Commit Graph

58 Commits

Author SHA1 Message Date
Trond Myklebust
75bf47ebf6 pNFS/flexfile: Fix erroneous fall back to read/write through the MDS
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: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-05-17 15:48:07 -04:00
Trond Myklebust
93b717fd81 NFSv4: Label stateids with the type
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: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-05-17 15:48:06 -04:00
Jeff Layton
3064b6861d nfs: have flexfiles mirror keep creds for both ro and rw layouts
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: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-05-09 09:05:40 -04:00
Jeff Layton
90a0be00e9 nfs: get a reference to the credential in ff_layout_alloc_lseg
We're just as likely to have allocation problems here as we would if we
delay looking up the credential like we currently do. Fix the code to
get a rpc_cred reference early, as soon as the mirror is set up.

This allows us to eliminate the mirror early if there is a problem
getting an rpc credential. This also allows us to drop the uid/gid
from the layout_mirror struct as well.

In the event that we find an existing mirror where this one would go, we
swap in the new creds unconditionally, and drop the reference to the old
one.

Note that the old ff_layout_update_mirror_cred function wouldn't set
this pointer unless the DS version was 3, but we don't know what the DS
version is at this point. I'm a little unclear on why it did that as you
still need creds to talk to v4 servers as well. I have the code set
it regardless of the DS version here.

Also note the change to using generic creds instead of calling
lookup_cred directly. With that change, we also need to populate the
group_info pointer in the acred as some functions expect that to never
be NULL. Instead of allocating one every time however, we can allocate
one when the module is loaded and share it since the group_info is
refcounted.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-05-09 09:05:40 -04:00
Jeff Layton
57f3f4c0cd nfs: have ff_layout_get_ds_cred take a reference to the cred
In later patches, we're going to want to allow the creds to be updated
when we get a new layout with updated creds. Have this function take
a reference to the cred that is later put once the call has been
dispatched.

Also, prepare for this change by ensuring we follow RCU rules when
getting a reference to the cred as well.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-05-09 09:05:40 -04:00
Dave Wysochanski
fe238e601d NFS: Save struct inode * inside nfs_commit_info to clarify usage of i_lock
Commit ea2cf22 created nfs_commit_info and saved &inode->i_lock inside
this NFS specific structure.  This obscures the usage of i_lock.
Instead, save struct inode * so later it's clear the spinlock taken is
i_lock.

Should be no functional change.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-05-09 09:05:40 -04:00
Trond Myklebust
2370abdab5 NFS: Cleanup - rename NFS_LAYOUT_RETURN_BEFORE_CLOSE
NFS_LAYOUT_RETURN_BEFORE_CLOSE is being used to signal that a
layoutreturn is needed, either due to a layout recall or to a
layout error. Rename it to NFS_LAYOUT_RETURN_REQUESTED in order
to clarify its purpose.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-01-27 20:40:05 -05:00
Trond Myklebust
6d45c042f3 Merge branch 'bugfixes'
* bugfixes:
  pNFS/flexfiles: Fix an XDR encoding bug in layoutreturn
  pNFS/flexfiles: Improve merging of errors in LAYOUTRETURN
2016-01-22 11:02:36 -05:00
Trond Myklebust
082fa37d13 pNFS/flexfiles: Fix an XDR encoding bug in layoutreturn
We must not skip encoding the statistics, or the server will see an
XDR encoding error.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # 4.0+
2016-01-22 11:01:44 -05:00
Trond Myklebust
daaadd2283 Merge branch 'bugfixes'
* bugfixes:
  SUNRPC: Fixup socket wait for memory
  SUNRPC: Fix a missing break in rpc_anyaddr()
  pNFS/flexfiles: Fix an Oopsable typo in ff_mirror_match_fh()
  NFS: Fix attribute cache revalidation
  NFS: Ensure we revalidate attributes before using execute_ok()
  NFS: Flush reclaim writes using FLUSH_COND_STABLE
  NFS: Background flush should not be low priority
  NFSv4.1/pnfs: Fixup an lo->plh_block_lgets imbalance in layoutreturn
  NFSv4: Don't perform cached access checks before we've OPENed the file
  NFS: Allow the combination pNFS and labeled NFS
  NFS42: handle layoutstats stateid error
  nfs: Fix race in __update_open_stateid()
  nfs: fix missing assignment in nfs4_sequence_done tracepoint
2016-01-07 18:45:36 -05:00
Trond Myklebust
942e3d72a6 Merge branch 'pnfs_generic'
* pnfs_generic:
  NFSv4.1/pNFS: Cleanup constify struct pnfs_layout_range arguments
  NFSv4.1/pnfs: Cleanup copying of pnfs_layout_range structures
  NFSv4.1/pNFS: Cleanup pnfs_mark_matching_lsegs_invalid()
  NFSv4.1/pNFS: Fix a race in initiate_file_draining()
  NFSv4.1/pNFS: pnfs_error_mark_layout_for_return() must always return layout
  NFSv4.1/pNFS: pnfs_mark_matching_lsegs_return() should set the iomode
  NFSv4.1/pNFS: Use nfs4_stateid_copy for copying stateids
  NFSv4.1/pNFS: Don't pass stateids by value to pnfs_send_layoutreturn()
  NFS: Relax requirements in nfs_flush_incompatible
  NFSv4.1/pNFS: Don't queue up a new commit if the layout segment is invalid
  NFS: Allow multiple commit requests in flight per file
  NFS/pNFS: Fix up pNFS write reschedule layering violations and bugs
  NFSv4: List stateid information in the callback tracepoints
  NFSv4.1/pNFS: Don't return NFS4ERR_DELAY unnecessarily in CB_LAYOUTRECALL
  NFSv4.1/pNFS: Ensure we enforce RFC5661 Section 12.5.5.2.1
  pNFS: If we have to delay the layout callback, mark the layout for return
  NFSv4.1/pNFS: Add a helper to mark the layout as returned
  pNFS: Ensure nfs4_layoutget_prepare returns the correct error
2016-01-04 13:19:55 -05:00
Trond Myklebust
dc602dd706 NFS/pNFS: Fix up pNFS write reschedule layering violations and bugs
The flexfiles layout in particular, seems to want to poke around in the
O_DIRECT flags when retransmitting.
This patch sets up an interface to allow it to call back into O_DIRECT
to handle retransmission correctly. It also fixes a potential bug whereby
we could change the behaviour of O_DIRECT if an error is already pending.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-31 13:50:42 -05:00
Trond Myklebust
86fb449b07 pNFS/flexfiles: Fix an Oopsable typo in ff_mirror_match_fh()
Jeff reports seeing an Oops in ff_layout_alloc_lseg. Turns out
copy+paste has played cruel tricks on a nested loop.

