mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCYCegywAKCRCRxhvAZXjc
ouJ6AQDlf+7jCQlQdeKKoN9QDFfMzG1ooemat36EpRRTONaGuAD8D9A4sUsG4+5f
4IU5Lj9oY4DEmF8HenbWK2ZHsesL2Qg=
=yPaw
-----END PGP SIGNATURE-----
Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
https://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
1d7b902e28
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
538 lines
18 KiB
C
538 lines
18 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
*
|
|
* Copyright (C) 2011 Novell Inc.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/uuid.h>
|
|
#include <linux/fs.h>
|
|
#include "ovl_entry.h"
|
|
|
|
#undef pr_fmt
|
|
#define pr_fmt(fmt) "overlayfs: " fmt
|
|
|
|
enum ovl_path_type {
|
|
__OVL_PATH_UPPER = (1 << 0),
|
|
__OVL_PATH_MERGE = (1 << 1),
|
|
__OVL_PATH_ORIGIN = (1 << 2),
|
|
};
|
|
|
|
#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
|
|
#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
|
|
#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
|
|
|
|
#define OVL_XATTR_NAMESPACE "overlay."
|
|
#define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE
|
|
#define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE
|
|
|
|
enum ovl_xattr {
|
|
OVL_XATTR_OPAQUE,
|
|
OVL_XATTR_REDIRECT,
|
|
OVL_XATTR_ORIGIN,
|
|
OVL_XATTR_IMPURE,
|
|
OVL_XATTR_NLINK,
|
|
OVL_XATTR_UPPER,
|
|
OVL_XATTR_METACOPY,
|
|
};
|
|
|
|
enum ovl_inode_flag {
|
|
/* Pure upper dir that may contain non pure upper entries */
|
|
OVL_IMPURE,
|
|
/* Non-merge dir that may contain whiteout entries */
|
|
OVL_WHITEOUTS,
|
|
OVL_INDEX,
|
|
OVL_UPPERDATA,
|
|
/* Inode number will remain constant over copy up. */
|
|
OVL_CONST_INO,
|
|
};
|
|
|
|
enum ovl_entry_flag {
|
|
OVL_E_UPPER_ALIAS,
|
|
OVL_E_OPAQUE,
|
|
OVL_E_CONNECTED,
|
|
};
|
|
|
|
enum {
|
|
OVL_XINO_OFF,
|
|
OVL_XINO_AUTO,
|
|
OVL_XINO_ON,
|
|
};
|
|
|
|
/*
|
|
* The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
|
|
* where:
|
|
* origin.fh - exported file handle of the lower file
|
|
* origin.uuid - uuid of the lower filesystem
|
|
*/
|
|
#define OVL_FH_VERSION 0
|
|
#define OVL_FH_MAGIC 0xfb
|
|
|
|
/* CPU byte order required for fid decoding: */
|
|
#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
|
|
#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
|
|
/* Is the real inode encoded in fid an upper inode? */
|
|
#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
|
|
|
|
#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
|
|
OVL_FH_FLAG_PATH_UPPER)
|
|
|
|
#if defined(__LITTLE_ENDIAN)
|
|
#define OVL_FH_FLAG_CPU_ENDIAN 0
|
|
#elif defined(__BIG_ENDIAN)
|
|
#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
|
|
#else
|
|
#error Endianness not defined
|
|
#endif
|
|
|
|
/* The type used to be returned by overlay exportfs for misaligned fid */
|
|
#define OVL_FILEID_V0 0xfb
|
|
/* The type returned by overlay exportfs for 32bit aligned fid */
|
|
#define OVL_FILEID_V1 0xf8
|
|
|
|
/* On-disk format for "origin" file handle */
|
|
struct ovl_fb {
|
|
u8 version; /* 0 */
|
|
u8 magic; /* 0xfb */
|
|
u8 len; /* size of this header + size of fid */
|
|
u8 flags; /* OVL_FH_FLAG_* */
|
|
u8 type; /* fid_type of fid */
|
|
uuid_t uuid; /* uuid of filesystem */
|
|
u32 fid[]; /* file identifier should be 32bit aligned in-memory */
|
|
} __packed;
|
|
|
|
/* In-memory and on-wire format for overlay file handle */
|
|
struct ovl_fh {
|
|
u8 padding[3]; /* make sure fb.fid is 32bit aligned */
|
|
union {
|
|
struct ovl_fb fb;
|
|
u8 buf[0];
|
|
};
|
|
} __packed;
|
|
|
|
#define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb)
|
|
#define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len)
|
|
#define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \
|
|
offsetof(struct ovl_fb, fid))
|
|
|
|
extern const char *const ovl_xattr_table[][2];
|
|
static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox)
|
|
{
|
|
return ovl_xattr_table[ox][ofs->config.userxattr];
|
|
}
|
|
|
|
static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
int err = vfs_rmdir(&init_user_ns, dir, dentry);
|
|
|
|
