linux/fs/jfs/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

155 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) International Business Machines Corp., 2002-2004
* Copyright (C) Andreas Gruenbacher, 2001
* Copyright (C) Linus Torvalds, 1991, 1992
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/posix_acl_xattr.h>
#include "jfs_incore.h"
#include "jfs_txnmgr.h"
#include "jfs_xattr.h"
#include "jfs_acl.h"
struct posix_acl *jfs_get_acl(struct inode *inode, int type)
{
struct posix_acl *acl;
char *ea_name;
int size;
char *value = NULL;
switch(type) {
case ACL_TYPE_ACCESS:
ea_name = XATTR_NAME_POSIX_ACL_ACCESS;
break;
case ACL_TYPE_DEFAULT:
ea_name = XATTR_NAME_POSIX_ACL_DEFAULT;
break;
default:
return ERR_PTR(-EINVAL);
}
size = __jfs_getxattr(inode, ea_name, NULL, 0);
if (size > 0) {
value = kmalloc(size, GFP_KERNEL);
if (!value)
return ERR_PTR(-ENOMEM);
size = __jfs_getxattr(inode, ea_name, value, size);
}
if (size < 0) {
if (size == -ENODATA)
acl = NULL;
else
acl = ERR_PTR(size);
} else {
acl = posix_acl_from_xattr(&init_user_ns, value, size);
}
kfree(value);
return acl;
}
static int __jfs_set_acl(tid_t tid, struct inode *inode, int type,
struct posix_acl *acl)
{
char *ea_name;
int rc;
int size = 0;
char *value = NULL;
switch (type) {
case ACL_TYPE_ACCESS:
ea_name = XATTR_NAME_POSIX_ACL_ACCESS;
break;
case ACL_TYPE_DEFAULT:
ea_name = XATTR_NAME_POSIX_ACL_DEFAULT;
break;
default:
return -EINVAL;
}
if (acl) {
size = posix_acl_xattr_size(acl->a_count);
value = kmalloc(size, GFP_KERNEL);
if (!value)
return -ENOMEM;
rc = posix_acl_to_xattr(&init_user_ns, acl, value, size);
if (rc < 0)
goto out;
}
rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
out:
kfree(value);
if (!rc)
set_cached_acl(inode, type, acl);
return rc;
}
int jfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type)
{
int rc;
tid_t tid;
int update_mode = 0;
umode_t mode = inode->i_mode;
tid = txBegin(inode->i_sb, 0);
mutex_lock(&JFS_IP(inode)->commit_mutex);
if (type == ACL_TYPE_ACCESS && acl) {
rc = posix_acl_update_mode(&init_user_ns, inode, &mode, &acl);
if (rc)
goto end_tx;
if (mode != inode->i_mode)
update_mode = 1;
}
rc = __jfs_set_acl(tid, inode, type, acl);
if (!rc) {
if (update_mode) {
inode->i_mode = mode;
inode->i_ctime = current_time(inode);
mark_inode_dirty(inode);
}
rc = txCommit(tid, 1, &inode, 0);
}
end_tx:
txEnd(tid);
mutex_unlock(&JFS_IP(inode)->commit_mutex);
return rc;
}
int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
{
struct posix_acl *default_acl, *acl;
int rc = 0;
rc = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
if (rc)
return rc;
if (default_acl) {
rc = __jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, default_acl);
posix_acl_release(default_acl);
} else {
inode->i_default_acl = NULL;
}
if (acl) {
if (!rc)
rc = __jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
posix_acl_release(acl);
} else {
inode->i_acl = NULL;
}
JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
inode->i_mode;
return rc;
}