Clean up: C-structure style XDR encoding and decoding logic has
been replaced over the past several merge windows on both the
client and server. These data structures are no longer used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Lift the Send and LocalInv completion handlers out of soft IRQ mode
to make room for other work. Also, move the Send CQ to a different
CPU than the CPU where the Receive CQ is running, for improved
scalability.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The sendctx circular queue now guarantees that xprtrdma cannot
overflow the Send Queue, so remove the remaining bits of the
original Send WQE counting mechanism.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When an RPC Call includes a file data payload, that payload can come
from pages in the page cache, or a user buffer (for direct I/O).
If the payload can fit inline, xprtrdma includes it in the Send
using a scatter-gather technique. xprtrdma mustn't allow the RPC
consumer to re-use the memory where that payload resides before the
Send completes. Otherwise, the new contents of that memory would be
exposed by an HCA retransmit of the Send operation.
So, block RPC completion on Send completion, but only in the case
where a separate file data payload is part of the Send. This
prevents the reuse of that memory while it is still part of a Send
operation without an undue cost to other cases.
Waiting is avoided in the common case because typically the Send
will have completed long before the RPC Reply arrives.
These days, an RPC timeout will trigger a disconnect, which tears
down the QP. The disconnect flushes all waiting Sends. This bounds
the amount of time the reply handler has to wait for a Send
completion.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Invoke a common routine for releasing hardware resources (for
example, invalidating MRs). This needs to be done whether an
RPC Reply has arrived or the RPC was terminated early.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
We have one boolean flag in rpcrdma_req today. I'd like to add more
flags, so convert that boolean to a bit flag.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Problem statement:
Recently Sagi Grimberg <sagi@grimberg.me> observed that kernel RDMA-
enabled storage initiators don't handle delayed Send completion
correctly. If Send completion is delayed beyond the end of a ULP
transaction, the ULP may release resources that are still being used
by the HCA to complete a long-running Send operation.
This is a common design trait amongst our initiators. Most Send
operations are faster than the ULP transaction they are part of.
Waiting for a completion for these is typically unnecessary.
Infrequently, a network partition or some other problem crops up
where an ordering problem can occur. In NFS parlance, the RPC Reply
arrives and completes the RPC, but the HCA is still retrying the
Send WR that conveyed the RPC Call. In this case, the HCA can try
to use memory that has been invalidated or DMA unmapped, and the
connection is lost. If that memory has been re-used for something
else (possibly not related to NFS), and the Send retransmission
exposes that data on the wire.
Thus we cannot assume that it is safe to release Send-related
resources just because a ULP reply has arrived.
After some analysis, we have determined that the completion
housekeeping will not be difficult for xprtrdma:
- Inline Send buffers are registered via the local DMA key, and
are already left DMA mapped for the lifetime of a transport
connection, thus no additional handling is necessary for those
- Gathered Sends involving page cache pages _will_ need to
DMA unmap those pages after the Send completes. But like
inline send buffers, they are registered via the local DMA key,
and thus will not need to be invalidated
In addition, RPC completion will need to wait for Send completion
in the latter case. However, nearly always, the Send that conveys
the RPC Call will have completed long before the RPC Reply
arrives, and thus no additional latency will be accrued.
Design notes:
In this patch, the rpcrdma_sendctx object is introduced, and a
lock-free circular queue is added to manage a set of them per
transport.
The RPC client's send path already prevents sending more than one
RPC Call at the same time. This allows us to treat the consumer
side of the queue (rpcrdma_sendctx_get_locked) as if there is a
single consumer thread.
The producer side of the queue (rpcrdma_sendctx_put_locked) is
invoked only from the Send completion handler, which is a single
thread of execution (soft IRQ).
The only care that needs to be taken is with the tail index, which
is shared between the producer and consumer. Only the producer
updates the tail index. The consumer compares the head with the
tail to ensure that the a sendctx that is in use is never handed
out again (or, expressed more conventionally, the queue is empty).
When the sendctx queue empties completely, there are enough Sends
outstanding that posting more Send operations can result in a Send
Queue overflow. In this case, the ULP is told to wait and try again.
