[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 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;
}

static struct posix_acl *gfs2_acl_get(struct gfs2_inode *ip, int type)
{
	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(data, len);
	kfree(data);
	return acl;
}

struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
{
	return gfs2_acl_get(GFS2_I(inode), type);
}

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

	if (mode != inode->i_mode) {
		struct iattr iattr;

		iattr.ia_valid = ATTR_MODE;
		iattr.ia_mode = mode;

		error = gfs2_setattr_simple(inode, &iattr);
	}

	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(acl, NULL, 0);
	if (len == 0)
		return 0;
	data = kmalloc(len, GFP_NOFS);
	if (data == NULL)
		return -ENOMEM;
	error = posix_acl_to_xattr(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_acl_get(dip, ACL_TYPE_DEFAULT);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (!acl) {
		mode &= ~current_umask();
		if (mode != inode->i_mode)
			error = gfs2_set_mode(inode, mode);
		return error;
	}

	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_acl_get(ip, 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(acl, NULL, 0);
	data = kmalloc(len, GFP_NOFS);
	error = -ENOMEM;
	if (data == NULL)
		goto out;
	posix_acl_to_xattr(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_acl_get(GFS2_I(inode), type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl == NULL)
		return -ENODATA;

	error = posix_acl_to_xattr(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 ((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(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_equiv_mode(acl, &mode);

		if (error <= 0) {
			posix_acl_release(acl);
			acl = NULL;

