This patch provides basic data structures representing the nfs41
sessions and slots, plus helpers for keeping a reference count
on the session and freeing it.

Note that our server only support a headerpadsz of 0 and
it ignores backchannel attributes at the moment.
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: remove headerpadsz from channel attributes]
[nfsd41: embed nfsd4_channel in nfsd4_session]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: use bool inuse for slot state]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41 remove sl_session from nfsd4_slot]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Define all error code present in
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-29.
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: clean up error code definitions]
[nfsd41: change NFSERR_REPLAY_ME]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Define all NFSv4.1 common operation and error code constants.

Note that some of the definitions are used by both the nfs41 client
and the server code. This patch is duplicated in the nfs41 and nfsd41
sessions patchset.

Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: add exchange id flags]
Signed-off-by: NMike Sager <sager@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[removed server-only hunk changing NFSERR_REPLAY_ME]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: add SEQ4_XX to nfs41-common-protocol]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: generic error code update]
[nfs41: reverse EXCHGID4_INVAL_FLAG_MASK_{A,R}]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

On an NFSv4.1 server cache miss that causes an upcall, NFS4ERR_DELAY will be
returned. It is up to the NFSv4.1 client to resend only the operations that
have not been processed.

Initialize rq_usedeferral to 1 in svc_process(). It sill be turned off in
nfsd4_proc_compound() only when NFSv4.1 Sessions are used.

Note: this isn't an adequate solution on its own. It's acceptable as a way
to get some minimal 4.1 up and working, but we're going to have to find a
way to avoid returning DELAY in all common cases before 4.1 can really be
considered ready.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfsd41: reverse rq_nodeferral negative logic]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[sunrpc: initialize rq_usedeferral]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Remove the allocation of struct nfsd4_compound_state.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Fix a build warning about leaking CONFIG_NFSD to userspace.

The nfsd_stats data structure does not need to be available to
userspace; no kernel interface uses it.  So move it inside #ifdef
__KERNEL__ and the warning goes away.
Signed-off-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Clean up:  Enable the use of const arguments in higher level svc_ APIs
by adding const to the arguments of the helper functions in svc_xprt.h
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Add /proc/fs/nfsd/pool_stats to export to userspace various
statistics about the operation of rpc server thread pools.

This patch is based on a forward-ported version of
knfsd-add-pool-thread-stats which has been shipping in the SGI
"Enhanced NFS" product since 2006 and which was previously
posted:

http://article.gmane.org/gmane.linux.nfs/10375

It has also been updated thus:

 * moved EXPORT_SYMBOL() to near the function it exports
 * made the new struct struct seq_operations const
 * used SEQ_START_TOKEN instead of ((void *)1)
 * merged fix from SGI PV 990526 "sunrpc: use dprintk instead of
   printk in svc_pool_stats_*()" by Harshula Jayasuriya.
 * merged fix from SGI PV 964001 "Crash reading pool_stats before
   nfsds are started".
Signed-off-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NHarshula Jayasuriya <harshula@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Avoid overloading the CPU scheduler with enormous load averages
when handling high call-rate NFS loads.  When the knfsd bottom half
is made aware of an incoming call by the socket layer, it tries to
choose an nfsd thread and wake it up.  As long as there are idle
threads, one will be woken up.

If there are lot of nfsd threads (a sensible configuration when
the server is disk-bound or is running an HSM), there will be many
more nfsd threads than CPUs to run them.  Under a high call-rate
low service-time workload, the result is that almost every nfsd is
runnable, but only a handful are actually able to run.  This situation
causes two significant problems:

1. The CPU scheduler takes over 10% of each CPU, which is robbing
   the nfsd threads of valuable CPU time.

2. At a high enough load, the nfsd threads starve userspace threads
   of CPU time, to the point where daemons like portmap and rpc.mountd
   do not schedule for tens of seconds at a time.  Clients attempting
   to mount an NFS filesystem timeout at the very first step (opening
   a TCP connection to portmap) because portmap cannot wake up from
   select() and call accept() in time.

