[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / gfs2 / acl.c

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#include <linux/gfs2_ondisk.h>

#include "gfs2.h"
#include "incore.h"
#include "acl.h"
#include "xattr.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "trans.h"
#include "util.h"

static const char *gfs2_acl_name(int type)
{
	switch (type) {
	case ACL_TYPE_ACCESS:
		return GFS2_POSIX_ACL_ACCESS;
	case ACL_TYPE_DEFAULT:
		return GFS2_POSIX_ACL_DEFAULT;
	}
	return NULL;
}

struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct posix_acl *acl;
	const char *name;
	char *data;
	int len;

	if (!ip->i_eattr)
		return NULL;

	acl = get_cached_acl(&ip->i_inode, type);
	if (acl != ACL_NOT_CACHED)
		return acl;

	name = gfs2_acl_name(type);
	if (name == NULL)
		return ERR_PTR(-EINVAL);

	len = gfs2_xattr_acl_get(ip, name, &data);
	if (len < 0)
		return ERR_PTR(len);
	if (len == 0)
		return NULL;

	acl = posix_acl_from_xattr(&init_user_ns, data, len);
	kfree(data);
	return acl;
}

static int gfs2_set_mode(struct inode *inode, umode_t mode)
{
	int error = 0;

	if (mode != inode->i_mode) {
		inode->i_mode = mode;
		mark_inode_dirty(inode);
	}

	return error;
}

static int gfs2_acl_set(struct inode *inode, int type, struct posix_acl *acl)
{
	int error;
	int len;
	char *data;
	const char *name = gfs2_acl_name(type);

	BUG_ON(name == NULL);
	len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
	if (len == 0)
		return 0;
	data = kmalloc(len, GFP_NOFS);
	if (data == NULL)
		return -ENOMEM;
	error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
	if (error < 0)
		goto out;
	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
	if (!error)
		set_cached_acl(inode, type, acl);
out:
	kfree(data);
	return error;
}

int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode)
{
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
	struct posix_acl *acl;
	umode_t mode = inode->i_mode;
	int error = 0;

	if (!sdp->sd_args.ar_posix_acl)
		return 0;
	if (S_ISLNK(inode->i_mode))
		return 0;

	acl = gfs2_get_acl(&dip->i_inode, ACL_TYPE_DEFAULT);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (!acl) {
		mode &= ~current_umask();
		return gfs2_set_mode(inode, mode);
	}

	if (S_ISDIR(inode->i_mode)) {
		error = gfs2_acl_set(inode, ACL_TYPE_DEFAULT, acl);
		if (error)
			goto out;
	}

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

	if (error == 0)
		goto munge;

	error = gfs2_acl_set(inode, ACL_TYPE_ACCESS, acl);
	if (error)
		goto out;
munge:
	error = gfs2_set_mode(inode, mode);
out:
	posix_acl_release(acl);
	return error;
}

int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr)
{
	struct inode *inode = &ip->i_inode;
	struct posix_acl *acl;
	char *data;
	unsigned int len;
	int error;

	acl = gfs2_get_acl(&ip->i_inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (!acl)
		return gfs2_setattr_simple(inode, attr);

	error = posix_acl_chmod(&acl, GFP_NOFS, attr->ia_mode);
	if (error)
		return error;

	len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
	data = kmalloc(len, GFP_NOFS);
	error = -ENOMEM;
	if (data == NULL)
		goto out;
	posix_acl_to_xattr(&init_user_ns, acl, data, len);
	error = gfs2_xattr_acl_chmod(ip, attr, data);
	kfree(data);
	set_cached_acl(&ip->i_inode, ACL_TYPE_ACCESS, acl);

out:
	posix_acl_release(acl);
	return error;
}

static int gfs2_acl_type(const char *name)
{
	if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
		return ACL_TYPE_ACCESS;
	if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
		return ACL_TYPE_DEFAULT;
	return -EINVAL;
}

static int gfs2_xattr_system_get(struct dentry *dentry, const char *name,
				 void *buffer, size_t size, int xtype)
{
	struct inode *inode = dentry->d_inode;
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct posix_acl *acl;
	int type;
	int error;

	if (!sdp->sd_args.ar_posix_acl)
		return -EOPNOTSUPP;

	type = gfs2_acl_type(name);
	if (type < 0)
		return type;

	acl = gfs2_get_acl(inode, type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl == NULL)
		return -ENODATA;

	error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
	posix_acl_release(acl);

