The cache_change_attribute is used to decide whether or not a directory has
changed, in which case we may need to look it up again. Again, the use of
'jiffies' leads to an issue of resolution.

Once again, the fix is to change nfs_inode->cache_change_attribute, and
just make it a simple counter.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

It appears that 'jiffies' timestamps do not have high enough resolution for
nfs_inode_attrs_need_update(). One problem is that a GETATTR can be
launched within < 1 jiffy of the last operation that updated the attribute.
Another problem is that RPC calls can take < 1 jiffy to execute.

We can fix this by switching the variables to use a simple global counter
that gets incremented every time we start another GETATTR call.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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

The RPC/RDMA connection logic could return early from reconnection
attempts, leading to additional spurious retries.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The RPC/RDMA code had a constant 5-second reconnect backoff, and
always performed it, even when re-establishing a connection to a
server after the RPC layer closed it due to being idle. Make it
an geometric backoff (up to 30 seconds), and don't delay idle
reconnect.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The send marshaling code split a particular dprintk across two
lines, which makes it hard to extract from logfiles.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Add defensive timeouts to wait_for_completion() calls in RDMA
address resolution, and make them interruptible. Fix the timeout
units to milliseconds (formerly jiffies) and move to private header.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The RPC/RDMA code can leak RDMA connection manager endpoints in
certain error cases on connect. Don't signal unwanted events,
and be certain to destroy any allocated qp.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The xprt_connect call path does not expect such errors as ECONNREFUSED
to be returned from failed transport connection attempts, otherwise it
translates them to EIO and signals fatal errors. For example, mount.nfs
prints simply "internal error". Translate all such errors to ENOTCONN
from RPC/RDMA to match sockets behavior.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The RPC/RDMA protocol allows clients and servers to avoid RDMA
operations for data which is purely the result of XDR padding.
On the client, automatically insert the necessary padding for
such server replies, and optionally don't marshal such chunks.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

RDMA disconnects yield an upcall from the RDMA connection manager,
which can race with rpc transport close, e.g. on ^C of a mount.
Ensure any rdma cm_id and qp are fully destroyed before continuing.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

An RPC/RDMA client cannot retransmit on an unbroken connection,
doing so violates its flow control with the server.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This logic sets the connection parameter that configures the local device
and informs the remote peer how many concurrent incoming RDMA_READ
requests are supported. The original logic didn't really do what was
intended for two reasons:

- The max number supported by the device is typically smaller than
any one factor in the calculation used, and

- The field in the connection parameter structure where the value is
stored is a u8 and always overflows for the default settings.

So what really happens is the value requested for responder resources
is the left over 8 bits from the "desired value". If the desired value
happened to be a multiple of 256, the result was zero and it wouldn't
connect at all.

Given the above and the fact that max_requests is almost always larger
than the max responder resources supported by the adapter, this patch
simplifies this logic and simply requests the max supported by the device,
subject to a reasonable limit.

This bug was found by Jim Schutt at Sandia.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Configure, detect and use "fastreg" support from IB/iWARP verbs
layer to perform RPC/RDMA memory registration.

Make FRMR the default memreg mode (will fall back if not supported
by the selected RDMA adapter).

This allows full and optimal operation over the cxgb3 adapter, and others.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Acked-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

At transport creation, check for, and use, any local dma lkey.
Then, check that the selected memory registration mode is in fact
supported by the RDMA adapter selected for the mount. Fall back
to best alternative if not.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Acked-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Internal RPC/RDMA structure updates in preparation for FRMR support.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Acked-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Refactor the memory registration and deregistration routines.
This saves stack space, makes the code more readable and prepares
to add the new FRMR registration methods.
Signed-off-by: Tom Talpey <talpey@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Bruce observed that nfs_parse_ip_address() will successfully parse an
IPv6 address that looks like this:

  "::1%"

A scope delimiter is present, but there is no scope ID following it.
This is harmless, as it would simply set the scope ID to zero.  However,
in some cases we would like to flag this as an improperly formed
address.

We are now also careful to reject addresses where garbage follows the
address (up to the length of the string), instead of ignoring the
non-address characters; and where the scope ID is nonsense (not a valid
device name, but also not numeric).  Before, both of these cases would
result in a harmless zero scope ID.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This fixes a regression seen when running the Connectathon testsuite
against an ext3 filesystem. The reason was that the inode was constantly
being marked as 'just updated' by the jiffy wraparound test.
This again meant that newer GETATTR calls were failing to pass the
nfs_inode_attrs_need_update() test unless the changes caused a ctime update
on the server, since they were perceived as having been started before the
latest inode update.

