BKL: Remove BKL from ext4 filesystem

The BKL is still used in ext4_put_super(), ext4_fill_super() and
ext4_remount(). All three calles are protected against concurrent calls by
the s_umount rw semaphore of struct super_block.

Therefore the BKL is protecting nothing in this case.
Signed-off-by: Jan Blunck <jblunck@infradead.org>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

fs/ext4/super.c

@@ -26,7 +26,6 @@
 #include <linux/init.h>
 #include <linux/blkdev.h>
 #include <linux/parser.h>
-#include <linux/smp_lock.h>
 #include <linux/buffer_head.h>
 #include <linux/exportfs.h>
 #include <linux/vfs.h>
@@ -708,7 +707,6 @@ static void ext4_put_super(struct super_block *sb)
 	destroy_workqueue(sbi->dio_unwritten_wq);
 
 	lock_super(sb);
-	lock_kernel();
 	if (sb->s_dirt)
 		ext4_commit_super(sb, 1);
 
@@ -775,7 +773,6 @@ static void ext4_put_super(struct super_block *sb)
 	 * Now that we are completely done shutting down the
 	 * superblock, we need to actually destroy the kobject.
 	 */
-	unlock_kernel();
 	unlock_super(sb);
 	kobject_put(&sbi->s_kobj);
 	wait_for_completion(&sbi->s_kobj_unregister);
@@ -2568,8 +2565,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	int err;
 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
 
-	lock_kernel();
-
 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
 	if (!sbi)
 		goto out_free_orig;
@@ -2590,8 +2585,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		sbi->s_sectors_written_start =
 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
 
-	unlock_kernel();
-
 	/* Cleanup superblock name */
 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
 		*cp = '!';
@@ -3214,11 +3207,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_fs_info = NULL;
 	kfree(sbi->s_blockgroup_lock);
 	kfree(sbi);
-	kfree(orig_data);
-	return ret;
-
 out_free_orig:
-	unlock_kernel();
 	kfree(orig_data);
 	return ret;
 }
@@ -3726,8 +3715,6 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 #endif
 	char *orig_data = kstrdup(data, GFP_KERNEL);
 
-	lock_kernel();
-
 	/* Store the original options */
 	lock_super(sb);
 	old_sb_flags = sb->s_flags;
@@ -3862,7 +3849,6 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 			kfree(old_opts.s_qf_names[i]);
 #endif
 	unlock_super(sb);
-	unlock_kernel();
 	if (enable_quota)
 		dquot_resume(sb, -1);
 
@@ -3888,7 +3874,6 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 	}
 #endif
 	unlock_super(sb);
-	unlock_kernel();
 	kfree(orig_data);
 	return err;
 }