Commit Graph

305 Commits

Author SHA1 Message Date
Linus Torvalds
6dea0737bc Merge branch 'for-3.18' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
 "Highlights:

   - support the NFSv4.2 SEEK operation (allowing clients to support
     SEEK_HOLE/SEEK_DATA), thanks to Anna.
   - end the grace period early in a number of cases, mitigating a
     long-standing annoyance, thanks to Jeff
   - improve SMP scalability, thanks to Trond"

* 'for-3.18' of git://linux-nfs.org/~bfields/linux: (55 commits)
  nfsd: eliminate "to_delegation" define
  NFSD: Implement SEEK
  NFSD: Add generic v4.2 infrastructure
  svcrdma: advertise the correct max payload
  nfsd: introduce nfsd4_callback_ops
  nfsd: split nfsd4_callback initialization and use
  nfsd: introduce a generic nfsd4_cb
  nfsd: remove nfsd4_callback.cb_op
  nfsd: do not clear rpc_resp in nfsd4_cb_done_sequence
  nfsd: fix nfsd4_cb_recall_done error handling
  nfsd4: clarify how grace period ends
  nfsd4: stop grace_time update at end of grace period
  nfsd: skip subsequent UMH "create" operations after the first one for v4.0 clients
  nfsd: set and test NFSD4_CLIENT_STABLE bit to reduce nfsdcltrack upcalls
  nfsd: serialize nfsdcltrack upcalls for a particular client
  nfsd: pass extra info in env vars to upcalls to allow for early grace period end
  nfsd: add a v4_end_grace file to /proc/fs/nfsd
  lockd: add a /proc/fs/lockd/nlm_end_grace file
  nfsd: reject reclaim request when client has already sent RECLAIM_COMPLETE
  nfsd: remove redundant boot_time parm from grace_done client tracking op
  ...
2014-10-08 12:51:44 -04:00
J. Bruce Fields
15b23ef5d3 nfsd4: fix corruption of NFSv4 read data
The calculation of page_ptr here is wrong in the case the read doesn't
start at an offset that is a multiple of a page.

The result is that nfs4svc_encode_compoundres sets rq_next_page to a
value one too small, and then the loop in svc_free_res_pages may
incorrectly fail to clear a page pointer in rq_respages[].

Pages left in rq_respages[] are available for the next rpc request to
use, so xdr data may be written to that page, which may hold data still
waiting to be transmitted to the client or data in the page cache.

The observed result was silent data corruption seen on an NFSv4 client.

We tag this as "fixing" 05638dc73a because that commit exposed this
bug, though the incorrect calculation predates it.

Particular thanks to Andrea Arcangeli and David Gilbert for analysis and
testing.

Fixes: 05638dc73a "nfsd4: simplify server xdr->next_page use"
Cc: stable@vger.kernel.org
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Tested-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-30 15:57:04 -04:00
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
Anna Schumaker
87a15a8090 NFSD: Add generic v4.2 infrastructure
It's cleaner to introduce everything at once and have the server reply
with "not supported" than it would be to introduce extra operations when
implementing a specific one in the middle of the list.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-29 14:35:19 -04:00
J. Bruce Fields
aee3776441 nfsd4: fix rd_dircount enforcement
Commit 3b29970909 "nfsd4: enforce rd_dircount" totally misunderstood
rd_dircount; it refers to total non-attribute bytes returned, not number
of directory entries returned.

Bring the code into agreement with RFC 3530 section 14.2.24.

Cc: stable@vger.kernel.org
Fixes: 3b29970909 "nfsd4: enforce rd_dircount"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-09-08 12:02:03 -04:00
J. Bruce Fields
f7b43d0c99 nfsd4: reserve adequate space for LOCK op
As of  8c7424cff6 "nfsd4: don't try to encode conflicting owner if low
on space", we permit the server to process a LOCK operation even if
there might not be space to return the conflicting lockowner, because
we've made returning the conflicting lockowner optional.

However, the rpc server still wants to know the most we might possibly
return, so we need to take into account the possible conflicting
lockowner in the svc_reserve_space() call here.

