Returning an undecorated integer is an age-old trope, but it's
not clear (even to previous experts in this code) that the only
valid return values are 1 and 0. These functions do not return
a negative errno, rpc_stat value, or a positive length.
Document there are only two valid return values by having
.pc_encode return only true or false.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The passed-in value of the "__be32 *p" parameter is now unused in
every server-side XDR encoder, and can be removed.
Note also that there is a line in each encoder that sets up a local
pointer to a struct xdr_stream. Passing that pointer from the
dispatcher instead saves one line per encoder function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Returning an undecorated integer is an age-old trope, but it's
not clear (even to previous experts in this code) that the only
valid return values are 1 and 0. These functions do not return
a negative errno, rpc_stat value, or a positive length.
Document there are only two valid return values by having
.pc_decode return only true or false.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The passed-in value of the "__be32 *p" parameter is now unused in
every server-side XDR decoder, and can be removed.
Note also that there is a line in each decoder that sets up a local
pointer to a struct xdr_stream. Passing that pointer from the
dispatcher instead saves one line per decoder function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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>
Most of the fields in 'struct knfsd_fh' are 2 levels deep (a union and a
struct) and are accessed using macros like:
#define fh_FOO fh_base.fh_new.fb_FOO
This patch makes the union and struct anonymous, so that "fh_FOO" can be
a name directly within 'struct knfsd_fh' and the #defines aren't needed.
The file handle as a whole is sometimes accessed as "fh_base" or
"fh_base.fh_pad", neither of which are particularly helpful names.
As the struct holding the filehandle is now anonymous, we
cannot use the name of that, so we union it with 'fh_raw' and use that
where the raw filehandle is needed. fh_raw also ensure the structure is
large enough for the largest possible filehandle.
fh_raw is a 'char' array, removing any need to cast it for memcpy etc.
SVCFH_fmt() is simplified using the "%ph" printk format. This
changes the appearance of filehandles in dprintk() debugging, making
them a little more precise.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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>
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>
Refactor: De-duplicate identical code that handles encoding of
directory offset cookies across page boundaries.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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>
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>
In the typical case of v4 and an i_version-supporting filesystem, we can
skip a stat which is only required to fake up a change attribute from
ctime.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit removes the last usage of the original decode_sattr3(),
so it is removed as a clean-up.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Similar to the WRITE decoder, code that checks the sanity of the
payload size is re-wired to work with xdr_stream infrastructure.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
As an additional clean up, neither nfsd3_proc_readdir() nor
nfsd3_proc_readdirplus() make use of the dircount argument, so
remove it from struct nfsd3_readdirargs.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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>
As part of the update, open code that sanity-checks the size of the
data payload against the length of the RPC Call message has to be
re-implemented to use xdr_stream infrastructure.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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>
If you export a subdirectory of a filesystem, a READDIRPLUS on the root
of that export will return the filehandle of the parent with the ".."
entry.
The filehandle is optional, so let's just not return the filehandle for
".." if we're at the root of an export.
Note that once the client learns one filehandle outside of the export,
they can trivially access the rest of the export using further lookups.
However, it is also not very difficult to guess filehandles outside of
the export. So exporting a subdirectory of a filesystem should
considered equivalent to providing access to the entire filesystem. To
avoid confusion, we recommend only exporting entire filesystems.
Reported-by: Youjipeng <wangzhibei1999@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
With NFSv3 nfsd will always attempt to send along WCC data to the
client. This generally involves saving off the in-core inode information
prior to doing the operation on the given filehandle, and then issuing a
vfs_getattr to it after the op.
Some filesystems (particularly clustered or networked ones) have an
expensive ->getattr inode operation. Atomicity is also often difficult
or impossible to guarantee on such filesystems. For those, we're best
off not trying to provide WCC information to the client at all, and to
simply allow it to poll for that information as needed with a GETATTR
RPC.
This patch adds a new flags field to struct export_operations, and
defines a new EXPORT_OP_NOWCC flag that filesystems can use to indicate
that nfsd should not attempt to provide WCC info in NFSv3 replies. It
also adds a blurb about the new flags field and flag to the exporting
documentation.
The server will also now skip collecting this information for NFSv2 as
well, since that info is never used there anyway.
Note that this patch does not add this flag to any filesystem
export_operations structures. This was originally developed to allow
reexporting nfs via nfsd.
Other filesystems may want to consider enabling this flag too. It's hard
to tell however which ones have export operations to enable export via
knfsd and which ones mostly rely on them for open-by-filehandle support,
so I'm leaving that up to the individual maintainers to decide. I am
cc'ing the relevant lists for those filesystems that I think may want to
consider adding this though.
Cc: HPDD-discuss@lists.01.org
Cc: ceph-devel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: fuse-devel@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
inode_query_iversion() has side effects, and there's no point calling it
when we're not even going to use it.
We check whether we're currently processing a v4 request by checking
fh_maxsize, which is arguably a little hacky; we could add a flag to
svc_fh instead.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Chuck Lever
NeilBrown
J. Bruce Fields
Jeff Layton