NFS: Fix memroy leak for double mounts

When double mounting same nfs filesystem, the devname saved in d_fsdata
will be lost.The second mount should not change the devname that
be saved in d_fsdata.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Don't declare inode uptodate unless all attributes were checked

Fix a bug, whereby nfs_update_inode() was declaring the inode to be
up to date despite not having checked all the attributes.
The bug occurs because the temporary variable in which we cache
the validity information is 'sanitised' before reapplying to
nfsi->cache_validity.

Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Cc: stable@vger.kernel.org # 3.5+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Don't ignore suid/sgid bit changes after a successful write

If we suspect that the server may have cleared the suid/sgid bit,
then mark the inode for revalidation.

Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
SUNRPC: Fix a module reference issue in rpcsec_gss

We're not taking a reference in the case where _gss_mech_get_by_pseudoflavor
loops without finding the correct rpcsec_gss flavour, so why are we
releasing it?

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
nfs: commit layouts in fdatasync

 "fdatasync() is similar to fsync(), but does not flush modified metadata
  unless that metadata is needed in order  to  allow  a  subsequent  data
  retrieval to be correctly handled."

We absolutely need to commit the layouts to be able to retrieve the data
in case either the client, the server or the storage subsystem go down.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
nfs: remove ->write_pageio_init from rpc ops

The write_pageio_init method is just a very convoluted way to grab the
right nfs_pageio_ops vector.  The vector to chose is not a choice of
protocol version, but just a pNFS vs MDS I/O choice that can simply be
done inside nfs_pageio_init_write based on the presence of a layout
driver, and a new force_mds flag to the special case of falling back
to MDS I/O on a pNFS-capable volume.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
nfs: remove ->read_pageio_init from rpc ops

The read_pageio_init method is just a very convoluted way to grab the
right nfs_pageio_ops vector.  The vector to chose is not a choice of
protocol version, but just a pNFS vs MDS I/O choice that can simply be
done inside nfs_pageio_init_read based on the presence of a layout
driver, and a new force_mds flag to the special case of falling back
to MDS I/O on a pNFS-capable volume.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common argument structure for reads and writes

Reads and writes have very similar arguments.  This patch combines them
together and documents the few fields used only by write.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common results structure for reads and writes

Reads and writes have very similar results.  This patch combines the two
structs together with comments to show where the differing fields are
used.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common read and write data struct

At this point, the only difference between nfs_read_data and
nfs_write_data is the write verifier.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common read and write header struct

The only difference is the write verifier field, but we can keep that
for a little bit longer.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Move the write verifier into the nfs_pgio_header

The header had a pointer to the verifier that was set from the old write
data struct.  We don't need to keep the pointer around now that we have
shared structures.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common pgio_alloc and pgio_release function

These functions are identical for the read and write paths so they can
be combined.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common rw_header_alloc and rw_header_free function

I create a new struct nfs_rw_ops to decide the differences between reads
and writes.  This struct will be set when initializing a new
nfs_pgio_descriptor, and then passed on to the nfs_rw_header when a new
header is allocated.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common pgio_rpc_prepare function

The read and write paths do exactly the same thing for the rpc_prepare
rpc_op.  This patch combines them together into a single function.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common nfs_pgio_result_common function

Combining these functions will let me make a single nfs_rw_common_ops
struct (see the next patch).

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common rpc_call_ops struct

The read and write paths set up this struct in exactly the same way, so
create a single shared struct.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common rpcsetup function for reads and writes

Write adds a little bit of code dealing with flush flags, but since
"how" will always be 0 when reading we can share the code.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a common pgio_error function

At this point, the read and write versions of this function look
identical so both should use the same function.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
NFS: Create a generic_pgio function

These functions are almost identical on both the read and write side.
FLUSH_COND_STABLE will never be set for the read path, so leaving it in
the generic code won't hurt anything.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>