new primitive: debugfs_create_automount()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2015-01-25 15:10:32 -05:00
parent 5233e31191
commit 77b3da6e32
2 changed files with 53 additions and 0 deletions

View File

@ -175,6 +175,18 @@ static const struct super_operations debugfs_super_operations = {
.show_options = debugfs_show_options,
};
static struct vfsmount *debugfs_automount(struct path *path)
{
struct vfsmount *(*f)(void *);
f = (struct vfsmount *(*)(void *))path->dentry->d_fsdata;
return f(path->dentry->d_inode->i_private);
}
static const struct dentry_operations debugfs_dops = {
.d_delete = always_delete_dentry,
.d_automount = debugfs_automount,
};
static int debug_fill_super(struct super_block *sb, void *data, int silent)
{
static struct tree_descr debug_files[] = {{""}};
@ -199,6 +211,7 @@ static int debug_fill_super(struct super_block *sb, void *data, int silent)
goto fail;
sb->s_op = &debugfs_super_operations;
sb->s_d_op = &debugfs_dops;
debugfs_apply_options(sb);
@ -367,6 +380,41 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
}
EXPORT_SYMBOL_GPL(debugfs_create_dir);
/**
* debugfs_create_automount - create automount point in the debugfs filesystem
* @name: a pointer to a string containing the name of the file to create.
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this parameter is NULL, then the
* file will be created in the root of the debugfs filesystem.
* @f: function to be called when pathname resolution steps on that one.
* @data: opaque argument to pass to f().
*
* @f should return what ->d_automount() would.
*/
struct dentry *debugfs_create_automount(const char *name,
struct dentry *parent,
struct vfsmount *(*f)(void *),
void *data)
{
struct dentry *dentry = start_creating(name, parent);
struct inode *inode;
if (IS_ERR(dentry))
return NULL;
inode = debugfs_get_inode(dentry->d_sb);
if (unlikely(!inode))
return failed_creating(dentry);
inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
inode->i_flags |= S_AUTOMOUNT;
inode->i_private = data;
dentry->d_fsdata = (void *)f;
d_instantiate(dentry, inode);
return end_creating(dentry);
}
EXPORT_SYMBOL(debugfs_create_automount);
/**
* debugfs_create_symlink- create a symbolic link in the debugfs filesystem
* @name: a pointer to a string containing the name of the symbolic link to

View File

@ -56,6 +56,11 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
const char *dest);
struct dentry *debugfs_create_automount(const char *name,
struct dentry *parent,
struct vfsmount *(*f)(void *),
void *data);
void debugfs_remove(struct dentry *dentry);
void debugfs_remove_recursive(struct dentry *dentry);