* 'nfs-rdma' of git://git.linux-nfs.org/projects/anna/nfs-rdma: (916 commits)
  xprtrdma: Handle additional connection events
  xprtrdma: Remove RPCRDMA_PERSISTENT_REGISTRATION macro
  xprtrdma: Make rpcrdma_ep_disconnect() return void
  xprtrdma: Schedule reply tasklet once per upcall
  xprtrdma: Allocate each struct rpcrdma_mw separately
  xprtrdma: Rename frmr_wr
  xprtrdma: Disable completions for LOCAL_INV Work Requests
  xprtrdma: Disable completions for FAST_REG_MR Work Requests
  xprtrdma: Don't post a LOCAL_INV in rpcrdma_register_frmr_external()
  xprtrdma: Reset FRMRs after a flushed LOCAL_INV Work Request
  xprtrdma: Reset FRMRs when FAST_REG_MR is flushed by a disconnect
  xprtrdma: Properly handle exhaustion of the rb_mws list
  xprtrdma: Chain together all MWs in same buffer pool
  xprtrdma: Back off rkey when FAST_REG_MR fails
  xprtrdma: Unclutter struct rpcrdma_mr_seg
  xprtrdma: Don't invalidate FRMRs if registration fails
  xprtrdma: On disconnect, don't ignore pending CQEs
  xprtrdma: Update rkeys after transport reconnect
  xprtrdma: Limit data payload size for ALLPHYSICAL
  xprtrdma: Protect ia->ri_id when unmapping/invalidating MRs
  ...

This may be used to limit the number of cached credentials building up
inside the access cache.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

In some cases where the credentials are not often reused, we may want
to limit their total number just in order to make the negative lookups
in the hash table more manageable.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Commit 38ca83a5 added RDMA_CM_EVENT_TIMEWAIT_EXIT. But that status
is relevant only for consumers that re-use their QPs on new
connections. xprtrdma creates a fresh QP on reconnection, so that
event should be explicitly ignored.

Squelch the alarming "unexpected CM event" message.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Clean up.

RPCRDMA_PERSISTENT_REGISTRATION was a compile-time switch between
RPCRDMA_REGISTER mode and RPCRDMA_ALLPHYSICAL mode.  Since
RPCRDMA_REGISTER has been removed, there's no need for the extra
conditional compilation.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: The return code is used only for dprintk's that are
already redundant.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Minor optimization: grab rpcrdma_tk_lock_g and disable hard IRQs
just once after clearing the receive completion queue.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Currently rpcrdma_buffer_create() allocates struct rpcrdma_mw's as
a single contiguous area of memory. It amounts to quite a bit of
memory, and there's no requirement for these to be carved from a
single piece of contiguous memory.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: Name frmr_wr after the opcode of the Work Request,
consistent with the send and local invalidation paths.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Instead of relying on a completion to change the state of an FRMR
to FRMR_IS_INVALID, set it in advance. If an error occurs, a completion
will fire anyway and mark the FRMR FRMR_IS_STALE.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Instead of relying on a completion to change the state of an FRMR
to FRMR_IS_VALID, set it in advance. If an error occurs, a completion
will fire anyway and mark the FRMR FRMR_IS_STALE.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Any FRMR arriving in rpcrdma_register_frmr_external() is now
guaranteed to be either invalid, or to be targeted by a queued
LOCAL_INV that will invalidate it before the adapter processes
the FAST_REG_MR being built here.

The problem with current arrangement of chaining a LOCAL_INV to the
FAST_REG_MR is that if the transport is not connected, the LOCAL_INV
is flushed and the FAST_REG_MR is flushed. This leaves the FRMR
valid with the old rkey. But rpcrdma_register_frmr_external() has
already bumped the in-memory rkey.

