[deliverable/linux.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 v.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 "gfs2.h"
#include "lm_interface.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->i_di, 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
	7	* of the GNU General Public License v.2.
	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>
b3b94faa DT	18
b3b94faa DT	19	#include "gfs2.h"
5c676f6d SW	20	#include "lm_interface.h"
5c676f6d SW	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
	68	out:
	69	posix_acl_release(acl);
	70
	71	return error;
	72	}
	73
	74	int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
	75	{
feaa7bba	76	if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
b3b94faa DT	77	return -EOPNOTSUPP;
	78	if (current->fsuid != ip->i_di.di_uid && !capable(CAP_FOWNER))
	79	return -EPERM;
	80	if (S_ISLNK(ip->i_di.di_mode))
	81	return -EOPNOTSUPP;
	82	if (!access && !S_ISDIR(ip->i_di.di_mode))
	83	return -EACCES;
	84
	85	return 0;
	86	}
	87
	88	static int acl_get(struct gfs2_inode ip, int access, struct posix_acl *acl,
	89	struct gfs2_ea_location el, char data, unsigned int len)
	90	{
	91	struct gfs2_ea_request er;
	92	struct gfs2_ea_location el_this;
	93	int error;
	94
	95	if (!ip->i_di.di_eattr)
	96	return 0;
	97
	98	memset(&er, 0, sizeof(struct gfs2_ea_request));
	99	if (access) {
	100	er.er_name = GFS2_POSIX_ACL_ACCESS;
	101	er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
	102	} else {
	103	er.er_name = GFS2_POSIX_ACL_DEFAULT;
	104	er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
	105	}
	106	er.er_type = GFS2_EATYPE_SYS;
	107
	108	if (!el)
	109	el = &el_this;
	110
	111	error = gfs2_ea_find(ip, &er, el);
	112	if (error)
	113	return error;
	114	if (!el->el_ea)
	115	return 0;
	116	if (!GFS2_EA_DATA_LEN(el->el_ea))
	117	goto out;
	118
	119	er.er_data_len = GFS2_EA_DATA_LEN(el->el_ea);
	120	er.er_data = kmalloc(er.er_data_len, GFP_KERNEL);
	121	error = -ENOMEM;
	122	if (!er.er_data)
	123	goto out;
	124
	125	error = gfs2_ea_get_copy(ip, el, er.er_data);
	126	if (error)
	127	goto out_kfree;
	128
	129	if (acl) {
	130	*acl = posix_acl_from_xattr(er.er_data, er.er_data_len);
	131	if (IS_ERR(*acl))
	132	error = PTR_ERR(*acl);
	133	}
	134
	135	out_kfree:
	136	if (error \|\| !data)
	137	kfree(er.er_data);
	138	else {
	139	*data = er.er_data;
	140	*len = er.er_data_len;
141	}
142
143	out:
144	if (error \|\| el == &el_this)
145	brelse(el->el_bh);
146
147	return error;
148	}
149
150	/**
151	* gfs2_check_acl_locked - Check an ACL to see if we're allowed to do something
152	* @inode: the file we want to do something to
153	* @mask: what we want to do
154	*
155	* Returns: errno
156	*/
157
158	int gfs2_check_acl_locked(struct inode *inode, int mask)
159	{
160	struct posix_acl *acl = NULL;
161	int error;
162
feaa7bba	163	error = acl_get(GFS2_I(inode), ACL_ACCESS, &acl, NULL, NULL, NULL);
b3b94faa DT	164	if (error)
	165	return error;
	166
	167	if (acl) {
	168	error = posix_acl_permission(inode, acl, mask);
	169	posix_acl_release(acl);
	170	return error;
	171	}
	172
	173	return -EAGAIN;
	174	}
	175
	176	int gfs2_check_acl(struct inode *inode, int mask)
	177	{
feaa7bba	178	struct gfs2_inode *ip = GFS2_I(inode);
b3b94faa DT	179	struct gfs2_holder i_gh;
	180	int error;
	181
	182	error = gfs2_glock_nq_init(ip->i_gl,