This introduces strong Send Queue accounting to xprtrdma.
As a final touch, Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
suggested a mechanism that does not require signaling every Send.
We signal once every N Sends, and perform SGE unmapping of N Send
operations during that one completion.
Reported-by: Sagi Grimberg <sagi@grimberg.me>
Suggested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Commit 655fec6987 ("xprtrdma: Use gathered Send for large inline
messages") assumed that, since the zeroeth element of the Send SGE
array always pointed to req->rl_rdmabuf, it needed to be initialized
just once. This was a valid assumption because the Send SGE array
and rl_rdmabuf both live in the same rpcrdma_req.
In a subsequent patch, the Send SGE array will be separated from the
rpcrdma_req, so the zeroeth element of the SGE array needs to be
initialized every time.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: Make rpcrdma_prepare_send_sges() return a negative errno
instead of a bool. Soon callers will want distinct treatments of
different types of failures.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When this function fails, it needs to undo the DMA mappings it's
done so far. Otherwise these are leaked.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up. rpcrdma_prepare_hdr_sge() sets num_sge to one, then
rpcrdma_prepare_msg_sges() sets num_sge again to the count of SGEs
it added, plus one for the header SGE just mapped in
rpcrdma_prepare_hdr_sge(). This is confusing, and nails in an
assumption about when these functions are called.
Instead, maintain a running count that both functions can update
with just the number of SGEs they have added to the SGE array.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
We need to decode and save the incoming rdma_credits field _after_
we know that the direction of the message is "forward direction
Reply". Otherwise, the credits value in reverse direction Calls is
also used to update the forward direction credits.
It is safe to decode the rdma_credits field in rpcrdma_reply_handler
now that rpcrdma_reply_handler is single-threaded. Receives complete
in the same order as they were sent on the NFS server.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
I noticed that the soft IRQ thread looked pretty busy under heavy
I/O workloads. perf suggested one area that was expensive was the
queue_work() call in rpcrdma_wc_receive. That gave me some ideas.
Instead of scheduling a separate worker to process RPC Replies,
promote the Receive completion handler to IB_POLL_WORKQUEUE, and
invoke rpcrdma_reply_handler directly.
Note that the poll workqueue is single-threaded. In order to keep
memory invalidation from serializing all RPC Replies, handle any
necessary invalidation tasks in a separate multi-threaded workqueue.
This provides a two-tier scheme, similar to OS I/O interrupt
handlers: A fast interrupt handler that schedules the slow handler
and re-enables the interrupt, and a slower handler that is invoked
for any needed heavy lifting.
Benefits include:
- One less context switch for RPCs that don't register memory
- Receive completion handling is moved out of soft IRQ context to
make room for other users of soft IRQ
- The same CPU core now DMA syncs and XDR decodes the Receive buffer
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: I'd like to be able to invoke the tail of
rpcrdma_reply_handler in two different places. Split the tail out
into its own helper function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: Make it easier to pass the decoded XID, vers, credits, and
proc fields around by moving these variables into struct rpcrdma_rep.
Note: the credits field will be handled in a subsequent patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
A reply with an unrecognized value in the version field means the
transport header is potentially garbled and therefore all the fields
are untrustworthy.
Fixes: 59aa1f9a3c ("xprtrdma: Properly handle RDMA_ERROR ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
I noticed the server was sometimes not closing the connection after
a flushed Send. For example, if the client responds with an RNR NAK
to a Reply from the server, that client might be deadlocked, and
thus wouldn't send any more traffic. Thus the server wouldn't have
any opportunity to notice the XPT_CLOSE bit has been set.
Enqueue the transport so that svcxprt notices the bit even if there
is no more transport activity after a flushed completion, QP access
error, or device removal event.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-By: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Clean up: There are no remaining callers of this method.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The "safe" version of ro_unmap is used here to avoid waiting
unnecessarily. However:
- It is safe to wait. After all, we have to wait anyway when using
FMR to register memory.
- This case is rare: it occurs only after a reconnect.
