Commit Graph

737 Commits

Author SHA1 Message Date
Jeff Layton
7077ecbabd nfsd: add support for NFSv4 callbacks over IPv6
The framework to add this is all in place. Now, add the code to allow
support for establishing a callback channel on an IPv6 socket.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-08-21 11:27:44 -04:00
Jeff Layton
aa9a4ec770 nfsd: convert nfs4_cb_conn struct to hold address in sockaddr_storage
...rather than as a separate address and port fields. This will be
necessary for implementing callbacks over IPv6. Also, convert
gen_callback to use the standard rpcuaddr2sockaddr routine rather than
its own private one.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-08-21 11:27:43 -04:00
Jeff Layton
363168b4ea nfsd: make nfs4_client->cl_addr a struct sockaddr_storage
It's currently a __be32, which isn't big enough to hold an IPv6 address.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-08-21 11:27:43 -04:00
J. Bruce Fields
e9dc122166 Merge branch 'nfs-for-2.6.32' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6 into for-2.6.32-incoming
Conflicts:
	net/sunrpc/cache.c
2009-08-21 11:27:29 -04:00
Trond Myklebust
f884dcaead Merge branch 'sunrpc_cache-for-2.6.32' into nfs-for-2.6.32 2009-08-10 17:45:58 -04:00
Trond Myklebust
bc74b4f5e6 SUNRPC: Allow the cache_detail to specify alternative upcall mechanisms
For events that are rare, such as referral DNS lookups, it makes limited
sense to have a daemon constantly listening for upcalls on a channel. An
alternative in those cases might simply be to run the app that fills the
cache using call_usermodehelper_exec() and friends.

The following patch allows the cache_detail to specify alternative upcall
mechanisms for these particular cases.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:29 -04:00
Trond Myklebust
2da8ca26c6 NFSD: Clean up the idmapper warning...
What part of 'internal use' is so hard to understand?

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:14:26 -04:00
Chuck Lever
4116092b92 NFSD: Support IPv6 addresses in write_failover_ip()
In write_failover_ip(), replace the sscanf() with a call to the common
sunrpc.ko presentation address parser.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-08-09 15:09:40 -04:00
Andy Adamson
abfabf8caf nfsd41: encode replay sequence from the slot values
The sequence operation is not cached; always encode the sequence operation on
a replay from the slot table and session values. This simplifies the sessions
replay logic in nfsd4_proc_compound.

If this is a replay of a compound that was specified not to be cached, return
NFS4ERR_RETRY_UNCACHED_REP.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 16:12:34 -04:00
Andy Adamson
c8647947f8 nfsd41: rename nfsd4_enc_uncached_replay
This function is only used for SEQUENCE replay.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:30:36 -04:00
Andy Adamson
49557cc74c nfsd41: Use separate DRC for setclientid
Instead of trying to share the generic 4.1 reply cache code for the
CREATE_SESSION reply cache, it's simpler to handle CREATE_SESSION
separately.

The nfs41 single slot clientid DRC holds the results of create session
processing.  CREATE_SESSION can be preceeded by a SEQUENCE operation
(an embedded CREATE_SESSION) and the create session single slot cache must be
maintained.  nfsd4_replay_cache_entry() and nfsd4_store_cache_entry() do not
implement the replay of an embedded CREATE_SESSION.

The clientid DRC slot does not need the inuse, cachethis or other fields that
the multiple slot session cache uses.  Replace the clientid DRC cache struct
nfs4_slot cache with a new nfsd4_clid_slot cache.  Save the xdr struct
nfsd4_create_session into the cache at the end of processing, and on a replay,
replace the struct for the replay request with the cached version all while
under the state lock.

nfsd4_proc_compound will handle both the solo and embedded CREATE_SESSION case
via the normal use of encode_operation.

Errors that do not change the create session cache:
A create session NFS4ERR_STALE_CLIENTID error means that a client record
(and associated create session slot) could not be found and therefore can't
be changed.  NFSERR_SEQ_MISORDERED errors do not change the slot cache.

All other errors get cached.

Remove the clientid DRC specific check in nfs4svc_encode_compoundres to
put the session only if cstate.session is set which will now always be true.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:30:29 -04:00
Andy Adamson
88e588d56a nfsd41: change check_slot_seqid parameters
For separation of session slot and clientid slot processing.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:30:23 -04:00
Andy Adamson
5261dcf8eb nfsd41: remove redundant forechannel max requests check
This check is done in set_forechannel_maxreqs.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:30:15 -04:00
Andy Adamson
0c193054a4 nfsd41: hange from page to memory based drc limits
NFSD_SLOT_CACHE_SIZE is the size of all encoded operation responses
(excluding the sequence operation) that we want to cache.

