Commit Graph

2950 Commits

Author SHA1 Message Date
Trond Myklebust
92ea011f7c SUNRPC: Make slot allocation more reliable
In xprt_alloc_slot(), the spin lock is only needed to provide atomicity
between the atomic_add_unless() failure and the call to xprt_add_backlog().
We do not actually need to hold it across the memory allocation itself.

By dropping the lock, we can use a more resilient GFP_NOFS allocation,
just as we now do in the rest of the RPC client code.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-07-13 15:58:04 -04:00
Christoph Hellwig
aa8217d5dc sunrpc: mark all struct svc_version instances as const
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-07-13 15:58:03 -04:00
Christoph Hellwig
b9c744c19c sunrpc: mark all struct svc_procinfo instances as const
struct svc_procinfo contains function pointers, and marking it as
constant avoids it being able to be used as an attach vector for
code injections.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-07-13 15:58:02 -04:00
Christoph Hellwig
0becc1181c sunrpc: move pc_count out of struct svc_procinfo
pc_count is the only writeable memeber of struct svc_procinfo, which is
a good candidate to be const-ified as it contains function pointers.

This patch moves it into out out struct svc_procinfo, and into a
separate writable array that is pointed to by struct svc_version.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-07-13 15:58:02 -04:00
Christoph Hellwig
d16d186721 sunrpc: properly type pc_encode callbacks
Drop the resp argument as it can trivially be derived from the rqstp
argument.  With that all functions now have the same prototype, and we
can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-07-13 15:58:00 -04:00
Christoph Hellwig
cc6acc20a6 sunrpc: properly type pc_decode callbacks
Drop the argp argument as it can trivially be derived from the rqstp
argument.  With that all functions now have the same prototype, and we
can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-07-13 15:58:00 -04:00
Christoph Hellwig
1150ded804 sunrpc: properly type pc_release callbacks
Drop the p and resp arguments as they are always NULL or can trivially
be derived from the rqstp argument.  With that all functions now have the
same prototype, and we can remove the unsafe casting to kxdrproc_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-07-13 15:57:59 -04:00
Christoph Hellwig
1c8a5409f3 sunrpc: properly type pc_func callbacks
Drop the argp and resp arguments as they can trivially be derived from
the rqstp argument.  With that all functions now have the same prototype,
and we can remove the unsafe casting to svc_procfunc as well as the
svc_procfunc typedef itself.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-07-13 15:57:59 -04:00
Christoph Hellwig
511e936bf2 sunrpc: mark all struct rpc_procinfo instances as const
struct rpc_procinfo contains function pointers, and marking it as
constant avoids it being able to be used as an attach vector for
code injections.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-07-13 15:57:57 -04:00
Christoph Hellwig
c551858a88 sunrpc: move p_count out of struct rpc_procinfo
p_count is the only writeable memeber of struct rpc_procinfo, which is
a good candidate to be const-ified as it contains function pointers.

This patch moves it into out out struct rpc_procinfo, and into a
separate writable array that is pointed to by struct rpc_version and
indexed by p_statidx.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-07-13 15:57:57 -04:00
Christoph Hellwig
c56c620b3e sunrpc/auth_gss: fix decoder callback prototypes
Declare the p_decode callbacks with the proper prototype instead of
casting to kxdrdproc_t and losing all type safety.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-07-13 15:57:55 -04:00
Christoph Hellwig
555966beff sunrpc: fix decoder callback prototypes
Declare the p_decode callbacks with the proper prototype instead of
casting to kxdrdproc_t and losing all type safety.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
2017-07-13 15:57:54 -04:00
Christoph Hellwig
993328e2b3 sunrpc: properly type argument to kxdrdproc_t
Pass struct rpc_request as the first argument instead of an untyped blob.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-07-13 15:57:54 -04:00
Christoph Hellwig
df17938122 sunrpc/auth_gss: nfsd: fix encoder callback prototypes
Declare the p_encode callbacks with the proper prototype instead of
casting to kxdreproc_t and losing all type safety.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-07-13 15:57:54 -04:00
Christoph Hellwig
8be9d07f0c sunrpc: fix encoder callback prototypes
Declare the p_encode callbacks with the proper prototype instead of
casting to kxdreproc_t and losing all type safety.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-07-13 15:57:53 -04:00
Christoph Hellwig
0aebdc52ca sunrpc: properly type argument to kxdreproc_t
Pass struct rpc_request as the first argument instead of an untyped blob,
and mark the data object as const.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
2017-07-13 15:57:52 -04:00
NeilBrown
6ea44adce9 SUNRPC: ensure correct error is reported by xs_tcp_setup_socket()
If you attempt a TCP mount from an host that is unreachable in a way
that triggers an immediate error from kernel_connect(), that error
does not propagate up, instead EAGAIN is reported.