By switching this call site to ro_unmap_sync, the final use of
ro_unmap_safe is removed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
In current kernels, waiting in xprt_release appears to be safe to
do. I had erroneously believed that for ASYNC RPCs, waiting of any
kind in xprt_release->xprt_rdma_free would result in deadlock. I've
done injection testing and consulted with Trond to confirm that
waiting in the RPC release path is safe.
For the very few times where RPC resources haven't yet been released
earlier by the reply handler, it is safe to wait synchronously in
xprt_rdma_free for invalidation rather than defering it to MR
recovery.
Note: When the QP is error state, posting a LocalInvalidate should
flush and mark the MR as bad. There is no way the remote HCA can
access that MR via a QP in error state, so it is effectively already
inaccessible and thus safe for the Upper Layer to access. The next
time the MR is used it should be recognized and cleaned up properly
by frwr_op_map.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The ib_mr->length represents the length of the MR in bytes as per
the IBTA spec 1.3 section 11.2.10.3 (REGISTER PHYSICAL MEMORY REGION).
Currently ib_mr->length field is defined as only 32-bits field.
This might result into truncation and failed WRs of consumers who
registers more than 4GB bytes memory regions and whose WRs accessing
such MRs.
This patch makes the length 64-bit to avoid such truncation.
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Faisal Latif <faisal.latif@intel.com>
Fixes: 4c67e2bfc8 ("IB/core: Introduce new fast registration API")
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Hightlights include:
Stable bugfixes:
- Fix mirror allocation in the writeback code to avoid a use after free
- Fix the O_DSYNC writes to use the correct byte range
- Fix 2 use after free issues in the I/O code
Features:
- Writeback fixes to split up the inode->i_lock in order to reduce contention
- RPC client receive fixes to reduce the amount of time the
xprt->transport_lock is held when receiving data from a socket into am
XDR buffer.
- Ditto fixes to reduce contention between call side users of the rdma
rb_lock, and its use in rpcrdma_reply_handler.
- Re-arrange rdma stats to reduce false cacheline sharing.
- Various rdma cleanups and optimisations.
- Refactor the NFSv4.1 exchange id code and clean up the code.
- Const-ify all instances of struct rpc_xprt_ops
Bugfixes:
- Fix the NFSv2 'sec=' mount option.
- NFSv4.1: don't use machine credentials for CLOSE when using 'sec=sys'
- Fix the NFSv3 GRANT callback when the port changes on the server.
- Fix livelock issues with COMMIT
- NFSv4: Use correct inode in _nfs4_opendata_to_nfs4_state() when doing
and NFSv4.1 open by filehandle.
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Merge tag 'nfs-for-4.14-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Hightlights include:
Stable bugfixes:
- Fix mirror allocation in the writeback code to avoid a use after
free
- Fix the O_DSYNC writes to use the correct byte range
- Fix 2 use after free issues in the I/O code
Features:
- Writeback fixes to split up the inode->i_lock in order to reduce
contention
- RPC client receive fixes to reduce the amount of time the
xprt->transport_lock is held when receiving data from a socket into
am XDR buffer.
- Ditto fixes to reduce contention between call side users of the
rdma rb_lock, and its use in rpcrdma_reply_handler.
- Re-arrange rdma stats to reduce false cacheline sharing.
- Various rdma cleanups and optimisations.
- Refactor the NFSv4.1 exchange id code and clean up the code.
- Const-ify all instances of struct rpc_xprt_ops
Bugfixes:
- Fix the NFSv2 'sec=' mount option.
- NFSv4.1: don't use machine credentials for CLOSE when using
'sec=sys'
- Fix the NFSv3 GRANT callback when the port changes on the server.
- Fix livelock issues with COMMIT
- NFSv4: Use correct inode in _nfs4_opendata_to_nfs4_state() when
doing and NFSv4.1 open by filehandle"
* tag 'nfs-for-4.14-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (69 commits)
NFS: Count the bytes of skipped subrequests in nfs_lock_and_join_requests()
NFS: Don't hold the group lock when calling nfs_release_request()
NFS: Remove pnfs_generic_transfer_commit_list()
NFS: nfs_lock_and_join_requests and nfs_scan_commit_list can deadlock
NFS: Fix 2 use after free issues in the I/O code
NFS: Sync the correct byte range during synchronous writes
lockd: Delete an error message for a failed memory allocation in reclaimer()
NFS: remove jiffies field from access cache
NFS: flush data when locking a file to ensure cache coherence for mmap.