			if (error < 0)
				return error;
		}

		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
479c427d SW	41	static struct posix_acl gfs2_acl_get(struct gfs2_inode ip, int type)
	42	{
	43	struct posix_acl *acl;
	44	const char *name;
	45	char *data;
	46	int len;
40b78a32	47
3767ac21	48	if (!ip->i_eattr)
479c427d	49	return NULL;
b3b94faa	50
106381bf SW	51	acl = get_cached_acl(&ip->i_inode, type);
	52	if (acl != ACL_NOT_CACHED)
	53	return acl;
	54
479c427d SW	55	name = gfs2_acl_name(type);
	56	if (name == NULL)
	57	return ERR_PTR(-EINVAL);
b3b94faa	58
479c427d SW	59	len = gfs2_xattr_acl_get(ip, name, &data);
	60	if (len < 0)
	61	return ERR_PTR(len);
	62	if (len == 0)
	63	return NULL;
b3b94faa	64
479c427d SW	65	acl = posix_acl_from_xattr(data, len);
	66	kfree(data);
	67	return acl;
b3b94faa DT	68	}
b3b94faa DT	69
4e34e719	70	struct posix_acl gfs2_get_acl(struct inode inode, int type)
b3b94faa	71	{
4e34e719	72	return gfs2_acl_get(GFS2_I(inode), type);
b3b94faa DT	73	}
b3b94faa DT	74
d3fb6120	75	static int gfs2_set_mode(struct inode *inode, umode_t mode)
b3b94faa	76	{
69dca424	77	int error = 0;
b3b94faa	78
69dca424 SW	79	if (mode != inode->i_mode) {
69dca424 SW	80	struct iattr iattr;
b3b94faa	81
69dca424 SW	82	iattr.ia_valid = ATTR_MODE;
69dca424 SW	83	iattr.ia_mode = mode;
b3b94faa	84
ab9bbda0	85	error = gfs2_setattr_simple(inode, &iattr);
69dca424	86	}
b3b94faa	87
69dca424	88	return error;
b3b94faa DT	89	}
b3b94faa DT	90
479c427d	91	static int gfs2_acl_set(struct inode inode, int type, struct posix_acl acl)
b3b94faa	92	{
b3b94faa	93	int error;
479c427d SW	94	int len;
	95	char *data;
	96	const char *name = gfs2_acl_name(type);
	97
	98	BUG_ON(name == NULL);
	99	len = posix_acl_to_xattr(acl, NULL, 0);
	100	if (len == 0)
	101	return 0;
	102	data = kmalloc(len, GFP_NOFS);
	103	if (data == NULL)
	104	return -ENOMEM;
	105	error = posix_acl_to_xattr(acl, data, len);
	106	if (error < 0)
	107	goto out;
431547b3	108	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
106381bf SW	109	if (!error)
106381bf SW	110	set_cached_acl(inode, type, acl);
479c427d SW	111	out:
	112	kfree(data);
	113	return error;
	114	}
	115
	116	int gfs2_acl_create(struct gfs2_inode dip, struct inode inode)
	117	{
	118	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
826cae2f	119	struct posix_acl *acl;
d3fb6120	120	umode_t mode = inode->i_mode;
479c427d	121	int error = 0;
b3b94faa DT	122
	123	if (!sdp->sd_args.ar_posix_acl)
	124	return 0;
479c427d	125	if (S_ISLNK(inode->i_mode))
b3b94faa DT	126	return 0;
b3b94faa DT	127
479c427d SW	128	acl = gfs2_acl_get(dip, ACL_TYPE_DEFAULT);
	129	if (IS_ERR(acl))
	130	return PTR_ERR(acl);
b3b94faa	131	if (!acl) {
ce3b0f8d	132	mode &= ~current_umask();
479c427d SW	133	if (mode != inode->i_mode)
479c427d SW	134	error = gfs2_set_mode(inode, mode);
b3b94faa DT	135	return error;
	136	}
	137
479c427d SW	138	if (S_ISDIR(inode->i_mode)) {
	139	error = gfs2_acl_set(inode, ACL_TYPE_DEFAULT, acl);
	140	if (error)
	141	goto out;
	142	}
	143
826cae2f	144	error = posix_acl_create(&acl, GFP_NOFS, &mode);
b3b94faa	145	if (error < 0)
826cae2f AV	146	return error;
826cae2f AV	147
40b78a32 SW	148	if (error == 0)
40b78a32 SW	149	goto munge;
b3b94faa	150
479c427d	151	error = gfs2_acl_set(inode, ACL_TYPE_ACCESS, acl);
40b78a32 SW	152	if (error)
	153	goto out;
	154	munge:
479c427d	155	error = gfs2_set_mode(inode, mode);
a91ea69f	156	out:
b3b94faa	157	posix_acl_release(acl);
b3b94faa DT	158	return error;
	159	}
	160
	161	int gfs2_acl_chmod(struct gfs2_inode ip, struct iattr attr)
	162	{
ab9bbda0	163	struct inode *inode = &ip->i_inode;
bc26ab5f	164	struct posix_acl *acl;
b3b94faa DT	165	char *data;
	166	unsigned int len;
	167	int error;
	168
479c427d SW	169	acl = gfs2_acl_get(ip, ACL_TYPE_ACCESS);
	170	if (IS_ERR(acl))
	171	return PTR_ERR(acl);
b3b94faa	172	if (!acl)
ab9bbda0	173	return gfs2_setattr_simple(inode, attr);
b3b94faa	174
