Signed-off-by: NAndrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: NJ. 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: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Remove duplicated #include('s) in
  net/sunrpc/cache.c
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

Pushdown the bkl to cache_ioctl_pipefs.
Signed-off-by: NFrederic 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>

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: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NFrederic 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: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NArnd 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: NLi 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJ. 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: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. 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: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

currently expired entries remain in the auth caches as long
as there is a reference.
This was needed long ago when the auth_domain cache used the same
cache infrastructure.  But since that (being a very different sort
of cache) was separated, this test is no longer needed.

So remove the test on refcnt and tidy up the surrounding code.

This allows the cache_dequeue call (which needed to be there to
drop a potentially awkward reference) can be moved outside of the
spinlock which is a better place for it.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Not including net/atm/

Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In cache_defer_req, 'dreq' is used for two significantly different
values that happen to be of the same type.

This is both confusing, and makes it hard to extend the range of one of
the values as we will in the next patch.
So introduce 'discard' to take one of the values.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Using list_del_init is generally safer than list_del, and it will
allow us, in a subsequent patch, to see if an entry has already been
processed or not.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The extra call to cache_revisit_request in cache_fresh_unlocked is not
needed, as should have been fairly clear at the time of
   commit 4013edea

If there are requests to be revisited, then we can be sure that
CACHE_PENDING is set, so the second call is sufficient.

So remove the first call.
Then remove the 'new' parameter,
then remove the return value for cache_fresh_locked which is only used
to provide the value for 'new'.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

As "cache_defer_req" does not sound like a predicate, having it return
a boolean value can be confusing.  It is more consistent to return
0 for success and negative for error.

Exactly what error code to return is not important as we don't
differentiate between reasons why the request wasn't deferred,
we only care about whether it was deferred or not.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Otherwise we Oops if the module containing the cache detail is removed
before all cache readers have closed the file.
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>

For events that are rare, such as referral DNS lookups, it makes limited
sense to have a daemon constantly listening for upcalls on a channel. An
alternative in those cases might simply be to run the app that fills the
cache using call_usermodehelper_exec() and friends.

The following patch allows the cache_detail to specify alternative upcall
mechanisms for these particular cases.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

While we do want to protect against multiple concurrent readers and writers
on each upcall/downcall pipe, we don't want to limit concurrent reading and
writing to separate caches.

This patch therefore replaces the static buffer 'write_buf', which can only
be used by one writer at a time, with use of the page cache as the
temporary buffer for downcalls. We still fall back to using the the old
global buffer if the downcall is larger than PAGE_CACHE_SIZE, since this is
apparently needed by the SPKM security context initialisation.

It then replaces the use of the global 'queue_io_mutex' with the
inode->i_mutex in cache_read() and cache_write().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Also ensure that we destroy those files before we destroy the cache_detail.
Otherwise, user processes might attempt to write into uninitialised caches.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

What part of 'internal use' is so hard to understand?
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If cache_defer_req did not leave the request on a queue, then it could
possibly have waited long enough that the cache became valid.  So check the
status after the call.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

While deferred requests normally get revisited quite quickly,
it is possible for a request to remain in the deferral queue
when the cache item is discarded.  We can easily make sure that
doesn't happen by calling cache_revisit_request just before
the final 'put'.

Also there is a small chance that a race would cause one thread to
defer a request against a cache item while another thread is failing
to queue an upcall for that item.  So when the upcall fails, make
sure to revisit all deferred requests.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

'loose' was a mis-spelling of 'lose', and even that wasn't a good
word choice.
So give this function a more useful name.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Align cache_clean work.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Simply replace proc_create and further data assigned with proc_create_data.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This field is set once and never used; probably some artifact of an
earlier implementation idea.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Use proc_create() to make sure that ->proc_fops be setup before gluing
PDE to main tree.
Signed-off-by: NWang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do it for the server code...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Newer server features such as nfsv4 and gss depend on proc to work, so a
failure to initialize the proc files they need should be treated as
fatal.

Thanks to Andrew Morton for style fix and compile fix in case where
CONFIG_NFSD_V4 is undefined.

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Just some minor cleanup.

Also I don't see much point in trying to register further proc entries
if initial entries fail; so just stop trying in that case.
Acked-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

There's really nothing much the caller can do if cache unregistration
fails.  And indeed, all any caller does in this case is print an error
and continue.  So just return void and move the printk's inside
cache_unregister.
Acked-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The path here must be left over from some earlier draft; fix it.  And do
some more minor cleanup while we're there.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Make sure we compare an unsigned length to an unsigned count in
read_flush().
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Add __acquires() and __releases() annotations to suppress some sparse
warnings.

example of warnings :

net/ipv4/udp.c:1555:14: warning: context imbalance in 'udp_seq_start' - wrong
count at exit
net/ipv4/udp.c:1571:13: warning: context imbalance in 'udp_seq_stop' -
unexpected unlock
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Just switch to the consolidated code.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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