nfsd: Fix NFSv3 atomicity bugs in nfsd_setattr()

The main point of the guarded SETATTR is to prevent races with other
WRITE and SETATTR calls. That requires that the check of the guard time
against the inode ctime be done after taking the inode lock.

Furthermore, we need to take into account the 32-bit nature of
timestamps in NFSv3, and the possibility that files may change at a
faster rate than once a second.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

nfsd: convert to new timestamp accessors

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-50-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

nfsd: Clean up errors in nfs3proc.c

Fix the following errors reported by checkpatch:

ERROR: need consistent spacing around '+' (ctx:WxV)
ERROR: spaces required around that '?' (ctx:VxW)

Signed-off-by: KaiLong Wang <wangkailong@jari.cn>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

nfsd: handle failure to collect pre/post-op attrs more sanely

Collecting pre_op_attrs can fail, in which case it's probably best to
fail the whole operation.

Change fh_fill_pre_attrs and fh_fill_both_attrs to return __be32, and
have the callers check the return code and abort the operation if it's
not nfs_ok.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: Hoist rq_vec preparation into nfsd_read()

Accrue the following benefits:

a) Deduplicate this common bit of code.

b) Don't prepare rq_vec for NFSv2 and NFSv3 spliced reads, which
don't use rq_vec. This is already the case for
nfsd4_encode_read().

c) Eventually, converting NFSD's read path to use a bvec iterator
will be simpler.

In the next patch, nfsd_iter_read() will replace nfsd_readv() for
all NFS versions.

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

SUNRPC: Use per-CPU counters to tally server RPC counts

- Improves counting accuracy
- Reduces cross-CPU memory traffic

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

fs: port vfs_*() helpers to struct mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

NFSD: Add an NFSD_FILE_GC flag to enable nfsd_file garbage collection

NFSv4 operations manage the lifetime of nfsd_file items they use by
means of NFSv4 OPEN and CLOSE. Hence there's no need for them to be
garbage collected.

Introduce a mechanism to enable garbage collection for nfsd_file
items used only by NFSv2/3 callers.

Note that the change in nfsd_file_put() ensures that both CLOSE and
DELEGRETURN will actually close out and free an nfsd_file on last
reference of a non-garbage-collected file.

Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=394
Suggested-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

NFSD: Pass the target nfsd_file to nfsd_commit()

In a moment I'm going to introduce separate nfsd_file types, one of
which is garbage-collected; the other, not. The garbage-collected
variety is to be used by NFSv2 and v3, and the non-garbage-collected
variety is to be used by NFSv4.

nfsd_commit() is invoked by both NFSv3 and NFSv4 consumers. We want
nfsd_commit() to find and use the correct variety of cached
nfsd_file object for the NFS version that is in use.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>

NFSD: Refactor common code out of dirlist helpers

The dust has settled a bit and it's become obvious what code is
totally common between nfsd_init_dirlist_pages() and
nfsd3_init_dirlist_pages(). Move that common code to SUNRPC.

The new helper brackets the existing xdr_init_decode_pages() API.

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

SUNRPC: Parametrize how much of argsize should be zeroed

Currently, SUNRPC clears the whole of .pc_argsize before processing
each incoming RPC transaction. Add an extra parameter to struct
svc_procedure to enable upper layers to reduce the amount of each
operation's argument structure that is zeroed by SUNRPC.

The size of struct nfsd4_compoundargs, in particular, is a lot to
clear on each incoming RPC Call. A subsequent patch will cut this
down to something closer to what NFSv2 and NFSv3 uses.

This patch should cause no behavior changes.

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

NFSD: Protect against send buffer overflow in NFSv3 READ

Since before the git era, NFSD has conserved the number of pages
held by each nfsd thread by combining the RPC receive and send
buffers into a single array of pages. This works because there are
no cases where an operation needs a large RPC Call message and a
large RPC Reply at the same time.

Once an RPC Call has been received, svc_process() updates
svc_rqst::rq_res to describe the part of rq_pages that can be
used for constructing the Reply. This means that the send buffer
(rq_res) shrinks when the received RPC record containing the RPC
Call is large.

A client can force this shrinkage on TCP by sending a correctly-
formed RPC Call header contained in an RPC record that is
excessively large. The full maximum payload size cannot be
constructed in that case.

Cc: <stable@vger.kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: Protect against send buffer overflow in NFSv3 READDIR

Since before the git era, NFSD has conserved the number of pages
held by each nfsd thread by combining the RPC receive and send
buffers into a single array of pages. This works because there are
no cases where an operation needs a large RPC Call message and a
large RPC Reply message at the same time.

Once an RPC Call has been received, svc_process() updates
svc_rqst::rq_res to describe the part of rq_pages that can be
used for constructing the Reply. This means that the send buffer
(rq_res) shrinks when the received RPC record containing the RPC
Call is large.

A client can force this shrinkage on TCP by sending a correctly-
formed RPC Call header contained in an RPC record that is
excessively large. The full maximum payload size cannot be
constructed in that case.

Thanks to Aleksi Illikainen and Kari Hulkko for uncovering this
issue.

Reported-by: Ben Ronallo <Benjamin.Ronallo@synopsys.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: use explicit lock/unlock for directory ops

When creating or unlinking a name in a directory use explicit
inode_lock_nested() instead of fh_lock(), and explicit calls to
fh_fill_pre_attrs() and fh_fill_post_attrs(). This is already done
for renames, with lock_rename() as the explicit locking.