Disclaimer: these effects were observed on a SLES9 kernel, modern
kernels' schedulers may behave more gracefully.

The solution is simple: keep in each svc_pool a counter of the number
of threads which have been woken but have not yet run, and do not wake
any more if that count reaches an arbitrary small threshold.

Testing was on a 4 CPU 4 NIC Altix using 4 IRIX clients, each with 16
synthetic client threads simulating an rsync (i.e. recursive directory
listing) workload reading from an i386 RH9 install image (161480
regular files in 10841 directories) on the server.  That tree is small
enough to fill in the server's RAM so no disk traffic was involved.
This setup gives a sustained call rate in excess of 60000 calls/sec
before being CPU-bound on the server.  The server was running 128 nfsds.

Profiling showed schedule() taking 6.7% of every CPU, and __wake_up()
taking 5.2%.  This patch drops those contributions to 3.0% and 2.2%.
Load average was over 120 before the patch, and 20.9 after.

This patch is a forward-ported version of knfsd-avoid-nfsd-overload
which has been shipping in the SGI "Enhanced NFS" product since 2006.
It has been posted before:

http://article.gmane.org/gmane.linux.nfs/10374Signed-off-by: NGreg Banks <gnb@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

If a filesystem being written to via NFS returns a short write count
(as opposed to an error) to nfsd, nfsd treats that as a success for
the entire write, rather than the short count that actually succeeded.

For example, given a 8192 byte write, if the underlying filesystem
only writes 4096 bytes, nfsd will ack back to the nfs client that all
8192 bytes were written.  The nfs client does have retry logic for
short writes, but this is never called as the client is told the
complete write succeeded.

There are probably other ways it could happen, but in my case it
happened with a fuse (filesystem in userspace) filesystem which can
rather easily have a partial write.

Here is a patch to properly return the short write count to the
client.
Signed-off-by: NDavid Shaw <dshaw@jabberwocky.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

As part of reducing the scope of the client_mutex, and in order to
remove the need for mutexes from the callback code (so that callbacks
can be done as asynchronous rpc calls), move manipulations of the
file_hashtable under the recall_lock.

Update the relevant comments while we're here.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Alexandros Batsakis <batsakis@netapp.com>
Reviewed-by: NBenny Halevy <bhalevy@panasas.com>

All users now pass this, so it's meaningless.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Delegreturn is enough a special case for preprocess_stateid_op to
warrant just open-coding it in delegreturn.

There should be no change in behavior here; we're just reshuffling code.

Thanks to Yang Hongyang for catching a critical typo.
Reviewed-by: NYang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The base versions handle constant folding now, none of these headers
are exported to userspace, so the __ prefixed versions are not
necessary.
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Reviewed-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Since creating a device node is normally an operation requiring special
privilege, Igor Zhbanov points out that it is surprising (to say the
least) that a client can, for example, create a device node on a
filesystem exported with root_squash.

So, make sure CAP_MKNOD is among the capabilities dropped when an nfsd
thread handles a request from a non-root user.
Reported-by: NIgor Zhbanov <izh1979@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Stricter gfp_mask might be required for clone allocation.
For example, request-based dm may clone bio in interrupt context
so it has to use GFP_ATOMIC.
Signed-off-by: NKiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: NJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

dma_map_sg could return a value different to 'nents' argument of
dma_map_sg so the ide stack needs to save it for the later usage
(e.g. for_each_sg).

