This patch adds mirrored write support to the pgio layer. The default
is to use one mirror, but pgio callers may define callbacks to change
this to any value up to the (arbitrarily selected) limit of 16.

The basic idea is to break out members of nfs_pageio_descriptor that cannot
be shared between mirrored DSes and put them in a new structure.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>

Pass ds_commit_idx through the nfs commit path. It's used to select
the commit bucket when using pnfs and is ignored when not using pnfs.
Several functions had to be changed: nfs_retry_commit,
nfs_mark_request_commit, pnfs_mark_request_commit and the pnfs layout
driver .mark_request_commit functions.
Signed-off-by: Tom Haynes <loghyr@primarydata.com>

'ds_commit_idx' is a better name - it is used to select the right
commit bucket for pnfs.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>

This is needed for mirrored DS support, where multuple requests
cover the same range.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>

This is needed to support mirrored writes - the first write can't just
trash the lseg, we need to keep it around until all mirrors have
written.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>

Add a new operation to nfs_pageio_ops that is called on nfs_pageio_complete.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>

Instead of calling layoutreturn directly, call pnfs_error_mark_layout_for_return
to mark layouts for return and let generic code return layout when
layout segments are freed.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

Conflicts:
	fs/nfs/filelayout/filelayout.c

So that pnfs path is not disabled for ever.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

If current lseg is the last lseg marked with NFS_LSEG_LAYOUTRETURN,
send layoutreturn.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

And if we are to return the same type of layouts, don't bother
sending more layoutgets.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

It marks all matching layout segments as NFS_LSEG_LAYOUTRETURN,
which is an indicator for pnfs_put_lseg() to send layoutreturn,
and also prevents pnfs_update_layout() from using the returning
segments. Once it is set, it never gets cleared.

It also sets proper io failure bit so that pnfs path can be retried
after PNFS_LAYOUTGET_RETRY_TIMEOUT second.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

It allows to specify different iomode to return.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

So that it is possible to return a specific iomode layouts.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

Flexfiles layout would want to use them to report DS IO status.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

Per RFC 5661 Errata 3208:
| A client MAY always forget its layout state and associated
| layout stateid at any time (See also section 12.5.5.1).
| In such case, the client MUST use a non-layout stateid for the next
| LAYOUTGET operation. This will signal the server that the client has
| no more layouts on the file and its respective layout state can be
| released before issuing a new layout in response to LAYOUTGET.

In order to make such a signal unique to server, client needs to serialize
all layoutgets using non-layout stateid. We implement this by serializing
layoutgets when client has no layout segments at hand.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

flexfiles needs to start layoutcommit when necessary
Signed-off-by: Peng Tao <tao.peng@primarydata.com>

lockd assumes hostname exists otherwise kernel oops.
It can be reproduced by following steps:
1. mount flexfile MDS
2. write some files
3. mount DS via nfsv3

BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [<ffffffff8134f332>] strlen+0x2/0x20
 PGD 0
 Oops: 0000 [#1] SMP
 Modules linked in: nfsd(F) nfs_layout_flexfiles(F) rpcsec_gss_krb5(F) auth_rpcgss(F) nfsv4(F) dns_resolver(F) nfsv3(F) nfs_acl(F) nfs(F) lockd(F) sunrpc(F) fscache(F) ebtable_nat(F) nf_conntrack_netbios_ns(F) nf_conntrack_broadcast(F) ipt_MASQUERADE(F) ip6table_nat(F) nf_nat_ipv6(F) ip6table_mangle(F) ip6t_REJECT(F) nf_conntrack_ipv6(F) nf_defrag_ipv6(F) iptable_nat(F) nf_nat_ipv4(F) nf_nat(F) iptable_mangle(F) nf_conntrack_ipv4(F) nf_defrag_ipv4(F) xt_conntrack(F) nf_conntrack(F) ebtable_filter(F) ebtables(F) ip6table_filter(F) ip6_tables(F) bnep(F) snd_ens1371(F) snd_rawmidi(F) snd_ac97_codec(F) btusb(F) ac97_bus(F) snd_seq(F) snd_seq_device(F) snd_pcm(F) ppdev(F) bluetooth(F) 6lowpan_iphc(F) rfkill(F) vmw_balloon(F) snd_timer(F) snd(F) soundcore(F) gameport(F) i2c_piix4(F) e1000(F) vmw_vmci(F) parport_pc(F) parport(F) shpchp(F) uinput(F) xfs(F) libcrc32c(F) vmwgfx(F) ttm(F) drm(F) mptspi(F) scsi_transport_spi(F) mptscsih(F) mptbase(F) i2c_core(F)
 CPU: 0 PID: 10397 Comm: mount.nfs Tainted: GF            3.14.7-100.pd_client.001.fc16.x86_64 #1
 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
 task: ffff880008942600 ti: ffff880007990000 task.ti: ffff880007990000
 RIP: 0010:[<ffffffff8134f332>]  [<ffffffff8134f332>] strlen+0x2/0x20
 RSP: 0018:ffff880007991aa0  EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffff880038d39c20 RCX: 0000000000000004
 RDX: 0000000000000006 RSI: 0000000000000010 RDI: 0000000000000000
 RBP: ffff880007991b38 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000014600 R11: 0000000000000400 R12: ffffffff81cc8580
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000004
 FS:  00007f90cd2ef880(0000) GS:ffff88003f600000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 0000000001710000 CR4: 00000000001407f0
 Stack:
  ffffffffa045f52c ffff880001782230 ffff880004141e28 0006880007991ac8
  ffffffff816dc14b ffff880000000000 ffff880038d39c20 0000000000000010
  0000000481cc0006 0000000000000000 ffffffffa0410be8 000000000000c014
 Call Trace:
  [<ffffffffa045f52c>] ? nlmclnt_lookup_host+0x4c/0x2c0 [lockd]
  [<ffffffff816dc14b>] ? _raw_spin_unlock_bh+0x1b/0x20
  [<ffffffffa0410be8>] ? svc_destroy+0xb8/0x140 [sunrpc]
  [<ffffffffa045c323>] nlmclnt_init+0x53/0xc0 [lockd]
  [<ffffffffa047d2dc>] ? nfs_get_client+0x1cc/0x340 [nfs]
  [<ffffffffa047c2e7>] nfs_start_lockd+0xa7/0xd0 [nfs]
  [<ffffffffa047df71>] nfs_create_server+0x181/0x5c0 [nfs]
  [<ffffffffa04460f3>] nfs3_create_server+0x13/0x30 [nfsv3]
  [<ffffffffa048a0bc>] nfs_try_mount+0x21c/0x300 [nfs]
  [<ffffffff811ca32d>] ? __kmalloc_track_caller+0x1ad/0x240
  [<ffffffffa048b677>] ? nfs_fs_mount+0xc37/0xd80 [nfs]
  [<ffffffffa048ad05>] nfs_fs_mount+0x2c5/0xd80 [nfs]
  [<ffffffffa048a830>] ? nfs_clone_super+0x140/0x140 [nfs]
  [<ffffffffa048a240>] ? nfs_clone_sb_security+0x40/0x40 [nfs]
  [<ffffffff811e7e43>] mount_fs+0x43/0x1b0
  [<ffffffff81193100>] ? __alloc_percpu+0x10/0x20
  [<ffffffff812026e6>] vfs_kern_mount+0x76/0x120
  [<ffffffff81204917>] do_mount+0x237/0xa80
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Add a call to tally stats for a task under a different statsidx than
what's contained in the task structure.

This is needed to properly account for pnfs reads/writes when the
DS nfs version != the MDS version.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

Enable pNFS callbacks to allow flex files to work correctly with a
NFSv3-enabled data server.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

so that flexfile layout client can pass in DS credential instead of
using user cred, which will be done in the next patch.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

flexclient needs this as there is no nfs_server to DS connection.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

pnfs flexfile layout client may want to use NFSv3 ops rather
than the default MDS v4 ops.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

Signed-off-by: Tom Haynes <loghyr@primarydata.com>

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

flexfile layout may need to set such when making DS connections.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

The flexfiles layout wants to create DS connection over NFSv3.
Add nfs3_set_ds_client to allow that to happen.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

They can be reused by flexfile layout as well.

