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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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![Linus Torvalds](/assets/img/avatar_default.png)
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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
...
1383 lines
35 KiB
C
1383 lines
35 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
|
|
* All Rights Reserved.
|
|
*/
|
|
#include "xfs.h"
|
|
#include "xfs_fs.h"
|
|
#include "xfs_shared.h"
|
|
#include "xfs_format.h"
|
|
#include "xfs_log_format.h"
|
|
#include "xfs_trans_resv.h"
|
|
#include "xfs_mount.h"
|
|
#include "xfs_inode.h"
|
|
#include "xfs_acl.h"
|
|
#include "xfs_quota.h"
|
|
#include "xfs_attr.h"
|
|
#include "xfs_trans.h"
|
|
#include "xfs_trace.h"
|
|
#include "xfs_icache.h"
|
|
#include "xfs_symlink.h"
|
|
#include "xfs_dir2.h"
|
|
#include "xfs_iomap.h"
|
|
#include "xfs_error.h"
|
|
|
|
#include <linux/posix_acl.h>
|
|
#include <linux/security.h>
|
|
#include <linux/iversion.h>
|
|
#include <linux/fiemap.h>
|
|
|
|
/*
|
|
* Directories have different lock order w.r.t. mmap_lock compared to regular
|
|
* files. This is due to readdir potentially triggering page faults on a user
|
|
* buffer inside filldir(), and this happens with the ilock on the directory
|
|
* held. For regular files, the lock order is the other way around - the
|
|
* mmap_lock is taken during the page fault, and then we lock the ilock to do
|
|
* block mapping. Hence we need a different class for the directory ilock so
|
|
* that lockdep can tell them apart.
|
|
*/
|
|
static struct lock_class_key xfs_nondir_ilock_class;
|
|
static struct lock_class_key xfs_dir_ilock_class;
|
|
|
|
static int
|
|
xfs_initxattrs(
|
|
struct inode *inode,
|
|
const struct xattr *xattr_array,
|
|
void *fs_info)
|
|
{
|
|
const struct xattr *xattr;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
int error = 0;
|
|
|
|
for (xattr = xattr_array; xattr->name != NULL; xattr++) {
|
|
struct xfs_da_args args = {
|
|
.dp = ip,
|
|
.attr_filter = XFS_ATTR_SECURE,
|
|
.name = xattr->name,
|
|
.namelen = strlen(xattr->name),
|
|
.value = xattr->value,
|
|
.valuelen = xattr->value_len,
|
|
};
|
|
error = xfs_attr_set(&args);
|
|
if (error < 0)
|
|
break;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Hook in SELinux. This is not quite correct yet, what we really need
|
|
* here (as we do for default ACLs) is a mechanism by which creation of
|
|
* these attrs can be journalled at inode creation time (along with the
|
|
* inode, of course, such that log replay can't cause these to be lost).
|
|
*/
|
|
|
|
STATIC int
|
|
xfs_init_security(
|
|
struct inode *inode,
|
|
struct inode *dir,
|
|
const struct qstr *qstr)
|
|
{
|
|
return security_inode_init_security(inode, dir, qstr,
|
|
&xfs_initxattrs, NULL);
|
|
}
|
|
|
|
static void
|
|
xfs_dentry_to_name(
|
|
struct xfs_name *namep,
|
|
struct dentry *dentry)
|
|
{
|
|
namep->name = dentry->d_name.name;
|
|
namep->len = dentry->d_name.len;
|
|
namep->type = XFS_DIR3_FT_UNKNOWN;
|
|
}
|
|
|
|
static int
|
|
xfs_dentry_mode_to_name(
|
|
struct xfs_name *namep,
|
|
struct dentry *dentry,
|
|
int mode)
|
|
{
|
|
namep->name = dentry->d_name.name;
|
|
namep->len = dentry->d_name.len;
|
|
namep->type = xfs_mode_to_ftype(mode);
|
|
|
|
if (unlikely(namep->type == XFS_DIR3_FT_UNKNOWN))
|
|
return -EFSCORRUPTED;
|
|
|
|
return 0;
|
|
}
|
|
|
|
STATIC void
|
|
xfs_cleanup_inode(
|
|
struct inode *dir,
|
|
struct inode *inode,
|
|
struct dentry *dentry)
|
|
{
|
|
struct xfs_name teardown;
|
|
|
|
/* Oh, the horror.
|
|
* If we can't add the ACL or we fail in
|
|
* xfs_init_security we must back out.
|
|
* ENOSPC can hit here, among other things.
|
|
*/
|
|
xfs_dentry_to_name(&teardown, dentry);
|
|
|
|
xfs_remove(XFS_I(dir), &teardown, XFS_I(inode));
|
|
}
|
|
|
|
STATIC int
|
|
xfs_generic_create(
|
|
struct user_namespace *mnt_userns,
|
|
struct inode *dir,
|
|
struct dentry *dentry,
|
|
umode_t mode,
|
|
dev_t rdev,
|
|
bool tmpfile) /* unnamed file */
|
|
{
|
|
struct inode *inode;
|
|
struct xfs_inode *ip = NULL;
|
|
struct posix_acl *default_acl, *acl;
|
|
struct xfs_name name;
|
|
int error;
|
|
|
|
/*
|
|
* Irix uses Missed'em'V split, but doesn't want to see
|
|
* the upper 5 bits of (14bit) major.
|
|
*/
|
|
if (S_ISCHR(mode) || S_ISBLK(mode)) {
|
|
if (unlikely(!sysv_valid_dev(rdev) || MAJOR(rdev) & ~0x1ff))
|
|
return -EINVAL;
|
|
} else {
|
|
rdev = 0;
|
|
}
|
|
|
|
error = posix_acl_create(dir, &mode, &default_acl, &acl);
|
|
if (error)
|
|
return error;
|
|
|
|
/* Verify mode is valid also for tmpfile case */
|
|
error = xfs_dentry_mode_to_name(&name, dentry, mode);
|
|
if (unlikely(error))
|
|
goto out_free_acl;
|
|
|
|
if (!tmpfile) {
|
|
error = xfs_create(mnt_userns, XFS_I(dir), &name, mode, rdev,
|
|
&ip);
|
|
} else {
|
|
error = xfs_create_tmpfile(mnt_userns, XFS_I(dir), mode, &ip);
|
|
}
|
|
if (unlikely(error))
|
|
goto out_free_acl;
|
|
|
|
inode = VFS_I(ip);
|
|
|
|
error = xfs_init_security(inode, dir, &dentry->d_name);
|
|
if (unlikely(error))
|
|
goto out_cleanup_inode;
|
|
|
|
#ifdef CONFIG_XFS_POSIX_ACL
|
|
if (default_acl) {
|
|
error = __xfs_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
|
|
if (error)
|
|
goto out_cleanup_inode;
|
|
}
|
|
if (acl) {
|
|
error = __xfs_set_acl(inode, acl, ACL_TYPE_ACCESS);
|
|
if (error)
|
|
goto out_cleanup_inode;
|
|
}
|
|
#endif
|
|
|
|
xfs_setup_iops(ip);
|
|
|
|
if (tmpfile) {
|
|
/*
|
|
* The VFS requires that any inode fed to d_tmpfile must have
|
|
* nlink == 1 so that it can decrement the nlink in d_tmpfile.