Also move the 'fill' calls closer to the operation that might change the
attributes. This way they are avoided on some error paths.

For the v2-only code in nfsproc.c, the fill calls are not replaced as
they aren't needed.

Making the locking explicit will simplify proposed future changes to
locking for directories. It also makes it easily visible exactly where
pre/post attributes are used - not all callers of fh_lock() actually
need the pre/post attributes.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: always drop directory lock in nfsd_unlink()

Some error paths in nfsd_unlink() allow it to exit without unlocking the
directory. This is not a problem in practice as the directory will be
locked with an fh_put(), but it is untidy and potentially confusing.

This allows us to remove all the fh_unlock() calls that are immediately
after nfsd_unlink() calls.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: change nfsd_create()/nfsd_symlink() to unlock directory before returning.

nfsd_create() usually returns with the directory still locked.
nfsd_symlink() usually returns with it unlocked. This is clumsy.

Until recently nfsd_create() needed to keep the directory locked until
ACLs and security label had been set. These are now set inside
nfsd_create() (in nfsd_setattr()) so this need is gone.

So change nfsd_create() and nfsd_symlink() to always unlock, and remove
any fh_unlock() calls that follow calls to these functions.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: set attributes when creating symlinks

The NFS protocol includes attributes when creating symlinks.
Linux does store attributes for symlinks and allows them to be set,
though they are not used for permission checking.

NFSD currently doesn't set standard (struct iattr) attributes when
creating symlinks, but for NFSv4 it does set ACLs and security labels.
This is inconsistent.

To improve consistency, pass the provided attributes into nfsd_symlink()
and call nfsd_create_setattr() to set them.

NOTE: this results in a behaviour change for all NFS versions when the
client sends non-default attributes with a SYMLINK request. With the
Linux client, the only attributes are:
attr.ia_mode = S_IFLNK | S_IRWXUGO;
attr.ia_valid = ATTR_MODE;
so the final outcome will be unchanged. Other clients might sent
different attributes, and if they did they probably expect them to be
honoured.

We ignore any error from nfsd_create_setattr(). It isn't really clear
what should be done if a file is successfully created, but the
attributes cannot be set. NFS doesn't allow partial success to be
reported. Reporting failure is probably more misleading than reporting
success, so the status is ignored.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: introduce struct nfsd_attrs

The attributes that nfsd might want to set on a file include 'struct
iattr' as well as an ACL and security label.
The latter two are passed around quite separately from the first, in
part because they are only needed for NFSv4. This leads to some
clumsiness in the code, such as the attributes NOT being set in
nfsd_create_setattr().

We need to keep the directory locked until all attributes are set to
ensure the file is never visibile without all its attributes. This need
combined with the inconsistent handling of attributes leads to more
clumsiness.

As a first step towards tidying this up, introduce 'struct nfsd_attrs'.
This is passed (by reference) to vfs.c functions that work with
attributes, and is assembled by the various nfs*proc functions which
call them. As yet only iattr is included, but future patches will
expand this.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: Refactor NFSv3 CREATE

The NFSv3 CREATE and NFSv4 OPEN(CREATE) use cases are about to
diverge such that it makes sense to split do_nfsd_create() into one
version for NFSv3 and one for NFSv4.

As a first step, copy do_nfsd_create() to nfs3proc.c and remove
NFSv4-specific logic.

One immediate legibility benefit is that the logic for handling
NFSv3 createhow is now quite straightforward. NFSv4 createhow
has some subtleties that IMO do not belong in generic code.

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

NFSD: Clean up nfsd3_proc_create()

As near as I can tell, mode bit masking and setting S_IFREG is
already done by do_nfsd_create() and vfs_create(). The NFSv4 path
(do_open_lookup), for example, does not bother with this special
processing.

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

NFSD: COMMIT operations must not return NFS?ERR_INVAL

Since, well, forever, the Linux NFS server's nfsd_commit() function
has returned nfserr_inval when the passed-in byte range arguments
were non-sensical.

However, according to RFC 1813 section 3.3.21, NFSv3 COMMIT requests
are permitted to return only the following non-zero status codes:

NFS3ERR_IO
NFS3ERR_STALE
NFS3ERR_BADHANDLE
NFS3ERR_SERVERFAULT

NFS3ERR_INVAL is not included in that list. Likewise, NFS4ERR_INVAL
is not listed in the COMMIT row of Table 6 in RFC 8881.

RFC 7530 does permit COMMIT to return NFS4ERR_INVAL, but does not
specify when it can or should be used.

Instead of dropping or failing a COMMIT request in a byte range that
is not supported, turn it into a valid request by treating one or
both arguments as zero. Offset zero means start-of-file, count zero
means until-end-of-file, so we only ever extend the commit range.
NFS servers are always allowed to commit more and sooner than
requested.

The range check is no longer bounded by NFS_OFFSET_MAX, but rather
by the value that is returned in the maxfilesize field of the NFSv3
FSINFO procedure or the NFSv4 maxfilesize file attribute.

Note that this change results in a new pynfs failure:

CMT4 st_commit.testCommitOverflow : RUNNING
CMT4 st_commit.testCommitOverflow : FAILURE
COMMIT with offset + count overflow should return
NFS4ERR_INVAL, instead got NFS4_OK

IMO the test is not correct as written: RFC 8881 does not allow the
COMMIT operation to return NFS4ERR_INVAL.

