In a later patch we're going to want to cycle over this list and attempt
to call ->create_server for each different flavor until one succeeds.
Move the list allocation to the stack of nfs_try_mount_request() and
pass a pointer to it and its length to nfs_request_mount().

Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This looks like pointless refactoring for now, but we'll flesh out
the need_mount case a little more in a later patch.

Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The GETDEVICEINFO gdia_maxcount represents all of the data being returned
within the GETDEVICEINFO4resok structure and includes the XDR overhead.

The CREATE_SESSION ca_maxresponsesize is the maximum reply and includes the RPC
headers (including security flavor credentials and verifiers).

Split out the struct pnfs_device field maxcount which is the gdia_maxcount
from the pglen field which is the reply (the total) buffer length.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fallback should happen only when the request_key() call fails, because
this indicates that there was a problem running the nfsidmap program.
We shouldn't call the legacy code if the error was elsewhere.
Signed-off-by: NBryan Schumaker <bjschuma@netappp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We need to ensure that we clear NFS4_SLOT_TBL_DRAINING on the back
channel when we're done recovering the session.

Regression introduced by commit 774d5f14 (NFSv4.1 Fix a pNFS session
draining deadlock)
Signed-off-by: NAndy Adamson <andros@netapp.com>
[Trond: Changed order to start back-channel first. Minor code cleanup]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>=3.10]

Give them names that are a bit more consistent with the general
pNFS naming scheme.

 - lo_seg_contained -> pnfs_lseg_range_contained
 - lo_seg_intersecting -> pnfs_lseg_range_intersecting
 - cmp_layout -> pnfs_lseg_range_cmp
 - is_matching_lseg -> pnfs_lseg_range_match
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Also strip off the unnecessary 'inline' declarations.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The other protocols don't use it, so make it local to NFSv4, and
remove the EXPORT.
Also ensure that we only compile in cache_lib.o if we're using
the legacy DNS resolver.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>

Make sure that NFSv4 SETCLIENTID does not parse the NETID as a
format string.
Signed-off-by: NDjalal Harouni <tixxdz@opendz.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

State recovery currently relies on being able to find a valid
nfs_open_context in the inode->open_files list.
We therefore need to put the nfs_open_context on the list while
we're still protected by the sp->so_reclaim_seqcount in order
to avoid reboot races.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Instead of having the callers set ctx->state, do it inside
_nfs4_open_and_get_state.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

All the callers have an open_context at this point, and since we always
need one in order to do state recovery, it makes sense to use it as the
basis for the nfs4_do_open() call.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We already check the EXEC access mode in the lower layers.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

ctx->cred == ctx->state->owner->so_cred, so let's just use the former.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Use the EXCHGID4_FLAG_BIND_PRINC_STATEID exchange_id flag to enable
stateid protection. This means that if we create a stateid using a
particular principal, then we must use the same principal if we
want to change that state.
IOW: if we OPEN a file using a particular credential, then we have
to use the same credential in subsequent OPEN_DOWNGRADE, CLOSE,
or DELEGRETURN operations that use that stateid.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This is not strictly needed, since get_deviceinfo is not allowed to
return NFS4ERR_ACCESS or NFS4ERR_WRONG_CRED, but lets do it anyway
for consistency with other pNFS operations.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We want to use the same credential for reclaim_complete as we used
for the exchange_id call.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We need to use the same credential as was used for the layoutget
and/or layoutcommit operations.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Ensure that we use the same credential for layoutget, layoutcommit and
layoutreturn.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Darrick J. Wong <darrick.wong@oracle.com> reports:
> I have a kvm-based testing setup that netboots VMs over NFS, the
> client end of which seems to have broken somehow in 3.10-rc1.  The
> server's exports file looks like this:
>
> /storage/mtr/x64	192.168.122.0/24(ro,sync,no_root_squash,no_subtree_check)
>
> On the client end (inside the VM), the initrd runs the following
> command to try to mount the rootfs over NFS:
>
> # mount -o nolock -o ro -o retrans=10 192.168.122.1:/storage/mtr/x64/ /root
>
> (Note: This is the busybox mount command.)
>
> The mount fails with -EINVAL.

