This patch ensures that we throttle new RPC requests if there are
requests already waiting in the xprt->backlog queue. The reason for
doing this is to fix livelock issues that can occur when an existing
(high priority) task is waiting in the backlog queue, gets woken up
by xprt_free_slot(), but a new task then steals the slot.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the socket is full, we're better off just waiting until it empties,
or until the connection is broken. The reason why we generally don't
want to time out is that the call to xprt->ops->release_xprt() will
trigger a connection reset, which isn't helpful...
Let's make an exception for soft RPC calls, since they have to provide
timeout guarantees.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org
tk_xprt is just a shortcut for tk_client->cl_xprt, however cl_xprt is
defined as an __rcu variable. Replace dereferences of tk_xprt with
non-rcu dereferences where it is safe to do so.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the rpc_task exits while holding the socket write lock before it has
allocated an rpc slot, then the usual mechanism for releasing the write
lock in xprt_release() is defeated.
The problem occurs if the call to xprt_lock_write() initially fails, so
that the rpc_task is put on the xprt->sending wait queue. If the task
exits after being assigned the lock by __xprt_lock_write_func, but
before it has retried the call to xprt_lock_and_alloc_slot(), then
it calls xprt_release() while holding the write lock, but will
immediately exit due to the test for task->tk_rqstp != NULL.
Reported-by: Chris Perl <chris.perl@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>= 3.1]
It is only set after everyone has dereferenced the transport,
and serves no useful purpose: setting it is racy, so all the
socket code, etc still needs to be able to cope with the cases
where they miss reading it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Commit 43cedbf0e8 (SUNRPC: Ensure that
we grab the XPRT_LOCK before calling xprt_alloc_slot) is causing
hangs in the case of NFS over UDP mounts.
Since neither the UDP or the RDMA transport mechanism use dynamic slot
allocation, we can skip grabbing the socket lock for those transports.
Add a new rpc_xprt_op to allow switching between the TCP and UDP/RDMA
case.
Note that the NFSv4.1 back channel assigns the slot directly
through rpc_run_bc_task, so we can ignore that case.
Reported-by: Dick Streefland <dick.streefland@altium.nl>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>= 3.1]
Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
New features include:
- Rewrite the O_DIRECT code so that it can share the same coalescing and
pNFS functionality as the page cache code.
- Allow the server to provide hints as to when we should use pNFS, and
when it is more efficient to read and write through the metadata
server.
- NFS cache consistency updates:
- Use the ctime to emulate a change attribute for NFSv2/v3 so that
all NFS versions can share the same cache management code.
- New cache management code will only look at the change attribute
and size attribute when deciding whether or not our cached data
is still valid or not.
- Don't request NFSv4 post-op attributes on writes in cases such as
O_DIRECT, where we don't care about data cache consistency, or
when we have a write delegation, and know that our cache is
still consistent.
- Don't request NFSv4 post-op attributes on operations such as
COMMIT, where there are no expected metadata updates.
- Don't request NFSv4 directory post-op attributes in cases where
the operations themselves already return change attribute updates:
i.e. operations such as OPEN, CREATE, REMOVE, LINK and RENAME.
- Speed up 'ls' and friends by using READDIR rather than READDIRPLUS
if we detect no attempts to lookup filenames.
- Improve the code sharing between NFSv2/v3 and v4 mounts
- NFSv4.1 state management efficiency improvements
- More patches in preparation for NFSv4/v4.1 migration functionality.
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Merge tag 'nfs-for-3.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"New features include:
- Rewrite the O_DIRECT code so that it can share the same coalescing
and pNFS functionality as the page cache code.
- Allow the server to provide hints as to when we should use pNFS,
and when it is more efficient to read and write through the
metadata server.
- NFS cache consistency updates:
* Use the ctime to emulate a change attribute for NFSv2/v3 so that
all NFS versions can share the same cache management code.
* New cache management code will only look at the change attribute
and size attribute when deciding whether or not our cached data
is still valid or not.
* Don't request NFSv4 post-op attributes on writes in cases such as
O_DIRECT, where we don't care about data cache consistency, or
when we have a write delegation, and know that our cache is still
consistent.
* Don't request NFSv4 post-op attributes on operations such as
COMMIT, where there are no expected metadata updates.
* Don't request NFSv4 directory post-op attributes in cases where
the operations themselves already return change attribute
updates: i.e. operations such as OPEN, CREATE, REMOVE, LINK and
RENAME.
- Speed up 'ls' and friends by using READDIR rather than READDIRPLUS
if we detect no attempts to lookup filenames.
- Improve the code sharing between NFSv2/v3 and v4 mounts
- NFSv4.1 state management efficiency improvements
- More patches in preparation for NFSv4/v4.1 migration functionality."
