[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/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#include <linux/gfs2_ondisk.h>
#include <linux/lm_interface.h>

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

#define ACL_ACCESS 1
#define ACL_DEFAULT 0

int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
		      struct gfs2_ea_request *er,
		      int *remove, mode_t *mode)
{
	struct posix_acl *acl;
	int error;

	error = gfs2_acl_validate_remove(ip, access);
	if (error)
		return error;

	if (!er->er_data)
		return -EINVAL;

	acl = posix_acl_from_xattr(er->er_data, er->er_data_len);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (!acl) {
		*remove = 1;
		return 0;
	}

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

	if (access) {
		error = posix_acl_equiv_mode(acl, mode);
		if (!error)
			*remove = 1;
		else if (error > 0)
			error = 0;
	}

out:
	posix_acl_release(acl);
	return error;
}

int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
{
	if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
		return -EOPNOTSUPP;
	if (current->fsuid != ip->i_di.di_uid && !capable(CAP_FOWNER))
		return -EPERM;
	if (S_ISLNK(ip->i_di.di_mode))
		return -EOPNOTSUPP;
	if (!access && !S_ISDIR(ip->i_di.di_mode))
		return -EACCES;

	return 0;
}

static int acl_get(struct gfs2_inode *ip, int access, struct posix_acl **acl,
		   struct gfs2_ea_location *el, char **data, unsigned int *len)
{
	struct gfs2_ea_request er;
	struct gfs2_ea_location el_this;
	int error;

	if (!ip->i_di.di_eattr)
		return 0;

	memset(&er, 0, sizeof(struct gfs2_ea_request));
	if (access) {
		er.er_name = GFS2_POSIX_ACL_ACCESS;
		er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
	} else {
		er.er_name = GFS2_POSIX_ACL_DEFAULT;
		er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
	}
	er.er_type = GFS2_EATYPE_SYS;

	if (!el)
		el = &el_this;

	error = gfs2_ea_find(ip, &er, el);
	if (error)
		return error;
	if (!el->el_ea)
		return 0;
	if (!GFS2_EA_DATA_LEN(el->el_ea))
		goto out;

	er.er_data_len = GFS2_EA_DATA_LEN(el->el_ea);
	er.er_data = kmalloc(er.er_data_len, GFP_KERNEL);
	error = -ENOMEM;
	if (!er.er_data)
		goto out;

	error = gfs2_ea_get_copy(ip, el, er.er_data);
	if (error)
		goto out_kfree;

	if (acl) {
		*acl = posix_acl_from_xattr(er.er_data, er.er_data_len);
		if (IS_ERR(*acl))
			error = PTR_ERR(*acl);
	}

out_kfree:
	if (error || !data)
		kfree(er.er_data);
	else {
		*data = er.er_data;
		*len = er.er_data_len;
	}
out:
	if (error || el == &el_this)
		brelse(el->el_bh);
	return error;
}

/**
 * gfs2_check_acl_locked - Check an ACL to see if we're allowed to do something
 * @inode: the file we want to do something to
 * @mask: what we want to do
 *
 * Returns: errno
 */

int gfs2_check_acl_locked(struct inode *inode, int mask)
{
	struct posix_acl *acl = NULL;
	int error;

	error = acl_get(GFS2_I(inode), ACL_ACCESS, &acl, NULL, NULL, NULL);
	if (error)
		return error;

	if (acl) {
		error = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
		return error;
	}

	return -EAGAIN;
}

int gfs2_check_acl(struct inode *inode, int mask)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder i_gh;
	int error;

	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
	if (!error) {
		error = gfs2_check_acl_locked(inode, mask);
		gfs2_glock_dq_uninit(&i_gh);
	}

	return error;
}

static int munge_mode(struct gfs2_inode *ip, mode_t mode)
{
	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	struct buffer_head *dibh;
	int error;

