The NFS4CLNT_LAYOUTRECALL bit is a long-term impediment to scalability. It
basically stops all other recalls by a given server once any layout recall
is requested.

If the recall is for a different file, then we don't care.
If the recall applies to the same file, then we're in one of two situations:
Either we are in the case of a replay of an existing request, in which case
the session is supposed to deal with matters, or we are dealing with a
completely different request, in which case we should just try to process
it.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Store a pointer to the rpc_task in struct nfs_seqid so that we can wake up
only that request that is able to grab the lock after we've released it.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We have to ensure that the wake up from the waitqueue and the assignment
of xprt->snd_task are atomic. We can do this by assigning the snd_task
while under the waitqueue spinlock.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Again, We're unlikely to ever need more than 2^31 simultaneous lock
owners, so let's replace the custom allocator.

Now that there are no more users, we can also get rid of the custom
allocator code.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We're unlikely to ever need more than 2^31 simultaneous open owners,
so let's replace the custom allocator with the generic ida allocator.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Servers have a finite amount of memory to store NFSv4 open and lock
owners.  Moreover, servers may have a difficult time determining when
they can reap their state owner table, thanks to gray areas in the
NFSv4 protocol specification.  Thus clients should be careful to reuse
state owners when possible.

Currently Linux is not too careful.  When a user has closed all her
files on one mount point, the state owner's reference count goes to
zero, and it is released.  The next OPEN allocates a new one.  A
workload that serially opens and closes files can run through a large
number of open owners this way.

When a state owner's reference count goes to zero, slap it onto a free
list for that nfs_server, with an expiry time.  Garbage collect before
looking for a state owner.  This makes state owners for active users
available for re-use.

Now that there can be unused state owners remaining at umount time,
purge the state owner free list when a server is destroyed.  Also be
sure not to reclaim unused state owners during state recovery.

This change has benefits for the client as well.  For some workloads,
this approach drops the number of OPEN_CONFIRM calls from the same as
the number of OPEN calls, down to just one.  This reduces wire traffic
and thus open(2) latency.  Before this patch, untarring a kernel
source tarball shows the OPEN_CONFIRM call counter steadily increasing
through the test.  With the patch, the OPEN_CONFIRM count remains at 1
throughout the entire untar.

As long as the expiry time is kept short, I don't think garbage
collection should be terribly expensive, although it does bounce the
clp->cl_lock around a bit.

[ At some point we should rationalize the use of the nfs_server
->destroy method. ]
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
[Trond: Fixed a garbage collection race and a few efficiency issues]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

The NFSv4 spec does not specify that the server must repeat that error,
so in order to avoid having the delegations revoked, we should handle
it immediately.

Also note that NFS4ERR_CB_PATH_DOWN does in fact renew the lease...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

RFC3530 states that if the client holds a delegation, then it is obliged
to continue to send RENEW calls once every lease period in order to allow
the server to return NFS4ERR_CB_PATH_DOWN if the callback path is
unreachable.

This is not required for NFSv4.1, since the server can at any time set
the SEQ4_STATUS_CB_PATH_DOWN_SESSION in any SEQUENCE operation.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Block layout needs it to determine IO size.
Signed-off-by: NFred Isaman <iisaman@citi.umich.edu>
Signed-off-by: NTao Guo <glorioustao@gmail.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NBenny Halevy <bhalevy@tonian.com>
Signed-off-by: NJim Rees <rees@umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

instead of path_get()/path_put(), we can just use nfs_sb_{,de}active()
to pin the superblock down.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If the client is using NFS v4.1, then we can use SECINFO_NO_NAME to find
the secflavor for the initial mount.  If the server doesn't support
SECINFO_NO_NAME then I fall back on the "guess and check" method used
for v4.0 mounts.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

can be skipped if the "eir_server_scope" from the exchange_id proc differs from
previous calls.

Also, in the future server_scope will be useful for determining whether client
trunking is available
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If a server for some reason keeps sending NFS4ERR_DELAY errors, we can end
up looping forever inside nfs4_proc_create_session, and so the usual
mechanisms for detecting if the nfs_client is dead don't work.

Fix this by ensuring that we loop inside the nfs4_state_manager thread
instead.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

A later patch will need to perform a lookup using an
alternate client with a different security flavor.
This patch adds support for doing that on NFS v4.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The filelayout driver sends LAYOUTCOMMIT only when COMMIT goes to
the data server (as opposed to the MDS) and the data server WRITE
is not NFS_FILE_SYNC.

Only whole file layout support means that there is only one IOMODE_RW layout
segment.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NAlexandros Batsakis <batsakis@netapp.com>
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NDean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: NFred Isaman <iisaman@citi.umich.edu>
Signed-off-by: NMingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: NTao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: NZhang Jingwang <zhangjingwang@nrchpc.ac.cn>
Tested-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NFred Isaman <iisaman@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Attempt a pNFS file layout read by setting up the nfs_read_data struct and
calling nfs_initiate_read with the data server rpc client and the
filelayout rpc call ops.

