Commit 65b38851a1
("NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes")
updated the following function:
static int nfs_volume_list_open(struct inode *inode, struct file *file)
it used &nfs_server_list_ops instead of &nfs_volume_list_ops
which means cat /proc/fs/nfsfs/volumes = /proc/fs/nfsfs/servers
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Fixes: 65b38851a1 (NFS: Fix /proc/fs/nfsfs/servers and...)
Cc: stable@vger.kernel.org # 3.4.x+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Highlights include:
- Stable fix for a bug in nfs3_list_one_acl()
- Speed up NFS path walks by supporting LOOKUP_RCU
- More read/write code cleanups
- pNFS fixes for layout return on close
- Fixes for the RCU handling in the rpcsec_gss code
- More NFS/RDMA fixes
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=KE07
-----END PGP SIGNATURE-----
Merge tag 'nfs-for-3.17-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Highlights include:
- stable fix for a bug in nfs3_list_one_acl()
- speed up NFS path walks by supporting LOOKUP_RCU
- more read/write code cleanups
- pNFS fixes for layout return on close
- fixes for the RCU handling in the rpcsec_gss code
- more NFS/RDMA fixes"
* tag 'nfs-for-3.17-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (79 commits)
nfs: reject changes to resvport and sharecache during remount
NFS: Avoid infinite loop when RELEASE_LOCKOWNER getting expired error
SUNRPC: remove all refcounting of groupinfo from rpcauth_lookupcred
NFS: fix two problems in lookup_revalidate in RCU-walk
NFS: allow lockless access to access_cache
NFS: teach nfs_lookup_verify_inode to handle LOOKUP_RCU
NFS: teach nfs_neg_need_reval to understand LOOKUP_RCU
NFS: support RCU_WALK in nfs_permission()
sunrpc/auth: allow lockless (rcu) lookup of credential cache.
NFS: prepare for RCU-walk support but pushing tests later in code.
NFS: nfs4_lookup_revalidate: only evaluate parent if it will be used.
NFS: add checks for returned value of try_module_get()
nfs: clear_request_commit while holding i_lock
pnfs: add pnfs_put_lseg_async
pnfs: find swapped pages on pnfs commit lists too
nfs: fix comment and add warn_on for PG_INODE_REF
nfs: check wait_on_bit_lock err in page_group_lock
sunrpc: remove "ec" argument from encrypt_v2 operation
sunrpc: clean up sparse endianness warnings in gss_krb5_wrap.c
sunrpc: clean up sparse endianness warnings in gss_krb5_seal.c
...
The usage of pid_ns->child_reaper->nsproxy->net_ns in
nfs_server_list_open and nfs_client_list_open is not safe.
/proc for a pid namespace can remain mounted after the all of the
process in that pid namespace have exited. There are also times
before the initial process in a pid namespace has started or after the
initial process in a pid namespace has exited where
pid_ns->child_reaper can be NULL or stale. Making the idiom
pid_ns->child_reaper->nsproxy a double whammy of problems.
Luckily all that needs to happen is to move /proc/fs/nfsfs/servers and
/proc/fs/nfsfs/volumes under /proc/net to /proc/net/nfsfs/servers and
/proc/net/nfsfs/volumes and add a symlink from the original location,
and to use seq_open_net as it has been designed.
Cc: stable@vger.kernel.org
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There is a couple of places in client code where returned value
of try_module_get() is ignored. As a result there is a small chance
to premature unload module because of unbalanced refcounting.
The patch adds error handling in that places.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The current CB_COMPOUND handling code tries to compare the principal
name of the request with the cl_hostname in the client. This is not
guaranteed to ever work, particularly if the client happened to mount
a CNAME of the server or a non-fqdn.
Fix this by instead comparing the cr_principal string with the acceptor
name that we get from gssd. In the event that gssd didn't send one
down (i.e. it was too old), then we fall back to trying to use the
cl_hostname as we do today.
Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
We reference cl_hostname in many places. Add a check to make
sure it exists.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cache the auth_info structure in nfs_server and pass these values to submounts.
This lays the groundwork for supporting multiple sec= options.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When filling parsed_mount_data, store the parsed sec= mount option in
the new struct nfs_auth_info and the chosen flavor in selected_flavor.
This patch lays the groundwork for supporting multiple sec= options.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
New function nfs4_update_server() moves an nfs_server to a different
nfs_client. This is done as part of migration recovery.
Though it may be appealing to think of them as the same thing,
migration recovery is not the same as following a referral.
For a referral, the client has not descended into the file system
yet: it has no nfs_server, no super block, no inodes or open state.