Also add a code such that if read fails on one DS and
there are other DSes available to use, don't resend
through MDS but through pNFS so that client can read
from other DSes.
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

flexfile layout may use different auth flavor as specified by MDS.
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

It can be reused by flexfiles layout client.
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

It can be reused by flexfile layout.
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

Also pull nfs4_pnfs_ds_addr and nfs4_pnfs_ds to generic pnfs.

They can all be reused by flexfile layout as well.
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

Acked-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Tom Haynes <loghyr@primarydata.com>

The flexfilelayout driver will share some common code
with the filelayout driver. This set of changes refactors
that common code out to avoid any module depenencies.
Signed-off-by: Tom Haynes <loghyr@primarydata.com>

Pull ARM SoC fixes from Olof Johansson:
 "We've been sitting on our fixes branch for a while, so this batch is
  unfortunately on the large side.

  A lot of these are tweaks and fixes to device trees, fixing various
  bugs around clocks, reg ranges, etc.  There's also a few defconfig
  updates (which are on the late side, no more of those).

  All in all the diffstat is bigger than ideal at this time, but nothing
  in here seems particularly risky"

* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
  reset: sunxi: fix spinlock initialization
  ARM: dts: disable CCI on exynos5420 based arndale-octa
  drivers: bus: check cci device tree node status
  ARM: rockchip: disable jtag/sdmmc autoswitching on rk3288
  ARM: nomadik: fix up leftover device tree pins
  ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree
  ARM: at91/dt: sam9263: Add missing clocks to lcdc node
  ARM: at91: sama5d3: dt: correct the sound route
  ARM: at91/dt: sama5d4: fix the timer reg length
  ARM: exynos_defconfig: Enable LM90 driver
  ARM: exynos_defconfig: Enable options for display panel support
  arm: dts: Use pmu_system_controller phandle for dp phy
  ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances
  ARM: dts: berlin: correct BG2Q's SM GPIO location.
  ARM: dts: berlin: add broken-cd and set bus width for eMMC in Marvell DMP DT
  ARM: dts: berlin: fix io clk and add missing core clk for BG2Q sdhci2 host
  ARM: dts: Revert disabling of smc91x for n900
  ARM: dts: imx51-babbage: Fix ULPI PHY reset modelling
  ARM: dts: dra7-evm: fix qspi device tree partition size
  ARM: omap2plus_defconfig: use CONFIG_CPUFREQ_DT
  ...

Pull clock driver fixes from Mike Turquette:
 "Small number of fixes for clock drivers and a single null pointer
  dereference fix in the framework core code.

  The driver fixes vary from fixing section mismatch warnings to
  preventing machines from hanging (and preventing developers from
  crying)"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk: fix possible null pointer dereference
  Revert "clk: ppc-corenet: Fix Section mismatch warning"
  clk: rockchip: fix deadlock possibility in cpuclk
  clk: berlin: bg2q: remove non-exist "smemc" gate clock
  clk: at91: keep slow clk enabled to prevent system hang
  clk: rockchip: fix rk3288 cpuclk core dividers
  clk: rockchip: fix rk3066 pll lock bit location
  clk: rockchip: Fix clock gate for rk3188 hclk_emem_peri
  clk: rockchip: add CLK_IGNORE_UNUSED flag to fix rk3066/rk3188 USB Host

Pull SCSI fixes from James Bottomley:
 "This is one fix for a Multiqueue sleeping in invalid context problem
  and a MAINTAINER file update for Qlogic"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ->queue_rq can't sleep
  MAINTAINERS: Update maintainer list for qla4xxx

The commit 646cafc6 (clk: Change clk_ops->determine_rate to
return a clk_hw as the best parent) opens a possibility for
null pointer dereference, fix this.
Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>