NFS: Avoid memcpy() run-time warning for struct sockaddr overflows

The 'nfs_server' and 'mount_server' structures include a union of
'struct sockaddr' (with the older 16 bytes max address size) and
'struct sockaddr_storage' which is large enough to hold all the
supported sa_family types (128 bytes max size). The runtime memcpy()
buffer overflow checker is seeing attempts to write beyond the 16
bytes as an overflow, but the actual expected size is that of 'struct
sockaddr_storage'. Plumb the use of 'struct sockaddr_storage' more
completely through-out NFS, which results in adjusting the memcpy()
buffers to the correct union members. Avoids this false positive run-time
warning under CONFIG_FORTIFY_SOURCE:

memcpy: detected field-spanning write (size 28) of single field "&ctx->nfs_server.address" at fs/nfs/namespace.c:178 (size 16)

Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/all/202210110948.26b43120-yujie.liu@intel.com
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Fix free of uninitialized nfs4_label on referral lookup.

Send along the already-allocated fattr along with nfs4_fs_locations, and
drop the memcpy of fattr. We end up growing two more allocations, but this
fixes up a crash as:

PID: 790 TASK: ffff88811b43c000 CPU: 0 COMMAND: "ls"
#0 [ffffc90000857920] panic at ffffffff81b9bfde
#1 [ffffc900008579c0] do_trap at ffffffff81023a9b
#2 [ffffc90000857a10] do_error_trap at ffffffff81023b78
#3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45
#4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de
#5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs]
#6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f
#7 [ffffc90000857c60] walk_component at ffffffff813a86c4
#8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553
#9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b

Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Fixes: 9558a007dbc3 ("NFS: Remove the label from the nfs4_lookup_res struct")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4 handle port presence in fs_location server string

An fs_location attribute returns a string that can be ipv4, ipv6,
or DNS name. An ip location can have a port appended to it and if
no port is present a default port needs to be set. If rpc_pton()
fails to parse, try calling rpc_uaddr2socaddr() that can convert
an universal address.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4 expose nfs_parse_server_name function

Make nfs_parse_server_name available outside of nfs4namespace.c.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs: Fix memory leak of export_path

The try_location function is called within a loop by nfs_follow_referral.
try_location calls nfs4_pathname_string to created the export_path.
nfs4_pathname_string allocates the memory. export_path is stored in the
nfs_fs_context/fs_context structure similarly as hostname and source.
But whereas the ctx hostname and source are freed before assignment,
export_path is not. So if there are multiple loops, the new export_path
will overwrite the old without the old being freed.

So call kfree for export_path.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs: Fix up documentation in nfs_follow_referral() and nfs_do_submount()

Fallout from the mount patches.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Replace various occurrences of kstrndup() with kmemdup_nul()

When we already know the string length, it is more efficient to
use kmemdup_nul().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
[Anna - Changes to super.c were already made during fscontext conversion]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add softreval behaviour to nfs_lookup_revalidate()

If the server is unavaliable, we want to allow the revalidating
lookup to time out, and to default to validating the cached dentry
if the 'softreval' mount option is set.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add missing null check for failed allocation

Currently the allocation of buf is not being null checked and
a null pointer dereference can occur when the memory allocation fails.
Fix this by adding a check and returning -ENOMEM.

Addresses-Coverity: ("Dereference null return")
Fixes: 6d972518b821 ("NFS: Add fs_context support.")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Additional refactoring for fs_context conversion

Split out from commit "NFS: Add fs_context support."

This patch adds additional refactoring for the conversion of NFS to use
fs_context, namely:

(*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context.
nfs_clone_mount has had several fields removed, and nfs_mount_info
has been removed altogether.
(*) Various functions now take an fs_context as an argument instead
of nfs_mount_info, nfs_fs_context, etc.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add fs_context support.

Add filesystem context support to NFS, parsing the options in advance and
attaching the information to struct nfs_fs_context. The highlights are:

(*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context. This
structure represents NFS's superblock config.

(*) Make use of the VFS's parsing support to split comma-separated lists

(*) Pin the NFS protocol module in the nfs_fs_context.

(*) Attach supplementary error information to fs_context. This has the
downside that these strings must be static and can't be formatted.

(*) Remove the auxiliary file_system_type structs since the information
necessary can be conveyed in the nfs_fs_context struct instead.

