Commit Graph

84 Commits

Author SHA1 Message Date
Anna Schumaker
c4a123d2e8 pNFS: Fix assignment of xprtdata.cred
The comma at the end of the line was leftover from an earlier refactor
of the _nfs4_pnfs_v3_ds_connect() function. This is technically valid C,
so the compilers didn't catch it, but if I'm understanding how it works
correctly it assigns the return value of rpc_clnt_add_xprtr() to
xprtdata.cred.

Reported-by: Olga Kornievskaia <kolga@netapp.com>
Fixes: a12f996d34 ("NFSv4/pNFS: Use connections to a DS that are all of the same protocol family")
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-08-30 14:31:31 -04:00
Trond Myklebust
537935f72e NFS/pNFS: Set the connect timeout for the pNFS flexfiles driver
Ensure that the connect timeout for the pNFS flexfiles driver is of the
same order as the I/O timeout, so that we can fail over quickly when
trying to read from a data server that is down.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-08-24 13:24:15 -04:00
Trond Myklebust
0c493b5cf1 NFS: Convert buffered writes to use folios
Mostly mechanical conversion of struct page and functions into struct
folio equivalents.
The lack of support for folios in write_cache_pages(), means we still
only support order 0 folio allocations. However the rest of the
writeback code should now be ready for order n > 0.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-02-14 14:22:32 -05:00
Kees Cook
cf0d7e7f45 NFS: Avoid memcpy() run-time warning for struct sockaddr overflows
The 'nfs_server' and 'mount_server' structures include a union of
'struct sockaddr' (with the older 16 bytes max address size) and
'struct sockaddr_storage' which is large enough to hold all the
supported sa_family types (128 bytes max size). The runtime memcpy()
buffer overflow checker is seeing attempts to write beyond the 16
bytes as an overflow, but the actual expected size is that of 'struct
sockaddr_storage'. Plumb the use of 'struct sockaddr_storage' more
completely through-out NFS, which results in adjusting the memcpy()
buffers to the correct union members. Avoids this false positive run-time
warning under CONFIG_FORTIFY_SOURCE:

  memcpy: detected field-spanning write (size 28) of single field "&ctx->nfs_server.address" at fs/nfs/namespace.c:178 (size 16)

Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/all/202210110948.26b43120-yujie.liu@intel.com
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2022-10-27 15:52:10 -04:00
Jiangshan Yi
74fd2ca0f6 fs/nfs/pnfs_nfs.c: fix spelling typo and syntax error in comment
Fix spelling typo and syntax error in comment.

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2022-10-05 15:29:23 -04:00
Trond Myklebust
515dcdcd48 NFS: nfsiod should not block forever in mempool_alloc()
The concern is that since nfsiod is sometimes required to kick off a
commit, it can get locked up waiting forever in mempool_alloc() instead
of failing gracefully and leaving the commit until later.

Try to allocate from the slab first, with GFP_KERNEL | __GFP_NORETRY,
then fall back to a non-blocking attempt to allocate from the memory
pool.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2022-03-22 15:52:56 -04:00
Trond Myklebust
133a48abf6 NFS: Fix up commit deadlocks
If O_DIRECT bumps the commit_info rpcs_out field, then that could lead
to fsync() hangs. The fix is to ensure that O_DIRECT calls
nfs_commit_end().

Fixes: 723c921e7d ("sched/wait, fs/nfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-10-20 18:09:45 -04:00
Baptiste Lepers
a2915fa062 pnfs/flexfiles: Fix misplaced barrier in nfs4_ff_layout_prepare_ds
_nfs4_pnfs_v3/v4_ds_connect do
   some work
   smp_wmb
   ds->ds_clp = clp;

And nfs4_ff_layout_prepare_ds currently does
   smp_rmb
   if(ds->ds_clp)
      ...

This patch places the smp_rmb after the if. This ensures that following
reads only happen once nfs4_ff_layout_prepare_ds has checked that data
has been properly initialized.