	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
	if (error)
		return error;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (!error) {
		gfs2_assert_withdraw(sdp,
				(ip->i_di.di_mode & S_IFMT) == (mode & S_IFMT));
		ip->i_di.di_mode = mode;
		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
		gfs2_dinode_out(ip, dibh->b_data);
		brelse(dibh);
	}

	gfs2_trans_end(sdp);

	return 0;
}

int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip)
{
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
	struct posix_acl *acl = NULL, *clone;
	struct gfs2_ea_request er;
	mode_t mode = ip->i_di.di_mode;
	int error;

	if (!sdp->sd_args.ar_posix_acl)
		return 0;
	if (S_ISLNK(ip->i_di.di_mode))
		return 0;

	memset(&er, 0, sizeof(struct gfs2_ea_request));
	er.er_type = GFS2_EATYPE_SYS;

	error = acl_get(dip, ACL_DEFAULT, &acl, NULL,
			&er.er_data, &er.er_data_len);
	if (error)
		return error;
	if (!acl) {
		mode &= ~current->fs->umask;
		if (mode != ip->i_di.di_mode)
			error = munge_mode(ip, mode);
		return error;
	}

	clone = posix_acl_clone(acl, GFP_KERNEL);
	error = -ENOMEM;
	if (!clone)
		goto out;
	posix_acl_release(acl);
	acl = clone;

	if (S_ISDIR(ip->i_di.di_mode)) {
		er.er_name = GFS2_POSIX_ACL_DEFAULT;
		er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
		error = gfs2_system_eaops.eo_set(ip, &er);
		if (error)
			goto out;
	}

	error = posix_acl_create_masq(acl, &mode);
	if (error < 0)
		goto out;
	if (error > 0) {
		er.er_name = GFS2_POSIX_ACL_ACCESS;
		er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
		posix_acl_to_xattr(acl, er.er_data, er.er_data_len);
		er.er_mode = mode;
		er.er_flags = GFS2_ERF_MODE;
		error = gfs2_system_eaops.eo_set(ip, &er);
		if (error)
			goto out;
	} else
		munge_mode(ip, mode);

out:
	posix_acl_release(acl);
	kfree(er.er_data);
	return error;
}

int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr)
{
	struct posix_acl *acl = NULL, *clone;
	struct gfs2_ea_location el;
	char *data;
	unsigned int len;
	int error;

	error = acl_get(ip, ACL_ACCESS, &acl, &el, &data, &len);
	if (error)
		return error;
	if (!acl)
		return gfs2_setattr_simple(ip, attr);

	clone = posix_acl_clone(acl, GFP_KERNEL);
	error = -ENOMEM;
	if (!clone)
		goto out;
	posix_acl_release(acl);
	acl = clone;

	error = posix_acl_chmod_masq(acl, attr->ia_mode);
	if (!error) {
		posix_acl_to_xattr(acl, data, len);
		error = gfs2_ea_acl_chmod(ip, &el, attr, data);
	}