It is enough to simply instantiate the nfs_server and super block,
and perform a referral mount.
For a migration, however, we have all of those things already, and
they have to be moved to a different nfs_client. No local namespace
changes are needed here.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The spec states that the client should not resend requests because
the server will disconnect if it needs to drop an RPC request.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* labeled-nfs:
NFS: Apply v4.1 capabilities to v4.2
NFS: Add in v4.2 callback operation
NFS: Make callbacks minor version generic
Kconfig: Add Kconfig entry for Labeled NFS V4 client
NFS: Extend NFS xattr handlers to accept the security namespace
NFS: Client implementation of Labeled-NFS
NFS: Add label lifecycle management
NFS:Add labels to client function prototypes
NFSv4: Extend fattr bitmaps to support all 3 words
NFSv4: Introduce new label structure
NFSv4: Add label recommended attribute and NFSv4 flags
NFSv4.2: Added NFS v4.2 support to the NFS client
SELinux: Add new labeling type native labels
LSM: Add flags field to security_sb_set_mnt_opts for in kernel mount data.
Security: Add Hook to test if the particular xattr is part of a MAC model.
Security: Add hook to calculate context based on a negative dentry.
NFS: Add NFSv4.2 protocol constants
Conflicts:
fs/nfs/nfs4proc.c
NFS_CS_MIGRATION makes sense only for NFSv4 mounts. Introduced by
commit 89652617 (NFS: Introduce "migration" mount option) Fri Sep 14
17:24:11 2012.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
After looking at all of the nfsv4 operations the label structure has been added
to the prototypes of the functions which can transmit label data.
Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated. Drop reference to idr_remove_all(). Note that the code
wasn't completely correct before because idr_remove() on all entries
doesn't necessarily release all idr_layers which could lead to memory
leak.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In rare circumstances, nfs_clone_server() of a v2 or v3 server can get
an error between setting server->destory (to nfs_destroy_server), and
calling nfs_start_lockd (which will set server->nlm_host).
If this happens, nfs_clone_server will call nfs_free_server which
will call nfs_destroy_server and thence nlmclnt_done(NULL). This
causes the NULL to be dereferenced.
So add a guard to only call nlmclnt_done() if ->nlm_host is not NULL.
The other guards there are irrelevant as nlm_host can only be non-NULL
if one of these flags are set - so remove those tests. (Thanks to Trond
for this suggestion).
This is suitable for any stable kernel since 2.6.25.
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
There are some unnecessary semicolons in function find_nfs_version. Just remove them.
Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
After commit e38eb650 (NFS: set_pnfs_layoutdriver() from
nfs4_proc_fsinfo()), set_pnfs_layoutdriver() is called inside
nfs4_proc_fsinfo(), but pnfs_blksize is not set. It causes setting
blocklayoutdriver failure and pnfsblock mount failure.
Cc: stable <stable@vger.kernel.org> [since v3.5]
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
"Server trunking" is a fancy named for a multi-homed NFS server.
Trunking might occur if a client sends NFS requests for a single
workload to multiple network interfaces on the same server. There
are some implications for NFSv4 state management that make it useful
for a client to know if a single NFSv4 server instance is
multi-homed. (Note this is only a consideration for NFSv4, not for
legacy versions of NFS, which are stateless).
If a client cares about server trunking, no NFSv4 operations can
proceed until that client determines who it is talking to. Thus
server IP trunking discovery must be done when the client first
encounters an unfamiliar server IP address.
The nfs_get_client() function walks the nfs_client_list and matches
on server IP address. The outcome of that walk tells us immediately
if we have an unfamiliar server IP address. It invokes
nfs_init_client() in this case. Thus, nfs4_init_client() is a good
spot to perform trunking discovery.
Discovery requires a client to establish a fresh client ID, so our
client will now send SETCLIENTID or EXCHANGE_ID as the first NFS
operation after a successful ping, rather than waiting for an
application to perform an operation that requires NFSv4 state.
The exact process for detecting trunking is different for NFSv4.0 and
NFSv4.1, so a minorversion-specific init_client callout method is
introduced.
CLID_INUSE recovery is important for the trunking discovery process.
CLID_INUSE is a sign the server recognizes the client's nfs_client_id4
id string, but the client is using the wrong principal this time for
the SETCLIENTID operation. The SETCLIENTID must be retried with a
series of different principals until one works, and then the rest of
trunking discovery can proceed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, the Linux client uses a unique nfs_client_id4.id string
when identifying itself to distinct NFS servers.
