linux/fs/kernfs/mount.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * fs/kernfs/mount.c - kernfs mount implementation
 *
 * Copyright (c) 2001-3 Patrick Mochel
 * Copyright (c) 2007 SUSE Linux Products GmbH
 * Copyright (c) 2007, 2013 Tejun Heo <[email protected]>
 */

#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/magic.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/namei.h>
#include <linux/seq_file.h>
#include <linux/exportfs.h>
#include <linux/uuid.h>
#include <linux/statfs.h>

#include "kernfs-internal.h"

struct kmem_cache *kernfs_node_cache __ro_after_init;
struct kmem_cache *kernfs_iattrs_cache __ro_after_init;
struct kernfs_global_locks *kernfs_locks __ro_after_init;

static int kernfs_sop_show_options(struct seq_file *sf, struct dentry *dentry)
{ … }

static int kernfs_sop_show_path(struct seq_file *sf, struct dentry *dentry)
{ … }

static int kernfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{ … }

const struct super_operations kernfs_sops = …;

static int kernfs_encode_fh(struct inode *inode, __u32 *fh, int *max_len,
			    struct inode *parent)
{ … }

static struct dentry *__kernfs_fh_to_dentry(struct super_block *sb,
					    struct fid *fid, int fh_len,
					    int fh_type, bool get_parent)
{ … }

static struct dentry *kernfs_fh_to_dentry(struct super_block *sb,
					  struct fid *fid, int fh_len,
					  int fh_type)
{ … }

static struct dentry *kernfs_fh_to_parent(struct super_block *sb,
					  struct fid *fid, int fh_len,
					  int fh_type)
{ … }

static struct dentry *kernfs_get_parent_dentry(struct dentry *child)
{ … }

static const struct export_operations kernfs_export_ops = …;

/**
 * kernfs_root_from_sb - determine kernfs_root associated with a super_block
 * @sb: the super_block in question
 *
 * Return: the kernfs_root associated with @sb.  If @sb is not a kernfs one,
 * %NULL is returned.
 */
struct kernfs_root *kernfs_root_from_sb(struct super_block *sb)
{ … }

/*
 * find the next ancestor in the path down to @child, where @parent was the
 * ancestor whose descendant we want to find.
 *
 * Say the path is /a/b/c/d.  @child is d, @parent is %NULL.  We return the root
 * node.  If @parent is b, then we return the node for c.
 * Passing in d as @parent is not ok.
 */
static struct kernfs_node *find_next_ancestor(struct kernfs_node *child,
					      struct kernfs_node *parent)
{ … }

/**
 * kernfs_node_dentry - get a dentry for the given kernfs_node
 * @kn: kernfs_node for which a dentry is needed
 * @sb: the kernfs super_block
 *
 * Return: the dentry pointer
 */
struct dentry *kernfs_node_dentry(struct kernfs_node *kn,
				  struct super_block *sb)
{ … }

static int kernfs_fill_super(struct super_block *sb, struct kernfs_fs_context *kfc)
{ … }

static int kernfs_test_super(struct super_block *sb, struct fs_context *fc)
{ … }

static int kernfs_set_super(struct super_block *sb, struct fs_context *fc)
{ … }

/**
 * kernfs_super_ns - determine the namespace tag of a kernfs super_block
 * @sb: super_block of interest
 *
 * Return: the namespace tag associated with kernfs super_block @sb.
 */
const void *kernfs_super_ns(struct super_block *sb)
{ … }

/**
 * kernfs_get_tree - kernfs filesystem access/retrieval helper
 * @fc: The filesystem context.
 *
 * This is to be called from each kernfs user's fs_context->ops->get_tree()
 * implementation, which should set the specified ->@fs_type and ->@flags, and
 * specify the hierarchy and namespace tag to mount via ->@root and ->@ns,
 * respectively.
 *
 * Return: %0 on success, -errno on failure.
 */
int kernfs_get_tree(struct fs_context *fc)
{ … }

void kernfs_free_fs_context(struct fs_context *fc)
{ … }

/**
 * kernfs_kill_sb - kill_sb for kernfs
 * @sb: super_block being killed
 *
 * This can be used directly for file_system_type->kill_sb().  If a kernfs
 * user needs extra cleanup, it can implement its own kill_sb() and call
 * this function at the end.
 */
void kernfs_kill_sb(struct super_block *sb)
{ … }

static void __init kernfs_mutex_init(void)
{ … }

static void __init kernfs_lock_init(void)
{ … }

void __init kernfs_init(void)
{ … }