A zpool has a zfs as its userspace interface; but the call to create it was
disabled as part of the porting effort.

Re-enable it so osv can create zpools.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

MAXPATHLEN on osv is larger than on bsd, leading to the zfs ioctl command
buffer overflowing the maximum allowable size.

Reduce the buffer size to avoid a compile time assert failure.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

This is a shortcut through various kernel layers to avoid complication,
intended to be called from the various zfs utilities.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Not supported under osv.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Fixed MAXPATHLEN

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

We have _KERNEL defines scattered throughout the code, which makes
understanding it difficult.

Define it just once, and adjust the source to build.

We define it in an overridable variable, so that non-kernel imported code
can undo it.

Import FreeBSD files, changeset 245655.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Imported with no change from FreeBSD 245655.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

bsd's ifconf conflicts with osv's; rename it.

We use the bsd version in <osv/ioctl.h>, since we currently don't support
the Linux-ABI variants of these ioctls.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Tested-By: Benoit Canet <benoit@irqsave.net>

The bsd ifaddr struct conflicts with the osv ifaddr struct, which is a
public interface.  Rename the bsd struct to avoid conflict.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Tested-By: Benoit Canet <benoit@irqsave.net>

Workaround a bytorder function conflict, and reconcile a declaration.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Tested-By: Benoit Canet <benoit@irqsave.net>

Some structures are duplicated; move the duplicates to a common header
<netinet/__in.h>.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Tested-By: Benoit Canet <benoit@irqsave.net>

Some structures are duplicated; deduplicate them.

A few are source-compatible but not binary-compatible; use the ones from
<bits/socket.h>.

Others are both source- and binary- compatible; put them in a new header
<sys/__socket.h> which is included from both.

Work around a problem with the byteorder functions/macros.

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Tested-By: Benoit Canet <benoit@irqsave.net>

Update ->va_nlink() in zfs_getattr() in preparation for sys_link().

Signed-off-by: Raphael S. Carvalho <raphael.scarv@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Wire up the VOP_LINK vnode operation for ZFS in preparation for
sys_link().

Signed-off-by: Raphael S. Carvalho <raphael.scarv@gmail.com>
[ penberg: drop FIGNORE, cleanup, split ]
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

* %lu => %u when reading flush. The barrier flag had the same bug, but I
ended up recreating it for flush.
* Move check of xb_flags to after we check sc->flags != NULL, as spotted by
Dima

Not all Xen versions implement the barrier feature in their pv disks. Such is
the case in Amazon EC2. For those, we should interpret the flush request and
wait for the requests until they are all handled. Also, we can still try to use
one of either barriers or flush-disk operations before we resort to guest-side
software implementation. Our driver currently only tests for one of them, so
this patch also implements flush requests.

Luckily, the implementation of xb_dump (which we don't currently use) needs to
do that as well, and this is also quite well isolated in xb_quiesce(). All we need
to do is call xb_quiesce() if flushing is not available in our backend

This patch implements GSI interrupt support for Xen bus.
Needed in Xen environments w/o vector callbacks for HVM.
One example of such an environment is Amazon EC2.

We cannot read the partition table from the device if the device is not marked
as ready, since all IO will stall. I believe it should be fine to just mark the
device ready before we mark our state as connected. With that change, it all
proceed normally.

Xen has hard requirements on page transfers, and how to feed the grant tables.
The address need to be page aligned, since the pfns and not addresses are used,
and we need to provide at least a full page per buffer, since the hypervisor is
free to fill any data within the page.

To achieve that, the netfront driver will use m_cljget to attach an extended
buffer to the mbuf, from the jumbop zone, since they are page-sized. However,
two problems arise from this:

1) Allocating a page goes through malloc_large. Our implementation of malloc_large
is currently terribly inefficient, and that creates a very heavy contention site.

What I am doing with this patch is to switch our uma implementation to
alloc_page / free_page instead of malloc if the caller of zcreate so specified
(and then of course, specify it for the jumbop cache)

2) The refcount that is attached in the end of the buffer would either extend the
buffer to 4100 bytes - defeating our purpose, or then the buffer would have to be
PAGE_SIZE - 4, to accomodate for the refcount. But since the hypervisor will write
to the whole page, it will eventually overwrite the refcount.

To address that, I am allocating an external reference counter. BSD already
have some infrastructure to do that, and I am taking advantage of this.
However, I have found no way of implementing this in a way in which the
reference count can be easily deduceable from the address of the extended
buffer, without having the supporting mbuf to start from. Any external data
structure such as hashes would probably make freeing way too slow. Thankfully,
uma_find_refcnt and the UMA_ZONE_REFCNT seems to be used mostly in the
setup/destruction phase (the mbuf refcount is used directly, open coded). So my
proposal here is to remove the UMA_ZONE_REFCNT for that zone.

