The VMI backend uses explicit page type notification to track shadow page
tables.  The allocation of page table roots is especially tricky.  We need to
clone the root for non-PAE mode while it is protected under the pgd lock to
correctly copy the shadow.

We don't need to allocate pgds in PAE mode, (PDPs in Intel terminology) as
they only have 4 entries, and are cached entirely by the processor, which
makes shadowing them rather simple.

For base page table level allocation, pmd_populate provides the exact hook
point we need.  Also, we need to allocate pages when splitting a large page,
and we must release pages before returning the page to any free pool.

Despite being required with these slightly odd semantics for VMI, Xen also
uses these hooks to determine the exact moment when page tables are created or
released.

AK: All nops for other architectures
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

ARCH_HAVE_XTIME_LOCK is used by x86_64 arch .  This arch needs to place a
read only copy of xtime_lock into vsyscall page.  This read only copy is
named __xtime_lock, and xtime_lock is defined in
arch/x86_64/kernel/vmlinux.lds.S as an alias.  So the declaration of
xtime_lock in kernel/timer.c was guarded by ARCH_HAVE_XTIME_LOCK define,
defined to true on x86_64.

We can get same result with _attribute__((weak)) in the declaration. linker
should do the job.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

Convert the PDA code to use %fs rather than %gs as the segment for
per-processor data.  This is because some processors show a small but
measurable performance gain for reloading a NULL segment selector (as %fs
generally is in user-space) versus a non-NULL one (as %gs generally is).

On modern processors the difference is very small, perhaps undetectable.
Some old AMD "K6 3D+" processors are noticably slower when %fs is used
rather than %gs; I have no idea why this might be, but I think they're
sufficiently rare that it doesn't matter much.

This patch also fixes the math emulator, which had not been adjusted to
match the changed struct pt_regs.

[frederik.deweerdt@gmail.com: fixit with gdb]
[mingo@elte.hu: Fix KVM too]
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Ian Campbell <Ian.Campbell@XenSource.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NZachary Amsden <zach@vmware.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NFrederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

Remove the statically allocated memory to NUMA node hash map in favor of a
dynamically allocated memory to node hash map (it is cache aligned).

This patch has the nice side effect in that it allows the hash map to grow
for systems with large amounts of memory (256GB - 1TB), but suffer from
having small PCI space tacked onto the boot node (which is somewhere
between 192MB to 512MB on the ES7000).
Signed-off-by: NAmul Shah <amul.shah@unisys.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Rohit Seth <rohitseth@google.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

This does user copies in fs write() into the page cache with write combining.
This pushes the destination out of the CPU's cache, but allows higher bandwidth
in some case.

The theory is that the page cache data is usually not touched by the
CPU again and it's better to not pollute the cache with it. Also it is a little
faster.
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No caller checks the return value, and since its usually called within the
module unload path there's nothing a module could do about errors anyway,
so BUG on invalid conditions and return void.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

NF_CT_STAT_INC assumes rcu_read_lock in nf_hook_slow disables
preemption as well, making it legal to use __get_cpu_var without
disabling preemption manually. The assumption is not correct anymore
with preemptable RCU, additionally we need to protect against softirqs
when not holding nf_conntrack_lock.

Add NF_CT_STAT_INC_ATOMIC macro, which disables local softirqs,
and use where necessary.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CONNTRACK_STAT_INC assumes rcu_read_lock in nf_hook_slow disables
preemption as well, making it legal to use __get_cpu_var without
disabling preemption manually. The assumption is not correct anymore
with preemptable RCU, additionally we need to protect against softirqs
when not holding ip_conntrack_lock.

Add CONNTRACK_STAT_INC_ATOMIC macro, which disables local softirqs,
and use where necessary.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace preempt_{enable,disable} based RCU by proper use of the
RCU API and add missing rcu_read_lock/rcu_read_unlock calls in
all paths not obviously only used within packet process context
(nfnetlink_conntrack).
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- rename nf_logging to nf_loggers since its an array of registered loggers

- rename nf_log_unregister_logger() to nf_log_unregister() to make it
  symetrical to nf_log_register() and convert all users
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the only user of nf_log_unregister_pf (nfnetlink_log) doesn't
check the return value, change it to void and bail out silently when
a non-existant address family is supplied.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is inspired by Arjan's "Patch series to mark struct
file_operations and struct inode_operations const".

