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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-02-20 22:53:11 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-02-20 22:53:11 +0300 |
commit | 05e6295f7b5e05f09e369a3eb2882ec5b40fff20 (patch) | |
tree | 60ea7c6806f58371bfafe6317089c7ae1a65fca4 /fs/overlayfs/inode.c | |
parent | de630176bdf885eed442902afe94eb60d8f5f826 (diff) | |
parent | 7a80e5b8c6fa7d0ae6624bd6aedc4a6a1cfc62fa (diff) | |
download | linux-05e6295f7b5e05f09e369a3eb2882ec5b40fff20.tar.xz |
Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
Pull vfs idmapping updates from Christian Brauner:
- Last cycle we introduced the dedicated struct mnt_idmap type for
mount idmapping and the required infrastucture in 256c8aed2b42 ("fs:
introduce dedicated idmap type for mounts"). As promised in last
cycle's pull request message this converts everything to rely on
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 relevant on the mount level. Especially for
non-vfs developers without detailed knowledge in this area this was a
potential source for bugs.
This finishes the conversion. Instead of passing the plain namespace
around this updates all places that currently take a pointer to a
mnt_userns with a pointer to struct mnt_idmap.
Now that the conversion is done all helpers down to the really
low-level helpers only accept a struct mnt_idmap argument instead of
two namespace arguments.
Conflating mount and other idmappings will now cause the compiler to
complain loudly thus eliminating the possibility of any bugs. This
makes it impossible for filesystem developers to mix up mount and
filesystem idmappings as they are two distinct types and require
distinct helpers that cannot be used interchangeably.
Everything associated with struct mnt_idmap is moved into a single
separate file. With that change no code can poke around in struct
mnt_idmap. It can only be interacted with through dedicated helpers.
That means all filesystems are and all of the vfs is completely
oblivious to the actual implementation of idmappings.
We are now also able to extend struct mnt_idmap as we see fit. For
example, we can decouple it completely from namespaces for users that
don't require or don't want to use them at all. We can also extend
the concept of idmappings so we can cover filesystem specific
requirements.
In combination with the vfs{g,u}id_t work we finished in v6.2 this
makes this feature substantially more robust and thus difficult to
implement wrong by a given filesystem and also protects the vfs.
- Enable idmapped mounts for tmpfs and fulfill a longstanding request.
A long-standing request from users had been to make it possible to
create idmapped mounts for tmpfs. For example, to share the host's
tmpfs mount between multiple sandboxes. This is a prerequisite for
some advanced Kubernetes cases. Systemd also has a range of use-cases
to increase service isolation. And there are more users of this.
However, with all of the other work going on this was way down on the
priority list but luckily someone other than ourselves picked this
up.
As usual the patch is tiny as all the infrastructure work had been
done multiple kernel releases ago. In addition to all the tests that
we already have I requested that Rodrigo add a dedicated tmpfs
testsuite for idmapped mounts to xfstests. It is to be included into
xfstests during the v6.3 development cycle. This should add a slew of
additional tests.
* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
shmem: support idmapped mounts for tmpfs
fs: move mnt_idmap
fs: port vfs{g,u}id helpers to mnt_idmap
fs: port fs{g,u}id helpers to mnt_idmap
fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
fs: port i_{g,u}id_{needs_}update() to mnt_idmap
quota: port to mnt_idmap
fs: port privilege checking helpers to mnt_idmap
fs: port inode_owner_or_capable() to mnt_idmap
fs: port inode_init_owner() to mnt_idmap
fs: port acl to mnt_idmap
fs: port xattr to mnt_idmap
fs: port ->permission() to pass mnt_idmap
fs: port ->fileattr_set() to pass mnt_idmap
fs: port ->set_acl() to pass mnt_idmap
fs: port ->get_acl() to pass mnt_idmap
fs: port ->tmpfile() to pass mnt_idmap
fs: port ->rename() to pass mnt_idmap
fs: port ->mknod() to pass mnt_idmap
fs: port ->mkdir() to pass mnt_idmap
...
