[mirror_ubuntu-zesty-kernel.git] / fs / ceph / acl.c

/*
 * linux/fs/ceph/acl.c
 *
 * Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/ceph/ceph_debug.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/posix_acl.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include "super.h"

static inline void ceph_set_cached_acl(struct inode *inode,
					int type, struct posix_acl *acl)
{
	struct ceph_inode_info *ci = ceph_inode(inode);

	spin_lock(&ci->i_ceph_lock);
	if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
		set_cached_acl(inode, type, acl);
	spin_unlock(&ci->i_ceph_lock);
}

static inline struct posix_acl *ceph_get_cached_acl(struct inode *inode,
							int type)
{
	struct ceph_inode_info *ci = ceph_inode(inode);
	struct posix_acl *acl = ACL_NOT_CACHED;

	spin_lock(&ci->i_ceph_lock);
	if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
		acl = get_cached_acl(inode, type);
	spin_unlock(&ci->i_ceph_lock);

	return acl;
}

struct posix_acl *ceph_get_acl(struct inode *inode, int type)
{
	int size;
	const char *name;
	char *value = NULL;
	struct posix_acl *acl;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name = POSIX_ACL_XATTR_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		name = POSIX_ACL_XATTR_DEFAULT;
		break;
	default:
		BUG();
	}

	size = __ceph_getxattr(inode, name, "", 0);
	if (size > 0) {
		value = kzalloc(size, GFP_NOFS);
		if (!value)
			return ERR_PTR(-ENOMEM);
		size = __ceph_getxattr(inode, name, value, size);
	}

	if (size > 0)
		acl = posix_acl_from_xattr(&init_user_ns, value, size);
	else if (size == -ERANGE || size == -ENODATA || size == 0)
		acl = NULL;
	else
		acl = ERR_PTR(-EIO);

	kfree(value);

	if (!IS_ERR(acl))
		ceph_set_cached_acl(inode, type, acl);

	return acl;
}

int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
	int ret = 0, size = 0;
	const char *name = NULL;
	char *value = NULL;
	struct iattr newattrs;
	umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
	struct dentry *dentry;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name = POSIX_ACL_XATTR_ACCESS;
		if (acl) {
			ret = posix_acl_equiv_mode(acl, &new_mode);
			if (ret < 0)
				goto out;
			if (ret == 0)
				acl = NULL;
		}
		break;
	case ACL_TYPE_DEFAULT:
		if (!S_ISDIR(inode->i_mode)) {
			ret = acl ? -EINVAL : 0;
			goto out;
		}
		name = POSIX_ACL_XATTR_DEFAULT;
		break;
	default:
		ret = -EINVAL;
		goto out;
	}

	if (acl) {
		size = posix_acl_xattr_size(acl->a_count);
		value = kmalloc(size, GFP_NOFS);
		if (!value) {
			ret = -ENOMEM;
			goto out;
		}

		ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
		if (ret < 0)
			goto out_free;
	}

	dentry = d_find_alias(inode);
	if (new_mode != old_mode) {
		newattrs.ia_mode = new_mode;
		newattrs.ia_valid = ATTR_MODE;
		ret = ceph_setattr(dentry, &newattrs);
		if (ret)
			goto out_dput;
	}

	ret = __ceph_setxattr(dentry, name, value, size, 0);
	if (ret) {
		if (new_mode != old_mode) {
			newattrs.ia_mode = old_mode;
			newattrs.ia_valid = ATTR_MODE;
			ceph_setattr(dentry, &newattrs);
		}
		goto out_dput;
	}

	ceph_set_cached_acl(inode, type, acl);

out_dput:
	dput(dentry);
out_free:
	kfree(value);
out:
	return ret;
}

int ceph_init_acl(struct dentry *dentry, struct inode *inode, struct inode *dir)
{
	struct posix_acl *default_acl, *acl;
	umode_t new_mode = inode->i_mode;
	int error;

	error = posix_acl_create(dir, &new_mode, &default_acl, &acl);
	if (error)
		return error;

	if (!default_acl && !acl) {
		cache_no_acl(inode);
		if (new_mode != inode->i_mode) {
			struct iattr newattrs = {
				.ia_mode = new_mode,
				.ia_valid = ATTR_MODE,
			};
			error = ceph_setattr(dentry, &newattrs);
		}
		return error;
	}

