Commit Graph

902159 Commits

Author SHA1 Message Date
Trond Myklebust
1de3af9883 NFS: Remove unused FLUSH_SYNC support in nfs_initiate_pgio()
If the FLUSH_SYNC flag is set, nfs_initiate_pgio() will currently
wait for completion, and then return the status of the I/O operation.
What we actually want to report in nfs_pageio_doio() is whether or
not the RPC call was launched successfully, whereas actual I/O
status is intended handled in the reply callbacks.

Since FLUSH_SYNC is never set by any of the callers anyway, let's
just remove that code altogether.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-28 11:54:20 -04:00
Trond Myklebust
cbd7be43c4 pNFS/flexfiles: Specify the layout segment range in LAYOUTGET
Move from requesting only full file layout segments, to requesting
layout segments that match our I/O size. This means the server is
still free to return a full file layout, but we will no longer
error out if it does not.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:35 -04:00
Trond Myklebust
e70430d939 pNFS/flexfiles: remove requirement for whole file layouts
Remove the requirement that the server always sends whole file
layouts.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:35 -04:00
Trond Myklebust
e1e54ab710 pNFS/flexfiles: Check the layout segment range before doing I/O
When starting to read or write with a layout segment, check that the
range matches our request.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:35 -04:00
Trond Myklebust
660d1eb223 pNFS/flexfile: Don't merge layout segments if the mirrors don't match
Check that the number of mirrors, and the mirror information matches
before deciding to merge layout segments in pNFS/flexfiles.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:35 -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
e3b9f7e60b NFS/pNFS: Support commit arrays in nfs_clear_pnfs_ds_commit_verifiers()
Add support for scanning the full list of per-layout segment commit
arrays to nfs_clear_pnfs_ds_commit_verifiers().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:34 -04:00
Trond Myklebust
1f28476dcb NFS: Fix O_DIRECT commit verifier handling
Instead of trying to save the commit verifiers and checking them against
previous writes, adopt the same strategy as for buffered writes, of
just checking the verifiers at commit time.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:34 -04:00
Trond Myklebust
fb5f7f20cd NFS: commit errors should be fatal
Fix the O_DIRECT code to avoid retries if the COMMIT fails with a fatal
error.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-27 16:34:34 -04:00
Trond Myklebust
18f4129696 NFS/pNFS: Allow O_DIRECT to release the DS commitinfo
Add a pNFS callback to allow the O_DIRECT code to release the DS
commitinfo when freeing the dreq.

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
c21e716884 NFSv4/pnfs: Support a list of commit arrays in struct pnfs_ds_commit_info
When we have multiple layout segments with different lists of mirrored
data, we need to track the commits on a per layout segment basis.
This patch adds a list to support this tracking in struct
pnfs_ds_commit_info.

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
329651b1f1 pNFS/flexfiles: Simplify allocation of the mirror array
Just allocate the array at the end of the layout segment structure,
instead of allocating it as a separate array of pointers.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-26 10:52:04 -04:00
Olga Kornievskaia
df513a7711 SUNRPC: fix krb5p mount to provide large enough buffer in rq_rcvsize
Ever since commit 2c94b8eca1 ("SUNRPC: Use au_rslack when computing
reply buffer size"). It changed how "req->rq_rcvsize" is calculated. It
used to use au_cslack value which was nice and large and changed it to
au_rslack value which turns out to be too small.

Since 5.1, v3 mount with sec=krb5p fails against an Ontap server
because client's receive buffer it too small.

For gss krb5p, we need to account for the mic token in the verifier,
and the wrap token in the wrap token.

