Commit Graph

85 Commits

Author SHA1 Message Date
Chuck Lever
eae03e2ac8 nfsd: Incoming xdr_bufs may have content in tail buffer
Since the beginning, svcsock has built a received RPC Call message
by populating the xdr_buf's head, then placing the remaining
message bytes in the xdr_buf's page list. The xdr_buf's tail is
never populated.

This means that an NFSv4 COMPOUND containing an NFS WRITE operation
plus trailing operations has a page list that contains the WRITE
data payload followed by the trailing operations. NFSv4 XDR decoders
will not look in the xdr_buf's tail, ever, because svcsock never put
anything there.

To support transports that can pass the write payload in the
xdr_buf's pagelist and trailing content in the xdr_buf's tail,
introduce logic in READ_BUF that switches to the xdr_buf's tail vec
when the decoder runs out of content in rq_arg.pages.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-09-05 15:15:29 -04:00
J. Bruce Fields
b7571e4cd3 nfsd4: skip encoder in trivial error cases
Most encoders do nothing in the error case.  But they can still screw
things up in that case: most errors happen very early in rpc processing,
possibly before argument fields are filled in and bounds-tested, so
encoders that do anything other than immediately bail on error can
easily crash in odd error cases.

So just handle errors centrally most of the time to remove the chance of
error.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-08-24 22:12:48 -04:00
J. Bruce Fields
34b1744c91 nfsd4: define ->op_release for compound ops
Run a separate ->op_release function if necessary instead of depending
on the xdr encoder to do this.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-08-24 22:12:48 -04:00
J. Bruce Fields
f4f9ef4a1b nfsd4: opdesc will be useful outside nfs4proc.c
Trivial cleanup, no change in behavior.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-08-24 21:12:20 -04:00
J. Bruce Fields
0020939f20 nfsd4: move some nfsd4 op definitions to xdr4.h
I want code in nfs4xdr.c to have access to this stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-08-01 17:36:35 -04:00
Christoph Hellwig
eb69853da9 nfsd4: properly type op_func callbacks
Pass union nfsd4_op_u to the op_func callbacks instead of using unsafe
function pointer casts.

It also adds two missing structures to struct nfsd4_op.u to facilitate
this.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15 17:42:29 +02:00
Christoph Hellwig
b60e985980 nfsd4: properly type op_set_currentstateid callbacks
Given the args union in struct nfsd4_op a name, and pass it to the
op_set_currentstateid callbacks instead of using unsafe function
pointer casts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15 17:42:27 +02:00
Christoph Hellwig
63f8de3795 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>
2017-05-15 17:42:25 +02:00
Christoph Hellwig
026fec7e7c 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>
2017-05-15 17:42:24 +02:00
Christoph Hellwig
8537488b5a 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>
2017-05-15 17:42:23 +02:00
Anna Schumaker
29ae7f9dc2 NFSD: Implement the COPY call
I only implemented the sync version of this call, since it's the
easiest.  I can simply call vfs_copy_range() and have the vfs do the
right thing for the filesystem being exported.

Signed-off-by: Anna Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-10-07 14:54:25 -04:00
Andrew Elble
ed94164398 nfsd: implement machine credential support for some operations
This addresses the conundrum referenced in RFC5661 18.35.3,
and will allow clients to return state to the server using the
machine credentials.

The biggest part of the problem is that we need to allow the client
to send a compound op with integrity/privacy on mounts that don't
have it enabled.

Add server support for properly decoding and using spo_must_enforce
and spo_must_allow bits. Add support for machine credentials to be
used for CLOSE, OPEN_DOWNGRADE, LOCKU, DELEGRETURN,
and TEST/FREE STATEID.
Implement a check so as to not throw WRONGSEC errors when these
operations are used if integrity/privacy isn't turned on.

Without this, Linux clients with credentials that expired while holding
delegations were getting stuck in an endless loop.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-13 15:32:47 -04:00
Andrew Elble
dedeb13f9e nfsd: allow mach_creds_match to be used more broadly
Rename mach_creds_match() to nfsd4_mach_creds_match() and un-staticify

Signed-off-by: Andrew Elble <aweits@rit.edu>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-13 15:32:47 -04:00
Christoph Hellwig
ffa0160a10 nfsd: implement the NFSv4.2 CLONE operation
This is basically a remote version of the btrfs CLONE operation,
so the implementation is fairly trivial.  Made even more trivial
by stealing the XDR code and general framework Anna Schumaker's
COPY prototype.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-07 23:12:00 -05:00
Jeff Layton
aaf91ec148 nfsd: switch unsigned char flags in svc_fh to bools
...just for clarity.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-10-12 17:31:04 -04:00
Christoph Hellwig
af90f707fa nfsd: take struct file setup fully into nfs4_preprocess_stateid_op
This patch changes nfs4_preprocess_stateid_op so it always returns
a valid struct file if it has been asked for that.  For that we
now allocate a temporary struct file for special stateids, and check
permissions if we got the file structure from the stateid.  This
ensures that all callers will get their handling of special stateids
right, and avoids code duplication.