Reported-by: Dan Aloni <dan.aloni@vastdata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Bruce Fields <bfields@fieldses.org>

NFSD: Clamp WRITE offsets

Ensure that a client cannot specify a WRITE range that falls in a
byte range outside what the kernel's internal types (such as loff_t,
which is signed) can represent. The kiocb iterators, invoked in
nfsd_vfs_write(), should properly limit write operations to within
the underlying file system's s_maxbytes.

Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: Fix the behavior of READ near OFFSET_MAX

Dan Aloni reports:
> Due to commit 8cfb9015280d ("NFS: Always provide aligned buffers to
> the RPC read layers") on the client, a read of 0xfff is aligned up
> to server rsize of 0x1000.
>
> As a result, in a test where the server has a file of size
> 0x7fffffffffffffff, and the client tries to read from the offset
> 0x7ffffffffffff000, the read causes loff_t overflow in the server
> and it returns an NFS code of EINVAL to the client. The client as
> a result indefinitely retries the request.

The Linux NFS client does not handle NFS?ERR_INVAL, even though all
NFS specifications permit servers to return that status code for a
READ.

Instead of NFS?ERR_INVAL, have out-of-range READ requests succeed
and return a short result. Set the EOF flag in the result to prevent
the client from retrying the READ request. This behavior appears to
be consistent with Solaris NFS servers.

Note that NFSv3 and NFSv4 use u64 offset values on the wire. These
must be converted to loff_t internally before use -- an implicit
type cast is not adequate for this purpose. Otherwise VFS checks
against sb->s_maxbytes do not work properly.

Reported-by: Dan Aloni <dan.aloni@vastdata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: Fix zero-length NFSv3 WRITEs

The Linux NFS server currently responds to a zero-length NFSv3 WRITE
request with NFS3ERR_IO. It responds to a zero-length NFSv4 WRITE
with NFS4_OK and count of zero.

RFC 1813 says of the WRITE procedure's @count argument:

count
The number of bytes of data to be written. If count is
0, the WRITE will succeed and return a count of 0,
barring errors due to permissions checking.

RFC 8881 has similar language for NFSv4, though NFSv4 removed the
explicit @count argument because that value is already contained in
the opaque payload array.

The synthetic client pynfs's WRT4 and WRT15 tests do emit zero-
length WRITEs to exercise this spec requirement. Commit fdec6114ee1f
("nfsd4: zero-length WRITE should succeed") addressed the same
problem there with the same fix.

But interestingly the Linux NFS client does not appear to emit zero-
length WRITEs, instead squelching them. I'm not aware of a test that
can generate such WRITEs for NFSv3, so I wrote a naive C program to
generate a zero-length WRITE and test this fix.

Fixes: 8154ef2776aa ("NFSD: Clean up legacy NFS WRITE argument XDR decoders")
Reported-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: Fix READDIR buffer overflow

If a client sends a READDIR count argument that is too small (say,
zero), then the buffer size calculation in the new init_dirlist
helper functions results in an underflow, allowing the XDR stream
functions to write beyond the actual buffer.

This calculation has always been suspect. NFSD has never sanity-
checked the READDIR count argument, but the old entry encoders
managed the problem correctly.

With the commits below, entry encoding changed, exposing the
underflow to the pointer arithmetic in xdr_reserve_space().

Modern NFS clients attempt to retrieve as much data as possible
for each READDIR request. Also, we have no unit tests that
exercise the behavior of READDIR at the lower bound of @count
values. Thus this case was missed during testing.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Fixes: f5dcccd647da ("NFSD: Update the NFSv2 READDIR entry encoder to use struct xdr_stream")
Fixes: 7f87fc2d34d4 ("NFSD: Update NFSv3 READDIR entry encoders to use struct xdr_stream")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: Have legacy NFSD WRITE decoders use xdr_stream_subsegment()

Refactor.

Now that the NFSv2 and NFSv3 XDR decoders have been converted to
use xdr_streams, the WRITE decoder functions can use
xdr_stream_subsegment() to extract the WRITE payload into its own
xdr_buf, just as the NFSv4 WRITE XDR decoder currently does.

That makes it possible to pass the first kvec, pages array + length,
page_base, and total payload length via a single function parameter.

The payload's page_base is not yet assigned or used, but will be in
subsequent patches.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Reduce svc_rqst::rq_pages churn during READDIR operations

During NFSv2 and NFSv3 READDIR/PLUS operations, NFSD advances
rq_next_page to the full size of the client-requested buffer, then
releases all those pages at the end of the request. The next request
to use that nfsd thread has to refill the pages.

NFSD does this even when the dirlist in the reply is small. With
NFSv3 clients that send READDIR operations with large buffer sizes,
that can be 256 put_page/alloc_page pairs per READDIR request, even
though those pages often remain unused.

We can save some work by not releasing dirlist buffer pages that
were not used to form the READDIR Reply. I've left the NFSv2 code
alone since there are never more than three pages involved in an
NFSv2 READDIR Reply.

Eventually we should nail down why these pages need to be released
at all in order to avoid allocating and releasing pages
unnecessarily.

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

NFSD: Update NFSv3 READDIR entry encoders to use struct xdr_stream

The benefit of the xdr_stream helpers is that they transparently
handle encoding an XDR data item that crosses page boundaries.
Most of the open-coded logic to do that here can be eliminated.

