Move the init_nsproxy definition out of arch/ into kernel/nsproxy.c.  This
avoids all arches having to be updated.  Compiles and boots on s390.
Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds a nsproxy structure to the task struct.  Later patches will
move the fs namespace pointer into this structure, and introduce a new utsname
namespace into the nsproxy.

The vserver and openvz functionality, then, would be implemented in large part
by virtualizing/isolating more and more resources into namespaces, each
contained in the nsproxy.

[akpm@osdl.org: build fix]
Signed-off-by: NSerge Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch makes the needlessly global _proc_do_string() static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The logic in proc_do_string is worth re-using without passing in a
ctl_table structure (say, we want to calculate a pointer and pass that in
instead); pass in the two fields it uses from that structure as explicit
arguments.
Signed-off-by: NSam Vilain <sam.vilain@catalyst.net.nz>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

while doing a kernel make modules_install install over an NFS mount.

  =============================================
  [ INFO: possible recursive locking detected ]
  ---------------------------------------------
  nfsd/9550 is trying to acquire lock:
   (&inode->i_mutex){--..}, at: [<c034c845>] mutex_lock+0x1c/0x1f

  but task is already holding lock:
   (&inode->i_mutex){--..}, at: [<c034c845>] mutex_lock+0x1c/0x1f

  other info that might help us debug this:
  2 locks held by nfsd/9550:
   #0:  (hash_sem){..--}, at: [<cc895223>] exp_readlock+0xd/0xf [nfsd]
   #1:  (&inode->i_mutex){--..}, at: [<c034c845>] mutex_lock+0x1c/0x1f

  stack backtrace:
   [<c0103508>] show_trace_log_lvl+0x58/0x152
   [<c0103b8b>] show_trace+0xd/0x10
   [<c0103c2f>] dump_stack+0x19/0x1b
   [<c012aa57>] __lock_acquire+0x77a/0x9a3
   [<c012af4a>] lock_acquire+0x60/0x80
   [<c034c6c2>] __mutex_lock_slowpath+0xa7/0x20e
   [<c034c845>] mutex_lock+0x1c/0x1f
   [<c0162edc>] vfs_unlink+0x34/0x8a
   [<cc891d98>] nfsd_unlink+0x18f/0x1e2 [nfsd]
   [<cc89884f>] nfsd3_proc_remove+0x95/0xa2 [nfsd]
   [<cc88f0d4>] nfsd_dispatch+0xc0/0x178 [nfsd]
   [<c033e84d>] svc_process+0x3a5/0x5ed
   [<cc88f5ba>] nfsd+0x1a7/0x305 [nfsd]
   [<c0101005>] kernel_thread_helper+0x5/0xb
  DWARF2 unwinder stuck at kernel_thread_helper+0x5/0xb
  Leftover inexact backtrace:
   [<c0103b8b>] show_trace+0xd/0x10
   [<c0103c2f>] dump_stack+0x19/0x1b
   [<c012aa57>] __lock_acquire+0x77a/0x9a3
   [<c012af4a>] lock_acquire+0x60/0x80
   [<c034c6c2>] __mutex_lock_slowpath+0xa7/0x20e
   [<c034c845>] mutex_lock+0x1c/0x1f
   [<c0162edc>] vfs_unlink+0x34/0x8a
   [<cc891d98>] nfsd_unlink+0x18f/0x1e2 [nfsd]
   [<cc89884f>] nfsd3_proc_remove+0x95/0xa2 [nfsd]
   [<cc88f0d4>] nfsd_dispatch+0xc0/0x178 [nfsd]
   [<c033e84d>] svc_process+0x3a5/0x5ed
   [<cc88f5ba>] nfsd+0x1a7/0x305 [nfsd]
   [<c0101005>] kernel_thread_helper+0x5/0xb

