linux-stable/fs/jfs/acl.c
Christian Brauner 700b794052
fs: port acl to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00

158 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, bool rcu)
{
struct posix_acl *acl;
char *ea_name;
int size;
char *value = NULL;
if (rcu)
return ERR_PTR(-ECHILD);
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 mnt_idmap *idmap, struct dentry *dentry,
struct posix_acl *acl, int type)
{
int rc;
tid_t tid;
int update_mode = 0;
struct inode *inode = d_inode(dentry);
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(&nop_mnt_idmap, 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;
}