linux/fs/btrfs/acl.c
Omar Sandoval 3538d68dbd btrfs: reserve correct number of items for inode creation
The various inode creation code paths do not account for the compression
property, POSIX ACLs, or the parent inode item when starting a
transaction. Fix it by refactoring all of these code paths to use a new
function, btrfs_new_inode_prepare(), which computes the correct number
of items. To do so, it needs to know whether POSIX ACLs will be created,
so move the ACL creation into that function. To reduce the number of
arguments that need to be passed around for inode creation, define
struct btrfs_new_inode_args containing all of the relevant information.

btrfs_new_inode_prepare() will also be a good place to set up the
fscrypt context and encrypted filename in the future.

Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-05-16 17:03:08 +02:00

130 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Red Hat. All rights reserved.
*/
#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/sched/mm.h>
#include <linux/slab.h>
#include "ctree.h"
#include "btrfs_inode.h"
#include "xattr.h"
struct posix_acl *btrfs_get_acl(struct inode *inode, int type, bool rcu)
{
int size;
const char *name;
char *value = NULL;
struct posix_acl *acl;
if (rcu)
return ERR_PTR(-ECHILD);
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:
return ERR_PTR(-EINVAL);
}
size = btrfs_getxattr(inode, name, NULL, 0);
if (size > 0) {
value = kzalloc(size, GFP_KERNEL);
if (!value)
return ERR_PTR(-ENOMEM);
size = btrfs_getxattr(inode, name, value, size);
}
if (size > 0)
acl = posix_acl_from_xattr(&init_user_ns, value, size);
else if (size == -ENODATA || size == 0)
acl = NULL;
else
acl = ERR_PTR(size);
kfree(value);
return acl;
}
int __btrfs_set_acl(struct btrfs_trans_handle *trans, struct inode *inode,
struct posix_acl *acl, int type)
{
int ret, size = 0;
const char *name;
char *value = NULL;
switch (type) {
case ACL_TYPE_ACCESS:
name = XATTR_NAME_POSIX_ACL_ACCESS;
break;
case ACL_TYPE_DEFAULT:
if (!S_ISDIR(inode->i_mode))
return acl ? -EINVAL : 0;
name = XATTR_NAME_POSIX_ACL_DEFAULT;
break;
default:
return -EINVAL;
}
if (acl) {
unsigned int nofs_flag;
size = posix_acl_xattr_size(acl->a_count);
/*
* We're holding a transaction handle, so use a NOFS memory
* allocation context to avoid deadlock if reclaim happens.
*/
nofs_flag = memalloc_nofs_save();
value = kmalloc(size, GFP_KERNEL);
memalloc_nofs_restore(nofs_flag);
if (!value) {
ret = -ENOMEM;
goto out;
}
ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
if (ret < 0)
goto out;
}
if (trans)
ret = btrfs_setxattr(trans, inode, name, value, size, 0);
else
ret = btrfs_setxattr_trans(inode, name, value, size, 0);
out:
kfree(value);
if (!ret)
set_cached_acl(inode, type, acl);
return ret;
}
int btrfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type)
{
int ret;
umode_t old_mode = inode->i_mode;
if (type == ACL_TYPE_ACCESS && acl) {
ret = posix_acl_update_mode(mnt_userns, inode,
&inode->i_mode, &acl);
if (ret)
return ret;
}
ret = __btrfs_set_acl(NULL, inode, acl, type);
if (ret)
inode->i_mode = old_mode;
return ret;
}