SUNRPC: remove some dead code.
NFS: don't expect errors from mempool_alloc().
xprtrdma: Use xprt_pin_rqst in rpcrdma_reply_handler
xprtrdma: Re-arrange struct rx_stats
NFS: Fix NFSv2 security settings
NFSv4.1: don't use machine credentials for CLOSE when using 'sec=sys'
SUNRPC: ECONNREFUSED should cause a rebind.
NFS: Remove unused parameter gfp_flags from nfs_pageio_init()
NFSv4: Fix up mirror allocation
SUNRPC: Add a separate spinlock to protect the RPC request receive list
SUNRPC: Cleanup xs_tcp_read_common()
...
Adopt the use of xprt_pin_rqst to eliminate contention between
Call-side users of rb_lock and the use of rb_lock in
rpcrdma_reply_handler.
This replaces the mechanism introduced in 431af645cf ("xprtrdma:
Fix client lock-up after application signal fires").
Use recv_lock to quickly find the completing rqst, pin it, then
drop the lock. At that point invalidation and pull-up of the Reply
XDR can be done. Both are often expensive operations.
Finally, take recv_lock again to signal completion to the RPC
layer. It also protects adjustment of "cwnd".
This greatly reduces the amount of time a lock is held by the
reply handler. Comparing lock_stat results shows a marked decrease
in contention on rb_lock and recv_lock.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
[trond.myklebust@primarydata.com: Remove call to rpcrdma_buffer_put() from
the "out_norqst:" path in rpcrdma_reply_handler.]
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
The rdma_rw API adjusts max_send_wr upwards during the
rdma_create_qp() call. If the ULP actually wants to take advantage
of these extra resources, it must increase the size of its send
completion queue (created before rdma_create_qp is called) and
increase its send queue accounting limit.
Use the new rdma_rw_mr_factor API to figure out the correct value
to use for the Send Queue and Send Completion Queue depths.
And, ensure that the chosen Send Queue depth for a newly created
transport does not overrun the QP WR limit of the underlying device.
Lastly, there's no longer a need to carry the Send Queue depth in
struct svcxprt_rdma, since the value is used only in the
svc_rdma_accept() path.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that the chosen Receive Queue depth for a newly created
transport does not overrun the QP WR limit of the underlying device.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
So that NFS WRITE payloads can eventually be placed directly into a
file's page cache, enable the RPC-over-RDMA transport to present
these payloads in the xdr_buf's page list, while placing trailing
content (such as a GETATTR operation) in the xdr_buf's tail.
After this change, the RPC-over-RDMA's "copy tail" hack, added by
commit a97c331f9a ("svcrdma: Handle additional inline content"),
is no longer needed and can be removed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Dan Carpenter <dan.carpenter@oracle.com> observed that the while()
loop in svc_rdma_build_read_chunk() does not document the assumption
that the loop interior is always executed at least once.
Defensive: the function now returns -EINVAL if this assumption
fails.
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Close an attack vector by moving the arrays of server-side transport
methods to read-only memory.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
To reduce false cacheline sharing, separate counters that are likely
to be accessed in the Call path from those accessed in the Reply
path.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This further reduces contention with the transport_lock, and allows us
to convert to using a non-bh-safe spinlock, since the list is now never
accessed from a bh context.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Re-arrange the pointer arithmetic in the chunk list encoders to
eliminate several more integer multiplication instructions during
Transport Header encoding.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Re-arrange the pointer arithmetic in rpcrdma_convert_iovs() to
eliminate several integer multiplication instructions during
Transport Header encoding.
