Trond Myklebust [Fri, 12 Oct 2018 17:28:26 +0000 (13:28 -0400)]
SUNRPC: Simplify lookup code
We no longer need to worry about whether or not the entry is hashed in
order to figure out if the contents are valid. We only care whether or
not the refcount is non-zero.
Trond Myklebust [Thu, 18 Oct 2018 21:29:00 +0000 (17:29 -0400)]
Merge tag 'nfs-rdma-for-4.20-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
NFS RDMA client updates for Linux 4.20
Stable bugfixes:
- Reset credit grant properly after a disconnect
Other bugfixes and cleanups:
- xprt_release_rqst_cong is called outside of transport_lock
- Create more MRs at a time and toss out old ones during recovery
- Various improvements to the RDMA connection and disconnection code:
- Improve naming of trace events, functions, and variables
- Add documenting comments
- Fix metrics and stats reporting
- Fix a tracepoint sparse warning
J. Bruce Fields [Thu, 18 Oct 2018 19:27:02 +0000 (15:27 -0400)]
sunrpc: safely reallow resvport min/max inversion
Commits 8d7ddf932d4c and 2cfd90ea262b prevent setting xprt_min_resvport
greater than xprt_max_resvport, but may also break simple code that sets
one parameter then the other, if the new range does not overlap the old.
Also it looks racy to me, unless there's some serialization I'm not
seeing. Granted it would probably require malicious privileged processes
(unless there's a chance these might eventually be settable in unprivileged
containers), but still it seems better not to let userspace panic the
kernel.
Simpler seems to be to allow setting the parameters to whatever you want
but interpret xprt_min_resvport > xprt_max_resvport as the empty range.
nfs: remove redundant call to nfs_context_set_write_error()
We don't need to call this in the direct, read, or pnfs resend paths and
the only other caller is the write path in nfs_page_async_flush() which
already checks and sets the pg_error on the context.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We must check pg_error and call error_cleanup after any call to pg_doio.
Currently, we are skipping the unlock of a page if we encounter an error in
nfs_pageio_complete() before handing off the work to the RPC layer.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
NFSv4.x: fix lock recovery during delegation recall
Running "./nfstest_delegation --runtest recall26" uncovers that
client doesn't recover the lock when we have an appending open,
where the initial open got a write delegation.
Instead of checking for the passed in open context against
the file lock's open context. Check that the state is the same.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Arnd Bergmann [Tue, 2 Oct 2018 20:57:46 +0000 (22:57 +0200)]
SUNRPC: use cmpxchg64() in gss_seq_send64_fetch_and_inc()
The newly introduced gss_seq_send64_fetch_and_inc() fails to build on
32-bit architectures:
net/sunrpc/auth_gss/gss_krb5_seal.c:144:14: note: in expansion of macro 'cmpxchg'
seq_send = cmpxchg(&ctx->seq_send64, old, old + 1);
^~~~~~~
arch/x86/include/asm/cmpxchg.h:128:3: error: call to '__cmpxchg_wrong_size' declared with attribute error: Bad argument size for cmpxchg
__cmpxchg_wrong_size(); \
As the message tells us, cmpxchg() cannot be used on 64-bit arguments,
that's what cmpxchg64() does.
Fixes: 8a4dd176ecbd ("SUNRPC: Replace krb5_seq_lock with a lockless scheme") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Chuck Lever [Mon, 1 Oct 2018 18:26:35 +0000 (14:26 -0400)]
xprtrdma: Report when there were zero posted Receives
To show that a caller did attempt to allocate and post more Receive
buffers, the trace point in rpcrdma_post_recvs() should report when
rpcrdma_post_recvs() was invoked but no new Receive buffers were
posted.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:26:29 +0000 (14:26 -0400)]
xprtrdma: Move rb_flags initialization
Clean up: rb_flags might be used for other things besides
RPCRDMA_BUF_F_EMPTY_SCQ, so initialize it in a generic spot
instead of in a send-completion-queue-related helper.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:26:24 +0000 (14:26 -0400)]
xprtrdma: Don't disable BH's in backchannel server
Clean up: This code was copied from xprtsock.c and
backchannel_rqst.c. For rpcrdma, the backchannel server runs
exclusively in process context, thus disabling bottom-halves is
unnecessary.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:26:19 +0000 (14:26 -0400)]
xprtrdma: Remove memory address of "ep" from an error message
Clean up: Replace the hashed memory address of the target rpcrdma_ep
with the server's IP address and port. The server address is more
useful in an administrative error message.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:26:13 +0000 (14:26 -0400)]
xprtrdma: Rename rpcrdma_qp_async_error_upcall
Clean up: Use a function name that is consistent with the RDMA core
API and with other consumers. Because this is a function that is
invoked from outside the rpcrdma.ko module, add an appropriate
documenting comment.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:26:08 +0000 (14:26 -0400)]
xprtrdma: Simplify RPC wake-ups on connect
Currently, when a connection is established, rpcrdma_conn_upcall
invokes rpcrdma_conn_func and then
wake_up_all(&ep->rep_connect_wait). The former wakes waiting RPCs,
but the connect worker is not done yet, and that leads to races,
double wakes, and difficulty understanding how this logic is
supposed to work.