|
|
* However, we created the temp file with nlink == 0 because
|
|
* we're not allowed to put an inode with nlink > 0 on the
|
|
* unlinked list. Therefore we have to set nlink to 1 so that
|
|
* d_tmpfile can immediately set it back to zero.
|
|
*/
|
|
set_nlink(inode, 1);
|
|
d_tmpfile(dentry, inode);
|
|
} else
|
|
d_instantiate(dentry, inode);
|
|
|
|
xfs_finish_inode_setup(ip);
|
|
|
|
out_free_acl:
|
|
posix_acl_release(default_acl);
|
|
posix_acl_release(acl);
|
|
return error;
|
|
|
|
out_cleanup_inode:
|
|
xfs_finish_inode_setup(ip);
|
|
if (!tmpfile)
|
|
xfs_cleanup_inode(dir, inode, dentry);
|
|
xfs_irele(ip);
|
|
goto out_free_acl;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_mknod(
|
|
struct user_namespace *mnt_userns,
|
|
struct inode *dir,
|
|
struct dentry *dentry,
|
|
umode_t mode,
|
|
dev_t rdev)
|
|
{
|
|
return xfs_generic_create(mnt_userns, dir, dentry, mode, rdev, false);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_create(
|
|
struct user_namespace *mnt_userns,
|
|
struct inode *dir,
|
|
struct dentry *dentry,
|
|
umode_t mode,
|
|
bool flags)
|
|
{
|
|
return xfs_generic_create(mnt_userns, dir, dentry, mode, 0, false);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_mkdir(
|
|
struct user_namespace *mnt_userns,
|
|
struct inode *dir,
|
|
struct dentry *dentry,
|
|
umode_t mode)
|
|
{
|
|
return xfs_generic_create(mnt_userns, dir, dentry, mode | S_IFDIR, 0,
|
|
false);
|
|
}
|
|
|
|
STATIC struct dentry *
|
|
xfs_vn_lookup(
|
|
struct inode *dir,
|
|
struct dentry *dentry,
|
|
unsigned int flags)
|
|
{
|
|
struct inode *inode;
|
|
struct xfs_inode *cip;
|
|
struct xfs_name name;
|
|
int error;
|
|
|
|
if (dentry->d_name.len >= MAXNAMELEN)
|
|
return ERR_PTR(-ENAMETOOLONG);
|
|
|
|
xfs_dentry_to_name(&name, dentry);
|
|
error = xfs_lookup(XFS_I(dir), &name, &cip, NULL);
|
|
if (likely(!error))
|
|
inode = VFS_I(cip);
|
|
else if (likely(error == -ENOENT))
|
|
inode = NULL;
|
|
else
|
|
inode = ERR_PTR(error);
|
|
return d_splice_alias(inode, dentry);
|
|
}
|
|
|
|
STATIC struct dentry *
|
|
xfs_vn_ci_lookup(
|
|
struct inode *dir,
|
|
struct dentry *dentry,
|
|
unsigned int flags)
|
|
{
|
|
struct xfs_inode *ip;
|
|
struct xfs_name xname;
|
|
struct xfs_name ci_name;
|
|
struct qstr dname;
|
|
int error;
|
|
|
|
if (dentry->d_name.len >= MAXNAMELEN)
|
|
return ERR_PTR(-ENAMETOOLONG);
|
|
|
|
xfs_dentry_to_name(&xname, dentry);
|
|
error = xfs_lookup(XFS_I(dir), &xname, &ip, &ci_name);
|
|
if (unlikely(error)) {
|
|
if (unlikely(error != -ENOENT))
|
|
return ERR_PTR(error);
|
|
/*
|
|
* call d_add(dentry, NULL) here when d_drop_negative_children
|
|
* is called in xfs_vn_mknod (ie. allow negative dentries
|
|
* with CI filesystems).
|
|
*/
|
|
return NULL;
|
|
}
|
|
|
|
/* if exact match, just splice and exit */
|
|
if (!ci_name.name)
|
|
return d_splice_alias(VFS_I(ip), dentry);
|
|
|
|
/* else case-insensitive match... */
|
|
dname.name = ci_name.name;
|
|
dname.len = ci_name.len;
|
|
dentry = d_add_ci(dentry, VFS_I(ip), &dname);
|
|
kmem_free(ci_name.name);
|
|
return dentry;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_link(
|
|
struct dentry *old_dentry,
|
|
struct inode *dir,
|
|
struct dentry *dentry)
|
|
{
|
|
struct inode *inode = d_inode(old_dentry);
|
|
struct xfs_name name;
|
|
int error;
|
|
|
|
error = xfs_dentry_mode_to_name(&name, dentry, inode->i_mode);
|
|
if (unlikely(error))
|
|
return error;
|
|
|
|
error = xfs_link(XFS_I(dir), XFS_I(inode), &name);
|
|
if (unlikely(error))
|
|
return error;
|
|
|
|
ihold(inode);
|
|
d_instantiate(dentry, inode);
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_unlink(
|
|
struct inode *dir,
|
|
struct dentry *dentry)
|
|
{
|
|
struct xfs_name name;
|
|
int error;
|
|
|
|
xfs_dentry_to_name(&name, dentry);
|
|
|
|
error = xfs_remove(XFS_I(dir), &name, XFS_I(d_inode(dentry)));
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* With unlink, the VFS makes the dentry "negative": no inode,
|
|
* but still hashed. This is incompatible with case-insensitive
|
|
* mode, so invalidate (unhash) the dentry in CI-mode.