Next time through rpcrdma_register_frmr_external(), a LOCAL_INV and
FAST_REG_MR is attempted again because the FRMR is still valid. But
the rkey no longer matches the hardware's rkey, and a memory
management operation error occurs.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

When a LOCAL_INV Work Request is flushed, it leaves an FRMR in the
VALID state. This FRMR can be returned by rpcrdma_buffer_get(), and
must be knocked down in rpcrdma_register_frmr_external() before it
can be re-used.

Instead, capture these in rpcrdma_buffer_get(), and reset them.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

FAST_REG_MR Work Requests update a Memory Region's rkey. Rkey's are
used to block unwanted access to the memory controlled by an MR. The
rkey is passed to the receiver (the NFS server, in our case), and is
also used by xprtrdma to invalidate the MR when the RPC is complete.

When a FAST_REG_MR Work Request is flushed after a transport
disconnect, xprtrdma cannot tell whether the WR actually hit the
adapter or not. So it is indeterminant at that point whether the
existing rkey is still valid.

After the transport connection is re-established, the next
FAST_REG_MR or LOCAL_INV Work Request against that MR can sometimes
fail because the rkey value does not match what xprtrdma expects.

The only reliable way to recover in this case is to deregister and
register the MR before it is used again. These operations can be
done only in a process context, so handle it in the transport
connect worker.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

If the rb_mws list is exhausted, clean up and return NULL so that
call_allocate() will delay and try again.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

During connection loss recovery, need to visit every MW in a
buffer pool. Any MW that is in use by an RPC will not be on the
rb_mws list.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

If posting a FAST_REG_MR Work Reqeust fails, revert the rkey update
to avoid subsequent IB_WC_MW_BIND_ERR completions.
Suggested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Clean ups:
 - make it obvious that the rl_mw field is a pointer -- allocated
   separately, not as part of struct rpcrdma_mr_seg
 - promote "struct {} frmr;" to a named type
 - promote the state enum to a named type
 - name the MW state field the same way other fields in
   rpcrdma_mw are named
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

If FRMR registration fails, it's likely to transition the QP to the
error state. Or, registration may have failed because the QP is
_already_ in ERROR.

Thus calling rpcrdma_deregister_external() in
rpcrdma_create_chunks() is useless in FRMR mode: the LOCAL_INVs just
get flushed.

It is safe to leave existing registrations: when FRMR registration
is tried again, rpcrdma_register_frmr_external() checks if each FRMR
is already/still VALID, and knocks it down first if it is.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma is currently throwing away queued completions during
a reconnect. RPC replies posted just before connection loss, or
successful completions that change the state of an FRMR, can be
missed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Various reports of:

  rpcrdma_qp_async_error_upcall: QP error 3 on device mlx4_0
		ep ffff8800bfd3e848

Ensure that rkeys in already-marshalled RPC/RDMA headers are
refreshed after the QP has been replaced by a reconnect.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=249Suggested-by: Selvin Xavier <Selvin.Xavier@Emulex.Com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

When the client uses physical memory registration, each page in the
payload gets its own array entry in the RPC/RDMA header's chunk list.

Therefore, don't advertise a maximum payload size that would require
more array entries than can fit in the RPC buffer where RPC/RDMA
headers are built.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=248Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Ensure ia->ri_id remains valid while invoking dma_unmap_page() or
posting LOCAL_INV during a transport reconnect. Otherwise,
ia->ri_id->device or ia->ri_id->qp is NULL, which triggers a panic.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=259
Fixes: ec62f40d 'xprtrdma: Ensure ia->ri_id->qp is not NULL when reconnecting'
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

seg1->mr_nsegs is not yet initialized when it is used to unmap
segments during an error exit. Use the same unmapping logic for
all error exits.

"if (frmr_wr.wr.fast_reg.length < len) {" used to be a BUG_ON check.
The broken code will never be executed under normal operation.