Instead, collect all the "connection established" logic in the
connect worker (xprt_rdma_connect_worker). A disconnect worker is
retained to handle provider upcalls safely.
Fixes: 58c3cde8f7fc ("xprtrdma: RPC/RDMA must invoke ... ") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:25:57 +0000 (14:25 -0400)]
xprtrdma: Eliminate "connstate" variable from rpcrdma_conn_upcall()
Clean up.
Since commit d8ca3454b45a ("xprtrdma: Demote "connect" log messages")
there has been no need to initialize connstat to zero. In fact, in
this code path there's now no reason not to set rep_connected
directly.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:25:52 +0000 (14:25 -0400)]
xprtrdma: Conventional variable names in rpcrdma_conn_upcall
Clean up: The convention throughout other parts of xprtrdma is to
name variables of type struct rpcrdma_xprt "r_xprt", not "xprt".
This convention enables the use of the name "xprt" for a "struct
rpc_xprt" type variable, as in other parts of the RPC client.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:25:47 +0000 (14:25 -0400)]
xprtrdma: Rename rpcrdma_conn_upcall
Clean up: Use a function name that is consistent with the RDMA core
API and with other consumers. Because this is a function that is
invoked from outside the rpcrdma.ko module, add an appropriate
documenting comment.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:25:36 +0000 (14:25 -0400)]
sunrpc: Fix connect metrics
For TCP, the logic in xprt_connect_status is currently never invoked
to record a successful connection. Commit e2bdfe4d2ff8 ("SUNRPC:
Return EAGAIN instead of ENOTCONN when waking up xprt->pending")
changed the way TCP xprt's are awoken after a connect succeeds.
Instead, change connection-oriented transports to bump connect_count
and compute connect_time the moment that XPRT_CONNECTED is set.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:25:25 +0000 (14:25 -0400)]
xprtrdma: Explicitly resetting MRs is no longer necessary
When a memory operation fails, the MR's driver state might not match
its hardware state. The only reliable recourse is to dereg the MR.
This is done in ->ro_recover_mr, which then attempts to allocate a
fresh MR to replace the released MR.
Since commit 9d4253b73cbb2 ("xprtrdma: Allocate MRs on demand"),
xprtrdma dynamically allocates MRs. It can add more MRs whenever
they are needed.
That makes it possible to simply release an MR when a memory
operation fails, instead of "recovering" it. It will automatically
be replaced by the on-demand MR allocator.
This commit is a little larger than I wanted, but it replaces
->ro_recover_mr, rb_recovery_lock, rb_recovery_worker, and the
rb_stale_mrs list with a generic work queue.
Since MRs are no longer orphaned, the mrs_orphaned metric is no
longer used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:25:20 +0000 (14:25 -0400)]
xprtrdma: Create more MRs at a time
Some devices require more than 3 MRs to build a single 1MB I/O.
Ensure that rpcrdma_mrs_create() will add enough MRs to build that
I/O.
In a subsequent patch I'm changing the MR recovery logic to just
toss out the MRs. In that case it's possible for ->send_request to
loop acquiring some MRs, not getting enough, getting called again,
recycling the previous MRs, then not getting enough, lather rinse
repeat. Thus first we need to ensure enough MRs are created to
prevent that loop.
I'm "reusing" ia->ri_max_segs. All of its accessors seem to want the
maximum number of data segments plus two, so I'm going to bake that
into the initial calculation.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:25:14 +0000 (14:25 -0400)]
xprtrdma: Reset credit grant properly after a disconnect
On a fresh connection, an RPC/RDMA client is supposed to send only
one RPC Call until it gets a credit grant in the first RPC Reply
from the server [RFC 8166, Section 3.3.3].
There is a bug in the Linux client's credit accounting mechanism
introduced by commit e70f01d8867a ("xprtrdma: Avoid deadlock when
credit window is reset"). On connect, it simply dumps all pending
RPC Calls onto the new connection.
Servers have been tolerant of this bad behavior. Currently no server
implementation ever changes its credit grant over reconnects, and
servers always repost enough Receives before connections are fully
established.
To correct this issue, ensure that the client resets both the credit
grant _and_ the congestion window when handling a reconnect.