Fixes: d67ae825a5 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-10-03 23:00:50 -04:00
Trond Myklebust
dd5c153ed7 NFSv4/pNFS: Return an error if _nfs4_pnfs_v3_ds_connect can't load NFSv3
Currently we fail to return an error if the NFSv3 module failed to load
when we're trying to connect to a pNFS data server.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-07-08 14:03:26 -04:00
Trond Myklebust
f46f84931a NFSv4/pNFS: Don't call _nfs4_pnfs_v3_ds_connect multiple times
After we grab the lock in nfs4_pnfs_ds_connect(), there is no check for
whether or not ds->ds_clp has already been initialised, so we can end up
adding the same transports multiple times.

Fixes: fc821d5920 ("pnfs/NFSv4.1: Add multipath capabilities to pNFS flexfiles servers over NFSv3")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-07-08 14:03:26 -04:00
Trond Myklebust
46c9ea1d4f NFS/pNFS: Don't leak DS commits in pnfs_generic_retry_commit()
We must ensure that we pass a layout segment to nfs_retry_commit() when
we're cleaning up after pnfs_bucket_alloc_ds_commits(). Otherwise,
requests that should be committed to the DS will get committed to the
MDS.
Do so by ensuring that pnfs_bucket_get_committing() always tries to
return a layout segment when it returns a non-empty page list.

Fixes: c84bea5944 ("NFS/pNFS: Simplify bucket layout segment reference counting")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-01-10 13:32:52 -05:00
Trond Myklebust
1757655d78 NFS/pNFS: Don't call pnfs_free_bucket_lseg() before removing the request
In pnfs_generic_clear_request_commit(), we try calling
pnfs_free_bucket_lseg() before we remove the request from the DS bucket.
That will always fail, since the point is to test for whether or not
that bucket is empty.

Fixes: c84bea5944 ("NFS/pNFS: Simplify bucket layout segment reference counting")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-01-10 13:32:52 -05:00
Trond Myklebust
9889981349 pNFS: Clean up open coded xdr string decoding
Use the existing xdr_stream_decode_string_dup() to safely decode into
kmalloced strings.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-12-02 14:05:53 -05:00
Trond Myklebust
4be78d2681 NFSv4/pNFS: Store the transport type in struct nfs4_pnfs_ds_addr
We want to enable RDMA and UDP as valid transport methods if a
GETDEVICEINFO call specifies it. Do so by adding a parser for the
netid that translates it to an appropriate argument for the RPC
transport layer.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-12-02 14:05:53 -05:00
Trond Myklebust
190c75a31f pNFS: Add helpers for allocation/free of struct nfs4_pnfs_ds_addr
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-12-02 14:05:53 -05:00
Trond Myklebust
a12f996d34 NFSv4/pNFS: Use connections to a DS that are all of the same protocol family
If the pNFS metadata server advertises multiple addresses for the same
data server, we should try to connect to just one protocol family and
transport type on the assumption that homogeneity will improve performance.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-12-02 14:05:53 -05:00
Trond Myklebust
4fa7ef69e2 NFS/pnfs: Don't use RPC_TASK_CRED_NOREF with pnfs
When we're doing pnfs then the credential being used for the RPC call
is not necessarily the same as the one used in the open context, so
don't use RPC_TASK_CRED_NOREF.

Fixes: 6129650720 ("NFSv4: Avoid referencing the cred unnecessarily during NFSv4 I/O")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-05-13 09:55:36 -04:00
Trond Myklebust
27d231c0c6 pNFS: Fix RCU lock leakage
Another brown paper bag moment. pnfs_alloc_ds_commits_list() is leaking
the RCU lock.

