linux.git/fs/nfs, branch v4.8

NFSv4.1: Fix the CREATE_SESSION slot number accounting

2016-09-11T18:56:44+00:00

Ensure that we conform to the algorithm described in RFC5661, section
18.36.4 for when to bump the sequence id. In essence we do it for all
cases except when the RPC call timed out, or in case of the server returning
NFS4ERR_DELAY or NFS4ERR_STALE_CLIENTID.

Signed-off-by: Trond Myklebust 
Cc: stable@vger.kernel.org

pNFS: Don't forget the layout stateid if there are outstanding LAYOUTGETs

2016-09-04T16:59:00+00:00

If there are outstanding LAYOUTGET rpc calls, then we want to ensure that
we keep the layout stateid around so we that don't inadvertently pick up
an old/misordered sequence id.
The race is as follows:

Client				Server
======				======
LAYOUTGET(seqid)
LAYOUTGET(seqid)
				return LAYOUTGET(seqid+1)
				return LAYOUTGET(seqid+2)
process LAYOUTGET(seqid+2)
	forget layout
process LAYOUTGET(seqid+1)

If it forgets the layout stateid before processing seqid+1, then
the client will not check the layout->plh_barrier, and so will set
the stateid with seqid+1.

Signed-off-by: Trond Myklebust

pNFS: Clear out all layout segments if the server unsets lrp->res.lrs_present

2016-09-03T16:10:38+00:00

If the server fails to set lrp->res.lrs_present in the LAYOUTRETURN reply,
then that means it believes the client holds no more layout state for that
file, and that the layout stateid is now invalid.

Signed-off-by: Trond Myklebust

pNFS: Fix pnfs_set_layout_stateid() to clear NFS_LAYOUT_INVALID_STID

2016-09-03T16:10:37+00:00

If the layout was marked as invalid, we want to ensure to initialise
the layout header fields correctly.

Signed-off-by: Trond Myklebust

pNFS: Ensure LAYOUTGET and LAYOUTRETURN are properly serialised

2016-09-03T16:10:37+00:00

According to RFC5661, the client is responsible for serialising
LAYOUTGET and LAYOUTRETURN to avoid ambiguity. Consider the case
where we send both in parallel.

Client					Server
======					======
LAYOUTGET(seqid=X)
LAYOUTRETURN(seqid=X)
					LAYOUTGET return seqid=X+1
					LAYOUTRETURN return seqid=X+2
Process LAYOUTRETURN
          Forget layout stateid
Process LAYOUTGET
          Set seqid=X+1

The client processes the layoutget/layoutreturn in the wrong order,
and since the result of the layoutreturn was to clear the only
existing layout segment, the client forgets the layout stateid.

When the LAYOUTGET comes in, it is treated as having a completely
new stateid, and so the client sets the wrong sequence id...

Fix is to check if there are outstanding LAYOUTGET requests
before we send the LAYOUTRETURN (note that LAYOUGET will already
wait if it sees an outstanding LAYOUTRETURN).

Signed-off-by: Trond Myklebust 
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Trond Myklebust

NFS: Fix error reporting in nfs_file_write()

2016-09-03T16:10:36+00:00

When doing O_DSYNC writes, the actual write errors are reported through
generic_write_sync(), so we must test the result.

Reported-by: J. R. Okajima 
Fixes: 18290650b1c8 ("NFS: Move buffered I/O locking into nfs_file_write()")
Signed-off-by: Trond Myklebust

NFSv4.x: Fix a refcount leak in nfs_callback_up_net

2016-08-30T13:26:57+00:00

On error, the callers expect us to return without bumping
nn->cb_users[].

Signed-off-by: Trond Myklebust 
Cc: stable@vger.kernel.org # v3.7+

NFS4: Avoid migration loops

2016-08-30T13:26:32+00:00

If a server returns itself as a location while migrating, the client may
end up getting stuck attempting to migrate twice to the same server.  Catch
this by checking if the nfs_client found is the same as the existing
client.  For the other two callers to nfs4_set_client, the nfs_client will
always be ERR_PTR(-EINVAL).

Signed-off-by: Benjamin Coddington 
Signed-off-by: Trond Myklebust

pNFS/flexfiles: Fix an Oopsable condition when connection to the DS fails

2016-08-29T19:21:16+00:00

If the attempt to connect to a DS fails inside ff_layout_pg_init_read or
ff_layout_pg_init_write, then we currently end up clearing the layout
segment carried by the struct nfs_pageio_descriptor, causing an Oops
when we later call into ff_layout_read_pagelist/ff_layout_write_pagelist.

The fix is to ensure we return the layout and then retry.

Fixes: 446ca2195303 ("pNFS/flexfiles: When initing reads or writes, we...")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Trond Myklebust

NFSv4.1: Remove obsolete and incorrrect assignment in nfs4_callback_sequence

2016-08-28T18:23:27+00:00

Signed-off-by: Trond Myklebust