RFC 4121 defines:
mic token
Octet no   Name        Description
         --------------------------------------------------------------
         0..1     TOK_ID     Identification field.  Tokens emitted by
                             GSS_GetMIC() contain the hex value 04 04
                             expressed in big-endian order in this
                             field.
         2        Flags      Attributes field, as described in section
                             4.2.2.
         3..7     Filler     Contains five octets of hex value FF.
         8..15    SND_SEQ    Sequence number field in clear text,
                             expressed in big-endian order.
         16..last SGN_CKSUM  Checksum of the "to-be-signed" data and
                             octet 0..15, as described in section 4.2.4.

that's 16bytes (GSS_KRB5_TOK_HDR_LEN) + chksum

wrap token
Octet no   Name        Description
         --------------------------------------------------------------
          0..1     TOK_ID    Identification field.  Tokens emitted by
                             GSS_Wrap() contain the hex value 05 04
                             expressed in big-endian order in this
                             field.
          2        Flags     Attributes field, as described in section
                             4.2.2.
          3        Filler    Contains the hex value FF.
          4..5     EC        Contains the "extra count" field, in big-
                             endian order as described in section 4.2.3.
          6..7     RRC       Contains the "right rotation count" in big-
                             endian order, as described in section
                             4.2.5.
          8..15    SND_SEQ   Sequence number field in clear text,
                             expressed in big-endian order.
          16..last Data      Encrypted data for Wrap tokens with
                             confidentiality, or plaintext data followed
                             by the checksum for Wrap tokens without
                             confidentiality, as described in section
                             4.2.4.

Also 16bytes of header (GSS_KRB5_TOK_HDR_LEN), encrypted data, and cksum
(other things like padding)

RFC 3961 defines known cksum sizes:
Checksum type              sumtype        checksum         section or
                                value            size         reference
   ---------------------------------------------------------------------
   CRC32                            1               4           6.1.3
   rsa-md4                          2              16           6.1.2
   rsa-md4-des                      3              24           6.2.5
   des-mac                          4              16           6.2.7
   des-mac-k                        5               8           6.2.8
   rsa-md4-des-k                    6              16           6.2.6
   rsa-md5                          7              16           6.1.1
   rsa-md5-des                      8              24           6.2.4
   rsa-md5-des3                     9              24             ??
   sha1 (unkeyed)                  10              20             ??
   hmac-sha1-des3-kd               12              20            6.3
   hmac-sha1-des3                  13              20             ??
   sha1 (unkeyed)                  14              20             ??
   hmac-sha1-96-aes128             15              20         [KRB5-AES]
   hmac-sha1-96-aes256             16              20         [KRB5-AES]
   [reserved]                  0x8003               ?         [GSS-KRB5]

Linux kernel now mainly supports type 15,16 so max cksum size is 20bytes.
(GSS_KRB5_MAX_CKSUM_LEN)

Re-use already existing define of GSS_KRB5_MAX_SLACK_NEEDED that's used
for encoding the gss_wrap tokens (same tokens are used in reply).

Fixes: 2c94b8eca1 ("SUNRPC: Use au_rslack when computing reply buffer size")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-26 10:51:01 -04:00
Petr Vorel
aa3367c91d NFS: Don't specify NFS version in "UDP not supported" error
UDP was originally disabled in 6da1a03436 for NFSv4. Later in
b24ee6c64c UDP is by default disabled by NFS_DISABLE_UDP_SUPPORT=y for
all NFS versions. Therefore remove v4 from error message.

Fixes: b24ee6c64c ("NFS: allow deprecation of NFS UDP protocol")

Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-25 08:46:34 -04:00
Liwei Song
89c8023fd4 nfsroot: set tcp as the default transport protocol
UDP is disabled by default in commit b24ee6c64c ("NFS: allow
deprecation of NFS UDP protocol"), but the default mount options
is still udp, change it to tcp to avoid the "Unsupported transport
protocol udp" error if no protocol is specified when mount nfs.

Fixes: b24ee6c64c ("NFS: allow deprecation of NFS UDP protocol")
Signed-off-by: Liwei Song <liwei.song@windriver.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-25 08:45:47 -04:00
Misono Tomohiro
8605cf0e85 NFS: direct.c: Fix memory leak of dreq when nfs_get_lock_context fails
When dreq is allocated by nfs_direct_req_alloc(), dreq->kref is
initialized to 2. Therefore we need to call nfs_direct_req_release()
twice to release the allocated dreq. Usually it is called in
nfs_file_direct_{read, write}() and nfs_direct_complete().

