The kernel's NFS client mount option parser currently doesn't allow
unrecognized or incorrect mount options.  This prevents misspellings or
incorrectly specified mount options from possibly causing silent data
corruption.

However, NFS mount options are not standardized, so different operating
systems can use differently spelled mount options to support similar
features, or can support mount options which no other operating system
supports.

"Sloppy" mount option parsing, which allows the parser to ignore any
option it doesn't recognize, is needed to support automounters that often
use maps that are shared between heterogenous operating systems.

The legacy mount command ignores the validity of the values of mount
options entirely, except for the "sec=" and "proto=" options.  If an
incorrect value is specified, the out-of-range value is passed to the
kernel; if a value is specified that contains non-numeric characters,
it appears as though the legacy mount command sets that option to zero
(probably incorrect behavior in general).

In any case, this sets a precedent which we will partially follow for
the kernel mount option parser:

	+ if "sloppy" is not set, the parser will be strict about both
	  unrecognized options (same as legacy) and invalid option
	  values (stricter than legacy)

	+ if "sloppy" is set, the parser will ignore unrecognized
	  options and invalid option values (same as legacy)

An "invalid" option value in this case means that either the type
(integer, short, or string) or sign (for integer values) of the specified
value is incorrect.

This patch does two things: it changes the NFS client's mount option
parsing loop so that it parses the whole string instead of failing at
the first unrecognized option or invalid option value.  An unrecognized
option or an invalid option value cause the option to be skipped.

Then, the patch adds a "sloppy" mount option that allows the parsing
to succeed anyway if there were any problems during parsing.  When
parsing a set of options is complete, if there are errors and "sloppy"
was specified, return success anyway.  Otherwise, only return success
if there are no errors.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Set the default security flavor when we set the other mount option
default values for NFSv4.  This cleans up the NFSv4 mount option parsing
path to look like the NFSv2/v3 one.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Set the default security flavor when we set the other mount option default
values.  After this change, only the legacy user-space mount path needs to
set the NFS_MOUNT_SECFLAVOUR flag.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: Refactor the NFS mount option parsing function to extract the
security flavor parsing logic into a separate function.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The remount path does not need to set the port in the server address.
Since it's not really a part of option parsing, move the nfs_set_port()
call to nfs_parse_mount_options()'s callers.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Move the UDP/TCP default timeo/retrans settings for text mounts to
nfs_init_timeout_values(), which was were they were always being
initialised (and sanity checked) for binary mounts.
Document the default timeout values using appropriate #defines.

Ensure that we initialise and sanity check the transport protocols that
may have been specified by the user.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Add support in the kernel NFS client's address parser for interface
identifiers.

IPv6 link-local addresses require an additional "interface identifier",
which is a network device name or an integer that indexes the array of
local network interfaces.  They are suffixed to the address with a '%'.
For example:

	fe80::215:c5ff:fe3b:e1b2%2

indicates an interface index of 2.  Or

	fe80::215:c5ff:fe3b:e1b2%eth0

indicates that requests should be routed through the eth0 device.
Without the interface ID, link-local addresses are not usable for NFS.

Both the kernel NFS client mount option parser and the mount.nfs command
can take either form.  The mount.nfs command always passes the address
through getnameinfo(3), which usually re-writes interface indices as
device names.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

To make nfs_parse_server_address() more generally useful, allow it to
accept input strings that are not terminated with '\0'.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Traditionally the mount command has looked for a ":" to separate the
server's hostname from the export path in the mounted on device name,
like this:

	mount server:/export /mounted/on/dir

The server's hostname is "server" and the export path is "/export".

You can also substitute a specific IPv4 network address for the server
hostname, like this:

	mount 192.168.0.55:/export /mounted/on/dir

Raw IPv6 addresses present a problem, however, because they look
something like this:

	fe80::200:5aff:fe00:30b

Note the use of colons.

To get around the presence of colons, copy the Solaris convention used for
mounting IPv6 servers by address: wrap a raw IPv6 address with square
brackets.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

To support passing a raw IPv6 address as a server hostname, we need to
expand the logic that handles splitting the passed-in device name into
a server hostname and export path

Start by pulling device name parsing out of the mount option validation
functions and into separate helper functions.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix the 'nfs4_fs_type' undeclared error in nfs_remount when compiling sans
NFSv4...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jeff Layton <jlayton@redhat.com>

Clean up.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up:  the "intr" and "nointr" mount options were recently retired.
Document this in the NFS mount option parser.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The kernel NFS mount option parser should ignore the retry= mount option
since it is meaningful only in user space.  Today it expects a number
rather than arbitrary text, so it ignores the option if the value is
numeric, but chokes if there are other characters in the value.

Change it to allow any text (except ",") as its value.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When remounting an NFS or NFS4 filesystem, the new NFS options are not
respected, yet the remount will still return success. This patch adds
a remount_fs sb op for NFS that checks any new nfs mount options against
the existing ones and fails the mount if any have changed.