Diffstat (limited to 'fs/overlayfs/inode.c')
-rw-r--r-- | fs/overlayfs/inode.c | 46 |
1 files changed, 23 insertions, 23 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index ee6dfa577c93..541cf3717fc2 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -19,7 +19,7 @@ #include "overlayfs.h" -int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, +int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *attr) { int err; @@ -28,7 +28,7 @@ int ovl_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, struct dentry *upperdentry; const struct cred *old_cred; - err = setattr_prepare(&init_user_ns, dentry, attr); + err = setattr_prepare(&nop_mnt_idmap, dentry, attr); if (err) return err; @@ -153,7 +153,7 @@ static void ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid) } } -int ovl_getattr(struct user_namespace *mnt_userns, const struct path *path, +int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, struct kstat *stat, u32 request_mask, unsigned int flags) { struct dentry *dentry = path->dentry; @@ -278,7 +278,7 @@ out: return err; } -int ovl_permission(struct user_namespace *mnt_userns, +int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, int mask) { struct inode *upperinode = ovl_inode_upper(inode); @@ -298,7 +298,7 @@ int ovl_permission(struct user_namespace *mnt_userns, * Check overlay inode with the creds of task and underlying inode * with creds of mounter */ - err = generic_permission(&init_user_ns, inode, mask); + err = generic_permission(&nop_mnt_idmap, inode, mask); if (err) return err; @@ -310,7 +310,7 @@ int ovl_permission(struct user_namespace *mnt_userns, /* Make sure mounter can read file for copy up later */ mask |= MAY_READ; } - err = inode_permission(mnt_user_ns(realpath.mnt), realinode, mask); + err = inode_permission(mnt_idmap(realpath.mnt), realinode, mask); revert_creds(old_cred); return err; @@ -361,7 +361,7 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, if (!value && !upperdentry) { ovl_path_lower(dentry, &realpath); old_cred = ovl_override_creds(dentry->d_sb); - err = vfs_getxattr(mnt_user_ns(realpath.mnt), realdentry, name, NULL, 0); + err = vfs_getxattr(mnt_idmap(realpath.mnt), realdentry, name, NULL, 0); revert_creds(old_cred); if (err < 0) goto out_drop_write; @@ -403,7 +403,7 @@ int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, ovl_i_path_real(inode, &realpath); old_cred = ovl_override_creds(dentry->d_sb); - res = vfs_getxattr(mnt_user_ns(realpath.mnt), realpath.dentry, name, value, size); + res = vfs_getxattr(mnt_idmap(realpath.mnt), realpath.dentry, name, value, size); revert_creds(old_cred); return res; } @@ -463,7 +463,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) * alter the POSIX ACLs for the underlying filesystem. */ static void ovl_idmap_posix_acl(const struct inode *realinode, - struct user_namespace *mnt_userns, + struct mnt_idmap *idmap, struct posix_acl *acl) { struct user_namespace *fs_userns = i_user_ns(realinode); @@ -475,11 +475,11 @@ static void ovl_idmap_posix_acl(const struct inode *realinode, struct posix_acl_entry *e = &acl->a_entries[i]; switch (e->e_tag) { case ACL_USER: - vfsuid = make_vfsuid(mnt_userns, fs_userns, e->e_uid); + vfsuid = make_vfsuid(idmap, fs_userns, e->e_uid); e->e_uid = vfsuid_into_kuid(vfsuid); break; case ACL_GROUP: - vfsgid = make_vfsgid(mnt_userns, fs_userns, e->e_gid); + vfsgid = make_vfsgid(idmap, fs_userns, e->e_gid); e->e_gid = vfsgid_into_kgid(vfsgid); break; } @@ -514,15 +514,15 @@ struct posix_acl *ovl_get_acl_path(const struct path *path, const char *acl_name, bool noperm) { struct posix_acl *real_acl, *clone; - struct user_namespace *mnt_userns; + struct mnt_idmap *idmap; struct inode *realinode = d_inode(path->dentry); - mnt_userns = mnt_user_ns(path->mnt); + idmap = mnt_idmap(path->mnt); if (noperm) real_acl = get_inode_acl(realinode, posix_acl_type(acl_name)); else - real_acl = vfs_get_acl(mnt_userns, path->dentry, acl_name); + real_acl = vfs_get_acl(idmap, path->dentry, acl_name); if (IS_ERR_OR_NULL(real_acl)) return real_acl; @@ -540,7 +540,7 @@ struct posix_acl *ovl_get_acl_path(const struct path *path, if (!clone) return ERR_PTR(-ENOMEM); - ovl_idmap_posix_acl(realinode, mnt_userns, clone); + ovl_idmap_posix_acl(realinode, idmap, clone); return clone; } @@ -555,7 +555,7 @@ struct posix_acl *ovl_get_acl_path(const struct path *path, * * This is obviously only relevant when idmapped layers are used. */ -struct posix_acl *do_ovl_get_acl(struct user_namespace *mnt_userns, +struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, struct inode *inode, int type, bool rcu, bool noperm) { @@ -618,7 +618,7 @@ static int ovl_set_or_remove_acl(struct dentry *dentry, struct inode *inode, ovl_path_lower(dentry, &realpath); old_cred = ovl_override_creds(dentry->d_sb); - real_acl = vfs_get_acl(mnt_user_ns(realpath.mnt), realdentry, + real_acl = vfs_get_acl(mnt_idmap(realpath.mnt), realdentry, acl_name); revert_creds(old_cred); if (IS_ERR(real_acl)) { @@ -651,7 +651,7 @@ out_drop_write: return err; } -int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, +int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, struct posix_acl *acl, int type) { int err; @@ -665,7 +665,7 @@ int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, return -EOPNOTSUPP; if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) return acl ? -EACCES : 0; - if (!inode_owner_or_capable(&init_user_ns, inode)) + if (!inode_owner_or_capable(&nop_mnt_idmap, inode)) return -EPERM; /* @@ -674,10 +674,10 @@ int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, */ if (unlikely(inode->i_mode & S_ISGID) && type == ACL_TYPE_ACCESS && !in_group_p(inode->i_gid) && - !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID)) { + !capable_wrt_inode_uidgid(&nop_mnt_idmap, inode, CAP_FSETID)) { struct iattr iattr = { .ia_valid = ATTR_KILL_SGID }; - err = ovl_setattr(&init_user_ns, dentry, &iattr); + err = ovl_setattr(&nop_mnt_idmap, dentry, &iattr); if (err) return err; } @@ -755,10 +755,10 @@ int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa) if (err) return err; - return vfs_fileattr_set(mnt_user_ns(realpath->mnt), realpath->dentry, fa); + return vfs_fileattr_set(mnt_idmap(realpath->mnt), realpath->dentry, fa); } -int ovl_fileattr_set(struct user_namespace *mnt_userns, +int ovl_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, struct fileattr *fa) { struct inode *inode = d_inode(dentry); |