The ide stack also needs to save the original sg_nents value for
pci_unmap_sg.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
[bart: backport to Linus' tree]
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

This is a fix for the following crash observed in 2.6.29-rc3:
http://lkml.org/lkml/2009/1/29/150

On ARM it doesn't make sense to trace a naked function because then
mcount is called without stack and frame pointer being set up and there
is no chance to restore the lr register to the value before mcount was
called.
Reported-by: NMatthias Kaehlcke <matthias@kaehlcke.net>
Tested-by: NMatthias Kaehlcke <matthias@kaehlcke.net>

Cc: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: Steven Rostedt <rostedt@home.goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This allows us to change the representation (to a dangling bitmap or
cpumask_var_t) without breaking all the callers: they can use
mm_cpumask() now and won't see a difference as the changes roll into
linux-next.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This allows us to change the representation (to a dangling bitmap or
cpumask_var_t) without breaking all the callers: they can use
tsk_cpumask() now and won't see a difference as the changes roll into
linux-next.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Comparing the layouts of struct detail_pixel_timing with
x.org's struct detailed_timings and how those are handled,
it appears that the hsync_positive and vsync_positive
fields are backwards.

This patch fixes https://bugs.freedesktop.org/show_bug.cgi?id=20019
for me. It was tested on 2 monitors, LG FLATRON L225WS 22" and
a YAKUMO 17" for which more details are unknown.
Signed-off-by: NPantelis Koukousoulas <pktoss@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Clean up/micro-optimatization:  Make the AF_INET-only version of
nlm_cmp_addr() smaller.  This matches the style of
nlm_privileged_requester(), and makes the AF_INET-only version of
nlm_cmp_addr() nearly the same size as it was before IPv6 support.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix a memory leak due to allocation in the XDR layer. In cases where the
RPC call needs to be retransmitted, we end up allocating new pages without
clearing the old ones. Fix this by moving the allocation into
nfs3_proc_setacls().

Also fix an issue discovered by Kevin Rudd, whereby the amount of memory
reserved for the acls in the xdr_buf->head was miscalculated, and causing
corruption.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

frames followed by these errors in log.

	[sdp] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
	[sdp] Sense Key : Aborted Command [current]
	[sdp] Add. Sense: Data phase error

This was causing some test apps to exit due to write failure under heavy
load.

This was due to a race around adding and removing tx frame skb in
fcoe_pending_queue, Chris Leech helped me to find that brief unlocking
period when pulling skb from fcoe_pending_queue in various contexts
(fcoe_watchdog and fcoe_xmit) and then adding skb back into fcoe_pending_queue
up on a failed fcoe_start_io could change skb/tx frame order in
fcoe_pending_queue. Thanks Chris.

This patch allows only single context to pull skb from fcoe_pending_queue
at any time to prevent above described ordering issue/race by use of
fcoe_pending_queue_active flag.

This patch simplified fcoe_watchdog with modified fcoe_check_wait_queue by
use of FCOE_LOW_QUEUE_DEPTH instead previously used several conditionals
to clear and set lp->qfull.

I think FCOE_MAX_QUEUE_DEPTH with FCOE_LOW_QUEUE_DEPTH  will work better
in re/setting lp->qfull and these could be fine tuned for performance.
Signed-off-by: NVasu Dev <vasu.dev@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Signed-off-by: NYi Zou <yi.zou@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Comment from "Andrew Morton <akpm@linux-foundation.org>"

> +{
> +     return (struct fcoe_softc *)lport_priv(lp);

unneeded/undesirable cast of void*.  There are probably zillions of
instances of this - there always are.

This whole inline function was unnecessary. The FCoE layer knows
that it's data structure is stored in the lport private data, it
can just access it from lport_priv().
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

1) Added '()' for function names in kerneldoc comments

2) Changed comment bookends from '**/' to '*/'. The comment on the the
   mailing list was that '**/' "is consistently unconventional.  Not
   wrong, just odd." The Documentation/kernel-doc-nano-HOWTO.txt
   states that kerneldoc comment blocks should end with '**/' but most
   (if not all) instance I found under drivers/scsi/ were only using
   the '*/' so I converted to that style.

3) Removed incorrect linebreaks in kerneldoc comments where found

4) Removed a few unnecessary blank comment lines in kerneldoc comment
   blocks
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This reverts commit e088e4c9.

