Skip to content

Commit

Permalink
new primitive: debugfs_create_automount()
Browse files Browse the repository at this point in the history
Signed-off-by: Al Viro <[email protected]>
  • Loading branch information
Al Viro committed Jan 25, 2015
1 parent 5233e31 commit 77b3da6
Show file tree
Hide file tree
Showing 2 changed files with 53 additions and 0 deletions.
48 changes: 48 additions & 0 deletions fs/debugfs/inode.c
Original file line number Diff line number Diff line change
Expand Up @@ -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[] = {{""}};
Expand All @@ -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);

Expand Down Expand Up @@ -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
Expand Down
5 changes: 5 additions & 0 deletions include/linux/debugfs.h
Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand Down

0 comments on commit 77b3da6

Please sign in to comment.