[PATCH] (2/8) ->get_sb() switchover

get_sb_bdev() et.al. get a new argument (fill_super) and become
exported.

fs/super.c

@@ -641,8 +641,9 @@ struct super_block *get_anon_super(struct file_system_type *type,
 	return s;
 }
 
-static struct super_block *get_sb_bdev(struct file_system_type *fs_type,
-	int flags, char *dev_name, void * data)
+struct super_block *get_sb_bdev(struct file_system_type *fs_type,
+	int flags, char *dev_name, void * data,
+	int (*fill_super)(struct super_block *, void *, int))
 {
 	struct inode *inode;
 	struct block_device *bdev;
@@ -698,7 +699,7 @@ static struct super_block *get_sb_bdev(struct file_system_type *fs_type,
 
 	list_for_each(p, &super_blocks) {
 		struct super_block *old = sb_entry(p);
-		if (!kdev_same(old->s_dev, dev))
+		if (old->s_bdev != bdev)
 			continue;
 		if (old->s_type != fs_type ||
 		    ((flags ^ old->s_flags) & MS_RDONLY)) {
@@ -718,8 +719,8 @@ static struct super_block *get_sb_bdev(struct file_system_type *fs_type,
 	s->s_flags = flags;
 	insert_super(s, fs_type);
 	strncpy(s->s_id, bdevname(dev), sizeof(s->s_id));
-	error = -EINVAL;
-	if (!fs_type->read_super(s, data, flags & MS_VERBOSE ? 1 : 0))
+	error = fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
+	if (error)
 		goto failed;
 	s->s_flags |= MS_ACTIVE;
 	path_release(&nd);
@@ -736,19 +737,23 @@ static struct super_block *get_sb_bdev(struct file_system_type *fs_type,
 	return ERR_PTR(error);
 }
 
-static struct super_block *get_sb_nodev(struct file_system_type *fs_type,
-	int flags, char *dev_name, void *data)
+struct super_block *get_sb_nodev(struct file_system_type *fs_type,
+	int flags, void *data,
+	int (*fill_super)(struct super_block *, void *, int))
 {
+	int error;
 	struct super_block *s = get_anon_super(fs_type, NULL, NULL);
 
 	if (IS_ERR(s))
 		return s;
 
 	s->s_flags = flags;
-	if (!fs_type->read_super(s, data, flags & MS_VERBOSE ? 1 : 0)) {
+
+	error = fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
+	if (error) {
 		deactivate_super(s);
 		remove_super(s);
-		return ERR_PTR(-EINVAL);
+		return ERR_PTR(error);
 	}
 	s->s_flags |= MS_ACTIVE;
 	return s;
@@ -759,19 +764,22 @@ static int compare_single(struct super_block *s, void *p)
 	return 1;
 }
 
-static struct super_block *get_sb_single(struct file_system_type *fs_type,
-	int flags, char *dev_name, void *data)
+struct super_block *get_sb_single(struct file_system_type *fs_type,
+	int flags, void *data,
+	int (*fill_super)(struct super_block *, void *, int))
 {
+	int error;
 	struct super_block *s = get_anon_super(fs_type, compare_single, NULL);
 
 	if (IS_ERR(s))
 		return s;
 	if (!s->s_root) {
 		s->s_flags = flags;
-		if (!fs_type->read_super(s, data, flags & MS_VERBOSE ? 1 : 0)) {
+		error = fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
+		if (error) {
 			deactivate_super(s);
 			remove_super(s);
-			return ERR_PTR(-EINVAL);
+			return ERR_PTR(error);
 		}
 		s->s_flags |= MS_ACTIVE;
 	}
@@ -779,6 +787,27 @@ static struct super_block *get_sb_single(struct file_system_type *fs_type,
 	return s;
 }
 
+/* Will go away */
+static int fill_super(struct super_block *sb, void *data, int verbose)
+{
+	return sb->s_type->read_super(sb, data, verbose) ? 0 : -EINVAL;
+}
+static struct super_block *__get_sb_bdev(struct file_system_type *fs_type,
+	int flags, char *dev_name, void * data)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, data, fill_super);
+}
+static struct super_block *__get_sb_nodev(struct file_system_type *fs_type,
+	int flags, char *dev_name, void * data)
+{
+	return get_sb_nodev(fs_type, flags, data, fill_super);
+}
+static struct super_block *__get_sb_single(struct file_system_type *fs_type,
+	int flags, char *dev_name, void * data)
+{
+	return get_sb_nodev(fs_type, flags, data, fill_super);
+}
+
 struct vfsmount *
 do_kern_mount(const char *fstype, int flags, char *name, void *data)
 {
@@ -795,11 +824,11 @@ do_kern_mount(const char *fstype, int flags, char *name, void *data)
 	if (type->get_sb)
 		sb = type->get_sb(type, flags, name, data);
 	else if (type->fs_flags & FS_REQUIRES_DEV)
-		sb = get_sb_bdev(type, flags, name, data);
+		sb = __get_sb_bdev(type, flags, name, data);
 	else if (type->fs_flags & FS_SINGLE)
-		sb = get_sb_single(type, flags, name, data);
+		sb = __get_sb_single(type, flags, name, data);
 	else
-		sb = get_sb_nodev(type, flags, name, data);
+		sb = __get_sb_nodev(type, flags, name, data);
 	if (IS_ERR(sb))
 		goto out_mnt;
 	if (type->fs_flags & FS_NOMOUNT)

include/linux/fs.h

@@ -946,6 +946,16 @@ struct file_system_type {
 	struct list_head fs_supers;
 };
 
+struct super_block *get_sb_bdev(struct file_system_type *fs_type,
+	int flags, char *dev_name, void * data,
+	int (*fill_super)(struct super_block *, void *, int));
+struct super_block *get_sb_single(struct file_system_type *fs_type,
+	int flags, void *data,
+	int (*fill_super)(struct super_block *, void *, int));
+struct super_block *get_sb_nodev(struct file_system_type *fs_type,
+	int flags, void *data,
+	int (*fill_super)(struct super_block *, void *, int));
+
 #define DECLARE_FSTYPE(var,type,read,flags) \
 struct file_system_type var = { \
 	name:		type, \

kernel/ksyms.c

@@ -275,6 +275,9 @@ EXPORT_SYMBOL(lock_may_write);
 EXPORT_SYMBOL(dcache_readdir);
 EXPORT_SYMBOL(fd_install);
 EXPORT_SYMBOL(put_unused_fd);
+EXPORT_SYMBOL(get_sb_bdev);
+EXPORT_SYMBOL(get_sb_nodev);
+EXPORT_SYMBOL(get_sb_single);
 
 /* for stackable file systems (lofs, wrapfs, cryptfs, etc.) */
 EXPORT_SYMBOL(default_llseek);