This results in call_connect_status receiving the wrong error.

A case that it easy to demonstrate is to attempt to mount from an
address that results in ENETUNREACH, but first deleting any default
route.
Without this patch, the mount.nfs process is persistently runnable
and is hard to kill.  With this patch it exits as it should.

The problem is caused by the fact that xs_tcp_force_close() eventually
calls
      xprt_wake_pending_tasks(xprt, -EAGAIN);
which causes an error return of -EAGAIN.  so when xs_tcp_setup_sock()
calls
      xprt_wake_pending_tasks(xprt, status);
the status is ignored.

Fixes: 4efdd92c92 ("SUNRPC: Remove TCP client connection reset hack")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-31 12:26:44 -04:00
Markus Elfring
d2c23c0075 xprtrdma: Delete an error message for a failed memory allocation in xprt_rdma_bc_setup()
Omit an extra message for a memory allocation failure in this function.

This issue was detected by using the Coccinelle software.

Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-24 07:53:37 -04:00
Linus Torvalds
c70422f760 Another RDMA update from Chuck Lever, and a bunch of miscellaneous
bugfixes.
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Merge tag 'nfsd-4.12' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Another RDMA update from Chuck Lever, and a bunch of miscellaneous
  bugfixes"

* tag 'nfsd-4.12' of git://linux-nfs.org/~bfields/linux: (26 commits)
  nfsd: Fix up the "supattr_exclcreat" attributes
  nfsd: encoders mustn't use unitialized values in error cases
  nfsd: fix undefined behavior in nfsd4_layout_verify
  lockd: fix lockd shutdown race
  NFSv4: Fix callback server shutdown
  SUNRPC: Refactor svc_set_num_threads()
  NFSv4.x/callback: Create the callback service through svc_create_pooled
  lockd: remove redundant check on block
  svcrdma: Clean out old XDR encoders
  svcrdma: Remove the req_map cache
  svcrdma: Remove unused RDMA Write completion handler
  svcrdma: Reduce size of sge array in struct svc_rdma_op_ctxt
  svcrdma: Clean up RPC-over-RDMA backchannel reply processing
  svcrdma: Report Write/Reply chunk overruns
  svcrdma: Clean up RDMA_ERROR path
  svcrdma: Use rdma_rw API in RPC reply path
  svcrdma: Introduce local rdma_rw API helpers
  svcrdma: Clean up svc_rdma_get_inv_rkey()
  svcrdma: Add helper to save pages under I/O
  svcrdma: Eliminate RPCRDMA_SQ_DEPTH_MULT
  ...
2017-05-10 13:29:23 -07:00
Trond Myklebust
ed6473ddc7 NFSv4: Fix callback server shutdown
We want to use kthread_stop() in order to ensure the threads are
shut down before we tear down the nfs_callback_info in nfs_callback_down.

Tested-and-reviewed-by: Kinglong Mee <kinglongmee@gmail.com>
Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Fixes: bb6aeba736 ("NFSv4.x: Switch to using svc_set_num_threads()...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-27 18:00:16 -04:00
Trond Myklebust
9e0d87680d SUNRPC: Refactor svc_set_num_threads()
Refactor to separate out the functions of starting and stopping threads
so that they can be used in other helpers.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-and-reviewed-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-27 17:59:58 -04:00
Trond Myklebust
35a2442189 NFS: NFS over RDMA Client Side Changes
New Features:
 - Break RDMA connections after a connection timeout
 - Support for unloading the underlying device driver
 
 Bugfixes and cleanups:
 - Mark the receive workqueue as "read-mostly"
 - Silence warnings caused by ENOBUFS
 - Update a comment in xdr_init_decode_pages()
 - Remove rpcrdma_buffer->rb_pool.
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Merge tag 'nfs-rdma-4.12-1' of git://git.linux-nfs.org/projects/anna/nfs-rdma

