... instead of mixing FMODE_ and O_
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

commit 1e41568d ("Take ima_path_check()
in nfsd past dentry_open() in nfsd_open()") moved this code back to its
original location but missed the "else".
Signed-off-by: NChuck Ebbert <cebbert@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit f39bde24 fixed the error return from PUTROOTFH in the
case where there is no pseudofilesystem.

This is really a case we shouldn't hit on a correctly configured server:
in the absence of a root filehandle, there's no point accepting version
4 NFS rpc calls at all.

But the shared responsibility between kernel and userspace here means
the kernel on its own can't eliminate the possiblity of this happening.
And we have indeed gotten this wrong in distro's, so new client-side
mount code that attempts to negotiate v4 by default first has to work
around this case.

Therefore when commit f39bde24 arrived at roughly the same
time as the new v4-default mount code, which explicitly checked only for
the previous error, the result was previously fine mounts suddenly
failing.

We'll fix both sides for now: revert the error change, and make the
client-side mount workaround more robust.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

ima_path_check actually deals with files!  call it ima_file_check instead.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The "Untangling ima mess, part 2 with counters" patch messed
up the counters.  Based on conversations with Al Viro, this patch
streamlines ima_path_check() by removing the counter maintaince.
The counters are now updated independently, from measuring the file,
in __dentry_open() and alloc_file() by calling ima_counts_get().
ima_path_check() is called from nfsd and do_filp_open().
It also did not measure all files that should have been measured.
Reason: ima_path_check() got bogus value passed as mask.
[AV: mea culpa]
[AV: add missing nfsd bits]
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

nfsd is not using vfs_fsync, so I missed it when changing the calling
convention during the 2.6.32 window.  This patch fixes it to not only
start the data writeout, but also wait for it to complete before calling
into ->fsync.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

A typo in 12045a6e "nfsd: let "insecure" flag vary by
pseudoflavor" reversed the sense of the "insecure" flag.
Reported-by: NMichael Guntsche <mike@it-loops.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A typo in 12045a6e "nfsd: let "insecure" flag vary by
pseudoflavor" reversed the sense of the "insecure" flag.
Reported-by: NMichael Guntsche <mike@it-loops.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Kill the 'update' argument of ima_path_check(), kill
dead code in ima.

Current rules: ima counters are bumped at the same time
when the file switches from put_filp() fodder to fput()
one.  Which happens exactly in two places - alloc_file()
and __dentry_open().  Nothing else needs to do that at
all.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* do ima_get_count() in __dentry_open()
* stop doing that in followups
* move ima_path_check() to right after nameidata_to_filp()
* don't bump counters on it
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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>

Most of this can be trivially moved to a private header as well.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

I can't see any use for writeable V4ROOT exports.
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>

We want to allow exports of symlinks, to allow mountd to communicate to
the kernel which symlinks lead to exports, and hence which symlinks need
to be visible on the pseudofilesystem.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

As with lookup, we treat every boject as a mountpoint and pretend it
doesn't exist if it isn't exported.

The preexisting code here is confusing, but I haven't yet figured out
how to make it clearer.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We treat every object as a mountpoint and pretend it doesn't exist if
it isn't exported.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

If /A/mount/point/ has filesystem "B" mounted on top of it, and if "A"
is exported, but not "B", then the nfs server has always returned to the
client a filehandle for the mountpoint, instead of for the root of "B",
allowing the client to see the subtree of "A" that would otherwise be
hidden by B.

Disable this behavior in the case of V4ROOT exports; we implement the
path restrictions of V4ROOT exports by treating *every* directory as if
it were a mountpoint, and allowing traversal *only* if the new directory
is exported.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

NFSv4 differs from v2 and v3 in that it presents a single unified
filesystem tree, whereas v2 and v3 exported multiple filesystem (whose
roots could be found using a separate mount protocol).

Our original NFSv4 server implementation asked the administrator to
designate a single filesystem as the NFSv4 root, then to mount
filesystems they wished to export underneath.  (Often using bind mounts
of already-existing filesystems.)

This was conceptually simple, and allowed easy implementation, but
created a serious obstacle to upgrading between v2/v3: since the paths
to v4 filesystems were different, administrators would have to adjust
all the paths in client-side mount commands when switching to v4.

Various workarounds are possible.  For example, the administrator could
export "/" and designate it as the v4 root.  However, the security risks
of that approach are obvious, and in any case we shouldn't be requiring
the administrator to take extra steps to fix this problem; instead, the
server should present consistent paths across different versions by
default.