Fixes: a9901899b6 ("pNFS: Add infrastructure for cleaning up per-layout commit structures")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-04-11 11:42:35 -04:00
Trond Myklebust
e18c18ebd7 NFS/pNFS: Fix pnfs_layout_mark_request_commit() invalid layout segment handling
Fix up pnfs_layout_mark_request_commit() to alway reschedule the write
if the layout segment is invalid. Also minor cleanup.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:35 -04:00
Trond Myklebust
c84bea5944 NFS/pNFS: Simplify bucket layout segment reference counting
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:35 -04:00
Trond Myklebust
9c455a8c1e NFS/pNFS: Clean up pNFS commit operations
Move the pNFS commit related operations into a separate structure
that can be carried by the pnfs_ds_commit_info.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:35 -04:00
Trond Myklebust
0aa647b736 NFS: Remove bucket array from struct pnfs_ds_commit_info
Remove the unused bucket array in struct pnfs_ds_commit_info.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:35 -04:00
Trond Myklebust
fb6b53ba40 NFS/pNFS: Add a helper pnfs_generic_search_commit_reqs()
Lift filelayout_search_commit_reqs() into the generic pnfs/nfs code,
and add support for commit arrays.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:35 -04:00
Trond Myklebust
ba827c9abb pNFS: Enable per-layout segment commit structures
Enable adding and lookup of per-layout segment commits in filelayout
and flexfilelayout.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:34 -04:00
Trond Myklebust
a9901899b6 pNFS: Add infrastructure for cleaning up per-layout commit structures
Ensure that both the file and flexfiles layout types clean up when
freeing the layout segments.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:34 -04:00
Trond Myklebust
0cb1f6df8a pNFS: Support per-layout segment commits in pnfs_generic_commit_pagelist()
Add support for scanning the full list of per-layout segment commit
arrays to pnfs_generic_commit_pagelist().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:34 -04:00
Trond Myklebust
fce9ed0302 pNFS: Support per-layout segment commits in pnfs_generic_recover_commit_reqs()
Add support for scanning the full list of per-layout segment commit
arrays to pnfs_generic_recover_commit_reqs().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:34 -04:00
Trond Myklebust
a8e3765e51 NFSv4/pNFS: Scan the full list of commit arrays when committing
Add support for scanning the full list of per-layout segment commit
arrays to pnfs_generic_scan_commit_lists()

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:34 -04:00
Trond Myklebust
d7242c4641 pNFS: Add a helper to allocate the array of buckets
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-26 10:52:04 -04:00
Trond Myklebust
19573c939a NFS/pNFS: Refactor pnfs_generic_commit_pagelist()
Refactor pnfs_generic_commit_pagelist() to simplify the conversion
to layout segment based commit lists.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-26 10:52:04 -04:00
Trond Myklebust
221203ce64 NFS/pnfs: Fix pnfs_generic_prepare_to_resend_writes()
Instead of making assumptions about the commit verifier contents, change
the commit code to ensure we always check that the verifier was set
by the XDR code.

Fixes: f54bcf2ece ("pnfs: Prepare for flexfiles by pulling out common code")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:54:32 -05:00
Trond Myklebust
bf2bf9b80e pNFS/flexfiles: Turn off soft RPC calls
The pNFS/flexfiles I/O requests are sent with the SOFTCONN flag set, so
they automatically time out if the connection breaks. It should
therefore not be necessary to have the soft flag set in addition.

Fixes: 5f01d95394 ("nfs41: create NFSv3 DS connection if specified")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-08-26 15:31:29 -04:00
Thomas Gleixner
457c899653 treewide: Add SPDX license identifier for missed files
Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:45 +02:00
NeilBrown
a52458b48a NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.
SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning.  A look-up of a low-level cred will
map this to a machine credential.

Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19 13:52:46 -05:00
Trond Myklebust
d0fbb1d8a1 NFSv4: Fix locking in pnfs_generic_recover_commit_reqs
The use of the inode->i_lock was converted to a mutex, but we forgot
to remove the old inode unlock/lock() pair that allowed the layout
segment to be put inside the loop.

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Fixes: e824f99ada ("NFSv4: Use a mutex to protect the per-inode commit...")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-08-15 11:43:38 -04:00
Peter Zijlstra
723c921e7d sched/wait, fs/nfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API
The old wait_on_atomic_t() is going to get removed, use the more
flexible wait_var_event() API instead.