|
|
*/
|
|
if (xfs_sb_version_hasasciici(&XFS_M(dir->i_sb)->m_sb))
|
|
d_invalidate(dentry);
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_symlink(
|
|
struct user_namespace *mnt_userns,
|
|
struct inode *dir,
|
|
struct dentry *dentry,
|
|
const char *symname)
|
|
{
|
|
struct inode *inode;
|
|
struct xfs_inode *cip = NULL;
|
|
struct xfs_name name;
|
|
int error;
|
|
umode_t mode;
|
|
|
|
mode = S_IFLNK |
|
|
(irix_symlink_mode ? 0777 & ~current_umask() : S_IRWXUGO);
|
|
error = xfs_dentry_mode_to_name(&name, dentry, mode);
|
|
if (unlikely(error))
|
|
goto out;
|
|
|
|
error = xfs_symlink(mnt_userns, XFS_I(dir), &name, symname, mode, &cip);
|
|
if (unlikely(error))
|
|
goto out;
|
|
|
|
inode = VFS_I(cip);
|
|
|
|
error = xfs_init_security(inode, dir, &dentry->d_name);
|
|
if (unlikely(error))
|
|
goto out_cleanup_inode;
|
|
|
|
xfs_setup_iops(cip);
|
|
|
|
d_instantiate(dentry, inode);
|
|
xfs_finish_inode_setup(cip);
|
|
return 0;
|
|
|
|
out_cleanup_inode:
|
|
xfs_finish_inode_setup(cip);
|
|
xfs_cleanup_inode(dir, inode, dentry);
|
|
xfs_irele(cip);
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_rename(
|
|
struct user_namespace *mnt_userns,
|
|
struct inode *odir,
|
|
struct dentry *odentry,
|
|
struct inode *ndir,
|
|
struct dentry *ndentry,
|
|
unsigned int flags)
|
|
{
|
|
struct inode *new_inode = d_inode(ndentry);
|
|
int omode = 0;
|
|
int error;
|
|
struct xfs_name oname;
|
|
struct xfs_name nname;
|
|
|
|
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
|
|
return -EINVAL;
|
|
|
|
/* if we are exchanging files, we need to set i_mode of both files */
|
|
if (flags & RENAME_EXCHANGE)
|
|
omode = d_inode(ndentry)->i_mode;
|
|
|
|
error = xfs_dentry_mode_to_name(&oname, odentry, omode);
|
|
if (omode && unlikely(error))
|
|
return error;
|
|
|
|
error = xfs_dentry_mode_to_name(&nname, ndentry,
|
|
d_inode(odentry)->i_mode);
|
|
if (unlikely(error))
|
|
return error;
|
|
|
|
return xfs_rename(mnt_userns, XFS_I(odir), &oname,
|
|
XFS_I(d_inode(odentry)), XFS_I(ndir), &nname,
|
|
new_inode ? XFS_I(new_inode) : NULL, flags);
|
|
}
|
|
|
|
/*
|
|
* careful here - this function can get called recursively, so
|
|
* we need to be very careful about how much stack we use.
|
|
* uio is kmalloced for this reason...
|
|
*/
|
|
STATIC const char *
|
|
xfs_vn_get_link(
|
|
struct dentry *dentry,
|
|
struct inode *inode,
|
|
struct delayed_call *done)
|
|
{
|
|
char *link;
|
|
int error = -ENOMEM;
|
|
|
|
if (!dentry)
|
|
return ERR_PTR(-ECHILD);
|
|
|
|
link = kmalloc(XFS_SYMLINK_MAXLEN+1, GFP_KERNEL);
|
|
if (!link)
|
|
goto out_err;
|
|
|
|
error = xfs_readlink(XFS_I(d_inode(dentry)), link);
|
|
if (unlikely(error))
|
|
goto out_kfree;
|
|
|
|
set_delayed_call(done, kfree_link, link);
|
|
return link;
|
|
|
|
out_kfree:
|
|
kfree(link);
|
|
out_err:
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
STATIC const char *
|
|
xfs_vn_get_link_inline(
|
|
struct dentry *dentry,
|
|
struct inode *inode,
|
|
struct delayed_call *done)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
char *link;
|
|
|
|
ASSERT(ip->i_df.if_flags & XFS_IFINLINE);
|
|
|
|
/*
|
|
* The VFS crashes on a NULL pointer, so return -EFSCORRUPTED if
|
|
* if_data is junk.
|
|
*/
|
|
link = ip->i_df.if_u1.if_data;
|
|
if (XFS_IS_CORRUPT(ip->i_mount, !link))
|
|
return ERR_PTR(-EFSCORRUPTED);
|
|
return link;
|
|
}
|
|
|
|
static uint32_t
|
|
xfs_stat_blksize(
|
|
struct xfs_inode *ip)
|
|
{
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
|
|
/*
|
|
* If the file blocks are being allocated from a realtime volume, then
|
|
* always return the realtime extent size.
|
|
*/
|
|
if (XFS_IS_REALTIME_INODE(ip))
|
|
return xfs_get_extsz_hint(ip) << mp->m_sb.sb_blocklog;
|
|
|
|
/*
|
|
* Allow large block sizes to be reported to userspace programs if the
|
|
* "largeio" mount option is used.
|
|
*
|
|
* If compatibility mode is specified, simply return the basic unit of
|
|
* caching so that we don't get inefficient read/modify/write I/O from
|
|
* user apps. Otherwise....
|
|
*
|
|
* If the underlying volume is a stripe, then return the stripe width in
|
|
* bytes as the recommended I/O size. It is not a stripe and we've set a
|
|
* default buffered I/O size, return that, otherwise return the compat
|
|
* default.