There is a little wart in here because the read code needs to know
if we allocated a file structure so that it can copy around the
read-ahead parameters.  In the long run we should probably aim to
cache full file structures used with special stateids instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-22 14:15:03 -04:00
Sachin Bhamare
8287f009bd nfsd: fix pNFS return on close semantics
For the sake of forgetful clients, the server should return the layouts
to the file system on 'last close' of a file (assuming that there are no
delegations outstanding to that particular client) or on delegreturn
(assuming that there are no opens on a file from that particular
client).

In theory the information is all there in current data structures, but
it's not efficiently available; nfs4_file->fi_ref includes references on
the file across all clients, but we need a per-(client, file) count.
Walking through lots of stateid's to calculate this on each close or
delegreturn would be painful.

This patch introduces infrastructure to maintain per-client opens and
delegation counters on a per-file basis.

[hch: ported to the mainline pNFS support, merged various fixes from Jeff]
Signed-off-by: Sachin Bhamare <sachin.bhamare@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-05-04 12:02:39 -04:00
Linus Torvalds
9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
David Howells
2b0143b5c9 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>
2015-04-15 15:06:57 -04:00
Kinglong Mee
1ec8c0c47f nfsd: Remove duplicate macro define for max sec label length
NFS4_MAXLABELLEN has defined for sec label max length, use it directly.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-03-31 16:46:39 -04:00
Jeff Layton
4229789993 nfsd: remove unused status arg to nfsd4_cleanup_open_state
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-03-31 16:46:39 -04:00
Christoph Hellwig
9cf514ccfa nfsd: implement pNFS operations
Add support for the GETDEVICEINFO, LAYOUTGET, LAYOUTCOMMIT and
LAYOUTRETURN NFSv4.1 operations, as well as backing code to manage
outstanding layouts and devices.

Layout management is very straight forward, with a nfs4_layout_stateid
structure that extends nfs4_stid to manage layout stateids as the
top-level structure.  It is linked into the nfs4_file and nfs4_client
structures like the other stateids, and contains a linked list of
layouts that hang of the stateid.  The actual layout operations are
implemented in layout drivers that are not part of this commit, but
will be added later.

The worst part of this commit is the management of the pNFS device IDs,
which suffers from a specification that is not sanely implementable due
to the fact that the device-IDs are global and not bound to an export,
and have a small enough size so that we can't store the fsid portion of
a file handle, and must never be reused.  As we still do need perform all
export authentication and validation checks on a device ID passed to
GETDEVICEINFO we are caught between a rock and a hard place.  To work
around this issue we add a new hash that maps from a 64-bit integer to a
fsid so that we can look up the export to authenticate against it,
a 32-bit integer as a generation that we can bump when changing the device,
and a currently unused 32-bit integer that could be used in the future
to handle more than a single device per export.  Entries in this hash
table are never deleted as we can't reuse the ids anyway, and would have
a severe lifetime problem anyway as Linux export structures are temporary
structures that can go away under load.

Parts of the XDR data, structures and marshaling/unmarshaling code, as
well as many concepts are derived from the old pNFS server implementation
from Andy Adamson, Benny Halevy, Dean Hildebrand, Marc Eshel, Fred Isaman,
Mike Sager, Ricardo Labiaga and many others.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-02 18:09:42 +01:00
Anna Schumaker
b0cb908523 nfsd: Add DEALLOCATE support
DEALLOCATE only returns a status value, meaning we can use the noop()
xdr encoder to reply to the client.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-11-07 16:20:15 -05:00
Anna Schumaker
95d871f03c nfsd: Add ALLOCATE support
The ALLOCATE operation is used to preallocate space in a file.  I can do
this by using vfs_fallocate() to do the actual preallocation.

ALLOCATE only returns a status indicator, so we don't need to write a
special encode() function.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-11-07 16:19:49 -05:00
Anna Schumaker
24bab49122 NFSD: Implement SEEK
This patch adds server support for the NFS v4.2 operation SEEK, which
returns the position of the next hole or data segment in a file.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-29 14:35:20 -04:00
Jeff Layton
58fb12e6a4 nfsd: Add a mutex to protect the NFSv4.0 open owner replay cache
We don't want to rely on the client_mutex for protection in the case of
NFSv4 open owners. Instead, we add a mutex that will only be taken for
NFSv4.0 state mutating operations, and that will be released once the
entire compound is done.

