Commit Graph

134 Commits

Author SHA1 Message Date
Chuck Lever ca1c671302 xprtrdma: Fix DMA scatter-gather list mapping imbalance
The @nents value that was passed to ib_dma_map_sg() has to be passed
to the matching ib_dma_unmap_sg() call. If ib_dma_map_sg() choses to
concatenate sg entries, it will return a different nents value than
it was passed.

The bug was exposed by recent changes to the AMD IOMMU driver, which
enabled sg entry concatenation.

Looking all the way back to commit 4143f34e01 ("xprtrdma: Port to
new memory registration API") and reviewing other kernel ULPs, it's
not clear that the frwr_map() logic was ever correct for this case.

Reported-by: Andre Tomt <andre@tomt.net>
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-02-13 15:35:33 -05:00
Chuck Lever 25868e610a xprtrdma: Refactor frwr_is_supported
Refactor: Perform the "is supported" check in rpcrdma_ep_create()
instead of in rpcrdma_ia_open(). frwr_open() is where most of the
logic to query device attributes is already located.

The current code displays a redundant error message when the device
does not support FRWR. As an additional clean-up, this patch removes
the extra message.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:54:32 -05:00
Chuck Lever 18d065a5d4 xprtrdma: Eliminate per-transport "max pages"
To support device hotplug and migrating a connection between devices
of different capabilities, we have to guarantee that all in-kernel
devices can support the same max NFS payload size (1 megabyte).

This means that possibly one or two in-tree devices are no longer
supported for NFS/RDMA because they cannot support 1MB rsize/wsize.
The only one I confirmed was cxgb3, but it has already been removed
from the kernel.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:54:32 -05:00
Chuck Lever 2e87036814 xprtrdma: Eliminate ri_max_send_sges
Clean-up. The max_send_sge value also happens to be stored in
ep->rep_attr. Let's keep just a single copy.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15 10:54:32 -05:00
Chuck Lever dc15c3d5f1 xprtrdma: Move the rpcrdma_sendctx::sc_wr field
Clean up: This field is not needed in the Send completion handler,
so it can be moved to struct rpcrdma_req to reduce the size of
struct rpcrdma_sendctx, and to reduce the amount of memory that
is sloshed between the sending process and the Send completion
process.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24 10:30:40 -04:00
Chuck Lever 15d9b015d3 xprtrdma: Ensure ri_id is stable during MR recycling
ia->ri_id is replaced during a reconnect. The connect_worker runs
with the transport send lock held to prevent ri_id from being
dereferenced by the send_request path during this process.

Currently, however, there is no guarantee that ia->ri_id is stable
in the MR recycling worker, which operates in the background and is
not serialized with the connect_worker in any way.

But now that Local_Inv completions are being done in process
context, we can handle the recycling operation there instead of
deferring the recycling work to another process. Because the
disconnect path drains all work before allowing tear down to
proceed, it is guaranteed that Local Invalidations complete only
while the ri_id pointer is stable.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24 10:30:40 -04:00
Chuck Lever 9d2da4ff00 xprtrdma: Manage MRs in context of a single connection
MRs are now allocated on demand so we can safely throw them away on
disconnect. This way an idle transport can disconnect and it won't
pin hardware MR resources.

Two additional changes:

- Now that all MRs are destroyed on disconnect, there's no need to
  check during header marshaling if a req has MRs to recycle. Each
  req is sent only once per connection, and now rl_registered is
  guaranteed to be empty when rpcrdma_marshal_req is invoked.

- Because MRs are now destroyed in a WQ_MEM_RECLAIM context, they
  also must be allocated in a WQ_MEM_RECLAIM context. This reduces
  the likelihood that device driver memory allocation will trigger
  memory reclaim during NFS writeback.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24 10:30:40 -04:00
Chuck Lever 4b93dab36f xprtrdma: Add unique trace points for posting Local Invalidate WRs
When adding frwr_unmap_async way back when, I re-used the existing
trace_xprtrdma_post_send() trace point to record the return code
of ib_post_send.

Unfortunately there are some cases where re-using that trace point
causes a crash. Instead, construct a trace point specific to posting
Local Invalidate WRs that will always be safe to use in that context,
and will act as a trace log eye-catcher for Local Invalidation.

