To ensure the NFS client displays IPv6 addresses properly, replace
address family-specific NIPQUAD() invocations with a call to the RPC
client to get a formatted string representing the remote peer's
address.
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>

We can get the same information from the rpc_ops structure instead.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up: mount option parsing uses kstrndup in several places, rather than
using kzalloc.  Replace the few remaining uses of kzalloc with kstrndup,
for consistency.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove the mount option that allows users to specify an alternate mountd
program number.  The client hasn't support setting an alternate mountd
program number for a very long time.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove the mount option that allows users to specify an alternate NFS
program number.  The client hasn't support setting an alternate NFS
program number for a very long time.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Text-based mount option parsing introduced a minor regression in the
behavior of NFS version 4 mounts.  NFS version 4 is not supposed to require
a running rpcbind service on the server in order for a mount to succeed.

In other words, if the mount options don't specify a port number, the port
number is supposed to default to 2049.  For earlier versions of NFS, the
default port number was zero in order to cause the RPC client to autobind
to the server's NFS service.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Added an active/deactive mechanism to the nfs_server structure
allowing async operations to hold off umount until the
operations are done.
Signed-off-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Sigh... commit 4584f520 (NFS: Fix NFS
mountpoint crossing...) had a slight flaw: server can be NULL if sget()
returned an existing superblock.

Fix the fix by dereferencing s->s_fs_info.

Thanks to Coverity/Adrian Bunk and Frank Filz for spotting the bug.
(See http://bugzilla.kernel.org/show_bug.cgi?id=9647)

Also add in the same namespace Oops fix for NFSv4 in both the mountpoint
crossing case, and the referral case.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The check that was added to nfs_xdev_get_sb() to work around broken
servers, works fine for NFSv2, but causes mountpoint crossing on NFSv3 to
always return ESTALE.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

While testing a kernel based upon ecd744ee
(with wrong boot arguments), I got the following bad page state entry while
NFS was trying to mount it's rootfs:

IP-Config: Complete:
      device=eth0, addr=192.168.1.101, mask=255.255.255.0, gw=255.255.255.255,
     host=192.168.1.101, domain=, nis-domain=(none),
     bootserver=192.168.1.100, rootserver=192.168.1.100, rootpath=
Looking up port of RPC 100003/2 on 192.168.1.100
rpcbind: server 192.168.1.100 not responding, timed out
Root-NFS: Unable to get nfsd port number from server, using default
Looking up port of RPC 100005/1 on 192.168.1.100
rpcbind: server 192.168.1.100 not responding, timed out
Root-NFS: Unable to get mountd port number from server, using default
mount: server 192.168.1.100 not responding, timed out
Root-NFS: Server returned error -5 while mounting /nfs/rootfs/
VFS: Unable to mount root fs via NFS, trying floppy.
Bad page state in process 'swapper'
page:c02b1260 flags:0x00000400 mapping:00000000 mapcount:0 count:0
Trying to fix it up, but a reboot is needed
Backtrace:
[<c0023e34>] (dump_stack+0x0/0x14) from [<c0062570>] (bad_page+0x70/0xac)
[<c0062500>] (bad_page+0x0/0xac) from [<c0064914>] (free_hot_cold_page+0x80/0x178)
[<c0064894>] (free_hot_cold_page+0x0/0x178) from [<c0064a74>] (free_hot_page+0x14/0x18)
[<c0064a60>] (free_hot_page+0x0/0x18) from [<c0067078>] (put_page+0xf8/0x154)
[<c0066f80>] (put_page+0x0/0x154) from [<c007dbc8>] (kfree+0xc8/0xd0)
[<c007db00>] (kfree+0x0/0xd0) from [<c00cbb54>] (nfs_get_sb+0x230/0x710)
[<c00cb924>] (nfs_get_sb+0x0/0x710) from [<c0084334>] (vfs_kern_mount+0x58/0xac)[<c00842dc>] (vfs_kern_mount+0x0/0xac) from [<c00843c0>] (do_kern_mount+0x38/0xf4)
[<c0084388>] (do_kern_mount+0x0/0xf4) from [<c0099c7c>] (do_mount+0x1e8/0x614)
...

This seems to be caused by use of an uninitialised structure due to NULL
options being passed to nfs_validate_mount_data().  Ensure that the
parsed mount data is always initialised.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
     (Trond: added fix for the same bug in nfs4_validate_mount_data()).
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Hi Trond,

I have discovered that the BUG_ON in nfs_follow_mountpoint:

	BUG_ON(IS_ROOT(dentry));

can be triggered by a misbehaving server.

What happens is the client does a lookup and discoveres that the named
directory has a different fsid, so it initiates a mount.
It then performs a GETATTR on the mounted directory and gets a
different fsid again (due to a bug in the NFS server).
This causes nfs_follow_mountpoint to be called on the newly mounted
root, which triggers the BUG_ON.

