[Xen-devel] [RFC Patch v2 13/17] don't call client_flush() when switching to unprotected mode

[Wen Congyang <wency@xxxxxxxxxxxxxx>]

If we switch the mode from primary to unprotected, the connection
between primary and backup cannot be used.

Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
Cc: Shriram Rajagopalan <rshriram@xxxxxxxxx>
---
 tools/blktap2/drivers/block-remus.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/tools/blktap2/drivers/block-remus.c 
b/tools/blktap2/drivers/block-remus.c
index 55363a3..d358b44 100644
--- a/tools/blktap2/drivers/block-remus.c
+++ b/tools/blktap2/drivers/block-remus.c
@@ -892,6 +892,7 @@ static void primary_queue_write(td_driver_t *driver, 
td_request_t treq)
 }
 
 
+/* It is called when the user writes "flush" to control file */
 static int client_flush(td_driver_t *driver)
 {
        struct tdremus_state *s = (struct tdremus_state *)driver->data;
@@ -902,7 +903,8 @@ static int client_flush(td_driver_t *driver)
                /* connection not yet established, nothing to flush */
                return 0;
 
-       if (mwrite(s->stream_fd.fd, TDREMUS_COMMIT, strlen(TDREMUS_COMMIT)) < 
0) {
+       if (mwrite(s->stream_fd.fd, TDREMUS_COMMIT,
+           strlen(TDREMUS_COMMIT)) < 0) {
                RPRINTF("error flushing output");
                close_stream_fd(s);
                return -1;
@@ -931,7 +933,6 @@ static int primary_start(td_driver_t *driver)
 
        tapdisk_remus.td_queue_read = primary_queue_read;
        tapdisk_remus.td_queue_write = primary_queue_write;
-       s->queue_flush = client_flush;
 
        s->stream_fd.fd = -1;
        s->stream_fd.id = -1;
@@ -1510,16 +1511,23 @@ static void ctl_request(event_id_t id, char mode, void 
*private)
                return;
        }
 
-       /* TODO: need to get driver somehow */
        msg[rc] = '\0';
-       if (!strncmp(msg, "flush", 5)) {
-               if (s->queue_flush)
-                       if ((rc = s->queue_flush(driver))) {
-                               RPRINTF("error passing flush request to 
backup");
-                               ctl_respond(s, TDREMUS_FAIL);
-                       }
-       } else {
+       if (strncmp(msg, "flush", 5)) {
                RPRINTF("unknown command: %s\n", msg);
+               ctl_respond(s, TDREMUS_FAIL);
+               return;
+       }
+
+       if (s->mode != mode_primary) {
+               RPRINTF("We are not in primary mode\n");
+               ctl_respond(s, TDREMUS_FAIL);
+               return;
+       }
+
+       rc = client_flush(driver);
+       if (rc) {
+               RPRINTF("error passing flush request to backup");
+               ctl_respond(s, TDREMUS_FAIL);
        }
 }
 
-- 
1.9.3


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