However, current code only calls nfs_direct_req_relese() once if
nfs_get_lock_context() fails in nfs_file_direct_{read, write}().
So, that case would result in memory leak.

Fix this by adding the missing call.

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-22 16:47:58 -04:00
Trond Myklebust
3cab1854b0 nfs: Fix up documentation in nfs_follow_referral() and nfs_do_submount()
Fallout from the mount patches.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-17 18:40:57 -04:00
Chuck Lever
d162372af3 SUNRPC: Trim stack utilization in the wrap and unwrap paths
By preventing compiler inlining of the integrity and privacy
helpers, stack utilization for the common case (authentication only)
goes way down.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 10:18:45 -04:00
Chuck Lever
8d6bda7f23 SUNRPC: Remove xdr_buf_read_mic()
Clean up: this function is no longer used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 10:18:45 -04:00
Chuck Lever
4047aa909c sunrpc: Fix gss_unwrap_resp_integ() again
xdr_buf_read_mic() tries to find unused contiguous space in a
received xdr_buf in order to linearize the checksum for the call
to gss_verify_mic. However, the corner cases in this code are
numerous and we seem to keep missing them. I've just hit yet
another buffer overrun related to it.

This overrun is at the end of xdr_buf_read_mic():

1284         if (buf->tail[0].iov_len != 0)
1285                 mic->data = buf->tail[0].iov_base + buf->tail[0].iov_len;
1286         else
1287                 mic->data = buf->head[0].iov_base + buf->head[0].iov_len;
1288         __read_bytes_from_xdr_buf(&subbuf, mic->data, mic->len);
1289         return 0;

This logic assumes the transport has set the length of the tail
based on the size of the received message. base + len is then
supposed to be off the end of the message but still within the
actual buffer.

In fact, the length of the tail is set by the upper layer when the
Call is encoded so that the end of the tail is actually the end of
the allocated buffer itself. This causes the logic above to set
mic->data to point past the end of the receive buffer.

The "mic->data = head" arm of this if statement is no less fragile.

As near as I can tell, this has been a problem forever. I'm not sure
that minimizing au_rslack recently changed this pathology much.

So instead, let's use a more straightforward approach: kmalloc a
separate buffer to linearize the checksum. This is similar to
how gss_validate() currently works.

Coming back to this code, I had some trouble understanding what
was going on. So I've cleaned up the variable naming and added
a few comments that point back to the XDR definition in RFC 2203
to help guide future spelunkers, including myself.

As an added clean up, the functionality that was in
xdr_buf_read_mic() is folded directly into gss_unwrap_resp_integ(),
as that is its only caller.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 10:18:44 -04:00
Gustavo A. R. Silva
5601cda82b nfs: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 10:16:26 -04:00
Murphy Zhou
f5fdf1243f NFSv4.2: error out when relink swapfile
This fixes xfstests generic/356 failure on NFSv4.2.

Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 10:14:30 -04:00
Zhouyi Zhou
eb095c1403 NFS:remove redundant call to nfs_do_access
In function nfs_permission:
1. the rcu_read_lock and rcu_read_unlock around nfs_do_access
is unnecessary because the rcu critical data structure is already
protected in subsidiary function nfs_access_get_cached_rcu. No other
data structure needs rcu_read_lock in nfs_do_access.

2. call nfs_do_access once is enough, because:
2-1. when mask has MAY_NOT_BLOCK bit
The second call to nfs_do_access will not happen.

2-2. when mask has no MAY_NOT_BLOCK bit
The second call to nfs_do_access will happen if res == -ECHILD, which
means the first nfs_do_access goes out after statement if (!may_block).
The second call to nfs_do_access will go through this procedure once
again except continue the work after if (!may_block).
But above work can be performed by only one call to nfs_do_access
without mangling the mask flag.

