For a while now any NFSv2 mount where sec= is specified uses
AUTH_NULL. If sec= is not specified, the mount uses AUTH_UNIX.
Commit e68fd7c8 ("mount: use sec= that was specified on the
command line") attempted to address a very similar problem with
NFSv3, and should have fixed this too, but it has a bug.

The MNTv1 MNT procedure does not return a list of security flavors,
so our client makes up a list containing just AUTH_NULL. This should
enable nfs_verify_authflavors() to assign the sec= specified flavor,
but instead, it incorrectly sets it to AUTH_NULL.

I expect this would also be a problem for any NFSv3 server whose
MNTv3 MNT procedure returned a security flavor list containing only
AUTH_NULL.

Fixes: e68fd7c8 ("mount: use sec= that was specified on ... ")
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=310Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

An NFSv4.1 client might close a file after the user who opened it has
logged off.  In this case the user's credentials may no longer be
valid, if they are e.g. kerberos credentials that have expired.

NFSv4.1 has a mechanism to allow the client to use machine credentials
to close a file.  However due to a short-coming in the RFC, a CLOSE
with those credentials may not be possible if the file in question
isn't exported to the same security flavor - the required PUTFH must
be rejected when this is the case.

Specifically if a server and client support kerberos in general and
have used it to form a machine credential, but the file is only
exported to "sec=sys", a PUTFH with the machine credentials will fail,
so CLOSE is not possible.

As RPC_AUTH_UNIX (used by sec=sys) credentials can never expire, there
is no value in using the machine credential in place of them.
So in that case, just use the users credentials for CLOSE etc, as you would
in NFSv4.0
Signed-off-by: NNeil Brown <neilb@suse.com>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Now that the mirror allocation has been moved, the parameter can go.
Also remove the redundant symbol export.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

There are a number of callers of nfs_pageio_complete() that want to
continue using the nfs_pageio_descriptor without needing to call
nfs_pageio_init() again. Examples include nfs_pageio_resend() and
nfs_pageio_cond_complete().

The problem is that nfs_pageio_complete() also calls
nfs_pageio_cleanup_mirroring(), which frees up the array of mirrors.
This can lead to writeback errors, in the next call to
nfs_pageio_setup_mirroring().

Fix by simply moving the allocation of the mirrors to
nfs_pageio_setup_mirroring().

Link: https://bugzilla.kernel.org/show_bug.cgi?id=196709Reported-by: NJianhongYin <yin-jianhong@163.com>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

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: NTrond Myklebust <trond.myklebust@primarydata.com>

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: NTrond Myklebust <trond.myklebust@primarydata.com>

Switch from using the inode->i_lock for this to avoid contention with
other metadata manipulation.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Rather than forcing us to take the inode->i_lock just in order to bump
the number.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The commit lists can get very large, so using the inode->i_lock can
end up affecting general metadata performance.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Split out the 2 cases so that we can treat the locking differently.
The issue is that the locking in the pageswapcache cache is highly
linked to the commit list locking.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Hide the locking from nfs_lock_and_join_requests() so that we can
separate out the requirements for swapcache pages.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Fix up the test in nfs_page_group_covers_page(). The simplest implementation
is to check that we have a set of intersecting or contiguous subrequests
that connect page offset 0 to nfs_page_length(req->wb_page).
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

nfs_page_group_lock() is now always called with the 'nonblock'
parameter set to 'false'.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

At this point, we only expect ever to potentially see PG_REMOVE and
PG_TEARDOWN being set on the subrequests.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Since nfs_page_group_destroy() does not take any locks on the requests
to be freed, we need to ensure that we don't inadvertently free the
request in nfs_destroy_unlinked_subrequests() while the last reference
is being released elsewhere.

Do this by:

1) Taking a reference to the request unless it is already being freed
2) Checking (under the page group lock) if PG_TEARDOWN is already set before
   freeing an unreferenced request in nfs_destroy_unlinked_subrequests()
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When locking the entire group in order to remove subrequests,
the locks are always taken in order, and with the page group
lock being taken after the page head is locked. The intention
is that:

1) The lock on the group head guarantees that requests may not
   be removed from the group (although new entries could be appended
   if we're not holding the group lock).
2) It is safe to drop and retake the page group lock while iterating
   through the list, in particular when waiting for a subrequest lock.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We should no longer need the inode->i_lock, now that we've
straightened out the request locking. The locking schema is now:

1) Lock page head request
2) Lock the page group
3) Lock the subrequests one by one

Note that there is a subtle race with nfs_inode_remove_request() due
to the fact that the latter does not lock the page head, when removing
it from the struct page. Only the last subrequest is locked, hence
we need to re-check that the PagePrivate(page) is still set after
we've locked all the subrequests.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

nfs_try_to_update_request() should be able to cope now.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Simplify the code, and avoid some flushes to disk.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Both nfs_destroy_unlinked_subrequests() and nfs_lock_and_join_requests()
manipulate the inode flags adjusting the NFS_I(inode)->nrequests.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We don't want nfs_lock_and_join_requests() to start fiddling with
the request before the call to nfs_page_group_sync_on_bit().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Request offsets and sizes are not guaranteed to be stable unless you
are holding the request locked.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

All other callers of nfs_page_group_lock() appear to already hold the
page lock on the head page, so doing it in the opposite order here
is inefficient, although not deadlock prone since we roll back all
locks on contention.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Yes, this is a situation that should never happen (hence the WARN_ON)
but we should still ensure that we free up the locks and references to
the faulty pages.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This fixes a race with nfs_page_group_sync_on_bit() whereby the
call to wake_up_bit() in nfs_page_group_unlock() could occur after
the page header had been freed.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Micro-optimisation to move the lockless check into the for(;;) loop.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Add a lockless check for whether or not the page might be carrying
an existing writeback before we grab the inode->i_lock.
Reported-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We don't expect the page header lock to ever be held across I/O, so
it should always be safe to wait for it, even if we're doing nonblocking
writebacks.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we're recovering a nfs4_state, then we should try to use that instead
of looking up a new stateid. Only do that if the inodes match, though.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When doing open by filehandle we don't really want to lookup a new inode,
but rather update the one we've got. Add a helper which does this for us.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The blocklayout code does not compile cleanly for a 32-bit sector_t,
and also has no reliable checks for devices sizes, which makes it
unsafe to use with a kernel that doesn't support large block devices.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 5c83746a ("pnfs/blocklayout: in-kernel GETDEVICEINFO XDR parsing")
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the call to TEST_STATEID returns NFS4ERR_OLD_STATEID, then it just
means we raced with other calls to OPEN.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The client was freeing the nfs4_ff_layout_ds, but not the contained
nfs4_ff_ds_version array.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the server changes, so that it no longer supports SP4_MACH_CRED, or
that it doesn't support the same set of SP4_MACH_CRED functionality,
then we want to ensure that we clear the unsupported flags.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Tease apart the functionality in nfs4_exchange_id_done() so that
it is easier to debug exchange id vs trunking issues by moving
all the processing out of nfs4_exchange_id_done() and into the
callers.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

rpc_clnt_add_xprt() expects the callback function to be synchronous, and
expects to release the transport and switch references itself.

Fixes: 04fa2c6b ("NFS pnfs data server multipath session trunking")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The verifier is allocated on the stack, but the EXCHANGE_ID RPC call was
changed to be asynchronous by commit 8d89bd70. If we interrrupt
the call to rpc_wait_for_completion_task(), we can therefore end up
transmitting random stack contents in lieu of the verifier.

Fixes: 8d89bd70 ("NFS setup async exchange_id")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>