Also, ensure that nfsd4_cstate_assign_replay/nfsd4_cstate_clear_replay
take a reference to the stateowner when they are using it for NFSv4.0
open and lock replay caching.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-31 14:20:19 -04:00
Jeff Layton
4b24ca7d30 nfsd: Allow struct nfsd4_compound_state to cache the nfs4_client
We want to use the nfsd4_compound_state to cache the nfs4_client in
order to optimise away extra lookups of the clid.

In the v4.0 case, we use this to ensure that we only have to look up the
client at most once per compound for each call into lookup_clientid. For
v4.1+ we set the pointer in the cstate during SEQUENCE processing so we
should never need to do a search for it.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-09 20:55:04 -04:00
Trond Myklebust
b607664ee7 nfsd: Cleanup nfs4svc_encode_compoundres
Move the slot return, put session etc into a helper in fs/nfsd/nfs4state.c
instead of open coding in nfs4svc_encode_compoundres.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:34 -04:00
J. Bruce Fields
d5e2338324 nfsd4: replace defer_free by svcxdr_tmpalloc
Avoid an extra allocation for the tmpbuf struct itself, and stop
ignoring some allocation failures.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:27 -04:00
J. Bruce Fields
ce043ac826 nfsd4: remove unused defer_free argument
28e05dd845 "knfsd: nfsd4: represent nfsv4 acl with array instead of
linked list" removed the last user that wanted a custom free function.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:25 -04:00
J. Bruce Fields
7fb84306f5 nfsd4: rename cr_linkname->cr_data
The name of a link is currently stored in cr_name and cr_namelen, and
the content in cr_linkname and cr_linklen.  That's confusing.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:24 -04:00
J. Bruce Fields
561f0ed498 nfsd4: allow large readdirs
Currently we limit readdir results to a single page.  This can result in
a performance regression compared to NFSv3 when reading large
directories.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:03 -04:00
J. Bruce Fields
4f0cefbf38 nfsd4: more precise nfsd4_max_reply
It will turn out to be useful to have a more accurate estimate of reply
size; so, piggyback on the existing op reply-size estimators.

Also move nfsd4_max_reply to nfs4proc.c to get easier access to struct
nfsd4_operation and friends.  (Thanks to Christoph Hellwig for pointing
out that simplification.)

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:31:57 -04:00
J. Bruce Fields
f5236013a2 nfsd4: convert 4.1 replay encoding
Limits on maxresp_sz mean that we only ever need to replay rpc's that
are contained entirely in the head.

The one exception is very small zero-copy reads.  That's an odd corner
case as clients wouldn't normally ask those to be cached.

in any case, this seems a little more robust.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:31:55 -04:00
J. Bruce Fields
d0a381dd0e nfsd4: teach encoders to handle reserve_space failures
We've tried to prevent running out of space with COMPOUND_SLACK_SPACE
and special checking in those operations (getattr) whose result can vary
enormously.

However:
	- COMPOUND_SLACK_SPACE may be difficult to maintain as we add
	  more protocol.
	- BUG_ON or page faulting on failure seems overly fragile.
	- Especially in the 4.1 case, we prefer not to fail compounds
	  just because the returned result came *close* to session
	  limits.  (Though perfect enforcement here may be difficult.)
	- I'd prefer encoding to be uniform for all encoders instead of
	  having special exceptions for encoders containing, for
	  example, attributes.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:31:49 -04:00
J. Bruce Fields
07d1f80207 nfsd4: fix encoding of out-of-space replies
If nfsd4_check_resp_size() returns an error then we should really be
truncating the reply here, otherwise we may leave extra garbage at the
end of the rpc reply.