Compile tested with gcc & sparse.
Signed-off-by: NJosef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PS3: Cleanup the frame buffer device before clearing the HPTE mapping
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: James Simmons <jsimmons@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If ps3fb is available, we have to disable display flipping while changing the
audio or video mode.
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: James Simmons <jsimmons@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add the PS3 Virtual Frame Buffer Driver.

As the actual graphics hardware cannot be accessed directly by Linux, ps3fb
uses a virtual frame buffer in main memory.  The actual screen image is copied
to graphics memory by the GPU on every vertical blank, by making a hypervisor
call.
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: James Simmons <jsimmons@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Preallocate bootmem memory for the PS3 frame buffer device, which needs a
large block of physically-contiguous memory. The size of this memory block is
configurable:
  - The config option CONFIG_FB_PS3_DEFAULT_SIZE_M allows to specify the
    default amount of memory (in MiB) allocated to the virtual frame buffer.
  - The early boot parameter `ps3fb=xxx' allows to override the default value.
    It will be rounded up to a multiple of 1 MiB, if needed.
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Cc: James Simmons <jsimmons@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fbdev modedb: make more input and output pointer parameters const
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: James Simmons <jsimmons@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add the PS3 AV Settings Driver.

The AV Settings driver is used to control Audio and Video settings.  It
communicates with the policy manager through the virtual uart.
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: James Simmons <jsimmons@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some of fb drivers uses atomic_t in bad manner, since there are still some
race-prone gaps.  Use mutexes to protect open/close code sections with
ref_count testing and finally use simple uint.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Acked-by: NDenis Oliver Kropp <dok@directfb.org>
Cc: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The FB_S3TRIO driver:
- has been marked as BROKEN for more than two years and
- is still marked as BROKEN.

Drivers that had been marked as BROKEN for such a long time seem to be
unlikely to be revived in the forseeable future.

But if anyone wants to ever revive this driver, the code is still
present in the older kernel releases.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: James Simmons <jsimmons@infradead.org>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a proper prototype for tosh_smm() to include/linux/toshiba.h
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a driver for S3 Trio / S3 Virge.  Driver is tested with most versions
of S3 Trio and with S3 Virge/DX, on i386.

(akpm: We kind-of have support for this hardware already, but...

virgefb.c
  - amiga/zorro specific,
  - broken (according to Kconfig),
  - uses obsolete/nonexistent interface (struct display_switch)
  - recent Adrian Bunk's patch removes this driver

S3triofb.c
  - ppc/openfirmware specific
  - minimal functionality
  - broken (according to Kconfig),
  - uses obsolete/nonexistent interface (struct display_switch)
)
Signed-off-by: NOndrej Zajicek <santiago@crfreenet.org>
Cc: James Simmons <jsimmons@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The following patchset allows a host with running virtual machines to be
suspended and, on at least a subset of the machines tested, resumed.  Note
that this is orthogonal to suspending and resuming an individual guest to a
file.

A side effect of implementing suspend/resume is that cpu hotplug is now
supported.  This should please the owners of big iron.

This patch:

KVM wants the cpu hotplug notifications, both for cpu hotplug itself, but more
commonly for host suspend/resume.

In order to avoid extensive #ifdefs, provide stubs when CONFIG_CPU_HOTPLUG is
not defined.

In all, we have four cases:

- UP: register and unregister stubbed out
- SMP+hotplug: full register and unregister
- SMP, no hotplug, core: register as __init, unregister stubbed
      (cpus are brought up during core initialization)
- SMP, no hotplug, module: register and unregister stubbed out
      (cpus cannot be brought up during module lifetime)
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Unfortunately requiring a version bump.
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We report the value of cr8 to userspace on an exit.  Also let userspace change
cr8 when we re-enter the guest.  The lets 64-bit guest code maintain the tpr
correctly.

Thanks for Yaniv Kamay for the idea.
Signed-off-by: NDor Laor <dor.laor@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch adds ability to work with 64bit metadata, this made by replacing work
with 32bit pointers by inline functions.
Signed-off-by: NEvgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds into write inode path function to write UFS2 inode, and
modifys allocate inode path to allocate and init additional inode chunks.

Also some cleanups:
- remove not used parameters in some functions
- remove i_gen field from ufs_inode_info structure,
there is i_generation in inode structure with same purposes.
Signed-off-by: NEvgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Current implementation allows the kernel to receive up to 255 characters from
the bootloader.  While the boot protocol allows greater buffers to be sent.

In current environment, the command-line is used in order to specify many
values, including suspend/resume, module arguments, splash, initramfs and
more.

