linux-stable/fs/ext4/acl.h
Christian Brauner 13e83a4923
fs: port ->set_acl() to pass 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 09:24:27 +01:00

74 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
File: fs/ext4/acl.h
(C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/
#include <linux/posix_acl_xattr.h>
#define EXT4_ACL_VERSION 0x0001
typedef struct {
__le16 e_tag;
__le16 e_perm;
__le32 e_id;
} ext4_acl_entry;
typedef struct {
__le16 e_tag;
__le16 e_perm;
} ext4_acl_entry_short;
typedef struct {
__le32 a_version;
} ext4_acl_header;
static inline size_t ext4_acl_size(int count)
{
if (count <= 4) {
return sizeof(ext4_acl_header) +
count * sizeof(ext4_acl_entry_short);
} else {
return sizeof(ext4_acl_header) +
4 * sizeof(ext4_acl_entry_short) +
(count - 4) * sizeof(ext4_acl_entry);
}
}
static inline int ext4_acl_count(size_t size)
{
ssize_t s;
size -= sizeof(ext4_acl_header);
s = size - 4 * sizeof(ext4_acl_entry_short);
if (s < 0) {
if (size % sizeof(ext4_acl_entry_short))
return -1;
return size / sizeof(ext4_acl_entry_short);
} else {
if (s % sizeof(ext4_acl_entry))
return -1;
return s / sizeof(ext4_acl_entry) + 4;
}
}
#ifdef CONFIG_EXT4_FS_POSIX_ACL
/* acl.c */
struct posix_acl *ext4_get_acl(struct inode *inode, int type, bool rcu);
int ext4_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
struct posix_acl *acl, int type);
extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
#else /* CONFIG_EXT4_FS_POSIX_ACL */
#include <linux/sched.h>
#define ext4_get_acl NULL
#define ext4_set_acl NULL
static inline int
ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
{
return 0;
}
#endif /* CONFIG_EXT4_FS_POSIX_ACL */