Fixes: c977dea2 (xprtrdma: Remove BUG_ON() call sites)
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Fix the following warning when DMA-API debug is enabled by checking ib_dma_map_single result:
[ 1455.345548] ------------[ cut here ]------------
[ 1455.346863] WARNING: CPU: 3 PID: 3929 at /home/yanb/kernel/net-next/lib/dma-debug.c:1140 check_unmap+0x4e5/0x990()
[ 1455.349350] mlx4_core 0000:00:07.0: DMA-API: device driver failed to check map error[device address=0x000000007c9f2090] [size=2656 bytes] [mapped as single]
[ 1455.349350] Modules linked in: xprtrdma netconsole configfs nfsv3 nfs_acl ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm autofs4 auth_rpcgss oid_registry nfsv4 nfs fscache lockd sunrpc dm_mirror dm_region_hash dm_log microcode pcspkr mlx4_ib ib_sa ib_mad ib_core ib_addr mlx4_en ipv6 ptp pps_core vxlan mlx4_core virtio_balloon cirrus ttm drm_kms_helper drm sysimgblt sysfillrect syscopyarea i2c_piix4 i2c_core button ext3 jbd virtio_blk virtio_net virtio_pci virtio_ring virtio uhci_hcd ata_generic ata_piix libata
[ 1455.349350] CPU: 3 PID: 3929 Comm: mount.nfs Not tainted 3.15.0-rc1-dbg+ #13
[ 1455.349350] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007
[ 1455.349350]  0000000000000474 ffff880069dcf628 ffffffff8151c341 ffffffff817b69d8
[ 1455.349350]  ffff880069dcf678 ffff880069dcf668 ffffffff8105b5fc 0000000069dcf658
[ 1455.349350]  ffff880069dcf778 ffff88007b0c9f00 ffffffff8255ec40 0000000000000a60
[ 1455.349350] Call Trace:
[ 1455.349350]  [<ffffffff8151c341>] dump_stack+0x52/0x81
[ 1455.349350]  [<ffffffff8105b5fc>] warn_slowpath_common+0x8c/0xc0
[ 1455.349350]  [<ffffffff8105b6e6>] warn_slowpath_fmt+0x46/0x50
[ 1455.349350]  [<ffffffff812e6305>] check_unmap+0x4e5/0x990
[ 1455.349350]  [<ffffffff81521fb0>] ? _raw_spin_unlock_irq+0x30/0x60
[ 1455.349350]  [<ffffffff812e6a0a>] debug_dma_unmap_page+0x5a/0x60
[ 1455.349350]  [<ffffffffa0389583>] rpcrdma_deregister_internal+0xb3/0xd0 [xprtrdma]
[ 1455.349350]  [<ffffffffa038a639>] rpcrdma_buffer_destroy+0x69/0x170 [xprtrdma]
[ 1455.349350]  [<ffffffffa03872ff>] xprt_rdma_destroy+0x3f/0xb0 [xprtrdma]
[ 1455.349350]  [<ffffffffa04a95ff>] xprt_destroy+0x6f/0x80 [sunrpc]
[ 1455.349350]  [<ffffffffa04a9625>] xprt_put+0x15/0x20 [sunrpc]
[ 1455.349350]  [<ffffffffa04a899a>] rpc_free_client+0x8a/0xe0 [sunrpc]
[ 1455.349350]  [<ffffffffa04a8a58>] rpc_release_client+0x68/0xa0 [sunrpc]
[ 1455.349350]  [<ffffffffa04a9060>] rpc_shutdown_client+0xb0/0xc0 [sunrpc]
[ 1455.349350]  [<ffffffffa04a8f5d>] ? rpc_ping+0x5d/0x70 [sunrpc]
[ 1455.349350]  [<ffffffffa04a91ab>] rpc_create_xprt+0xbb/0xd0 [sunrpc]
[ 1455.349350]  [<ffffffffa04a9273>] rpc_create+0xb3/0x160 [sunrpc]
[ 1455.349350]  [<ffffffff81129749>] ? __probe_kernel_read+0x69/0xb0
[ 1455.349350]  [<ffffffffa053851c>] nfs_create_rpc_client+0xdc/0x100 [nfs]
[ 1455.349350]  [<ffffffffa0538cfa>] nfs_init_client+0x3a/0x90 [nfs]
[ 1455.349350]  [<ffffffffa05391c8>] nfs_get_client+0x478/0x5b0 [nfs]
[ 1455.349350]  [<ffffffffa0538e50>] ? nfs_get_client+0x100/0x5b0 [nfs]
[ 1455.349350]  [<ffffffff81172c6d>] ? kmem_cache_alloc_trace+0x24d/0x260
[ 1455.349350]  [<ffffffffa05393f3>] nfs_create_server+0xf3/0x4c0 [nfs]
[ 1455.349350]  [<ffffffffa0545ff0>] ? nfs_request_mount+0xf0/0x1a0 [nfs]
[ 1455.349350]  [<ffffffffa031c0c3>] nfs3_create_server+0x13/0x30 [nfsv3]
[ 1455.349350]  [<ffffffffa0546293>] nfs_try_mount+0x1f3/0x230 [nfs]
[ 1455.349350]  [<ffffffff8108ea21>] ? get_parent_ip+0x11/0x50
[ 1455.349350]  [<ffffffff812d6343>] ? __this_cpu_preempt_check+0x13/0x20
[ 1455.349350]  [<ffffffff810d632b>] ? try_module_get+0x6b/0x190
[ 1455.349350]  [<ffffffffa05449f7>] nfs_fs_mount+0x187/0x9d0 [nfs]
[ 1455.349350]  [<ffffffffa0545940>] ? nfs_clone_super+0x140/0x140 [nfs]
[ 1455.349350]  [<ffffffffa0543b20>] ? nfs_auth_info_match+0x40/0x40 [nfs]
[ 1455.349350]  [<ffffffff8117e360>] mount_fs+0x20/0xe0
[ 1455.349350]  [<ffffffff811a1c16>] vfs_kern_mount+0x76/0x160
[ 1455.349350]  [<ffffffff811a29a8>] do_mount+0x428/0xae0
[ 1455.349350]  [<ffffffff811a30f0>] SyS_mount+0x90/0xe0
[ 1455.349350]  [<ffffffff8152af52>] system_call_fastpath+0x16/0x1b
[ 1455.349350] ---[ end trace f1f31572972e211d ]---
Signed-off-by: Yan Burman <yanb@mellanox.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Pull more IIO driver fixes from Greg KH:
 "Here are two IIO driver fixes for 3.16-rc6 that resolve some reported
  issues"

