Commit Graph

4162 Commits

Author SHA1 Message Date
Colin Ian King
f6260b98ec rpc: remove redundant initialization of variable status
The variable status is being initialized with a value that is never
read, the assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-07-06 20:14:42 -04:00
Zheng Yongjun
d50295255e xprtrdma: Fix spelling mistakes
Fix some spelling mistakes in comments:
succes  ==> success

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-07-06 20:14:41 -04:00
Linus Torvalds
a647034fe2 NFS client updates for Linux 5.13
Highlights include:
 
 Stable fixes:
 - Add validation of the UDP retrans parameter to prevent shift out-of-bounds
 - Don't discard pNFS layout segments that are marked for return
 
 Bugfixes:
 - Fix a NULL dereference crash in xprt_complete_bc_request() when the
   NFSv4.1 server misbehaves.
 - Fix the handling of NFS READDIR cookie verifiers
 - Sundry fixes to ensure attribute revalidation works correctly when the
   server does not return post-op attributes.
 - nfs4_bitmask_adjust() must not change the server global bitmasks
 - Fix major timeout handling in the RPC code.
 - NFSv4.2 fallocate() fixes.
 - Fix the NFSv4.2 SEEK_HOLE/SEEK_DATA end-of-file handling
 - Copy offload attribute revalidation fixes
 - Fix an incorrect filehandle size check in the pNFS flexfiles driver
 - Fix several RDMA transport setup/teardown races
 - Fix several RDMA queue wrapping issues
 - Fix a misplaced memory read barrier in sunrpc's call_decode()
 
 Features:
 - Micro optimisation of the TCP transmission queue using TCP_CORK
 - statx() performance improvements by further splitting up the tracking
   of invalid cached file metadata.
 - Support the NFSv4.2 "change_attr_type" attribute and use it to
   optimise handling of change attribute updates.
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Merge tag 'nfs-for-5.13-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

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

  Stable fixes:

   - Add validation of the UDP retrans parameter to prevent shift
     out-of-bounds

   - Don't discard pNFS layout segments that are marked for return

  Bugfixes:

   - Fix a NULL dereference crash in xprt_complete_bc_request() when the
     NFSv4.1 server misbehaves.

   - Fix the handling of NFS READDIR cookie verifiers

   - Sundry fixes to ensure attribute revalidation works correctly when
     the server does not return post-op attributes.

   - nfs4_bitmask_adjust() must not change the server global bitmasks

   - Fix major timeout handling in the RPC code.

   - NFSv4.2 fallocate() fixes.

   - Fix the NFSv4.2 SEEK_HOLE/SEEK_DATA end-of-file handling

   - Copy offload attribute revalidation fixes

   - Fix an incorrect filehandle size check in the pNFS flexfiles driver

   - Fix several RDMA transport setup/teardown races

   - Fix several RDMA queue wrapping issues

   - Fix a misplaced memory read barrier in sunrpc's call_decode()

  Features:

   - Micro optimisation of the TCP transmission queue using TCP_CORK

   - statx() performance improvements by further splitting up the
     tracking of invalid cached file metadata.

   - Support the NFSv4.2 'change_attr_type' attribute and use it to
     optimise handling of change attribute updates"

* tag 'nfs-for-5.13-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (85 commits)
  xprtrdma: Fix a NULL dereference in frwr_unmap_sync()
  sunrpc: Fix misplaced barrier in call_decode
  NFSv4.2: Remove ifdef CONFIG_NFSD from NFSv4.2 client SSC code.
  xprtrdma: Move fr_mr field to struct rpcrdma_mr
  xprtrdma: Move the Work Request union to struct rpcrdma_mr
  xprtrdma: Move fr_linv_done field to struct rpcrdma_mr
  xprtrdma: Move cqe to struct rpcrdma_mr
  xprtrdma: Move fr_cid to struct rpcrdma_mr
  xprtrdma: Remove the RPC/RDMA QP event handler
  xprtrdma: Don't display r_xprt memory addresses in tracepoints
  xprtrdma: Add an rpcrdma_mr_completion_class
  xprtrdma: Add tracepoints showing FastReg WRs and remote invalidation
  xprtrdma: Avoid Send Queue wrapping
  xprtrdma: Do not wake RPC consumer on a failed LocalInv
  xprtrdma: Do not recycle MR after FastReg/LocalInv flushes
  xprtrdma: Clarify use of barrier in frwr_wc_localinv_done()
  xprtrdma: Rename frwr_release_mr()
  xprtrdma: rpcrdma_mr_pop() already does list_del_init()
  xprtrdma: Delete rpcrdma_recv_buffer_put()
  xprtrdma: Fix cwnd update ordering
  ...
2021-05-07 11:23:41 -07:00
Linus Torvalds
a79cdfba68 Additional fixes and clean-ups for NFSD since tags/nfsd-5.13,
including a fix to grant read delegations for files open for
 writing.
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Merge tag 'nfsd-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull more nfsd updates from Chuck Lever:
 "Additional fixes and clean-ups for NFSD since tags/nfsd-5.13,
  including a fix to grant read delegations for files open for writing"