A sub-buffer and sub-stream are set up as a sink buffer for the
directory entry encoder. As an entry is encoded, it is added to
the end of the content in this buffer/stream. The total length of
the directory list is tracked in the buffer's @len field.

When it comes time to encode the Reply, the sub-buffer is merged
into rq_res's page array at the correct place using
xdr_write_pages().

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

NFSD: Update the NFSv3 READDIR3res encoder to use struct xdr_stream

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

NFSD: Count bytes instead of pages in the NFSv3 READDIR encoder

Clean up: Counting the bytes used by each returned directory entry
seems less brittle to me than trying to measure consumed pages after
the fact.

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

NFSD: Add a helper that encodes NFSv3 directory offset cookies

Refactor: De-duplicate identical code that handles encoding of
directory offset cookies across page boundaries.

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

NFSD: Update the NFSv3 READ3res encode to use struct xdr_stream

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

NFSD: Update the NFSv3 READLINK3res encoder to use struct xdr_stream

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

NFSD: Update the NFSv3 LOOKUP3res encoder to use struct xdr_stream

Also, clean up: Rename the encoder function to match the name of
the result structure in RFC 1813, consistent with other encoder
function names in nfs3xdr.c. "diropres" is an NFSv2 thingie.

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

NFSD: Update the GETATTR3res encoder to use struct xdr_stream

As an additional clean up, some renaming is done to more closely
reflect the data type and variable names used in the NFSv3 XDR
definition provided in RFC 1813. "attrstat" is an NFSv2 thingie.

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

NFSD: Add helper to set up the pages where the dirlist is encoded

De-duplicate some code that is used by both READDIR and READDIRPLUS
to build the dirlist in the Reply. Because this code is not related
to decoding READ arguments, it is moved to a more appropriate spot.

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

NFSD: Fix returned READDIR offset cookie

Code inspection shows that the server's NFSv3 READDIR implementation
handles offset cookies slightly differently than the NFSv2 READDIR,
NFSv3 READDIRPLUS, and NFSv4 READDIR implementations,
and there doesn't seem to be any need for this difference.

As a clean up, I copied the logic from nfsd3_proc_readdirplus().

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

NFSD: Update READLINK3arg decoder to use struct xdr_stream

The NFSv3 READLINK request takes a single filehandle, so it can
re-use GETATTR's decoder.

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

NFSD: Update READ3arg decoder to use struct xdr_stream

The code that sets up rq_vec is refactored so that it is now
adjacent to the nfsd_read() call site where it is used.

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

NFSD: Update GETATTR3args decoder to use struct xdr_stream

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

SUNRPC: Make trace_svc_process() display the RPC procedure symbolically

The next few patches will employ these strings to help make server-
side trace logs more human-readable. A similar technique is already
in use in kernel RPC client code.

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

NFSD: Add common helpers to decode void args and encode void results

Start off the conversion to xdr_stream by de-duplicating the functions
that decode void arguments and encode void results.

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

nfsd/nfs3: remove unused macro nfsd3_fhandleres

The macro is unused, remove it to tame gcc warning:
fs/nfsd/nfs3proc.c:702:0: warning: macro "nfsd3_fhandleres" is not used
[-Wunused-macros]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: linux-nfs@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSD: MKNOD should return NFSERR_BADTYPE instead of NFSERR_INVAL

A late paragraph of RFC 1813 Section 3.3.11 states:

| ... if the server does not support the target type or the
| target type is illegal, the error, NFS3ERR_BADTYPE, should
| be returned. Note that NF3REG, NF3DIR, and NF3LNK are
| illegal types for MKNOD.

The Linux NFS server incorrectly returns NFSERR_INVAL in these
cases.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Hoist status code encoding into XDR encoder functions

The original intent was presumably to reduce code duplication. The
trade-off was:

- No support for an NFSD proc function returning a non-success
RPC accept_stat value.
- No support for void NFS replies to non-NULL procedures.
- Everyone pays for the deduplication with a few extra conditional
branches in a hot path.

In addition, nfsd_dispatch() leaves *statp uninitialized in the
success path, unlike svc_generic_dispatch().

Address all of these problems by moving the logic for encoding
the NFS status code into the NFS XDR encoders themselves. Then
update the NFS .pc_func methods to return an RPC accept_stat
value.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Remove the RETURN_STATUS() macro

Refactor: I'm about to change the return value from .pc_func. Clear
the way by replacing the RETURN_STATUS() macro with logic that
plants the status code directly into the response structure.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Encoder and decoder functions are always present

nfsd_dispatch() is a hot path. Let's optimize the XDR method calls
for the by-far common case, which is that the XDR methods are indeed
present.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd: Ensure sampling of the write verifier is atomic with the write

When doing an unstable write, we need to ensure that we sample the
write verifier before releasing the lock, and allowing a commit to
the same file to proceed.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd: Ensure sampling of the commit verifier is atomic with the commit

When we have a successful commit, ensure we sample the commit verifier
before releasing the lock.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd: fix nfs read eof detection

Currently, the knfsd server assumes that a short read indicates an
end of file. That assumption is incorrect. The short read means that
either we've hit the end of file, or we've hit a read error.

In the case of a read error, the client may want to retry (as per the
implementation recommendations in RFC1813 and RFC7530), but currently it
is being told that it hit an eof.