	183	LM_ST_SHARED, LM_FLAG_ANY,
	184	&i_gh);
	185	if (!error) {
	186	error = gfs2_check_acl_locked(inode, mask);
	187	gfs2_glock_dq_uninit(&i_gh);
	188	}
	189
	190	return error;
	191	}
	192
	193	static int munge_mode(struct gfs2_inode *ip, mode_t mode)
	194	{
feaa7bba	195	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
b3b94faa DT	196	struct buffer_head *dibh;
	197	int error;
	198
	199	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
	200	if (error)
	201	return error;
	202
	203	error = gfs2_meta_inode_buffer(ip, &dibh);
	204	if (!error) {
	205	gfs2_assert_withdraw(sdp,
	206	(ip->i_di.di_mode & S_IFMT) == (mode & S_IFMT));
	207	ip->i_di.di_mode = mode;
d4e9c4c3	208	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
b3b94faa DT	209	gfs2_dinode_out(&ip->i_di, dibh->b_data);
	210	brelse(dibh);
	211	}
	212
	213	gfs2_trans_end(sdp);
	214
	215	return 0;
	216	}
	217
	218	int gfs2_acl_create(struct gfs2_inode dip, struct gfs2_inode ip)
	219	{
feaa7bba	220	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
b3b94faa DT	221	struct posix_acl acl = NULL, clone;
	222	struct gfs2_ea_request er;
	223	mode_t mode = ip->i_di.di_mode;
	224	int error;
	225
	226	if (!sdp->sd_args.ar_posix_acl)
	227	return 0;
	228	if (S_ISLNK(ip->i_di.di_mode))
	229	return 0;
	230
	231	memset(&er, 0, sizeof(struct gfs2_ea_request));
	232	er.er_type = GFS2_EATYPE_SYS;
	233
	234	error = acl_get(dip, ACL_DEFAULT, &acl, NULL,
	235	&er.er_data, &er.er_data_len);
	236	if (error)
	237	return error;
	238	if (!acl) {
	239	mode &= ~current->fs->umask;
	240	if (mode != ip->i_di.di_mode)
	241	error = munge_mode(ip, mode);
	242	return error;
	243	}
	244
	245	clone = posix_acl_clone(acl, GFP_KERNEL);
	246	error = -ENOMEM;
	247	if (!clone)
	248	goto out;
	249	posix_acl_release(acl);
	250	acl = clone;
	251
	252	if (S_ISDIR(ip->i_di.di_mode)) {
	253	er.er_name = GFS2_POSIX_ACL_DEFAULT;
	254	er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
	255	error = gfs2_system_eaops.eo_set(ip, &er);
	256	if (error)
	257	goto out;
	258	}
	259
	260	error = posix_acl_create_masq(acl, &mode);
	261	if (error < 0)
	262	goto out;
	263	if (error > 0) {
	264	er.er_name = GFS2_POSIX_ACL_ACCESS;
	265	er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
	266	posix_acl_to_xattr(acl, er.er_data, er.er_data_len);
	267	er.er_mode = mode;
	268	er.er_flags = GFS2_ERF_MODE;
	269	error = gfs2_system_eaops.eo_set(ip, &er);
	270	if (error)
	271	goto out;
	272	} else
	273	munge_mode(ip, mode);
	274
	275	out:
	276	posix_acl_release(acl);
	277	kfree(er.er_data);
	278	return error;
	279	}
	280
	281	int gfs2_acl_chmod(struct gfs2_inode ip, struct iattr attr)
	282	{
	283	struct posix_acl acl = NULL, clone;
	284	struct gfs2_ea_location el;
285	char *data;
286	unsigned int len;
287	int error;
288
289	error = acl_get(ip, ACL_ACCESS, &acl, &el, &data, &len);
290	if (error)
291	return error;
292	if (!acl)
293	return gfs2_setattr_simple(ip, attr);
294
295	clone = posix_acl_clone(acl, GFP_KERNEL);
296	error = -ENOMEM;
297	if (!clone)
298	goto out;
299	posix_acl_release(acl);
300	acl = clone;
301
302	error = posix_acl_chmod_masq(acl, attr->ia_mode);
303	if (!error) {
304	posix_acl_to_xattr(acl, data, len);
305	error = gfs2_ea_acl_chmod(ip, &el, attr, data);
306	}
307
308	out:
309	posix_acl_release(acl);
310	brelse(el.el_bh);
311	kfree(data);
312
313	return error;
314	}
315