* tag 'nfsd-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  SUNRPC: Fix null pointer dereference in svc_rqst_free()
  SUNRPC: fix ternary sign expansion bug in tracing
  nfsd: Fix fall-through warnings for Clang
  nfsd: grant read delegations to clients holding writes
  nfsd: reshuffle some code
  nfsd: track filehandle aliasing in nfs4_files
  nfsd: hash nfs4_files by inode number
  nfsd: ensure new clients break delegations
  nfsd: removed unused argument in nfsd_startup_generic()
  nfsd: remove unused function
  svcrdma: Pass a useful error code to the send_err tracepoint
  svcrdma: Rename goto labels in svc_rdma_sendto()
  svcrdma: Don't leak send_ctxt on Send errors
2021-05-05 13:44:19 -07:00
Chuck Lever
9e895cd964 xprtrdma: Fix a NULL dereference in frwr_unmap_sync()
The normal mechanism that invalidates and unmaps MRs is
frwr_unmap_async(). frwr_unmap_sync() is used only when an RPC
Reply bearing Write or Reply chunks has been lost (ie, almost
never).

Coverity found that after commit 9a301cafc8 ("xprtrdma: Move
fr_linv_done field to struct rpcrdma_mr"), the while() loop in
frwr_unmap_sync() exits only once @mr is NULL, unconditionally
causing subsequent dereferences of @mr to Oops.

I've tested this fix by creating a client that skips invoking
frwr_unmap_async() when RPC Replies complete. That forces all
invalidation tasks to fall upon frwr_unmap_sync(). Simple workloads
with this fix applied to the adulterated client work as designed.

Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1504556 ("Null pointer dereferences")
Fixes: 9a301cafc8 ("xprtrdma: Move fr_linv_done field to struct rpcrdma_mr")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-05-01 19:42:22 -04:00
Baptiste Lepers
f8f7e0fb22 sunrpc: Fix misplaced barrier in call_decode
Fix a misplaced barrier in call_decode. The struct rpc_rqst is modified
as follows by xprt_complete_rqst:

req->rq_private_buf.len = copied;
/* Ensure all writes are done before we update */
/* req->rq_reply_bytes_recvd */
smp_wmb();
req->rq_reply_bytes_recvd = copied;

And currently read as follows by call_decode:

smp_rmb(); // misplaced
if (!req->rq_reply_bytes_recvd)
   goto out;
req->rq_rcv_buf.len = req->rq_private_buf.len;

This patch places the smp_rmb after the if to ensure that
rq_reply_bytes_recvd and rq_private_buf.len are read in order.

Fixes: 9ba828861c ("SUNRPC: Don't try to parse incomplete RPC messages")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-05-01 19:42:14 -04:00
Chuck Lever
f6e70aab9d SUNRPC: refresh rq_pages using a bulk page allocator
Reduce the rate at which nfsd threads hammer on the page allocator.  This
improves throughput scalability by enabling the threads to run more
independently of each other.

[mgorman: Update interpretation of alloc_pages_bulk return value]

Link: https://lkml.kernel.org/r/20210325114228.27719-8-mgorman@techsingularity.net
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:43 -07:00
Chuck Lever
ab8362645f SUNRPC: set rq_page_end differently
Patch series "SUNRPC consumer for the bulk page allocator"

This patch set and the measurements below are based on yesterday's
bulk allocator series:

  git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git mm-bulk-rebase-v5r9

The patches change SUNRPC to invoke the array-based bulk allocator
instead of alloc_page().