Removing the sysfs interface for p4-clockmod was flagged as a
regression in bug 12826.

Course of action:
 - Find out the remaining causes of overheating, and fix them
   if possible. ACPI should be doing the right thing automatically.
   If it isn't, we need to fix that.
 - mark p4-clockmod ui as deprecated
 - try again with the removal in six months.

It's not really feasible to printk about the deprecation, because
it needs to happen at all the sysfs entry points, which means adding
a lot of strcmp("p4-clockmod".. calls to the core, which.. bleuch.
Signed-off-by: NDave Jones <davej@redhat.com>

Protocol 0x37 has been reserved for iNexio devices and Sahara
was supposed to get 0x38.
Reported-by: NClaudio Nieder <private@claudio.ch>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Made the comments more like the comments for struct scsi_host_template.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This allows any rport ELS to retry on LS_RJT.

The rport error handling would only retry on resource allocation failures
and exchange timeouts.  I have a target that will occasionally reject PLOGI
when we do a quick LOGO/PLOGI.  When a critical ELS was rejected, libfc would
fail silently leaving the rport in a dead state.

The retry count and delay are managed by fc_rport_error_retry.  If the retry
count is exceeded fc_rport_error will be called.  When retrying is not the
correct course of action, fc_rport_error can be called directly.
Signed-off-by: NChris Leech <christopher.leech@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The fcoe_xmit could call fc_pause in case the pending skb queue len is larger
than FCOE_MAX_QUEUE_DEPTH, the fc_pause was trying to grab lport->lp_muex to
change lport->link_status and that had these issues :-

1. The fcoe_xmit was getting called with bh disabled, thus causing
"BUG: scheduling while atomic" when grabbing lport->lp_muex with bh disabled.

2. fc_linkup and fc_linkdown function calls lport_enter function with
lport->lp_mutex held and these enter function in turn calls fcoe_xmit to send
lport related FC frame, e.g. fc_linkup => fc_lport_enter_flogi to send flogi
req. In this case grabbing the same lport->lp_mutex again in fc_puase from
fcoe_xmit would cause deadlock.

The lport->lp_mutex was used for setting FC_PAUSE in fcoe_xmit path but
FC_PAUSE bit was not used anywhere beside just setting and clear this
bit in lport->link_status, instead used a separate field qfull in fc_lport
to eliminate need for lport->lp_mutex to track pending queue full condition
and in turn avoid above described two locking issues.

Also added check for lp->qfull in fc_fcp_lport_queue_ready to trigger
SCSI_MLQUEUE_HOST_BUSY when lp->qfull is set to prevent more scsi-ml cmds
while lp->qfull is set.

This patch eliminated FC_LINK_UP and FC_PAUSE and instead used dedicated
fields in fc_lport for this, this simplified all related conditional
code.

Also removed fc_pause and fc_unpause functions and instead used newly added
lport->qfull directly in fcoe.
Signed-off-by: NVasu Dev <vasu.dev@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

fc_exch_mgr structure is private to fc_exch.c. To export exch_mgr_reset to
transport, transport needs access to the exch manager. Change
exch_mgr_reset to use lport param which is the shared structure between
libFC and transport.

Alternatively, fc_exch_mgr definition can be moved to libfc.h so that lport
can be accessed from mp*.
Signed-off-by: NAbhijeet Joglekar <abjoglek@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Declare CFA specific identify data words 162 and 163 for future use.
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>
[bart: update patch summary/description]
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

HDIO_GET_IDENTITY returns 256 words currently.

Noticed by Norman Diamond.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: NStanislaw Gruszka <stf_xl@wp.pl>
Cc: Andrew Victor <linux@maxim.org.za>
[bart: minor checkpatch.pl / CodingStyle fixups]
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

ap->sector_buf is used as DMA target and should at least be aligned on
cacheline.  This caused problems on some embedded machines.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>