Also, array overflow does not occur outside development
environments, so replace overflow checking with one spot check
at the end. This reduces the number of conditional branches in
the common case.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Same changes as in rpcrdma_marshal_req(). This removes
C-structure style encoding from the backchannel.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
While marshaling chunk lists which are variable-length XDR objects,
check for XDR buffer overflow at every step. Measurements show no
significant changes in CPU utilization.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Initialize an xdr_stream at the top of rpcrdma_marshal_req(), and
use it to encode the fixed transport header fields. This xdr_stream
will be used to encode the chunk lists in a subsequent patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: Remove a variable whose result is no longer used.
Commit 655fec6987 ("xprtrdma: Use gathered Send for large inline
messages") should have removed it.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: The caller already has rpcrdma_xprt, so pass that directly
instead. And provide a documenting comment for this critical
function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: Replace C-structure based XDR decoding for consistency
with other areas.
struct rpcrdma_rep is rearranged slightly so that the relevant fields
are in cache when the Receive completion handler is invoked.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This field is no longer used outside the Receive completion handler.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: The opcode check is no longer necessary, because since
commit 2fa8f88d88 ("xprtrdma: Use new CQ API for RPC-over-RDMA
client send CQs"), this completion handler is invoked only for
RECV work requests.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up chunk list decoding by using the xdr_stream set up in
rpcrdma_reply_handler. This hardens decoding by checking for buffer
overflow at every step while unmarshaling variable-length XDR
objects.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Refactor the reply handler's transport header decoding logic to make
it easier to understand and update.
Convert some of the handler to use xdr_streams, which will enable
stricter validation of input data and enable the eventual addition
of support for new combinations of chunks, such as "Write + Reply"
or "PZRC + normal Read".
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Transport header decoding deals with untrusted input data, therefore
decoding this header needs to be hardened.
Adopt the same infrastructure that is used when XDR decoding NFS
replies. This is slightly more CPU-intensive than the replaced code,
but we're not adding new atomics, locking, or context switches. The
cost is manageable.
Start by initializing an xdr_stream in rpcrdma_reply_handler().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
After transport instance creation, these function pointers never
change. Mark them as constant to prevent their use as an attack
vector for code injections.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Stable bugfixes:
- Fix -EACCESS on commit to DS handling
- Fix initialization of nfs_page_array->npages
- Only invalidate dentries that are actually invalid
Features:
- Enable NFSoRDMA transparent state migration
- Add support for lookup-by-filehandle
- Add support for nfs re-exporting
Other bugfixes and cleanups:
- Christoph cleaned up the way we declare NFS operations
- Clean up various internal structures
- Various cleanups to commits
- Various improvements to error handling
- Set the dt_type of . and .. entries in NFS v4
- Make slot allocation more reliable
- Fix fscache stat printing
- Fix uninitialized variable warnings
- Fix potential list overrun in nfs_atomic_open()
- Fix a race in NFSoRDMA RPC reply handler
- Fix return size for nfs42_proc_copy()
- Fix against MAC forgery timing attacks
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Merge tag 'nfs-for-4.13-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client updates from Anna Schumaker:
"Stable bugfixes:
- Fix -EACCESS on commit to DS handling
- Fix initialization of nfs_page_array->npages
- Only invalidate dentries that are actually invalid
Features:
- Enable NFSoRDMA transparent state migration
- Add support for lookup-by-filehandle
- Add support for nfs re-exporting
Other bugfixes and cleanups:
- Christoph cleaned up the way we declare NFS operations
- Clean up various internal structures
- Various cleanups to commits
- Various improvements to error handling
- Set the dt_type of . and .. entries in NFS v4
- Make slot allocation more reliable
- Fix fscache stat printing
- Fix uninitialized variable warnings
- Fix potential list overrun in nfs_atomic_open()
- Fix a race in NFSoRDMA RPC reply handler
- Fix return size for nfs42_proc_copy()
- Fix against MAC forgery timing attacks"
* tag 'nfs-for-4.13-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (68 commits)
NFS: Don't run wake_up_bit() when nobody is waiting...