255 characters are not enough anymore.

After edd issue was fixed, and dynammic kernel command-line patch was
accepted, we can extend the COMMAND_LINE_SIZE without runtime memory
requirements.
Signed-off-by: NAlon Bar-Lev <alon.barlev@gmail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Current implementation allows the kernel to receive up to 255 characters from
the bootloader.  While the boot protocol allows greater buffers to be sent.

In current environment, the command-line is used in order to specify many
values, including suspend/resume, module arguments, splash, initramfs and
more.

255 characters are not enough anymore.

After edd issue was fixed, and dynammic kernel command-line patch was
accepted, we can extend the COMMAND_LINE_SIZE without runtime memory
requirements.
Signed-off-by: NAlon Bar-Lev <alon.barlev@gmail.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Current implementation allows the kernel to receive up to 255 characters from
the bootloader.  While the boot protocol allows greater buffers to be sent.

In current environment, the command-line is used in order to specify many
values, including suspend/resume, module arguments, splash, initramfs and
more.

255 characters are not enough anymore.

After edd issue was fixed, and dynammic kernel command-line patch was
accepted, we can extend the COMMAND_LINE_SIZE without runtime memory
requirements.
Signed-off-by: NAlon Bar-Lev <alon.barlev@gmail.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

1. Rename saved_command_line into boot_command_line.
2. Set command_line as __initdata.
Signed-off-by: NAlon Bar-Lev <alon.barlev@gmail.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Current implementation stores a static command-line buffer allocated to
COMMAND_LINE_SIZE size.  Most architectures stores two copies of this buffer,
one for future reference and one for parameter parsing.

Current kernel command-line size for most architecture is much too small for
module parameters, video settings, initramfs paramters and much more.  The
problem is that setting COMMAND_LINE_SIZE to a grater value, allocates static
buffers.

In order to allow a greater command-line size, these buffers should be
dynamically allocated or marked as init disposable buffers, so unused memory
can be released.

This patch renames the static saved_command_line variable into
boot_command_line adding __initdata attribute, so that it can be disposed
after initialization.  This rename is required so applications that use
saved_command_line will not be affected by this change.

It reintroduces saved_command_line as dynamically allocated buffer to match
the data in boot_command_line.

It also mark secondary command-line buffer as __initdata, and copies it to
dynamically allocated static_command_line buffer components may hold reference
to it after initialization.

This patch is for linux-2.6.20-rc4-mm1 and is divided to target each
architecture.  I could not check this in any architecture so please forgive me
if I got it wrong.

The per-architecture modification is very simple, use boot_command_line in
place of saved_command_line.  The common code is the change into dynamic
command-line.

This patch:

1. Rename saved_command_line into boot_command_line, mark as init
   disposable.

2. Add dynamic allocated saved_command_line.

3. Add dynamic allocated static_command_line.

4. During startup copy: boot_command_line into saved_command_line.  arch
   command_line into static_command_line.

5. Parse static_command_line and not arch command_line, so arch
   command_line may be freed.
Signed-off-by: NAlon Bar-Lev <alon.barlev@gmail.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is the transport code for public key functionality in eCryptfs.  It
manages encryption/decryption request queues with a transport mechanism.
Currently, netlink is the only implemented transport.

Each inode has a unique File Encryption Key (FEK).  Under passphrase, a File
Encryption Key Encryption Key (FEKEK) is generated from a salt/passphrase
combo on mount.  This FEKEK encrypts each FEK and writes it into the header of
each file using the packet format specified in RFC 2440.  This is all
symmetric key encryption, so it can all be done via the kernel crypto API.

These new patches introduce public key encryption of the FEK.  There is no
asymmetric key encryption support in the kernel crypto API, so eCryptfs pushes
the FEK encryption and decryption out to a userspace daemon.  After
considering our requirements and determining the complexity of using various
transport mechanisms, we settled on netlink for this communication.

eCryptfs stores authentication tokens into the kernel keyring.  These tokens
correlate with individual keys.  For passphrase mode of operation, the
authentication token contains the symmetric FEKEK.  For public key, the
authentication token contains a PKI type and an opaque data blob managed by
individual PKI modules in userspace.

Each user who opens a file under an eCryptfs partition mounted in public key
mode must be running a daemon.  That daemon has the user's credentials and has
access to all of the keys to which the user should have access.  The daemon,
when started, initializes the pluggable PKI modules available on the system
and registers itself with the eCryptfs kernel module.  Userspace utilities
register public key authentication tokens into the user session keyring.
These authentication tokens correlate key signatures with PKI modules and PKI
blobs.  The PKI blobs contain PKI-specific information necessary for the PKI
module to carry out asymmetric key encryption and decryption.