To support transparent state migration, the Linux client will have to
use the same nfs_client_id4 string for all servers it communicates
with (also known as the "uniform client string" approach). Otherwise
NFS servers can not recognize that open and lock state need to be
merged after a file system transition.
Unfortunately, there are some NFSv4.0 servers currently in the field
that do not tolerate the uniform client string approach.
Thus, by default, our NFSv4.0 mounts will continue to use the current
approach, and we introduce a mount option that switches them to use
the uniform model. Client administrators must identify which servers
can be mounted with this option. Eventually most NFSv4.0 servers will
be able to handle the uniform approach, and we can change the default.
The first mount of a server controls the behavior for all subsequent
mounts for the lifetime of that set of mounts of that server. After
the last mount of that server is gone, the client erases the data
structure that tracks the lease. A subsequent lease may then honor
a different "migration" setting.
This patch adds only the infrastructure for parsing the new mount
option. Support for uniform client strings is added in a subsequent
patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
An ULP is supposed to be able to replace a GSS rpc_auth object with
another GSS rpc_auth object using rpcauth_create(). However,
rpcauth_create() in 3.5 reliably fails with -EEXIST in this case.
This is because when gss_create() attempts to create the upcall pipes,
sometimes they are already there. For example if a pipe FS mount
event occurs, or a previous GSS flavor was in use for this rpc_clnt.
It turns out that's not the only problem here. While working on a
fix for the above problem, we noticed that replacing an rpc_clnt's
rpc_auth is not safe, since dereferencing the cl_auth field is not
protected in any way.
So we're deprecating the ability of rpcauth_create() to switch an
rpc_clnt's security flavor during normal operation. Instead, let's
add a fresh API that clones an rpc_clnt and gives the clone a new
flavor before it's used.
This makes immediate use of the new __rpc_clone_client() helper.
This can be used in a similar fashion to rpcauth_create() when a
client is hunting for the correct security flavor. Instead of
replacing an rpc_clnt's security flavor in a loop, the ULP replaces
the whole rpc_clnt.
To fix the -EEXIST problem, any ULP logic that relies on replacing
an rpc_clnt's rpc_auth with rpcauth_create() must be changed to use
this API instead.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Some systems have a modprobe.d/nfs.conf file that sets an nfs4 alias
pointing to nfs.ko, rather than nfs4.ko. This can prevent the v4 module
from loading on mount, since the kernel sees that something named "nfs4"
has already been loaded. To work around this, I've renamed the modules
to "nfsv2.ko" "nfsv3.ko" and "nfsv4.ko".
I also had to move the nfs4_fs_type back to nfs.ko to ensure that `mount
-t nfs4` still works.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch exports symbols needed by the v4 module. In addition, I also
switch over to using IS_ENABLED() to check if CONFIG_NFS_V4 or
CONFIG_NFS_V4_MODULE are set.
The module (nfs4.ko) will be created in the same directory as nfs.ko and
will be automatically loaded the first time you try to mount over NFS v4.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch exports symbols and moves over the final structures needed by
the v3 module. In addition, I also switch over to using IS_ENABLED() to
check if CONFIG_NFS_V3 or CONFIG_NFS_V3_MODULE are set.
The module (nfs3.ko) will be created in the same directory as nfs.ko and
will be automatically loaded the first time you try to mount over NFS v3.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The module (nfs2.ko) will be created in the same directory as nfs.ko and
will be automatically loaded the first time you try to mount over NFS v2.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
v2 and v4 don't use it, so I create two new nfs_rpc_ops functions to
initialize the ACL client only when we are using v3.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch adds in the code to track multiple versions of the NFS
protocol. I created default structures for v2, v3 and v4 so that each
version can continue to work while I convert them into kernel modules.
I also removed the const parameter from the rpc_version array so that I
can change it at runtime.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
These functions are only needed by NFS v4, so they can be moved into a
v4 specific file.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
These functions are specific to NFS v4 and can be moved to nfs4client.c
to keep them out of the generic client.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
And split these functions out of the generic client into a v4 specific
file.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This gives NFS v4 a way to set up callbacks and sessions without v2 or
v3 having to do them as well.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS v4 needs a way to shut down callbacks and sessions, but v2 and v3
don't.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
I can use this function to return delegations and unset the pnfs layout
driver rather than continuing to do these things in the generic client.
With this change, we no longer need an nfs4_kill_super().
