Use the small id to pointer translator service to provide a unique callback
identifier per SETCLIENTID call used to identify the v4.0 callback service
associated with the clientid.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.

The pointer returned by ->decode_dirent() is no longer used as a
pointer.  The only call site (xdr_decode() in fs/nfs/dir.c) simply
extracts the errno value encoded in the pointer.  Replace the
returned pointer with a standard integer errno return value.

Also, pass the "server" argument as part of the nfs_entry instead of
as a separate parameter.  It's faster to derive "server" in
nfs_readdir_xdr_to_array() since we already have the directory's inode
handy.  "server" ought to be invariant for a set of entries in the
same directory, right?

The legacy versions of decode_dirent() don't use "server" anyway, so
it's wasted work for them to derive and pass "server" for each entry.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We'd like to prevent local buffer overflows caused by malicious or
broken servers.  New xdr_stream style decoders can do that.

For efficiency, we also eventually want to be able to pass xdr_streams
from call_decode() to all XDR decoding functions, rather than building
an xdr_stream in every XDR decoding function in the kernel.

nfs_decode_dirent() is renamed to follow the naming convention of the
other two dirent decoders.

Static helper functions are left without the "inline" directive.  This
allows the compiler to choose automatically how to optimize these for
size or speed.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.

To distinguish more clearly between the on-the-wire NFSERR_ value and
our local errno values, use the proper type for the argument of
nfs_stat_to_errno().

Add a documenting comment appropriate for a global function shared
outside this source file.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Store the dirent->d_type in the struct nfs_cache_array_entry so that we
can use it in getdents() calls.

This fixes a regression with the new readdir code.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

By requsting more attributes during a readdir, we can mimic the readdir plus
operation that was in NFSv3.

To test, I ran the command `ls -lU --color=none` on directories with various
numbers of files.  Without readdir plus, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.153s | 0m00.589s | 0m05.601s | 0m56.691s | 9m59.128s
user    | 0m00.007s | 0m00.007s | 0m00.077s | 0m00.703s | 0m06.800s
sys     | 0m00.010s | 0m00.070s | 0m00.633s | 0m06.423s | 1m10.005s
access  | 3         | 1         | 1         | 4         | 31
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 104       | 1,003     | 10,003    | 100,003   | 1,000,003
readdir | 2         | 16        | 158       | 1,575     | 15,749
total   | 111       | 1,021     | 10,163    | 101,583   | 1,015,784

With readdir plus enabled, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.115s | 0m00.206s | 0m01.079s | 0m12.521s | 2m07.528s
user    | 0m00.003s | 0m00.003s | 0m00.040s | 0m00.290s | 0m03.296s
sys     | 0m00.007s | 0m00.020s | 0m00.120s | 0m01.357s | 0m17.556s
access  | 3         | 1         | 1         | 1         | 7
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 4         | 3         | 3         | 3         | 3
readdir | 6         | 62        | 630       | 6,300     | 62,993
total   | 15        | 67        | 635       | 6,305     | 63,004

Readdir plus disabled has about a 16x increase in the number of rpc calls and
is 4 - 5 times slower on large directories.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We can use vmapped pages to read more information from the network at once.
This will reduce the number of calls needed to complete a readdir.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
[trondmy: Added #include for linux/vmalloc.h> in fs/nfs/dir.c]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Convert nfs*xdr.c to use an xdr stream in decode_dirent.  This will prevent a
kernel oops that has been occuring when reading a vmapped page.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Fix up those functions that depend on knowing whether or not
rpc_restart_call is successful or not.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

All we really want is the ability to retrieve the root file handle. We no
longer need the ability to walk down the path, since that is now done in
nfs_follow_remote_path().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This gives the filesystem more information about the writeback that
is happening.  Trond requested this for the NFS unstable write handling,
and other filesystems might benefit from this too by beeing able to
distinguish between the different callers in more detail.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Also rename it: it is used in generic code, and so should not have a 'nfs4'
prefix.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We no longer need to maintain a distinction between nfs41_sequence_done and
nfs41_sequence_free_slot.

This fixes a number of slot table leakages in the NFSv4.1 code.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The v4.1 client should take into account the desired rsize, wsize when
negotiating the max size in CREATE_SESSION. Accordingly, it should use
rsize, wsize that are smaller than the session negotiated values.
Signed-off-by: NAlexandros Batsakis <batsakis@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

The NFSv4.1 spec-29 (18.36.3) says that the server MUST use an ONC RPC
(program) version number equal to 4 in callbacks sent to the client.
For now we allow both versions 1 and 4.
Signed-off-by: NAlexandros Batsakis <batsakis@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

nfs41_sequence_free_slot can be called multiple times on SEQUENCE operation
errors.
No reason to inline nfs4_restart_rpc
Reported-by: NTrond Myklebust <trond.myklebust@netapp.com>

nfs_writeback_done and nfs_readpage_retry call nfs4_restart_rpc outside the
error handler, and the slot is not freed prior to restarting in the rpc_prepare
state during session reset.