If a crashed OSv guest is restarted, ZFS mount causes a GPF in early
startup:

  VFS: mounting zfs at /usr
  zfs: mounting osv/usr from device /dev/vblk1
  Aborted

GDB backtrace points finger at zfs_rmnode():

  #0  processor::halt_no_interrupts () at ../../arch/x64/processor.hh:212
  #1  0x00000000003e7f2a in osv::halt () at ../../core/power.cc:20
  #2  0x000000000021cdd4 in abort (msg=0x636df0 "Aborted\n") at ../../runtime.cc:95
  #3  0x000000000021cda2 in abort () at ../../runtime.cc:86
  #4  0x000000000044c149 in osv::generate_signal (siginfo=..., ef=0xffffc0003ffe7008) at ../../libc/signal.cc:44
  #5  0x000000000044c220 in osv::handle_segmentation_fault (addr=72, ef=0xffffc0003ffe7008) at ../../libc/signal.cc:55
  #6  0x0000000000366df3 in page_fault (ef=0xffffc0003ffe7008) at ../../core/mmu.cc:876
  #7  <signal handler called>
  #8  0x0000000000345eaa in zfs_rmnode (zp=0xffffc0003d1de400)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.c:611
  #9  0x000000000035650c in zfs_zinactive (zp=0xffffc0003d1de400)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c:1355
  #10 0x0000000000345be1 in zfs_unlinked_drain (zfsvfs=0xffffc0003ddfe000)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.c:523
  #11 0x000000000034f45c in zfsvfs_setup (zfsvfs=0xffffc0003ddfe000, mounting=true)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:881
  #12 0x000000000034f7a4 in zfs_domount (vfsp=0xffffc0003de02000, osname=0x6b14cb "osv/usr")
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:1016
  #13 0x000000000034f98c in zfs_mount (mp=0xffffc0003de02000, dev=0x6b14d7 "/dev/vblk1", flags=0, data=0x6b14cb)
      at ../../bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:1415
  #14 0x0000000000406852 in sys_mount (dev=0x6b14d7 "/dev/vblk1", dir=0x6b14a3 "/usr", fsname=0x6b14d3 "zfs", flags=0, data=0x6b14cb)
      at ../../fs/vfs/vfs_mount.c:171
  #15 0x00000000003eff97 in mount_usr () at ../../fs/vfs/main.cc:1415
  #16 0x0000000000203a89 in do_main_thread (_args=0xffffc0003fe9ced0) at ../../loader.cc:215
  #17 0x0000000000448575 in pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, pthread_private::thread_attr const*)::{lambda()#1}::operator()() const () at ../../libc/pthread.cc:59
  #18 0x00000000004499d3 in std::_Function_handler<void(), pthread_private::pthread::pthread(void* (*)(void*), void*, sigset_t, const pthread_private::thread_attr*)::__lambda0>::_M_invoke(const std::_Any_data &) (__functor=...)
      at ../../external/gcc.bin/usr/include/c++/4.8.1/functional:2071
  #19 0x000000000037e602 in std::function<void ()>::operator()() const (this=0xffffc0003e170038)
      at ../../external/gcc.bin/usr/include/c++/4.8.1/functional:2468
  #20 0x00000000003bae3e in sched::thread::main (this=0xffffc0003e170010) at ../../core/sched.cc:581
  #21 0x00000000003b8c92 in sched::thread_main_c (t=0xffffc0003e170010) at ../../arch/x64/arch-switch.hh:133
  #22 0x0000000000399c8e in thread_main () at ../../arch/x64/entry.S:101

The problem is that ZFS tries to check if the znode is an attribute
directory and trips over zp->z_vnode being NULL.  However, as explained
in commit b7ee91ef ("zfs: port vop_lookup"), we don't even support
extended attributes so drop the check completely for OSv.

We'll need this for any pathname related actions.

Create a new dentry structure for pathname components, following the Linux
VFS model.  The vnodes are left-as is for now but are always fronted by
dentries for pathname lookups.  In a second step they will be moved to
use non-pathname indices.

[penberg: fix open(O_CREAT|O_EXCL) breakage ]

While planning to run tests on Xen today, I found my guests in current tip
failing to mount ZFS. I spent some time debugging the memory allocator, since
it was the culprit last time: only to find out we were not even reaching the
memory allocator.

I noticed then that ZFS was failing with error 75 -> EOVERFLOW. Looking
further, one of our bootup messages was showing the disks as "0MB".

That information is read from the xenstore, and it was being read correctly.
However, by the time we calculate the disk size, this is no longer correct,
indicating a stack corruption.

I found out the culprit to be a subsequent call to xs_gather, which calls a
variant of scanf internally. The call was being passed a %lu argument to read
an int variable, which would explain the corruption if the # of sectors was
right before it in the stack.

Indeed, with this fix, ZFS fails in a different way now =)

The xen block driver needs some extra state not needed for the network drivers.
Namely, the same way virtio-blk does, we need to tell the block layer which is
our strategy, read and write functions. For that, we need some extra code that
I am implementing in xenfront-blk.cc.

BSD expects its sector number to be already provided by the bio. We could add this field
to the bio, but it is easier just to calculate it from the given offset.

There are many places in which the bios are filled up, including many in the zfs code. So
it is easier to change them just here.