The original code here assumed we'd allow the user to change the lease
any time, but only allow the change to take effect on restart.  Since
then we modified the code to allow setting the lease on when the server
is down.  Update the rest of the code to reflect that fact, clarify
variable names, and add document.

Also, the code insisted that the grace period always be the longer of
the old and new lease periods, but that's overly conservative--as long
as it lasts at least the old lease period, old clients should still know
to recover in time.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Instead of accessing the lease time directly, some users call
nfs4_lease_time(), and some a macro, NFSD_LEASE_TIME, defined as
nfs4_lease_time().  Neither layer of indirection serves any purpose.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

There's no need to allocate this cred more than once.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The server's callback client should stop trying to connect to the
client's callback server as soon as it gets ECONNREFUSED.

The NFS server's callback client does not call rpc_ping(), but appears
to have it's own "ping" procedure, so it wasn't covered by commit
caabea8a.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

- Add commit_metadata export_operation to allow the underlying filesystem to
decide how to commit an inode most efficiently.

- Usage of nfsd_sync_dir and write_inode_now has been replaced with the
commit_metadata function that takes a svc_fh.

- The commit_metadata function calls the commit_metadata export_op if it's
there, or else falls back to sync_inode instead of fsync and write_inode_now
because only metadata need be synced here.

- nfsd4_sync_rec_dir now uses vfs_fsync so that commit_metadata can be static
Signed-off-by: NBen Myers <bpm@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

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>

The NFS COMMIT operation allows the client to specify the exact byte range
that it wishes to sync to disk in order to optimise server performance.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Try to create a PF_INET6 listener for NFSD, if IPv6 is enabled in the
kernel.

Make sure nfsd_serv's reference count is decreased if
__write_ports_addxprt() failed to create a listener.  See
__write_ports_addfd().

Our current plan is to rely on rpc.nfsd to create appropriate IPv6
listeners when server-side NFS/IPv6 support is desired.  Legacy
behavior, via the write_threads or write_svc kernel APIs, will remain
the same -- only IPv4 listeners are created.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
[bfields@citi.umich.edu: Move error-handling code to end]
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

write_ports() converts svc_create_xprt()'s ENOENT error return to
EPROTONOSUPPORT so that rpc.nfsd (in user space) can report an error
message that makes sense.

It turns out that several of the other kernel APIs rpc.nfsd use can
also return ENOENT from svc_create_xprt(), by way of lockd_up().

On the client side, an NFSv2 or NFSv3 mount request can also return
the result of lockd_up().  This error may also be returned during an
NFSv4 mount request, since the NFSv4 callback service uses
svc_create_xprt() to create the callback listener.  An ENOENT error
return results in a confusing error message from the mount command.

Let's have svc_create_xprt() return EPROTONOSUPPORT instead of ENOENT.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Instead of opencoding the fsync calling sequence use vfs_fsync.  This also
gets rid of the useless i_mutex over the data writeout.

Consolidate the remaining special code for syncing directories and document
it's quirks.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Since we're checking for LAST_NFS4_OP, use FIRST_NFS4_OP to be consistent.
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

The server incorrectly assumes that the operations in the
array start with value 0.  The first operation (OP_ACCESS)
has a value of 3, causing the check in nfsd4_decode_compound
to be off.

Instead of comparing that the operation number is less than
the number of elements in the array, the server should verify
that it is less than the maximum valid operation number
defined by LAST_NFS4_OP.
Signed-off-by: NRicardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

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>