For now, keep NFSD_SLOT_CACHE_SIZE at PAGE_SIZE. It will be reduced
when the DRC is changed from page based to memory based.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:30:05 -04:00
Andy Adamson
6a14dd1a4f nfsd41: reserve less memory for DRC
Also remove a slightly misleading comment.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:29:59 -04:00
Andy Adamson
b101ebbc39 nfsd41: minor set_forechannel_maxreqs cleanup
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:29:54 -04:00
Andy Adamson
be98d1bbd1 nfsd41: reclaim DRC memory on session free
This fixes a leak which would eventually lock out new clients.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:29:48 -04:00
J. Bruce Fields
413d63d710 nfsd: minor write_pool_threads exit cleanup
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:29:41 -04:00
Eric Sesterhenn
2522a776c1 Fix memory leak in write_pool_threads
kmemleak produces the following warning

unreferenced object 0xc9ec02a0 (size 8):
  comm "cat", pid 19048, jiffies 730243
  backtrace:
    [<c01bf970>] create_object+0x100/0x240
    [<c01bfadb>] kmemleak_alloc+0x2b/0x60
    [<c01bcd4b>] __kmalloc+0x14b/0x270
    [<c02fd027>] write_pool_threads+0x87/0x1d0
    [<c02fcc08>] nfsctl_transaction_write+0x58/0x70
    [<c02fcc6f>] nfsctl_transaction_read+0x4f/0x60
    [<c01c2574>] vfs_read+0x94/0x150
    [<c01c297d>] sys_read+0x3d/0x70
    [<c0102d6b>] sysenter_do_call+0x12/0x32
    [<ffffffff>] 0xffffffff

write_pool_threads() only frees nthreads on error paths, in the success case
we leak it.

Signed-off-by: Eric Sesterhenn <eric.sesterhenn@lsexperts.de>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-28 14:29:34 -04:00
Andy Adamson
4bd9b0f4af nfsd41: use globals for DRC limits
The version 4.1 DRC memory limit and tracking variables are server wide and
session specific. Replace struct svc_serv fields with globals.
Stop using the svc_serv sv_lock.

Add a spinlock to serialize access to the DRC limit management variables which
change on session creation and deletion (usage counter) or (future)
administrative action to adjust the total DRC memory limit.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-07-14 17:52:40 -04:00
Yu Zhiguo
9208faf297 NFSv4: ACL in operations 'open' and 'create' should be used
ACL in operations 'open' and 'create' is decoded but never be used.
It should be set as the initial ACL for the object according to RFC3530.
If error occurs when setting the ACL, just clear the ACL bit in the
returned attr bitmap.

Signed-off-by: Yu Zhiguo <yuzg@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-14 12:16:47 -04:00
Alexey Dobriyan
405f55712d headers: smp_lock.h redux
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-12 12:22:34 -07:00
David Howells
033a666ccb NFSD: Don't hold unrefcounted creds over call to nfsd_setuser()
nfsd_open() gets an unrefcounted pointer to the current process's effective
credentials at the top of the function, then calls nfsd_setuser() via
fh_verify() - which may replace and destroy the current process's effective
credentials - and then passes the unrefcounted pointer to dentry_open() - but
the credentials may have been destroyed by this point.

Instead, the value from current_cred() should be passed directly to
dentry_open() as one of its arguments, rather than being cached in a variable.

Possibly fh_verify() should return the creds to use.

This is a regression introduced by
745ca2475a "CRED: Pass credentials through
dentry_open()".

