ext4: Reduce logging

186527f ("ext4: Reduce "mounted" log from INFO to DEBUG") reduced
the logging of "EXT4-fs (): mounted filesystem..."- messages by setting
the level from KERN_INFO to KERN_DEBUG.

This did not have the desired effect, because we usually log DEBUG
messages to /var/log/messages as well. Also we still fill the ring
buffer and lose other information in dmesg.

Disable the logging completly.

While we are at it, disable "EXT4-fs (): shut down requested (2)"-
messages, too, as we _might_ use that ioctl in the future for our
cluster jobs.

fs/ext4/ioctl.c

@@ -570,7 +570,7 @@ static int ext4_shutdown(struct super_block *sb, unsigned long arg)
 	if (ext4_forced_shutdown(sbi))
 		return 0;
 
-	ext4_msg(sb, KERN_ALERT, "shut down requested (%d)", flags);
+	while (0) ext4_msg(sb, KERN_ALERT, "shut down requested (%d)", flags);
 	trace_ext4_shutdown(sb, flags);
 
 	switch (flags) {

fs/ext4/super.c

@@ -4998,7 +4998,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 				 "the device does not support discard");
 	}
 
-	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
+	if (0 && ___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
 		ext4_msg(sb, KERN_DEBUG, "mounted filesystem with%s. "
 			 "Opts: %.*s%s%s. Quota mode: %s.", descr,
 			 (int) sizeof(sbi->s_es->s_mount_opts),