Fixes: 847568942f ("xprtrdma: Remove fr_state")
Fixes: d8099feda4 ("xprtrdma: Reduce context switching due ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Bill Baker <bill.baker@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-24 10:30:39 -04:00
Chuck Lever ee2f412ece xprtrdma: Recycle MRs after disconnect
The optimization done in "xprtrdma: Simplify rpcrdma_mr_pop" was a
bit too optimistic. MRs left over after a reconnect still need to
be recycled, not added back to the free list, since they could be
in flight or actually fully registered.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-26 15:22:31 -04:00
Chuck Lever 4d6b8890dd xprtrdma: Remove rpcrdma_buffer::rb_mrlock
Clean up: Now that the free list is used sparingly, get rid of the
separate spin lock protecting it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-21 11:40:00 -04:00
Chuck Lever 6dc6ec9e04 xprtrdma: Cache free MRs in each rpcrdma_req
Instead of a globally-contended MR free list, cache MRs in each
rpcrdma_req as they are released. This means acquiring and releasing
an MR will be lock-free in the common case, even outside the
transport send lock.

The original idea of per-rpcrdma_req MR free lists was suggested by
Shirley Ma <shirley.ma@oracle.com> several years ago. I just now
figured out how to make that idea work with on-demand MR allocation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-21 11:06:24 -04:00
Chuck Lever 805a1f620b xprtrdma: Ensure creating an MR does not trigger FS writeback
Probably would be good to also pass GFP flags to ib_alloc_mr.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20 16:35:30 -04:00
Chuck Lever 3b39f52a02 xprtrdma: Move rpcrdma_mr_get out of frwr_map
Refactor: Retrieve an MR and handle error recovery entirely in
rpc_rdma.c, as this is not a device-specific function.

Note that since commit 89f90fe1ad ("SUNRPC: Allow calls to
xprt_transmit() to drain the entire transmit queue"), the
xprt_transmit function handles the cond_resched. The transport no
longer has to do this itself.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20 16:23:35 -04:00
Chuck Lever 1ca3f4c054 xprtrdma: Combine rpcrdma_mr_put and rpcrdma_mr_unmap_and_put
Clean up. There is only one remaining rpcrdma_mr_put call site, and
it can be directly replaced with unmap_and_put because mr->mr_dir is
set to DMA_NONE just before the call.

Now all the call sites do a DMA unmap, and we can just rename
mr_unmap_and_put to mr_put, which nicely matches mr_get.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20 16:11:56 -04:00
Chuck Lever 265a38d461 xprtrdma: Simplify rpcrdma_mr_pop
Clean up: rpcrdma_mr_pop call sites check if the list is empty
first. Let's replace the list_empty with less costly logic.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20 16:03:41 -04:00
Chuck Lever 36bdd9056b xprtrdma: Fix calculation of ri_max_segs again
Commit 302d3deb20 ("xprtrdma: Prevent inline overflow") added this
calculation back in 2016, but got it wrong. I tested only the lower
bound, which is why there is a max_t there. The upper bound should be
rounded up too.

Now, when using DIV_ROUND_UP, that takes care of the lower bound as
well.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20 11:01:03 -04:00
Chuck Lever 2fb2a4d529 xprtrdma: Refresh the documenting comment in frwr_ops.c
Things have changed since this comment was written. In particular,
the reworking of connection closing, on-demand creation of MRs, and
the removal of fr_state all mean that deferring MR recovery to
frwr_map is no longer needed. The description is obsolete.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-20 10:51:35 -04:00
Chuck Lever d8099feda4 xprtrdma: Reduce context switching due to Local Invalidation
Since commit ba69cd122e ("xprtrdma: Remove support for FMR memory
registration"), FRWR is the only supported memory registration mode.

We can take advantage of the asynchronous nature of FRWR's LOCAL_INV
Work Requests to get rid of the completion wait by having the
LOCAL_INV completion handler take care of DMA unmapping MRs and
waking the upper layer RPC waiter.

This eliminates two context switches when local invalidation is
necessary. As a side benefit, we will no longer need the per-xprt
deferred completion work queue.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-07-09 10:30:25 -04:00
Chuck Lever 40088f0e9b xprtrdma: Add mechanism to place MRs back on the free list
When a marshal operation fails, any MRs that were already set up for
that request are recycled. Recycling releases MRs and creates new
ones, which is expensive.

