In orangefs_inode_getxattr(), an fsuid is written to dmesg. The kuid is
converted to a userspace uid via from_kuid(current_user_ns(), [...]), but
since dmesg is global, init_user_ns should be used here instead.

In copy_attributes_from_inode(), op_alloc() and fill_default_sys_attrs(),
upcall structures are populated with uids/gids that have been mapped into
the caller's namespace. However, those upcall structures are read by
another process (the userspace filesystem driver), and that process might
be running in another namespace. This effectively lets any user spoof its
uid and gid as seen by the userspace filesystem driver.

To fix the second issue, I just construct the opcall structures with
init_user_ns uids/gids and require the filesystem server to run in the
init namespace. Since orangefs is full of global state anyway (as the error
message in DUMP_DEVICE_ERROR explains, there can only be one userspace
orangefs filesystem driver at once), that shouldn't be a problem.

[
Why does orangefs even exist in the kernel if everything does upcalls into
userspace? What does orangefs do that couldn't be done with the FUSE
interface? If there is no good answer to those questions, I'd prefer to see
orangefs kicked out of the kernel. Can that be done for something that
shipped in a release?

According to commit f7ab093f ("Orangefs: kernel client part 1"), they
even already have a FUSE daemon, and the only rational reason (apart from
"but most of our users report preferring to use our kernel module instead")
given for not wanting to use FUSE is one "in-the-works" feature that could
probably be integated into FUSE instead.
]

This patch has been compile-tested.
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

not needed anymore
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

shouldn't be needed now
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

turn op->waitq into struct completion...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

Make cancels reuse the aborted read/write op, to make sure they do not
fail on lack of memory.

Don't issue a cancel unless the daemon has seen our read/write, has not
replied and isn't being shut down.

If cancel *is* issued, don't wait for it to complete; stash the slot
in there and just have it freed when cancel is finally replied to or
purged (and delay dropping the reference until then, obviously).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

A couple of caches were no longer needed:

 - iov_iter improvements to orangefs_devreq_write_iter eliminated
   the need for the dev_req_cache.

 - removal (months ago) of the old AIO code eliminated the need
   for the kiocb_cache.

Also, deobfuscation of use of GFP_KERNEL when calling kmem_cache_(z)alloc
for remaining caches.
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

fold orangefs_op_initialize() in there, don't bother locking something
nobody else could've seen yet, use kmem_cache_zalloc() instead of
explicit memset()...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

* create with refcount 1
* make op_release() decrement and free if zero (i.e. old put_op()
  has become that).
* mark when submitter has given up waiting; from that point nobody
  else can move between the lists, change state, etc.
* have daemon read/write_iter grab a reference when picking op
  and *always* give it up in the end
* don't put into hash until we know it's been successfully passed to
  daemon

* move op->lock _lower_ than htab_in_progress_lock (and make sure
  to take it in purge_inprogress_ops())
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

The op structure's ref_count member hasn't got anything to do with
asynchronous I/O.
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

There was previously MAX_ALIGNED_DEV_REQ_(UP|DOWN)SIZE macros which
evaluated to MAX_DEV_REQ_(UP|DOWN)SIZE+8. As it is unclear what this is
for, other than creating a situation where we accept more data than we
can parse, it is removed.
Signed-off-by: NMike Marshall <hubcap@omnibond.com>
Signed-off-by: NMartin Brandenburg <martin@omnibond.com>

Also changed references within source files that referred to
header files whose names had changed.
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

OrangeFS was formerly known as PVFS2 and retains the name in many places.

I leave the device /dev/pvfs2-req since this affects userspace.

I leave the filesystem type pvfs2 since this affects userspace. Further
the OrangeFS sysint library reads fstab for an entry of type pvfs2
independently of kernel mounts.

I leave extended attribute keys user.pvfs2 and system.pvfs2 as the
sysint library understands these.

I leave references to userspace binaries still named pvfs2.

I leave the filenames.
Signed-off-by: NYi Liu <yi9@clemson.edu>
[martin@omnibond.com: clairify above constraints and merge]
Signed-off-by: NMartin Brandenburg <martin@omnibond.com>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

Also removes remnants of iox (readx/writex) which previously used
trailers, but no longer exist.
Signed-off-by: NMartin Brandenburg <martin@omnibond.com>
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

Signed-off-by: NMike Marshall <hubcap@omnibond.com>