The micro-benchmark results are promising.  I ran a mixture of 256KB
reads and writes over NFSv3.  The server's kernel is built with KASAN
enabled, so the comparison is exaggerated but I believe it is still
valid.

I instrumented svc_recv() to measure the latency of each call to
svc_alloc_arg() and report it via a trace point.  The following results
are averages across the trace events.

  Single page: 25.007 us per call over 532,571 calls
  Bulk list:    6.258 us per call over 517,034 calls
  Bulk array:   4.590 us per call over 517,442 calls

This patch (of 2)

Refactor:

I'm about to use the loop variable @i for something else.

As far as the "i++" is concerned, that is a post-increment. The
value of @i is not used subsequently, so the increment operator
is unnecessary and can be removed.

Also note that nfsd_read_actor() was renamed nfsd_splice_actor()
by commit cf8208d0ea ("sendfile: convert nfsd to
splice_direct_to_actor()").

Link: https://lkml.kernel.org/r/20210325114228.27719-7-mgorman@techsingularity.net
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:43 -07:00
Chuck Lever
13bcf7e32a xprtrdma: Move fr_mr field to struct rpcrdma_mr
Clean up: The last remaining field in struct rpcrdma_frwr has been
removed, so the struct can be eliminated.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:27:23 -04:00
Chuck Lever
dcff9ed209 xprtrdma: Move the Work Request union to struct rpcrdma_mr
Clean up.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:27:13 -04:00
Chuck Lever
9a301cafc8 xprtrdma: Move fr_linv_done field to struct rpcrdma_mr
Clean up: Move more of struct rpcrdma_frwr into its parent.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:27:06 -04:00
Chuck Lever
e10fa96d34 xprtrdma: Move cqe to struct rpcrdma_mr
Clean up.

- Simplify variable initialization in the completion handlers.

- Move another field out of struct rpcrdma_frwr.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:27:00 -04:00
Chuck Lever
0a26d10e30 xprtrdma: Move fr_cid to struct rpcrdma_mr
Clean up (for several purposes):

- The MR's cid is initialized sooner so that tracepoints can show
  something reasonable even if the MR is never posted.
- The MR's res.id doesn't change so the cid won't change either.
  Initializing the cid once is sufficient.
- struct rpcrdma_frwr is going away soon.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:26:53 -04:00
Chuck Lever
e1648eb23d xprtrdma: Remove the RPC/RDMA QP event handler
Clean up: The handler only recorded a trace event. If indeed no
action is needed by the RPC/RDMA consumer, then the event can be
ignored.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:26:31 -04:00
Chuck Lever
4ddd0fc32c xprtrdma: Add tracepoints showing FastReg WRs and remote invalidation
The Send signaling logic is a little subtle, so add some
observability around it. For every xprtrdma_mr_fastreg event, there
should be an xprtrdma_mr_localinv or xprtrdma_mr_reminv event.

When these tracepoints are enabled, we can see exactly when an MR is
DMA-mapped, registered, invalidated (either locally or remotely) and
then DMA-unmapped.

   kworker/u25:2-190   [000]   787.979512: xprtrdma_mr_map:      task:351@5 mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE)
   kworker/u25:2-190   [000]   787.979515: xprtrdma_chunk_read:  task:351@5 pos=148 5608@0x8679e0c8f6f56000:0x00000503 (last)
   kworker/u25:2-190   [000]   787.979519: xprtrdma_marshal:     task:351@5 xid=0x8679e0c8: hdr=52 xdr=148/5608/0 read list/inline
   kworker/u25:2-190   [000]   787.979525: xprtrdma_mr_fastreg:  task:351@5 mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE)
   kworker/u25:2-190   [000]   787.979526: xprtrdma_post_send:   task:351@5 cq.id=0 cid=73 (2 SGEs)

 ...

