The new .h files have paths at the top that are now out of date.  While
we're here, just remove all of those from fs/nfsd; they never served any
purpose.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

On V4ROOT exports, only accept filehandles that are the *root* of some
export.  This allows mountd to allow or deny access to individual
directories and symlinks on the pseudofilesystem.

Note that the checks in readdir and lookup are not enough, since a
malicious host with access to the network could guess filehandles that
they weren't able to obtain through lookup or readdir.
Signed-off-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

This was an oversight; it should be among the export flags that can be
allowed to vary by pseudoflavor.  This allows an administrator to (for
example) allow auth_sys mounts only from low ports, but allow auth_krb5
mounts to use any port.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Lots of include/linux/nfsd/* headers are only used by
nfsd module. Move them to the source directory
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Now that the headers are fixed and carry their own wait, all fs/nfsd/
source files can include a minimal set of headers. and still compile just
fine.

This patch should improve the compilation speed of the nfsd module.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

All nfsd security depends on the security checks in fh_verify, and
especially on nfsd_setuser().

It therefore bothers me that the nfsd_setuser call may be made from
three different places, depending on whether the filehandle has already
been mapped to a dentry, and on whether subtreechecking is in force.

Instead, make an unconditional call in fh_verify(), so it's trivial to
verify that the call always occurs.

That leaves us with a redundant nfsd_setuser() call in the subtreecheck
case--it needs the correct user set earlier in order to check execute
permissions on the path to this filehandle--but I'm willing to accept
that minor inefficiency in the subtreecheck case in return for more
straightforward permission checking.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

None of this stuff is used outside nfsd, so move it out of the common
linux include directory.

Actually, probably none of the stuff in include/linux/nfsd/nfsd.h really
belongs there, so later we may remove that file entirely.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

A number of callers (nfsd4_encode_fattr(), at least) don't bother to
release the filehandle returned to fh_compose() if fh_compose() returns
an error.  So, modify fh_compose() to release the filehandle before
returning an error.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

More trivial cleanup.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The file nfsfh.c contains two static variables nfsd_nr_verified and
nfsd_nr_put.  These are counters which are incremented as a side
effect of the fh_verify() fh_compose() and fh_put() operations,
i.e. at least twice per NFS call for any non-trivial workload.
Needless to say this makes the cacheline that contains them (and any
other innocent victims) a very hot contention point indeed under high
call-rate workloads on multiprocessor NFS server.  It also turns out
that these counters are not used anywhere.  They're not reported to
userspace, they're not used in logic, they're not even exported from
the object file (let alone the module).  All they do is waste CPU time.

So this patch removes them.

Tests on a 16 CPU Altix A4700 with 2 10gige Myricom cards, configured
separately (no bonding).  Workload is 640 client threads doing directory
traverals with random small reads, from server RAM.

Before
======

Kernel profile:

  %   cumulative   self              self     total
 time   samples   samples    calls   1/call   1/call  name
  6.05   2716.00  2716.00    30406     0.09     1.02  svc_process
  4.44   4706.00  1990.00     1975     1.01     1.01  spin_unlock_irqrestore
  3.72   6376.00  1670.00     1666     1.00     1.00  svc_export_put
  3.41   7907.00  1531.00     1786     0.86     1.02  nfsd_ofcache_lookup
  3.25   9363.00  1456.00    10965     0.13     1.01  nfsd_dispatch
  3.10  10752.00  1389.00     1376     1.01     1.01  nfsd_cache_lookup
  2.57  11907.00  1155.00     4517     0.26     1.03  svc_tcp_recvfrom
  ...
  2.21  15352.00  1003.00     1081     0.93     1.00  nfsd_choose_ofc  <----
  ^^^^

Here the function nfsd_choose_ofc() reads a global variable
which by accident happened to be located in the same cacheline as
nfsd_nr_verified.