nfs: add export operations
nfs4: add NFSv4 LOOKUPP handlers
nfs: add a nfs_ilookup helper
nfs: replace d_add with d_splice_alias in atomic_open
sunrpc: use constant time memory comparison for mac
NFSv4.2 fix size storage for nfs42_proc_copy
xprtrdma: Fix documenting comments in frwr_ops.c
xprtrdma: Replace PAGE_MASK with offset_in_page()
xprtrdma: FMR does not need list_del_init()
xprtrdma: Demote "connect" log messages
NFSv4.1: Use seqid returned by EXCHANGE_ID after state migration
NFSv4.1: Handle EXCHGID4_FLAG_CONFIRMED_R during NFSv4.1 migration
xprtrdma: Don't defer MR recovery if ro_map fails
xprtrdma: Fix FRWR invalidation error recovery
xprtrdma: Fix client lock-up after application signal fires
xprtrdma: Rename rpcrdma_req::rl_free
xprtrdma: Pass only the list of registered MRs to ro_unmap_sync
xprtrdma: Pre-mark remotely invalidated MRs
xprtrdma: On invalidation failure, remove MWs from rl_registered
...
Clean up.
FASTREG and LOCAL_INV WRs are typically not signaled. localinv_wake
is used for the last LOCAL_INV WR in a chain, which is always
signaled. The documenting comments should reflect that.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up.
Commit 38f1932e60 ("xprtrdma: Remove FMRs from the unmap list
after unmapping") utilized list_del_init() to try to prevent some
list corruption. The corruption was actually caused by the reply
handler racing with a signal. Now that MR invalidation is properly
serialized, list_del_init() can safely be replaced.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Some have complained about the log messages generated when xprtrdma
opens or closes a connection to a server. When an NFS mount is
mostly idle these can appear every few minutes as the client idles
out the connection and reconnects.
Connection and disconnection is a normal part of operation, and not
exceptional, so change these to dprintk's for now. At some point
all of these will be converted to tracepoints, but that's for
another day.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Deferred MR recovery does a DMA-unmapping of the MW. However, ro_map
invokes rpcrdma_defer_mr_recovery in some error cases where the MW
has not even been DMA-mapped yet.
Avoid a DMA-unmapping error replacing rpcrdma_defer_mr_recovery.
Also note that if ib_dma_map_sg is asked to map 0 nents, it will
return 0. So the extra "if (i == 0)" check is no longer needed.
Fixes: 42fe28f607 ("xprtrdma: Do not leak an MW during a DMA ...")
Fixes: 505bbe64dd ("xprtrdma: Refactor MR recovery work queues")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When ib_post_send() fails, all LOCAL_INV WRs past @bad_wr have to be
examined, and the MRs reset by hand.
I'm not sure how the existing code can work by comparing R_keys.
Restructure the logic so that instead it walks the chain of WRs,
starting from the first bad one.
Make sure to wait for completion if at least one WR was actually
posted. Otherwise, if the ib_post_send fails, we can end up
DMA-unmapping the MR while LOCAL_INV operations are in flight.
Commit 7a89f9c626 ("xprtrdma: Honor ->send_request API contract")
added the rdma_disconnect() call site. The disconnect actually
causes more problems than it solves, and SQ overruns happen only as
a result of software bugs. So remove it.
Fixes: d7a21c1bed ("xprtrdma: Reset MRs in frwr_op_unmap_sync()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
After a signal, the RPC client aborts synchronous RPCs running on
behalf of the signaled application.
The server is still executing those RPCs, and will write the results
back into the client's memory when it's done. By the time the server
writes the results, that memory is likely being used for other
purposes. Therefore xprtrdma has to immediately invalidate all
memory regions used by those aborted RPCs to prevent the server's
writes from clobbering that re-used memory.
With FMR memory registration, invalidation takes a relatively long
time. In fact, the invalidation is often still running when the
server tries to write the results into the memory regions that are
being invalidated.
This sets up a race between two processes:
1. After the signal, xprt_rdma_free calls ro_unmap_safe.
2. While ro_unmap_safe is still running, the server replies and
rpcrdma_reply_handler runs, calling ro_unmap_sync.