Fixes: e70f01d8867a ("xprtrdma: Avoid deadlock when credit ... ") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: stable@kernel.org Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Chuck Lever [Mon, 1 Oct 2018 18:25:09 +0000 (14:25 -0400)]
xprtrdma: xprt_release_rqst_cong is called outside of transport_lock
Since commit 8bd766bd6d9a ("SUNRPC: Add a separate spinlock to
protect the RPC request receive list") the RPC/RDMA reply handler
has been calling xprt_release_rqst_cong without holding
xprt->transport_lock.
I think the only way this call is ever made is if the credit grant
increases and there are RPCs pending. Current server implementations
do not change their credit grant during operation (except at
connect time).
Commit e70f01d8867a ("xprtrdma: Avoid deadlock when credit window is
reset") added the ->release_rqst call because UDP invokes
xprt_adjust_cwnd(), which calls __xprt_put_cong() after adjusting
xprt->cwnd. Both xprt_release() and ->xprt_release_xprt already wake
another task in this case, so it is safe to remove this call from
the reply handler.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If we're revalidating an existing dentry in order to open a file, we need
to ensure that we check the directory has not changed before we optimise
away the lookup.
We need to ensure that inode and dentry revalidation occurs correctly
on reopen of a file that is already open. Currently, we can end up
not revalidating either in the case of NFSv4.0, due to the 'cached open'
path.
Let's fix that by ensuring that we only do cached open for the special
cases of open recovery and delegation return.
Reported-by: Stan Hu <stanhu@gmail.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
SUNRPC: Remove rpc_authflavor_lock in favour of RCU locking
Module removal is RCU safe by design, so we really have no need to
lock the auth_flavors[] array. Substitute a lockless scheme to
add/remove entries in the array, and then use rcu.
Trond Myklebust [Mon, 5 Mar 2018 17:03:00 +0000 (12:03 -0500)]
NFSv3: Improve NFSv3 performance when server returns no post-op attributes
When the server fails to return post-op attributes, the client's
attempt to place read data directly in the page cache fails, and
so we have to do an extra copy in order to realign the data with
page borders.
This patch attempts to detect servers that don't return post-op
attributes on read (e.g. for pNFS) and adjusts the placement
calculation accordingly.
Anna Schumaker [Tue, 11 Sep 2018 20:23:47 +0000 (16:23 -0400)]
NFS: Reduce indentation of the switch statement in nfs4_reclaim_open_state()
Most places in the kernel tend to line up cases with the switch to
reduce indentation, so move this over to match that style.
Additionally, I handle the (status >= 0) case in the switch so that we
only "goto restart" from a single place after error handling.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Anna Schumaker [Tue, 11 Sep 2018 20:23:46 +0000 (16:23 -0400)]
NFS: Split out the body of nfs4_reclaim_open_state()
Moving all of this into a new function removes the need for cramped
indentation, making the code overall easier to look at. I also take
this chance to switch copy recovery over to using
nfs4_stateid_match_other()
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
The intention of nfs4_session_set_rwsize() was to cap the r/wsize to the
buffer sizes negotiated by the CREATE_SESSION. The initial code had a
bug whereby we would not check the values negotiated by nfs_probe_fsinfo()
(the assumption being that CREATE_SESSION will always negotiate buffer values
that are sane w.r.t. the server's preferred r/wsizes) but would only check
values set by the user in the 'mount' command.
The code was changed in 4.11 to _always_ set the r/wsize, meaning that we
now never use the server preferred r/wsizes. This is the regression that
this patch fixes.
Also rename the function to nfs4_session_limit_rwsize() in order to avoid
future confusion.
Fixes: 6651fe3aed4c (NFSv4.1 respect server's max size in CREATE_SESSION") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
pNFS: Don't allocate more pages than we need to fit a layoutget response
For the 'files' and 'flexfiles' layout types, we do not expect the reply
to be any larger than 4k. The block and scsi layout types are a little more
greedy, so we keep allocating the maximum response size for now.
SUNRPC: Add a label for RPC calls that require allocation on receive
If the RPC call relies on the receive call allocating pages as buffers,
then let's label it so that we
a) Don't leak memory by allocating pages for requests that do not expect
this behaviour
b) Can optimise for the common case where calls do not require allocation.
SUNRPC: Convert the xprt->sending queue back to an ordinary wait queue
We no longer need priority semantics on the xprt->sending queue, because
the order in which tasks are sent is now dictated by their position in
the send queue.
Note that the backlog queue remains a priority queue, meaning that
slot resources are still managed in order of task priority.
Fix up the priority queue to not batch by owner, but by queue, so that
we allow '1 << priority' elements to be dequeued before switching to
the next priority queue.