No change in functionality.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:23:21 +01:00
Elena Reshetova
a2a5dea7b6 fs, nfs: convert nfs4_pnfs_ds.ds_count from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs4_pnfs_ds.ds_count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 13:47:59 -05:00
Trond Myklebust
5d2a9d9dac NFS: Remove pnfs_generic_transfer_commit_list()
It's pretty much a duplicate of nfs_scan_commit_list() that also
clears the PG_COMMIT_TO_DS flag.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-09 12:51:40 -04:00
Trond Myklebust
137da553db NFS: nfs_lock_and_join_requests and nfs_scan_commit_list can deadlock
Since the commit list is not ordered, it is possible for nfs_scan_commit_list
to hold a request that nfs_lock_and_join_requests() is waiting for, while
at the same time trying to grab a request that nfs_lock_and_join_requests
already holds.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-09 12:28:01 -04:00
Trond Myklebust
2ce209c42c NFS: Wait for requests that are locked on the commit list
If a request is on the commit list, but is locked, we will currently skip
it, which can lead to livelocking when the commit count doesn't reduce
to zero.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:48 -04:00
Trond Myklebust
8205b9ce03 NFSv4/pnfs: Replace pnfs_put_lseg_locked() with pnfs_put_lseg()
Now that we no longer hold the inode->i_lock when manipulating the
commit lists, it is safe to call pnfs_put_lseg() again.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:48 -04:00
Trond Myklebust
e824f99ada NFSv4: Use a mutex to protect the per-inode commit lists
The commit lists can get very large, so using the inode->i_lock can
end up affecting general metadata performance.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:47 -04:00
Trond Myklebust
213297369c Revert commit 722f0b8911 ("pNFS: Don't send COMMITs to the DSes if...")
Doing the test without taking any locks is racy, and so really it makes
more sense to do it in the flexfiles code (which is the only case that
cares).

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-19 15:28:21 -04:00
Trond Myklebust
4118188645 NFS: Fix another COMMIT race in pNFS
We must make sure that cinfo->ds->ncommitting is in sync with the
commit list, since it is checked as part of pnfs_commit_list().

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-19 15:28:21 -04:00
Trond Myklebust
e39928f942 NFS: Fix a COMMIT race in pNFS
We must make sure that cinfo->ds->nwritten is in sync with the
commit list, since it is checked as part of pnfs_scan_commit_lists().

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-19 15:28:21 -04:00
Fred Isaman
c296cfe26b pNFS: Fix NULL dereference in pnfs_generic_alloc_ds_commits
Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-03 12:29:41 -04:00
Trond Myklebust
5f0114832a pNFS: Fix a typo in pnfs_generic_alloc_ds_commits
If the layout segment is invalid, we want to just resend the remaining
writes.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-02 12:35:34 -04:00
Trond Myklebust
722f0b8911 pNFS: Don't send COMMITs to the DSes if the server invalidated our layout
If the layout was invalidated, then assume we should requeue all the
pending writes for the DS in question.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-04-29 11:29:24 -04:00
Trond Myklebust
675e508f53 pNFS: unexport nfs4_pnfs_v3_ds_connect_unload
It is not used outside the NFSv4 module.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-04-20 16:58:50 -04:00
NeilBrown
518662e0fc NFS: fix usage of mempools.
When passed GFP flags that allow sleeping (such as
GFP_NOIO), mempool_alloc() will never return NULL, it will
wait until memory is available.

This means that we don't need to handle failure, but that we
do need to ensure one thread doesn't call mempool_alloc()
twice on the one pool without queuing or freeing the first
allocation.  If multiple threads did this during times of
high memory pressure, the pool could be exhausted and a
deadlock could result.

pnfs_generic_alloc_ds_commits() attempts to allocate from
the nfs_commit_mempool while already holding an allocation
from that pool.  This is not safe.  So change
nfs_commitdata_alloc() to take a flag that indicates whether
failure is acceptable.

In pnfs_generic_alloc_ds_commits(), accept failure and
handle it as we currently do.  Else where, do not accept
failure, and do not handle it.

Even when failure is acceptable, we want to succeed if
possible.  That means both
 - using an entry from the pool if there is one
 - waiting for direct reclaim is there isn't.

We call mempool_alloc(GFP_NOWAIT) to achieve the first, then
kmem_cache_alloc(GFP_NOIO|__GFP_NORETRY) to achieve the
second.  Each of these can fail, but together they do the
best they can without blocking indefinitely.

The objects returned by kmem_cache_alloc() will still be freed
by mempool_free().  This is safe as mempool_alloc() uses
exactly the same function to allocate objects (since the mempool
was created with mempool_create_slab_pool()).  The object returned
by mempool_alloc() and kmem_cache_alloc() are indistinguishable
so mempool_free() will handle both identically, either adding to the
pool or calling kmem_cache_free().

Also, don't test for failure when allocating from
nfs_wdata_mempool.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-04-20 13:44:05 -04:00