  =============================================
  [ INFO: possible recursive locking detected ]
  ---------------------------------------------
  nfsd/9580 is trying to acquire lock:
   (&inode->i_mutex){--..}, at: [<c034cc1d>] mutex_lock+0x1c/0x1f

  but task is already holding lock:
   (&inode->i_mutex){--..}, at: [<c034cc1d>] mutex_lock+0x1c/0x1f

  other info that might help us debug this:
  2 locks held by nfsd/9580:
   #0:  (hash_sem){..--}, at: [<cc89522b>] exp_readlock+0xd/0xf [nfsd]
   #1:  (&inode->i_mutex){--..}, at: [<c034cc1d>] mutex_lock+0x1c/0x1f

  stack backtrace:
   [<c0103508>] show_trace_log_lvl+0x58/0x152
   [<c0103b8b>] show_trace+0xd/0x10
   [<c0103c2f>] dump_stack+0x19/0x1b
   [<c012aa63>] __lock_acquire+0x77a/0x9a3
   [<c012af56>] lock_acquire+0x60/0x80
   [<c034ca9a>] __mutex_lock_slowpath+0xa7/0x20e
   [<c034cc1d>] mutex_lock+0x1c/0x1f
   [<cc892ad1>] nfsd_setattr+0x2c8/0x499 [nfsd]
   [<cc893ede>] nfsd_create_v3+0x31b/0x4ac [nfsd]
   [<cc8984a1>] nfsd3_proc_create+0x128/0x138 [nfsd]
   [<cc88f0d4>] nfsd_dispatch+0xc0/0x178 [nfsd]
   [<c033ec1d>] svc_process+0x3a5/0x5ed
   [<cc88f5ba>] nfsd+0x1a7/0x305 [nfsd]
   [<c0101005>] kernel_thread_helper+0x5/0xb
  DWARF2 unwinder stuck at kernel_thread_helper+0x5/0xb
  Leftover inexact backtrace:
   [<c0103b8b>] show_trace+0xd/0x10
   [<c0103c2f>] dump_stack+0x19/0x1b
   [<c012aa63>] __lock_acquire+0x77a/0x9a3
   [<c012af56>] lock_acquire+0x60/0x80
   [<c034ca9a>] __mutex_lock_slowpath+0xa7/0x20e
   [<c034cc1d>] mutex_lock+0x1c/0x1f
   [<cc892ad1>] nfsd_setattr+0x2c8/0x499 [nfsd]
   [<cc893ede>] nfsd_create_v3+0x31b/0x4ac [nfsd]
   [<cc8984a1>] nfsd3_proc_create+0x128/0x138 [nfsd]
   [<cc88f0d4>] nfsd_dispatch+0xc0/0x178 [nfsd]
   [<c033ec1d>] svc_process+0x3a5/0x5ed
   [<cc88f5ba>] nfsd+0x1a7/0x305 [nfsd]
   [<c0101005>] kernel_thread_helper+0x5/0xb
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Neil Brown <neilb@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add /proc/fs/nfsd/pool_threads which allows the sysadmin (or a userspace
daemon) to read and change the number of nfsd threads in each pool.  The
format is a list of space-separated integers, one per pool.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Actually implement multiple pools.  On NUMA machines, allocate a svc_pool per
NUMA node; on SMP a svc_pool per CPU; otherwise a single global pool.  Enqueue
sockets on the svc_pool corresponding to the CPU on which the socket bh is run
(i.e.  the NIC interrupt CPU).  Threads have their cpu mask set to limit them
to the CPUs in the svc_pool that owns them.

This is the patch that allows an Altix to scale NFS traffic linearly
beyond 4 CPUs and 4 NICs.

Incorporates changes and feedback from Neil Brown, Trond Myklebust, and
Christoph Hellwig.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Replace the existing list of all nfsd threads with new code using
svc_create_pooled().
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently knfsd keeps its own list of all nfsd threads in nfssvc.c; add a new
way of managing the list of all threads in a svc_serv.  Add
svc_create_pooled() to allow creation of a svc_serv whose threads are managed
by the sunrpc code.  Add svc_set_num_threads() to manage the number of threads
in a service, either per-pool or globally across the service.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

add svc_get() for those occasions when we need to temporarily bump up
svc_serv->sv_nrthreads as a pseudo refcount.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Split out the list of idle threads and pending sockets from svc_serv into a
new svc_pool structure, and allocate a fixed number (in this patch, 1) of
pools per svc_serv.  The new structure contains a lock which takes over
several of the duties of svc_serv->sv_lock, which is now relegated to
protecting only sv_tempsocks, sv_permsocks, and sv_tmpcnt in svc_serv.

