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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Make REQHASH() an inline function. Rename hash_list to cache_hash.
Fix an obsolete comment.
Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
After 2f9092e102 "Fix i_mutex vs. readdir
handling in nfsd" (and 14f7dd63 "Copy XFS readdir hack into nfsd code"),
an entry may be removed between the first mutex_unlock and the second
mutex_lock. In this case, lookup_one_len() will return a negative
dentry. Check for this case to avoid a NULL dereference.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Reviewed-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Cc: stable@kernel.org
Eliminate 56 sparse warnings like this one:
fs/nfsd/nfs4xdr.c:1331:15: warning: obsolete array initializer, use C99 syntax
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The session and slots are allocated all in one piece.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Move this out of a local variable into the nfs4_delegation object in
preparation for making this an async rpc call (at which point we'll need
any state like this in a common object that's preserved across function
calls).
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
There's no point in keeping this field around--it's always zero.
(Background: the protocol allows you to tell the client that the file is
about to be truncated, as an optimization to save the client from
writing back dirty pages that will just be discarded. We don't
implement this hint. If we do some day, adding this field back in will
be the least of the work involved.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The nfs4_cb_recall struct is used only in nfs4_delegation, so its
pointer to the containing delegation is unnecessary--we could just use
container_of().
But there's no real reason to have this a separate struct at all--just
move these fields to nfs4_delegation.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
I want to use the name for a struct that actually does represent a
single callback.
(Actually, I've never been sure it helps to a separate struct for the
callback information. Some day maybe those fields could just be dumped
into struct nfs4_client. I don't know.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We don't really need a synchronous rpc, and moving to an asynchronous
rpc allows us to do without this extra kthread.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The code is a little simpler, and it should be easier to avoid races, if
we just do all rpc client creation/destruction from nfsd or laundromat
threads and do only the rpc calls themselves asynchronously. The rpc
creation doesn't involve any significant waiting (it doesn't call the
client, for example), so there's no reason not to do this.
Also don't bother destroying the client on failure of the rpc null
probe. We may want to retry the probe later anyway.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
We tried to do something overly complicated with the callback rpc
timeouts here. And they're wrong--the result is that by the time a
single callback times out, it's already too late to tell the client
(using the cb_path_down return to RENEW) that the callback is down.
Use a much shorter, simpler timeout.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This setclientid_confirm case should allow the client to change
callbacks, but it currently has a dummy implementation that just turns
off callbacks completely. That dummy implementation isn't completely
correct either, though:
- There's no need to remove any client recovery directory in
this case.
- New clientid confirm verifiers should be generated (and
returned) in setclientid; there's no need to generate a new
one here.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Stephen Rothwell said:
"Today's linux-next build (powerpc ppc64_defconfig) produced this new
warning:
fs/nfsd/nfs4state.c: In function 'EXPIRED_STATEID':
fs/nfsd/nfs4state.c:2757: warning: comparison of distinct pointer types lacks a cast
Caused by commit 78155ed75f ("nfsd4:
distinguish expired from stale stateids")."
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
ext4 supports a real NFSv4 change attribute, which is bumped whenever
the ctime would be updated, including times when two updates arrive
within a jiffy of each other. (Note that although ext4 has space for
nanosecond-precision ctime, the real resolution is lower: it actually
uses jiffies as the time-source.) This ensures clients will invalidate
their caches when they need to.
There is some fear that keeping the i_version up-to-date could have
performance drawbacks, so for now it's turned on only by a mount option.
We hope to do something better eventually.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Theodore Tso <tytso@mit.edu>
We don't need comments to tell us these macros are ugly. And we're long
past trying to share any of this code with the BSD's.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: For consistency, handle output buffer size checking in a
other nfsctl functions the same way it's done for write_versions().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
While it's not likely today that there are enough NFS versions to
overflow the output buffer in write_versions(), we should be more
careful about detecting the end of the buffer.
The number of NFS versions will only increase as NFSv4 minor versions
are added.
Note that this API doesn't behave the same as portlist. Here we
attempt to display as many versions as will fit in the buffer, and do
not provide any indication that an overflow would have occurred. I
don't have any good rationale for that.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
While it's not likely a pathname will be longer than
SIMPLE_TRANSACTION_SIZE, we should be more careful about just
plopping it into the output buffer without bounds checking.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Adjust the synopsis of svc_sock_names() to pass in the size of the
output buffer. Add a documenting comment.
This is a cosmetic change for now. A subsequent patch will make sure
the buffer length is passed to one_sock_name(), where the length will
actually be useful.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Adjust the synopsis of svc_addsock() to pass in the size of the output
buffer. Add a documenting comment.
This is a cosmetic change for now. A subsequent patch will make sure
the buffer length is passed to one_sock_name(), where the length will
actually be useful.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The svc_xprt_names() function can overflow its buffer if it's so near
the end of the passed in buffer that the "name too long" string still
doesn't fit. Of course, it could never tell if it was near the end
of the passed in buffer, since its only caller passes in zero as the
buffer length.
Let's make this API a little safer.
Change svc_xprt_names() so it *always* checks for a buffer overflow,
and change its only caller to pass in the correct buffer length.
If svc_xprt_names() does overflow its buffer, it now fails with an
ENAMETOOLONG errno, instead of trying to write a message at the end
of the buffer. I don't like this much, but I can't figure out a clean
way that's always safe to return some of the names, *and* an
indication that the buffer was not long enough.
The displayed error when doing a 'cat /proc/fs/nfsd/portlist' is
"File name too long".
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up.
A couple of years ago, a series of commits, finishing with commit
5680c446, swapped the order of the lockd_up() and svc_addsock() calls
in __write_ports(). At that time lockd_up() needed to know the
transport protocol of the passed-in socket to start a listener on the
same transport protocol.
These days, lockd_up() doesn't take a protocol argument; it always
starts both a UDP and TCP listener. It's now more straightforward to
try the lockd_up() first, then do a lockd_down() if the svc_addsock()
fails.
Careful review of this code shows that the svc_sock_names() call is
used only to close the just-opened socket in case lockd_up() fails.
So it is no longer needed if lockd_up() is done first.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: Refactor transport name listing out of __write_ports() to
make it easier to understand and maintain.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
User space must call listen(3) on SOCK_STREAM sockets passed into
/proc/fs/nfsd/portlist, otherwise that listener is ignored. Document
this.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: Refactor the socket creation logic out of __write_ports() to
make it easier to understand and maintain.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: Refactor the socket closing logic out of __write_ports() to
make it easier to understand and maintain.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: Refactor transport addition out of __write_ports() to make
it easier to understand and maintain.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: Refactor transport removal out of __write_ports() to make it
easier to understand and maintain.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
If we encode the time of client creation into the stateid instead of the
time of server boot, then we can determine whether that stateid is from
a previous instance of the a server, or from a client that has expired,
and return an appropriate error to the client.
Signed-off-by: Bian Naimeng <biannm@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