Tested in x86_64
Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 10:11:59 -04:00
Colin Ian King
68e9a2463d SUNRPC: remove redundant assignments to variable status
The variable status is being initialized with a value that is never
read and it is being updated later with a new value.  The initialization
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 10:10:36 -04:00
Trond Myklebust
b5fdf8418c NFSv4: Add support for CB_RECALL_ANY for flexfiles layouts
When we receive a CB_RECALL_ANY that asks us to return flexfiles
layouts, we iterate through all the layouts and look at whether or
not there are active open file descriptors that might need them
for I/O. If there are no such descriptors, we return the layouts.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:30 -04:00
Trond Myklebust
7f156ef0bf NFSv4: Clean up nfs_delegation_reap_expired()
Convert to use nfs_client_for_each_server() for efficiency.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:30 -04:00
Trond Myklebust
1bba38b283 NFSv4: Clean up nfs_delegation_reap_unclaimed()
Convert nfs_delegation_reap_unclaimed() to use nfs_client_for_each_server()
for efficiency.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:30 -04:00
Trond Myklebust
af3b61bf61 NFSv4: Clean up nfs_client_return_marked_delegations()
Convert it to use the nfs_client_for_each_server() helper, and
make it more efficient by skipping delegations for inodes we
know are in the process of being freed. Also improve the efficiency
of the cursor by skipping delegations that are being freed.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:30 -04:00
Trond Myklebust
3c9e502b59 NFS: Add a helper nfs_client_for_each_server()
Add a helper nfs_client_for_each_server() to iterate through all the
filesystems that are attached to a struct nfs_client, and apply
a function to all the active ones.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:30 -04:00
Trond Myklebust
58ac3e5923 NFSv4/pnfs: Clean up nfs_layout_find_inode()
Now that we can rely on just the rcu_read_lock(), remove the
clp->cl_lock and clean up.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00
Trond Myklebust
cf6605d194 NFSv4: Ensure layout headers are RCU safe
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00
Trond Myklebust
d911c57a19 NFSv4/pnfs: Return valid stateids in nfs_layout_find_inode_by_stateid()
Make sure to test the stateid for validity so that we catch instances
where the server may have been reusing stateids in
nfs_layout_find_inode_by_stateid().

Fixes: 7b410d9ce4 ("pNFS: Delay getting the layout header in CB_LAYOUTRECALL handlers")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00
Trond Myklebust
194a0dc8e2 pNFS/flexfiles: Report DELAY and GRACE errors from the DS to the server
Ensure that if the DS is returning too many DELAY and GRACE errors, we
also report that to the MDS through the layouterror mechanism.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00
Trond Myklebust
a8b373eefc NFS: Limit the size of the access cache by default
Currently, we have no real limit on the access cache size (we set it
to ULONG_MAX). That can lead to credentials getting pinned for a
very long time on lots of files if you have a system with a lot of
memory.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00
Trond Myklebust
49cd32543f NFS: Avoid referencing the cred twice in async rename/unlink
In both async rename and rename, we take a reference to the
cred in the call arguments.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00
Trond Myklebust
63ec2b69e9 NFSv4: Avoid unnecessary credential references in layoutget
Layoutget is just using the credential attached to the open context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00
Trond Myklebust
6129650720 NFSv4: Avoid referencing the cred unnecessarily during NFSv4 I/O
Avoid unnecessary references to the cred when we have already referenced
it through the open context or the open owner.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00
Trond Myklebust
542b994bdb NFS: Assume cred is pinned by open context in I/O requests
In read/write/commit, we should be able to assume that the cred is
pinned by the open context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00
Trond Myklebust
263fb9c21e SUNRPC: Don't take a reference to the cred on synchronous tasks
If the RPC call is synchronous, assume the cred is already pinned
by the caller.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-03-16 08:34:29 -04:00