* tag 'staging-3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: mma8452: Use correct acceleration units.
  iio:core: Handle error when mask type is not separate

Pull USB fixes from Greg KH:
 "Here are two USB patches that resolve some reported issues, one with
  an odd HUB, and one in the chipidea driver"

* tag 'usb-3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: Check if port status is equal to RxDetect
  usb: chipidea: udc: Disable auto ZLP generation on ep0

Merge tag 'driver-core-3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fix from Greg KH:
 "Here is a single driver core fix that reverts an older patch that has
  been causing a number of reported problems with the platform devices.

  This revert has been in linux-next for a while with no reported issues"

* tag 'driver-core-3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  platform_get_irq: Revert to platform_get_resource if of_irq_get fails

Pull char/misc fix from Greg KH:
 "Here's a single hyper-v driver fix for a reported issue"

* tag 'char-misc-3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Drivers: hv: hv_fcopy: fix a race condition for SMP guest

Pull intel drm fixes from Dave Airlie:
 "Intel fixes came in late, but since I debugged one of them I'll send
  them on,

  Two reverts, a quirk and one warn regression"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  Revert "drm/i915: reverse dp link param selection, prefer fast over wide again"
  drm/i915: Track the primary plane correctly when reassigning planes
  drm/i915: Ignore VBT backlight presence check on HP Chromebook 14
  Revert "drm/i915: Don't set the 8to6 dither flag when not scaling"

Pull UML fixes from Richard Weinberger:
 "Four fixes, all discovered by Trinity"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: segv: Save regs only in case of a kernel mode fault
  um: Fix hung task in fix_range_common()
  um: Ensure that a stub page cannot get unmapped
  Revert "um: Fix wait_stub_done() error handling"

Pull btrfs fixes from Chris Mason:
 "We have two more fixes in my for-linus branch.

