Commit 5289d3d1 authored by K. Y. Srinivasan's avatar K. Y. Srinivasan Committed by Greg Kroah-Hartman
Browse files

Staging: hv: vmbus: Retry vmbus_post_msg() before giving up 



The function hv_post_msg() can fail because of transient resource
conditions. It may be useful to retry the operation.

Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 0293e5ca

arch/x86/include/asm/hyperv.h

+1 −0
Original line number Diff line number Diff line
@@ -189,5 +189,6 @@ 
#define HV_STATUS_INVALID_HYPERCALL_CODE	2

#define HV_STATUS_INVALID_HYPERCALL_INPUT	3

#define HV_STATUS_INVALID_ALIGNMENT		4

#define HV_STATUS_INSUFFICIENT_BUFFERS		19



#endif

drivers/staging/hv/connection.c

+17 −1
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/kernel.h>

#include <linux/sched.h>

#include <linux/wait.h>

#include <linux/delay.h>

#include <linux/mm.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>
@@ -268,10 +269,25 @@ void vmbus_on_event(unsigned long data) 
int vmbus_post_msg(void *buffer, size_t buflen)

{

	union hv_connection_id conn_id;

	int ret = 0;

	int retries = 0;



	conn_id.asu32 = 0;

	conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;

	return hv_post_message(conn_id, 1, buffer, buflen);



	/*

	 * hv_post_message() can have transient failures because of

	 * insufficient resources. Retry the operation a couple of

	 * times before giving up.

	 */

	while (retries < 3) {

		ret =  hv_post_message(conn_id, 1, buffer, buflen);

		if (ret != HV_STATUS_INSUFFICIENT_BUFFERS)

			return ret;

		retries++;

		msleep(100);

	}

	return ret;

}



/*