int wait_reply(int fd, int tmo)
{
struct metadata_update msg;
- return receive_message(fd, &msg, tmo);
+ int err = receive_message(fd, &msg, tmo);
+
+ /* mdmon sent extra data, but caller only cares that we got a
+ * successful reply
+ */
+ if (err == 0 && msg.len > 0)
+ free(msg.buf);
+
+ return err;
}
int connect_monitor(char *devname)
return err;
}
-
/* give the monitor a chance to update the metadata */
int ping_monitor(char *devname)
{
return err;
}
+static char *ping_monitor_version(char *devname)
+{
+ int sfd = connect_monitor(devname);
+ struct metadata_update msg;
+ int err = 0;
+
+ if (sfd < 0)
+ return NULL;
+
+ if (ack(sfd, 20) != 0)
+ err = -1;
+
+ if (!err && receive_message(sfd, &msg, 20) != 0)
+ err = -1;
+
+ close(sfd);
+
+ if (err || !msg.len || !msg.buf)
+ return NULL;
+ return msg.buf;
+}
+
+static int unblock_subarray(struct mdinfo *sra, const int unfreeze)
+{
+ char buf[64];
+ int rc = 0;
+
+ if (sra) {
+ sprintf(buf, "external:%s\n", sra->text_version);
+ buf[9] = '/';
+ } else
+ buf[9] = '-';
+
+ if (buf[9] == '-' ||
+ sysfs_set_str(sra, NULL, "metadata_version", buf) ||
+ (unfreeze &&
+ sysfs_attribute_available(sra, NULL, "sync_action") &&
+ sysfs_set_str(sra, NULL, "sync_action", "idle")))
+ rc = -1;
+ return rc;
+}
+
+/**
+ * block_monitor - prevent mdmon spare assignment
+ * @container - container to block
+ * @freeze - flag to additionally freeze sync_action
+ *
+ * This is used by the reshape code to freeze the container, and the
+ * auto-rebuild implementation to atomically move spares. For reshape
+ * we need to freeze sync_action in the auto-rebuild we only need to
+ * block new spare assignment, existing rebuilds can continue
+ */
+int block_monitor(char *container, const int freeze)
+{
+ int devnum = devname2devnum(container);
+ struct mdstat_ent *ent, *e, *e2;
+ struct mdinfo *sra = NULL;
+ char *version = NULL;
+ char buf[64];
+ int rv = 0;
+
+ if (!mdmon_running(devnum)) {
+ /* if mdmon is not active we assume that any instance that is
+ * later started will match the current mdadm version, if this
+ * assumption is violated we may inadvertantly rebuild an array
+ * that was meant for reshape, or start rebuild on a spare that
+ * was to be moved to another container
+ */
+ /* pass */;
+ } else {
+ int ver;
+
+ version = ping_monitor_version(container);
+ ver = version ? mdadm_version(version) : -1;
+ free(version);
+ if (ver < 3002000) {
+ fprintf(stderr, Name
+ ": mdmon instance for %s cannot be disabled\n",
+ container);
+ return -1;
+ }
+ }
+
+ ent = mdstat_read(0, 0);
+ if (!ent) {
+ fprintf(stderr, Name
+ ": failed to read /proc/mdstat while disabling mdmon\n");
+ return -1;
+ }
+
+ /* freeze container contents */
+ for (e = ent; e; e = e->next) {
+ if (!is_container_member(e, container))
+ continue;
+ sysfs_free(sra);
+ sra = sysfs_read(-1, e->devnum, GET_VERSION);
+ if (!sra) {
+ fprintf(stderr, Name
+ ": failed to read sysfs for subarray%s\n",
+ to_subarray(e, container));
+ break;
+ }
+ /* can't reshape an array that we can't monitor */
+ if (sra->text_version[0] == '-')
+ break;
+
+ if (freeze && sysfs_freeze_array(sra) < 1)
+ break;
+ /* flag this array to not be modified by mdmon (close race with
+ * takeover in reshape case and spare reassignment in the
+ * auto-rebuild case)
+ */
+ sprintf(buf, "external:%s\n", sra->text_version);
+ buf[9] = '-';
+ if (sysfs_set_str(sra, NULL, "metadata_version", buf))
+ break;
+ ping_monitor(container);
+
+ /* check that we did not race with recovery */
+ if ((freeze &&
+ !sysfs_attribute_available(sra, NULL, "sync_action")) ||
+ (freeze &&
+ sysfs_attribute_available(sra, NULL, "sync_action") &&
+ sysfs_get_str(sra, NULL, "sync_action", buf, 20) > 0 &&
+ strcmp(buf, "frozen\n") == 0))
+ /* pass */;
+ else
+ break;
+ }
+
+ if (e) {
+ fprintf(stderr, Name ": failed to freeze subarray%s\n",
+ to_subarray(e, container));
+
+ /* thaw the partially frozen container */
+ for (e2 = ent; e2 && e2 != e; e2 = e2->next) {
+ if (!is_container_member(e2, container))
+ continue;
+ sysfs_free(sra);
+ sra = sysfs_read(-1, e2->devnum, GET_VERSION);
+ if (unblock_subarray(sra, freeze))
+ fprintf(stderr, Name ": Failed to unfreeze %s\n", e2->dev);
+ }
+
+ ping_monitor(container); /* cleared frozen */
+ rv = -1;
+ }
+
+ sysfs_free(sra);
+ free_mdstat(ent);
+ free(container);
+
+ return rv;
+}
+
+void unblock_monitor(char *container, const int unfreeze)
+{
+ struct mdstat_ent *ent, *e;
+ struct mdinfo *sra = NULL;
+
+ ent = mdstat_read(0, 0);
+ if (!ent) {
+ fprintf(stderr, Name
+ ": failed to read /proc/mdstat while unblocking container\n");
+ return;
+ }
+
+ /* unfreeze container contents */
+ for (e = ent; e; e = e->next) {
+ if (!is_container_member(e, container))
+ continue;
+ sysfs_free(sra);
+ sra = sysfs_read(-1, e->devnum, GET_VERSION);
+ if (unblock_subarray(sra, unfreeze))
+ fprintf(stderr, Name ": Failed to unfreeze %s\n", e->dev);
+ }
+ ping_monitor(container);
+
+ sysfs_free(sra);
+ free_mdstat(ent);
+}
+
+
+
/* give the manager a chance to view the updated container state. This
* would naturally happen due to the manager noticing a change in
* /proc/mdstat; however, pinging encourages this detection to happen
projects / thirdparty / mdadm.git / blobdiff