When the eCryptfs module parses the header of an existing file and finds a Tag
1 (Public Key) packet (see RFC 2440), it reads in the public key identifier
(signature).  The asymmetrically encrypted FEK is in the Tag 1 packet;
eCryptfs puts together a decrypt request packet containing the signature and
the encrypted FEK, then it passes it to the daemon registered for the
current->euid via a netlink unicast to the PID of the daemon, which was
registered at the time the daemon was started by the user.

The daemon actually just makes calls to libecryptfs, which implements request
packet parsing and manages PKI modules.  libecryptfs grabs the public key
authentication token for the given signature from the user session keyring.
This auth tok tells libecryptfs which PKI module should receive the request.
libecryptfs then makes a decrypt() call to the PKI module, and it passes along
the PKI block from the auth tok.  The PKI uses the blob to figure out how it
should decrypt the data passed to it; it performs the decryption and passes
the decrypted data back to libecryptfs.  libecryptfs then puts together a
reply packet with the decrypted FEK and passes that back to the eCryptfs
module.

The eCryptfs module manages these request callouts to userspace code via
message context structs.  The module maintains an array of message context
structs and places the elements of the array on two lists: a free and an
allocated list.  When eCryptfs wants to make a request, it moves a msg ctx
from the free list to the allocated list, sets its state to pending, and fires
off the message to the user's registered daemon.

When eCryptfs receives a netlink message (via the callback), it correlates the
msg ctx struct in the alloc list with the data in the message itself.  The
msg->index contains the offset of the array of msg ctx structs.  It verifies
that the registered daemon PID is the same as the PID of the process that sent
the message.  It also validates a sequence number between the received packet
and the msg ctx.  Then, it copies the contents of the message (the reply
packet) into the msg ctx struct, sets the state in the msg ctx to done, and
wakes up the process that was sleeping while waiting for the reply.

The sleeping process was whatever was performing the sys_open().  This process
originally called ecryptfs_send_message(); it is now in
ecryptfs_wait_for_response().  When it wakes up and sees that the msg ctx
state was set to done, it returns a pointer to the message contents (the reply
packet) and returns.  If all went well, this packet contains the decrypted
FEK, which is then copied into the crypt_stat struct, and life continues as
normal.

The case for creation of a new file is very similar, only instead of a decrypt
request, eCryptfs sends out an encrypt request.

> - We have a great clod of key mangement code in-kernel.  Why is that
>   not suitable (or growable) for public key management?

eCryptfs uses Howells' keyring to store persistent key data and PKI state
information.  It defers public key cryptographic transformations to userspace
code.  The userspace data manipulation request really is orthogonal to key
management in and of itself.  What eCryptfs basically needs is a secure way to
communicate with a particular daemon for a particular task doing a syscall,
based on the UID.  Nothing running under another UID should be able to access
that channel of communication.

> - Is it appropriate that new infrastructure for public key
> management be private to a particular fs?

The messaging.c file contains a lot of code that, perhaps, could be extracted
into a separate kernel service.  In essence, this would be a sort of
request/reply mechanism that would involve a userspace daemon.  I am not aware
of anything that does quite what eCryptfs does, so I was not aware of any
existing tools to do just what we wanted.

>   What happens if one of these daemons exits without sending a quit
>   message?

There is a stale uid<->pid association in the hash table for that user.  When
the user registers a new daemon, eCryptfs cleans up the old association and
generates a new one.  See ecryptfs_process_helo().

> - _why_ does it use netlink?

Netlink provides the transport mechanism that would minimize the complexity of
the implementation, given that we can have multiple daemons (one per user).  I
explored the possibility of using relayfs, but that would involve having to
introduce control channels and a protocol for creating and tearing down
channels for the daemons.  We do not have to worry about any of that with
netlink.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

NFS_SUPER_MAGIC is already defined in include/linux/magic.h
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for IPv6 addresses in the RPC server's UDP receive path.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The rq_daddr field must support larger addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Expand the rq_addr field to allow it to contain larger addresses.

Specifically, we replace a 'sockaddr_in' with a 'sockaddr_storage', then
everywhere the 'sockaddr_in' was referenced, we use instead an accessor
function (svc_addr_in) which safely casts the _storage to _in.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>