[PATCH 2/3][RFC] ext3: add a message in remount/umount for ext3

[Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>]

From: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>

ext3 doesn't log a record of having unmounted the filesystem. And ext3 doesn't 
log a record when the filesystem is remounted also with read-only. Therefore 
in the system log, we cannot judge whether or not at the certain time this 
filesystem user touches it.
For enterprise users, they often want to know when a certain filesystem is 
mounted/remounted/unmounted.

So, we output the message to the system log when the filesystem is 
remounted/unmounted.

Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
---
 fs/ext3/super.c |   32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff -Nurp linux-2.6.31.orig/fs/ext3/super.c linux-2.6.31/fs/ext3/super.c
--- linux-2.6.31.orig/fs/ext3/super.c	2009-09-10 07:13:59.000000000 +0900
+++ linux-2.6.31/fs/ext3/super.c	2009-09-11 17:08:24.742407628 +0900
@@ -328,6 +328,26 @@ void ext3_update_dynamic_rev(struct supe
 	 */
 }
 
+static void ext3_print_mount_message(struct super_block *sb, 
+					int is_remount)
+{
+	printk(KERN_INFO "EXT3 FS %s on %s, ", 
+			is_remount? "remounted": "mounted", sb->s_id);
+	if (EXT3_SB(sb)->s_journal->j_inode == NULL) {
+		char b[BDEVNAME_SIZE];
+
+		printk("external journal on %s\n",
+			bdevname(EXT3_SB(sb)->s_journal->j_dev, b));
+	} else {
+		printk("internal journal\n");
+	}
+}
+
+static void ext3_print_umount_message(struct super_block *sb)
+{
+	printk(KERN_INFO "EXT3 FS unmounted from %s\n", sb->s_id);
+}
+
 /*
  * Open the external journal device
  */
@@ -448,6 +468,7 @@ static void ext3_put_super (struct super
 	sb->s_fs_info = NULL;
 	kfree(sbi->s_blockgroup_lock);
 	kfree(sbi);
+	ext3_print_umount_message(sb);
 
 	unlock_kernel();
 }
@@ -1296,15 +1317,6 @@ static int ext3_setup_super(struct super
 			EXT3_INODES_PER_GROUP(sb),
 			sbi->s_mount_opt);
 
-	printk(KERN_INFO "EXT3 FS on %s, ", sb->s_id);
-	if (EXT3_SB(sb)->s_journal->j_inode == NULL) {
-		char b[BDEVNAME_SIZE];