NFS: NFS over RDMA Client Side Changes

New Features:
- Break RDMA connections after a connection timeout
- Support for unloading the underlying device driver

Bugfixes and cleanups:
- Mark the receive workqueue as "read-mostly"
- Silence warnings caused by ENOBUFS
- Update a comment in xdr_init_decode_pages()
- Remove rpcrdma_buffer->rb_pool.
2017-04-25 18:42:48 -04:00
Chuck Lever
dadf3e435d svcrdma: Clean out old XDR encoders
Clean up: These have been replaced and are no longer used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:56 -04:00
Chuck Lever
2cf32924c6 svcrdma: Remove the req_map cache
req_maps are no longer used by the send path and can thus be removed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:55 -04:00
Chuck Lever
68cc4636bb svcrdma: Remove unused RDMA Write completion handler
Clean up. All RDMA Write completions are now handled by
svc_rdma_wc_write_ctx.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:55 -04:00
Chuck Lever
ded8d19641 svcrdma: Reduce size of sge array in struct svc_rdma_op_ctxt
The sge array in struct svc_rdma_op_ctxt is no longer used for
sending RDMA Write WRs. It need only accommodate the construction of
Send and Receive WRs. The maximum inline size is the largest payload
it needs to handle now.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:55 -04:00
Chuck Lever
f5821c76b2 svcrdma: Clean up RPC-over-RDMA backchannel reply processing
Replace C structure-based XDR decoding with pointer arithmetic.
Pointer arithmetic is considered more portable.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:55 -04:00
Chuck Lever
4757d90b15 svcrdma: Report Write/Reply chunk overruns
Observed at Connectathon 2017.

If a client has underestimated the size of a Write or Reply chunk,
the Linux server writes as much payload data as it can, then it
recognizes there was a problem and closes the connection without
sending the transport header.

This creates a couple of problems:

<> The client never receives indication of the server-side failure,
   so it continues to retransmit the bad RPC. Forward progress on
   the transport is blocked.

<> The reply payload pages are not moved out of the svc_rqst, thus
   they can be released by the RPC server before the RDMA Writes
   have completed.

The new rdma_rw-ized helpers return a distinct error code when a
Write/Reply chunk overrun occurs, so it's now easy for the caller
(svc_rdma_sendto) to recognize this case.

Instead of dropping the connection, post an RDMA_ERROR message. The
client now sees an RDMA_ERROR and can properly terminate the RPC
transaction.

As part of the new logic, set up the same delayed release for these
payload pages as would have occurred in the normal case.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:55 -04:00
Chuck Lever
6b19cc5ca2 svcrdma: Clean up RDMA_ERROR path
Now that svc_rdma_sendto has been renovated, svc_rdma_send_error can
be refactored to reduce code duplication and remove C structure-
based XDR encoding. It is also relocated to the source file that
contains its only caller.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:55 -04:00
Chuck Lever
9a6a180b78 svcrdma: Use rdma_rw API in RPC reply path
The current svcrdma sendto code path posts one RDMA Write WR at a
time. Each of these Writes typically carries a small number of pages
(for instance, up to 30 pages for mlx4 devices). That means a 1MB
NFS READ reply requires 9 ib_post_send() calls for the Write WRs,
and one for the Send WR carrying the actual RPC Reply message.

Instead, use the new rdma_rw API. The details of Write WR chain
construction and memory registration are taken care of in the RDMA
core. svcrdma can focus on the details of the RPC-over-RDMA
protocol. This gives three main benefits:

1. All Write WRs for one RDMA segment are posted in a single chain.
As few as one ib_post_send() for each Write chunk.

2. The Write path can now use FRWR to register the Write buffers.
If the device's maximum page list depth is large, this means a
single Write WR is needed for each RPC's Write chunk data.

3. The new code introduces support for RPCs that carry both a Write
list and a Reply chunk. This combination can be used for an NFSv4
READ where the data payload is large, and thus is removed from the
Payload Stream, but the Payload Stream is still larger than the
inline threshold.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:55 -04:00
Chuck Lever
f13193f50b svcrdma: Introduce local rdma_rw API helpers
The plan is to replace the local bespoke code that constructs and
posts RDMA Read and Write Work Requests with calls to the rdma_rw
API. This shares code with other RDMA-enabled ULPs that manages the
gory details of buffer registration and posting Work Requests.