Fix this by moving the call to nfs41_sequence_free_slot from the error
path of nfs41_sequence_done into nfs4_restart_rpc, and by removing the test
for NFS4CLNT_SESSION_SETUP.
Always free slot and goto the rpc prepare state on async errors.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The bit is no longer used for session setup, only for session reset.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When mounting an "nfs" type file system, recognize "v4," "vers=4," or
"nfsvers=4" mount options, and convert the file system to "nfs4" under
the covers.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
[trondmy: fixed up binary mount code so it sets the 'version' field too]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The meaning of not specifying the "port=" mount option is different
for "-t nfs" and "-t nfs4" mounts.  The default port value for
NFSv2/v3 mounts is 0, but the default for NFSv4 mounts is 2049.

To support "-t nfs -o vers=4", the mount option parser must detect
when "port=" is missing so that the correct default port value can be
set depending on which NFS version is requested.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Make NFS a bit more friendly to NUMA and memory hot removal...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Clean up: Use the common routine now provided in sunrpc.ko for parsing mount
addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Introduce a set of functions in the kernel's RPC implementation for
converting between a socket address and either a standard
presentation address string or an RPC universal address.

The universal address functions will be used to encode and decode
RPCB_FOO and NFSv4 SETCLIENTID arguments.  The other functions are
part of a previous promise to deliver shared functions that can be
used by upper-layer protocols to display and manipulate IP
addresses.

The kernel's current address printf formatters were designed
specifically for kernel to user-space APIs that require a particular
string format for socket addresses, thus are somewhat limited for the
purposes of sunrpc.ko.  The formatter for IPv6 addresses, %pI6, does
not support short-handing or scope IDs.  Also, these printf formatters
are unique per address family, so a separate formatter string is
required for printing AF_INET and AF_INET6 addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

After certain failure modes of an NFS mount, an NFS client should send
a MOUNTPROC_UMNT request to remove the just-added mount entry from the
server's mount table.  While no-one should rely on the accuracy of the
server's mount table, sending a UMNT is simply being a good internet
neighbor.

Since NFS mount processing is handled in the kernel now, we will need
a function in the kernel's mountd client that can post a MOUNTRPC_UMNT
request, in order to handle these failure modes.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Solder xdr_stream-based XDR decoding functions into the in-kernel mountd
client that are more careful about checking data types and watching for
buffer overflows.  The new MNT3 decoder includes support for auth-flavor
list decoding.

The "_sz" macro for MNT3 replies was missing the size of the file handle.
I've added this back, and included the size of the auth flavor array.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Introduce an xdr_stream-based XDR decoder that can unpack the auth-
flavor list returned in a MNT3 reply.

The nfs_mount() function's caller allocates an array, and passes the
size and a pointer to it.  The decoder decodes all the flavors it can
into the array, and returns the number of decoded flavors.

If the caller is not interested in the auth flavors, it can pass a
value of zero as the size of the pre-allocated array.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This creates the nfsv4.1 session on mount.
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

[nfs41: change nfs4_restart_rpc argument]
[nfs41: check for session not minorversion]
[nfs41: trigger the state manager for session reset]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[always define nfs4_restart_rpc]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

At mount, nfs_alloc_client sets the cl_state NFS4CLNT_LEASE_EXPIRED bit
and nfs4_alloc_session sets the NFS4CLNT_SESSION_SETUP bit, so both bits are
set when nfs4_lookup_root calls nfs4_recover_expired_lease which schedules
the nfs4_state_manager and waits for it to complete.

Place the session setup after the clientid establishment in nfs4_state_manager
so that the session is setup right after the clientid has been established
without rescheduling the state manager.

Unlike nfsv4.0, the nfs_client struct is not ready to use until the session
has been established.  Postpone marking the nfs_client struct to NFS_CS_READY
until after a successful CREATE_SESSION call so that other threads cannot use
the client until the session is established.

If the EXCHANGE_ID call fails and the session has not been setup (the
NFS4CLNT_SESSION_SETUP bit is set), mark the client with the error and return.

If the session setup CREATE_SESSION call fails with NFS4ERR_STALE_CLIENTID
which could occur due to server reboot or network partition inbetween the
EXCHANGE_ID and CREATE_SESSION call, reset the NFS4CLNT_LEASE_EXPIRED and
NFS4CLNT_SESSION_SETUP bits and try again.