Reported-by: Jeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-30 10:57:01 -05:00
Trond Myklebust
4d0ac22109 pNFS/flexfiles: Ensure we record layoutstats even if RPC is terminated early
Currently, we will only record the layoutstats correctly if the
RPC call successfully obtains a slot. If we exit before that
happens, then we may find ourselves starting the busy timer through
the call in ff_layout_(read|write)_prepare_layoutstats, but never stopping it.

The same thing happens if we're doing DA-DS.

The fix is to ensure that we catch these cases in the rpc_release()
callback.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:41 -05:00
Trond Myklebust
37e9ed22b1 pNFS: Add flag to track if we've called nfs4_ff_layout_stat_io_start_read/write
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:41 -05:00
Trond Myklebust
7eeea16797 pNFS/flexfiles: Fix a statistics gathering imbalance
When we replay a failed read, write or commit to the dataserver, we
need to ensure that we call ff_layout_read_prepare_v3(),
ff_layout_write_prepare_v3 or ff_layout_commit_prepare_v3() so that we
reset the statistics.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:40 -05:00
Trond Myklebust
2e5b29f044 pNFS/flexfiles: Don't prevent flexfiles client from retrying LAYOUTGET
Fix a bug in which flexfiles clients are falling back to I/O through the
MDS even when the FF_FLAGS_NO_IO_THRU_MDS flag is set.

The flexfiles client will always report errors through the LAYOUTRETURN
and/or LAYOUTERROR mechanisms, so it should normally be safe for it
to retry the LAYOUTGET until it fails or succeeds.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:40 -05:00
Peng Tao
141b9b59ed pnfs/flexfiles: count io stat in rpc_count_stats callback
If client ever restarts IO due to some errors, we'll endup
mis-counting IO stats if we do the counting in .rpc_done
callback. Move it to .rpc_count_stats callback that is only
called when releasing RPC.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:39 -05:00
Peng Tao
c22eeb8697 pnfs/flexfiles: do not mark delay-like status as DS failure
We just need to delay and retry in these cases.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:39 -05:00
Peng Tao
d600ad1f2b NFS41: pop some layoutget errors to application
For ERESTARTSYS/EIO/EROFS/ENOSPC/E2BIG in layoutget, we
should just bail out instead of hiding the error and
retrying inband IO.

