ext4: nuke write_super from comments

The '->write_super' superblock method is gone, and this patch removes all the
references to 'write_super' from ext3.

Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ext4/inode.c

@@ -4589,14 +4589,6 @@ static int ext4_expand_extra_isize(struct inode *inode,
  * inode out, but prune_icache isn't a user-visible syncing function.
  * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
  * we start and wait on commits.
- *
- * Is this efficient/effective?  Well, we're being nice to the system
- * by cleaning up our inodes proactively so they can be reaped
- * without I/O.  But we are potentially leaving up to five seconds'
- * worth of inodes floating about which prune_icache wants us to
- * write out.  One way to fix that would be to get prune_icache()
- * to do a write_super() to free up some memory.  It has the desired
- * effect.
  */
 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
 {

fs/ext4/super.c

@@ -326,11 +326,6 @@ static void ext4_put_nojournal(handle_t *handle)
 
 /*
  * Wrappers for jbd2_journal_start/end.
- *
- * The only special thing we need to do here is to make sure that all
- * journal_end calls result in the superblock being marked dirty, so
- * that sync() will call the filesystem's write_super callback if
- * appropriate.
  */
 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 {
@@ -356,12 +351,6 @@ handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 	return jbd2_journal_start(journal, nblocks);
 }
 
-/*
- * The only special thing we need to do here is to make sure that all
- * jbd2_journal_stop calls result in the superblock being marked dirty, so
- * that sync() will call the filesystem's write_super callback if
- * appropriate.
- */
 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 {
 	struct super_block *sb;