linux-toradex.git/include/linux/sunrpc/cache.h, branch v2.6.38.5

Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linux

2011-01-14T21:17:26+00:00

* 'for-2.6.38' of git://linux-nfs.org/~bfields/linux: (62 commits)
  nfsd4: fix callback restarting
  nfsd: break lease on unlink, link, and rename
  nfsd4: break lease on nfsd setattr
  nfsd: don't support msnfs export option
  nfsd4: initialize cb_per_client
  nfsd4: allow restarting callbacks
  nfsd4: simplify nfsd4_cb_prepare
  nfsd4: give out delegations more quickly in 4.1 case
  nfsd4: add helper function to run callbacks
  nfsd4: make sure sequence flags are set after destroy_session
  nfsd4: re-probe callback on connection loss
  nfsd4: set sequence flag when backchannel is down
  nfsd4: keep finer-grained callback status
  rpc: allow xprt_class->setup to return a preexisting xprt
  rpc: keep backchannel xprt as long as server connection
  rpc: move sk_bc_xprt to svc_xprt
  nfsd4: allow backchannel recovery
  nfsd4: support BIND_CONN_TO_SESSION
  nfsd4: modify session list under cl_lock
  Documentation: fl_mylease no longer exists
  ...

Fix up conflicts in fs/nfsd/vfs.c with the vfs-scale work.  The
vfs-scale work touched some msnfs cases, and this merge removes support
for that entirely, so the conflict was trivial to resolve.

headers: kobject.h redux

2011-01-10T16:51:44+00:00

Remove kobject.h from files which don't need it, notably,
sched.h and fs.h.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

SUNRPC: Remove more code when NFSD_DEPRECATED is not configured

2011-01-04T21:48:02+00:00

Signed-off-by: NeilBrown 
[bfields@redhat.com: moved svcauth_unix_purge outside ifdef's.]
Signed-off-by: J. Bruce Fields

sunrpc: Add routines that allow registering per-net caches

2010-09-27T14:16:11+00:00

Existing calls do the same, but for the init_net.

Signed-off-by: Pavel Emelyanov 
Signed-off-by: J. Bruce Fields

sunrpc/cache: change deferred-request hash table to use hlist.

2010-09-22T01:51:11+00:00

Being a hash table, hlist is the best option.

There is currently some ugliness were we treat "->next == NULL" as
a special case to avoid having to initialise the whole array.
This change nicely gets rid of that case.

Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields

sunrpc/cache: allow threads to block while waiting for cache update.

2010-09-07T23:22:07+00:00

The current practice of waiting for cache updates by queueing the
whole request to be retried has (at least) two problems.

1/ With NFSv4, requests can be quite complex and re-trying a whole
  request when a later part fails should only be a last-resort, not a
  normal practice.

2/ Large requests, and in particular any 'write' request, will not be
  queued by the current code and doing so would be undesirable.

In many cases only a very sort wait is needed before the cache gets
valid data.

So, providing the underlying transport permits it by setting
 ->thread_wait,
arrange to wait briefly for an upcall to be completed (as reflected in
the clearing of CACHE_PENDING).
If the short wait was not long enough and CACHE_PENDING is still set,
fall back on the old approach.

The 'thread_wait' value is set to 5 seconds when there are spare
threads, and 1 second when there are no spare threads.

These values are probably much higher than needed, but will ensure
some forward progress.

Note that as we only request an update for a non-valid item, and as
non-valid items are updated in place it is extremely unlikely that
cache_check will return -ETIMEDOUT.  Normally cache_defer_req will
sleep for a short while and then find that the item is_valid.

Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields

sunrpc: use seconds since boot in expiry cache

2010-09-07T23:21:20+00:00

This protects us from confusion when the wallclock time changes.

We convert to and from wallclock when  setting or reading expiry
times.

Also use seconds since boot for last_clost time.

Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields

sunrpc: extract some common sunrpc_cache code from nfsd

2010-09-07T23:21:19+00:00

Rather can duplicating this idiom twice, put it in an inline function.
This reduces the usage of 'expiry_time' out side the sunrpc/cache.c
code and thus the impact of a change that is about to be made to that
field.

Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields

sunrpc: make the cache cleaner workqueue deferrable

2010-07-06T16:27:48+00:00

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 
Signed-off-by: J. Bruce Fields

SUNRPC: Add an rpc_pipefs front end for the sunrpc cache code

2009-08-09T19:14:30+00:00

Signed-off-by: Trond Myklebust