Upon receiving a stateid error such as BAD_STATEID, the client
should retry the operation against the MDS before deciding to
do stateid recovery.

Previously, the code would initiate state recovery and it could
lead to a race in a state manager that could chose an incorrect
recovery method which would lead to the EIO failure for the
application.
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If xdr_inline_decode() fails then we end up returning ERR_PTR(0).  The
caller treats NULL returns as -ENOMEM so it doesn't really hurt runtime,
but obviously we intended to set an error code here.

Fixes: d67ae825 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Layoutstats is always desirable when using the flexfiles driver, so
we should enable it if that driver is being loaded. It is safe to do
so, because even when the mount specifies NFSv4.1, we will turn it
off if the server tells us it is unsupported.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the attempt to write through pNFS fails, we need to use the same
failure semantics as for the read path: If the FF_FLAGS_NO_IO_THRU_MDS
flag is set or we have sufficient valid DSes, then we must retry through
pNFS

Fixes: d67ae825 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we have a layout segment cached in pgio->pg_lseg, we should check it
for validity before reusing it in a new RPC request. Otherwise, if we
recoalesce, we can end up looping forever.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Now that %z is standartised in C99 there is no reason to support %Z.
Unlike %L it doesn't even make format strings smaller.

Use BUILD_BUG_ON in a couple ATM drivers.

In case anyone didn't notice lib/vsprintf.o is about half of SLUB which
is in my opinion is quite an achievement.  Hopefully this patch inspires
someone else to trim vsprintf.c more.

Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If we see that our pNFS READ/WRITE/COMMIT operation failed, but we
also see that our layout segment is no longer valid, then we need to
get a new layout segment before retrying.

Fixes: 90816d1d ("NFSv4.1/flexfiles: Don't mark the entire deviceid...")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Fixes the following sparse warning:

fs/nfs/flexfilelayout/flexfilelayout.c:2114:34: warning:
 symbol 'layoutreturn_ops' was not declared. Should it be static?
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

This does the right thing depending on if we have a session, rather than
needing to handle this manually in multiple places.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

No point in going through loops and hoops instead of just comparing the
values.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

ktime is a union because the initial implementation stored the time in
scalar nanoseconds on 64 bit machine and in a endianess optimized timespec
variant for 32bit machines. The Y2038 cleanup removed the timespec variant
and switched everything to scalar nanoseconds. The union remained, but
become completely pointless.

Get rid of the union and just keep ktime_t as simple typedef of type s64.

The conversion was done with coccinelle and some manual mopping up.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

Instead of marking a device inactive, remove it from the cache entirely.

Flexfiles has a way to report errors back to the server, so we don't want
to stop devices from being tried again for 120 seconds.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The flexfiles client can piggyback both layout errors and layoutstats
as part of the layoutreturn. Both these payloads can get large, with
20 layout error entries taking up about 1.2K, and 4 layoutstats entries
taking up another 1K.
This patch allows a maximum payload of 4k by allocating a full page.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

  We encountered a deadlock where the SEQUENCE that accompanied the
LAYOUTGET triggered a session drain, while ff_layout_alloc_lseg
triggered a GETDEVICEINFO.  The GETDEVICEINFO hung waiting for the
session drain, while the LAYOUTGET held the slot waiting for
alloc_lseg to finish.
  Avoid this by moving the call to nfs4_find_get_deviceid out of
ff_layout_alloc_lseg and into nfs4_ff_layout_prepare_ds.
Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
[dros@primarydata.com: pNFS/flexfiles: fix races in ff_layout_mirror_valid]
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Add the ability to send an array of layoutstats entries as part of
layoutreturn.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Need to lock while reading in order to ensure 64-bit reads are correct.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Add the layout error payload to the flexfiles layoutreturn private
data, and set up the encoding mechanisms. This is a refactoring in
preparation for adding the layout iostats payload.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If there have been no reads or writes to a given mirror since the last
layoutstats update, then don't resend the same data.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the list of mirrors is empty, then don't send an RPC call.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The parameter is already present in the "args" structure.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We must not call nfs_pageio_init_read() on a new nfs_pageio_descriptor
while holding a reference to a layout segment, as that can deadlock
pnfs_update_layout().