Since commit f287762308 ("xprtrdma: Chain Send to FastReg WRs")
was merged, recycling FRWRs is unnecessary. This is because before
that commit, frwr_map had already posted FAST_REG Work Requests,
so ownership of the MRs had already been passed to the NIC and thus
dealing with them had to be delayed until they completed.

Since that commit, however, FAST_REG WRs are posted at the same time
as the Send WR. This means that if marshaling fails, we are certain
the MRs are safe to simply unmap and place back on the free list
because neither the Send nor the FAST_REG WRs have been posted yet.
The kernel still has ownership of the MRs at this point.

This reduces the total number of MRs that the xprt has to create
under heavy workloads and makes the marshaling logic less brittle.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-07-09 10:30:25 -04:00
Chuck Lever 847568942f xprtrdma: Remove fr_state
Now that both the Send and Receive completions are handled in
process context, it is safe to DMA unmap and return MRs to the
free or recycle lists directly in the completion handlers.

Doing this means rpcrdma_frwr no longer needs to track the state of
each MR, meaning that a VALID or FLUSHED MR can no longer appear on
an xprt's MR free list. Thus there is no longer a need to track the
MR's registration state in rpcrdma_frwr.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-07-09 10:30:25 -04:00
Chuck Lever 05eb06d866 xprtrdma: Fix occasional transport deadlock
Under high I/O workloads, I've noticed that an RPC/RDMA transport
occasionally deadlocks (IOPS goes to zero, and doesn't recover).
Diagnosis shows that the sendctx queue is empty, but when sendctxs
are returned to the queue, the xprt_write_space wake-up never
occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy.

I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented
via an atomic bit. Just one of those is sufficient. Removing
EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock
un-reproducible.

Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and
is therefore removed.

Unfortunately this patch does not apply cleanly to stable. If
needed, someone will have to port it and test it.

Fixes: 2fad659209 ("xprtrdma: Wait on empty sendctx queue")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-07-09 10:30:16 -04:00
Chuck Lever 5f2311f5bd xprtrdma: Remove pr_err() call sites from completion handlers
Clean up: rely on the trace points instead.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 15:40:09 -04:00
Chuck Lever 86c4ccd9b9 xprtrdma: Eliminate struct rpcrdma_create_data_internal
Clean up.

Move the remaining field in rpcrdma_create_data_internal so the
structure can be removed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 15:39:40 -04:00
Chuck Lever f19bd0bbd3 xprtrdma: Eliminate rpcrdma_ia::ri_device
Clean up.

Since commit 54cbd6b0c6 ("xprtrdma: Delay DMA mapping Send and
Receive buffers"), a pointer to the device is now saved in each
regbuf when it is DMA mapped.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 15:21:18 -04:00
Chuck Lever b2ca473b92 xprtrdma: Fix an frwr_map recovery nit
After a DMA map failure in frwr_map, mark the MR so that recycling
won't attempt to DMA unmap it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Fixes: e2f34e2671 ("xprtrdma: Yet another double DMA-unmap")
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:59:25 -04:00
Chuck Lever ec482cc1c1 xprtrdma: Fix sparse warnings
linux/net/sunrpc/xprtrdma/rpc_rdma.c:375:63: warning: incorrect type in argument 5 (different base types)
linux/net/sunrpc/xprtrdma/rpc_rdma.c:375:63:    expected unsigned int [usertype] xid
linux/net/sunrpc/xprtrdma/rpc_rdma.c:375:63:    got restricted __be32 [usertype] rq_xid
linux/net/sunrpc/xprtrdma/rpc_rdma.c:432:62: warning: incorrect type in argument 5 (different base types)
linux/net/sunrpc/xprtrdma/rpc_rdma.c:432:62:    expected unsigned int [usertype] xid
linux/net/sunrpc/xprtrdma/rpc_rdma.c:432:62:    got restricted __be32 [usertype] rq_xid
linux/net/sunrpc/xprtrdma/rpc_rdma.c:489:62: warning: incorrect type in argument 5 (different base types)
linux/net/sunrpc/xprtrdma/rpc_rdma.c:489:62:    expected unsigned int [usertype] xid
linux/net/sunrpc/xprtrdma/rpc_rdma.c:489:62:    got restricted __be32 [usertype] rq_xid