out:
	posix_acl_release(acl);
	brelse(el.el_bh);
	kfree(data);
	return error;
}
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>
	15	#include <linux/posix_acl.h>
	16	#include <linux/posix_acl_xattr.h>
5c676f6d	17	#include <linux/gfs2_ondisk.h>
7d308590	18	#include <linux/lm_interface.h>
b3b94faa DT	19
b3b94faa DT	20	#include "gfs2.h"
5c676f6d	21	#include "incore.h"
b3b94faa DT	22	#include "acl.h"
	23	#include "eaops.h"
	24	#include "eattr.h"
	25	#include "glock.h"
	26	#include "inode.h"
	27	#include "meta_io.h"
	28	#include "trans.h"
5c676f6d	29	#include "util.h"
b3b94faa DT	30
	31	#define ACL_ACCESS 1
	32	#define ACL_DEFAULT 0
	33
	34	int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
	35	struct gfs2_ea_request *er,
	36	int remove, mode_t mode)
	37	{
	38	struct posix_acl *acl;
	39	int error;
	40
	41	error = gfs2_acl_validate_remove(ip, access);
	42	if (error)
	43	return error;
	44
	45	if (!er->er_data)
	46	return -EINVAL;
	47
	48	acl = posix_acl_from_xattr(er->er_data, er->er_data_len);
	49	if (IS_ERR(acl))
	50	return PTR_ERR(acl);
	51	if (!acl) {
	52	*remove = 1;
	53	return 0;
	54	}
	55
	56	error = posix_acl_valid(acl);
	57	if (error)
	58	goto out;
	59
	60	if (access) {
	61	error = posix_acl_equiv_mode(acl, mode);
	62	if (!error)
	63	*remove = 1;
	64	else if (error > 0)
	65	error = 0;
	66	}
	67
a91ea69f	68	out:
b3b94faa	69	posix_acl_release(acl);
b3b94faa DT	70	return error;
	71	}
	72
	73	int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
	74	{
feaa7bba	75	if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
b3b94faa DT	76	return -EOPNOTSUPP;
	77	if (current->fsuid != ip->i_di.di_uid && !capable(CAP_FOWNER))
	78	return -EPERM;
	79	if (S_ISLNK(ip->i_di.di_mode))
	80	return -EOPNOTSUPP;
	81	if (!access && !S_ISDIR(ip->i_di.di_mode))
	82	return -EACCES;
	83
	84	return 0;
	85	}
	86
	87	static int acl_get(struct gfs2_inode ip, int access, struct posix_acl *acl,
	88	struct gfs2_ea_location el, char data, unsigned int len)
	89	{
	90	struct gfs2_ea_request er;
	91	struct gfs2_ea_location el_this;
	92	int error;
	93
	94	if (!ip->i_di.di_eattr)
	95	return 0;
	96
	97	memset(&er, 0, sizeof(struct gfs2_ea_request));
	98	if (access) {
	99	er.er_name = GFS2_POSIX_ACL_ACCESS;
	100	er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
	101	} else {
	102	er.er_name = GFS2_POSIX_ACL_DEFAULT;
	103	er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
	104	}
	105	er.er_type = GFS2_EATYPE_SYS;
	106
	107	if (!el)
	108	el = &el_this;
	109
	110	error = gfs2_ea_find(ip, &er, el);
	111	if (error)
	112	return error;
	113	if (!el->el_ea)
	114	return 0;
	115	if (!GFS2_EA_DATA_LEN(el->el_ea))
	116	goto out;
	117
	118	er.er_data_len = GFS2_EA_DATA_LEN(el->el_ea);
	119	er.er_data = kmalloc(er.er_data_len, GFP_KERNEL);
	120	error = -ENOMEM;
	121	if (!er.er_data)
	122	goto out;
	123
	124	error = gfs2_ea_get_copy(ip, el, er.er_data);
	125	if (error)
	126	goto out_kfree;
	127
	128	if (acl) {
	129	*acl = posix_acl_from_xattr(er.er_data, er.er_data_len);
	130	if (IS_ERR(*acl))
	131	error = PTR_ERR(*acl);
	132	}
	133
a91ea69f	134	out_kfree:
b3b94faa DT	135	if (error \|\| !data)
	136	kfree(er.er_data);
	137	else {
	138	*data = er.er_data;
	139	*len = er.er_data_len;
	140	}
a91ea69f	141	out:
b3b94faa DT	142	if (error \|\| el == &el_this)
b3b94faa DT	143	brelse(el->el_bh);
b3b94faa DT	144	return error;
	145	}
	146
	147	/**
	148	* gfs2_check_acl_locked - Check an ACL to see if we're allowed to do something
	149	* @inode: the file we want to do something to
	150	* @mask: what we want to do
	151	*
	152	* Returns: errno
	153	*/
	154
	155	int gfs2_check_acl_locked(struct inode *inode, int mask)
	156	{
	157	struct posix_acl *acl = NULL;
	158	int error;
	159
feaa7bba	160	error = acl_get(GFS2_I(inode), ACL_ACCESS, &acl, NULL, NULL, NULL);
b3b94faa DT	161	if (error)
	162	return error;