Both processes invoke ib_unmap_fmr on the same FMR.
The mlx4 driver allows two ib_unmap_fmr calls on the same FMR at
the same time, but HCAs generally don't tolerate this. Sometimes
this can result in a system crash.
If the HCA happens to survive, rpcrdma_reply_handler continues. It
removes the rpc_rqst from rq_list and releases the transport_lock.
This enables xprt_rdma_free to run in another process, and the
rpc_rqst is released while rpcrdma_reply_handler is still waiting
for the ib_unmap_fmr call to finish.
But further down in rpcrdma_reply_handler, the transport_lock is
taken again, and "rqst" is dereferenced. If "rqst" has already been
released, this triggers a general protection fault. Since bottom-
halves are disabled, the system locks up.
Address both issues by reversing the order of the xprt_lookup_rqst
call and the ro_unmap_sync call. Introduce a separate lookup
mechanism for rpcrdma_req's to enable calling ro_unmap_sync before
xprt_lookup_rqst. Now the handler takes the transport_lock once
and holds it for the XID lookup and RPC completion.
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305
Fixes: 68791649a7 ('xprtrdma: Invalidate in the RPC reply ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up: I'm about to use the rl_free field for purposes other than
a free list. So use a more generic name.
This is a refactoring change only.
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305
Fixes: 68791649a7 ('xprtrdma: Invalidate in the RPC reply ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
There are rare cases where an rpcrdma_req can be re-used (via
rpcrdma_buffer_put) while the RPC reply handler is still running.
This is due to a signal firing at just the wrong instant.
Since commit 9d6b040978 ("xprtrdma: Place registered MWs on a
per-req list"), rpcrdma_mws are self-contained; ie., they fully
describe an MR and scatterlist, and no part of that information is
stored in struct rpcrdma_req.
As part of closing the above race window, pass only the req's list
of registered MRs to ro_unmap_sync, rather than the rpcrdma_req
itself.
Some extra transport header sanity checking is removed. Since the
client depends on its own recollection of what memory had been
registered, there doesn't seem to be a way to abuse this change.
And, the check was not terribly effective. If the client had sent
Read chunks, the "list_empty" test is negative in both of the
removed cases, which are actually looking for Write or Reply
chunks.
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305
Fixes: 68791649a7 ('xprtrdma: Invalidate in the RPC reply ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
There are rare cases where an rpcrdma_req and its matched
rpcrdma_rep can be re-used, via rpcrdma_buffer_put, while the RPC
reply handler is still using that req. This is typically due to a
signal firing at just the wrong instant.
As part of closing this race window, avoid using the wrong
rpcrdma_rep to detect remotely invalidated MRs. Mark MRs as
invalidated while we are sure the rep is still OK to use.
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305
Fixes: 68791649a7 ('xprtrdma: Invalidate in the RPC reply ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Callers assume the ro_unmap_sync and ro_unmap_safe methods empty
the list of registered MRs. Ensure that all paths through
fmr_op_unmap_sync() remove MWs from that list.
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>
The current check will always be true and will always jump to
err1, this looks dubious to me. I believe && should be used
instead of ||.
Detected by CoverityScan, CID#1450120 ("Logically Dead Code")
Fixes: 107c1d0a99 ("svcrdma: Avoid Send Queue overflow")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Clean up: No need to save the I/O direction. The functions that
release svc_rdma_chunk_ctxt already know what direction to use.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Clean up: Use offset_in_page() macro instead of open-coding.
Reported-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Clean up: Registration mode details are now handled by the rdma_rw
API, and thus can be removed from svcrdma.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There's no longer a need to compare each SGE's lkey with the PD's
local_dma_lkey. Now that FRWR is gone, all DMA mappings are for
pages that were registered with this key.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Clean up: Now that the svc_rdma_recvfrom path uses the rdma_rw API,
the details of Read sink buffer registration are dealt with by the
kernel's RDMA core. This cache is no longer used, and can be
removed.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Clean up:
The generic RDMA R/W API conversion of svc_rdma_recvfrom replaced
the Register, Read, and Invalidate completion handlers. Remove the
old ones, which are no longer used.