	return error;
}

static int gfs2_xattr_system_set(struct dentry *dentry, const char *name,
				 const void *value, size_t size, int flags,
				 int xtype)
{
	struct inode *inode = dentry->d_inode;
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct posix_acl *acl = NULL;
	int error = 0, type;

	if (!sdp->sd_args.ar_posix_acl)
		return -EOPNOTSUPP;

	type = gfs2_acl_type(name);
	if (type < 0)
		return type;
	if (flags & XATTR_CREATE)
		return -EINVAL;
	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
		return value ? -EACCES : 0;
	if (!uid_eq(current_fsuid(), inode->i_uid) && !capable(CAP_FOWNER))
		return -EPERM;
	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	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 > GFS2_ACL_MAX_ENTRIES)
		goto out_release;

	if (type == ACL_TYPE_ACCESS) {
		umode_t mode = inode->i_mode;

		error = posix_acl_update_mode(inode, &inode->i_mode, &acl);

		if (error)
			goto out_release;

		error = gfs2_set_mode(inode, mode);
		if (error)
			goto out_release;
	}

set_acl:
	error = __gfs2_xattr_set(inode, name, value, size, 0, GFS2_EATYPE_SYS);
	if (!error) {
		if (acl)
			set_cached_acl(inode, type, acl);
		else
			forget_cached_acl(inode, type);
	}
out_release:
	posix_acl_release(acl);
out:
	return error;
}