    kworker/5:1H-219   [005]   787.980567: xprtrdma_wc_receive:  cq.id=1 cid=161 status=SUCCESS (0/0x0) received=164
    kworker/5:1H-219   [005]   787.980571: xprtrdma_post_recvs:  peer=[192.168.100.55]:20049 r_xprt=0xffff8884974d4000: 0 new recvs, 70 active (rc 0)
    kworker/5:1H-219   [005]   787.980573: xprtrdma_reply:       task:351@5 xid=0x8679e0c8 credits=64
    kworker/5:1H-219   [005]   787.980576: xprtrdma_mr_reminv:   task:351@5 mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE)
    kworker/5:1H-219   [005]   787.980577: xprtrdma_mr_unmap:    mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE)

Note that I've moved the xprtrdma_post_send tracepoint so that event
always appears after the xprtrdma_mr_fastreg tracepoint. Otherwise
the event log looks counterintuitive (FastReg is always supposed to
happen before Send).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:25:58 -04:00
Chuck Lever
b3ce7a25f4 xprtrdma: Avoid Send Queue wrapping
Send WRs can be signalled or unsignalled. A signalled Send WR
always has a matching Send completion, while a unsignalled Send
has a completion only if the Send WR fails.

xprtrdma has a Send account mechanism that is designed to reduce
the number of signalled Send WRs. This in turn mitigates the
interrupt rate of the underlying device.

RDMA consumers can't leave all Sends unsignaled, however, because
providers rely on Send completions to maintain their Send Queue head
and tail pointers. xprtrdma counts the number of unsignaled Send WRs
that have been posted to ensure that Sends are signalled often
enough to prevent the Send Queue from wrapping.

This mechanism neglected to account for FastReg WRs, which are
posted on the Send Queue but never signalled. As a result, the
Send Queue wrapped on occasion, resulting in duplication completions
of FastReg and LocalInv WRs.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:25:43 -04:00
Chuck Lever
8a053433de xprtrdma: Do not wake RPC consumer on a failed LocalInv
Throw away any reply where the LocalInv flushes or could not be
posted. The registered memory region is in an unknown state until
the disconnect completes.

rpcrdma_xprt_disconnect() will find and release the MR. No need to
put it back on the MR free list in this case.

The client retransmits pending RPC requests once it reestablishes a
fresh connection, so a replacement reply should be forthcoming on
the next connection instance.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:25:19 -04:00
Chuck Lever
e4b52ca013 xprtrdma: Do not recycle MR after FastReg/LocalInv flushes
Better not to touch MRs involved in a flush or post error until the
Send and Receive Queues are drained and the transport is fully
quiescent. Simply don't insert such MRs back onto the free list.
They remain on mr_all and will be released when the connection is
torn down.

I had thought that recycling would prevent hardware resources from
being tied up for a long time. However, since v5.7, a transport
disconnect destroys the QP and other hardware-owned resources. The
MRs get cleaned up nicely at that point.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:25:12 -04:00
Chuck Lever
44438ad9ae xprtrdma: Clarify use of barrier in frwr_wc_localinv_done()
Clean up: The comment and the placement of the memory barrier is
confusing. Humans want to read the function statements from head
to tail.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:24:47 -04:00
Chuck Lever
f912af77e2 xprtrdma: Rename frwr_release_mr()
Clean up: To be consistent with other functions in this source file,
follow the naming convention of putting the object being acted upon
before the action itself.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:24:29 -04:00
Chuck Lever
1363e6388c xprtrdma: rpcrdma_mr_pop() already does list_del_init()
The rpcrdma_mr_pop() earlier in the function has already cleared
out mr_list, so it must not be done again in the error path.

Fixes: 847568942f ("xprtrdma: Remove fr_state")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:24:22 -04:00
Chuck Lever
c35ca60d49 xprtrdma: Delete rpcrdma_recv_buffer_put()
Clean up: The name recv_buffer_put() is a vestige of older code,
and the function is just a wrapper for the newer rpcrdma_rep_put().
In most of the existing call sites, a pointer to the owning
rpcrdma_buffer is already available.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:24:12 -04:00
Chuck Lever
35d8b10a25 xprtrdma: Fix cwnd update ordering
After a reconnect, the reply handler is opening the cwnd (and thus
enabling more RPC Calls to be sent) /before/ rpcrdma_post_recvs()
can post enough Receive WRs to receive their replies. This causes an
RNR and the new connection is lost immediately.