|
|
*/
|
|
if (mp->m_flags & XFS_MOUNT_LARGEIO) {
|
|
if (mp->m_swidth)
|
|
return mp->m_swidth << mp->m_sb.sb_blocklog;
|
|
if (mp->m_flags & XFS_MOUNT_ALLOCSIZE)
|
|
return 1U << mp->m_allocsize_log;
|
|
}
|
|
|
|
return PAGE_SIZE;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_getattr(
|
|
struct user_namespace *mnt_userns,
|
|
const struct path *path,
|
|
struct kstat *stat,
|
|
u32 request_mask,
|
|
unsigned int query_flags)
|
|
{
|
|
struct inode *inode = d_inode(path->dentry);
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
|
|
trace_xfs_getattr(ip);
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
return -EIO;
|
|
|
|
stat->size = XFS_ISIZE(ip);
|
|
stat->dev = inode->i_sb->s_dev;
|
|
stat->mode = inode->i_mode;
|
|
stat->nlink = inode->i_nlink;
|
|
stat->uid = i_uid_into_mnt(mnt_userns, inode);
|
|
stat->gid = i_gid_into_mnt(mnt_userns, inode);
|
|
stat->ino = ip->i_ino;
|
|
stat->atime = inode->i_atime;
|
|
stat->mtime = inode->i_mtime;
|
|
stat->ctime = inode->i_ctime;
|
|
stat->blocks =
|
|
XFS_FSB_TO_BB(mp, ip->i_d.di_nblocks + ip->i_delayed_blks);
|
|
|
|
if (xfs_sb_version_has_v3inode(&mp->m_sb)) {
|
|
if (request_mask & STATX_BTIME) {
|
|
stat->result_mask |= STATX_BTIME;
|
|
stat->btime = ip->i_d.di_crtime;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Note: If you add another clause to set an attribute flag, please
|
|
* update attributes_mask below.
|
|
*/
|
|
if (ip->i_d.di_flags & XFS_DIFLAG_IMMUTABLE)
|
|
stat->attributes |= STATX_ATTR_IMMUTABLE;
|
|
if (ip->i_d.di_flags & XFS_DIFLAG_APPEND)
|
|
stat->attributes |= STATX_ATTR_APPEND;
|
|
if (ip->i_d.di_flags & XFS_DIFLAG_NODUMP)
|
|
stat->attributes |= STATX_ATTR_NODUMP;
|
|
|
|
stat->attributes_mask |= (STATX_ATTR_IMMUTABLE |
|
|
STATX_ATTR_APPEND |
|
|
STATX_ATTR_NODUMP);
|
|
|
|
switch (inode->i_mode & S_IFMT) {
|
|
case S_IFBLK:
|
|
case S_IFCHR:
|
|
stat->blksize = BLKDEV_IOSIZE;
|
|
stat->rdev = inode->i_rdev;
|
|
break;
|
|
default:
|
|
stat->blksize = xfs_stat_blksize(ip);
|
|
stat->rdev = 0;
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
xfs_setattr_mode(
|
|
struct xfs_inode *ip,
|
|
struct iattr *iattr)
|
|
{
|
|
struct inode *inode = VFS_I(ip);
|
|
umode_t mode = iattr->ia_mode;
|
|
|
|
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
|
|
|
|
inode->i_mode &= S_IFMT;
|
|
inode->i_mode |= mode & ~S_IFMT;
|
|
}
|
|
|
|
void
|
|
xfs_setattr_time(
|
|
struct xfs_inode *ip,
|
|
struct iattr *iattr)
|
|
{
|
|
struct inode *inode = VFS_I(ip);
|
|
|
|
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
|
|
|
|
if (iattr->ia_valid & ATTR_ATIME)
|
|
inode->i_atime = iattr->ia_atime;
|
|
if (iattr->ia_valid & ATTR_CTIME)
|
|
inode->i_ctime = iattr->ia_ctime;
|
|
if (iattr->ia_valid & ATTR_MTIME)
|
|
inode->i_mtime = iattr->ia_mtime;
|
|
}
|
|
|
|
static int
|
|
xfs_vn_change_ok(
|
|
struct user_namespace *mnt_userns,
|
|
struct dentry *dentry,
|
|
struct iattr *iattr)
|
|
{
|
|
struct xfs_mount *mp = XFS_I(d_inode(dentry))->i_mount;
|
|
|
|
if (mp->m_flags & XFS_MOUNT_RDONLY)
|
|
return -EROFS;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
return -EIO;
|
|
|
|
return setattr_prepare(mnt_userns, dentry, iattr);
|
|
}
|
|
|
|
/*
|
|
* Set non-size attributes of an inode.
|
|
*
|
|
* Caution: The caller of this function is responsible for calling
|
|
* setattr_prepare() or otherwise verifying the change is fine.
|
|
*/
|
|
static int
|
|
xfs_setattr_nonsize(
|
|
struct user_namespace *mnt_userns,
|
|
struct xfs_inode *ip,
|
|
struct iattr *iattr)
|
|
{
|
|
xfs_mount_t *mp = ip->i_mount;
|
|
struct inode *inode = VFS_I(ip);
|
|
int mask = iattr->ia_valid;
|
|
xfs_trans_t *tp;
|
|
int error;
|
|
kuid_t uid = GLOBAL_ROOT_UID, iuid = GLOBAL_ROOT_UID;
|
|
kgid_t gid = GLOBAL_ROOT_GID, igid = GLOBAL_ROOT_GID;
|
|
struct xfs_dquot *udqp = NULL, *gdqp = NULL;
|
|
struct xfs_dquot *olddquot1 = NULL, *olddquot2 = NULL;
|
|
|
|
ASSERT((mask & ATTR_SIZE) == 0);
|
|
|
|
/*
|
|
* If disk quotas is on, we make sure that the dquots do exist on disk,
|
|
* before we start any other transactions. Trying to do this later
|
|
* is messy. We don't care to take a readlock to look at the ids
|
|
* in inode here, because we can't hold it across the trans_reserve.
|
|
* If the IDs do change before we take the ilock, we're covered
|
|
* because the i_*dquot fields will get updated anyway.
|
|
*/
|
|
if (XFS_IS_QUOTA_ON(mp) && (mask & (ATTR_UID|ATTR_GID))) {
|
|
uint qflags = 0;
|
|
|
|
if ((mask & ATTR_UID) && XFS_IS_UQUOTA_ON(mp)) {
|
|
uid = iattr->ia_uid;
|
|
qflags |= XFS_QMOPT_UQUOTA;
|
|
} else {
|
|
uid = inode->i_uid;
|
|
}
|
|
if ((mask & ATTR_GID) && XFS_IS_GQUOTA_ON(mp)) {
|
|
gid = iattr->ia_gid;
|
|
qflags |= XFS_QMOPT_GQUOTA;
|
|
} else {
|
|
gid = inode->i_gid;
|
|
}
|
|
|
|
/*
|
|
* We take a reference when we initialize udqp and gdqp,
|
|
* so it is important that we never blindly double trip on
|
|
* the same variable. See xfs_create() for an example.