Also add a warning to catch any cases where our reply-size estimates may
be wrong in the case of a non-idempotent operation.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-27 11:09:08 -04:00
J. Bruce Fields
d518465866 nfsd4: tweak nfsd4_encode_getattr to take xdr_stream
Just change the nfsd4_encode_getattr api.  Not changing any code or
adding any new functionality yet.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-23 09:03:46 -04:00
J. Bruce Fields
4aea24b2ff nfsd4: embed xdr_stream in nfsd4_compoundres
This is a mechanical transformation with no change in behavior.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-23 09:03:45 -04:00
J. Bruce Fields
3ca2eb9814 nfsd4: nfsd4_replay_cache_entry should be static
This isn't actually used anywhere else.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-03-28 21:24:51 -04:00
Kinglong Mee
3ff69309fe Define op_iattr for nfsd4_open instead using macro
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-01-06 12:23:32 -05:00
Kinglong Mee
43212cc7df nfsd: using nfsd4_encode_noop for encoding destroy_session/free_stateid
Get rid of the extra code, using nfsd4_encode_noop for encoding destroy_session and free_stateid.
And, delete unused argument (fr_status) int nfsd4_free_stateid.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-01-03 13:44:22 -05:00
David Quigley
18032ca062 NFSD: Server implementation of MAC Labeling
Implement labeled NFS on the server: encoding and decoding, and writing
and reading, of file labels.

Enabled with CONFIG_NFSD_V4_SECURITY_LABEL.

Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-05-15 09:27:02 -04:00
J. Bruce Fields
9411b1d4c7 nfsd4: cleanup handling of nfsv4.0 closed stateid's
Closed stateid's are kept around a little while to handle close replays
in the 4.0 case.  So we stash them in the last-used stateid in the
oo_last_closed_stateid field of the open owner.  We can free that in
encode_seqid_op_tail once the seqid on the open owner is next
incremented.  But we don't want to do that on the close itself; so we
set NFS4_OO_PURGE_CLOSE flag set on the open owner, skip freeing it the
first time through encode_seqid_op_tail, then when we see that flag set
next time we free it.

This is unnecessarily baroque.

Instead, just move the logic that increments the seqid out of the xdr
code and into the operation code itself.

The justification given for the current placement is that we need to
wait till the last minute to be sure we know whether the status is a
sequence-id-mutating error or not, but examination of the code shows
that can't actually happen.

Reported-by: Yanchuan Nian <ycnian@gmail.com>
Tested-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-08 09:55:32 -04:00
Yanchuan Nian
9c6bdbb8dd nfsd: remove unused macro in nfsv4
lk_rflags is never used anywhere, and rflags is not defined in struct
nfsd4_lock.

Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03 11:48:33 -04:00
J. Bruce Fields
9d313b17db nfsd4: handle seqid-mutating open errors from xdr decoding
If a client sets an owner (or group_owner or acl) attribute on open for
create, and the mapping of that owner to an id fails, then we return
BAD_OWNER.  But BAD_OWNER is a seqid-mutating error, so we can't
shortcut the open processing that case: we have to at least look up the
owner so we can find the seqid to bump.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03 11:47:53 -04:00
J. Bruce Fields
84822d0b3b nfsd4: simplify nfsd4_encode_fattr interface slightly
It seems slightly simpler to make nfsd4_encode_fattr rather than its
callers responsible for advancing the write pointer on success.

(Also: the count == 0 check in the verify case looks superfluous.
Running out of buffer space is really the only reason fattr encoding
should fail with eresource.)

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-01-23 18:17:35 -05:00
J. Bruce Fields
9b3234b922 nfsd4: disable zero-copy on non-final read ops
To ensure ordering of read data with any following operations, turn off
zero copy if the read is not the final operation in the compound.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-12-17 16:02:41 -05:00
J. Bruce Fields
ffe1137ba7 nfsd4: delay filling in write iovec array till after xdr decoding
Our server rejects compounds containing more than one write operation.
It's unclear whether this is really permitted by the spec; with 4.0,
it's possibly OK, with 4.1 (which has clearer limits on compound
parameters), it's probably not OK.  No client that we're aware of has
ever done this, but in theory it could be useful.

The source of the limitation: we need an array of iovecs to pass to the
write operation.  In the worst case that array of iovecs could have
hundreds of elements (the maximum rwsize divided by the page size), so
it's too big to put on the stack, or in each compound op.  So we instead
keep a single such array in the compound argument.

We fill in that array at the time we decode the xdr operation.

But we decode every op in the compound before executing any of them.  So
once we've used that array we can't decode another write.

If we instead delay filling in that array till the time we actually
perform the write, we can reuse it.

Another option might be to switch to decoding compound ops one at a
time.  I considered doing that, but it has a number of other side
effects, and I'd rather fix just this one problem for now.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-11-26 09:08:15 -05:00
J. Bruce Fields
70cc7f75b1 nfsd4: move more write parameters into xdr argument
In preparation for moving some of this elsewhere.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-11-26 09:08:14 -05:00
Stanislav Kinsbursky
3320fef19b nfsd: use service net instead of hard-coded init_net
This patch replaces init_net by SVC_NET(), where possible and also passes
proper context to nested functions where required.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-11-15 07:40:50 -05:00