347	return PTR_ERR(acl);
	348
bc26ab5f AV	349	error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
	350	if (error)
	351	return error;
ef14f0c1	352
bc26ab5f AV	353	error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
bc26ab5f AV	354	posix_acl_release(acl);
ef14f0c1 CH	355	return error;
	356	}
	357
ef14f0c1	358	static int
431547b3 CH	359	xfs_xattr_acl_get(struct dentry dentry, const char name,
431547b3 CH	360	void *value, size_t size, int type)
ef14f0c1 CH	361	{
ef14f0c1 CH	362	struct posix_acl *acl;
431547b3	363	int error;
ef14f0c1	364
431547b3	365	acl = xfs_get_acl(dentry->d_inode, type);
ef14f0c1 CH	366	if (IS_ERR(acl))
	367	return PTR_ERR(acl);
	368	if (acl == NULL)
	369	return -ENODATA;
	370
5f3a4a28	371	error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
ef14f0c1 CH	372	posix_acl_release(acl);
	373
	374	return error;
	375	}
	376
	377	static int
431547b3 CH	378	xfs_xattr_acl_set(struct dentry dentry, const char name,
431547b3 CH	379	const void *value, size_t size, int flags, int type)
ef14f0c1	380	{
431547b3	381	struct inode *inode = dentry->d_inode;
ef14f0c1	382	struct posix_acl *acl = NULL;
431547b3	383	int error = 0;
ef14f0c1	384
ef14f0c1 CH	385	if (flags & XATTR_CREATE)
	386	return -EINVAL;
	387	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
	388	return value ? -EACCES : 0;
288bbe0e	389	if (!inode_owner_or_capable(inode))
ef14f0c1 CH	390	return -EPERM;
	391
	392	if (!value)
	393	goto set_acl;
	394
5f3a4a28	395	acl = posix_acl_from_xattr(&init_user_ns, value, size);
ef14f0c1 CH	396	if (!acl) {
	397	/*
	398	* acl_set_file(3) may request that we set default ACLs with
	399	* zero length -- defend (gracefully) against that here.
	400	*/
	401	goto out;
	402	}
	403	if (IS_ERR(acl)) {
	404	error = PTR_ERR(acl);
	405	goto out;
	406	}
	407
	408	error = posix_acl_valid(acl);
	409	if (error)
	410	goto out_release;
	411
	412	error = -EINVAL;
0a8aa193	413	if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb)))
ef14f0c1 CH	414	goto out_release;
	415
	416	if (type == ACL_TYPE_ACCESS) {
d6952123	417	umode_t mode = inode->i_mode;
ef14f0c1 CH	418	error = posix_acl_equiv_mode(acl, &mode);
	419
	420	if (error <= 0) {
	421	posix_acl_release(acl);
	422	acl = NULL;
	423
	424	if (error < 0)
	425	return error;
	426	}
	427
	428	error = xfs_set_mode(inode, mode);
	429	if (error)
	430	goto out_release;
	431	}
	432
	433	set_acl:
	434	error = xfs_set_acl(inode, type, acl);
	435	out_release:
	436	posix_acl_release(acl);
	437	out:
	438	return error;
	439	}
	440
46e58764	441	const struct xattr_handler xfs_xattr_acl_access_handler = {
431547b3 CH	442	.prefix = POSIX_ACL_XATTR_ACCESS,
	443	.flags = ACL_TYPE_ACCESS,
	444	.get = xfs_xattr_acl_get,
	445	.set = xfs_xattr_acl_set,
	446	};
	447
46e58764	448	const struct xattr_handler xfs_xattr_acl_default_handler = {
431547b3 CH	449	.prefix = POSIX_ACL_XATTR_DEFAULT,
	450	.flags = ACL_TYPE_DEFAULT,
	451	.get = xfs_xattr_acl_get,
	452	.set = xfs_xattr_acl_set,
ef14f0c1	453	};