Allow mount to do authenticated mounts below the root of the exported tree.
The wording in RFC 2623, sec 2.3.2. allows fsinfo with UNIX authentication
on the root of the export. Mounts are not always done on the root
of the exported tree. Especially autoumounts often mount below the root of
the exported tree.
Some server implementations (justly) require full authentication for the
so-called deep mounts. The old code used AUTH_SYS only. This caused deep
mounts to fail on systems requiring stronger authentication..
The client should try both authentication types and use the first one that
succeeds.
This method was already partially implemented. This patch completes
the implementation for NFS2 and NFS3.
This patch was developed to allow Debian systems to automount home directories
on Solaris servers with krb5 authentication.

Tested on kernel 2.6.24-etchnhalf.1
Signed-off-by: NE.G. Keizer <keie@few.vu.nl>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

All instances are set to nfs_open(), so we should just remove the redundant
indirection. Ditto for the file_release op
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

ftruncate() access checking is supposed to be performed at open() time,
just like reads and writes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-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>

Now that each NFS mount point caches its own nlm_host structure, it can be
passed to nlmclnt_proc() for each lock request.  By pinning an nlm_host for
each mount point, we trade the overhead of looking up or creating a fresh
nlm_host struct during every NLM procedure call for a little extra memory.

We also restrict the nlmclnt_proc symbol to limit the use of this call to
in-tree modules.

Note that nlm_lookup_host() (just removed from the client's per-request
NLM processing) could also trigger an nlm_host garbage collection.  Now
client-side nlm_host garbage collection occurs only during NFS mount
processing.  Since the NFS client now holds a reference on these nlm_host
structures, they wouldn't have been affected by garbage collection
anyway.

Given that nlm_lookup_host() reorders the global nlm_host chain after
every successful lookup, and that a garbage collection could be triggered
during the call, we've removed a significant amount of per-NLM-request
CPU processing overhead.

Sidebar: there are only a few remaining references to the internals of
NFS inodes in the client-side NLM code.  The only references I found are
related to extracting or comparing the inode's file handle via NFS_FH().
One is in nlmclnt_grant(); the other is in nlmclnt_setlockargs().
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Move the common code for setting up the nfs_write_data and nfs_read_data
structures into fs/nfs/read.c, fs/nfs/write.c and fs/nfs/direct.c.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

By using the TASK_KILLABLE infrastructure, we can get rid of the 'intr'
mount option.  We have to use _killable everywhere instead of _interruptible
as we get rid of rpc_clnt_sigmask/sigunmask.
Signed-off-by: NLiam R. Howlett <howlett@gmail.com>
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>

nfs_post_op_update_inode() is really only meant to be used if we expect the
inode and its attributes to have changed in some way.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

LOOKUP returns the directory post-op attributes whether or not the
operation was successful.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFSv2 and v4 don't offer weak cache consistency attributes on WRITE calls.
In NFSv3, returning wcc data is optional. In all cases, we want to prevent
the client from invalidating our cached data whenever ->write_done()
attempts to update the inode attributes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFSv3 will correctly update atime on a read() call, so there is no need to
set the NFS_INO_INVALID_ATIME flag unless the call to nfs_refresh_inode()
fails.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFSv3 will correctly update atime on a readdir call, so there is no need to
set the NFS_INO_INVALID_ATIME flag unless the call to nfs_refresh_inode()
fails.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix a couple of bugs:
 - Don't rely on the parent dentry still being valid when the call completes.
   Fixes a race with shrink_dcache_for_umount_subtree()

 - Don't remove the file if the filehandle has been labelled as stale.

Fix a couple of inefficiencies
 - Remove the global list of sillyrenamed files. Instead we can cache the
   sillyrename information in the dentry->d_fsdata
 - Move common code from unlink_setup/unlink_done into fs/nfs/unlink.c
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We need a common structure for setting up an unlink() rpc call in order to
fix the asynchronous unlink code.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Also get rid of a redundant call to nfs_setattr_update_inode(). The call to
nfs3_proc_setattr() already takes care of that.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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>

It makes no sense to maintain 2 parallel systems for reading in pages.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the nfs
client code.
Signed-off-by: NJosef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Maintaining two parallel ways of doing synchronous writes is rather
pointless. This patch gets rid of the legacy nfs_writepage_sync(), and
replaces it with the faster asynchronous writes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove use of the Big Kernel Lock around calls to rpc_call_sync.
Signed-off-by: NFrank Filz <ffilz@us.ibm.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When trying to open a file with the O_EXCL flag over NFS on a server that does
not support exclusive mode, the file does not open.  The reason,
rpc_call_sync returns a errno number, and not the nfs error number.  I fixed
it by changing the status check in nfs3proc.c.  Either this is how it should
be fixed, or rpc_call_sync should be fixed to return the NFS error.
Signed-off-by: NAndy Ryan <genanr@allantgroup.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

* Removing useless casts
* Removing useless wrapper
* Conversion from kmalloc+memset to kzalloc
Signed-off-by: NPanagiotis Issaris <takis@issaris.org>
Acked-by: NDave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Now that we have a copy of the symlink path in the page cache, we can pass
a struct page down to the XDR routines instead of a string buffer.