If the CREATE_SESSION call fails with other errors, mark the client with
the error and return.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>

[nfs41: NFS_CS_SESSION_SETUP cl_cons_state for back channel setup]
  On session setup, the CREATE_SESSION reply races with the server back channel
  probe which needs to succeed to setup the back channel. Set a new
  cl_cons_state NFS_CS_SESSION_SETUP just prior to the CREATE_SESSION call
  and add it as a valid state to nfs_find_client so that the client back channel
  can find the nfs_client struct and won't drop the server backchannel probe.
  Use a new cl_cons_state so that NFSv4.0 back channel behaviour which only
  sets NFS_CS_READY is unchanged.
  Adjust waiting on the nfs_client_active_wq accordingly.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>

[nfs41: rename NFS_CS_SESSION_SETUP to NFS_CS_SESSION_INITING]
Signed-off-by: NAndy Adamson <andros@netapp.com>
[nfs41: set NFS_CL_SESSION_INITING in alloc_session]
Signed-off-by: NAndy Adamson <andros@netapp.com>
[nfs41: move session setup into a function]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[moved nfs4_proc_create_session declaration here]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Separate write calls from nfs41: sequence setup/done support

Implement the write rpc_call_prepare method for
asynchronuos nfs rpcs, call nfs41_setup_sequence from
respective rpc_call_validate_args methods.

Call nfs4_sequence_done from respective rpc_call_done methods.

Note that we need to pass a pointer to the nfs_server in calls data
for passing on to nfs4_sequence_done.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[pnfs: client data server write validate and release]
Signed-off-by: NAndy Adamson <andros@umich.edu>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[move the nfs4_sequence_free_slot call in nfs_readpage_retry from]
[nfs41: separate free slot from sequence done
Signed-off-by: NAndy Adamson <andros@umich.edu>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: Support sessions with O_DIRECT.]
Signed-off-by: NDean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: nfs4_sequence_free_slot use nfs_client for data server]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Implement the read rpc_call_prepare method for
asynchronuos nfs rpcs, call nfs41_setup_sequence from
respective rpc_call_validate_args methods.

Call nfs4_sequence_done from respective rpc_call_done methods.

Note that we need to pass a pointer to the nfs_server in calls data
for passing on to nfs4_sequence_done.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[pnfs: client data server write validate and release]
Signed-off-by: NAndy Adamson <andros@umich.edu>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[move the nfs4_sequence_free_slot call in nfs_readpage_retry from]
[nfs41: separate free slot from sequence done]
[remove nfs_readargs.nfs_server, use calldata->inode instead]
Signed-off-by: NAndy Adamson <andros@umich.edu>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: Support sessions with O_DIRECT]
Signed-off-by: NDean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: nfs4_sequence_free_slot use nfs_client for data server]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

[from nfs41: separate free slot from sequence done]

Don't free the slot until after all rpc_restart_calls have completed.
Session reset will require more work.

As noted by Trond, since we're using rpc_wake_up_next rather than
rpc_wake_up() we must always wake up the next task in the queue
either by going through nfs4_free_slot, or just calling
rpc_wake_up_next if no slot is to be freed.

[nfs41: sequence res use slotid]
[nfs41: remove SEQ4_STATUS_USE_TK_STATUS]
[got rid of nfs4_sequence_res.sr_session, use nfs_client.cl_session instead]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: rpc_wake_up_next if sessions slot was not consumed.]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: nfs4_sequence_free_slot use nfs_client for data server]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Use nfs4_call_sync rather than rpc_call_sync to provide
for a nfs41 sessions-enabled interface for sessions manipulation.

The nfs41 rpc logic uses the rpc_call_prepare method to
recover and create the session, as well as selecting a free slot id
and the rpc_call_done to free the slot and update slot table
related metadata.

In the coming patches we'll add rpc prepare and done routines
for setting up the sequence op and processing the sequence result.
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: nfs4_call_sync]
As per 11-14-08 review.
Squash into "nfs41: introduce nfs4_call_sync" and "nfs41: nfs4_setup_sequence"
Define two functions one for v4 and one for v41
add a pointer to struct nfs4_client to the correct one.
Signed-off-by: NAndy Adamson <andros@netapp.com>
[added BUG() in _nfs4_call_sync_session if !CONFIG_NFS_V4_1]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: check for session not minorversion]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[group minorversion specific stuff together]
Signed-off-by: NAlexandros Batsakis <Alexandros.Batsakis@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NAndy Adamson <andros@netapp.com>
[nfs41: fixup nfs4_clear_client_minor_version]
[introduce nfs4_init_client_minor_version() in this patch]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[cleaned-up patch: got rid of nfs_call_sync_t, dprintks, cosmetics, extra server defs]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFSv4.1 Sessions basic data types, initialization, and destruction.

