The NFSv4 delegation recovery code is required by the protocol to handle
more errors. Rather than add NFSv4.0 specific errors into 'generic'
delegation code, we should move the error handling into the NFSv4 layer.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

If the client is not using a delegation, the right thing to do is to return
it as soon as possible. This helps reduce the amount of state the server
has to track, as well as reducing the potential for conflicts with other
clients.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Reuse the state management thread in order to return delegations when we
get a callback.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Let the actual delegreturn stuff be run in the state manager thread rather
than allocating a separate kthread.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

It is really a more general purpose state management thread at this point.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Add a delegation cleanup phase to the state management loop, and do the
NFS4ERR_CB_PATH_DOWN recovery there.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Add a flag to mark delegations as requiring return, then run a garbage
collector. In the future, this will allow for more flexible delegation
management, where delegations may be marked for return if it turns out
that they are not being referenced.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Now that we're using the flags to indicate state that needs to be
recovered, as well as having implemented proper refcounting and spinlocking
on the state and open_owners, we can get rid of nfs_client->cl_sem. The
only remaining case that was dubious was the file locking, and that case is
now covered by the nfsi->rwsem.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Without an extra lock, we cannot just assume that the delegation->inode is
valid when we're traversing the rcu-protected nfs_client lists. Use the
delegation->lock to ensure that it is truly valid.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When we can update_open_stateid(), we need to be certain that we don't
race with a delegation return. While we could do this by grabbing the
nfs_client->cl_lock, a dedicated spin lock in the delegation structure
will scale better.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4state.c:788:34: warning: Using plain integer as NULL pointer
fs/nfs/delegation.c:52:34: warning: Using plain integer as NULL pointer
fs/nfs/idmap.c:312:12: warning: Using plain integer as NULL pointer
fs/nfs/callback_xdr.c:257:6: warning: Using plain integer as NULL pointer
fs/nfs/callback_xdr.c:270:6: warning: Using plain integer as NULL pointer
fs/nfs/callback_xdr.c:281:6: warning: Using plain integer as NULL pointer
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If a (broken?) server hands out two different delegations for the same
file, then we should return one of them.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Otherwise, there is a potential deadlock if the last dput() from an NFSv4
close() or other asynchronous operation leads to nfs_clear_inode calling
the synchronous delegreturn.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

To ensure the NFS client displays IPv6 addresses properly, replace
address family-specific NIPQUAD() invocations with a call to the RPC
client to get a formatted string representing the remote peer's
address.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

We were intending to put the previous instance of delegation->cred
before setting a new one.

Thanks to David Howells for spotting this.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Doing so would require us to introduce bh-safe locks into put_rpccred().
This patch fixes the lockdep complaint reported by Marc Dietrich:

inconsistent {softirq-on-W} -> {in-softirq-W} usage.
swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
 (rpc_credcache_lock){-+..}, at: [<c01dc487>]
_atomic_dec_and_lock+0x17/0x60
{softirq-on-W} state was registered at:
  [<c013e870>] __lock_acquire+0x650/0x1030
  [<c013f2b1>] lock_acquire+0x61/0x80
  [<c02db9ac>] _spin_lock+0x2c/0x40
  [<c01dc487>] _atomic_dec_and_lock+0x17/0x60
  [<dced55fd>] put_rpccred+0x5d/0x100 [sunrpc]
  [<dced56c1>] rpcauth_unbindcred+0x21/0x60 [sunrpc]
  [<dced3fd4>] a0 [sunrpc]
  [<dcecefe0>] rpc_call_sync+0x30/0x40 [sunrpc]
  [<dcedc73b>] rpcb_register+0xdb/0x180 [sunrpc]
  [<dced65b3>] svc_register+0x93/0x160 [sunrpc]
  [<dced6ebe>] __svc_create+0x1ee/0x220 [sunrpc]
  [<dced7053>] svc_create+0x13/0x20 [sunrpc]
  [<dcf6d722>] nfs_callback_up+0x82/0x120 [nfs]
  [<dcf48f36>] nfs_get_client+0x176/0x390 [nfs]
  [<dcf49181>] nfs4_set_client+0x31/0x190 [nfs]
  [<dcf49983>] nfs4_create_server+0x63/0x3b0 [nfs]
  [<dcf52426>] nfs4_get_sb+0x346/0x5b0 [nfs]
  [<c017b444>] vfs_kern_mount+0x94/0x110
  [<c0190a62>] do_mount+0x1f2/0x7d0
  [<c01910a6>] sys_mount+0x66/0xa0
  [<c0104046>] syscall_call+0x7/0xb
  [<ffffffff>] 0xffffffff
irq event stamp: 5277830
hardirqs last  enabled at (5277830): [<c017530a>] kmem_cache_free+0x8a/0xc0
hardirqs last disabled at (5277829): [<c01752d2>] kmem_cache_free+0x52/0xc0
softirqs last  enabled at (5277798): [<c0124173>] __do_softirq+0xa3/0xc0
softirqs last disabled at (5277817): [<c01241d7>] do_softirq+0x47/0x50

other info that might help us debug this:
no locks held by swapper/0.