  I was hoping to also include a fix for a btrfs deadlock with
  compression enabled, but we're still nailing that one down"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: test for valid bdev before kobj removal in btrfs_rm_device
  Btrfs: fix abnormal long waiting in fsync

Pull NFS client fixes from Trond Myklebust:
 "Apologies for the relative lateness of this pull request, however the
  commits fix some issues with the NFS read/write code updates in
  3.16-rc1 that can cause serious Oopsing when using small r/wsize.  The
  delay was mainly due to extra testing to make sure that the fixes
  behave correctly.

  Highlights include;
   - Stable fix for an NFSv3 posix ACL regression
   - Multiple fixes for regressions to the NFS generic read/write code:
     - Fix page splitting bugs that come into play when a small
       rsize/wsize read/write needs to be sent again (due to error
       conditions or page redirty)
     - Fix nfs_wb_page_cancel, which is called by the "invalidatepage"
       method
   - Fix 2 compile warnings about unused variables
   - Fix a performance issue affecting unstable writes"

* tag 'nfs-for-3.16-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: Don't reset pg_moreio in __nfs_pageio_add_request
  NFS: Remove 2 unused variables
  nfs: handle multiple reqs in nfs_wb_page_cancel
  nfs: handle multiple reqs in nfs_page_async_flush
  nfs: change find_request to find_head_request
  nfs: nfs_page should take a ref on the head req
  nfs: mark nfs_page reqs with flag for extra ref
  nfs: only show Posix ACLs in listxattr if actually present

...otherwise me lose user mode regs and the resulting
stack trace is useless.
Signed-off-by: Richard Weinberger <richard@nod.at>

If do_ops() fails we have to release current->mm->mmap_sem
otherwise the failing task will never terminate.
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

Trinity discovered an execution path such that a task
can unmap his stub page.
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

This reverts commit 0974a9ca.
The real for for that issue is to release current->mm->mmap_sem in
fix_range_common().
Signed-off-by: Richard Weinberger <richard@nod.at>

commit 99994cde btrfs: dev delete should remove sysfs entry
added a btrfs_kobj_rm_device, which dereferences device->bdev...
right after we check whether device->bdev might be NULL.

I don't honestly know if it's possible to have a NULL device->bdev
here, but assuming that it is (given the test), we need to move
the kobject removal to be under that test.

(Coverity spotted this)
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>

xfstests generic/127 detected this problem.

With commit 7fc34a62, now fsync will only flush
data within the passed range.  This is the cause of the above problem,
-- btrfs's fsync has a stage called 'sync log' which will wait for all the
ordered extents it've recorded to finish.

In xfstests/generic/127, with mixed operations such as truncate, fallocate,
punch hole, and mapwrite, we get some pre-allocated extents, and mapwrite will
mmap, and then msync.  And I find that msync will wait for quite a long time
(about 20s in my case), thanks to ftrace, it turns out that the previous
fallocate calls 'btrfs_wait_ordered_range()' to flush dirty pages, but as the
range of dirty pages may be larger than 'btrfs_wait_ordered_range()' wants,
there can be some ordered extents created but not getting corresponding pages
flushed, then they're left in memory until we fsync which runs into the
stage 'sync log', and fsync will just wait for the system writeback thread
to flush those pages and get ordered extents finished, so the latency is
inevitable.

This adds a flush similar to btrfs_start_ordered_extent() in
btrfs_wait_logged_extents() to fix that.
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>