pr_debug("rmdir(%pd2) = %i\n", dentry, err);
|
|
return err;
|
|
}
|
|
|
|
static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
int err = vfs_unlink(&init_user_ns, dir, dentry, NULL);
|
|
|
|
pr_debug("unlink(%pd2) = %i\n", dentry, err);
|
|
return err;
|
|
}
|
|
|
|
static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
|
|
struct dentry *new_dentry)
|
|
{
|
|
int err = vfs_link(old_dentry, &init_user_ns, dir, new_dentry, NULL);
|
|
|
|
pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
|
|
return err;
|
|
}
|
|
|
|
static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
|
|
umode_t mode)
|
|
{
|
|
int err = vfs_create(&init_user_ns, dir, dentry, mode, true);
|
|
|
|
pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
|
|
return err;
|
|
}
|
|
|
|
static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
|
|
umode_t mode)
|
|
{
|
|
int err = vfs_mkdir(&init_user_ns, dir, dentry, mode);
|
|
pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
|
|
return err;
|
|
}
|
|
|
|
static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
|
|
umode_t mode, dev_t dev)
|
|
{
|
|
int err = vfs_mknod(&init_user_ns, dir, dentry, mode, dev);
|
|
|
|
pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
|
|
return err;
|
|
}
|
|
|
|
static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
|
|
const char *oldname)
|
|
{
|
|
int err = vfs_symlink(&init_user_ns, dir, dentry, oldname);
|
|
|
|
pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
|
|
return err;
|
|
}
|
|
|
|
static inline ssize_t ovl_do_getxattr(struct ovl_fs *ofs, struct dentry *dentry,
|
|
enum ovl_xattr ox, void *value,
|
|
size_t size)
|
|
{
|
|
const char *name = ovl_xattr(ofs, ox);
|
|
return vfs_getxattr(&init_user_ns, dentry, name, value, size);
|
|
}
|
|
|
|
static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
|
|
enum ovl_xattr ox, const void *value,
|
|
size_t size)
|
|
{
|
|
const char *name = ovl_xattr(ofs, ox);
|
|
int err = vfs_setxattr(&init_user_ns, dentry, name, value, size, 0);
|
|
pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n",
|
|
dentry, name, min((int)size, 48), value, size, err);
|
|
return err;
|
|
}
|
|
|
|
static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
|
|
enum ovl_xattr ox)
|
|
{
|
|
const char *name = ovl_xattr(ofs, ox);
|
|
int err = vfs_removexattr(&init_user_ns, dentry, name);
|
|
pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
|
|
return err;
|
|
}
|
|
|
|
static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
|
|
struct inode *newdir, struct dentry *newdentry,
|
|
unsigned int flags)
|
|
{
|
|
int err;
|
|
struct renamedata rd = {
|
|
.old_mnt_userns = &init_user_ns,
|
|
.old_dir = olddir,
|
|
.old_dentry = olddentry,
|
|
.new_mnt_userns = &init_user_ns,
|
|
.new_dir = newdir,
|
|
.new_dentry = newdentry,
|
|
.flags = flags,
|
|
};
|
|
|
|
pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
|
|
err = vfs_rename(&rd);
|
|
if (err) {
|
|
pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
|
|
olddentry, newdentry, err);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
int err = vfs_whiteout(&init_user_ns, dir, dentry);
|
|
pr_debug("whiteout(%pd2) = %i\n", dentry, err);
|
|
return err;
|
|
}
|
|
|
|
static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
|
|
{
|
|
struct dentry *ret = vfs_tmpfile(&init_user_ns, dentry, mode, 0);
|
|
int err = PTR_ERR_OR_ZERO(ret);
|
|
|
|
pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
|
|
return ret;
|
|
}
|
|
|
|
static inline bool ovl_open_flags_need_copy_up(int flags)
|
|
{
|
|
if (!flags)
|
|
return false;
|
|
|
|
return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
|
|
}
|
|
|
|
/* util.c */
|
|
int ovl_want_write(struct dentry *dentry);
|
|
void ovl_drop_write(struct dentry *dentry);
|
|
struct dentry *ovl_workdir(struct dentry *dentry);
|
|
const struct cred *ovl_override_creds(struct super_block *sb);
|
|
int ovl_can_decode_fh(struct super_block *sb);
|
|
struct dentry *ovl_indexdir(struct super_block *sb);
|
|
bool ovl_index_all(struct super_block *sb);
|
|
bool ovl_verify_lower(struct super_block *sb);
|
|
struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
|
|
bool ovl_dentry_remote(struct dentry *dentry);
|
|
void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry,
|
|
unsigned int mask);
|
|
bool ovl_dentry_weird(struct dentry *dentry);
|
|
enum ovl_path_type ovl_path_type(struct dentry *dentry);
|
|
void ovl_path_upper(struct dentry *dentry, struct path *path);
|
|
void ovl_path_lower(struct dentry *dentry, struct path *path);
|
|
void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
|
|
enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
|
|
struct dentry *ovl_dentry_upper(struct dentry *dentry);
|
|
struct dentry *ovl_dentry_lower(struct dentry *dentry);
|
|
struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
|
|
const struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
|
|
struct dentry *ovl_dentry_real(struct dentry *dentry);
|
|
struct dentry *ovl_i_dentry_upper(struct inode *inode);
|
|
struct inode *ovl_inode_upper(struct inode *inode);
|
|
struct inode *ovl_inode_lower(struct inode *inode);
|
|
struct inode *ovl_inode_lowerdata(struct inode *inode);
|
|
struct inode *ovl_inode_real(struct inode *inode);
|
|
struct inode *ovl_inode_realdata(struct inode *inode);
|
|
struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
|
|
void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
|
|
void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
|
|
void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
|
|
bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
|
|
bool ovl_dentry_is_opaque(struct dentry *dentry);
|
|
bool ovl_dentry_is_whiteout(struct dentry *dentry);
|
|
void ovl_dentry_set_opaque(struct dentry *dentry);
|
|
bool ovl_dentry_has_upper_alias(struct dentry *dentry);
|
|
void ovl_dentry_set_upper_alias(struct dentry *dentry);
|
|
bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
|
|
bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
|
|
bool ovl_has_upperdata(struct inode *inode);
|
|
void ovl_set_upperdata(struct inode *inode);
|
|
bool ovl_redirect_dir(struct super_block *sb);
|
|
const char *ovl_dentry_get_redirect(struct dentry *dentry);
|
|
void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
|
|
void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
|
|
void ovl_dir_modified(struct dentry *dentry, bool impurity);
|
|
u64 ovl_dentry_version_get(struct dentry *dentry);
|
|
bool ovl_is_whiteout(struct dentry *dentry);
|
|
struct file *ovl_path_open(struct path *path, int flags);
|
|
int ovl_copy_up_start(struct dentry *dentry, int flags);
|
|
void ovl_copy_up_end(struct dentry *dentry);
|
|
bool ovl_already_copied_up(struct dentry *dentry, int flags);
|
|
bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry);
|
|
bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry,
|
|
enum ovl_xattr ox);
|
|
int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
|
|
enum ovl_xattr ox, const void *value, size_t size,
|
|
int xerr);
|
|
int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
|
|
void ovl_set_flag(unsigned long flag, struct inode *inode);
|
|
void ovl_clear_flag(unsigned long flag, struct inode *inode);
|
|
bool ovl_test_flag(unsigned long flag, struct inode *inode);
|
|
bool ovl_inuse_trylock(struct dentry *dentry);
|
|
void ovl_inuse_unlock(struct dentry *dentry);
|
|
bool ovl_is_inuse(struct dentry *dentry);
|
|
bool ovl_need_index(struct dentry *dentry);
|
|
int ovl_nlink_start(struct dentry *dentry);
|
|
void ovl_nlink_end(struct dentry *dentry);
|
|
int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
|
|
int ovl_check_metacopy_xattr(struct ovl_fs *ofs, struct dentry *dentry);
|
|
bool ovl_is_metacopy_dentry(struct dentry *dentry);
|
|
char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry,
|
|
int padding);
|
|
int ovl_sync_status(struct ovl_fs *ofs);
|
|
|
|
static inline bool ovl_is_impuredir(struct super_block *sb,
|
|
struct dentry *dentry)
|
|
{
|
|
return ovl_check_dir_xattr(sb, dentry, OVL_XATTR_IMPURE);
|
|
}
|
|
|
|
/*
|
|
* With xino=auto, we do best effort to keep all inodes on same st_dev and
|
|
* d_ino consistent with st_ino.