|
|
*/
|
|
ASSERT(udqp == NULL);
|
|
ASSERT(gdqp == NULL);
|
|
error = xfs_qm_vop_dqalloc(ip, uid, gid, ip->i_d.di_projid,
|
|
qflags, &udqp, &gdqp, NULL);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
error = xfs_trans_alloc_ichange(ip, udqp, gdqp, NULL,
|
|
capable(CAP_FOWNER), &tp);
|
|
if (error)
|
|
goto out_dqrele;
|
|
|
|
/*
|
|
* Change file ownership. Must be the owner or privileged.
|
|
*/
|
|
if (mask & (ATTR_UID|ATTR_GID)) {
|
|
/*
|
|
* These IDs could have changed since we last looked at them.
|
|
* But, we're assured that if the ownership did change
|
|
* while we didn't have the inode locked, inode's dquot(s)
|
|
* would have changed also.
|
|
*/
|
|
iuid = inode->i_uid;
|
|
igid = inode->i_gid;
|
|
gid = (mask & ATTR_GID) ? iattr->ia_gid : igid;
|
|
uid = (mask & ATTR_UID) ? iattr->ia_uid : iuid;
|
|
|
|
/*
|
|
* CAP_FSETID overrides the following restrictions:
|
|
*
|
|
* The set-user-ID and set-group-ID bits of a file will be
|
|
* cleared upon successful return from chown()
|
|
*/
|
|
if ((inode->i_mode & (S_ISUID|S_ISGID)) &&
|
|
!capable(CAP_FSETID))
|
|
inode->i_mode &= ~(S_ISUID|S_ISGID);
|
|
|
|
/*
|
|
* Change the ownerships and register quota modifications
|
|
* in the transaction.
|
|
*/
|
|
if (!uid_eq(iuid, uid)) {
|
|
if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_UQUOTA_ON(mp)) {
|
|
ASSERT(mask & ATTR_UID);
|
|
ASSERT(udqp);
|
|
olddquot1 = xfs_qm_vop_chown(tp, ip,
|
|
&ip->i_udquot, udqp);
|
|
}
|
|
inode->i_uid = uid;
|
|
}
|
|
if (!gid_eq(igid, gid)) {
|
|
if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_GQUOTA_ON(mp)) {
|
|
ASSERT(xfs_sb_version_has_pquotino(&mp->m_sb) ||
|
|
!XFS_IS_PQUOTA_ON(mp));
|
|
ASSERT(mask & ATTR_GID);
|
|
ASSERT(gdqp);
|
|
olddquot2 = xfs_qm_vop_chown(tp, ip,
|
|
&ip->i_gdquot, gdqp);
|
|
}
|
|
inode->i_gid = gid;
|
|
}
|
|
}
|
|
|
|
if (mask & ATTR_MODE)
|
|
xfs_setattr_mode(ip, iattr);
|
|
if (mask & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME))
|
|
xfs_setattr_time(ip, iattr);
|
|
|
|
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
|
|
|
|
XFS_STATS_INC(mp, xs_ig_attrchg);
|
|
|
|
if (mp->m_flags & XFS_MOUNT_WSYNC)
|
|
xfs_trans_set_sync(tp);
|
|
error = xfs_trans_commit(tp);
|
|
|
|
/*
|
|
* Release any dquot(s) the inode had kept before chown.
|
|
*/
|
|
xfs_qm_dqrele(olddquot1);
|
|
xfs_qm_dqrele(olddquot2);
|
|
xfs_qm_dqrele(udqp);
|
|
xfs_qm_dqrele(gdqp);
|
|
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* XXX(hch): Updating the ACL entries is not atomic vs the i_mode
|
|
* update. We could avoid this with linked transactions
|
|
* and passing down the transaction pointer all the way
|
|
* to attr_set. No previous user of the generic
|
|
* Posix ACL code seems to care about this issue either.
|
|
*/
|
|
if (mask & ATTR_MODE) {
|
|
error = posix_acl_chmod(mnt_userns, inode, inode->i_mode);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_dqrele:
|
|
xfs_qm_dqrele(udqp);
|
|
xfs_qm_dqrele(gdqp);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Truncate file. Must have write permission and not be a directory.
|
|
*
|
|
* Caution: The caller of this function is responsible for calling
|
|
* setattr_prepare() or otherwise verifying the change is fine.
|
|
*/
|
|
STATIC int
|
|
xfs_setattr_size(
|
|
struct user_namespace *mnt_userns,
|
|
struct xfs_inode *ip,
|
|
struct iattr *iattr)
|
|
{
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
struct inode *inode = VFS_I(ip);
|
|
xfs_off_t oldsize, newsize;
|
|
struct xfs_trans *tp;
|
|
int error;
|
|
uint lock_flags = 0;
|
|
bool did_zeroing = false;
|
|
|
|
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
|
|
ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
|
|
ASSERT(S_ISREG(inode->i_mode));
|
|
ASSERT((iattr->ia_valid & (ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET|
|
|
ATTR_MTIME_SET|ATTR_TIMES_SET)) == 0);
|
|
|
|
oldsize = inode->i_size;
|
|
newsize = iattr->ia_size;
|
|
|
|
/*
|
|
* Short circuit the truncate case for zero length files.
|
|
*/
|
|
if (newsize == 0 && oldsize == 0 && ip->i_df.if_nextents == 0) {
|
|
if (!(iattr->ia_valid & (ATTR_CTIME|ATTR_MTIME)))
|
|
return 0;
|
|
|
|
/*
|
|
* Use the regular setattr path to update the timestamps.
|
|
*/
|
|
iattr->ia_valid &= ~ATTR_SIZE;
|
|
return xfs_setattr_nonsize(mnt_userns, ip, iattr);
|
|
}
|
|
|
|
/*
|
|
* Make sure that the dquots are attached to the inode.
|
|
*/
|
|
error = xfs_qm_dqattach(ip);
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* Wait for all direct I/O to complete.
|
|
*/
|
|
inode_dio_wait(inode);
|
|
|
|
/*
|
|
* File data changes must be complete before we start the transaction to
|
|
* modify the inode. This needs to be done before joining the inode to
|
|
* the transaction because the inode cannot be unlocked once it is a
|
|
* part of the transaction.
|
|
*
|
|
* Start with zeroing any data beyond EOF that we may expose on file
|
|
* extension, or zeroing out the rest of the block on a downward
|
|
* truncate.