(*) Root mounts are made by duplicating the config for the requested mount
so as to have the same parameters. Submounts pick up their parameters
from the parent superblock.

[AV -- retrans is u32, not string]
[SM -- Renamed cfg to ctx in a few functions in an earlier patch]
[SM -- Moved fs_context mount option parsing to an earlier patch]
[SM -- Moved fs_context error logging to a later patch]
[SM -- Fixed printks in nfs4_try_get_tree() and nfs4_get_referral_tree()]
[SM -- Added is_remount_fc() helper]
[SM -- Deferred some refactoring to a later patch]
[SM -- Fixed referral mounts, which were broken in the original patch]
[SM -- Fixed leak of nfs_fattr when fs_context is freed]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Fix up documentation warnings

Fix up some compiler warnings about function parameters, etc not being
correctly described or formatted.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs: Referrals should use the same proto setting as their parent

Helen Chao <helen.chao@oracle.com> noticed that when a user
traverses a referral on an NFS/RDMA mount, the resulting submount
always uses TCP.

This behavior does not match the vers= setting when traversing
a referral (vers=4.1 is preserved). It also does not match the
behavior of crossing from the pseudofs into a real filesystem
(proto=rdma is preserved in that case).

The Linux NFS client does not currently support the
fs_locations_info attribute. The situation is similar for all
NFSv4 servers I know of. Therefore until the community has broad
support for fs_locations_info, when following a referral:

- First try to connect with RPC-over-RDMA. This will fail quickly
if the client has no RDMA-capable interfaces.

- If connecting with RPC-over-RDMA fails, or the RPC-over-RDMA
transport is not available, use TCP.

Reported-by: Helen Chao <helen.chao@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

NFS: Remove extra dprintk()s from nfs4namespace.c

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs: Better permission checking for submounts

To support unprivileged users mounting filesystems two permission
checks have to be performed: a test to see if the user allowed to
create a mount in the mount namespace, and a test to see if
the user is allowed to access the specified filesystem.

The automount case is special in that mounting the original filesystem
grants permission to mount the sub-filesystems, to any user who
happens to stumble across the their mountpoint and satisfies the
ordinary filesystem permission checks.

Attempting to handle the automount case by using override_creds
almost works. It preserves the idea that permission to mount
the original filesystem is permission to mount the sub-filesystem.
Unfortunately using override_creds messes up the filesystems
ordinary permission checks.

Solve this by being explicit that a mount is a submount by introducing
vfs_submount, and using it where appropriate.

vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let
sget and friends know that a mount is a submount so they can take appropriate
action.

sget and sget_userns are modified to not perform any permission checks
on submounts.

follow_automount is modified to stop using override_creds as that
has proven problemantic.

do_mount is modified to always remove the new MS_SUBMOUNT flag so
that we know userspace will never by able to specify it.

autofs4 is modified to stop using current_real_cred that was put in
there to handle the previous version of submount permission checking.

cifs is modified to pass the mountpoint all of the way down to vfs_submount.

debugfs is modified to pass the mountpoint all of the way down to
trace_automount by adding a new parameter. To make this change easier
a new typedef debugfs_automount_t is introduced to capture the type of
the debugfs automount function.

Cc: stable@vger.kernel.org
Fixes: 069d5ac9ae0d ("autofs: Fix automounts by using current_real_cred()->uid")
Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds")
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

qstr: constify instances in nfs

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

VFS: normal filesystems (and lustre): d_inode() annotations

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

NFSv4: test SECINFO RPC_AUTH_GSS pseudoflavors for support

Fix nfs4_negotiate_security to create an rpc_clnt used to test each SECINFO
returned pseudoflavor. Check credential creation (and gss_context creation)
which is important for RPC_AUTH_GSS pseudoflavors which can fail for multiple
reasons including mis-configuration.

Don't call nfs4_negotiate in nfs4_submount as it was just called by
nfs4_proc_lookup_mountpoint (nfs4_proc_lookup_common)

Signed-off-by: Andy Adamson <andros@netapp.com>
[Trond: fix corrupt return value from nfs_find_best_sec()]
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS Return -EPERM if no supported or matching SECINFO flavor

Do not return RPC_AUTH_UNIX if SEINFO reply tests fail. This
prevents an infinite loop of NFS4ERR_WRONGSEC for non RPC_AUTH_UNIX mounts.