Symptoms were log messages like "RPC request reserved 88 but used 108".

Fixes: 8c7424cff6 "nfsd4: don't try to encode conflicting owner if low on space"
Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-17 12:00:14 -04:00
J. Bruce Fields
1383bf37ce nfsd4: remove obsolete comment
We do what Neil suggests now.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-17 12:00:14 -04:00
Linus Torvalds
0d10c2c170 Merge branch 'for-3.17' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
 "This includes a major rewrite of the NFSv4 state code, which has
  always depended on a single mutex.  As an example, open creates are no
  longer serialized, fixing a performance regression on NFSv3->NFSv4
  upgrades.  Thanks to Jeff, Trond, and Benny, and to Christoph for
  review.

  Also some RDMA fixes from Chuck Lever and Steve Wise, and
  miscellaneous fixes from Kinglong Mee and others"

* 'for-3.17' of git://linux-nfs.org/~bfields/linux: (167 commits)
  svcrdma: remove rdma_create_qp() failure recovery logic
  nfsd: add some comments to the nfsd4 object definitions
  nfsd: remove the client_mutex and the nfs4_lock/unlock_state wrappers
  nfsd: remove nfs4_lock_state: nfs4_state_shutdown_net
  nfsd: remove nfs4_lock_state: nfs4_laundromat
  nfsd: Remove nfs4_lock_state(): reclaim_complete()
  nfsd: Remove nfs4_lock_state(): setclientid, setclientid_confirm, renew
  nfsd: Remove nfs4_lock_state(): exchange_id, create/destroy_session()
  nfsd: Remove nfs4_lock_state(): nfsd4_open and nfsd4_open_confirm
  nfsd: Remove nfs4_lock_state(): nfsd4_delegreturn()
  nfsd: Remove nfs4_lock_state(): nfsd4_open_downgrade + nfsd4_close
  nfsd: Remove nfs4_lock_state(): nfsd4_lock/locku/lockt()
  nfsd: Remove nfs4_lock_state(): nfsd4_release_lockowner
  nfsd: Remove nfs4_lock_state(): nfsd4_test_stateid/nfsd4_free_stateid
  nfsd: Remove nfs4_lock_state(): nfs4_preprocess_stateid_op()
  nfsd: remove old fault injection infrastructure
  nfsd: add more granular locking to *_delegations fault injectors
  nfsd: add more granular locking to forget_openowners fault injector
  nfsd: add more granular locking to forget_locks fault injector
  nfsd: add a list_head arg to nfsd_foreach_client_lock
  ...
2014-08-09 14:31:18 -07:00
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
Kinglong Mee
f98bac5a30 NFSD: Fix crash encoding lock reply on 32-bit
Commit 8c7424cff6 "nfsd4: don't try to encode conflicting owner if low
on space" forgot to free conf->data in nfsd4_encode_lockt and before
sign conf->data to NULL in nfsd4_encode_lock_denied, causing a leak.

Worse, kfree() can be called on an uninitialized pointer in the case of
a succesful lock (or one that fails for a reason other than a conflict).

(Note that lock->lk_denied.ld_owner.data appears it should be zero here,
until you notice that it's one arm of a union the other arm of which is
written to in the succesful case by the

	memcpy(&lock->lk_resp_stateid, &lock_stp->st_stid.sc_stateid,
	                                sizeof(stateid_t));

in nfsd4_lock().  In the 32-bit case this overwrites ld_owner.data.)

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Fixes: 8c7424cff6 ""nfsd4: don't try to encode conflicting owner if low on space"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-23 10:31:56 -04:00
J. Bruce Fields
5d6031ca74 nfsd4: zero op arguments beyond the 8th compound op
The first 8 ops of the compound are zeroed since they're a part of the
argument that's zeroed by the

	memset(rqstp->rq_argp, 0, procp->pc_argsize);

in svc_process_common().  But we handle larger compounds by allocating
the memory on the fly in nfsd4_decode_compound().  Other than code
recently fixed by 01529e3f81 "NFSD: Fix memory leak in encoding denied
lock", I don't know of any examples of code depending on this
initialization. But it definitely seems possible, and I'd rather be
safe.