The point is to move the hottest fields out of svc_serv and into svc_pool,
allowing a following patch to arrange for a svc_pool per NUMA node or per CPU.
 This is a major step towards making the NFS server NUMA-friendly.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The SK_BUSY bit in svc_sock->sk_flags ensures that we do not attempt to
enqueue a socket twice.  Currently, setting and clearing the bit is protected
by svc_serv->sv_lock.  As I intend to reduce the data that the lock protects
so it's not held when svc_sock_enqueue() tests and sets SK_BUSY, that test and
set needs to be atomic.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Convert the svc_sock->sk_reserved variable from an int protected by
svc_serv->sv_lock, to an atomic.  This reduces (by 1) the number of places we
need to take the (effectively global) svc_serv->sv_lock.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Protect the svc_sock->sk_deferred list with a new lock svc_sock->sk_defer_lock
instead of svc_serv->sv_lock.  Using the more fine-grained lock reduces the
number of places we need to take the svc_serv lock.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Convert the svc_sock->sk_inuse counter from an int protected by
svc_serv->sv_lock, to an atomic.  This reduces the number of places we need to
take the (effectively global) svc_serv->sv_lock.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Following are 11 patches from Greg Banks which combine to make knfsd more
Numa-aware.  They reduce hitting on 'global' data structures, and create some
data-structures that can be node-local.

knfsd threads are bound to a particular node, and the thread to handle a new
request is chosen from the threads that are attach to the node that received
the interrupt.

The distribution of threads across nodes can be controlled by a new file in
the 'nfsd' filesystem, though the default approach of an even spread is
probably fine for most sites.

Some (old) numbers that show the efficacy of these patches: N == number of
NICs == number of CPUs == nmber of clients.  Number of NUMA nodes == N/2

N	Throughput, MiB/s	CPU usage, % (max=N*100)
	Before	After		Before	After
	---	------	----		-----	-----
	4	312	435		350	228
	6	500	656		501	418
	8	562	804		690	589

This patch:

Move the aging of RPC/TCP connection sockets from the main svc_recv() loop to
a timer which uses a mark-and-sweep algorithm every 6 minutes.  This reduces
the amount of work that needs to be done in the main RPC loop and the length
of time we need to hold the (effectively global) svc_serv->sv_lock.

[akpm@osdl.org: cleanup]
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If lockd_up fails - what should we expect?  Do we have to later call
lockd_down?

Well the nfs client thinks "no", the nfs server thinks "yes".  lockd thinks
"yes".

The only answer that really makes sense is "no" !!

So:
  Make lockd_up only increment  nlmsvc_users on success.
  Make nfsd handle errors from lockd_up properly.
  Make sure lockd_up(0) never fails when lockd is running
    so that the 'reclaimer' call to lockd_up doesn't need to
    be error checked.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Thus it is printed for any path that leads to failure (make_socks is called
from two places).

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We should be checking the return value of lockd_up when adding a new socket to
nfsd.  So move the lockd_up before the svc_addsock and check the return value.

The move is because lockd_down is easy, but there is no easy way to remove a
recently added socket.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It isn't needed as it is available in rqstp->rq_server, and dropping it allows
some local vars to be dropped.

[akpm@osdl.org: build fix]
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

e_start acquires svc_export_cache.hash_lock, and e_stop releases it.  Add
lock annotations to these two functions so that sparse can check callers
for lock pairing, and so that sparse will not complain about these
functions since they intentionally use locks in this manner.
Signed-off-by: NJosh Triplett <josh@freedesktop.org>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Acked-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Userspace should create and bind a socket (but not connectted) and write the
'fd' to portlist.  This will cause the nfs server to listen on that socket.

To close a socket, the name of the socket - as read from 'portlist' can be
written to 'portlist' with a preceding '-'.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This file will list all ports that nfsd has open.
Default when TCP enabled will be
   ipv4 udp 0.0.0.0 2049
   ipv4 tcp 0.0.0.0 2049

Later, the list of ports will be settable.

'portlist' chosen rather than 'ports', to avoid unnecessary confusion with
non-mainline patches which created 'ports' with different semantics.

[akpm@osdl.org: cleanups, build fix]
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Separate out the code for creating a new service, and for creating initial
sockets.

Some of these new functions will have multiple callers soon.

