[PATCH] ext3: Wrong return value for EXT3_IOC_GROUP_ADD

This patch corrects the return value for the EXT3_IOC_GROUP_ADD in case it
fails due to the presence of multiple resizers at the filesystem.

The problem is a little bit more serious than a wrong return value in this
case, since the clause err=0 in the exit_journal path will lead to a call
to update_backups which in turns causes a NULL pointer dereference.

Signed-off-by: Glauber de Oliveira Costa <[e-mail]>
Cc: "Stephen C. Tweedie" <[e-mail]>
Cc: Andreas Dilger <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

fs/ext3/resize.c

···
 	if (input->group != EXT3_SB(sb)->s_groups_count) {
 		ext3_warning(sb, __FUNCTION__,
 			     "multiple resizers run on filesystem!\n");
+		err = -EBUSY;
 		goto exit_journal;
 	}