linux/fs/afs/volume.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* AFS volume management
 *
 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include "internal.h"

static unsigned __read_mostly afs_volume_record_life = …;

static void afs_destroy_volume(struct work_struct *work);

/*
 * Insert a volume into a cell.  If there's an existing volume record, that is
 * returned instead with a ref held.
 */
static struct afs_volume *afs_insert_volume_into_cell(struct afs_cell *cell,
						      struct afs_volume *volume)
{ … }

static void afs_remove_volume_from_cell(struct afs_volume *volume)
{ … }

/*
 * Allocate a volume record and load it up from a vldb record.
 */
static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params,
					   struct afs_vldb_entry *vldb,
					   struct afs_server_list **_slist)
{ … }

/*
 * Look up or allocate a volume record.
 */
static struct afs_volume *afs_lookup_volume(struct afs_fs_context *params,
					    struct afs_vldb_entry *vldb)
{ … }

/*
 * Look up a VLDB record for a volume.
 */
static struct afs_vldb_entry *afs_vl_lookup_vldb(struct afs_cell *cell,
						 struct key *key,
						 const char *volname,
						 size_t volnamesz)
{ … }

/*
 * Look up a volume in the VL server and create a candidate volume record for
 * it.
 *
 * The volume name can be one of the following:
 *	"%[cell:]volume[.]"		R/W volume
 *	"#[cell:]volume[.]"		R/O or R/W volume (rwparent=0),
 *					 or R/W (rwparent=1) volume
 *	"%[cell:]volume.readonly"	R/O volume
 *	"#[cell:]volume.readonly"	R/O volume
 *	"%[cell:]volume.backup"		Backup volume
 *	"#[cell:]volume.backup"		Backup volume
 *
 * The cell name is optional, and defaults to the current cell.
 *
 * See "The Rules of Mount Point Traversal" in Chapter 5 of the AFS SysAdmin
 * Guide
 * - Rule 1: Explicit type suffix forces access of that type or nothing
 *           (no suffix, then use Rule 2 & 3)
 * - Rule 2: If parent volume is R/O, then mount R/O volume by preference, R/W
 *           if not available
 * - Rule 3: If parent volume is R/W, then only mount R/W volume unless
 *           explicitly told otherwise
 */
struct afs_volume *afs_create_volume(struct afs_fs_context *params)
{ … }

/*
 * Destroy a volume record
 */
static void afs_destroy_volume(struct work_struct *work)
{ … }

/*
 * Try to get a reference on a volume record.
 */
bool afs_try_get_volume(struct afs_volume *volume, enum afs_volume_trace reason)
{ … }

/*
 * Get a reference on a volume record.
 */
struct afs_volume *afs_get_volume(struct afs_volume *volume,
				  enum afs_volume_trace reason)
{ … }


/*
 * Drop a reference on a volume record.
 */
void afs_put_volume(struct afs_volume *volume, enum afs_volume_trace reason)
{ … }

/*
 * Activate a volume.
 */
int afs_activate_volume(struct afs_volume *volume)
{ … }

/*
 * Deactivate a volume.
 */
void afs_deactivate_volume(struct afs_volume *volume)
{ … }

/*
 * Query the VL service to update the volume status.
 */
static int afs_update_volume_status(struct afs_volume *volume, struct key *key)
{ … }

/*
 * Make sure the volume record is up to date.
 */
int afs_check_volume_status(struct afs_volume *volume, struct afs_operation *op)
{ … }