[akpm@osdl.org: cleanups]
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We have an array 'nfsd_version' which lists the available versions of nfsd,
and 'nfsd_versions' (poor choice there :-() which lists the currently active
versions.

Then we have a bitmap - nfsd_versbits which says which versions are wanted.
The bits in this bitset cause content to be copied from nfsd_version to
nfsd_versions when nfsd starts.

This patch removes nfsd_versbits and moves information directly from
nfsd_version to nfsd_versions when requests for version changes arrive.

Note that this doesn't make it possible to change versions while the server is
running.  This is because serv->sv_xdrsize is calculated when a service is
created, and used when threads are created, and xdrsize depends on the active
versions.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently lockd listens on UDP always, and TCP if CONFIG_NFSD_TCP is set.

However as lockd performs services of the client as well, this is a problem.
If CONFIG_NfSD_TCP is not set, and a tcp mount is used, the server will not be
able to call back to lockd.

So:
 - add an option to lockd_up saying which protocol is needed
 - Always open sockets for which an explicit port was given, otherwise
   only open a socket of the type required
 - Change nfsd to do one lockd_up per socket rather than one per thread.

This
 - removes the dependancy on CONFIG_NFSD_TCP
 - means that lockd may open sockets other than at startup
 - means that lockd will *not* listen on UDP if the only
   mounts are TCP mount (and nfsd hasn't started).

The latter is the only one that concerns me at all - I don't know if this
might be a problem with some servers.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

nfsd has some cleanup that it wants to do when the last thread exits, and
there will shortly be some more.  So collect this all into one place and
define a callback for an rpc service to call when the service is about to be
destroyed.

[akpm@osdl.org: cleanups, build fix]
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

cpumask: ensure that node_to_cpumask() is available to modules for all
supported combinations of architecture and CONFIG_NUMA.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

cpumask: ensure that the cpu_online_map and cpu_possible_map bitmasks, and
hence all the macros in <linux/cpumask.h> that require them, are available to
modules for all supported combinations of architecture and CONFIG_SMP.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

cpumask: add highest_possible_node_id(), analogous to
highest_possible_processor_id().

[pj@sgi.com: fix typo]
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

As reported in http://bugzilla.kernel.org/show_bug.cgi?id=6970, ISDN can issue
excessively-long udelays, which triggers a build-time error on ARM.

This is very sucky of ISDN, but I doubt if anyone is going to suddenly fix it.
So change the macro to do the microsecond counting itself.

Cc: <tch@wpkg.org>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch to the Siemens Gigaset driver fixes the compile warning
"ignoring return value of 'class_device_create_file', declared with
attribute warn_unused_result" appearing with CONFIG_ENABLE_MUST_CHECK=y in
release 2.6.18-rc1-mm1.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Acked-by: NHansjoerg Lipp <hjlipp@web.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A simple module to test Linux Kernel Dump mechanism.  This module uses
jprobes to install/activate pre-defined crash points.  At different crash
points, various types of crashing scenarios are created like a BUG(),
panic(), exception, recursive loop and stack overflow.  The user can
activate a crash point with specific type by providing parameters at the
time of module insertion.  Please see the file header for usage
information.  The module is based on the Linux Kernel Dump Test Tool by
Fernando <http://lkdtt.sourceforge.net>.

This module could be merged with mainline. Jprobes is used here so that the
context in which crash point is hit, could be maintained. This implements
all the crash points as done by LKDTT except the one in the middle of
tasklet_action().
Signed-off-by: NAnkita Garg <ankita@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kprobe_flush_task() possibly calls kfree function during holding
kretprobe_lock spinlock, if kfree function is probed by kretprobe that will
incur spinlock deadlock.  This patch moves kfree function out scope of
kretprobe_lock.
Signed-off-by: Nbibo, mao <bibo.mao@intel.com>
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When kprobe is re-entered, the re-entered kprobe kernel path will will call
atomic_notifier_call_chain function, if this function is kprobed that will
incur numerous kprobe recursive fault.  This patch disallows kprobes on
atomic_notifier_call_chain function.
Signed-off-by: Nbibo, mao <bibo.mao@intel.com>
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Whitespace is used to indent, this patch cleans up these sentences by
kernel coding style.
Signed-off-by: Nbibo, mao <bibo.mao@intel.com>
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>