Call rate:

nullarbor:~ # pmdumptext nfs3.server.calls
...
Thu Dec 13 00:15:27     184780.663
Thu Dec 13 00:15:28     184885.881
Thu Dec 13 00:15:29     184449.215
Thu Dec 13 00:15:30     184971.058
Thu Dec 13 00:15:31     185036.052
Thu Dec 13 00:15:32     185250.475
Thu Dec 13 00:15:33     184481.319
Thu Dec 13 00:15:34     185225.737
Thu Dec 13 00:15:35     185408.018
Thu Dec 13 00:15:36     185335.764

After
=====

kernel profile:

  %   cumulative   self              self     total
 time   samples   samples    calls   1/call   1/call  name
  6.33   2813.00  2813.00    29979     0.09     1.01  svc_process
  4.66   4883.00  2070.00     2065     1.00     1.00  spin_unlock_irqrestore
  4.06   6687.00  1804.00     2182     0.83     1.00  nfsd_ofcache_lookup
  3.20   8110.00  1423.00    10932     0.13     1.00  nfsd_dispatch
  3.03   9456.00  1346.00     1343     1.00     1.00  nfsd_cache_lookup
  2.62  10622.00  1166.00     4645     0.25     1.01  svc_tcp_recvfrom
[...]
  0.10  42586.00    44.00       74     0.59     1.00  nfsd_choose_ofc  <--- HA!!
  ^^^^

Call rate:

nullarbor:~ # pmdumptext nfs3.server.calls
...
Thu Dec 13 01:45:28     194677.118
Thu Dec 13 01:45:29     193932.692
Thu Dec 13 01:45:30     194294.364
Thu Dec 13 01:45:31     194971.276
Thu Dec 13 01:45:32     194111.207
Thu Dec 13 01:45:33     194999.635
Thu Dec 13 01:45:34     195312.594
Thu Dec 13 01:45:35     195707.293
Thu Dec 13 01:45:36     194610.353
Thu Dec 13 01:45:37     195913.662
Thu Dec 13 01:45:38     194808.675

i.e. about a 5.3% improvement in call rate.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Reviewed-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

When determining the fsid_type in fh_compose(), the setting of the FID
via fsid= export option needs to take precedence over using the UUID
device id.
Signed-off-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Inaugurate copy-on-write credentials management.  This uses RCU to manage the
credentials pointer in the task_struct with respect to accesses by other tasks.
A process may only modify its own credentials, and so does not need locking to
access or modify its own credentials.

A mutex (cred_replace_mutex) is added to the task_struct to control the effect
of PTRACE_ATTACHED on credential calculations, particularly with respect to
execve().

With this patch, the contents of an active credentials struct may not be
changed directly; rather a new set of credentials must be prepared, modified
and committed using something like the following sequence of events:

	struct cred *new = prepare_creds();
	int ret = blah(new);
	if (ret < 0) {
		abort_creds(new);
		return ret;
	}
	return commit_creds(new);

There are some exceptions to this rule: the keyrings pointed to by the active
credentials may be instantiated - keyrings violate the COW rule as managing
COW keyrings is tricky, given that it is possible for a task to directly alter
the keys in a keyring in use by another task.

To help enforce this, various pointers to sets of credentials, such as those in
the task_struct, are declared const.  The purpose of this is compile-time
discouragement of altering credentials through those pointers.  Once a set of
credentials has been made public through one of these pointers, it may not be
modified, except under special circumstances:

  (1) Its reference count may incremented and decremented.

  (2) The keyrings to which it points may be modified, but not replaced.

The only safe way to modify anything else is to create a replacement and commit
using the functions described in Documentation/credentials.txt (which will be
added by a later patch).

This patch and the preceding patches have been tested with the LTP SELinux
testsuite.

This patch makes several logical sets of alteration:

 (1) execve().

     This now prepares and commits credentials in various places in the
     security code rather than altering the current creds directly.

 (2) Temporary credential overrides.

     do_coredump() and sys_faccessat() now prepare their own credentials and
     temporarily override the ones currently on the acting thread, whilst
     preventing interference from other threads by holding cred_replace_mutex
     on the thread being dumped.

     This will be replaced in a future patch by something that hands down the
     credentials directly to the functions being called, rather than altering
     the task's objective credentials.

 (3) LSM interface.