To duplicate this, have a directory which contains some mountpoints,
and export that directory with the "crossmnt" flag using nfs-utils
1.1.1 (or 1.1.0 I think)

The GETATTR on the root of the mounted filesystem will return the
information for the top exportpoint, while a lookup will return the
correct information.  This difference causes the NFS client to BUG.

I think the best way to fix this is to trap this possibility early, so
just before completing the mount in the NFS client, check that it isn't
going to use nfs_mountpoint_inode_operations.
As long as i_op will never change once set (is that true?), this
should be adequately safe.

The following patch shows a possible approach, and it works for me.
i.e. when the NFS server is misbehaving, I get ESTALE on those
mountpoints, while when the NFS server is working correctly, I get
correct behaviour on the client.

NeilBrown
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The default "intr" setting is different for NFS and NFSv4.  To avoid
confusion on this issue, don't hide the "nointr" option in /proc/mounts.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Re-order mount option sanity checking slightly to ensure we have a valid
server address *before* trying to do the mountd RPC call.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Adds hooks to the string-based NFS mount to support an "rdma" protocol option.
Signed-off-by: NTom Talpey <tmt@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Use the per-transport strings to display the transport protocol accurately.
Signed-off-by: NTom Talpey <tmt@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Instead of an { address family, raw IP protocol number }-tuple, use the
newly-defined RPC identifier when creating clients in the upper layers.
Signed-off-by: NTom Talpey <tmt@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The previous patch introduced a bug when copying the server address.

Also clarify a copy into the auth_flavours array: currently the two
size calculations are equivalent, but we may decide to change the size
of auth_flavors[] at some point.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The user-visible nfs4_mount_data does not contain sufficient data to
describe new mount options, and also is now a legacy structure. Replace
it with the internal nfs_parsed_mount_data for nfsv4 in-kernel use.
Signed-off-by: NTom Talpey <tmt@netapp.com>
Acked-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The user-visible nfs_mount_data does not contain sufficient data to
describe new mount options, and also is now a legacy structure. Replace
it with the internal nfs_parsed_mount_data for nfsv[23] in-kernel use.
Signed-off-by: NTom Talpey <tmt@netapp.com>
Acked-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In preparation for rearranging the nfs mount argument passing, make the
nfs_parsed_mount_data struct visible across nfs kernel files.
Signed-off-by: NTom Talpey <tmt@netapp.com>
Acked-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

I got the 'mounthost=' option wrong - it shouldn't look for an address
value, but rather a hostname value.  However, the in-kernel mount client
and NFS client cannot resolve a hostname by themselves; they rely on
user-land to pass in the resolved address.

Create a new mount option that does take an address so that the mount
program's address can be passed in.  The mount hostname is now ignored
by the kernel.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If no mount server port number is specified, the previous change to the
kernel mount client inadvertently allows the NFS server's port number to be
the used as the mount server's port number. If the user specifies an NFS
server port (-o port=x), the mount will fail.

The fix below sets the mount server's port to 0 if no mount server
port is specified by the user.
Signed-off-by: NJames Lentini <jlentini@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Simplify the in-kernel mount client by using autobind instead of an
explicit call to rpc_getport_sync.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

A minor thing, but useful when working with a server with multiple
addrs. This looks like it might also be necessary if Miklos' effort
to eliminate /etc/mtab ever comes to fruition.

When displaying mount options in /proc/mounts, the kernel prints
"addr=hostname". This info is redundant since we already have the
hostname displayed as part of the "device" section of the mount. This
patch changes it to display the IP address to which the socket is
connected.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFS unregisters sysctls only if V4 support is compiled in.  However, sysctl
table is not V4 specific, so unregister it always.

Steps to reproduce:

	[build nfs.ko with CONFIG_NFS_V4=n]
	modrobe nfs
	rmmod nfs
	ls /proc/sys

Unable to handle kernel paging request at ffffffff880661c0 RIP:
 [<ffffffff802af8e3>] proc_sys_readdir+0xd3/0x350
PGD 203067 PUD 207063 PMD 7e216067 PTE 0
Oops: 0000 [1] SMP
CPU 1
Modules linked in: lockd nfs_acl sunrpc
Pid: 3335, comm: ls Not tainted 2.6.23-rc3-bloat #2
RIP: 0010:[<ffffffff802af8e3>]  [<ffffffff802af8e3>] proc_sys_readdir+0xd3/0x350
RSP: 0018:ffff81007fd93e78  EFLAGS: 00010286
RAX: ffffffff880661c0 RBX: ffffffff80466370 RCX: ffffffff880661c0
RDX: 00000000000014c0 RSI: ffff81007f3ad020 RDI: ffff81007efd8b40
RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff802a8570 R12: ffffffff880661c0
R13: ffff81007e219640 R14: ffff81007efd8b40 R15: ffff81007ded7280
FS:  00002ba25ef03060(0000) GS:ffff81007ff81258(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffffffff880661c0 CR3: 000000007dfaf000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process ls (pid: 3335, threadinfo ffff81007fd92000, task ffff81007d8a0000)
Stack:  ffff81007f3ad150 ffffffff80283f30 ffff81007fd93f48 ffff81007efd8b40
 ffff81007ee00440 0000000422222222 0000000200035593 ffffffff88037e9a
 2222222222222222 ffffffff80466500 ffff81007e416400 ffff81007e219640
Call Trace:
 [<ffffffff80283f30>] filldir+0x0/0xf0
 [<ffffffff80283f30>] filldir+0x0/0xf0
 [<ffffffff802840c7>] vfs_readdir+0xa7/0xc0
 [<ffffffff80284376>] sys_getdents+0x96/0xe0
 [<ffffffff8020bb3e>] system_call+0x7e/0x83

Code: 41 8b 14 24 85 d2 74 dc 49 8b 44 24 08 48 85 c0 74 e7 49 3b
RIP  [<ffffffff802af8e3>] proc_sys_readdir+0xd3/0x350
 RSP <ffff81007fd93e78>
CR2: ffffffff880661c0
Kernel panic - not syncing: Fatal exception
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Acked-by: NTrond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

According to the mount(2) man page, the proper error return code for the
mount(2) system call when the special device name or the mounted-on
directory name is too long is ENAMETOOLONG.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The hostname was getting truncated in the new text-based NFS mount API.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Don't filter the return code from the in-kernel rpcbind or NFS mount
clients.  Return the real error code so that callers of the new NFS
text-based mount API can apply a useful retry strategy.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The new text-based NFS mount option parsing logic doesn't recognize any
valid transport protocols due to a silly mistake in the protocol token
matching logic.  This prevents basic mount requests such as:

   mount.nfs server:/export /mnt -o proto=tcp

from working with the new text-based NFS mount API.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This avoids the recent NFS mount regression (returning EBUSY when
mounting the same filesystem twice with different parameters).

The best I can do given the constraints appears to be to have the kernel
first look for a superblock that matches both the fsid and the
user-specified mount options, and then spawn off a new superblock if
that search fails.

Note that this is not the same as specifying nosharecache everywhere
since nosharecache will never attempt to match an existing superblock.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: NHua Zhong <hzhong@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Obviously broken on little-endian; fortunately, the option is not
frequently used...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
[ Hey, sparse is wonderful, but even better than sparse is having people
  like Al that actually _run_ it and fix bugs using it.    - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If a NFSv4 mount is attempted  with string based options, and the
option string doesn't contain a clientaddr= option, the kernel will
currently oops. Check for this situation and return a proper error.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

I can never remember what the function to register to receive VM pressure
is called.  I have to trace down from __alloc_pages() to find it.

It's called "set_shrinker()", and it needs Your Help.

1) Don't hide struct shrinker.  It contains no magic.
2) Don't allocate "struct shrinker".  It's not helpful.
3) Call them "register_shrinker" and "unregister_shrinker".
4) Call the function "shrink" not "shrinker".
5) Reduce the 17 lines of waffly comments to 13, but document it properly.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: David Chinner <dgc@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Unless the user sets the NFS_MOUNT_NOSHAREDCACHE mount flag, we should
return EBUSY if the filesystem is already mounted on a superblock that
has set conflicting mount options.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Prior to David Howell's mount changes in 2.6.18, users who mounted
different directories which happened to be from the same filesystem on the
server would get different super blocks, and hence could choose different
mount options. As long as there were no hard linked files that crossed from
one subtree to another, this was quite safe.
Post the changes, if the two directories are on the same filesystem (have
the same 'fsid'), they will share the same super block, and hence the same
mount options.

Add a flag to allow users to elect not to share the NFS super block with
another mount point, even if the fsids are the same. This will allow
users to set different mount options for the two different super blocks, as
was previously possible. It is still up to the user to ensure that there
are no cache coherency issues when doing this, however the default
behaviour will be to share super blocks whenever two paths result in
the same fsid.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Hook in final components required for supporting in-kernel mount option
parsing for NFSv2 and NFSv3 mounts.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

For NFSv2 and v3 mounts, the first step is to contact the server's MOUNTD
and request the file handle for the root of the mounted share.  Add a
function to the NFS client that handles this operation.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This generic infrastructure works for both NFS and NFSv4 mounts.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Refactor NFSv4 mount processing to break out mount data validation
in the same way it's broken out in the NFSv2/v3 mount path.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>