|
|
* With xino=on, we do the same effort but we warn if we failed.
|
|
*/
|
|
static inline bool ovl_xino_warn(struct super_block *sb)
|
|
{
|
|
return OVL_FS(sb)->config.xino == OVL_XINO_ON;
|
|
}
|
|
|
|
/* All layers on same fs? */
|
|
static inline bool ovl_same_fs(struct super_block *sb)
|
|
{
|
|
return OVL_FS(sb)->xino_mode == 0;
|
|
}
|
|
|
|
/* All overlay inodes have same st_dev? */
|
|
static inline bool ovl_same_dev(struct super_block *sb)
|
|
{
|
|
return OVL_FS(sb)->xino_mode >= 0;
|
|
}
|
|
|
|
static inline unsigned int ovl_xino_bits(struct super_block *sb)
|
|
{
|
|
return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0;
|
|
}
|
|
|
|
static inline void ovl_inode_lock(struct inode *inode)
|
|
{
|
|
mutex_lock(&OVL_I(inode)->lock);
|
|
}
|
|
|
|
static inline int ovl_inode_lock_interruptible(struct inode *inode)
|
|
{
|
|
return mutex_lock_interruptible(&OVL_I(inode)->lock);
|
|
}
|
|
|
|
static inline void ovl_inode_unlock(struct inode *inode)
|
|
{
|
|
mutex_unlock(&OVL_I(inode)->lock);
|
|
}
|
|
|
|
|
|
/* namei.c */
|
|
int ovl_check_fb_len(struct ovl_fb *fb, int fb_len);
|
|
|
|
static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
|
|
{
|
|
if (fh_len < sizeof(struct ovl_fh))
|
|
return -EINVAL;
|
|
|
|
return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET);
|
|
}
|
|
|
|
struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
|
|
struct vfsmount *mnt, bool connected);
|
|
int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
|
|
struct dentry *upperdentry, struct ovl_path **stackp);
|
|
int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,
|
|
enum ovl_xattr ox, struct dentry *real, bool is_upper,
|
|
bool set);
|
|
struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
|
|
int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
|
|
int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin,
|
|
struct qstr *name);
|
|
struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
|
|
struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
|
|
struct dentry *origin, bool verify);
|
|
int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
|
|
struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
|
|
unsigned int flags);
|
|
bool ovl_lower_positive(struct dentry *dentry);
|
|
|
|
static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper,
|
|
struct dentry *origin, bool set)
|
|
{
|
|
return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, origin,
|
|
false, set);
|
|
}
|
|
|
|
static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index,
|
|
struct dentry *upper, bool set)
|
|
{
|
|
return ovl_verify_set_fh(ofs, index, OVL_XATTR_UPPER, upper, true, set);
|
|
}
|
|
|
|
/* readdir.c */
|
|
extern const struct file_operations ovl_dir_operations;
|
|
struct file *ovl_dir_real_file(const struct file *file, bool want_upper);
|
|
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
|
|
void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
|
|
void ovl_cache_free(struct list_head *list);
|
|
void ovl_dir_cache_free(struct inode *inode);
|
|
int ovl_check_d_type_supported(struct path *realpath);
|
|
int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
|
|
struct dentry *dentry, int level);
|
|
int ovl_indexdir_cleanup(struct ovl_fs *ofs);
|
|
|
|
/* inode.c */
|
|
int ovl_set_nlink_upper(struct dentry *dentry);
|
|
int ovl_set_nlink_lower(struct dentry *dentry);
|
|
unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry,
|
|
struct dentry *upperdentry,
|
|
unsigned int fallback);
|
|
