[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;
}

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(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) {
		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_get_acl(&dip->i_inode, 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_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(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_get_acl(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
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
479c427d SW	66	acl = posix_acl_from_xattr(data, len);
	67	kfree(data);
	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 SW	75	if (mode != inode->i_mode) {
69dca424 SW	76	struct iattr iattr;
b3b94faa	77
69dca424 SW	78	iattr.ia_valid = ATTR_MODE;
69dca424 SW	79	iattr.ia_mode = mode;
b3b94faa	80
ab9bbda0	81	error = gfs2_setattr_simple(inode, &iattr);
69dca424	82	}
b3b94faa	83
69dca424	84	return error;
b3b94faa DT	85	}
b3b94faa DT	86
479c427d	87	static int gfs2_acl_set(struct inode inode, int type, struct posix_acl acl)
b3b94faa	88	{
b3b94faa	89	int error;
479c427d SW	90	int len;
	91	char *data;
	92	const char *name = gfs2_acl_name(type);
	93
	94	BUG_ON(name == NULL);
	95	len = posix_acl_to_xattr(acl, NULL, 0);
	96	if (len == 0)
	97	return 0;
	98	data = kmalloc(len, GFP_NOFS);
	99	if (data == NULL)
	100	return -ENOMEM;
	101	error = posix_acl_to_xattr(acl, data, len);
	102	if (error < 0)
	103	goto out;
431547b3	104	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
106381bf SW	105	if (!error)
106381bf SW	106	set_cached_acl(inode, type, acl);
479c427d SW	107	out:
	108	kfree(data);
	109	return error;
	110	}
	111
	112	int gfs2_acl_create(struct gfs2_inode dip, struct inode inode)
	113	{
	114	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
826cae2f	115	struct posix_acl *acl;
d3fb6120	116	umode_t mode = inode->i_mode;
479c427d	117	int error = 0;
b3b94faa DT	118
	119	if (!sdp->sd_args.ar_posix_acl)
	120	return 0;
479c427d	121	if (S_ISLNK(inode->i_mode))
b3b94faa DT	122	return 0;
b3b94faa DT	123
018a01cd	124	acl = gfs2_get_acl(&dip->i_inode, ACL_TYPE_DEFAULT);
479c427d SW	125	if (IS_ERR(acl))
479c427d SW	126	return PTR_ERR(acl);
b3b94faa	127	if (!acl) {
ce3b0f8d	128	mode &= ~current_umask();
479c427d SW	129	if (mode != inode->i_mode)
479c427d SW	130	error = gfs2_set_mode(inode, mode);
b3b94faa DT	131	return error;
	132	}
	133
479c427d SW	134	if (S_ISDIR(inode->i_mode)) {
	135	error = gfs2_acl_set(inode, ACL_TYPE_DEFAULT, acl);
	136	if (error)
	137	goto out;
	138	}
	139
826cae2f	140	error = posix_acl_create(&acl, GFP_NOFS, &mode);
b3b94faa	141	if (error < 0)
826cae2f AV	142	return error;
826cae2f AV	143
40b78a32 SW	144	if (error == 0)
40b78a32 SW	145	goto munge;
b3b94faa	146
479c427d	147	error = gfs2_acl_set(inode, ACL_TYPE_ACCESS, acl);
40b78a32 SW	148	if (error)
	149	goto out;
	150	munge:
479c427d	151	error = gfs2_set_mode(inode, mode);
a91ea69f	152	out:
b3b94faa	153	posix_acl_release(acl);
b3b94faa DT	154	return error;
	155	}
	156
	157	int gfs2_acl_chmod(struct gfs2_inode ip, struct iattr attr)
	158	{
ab9bbda0	159	struct inode *inode = &ip->i_inode;
bc26ab5f	160	struct posix_acl *acl;
b3b94faa DT	161	char *data;
	162	unsigned int len;
	163	int error;
	164
018a01cd	165	acl = gfs2_get_acl(&ip->i_inode, ACL_TYPE_ACCESS);
479c427d SW	166	if (IS_ERR(acl))
479c427d SW	167	return PTR_ERR(acl);
b3b94faa	168	if (!acl)
ab9bbda0	169	return gfs2_setattr_simple(inode, attr);
b3b94faa	170
bc26ab5f AV	171	error = posix_acl_chmod(&acl, GFP_NOFS, attr->ia_mode);
	172	if (error)
	173	return error;
	174
	175	len = posix_acl_to_xattr(acl, NULL, 0);
	176	data = kmalloc(len, GFP_NOFS);
b3b94faa	177	error = -ENOMEM;