	if (default_acl) {
		error = ceph_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
		posix_acl_release(default_acl);
	}
	if (acl) {
		if (!error)
			error = ceph_set_acl(inode, acl, ACL_TYPE_ACCESS);
		posix_acl_release(acl);
	}
	return error;
}
Commit	Line	Data
7221fe4c GZ	1	/*
	2	* linux/fs/ceph/acl.c
	3	*
	4	* Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public
	8	* License v2 as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public
	16	* License along with this program; if not, write to the
	17	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	18	* Boston, MA 021110-1307, USA.
	19	*/
	20
	21	#include <linux/ceph/ceph_debug.h>
	22	#include <linux/fs.h>
	23	#include <linux/string.h>
	24	#include <linux/xattr.h>
	25	#include <linux/posix_acl_xattr.h>
	26	#include <linux/posix_acl.h>
	27	#include <linux/sched.h>
	28	#include <linux/slab.h>
	29
	30	#include "super.h"
	31
	32	static inline void ceph_set_cached_acl(struct inode *inode,
	33	int type, struct posix_acl *acl)
	34	{
	35	struct ceph_inode_info *ci = ceph_inode(inode);
	36
	37	spin_lock(&ci->i_ceph_lock);
	38	if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
	39	set_cached_acl(inode, type, acl);
	40	spin_unlock(&ci->i_ceph_lock);
	41	}
	42
	43	static inline struct posix_acl ceph_get_cached_acl(struct inode inode,
	44	int type)
	45	{
	46	struct ceph_inode_info *ci = ceph_inode(inode);
	47	struct posix_acl *acl = ACL_NOT_CACHED;
	48
	49	spin_lock(&ci->i_ceph_lock);
	50	if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
	51	acl = get_cached_acl(inode, type);
	52	spin_unlock(&ci->i_ceph_lock);
	53
	54	return acl;
	55	}
	56
7221fe4c GZ	57	struct posix_acl ceph_get_acl(struct inode inode, int type)
	58	{
	59	int size;
	60	const char *name;
	61	char *value = NULL;
	62	struct posix_acl *acl;
	63
7221fe4c GZ	64	switch (type) {
	65	case ACL_TYPE_ACCESS:
	66	name = POSIX_ACL_XATTR_ACCESS;
	67	break;
	68	case ACL_TYPE_DEFAULT:
	69	name = POSIX_ACL_XATTR_DEFAULT;
	70	break;
	71	default:
	72	BUG();
	73	}
	74
	75	size = __ceph_getxattr(inode, name, "", 0);
	76	if (size > 0) {
	77	value = kzalloc(size, GFP_NOFS);
	78	if (!value)
	79	return ERR_PTR(-ENOMEM);
	80	size = __ceph_getxattr(inode, name, value, size);
	81	}
	82
	83	if (size > 0)
	84	acl = posix_acl_from_xattr(&init_user_ns, value, size);
	85	else if (size == -ERANGE \|\| size == -ENODATA \|\| size == 0)
	86	acl = NULL;
	87	else
	88	acl = ERR_PTR(-EIO);
	89
	90	kfree(value);
	91
	92	if (!IS_ERR(acl))
	93	ceph_set_cached_acl(inode, type, acl);
	94
	95	return acl;
	96	}
	97
72466d0b	98	int ceph_set_acl(struct inode inode, struct posix_acl acl, int type)
7221fe4c GZ	99	{
	100	int ret = 0, size = 0;
	101	const char *name = NULL;
	102	char *value = NULL;
	103	struct iattr newattrs;
	104	umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
77516dc9	105	struct dentry *dentry;
7221fe4c	106
7221fe4c GZ	107	switch (type) {
	108	case ACL_TYPE_ACCESS:
	109	name = POSIX_ACL_XATTR_ACCESS;
	110	if (acl) {
	111	ret = posix_acl_equiv_mode(acl, &new_mode);
	112	if (ret < 0)
	113	goto out;
	114	if (ret == 0)
	115	acl = NULL;
	116	}
	117	break;
	118	case ACL_TYPE_DEFAULT:
	119	if (!S_ISDIR(inode->i_mode)) {
	120	ret = acl ? -EINVAL : 0;
	121	goto out;
	122	}
	123	name = POSIX_ACL_XATTR_DEFAULT;
	124	break;
	125	default:
	126	ret = -EINVAL;
	127	goto out;
	128	}
	129
	130	if (acl) {
	131	size = posix_acl_xattr_size(acl->a_count);
	132	value = kmalloc(size, GFP_NOFS);
	133	if (!value) {
	134	ret = -ENOMEM;
	135	goto out;
	136	}
	137
	138	ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
	139	if (ret < 0)
	140	goto out_free;
	141	}
	142
77516dc9	143	dentry = d_find_alias(inode);
7221fe4c GZ	144	if (new_mode != old_mode) {
	145	newattrs.ia_mode = new_mode;
	146	newattrs.ia_valid = ATTR_MODE;
	147	ret = ceph_setattr(dentry, &newattrs);
	148	if (ret)
77516dc9	149	goto out_dput;
7221fe4c GZ	150	}
7221fe4c GZ	151
7a92d647	152	ret = __ceph_setxattr(dentry, name, value, size, 0);
7221fe4c GZ	153	if (ret) {
	154	if (new_mode != old_mode) {
	155	newattrs.ia_mode = old_mode;
	156	newattrs.ia_valid = ATTR_MODE;
	157	ceph_setattr(dentry, &newattrs);
	158	}
77516dc9	159	goto out_dput;
7221fe4c GZ	160	}
	161
	162	ceph_set_cached_acl(inode, type, acl);
	163
77516dc9 SW	164	out_dput:
77516dc9 SW	165	dput(dentry);
7221fe4c GZ	166	out_free:
	167	kfree(value);
	168	out:
	169	return ret;
	170	}
	171
	172	int ceph_init_acl(struct dentry dentry, struct inode inode, struct inode *dir)
	173	{
75858236	174	struct posix_acl default_acl, acl;
f5f18647	175	umode_t new_mode = inode->i_mode;
75858236	176	int error;
7221fe4c	177
f5f18647	178	error = posix_acl_create(dir, &new_mode, &default_acl, &acl);
75858236 CH	179	if (error)
75858236 CH	180	return error;
7221fe4c	181
f5f18647	182	if (!default_acl && !acl) {
7221fe4c	183	cache_no_acl(inode);
f5f18647 YZ	184	if (new_mode != inode->i_mode) {
	185	struct iattr newattrs = {
	186	.ia_mode = new_mode,
	187	.ia_valid = ATTR_MODE,
	188	};
	189	error = ceph_setattr(dentry, &newattrs);
	190	}
	191	return error;
	192	}
7221fe4c	193
75858236 CH	194	if (default_acl) {
	195	error = ceph_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
	196	posix_acl_release(default_acl);
	197	}
	198	if (acl) {
	199	if (!error)
	200	error = ceph_set_acl(inode, acl, ACL_TYPE_ACCESS);
	201	posix_acl_release(acl);
	202	}
	203	return error;
7221fe4c	204	}