The owner field is still used to wake up requests in round robin order
by owner to avoid single processes hogging the RPC layer by loading the
queues.
SUNRPC: Convert xprt receive queue to use an rbtree
If the server is slow, we can find ourselves with quite a lot of entries
on the receive queue. Converting the search from an O(n) to O(log(n))
can make a significant difference, particularly since we have to hold
a number of locks while searching.
Treat socket write space handling in the same way we now treat transport
congestion: by denying the XPRT_LOCK until the transport signals that it
has free buffer space.
Trond Myklebust [Wed, 29 Aug 2018 21:40:55 +0000 (17:40 -0400)]
SUNRPC: Allow calls to xprt_transmit() to drain the entire transmit queue
Rather than forcing each and every RPC task to grab the socket write
lock in order to send itself, we allow whichever task is holding the
write lock to attempt to drain the entire transmit queue.
SUNRPC: Support for congestion control when queuing is enabled
Both RDMA and UDP transports require the request to get a "congestion control"
credit before they can be transmitted. Right now, this is done when
the request locks the socket. We'd like it to happen when a request attempts
to be transmitted for the first time.
In order to support retransmission of requests that already hold such
credits, we also want to ensure that they get queued first, so that we
don't deadlock with requests that have yet to obtain a credit.
One of the intentions with the priority queues was to ensure that no
single process can hog the transport. The field task->tk_owner therefore
identifies the RPC call's origin, and is intended to allow the RPC layer
to organise queues for fairness.
This commit therefore modifies the transmit queue to group requests
by task->tk_owner, and ensures that we round robin among those groups.
Remove the checks for whether or not we need to transmit, and whether
or not a reply has been received. Those are already handled in
call_transmit() itself.
Fix up the back channel code to recognise that it has already been
transmitted, so does not need to be called again.
Also ensure that we set req->rq_task.
Trond Myklebust [Wed, 8 Aug 2018 13:23:32 +0000 (09:23 -0400)]
SUNRPC: Distinguish between the slot allocation list and receive queue
When storing a struct rpc_rqst on the slot allocation list, we currently
use the same field 'rq_list' as we use to store the request on the
receive queue. Since the structure is never on both lists at the same
time, this is OK.
However, for clarity, let's make that a union with different names for
the different lists so that we can more easily distinguish between
the two states.
Trond Myklebust [Thu, 23 Aug 2018 04:03:43 +0000 (00:03 -0400)]
SUNRPC: Refactor xprt_transmit() to remove wait for reply code
Allow the caller in clnt.c to call into the code to wait for a reply
after calling xprt_transmit(). Again, the reason is that the backchannel
code does not need this functionality.
Trond Myklebust [Wed, 29 Aug 2018 13:22:28 +0000 (09:22 -0400)]
SUNRPC: Add a helper to wake up a sleeping rpc_task and set its status
Add a helper that will wake up a task that is sleeping on a specific
queue, and will set the value of task->tk_status. This is mainly
intended for use by the transport layer to notify the task of an
error condition.
Trond Myklebust [Fri, 31 Aug 2018 14:00:02 +0000 (10:00 -0400)]
SUNRPC: Simplify dealing with aborted partially transmitted messages
If the previous message was only partially transmitted, we need to close
the socket in order to avoid corruption of the message stream. To do so,
we currently hijack the unlocking of the socket in order to schedule
the close.
Now that we track the message offset in the socket state, we can move
that kind of checking out of the socket lock code, which is needed to
allow messages to remain queued after dropping the socket lock.
Trond Myklebust [Mon, 13 Aug 2018 19:48:42 +0000 (15:48 -0400)]
SUNRPC: Rename TCP receive-specific state variables
Since we will want to introduce similar TCP state variables for the
transmission of requests, let's rename the existing ones to label
that they are for the receive side.
Trond Myklebust [Tue, 14 Aug 2018 17:58:34 +0000 (13:58 -0400)]
SUNRPC: Avoid holding locks across the XDR encoding of the RPC message
Currently, we grab the socket bit lock before we allow the message
to be XDR encoded. That significantly slows down the transmission
rate, since we serialise on a potentially blocking operation.
Trond Myklebust [Tue, 14 Aug 2018 17:50:21 +0000 (13:50 -0400)]
SUNRPC: The transmitted message must lie in the RPCSEC window of validity
If a message has been encoded using RPCSEC_GSS, the server is
maintaining a window of sequence numbers that it considers valid.
The client should normally be tracking that window, and needs to
verify that the sequence number used by the message being transmitted
still lies inside the window of validity.
So far, we've been able to assume this condition would be realised
automatically, since the client has been encoding the message only
after taking the socket lock. Once we change that condition, we
will need the explicit check.
projects / kernel.git / log