Some design notes:

 o The structure of RPC-over-RDMA transport headers is flexible,
   allowing multiple segments per Reply with arbitrary alignment,
   each with a unique R_key. Write and Send WRs continue to be
   built and posted in separate code paths. However, one whole
   chunk (with one or more RDMA segments apiece) gets exactly
   one ib_post_send and one work completion.

 o svc_xprt reference counting is modified, since a chain of
   rdma_rw_ctx structs generates one completion, no matter how
   many Write WRs are posted.

 o The current code builds the transport header as it is construct-
   ing Write WRs. I've replaced that with marshaling of transport
   header data items in a separate step. This is because the exact
   structure of client-provided segments may not align with the
   components of the server's reply xdr_buf, or the pages in the
   page list. Thus parts of each client-provided segment may be
   written at different points in the send path.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:55 -04:00
Chuck Lever
c238c4c034 svcrdma: Clean up svc_rdma_get_inv_rkey()
Replace C structure-based XDR decoding with more portable code that
instead uses pointer arithmetic.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:54 -04:00
Chuck Lever
c55ab0707b svcrdma: Add helper to save pages under I/O
Clean up: extract the logic to save pages under I/O into a helper to
add a big documenting comment without adding clutter in the send
path.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:54 -04:00
Chuck Lever
b623589dba svcrdma: Eliminate RPCRDMA_SQ_DEPTH_MULT
The Send Queue depth is temporarily reduced to 1 SQE per credit. The
new rdma_rw API does an internal computation, during QP creation, to
increase the depth of the Send Queue to handle RDMA Read and Write
operations.

This change has to come before the NFSD code paths are updated to
use the rdma_rw API. Without this patch, rdma_rw_init_qp() increases
the size of the SQ too much, resulting in memory allocation failures
during QP creation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:54 -04:00
Chuck Lever
6e6092ca30 svcrdma: Add svc_rdma_map_reply_hdr()
Introduce a helper to DMA-map a reply's transport header before
sending it. This will in part replace the map vector cache.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:54 -04:00
Chuck Lever
17f5f7f506 svcrdma: Move send_wr to svc_rdma_op_ctxt
Clean up: Move the ib_send_wr off the stack, and move common code
to post a Send Work Request into a helper.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-04-25 17:25:54 -04:00
Chuck Lever
2be1fce95e xprtrdma: Remove rpcrdma_buffer::rb_pool
Since commit 1e465fd4ff ("xprtrdma: Replace send and receive
arrays"), this field is no longer used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:35 -04:00
Chuck Lever
7ecce75fc3 sunrpc: Fix xdr_init_decode_pages() documenting comment
Clean up.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:34 -04:00
Chuck Lever
0031e47c76 xprtrdma: Squelch ENOBUFS warnings
When ro_map is out of buffers, that's not a permanent error, so
don't report a problem.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:33 -04:00
Chuck Lever
7d7fa9b550 xprtrdma: Annotate receive workqueue
Micro-optimize the receive workqueue by marking it's anchor "read-
mostly."

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:31 -04:00
Chuck Lever
56a6bd154d xprtrdma: Revert commit d0f36c46de
Device removal is now adequately supported. Pinning the underlying
device driver to prevent removal while an NFS mount is active is no
longer necessary.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:30 -04:00
Chuck Lever
a9b0e381ca xprtrdma: Restore transport after device removal
After a device removal, enable the transport connect worker to
restore normal operation if there is another device with
connectivity to the server.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:28 -04:00
Chuck Lever
1890896b4e xprtrdma: Refactor rpcrdma_ep_connect
I'm about to add another arm to

    if (ep->rep_connected != 0)

It will be cleaner to use a switch statement here. We'll be looking
for a couple of specific errnos, or "anything else," basically to
sort out the difference between a normal reconnect and recovery from
device removal.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:27 -04:00
Chuck Lever
bebd031866 xprtrdma: Support unplugging an HCA from under an NFS mount
The device driver for the underlying physical device associated
with an RPC-over-RDMA transport can be removed while RPC-over-RDMA
transports are still in use (ie, while NFS filesystems are still
mounted and active). The IB core performs a connection event upcall
to request that consumers free all RDMA resources associated with
a transport.

There may be pending RPCs when this occurs. Care must be taken to
release associated resources without leaving references that can
trigger a subsequent crash if a signal or soft timeout occurs. We
rely on the caller of the transport's ->close method to ensure that
the previous RPC task has invoked xprt_release but the transport
remains write-locked.