Given that nfs_inode_attrs_need_update() already checks for wraparound
of nfsi->last_updated, we can drop the buggy "protection" in
nfs_update_inode().

Also make a slight micro-optimisation of nfs_inode_attrs_need_update(): we
are more often going to see time_after(fattr->time_start, nfsi->last_updated)
be true, rather than seeing an update of ctime/size, so put that test
first to ensure that we optimise away the ctime/size tests.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Peter Staubach suggested reducing NFS4_SETCLIENTID_NAMELEN by one byte so
as to avoid 7 bytes of unnecessary padding.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

On a system with nfs mounts, if a task unshares its mount namespace,
a oops can occur when the system is rebooted if the task is the last
to unreference the nfs mount. It will try to create a rpc request
using utsname() which has been invalidated by free_nsproxy().

The patch fixes the issue by using the global init_utsname() which is
always valid. the capability of identifying rpc clients per uts namespace
stills needs some extra work so this should not be a problem.

BUG: unable to handle kernel NULL pointer dereference at 00000004
IP: [<c024c9ab>] rpc_create+0x332/0x42f
Oops: 0000 [#1] DEBUG_PAGEALLOC

Pid: 1857, comm: uts-oops Not tainted (2.6.27-rc5-00319-g7686ad56 #4)
EIP: 0060:[<c024c9ab>] EFLAGS: 00210287 CPU: 0
EIP is at rpc_create+0x332/0x42f
EAX: 00000000 EBX: df26adf0 ECX: c0251887 EDX: 00000001
ESI: df26ae58 EDI: c02f293c EBP: dda0fc9c ESP: dda0fc2c
 DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
Process uts-oops (pid: 1857, ti=dda0e000 task=dd9a0778 task.ti=dda0e000)
Stack: c0104532 dda0fffc dda0fcac dda0e000 dda0e000 dd93b7f0 00000009 c02f2880
       df26aefc dda0fc68 c01096b7 00000000 c0266ee0 c039a070 c039a070 dda0fc74
       c012ca67 c039a064 dda0fc8c c012cb20 c03daf74 00000011 00000000 c0275c90
Call Trace:
 [<c0104532>] ? dump_trace+0xc2/0xe2
 [<c01096b7>] ? save_stack_trace+0x1c/0x3a
 [<c012ca67>] ? save_trace+0x37/0x8c
 [<c012cb20>] ? add_lock_to_list+0x64/0x96
 [<c0256fc4>] ? rpcb_register_call+0x62/0xbb
 [<c02570c8>] ? rpcb_register+0xab/0xb3
 [<c0252f4d>] ? svc_register+0xb4/0x128
 [<c0253114>] ? svc_destroy+0xec/0x103
 [<c02531b2>] ? svc_exit_thread+0x87/0x8d
 [<c01a75cd>] ? lockd_down+0x61/0x81
 [<c01a577b>] ? nlmclnt_done+0xd/0xf
 [<c01941fe>] ? nfs_destroy_server+0x14/0x16
 [<c0194328>] ? nfs_free_server+0x4c/0xaa
 [<c019a066>] ? nfs_kill_super+0x23/0x27
 [<c0158585>] ? deactivate_super+0x3f/0x51
 [<c01695d1>] ? mntput_no_expire+0x95/0xb4
 [<c016965b>] ? release_mounts+0x6b/0x7a
 [<c01696cc>] ? __put_mnt_ns+0x62/0x70
 [<c0127501>] ? free_nsproxy+0x25/0x80
 [<c012759a>] ? switch_task_namespaces+0x3e/0x43
 [<c01275a9>] ? exit_task_namespaces+0xa/0xc
 [<c0117fed>] ? do_exit+0x4fd/0x666
 [<c01181b3>] ? do_group_exit+0x5d/0x83
 [<c011fa8c>] ? get_signal_to_deliver+0x2c8/0x2e0
 [<c0102630>] ? do_notify_resume+0x69/0x700
 [<c011d85a>] ? do_sigaction+0x134/0x145
 [<c0127205>] ? hrtimer_nanosleep+0x8f/0xce
 [<c0126d1a>] ? hrtimer_wakeup+0x0/0x1c
 [<c0103488>] ? work_notifysig+0x13/0x1b
 =======================
Code: 70 20 68 cb c1 2c c0 e8 75 4e 01 00 8b 83 ac 00 00 00 59 3d 00 f0 ff ff 5f 77 63 eb 57 a1 00 80 2d c0 8b 80 a8 02 00 00 8d 73 68 <8b> 40 04 83 c0 45 e8 41 46 f7 ff ba 20 00 00 00 83 f8 21 0f 4c
EIP: [<c024c9ab>] rpc_create+0x332/0x42f SS:ESP 0068:dda0fc2c
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

It is more efficient to write linearly starting from the beginning of the
file.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This patch fixes a regression that was introduced by the string based mounts.

nfs_mount() statically returns -EACCES for every error returned
by the remote mounted. This is incorrect because -EACCES is
an non-fatal error to the mount.nfs command. This error causes
mount.nfs to retry the mount even in the case when the exported
directory does not exist.