Change all the call sites to pop the error all the way up.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:36 -05:00
Trond Myklebust
d0379a5d06 pNFS/flexfiles: Support server-supplied layoutstats sampling period
Some servers want to be able to control the frequency with which clients
report layoutstats, for instance, in order to monitor QoS for a particular
file or set of file. In order to support this, the flexfiles layout allows
the server to pass this info as a hint in the layout payload.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:36 -05:00
Trond Myklebust
260074cd84 pNFS/flexfiles: Add support for FF_FLAGS_NO_IO_THRU_MDS
For loosely coupled pNFS/flexfiles systems, there is often no advantage
at all in going through the MDS for I/O, since the MDS is subject to
the same limitations as all other clients when talking to DSes. If a
DS is unresponsive, I/O through the MDS will fail.

For such systems, the only scalable solution is to have the pNFS clients
retry doing pNFS, and so the protocol now provides a flag that allows
the pNFS server to signal this.

If LAYOUTGET returns FF_FLAGS_NO_IO_THRU_MDS, then we should assume that
the MDS wants the client to retry using these devices, even if they were
previously marked as being unavailable. To do so, we add a helper,
ff_layout_mark_devices_valid() that will be called from layoutget.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-11-02 13:50:37 -05:00
Trond Myklebust
135444126a pNFS/flexfiles: When mirrored, retry failed reads by switching mirrors
If the pNFS/flexfiles file is mirrored, and a read to one mirror fails,
then we should bump the mirror index, so that we retry to a different
mirror. Once we've iterated through all mirrors and all failed, we can
return the layout and issue a new LAYOUTGET.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-11-02 13:50:35 -05:00
Trond Myklebust
7cc8c5cde0 NFSv4.1/flexfiles: Clean up ff_layout_write_done_cb/ff_layout_commit_done_cb
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-09-02 15:24:54 -07:00
Trond Myklebust
f95c03b2d5 NFSv4.1/flexfiles: Mark the layout for return in ff_layout_io_track_ds_error()
When I/O cannot complete due to a fatal error on the DS, ensure that we
invalidate the corresponding layout segment and return it.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-09-02 15:24:26 -07:00
Trond Myklebust
972398fa0a NFSv4.1/flexfiles: Fix freeing of mirrors
Mirrors are now shared objects, so we should not be freeing them directly
inside ff_layout_free_lseg(). We should already be doing the right thing
in _ff_layout_free_lseg(), so just let it handle things.

Also ensure that ff_layout_free_mirror() frees the RPC credential if it
is set.

Fixes: 28a0d72c68 ("Add refcounting to struct nfs4_ff_layout_mirror")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-09-01 12:18:57 -07:00
Trond Myklebust
90816d1dda NFSv4.1/flexfiles: Don't mark the entire deviceid as bad for file errors
If the file was fenced and/or has been deleted on the DS, then we want
to retry pNFS after a layoutreturn with error report. If the server
cannot fix the problem, then we rely on it to tell us so in the
response to the LAYOUTGET.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-30 13:10:27 -07:00
Trond Myklebust
0762ed2ced NFSv4.1/flexfiles: Allow coalescing of new layout segments and existing ones
In order to ensure atomicity of updates, we merge the old layout segments
into the new ones, and then invalidate the old ones.

Also ensure that we order the list of layout segments so that
RO segments are preferred over RW.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-25 19:42:43 -04:00
kbuild test robot
e3b1df2dbd NFSv4.1/flexfile: ff_layout_remove_mirror can be static
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-25 14:40:09 -04:00
Trond Myklebust
bbf58bf348 NFSv4.2/pnfs: Make the layoutstats timer configurable
Allow advanced users to set the layoutstats timer in order to lengthen
or shorten the period between layoutstat transmissions to the server.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-25 14:40:08 -04:00
Trond Myklebust
266d12d42e NFSv4.1/flexfile: Ensure uniqueness of mirrors across layout segments
Keep the full list of mirrors in the struct nfs4_ff_layout_mirror so that
they can be shared among the layout segments that use them.
Also ensure that we send out only one copy of the layoutstats per mirror.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-25 14:40:08 -04:00
Trond Myklebust
0b7baf9433 NFSv4.1/flexfiles: Remove mirror backpointer to lseg.
When we start sharing mirrors between several lsegs, we won't be able to
keep it.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-25 14:40:08 -04:00
Trond Myklebust
28a0d72c68 NFSv4.1/flexfiles: Add refcounting to struct nfs4_ff_layout_mirror
We do want to share mirrors between layout segments, so add a refcount
to enable that.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-25 14:40:07 -04:00
Peng Tao
5420401079 NFS41/flexfiles: zero out DS write wcc
We do not want to update inode attributes with DS values.

Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-25 14:40:06 -04:00
Trond Myklebust
dd52128afd NFSv4.1/pnfs Ensure flexfiles reports all connection related errors
Make sure that we also handle RPC level connection and protocol
negotiation errors.

Reported-by: Tom Haynes <loghyr@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-20 18:33:42 -05:00
Trond Myklebust
e76d28dd9c NFSv4.1/pnfs: Ensure the flexfiles layoutstats timers are consistent
We want to ensure that the stopwatches for the busy timer and the
aggregate timer are consistent. This means that they need to use
the same start/stop times.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-20 13:43:53 -05:00
Peng Tao
69f230d907 NFS41/flexfiles: update inode after write finishes
Otherwise we break fstest case tests/read_write/mctime.t

Does files layout need the same fix as well?

Cc: stable@vger.kernel.org # v4.0+
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-19 13:51:16 -05:00
Jeff Layton
ce60328146 nfs: remove some dead code in ff_layout_pg_get_mirror_count_write
We already know that pg_lseg is NULL here.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-17 13:25:03 -05:00
Trond Myklebust
c8ad8894e9 NFSv4.2/pnfs: Use GFP_NOIO for layoutstat reporting in the writeback path
Prevent a potential deadlock.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-12 14:27:23 -04:00
Peng Tao
d099d7b831 pnfs/flexfiles: LAYOUTSTATS ii_count should be ops instead of bytes
Turned out I misinterpreted the spec...

Cc: Tom Haynes <thomas.haynes@primarydata.com>
Reported-by: Jean Spector <jean@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-08-12 14:26:17 -04:00
Trond Myklebust
690edcfad0 NFSv4.2/flexfiles: Fix a typo in the flexfiles layoutstats code
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-07-08 20:25:41 +02:00
Trond Myklebust
d620876990 pNFS/flexfiles: Fix the reset of struct pgio_header when resending
hdr->good_bytes needs to be set to the length of the request, not
zero.

Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-26 15:39:50 -04:00
Trond Myklebust
c0f5f5059f pNFS/flexfiles: Turn off layoutcommit for servers that don't need it
This patch ensures that we record the value of 'ffl_flags' from
the layout, and then checks for the presence of the
FF_FLAGS_NO_LAYOUTCOMMIT flag before deciding whether or not to
call pnfs_set_layoutcommit().

The effect is that servers now can decide whether or not they want
the client to call layoutcommit before returning a writeable layout.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-26 14:51:32 -04:00
Peng Tao
9bbd9bb40c pnfs/flexfiles: protect ktime manipulation with mirror lock
It looks as if xchg() and cmpxchg() are not available for 64-bit integers on sparc32:

> New breakage seen in linux-next today:
>
> ERROR: "__xchg_called_with_bad_pointer" [fs/nfs/flexfilelayout/nfs_layout_flexfiles.ko] undefined!
> ERROR: "__cmpxchg_called_with_bad_pointer" [fs/nfs/flexfilelayout/nfs_layout_flexfiles.ko] undefined!
> make[2]: *** [__modpost] Error 1
> make[1]: *** [modules] Error 2

Given that mirror ktime manipulation is already under mirror->lock, let's make use of the fact.

Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-26 14:01:37 -04:00
Peng Tao
97ba375b5d pnfs/flexfiles: report layoutstat regularly
As a simple scheme, report every minute if IO is still going on.

Reviewed-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-24 10:54:23 -04:00
Peng Tao
27c4306443 pnfs/flexfiles: encode LAYOUTSTATS flexfiles specific data
Reviewed-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-24 10:53:11 -04:00
Peng Tao
ad4dc53e64 pnfs/flexfiles: add ff_layout_prepare_layoutstats
It fills in the generic part of LAYOUTSTATS call. One thing to note
is that we don't really track if IO is continuous or not. So just fake
to use the completed bytes for it.

Still missing flexfiles specific part, which will be included in the next patch.

Reviewed-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-24 10:53:11 -04:00
Peng Tao
d983803d38 pNFS/flexfiles: track when layout is first used
So that we can report cumulative time since the beginning
of statistics collection of the layout.

Reviewed-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-24 10:53:10 -04:00
Trond Myklebust
abcb7bfc9f pNFS/flexfiles: add layoutstats tracking
Reviewed-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-24 10:53:10 -04:00
Fabian Frederick
455b6ee645 pnfs/flexfiles: use swap() in ff_layout_sort_mirrors()
Use kernel.h macro definition.

Thanks to Julia Lawall for Coccinelle scripting support.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-16 11:14:03 -04:00