Move the code to detect eof from version specific code into the generic
nfsd read.

Report eof only in the two following cases:
1) read() returns a zero length short read with no error.
2) the offset+length of the read is >= the file size.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd/nfsd3_proc_readdir: fix buffer count and page pointers

After this commit
f875a79 nfsd: allow nfsv3 readdir request to be larger.
nfsv3 readdir request size can be larger than PAGE_SIZE. So if the
directory been read is large enough, we can use multiple pages
in rq_respages. Update buffer count and page pointers like we do
in readdirplus to make this happen.

Now listing a directory within 3000 files will panic because we
are counting in a wrong way and would write on random page.

Fixes: f875a79 "nfsd: allow nfsv3 readdir request to be larger"
Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd: allow nfsv3 readdir request to be larger.

nfsd currently reports the NFSv3 dtpref FSINFO parameter
to be PAGE_SIZE, so NFS clients will typically ask for one
page of directory entries at a time. This is needlessly restrictive
as nfsd can handle larger replies easily.

Also, a READDIR request (but not a READDIRPLUS request) has the count
size clipped to PAGE_SIE, again unnecessary.

This patch lifts these limits so that larger readdir requests can be
used.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd: fix memory corruption caused by readdir

If the result of an NFSv3 readdir{,plus} request results in the
"offset" on one entry having to be split across 2 pages, and is sized
so that the next directory entry doesn't fit in the requested size,
then memory corruption can happen.

When encode_entry() is called after encoding the last entry that fits,
it notices that ->offset and ->offset1 are set, and so stores the
offset value in the two pages as required. It clears ->offset1 but
*does not* clear ->offset.

Normally this omission doesn't matter as encode_entry_baggage() will
be called, and will set ->offset to a suitable value (not on a page
boundary).
But in the case where cd->buflen < elen and nfserr_toosmall is
returned, ->offset is not reset.

This means that nfsd3proc_readdirplus will see ->offset with a value 4
bytes before the end of a page, and ->offset1 set to NULL.
It will try to write 8bytes to ->offset.
If we are lucky, the next page will be read-only, and the system will
BUG: unable to handle kernel paging request at...

If we are unlucky, some innocent page will have the first 4 bytes
corrupted.

nfsd3proc_readdir() doesn't even check for ->offset1, it just blindly
writes 8 bytes to the offset wherever it is.

Fix this by clearing ->offset after it is used, and copying the
->offset handling code from nfsd3_proc_readdirplus into
nfsd3_proc_readdir.

(Note that the commit hash in the Fixes tag is from the 'history'
tree - this bug predates git).

Fixes: 0b1d57cf7654 ("[PATCH] kNFSd: Fix nfs3 dentry encoding")
Fixes-URL: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=0b1d57cf7654
Cc: stable@vger.kernel.org (v2.6.12+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Handle full-length symlinks

I've given up on the idea of zero-copy handling of SYMLINK on the
server side. This is because the Linux VFS symlink API requires the
symlink pathname to be in a NUL-terminated kmalloc'd buffer. The
NUL-termination is going to be problematic (watching out for
landing on a page boundary and dealing with a 4096-byte pathname).

I don't believe that SYMLINK creation is on a performance path or is
requested frequently enough that it will cause noticeable CPU cache
pollution due to data copies.

There will be two places where a transport callout will be necessary
to fill in the rqstp: one will be in the svc_fill_symlink_pathname()
helper that is used by NFSv2 and NFSv3, and the other will be in
nfsd4_decode_create().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Refactor the generic write vector fill helper

fill_in_write_vector() is nearly the same logic as
svc_fill_write_vector(), but there are a few differences so that
the former can handle multiple WRITE payloads in a single COMPOUND.

svc_fill_write_vector() can be adjusted so that it can be used in
the NFSv4 WRITE code path too. Instead of assuming the pages are
coming from rq_args.pages, have the caller pass in the page list.

The immediate benefit is a reduction of code duplication. It also
prevents the NFSv4 WRITE decoder from passing an empty vector
element when the transport has provided the payload in the xdr_buf's
page array.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Clean up legacy NFS SYMLINK argument XDR decoders

Move common code in NFSD's legacy SYMLINK decoders into a helper.
The immediate benefits include:

- one fewer data copies on transports that support DDP
- consistent error checking across all versions
- reduction of code duplication
- support for both legal forms of SYMLINK requests on RDMA
transports for all versions of NFS (in particular, NFSv2, for
completeness)

In the long term, this helper is an appropriate spot to perform a
per-transport call-out to fill the pathname argument using, say,
RDMA Reads.

Filling the pathname in the proc function also means that eventually
the incoming filehandle can be interpreted so that filesystem-
specific memory can be allocated as a sink for the pathname
argument, rather than using anonymous pages.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Clean up legacy NFS WRITE argument XDR decoders

Move common code in NFSD's legacy NFS WRITE decoders into a helper.
The immediate benefit is reduction of code duplication and some nice
micro-optimizations (see below).

In the long term, this helper can perform a per-transport call-out
to fill the rq_vec (say, using RDMA Reads).

The legacy WRITE decoders and procs are changed to work like NFSv4,
which constructs the rq_vec just before it is about to call
vfs_writev.