The race is most clearly exposed when KASAN and disconnect injection
are enabled. This slows down rpcrdma_rep_create() enough to allow
the send side to post a bunch of RPC Calls before the Receive
completion handler can invoke ib_post_recv().

Fixes: 2ae50ad68c ("xprtrdma: Close window between waking RPC senders and posting Receives")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:24:05 -04:00
Chuck Lever
9e3ca33b62 xprtrdma: Improve locking around rpcrdma_rep creation
Defensive clean up: Protect the rb_all_reps list during rep
creation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:23:40 -04:00
Chuck Lever
8b5292be68 xprtrdma: Improve commentary around rpcrdma_reps_unmap()
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:23:19 -04:00
Chuck Lever
eaf86e8cc8 xprtrdma: Improve locking around rpcrdma_rep destruction
Currently rpcrdma_reps_destroy() assumes that, at transport
tear-down, the content of the rb_free_reps list is the same as the
content of the rb_all_reps list. Although that is usually true,
using the rb_all_reps list should be more reliable because of
the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps;
these two functions should both traverse the "all" list.

Ensure that all rpcrdma_reps are always destroyed whether they are
on the rep free list or not.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:22:29 -04:00
Chuck Lever
5030c9a938 xprtrdma: Put flushed Receives on free list instead of destroying them
Defer destruction of an rpcrdma_rep until transport tear-down to
preserve the rb_all_reps list while Receives flush.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:21:49 -04:00
Chuck Lever
15788d1d10 xprtrdma: Do not refresh Receive Queue while it is draining
Currently the Receive completion handler refreshes the Receive Queue
whenever a successful Receive completion occurs.

On disconnect, xprtrdma drains the Receive Queue. The first few
Receive completions after a disconnect are typically successful,
until the first flushed Receive.

This means the Receive completion handler continues to post more
Receive WRs after the drain sentinel has been posted. The late-
posted Receives flush after the drain sentinel has completed,
leading to a crash later in rpcrdma_xprt_disconnect().

To prevent this crash, xprtrdma has to ensure that the Receive
handler stops posting Receives before ib_drain_rq() posts its
drain sentinel.

Suggested-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:21:44 -04:00
Chuck Lever
32e6b68167 xprtrdma: Avoid Receive Queue wrapping
Commit e340c2d6ef ("xprtrdma: Reduce the doorbell rate (Receive)")
increased the number of Receive WRs that are posted by the client,
but did not increase the size of the Receive Queue allocated during
transport set-up.

This is usually not an issue because RPCRDMA_BACKWARD_WRS is defined
as (32) when SUNRPC_BACKCHANNEL is defined. In cases where it isn't,
there is a real risk of Receive Queue wrapping.

Fixes: e340c2d6ef ("xprtrdma: Reduce the doorbell rate (Receive)")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26 09:21:36 -04:00
Yunjian Wang
b9f83ffaa0 SUNRPC: Fix null pointer dereference in svc_rqst_free()
When alloc_pages_node() returns null in svc_rqst_alloc(), the
null rq_scratch_page pointer will be dereferenced when calling
put_page() in svc_rqst_free(). Fix it by adding a null check.

Addresses-Coverity: ("Dereference after null check")
Fixes: 5191955d6f ("SUNRPC: Prepare for xdr_stream-style decoding on the server-side")
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-23 10:43:05 -04:00
Dan Carpenter
cb57908653 SUNRPC: fix ternary sign expansion bug in tracing
This code is supposed to pass negative "err" values for tracing but it
passes positive values instead.  The problem is that the
trace_svcsock_tcp_send() function takes a long but "err" is an int and
"sent" is a u32.  The negative is first type promoted to u32 so it
becomes a high positive then it is promoted to long and it stays
positive.

Fix this by casting "err" directly to long.