Compounds this long are unusual so I'm much more worried about failure
in this poorly tested cases than about an insignificant performance hit.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-17 16:20:39 -04:00
Kinglong Mee
d5d5c304b1 NFSD: Fix bad checking of space for padding in splice read
Note that the caller has already reserved space for count and eof, so
xdr->p has already moved past them, only the padding remains.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Fixes dc97618ddd (nfsd4: separate splice and readv cases)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-11 15:19:25 -04:00
Kinglong Mee
01529e3f81 NFSD: Fix memory leak in encoding denied lock
Commit 8c7424cff6 (nfsd4: don't try to encode conflicting owner if low on space)
forgot free conf->data in nfsd4_encode_lockt and before sign conf->data to NULL
in nfsd4_encode_lock_denied.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-09 20:55:08 -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
Kinglong Mee
1055414fe1 NFSD: Avoid warning message when compile at i686 arch
fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_readv':
>> fs/nfsd/nfs4xdr.c:3137:148: warning: comparison of distinct pointer types lacks a cast [enabled by default]
thislen = min(len, ((void *)xdr->end - (void *)xdr->p));

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:28 -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
bcaab953b1 nfsd4: remove nfs4_acl_new
This is a not-that-useful kmalloc wrapper.  And I'd like one of the
callers to actually use something other than kmalloc.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:27 -04:00
J. Bruce Fields
29c353b3fe nfsd4: define svcxdr_dupstr to share some common code
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:26 -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
b829e9197a nfsd: fix rare symlink decoding bug
An NFS operation that creates a new symlink includes the symlink data,
which is xdr-encoded as a length followed by the data plus 0 to 3 bytes
of zero-padding as required to reach a 4-byte boundary.

The vfs, on the other hand, wants null-terminated data.

The simple way to handle this would be by copying the data into a newly
allocated buffer with space for the final null.

The current nfsd_symlink code tries to be more clever by skipping that
step in the (likely) case where the byte following the string is already
0.

But that assumes that the byte following the string is ours to look at.
In fact, it might be the first byte of a page that we can't read, or of
some object that another task might modify.

Worse, the NFSv4 code tries to fix the problem by actually writing to
that byte.

In the NFSv2/v3 cases this actually appears to be safe:

	- nfs3svc_decode_symlinkargs explicitly null-terminates the data
	  (after first checking its length and copying it to a new
	  page).
	- NFSv2 limits symlinks to 1k.  The buffer holding the rpc
	  request is always at least a page, and the link data (and
	  previous fields) have maximum lengths that prevent the request
	  from reaching the end of a page.

In the NFSv4 case the CREATE op is potentially just one part of a long
compound so can end up on the end of a page if you're unlucky.

The minimal fix here is to copy and null-terminate in the NFSv4 case.
The nfsd_symlink() interface here seems too fragile, though.  It should
really either do the copy itself every time or just require a
null-terminated string.

Reported-by: Jeff Layton <jlayton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:22 -04:00
Kinglong Mee
c3a4561796 nfsd: Fix bad reserving space for encoding rdattr_error
Introduced by commit 561f0ed498 (nfsd4: allow large readdirs).

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-07 14:16:31 -04:00
Avi Kivity
69bbd9c7b9 nfs: fix nfs4d readlink truncated packet
XDR requires 4-byte alignment; nfs4d READLINK reply writes out the padding,
but truncates the packet to the padding-less size.

Fix by taking the padding into consideration when truncating the packet.

Symptoms:

	# ll /mnt/
	ls: cannot read symbolic link /mnt/test: Input/output error
	total 4
	-rw-r--r--. 1 root root  0 Jun 14 01:21 123456
	lrwxrwxrwx. 1 root root  6 Jul  2 03:33 test
	drwxr-xr-x. 1 root root  0 Jul  2 23:50 tmp
	drwxr-xr-x. 1 root root 60 Jul  2 23:44 tree

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
Fixes: 476a7b1f4b (nfsd4: don't treat readlink like a zero-copy operation)
Reviewed-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-02 17:37:13 -04:00
J. Bruce Fields
76f47128f9 nfsd: fix rare symlink decoding bug
An NFS operation that creates a new symlink includes the symlink data,
which is xdr-encoded as a length followed by the data plus 0 to 3 bytes
of zero-padding as required to reach a 4-byte boundary.