These patches take a modified version of that approach: we provide a new
export option which exports only a subset of a filesystem.  With this
flag, it becomes safe for mountd to export "/" by default, with no need
for additional configuration.

We begin just by defining the new flag.
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>

Soon we will add the new V4ROOT flag, and allow the INSECURE flag to
vary by pseudoflavor.  It would be useful for nfs-utils (for example,
for improved exportfs error reporting) to be able to know when this
happens.  Use this new interface for that purpose.
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>

NFSv4 opens may function as locks denying other NFSv4 users the rights
to open a file.

We're requiring a user to have write permissions before they can deny
write.  We're *not* requiring a user to have write permissions to deny
read, which is if anything a more drastic denial.

What was intended was to require write permissions for DENY_READ.
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>

Commit 8177e6d6 ("nfsd: clean up
readdirplus encoding") introduced single character typo in nfs3 readdir+
implementation.  Unfortunately that typo has quite bad side effects:
random memory corruption, followed (on my box) with immediate
spontaneous box reboot.

Using 'p1' instead of 'p' fixes my Linux box rebooting whenever VMware
ESXi box tries to list contents of my home directory.
Signed-off-by: NPetr Vandrovec <petr@vandrovec.name>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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>

Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Modify the NFS server to register the NFS_ACL services with the rpcbind
daemon.  This allows the client to ping for the existence of the NFS_ACL
support via commands such as "rpcinfo -t <server> nfs_acl".

This patch also modifies the NFS_ACL support so that responses to
version 2 NULLPROC requests can be made.

The changelog for the patch which turned off this functionality
mentioned something about not registering the NFS_ACL as being part of
some tradition.  I can't find this tradition and the only other
implementation which supports NFS_ACL does register them with the
rpcbind daemon.
Signed-off-by: NPeter Staubach <staubach@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We have been doing some extensive testing of Linux support for ACLs on
NFDS v4. We have noticed that the server rejects ACLs where the groups
are out of order, for example, the following ACL is rejected:

A::OWNER@:rwaxtTcCy
A::user101@domain:rwaxtcy
A::GROUP@:rwaxtcy
A:g:group102@domain:rwaxtcy
A:g:group101@domain:rwaxtcy
A::EVERYONE@:rwaxtcy

Examining the server code, I found that after converting an NFS v4 ACL
to POSIX, sort_pacl is called to sort the user ACEs and group ACEs.
Unfortunately, a minor bug causes the group sort to be skipped.
Signed-off-by: NFrank Filz <ffilzlnx@us.ibm.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We do the same calculation in a couple places; use a helper function,
and add a little documentation, in the hopes of preventing bugs like
that fixed in the last patch.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Unbalanced calculations on creation and destruction of sessions could
cause our estimate of cache memory used to become negative, sometimes
resulting in spurious SERVERFAULT returns to client CREATE_SESSION
requests.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

[akpm@linux-foundation.org: fix KVM]
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ca_maxresponsesize and ca_maxrequest size include the RPC header.

sv_max_mesg is sv_max_payolad plus a page for overhead and is used in
svc_init_buffer to allocate server buffer space for both the request and reply.
Note that this means we can service an RPC compound that requires
ca_maxrequestsize (MAXWRITE) or ca_max_responsesize (MAXREAD) but that we do
not support an RPC compound that requires both ca_maxrequestsize and
ca_maxresponsesize.
Signed-off-by: NAndy Adamson <andros@netapp.com>
[bfields@citi.umich.edu: more documentation updates]
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

We really shouldn't hit this case at all, and forthcoming kernel and
nfs-utils changes should eliminate this case; if it does happen,
consider it a bug rather than reporting an error that doesn't really
make sense for the operation (since there's no reason for a server to be
accepting v4 traffic yet have no root filehandle).

Also move some exp_pseudoroot code into a helper function while we're
here.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Break out some of nfsd_lookup_dentry into helper functions.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

3c394dda "nfsd4: nfsv4 clients should
cross mountpoints" forgot to handle lookups of parents directories.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

* remove asm/atomic.h inclusion from linux/utsname.h --
   not needed after kref conversion
 * remove linux/utsname.h inclusion from files which do not need it

NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however
due to some personality stuff it _is_ needed -- cowardly leave ELF-related
headers and files alone.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make all seq_operations structs const, to help mitigate against
revectoring user-triggerable function pointers.

This is derived from the grsecurity patch, although generated from scratch
because it's simpler than extracting the changes from there.
Signed-off-by: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>