[linux-block.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 "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 (!is_owner_or_cap(&ip->i_inode))
		return -EPERM;
	if (S_ISLNK(ip->i_inode.i_mode))
		return -EOPNOTSUPP;
	if (!access && !S_ISDIR(ip->i_inode.i_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_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_NOFS);
	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 - 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(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;
}

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_inode.i_mode & S_IFMT) == (mode & S_IFMT));
		ip->i_inode.i_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_inode.i_mode;
	int error;

	if (!sdp->sd_args.ar_posix_acl)
		return 0;
	if (S_ISLNK(ip->i_inode.i_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_umask();
		if (mode != ip->i_inode.i_mode)
			error = munge_mode(ip, mode);
		return error;
	}

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

	if (S_ISDIR(ip->i_inode.i_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_NOFS);
	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>
b3b94faa DT	18
b3b94faa DT	19	#include "gfs2.h"
5c676f6d	20	#include "incore.h"
b3b94faa DT	21	#include "acl.h"
	22	#include "eaops.h"
	23	#include "eattr.h"
	24	#include "glock.h"
	25	#include "inode.h"
	26	#include "meta_io.h"
	27	#include "trans.h"
5c676f6d	28	#include "util.h"
b3b94faa DT	29
	30	#define ACL_ACCESS 1
	31	#define ACL_DEFAULT 0
	32
	33	int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
	34	struct gfs2_ea_request *er,
	35	int remove, mode_t mode)
	36	{
	37	struct posix_acl *acl;
	38	int error;
	39
	40	error = gfs2_acl_validate_remove(ip, access);
	41	if (error)
	42	return error;
	43
	44	if (!er->er_data)
	45	return -EINVAL;
	46
	47	acl = posix_acl_from_xattr(er->er_data, er->er_data_len);
	48	if (IS_ERR(acl))
	49	return PTR_ERR(acl);
	50	if (!acl) {
	51	*remove = 1;
	52	return 0;
	53	}
	54
	55	error = posix_acl_valid(acl);
	56	if (error)
	57	goto out;
	58
	59	if (access) {
	60	error = posix_acl_equiv_mode(acl, mode);
	61	if (!error)
	62	*remove = 1;
	63	else if (error > 0)
	64	error = 0;
	65	}
	66
a91ea69f	67	out:
b3b94faa	68	posix_acl_release(acl);
b3b94faa DT	69	return error;
	70	}
	71
	72	int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
	73	{
feaa7bba	74	if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
b3b94faa	75	return -EOPNOTSUPP;
3bd858ab	76	if (!is_owner_or_cap(&ip->i_inode))
b3b94faa	77	return -EPERM;
b60623c2	78	if (S_ISLNK(ip->i_inode.i_mode))
b3b94faa	79	return -EOPNOTSUPP;
b60623c2	80	if (!access && !S_ISDIR(ip->i_inode.i_mode))
b3b94faa DT	81	return -EACCES;
	82
	83	return 0;
	84	}
	85
	86	static int acl_get(struct gfs2_inode ip, int access, struct posix_acl *acl,
	87	struct gfs2_ea_location el, char data, unsigned int len)
	88	{
	89	struct gfs2_ea_request er;
	90	struct gfs2_ea_location el_this;
	91	int error;
	92
3767ac21	93	if (!ip->i_eattr)
b3b94faa DT	94	return 0;
	95
	96	memset(&er, 0, sizeof(struct gfs2_ea_request));
	97	if (access) {
	98	er.er_name = GFS2_POSIX_ACL_ACCESS;
	99	er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
	100	} else {
	101	er.er_name = GFS2_POSIX_ACL_DEFAULT;
	102	er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
	103	}
	104	er.er_type = GFS2_EATYPE_SYS;
	105
	106	if (!el)
	107	el = &el_this;
	108
	109	error = gfs2_ea_find(ip, &er, el);
	110	if (error)
	111	return error;
	112	if (!el->el_ea)
	113	return 0;
	114	if (!GFS2_EA_DATA_LEN(el->el_ea))
	115	goto out;
	116
	117	er.er_data_len = GFS2_EA_DATA_LEN(el->el_ea);
16c5f06f	118	er.er_data = kmalloc(er.er_data_len, GFP_NOFS);
b3b94faa DT	119	error = -ENOMEM;
	120	if (!er.er_data)
	121	goto out;
	122
	123	error = gfs2_ea_get_copy(ip, el, er.er_data);
	124	if (error)
	125	goto out_kfree;
	126
	127	if (acl) {
	128	*acl = posix_acl_from_xattr(er.er_data, er.er_data_len);
	129	if (IS_ERR(*acl))
	130	error = PTR_ERR(*acl);
	131	}
	132
a91ea69f	133	out_kfree:
b3b94faa DT	134	if (error \|\| !data)
	135	kfree(er.er_data);
	136	else {
	137	*data = er.er_data;
	138	*len = er.er_data_len;
	139	}
a91ea69f	140	out:
