linux/fs/autofs/expire.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
 * Copyright 1999-2000 Jeremy Fitzhardinge <[email protected]>
 * Copyright 2001-2006 Ian Kent <[email protected]>
 */

#include "autofs_i.h"

/* Check if a dentry can be expired */
static inline int autofs_can_expire(struct dentry *dentry,
				    unsigned long timeout, unsigned int how)
{ … }

/* Check a mount point for busyness */
static int autofs_mount_busy(struct vfsmount *mnt,
			     struct dentry *dentry, unsigned int how)
{ … }

/* p->d_lock held */
static struct dentry *positive_after(struct dentry *p, struct dentry *child)
{ … }

/*
 * Calculate and dget next entry in the subdirs list under root.
 */
static struct dentry *get_next_positive_subdir(struct dentry *prev,
					       struct dentry *root)
{ … }

/*
 * Calculate and dget next entry in top down tree traversal.
 */
static struct dentry *get_next_positive_dentry(struct dentry *prev,
					       struct dentry *root)
{ … }

/*
 * Check a direct mount point for busyness.
 * Direct mounts have similar expiry semantics to tree mounts.
 * The tree is not busy iff no mountpoints are busy and there are no
 * autofs submounts.
 */
static int autofs_direct_busy(struct vfsmount *mnt,
			      struct dentry *top,
			      unsigned long timeout,
			      unsigned int how)
{ … }

/*
 * Check a directory tree of mount points for busyness
 * The tree is not busy iff no mountpoints are busy
 */
static int autofs_tree_busy(struct vfsmount *mnt,
			    struct dentry *top,
			    unsigned long timeout,
			    unsigned int how)
{ … }

static struct dentry *autofs_check_leaves(struct vfsmount *mnt,
					  struct dentry *parent,
					  unsigned long timeout,
					  unsigned int how)
{ … }

/* Check if we can expire a direct mount (possibly a tree) */
static struct dentry *autofs_expire_direct(struct super_block *sb,
					   struct vfsmount *mnt,
					   struct autofs_sb_info *sbi,
					   unsigned int how)
{ … }

/* Check if 'dentry' should expire, or return a nearby
 * dentry that is suitable.
 * If returned dentry is different from arg dentry,
 * then a dget() reference was taken, else not.
 */
static struct dentry *should_expire(struct dentry *dentry,
				    struct vfsmount *mnt,
				    unsigned long timeout,
				    unsigned int how)
{ … }

/*
 * Find an eligible tree to time-out
 * A tree is eligible if :-
 *  - it is unused by any user process
 *  - it has been unused for exp_timeout time
 */
static struct dentry *autofs_expire_indirect(struct super_block *sb,
					     struct vfsmount *mnt,
					     struct autofs_sb_info *sbi,
					     unsigned int how)
{ … }

int autofs_expire_wait(const struct path *path, int rcu_walk)
{ … }

/* Perform an expiry operation */
int autofs_expire_run(struct super_block *sb,
		      struct vfsmount *mnt,
		      struct autofs_sb_info *sbi,
		      struct autofs_packet_expire __user *pkt_p)
{ … }

int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
			   struct autofs_sb_info *sbi, unsigned int how)
{ … }

/*
 * Call repeatedly until it returns -EAGAIN, meaning there's nothing
 * more to be done.
 */
int autofs_expire_multi(struct super_block *sb, struct vfsmount *mnt,
			struct autofs_sb_info *sbi, int __user *arg)
{ … }