Fixes: 0a93fbcb16 ("xprtrdma: Plant XID in on-the-wire RDMA ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-02-13 10:05:24 -05:00
Chuck Lever f85adb1bf5 xprtrdma: Don't leak freed MRs
Defensive clean up. Don't set frwr->fr_mr until we know that the
scatterlist allocation has succeeded.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:18 -05:00
Chuck Lever e0f86bc4f9 xprtrdma: Update comments in frwr_op_send
Commit f287762308 ("xprtrdma: Chain Send to FastReg WRs") was
written before commit ce5b371782 ("xprtrdma: Replace all usage of
"frmr" with "frwr""), but was merged afterwards. Thus it still
refers to FRMR and MWs.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:18 -05:00
Chuck Lever 53b2c1cb9b xprtrdma: Trace mapping, alloc, and dereg failures
These are rare, but can be helpful at tracking down DMAR and other
problems.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:18 -05:00
Chuck Lever ba217ec64a xprtrdma: Relocate the xprtrdma_mr_map trace points
The mr_map trace points were capturing information about the previous
use of the MR rather than about the segment that was just mapped.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:18 -05:00
Chuck Lever 0a93fbcb16 xprtrdma: Plant XID in on-the-wire RDMA offset (FRWR)
Place the associated RPC transaction's XID in the upper 32 bits of
each RDMA segment's rdma_offset field. There are two reasons to do
this:

- The R_key only has 8 bits that are different from registration to
  registration. The XID adds more uniqueness to each RDMA segment to
  reduce the likelihood of a software bug on the server reading from
  or writing into memory it's not supposed to.

- On-the-wire RDMA Read and Write requests do not otherwise carry
  any identifier that matches them up to an RPC. The XID in the
  upper 32 bits will act as an eye-catcher in network captures.

Suggested-by: Tom Talpey <ttalpey@microsoft.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:17 -05:00
Chuck Lever 5f62412be3 xprtrdma: Remove rpcrdma_memreg_ops
Clean up: Now that there is only FRWR, there is no need for a memory
registration switch. The indirect calls to the memreg operations can
be replaced with faster direct calls.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:17 -05:00
Chuck Lever a78868497c xprtrdma: Reduce max_frwr_depth
Some devices advertise a large max_fast_reg_page_list_len
capability, but perform optimally when MRs are significantly smaller
than that depth -- probably when the MR itself is no larger than a
page.

By default, the RDMA R/W core API uses max_sge_rd as the maximum
page depth for MRs. For some devices, the value of max_sge_rd is
1, which is also not optimal. Thus, when max_sge_rd is larger than
1, use that value. Otherwise use the value of the
max_fast_reg_page_list_len attribute.

I've tested this with CX-3 Pro, FastLinq, and CX-5 devices. It
reproducibly improves the throughput of large I/Os by several
percent.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:17 -05:00
Chuck Lever 6946f82380 xprtrdma: Fix ri_max_segs and the result of ro_maxpages
With certain combinations of krb5i/p, MR size, and r/wsize, I/O can
fail with EMSGSIZE. This is because the calculated value of
ri_max_segs (the max number of MRs per RPC) exceeded
RPCRDMA_MAX_HDR_SEGS, which caused Read or Write list encoding to
walk off the end of the transport header.

Once that was addressed, the ro_maxpages result has to be corrected
to account for the number of MRs needed for Reply chunks, which is
2 MRs smaller than a normal Read or Write chunk.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:16 -05:00
Chuck Lever b674c4b4a1 xprtrdma: Ensure MRs are DMA-unmapped when posting LOCAL_INV fails
The recovery case in frwr_op_unmap_sync needs to DMA unmap each MR.
frwr_release_mr does not DMA-unmap, but the recycle worker does.

