Grow: use mdstat_wait to wait for delayed reshape.

Having a fix time for a wait is clumsy and can make us
wait much too long.
So use mdstat_wait and keep the mdstat_fd open.
This requires an 'mdstat_close' so it doesn't stay open
forever.

Signed-off-by: NeilBrown <[email protected]>

Author: neilbrown

Grow.c

@@ -3228,7 +3228,7 @@ static int reshape_array(char *container, int fd, char *devname,
 	do {
 		struct mdstat_ent *mds, *m;
 		delayed = 0;
-		mds = mdstat_read(0, 0);
+		mds = mdstat_read(1, 0);
 		for (m = mds; m; m = m->next)
 			if (strcmp(m->devnm, sra->sys_name) == 0) {
 				if (m->resync &&
@@ -3248,9 +3248,9 @@ static int reshape_array(char *container, int fd, char *devname,
 			delayed = 0;
 		}
 		if (delayed)
-			sleep(30 - (delayed-1) * 25);
+			mdstat_wait(30 - (delayed-1) * 25);
 	} while (delayed);
-
+	mdstat_close();
 	close(fd);
 	if (check_env("MDADM_GROW_VERIFY"))
 		fd = open(devname, O_RDONLY | O_DIRECT);

mdadm.h

@@ -465,6 +465,7 @@ struct mdstat_ent {
 };
 
 extern struct mdstat_ent *mdstat_read(int hold, int start);
+extern void mdstat_close(void);
 extern void free_mdstat(struct mdstat_ent *ms);
 extern void mdstat_wait(int seconds);
 extern void mdstat_wait_fd(int fd, const sigset_t *sigmask);

mdstat.c

@@ -289,6 +289,13 @@ struct mdstat_ent *mdstat_read(int hold, int start)
 	return rv;
 }
 
+void mdstat_close(void)
+{
+	if (mdstat_fd >= 0)
+		close(mdstat_fd);
+	mdstat_fd = -1;
+}
+
 void mdstat_wait(int seconds)
 {
 	fd_set fds;