Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This patch makes the cache_cleaner workqueue deferrable, to prevent
unnecessary system wake-ups, which is very important for embedded
battery-powered devices.

do_cache_clean() is called every 30 seconds at the moment, and often
makes the system wake up from its power-save sleep state. With this
change, when the workqueue uses a deferrable timer, the
do_cache_clean() invocation will be delayed and combined with the
closest "real" wake-up. This improves the power consumption situation.

Note, I tried to create a DECLARE_DELAYED_WORK_DEFERRABLE() helper
macro, similar to DECLARE_DELAYED_WORK(), but failed because of the
way the timer wheel core stores the deferrable flag (it is the
LSBit in the time->base pointer). My attempt to define a static
variable with this bit set ended up with the "initializer element is
not constant" error.

Thus, I have to use run-time initialization, so I created a new
cache_initialize() function which is called once when sunrpc is
being initialized.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

* 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
  uml: Pushdown the bkl from harddog_kern ioctl
  sunrpc: Pushdown the bkl from sunrpc cache ioctl
  sunrpc: Pushdown the bkl from ioctl
  autofs4: Pushdown the bkl from ioctl
  uml: Convert to unlocked_ioctls to remove implicit BKL
  ncpfs: BKL ioctl pushdown
  coda: Clean-up whitespace problems in pioctl.c
  coda: BKL ioctl pushdown
  drivers: Push down BKL into various drivers
  isdn: Push down BKL into ioctl functions
  scsi: Push down BKL into ioctl functions
  dvb: Push down BKL into ioctl functions
  smbfs: Push down BKL into ioctl function
  coda/psdev: Remove BKL from ioctl function
  um/mmapper: Remove BKL usage
  sn_hwperf: Kill BKL usage
  hfsplus: Push down BKL into ioctl function

Pushdown the bkl to cache_ioctl_pipefs.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Nfs <linux-nfs@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>

* 'for-2.6.35' of git://linux-nfs.org/~bfields/linux: (45 commits)
  Revert "nfsd4: distinguish expired from stale stateids"
  nfsd: safer initialization order in find_file()
  nfs4: minor callback code simplification, comment
  NFSD: don't report compiled-out versions as present
  nfsd4: implement reclaim_complete
  nfsd4: nfsd4_destroy_session must set callback client under the state lock
  nfsd4: keep a reference count on client while in use
  nfsd4: mark_client_expired
  nfsd4: introduce nfs4_client.cl_refcount
  nfsd4: refactor expire_client
  nfsd4: extend the client_lock to cover cl_lru
  nfsd4: use list_move in move_to_confirmed
  nfsd4: fold release_session into expire_client
  nfsd4: rename sessionid_lock to client_lock
  nfsd4: fix bare destroy_session null dereference
  nfsd4: use local variable in nfs4svc_encode_compoundres
  nfsd: further comment typos
  sunrpc: centralise most calls to svc_xprt_received
  nfsd4: fix unlikely race in session replay case
  nfsd4: fix filehandle comment
  ...

Now that cache_ioctl_procfs() calls the bkl explicitly, we need to
include the relevant header as well.

This fixes the following build error:

	net/sunrpc/cache.c: In function 'cache_ioctl_procfs':
	net/sunrpc/cache.c:1355: error: implicit declaration of function 'lock_kernel'
	net/sunrpc/cache.c:1359: error: implicit declaration of function 'unlock_kernel'

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

Push down the bkl from procfs's ioctl main handler to its users.
Only three procfs users implement an ioctl (non unlocked) handler.
Turn them into unlocked_ioctl and push down the Devil inside.

v2: PDE(inode)->data doesn't need to be under bkl
v3: And don't forget to git-add the result
v4: Use wrappers to pushdown instead of an invasive and error prone
    handlers surgery.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>

Don't forget to release the module refcnt if seq_open() returns failure.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

If sunrpc_cache_lookup finds an expired entry, remove it from
the cache and return a freshly created non-VALID entry instead.
This ensures that we only ever get a usable entry, or an
entry that will become usable once an update arrives.
i.e. we will never need to repeat the lookup.

This allows us to remove the 'is_expired' test from cache_check
(i.e. from cache_is_valid).  cache_check should never get an expired
entry as 'lookup' will never return one.  If it does happen - due to
inconvenient timing - then just accept it as still valid, it won't be
very much past it's use-by date.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

This removes a tiny bit of code duplication, but more important
prepares for following patch which will perform the expiry check in
cache_lookup and the rest of the validity check in cache_check.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>