A DEVICE_REMOVE upcall forces a disconnect then sleeps. When ->close
is invoked, it destroys the transport's H/W resources, then wakes
the upcall, which completes and allows the core driver unload to
continue.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=266
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:24 -04:00
Chuck Lever
91a10c5297 xprtrdma: Use same device when mapping or syncing DMA buffers
When the underlying device driver is reloaded, ia->ri_device will be
replaced. All cached copies of that device pointer have to be
updated as well.

Commit 54cbd6b0c6 ("xprtrdma: Delay DMA mapping Send and Receive
buffers") added the rg_device field to each regbuf. As part of
handling a device removal, rpcrdma_dma_unmap_regbuf is invoked on
all regbufs for a transport.

Simply calling rpcrdma_dma_map_regbuf for each Receive buffer after
the driver has been reloaded should reinitialize rg_device correctly
for every case except rpcrdma_wc_receive, which still uses
rpcrdma_rep::rr_device.

Ensure the same device that was used to map a Receive buffer is also
used to sync it in rpcrdma_wc_receive by using rg_device there
instead of rr_device.

This is the only use of rr_device, so it can be removed.

The use of regbufs in the send path is also updated, for
completeness.

Fixes: 54cbd6b0c6 ("xprtrdma: Delay DMA mapping Send and ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:22 -04:00
Chuck Lever
fff09594ed xprtrdma: Refactor rpcrdma_ia_open()
In order to unload a device driver and reload it, xprtrdma will need
to close a transport's interface adapter, and then call
rpcrdma_ia_open again, possibly finding a different interface
adapter.

Make rpcrdma_ia_open safe to call on the same transport multiple
times.

This is a refactoring change only.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:20 -04:00
Chuck Lever
33849792cb xprtrdma: Detect unreachable NFS/RDMA servers more reliably
Current NFS clients rely on connection loss to determine when to
retransmit. In particular, for protocols like NFSv4, clients no
longer rely on RPC timeouts to drive retransmission: NFSv4 servers
are required to terminate a connection when they need a client to
retransmit pending RPCs.

When a server is no longer reachable, either because it has crashed
or because the network path has broken, the server cannot actively
terminate a connection. Thus NFS clients depend on transport-level
keepalive to determine when a connection must be replaced and
pending RPCs retransmitted.

However, RDMA RC connections do not have a native keepalive
mechanism. If an NFS/RDMA server crashes after a client has sent
RPCs successfully (an RC ACK has been received for all OTW RDMA
requests), there is no way for the client to know the connection is
moribund.

In addition, new RDMA requests are subject to the RPC-over-RDMA
credit limit. If the client has consumed all granted credits with
NFS traffic, it is not allowed to send another RDMA request until
the server replies. Thus it has no way to send a true keepalive when
the workload has already consumed all credits with pending RPCs.

To address this, forcibly disconnect a transport when an RPC times
out. This prevents moribund connections from stopping the
detection of failover or other configuration changes on the server.

Note that even if the connection is still good, retransmitting
any RPC will trigger a disconnect thanks to this logic in
xprt_rdma_send_request:

	/* Must suppress retransmit to maintain credits */
	if (req->rl_connect_cookie == xprt->connect_cookie)
		goto drop_connection;
	req->rl_connect_cookie = xprt->connect_cookie;

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:19 -04:00
Chuck Lever
e2a4f4fbef sunrpc: Export xprt_force_disconnect()
xprt_force_disconnect() is already invoked from the socket
transport. I want to invoke xprt_force_disconnect() from the
RPC-over-RDMA transport, which is a separate module from sunrpc.ko.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:16 -04:00
Chuck Lever
9378b274e1 xprtrdma: Cancel refresh worker during buffer shutdown
Trying to create MRs while the transport is being torn down can
cause a crash.

Fixes: e2ac236c0b ("xprtrdma: Allocate MRs on demand")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-04-25 16:12:14 -04:00
NeilBrown
62b2417e84 sunrpc: don't check for failure from mempool_alloc()
When mempool_alloc() is allowed to sleep (GFP_NOIO allows
sleeping) it cannot fail.
So rpc_alloc_task() cannot fail, so rpc_new_task doesn't need
to test for failure.
Consequently rpc_new_task() cannot fail, so the callers
don't need to test.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-04-20 13:44:57 -04:00