Test plan:
Connectathon, all NFS versions.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the LOOKUP or GETATTR in nfs_instantiate fail, nfs_instantiate will do a
d_drop before returning.  But some callers already do a d_drop in the case
of an error return.  Make certain we do only one d_drop in all error paths.

This issue was introduced because over time, the symlink proc API diverged
slightly from the create/mkdir/mknod proc API.  To prevent other coding
mistakes of this type, change the symlink proc API to be more like
create/mkdir/mknod and move the nfs_instantiate call into the symlink proc
routines so it is used in exactly the same way for create, mkdir, mknod,
and symlink.

Test plan:
Connectathon, all versions of NFS.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The attached patch makes NFS share superblocks between mounts from the same
server and FSID over the same protocol.

It does this by creating each superblock with a false root and returning the
real root dentry in the vfsmount presented by get_sb(). The root dentry set
starts off as an anonymous dentry if we don't already have the dentry for its
inode, otherwise it simply returns the dentry we already have.

We may thus end up with several trees of dentries in the superblock, and if at
some later point one of anonymous tree roots is discovered by normal filesystem
activity to be located in another tree within the superblock, the anonymous
root is named and materialises attached to the second tree at the appropriate
point.

Why do it this way? Why not pass an extra argument to the mount() syscall to
indicate the subpath and then pathwalk from the server root to the desired
directory? You can't guarantee this will work for two reasons:

 (1) The root and intervening nodes may not be accessible to the client.

     With NFS2 and NFS3, for instance, mountd is called on the server to get
     the filehandle for the tip of a path. mountd won't give us handles for
     anything we don't have permission to access, and so we can't set up NFS
     inodes for such nodes, and so can't easily set up dentries (we'd have to
     have ghost inodes or something).

     With this patch we don't actually create dentries until we get handles
     from the server that we can use to set up their inodes, and we don't
     actually bind them into the tree until we know for sure where they go.

 (2) Inaccessible symbolic links.

     If we're asked to mount two exports from the server, eg:

	mount warthog:/warthog/aaa/xxx /mmm
	mount warthog:/warthog/bbb/yyy /nnn

     We may not be able to access anything nearer the root than xxx and yyy,
     but we may find out later that /mmm/www/yyy, say, is actually the same
     directory as the one mounted on /nnn. What we might then find out, for
     example, is that /warthog/bbb was actually a symbolic link to
     /warthog/aaa/xxx/www, but we can't actually determine that by talking to
     the server until /warthog is made available by NFS.

     This would lead to having constructed an errneous dentry tree which we
     can't easily fix. We can end up with a dentry marked as a directory when
     it should actually be a symlink, or we could end up with an apparently
     hardlinked directory.

     With this patch we need not make assumptions about the type of a dentry
     for which we can't retrieve information, nor need we assume we know its
     place in the grand scheme of things until we actually see that place.

This patch reduces the possibility of aliasing in the inode and page caches for
inodes that may be accessed by more than one NFS export. It also reduces the
number of superblocks required for NFS where there are many NFS exports being
used from a server (home directory server + autofs for example).

This in turn makes it simpler to do local caching of network filesystems, as it
can then be guaranteed that there won't be links from multiple inodes in
separate superblocks to the same cache file.

Obviously, cache aliasing between different levels of NFS protocol could still
be a problem, but at least that gives us another key to use when indexing the
cache.

This patch makes the following changes:

 (1) The server record construction/destruction has been abstracted out into
     its own set of functions to make things easier to get right.  These have
     been moved into fs/nfs/client.c.

     All the code in fs/nfs/client.c has to do with the management of
     connections to servers, and doesn't touch superblocks in any way; the
     remaining code in fs/nfs/super.c has to do with VFS superblock management.

 (2) The sequence of events undertaken by NFS mount is now reordered:

     (a) A volume representation (struct nfs_server) is allocated.

     (b) A server representation (struct nfs_client) is acquired.  This may be
     	 allocated or shared, and is keyed on server address, port and NFS
     	 version.

     (c) If allocated, the client representation is initialised.  The state
     	 member variable of nfs_client is used to prevent a race during
     	 initialisation from two mounts.

     (d) For NFS4 a simple pathwalk is performed, walking from FH to FH to find
     	 the root filehandle for the mount (fs/nfs/getroot.c).  For NFS2/3 we
     	 are given the root FH in advance.

     (e) The volume FSID is probed for on the root FH.

     (f) The volume representation is initialised from the FSINFO record
     	 retrieved on the root FH.

     (g) sget() is called to acquire a superblock.  This may be allocated or
     	 shared, keyed on client pointer and FSID.

     (h) If allocated, the superblock is initialised.

     (i) If the superblock is shared, then the new nfs_server record is
     	 discarded.

     (j) The root dentry for this mount is looked up from the root FH.

     (k) The root dentry for this mount is assigned to the vfsmount.