The vfs, on the other hand, wants null-terminated data.

The simple way to handle this would be by copying the data into a newly
allocated buffer with space for the final null.

The current nfsd_symlink code tries to be more clever by skipping that
step in the (likely) case where the byte following the string is already
0.

But that assumes that the byte following the string is ours to look at.
In fact, it might be the first byte of a page that we can't read, or of
some object that another task might modify.

Worse, the NFSv4 code tries to fix the problem by actually writing to
that byte.

In the NFSv2/v3 cases this actually appears to be safe:

	- nfs3svc_decode_symlinkargs explicitly null-terminates the data
	  (after first checking its length and copying it to a new
	  page).
	- NFSv2 limits symlinks to 1k.  The buffer holding the rpc
	  request is always at least a page, and the link data (and
	  previous fields) have maximum lengths that prevent the request
	  from reaching the end of a page.

In the NFSv4 case the CREATE op is potentially just one part of a long
compound so can end up on the end of a page if you're unlucky.

The minimal fix here is to copy and null-terminate in the NFSv4 case.
The nfsd_symlink() interface here seems too fragile, though.  It should
really either do the copy itself every time or just require a
null-terminated string.

Reported-by: Jeff Layton <jlayton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-06-27 16:10:46 -04:00
Kinglong Mee
3c7aa15d20 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>
2014-06-23 11:31:36 -04:00
Kinglong Mee
f41c5ad2ff NFSD: fix bug for readdir of pseudofs
Commit 561f0ed498 (nfsd4: allow large readdirs) introduces a bug
about readdir the root of pseudofs.

Call xdr_truncate_encode() revert encoded name when skipping.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-06-17 16:42:48 -04:00
J. Bruce Fields
542d1ab3c7 nfsd4: kill READ64
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-06-06 19:22:48 -04:00
J. Bruce Fields
06553991e7 nfsd4: kill READ32
While we're here, let's kill off a couple of the read-side macros.

Leaving the more complicated ones alone for now.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-06-06 19:22:47 -04:00
Jeff Layton
da2ebce6a0 nfsd: make nfsd4_encode_fattr static
sparse says:

      CHECK   fs/nfsd/nfs4xdr.c
    fs/nfsd/nfs4xdr.c:2043:1: warning: symbol 'nfsd4_encode_fattr' was not declared. Should it be static?

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 20:25:28 -04:00
Christoph Hellwig
12337901d6 nfsd: getattr for FATTR4_WORD0_FILES_AVAIL needs the statfs buffer
Note nobody's ever noticed because the typical client probably never
requests FILES_AVAIL without also requesting something else on the list.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:26 -04:00
Kinglong Mee
94eb36892d NFSD: Adds macro EX_UUID_LEN for exports uuid's length
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:19 -04:00
J. Bruce Fields
a5cddc885b nfsd4: better reservation of head space for krb5
RPC_MAX_AUTH_SIZE is scattered around several places.  Better to set it
once in the auth code, where this kind of estimate should be made.  And
while we're at it we can leave it zero when we're not using krb5i or
krb5p.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:17 -04:00
J. Bruce Fields
d05d5744ef nfsd4: kill write32, write64
And switch a couple other functions from the encode(&p,...) convention
to the p = encode(p,...) convention mostly used elsewhere.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:16 -04:00
J. Bruce Fields
0c0c267ba9 nfsd4: kill WRITEMEM
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:15 -04:00
J. Bruce Fields
b64c7f3bdf nfsd4: kill WRITE64
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:14 -04:00
J. Bruce Fields
c373b0a428 nfsd4: kill WRITE32
These macros just obscure what's going on.  Adopt the convention of the
client-side code.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:13 -04:00
J. Bruce Fields
c8f13d9775 nfsd4: really fix nfs4err_resource in 4.1 case
encode_getattr, for example, can return nfserr_resource to indicate it
ran out of buffer space.  That's not a legal error in the 4.1 case.
And in the 4.1 case, if we ran out of buffer space, we should have
exceeded a session limit too.