int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
|
|
struct iattr *attr);
|
|
int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path,
|
|
struct kstat *stat, u32 request_mask, unsigned int flags);
|
|
int ovl_permission(struct user_namespace *mnt_userns, struct inode *inode,
|
|
int mask);
|
|
int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
|
|
const void *value, size_t size, int flags);
|
|
int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
|
|
void *value, size_t size);
|
|
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
|
|
struct posix_acl *ovl_get_acl(struct inode *inode, int type);
|
|
int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
|
|
bool ovl_is_private_xattr(struct super_block *sb, const char *name);
|
|
|
|
struct ovl_inode_params {
|
|
struct inode *newinode;
|
|
struct dentry *upperdentry;
|
|
struct ovl_path *lowerpath;
|
|
bool index;
|
|
unsigned int numlower;
|
|
char *redirect;
|
|
struct dentry *lowerdata;
|
|
};
|
|
void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
|
|
unsigned long ino, int fsid);
|
|
struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
|
|
struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
|
|
bool is_upper);
|
|
bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir);
|
|
struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir);
|
|
struct inode *ovl_get_inode(struct super_block *sb,
|
|
struct ovl_inode_params *oip);
|
|
static inline void ovl_copyattr(struct inode *from, struct inode *to)
|
|
{
|
|
to->i_uid = from->i_uid;
|
|
to->i_gid = from->i_gid;
|
|
to->i_mode = from->i_mode;
|
|
to->i_atime = from->i_atime;
|
|
to->i_mtime = from->i_mtime;
|
|
to->i_ctime = from->i_ctime;
|
|
i_size_write(to, i_size_read(from));
|
|
}
|
|
|
|
static inline void ovl_copyflags(struct inode *from, struct inode *to)
|
|
{
|
|
unsigned int mask = S_SYNC | S_IMMUTABLE | S_APPEND | S_NOATIME;
|
|
|
|
inode_set_flags(to, from->i_flags & mask, mask);
|
|
}
|
|
|
|
/* dir.c */
|
|
extern const struct inode_operations ovl_dir_inode_operations;
|
|
int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
|
|
struct dentry *dentry);
|
|
struct ovl_cattr {
|
|
dev_t rdev;
|
|
umode_t mode;
|
|
const char *link;
|
|
struct dentry *hardlink;
|
|
};
|
|
|
|
#define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
|
|
|
|
struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
|
|
struct ovl_cattr *attr);
|
|
int ovl_cleanup(struct inode *dir, struct dentry *dentry);
|
|
struct dentry *ovl_lookup_temp(struct dentry *workdir);
|
|
struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
|
|
|
|
/* file.c */
|
|
extern const struct file_operations ovl_file_operations;
|
|
int __init ovl_aio_request_cache_init(void);
|
|
void ovl_aio_request_cache_destroy(void);
|
|
long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
|
|
long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
|
|
|
|
/* copy_up.c */
|
|
int ovl_copy_up(struct dentry *dentry);
|
|
int ovl_copy_up_with_data(struct dentry *dentry);
|
|
int ovl_maybe_copy_up(struct dentry *dentry, int flags);
|
|
int ovl_copy_xattr(struct super_block *sb, struct dentry *old,
|
|
struct dentry *new);
|
|
int ovl_set_attr(struct dentry *upper, struct kstat *stat);
|
|
struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real,
|
|
bool is_upper);
|
|
int ovl_set_origin(struct ovl_fs *ofs, struct dentry *dentry,
|
|
struct dentry *lower, struct dentry *upper);
|
|
|
|
/* export.c */
|
|
extern const struct export_operations ovl_export_operations;
|