Why? Calling a transport call-out from the proc instead of the XDR
decoder means that the incoming FH can be resolved to a particular
filesystem and file. This would allow pages from the backing file to
be presented to the transport to be filled, rather than presenting
anonymous pages and copying or flipping them into the file's page
cache later.

I also prefer using the pages in rq_arg.pages, instead of pulling
the data pages directly out of the rqstp::rq_pages array. This is
currently the way the NFSv3 write decoder works, but the other two
do not seem to take this approach. Fixing this removes the only
reference to rq_pages found in NFSD, eliminating an NFSD assumption
about how transports use the pages in rq_pages.

Lastly, avoid setting up the first element of rq_vec as a zero-
length buffer. This happens with an RDMA transport when a normal
Read chunk is present because the data payload is in rq_arg's
page list (none of it is in the head buffer).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.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>

sunrpc: mark all struct svc_version instances as const

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>

sunrpc: mark all struct svc_procinfo instances as const

struct svc_procinfo contains function pointers, and marking it as
constant avoids it being able to be used as an attach vector for
code injections.

Signed-off-by: Christoph Hellwig <hch@lst.de>

sunrpc: move pc_count out of struct svc_procinfo

pc_count is the only writeable memeber of struct svc_procinfo, which is
a good candidate to be const-ified as it contains function pointers.

This patch moves it into out out struct svc_procinfo, and into a
separate writable array that is pointed to by struct svc_version.

Signed-off-by: Christoph Hellwig <hch@lst.de>

sunrpc: properly type pc_encode callbacks

Drop the resp argument as it can trivially be derived from the rqstp
argument. With that all functions now have the same prototype, and we
can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>

sunrpc: properly type pc_decode callbacks

Drop the argp argument as it can trivially be derived from the rqstp
argument. With that all functions now have the same prototype, and we
can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>

sunrpc: properly type pc_release callbacks

Drop the p and resp arguments as they are always NULL or can trivially
be derived from the rqstp argument. With that all functions now have the
same prototype, and we can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>

sunrpc: properly type pc_func callbacks

Drop the argp and resp arguments as they can trivially be derived from
the rqstp argument. With that all functions now have the same prototype,
and we can remove the unsafe casting to svc_procfunc as well as the
svc_procfunc typedef itself.

Signed-off-by: Christoph Hellwig <hch@lst.de>

nfsd: remove the unused PROC() macro in nfs3proc.c

Signed-off-by: Christoph Hellwig <hch@lst.de>

sunrpc: mark all struct svc_version instances as const

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>

sunrpc: mark all struct svc_procinfo instances as const

struct svc_procinfo contains function pointers, and marking it as
constant avoids it being able to be used as an attach vector for
code injections.

Signed-off-by: Christoph Hellwig <hch@lst.de>

sunrpc: move pc_count out of struct svc_procinfo

pc_count is the only writeable memeber of struct svc_procinfo, which is
a good candidate to be const-ified as it contains function pointers.

This patch moves it into out out struct svc_procinfo, and into a
separate writable array that is pointed to by struct svc_version.

Signed-off-by: Christoph Hellwig <hch@lst.de>

sunrpc: properly type pc_encode callbacks

Drop the resp argument as it can trivially be derived from the rqstp
argument. With that all functions now have the same prototype, and we
can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>

sunrpc: properly type pc_decode callbacks

Drop the argp argument as it can trivially be derived from the rqstp
argument. With that all functions now have the same prototype, and we
can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>

sunrpc: properly type pc_release callbacks

Drop the p and resp arguments as they are always NULL or can trivially
be derived from the rqstp argument. With that all functions now have the
same prototype, and we can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>

sunrpc: properly type pc_func callbacks

Drop the argp and resp arguments as they can trivially be derived from
the rqstp argument. With that all functions now have the same prototype,
and we can remove the unsafe casting to svc_procfunc as well as the
svc_procfunc typedef itself.

Signed-off-by: Christoph Hellwig <hch@lst.de>

nfsd: remove the unused PROC() macro in nfs3proc.c

Signed-off-by: Christoph Hellwig <hch@lst.de>

NFSD: cleanup dead codes and values in nfsd_write

This is just cleanup, no change in functionality.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: pass an integer for stable type to nfsd_vfs_write

After fae5096ad217 "nfsd: assume writeable exportabled filesystems have
f_sync" we no longer modify this argument.

This is just cleanup, no change in functionality.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

don't bother with ->d_inode->i_sb - it's always equal to ->d_sb

... and neither can ever be NULL

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

nfsd: use short read as well as i_size to set eof

Use the result of a local read to determine when to set the eof flag. This
allows us to return the location of the end of the file atomically at the
time of the read.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
[bfields: add some documentation]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

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>

nfsd: allow turning off nfsv3 readdir_plus

One of our customer's application only needs file names, not file
attributes. With directories having 10K+ inodes (assuming buffer cache
has directory blocks cached having file names, but inode cache is
limited and hence need eviction of older cached inodes), older inodes
are evicted periodically. So if they keep on doing readdir(2) from NSF
client on multiple directories, some directory's files are periodically
removed from inode cache and hence new readdir(2) on same directory
requires disk access to bring back inodes again to inode cache.

As READDIRPLUS request fetches attributes also, doing getattr on each
file on server, it causes unnecessary disk accesses. If READDIRPLUS on
NFS client is returned with -ENOTSUPP, NFS client uses READDIR request
which just gets the names of the files in a directory, not attributes,
hence avoiding disk accesses on server.