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-and-Verified-By: Steve Dickson <steved@redhat.com>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-07-03 10:21:10 -04:00
Linus Torvalds
7e0338c0de Merge branch 'for-2.6.31' of git://fieldses.org/git/linux-nfsd
* 'for-2.6.31' of git://fieldses.org/git/linux-nfsd: (60 commits)
  SUNRPC: Fix the TCP server's send buffer accounting
  nfsd41: Backchannel: minorversion support for the back channel
  nfsd41: Backchannel: cleanup nfs4.0 callback encode routines
  nfsd41: Remove ip address collision detection case
  nfsd: optimise the starting of zero threads when none are running.
  nfsd: don't take nfsd_mutex twice when setting number of threads.
  nfsd41: sanity check client drc maxreqs
  nfsd41: move channel attributes from nfsd4_session to a nfsd4_channel_attr struct
  NFS: kill off complicated macro 'PROC'
  sunrpc: potential memory leak in function rdma_read_xdr
  nfsd: minor nfsd_vfs_write cleanup
  nfsd: Pull write-gathering code out of nfsd_vfs_write
  nfsd: track last inode only in use_wgather case
  sunrpc: align cache_clean work's timer
  nfsd: Use write gathering only with NFSv2
  NFSv4: kill off complicated macro 'PROC'
  NFSv4: do exact check about attribute specified
  knfsd: remove unreported filehandle stats counters
  knfsd: fix reply cache memory corruption
  knfsd: reply cache cleanups
  ...
2009-06-22 12:55:50 -07:00
Andy Adamson
ab52ae6db0 nfsd41: Backchannel: minorversion support for the back channel
Prepare to share backchannel code with NFSv4.1.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[nfsd41: use nfsd4_cb_sequence for callback minorversion]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-18 18:33:57 -07:00
Andy Adamson
ef52bff840 nfsd41: Backchannel: cleanup nfs4.0 callback encode routines
Mimic the client and prepare to share the back channel xdr with NFSv4.1.
Bump the number of operations in each encode routine, then backfill the
number of operations.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-18 18:33:57 -07:00
Mike Sager
6ddbbbfe52 nfsd41: Remove ip address collision detection case
Verified that cthon and pynfs exchange id tests pass (except for the
two expected fails: EID8 and EID50)

Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-18 17:43:53 -07:00
NeilBrown
671e1fcf63 nfsd: optimise the starting of zero threads when none are running.
Currently, if we ask to set then number of nfsd threads to zero when
there are none running, we set up all the sockets and register the
service, and then tear it all down again.
This is pointless.

So detect that case and exit promptly.
(also remove an assignment to 'error' which was never used.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Jeff Layton <jlayton@redhat.com>
2009-06-18 09:42:41 -07:00
NeilBrown
82e12fe924 nfsd: don't take nfsd_mutex twice when setting number of threads.
Currently when we write a number to 'threads' in nfsdfs,
we take the nfsd_mutex, update the number of threads, then take the
mutex again to read the number of threads.

Mostly this isn't a big deal.  However if we are write '0', and
portmap happens to be dead, then we can get unpredictable behaviour.
If the nfsd threads all got killed quickly and the last thread is
waiting for portmap to respond, then the second time we take the mutex
we will block waiting for the last thread.
However if the nfsd threads didn't die quite that fast, then there
will be no contention when we try to take the mutex again.

Unpredictability isn't fun, and waiting for the last thread to exit is
pointless, so avoid taking the lock twice.
To achieve this, get nfsd_svc return a non-negative number of active
threads when not returning a negative error.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 09:40:31 -07:00
Andy Adamson
5d77ddfbcb nfsd41: sanity check client drc maxreqs
Ensure the client requested maximum requests are between 1 and
NFSD_MAX_SLOTS_PER_SESSION

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-16 17:13:16 -07:00
Alexandros Batsakis
6c18ba9f5e nfsd41: move channel attributes from nfsd4_session to a nfsd4_channel_attr struct
the change is valid for both the forechannel and the backchannel (currently dummy)

Signed-off-by: Alexandros Batsakis <Alexandros.Batsakis@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-16 10:13:45 -07:00
Yu Zhiguo
b9081d90f5 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>
2009-06-15 19:34:32 -07:00
J. Bruce Fields
e4636d535e nfsd: minor nfsd_vfs_write cleanup
There's no need to check host_err >= 0 every time here when we could
check host_err < 0 once, following the usual kernel style.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-15 19:18:34 -07:00
J. Bruce Fields
d911df7b8d nfsd: Pull write-gathering code out of nfsd_vfs_write
This is a relatively self-contained piece of code that handles a special
case--move it to its own function.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-15 18:54:05 -07:00
J. Bruce Fields
9d2a3f31d6 nfsd: track last inode only in use_wgather case
Updating last_ino and last_dev probably isn't useful in the !use_wgather
case.

Also remove some pointless ifdef'd-out code.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-15 18:52:47 -07:00
Trond Myklebust
48e03bc515 nfsd: Use write gathering only with NFSv2
NFSv3 and above can use unstable writes whenever they are sending more
than one write, rather than relying on the flaky write gathering
heuristics. More often than not, write gathering is currently getting it
wrong when the NFSv3 clients are sending a single write with FILE_SYNC
for efficiency reasons.