     A number of functions have been changed, added or removed:

     (*) security_capset_check(), ->capset_check()
     (*) security_capset_set(), ->capset_set()

     	 Removed in favour of security_capset().

     (*) security_capset(), ->capset()

     	 New.  This is passed a pointer to the new creds, a pointer to the old
     	 creds and the proposed capability sets.  It should fill in the new
     	 creds or return an error.  All pointers, barring the pointer to the
     	 new creds, are now const.

     (*) security_bprm_apply_creds(), ->bprm_apply_creds()

     	 Changed; now returns a value, which will cause the process to be
     	 killed if it's an error.

     (*) security_task_alloc(), ->task_alloc_security()

     	 Removed in favour of security_prepare_creds().

     (*) security_cred_free(), ->cred_free()

     	 New.  Free security data attached to cred->security.

     (*) security_prepare_creds(), ->cred_prepare()

     	 New. Duplicate any security data attached to cred->security.

     (*) security_commit_creds(), ->cred_commit()

     	 New. Apply any security effects for the upcoming installation of new
     	 security by commit_creds().

     (*) security_task_post_setuid(), ->task_post_setuid()

     	 Removed in favour of security_task_fix_setuid().

     (*) security_task_fix_setuid(), ->task_fix_setuid()

     	 Fix up the proposed new credentials for setuid().  This is used by
     	 cap_set_fix_setuid() to implicitly adjust capabilities in line with
     	 setuid() changes.  Changes are made to the new credentials, rather
     	 than the task itself as in security_task_post_setuid().

     (*) security_task_reparent_to_init(), ->task_reparent_to_init()

     	 Removed.  Instead the task being reparented to init is referred
     	 directly to init's credentials.

	 NOTE!  This results in the loss of some state: SELinux's osid no
	 longer records the sid of the thread that forked it.

     (*) security_key_alloc(), ->key_alloc()
     (*) security_key_permission(), ->key_permission()

     	 Changed.  These now take cred pointers rather than task pointers to
     	 refer to the security context.

 (4) sys_capset().

     This has been simplified and uses less locking.  The LSM functions it
     calls have been merged.

 (5) reparent_to_kthreadd().

     This gives the current thread the same credentials as init by simply using
     commit_thread() to point that way.

 (6) __sigqueue_alloc() and switch_uid()

     __sigqueue_alloc() can't stop the target task from changing its creds
     beneath it, so this function gets a reference to the currently applicable
     user_struct which it then passes into the sigqueue struct it returns if
     successful.

     switch_uid() is now called from commit_creds(), and possibly should be
     folded into that.  commit_creds() should take care of protecting
     __sigqueue_alloc().

 (7) [sg]et[ug]id() and co and [sg]et_current_groups.

     The set functions now all use prepare_creds(), commit_creds() and
     abort_creds() to build and check a new set of credentials before applying
     it.

     security_task_set[ug]id() is called inside the prepared section.  This
     guarantees that nothing else will affect the creds until we've finished.

     The calling of set_dumpable() has been moved into commit_creds().

     Much of the functionality of set_user() has been moved into
     commit_creds().

     The get functions all simply access the data directly.

 (8) security_task_prctl() and cap_task_prctl().

     security_task_prctl() has been modified to return -ENOSYS if it doesn't
     want to handle a function, or otherwise return the return value directly
     rather than through an argument.

     Additionally, cap_task_prctl() now prepares a new set of credentials, even
     if it doesn't end up using it.

 (9) Keyrings.

     A number of changes have been made to the keyrings code:

     (a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have
     	 all been dropped and built in to the credentials functions directly.
     	 They may want separating out again later.

     (b) key_alloc() and search_process_keyrings() now take a cred pointer
     	 rather than a task pointer to specify the security context.

     (c) copy_creds() gives a new thread within the same thread group a new
     	 thread keyring if its parent had one, otherwise it discards the thread
     	 keyring.

     (d) The authorisation key now points directly to the credentials to extend
     	 the search into rather pointing to the task that carries them.

     (e) Installing thread, process or session keyrings causes a new set of
     	 credentials to be created, even though it's not strictly necessary for
     	 process or session keyrings (they're shared).