Fixes: 998024dee1 ("SUNRPC: Add more svcsock tracepoints")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-22 11:02:28 -04:00
Chuck Lever
8727f78855 svcrdma: Pass a useful error code to the send_err tracepoint
Capture error codes in @ret, which is passed to the send_err
tracepoint, so that they can be logged when something goes awry.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14 12:09:27 -04:00
Chuck Lever
c7731d5e05 svcrdma: Rename goto labels in svc_rdma_sendto()
Clean up: Make the goto labels consistent with other similar
functions.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14 12:09:27 -04:00
Chuck Lever
351461f332 svcrdma: Don't leak send_ctxt on Send errors
Address a rare send_ctxt leak in the svc_rdma_sendto() error paths.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14 12:09:27 -04:00
Chris Dion
09252177d5 SUNRPC: Handle major timeout in xprt_adjust_timeout()
Currently if a major timeout value is reached, but the minor value has
not been reached, an ETIMEOUT will not be sent back to the caller.
This can occur if the v4 server is not responding to requests and
retrans is configured larger than the default of two.

For example, A TCP mount with a configured timeout value of 50 and a
retransmission count of 3 to a v4 server which is not responding:

1. Initial value and increment set to 5s, maxval set to 20s, retries at 3
2. Major timeout is set to 20s, minor timeout set to 5s initially
3. xport_adjust_timeout() is called after 5s, retry with 10s timeout,
   minor timeout is bumped to 10s
4. And again after another 10s, 15s total time with minor timeout set
   to 15s
5. After 20s total time xport_adjust_timeout is called as major timeout is
   reached, but skipped because the minor timeout is not reached
       - After this time the cpu spins continually calling
       	 xport_adjust_timeout() and returning 0 for 10 seconds.
	 As seen on perf sched:
   	 39243.913182 [0005]  mount.nfs[3794] 4607.938      0.017   9746.863
6. This continues until the 15s minor timeout condition is reached (in
   this case for 10 seconds). After which the ETIMEOUT is processed
   back to the caller, the cpu spinning stops, and normal operations
   continue

Fixes: 7de62bc09f ("SUNRPC dont update timeout value on connection reset")
Signed-off-by: Chris Dion <Christopher.Dion@dell.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14 09:36:30 -04:00
Chuck Lever
6cf23783f7 SUNRPC: Remove trace_xprt_transmit_queued
This tracepoint can crash when dereferencing snd_task because
when some transports connect, they put a cookie in that field
instead of a pointer to an rpc_task.

BUG: KASAN: use-after-free in trace_event_raw_event_xprt_writelock_event+0x141/0x18e [sunrpc]
Read of size 2 at addr ffff8881a83bd3a0 by task git/331872

CPU: 11 PID: 331872 Comm: git Tainted: G S                5.12.0-rc2-00007-g3ab6e585a7f9 #1453
Hardware name: Supermicro SYS-6028R-T/X10DRi, BIOS 1.1a 10/16/2015
Call Trace:
 dump_stack+0x9c/0xcf
 print_address_description.constprop.0+0x18/0x239
 kasan_report+0x174/0x1b0
 trace_event_raw_event_xprt_writelock_event+0x141/0x18e [sunrpc]
 xprt_prepare_transmit+0x8e/0xc1 [sunrpc]
 call_transmit+0x4d/0xc6 [sunrpc]

Fixes: 9ce07ae5eb ("SUNRPC: Replace dprintk() call site in xprt_prepare_transmit")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14 09:36:30 -04:00
Chuck Lever
e936a5970e SUNRPC: Add tracepoint that fires when an RPC is retransmitted
A separate tracepoint can be left enabled all the time to capture
rare but important retransmission events. So for example:

kworker/u26:3-568   [009]   156.967933: xprt_retransmit:      task:44093@5 xid=0xa25dbc79 nfsv3 WRITE ntrans=2

Or, for example, enable all nfs and nfs4 tracepoints, and set up a
trigger to disable tracing when xprt_retransmit fires to capture
everything that leads up to it.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14 09:36:29 -04:00
Chuck Lever
7638e0bfae SUNRPC: Move fault injection call sites
I've hit some crashes that occur in the xprt_rdma_inject_disconnect
path. It appears that, for some provides, rdma_disconnect() can
take so long that the transport can disconnect and release its
hardware resources while rdma_disconnect() is still running,
resulting in a UAF in the provider.

The transport's fault injection method may depend on the stability
of transport data structures. That means it needs to be invoked
only from contexts that hold the transport write lock.

