This patch provides basic data structures representing the nfs41
sessions and slots, plus helpers for keeping a reference count
on the session and freeing it.

Note that our server only support a headerpadsz of 0 and
it ignores backchannel attributes at the moment.
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: remove headerpadsz from channel attributes]
[nfsd41: embed nfsd4_channel in nfsd4_session]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: use bool inuse for slot state]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41 remove sl_session from nfsd4_slot]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

As part of reducing the scope of the client_mutex, and in order to
remove the need for mutexes from the callback code (so that callbacks
can be done as asynchronous rpc calls), move manipulations of the
file_hashtable under the recall_lock.

Update the relevant comments while we're here.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Alexandros Batsakis <batsakis@netapp.com>
Reviewed-by: NBenny Halevy <bhalevy@panasas.com>

All users now pass this, so it's meaningless.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Delegreturn is enough a special case for preprocess_stateid_op to
warrant just open-coding it in delegreturn.

There should be no change in behavior here; we're just reshuffling code.

Thanks to Yang Hongyang for catching a critical typo.
Reviewed-by: NYang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This patch adds server-side support for callbacks other than AUTH_SYS.
Signed-off-by: NOlga Kornievskaia <aglo@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Two principals are involved in krb5 authentication: the target, who we
authenticate *to* (normally the name of the server, like
nfs/server.citi.umich.edu@CITI.UMICH.EDU), and the source, we we
authenticate *as* (normally a user, like bfields@UMICH.EDU)

In the case of NFSv4 callbacks, the target of the callback should be the
source of the client's setclientid call, and the source should be the
nfs server's own principal.

Therefore we allow svcgssd to pass down the name of the principal that
just authenticated, so that on setclientid we can store that principal
name with the new client, to be used later on callbacks.
Signed-off-by: NOlga Kornievskaia <aglo@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The cb_stat member of struct nfs4_callback is unused
since commit ff7d9756 nfsd: use static memory for callback program and stats
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The cb_program member of struct nfs4_callback unused
since commit ff7d9756 nfsd: use static memory for callback program and stats
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

One more incremental delegation policy improvement: don't give out a
delegation on a file if conflicting access has previously required that a
delegation be revoked on that file.  (In practice we'll forget about the
conflict when the struct nfs4_file is removed on close, so this is of limited
use for now, though it should at least solve a temporary problem with
self-conflicts on write opens from the same client.)
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

NFS4_FHSIZE is measured in bytes, not 4-byte words, so much more space than
necessary is being allocated for struct nfs4_cb_recall.

I should have wondered why this structure was so much larger than it needed to
be!
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Define an op descriptor struct, use it to simplify nfsd4_proc_compound().
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We shouldn't be allowing, e.g., write locks on files not open for read.  To
enforce this, we add a pointer from the lock stateid back to the open stateid
it came from, so that the check will continue to be correct even after the
open is upgraded or downgraded.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add some comments on the use of so_seqid, in an attempt to avoid some of the
confusion outlined in the previous patch....
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds the code to create and remove client subdirectories from the
recovery directory, as described in the previous patch comment.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

NFSv4 clients are required to know what state they have on the server so that
they can reclaim it on server reboot.  However, it is possible for
pathalogical combinations of server reboots and network partitions to leave a
client in a state where it cannot know whether it has lost its state on the
server.

For this reason, rfc3530 requires that we store some information about clients
to stable storage.

So we maintain a directory /var/lib/nfs/v4recovery with a subdirectory for
each client with active state.  We leave open the possibility of including
files underneath each such subdirectory with information about the client, but
for now the subdirectories are empty.

We create a client subdirectory whenever a client makes its first non-reclaim
open_confirm.

We remove a client subdirectory whenever either
        a) its lease expires, or
	b) the grace period ends without it reclaiming anything.
When handling reclaims, we allow the reclaim if and only if the client doing
the reclaim has a subdirectory.

This patch adds just the code to scan the recovery directory on nfsd startup.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The cb_parsed field is only used by probe_callback, to determine whether the
callback information has been filled in by setclientid.  But there is no way
that probe_callback() can be called without that having already happened, so
that check is superfluous, as is cb_parsed.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Trivial renaming patch:

I can never remember, while looking at various lists relating the nfsd4 state
structures, which are the "heads" and which are items on other lists, or which
structures are actually on the various lists.  The following convention helps
me: given structures foo and bar, with foo containing the head of a list of
bars, use "bars" for the name of the head of the list contained in the struct
foo, and use "per_foo" for the entries in the struct bars.

Already done for struct nfs4_file; go ahead and do it for the other nfsd4
state structures.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch contains the following possible cleanups:

- make needlessly global code static
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

For the purposes of reboot recovery we keep a directory with subdirectories
each having a name that is the ascii hex representation of the md5 sum of a
client identifier for an active client.

This adds the code to calculate that name.  We also use it for the purposes of
comparing clients, so if someone ever manages to find two client names that
are md5 collisions, then we'll return clid_inuse to the second.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a struct kref to each nfs4_file and take a reference to it from each
stateid and delegation that refers to it.  The atomicity guarantees are
overkill given that all this stuff is done under the single nfsd4 state lock,
but a) we'd like finer-grained locking some day, and b) this simplifies the
cleanup of the structures a bit, something that has previously been a bit
complicated and bug-prone.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Trivial renaming patch:

I can never remember, while looking at various lists relating the nfsd4 state
structures, which are the "heads" and which are items on other lists, or which
structures are actually on the various lists.  The following convention helps
me: given structures foo and bar, with foo containing the head of a list of
bars, use "bars" for the name of the head of the list contained in the struct
foo, and use "per_foo" for the entries in the struct bars.

Go ahead and do this for struct nfs4_file.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!