[Qemu-devel] [PATCH 23/27] migration: remove unfreeze logic

[Juan Quintela <quintela@redhat.com>]

Now that we have a thread, and blocking writes, we don't need it.

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 buffered_file.c |   19 +------------------
 migration.c     |   22 ----------------------
 migration.h     |    1 -
 3 files changed, 1 insertion(+), 41 deletions(-)

diff --git a/buffered_file.c b/buffered_file.c
index 94830fa..b5e809c 100644
--- a/buffered_file.c
+++ b/buffered_file.c
@@ -26,7 +26,6 @@ typedef struct QEMUFileBuffered
 {
     MigrationState *migration_state;
     QEMUFile *file;
-    int freeze_output;
     size_t bytes_xfer;
     size_t xfer_limit;
     uint8_t *buffer;
@@ -77,12 +76,6 @@ static void buffered_flush(QEMUFileBuffered *s)

         ret = migrate_fd_put_buffer(s->migration_state, s->buffer + offset,
                                     s->buffer_size - offset);
-        if (ret == -EAGAIN) {
-            DPRINTF("backend not ready, freezing\n");
-            s->freeze_output = 1;
-            break;
-        }
-
         if (ret <= 0) {
             DPRINTF("error flushing data, %zd\n", ret);
             qemu_file_set_error(s->file, ret);
@@ -112,9 +105,6 @@ static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, in
         return error;
     }

-    DPRINTF("unfreezing output\n");
-    s->freeze_output = 0;
-
     if (size > 0) {
         DPRINTF("buffering %d bytes\n", size - offset);
         buffered_append(s, buf, size);
@@ -124,7 +114,7 @@ static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, in

     if (pos == 0 && size == 0) {
         DPRINTF("file is ready\n");
-        if (!s->freeze_output && s->bytes_xfer < s->xfer_limit) {
+        if (s->bytes_xfer < s->xfer_limit) {
             DPRINTF("notifying client\n");
             migrate_fd_put_ready(s->migration_state);
         }
@@ -143,8 +133,6 @@ static int buffered_close(void *opaque)
     s->xfer_limit = INT_MAX;
     while (!qemu_file_get_error(s->file) && s->buffer_size) {
         buffered_flush(s);
-        if (s->freeze_output)
-            migrate_fd_wait_for_unfreeze(s->migration_state);
     }

     ret = migrate_fd_close(s->migration_state);
@@ -167,8 +155,6 @@ static int buffered_rate_limit(void *opaque)
     if (ret) {
         return ret;
     }
-    if (s->freeze_output)
-        return 1;

     if (s->bytes_xfer > s->xfer_limit)
         return 1;
@@ -213,9 +199,6 @@ static void *buffered_file_thread(void *opaque)
         if (s->migration_state->complete) {
             break;
         }
-        if (s->freeze_output) {
-            continue;
-        }
         if (current_time >= expire_time) {
             s->bytes_xfer = 0;
             expire_time = current_time + BUFFER_DELAY;
diff --git a/migration.c b/migration.c
index fe2afd0..da0f192 100644
--- a/migration.c
+++ b/migration.c
@@ -390,28 +390,6 @@ static void migrate_fd_cancel(MigrationState *s)
     migrate_fd_cleanup(s);
 }

-void migrate_fd_wait_for_unfreeze(MigrationState *s)
-{
-    int ret;
-
-    DPRINTF("wait for unfreeze\n");
-    if (s->state != MIG_STATE_ACTIVE)
-        return;
-
-    do {
-        fd_set wfds;
-
-        FD_ZERO(&wfds);
-        FD_SET(s->fd, &wfds);
-
-        ret = select(s->fd + 1, NULL, &wfds, NULL, NULL);
-    } while (ret == -1 && (s->get_error(s)) == EINTR);
-
-    if (ret == -1) {
-        qemu_file_set_error(s->file, -s->get_error(s));
-    }
-}
-
 int migrate_fd_close(MigrationState *s)
 {
     return s->close(s);
diff --git a/migration.h b/migration.h
index a05795b..7c7a261 100644
--- a/migration.h
+++ b/migration.h
@@ -79,7 +79,6 @@ void migrate_fd_connect(MigrationState *s);
 ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data,
                               size_t size);
 void migrate_fd_put_ready(MigrationState *s);
-void migrate_fd_wait_for_unfreeze(MigrationState *s);
 int migrate_fd_close(MigrationState *s);

 void add_migration_state_change_notifier(Notifier *notify);
-- 
1.7.10.4