Fixes: d67ae825 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.0+

Allow the callers of nfs_remove_bad_delegation() to specify the stateid
that needs to be marked as bad.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Tested-by: NOleg Drokin <green@linuxhacker.ru>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the attempt to connect to a DS fails inside ff_layout_pg_init_read or
ff_layout_pg_init_write, then we currently end up clearing the layout
segment carried by the struct nfs_pageio_descriptor, causing an Oops
when we later call into ff_layout_read_pagelist/ff_layout_write_pagelist.

The fix is to ensure we return the layout and then retry.

Fixes: 446ca219 ("pNFS/flexfiles: When initing reads or writes, we...")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Putting the periodicity timer in the mirror instances is causing
non-scalable reporting behaviour and missed reporting intervals.
When you recall layouts and/or implement client side mirroring, it
leads to consecutive reports with only a few ms between RPC calls.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Fixes: d0379a5d ("pNFS/flexfiles: Support server-supplied...")

So ensure that we mark the layout for commit once the write is done,
and then ensure that the commit to ds is finished before sending
layoutcommit.

Note that by doing this, we're able to optimise away the commit
for the case of servers that don't need layoutcommit in order to
return updated attributes.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Let's just have one place where we check ff_layout_need_layoutcommit().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We should always do a layoutcommit after commit to DS, except if
the layout segment we're using has set FF_FLAGS_NO_LAYOUTCOMMIT.

Fixes: d67ae825 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

As flexfiles has FF_FLAGS_NO_READ_IO, there is a need to generically
support enforcing that a IOMODE_RW segment will not allow READ I/O.
Signed-off-by: NTom Haynes <loghyr@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Signed-off-by: NTom Haynes <loghyr@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Setting just the NFS_LAYOUT_RETURN_REQUESTED flag doesn't do anything,
unless there are lsegs that are also being marked for return. At the
point where that happens this flag is also set, so these set_bit calls
don't do anything useful.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Otherwise, we'll end up returning layouts that we've just received if
the client issues a new LAYOUTGET prior to the LAYOUTRETURN.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If we are initializing reads or writes and can not connect to a DS, then
check whether or not IO is allowed through the MDS. If it is allowed,
reset to the MDS. Else, fail the layout segment and force a retry
of a new layout segment.
Signed-off-by: NTom Haynes <loghyr@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Whenever we check to see if we have the needed number of DSes for the
action, we may also have to check to see whether IO is allowed to go to
the MDS or not.

[jlayton: fix merge conflict due to lack of localio patches here]
Signed-off-by: NTom Haynes <loghyr@primarydata.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

This patch fixes a problem whereby the pNFS client falls back to doing
reads and writes through the metadata server even when the layout flag
FF_FLAGS_NO_IO_THRU_MDS is set.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

In order to more easily distinguish what kind of stateid we are dealing
with, introduce a type that can be used to label the stateid structure.

The label will be useful both for debugging, but also when dealing with
operations like SETATTR, READ and WRITE that can take several different
types of stateid as arguments.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

A mirror can be shared between multiple layouts, even with different
iomodes. That makes stats gathering simpler, but it causes a problem
when we get different creds in READ vs. RW layouts.

The current code drops the newer credentials onto the floor when this
occurs. That's problematic when you fetch a READ layout first, and then
a RW. If the READ layout doesn't have the correct creds to do a write,
then writes will fail.

We could just overwrite the READ credentials with the RW ones, but that
would break the ability for the server to fence the layout for reads if
things go awry. We need to be able to revert to the earlier READ creds
if the RW layout is returned afterward.

The simplest fix is to just keep two sets of creds per mirror. One for
READ layouts and one for RW, and then use the appropriate set depending
on the iomode of the layout segment.

Also fix up some RCU nits that sparse found.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>