(10) Usermode helper.

     The usermode helper code now carries a cred struct pointer in its
     subprocess_info struct instead of a new session keyring pointer.  This set
     of credentials is derived from init_cred and installed on the new process
     after it has been cloned.

     call_usermodehelper_setup() allocates the new credentials and
     call_usermodehelper_freeinfo() discards them if they haven't been used.  A
     special cred function (prepare_usermodeinfo_creds()) is provided
     specifically for call_usermodehelper_setup() to call.

     call_usermodehelper_setkeys() adjusts the credentials to sport the
     supplied keyring as the new session keyring.

(11) SELinux.

     SELinux has a number of changes, in addition to those to support the LSM
     interface changes mentioned above:

     (a) selinux_setprocattr() no longer does its check for whether the
     	 current ptracer can access processes with the new SID inside the lock
     	 that covers getting the ptracer's SID.  Whilst this lock ensures that
     	 the check is done with the ptracer pinned, the result is only valid
     	 until the lock is released, so there's no point doing it inside the
     	 lock.

(12) is_single_threaded().

     This function has been extracted from selinux_setprocattr() and put into
     a file of its own in the lib/ directory as join_session_keyring() now
     wants to use it too.

     The code in SELinux just checked to see whether a task shared mm_structs
     with other tasks (CLONE_VM), but that isn't good enough.  We really want
     to know if they're part of the same thread group (CLONE_THREAD).

(13) nfsd.

     The NFS server daemon now has to use the COW credentials to set the
     credentials it is going to use.  It really needs to pass the credentials
     down to the functions it calls, but it can't do that until other patches
     in this series have been applied.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NJames Morris <jmorris@namei.org>

Separate the task security context from task_struct.  At this point, the
security data is temporarily embedded in the task_struct with two pointers
pointing to it.

Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in
entry.S via asm-offsets.

With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

RFC 2623 section 2.3.2 permits the server to bypass gss authentication
checks for certain operations that a client may perform when mounting.
In the case of a client that doesn't have some form of credentials
available to it on boot, this allows it to perform the mount unattended.
(Presumably real file access won't be needed until a user with
credentials logs in.)

Being slightly more lenient allows lots of old clients to access
krb5-only exports, with the only loss being a small amount of
information leaked about the root directory of the export.

This affects only v2 and v3; v4 still requires authentication for all
access.

Thanks to Peter Staubach testing against a Solaris client, which
suggesting addition of v3 getattr, to the list, and to Trond for noting
that doing so exposes no additional information.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Peter Staubach <staubach@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>

Incidentally, the name that gives hundreds of false positives on grep
is not a good idea...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Thanks to Frank Van Maarseveen for the original problem report: "A
privileged process on an NFS client which drops privileges after using
them to change the current working directory, will experience incorrect
EACCES after an NFS server reboot. This problem can also occur after
memory pressure on the server, particularly when the client side is
quiet for some time."

This occurs because the filehandle points to a directory whose parents
are no longer in the dentry cache, and we're attempting to reconnect the
directory to its parents without adequate permissions to perform lookups
in the parent directories.

We can therefore fix the problem by acquiring the necessary capabilities
before attempting the reconnection.  We do this only in the
no_subtree_check case, since the documented behavior of the
subtree_check export option requires the server to check that the user
has lookup permissions on all parents.

The subtree_check case still has a problem, since reconnect_path()
unnecessarily requires both read and lookup permissions on all parent
directories.  However, a fix in that case would be more delicate, and
use of subtree_check is already discouraged for other reasons.
Signed-off-by: NNeil Brown <neilb@suse.de>
Cc: Frank van Maarseveen <frankvm@frankvm.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Rename nfsd_permission() specific MAY_* flags to NFSD_MAY_* to make it
clear, that these are not used outside nfsd, and to avoid name and
number space conflicts with the VFS.