stack backtrace:
 [<c0104fda>] show_trace_log_lvl+0x1a/0x30
 [<c0105c02>] show_trace+0x12/0x20
 [<c0105d15>] dump_stack+0x15/0x20
 [<c013ccc3>] print_usage_bug+0x153/0x160
 [<c013d8b9>] mark_lock+0x449/0x620
 [<c013e824>] __lock_acquire+0x604/0x1030
 [<c013f2b1>] lock_acquire+0x61/0x80
 [<c02db9ac>] _spin_lock+0x2c/0x40
 [<c01dc487>] _atomic_dec_and_lock+0x17/0x60
 [<dced55fd>] put_rpccred+0x5d/0x100 [sunrpc]
 [<dcf6bf83>] nfs_free_delegation_callback+0x13/0x20 [nfs]
 [<c012f9ea>] __rcu_process_callbacks+0x6a/0x1c0
 [<c012fb52>] rcu_process_callbacks+0x12/0x30
 [<c0124218>] tasklet_action+0x38/0x80
 [<c0124125>] __do_softirq+0x55/0xc0
 [<c01241d7>] do_softirq+0x47/0x50
 [<c0124605>] irq_exit+0x35/0x40
 [<c0112463>] smp_apic_timer_interrupt+0x43/0x80
 [<c0104a77>] apic_timer_interrupt+0x33/0x38
 [<c02690df>] cpuidle_idle_call+0x6f/0x90
 [<c01023c3>] cpu_idle+0x43/0x70
 [<c02d8c27>] rest_init+0x47/0x50
 [<c03bcb6a>] start_kernel+0x22a/0x2b0
 [<00000000>] 0x0
 =======================
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Currently we force a synchronous call to __nfs_revalidate_inode() in
nfs_inode_set_delegation(). This not only ensures that we cannot call
nfs_inode_set_delegation from an asynchronous context, but it also slows
down any call to open().
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>

There appear to be some rogue servers out there that issue multiple
delegations with different stateids for the same file. Ensure that when we
return delegations, we do so on a per-stateid basis rather than a per-file
basis.
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>

 - fs/nfs/dir.c:610:8: warning: symbol 'nfs_llseek_dir' was not declared.
   Should it be static?
 - fs/nfs/dir.c:636:5: warning: symbol 'nfs_fsync_dir' was not declared.
   Should it be static?
 - fs/nfs/write.c:925:19: warning: symbol 'req' shadows an earlier one
 - fs/nfs/write.c:61:6: warning: symbol 'nfs_commit_rcu_free' was not
   declared. Should it be static?
 - fs/nfs/nfs4proc.c:793:5: warning: symbol 'nfs4_recover_expired_lease'
   was not declared. Should it be static?
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

* Removing useless casts
* Removing useless wrapper
* Conversion from kmalloc+memset to kzalloc
Signed-off-by: NPanagiotis Issaris <takis@issaris.org>
Acked-by: NDave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Generalise the nfs_client structure by:

 (1) Moving nfs_client to a more general place (nfs_fs_sb.h).

 (2) Renaming its maintenance routines to be non-NFS4 specific.

 (3) Move those maintenance routines to a new non-NFS4 specific file (client.c)
     and move the declarations to internal.h.

 (4) Make nfs_find/get_client() take a full sockaddr_in to include the port
     number (will be required for NFS2/3).

 (5) Make nfs_find/get_client() take the NFS protocol version (again will be
     required to differentiate NFS2, 3 & 4 client records).

Also:

 (6) Make nfs_client construction proceed akin to inodes, marking them as under
     construction and providing a function to indicate completion.

 (7) Make nfs_get_client() wait interruptibly if it finds a client that it can
     share, but that client is currently being constructed.

 (8) Make nfs4_create_client() use (6) and (7) instead of locking cl_sem.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Rename nfs_server::nfs4_state to nfs_client as it will be used to represent the
client state for NFS2 and NFS3 also.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Rename struct nfs4_client to struct nfs_client so that it can become the basis
for a general client record for NFS2 and NFS3 in addition to NFS4.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

In the case where we hold a delegation stateid, use that in for inside
SETATTR calls.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 If the loop errors, we need to exit.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Upon return of a write delegation, the server will almost always bump the
 change attribute. Ensure that we pick up that change so that we don't
 invalidate our data cache unnecessarily.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 According to RFC3530 we're supposed to cache the change attribute
 at the time the client receives a write delegation.
 If the inode is clean, a CB_GETATTR callback by the server to the
 client is supposed to return the cached change attribute.
 If, OTOH, the inode is dirty, the client should bump the cached
 change attribute by 1.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

This is the fs/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in fs/.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 Delegations allow us to cache posix and BSD locks, however when the
 delegation is recalled, we need to "flush the cache" and send
 the cached LOCK requests to the server.

 This patch sets up the mechanism for doing so.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>