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| author |   Chuck Lever <chuck.lever@oracle.com> | 2016-06-29 13:53:35 -0400 |
|---|---|---|
| committer |   Anna Schumaker <Anna.Schumaker@Netapp.com> | 2016-07-11 15:50:43 -0400 |
| commit | 3d4cf35bd4fab56c3aa0ec4323fccb24970aaf79 (patch) | |
| tree | 320f7686025dd43b0470f75ac44ef37dc5eb090c /net/sunrpc/xprtrdma/verbs.c | |
| parent | xprtrdma: Clean up device capability detection (diff) | |
| download | linux-dev-3d4cf35bd4fab56c3aa0ec4323fccb24970aaf79.tar.xz linux-dev-3d4cf35bd4fab56c3aa0ec4323fccb24970aaf79.zip | |
xprtrdma: Reply buffer exhaustion can be catastrophic
Not having an rpcrdma_rep at call_allocate time can be a problem.
It means that send_request can't post a receive buffer to catch
the RPC's reply. Possible consequences are RPC timeouts or even
transport deadlock.
Instead of allowing an RPC to proceed if an rpcrdma_rep is
not available, return NULL to force call_allocate to wait and
try again.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc/xprtrdma/verbs.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/verbs.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index cd4c5f1d554a..6fb73ff26183 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -871,7 +871,7 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt) } INIT_LIST_HEAD(&buf->rb_recv_bufs); - for (i = 0; i < buf->rb_max_requests + 2; i++) { + for (i = 0; i < buf->rb_max_requests; i++) { struct rpcrdma_rep *rep; rep = rpcrdma_create_rep(r_xprt); @@ -989,8 +989,6 @@ rpcrdma_put_mw(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw) /* * Get a set of request/reply buffers. - * - * Reply buffer (if available) is attached to send buffer upon return. */ struct rpcrdma_req * rpcrdma_buffer_get(struct rpcrdma_buffer *buffers) @@ -1009,13 +1007,13 @@ rpcrdma_buffer_get(struct rpcrdma_buffer *buffers) out_reqbuf: spin_unlock(&buffers->rb_lock); - pr_warn("RPC: %s: out of request buffers\n", __func__); + pr_warn("rpcrdma: out of request buffers (%p)\n", buffers); return NULL; out_repbuf: + list_add(&req->rl_free, &buffers->rb_send_bufs); spin_unlock(&buffers->rb_lock); - pr_warn("RPC: %s: out of reply buffers\n", __func__); - req->rl_reply = NULL; - return req; + pr_warn("rpcrdma: out of reply buffers (%p)\n", buffers); + return NULL; } /* |