Without this patch, a mount with no sec= option to a server
that does not include RPC_AUTH_UNIX in the
SECINFO return can be presented with an attemtp to use RPC_AUTH_UNIX
which will result in an NFS4ERR_WRONG_SEC which will prompt the SECINFO
call which will again try RPC_AUTH_UNIX....

Signed-off-by: Andy Adamson <andros@netapp.com>
Tested-By: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS check the return of nfs4_negotiate_security in nfs4_submount

Signed-off-by: Andy Adamson <andros@netapp.com>
Tested-By: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Use the correct net namespace in nfs4_update_server

We need to use the same net namespace that was used to resolve
the hostname and sockaddr arguments.

Fixes: 32e62b7c3ef09 (NFS: Add nfs4_update_server)
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: add support for multiple sec= mount options

This patch adds support for multiple security options which can be
specified using a colon-delimited list of security flavors (the same
syntax as nfsd's exports file).

This is useful, for instance, when NFSv4.x mounts cross SECINFO
boundaries. With this patch a user can use "sec=krb5i,krb5p"
to mount a remote filesystem using krb5i, but can still cross
into krb5p-only exports.

New mounts will try all security options before failing. NFSv4.x
SECINFO results will be compared against the sec= flavors to
find the first flavor in both lists or if no match is found will
return -EPERM.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: stop using NFS_MOUNT_SECFLAVOUR server flag

Since the parsed sec= flavor is now stored in nfs_server->auth_info,
we no longer need an nfs_server flag to determine if a sec= option was
used.

This flag has not been completely removed because it is still needed for
the (old but still supported) non-text parsed mount options ABI
compatability.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFSv4: make nfs_find_best_sec static

It's not used outside of nfs4namespace.c anymore.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Add functions to swap transports during migration recovery

Introduce functions that can walk through an array of returned
fs_locations information and connect a transport to one of the
destination servers listed therein.

Note that NFS minor version 1 introduces "fs_locations_info" which
extends the locations array sorting criteria available to clients.
This is not supported yet.

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

nfs: use %p[dD] instead of open-coded (and often racy) equivalents

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

NFSv4: Allow security autonegotiation for submounts

In cases where the parent super block was not mounted with a 'sec=' line,
allow autonegotiation of security for the submounts.

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

SUNRPC: Introduce rpcauth_get_pseudoflavor()

A SECINFO reply may contain flavors whose kernel module is not
yet loaded by the client's kernel. A new RPC client API, called
rpcauth_get_pseudoflavor(), is introduced to do proper checking
for support of a security flavor.

When this API is invoked, the RPC client now tries to load the
module for each flavor first before performing the "is this
supported?" check. This means if a module is available on the
client, but has not been loaded yet, it will be loaded and
registered automatically when the SECINFO reply is processed.

The new API can take a full GSS tuple (OID, QoP, and service).
Previously only the OID and service were considered.

nfs_find_best_sec() is updated to verify all flavors requested in a
SECINFO reply, including AUTH_NULL and AUTH_UNIX. Previously these
two flavors were simply assumed to be supported without consulting
the RPC client.

Note that the replaced version of nfs_find_best_sec() can return
RPC_AUTH_MAXFLAVOR if the server returns a recognized OID but an
unsupported "service" value. nfs_find_best_sec() now returns
RPC_AUTH_UNIX in this case.

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

SUNRPC: Define rpcsec_gss_info structure

The NFSv4 SECINFO procedure returns a list of security flavors. Any
GSS flavor also has a GSS tuple containing an OID, a quality-of-
protection value, and a service value, which specifies a particular
GSS pseudoflavor.

For simplicity and efficiency, I'd like to return each GSS tuple
from the NFSv4 SECINFO XDR decoder and pass it straight into the RPC
client.

Define a data structure that is visible to both the NFS client and
the RPC client. Take structure and field names from the relevant
standards to avoid confusion.

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

sunrpc: move address copy/cmp/convert routines and prototypes from clnt.h to addr.h

These routines are used by server and client code, so having them in a
separate header would be best.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfs: Show original device name verbatim in /proc/*/mount{s,info}

Since commit c7f404b ('vfs: new superblock methods to override
/proc/*/mount{s,info}'), nfs_path() is used to generate the mounted
device name reported back to userland.

nfs_path() always generates a trailing slash when the given dentry is
the root of an NFS mount, but userland may expect the original device
name to be returned verbatim (as it used to be). Make this
canonicalisation optional and change the callers accordingly.