[comment from hch: rename MAY_READ, MAY_WRITE and MAY_EXEC as well]
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Move the code that actually parses the filehandle and looks up the
dentry and export to a separate function.  This simplifies the reference
counting a little and moves fh_verify() a little closer to the kernel
ideal of small, minimally-indentended functions.  Clean up a few other
minor style sins along the way.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Neil Brown <neilb@suse.de>

This bug was always here, but before my commit 6fa02839
("recheck for secure ports in fh_verify"), it could only be triggered by
failure of a kmalloc().  After that commit it could be triggered by a
client making a request from a non-reserved port for access to an export
marked "secure".  (Exports are "secure" by default.)

The result is a struct svc_export with a reference count one too low,
resulting in likely oopses next time the export is accessed.

The reference counting here is not straightforward; a later patch will
clean up fh_verify().

Thanks to Lukas Hejtmanek for the bug report and followup.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Lukas Hejtmanek <xhejtman@ics.muni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sorry for the noise, but here's the v3 of this compilation fix :)

There are some places, which declare the char buf[...] on the stack
to push it later into dprintk(). Since the dprintk sometimes (if the
CONFIG_SYSCTL=n) becomes an empty do { } while (0) stub, these buffers
cause gcc to produce appropriate warnings.

Wrap these buffers with RPC_IFDEBUG macro, as Trond proposed, to
compile them out when not needed.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

I'm embedding struct path into struct svc_export.

[akpm@linux-foundation.org: coding-style fixes]
[ezk@cs.sunysb.edu: NFSD: fix wrong mnt_writer count in rename]
Signed-off-by: NJan Blunck <jblunck@suse.de>
Acked-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NErez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This header is used only in a few places in fs/nfsd, so there seems to
be little point to having it in include/.  (Thanks to Robert Day for
pointing this out.)

Cc: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

As with commit 7fc90ec9 ("knfsd: nfsd:
call nfsd_setuser() on fh_compose(), fix nfsd4 permissions problem")
this is a case where we need to redo a security check in fh_verify()
even though the filehandle already has an associated dentry--if the
filehandle was created by fh_compose() in an earlier operation of the
nfsv4 compound, then we may not have done these checks yet.

Without this fix it is possible, for example, to traverse from an export
without the secure ports requirement to one with it in a single
compound, and bypass the secure port check on the new export.

While we're here, fix up some minor style problems and change a printk()
to a dprintk(), to make it harder for random unprivileged users to spam
the logs.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Reviewed-By: NNeilBrown <neilb@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patchset is a medium scale rewrite of the export operations interface.
The goal is to make the interface less complex, and easier to understand from
the filesystem side, aswell as preparing generic support for exporting of
64bit inode numbers.

This touches all nfs exporting filesystems, and I've done testing on all of
the filesystems I have here locally (xfs, ext2, ext3, reiserfs, jfs)

This patch:

Add a structured fid type so that we don't have to pass an array of u32 values
around everywhere.  It's a union of possible layouts.

As a start there's only the u32 array and the traditional 32bit inode format,
but there will be more in one of my next patchset when I start to document the
various filehandle formats we have in lowlevel filesystems better.

Also add an enum that gives the various filehandle types human- readable
names.

Note: Some people might think the struct containing an anonymous union is
ugly, but I didn't want to pass around a raw union type.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Chris Mason <mason@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fsid_source decided where to get the 'fsid' number to
return for a GETATTR based on the type of filehandle.
It can be from the device, from the fsid, or from the
UUID.

It is possible for the filehandle to be inconsistent
with the export information, so make sure the export information
actually has the info implied by the value returned by
fsid_source.
Signed-off-by: NNeil Brown <neilb@suse.de>
Cc: "Luiz Fernando N. Capitulino" <lcapitulino@gmail.com>
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Our clients (like other clients, as far as I know) use only auth_sys for nlm,
even when using rpcsec_gss for the main nfs operations.