|
|
*/
|
|
if (newsize > oldsize) {
|
|
trace_xfs_zero_eof(ip, oldsize, newsize - oldsize);
|
|
error = iomap_zero_range(inode, oldsize, newsize - oldsize,
|
|
&did_zeroing, &xfs_buffered_write_iomap_ops);
|
|
} else {
|
|
/*
|
|
* iomap won't detect a dirty page over an unwritten block (or a
|
|
* cow block over a hole) and subsequently skips zeroing the
|
|
* newly post-EOF portion of the page. Flush the new EOF to
|
|
* convert the block before the pagecache truncate.
|
|
*/
|
|
error = filemap_write_and_wait_range(inode->i_mapping, newsize,
|
|
newsize);
|
|
if (error)
|
|
return error;
|
|
error = iomap_truncate_page(inode, newsize, &did_zeroing,
|
|
&xfs_buffered_write_iomap_ops);
|
|
}
|
|
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* We've already locked out new page faults, so now we can safely remove
|
|
* pages from the page cache knowing they won't get refaulted until we
|
|
* drop the XFS_MMAP_EXCL lock after the extent manipulations are
|
|
* complete. The truncate_setsize() call also cleans partial EOF page
|
|
* PTEs on extending truncates and hence ensures sub-page block size
|
|
* filesystems are correctly handled, too.
|
|
*
|
|
* We have to do all the page cache truncate work outside the
|
|
* transaction context as the "lock" order is page lock->log space
|
|
* reservation as defined by extent allocation in the writeback path.
|
|
* Hence a truncate can fail with ENOMEM from xfs_trans_alloc(), but
|
|
* having already truncated the in-memory version of the file (i.e. made
|
|
* user visible changes). There's not much we can do about this, except
|
|
* to hope that the caller sees ENOMEM and retries the truncate
|
|
* operation.
|
|
*
|
|
* And we update in-core i_size and truncate page cache beyond newsize
|
|
* before writeback the [di_size, newsize] range, so we're guaranteed
|
|
* not to write stale data past the new EOF on truncate down.
|
|
*/
|
|
truncate_setsize(inode, newsize);
|
|
|
|
/*
|
|
* We are going to log the inode size change in this transaction so
|
|
* any previous writes that are beyond the on disk EOF and the new
|
|
* EOF that have not been written out need to be written here. If we
|
|
* do not write the data out, we expose ourselves to the null files
|
|
* problem. Note that this includes any block zeroing we did above;
|
|
* otherwise those blocks may not be zeroed after a crash.
|
|
*/
|
|
if (did_zeroing ||
|
|
(newsize > ip->i_d.di_size && oldsize != ip->i_d.di_size)) {
|
|
error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
|
|
ip->i_d.di_size, newsize - 1);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
|
|
if (error)
|
|
return error;
|
|
|
|
lock_flags |= XFS_ILOCK_EXCL;
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
xfs_trans_ijoin(tp, ip, 0);
|
|
|
|
/*
|
|
* Only change the c/mtime if we are changing the size or we are
|
|
* explicitly asked to change it. This handles the semantic difference
|
|
* between truncate() and ftruncate() as implemented in the VFS.
|
|
*
|
|
* The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
|
|
* special case where we need to update the times despite not having
|
|
* these flags set. For all other operations the VFS set these flags
|
|
* explicitly if it wants a timestamp update.
|
|
*/
|
|
if (newsize != oldsize &&
|
|
!(iattr->ia_valid & (ATTR_CTIME | ATTR_MTIME))) {
|
|
iattr->ia_ctime = iattr->ia_mtime =
|
|
current_time(inode);
|
|
iattr->ia_valid |= ATTR_CTIME | ATTR_MTIME;
|
|
}
|
|
|
|
/*
|
|
* The first thing we do is set the size to new_size permanently on
|
|
* disk. This way we don't have to worry about anyone ever being able
|
|
* to look at the data being freed even in the face of a crash.
|
|
* What we're getting around here is the case where we free a block, it
|
|
* is allocated to another file, it is written to, and then we crash.
|
|
* If the new data gets written to the file but the log buffers
|
|
* containing the free and reallocation don't, then we'd end up with
|
|
* garbage in the blocks being freed. As long as we make the new size
|
|
* permanent before actually freeing any blocks it doesn't matter if
|
|
* they get written to.
|
|
*/
|
|
ip->i_d.di_size = newsize;
|
|
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
|
|
|
|
if (newsize <= oldsize) {
|
|
error = xfs_itruncate_extents(&tp, ip, XFS_DATA_FORK, newsize);
|
|
if (error)
|
|
goto out_trans_cancel;
|
|
|
|
/*
|
|
* Truncated "down", so we're removing references to old data
|
|
* here - if we delay flushing for a long time, we expose
|
|
* ourselves unduly to the notorious NULL files problem. So,
|
|
* we mark this inode and flush it when the file is closed,
|
|
* and do not wait the usual (long) time for writeout.