This patch turns off write gathering for NFSv3/v4, and ensures that
it only applies to the one case that can actually benefit: namely NFSv2.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-15 18:14:57 -07:00
J. Bruce Fields
7eef4091a6 Merge commit 'v2.6.30' into for-2.6.31 2009-06-15 18:08:07 -07:00
Al Viro
9393bd07cf switch follow_down()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:01 -04:00
Al Viro
bab77ebf51 switch follow_up() to struct path
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:00 -04:00
Al Viro
e64c390ca0 switch rqst_exp_parent()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:00 -04:00
Al Viro
91c9fa8f75 switch rqst_exp_get_by_name()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:00 -04:00
Al Viro
5bf3bd2b5c switch exp_parent() to struct path
... and lose the always-NULL last argument (non-NULL case had been
split off a while ago).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:00 -04:00
Al Viro
55430e2ece nfsd struct path use: exp_get_by_name()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:35:59 -04:00
James Morris
0b4ec6e4e0 Merge branch 'master' into next 2009-06-09 09:27:53 +10:00
Yu Zhiguo
0a93a47f04 NFSv4: kill off complicated macro 'PROC'
J. Bruce Fields wrote:
...
> (This is extremely confusing code to track down: note that
> proc->pc_decode is set to nfs4svc_decode_compoundargs() by the PROC()
> macro at the end of fs/nfsd/nfs4proc.c.  Which means, for example, that
> grepping for nfs4svc_decode_compoundargs() gets you nowhere.  Patches to
> kill off that macro would be welcomed....)

the macro 'PROC' is complicated and obscure, it had better
be killed off in order to make the code more clear.

Signed-off-by: Yu Zhiguo <yuzg@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-01 18:09:20 -04:00
Yu Zhiguo
3c8e03166a NFSv4: do exact check about attribute specified
Server should return NFS4ERR_ATTRNOTSUPP if an attribute specified is
not supported in current environment.
Operations CREATE, NVERIFY, OPEN, SETATTR and VERIFY should do this check.

This bug is found when do newpynfs tests. The names of the tests that failed
are following:
  CR12 NVF7a NVF7b NVF7c NVF7d NVF7f NVF7r NVF7s
  OPEN15 VF7a VF7b VF7c VF7d VF7f VF7r VF7s

Add function do_check_fattr() to do exact check:
1, Check attribute specified is supported by the NFSv4 server or not.
2, Check FATTR4_WORD0_ACL & FATTR4_WORD0_FS_LOCATIONS are supported
   in current environment or not.
3, Check attribute specified is writable or not.

step 1 and 3 are done in function nfsd4_decode_fattr() but removed
to this function now.

Signed-off-by: Yu Zhiguo <yuzg@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-06-01 18:01:54 -04:00
Mimi Zohar
14dba5331b integrity: nfsd imbalance bug fix
An nfsd exported file is opened/closed by the kernel causing the
integrity imbalance message.

Before a file is opened, there normally is permission checking, which
is done in inode_permission().  However, as integrity checking requires
a dentry and mount point, which is not available in inode_permission(),
the integrity (permission) checking must be called separately.

In order to detect any missing integrity checking calls, we keep track
of file open/closes.  ima_path_check() increments these counts and
does the integrity (permission) checking. As a result, the number of
calls to ima_path_check()/ima_file_free() should be balanced.  An extra
call to fput(), indicates the file could have been accessed without first
calling ima_path_check().

In nfsv3 permission checking is done once, followed by multiple reads,
which do an open/close for each read.  The integrity (permission) checking
call should be in nfsd_permission() after the inode_permission() call, but
as there is no correlation between the number of permission checking and
open calls, the integrity checking call should not increment the counters,
but defer it to when the file is actually opened.

This patch adds:
- integrity (permission) checking for nfsd exported files in nfsd_permission().
- a call to increment counts for files opened by nfsd.

This patch has been updated to return the nfs error types.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-05-28 09:32:43 +10:00
Wei Yongjun
a0d24b295a nfsd: fix hung up of nfs client while sync write data to nfs server
Commit 'Short write in nfsd becomes a full write to the client'
(31dec2538e) broken the sync write.
With the following commands to reproduce:

  $ mount -t nfs -o sync 192.168.0.21:/nfsroot /mnt
  $ cd /mnt
  $ echo aaaa > temp.txt

Then nfs client is hung up.

In SYNC mode the server alaways return the write count 0 to the
client. This is because the value of host_err in nfsd_vfs_write()
will be overwrite in SYNC mode by 'host_err=nfsd_sync(file);',
and then we return host_err(which is now 0) as write count.