There's already a corresponding client-side mount option, but an export
option reduces the need for configuration across multiple clients.

This flag affects NFSv3 only. If it turns out it's needed for NFSv4 as
well then we may have to figure out how to extend the behavior to NFSv4,
but it's not currently obvious how to do that.

Signed-off-by: Rajesh Ghanekar <rajesh_ghanekar@symantec.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd3: Check write permission after checking existence

When creating a file that already exists in a read-only directory with
O_EXCL, the NFSv3 server returns EACCES rather than EEXIST (which local
files and the NFSv4 server return). Fix this by checking the MAY_CREATE
permission only if the file does not exist. Since this already happens
in do_nfsd_create, the check in nfsd3_proc_create can simply be removed.

Signed-off-by: Ross Lagerwall <rosslagerwall@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Remove iattr parameter from nfsd_symlink()

Commit db2e747b1499 (vfs: remove mode parameter from vfs_symlink())
have remove mode parameter from vfs_symlink.
So that, iattr isn't needed by nfsd_symlink now, just remove it.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd: let nfsd_symlink assume null-terminated data

Currently nfsd_symlink has a weird hack to serve callers who don't
null-terminate symlink data: it looks ahead at the next byte to see if
it's zero, and copies it to a new buffer to null-terminate if not.

That means callers don't have to null-terminate, but they *do* have to
ensure that the byte following the end of the data is theirs to read.

That's a bit subtle, and the NFSv4 code actually got this wrong.

So let's just throw out that code and let callers pass null-terminated
strings; we've already fixed them to do that.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Using min/max/min_t/max_t for calculate

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

switch vfs_getattr() to struct path

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

nfsd4: cleanup: replace rq_resused count by rq_next_page pointer

It may be a matter of personal taste, but I find this makes the code
clearer.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd: do_nfsd_create verf argument is a u32

The types here are actually a bit of a mess. For now cast as we do in
the v4 case.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd41: make sure nfs server process OPEN with EXCLUSIVE4_1 correctly

The NFS server uses nfsd_create_v3 to handle EXCLUSIVE4_1 opens, but
that function is not prepared to handle them.

Rename nfsd_create_v3() to do_nfsd_create(), and add handling of
EXCLUSIVE4_1.

Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd: fix offset printk's in nfsd3 read/write

Thanks to dysbr01@ca.com for noticing that the debugging printk in
the v3 write procedure can print >2GB offsets as negative numbers:
https://bugzilla.kernel.org/show_bug.cgi?id=23342

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

nfsd: minor nfsd read api cleanup

Christoph points that the NFSv2/v3 callers know which case they want
here, so we may as well just call the file=NULL case directly instead of
making this conditional.

Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFSD: Fill in WCC data for REMOVE, RMDIR, MKNOD, and MKDIR

Some well-known NFSv3 clients drop their directory entry caches when
they receive replies with no WCC data. Without this data, they
employ extra READ, LOOKUP, and GETATTR requests to ensure their
directory entry caches are up to date, causing performance to suffer
needlessly.

In order to return WCC data, our server has to have both the pre-op
and the post-op attribute data on hand when a reply is XDR encoded.
The pre-op data is filled in when the incoming fh is locked, and the
post-op data is filled in when the fh is unlocked.

Unfortunately, for REMOVE, RMDIR, MKNOD, and MKDIR, the directory fh
is not unlocked until well after the reply has been XDR encoded. This
means that encode_wcc_data() does not have wcc_data for the parent
directory, so none is returned to the client after these operations
complete.

By unlocking the parent directory fh immediately after the internal
operations for each NFS procedure is complete, the post-op data is
filled in before XDR encoding starts, so it can be returned to the
client properly.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

nfsd: remove pointless paths in file headers

The new .h files have paths at the top that are now out of date. While
we're here, just remove all of those from fs/nfsd; they never served any
purpose.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

nfsd: Move private headers to source directory

Lots of include/linux/nfsd/* headers are only used by
nfsd module. Move them to the source directory

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

nfsd: Source files #include cleanups

Now that the headers are fixed and carry their own wait, all fs/nfsd/
source files can include a minimal set of headers. and still compile just
fine.

This patch should improve the compilation speed of the nfsd module.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

nfsd: make fs/nfsd/vfs.h for common includes

None of this stuff is used outside nfsd, so move it out of the common
linux include directory.

Actually, probably none of the stuff in include/linux/nfsd/nfsd.h really
belongs there, so later we may remove that file entirely.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

NFS: kill off complicated macro 'PROC'

kill off obscure macro 'PROC' of NFSv2&3 in order to make the code more clear.

Among other things, this makes it simpler to grep for callers of these
functions--something which has frequently caused confusion among nfs
developers.

Signed-off-by: Yu Zhiguo <yuzg@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Short write in nfsd becomes a full write to the client

If a filesystem being written to via NFS returns a short write count
(as opposed to an error) to nfsd, nfsd treats that as a success for
the entire write, rather than the short count that actually succeeded.

For example, given a 8192 byte write, if the underlying filesystem
only writes 4096 bytes, nfsd will ack back to the nfs client that all
8192 bytes were written. The nfs client does have retry logic for
short writes, but this is never called as the client is told the
complete write succeeded.

There are probably other ways it could happen, but in my case it
happened with a fuse (filesystem in userspace) filesystem which can
rather easily have a partial write.