This patch maps the errors returned by the remote mountd into
valid errno values, exactly how it was done pre-string based
mounts. By returning the correct errno enables mount.nfs
to do the right thing.
Signed-off-by: Steve Dickson <steved@redhat.com>
[Trond.Myklebust@netapp.com: nfs_stat_to_errno() now correctly returns
 negative errors, so remove the sign change.]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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

Despite the fact that cloned rpc clients won't have the cl_autobind flag
set, they may still find themselves calling rpcb_getport_async(). For this
to happen, it suffices for a _parent_ rpc_clnt to use autobinding, in which
case any clone may find itself triggering the !xprt_bound() case in
call_bind().

The correct fix for this is to walk back up the tree of cloned rpc clients,
in order to find the parent that 'owns' the transport, either because it
has clnt->cl_autobind set, or because it originally created the
transport...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The sc_name field is currently 56 bytes long.  This is not large enough
to hold a pair of IPv6 addresses, the authentication type, the protocol
name, and a uniquifier number.  The maximum possible size of the name
string using IPv6 addresses is just under 110 bytes, so I increased the
size of the sc_name field to accomodate this maximum.

In addition, the strings in the nfs4_setclientid structure are
constructed with scnprintf(), which wants to terminate its output with
'\0'.  The sc_netid field was large enough only for a three byte netid
string and a '\0' so inet6 netids were being truncated.  Perhaps we
don't need the overhead of scnprintf() to do a simple string copy, but
I fixed this by increasing the size of the buffer by one byte.

Since all three of the string buffers in nfs4_setclientid are
constructed with scnprintf(), I increased the size of all three by one
byte to document the requirement, although I don't think either the
universal address field or the name field will be so small that these
strings get truncated in this way.

The size of the Linux client's client ID on the wire will be larger
than before.  RFC 3530 suggests the size limit for client IDs is 1024,
and we are still well below that.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

remove 8 bytes of padding from struct nfs_fattr on 64 bit builds

This also removes padding from several nfs structures, including
16 bytes from  nfs4_opendata, nfs4_createdata,nfs3_createdata
& 8 bytes from nfs_read_data,nfs_write_data,nfs_removeres,nfs4_closedata

This also reduces the reported stack usage of many nfs functions (30+).
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
----

This patch is against the latest git 2.6.27-rc4.
I've built & run this on my AMD64 desktop, & successfully run _simple_
tests with a  64 bit client => 32 bit server & 32 bit client to 64 bit
server.

On fedora with gcc (GCC) 4.3.0 20080428 (Red Hat 4.3.0-8) checkpatch
reports 33 functions with reduced stack usage.
e.g.
__nfs_revalidate_inode [nfs] 216 => 200
_nfs4_proc_access [nfs] 304 => 288
_nfs4_proc_link [nfs] 536 => 504
_nfs4_proc_remove [nfs] 304 => 288
_nfs4_proc_rename [nfs] 584 => 552
nfs3_proc_access [nfs] 272 => 256
nfs3_proc_getacl [nfs] 384 => 368
nfs3_proc_link [nfs] 496 => 464
etc
I can supply the complete list if anyone is interested.

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

The code incorrectly assumes here that the server name (or ip address)
is null-terminated.  This can cause referrals to fail in some cases.

Also support ipv6 addresses.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

We plan to use this function elsewhere.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Whoever wrote this had a bizarre allergy to for loops.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

This function is a little longer and more deeply nested than necessary.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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: E.G. Keizer <keie@few.vu.nl>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

The fattrs used in the NFSv3 getacl/setacl calls are not being properly
initialized. This occasionally causes nfs_update_inode to fall into
NFSv4 specific codepaths when handling post-op attrs from these calls.

Thanks to Cai Qian for noticing the spurious NFSv4 messages in debug
output from a v3 mount...
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

We *do* now allow bsd flocks over nfs.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Unfortunately, BUG_ON(IS_ROOT(dentry)) can happen inside
nfs_follow_mountpoint with NFS running Fedora 8 using a
specific setup.
https://bugzilla.redhat.com/show_bug.cgi?id=458622

So, the situation should be handled on NFS client gracefully.
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
CC: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Basically, try_module_get here are pretty useless. Any other module using
this API will pin sunrpc in memory due using exported symbols.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

Replace NULL with ERR_PTR(-EINVAL).
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>