Add a new client tracker upcall type that uses call_usermodehelper to
call out to a program. This seems to be the preferred method of
calling out to usermode these days for seldom-called upcalls. It's
simple and doesn't require a running daemon, so it should "just work"
as long as the binary is installed.

The client tracking exit operation is also changed to check for a
NULL pointer before running. The UMH upcall doesn't need to do anything
at module teardown time.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If the credential save fails, then we'll leak our mnt_want_write_file
reference.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

For now this only adds support for AUTH_NULL.  (Previously we assumed
AUTH_UNIX.)  We'll also need AUTH_GSS, which is trickier.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

I've found it confusing having the only references to
nfsd4_do_callback_rpc() in a different file.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This operation is mandatory for servers to implement.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We're currently ignoring the callback security parameters specified in
create_session, and just assuming the client wants auth_sys, because
that's all the current linux client happens to care about.  But this
could cause us callbacks to fail to a client that wanted something
different.

For now, all we're doing is no longer ignoring the uid and gid passed in
the auth_sys case.  Further patches will add support for auth_null and
gss (and possibly use more of the auth_sys information; the spec wants
us to use exactly the credential we're passed, though it's hard to
imagine why a client would care).
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Move the callback parsing into a separate function.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

NFSv4 shares the same struct file across multiple writes.  (And we'd
like NFSv2 and NFSv3 to do that as well some day.)

So setting O_SYNC on the struct file as a way to request a synchronous
write doesn't work.

Instead, do a vfs_fsync_range() in that case.
Reported-by: NPeter Staubach <pstaubach@exagrid.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

I don't really see how you could claim to support nfsd and not support
fsync somehow.

And in practice a quick look through the exportable filesystems suggests
the only ones without an ->fsync are read-only (efs, isofs, squashfs) or
in-memory (shmem).

Also, performing a write and then returning an error if the sync fails
(as we would do here in the wgather case) seems unhelpful to clients.

Also remove an incorrect comment.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

These conditions would indeed indicate bugs in the code, but if we want
to hear about them we're likely better off warning and returning than
immediately dying while holding file_lock_lock.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The object type in the cache of lockowner_slab is wrong, and it is
better to fix it.

Cc: stable@vger.kernel.org
Signed-off-by: NYanchuan Nian <ycnian@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The variable inode is initialized but never used
otherwise, so remove the unused variable.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This commit adds FILEID_INVALID = 0xff in fid_type to
indicate invalid fid_type

It avoids using magic number 255
Signed-off-by: NNamjae Jeon <linkinjeon@gmail.com>
Signed-off-by: NVivek Trivedi <vtrivedi018@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

When a confirmed client expires, we normally also need to expire any
stable storage record which would allow that client to reclaim state on
the next boot.  We forgot to do this in some cases.  (For example, in
destroy_clientid, and in the cases in exchange_id and create_session
that destroy and existing confirmed client.)

But in most other cases, there's really no harm to calling
nfsd4_client_record_remove(), because it is a no-op in the case the
client doesn't have an existing

The single exception is destroying a client on shutdown, when we want to
keep the stable storage records so we can recognize which clients will
be allowed to reclaim when we come back up.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Both nfsd4_init_conn and alloc_init_session are probing the callback
channel, harmless but pointless.

Also, nfsd4_init_conn should probably be probing in the "unknown" case
as well.  In fact I don't see any harm to just doing it unconditionally
when we get a new backchannel connection.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Before we had to delay expiring a client till we'd found out whether the
session and connection allocations would succeed.  That's no longer
necessary.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This will allow some further simplification.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Do the initialization in the caller, and clarify that the only failure
ever possible here was due to allocation.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

It'll be useful to have connection allocation and initialization as
separate functions.

Also, note we'd been ignoring the alloc_conn error return in
bind_conn_to_session.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This could simplify the logic a little later.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Something like creating a client with setclientid and then trying to
confirm it with create_session may not crash the server, but I'm not
completely positive of that, and in any case it's obviously bad client
behavior.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

And remove some mostly obsolete comments.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

I added cr_flavor to the data compared in same_creds without any
justification, in d5497fc6 "nfsd4: move
rq_flavor into svc_cred".

Recent client changes then started making

	mount -osec=krb5 server:/export /mnt/
	echo "hello" >/mnt/TMP
	umount /mnt/
	mount -osec=krb5i server:/export /mnt/
	echo "hello" >/mnt/TMP

to fail due to a clid_inuse on the second open.

Mounting sequentially like this with different flavors probably isn't
that common outside artificial tests.  Also, the real bug here may be
that the server isn't just destroying the former clientid in this case
(because it isn't good enough at recognizing when the old state is
gone).  But it prompted some discussion and a look back at the spec, and
I think the check was probably wrong.  Fix and document.

Cc: stable@kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

simplifies a bunch of callers...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

 - Pass the user namespace the uid and gid values in the xattr are stored
   in into posix_acl_from_xattr.

 - Pass the user namespace kuid and kgid values should be converted into
   when storing uid and gid values in an xattr in posix_acl_to_xattr.

- Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to
  pass in &init_user_ns.

In the short term this change is not strictly needed but it makes the
code clearer.  In the longer term this change is necessary to be able to
mount filesystems outside of the initial user namespace that natively
store posix acls in the linux xattr format.

Cc: Theodore Tso <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

As we already do in readv, writev.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The 'buf' is prepared with null termination with intention of using it for
this purpose, but 'name' is passed instead!
Signed-off-by: NMalahal Naineni <malahal@us.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

remove duplicate init in nfsd4_cb_recall
Signed-off-by: NNamjae Jeon <linkinjeon@gmail.com>
Signed-off-by: NVivek Trivedi <vtrivedi018@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Somehow we ended up with identical functions "nfs4_free_stateid" and
"free_generic_stateid".
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Change the call to PTR_ERR to access the value just tested by IS_ERR.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression e,e1;
@@

(
if (IS_ERR(e)) { ... PTR_ERR(e) ... }
|
if (IS_ERR(e=e1)) { ... PTR_ERR(e) ... }
|
*if (IS_ERR(e))
 { ...
*  PTR_ERR(e1)
   ... }
)
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

You can use nfsd/portlist to give nfsd additional sockets to listen on.
In theory you can also remove listening sockets this way.  But nobody's
ever done that as far as I can tell.

Also this was partially broken in 2.6.25, by
a217813f "knfsd: Support adding
transports by writing portlist file".

(Note that we decide whether to take the "delfd" case by checking for a
digit--but what's actually expected in that case is something made by
svc_one_sock_name(), which won't begin with a digit.)

So, let's just rip out this stuff.
Acked-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Processes that open and close multiple files may end up setting this
oo_last_closed_stid without freeing what was previously pointed to.
This can result in a major leak, visible for example by watching the
nfsd4_stateids line of /proc/slabinfo.
Reported-by: NCyril B. <cbay@excellency.fr>
Tested-by: NCyril B. <cbay@excellency.fr>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

svc_recv() returns only -EINTR or -EAGAIN.  If we really want to worry
about the case where it has a bug that causes it to return something
else, we could stick a WARN() in svc_recv.  But it's silly to require
every caller to have all this boilerplate to handle that case.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Note a 16-bit value can require up to 5 digits.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>