Fixes: 61da886bf7 ("xprtrdma: Explicitly resetting MRs is ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:16 -05:00
Chuck Lever e2f34e2671 xprtrdma: Yet another double DMA-unmap
While chasing yet another set of DMAR fault reports, I noticed that
the frwr recycler conflates whether or not an MR has been DMA
unmapped with frwr->fr_state. Actually the two have only an indirect
relationship. It's in fact impossible to guess reliably whether the
MR has been DMA unmapped based on its fr_state field, especially as
the surrounding code and its assumptions have changed over time.

A better approach is to track the DMA mapping status explicitly so
that the recycler is less brittle to unexpected situations, and
attempts to DMA-unmap a second time are prevented.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org # v4.20
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-02 12:05:16 -05:00
Chuck Lever d379eaa838 xprtrdma: Name MR trace events consistently
Clean up the names of trace events related to MRs so that it's
easy to enable these with a glob.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-10-02 15:55:36 -04:00
Chuck Lever 61da886bf7 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 e2ac236c0b ("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>
2018-10-02 15:48:12 -04:00
Chuck Lever c421ece68f 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>
2018-10-02 15:46:35 -04:00
Bart Van Assche d34ac5cd3a RDMA, core and ULPs: Declare ib_post_send() and ib_post_recv() arguments const
Since neither ib_post_send() nor ib_post_recv() modify the data structure
their second argument points at, declare that argument const. This change
makes it necessary to declare the 'bad_wr' argument const too and also to
modify all ULPs that call ib_post_send(), ib_post_recv() or
ib_post_srq_recv(). This patch does not change any functionality but makes
it possible for the compiler to verify whether the
ib_post_(send|recv|srq_recv) really do not modify the posted work request.

To make this possible, only one cast had to be introduce that casts away
constness, namely in rpcrdma_post_recvs(). The only way I can think of to
avoid that cast is to introduce an additional loop in that function or to
change the data type of bad_wr from struct ib_recv_wr ** into int
(an index that refers to an element in the work request list). However,
both approaches would require even more extensive changes than this
patch.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-30 20:09:34 -06:00
Bart Van Assche ed288d74a9 net/xprtrdma: Simplify ib_post_(send|recv|srq_recv)() calls
Instead of declaring and passing a dummy 'bad_wr' pointer, pass NULL
as third argument to ib_post_(send|recv|srq_recv)().

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-24 16:06:37 -06:00
Linus Torvalds 0725d4e1b8 NFS client updates for Linux 4.18
Highlights include:
 
 Stable fixes:
 - Fix a 1-byte stack overflow in nfs_idmap_read_and_verify_message
 - Fix a hang due to incorrect error returns in rpcrdma_convert_iovs()
 - Revert an incorrect change to the NFSv4.1 callback channel
 - Fix a bug in the NFSv4.1 sequence error handling
 
 Features and optimisations:
 - Support for piggybacking a LAYOUTGET operation to the OPEN compound
 - RDMA performance enhancements to deal with transport congestion
 - Add proper SPDX tags for NetApp-contributed RDMA source
 - Do not request delegated file attributes (size+change) from the server
 - Optimise away a GETATTR in the lookup revalidate code when doing NFSv4 OPEN
 - Optimise away unnecessary lookups for rename targets
 - Misc performance improvements when freeing NFSv4 delegations
 
 Bugfixes and cleanups:
 - Try to fail quickly if proto=rdma
 - Clean up RDMA receive trace points
 - Fix sillyrename to return the delegation when appropriate
 - Misc attribute revalidation fixes
 - Immediately clear the pNFS layout on a file when the server returns ESTALE
 - Return NFS4ERR_DELAY when delegation/layout recalls fail due to igrab()
 - Fix the client behaviour on NFS4ERR_SEQ_FALSE_RETRY
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Merge tag 'nfs-for-4.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:

   - Fix a 1-byte stack overflow in nfs_idmap_read_and_verify_message

   - Fix a hang due to incorrect error returns in rpcrdma_convert_iovs()

   - Revert an incorrect change to the NFSv4.1 callback channel

   - Fix a bug in the NFSv4.1 sequence error handling

  Features and optimisations:

   - Support for piggybacking a LAYOUTGET operation to the OPEN compound

   - RDMA performance enhancements to deal with transport congestion

   - Add proper SPDX tags for NetApp-contributed RDMA source

   - Do not request delegated file attributes (size+change) from the
     server

   - Optimise away a GETATTR in the lookup revalidate code when doing
     NFSv4 OPEN