[jrnieder@gmail.com: use flag instead of bool argument]
Reported-and-tested-by: Chris Hiestand <chiestand@salk.edu>
Reference: http://bugs.debian.org/669314
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: <stable@vger.kernel.org> # v2.6.39+
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

SUNRPC: Introduce rpc_clone_client_set_auth()

An ULP is supposed to be able to replace a GSS rpc_auth object with
another GSS rpc_auth object using rpcauth_create(). However,
rpcauth_create() in 3.5 reliably fails with -EEXIST in this case.
This is because when gss_create() attempts to create the upcall pipes,
sometimes they are already there. For example if a pipe FS mount
event occurs, or a previous GSS flavor was in use for this rpc_clnt.

It turns out that's not the only problem here. While working on a
fix for the above problem, we noticed that replacing an rpc_clnt's
rpc_auth is not safe, since dereferencing the cl_auth field is not
protected in any way.

So we're deprecating the ability of rpcauth_create() to switch an
rpc_clnt's security flavor during normal operation. Instead, let's
add a fresh API that clones an rpc_clnt and gives the clone a new
flavor before it's used.

This makes immediate use of the new __rpc_clone_client() helper.

This can be used in a similar fashion to rpcauth_create() when a
client is hunting for the correct security flavor. Instead of
replacing an rpc_clnt's security flavor in a loop, the ULP replaces
the whole rpc_clnt.

To fix the -EEXIST problem, any ULP logic that relies on replacing
an rpc_clnt's rpc_auth with rpcauth_create() must be changed to use
this API instead.

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

NFS4: avoid underflow when converting error to pointer.

In nfs4_create_sec_client, 'flavor' can hold a negative error
code (returned from nfs4_negotiate_security), even though it
is an 'enum' and hence unsigned.

The code is careful to cast it to an (int) before testing if it
is negative, however it doesn't cast to an (int) before calling
ERR_PTR.

On a machine where "void*" is larger than "int", this results in
the unsigned equivalent of -1 (e.g. 0xffffffff) being converted
to a pointer. Subsequent code determines that this is not
negative, and so dereferences it with predictable results.

So: cast 'flavor' to a (signed) int before passing to ERR_PTR.

cc: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: fix the return value check by using IS_ERR

In case of error, the function rpcauth_create() returns ERR_PTR()
and never returns NULL pointer. The NULL test in the return value
check should be replaced with IS_ERR().

dpatch engine is used to auto generated this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: fix unsigned comparison in nfs4_create_sec_client

fs/nfs/nfs4namespace.c: In function ‘nfs4_create_sec_client’:
fs/nfs/nfs4namespace.c:171:2: error: comparison of unsigned expression < 0 is always false [-Werror=type-limits]

Introduced by commit 72de53ec4bca39c26709122a8f78bfefe7b6bca4
"NFS: Do secinfo as part of lookup"

Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Create a submount rpc_op

This simplifies the code for v2 and v3 and gives v4 a chance to decide
on referrals without needing to modify the generic client.

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

NFS: Remove secinfo knowledge out of the generic client

And also remove the unneeded rpc_op.

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

NFS: Fix following referral mount points with different security

I create a new proc_lookup_mountpoint() to use when submounting an NFS
v4 share. This function returns an rpc_clnt to use for performing an
fs_locations() call on a referral's mountpoint.

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

NFS: Do secinfo as part of lookup

Whenever lookup sees wrongsec do a secinfo and retry the lookup to find
attributes of the file or directory, such as "is this a referral
mountpoint?". This also allows me to remove handling -NFS4ERR_WRONSEC
as part of getattr xdr decoding.

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

nfs4: fix referrals on mounts that use IPv6 addrs

All referrals (IPv4 addr, IPv6 addr, and DNS) are broken on mounts of
IPv6 addresses, because validation code uses a path that is parsed
from the dev_name ("<server>:<path>") by splitting on the first colon and
colons are used in IPv6 addrs.
This patch ignores colons within IPv6 addresses that are escaped by '[' and ']'.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

SUNRPC: Use RCU to dereference the rpc_clnt.cl_xprt field

A migration event will replace the rpc_xprt used by an rpc_clnt. To
ensure this can be done safely, all references to cl_xprt must now use
a form of rcu_dereference().