Fix trivial conflict in fs/nfs/nfs4proc.c that was due to the dcache
qstr name initialization changes (that made the length/hash a 64-bit
union)
* tag 'nfs-for-3.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (146 commits)
NFSv4: Add debugging printks to state manager
NFSv4: Map NFS4ERR_SHARE_DENIED into an EACCES error instead of EIO
NFSv4: update_changeattr does not need to set NFS_INO_REVAL_PAGECACHE
NFSv4.1: nfs4_reset_session should use nfs4_handle_reclaim_lease_error
NFSv4.1: Handle other occurrences of NFS4ERR_CONN_NOT_BOUND_TO_SESSION
NFSv4.1: Handle NFS4ERR_CONN_NOT_BOUND_TO_SESSION in the state manager
NFSv4.1: Handle errors in nfs4_bind_conn_to_session
NFSv4.1: nfs4_bind_conn_to_session should drain the session
NFSv4.1: Don't clobber the seqid if exchange_id returns a confirmed clientid
NFSv4.1: Add DESTROY_CLIENTID
NFSv4.1: Ensure we use the correct credentials for bind_conn_to_session
NFSv4.1: Ensure we use the correct credentials for session create/destroy
NFSv4.1: Move NFSPROC4_CLNT_BIND_CONN_TO_SESSION to the end of the operations
NFSv4.1: Handle NFS4ERR_SEQ_MISORDERED when confirming the lease
NFSv4: When purging the lease, we must clear NFS4CLNT_LEASE_CONFIRM
NFSv4: Clean up the error handling for nfs4_reclaim_lease
NFSv4.1: Exchange ID must use GFP_NOFS allocation mode
nfs41: Use BIND_CONN_TO_SESSION for CB_PATH_DOWN*
nfs4.1: add BIND_CONN_TO_SESSION operation
NFSv4.1 test the mdsthreshold hint parameters
...
xprt_alloc_slot will call rpc_delay() to make the task wait a bit before
retrying when it gets back an -ENOMEM error from xprt_dynamic_alloc_slot.
The problem is that rpc_delay will clear the task->tk_status, causing
call_reserveresult to abort the task.
The solution is simply to let call_reserveresult handle the ENOMEM error
directly.
Reported-by: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org [>= 3.1]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It's easily possible for these allocations to fail since we're using
GFP_NOWAIT here. We don't want to spam the logs with warnings about
that though.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Use of "unsigned int" is preferred to bare "unsigned" in net tree.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the cl_xprt field is updated, the cl_server field will also have
to change. Since the contents of cl_server follow the remote endpoint
of cl_xprt, just move that field to the rpc_xprt.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[ cel: simplify check_gss_callback_principal(), whitespace changes ]
[ cel: forward ported to 3.4 ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Include RPC statistics from all data servers in /proc/self/mountstats for pNFS
filelayout mounts.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
With static RPC slots, the xprt backlog queue stats were useful in showing
when the transport (TCP) was starved by lack of RPC slots. The new dynamic
RPC slot code, commit d9ba131d8f, always
provides an RPC slot and so only uses the xprt backlog queue when the
tcp_max_slot_table_entries value has been hit or when an allocation error
occurs. All requests are now placed on the xprt sending or pending queue which
need to be monitored for debugging.
The max_slot stat shows the maximum number of dynamic RPC slots reached which is
useful when debugging performance issues.
Add the new fields at the end of the mountstats xprt stanza so that mountstats
outputs the previous correct values and ignores the new fields. Bump
NFS_IOSTATS_VERS.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We check "task->tk_rqstp" and then we dereference it without checking on
the next line. The only caller is call_connect() and that has a check
which prevents it from calling xprt_connect() with a NULL.
if (task->tk_status < 0)
return;
If "task->tk_rqstp" were NULL then "tk_status" would be -EAGAIN.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We have to ensure that the wake up from the waitqueue and the assignment
of xprt->snd_task are atomic. We can do this by assigning the snd_task
while under the waitqueue spinlock.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Whenever we free a slot, we know that the resulting xprt->num_reqs will
be less than xprt->max_reqs, so we know that we can release at least one
backlogged rpc_task.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [>=3.1]
Fix new kernel-doc warning in sunrpc:
Warning(net/sunrpc/xprt.c:196): No description found for parameter 'xprt'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This throttles the allocation of new slots when the socket is busy
reconnecting and/or is out of buffer space.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Change explicit references to CONFIG_NFS_V4_1 to implicit ones
Get rid of the unnecessary defines in backchannel_rqst.c and
bc_svc.c: the Makefile takes care of those dependency.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If we fail to contact the gss upcall program, then no message will
be sent to the server. The client still updated the sequence number,
however, and this lead to NFS4ERR_SEQ_MISMATCH for the next several
RPC calls.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
'req' is dereferenced before checked for NULL.
The patch simply removes the check.
Signed-off-by: Jinqiu Yang<crindy646@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This allows us to reuse the xprt associated with a server connection if
one has already been set up.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Multiple backchannels can share the same tcp connection; from rfc 5661 section
2.10.3.1:
A connection's association with a session is not exclusive. A
connection associated with the channel(s) of one session may be
simultaneously associated with the channel(s) of other sessions
including sessions associated with other client IDs.