Commit 4580a92d "NFS: Use server-recommended security flavor by
default (NFSv3)" introduced a behavior regression for NFS mounts
done via a legacy binary mount(2) call.

Ensure that a default security flavor is specified for legacy binary
mount requests, since they do not invoke nfs_select_flavor() in the
kernel.

Busybox uses klibc's nfsmount command, which performs NFS mounts
using the legacy binary mount data format.  /sbin/mount.nfs is not
affected by this regression.
Reported-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NDarrick J. Wong <darrick.wong@oracle.com>
Acked-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We need to pass the full open mode flags to nfs_may_open() when doing
a delegated open.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

Commit 79d852bf "NFS: Retry SETCLIENTID with AUTH_SYS instead of
AUTH_NONE" did not take into account commit 23631227 "NFSv4: Fix the
fallback to AUTH_NULL if krb5i is not available".
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

On a CB_RECALL the callback service thread flushes the inode using
filemap_flush prior to scheduling the state manager thread to return the
delegation. When pNFS is used and I/O has not yet gone to the data server
servicing the inode, a LAYOUTGET can preceed the I/O. Unlike the async
filemap_flush call, the LAYOUTGET must proceed to completion.

If the state manager starts to recover data while the inode flush is sending
the LAYOUTGET, a deadlock occurs as the callback service thread holds the
single callback session slot until the flushing is done which blocks the state
manager thread, and the state manager thread has set the session draining bit
which puts the inode flush LAYOUTGET RPC to sleep on the forechannel slot
table waitq.

Separate the draining of the back channel from the draining of the fore channel
by moving the NFS4_SESSION_DRAINING bit from session scope into the fore
and back slot tables.  Drain the back channel first allowing the LAYOUTGET
call to proceed (and fail) so the callback service thread frees the callback
slot. Then proceed with draining the forechannel.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Unlike meta data server mounts which support multiple mount points to
the same server via struct nfs_server, data servers support a single connection.

Concurrent calls to setup the data server connection can race where the first
call allocates the nfs_client struct, and before the cache struct nfs_client
pointer can be set, a second call also tries to setup the connection, finds the
already allocated nfs_client, bumps the reference count, re-initializes the
session,etc. This results in a hanging data server session after umount.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

same story as with the previous patches - note that return
value of blkdev_close() is lost, since there's nowhere the
caller (__fput()) could return it to.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Older linux clients match the 'sec=' mount option flavor against the server's
flavor list (if available) and return EPERM if the specified flavor or AUTH_NULL
(which "matches" any flavor) is not found.

Recent changes skip this step and allow the vfs mount even though no operations
will succeed, creating a 'dud' mount.

This patch reverts back to the old behavior of matching specified flavors
against the server list and also returns EPERM when no sec= is specified and
none of the flavors returned by the server are supported by the client.

Example of behavior change:

the server's /etc/exports:

/export/krb5      *(sec=krb5,rw,no_root_squash)

old client behavior:

$ uname -a
Linux one.apikia.fake 3.8.8-202.fc18.x86_64 #1 SMP Wed Apr 17 23:25:17 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
$ sudo mount -v -o sec=sys,vers=3 zero:/export/krb5 /mnt
mount.nfs: timeout set for Sun May  5 17:32:04 2013
mount.nfs: trying text-based options 'sec=sys,vers=3,addr=192.168.100.10'
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying 192.168.100.10 prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying 192.168.100.10 prog 100005 vers 3 prot UDP port 20048
mount.nfs: mount(2): Permission denied
mount.nfs: access denied by server while mounting zero:/export/krb5

recently changed behavior:

