xprtrdma: Return -ENOBUFS when no pages are available

chucklever · amschuma-ntap · commit a8f688ec437d · 2018-06-01T13:56:30.000-04:00
The use of -EAGAIN in rpcrdma_convert_iovs() is a latent bug: the transport never calls xprt_write_space() when more pages become available. -ENOBUFS will trigger the correct "delay briefly and call again" logic. Fixes: 7a89f9c ("xprtrdma: Honor ->send_request API contract") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -231,7 +231,7 @@ rpcrdma_convert_iovs(struct rpcrdma_xprt *r_xprt, struct xdr_buf *xdrbuf,
 			 */
 			*ppages = alloc_page(GFP_ATOMIC);
 			if (!*ppages)
-				return -EAGAIN;
+				return -ENOBUFS;
 		}
 		seg->mr_page = *ppages;
 		seg->mr_offset = (char *)page_base;

Original file line number	Diff line number	Diff line change
`@@ -231,7 +231,7 @@ rpcrdma_convert_iovs(struct rpcrdma_xprt r_xprt, struct xdr_buf xdrbuf,`
`231`	`231`	`*/`
`232`	`232`	`*ppages = alloc_page(GFP_ATOMIC);`
`233`	`233`	`if (!*ppages)`
`234`		`- return -EAGAIN;`
	`234`	`+ return -ENOBUFS;`
`235`	`235`	`}`
`236`	`236`	`seg->mr_page = *ppages;`
`237`	`237`	`seg->mr_offset = (char *)page_base;`