The session is always associated with a struct nfs_client that holds
the exchange_id results.
Signed-off-by: NRahul Iyer <iyer@netapp.com>
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[remove extraneous rpc_clnt pointer, use the struct nfs_client cl_rpcclient.
remove the rpc_clnt parameter from nfs4 nfs4_init_session]
Signed-off-by: Andy Adamson<andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[Use the presence of a session to determine behaviour instead of the
minorversion number.]
Signed-off-by: NAndy Adamson <andros@netapp.com>
[constified nfs4_has_session's struct nfs_client parameter]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[Rename nfs4_put_session() to nfs4_destroy_session() and call it from nfs4_free_client() not nfs4_free_server().
Also get rid of nfs4_get_session() and the ref_count in nfs4_session struct as keeping track of nfs_client should be sufficient]
Signed-off-by: NAlexandros Batsakis <Alexandros.Batsakis@netapp.com>
[nfs41: pass rsize and wsize into nfs4_init_session]
Signed-off-by: NAndy Adamson <andros@netapp.com>
[separated out removal of rpc_clnt parameter from nfs4_init_session ot a
 patch of its own]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[Pass the nfs_client pointer into nfs4_alloc_session]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: don't assign to session->clp->cl_session in nfs4_destroy_session]
[nfs41: fixup nfs4_clear_client_minor_version]
[introduce nfs4_clear_client_minor_version() in this patch]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[Refactor nfs4_init_session]
    Moved session allocation into nfs4_init_client_minor_version, called from
    nfs4_init_client.
    Leave rwise and wsize initialization in nfs4_init_session, called from
    nfs4_init_server.
    Reverted moving of nfs_fsid definition to nfs_fs_sb.h
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: Move NFS4_MAX_SLOT_TABLE define from under CONFIG_NFS_V4_1]
[Fix comile error when CONFIG_NFS_V4_1 is not set.]
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[moved nfs4_init_slot_table definition to "create_session operation"]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
[nfs41: alloc session with GFP_KERNEL]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

mount -t nfs4 -o minorversion=[0|1] specifies whether to use 4.0 or 4.1.
By default, the minorversion is set to 0.
Signed-off-by: NMike Sager <sager@netapp.com>
[set default minorversion to 0 as per Trond and SteveD's request]
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Add NFS mount options to allow the local caching support to be enabled.

The attached patch makes it possible for the NFS filesystem to be told to make
use of the network filesystem local caching service (FS-Cache).

To be able to use this, a recent nfsutils package is required.

There are three variant NFS mount options that can be added to a mount command
to control caching for a mount.  Only the last one specified takes effect:

 (*) Adding "fsc" will request caching.

 (*) Adding "fsc=<string>" will request caching and also specify a uniquifier.

 (*) Adding "nofsc" will disable caching.

For example:

	mount warthog:/ /a -o fsc

The cache of a particular superblock (NFS FSID) will be shared between all
mounts of that volume, provided they have the same connection parameters and
are not marked 'nosharecache'.

Where it is otherwise impossible to distinguish superblocks because all the
parameters are identical, but the 'nosharecache' option is supplied, a
uniquifying string must be supplied, else only the first mount will be
permitted to use the cache.

If there's a key collision, then the second mount will disable caching and give
a warning into the kernel log.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NSteve Dickson <steved@redhat.com>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Tested-by: NDaire Byrne <Daire.Byrne@framestore.com>

Define and create superblock-level cache index objects (as managed by
nfs_server structs).

Each superblock object is created in a server level index object and is itself
an index into which inode-level objects are inserted.

Ideally there would be one superblock-level object per server, and the former
would be folded into the latter; however, since the "nosharecache" option
exists this isn't possible.

The superblock object key is a sequence consisting of:

 (1) Certain superblock s_flags.

 (2) Various connection parameters that serve to distinguish superblocks for
     sget().

 (3) The volume FSID.

 (4) The security flavour.

 (5) The uniquifier length.

 (6) The uniquifier text.  This is normally an empty string, unless the fsc=xyz
     mount option was used to explicitly specify a uniquifier.

The key blob is of variable length, depending on the length of (6).

The superblock object is given no coherency data to carry in the auxiliary data
permitted by the cache.  It is assumed that the superblock is always coherent.

This patch also adds uniquification handling such that two otherwise identical
superblocks, at least one of which is marked "nosharecache", won't end up
trying to share the on-disk cache.  It will be possible to manually provide a
uniquifier through a mount option with a later patch to avoid the error
otherwise produced.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NSteve Dickson <steved@redhat.com>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Tested-by: NDaire Byrne <Daire.Byrne@framestore.com>