	163
	164	if (acl) {
	165	error = posix_acl_permission(inode, acl, mask);
	166	posix_acl_release(acl);
	167	return error;
	168	}
	169
	170	return -EAGAIN;
	171	}
	172
	173	int gfs2_check_acl(struct inode *inode, int mask)
	174	{
feaa7bba	175	struct gfs2_inode *ip = GFS2_I(inode);
b3b94faa DT	176	struct gfs2_holder i_gh;
	177	int error;
	178
faf450ef	179	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
b3b94faa DT	180	if (!error) {
	181	error = gfs2_check_acl_locked(inode, mask);
	182	gfs2_glock_dq_uninit(&i_gh);
	183	}
907b9bce	184
b3b94faa DT	185	return error;
	186	}
	187
	188	static int munge_mode(struct gfs2_inode *ip, mode_t mode)
	189	{
feaa7bba	190	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
b3b94faa DT	191	struct buffer_head *dibh;
	192	int error;
	193
	194	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
	195	if (error)
	196	return error;
	197
	198	error = gfs2_meta_inode_buffer(ip, &dibh);
	199	if (!error) {
	200	gfs2_assert_withdraw(sdp,
	201	(ip->i_di.di_mode & S_IFMT) == (mode & S_IFMT));
	202	ip->i_di.di_mode = mode;
d4e9c4c3	203	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
539e5d6b	204	gfs2_dinode_out(ip, dibh->b_data);
b3b94faa DT	205	brelse(dibh);
	206	}
	207
	208	gfs2_trans_end(sdp);
	209
	210	return 0;
	211	}
	212
	213	int gfs2_acl_create(struct gfs2_inode dip, struct gfs2_inode ip)
	214	{
feaa7bba	215	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
b3b94faa DT	216	struct posix_acl acl = NULL, clone;
	217	struct gfs2_ea_request er;
	218	mode_t mode = ip->i_di.di_mode;
	219	int error;
	220
	221	if (!sdp->sd_args.ar_posix_acl)
	222	return 0;
	223	if (S_ISLNK(ip->i_di.di_mode))
	224	return 0;
	225
	226	memset(&er, 0, sizeof(struct gfs2_ea_request));
	227	er.er_type = GFS2_EATYPE_SYS;
	228
	229	error = acl_get(dip, ACL_DEFAULT, &acl, NULL,
	230	&er.er_data, &er.er_data_len);
	231	if (error)
	232	return error;
	233	if (!acl) {
	234	mode &= ~current->fs->umask;
	235	if (mode != ip->i_di.di_mode)
	236	error = munge_mode(ip, mode);
	237	return error;
	238	}
	239
	240	clone = posix_acl_clone(acl, GFP_KERNEL);
	241	error = -ENOMEM;
	242	if (!clone)
	243	goto out;
	244	posix_acl_release(acl);
	245	acl = clone;
	246
	247	if (S_ISDIR(ip->i_di.di_mode)) {
	248	er.er_name = GFS2_POSIX_ACL_DEFAULT;
	249	er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
	250	error = gfs2_system_eaops.eo_set(ip, &er);
	251	if (error)
	252	goto out;
	253	}
	254
	255	error = posix_acl_create_masq(acl, &mode);
	256	if (error < 0)
	257	goto out;
	258	if (error > 0) {
	259	er.er_name = GFS2_POSIX_ACL_ACCESS;
	260	er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
	261	posix_acl_to_xattr(acl, er.er_data, er.er_data_len);
	262	er.er_mode = mode;
	263	er.er_flags = GFS2_ERF_MODE;
	264	error = gfs2_system_eaops.eo_set(ip, &er);
	265	if (error)
	266	goto out;
	267	} else
	268	munge_mode(ip, mode);
	269
a91ea69f	270	out:
b3b94faa DT	271	posix_acl_release(acl);
	272	kfree(er.er_data);
	273	return error;
	274	}
	275
	276	int gfs2_acl_chmod(struct gfs2_inode ip, struct iattr attr)
	277	{
	278	struct posix_acl acl = NULL, clone;
	279	struct gfs2_ea_location el;
	280	char *data;
	281	unsigned int len;
	282	int error;
	283
	284	error = acl_get(ip, ACL_ACCESS, &acl, &el, &data, &len);
	285	if (error)
	286	return error;
	287	if (!acl)
	288	return gfs2_setattr_simple(ip, attr);
	289
	290	clone = posix_acl_clone(acl, GFP_KERNEL);
	291	error = -ENOMEM;
	292	if (!clone)
	293	goto out;
	294	posix_acl_release(acl);
	295	acl = clone;
	296
	297	error = posix_acl_chmod_masq(acl, attr->ia_mode);
	298	if (!error) {
	299	posix_acl_to_xattr(acl, data, len);
	300	error = gfs2_ea_acl_chmod(ip, &el, attr, data);
	301	}
	302
a91ea69f	303	out:
b3b94faa DT	304	posix_acl_release(acl);
	305	brelse(el.el_bh);
	306	kfree(data);
b3b94faa DT	307	return error;
	308	}
	309