Administrators that want to deny non-kerberos-authenticated locking requests
will need to turn off NFS protocol versions less than 4....
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Allow readonly access to vary depending on the pseudoflavor, using the flag
passed with each pseudoflavor in the export downcall.  The rest of the flags
are ignored for now, though some day we might also allow id squashing to vary
based on the flavor.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make the first actual use of the secinfo information by using it to return
nfserr_wrongsec when an export is found that doesn't allow the flavor used on
this request.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We want it to be possible for users to restrict exports both by IP address and
by pseudoflavor.  The pseudoflavor information has previously been passed
using special auth_domains stored in the rq_client field.  After the preceding
patch that stored the pseudoflavor in rq_pflavor, that's now superfluous; so
now we use rq_client for the ip information, as auth_null and auth_unix do.

However, we keep around the special auth_domain in the rq_gssclient field for
backwards compatibility purposes, so we can still do upcalls using the old
"gss/pseudoflavor" auth_domain if upcalls using the unix domain to give us an
appropriate export.  This allows us to continue supporting old mountd.

In fact, for this first patch, we always use the "gss/pseudoflavor"
auth_domain (and only it) if it is available; thus rq_client is ignored in the
auth_gss case, and this patch on its own makes no change in behavior; that
will be left to later patches.

Note on idmap: I'm almost tempted to just replace the auth_domain in the idmap
upcall by a dummy value--no version of idmapd has ever used it, and it's
unlikely anyone really wants to perform idmapping differently depending on the
where the client is (they may want to perform *credential* mapping
differently, but that's a different matter--the idmapper just handles id's
used in getattr and setattr).  But I'm updating the idmapd code anyway, just
out of general backwards-compatibility paranoia.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Split the callers of exp_get_by_name(), exp_find(), and exp_parent() into
those that are processing requests and those that are doing other stuff (like
looking up filehandles for mountd).

No change in behavior, just a (fairly pointless, on its own) cleanup.

(Note this has the effect of making nfsd_cross_mnt() pass rqstp->rq_client
instead of exp->ex_client into exp_find_by_name().  However, the two should
have the same value at this point.)
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently exp_find(), exp_get_by_name(), and friends, return an export on
success, and on failure return:

	errors -EAGAIN (drop this request pending an upcall) or
		-ETIMEDOUT (an upcall has timed out), or
	return NULL, which can mean either that there was a memory allocation
		failure, or that an export was not found, or that a passed-in
		export lacks an auth_domain.

Many callers seem to assume that NULL means that an export was not found,
which may lead to bugs in the case of a memory allocation failure.

Modify these functions to distinguish between the two NULL cases by returning
either -ENOENT or -ENOMEM.  They now never return NULL.  We get to simplify
some code in the process.

We return -ENOENT in the case of a missing auth_domain.  This case should
probably be removed (or converted to a bug) after confirming that it can never
happen.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently NFSD calls directly into filesystems through the export_operations
structure.  I plan to change this interface in various ways in later patches,
and want to avoid the export of the default operations to NFSD, so this patch
adds two simple exportfs_encode_fh/exportfs_decode_fh helpers for NFSD to call
instead of poking into exportfs guts.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

currently the export_operation structure and helpers related to it are in
fs.h.  fs.h is already far too large and there are very few places needing the
export bits, so split them off into a separate header.

[akpm@linux-foundation.org: fix cifs build]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNeil Brown <neilb@suse.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a lookup request arrives, nfsd uses information provided by userspace
(mountd) to find the right filesystem.

It then assumes that the same filehandle type as the incoming filehandle can
be used to create an outgoing filehandle.

However if mountd is buggy, or maybe just being creative, the filesystem may
not support that filesystem type, and the kernel could oops, particularly if
'ex_uuid' is NULL but a FSID_UUID* filehandle type is used.

So add some proper checking that the fsid version/type from the incoming
filehandle is actually supportable, and ignore that information if it isn't
supportable.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

not needed and actually breaks build on frv, while we are at it
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for using a filesystem UUID to identify and export point in the
filehandle.

For NFSv2, this UUID is xor-ed down to 4 or 8 bytes so that it doesn't take up
too much room.  For NFSv3+, we use the full 16 bytes, and possibly also a
64bit inode number for exports beneath the root of a filesystem.

When generating an fsid to return in 'stat' information, use the UUID (hashed
down to size) if it is available and a small 'fsid' was not specifically
provided.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>