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/*
* Copyright IBM Corporation, 2010
* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/posix_acl_xattr.h>
#include "xattr.h"
#include "acl.h"
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name)
{
ssize_t size;
void *value = NULL;
struct posix_acl *acl = NULL;
size = v9fs_fid_xattr_get(fid, name, NULL, 0);
if (size > 0) {
value = kzalloc(size, GFP_NOFS);
if (!value)
return ERR_PTR(-ENOMEM);
size = v9fs_fid_xattr_get(fid, name, value, size);
if (size > 0) {
acl = posix_acl_from_xattr(&init_user_ns, value, size);
if (IS_ERR(acl))
goto err_out;
}
} else if (size == -ENODATA || size == 0 ||
size == -ENOSYS || size == -EOPNOTSUPP) {
acl = NULL;
} else
acl = ERR_PTR(-EIO);
err_out:
kfree(value);
return acl;
}
int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
{
int retval = 0;
struct posix_acl *pacl, *dacl;
struct v9fs_session_info *v9ses;
v9ses = v9fs_inode2v9ses(inode);
if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
return 0;
}
/* get the default/access acl values and cache them */
dacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_DEFAULT);
pacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_ACCESS);
if (!IS_ERR(dacl) && !IS_ERR(pacl)) {
set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);
} else
retval = -EIO;
if (!IS_ERR(dacl))
posix_acl_release(dacl);
if (!IS_ERR(pacl))
posix_acl_release(pacl);
return retval;
}
static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
{
struct posix_acl *acl;
/*
* 9p Always cache the acl value when
* instantiating the inode (v9fs_inode_from_fid)
*/
acl = get_cached_acl(inode, type);
BUG_ON(acl == ACL_NOT_CACHED);
return acl;
}
struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type)
{
struct v9fs_session_info *v9ses;
v9ses = v9fs_inode2v9ses(inode);
if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
/*
* On access = client and acl = on mode get the acl
* values from the server
*/
return NULL;
}
return v9fs_get_cached_acl(inode, type);
}
static int v9fs_set_acl(struct p9_fid *fid, int type, struct posix_acl *acl)
{
int retval;
char *name;
size_t size;
void *buffer;
if (!acl)
return 0;
/* Set a setxattr request to server */
size = posix_acl_xattr_size(acl->a_count);
buffer = kmalloc(size, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
retval = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
if (retval < 0)
goto err_free_out;
switch (type) {
case ACL_TYPE_ACCESS:
name = XATTR_NAME_POSIX_ACL_ACCESS;
break;
case ACL_TYPE_DEFAULT:
name = XATTR_NAME_POSIX_ACL_DEFAULT;
break;
default:
BUG();
}
retval = v9fs_fid_xattr_set(fid, name, buffer, size, 0);
err_free_out:
kfree(buffer);
return retval;
}
int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid)
{
int retval = 0;
struct posix_acl *acl;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
if (acl) {
retval = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
if (retval)
return retval;
set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
retval = v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
posix_acl_release(acl);
}
return retval;
}
int v9fs_set_create_acl(struct inode *inode, struct p9_fid *fid,
struct posix_acl *dacl, struct posix_acl *acl)
{
set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
v9fs_set_acl(fid, ACL_TYPE_DEFAULT, dacl);
v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl);
return 0;
}
void v9fs_put_acl(struct posix_acl *dacl,
struct posix_acl *acl)
{
posix_acl_release(dacl);
posix_acl_release(acl);
}
int v9fs_acl_mode(struct inode *dir, umode_t *modep,
struct posix_acl **dpacl, struct posix_acl **pacl)
{
int retval = 0;
umode_t mode = *modep;
struct posix_acl *acl = NULL;
if (!S_ISLNK(mode)) {
acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (!acl)
mode &= ~current_umask();
}
if (acl) {
if (S_ISDIR(mode))
*dpacl = posix_acl_dup(acl);
retval = __posix_acl_create(&acl, GFP_NOFS, &mode);
if (retval < 0)
return retval;
if (retval > 0)
*pacl = acl;
else
posix_acl_release(acl);
}
*modep = mode;
return 0;
}
static int v9fs_xattr_get_acl(const struct xattr_handler *handler,
struct dentry *dentry, const char *name,
void *buffer, size_t size)
{
struct v9fs_session_info *v9ses;
struct posix_acl *acl;
int error;
if (strcmp(name, "") != 0)
return -EINVAL;
v9ses = v9fs_dentry2v9ses(dentry);
/*
* We allow set/get/list of acl when access=client is not specified
*/
if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
return v9fs_xattr_get(dentry, handler->prefix, buffer, size);
acl = v9fs_get_cached_acl(d_inode(dentry), handler->flags);
if (IS_ERR(acl))
return PTR_ERR(acl);
if (acl == NULL)
return -ENODATA;
error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
posix_acl_release(acl);
return error;
}
static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
int retval;
struct posix_acl *acl;
struct v9fs_session_info *v9ses;
struct inode *inode = d_inode(dentry);
if (strcmp(name, "") != 0)
return -EINVAL;
v9ses = v9fs_dentry2v9ses(dentry);
/*
* set the attribute on the remote. Without even looking at the
* xattr value. We leave it to the server to validate
*/
if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
return v9fs_xattr_set(dentry, handler->prefix, value, size,
flags);
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
if (!inode_owner_or_capable(inode))
return -EPERM;
if (value) {
/* update the cached acl value */
acl = posix_acl_from_xattr(&init_user_ns, value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
else if (acl) {
retval = posix_acl_valid(acl);
if (retval)
goto err_out;
}
} else
acl = NULL;
switch (handler->flags) {
case ACL_TYPE_ACCESS:
if (acl) {
umode_t mode = inode->i_mode;
retval = posix_acl_equiv_mode(acl, &mode);
if (retval < 0)
goto err_out;
else {
struct iattr iattr;
if (retval == 0) {
/*
* ACL can be represented
* by the mode bits. So don't
* update ACL.
*/
acl = NULL;
value = NULL;
size = 0;
}
/* Updte the mode bits */
iattr.ia_mode = ((mode & S_IALLUGO) |
(inode->i_mode & ~S_IALLUGO));
iattr.ia_valid = ATTR_MODE;
/* FIXME should we update ctime ?
* What is the following setxattr update the
* mode ?
*/
v9fs_vfs_setattr_dotl(dentry, &iattr);
}
}
break;
case ACL_TYPE_DEFAULT:
if (!S_ISDIR(inode->i_mode)) {
retval = acl ? -EINVAL : 0;
goto err_out;
}
break;
default:
BUG();
}
retval = v9fs_xattr_set(dentry, handler->prefix, value, size, flags);
if (!retval)
set_cached_acl(inode, handler->flags, acl);
err_out:
posix_acl_release(acl);
return retval;
}
const struct xattr_handler v9fs_xattr_acl_access_handler = {
.prefix = XATTR_NAME_POSIX_ACL_ACCESS,
.flags = ACL_TYPE_ACCESS,
.get = v9fs_xattr_get_acl,
.set = v9fs_xattr_set_acl,
};
const struct xattr_handler v9fs_xattr_acl_default_handler = {
.prefix = XATTR_NAME_POSIX_ACL_DEFAULT,
.flags = ACL_TYPE_DEFAULT,
.get = v9fs_xattr_get_acl,
.set = v9fs_xattr_set_acl,
};
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