Fixes: 4a06825839 ("SUNRPC: Transport fault injection")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14 09:36:29 -04:00
Jiapeng Chong
dee9f6ade3 sunrpc: Remove unused function ip_map_lookup
Fix the following clang warnings:

net/sunrpc/svcauth_unix.c:306:30: warning: unused function
'ip_map_lookup' [-Wunused-function].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-06 11:24:31 -04:00
Benjamin Coddington
98b5cee373 SUNRPC: Ensure the transport backchannel association
If the server sends CB_ calls on a connection that is not associated
with the backchannel, refuse to process the call and shut down the
connection.  This avoids a NULL dereference crash in
xprt_complete_bc_request().  There's not much more we can do in this
situation unless we want to look into allowing all connections to be
associated with the fore and back channel.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-05 09:04:21 -04:00
Eryu Guan
6b996476f3 sunrpc: honor rpc_task's timeout value in rpcb_create()
Currently rpcbind client is created without setting rpc timeout (thus
using the default value). But if the rpc_task already has a customized
timeout in its tk_client field, it's also ignored.

Let's use the same timeout setting in rpc_task->tk_client->cl_timeout
for rpcbind connection.

Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-05 09:04:21 -04:00
Trond Myklebust
d737e5d418 SUNRPC: Set TCP_CORK until the transmit queue is empty
When we have multiple RPC requests queued up, it makes sense to set the
TCP_CORK option while the transmit queue is non-empty.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-05 09:04:20 -04:00
Chuck Lever
e3eded5e81 svcrdma: Clean up dto_q critical section in svc_rdma_recvfrom()
This, to me, seems less cluttered and less redundant. I was hoping
it could help reduce lock contention on the dto_q lock by reducing
the size of the critical section, but alas, the only improvement is
readability.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31 15:58:48 -04:00
Chuck Lever
5533c4f4b9 svcrdma: Remove svc_rdma_recv_ctxt::rc_pages and ::rc_arg
These fields are no longer used.

The size of struct svc_rdma_recv_ctxt is now less than 300 bytes on
x86_64, down from 2440 bytes.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31 15:57:48 -04:00
Chuck Lever
9af723be86 svcrdma: Remove sc_read_complete_q
Now that svc_rdma_recvfrom() waits for Read completion,
sc_read_complete_q is no longer used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31 15:57:48 -04:00
Chuck Lever
7d81ee8722 svcrdma: Single-stage RDMA Read
Currently the generic RPC server layer calls svc_rdma_recvfrom()
twice to retrieve an RPC message that uses Read chunks. I'm not
exactly sure why this design was chosen originally.

Instead, let's wait for the Read chunk completion inline in the
first call to svc_rdma_recvfrom().

The goal is to eliminate some page allocator churn.
rdma_read_complete() replaces pages in the second svc_rqst by
calling put_page() repeatedly while the upper layer waits for the
request to be constructed, which adds unnecessary NFS WRITE round-
trip latency.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
2021-03-31 15:57:39 -04:00
Chuck Lever
82011c80b3 SUNRPC: Move svc_xprt_received() call sites
Currently, XPT_BUSY is not cleared until xpo_recvfrom returns.
That effectively blocks the receipt and handling of the next RPC
message until the current one has been taken off the transport.
This strict ordering is a requirement for socket transports.

For our kernel RPC/RDMA transport implementation, however, dequeuing
an ingress message is nothing more than a list_del(). The transport
can safely be marked un-busy as soon as that is done.

To keep the changes simpler, this patch just moves the
svc_xprt_received() call site from svc_handle_xprt() into the
transports, so that the actual optimization can be done in a
subsequent patch.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22 13:22:13 -04:00
Chuck Lever
7dcfbd86ad SUNRPC: Export svc_xprt_received()
Prepare svc_xprt_received() to be called from transport code instead
of from generic RPC server code.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22 13:22:13 -04:00
Chuck Lever
cc93ce9529 svcrdma: Retain the page backing rq_res.head[0].iov_base
svc_rdma_sendto() now waits for the NIC hardware to finish with
the pages backing rq_res. We still have to release the page array
in some cases, but now it's always safe to immediately re-use the
page backing rq_res's head buffer.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22 13:22:13 -04:00
Chuck Lever
579900670a svcrdma: Remove unused sc_pages field
Clean up. This significantly reduces the size of struct
svc_rdma_send_ctxt.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22 13:22:13 -04:00