Here is a patch to properly return the short write count to the
client.

Signed-off-by: David Shaw <dshaw@jabberwocky.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

NFSD: cleanup for nfs3proc.c

MSDOS_SUPER_MAGIC is defined in <linux/magic.h>,
so use MSDOS_SUPER_MAGIC directly.

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

nfsd: permit unauthenticated stat of export root

RFC 2623 section 2.3.2 permits the server to bypass gss authentication
checks for certain operations that a client may perform when mounting.
In the case of a client that doesn't have some form of credentials
available to it on boot, this allows it to perform the mount unattended.
(Presumably real file access won't be needed until a user with
credentials logs in.)

Being slightly more lenient allows lots of old clients to access
krb5-only exports, with the only loss being a small amount of
information leaked about the root directory of the export.

This affects only v2 and v3; v4 still requires authentication for all
access.

Thanks to Peter Staubach testing against a Solaris client, which
suggesting addition of v3 getattr, to the list, and to Trond for noting
that doing so exposes no additional information.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Peter Staubach <staubach@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>

nfsd: rename MAY_ flags

Rename nfsd_permission() specific MAY_* flags to NFSD_MAY_* to make it
clear, that these are not used outside nfsd, and to avoid name and
number space conflicts with the VFS.

[comment from hch: rename MAY_READ, MAY_WRITE and MAY_EXEC as well]

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

Use struct path in struct svc_export

I'm embedding struct path into struct svc_export.

[akpm@linux-foundation.org: coding-style fixes]
[ezk@cs.sunysb.edu: NFSD: fix wrong mnt_writer count in rename]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

RPC: add wrapper for svc_reserve to account for checksum

When the kernel calls svc_reserve to downsize the expected size of an RPC
reply, it fails to account for the possibility of a checksum at the end of
the packet. If a client mounts a NFSv2/3 with sec=krb5i/p, and does I/O
then you'll generally see messages similar to this in the server's ring
buffer:

RPC request reserved 164 but used 208

While I was never able to verify it, I suspect that this problem is also
the root cause of some oopses I've seen under these conditions:

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=227726

This is probably also a problem for other sec= types and for NFSv4. The
large reserved size for NFSv4 compound packets seems to generally paper
over the problem, however.

This patch adds a wrapper for svc_reserve that accounts for the possibility
of a checksum. It also fixes up the appropriate callers of svc_reserve to
call the wrapper. For now, it just uses a hardcoded value that I
determined via testing. That value may need to be revised upward as things
change, or we may want to eventually add a new auth_op that attempts to
calculate this somehow.

Unfortunately, there doesn't seem to be a good way to reliably determine
the expected checksum length prior to actually calculating it, particularly
with schemes like spkm3.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] nfsd4: fix open-create permissions

In the case where an open creates the file, we shouldn't be rechecking
permissions to open the file; the open succeeds regardless of what the new
file's mode bits say.

This patch fixes the problem, but only by introducing yet another parameter
to nfsd_create_v3. This is ugly. This will be fixed by later patches.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Neil Brown <neilb@suse.de>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] nfsd: NFSv{2,3} trivial endianness annotations for error values

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] fix svc_procfunc declaration

svc_procfunc instances return __be32, not int

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] knfsd: Prepare knfsd for support of rsize/wsize of up to 1MB, over TCP

The limit over UDP remains at 32K. Also, make some of the apparently
arbitrary sizing constants clearer.

The biggest change here involves replacing NFSSVC_MAXBLKSIZE by a function of
the rqstp. This allows it to be different for different protocols (udp/tcp)
and also allows it to depend on the servers declared sv_bufsiz.

Note that we don't actually increase sv_bufsz for nfs yet. That comes next.

Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] knfsd: Avoid excess stack usage in svc_tcp_recvfrom

.. by allocating the array of 'kvec' in 'struct svc_rqst'.

As we plan to increase RPCSVC_MAXPAGES from 8 upto 256, we can no longer
allocate an array of this size on the stack. So we allocate it in 'struct
svc_rqst'.

However svc_rqst contains (indirectly) an array of the same type and size
(actually several, but they are in a union). So rather than waste space, we
move those arrays out of the separately allocated union and into svc_rqst to
share with the kvec moved out of svc_tcp_recvfrom (various arrays are used at
different times, so there is no conflict).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] knfsd: Correct reserved reply space for read requests.

NFSd makes sure there is enough space to hold the maximum possible reply
before accepting a request. The units for this maximum is (4byte) words.
However in three places, particularly for read request, the number given is
a number of bytes.

This means too much space is reserved which is slightly wasteful.

This is the sort of patch that could uncover a deeper bug, and it is not
critical, so it would be best for it to spend a while in -mm before going
in to mainline.

(akpm: target 2.6.17-rc2, 2.6.16.3 (approx))

Discovered-by: "Eivind Sarto" <ivan@kasenna.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] knfsd: check error status from vfs_getattr and i_op->fsync

Both vfs_getattr and i_op->fsync return error statuses which nfsd was
largely ignoring. This as noticed when exporting directories using fuse.

This patch cleans up most of the offences, which involves moving the call
to vfs_getattr out of the xdr encoding routines (where it is too late to
report an error) into the main NFS procedure handling routines.

There is still a called to vfs_gettattr (related to the ACL code) where the
status is ignored, and called to nfsd_sync_dir don't check return status
either.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!