This patch fixed the problem.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-05-27 17:40:06 -04:00
Greg Banks
1dbd0d53f3 knfsd: remove unreported filehandle stats counters
The file nfsfh.c contains two static variables nfsd_nr_verified and
nfsd_nr_put.  These are counters which are incremented as a side
effect of the fh_verify() fh_compose() and fh_put() operations,
i.e. at least twice per NFS call for any non-trivial workload.
Needless to say this makes the cacheline that contains them (and any
other innocent victims) a very hot contention point indeed under high
call-rate workloads on multiprocessor NFS server.  It also turns out
that these counters are not used anywhere.  They're not reported to
userspace, they're not used in logic, they're not even exported from
the object file (let alone the module).  All they do is waste CPU time.

So this patch removes them.

Tests on a 16 CPU Altix A4700 with 2 10gige Myricom cards, configured
separately (no bonding).  Workload is 640 client threads doing directory
traverals with random small reads, from server RAM.

Before
======

Kernel profile:

  %   cumulative   self              self     total
 time   samples   samples    calls   1/call   1/call  name
  6.05   2716.00  2716.00    30406     0.09     1.02  svc_process
  4.44   4706.00  1990.00     1975     1.01     1.01  spin_unlock_irqrestore
  3.72   6376.00  1670.00     1666     1.00     1.00  svc_export_put
  3.41   7907.00  1531.00     1786     0.86     1.02  nfsd_ofcache_lookup
  3.25   9363.00  1456.00    10965     0.13     1.01  nfsd_dispatch
  3.10  10752.00  1389.00     1376     1.01     1.01  nfsd_cache_lookup
  2.57  11907.00  1155.00     4517     0.26     1.03  svc_tcp_recvfrom
  ...
  2.21  15352.00  1003.00     1081     0.93     1.00  nfsd_choose_ofc  <----
  ^^^^

Here the function nfsd_choose_ofc() reads a global variable
which by accident happened to be located in the same cacheline as
nfsd_nr_verified.

Call rate:

nullarbor:~ # pmdumptext nfs3.server.calls
...
Thu Dec 13 00:15:27     184780.663
Thu Dec 13 00:15:28     184885.881
Thu Dec 13 00:15:29     184449.215
Thu Dec 13 00:15:30     184971.058
Thu Dec 13 00:15:31     185036.052
Thu Dec 13 00:15:32     185250.475
Thu Dec 13 00:15:33     184481.319
Thu Dec 13 00:15:34     185225.737
Thu Dec 13 00:15:35     185408.018
Thu Dec 13 00:15:36     185335.764

After
=====

kernel profile:

  %   cumulative   self              self     total
 time   samples   samples    calls   1/call   1/call  name
  6.33   2813.00  2813.00    29979     0.09     1.01  svc_process
  4.66   4883.00  2070.00     2065     1.00     1.00  spin_unlock_irqrestore
  4.06   6687.00  1804.00     2182     0.83     1.00  nfsd_ofcache_lookup
  3.20   8110.00  1423.00    10932     0.13     1.00  nfsd_dispatch
  3.03   9456.00  1346.00     1343     1.00     1.00  nfsd_cache_lookup
  2.62  10622.00  1166.00     4645     0.25     1.01  svc_tcp_recvfrom
[...]
  0.10  42586.00    44.00       74     0.59     1.00  nfsd_choose_ofc  <--- HA!!
  ^^^^

Call rate:

nullarbor:~ # pmdumptext nfs3.server.calls
...
Thu Dec 13 01:45:28     194677.118
Thu Dec 13 01:45:29     193932.692
Thu Dec 13 01:45:30     194294.364
Thu Dec 13 01:45:31     194971.276
Thu Dec 13 01:45:32     194111.207
Thu Dec 13 01:45:33     194999.635
Thu Dec 13 01:45:34     195312.594
Thu Dec 13 01:45:35     195707.293
Thu Dec 13 01:45:36     194610.353
Thu Dec 13 01:45:37     195913.662
Thu Dec 13 01:45:38     194808.675

i.e. about a 5.3% improvement in call rate.

Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Reviewed-by: David Chinner <dgc@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-05-27 14:14:03 -04:00
Greg Banks
cf0a586cf4 knfsd: fix reply cache memory corruption
Fix a regression in the reply cache introduced when the code was
converted to use proper Linux lists.  When a new entry needs to be
inserted, the case where all the entries are currently being used
by threads is not correctly detected.  This can result in memory
corruption and a crash.  In the current code this is an extremely
unlikely corner case; it would require the machine to have 1024
nfsd threads and all of them to be busy at the same time.  However,
upcoming reply cache changes make this more likely; a crash due to
this problem was actually observed in field.

Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-05-27 14:14:02 -04:00