 (3) nfs_readdir_lookup() creates dentries for each of the entries readdir()
     returns; this function now attaches disconnected trees from alternate
     roots that happen to be discovered attached to a directory being read (in
     the same way nfs_lookup() is made to do for lookup ops).

     The new d_materialise_unique() function is now used to do this, thus
     permitting the whole thing to be done under one set of locks, and thus
     avoiding any race between mount and lookup operations on the same
     directory.

 (4) The client management code uses a new debug facility: NFSDBG_CLIENT which
     is set by echoing 1024 to /proc/net/sunrpc/nfs_debug.

 (5) Clone mounts are now called xdev mounts.

 (6) Use the dentry passed to the statfs() op as the handle for retrieving fs
     statistics rather than the root dentry of the superblock (which is now a
     dummy).
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Eliminate nfs_server::client_sys in favour of nfs_client::cl_rpcclient as we
only really need one per server that we're talking to since it doesn't have any
security on it.

The retransmission management variables are also moved to the common struct as
they're required to set up the cl_rpcclient connection.

The NFS2/3 client and client_acl connections are thenceforth derived by cloning
the cl_rpcclient connection and post-applying the authorisation flavour.

The code for setting up the initial common connection has been moved to
client.c as nfs_create_rpc_client().  All the NFS program definition tables are
also moved there as that's where they're now required rather than super.c.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Add some extra const qualifiers into NFS.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

As fs/nfs/inode.c is rather large, heterogenous and unwieldy, the attached
patch splits it up into a number of files:

 (*) fs/nfs/inode.c

     Strictly inode specific functions.

 (*) fs/nfs/super.c

     Superblock management functions for NFS and NFS4, normal access, clones
     and referrals.  The NFS4 superblock functions _could_ move out into a
     separate conditionally compiled file, but it's probably not worth it as
     there're so many common bits.

 (*) fs/nfs/namespace.c

     Some namespace-specific functions have been moved here.

 (*) fs/nfs/nfs4namespace.c

     NFS4-specific namespace functions (this could be merged into the previous
     file).  This file is conditionally compiled.

 (*) fs/nfs/internal.h

     Inter-file declarations, plus a few simple utility functions moved from
     fs/nfs/inode.c.

     Additionally, all the in-.c-file externs have been moved here, and those
     files they were moved from now includes this file.

For the most part, the functions have not been changed, only some multiplexor
functions have changed significantly.

I've also:

 (*) Added some extra banner comments above some functions.

 (*) Rearranged the function order within the files to be more logical and
     better grouped (IMO), though someone may prefer a different order.

 (*) Reduced the number of #ifdefs in .c files.

 (*) Added missing __init and __exit directives.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

Same callback hierarchy inversion as for the NFS write calls. This patch is
not strictly speaking needed by the O_DIRECT code, but avoids confusing
differences between the asynchronous read and write code.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch inverts the callback hierarchy for NFS write calls.

Instead of having the NFSv2/v3/v4-specific code set up the RPC callback
ops, we allow the original caller to do so. This allows for more
flexibility w.r.t. how to set up and tear down the nfs_write_data
structure while still allowing the NFSv3/v4 code to perform error
handling.

The greater flexibility is needed by the asynchronous O_DIRECT code, which
wants to be able to hold on to the original nfs_write_data structures after
the WRITE RPC call has completed in order to be able to replay them if the
COMMIT call determines that the server has rebooted.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean-up: replace rpc_call() helper with direct call to rpc_call_sync.

This makes NFSv2 and NFSv3 synchronous calls more computationally
efficient, and reduces stack consumption in functions that used to
invoke rpc_call more than once.

Test plan:
Compile kernel with CONFIG_NFS enabled.  Connectathon on NFS version 2,
version 3, and version 4 mount points.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Make an inode or an nfs_server struct available in the logic that handles
JUKEBOX/DELAY type errors so the NFS client can account for them.

This patch is split out from the main nfs iostat patch to highlight minor
architectural changes required to support this statistic.

Test plan:
None.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Thanks to Ed Keizer for bug and root cause.  He says: "... we could only mount
 the top-level Solaris share. We could not mount deeper into the tree.
 Investigation showed that Solaris allows UNIX authenticated FSINFO only on the
 top level of the share. This is a problem because we share/export our home
 directories one level higher than we mount them. I.e. we share the partition
 and not the individual home directories. This prevented access to home
 directories."

 We still may need to try auth_sys for the case where the client doesn't have
 appropriate credentials.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Shrink the RPC task structure. Instead of storing separate pointers
 for task->tk_exit and task->tk_release, put them in a structure.

 Also pass the user data pointer as a parameter instead of passing it via
 task->tk_calldata. This enables us to nest callbacks.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Since we almost always call nfs_end_data_update() after we called
 nfs_refresh_inode(), we now end up marking the inode metadata
 as needing revalidation immediately after having updated it.

 This patch rearranges things so that we mark the inode as needing
 revalidation _before_ we call nfs_refresh_inode() on those operations
 that need it.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

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

 Make NFSv4 return the fully initialized file pointer with the
 stateid that it created in the lookup w/intent.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>