const struct xattr_handler gfs2_xattr_system_handler = {
	.prefix = XATTR_SYSTEM_PREFIX,
	.flags  = GFS2_EATYPE_SYS,
	.get    = gfs2_xattr_system_get,
	.set    = gfs2_xattr_system_set,
};
Commit	Line	Data
b3b94faa DT	1	/*
b3b94faa DT	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3a8a9a10	3	* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
b3b94faa DT	4	*
	5	* This copyrighted material is made available to anyone wishing to use,
	6	* modify, copy, or redistribute it subject to the terms and conditions
e9fc2aa0	7	* of the GNU General Public License version 2.
b3b94faa DT	8	*/
	9
	10	#include <linux/sched.h>
	11	#include <linux/slab.h>
	12	#include <linux/spinlock.h>
	13	#include <linux/completion.h>
	14	#include <linux/buffer_head.h>
2646a1f6	15	#include <linux/xattr.h>
b3b94faa DT	16	#include <linux/posix_acl.h>
b3b94faa DT	17	#include <linux/posix_acl_xattr.h>
5c676f6d	18	#include <linux/gfs2_ondisk.h>
b3b94faa DT	19
b3b94faa DT	20	#include "gfs2.h"
5c676f6d	21	#include "incore.h"
b3b94faa	22	#include "acl.h"
307cf6e6	23	#include "xattr.h"
b3b94faa DT	24	#include "glock.h"
	25	#include "inode.h"
	26	#include "meta_io.h"
	27	#include "trans.h"
5c676f6d	28	#include "util.h"
b3b94faa	29
479c427d	30	static const char *gfs2_acl_name(int type)
b3b94faa	31	{
479c427d SW	32	switch (type) {
	33	case ACL_TYPE_ACCESS:
	34	return GFS2_POSIX_ACL_ACCESS;
	35	case ACL_TYPE_DEFAULT:
	36	return GFS2_POSIX_ACL_DEFAULT;
	37	}
	38	return NULL;
	39	}
b3b94faa	40
018a01cd	41	struct posix_acl gfs2_get_acl(struct inode inode, int type)
479c427d	42	{
018a01cd	43	struct gfs2_inode *ip = GFS2_I(inode);
479c427d SW	44	struct posix_acl *acl;
	45	const char *name;
	46	char *data;
	47	int len;
40b78a32	48
3767ac21	49	if (!ip->i_eattr)
479c427d	50	return NULL;
b3b94faa	51
106381bf SW	52	acl = get_cached_acl(&ip->i_inode, type);
	53	if (acl != ACL_NOT_CACHED)
	54	return acl;
	55
479c427d SW	56	name = gfs2_acl_name(type);
	57	if (name == NULL)
	58	return ERR_PTR(-EINVAL);
b3b94faa	59
479c427d SW	60	len = gfs2_xattr_acl_get(ip, name, &data);
	61	if (len < 0)
	62	return ERR_PTR(len);
	63	if (len == 0)
	64	return NULL;
b3b94faa	65
5f3a4a28	66	acl = posix_acl_from_xattr(&init_user_ns, data, len);
479c427d SW	67	kfree(data);
479c427d SW	68	return acl;
b3b94faa DT	69	}
b3b94faa DT	70
d3fb6120	71	static int gfs2_set_mode(struct inode *inode, umode_t mode)
b3b94faa	72	{
69dca424	73	int error = 0;
b3b94faa	74
69dca424	75	if (mode != inode->i_mode) {
f9425ad4 SW	76	inode->i_mode = mode;
f9425ad4 SW	77	mark_inode_dirty(inode);
69dca424	78	}
b3b94faa	79
69dca424	80	return error;
b3b94faa DT	81	}
b3b94faa DT	82
479c427d	83	static int gfs2_acl_set(struct inode inode, int type, struct posix_acl acl)
b3b94faa	84	{
b3b94faa	85	int error;
479c427d SW	86	int len;
	87	char *data;
	88	const char *name = gfs2_acl_name(type);
	89
	90	BUG_ON(name == NULL);
5f3a4a28	91	len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
479c427d SW	92	if (len == 0)
	93	return 0;
	94	data = kmalloc(len, GFP_NOFS);
	95	if (data == NULL)
	96	return -ENOMEM;
5f3a4a28	97	error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
479c427d SW	98	if (error < 0)
479c427d SW	99	goto out;
431547b3	100	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
106381bf SW	101	if (!error)
106381bf SW	102	set_cached_acl(inode, type, acl);
479c427d SW	103	out:
	104	kfree(data);
	105	return error;
	106	}
	107
	108	int gfs2_acl_create(struct gfs2_inode dip, struct inode inode)
	109	{
	110	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
826cae2f	111	struct posix_acl *acl;
d3fb6120	112	umode_t mode = inode->i_mode;
479c427d	113	int error = 0;
b3b94faa DT	114
	115	if (!sdp->sd_args.ar_posix_acl)
	116	return 0;
479c427d	117	if (S_ISLNK(inode->i_mode))
b3b94faa DT	118	return 0;
b3b94faa DT	119
018a01cd	120	acl = gfs2_get_acl(&dip->i_inode, ACL_TYPE_DEFAULT);
479c427d SW	121	if (IS_ERR(acl))
479c427d SW	122	return PTR_ERR(acl);
b3b94faa	123	if (!acl) {
ce3b0f8d	124	mode &= ~current_umask();
f9425ad4	125	return gfs2_set_mode(inode, mode);
b3b94faa DT	126	}
b3b94faa DT	127
479c427d SW	128	if (S_ISDIR(inode->i_mode)) {
	129	error = gfs2_acl_set(inode, ACL_TYPE_DEFAULT, acl);
	130	if (error)
	131	goto out;
	132	}
	133
826cae2f	134	error = posix_acl_create(&acl, GFP_NOFS, &mode);
b3b94faa	135	if (error < 0)
826cae2f AV	136	return error;
826cae2f AV	137
40b78a32 SW	138	if (error == 0)
40b78a32 SW	139	goto munge;
b3b94faa	140
479c427d	141	error = gfs2_acl_set(inode, ACL_TYPE_ACCESS, acl);
40b78a32 SW	142	if (error)
	143	goto out;
	144	munge:
479c427d	145	error = gfs2_set_mode(inode, mode);