$ uname -a
Linux one.apikia.fake 3.9.0-testing+ #2 SMP Fri May 3 20:29:32 EDT 2013 x86_64 x86_64 x86_64 GNU/Linux
$ sudo mount -v -o sec=sys,vers=3 zero:/export/krb5 /mnt
mount.nfs: timeout set for Sun May  5 17:37:17 2013
mount.nfs: trying text-based options 'sec=sys,vers=3,addr=192.168.100.10'
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying 192.168.100.10 prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying 192.168.100.10 prog 100005 vers 3 prot UDP port 20048
$ ls /mnt
ls: cannot open directory /mnt: Permission denied
$ sudo ls /mnt
ls: cannot open directory /mnt: Permission denied
$ sudo df /mnt
df: ‘/mnt’: Permission denied
df: no file systems processed
$ sudo umount /mnt
$
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This ensures that the server doesn't need to keep huge numbers of
lock stateids waiting around for the final CLOSE.
See section 8.2.4 in RFC5661.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The main reason for doing this is will be to allow for an asynchronous
RPC mode that we can use for freeing lock stateids as per section
8.2.4 of RFC5661.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If a NFS client receives a delegation for a file after it has taken
a lock on that file, we can currently end up in a situation where
we mistakenly skip unlocking that file.

The following patch swaps an erroneous check in nfs4_proc_unlck for
whether or not the file has a delegation to one which checks whether
or not we hold a lock stateid for that file.
Reported-by: NChuck Lever <Chuck.Lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>=3.7]
Tested-by: NChuck Lever <Chuck.Lever@oracle.com>

Debugging aid to help identify servers that incorrectly apply open mode
checks to setattr requests that are not changing the file size.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The NFSv4 and NFSv4.1 specs are both clear that the server should only check
stateid open mode if a SETATTR specifies the size attribute. If the
open mode is not one that allows writing, then it returns NFS4ERR_OPENMODE.

In the case where the SETATTR is not changing the size, the client will
still pass it the delegation stateid to ensure that the server does not
recall that delegation. In that case, the server should _ignore_ the
delegation open mode, and simply apply standard permission checks.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If we already checked the user access permissions on the original open,
then don't bother checking again on recovery. Doing so can cause a
deadlock with NFSv4.1, since the may_open() operation is not privileged.
Furthermore, we can't report an access permission failure here anyway.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If we're in a delegation recall situation, we can't do a delegated open.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When we're doing open-by-filehandle in NFSv4.1, we shouldn't need to
do the cache consistency revalidation on the directory. It is
therefore more efficient to just use open_noattr, which returns the
file attributes, but not the directory attributes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Recently I changed the SETCLIENTID code to use AUTH_GSS(krb5i), and
then retry with AUTH_NONE if that didn't work.  This was to enable
Kerberos NFS mounts to work without forcing Linux NFS clients to
have a keytab on hand.

Rick Macklem reports that the FreeBSD server accepts AUTH_NONE only
for NULL operations (thus certainly not for SETCLIENTID).  Falling
back to AUTH_NONE means our proposed 3.10 NFS client will not
interoperate with FreeBSD servers over NFSv4 unless Kerberos is
fully configured on both ends.

If the Linux client falls back to using AUTH_SYS instead for
SETCLIENTID, all should work fine as long as the NFS server is
configured to allow AUTH_SYS for SETCLIENTID.

This may still prevent access to Kerberos-only FreeBSD servers by
Linux clients with no keytab.  Rick is of the opinion that the
security settings the server applies to its pseudo-fs should also
apply to the SETCLIENTID operation.

Linux and Solaris NFS servers do not place that limitation on
SETCLIENTID.  The security settings for the server's pseudo-fs are
determined automatically as the union of security flavors allowed on
real exports, as recommended by RFC 3530bis; and the flavors allowed
for SETCLIENTID are all flavors supported by the respective server
implementation.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We should always clear it before initiating file recovery.
Also ensure that we clear it after a CLOSE and/or after TEST_STATEID fails.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>