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The generic client doesn't need to know about pnfs layout drivers, so
this should be done in the v4 code.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently there is a 'chicken and egg' issue when the DS is also the mounted
MDS. The nfs_match_client() reference from nfs4_set_ds_client bumps the
cl_count, the nfs_client is not freed at umount, and nfs4_deviceid_purge_client
is not called to dereference the MDS usage of a deviceid which holds a
reference to the DS nfs_client. The result is the umount program returns,
but the nfs_client is not freed, and the cl_session hearbeat continues.
The MDS (and all other nfs mounts) lose their last nfs_client reference in
nfs_free_server when the last nfs_server (fsid) is umounted.
The file layout DS lose their last nfs_client reference in destroy_ds
when the last deviceid referencing the data server is put and destroy_ds is
called. This is triggered by a call to nfs4_deviceid_purge_client which
removes references to a pNFS deviceid used by an MDS mount.
The fix is to track how many pnfs enabled filesystems are mounted from
this server, and then to purge the device id cache once that count reaches
zero.
Reported-by: Jorge Mora <Jorge.Mora@netapp.com>
Reported-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It is perfectly valid for nfs_get_client() to return a nfs_client that
is in the process of setting up the NFSv4.1 session.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ensure that a process that uses the nfs_client->cl_cons_state test
for whether the initialisation process is finished does not read
stale data.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Since the struct nfs_client gets added to the global nfs_client_list
before it is initialised, it is possible that rpc_pipefs_event can
end up trying to create idmapper entries on such a thing.
The solution is to have the mount notification wait for the
initialisation of each nfs_client to complete, and then to
skip any entries for which the it failed.
Reported-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Session initialisation is not complete until the lease manager
has run. We need to ensure that both nfs4_init_session and
nfs4_init_ds_session do so, and that they check for any resulting
errors in clp->cl_cons_state.
Only after this is done, can nfs4_ds_connect check the contents
of clp->cl_exchange_flags.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Andy Adamson <andros@netapp.com>
Save the server major and minor ID results from EXCHANGE_ID, as they
are needed for detecting server trunking.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
"noresvport" and "discrtry" can be passed to nfs_create_rpc_client()
by setting flags in the passed-in nfs_client. This change makes it
easy to add new flags.
Note that these settings are now "sticky" over the lifetime of a
struct nfs_client, and may even be copied when an nfs_client is
cloned.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: Continue to rationalize the locking in nfs_get_client() by
moving the logic that handles the case where a matching server IP
address is not found.
When we support server trunking detection, client initialization may
return a different nfs_client struct than was passed to it. Change
the synopsis of the init_client methods to return an nfs_client.
The client initialization logic in nfs_get_client() is not much more
than a wrapper around ->init_client. It's simpler to keep the little
bits of error handling in the version-specific init_client methods.
No behavior change is expected.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: Code that takes and releases nfs_client_lock remains in
nfs_get_client(). Logic that handles a pre-existing nfs_client is
moved to a separate function.
No behavior change is expected.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently our NFS client assigns a unique SETCLIENTID boot verifier
for each server IP address it knows about. It's set to CURRENT_TIME
when the struct nfs_client for that server IP is created.
During the SETCLIENTID operation, our client also presents an
nfs_client_id4 string to servers, as an identifier on which the server
can hang all of this client's NFSv4 state. Our client's
nfs_client_id4 string is unique for each server IP address.
An NFSv4 server is obligated to wipe all NFSv4 state associated with
an nfs_client_id4 string when the client presents the same
nfs_client_id4 string along with a changed SETCLIENTID boot verifier.
When our client unmounts the last of a server's shares, it destroys
that server's struct nfs_client. The next time the client mounts that
NFS server, it creates a fresh struct nfs_client with a fresh boot
verifier. On seeing the fresh verifer, the server wipes any previous
NFSv4 state associated with that nfs_client_id4.
However, NFSv4.1 clients are supposed to present the same
nfs_client_id4 string to all servers. And, to support Transparent
State Migration, the same nfs_client_id4 string should be presented
to all NFSv4.0 servers so they recognize that migrated state for this
client belongs with state a server may already have for this client.
(This is known as the Uniform Client String model).
If the nfs_client_id4 string is the same but the boot verifier changes
for each server IP address, SETCLIENTID and EXCHANGE_ID operations
from such a client could unintentionally result in a server wiping a
client's previously obtained lease.
Thus, if our NFS client is going to use a fixed nfs_client_id4 string,
either for NFSv4.0 or NFSv4.1 mounts, our NFS client should use a
boot verifier that does not change depending on server IP address.
Replace our current per-nfs_client boot verifier with a per-nfs_net
boot verifier.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Trond Myklebust