bc26ab5f	178	if (data == NULL)
b3b94faa	179	goto out;
bc26ab5f AV	180	posix_acl_to_xattr(acl, data, len);
	181	error = gfs2_xattr_acl_chmod(ip, attr, data);
	182	kfree(data);
	183	set_cached_acl(&ip->i_inode, ACL_TYPE_ACCESS, acl);
b3b94faa	184
a91ea69f	185	out:
b3b94faa	186	posix_acl_release(acl);
b3b94faa DT	187	return error;
	188	}
	189
2646a1f6 SW	190	static int gfs2_acl_type(const char *name)
	191	{
	192	if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
	193	return ACL_TYPE_ACCESS;
	194	if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
	195	return ACL_TYPE_DEFAULT;
	196	return -EINVAL;
	197	}
	198
431547b3 CH	199	static int gfs2_xattr_system_get(struct dentry dentry, const char name,
431547b3 CH	200	void *buffer, size_t size, int xtype)
2646a1f6	201	{
431547b3	202	struct inode *inode = dentry->d_inode;
f72f2d2e	203	struct gfs2_sbd *sdp = GFS2_SB(inode);
106381bf	204	struct posix_acl *acl;
2646a1f6	205	int type;
106381bf	206	int error;
2646a1f6	207
f72f2d2e SW	208	if (!sdp->sd_args.ar_posix_acl)
	209	return -EOPNOTSUPP;
	210
2646a1f6 SW	211	type = gfs2_acl_type(name);
	212	if (type < 0)
	213	return type;
	214
018a01cd	215	acl = gfs2_get_acl(inode, type);
106381bf SW	216	if (IS_ERR(acl))
	217	return PTR_ERR(acl);
	218	if (acl == NULL)
	219	return -ENODATA;
2646a1f6	220
106381bf SW	221	error = posix_acl_to_xattr(acl, buffer, size);
	222	posix_acl_release(acl);
	223
	224	return error;
	225	}
2646a1f6	226
431547b3 CH	227	static int gfs2_xattr_system_set(struct dentry dentry, const char name,
	228	const void *value, size_t size, int flags,
	229	int xtype)
2646a1f6	230	{
431547b3	231	struct inode *inode = dentry->d_inode;
2646a1f6 SW	232	struct gfs2_sbd *sdp = GFS2_SB(inode);
	233	struct posix_acl *acl = NULL;
	234	int error = 0, type;
	235
	236	if (!sdp->sd_args.ar_posix_acl)
	237	return -EOPNOTSUPP;
	238
	239	type = gfs2_acl_type(name);
	240	if (type < 0)
	241	return type;
	242	if (flags & XATTR_CREATE)
	243	return -EINVAL;
	244	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
	245	return value ? -EACCES : 0;
	246	if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
	247	return -EPERM;
	248	if (S_ISLNK(inode->i_mode))
	249	return -EOPNOTSUPP;
	250
	251	if (!value)
	252	goto set_acl;
	253
	254	acl = posix_acl_from_xattr(value, size);
	255	if (!acl) {
	256	/*
	257	* acl_set_file(3) may request that we set default ACLs with
	258	* zero length -- defend (gracefully) against that here.
	259	*/
	260	goto out;
	261	}
	262	if (IS_ERR(acl)) {
	263	error = PTR_ERR(acl);
	264	goto out;
	265	}
	266
	267	error = posix_acl_valid(acl);
	268	if (error)
	269	goto out_release;
	270
	271	error = -EINVAL;
	272	if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
	273	goto out_release;
	274
	275	if (type == ACL_TYPE_ACCESS) {
d6952123	276	umode_t mode = inode->i_mode;
2646a1f6 SW	277	error = posix_acl_equiv_mode(acl, &mode);
	278
	279	if (error <= 0) {
	280	posix_acl_release(acl);
	281	acl = NULL;
	282
	283	if (error < 0)
	284	return error;
	285	}
	286
	287	error = gfs2_set_mode(inode, mode);
	288	if (error)
	289	goto out_release;
	290	}
	291
	292	set_acl:
431547b3	293	error = __gfs2_xattr_set(inode, name, value, size, 0, GFS2_EATYPE_SYS);
106381bf SW	294	if (!error) {
	295	if (acl)
	296	set_cached_acl(inode, type, acl);
	297	else
	298	forget_cached_acl(inode, type);
	299	}
2646a1f6 SW	300	out_release:
	301	posix_acl_release(acl);
	302	out:
	303	return error;
	304	}
	305
b7bb0a12	306	const struct xattr_handler gfs2_xattr_system_handler = {
2646a1f6	307	.prefix = XATTR_SYSTEM_PREFIX,
431547b3	308	.flags = GFS2_EATYPE_SYS,
2646a1f6 SW	309	.get = gfs2_xattr_system_get,
	310	.set = gfs2_xattr_system_set,
	311	};
	312