Special care is taken with rpc_peeraddr2str(), which returns a pointer
to memory whose lifetime is the same as the rpc_xprt.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[ cel: fix lockdep splats and layering violations ]
[ cel: forward ported to 3.4 ]
[ cel: remove rpc_max_reqs(), add rpc_net_ns() ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: pass transport net to rpc_pton() while parse server name

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

SUNRPC: parametrize rpc_pton() by network context

Parametrize rpc_pton() by network context and thus force it's callers to pass
in network context instead of using hard-coded "init_net".

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: DNS resolver cache per network namespace context introduced

This patch implements DNS resolver cache creation and registration for each
alive network namespace context.
This was done by registering NFS per-net operations, responsible for DNS cache
allocation/register and unregister/destructioning instead of initialization and
destruction of static "nfs_dns_resolve" cache detail (this one was removed).
Pointer to network dns resolver cache is stored in new per-net "nfs_net"
structure.
This patch also changes nfs_dns_resolve_name() function prototype (and it's
calls) by adding network pointer parameter, which is used to get proper DNS
resolver cache pointer for do_cache_lookup_wait() call.

Note: empty nfs_dns_resolver_init() and nfs_dns_resolver_destroy() functions
will be used in next patch in the series.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

nfs: nfs_do_{ref,sub}mount() superblock argument is redundant

It's always equal to dentry->d_sb

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

nfs: make nfs_path() work without vfsmount

part 3: now we have everything to get nfs_path() just by dentry -
just follow to (disconnected) root and pick the rest of the thing
there.

Start killing propagation of struct vfsmount * on the paths that
used to bring it to nfs_path().

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

NFSv4: Fix up the documentation for nfs_do_refmount

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

NFSv4: Reduce the stack footprint of try_location()

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

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

NFSv4: Fix the referral mount code

Fix a typo which causes try_location() to use the wrong length argument
when calling nfs_parse_server_name(). This again, causes the initialisation
of the mount's sockaddr structure to fail.

Also ensure that if nfs4_pathname_string() returns an error, then we pass
that error back up the stack instead of ENOENT.

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

NFS: Use the DNS resolver in the mount code.

In the referral code, use it to look up the new server's ip address if the
fs_locations attribute contains a hostname.

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

NFS: Replace nfs_set_port() with rpc_set_port()

Clean up.

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

NFS: Replace nfs_parse_ip_address() with rpc_pton()

Clean up: Use the common routine now provided in sunrpc.ko for parsing mount
addresses.

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

NFS: Fix misparsing of nfsv4 fs_locations attribute (take 2)

The changeset ea31a4437c59219bf3ea946d58984b01a45a289c (nfs: Fix
misparsing of nfsv4 fs_locations attribute) causes the mountpath that is
calculated at the beginning of try_location() to be clobbered when we
later strncpy a non-nul terminated hostname using an incorrect buffer
length.

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

nfs: Fix misparsing of nfsv4 fs_locations attribute

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>

nfs: replace while loop by for loops in nfs_follow_referral

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>

nfs: break up nfs_follow_referral

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>

nfs: replace remaining __FUNCTION__ occurrences

__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Adjust nfs_clone_mount structure to store "struct sockaddr *"

Change the addr field in the nfs_clone_mount structure to store a "struct
sockaddr *" to support non-IPv4 addresses in the NFS client.

Note this is mostly a cosmetic change, and does not actually allow
referrals using IPv6 addresses. The existing referral code assumes that
the server returns a string that represents an IPv4 address. This code
needs to support hostnames and IPv6 addresses as well as IPv4 addresses,
thus it will need to be reorganized completely (to handle DNS resolution
in user space).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Address a couple of nits in nfs_follow_referral()

Clean up: fix an outdated block comment, and address a comparison
between a signed and unsigned integer.

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

NFSv4: /proc/mounts displays the wrong server name for referrals

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

NFSv4: Cleanups for fs_locations code.

Start long arduous project... What the hell is

struct dentry = {};

all about?

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

Remove all inclusions of <linux/config.h>
kbuild explicitly includes this at build time.

Signed-off-by: Dave Jones <davej@redhat.com>

NFS: Share NFS superblocks per-protocol per-server per-FSID

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: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Add extra const qualifiers

Add some extra const qualifiers into NFS.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

NFS: Split fs/nfs/inode.c

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: David Howells <dhowells@redhat.com>