Pull fs idmapping updates from Christian Brauner:
"This introduces the new vfs{g,u}id_t types we agreed on. Similar to
k{g,u}id_t the new types are just simple wrapper structs around
regular {g,u}id_t types.
They allow to establish a type safety boundary in the VFS for idmapped
mounts preventing confusion betwen {g,u}ids mapped into an idmapped
mount and {g,u}ids mapped into the caller's or the filesystem's
idmapping.
An initial set of helpers is introduced that allows to operate on
vfs{g,u}id_t types. We will remove all references to non-type safe
idmapped mounts helpers in the very near future. The patches do
already exist.
This converts the core attribute changing codepaths which become
significantly easier to reason about because of this change.
Just a few highlights here as the patches give detailed overviews of
what is happening in the commit messages:
- The kernel internal struct iattr contains type safe vfs{g,u}id_t
values clearly communicating that these values have to take a given
mount's idmapping into account.
- The ownership values placed in struct iattr to change ownership are
identical for idmapped and non-idmapped mounts going forward. This
also allows to simplify stacking filesystems such as overlayfs that
change attributes In other words, they always represent the values.
- Instead of open coding checks for whether ownership changes have
been requested and an actual update of the inode is required we now
have small static inline wrappers that abstract this logic away
removing a lot of code duplication from individual filesystems that
all open-coded the same checks"
* tag 'fs.idmapped.vfsuid.v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
mnt_idmapping: align kernel doc and parameter order
mnt_idmapping: use new helpers in mapped_fs{g,u}id()
fs: port HAS_UNMAPPED_ID() to vfs{g,u}id_t
mnt_idmapping: return false when comparing two invalid ids
attr: fix kernel doc
attr: port attribute changes to new types
security: pass down mount idmapping to setattr hook
quota: port quota helpers mount ids
fs: port to iattr ownership update helpers
fs: introduce tiny iattr ownership update helpers
fs: use mount types in iattr
fs: add two type safe mapping helpers
mnt_idmapping: add vfs{g,u}id_t