Error handling is implemented in a subsequent patch.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NDean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: NFred Isaman <iisaman@citi.umich.edu>
Signed-off-by: NFred Isaman <iisaman@netapp.com>
Signed-off-by: NMingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: NOleg Drokin <green@linuxhacker.ru>
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Tested-by: NGuo Mingyang <guomingyang@nrchpc.ac.cn>
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Introduce a data server set_client and init session following the
nfs4_set_client and  nfs4_init_session convention.

Once a new nfs_client is on the nfs_client_list, the nfs_client cl_cons_state
serializes access to creating an nfs_client struct with matching properties.

Use the new nfs_get_client() that initializes new clients.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The DS only role cannot be used to mount.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

There are no more external users of nfs4_state_mark_reclaim_nograce() or
nfs4_state_mark_reclaim_reboot(), so mark them as static.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

nfs4_schedule_state_recovery() should only be used when we need to force
the state manager to check the lease. If we just want to start the
state manager in order to handle a state recovery situation, we should be
using nfs4_schedule_state_manager().

This patch fixes the abuses of nfs4_schedule_state_recovery() by replacing
its use with a set of helper functions that do the right thing.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFSv4 migration needs to reassociate state owners from the source to
the destination nfs_server data structures.  To make that easier, move
the cl_state_owners field to the nfs_server struct.  cl_openowner_id
and cl_lockowner_id accompany this move, as they are used in
conjunction with cl_state_owners.

The cl_lock field in the parent nfs_client continues to protect all
three of these fields.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

A layout can request return-on-close.  How this interacts with the
forgetful model of never sending LAYOUTRETURNS is a bit ambiguous.
We forget any layouts marked roc, and wait for them to be completely
forgotten before continuing with the close.  In addition, to compensate
for races with any inflight LAYOUTGETs, and the fact that we do not get
any layout stateid back from the server, we set the barrier to the worst
case scenario of current_seqid + number of outstanding LAYOUTGETS.
Signed-off-by: NFred Isaman <iisaman@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This is the heart of the wave 2 submission.  Add the code to trigger
drain and forget of any afected layouts.  In addition, we set a
"barrier", below which any LAYOUTGET reply is ignored.  This is to
compensate for the fact that we do not wait for outstanding LAYOUTGETs
to complete as per section 12.5.5.2.1 of RFC 5661.
Signed-off-by: NFred Isaman <iisaman@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch make nfsv4 use the generic xattr handling code
to get the nfsv4 acl. This will help us to add richacl
support to nfsv4 in later patches
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.

The pointer returned by ->decode_dirent() is no longer used as a
pointer.  The only call site (xdr_decode() in fs/nfs/dir.c) simply
extracts the errno value encoded in the pointer.  Replace the
returned pointer with a standard integer errno return value.

Also, pass the "server" argument as part of the nfs_entry instead of
as a separate parameter.  It's faster to derive "server" in
nfs_readdir_xdr_to_array() since we already have the directory's inode
handy.  "server" ought to be invariant for a set of entries in the
same directory, right?

The legacy versions of decode_dirent() don't use "server" anyway, so
it's wasted work for them to derive and pass "server" for each entry.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

By requsting more attributes during a readdir, we can mimic the readdir plus
operation that was in NFSv3.

To test, I ran the command `ls -lU --color=none` on directories with various
numbers of files.  Without readdir plus, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.153s | 0m00.589s | 0m05.601s | 0m56.691s | 9m59.128s
user    | 0m00.007s | 0m00.007s | 0m00.077s | 0m00.703s | 0m06.800s
sys     | 0m00.010s | 0m00.070s | 0m00.633s | 0m06.423s | 1m10.005s
access  | 3         | 1         | 1         | 4         | 31
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 104       | 1,003     | 10,003    | 100,003   | 1,000,003
readdir | 2         | 16        | 158       | 1,575     | 15,749
total   | 111       | 1,021     | 10,163    | 101,583   | 1,015,784

With readdir plus enabled, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.115s | 0m00.206s | 0m01.079s | 0m12.521s | 2m07.528s
user    | 0m00.003s | 0m00.003s | 0m00.040s | 0m00.290s | 0m03.296s
sys     | 0m00.007s | 0m00.020s | 0m00.120s | 0m01.357s | 0m17.556s
access  | 3         | 1         | 1         | 1         | 7
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 4         | 3         | 3         | 3         | 3
readdir | 6         | 62        | 630       | 6,300     | 62,993
total   | 15        | 67        | 635       | 6,305     | 63,004

Readdir plus disabled has about a 16x increase in the number of rpc calls and
is 4 - 5 times slower on large directories.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Convert nfs*xdr.c to use an xdr stream in decode_dirent.  This will prevent a
kernel oops that has been occuring when reading a vmapped page.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove references to 'struct nameidata' from the low-level open_revalidate
code, and replace them with a struct nfs_open_context which will be
correctly initialised upon success.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Start moving the 'struct nameidata' dependent code out of the lower level
NFS code in preparation for the removal of open intents.

Instead of the struct nameidata, we pass down a partially initialised
struct nfs_open_context that will be fully initialised by the atomic open
upon success.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

flock locks want to be labelled using the process pid, while posix locks
want to be labelled using the fl_owner.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>