Pull block layer updates from Jens Axboe:
 "I've got a few bits pending for 3.8 final, that I better get sent out.
  It's all been sitting for a while, I consider it safe.

  It contains:

   - Two bug fixes for mtip32xx, fixing a driver hang and a crash.

   - A few-liner protocol error fix for drbd.

   - A few fixes for the xen block front/back driver, fixing a potential
     data corruption issue.

   - A race fix for disk_clear_events(), causing spurious warnings.  Out
     of the Chrome OS base.

   - A deadlock fix for disk_clear_events(), moving it to the a
     unfreezable workqueue.  Also from the Chrome OS base."

* 'for-linus' of git://git.kernel.dk/linux-block:
  drbd: fix potential protocol error and resulting disconnect/reconnect
  mtip32xx: fix for crash when the device surprise removed during rebuild
  mtip32xx: fix for driver hang after a command timeout
  block: prevent race/cleanup
  block: remove deadlock in disk_clear_events
  xen-blkfront: handle bvecs with partial data
  llist/xen-blkfront: implement safe version of llist_for_each_entry
  xen-blkback: implement safe iterator for the list of persistent grants

When we notice a disk failure on the receiving side,
we stop sending it new incoming writes.

Depending on exact timing of various events, the same transfer log epoch
could end up containing both replicated (before we noticed the failure)
and local-only requests (after we noticed the failure).

The sanity checks in tl_release(), called when receiving a
P_BARRIER_ACK, check that the ack'ed transfer log epoch matches
the expected epoch, and the number of contained writes matches
the number of ack'ed writes.

In this case, they counted both replicated and local-only writes,
but the peer only acknowledges those it has seen.  We get a mismatch,
resulting in a protocol error and disconnect/reconnect cycle.

Messages logged are
  "BAD! BarrierAck #%u received with n_writes=%u, expected n_writes=%u!\n"

A similar issue can also be triggered when starting a resync while
having a healthy replication link, by invalidating one side, forcing a
full sync, or attaching to a diskless node.

Fix this by closing the current epoch if the state changes in a way
that would cause the replication intent of the next write.

Epochs now contain either only non-replicated,
or only replicated writes.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

Pull module fixes and a virtio block fix from Rusty Russell:
 "Various minor fixes, but a slightly more complex one to fix the
  per-cpu overload problem introduced recently by kvm id changes."

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  module: put modules in list much earlier.
  module: add new state MODULE_STATE_UNFORMED.
  module: prevent warning when finit_module a 0 sized file
  virtio-blk: Don't free ida when disk is in use

When rebuild is in progress, disk->queue is yet to be created. Surprise
removing the device will call remove()-> del_gendisk(). del_gendisk()
expect disk->queue be not NULL. Fix is to call put_disk() when disk_queue
is NULL.

Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

If an I/O command times out when a PIO command is active,
MTIP_PF_EH_ACTIVE_BIT is not cleared. This results in I/O
hang in the driver. Fix is to clear this bit.

Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

CONFIG_HOTPLUG is going away as an option.  As a result, the __dev*
markings need to be removed.

This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Chirag Kantharia <chirag.kantharia@hp.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Jim Paris <jim@jtan.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Tao Guo <Tao.Guo@emc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When a file system is mounted on a virtio-blk disk, we then remove it
and then reattach it, the reattached disk gets the same disk name and
ids as the hot removed one.

This leads to very nasty effects - mostly rendering the newly attached
device completely unusable.

Trying what happens when I do the same thing with a USB device, I saw
that the sd node simply doesn't get free'd when a device gets forcefully
removed.

Imitate the same behavior for vd devices. This way broken vd devices
simply are never free'd and newly attached ones keep working just fine.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org

Pull Ceph update from Sage Weil:
 "There are a few different groups of commits here.  The largest is
  Alex's ongoing work to enable the coming RBD features (cloning,
  striping).  There is some cleanup in libceph that goes along with it.

  Cyril and David have fixed some problems with NFS reexport (leaking
  dentries and page locks), and there is a batch of patches from Yan
  fixing problems with the fs client when running against a clustered
  MDS.  There are a few bug fixes mixed in for good measure, many of
  which will be going to the stable trees once they're upstream.

  My apologies for the late pull.  There is still a gremlin in the rbd
  map/unmap code and I was hoping to include the fix for that as well,
  but we haven't been able to confirm the fix is correct yet; I'll send
  that in a separate pull once it's nailed down."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (68 commits)
  rbd: get rid of rbd_{get,put}_dev()
  libceph: register request before unregister linger
  libceph: don't use rb_init_node() in ceph_osdc_alloc_request()
  libceph: init event->node in ceph_osdc_create_event()
  libceph: init osd->o_node in create_osd()
  libceph: report connection fault with warning
  libceph: socket can close in any connection state
  rbd: don't use ENOTSUPP
  rbd: remove linger unconditionally
  rbd: get rid of RBD_MAX_SEG_NAME_LEN
  libceph: avoid using freed osd in __kick_osd_requests()
  ceph: don't reference req after put
  rbd: do not allow remove of mounted-on image
  libceph: Unlock unprocessed pages in start_read() error path
  ceph: call handle_cap_grant() for cap import message
  ceph: Fix __ceph_do_pending_vmtruncate
  ceph: Don't add dirty inode to dirty list if caps is in migration
  ceph: Fix infinite loop in __wake_requests
  ceph: Don't update i_max_size when handling non-auth cap
  bdi_register: add __printf verification, fix arg mismatch
  ...

The functions rbd_get_dev() and rbd_put_dev() are trivial wrappers
that add no value, and their existence suggests they may do more
than what they do.

Get rid of them.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>