   - Optimise away unnecessary lookups for rename targets

   - Misc performance improvements when freeing NFSv4 delegations

  Bugfixes and cleanups:

   - Try to fail quickly if proto=rdma

   - Clean up RDMA receive trace points

   - Fix sillyrename to return the delegation when appropriate

   - Misc attribute revalidation fixes

   - Immediately clear the pNFS layout on a file when the server returns
     ESTALE

   - Return NFS4ERR_DELAY when delegation/layout recalls fail due to
     igrab()

   - Fix the client behaviour on NFS4ERR_SEQ_FALSE_RETRY"

* tag 'nfs-for-4.18-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (80 commits)
  skip LAYOUTRETURN if layout is invalid
  NFSv4.1: Fix the client behaviour on NFS4ERR_SEQ_FALSE_RETRY
  NFSv4: Fix a typo in nfs41_sequence_process
  NFSv4: Revert commit 5f83d86cf5 ("NFSv4.x: Fix wraparound issues..")
  NFSv4: Return NFS4ERR_DELAY when a layout recall fails due to igrab()
  NFSv4: Return NFS4ERR_DELAY when a delegation recall fails due to igrab()
  NFSv4.0: Remove transport protocol name from non-UCS client ID
  NFSv4.0: Remove cl_ipaddr from non-UCS client ID
  NFSv4: Fix a compiler warning when CONFIG_NFS_V4_1 is undefined
  NFS: Filter cache invalidation when holding a delegation
  NFS: Ignore NFS_INO_REVAL_FORCED in nfs_check_inode_attributes()
  NFS: Improve caching while holding a delegation
  NFS: Fix attribute revalidation
  NFS: fix up nfs_setattr_update_inode
  NFSv4: Ensure the inode is clean when we set a delegation
  NFSv4: Ignore NFS_INO_REVAL_FORCED in nfs4_proc_access
  NFSv4: Don't ask for delegated attributes when adding a hard link
  NFSv4: Don't ask for delegated attributes when revalidating the inode
  NFS: Pass the inode down to the getattr() callback
  NFSv4: Don't request size+change attribute if they are delegated to us
  ...
2018-06-12 10:09:03 -07:00
Linus Torvalds 89e255678f A relatively quiet cycle for nfsd. The largest piece is an RDMA update
from Chuck Lever with new trace points, miscellaneous cleanups, and
 streamlining of the send and receive paths.  Other than that, some
 miscellaneous bugfixes.
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Merge tag 'nfsd-4.18' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "A relatively quiet cycle for nfsd.

  The largest piece is an RDMA update from Chuck Lever with new trace
  points, miscellaneous cleanups, and streamlining of the send and
  receive paths.

  Other than that, some miscellaneous bugfixes"

* tag 'nfsd-4.18' of git://linux-nfs.org/~bfields/linux: (26 commits)
  nfsd: fix error handling in nfs4_set_delegation()
  nfsd: fix potential use-after-free in nfsd4_decode_getdeviceinfo
  Fix 16-byte memory leak in gssp_accept_sec_context_upcall
  svcrdma: Fix incorrect return value/type in svc_rdma_post_recvs
  svcrdma: Remove unused svc_rdma_op_ctxt
  svcrdma: Persistently allocate and DMA-map Send buffers
  svcrdma: Simplify svc_rdma_send()
  svcrdma: Remove post_send_wr
  svcrdma: Don't overrun the SGE array in svc_rdma_send_ctxt
  svcrdma: Introduce svc_rdma_send_ctxt
  svcrdma: Clean up Send SGE accounting
  svcrdma: Refactor svc_rdma_dma_map_buf
  svcrdma: Allocate recv_ctxt's on CPU handling Receives
  svcrdma: Persistently allocate and DMA-map Receive buffers
  svcrdma: Preserve Receive buffer until svc_rdma_sendto
  svcrdma: Simplify svc_rdma_recv_ctxt_put
  svcrdma: Remove sc_rq_depth
  svcrdma: Introduce svc_rdma_recv_ctxt
  svcrdma: Trace key RDMA API events
  svcrdma: Trace key RPC/RDMA protocol events
  ...
2018-06-12 09:49:33 -07:00
Trond Myklebust fcda3d5d22 NFS-over-RDMA client updates for Linux 4.18
Stable patches:
 - xprtrdma: Return -ENOBUFS when no pages are available
 