|
|
*/
|
|
xfs_iflags_set(ip, XFS_ITRUNCATED);
|
|
|
|
/* A truncate down always removes post-EOF blocks. */
|
|
xfs_inode_clear_eofblocks_tag(ip);
|
|
}
|
|
|
|
if (iattr->ia_valid & ATTR_MODE)
|
|
xfs_setattr_mode(ip, iattr);
|
|
if (iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME))
|
|
xfs_setattr_time(ip, iattr);
|
|
|
|
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
|
|
|
|
XFS_STATS_INC(mp, xs_ig_attrchg);
|
|
|
|
if (mp->m_flags & XFS_MOUNT_WSYNC)
|
|
xfs_trans_set_sync(tp);
|
|
|
|
error = xfs_trans_commit(tp);
|
|
out_unlock:
|
|
if (lock_flags)
|
|
xfs_iunlock(ip, lock_flags);
|
|
return error;
|
|
|
|
out_trans_cancel:
|
|
xfs_trans_cancel(tp);
|
|
goto out_unlock;
|
|
}
|
|
|
|
int
|
|
xfs_vn_setattr_size(
|
|
struct user_namespace *mnt_userns,
|
|
struct dentry *dentry,
|
|
struct iattr *iattr)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(d_inode(dentry));
|
|
int error;
|
|
|
|
trace_xfs_setattr(ip);
|
|
|
|
error = xfs_vn_change_ok(mnt_userns, dentry, iattr);
|
|
if (error)
|
|
return error;
|
|
return xfs_setattr_size(mnt_userns, ip, iattr);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_setattr(
|
|
struct user_namespace *mnt_userns,
|
|
struct dentry *dentry,
|
|
struct iattr *iattr)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
int error;
|
|
|
|
if (iattr->ia_valid & ATTR_SIZE) {
|
|
uint iolock;
|
|
|
|
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
|
|
iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
|
|
|
|
error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
|
|
if (error) {
|
|
xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
|
|
return error;
|
|
}
|
|
|
|
error = xfs_vn_setattr_size(mnt_userns, dentry, iattr);
|
|
xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
|
|
} else {
|
|
trace_xfs_setattr(ip);
|
|
|
|
error = xfs_vn_change_ok(mnt_userns, dentry, iattr);
|
|
if (!error)
|
|
error = xfs_setattr_nonsize(mnt_userns, ip, iattr);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_update_time(
|
|
struct inode *inode,
|
|
struct timespec64 *now,
|
|
int flags)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
int log_flags = XFS_ILOG_TIMESTAMP;
|
|
struct xfs_trans *tp;
|
|
int error;
|
|
|
|
trace_xfs_update_time(ip);
|
|
|
|
if (inode->i_sb->s_flags & SB_LAZYTIME) {
|
|
if (!((flags & S_VERSION) &&
|
|
inode_maybe_inc_iversion(inode, false)))
|
|
return generic_update_time(inode, now, flags);
|
|
|
|
/* Capture the iversion update that just occurred */
|
|
log_flags |= XFS_ILOG_CORE;
|
|
}
|
|
|
|
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp);
|
|
if (error)
|
|
return error;
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
if (flags & S_CTIME)
|
|
inode->i_ctime = *now;
|
|
if (flags & S_MTIME)
|
|
inode->i_mtime = *now;
|
|
if (flags & S_ATIME)
|
|
inode->i_atime = *now;
|
|
|
|
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
|
|
xfs_trans_log_inode(tp, ip, log_flags);
|
|
return xfs_trans_commit(tp);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_fiemap(
|
|
struct inode *inode,
|
|
struct fiemap_extent_info *fieinfo,
|
|
u64 start,
|
|
u64 length)
|
|
{
|
|
int error;
|
|
|
|
xfs_ilock(XFS_I(inode), XFS_IOLOCK_SHARED);
|
|
if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
|
|
fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
|
|
error = iomap_fiemap(inode, fieinfo, start, length,
|
|
&xfs_xattr_iomap_ops);
|
|
} else {
|
|
error = iomap_fiemap(inode, fieinfo, start, length,
|
|
&xfs_read_iomap_ops);
|
|
}
|
|
xfs_iunlock(XFS_I(inode), XFS_IOLOCK_SHARED);
|
|
|
|
return error;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_vn_tmpfile(
|
|
struct user_namespace *mnt_userns,
|
|
struct inode *dir,
|
|
struct dentry *dentry,
|
|
umode_t mode)
|
|
{
|
|
return xfs_generic_create(mnt_userns, dir, dentry, mode, 0, true);
|
|
}
|
|
|
|
static const struct inode_operations xfs_inode_operations = {
|
|
.get_acl = xfs_get_acl,
|
|
.set_acl = xfs_set_acl,
|
|
.getattr = xfs_vn_getattr,
|
|
.setattr = xfs_vn_setattr,
|
|
.listxattr = xfs_vn_listxattr,
|
|
.fiemap = xfs_vn_fiemap,
|
|
.update_time = xfs_vn_update_time,
|
|
};
|
|
|
|
static const struct inode_operations xfs_dir_inode_operations = {
|
|
.create = xfs_vn_create,
|
|
.lookup = xfs_vn_lookup,
|
|
.link = xfs_vn_link,
|
|
.unlink = xfs_vn_unlink,
|
|
.symlink = xfs_vn_symlink,
|
|
.mkdir = xfs_vn_mkdir,
|
|
/*
|
|
* Yes, XFS uses the same method for rmdir and unlink.
|
|
*
|
|
* There are some subtile differences deeper in the code,
|
|
* but we use S_ISDIR to check for those.
|
|
*/
|
|
.rmdir = xfs_vn_unlink,
|
|
.mknod = xfs_vn_mknod,
|
|
.rename = xfs_vn_rename,
|
|
.get_acl = xfs_get_acl,
|
|
.set_acl = xfs_set_acl,
|
|
.getattr = xfs_vn_getattr,
|
|
.setattr = xfs_vn_setattr,
|
|
.listxattr = xfs_vn_listxattr,
|
|
.update_time = xfs_vn_update_time,
|
|
.tmpfile = xfs_vn_tmpfile,
|
|
};
|
|
|
|
static const struct inode_operations xfs_dir_ci_inode_operations = {
|
|
.create = xfs_vn_create,
|
|
.lookup = xfs_vn_ci_lookup,
|
|
.link = xfs_vn_link,
|
|
.unlink = xfs_vn_unlink,
|
|
.symlink = xfs_vn_symlink,
|
|
.mkdir = xfs_vn_mkdir,
|
|
/*
|
|
* Yes, XFS uses the same method for rmdir and unlink.
|
|
*
|
|
* There are some subtile differences deeper in the code,
|
|
* but we use S_ISDIR to check for those.