bc26ab5f AV	175	error = posix_acl_chmod(&acl, GFP_NOFS, attr->ia_mode);
	176	if (error)
	177	return error;
	178
	179	len = posix_acl_to_xattr(acl, NULL, 0);
	180	data = kmalloc(len, GFP_NOFS);
b3b94faa	181	error = -ENOMEM;
bc26ab5f	182	if (data == NULL)
b3b94faa	183	goto out;
bc26ab5f AV	184	posix_acl_to_xattr(acl, data, len);
	185	error = gfs2_xattr_acl_chmod(ip, attr, data);
	186	kfree(data);
	187	set_cached_acl(&ip->i_inode, ACL_TYPE_ACCESS, acl);
b3b94faa	188
a91ea69f	189	out:
b3b94faa	190	posix_acl_release(acl);
b3b94faa DT	191	return error;
	192	}
	193
2646a1f6 SW	194	static int gfs2_acl_type(const char *name)
	195	{
	196	if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
	197	return ACL_TYPE_ACCESS;
	198	if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
	199	return ACL_TYPE_DEFAULT;
	200	return -EINVAL;
	201	}
	202
431547b3 CH	203	static int gfs2_xattr_system_get(struct dentry dentry, const char name,
431547b3 CH	204	void *buffer, size_t size, int xtype)
2646a1f6	205	{
431547b3	206	struct inode *inode = dentry->d_inode;
f72f2d2e	207	struct gfs2_sbd *sdp = GFS2_SB(inode);
106381bf	208	struct posix_acl *acl;
2646a1f6	209	int type;
106381bf	210	int error;
2646a1f6	211
f72f2d2e SW	212	if (!sdp->sd_args.ar_posix_acl)
	213	return -EOPNOTSUPP;
	214
2646a1f6 SW	215	type = gfs2_acl_type(name);
	216	if (type < 0)
	217	return type;
	218
106381bf SW	219	acl = gfs2_acl_get(GFS2_I(inode), type);
	220	if (IS_ERR(acl))
	221	return PTR_ERR(acl);
	222	if (acl == NULL)
	223	return -ENODATA;
2646a1f6	224
106381bf SW	225	error = posix_acl_to_xattr(acl, buffer, size);
	226	posix_acl_release(acl);
	227
	228	return error;
	229	}
2646a1f6	230
431547b3 CH	231	static int gfs2_xattr_system_set(struct dentry dentry, const char name,
	232	const void *value, size_t size, int flags,
	233	int xtype)
2646a1f6	234	{
431547b3	235	struct inode *inode = dentry->d_inode;
2646a1f6 SW	236	struct gfs2_sbd *sdp = GFS2_SB(inode);
	237	struct posix_acl *acl = NULL;
	238	int error = 0, type;
	239
	240	if (!sdp->sd_args.ar_posix_acl)
	241	return -EOPNOTSUPP;
	242
	243	type = gfs2_acl_type(name);
	244	if (type < 0)
	245	return type;
	246	if (flags & XATTR_CREATE)
	247	return -EINVAL;
	248	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
	249	return value ? -EACCES : 0;
	250	if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
	251	return -EPERM;
	252	if (S_ISLNK(inode->i_mode))
	253	return -EOPNOTSUPP;
	254
	255	if (!value)
	256	goto set_acl;
	257
	258	acl = posix_acl_from_xattr(value, size);
	259	if (!acl) {
	260	/*
	261	* acl_set_file(3) may request that we set default ACLs with
	262	* zero length -- defend (gracefully) against that here.
	263	*/
	264	goto out;
	265	}
	266	if (IS_ERR(acl)) {
	267	error = PTR_ERR(acl);
	268	goto out;
	269	}
	270
	271	error = posix_acl_valid(acl);
	272	if (error)
	273	goto out_release;
	274
	275	error = -EINVAL;
	276	if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
	277	goto out_release;
	278
	279	if (type == ACL_TYPE_ACCESS) {
d6952123	280	umode_t mode = inode->i_mode;
2646a1f6 SW	281	error = posix_acl_equiv_mode(acl, &mode);
	282
	283	if (error <= 0) {
	284	posix_acl_release(acl);
	285	acl = NULL;
	286
	287	if (error < 0)
	288	return error;
	289	}
	290
	291	error = gfs2_set_mode(inode, mode);
	292	if (error)
	293	goto out_release;
	294	}
	295
	296	set_acl:
431547b3	297	error = __gfs2_xattr_set(inode, name, value, size, 0, GFS2_EATYPE_SYS);
106381bf SW	298	if (!error) {
	299	if (acl)
	300	set_cached_acl(inode, type, acl);
	301	else
	302	forget_cached_acl(inode, type);
	303	}
2646a1f6 SW	304	out_release:
	305	posix_acl_release(acl);
	306	out:
	307	return error;
	308	}
	309
b7bb0a12	310	const struct xattr_handler gfs2_xattr_system_handler = {
2646a1f6	311	.prefix = XATTR_SYSTEM_PREFIX,
431547b3	312	.flags = GFS2_EATYPE_SYS,
2646a1f6 SW	313	.get = gfs2_xattr_system_get,
	314	.set = gfs2_xattr_system_set,
	315	};
	316