 New features:
 - Add ->alloc_slot() and ->free_slot() functions
 
 Bugfixes and cleanups:
 - Add missing SPDX tags to some files
 - Try to fail mount quickly if client has no RDMA devices
 - Create transport IDs in the correct network namespace
 - Fix max_send_wr computation
 - Clean up receive tracepoints
 - Refactor receive handling
 - Remove unused functions
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Merge tag 'nfs-rdma-for-4.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

NFS-over-RDMA client updates for Linux 4.18

Stable patches:
- xprtrdma: Return -ENOBUFS when no pages are available

New features:
- Add ->alloc_slot() and ->free_slot() functions

Bugfixes and cleanups:
- Add missing SPDX tags to some files
- Try to fail mount quickly if client has no RDMA devices
- Create transport IDs in the correct network namespace
- Fix max_send_wr computation
- Clean up receive tracepoints
- Refactor receive handling
- Remove unused functions
2018-06-04 18:57:13 -04:00
Chuck Lever 8335640cf8 xprtrdma: Add trace_xprtrdma_dma_map(mr)
Matches trace_xprtrdma_dma_unmap(mr).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-06-01 13:56:30 -04:00
Chuck Lever bd2abef333 svcrdma: Trace key RDMA API events
This includes:
  * Posting on the Send and Receive queues
  * Send, Receive, Read, and Write completion
  * Connect upcalls
  * QP errors

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever b6e717cbf2 xprtrdma: Prepare RPC/RDMA includes for server-side trace points
Clean up: Move #include <trace/events/rpcrdma.h> into source files,
similar to how it is done with trace/events/sunrpc.h.

Server-side trace points will be part of the rpcrdma subsystem,
just like the client-side trace points.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-05-11 15:48:57 -04:00
Chuck Lever 914fcad987 xprtrdma: Fix max_send_wr computation
For FRWR, the computation of max_send_wr is split between
frwr_op_open and rpcrdma_ep_create, which makes it difficult to tell
that the max_send_wr result is currently incorrect if frwr_op_open
has to reduce the credit limit to accommodate a small max_qp_wr.
This is a problem now that extra WRs are needed for backchannel
operations and a drain CQE.

So, refactor the computation so that it is all done in ->ro_open,
and fix the FRWR version of this computation so that it
accommodates HCAs with small max_qp_wr correctly.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-07 09:20:03 -04:00
Chuck Lever 054f155721 xprtrdma: Fix list corruption / DMAR errors during MR recovery
The ro_release_mr methods check whether mr->mr_list is empty.
Therefore, be sure to always use list_del_init when removing an MR
linked into a list using that field. Otherwise, when recovering from
transport failures or device removal, list corruption can result, or
MRs can get mapped or unmapped an odd number of times, resulting in
IOMMU-related failures.

In general this fix is appropriate back to v4.8. However, code
changes since then make it impossible to apply this patch directly
to stable kernels. The fix would have to be applied by hand or
reworked for kernels earlier than v4.16.

Backport guidance -- there are several cases:
- When creating an MR, initialize mr_list so that using list_empty
  on an as-yet-unused MR is safe.
- When an MR is being handled by the remote invalidation path,
  ensure that mr_list is reinitialized when it is removed from
  rl_registered.
- When an MR is being handled by rpcrdma_destroy_mrs, it is removed
  from mr_all, but it may still be on an rl_registered list. In
  that case, the MR needs to be removed from that list before being
  released.
- Other cases are covered by using list_del_init in rpcrdma_mr_pop.

Fixes: 9d6b040978 ('xprtrdma: Place registered MWs on a ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-01 13:29:43 -04:00
Chuck Lever f287762308 xprtrdma: Chain Send to FastReg WRs
With FRWR, the client transport can perform memory registration and
post a Send with just a single ib_post_send.

This reduces contention between the send_request path and the Send
Completion handlers, and reduces the overhead of registering a chunk
that has multiple segments.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:06:22 -04:00