b3b94faa DT	141	if (error \|\| el == &el_this)
b3b94faa DT	142	brelse(el->el_bh);
b3b94faa DT	143	return error;
	144	}
	145
	146	/**
77386e1f	147	* gfs2_check_acl - Check an ACL to see if we're allowed to do something
b3b94faa DT	148	* @inode: the file we want to do something to
	149	* @mask: what we want to do
	150	*
	151	* Returns: errno
	152	*/
	153
77386e1f	154	int gfs2_check_acl(struct inode *inode, int mask)
b3b94faa DT	155	{
	156	struct posix_acl *acl = NULL;
	157	int error;
	158
feaa7bba	159	error = acl_get(GFS2_I(inode), ACL_ACCESS, &acl, NULL, NULL, NULL);
b3b94faa DT	160	if (error)
	161	return error;
	162
	163	if (acl) {
	164	error = posix_acl_permission(inode, acl, mask);
	165	posix_acl_release(acl);
	166	return error;
	167	}
	168
	169	return -EAGAIN;
	170	}
	171
b3b94faa DT	172	static int munge_mode(struct gfs2_inode *ip, mode_t mode)
b3b94faa DT	173	{
feaa7bba	174	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
b3b94faa DT	175	struct buffer_head *dibh;
	176	int error;
	177
	178	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
	179	if (error)
	180	return error;
	181
	182	error = gfs2_meta_inode_buffer(ip, &dibh);
	183	if (!error) {
	184	gfs2_assert_withdraw(sdp,
b60623c2 SW	185	(ip->i_inode.i_mode & S_IFMT) == (mode & S_IFMT));
b60623c2 SW	186	ip->i_inode.i_mode = mode;
d4e9c4c3	187	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
539e5d6b	188	gfs2_dinode_out(ip, dibh->b_data);
b3b94faa DT	189	brelse(dibh);
	190	}
	191
	192	gfs2_trans_end(sdp);
	193
	194	return 0;
	195	}
	196
	197	int gfs2_acl_create(struct gfs2_inode dip, struct gfs2_inode ip)
	198	{
feaa7bba	199	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
b3b94faa DT	200	struct posix_acl acl = NULL, clone;
b3b94faa DT	201	struct gfs2_ea_request er;
b60623c2	202	mode_t mode = ip->i_inode.i_mode;
b3b94faa DT	203	int error;
	204
	205	if (!sdp->sd_args.ar_posix_acl)
	206	return 0;
b60623c2	207	if (S_ISLNK(ip->i_inode.i_mode))
b3b94faa DT	208	return 0;
	209
	210	memset(&er, 0, sizeof(struct gfs2_ea_request));
	211	er.er_type = GFS2_EATYPE_SYS;
	212
	213	error = acl_get(dip, ACL_DEFAULT, &acl, NULL,
	214	&er.er_data, &er.er_data_len);
	215	if (error)
	216	return error;
	217	if (!acl) {
ce3b0f8d	218	mode &= ~current_umask();
b60623c2	219	if (mode != ip->i_inode.i_mode)
b3b94faa DT	220	error = munge_mode(ip, mode);
	221	return error;
	222	}
	223
16c5f06f	224	clone = posix_acl_clone(acl, GFP_NOFS);
b3b94faa DT	225	error = -ENOMEM;
	226	if (!clone)
	227	goto out;
	228	posix_acl_release(acl);
	229	acl = clone;
	230
b60623c2	231	if (S_ISDIR(ip->i_inode.i_mode)) {
b3b94faa DT	232	er.er_name = GFS2_POSIX_ACL_DEFAULT;
	233	er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
	234	error = gfs2_system_eaops.eo_set(ip, &er);
	235	if (error)
	236	goto out;
	237	}
	238
	239	error = posix_acl_create_masq(acl, &mode);
	240	if (error < 0)
	241	goto out;
	242	if (error > 0) {
	243	er.er_name = GFS2_POSIX_ACL_ACCESS;
	244	er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
	245	posix_acl_to_xattr(acl, er.er_data, er.er_data_len);
	246	er.er_mode = mode;
	247	er.er_flags = GFS2_ERF_MODE;
	248	error = gfs2_system_eaops.eo_set(ip, &er);
	249	if (error)
	250	goto out;
	251	} else
	252	munge_mode(ip, mode);
	253
a91ea69f	254	out:
b3b94faa DT	255	posix_acl_release(acl);
	256	kfree(er.er_data);
	257	return error;
	258	}
	259
	260	int gfs2_acl_chmod(struct gfs2_inode ip, struct iattr attr)
	261	{
	262	struct posix_acl acl = NULL, clone;
	263	struct gfs2_ea_location el;
	264	char *data;
	265	unsigned int len;
	266	int error;
	267
	268	error = acl_get(ip, ACL_ACCESS, &acl, &el, &data, &len);
	269	if (error)
	270	return error;
	271	if (!acl)
	272	return gfs2_setattr_simple(ip, attr);
	273
16c5f06f	274	clone = posix_acl_clone(acl, GFP_NOFS);
b3b94faa DT	275	error = -ENOMEM;
	276	if (!clone)
	277	goto out;
	278	posix_acl_release(acl);
	279	acl = clone;
	280
	281	error = posix_acl_chmod_masq(acl, attr->ia_mode);
	282	if (!error) {
	283	posix_acl_to_xattr(acl, data, len);
	284	error = gfs2_ea_acl_chmod(ip, &el, attr, data);
	285	}
	286
a91ea69f	287	out:
b3b94faa DT	288	posix_acl_release(acl);
	289	brelse(el.el_bh);
	290	kfree(data);
b3b94faa DT	291	return error;
	292	}
	293