This is only implemented for string-based mount options since doing
this with binary options isn't really feasible.

This is essentially the same as the original patch I sent out, but
adds a check to see if the addr= option has changed.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix a sign issue in xdr_decode_fhstatus3()
Fix incorrect comparison in nfs_validate_mount_data()
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This appears to fix the Oops reported in
  http://bugzilla.kernel.org/show_bug.cgi?id=10826Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFSv3 get_sb operations call into the LSM layer to set security options passed
from userspace.  NFSv4 hooks were not originally added since it was reasonably
late in the merge window and NFSv3 was the only thing that had regressed (v4
has never supported any LSM options)

This patch makes NFSv4 call into the LSM to set security options rather than
just blindly dropping them with no notice to the user as happens today.  This
patch was tested in a simple NFSv4 environment with the context= option and
appeared to work as expected.
Signed-off-by: NEric Paris <eparis@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: NJames Morris <jmorris@namei.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Register NFS' backing_dev_info under sysfs with the name "nfs-MAJOR:MINOR"
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

There is possible NULL pointer dereference if kstr[n]dup failed.
So fix them for safety.
Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

... and take it out of ->umount_begin() instances.  Call with all locks
already taken (by do_umount()) and leave calling release_mounts() to
caller (it will do release_mounts() anyway, so we can just put into
the same list).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Display all mount options in /proc/mount which may be needed to reconstruct
a previous mount.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

During a remount based on the mount options displayed in /proc/mounts, we
want to preserve the original behavior of the mount request.  Let's save
the original setting of the "port=" mount option in the mount's nfs_server
structure.

This allows us to simplify the default behavior of port setting for NFSv4
mounts: by default, NFSv2/3 mounts first try an RPC bind to determine the
NFS server's port, unless the user specified the "port=" mount option;
Users can force the client to skip the RPC bind by explicitly specifying
"port=<value>".

NFSv4, by contrast, assumes the NFS server port is 2049 and skips the RPC
bind, unless the user specifies "port=".  Users can force an RPC bind for
NFSv4 by explicitly specifying "port=0".

I added a couple of extra comments to clarify this behavior.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: use %u instead of %d when displaying NFS mount options.

Nit: Fix reporting of "namlen=" option in nfs_show_mount_stats.  The mount
option is called "namlen" without the "e".
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

NFS and SELinux worked together previously because SELinux had NFS
specific knowledge built in.  This design was approved by both groups
back in 2004 but the recent NFS changes to use nfs_parsed_mount_data and
the usage of nfs_clone_mount_data showed this to be a poor fragile
solution.  This patch fixes the NFS functionality regression by making
use of the new LSM interfaces to allow an FS to explicitly set its own
mount options.

The explicit setting of mount options is done in the nfs get_sb
functions which are called before the generic vfs hooks try to set mount
options for filesystems which use text mount data.

This does not currently support NFSv4 as that functionality did not
exist in previous kernels and thus there is no regression.  I will be
adding the needed code, which I believe to be the exact same as the v3
code, in nfs4_get_sb for 2.6.26.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

This patch adds previous missing spkm3 string values that are needed
to parse mount options in the kernel.

David Howells noticed that repeating the same mount option twice during an
NFS mount request can result in orphaned memory in certain cases.

Only the client_address and mount_server.hostname strings are initialized
in the mount parsing loop, so those appear to be the only two pointers that
might be written over by repeating a mount option.  The strings in the
nfs_server section of the nfs_parsed_mount_data structure are set only once
after the options are parsed, thus these are not susceptible to being
overwritten.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Now that the needed IPv6 infrastructure is in place, allow the NFS client's
IP address parser to generate AF_INET6 addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Replace the nfs_server and mount_server address fields in the
nfs_parsed_mount_data structure with a "struct sockaddr_storage"
instead of a "struct sockaddr_in".
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Refactor the logic to parse incoming text-based IP addresses.  Use the
in4_pton() function instead of the older in_aton(), following the lead
of the in-kernel CIFS client.

Later we'll add IPv6 address parsing using the matching in6_pton()
function.  For now we can't allow IPv6 address parsing: we must expand
the size of the address storage fields in the nfs_parsed_mount_options
struct before we can parse and store IPv6 addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In the name of address family compatibility, we can't have the NIP_FMT and
NIPQUAD macros in nfs_try_mount().  Instead, we can make use of an unused
mount option to display the mount server's hostname.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Create a helper function to set the default NFS port for NFSv4 mount
points.  The helper supports both AF_INET and AF_INET6 family addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We'll need to set the port number of an AF_INET or AF_INET6 address in
several places in fs/nfs/super.c, so introduce a helper that can manage
this for us.  We put this helper to immediate use.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Add support to nfs_verify_server_address for recognizing AF_INET6
addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>