However, multiple backchannels share a connection, they must all share
the same xid stream (hence the same rpc_xprt); the only way we have to
match replies with calls at the rpc layer is using the xid.
So, keep the rpc_xprt around as long as the connection lasts, in case
we're asked to use the connection as a backchannel again.
Requests to create new backchannel clients over a given server
connection should results in creating new clients that reuse the
existing rpc_xprt.
But to start, just reject attempts to associate multiple rpc_xprt's with
the same underlying bc_xprt.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Saves some lines of code and some branticks when reading one.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The task in question is dereferenced above (and is actually never NULL).
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The net is known from the xprt_create and this tagging will also
give un the context in the conntection workers where real sockets
are created.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We saw a report of a NULL dereference in xprt_autoclose:
https://bugzilla.redhat.com/show_bug.cgi?id=611938
This appears to be the result of an xprt's task_cleanup running after
the xprt is destroyed. Nothing in the current code appears to prevent
that.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This will allow us to save the original generic cred in rpc_message, so
that if we migrate from one server to another, we can generate a new bound
cred without having to punt back to the NFS layer.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
gcc-4.3.3 produces the warning:
"format not a string literal and no format arguments"
Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <cel@citi.umich.edu>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Tom Talpey <tmtalpey@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1674 commits)
qlcnic: adding co maintainer
ixgbe: add support for active DA cables
ixgbe: dcb, do not tag tc_prio_control frames
ixgbe: fix ixgbe_tx_is_paused logic
ixgbe: always enable vlan strip/insert when DCB is enabled
ixgbe: remove some redundant code in setting FCoE FIP filter
ixgbe: fix wrong offset to fc_frame_header in ixgbe_fcoe_ddp
ixgbe: fix header len when unsplit packet overflows to data buffer
ipv6: Never schedule DAD timer on dead address
ipv6: Use POSTDAD state
ipv6: Use state_lock to protect ifa state
ipv6: Replace inet6_ifaddr->dead with state
cxgb4: notify upper drivers if the device is already up when they load
cxgb4: keep interrupts available when the ports are brought down
cxgb4: fix initial addition of MAC address
cnic: Return SPQ credit to bnx2x after ring setup and shutdown.
cnic: Convert cnic_local_flags to atomic ops.
can: Fix SJA1000 command register writes on SMP systems
bridge: fix build for CONFIG_SYSFS disabled
ARCNET: Limit com20020 PCI ID matches for SOHARD cards
...
Fix up various conflicts with pcmcia tree drivers/net/
{pcmcia/3c589_cs.c, wireless/orinoco/orinoco_cs.c and
wireless/orinoco/spectrum_cs.c} and feature removal
(Documentation/feature-removal-schedule.txt).
Also fix a non-content conflict due to pm_qos_requirement getting
renamed in the PM tree (now pm_qos_request) in net/mac80211/scan.c
This patch removes from net/ (but not any netfilter files)
all the unnecessary return; statements that precede the
last closing brace of void functions.
It does not remove the returns that are immediately
preceded by a label as gcc doesn't like that.
Done via:
$ grep -rP --include=*.[ch] -l "return;\n}" net/ | \
xargs perl -i -e 'local $/ ; while (<>) { s/\n[ \t\n]+return;\n}/\n}/g; print; }'
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It seems strange to maintain stats for bytes_sent in one structure, and
bytes received in another. Try to assemble all the RPC request-related
stats in struct rpc_rqst
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently RPC performance metrics that tabulate elapsed time use
jiffies time values. This is problematic on systems that use slow
jiffies (for instance 100HZ systems built for paravirtualized
environments). It is also a problem for computing precise latency
statistics for advanced network transports, such as InfiniBand,
that can have round-trip latencies significanly faster than a single
clock tick.
For the RPC client, adopt the high resolution time stamp mechanism
already used by the network layer and blktrace: ktime.
We use ktime format time stamps for all internal computations, and
convert to milliseconds for presentation. As a result, we need only
addition operations in the performance critical paths; multiply/divide
is required only for presentation.
We could report RTT metrics in microseconds. In fact the mountstats
format is versioned to accomodate exactly this kind of interface
improvement.
For now, however, we'll stay with millisecond precision for
presentation to maintain backwards compatibility with the handful of
currently deployed user space tools. At a later point, we'll move to
an API such as BDI_STATS where a finer timestamp precision can be
reported.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Compute an RPC request's RTT once, and use that value both for reporting
RPC metrics, and for adjusting the RTT context used by the RPC client's RTT
estimator algorithm.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We should not allow soft tasks to wait for longer than the major timeout
period when waiting for a reconnect to occur.
Remove the field xprt->connect_timeout since it has been obsoleted by
xprt->reestablish_timeout.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This fixes a bug with setting xprt->stat.connect_start.
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
