linux/fs/orangefs/acl.c
Christian Brauner 549c729771
fs: make helpers idmap mount aware
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:20 +01:00

196 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* (C) 2001 Clemson University and The University of Chicago
*
* See COPYING in top-level directory.
*/
#include "protocol.h"
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"
#include <linux/posix_acl_xattr.h>
struct posix_acl *orangefs_get_acl(struct inode *inode, int type)
{
struct posix_acl *acl;
int ret;
char *key = NULL, *value = NULL;
switch (type) {
case ACL_TYPE_ACCESS:
key = XATTR_NAME_POSIX_ACL_ACCESS;
break;
case ACL_TYPE_DEFAULT:
key = XATTR_NAME_POSIX_ACL_DEFAULT;
break;
default:
gossip_err("orangefs_get_acl: bogus value of type %d\n", type);
return ERR_PTR(-EINVAL);
}
/*
* Rather than incurring a network call just to determine the exact
* length of the attribute, I just allocate a max length to save on
* the network call. Conceivably, we could pass NULL to
* orangefs_inode_getxattr() to probe the length of the value, but
* I don't do that for now.
*/
value = kmalloc(ORANGEFS_MAX_XATTR_VALUELEN, GFP_KERNEL);
if (!value)
return ERR_PTR(-ENOMEM);
gossip_debug(GOSSIP_ACL_DEBUG,
"inode %pU, key %s, type %d\n",
get_khandle_from_ino(inode),
key,
type);
ret = orangefs_inode_getxattr(inode, key, value,
ORANGEFS_MAX_XATTR_VALUELEN);
/* if the key exists, convert it to an in-memory rep */
if (ret > 0) {
acl = posix_acl_from_xattr(&init_user_ns, value, ret);
} else if (ret == -ENODATA || ret == -ENOSYS) {
acl = NULL;
} else {
gossip_err("inode %pU retrieving acl's failed with error %d\n",
get_khandle_from_ino(inode),
ret);
acl = ERR_PTR(ret);
}
/* kfree(NULL) is safe, so don't worry if value ever got used */
kfree(value);
return acl;
}
static int __orangefs_set_acl(struct inode *inode, struct posix_acl *acl,
int type)
{
int error = 0;
void *value = NULL;
size_t size = 0;
const char *name = NULL;
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:
gossip_err("%s: invalid type %d!\n", __func__, type);
return -EINVAL;
}
gossip_debug(GOSSIP_ACL_DEBUG,
"%s: inode %pU, key %s type %d\n",
__func__, get_khandle_from_ino(inode),
name,
type);
if (acl) {
size = posix_acl_xattr_size(acl->a_count);
value = kmalloc(size, GFP_KERNEL);
if (!value)
return -ENOMEM;
error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
if (error < 0)
goto out;
}
gossip_debug(GOSSIP_ACL_DEBUG,
"%s: name %s, value %p, size %zd, acl %p\n",
__func__, name, value, size, acl);
/*
* Go ahead and set the extended attribute now. NOTE: Suppose acl
* was NULL, then value will be NULL and size will be 0 and that
* will xlate to a removexattr. However, we don't want removexattr
* complain if attributes does not exist.
*/
error = orangefs_inode_setxattr(inode, name, value, size, 0);
out:
kfree(value);
if (!error)
set_cached_acl(inode, type, acl);
return error;
}
int orangefs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type)
{
int error;
struct iattr iattr;
int rc;
memset(&iattr, 0, sizeof iattr);
if (type == ACL_TYPE_ACCESS && acl) {
/*
* posix_acl_update_mode checks to see if the permissions
* described by the ACL can be encoded into the
* object's mode. If so, it sets "acl" to NULL
* and "mode" to the new desired value. It is up to
* us to propagate the new mode back to the server...
*/
error = posix_acl_update_mode(&init_user_ns, inode,
&iattr.ia_mode, &acl);
if (error) {
gossip_err("%s: posix_acl_update_mode err: %d\n",
__func__,
error);
return error;
}
if (inode->i_mode != iattr.ia_mode)
iattr.ia_valid = ATTR_MODE;
}
rc = __orangefs_set_acl(inode, acl, type);
if (!rc && (iattr.ia_valid == ATTR_MODE))
rc = __orangefs_setattr(inode, &iattr);
return rc;
}
int orangefs_init_acl(struct inode *inode, struct inode *dir)
{
struct posix_acl *default_acl, *acl;
umode_t mode = inode->i_mode;
struct iattr iattr;
int error = 0;
error = posix_acl_create(dir, &mode, &default_acl, &acl);
if (error)
return error;
if (default_acl) {
error = __orangefs_set_acl(inode, default_acl,
ACL_TYPE_DEFAULT);
posix_acl_release(default_acl);
} else {
inode->i_default_acl = NULL;
}
if (acl) {
if (!error)
error = __orangefs_set_acl(inode, acl, ACL_TYPE_ACCESS);
posix_acl_release(acl);
} else {
inode->i_acl = NULL;
}
/* If mode of the inode was changed, then do a forcible ->setattr */
if (mode != inode->i_mode) {
memset(&iattr, 0, sizeof iattr);
inode->i_mode = mode;
iattr.ia_mode = mode;
iattr.ia_valid |= ATTR_MODE;
__orangefs_setattr(inode, &iattr);
}
return error;
}