|
|
*/
|
|
.rmdir = xfs_vn_unlink,
|
|
.mknod = xfs_vn_mknod,
|
|
.rename = xfs_vn_rename,
|
|
.get_acl = xfs_get_acl,
|
|
.set_acl = xfs_set_acl,
|
|
.getattr = xfs_vn_getattr,
|
|
.setattr = xfs_vn_setattr,
|
|
.listxattr = xfs_vn_listxattr,
|
|
.update_time = xfs_vn_update_time,
|
|
.tmpfile = xfs_vn_tmpfile,
|
|
};
|
|
|
|
static const struct inode_operations xfs_symlink_inode_operations = {
|
|
.get_link = xfs_vn_get_link,
|
|
.getattr = xfs_vn_getattr,
|
|
.setattr = xfs_vn_setattr,
|
|
.listxattr = xfs_vn_listxattr,
|
|
.update_time = xfs_vn_update_time,
|
|
};
|
|
|
|
static const struct inode_operations xfs_inline_symlink_inode_operations = {
|
|
.get_link = xfs_vn_get_link_inline,
|
|
.getattr = xfs_vn_getattr,
|
|
.setattr = xfs_vn_setattr,
|
|
.listxattr = xfs_vn_listxattr,
|
|
.update_time = xfs_vn_update_time,
|
|
};
|
|
|
|
/* Figure out if this file actually supports DAX. */
|
|
static bool
|
|
xfs_inode_supports_dax(
|
|
struct xfs_inode *ip)
|
|
{
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
|
|
/* Only supported on regular files. */
|
|
if (!S_ISREG(VFS_I(ip)->i_mode))
|
|
return false;
|
|
|
|
/* Only supported on non-reflinked files. */
|
|
if (xfs_is_reflink_inode(ip))
|
|
return false;
|
|
|
|
/* Block size must match page size */
|
|
if (mp->m_sb.sb_blocksize != PAGE_SIZE)
|
|
return false;
|
|
|
|
/* Device has to support DAX too. */
|
|
return xfs_inode_buftarg(ip)->bt_daxdev != NULL;
|
|
}
|
|
|
|
static bool
|
|
xfs_inode_should_enable_dax(
|
|
struct xfs_inode *ip)
|
|
{
|
|
if (!IS_ENABLED(CONFIG_FS_DAX))
|
|
return false;
|
|
if (ip->i_mount->m_flags & XFS_MOUNT_DAX_NEVER)
|
|
return false;
|
|
if (!xfs_inode_supports_dax(ip))
|
|
return false;
|
|
if (ip->i_mount->m_flags & XFS_MOUNT_DAX_ALWAYS)
|
|
return true;
|
|
if (ip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
void
|
|
xfs_diflags_to_iflags(
|
|
struct xfs_inode *ip,
|
|
bool init)
|
|
{
|
|
struct inode *inode = VFS_I(ip);
|
|
unsigned int xflags = xfs_ip2xflags(ip);
|
|
unsigned int flags = 0;
|
|
|
|
ASSERT(!(IS_DAX(inode) && init));
|
|
|
|
if (xflags & FS_XFLAG_IMMUTABLE)
|
|
flags |= S_IMMUTABLE;
|
|
if (xflags & FS_XFLAG_APPEND)
|
|
flags |= S_APPEND;
|
|
if (xflags & FS_XFLAG_SYNC)
|
|
flags |= S_SYNC;
|
|
if (xflags & FS_XFLAG_NOATIME)
|
|
flags |= S_NOATIME;
|
|
if (init && xfs_inode_should_enable_dax(ip))
|
|
flags |= S_DAX;
|
|
|
|
/*
|
|
* S_DAX can only be set during inode initialization and is never set by
|
|
* the VFS, so we cannot mask off S_DAX in i_flags.
|
|
*/
|
|
inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC | S_NOATIME);
|
|
inode->i_flags |= flags;
|
|
}
|
|
|
|
/*
|
|
* Initialize the Linux inode.
|
|
*
|
|
* When reading existing inodes from disk this is called directly from xfs_iget,
|
|
* when creating a new inode it is called from xfs_ialloc after setting up the
|
|
* inode. These callers have different criteria for clearing XFS_INEW, so leave
|
|
* it up to the caller to deal with unlocking the inode appropriately.
|
|
*/
|
|
void
|
|
xfs_setup_inode(
|
|
struct xfs_inode *ip)
|
|
{
|
|
struct inode *inode = &ip->i_vnode;
|
|
gfp_t gfp_mask;
|
|
|
|
inode->i_ino = ip->i_ino;
|
|
inode->i_state = I_NEW;
|
|
|
|
inode_sb_list_add(inode);
|
|
/* make the inode look hashed for the writeback code */
|
|
inode_fake_hash(inode);
|
|
|
|
i_size_write(inode, ip->i_d.di_size);
|
|
xfs_diflags_to_iflags(ip, true);
|
|
|
|
if (S_ISDIR(inode->i_mode)) {
|
|
/*
|
|
* We set the i_rwsem class here to avoid potential races with
|
|
* lockdep_annotate_inode_mutex_key() reinitialising the lock
|
|
* after a filehandle lookup has already found the inode in
|
|
* cache before it has been unlocked via unlock_new_inode().
|
|
*/
|
|
lockdep_set_class(&inode->i_rwsem,
|
|
&inode->i_sb->s_type->i_mutex_dir_key);
|
|
lockdep_set_class(&ip->i_lock.mr_lock, &xfs_dir_ilock_class);
|
|
} else {
|
|
lockdep_set_class(&ip->i_lock.mr_lock, &xfs_nondir_ilock_class);
|
|
}
|
|
|
|
/*
|
|
* Ensure all page cache allocations are done from GFP_NOFS context to
|
|
* prevent direct reclaim recursion back into the filesystem and blowing
|
|
* stacks or deadlocking.
|
|
*/
|
|
gfp_mask = mapping_gfp_mask(inode->i_mapping);
|
|
mapping_set_gfp_mask(inode->i_mapping, (gfp_mask & ~(__GFP_FS)));
|
|
|
|
/*
|
|
* If there is no attribute fork no ACL can exist on this inode,
|
|
* and it can't have any file capabilities attached to it either.
|
|
*/
|
|
if (!XFS_IFORK_Q(ip)) {
|
|
inode_has_no_xattr(inode);
|
|
cache_no_acl(inode);
|
|
}
|
|
}
|
|
|
|
void
|
|
xfs_setup_iops(
|
|
struct xfs_inode *ip)
|
|
{
|
|
struct inode *inode = &ip->i_vnode;
|
|
|
|
switch (inode->i_mode & S_IFMT) {
|
|
case S_IFREG:
|
|
inode->i_op = &xfs_inode_operations;
|
|
inode->i_fop = &xfs_file_operations;
|
|
if (IS_DAX(inode))
|
|
inode->i_mapping->a_ops = &xfs_dax_aops;
|
|
else
|
|
inode->i_mapping->a_ops = &xfs_address_space_operations;
|
|
break;
|
|
case S_IFDIR:
|
|
if (xfs_sb_version_hasasciici(&XFS_M(inode->i_sb)->m_sb))
|
|
inode->i_op = &xfs_dir_ci_inode_operations;
|
|
else
|
|
inode->i_op = &xfs_dir_inode_operations;
|
|
inode->i_fop = &xfs_dir_file_operations;
|
|
break;
|
|
case S_IFLNK:
|
|
if (ip->i_df.if_flags & XFS_IFINLINE)
|
|
inode->i_op = &xfs_inline_symlink_inode_operations;
|
|
else
|
|
inode->i_op = &xfs_symlink_inode_operations;
|
|
break;
|
|
default:
|
|
inode->i_op = &xfs_inode_operations;
|
|
init_special_inode(inode, inode->i_mode, inode->i_rdev);
|
|
break;
|
|
}
|
|
}
|