a91ea69f	146	out:
b3b94faa	147	posix_acl_release(acl);
b3b94faa DT	148	return error;
	149	}
	150
	151	int gfs2_acl_chmod(struct gfs2_inode ip, struct iattr attr)
	152	{
ab9bbda0	153	struct inode *inode = &ip->i_inode;
bc26ab5f	154	struct posix_acl *acl;
b3b94faa DT	155	char *data;
	156	unsigned int len;
	157	int error;
	158
018a01cd	159	acl = gfs2_get_acl(&ip->i_inode, ACL_TYPE_ACCESS);
479c427d SW	160	if (IS_ERR(acl))
479c427d SW	161	return PTR_ERR(acl);
b3b94faa	162	if (!acl)
ab9bbda0	163	return gfs2_setattr_simple(inode, attr);
b3b94faa	164
bc26ab5f AV	165	error = posix_acl_chmod(&acl, GFP_NOFS, attr->ia_mode);
	166	if (error)
	167	return error;
	168
5f3a4a28	169	len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
bc26ab5f	170	data = kmalloc(len, GFP_NOFS);
b3b94faa	171	error = -ENOMEM;
bc26ab5f	172	if (data == NULL)
b3b94faa	173	goto out;
5f3a4a28	174	posix_acl_to_xattr(&init_user_ns, acl, data, len);
bc26ab5f AV	175	error = gfs2_xattr_acl_chmod(ip, attr, data);
	176	kfree(data);
	177	set_cached_acl(&ip->i_inode, ACL_TYPE_ACCESS, acl);
b3b94faa	178
a91ea69f	179	out:
b3b94faa	180	posix_acl_release(acl);
b3b94faa DT	181	return error;
	182	}
	183
2646a1f6 SW	184	static int gfs2_acl_type(const char *name)
	185	{
	186	if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
	187	return ACL_TYPE_ACCESS;
	188	if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
	189	return ACL_TYPE_DEFAULT;
	190	return -EINVAL;
	191	}
	192
431547b3 CH	193	static int gfs2_xattr_system_get(struct dentry dentry, const char name,
431547b3 CH	194	void *buffer, size_t size, int xtype)
2646a1f6	195	{
431547b3	196	struct inode *inode = dentry->d_inode;
f72f2d2e	197	struct gfs2_sbd *sdp = GFS2_SB(inode);
106381bf	198	struct posix_acl *acl;
2646a1f6	199	int type;
106381bf	200	int error;
2646a1f6	201
f72f2d2e SW	202	if (!sdp->sd_args.ar_posix_acl)
	203	return -EOPNOTSUPP;
	204
2646a1f6 SW	205	type = gfs2_acl_type(name);
	206	if (type < 0)
	207	return type;
	208
018a01cd	209	acl = gfs2_get_acl(inode, type);
106381bf SW	210	if (IS_ERR(acl))
	211	return PTR_ERR(acl);
	212	if (acl == NULL)
	213	return -ENODATA;
2646a1f6	214
5f3a4a28	215	error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
106381bf SW	216	posix_acl_release(acl);
	217
	218	return error;
	219	}
2646a1f6	220
431547b3 CH	221	static int gfs2_xattr_system_set(struct dentry dentry, const char name,
	222	const void *value, size_t size, int flags,
	223	int xtype)
2646a1f6	224	{
431547b3	225	struct inode *inode = dentry->d_inode;
2646a1f6 SW	226	struct gfs2_sbd *sdp = GFS2_SB(inode);
	227	struct posix_acl *acl = NULL;
	228	int error = 0, type;
	229
	230	if (!sdp->sd_args.ar_posix_acl)
	231	return -EOPNOTSUPP;
	232
	233	type = gfs2_acl_type(name);
	234	if (type < 0)
	235	return type;
	236	if (flags & XATTR_CREATE)
	237	return -EINVAL;
	238	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
	239	return value ? -EACCES : 0;
6b24c0d2	240	if (!uid_eq(current_fsuid(), inode->i_uid) && !capable(CAP_FOWNER))
2646a1f6 SW	241	return -EPERM;
	242	if (S_ISLNK(inode->i_mode))
	243	return -EOPNOTSUPP;
	244
	245	if (!value)
	246	goto set_acl;
	247
5f3a4a28	248	acl = posix_acl_from_xattr(&init_user_ns, value, size);
2646a1f6 SW	249	if (!acl) {
	250	/*
	251	* acl_set_file(3) may request that we set default ACLs with
	252	* zero length -- defend (gracefully) against that here.
	253	*/
	254	goto out;
	255	}
	256	if (IS_ERR(acl)) {
	257	error = PTR_ERR(acl);
	258	goto out;
	259	}
	260
	261	error = posix_acl_valid(acl);
	262	if (error)
	263	goto out_release;
	264
	265	error = -EINVAL;
	266	if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
	267	goto out_release;
	268
	269	if (type == ACL_TYPE_ACCESS) {
d6952123	270	umode_t mode = inode->i_mode;
2646a1f6	271
4b9e9796	272	error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
2646a1f6	273
4b9e9796 S	274	if (error)
4b9e9796 S	275	goto out_release;
2646a1f6 SW	276
	277	error = gfs2_set_mode(inode, mode);
	278	if (error)
	279	goto out_release;
	280	}
	281
	282	set_acl:
431547b3	283	error = __gfs2_xattr_set(inode, name, value, size, 0, GFS2_EATYPE_SYS);
106381bf SW	284	if (!error) {
	285	if (acl)
	286	set_cached_acl(inode, type, acl);
	287	else
	288	forget_cached_acl(inode, type);
	289	}
2646a1f6 SW	290	out_release:
	291	posix_acl_release(acl);
	292	out:
	293	return error;
	294	}
	295
b7bb0a12	296	const struct xattr_handler gfs2_xattr_system_handler = {
2646a1f6	297	.prefix = XATTR_SYSTEM_PREFIX,
431547b3	298	.flags = GFS2_EATYPE_SYS,
2646a1f6 SW	299	.get = gfs2_xattr_system_get,
	300	.set = gfs2_xattr_system_set,
	301	};
	302