(Note in 1bc49d83c3 "nfsd4: fix
nfs4err_resource in 4.1 case" we originally tried fixing this error
return before fixing the problem that we could error out while we still
had lots of available space.  The result was to trade one illegal error
for another in those cases.  We decided that was helpful, so reverted
the change in fc208d026b, and are only
reinstating it now that we've elimited almost all of those cases.)

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:13 -04:00
J. Bruce Fields
b042098063 nfsd4: allow exotic read compounds
I'm not sure why a client would want to stuff multiple reads in a
single compound rpc, but it's legal for them to do it, and we should
really support it.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:12 -04:00
J. Bruce Fields
fec25fa4ad nfsd4: more read encoding cleanup
More cleanup, no change in functionality.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:11 -04:00
J. Bruce Fields
34a78b488f nfsd4: read encoding cleanup
Trivial cleanup, no change in functionality.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:10 -04:00
J. Bruce Fields
dc97618ddd nfsd4: separate splice and readv cases
The splice and readv cases are actually quite different--for example the
former case ignores the array of vectors we build up for the latter.

It is probably clearer to separate the two cases entirely.

There's some code duplication between the split out encoders, but this
is only temporary and will be fixed by a later patch.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:09 -04:00
J. Bruce Fields
b0e35fda82 nfsd4: turn off zero-copy-read in exotic cases
We currently allow only one read per compound, with operations before
and after whose responses will require no more than about a page to
encode.

While we don't expect clients to violate those limits any time soon,
this limitation isn't really condoned by the spec, so to future proof
the server we should lift the limitation.

At the same time we'd like to continue to support zero-copy reads.

Supporting multiple zero-copy-reads per compound would require a new
data structure to replace struct xdr_buf, which can represent only one
set of included pages.

So for now we plan to modify encode_read() to support either zero-copy
or non-zero-copy reads, and use some heuristics at the start of the
compound processing to decide whether a zero-copy read will work.

This will allow us to support more exotic compounds without introducing
a performance regression in the normal case.

Later patches handle those "exotic compounds", this one just makes sure
zero-copy is turned off in those cases.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:08 -04:00
J. Bruce Fields
476a7b1f4b nfsd4: don't treat readlink like a zero-copy operation
There's no advantage to this zero-copy-style readlink encoding, and it
unnecessarily limits the kinds of compounds we can handle.  (In practice
I can't see why a client would want e.g. multiple readlink calls in a
comound, but it's probably a spec violation for us not to handle it.)

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:05 -04:00
J. Bruce Fields
3b29970909 nfsd4: enforce rd_dircount
As long as we're here, let's enforce the protocol's limit on the number
of directory entries to return in a readdir.

I don't think anyone's ever noticed our lack of enforcement, but maybe
there's more of a chance they will now that we allow larger readdirs.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:04 -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
47ee529864 nfsd4: adjust buflen to session channel limit
We can simplify session limit enforcement by restricting the xdr buflen
to the session size.

Also fix a preexisting bug: we should really have been taking into
account the auth-required space when comparing against session limits,
which are limits on the size of the entire rpc reply, including any krb5
overhead.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:02 -04:00
J. Bruce Fields
30596768b3 nfsd4: fix buflen calculation after read encoding
We don't necessarily want to assume that the buflen is the same
as the number of bytes available in the pages.  We may have some reason
to set it to something less (for example, later patches will use a
smaller buflen to enforce session limits).

So, calculate the buflen relative to the previous buflen instead of
recalculating it from scratch.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:00 -04:00
J. Bruce Fields
89ff884ebb nfsd4: nfsd4_check_resp_size should check against whole buffer
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:31:59 -04:00
J. Bruce Fields
6ff9897d2b nfsd4: minor encode_read cleanup
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:31:58 -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