These handlers shared some helper code with svc_rdma_wc_send. Fold
the wc_common helper back into the one remaining completion handler.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When an RPC-over-RDMA request is received, the Receive buffer
contains a Transport Header possibly followed by an RPC message.
Even though rq_arg.head[0] (as passed to NFSD) does not contain the
Transport Header header, currently rq_arg.len includes the size of
the Transport Header.
That violates the intent of the xdr_buf API contract. .buflen should
include everything, but .len should be exactly the length of the RPC
message in the buffer.
The rq_arg fields are summed together at the end of
svc_rdma_recvfrom to obtain the correct return value. rq_arg.len
really ought to contain the correct number of bytes already, but it
currently doesn't due to the above misbehavior.
Let's instead ensure that .buflen includes the length of the
transport header, and that .len is always equal to head.iov_len +
.page_len + tail.iov_len .
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The current svcrdma recvfrom code path has a lot of detail about
registration mode and the type of port (iWARP, IB, etc).
Instead, use the RDMA core's generic R/W API. This shares code with
other RDMA-enabled ULPs that manages the gory details of buffer
registration and the posting of RDMA Read Work Requests.
Since the Read list marshaling code is being replaced, I took the
opportunity to replace C structure-based XDR encoding code with more
portable code that uses pointer arithmetic.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
svc_rdma_rw.c already contains helpers for the sendto path.
Introduce helpers for the recvfrom path.
The plan is to replace the local NFSD bespoke code that constructs
and posts RDMA Read 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.
This new code also puts all RDMA_NOMSG-specific logic in one place.
Lastly, the use of rqstp->rq_arg.pages is deprecated in favor of
using rqstp->rq_pages directly, for clarity.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
>From what I can tell, calling ->recvfrom when there is no work to do
is a normal part of operation. This is the only way svc_recv can
tell when there is no more data ready to receive on the transport.
Neither the TCP nor the UDP transport implementations have a
"starve" metric.
The cost of receive starvation accounting is bumping an atomic, which
results in extra (IMO unnecessary) bus traffic between CPU sockets,
while holding a spin lock.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Identify malformed transport headers and unsupported chunk
combinations as early as possible.
- Ensure that segment lengths are not crazy.
- Ensure that the Reply chunk's segment count is not crazy.
With a 1KB inline threshold, the largest number of Write segments
that can be conveyed is about 60 (for a RDMA_NOMSG Reply message).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Identify malformed transport headers and unsupported chunk
combinations as early as possible.
- Reject RPC-over-RDMA messages that contain more than one Write
chunk, since this implementation does not support more than one per
message.
- Ensure that segment lengths are not crazy.
- Ensure that the chunk's segment count is not crazy.
With a 1KB inline threshold, the largest number of Write segments
that can be conveyed is about 60 (for a RDMA_NOMSG Reply message).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Identify malformed transport headers and unsupported chunk
combinations as early as possible.
- Reject RPC-over-RDMA messages that contain more than one Read chunk,
since this implementation currently does not support more than one
per RPC transaction.
- Ensure that segment lengths are not crazy.
- Remove the segment count check. With a 1KB inline threshold, the
largest number of Read segments that can be conveyed is about 40
(for a RDMA_NOMSG Call message). This is nowhere near
RPCSVC_MAXPAGES. As far as I can tell, that was just a sanity
check and does not enforce an implementation limit.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
svc_rdma_marshal.c has one remaining exported function --
svc_rdma_xdr_decode_req -- and it has a single call site. Take
the same approach as the sendto path, and move this function
into the source file where it is called.
This is a refactoring change only.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Sanity case: Catch the case where more Work Requests are being
posted to the Send Queue than there are Send Queue Entries.
This might happen if a client sends a chunk with more segments than
there are SQEs for the transport. The server can't send that reply,
so the transport will deadlock unless the client drops the RPC.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The server displays "svcrdma: failed to post Send WR (-107)" in the
kernel log when the client disconnects. This could flood the server's
log, so remove the message.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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>
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
