linux/fs/afs/callback.c

/*
 * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
 *
 * This software may be freely redistributed under the terms of the
 * GNU General Public License.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Authors: David Woodhouse <[email protected]>
 *          David Howells <[email protected]>
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/circ_buf.h>
#include <linux/sched.h>
#include "internal.h"

/*
 * Handle invalidation of an mmap'd file.  We invalidate all the PTEs referring
 * to the pages in this file's pagecache, forcing the kernel to go through
 * ->fault() or ->page_mkwrite() - at which point we can handle invalidation
 * more fully.
 */
void afs_invalidate_mmap_work(struct work_struct *work)
{ … }

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

/*
 * Allow the fileserver to request callback state (re-)initialisation.
 * Unfortunately, UUIDs are not guaranteed unique.
 */
void afs_init_callback_state(struct afs_server *server)
{ … }

/*
 * actually break a callback
 */
void __afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason)
{ … }

void afs_break_callback(struct afs_vnode *vnode, enum afs_cb_break_reason reason)
{ … }

/*
 * Look up a volume by volume ID under RCU conditions.
 */
static struct afs_volume *afs_lookup_volume_rcu(struct afs_cell *cell,
						afs_volid_t vid)
{ … }

/*
 * Allow the fileserver to break callbacks at the volume-level.  This is
 * typically done when, for example, a R/W volume is snapshotted to a R/O
 * volume (the only way to change an R/O volume).  It may also, however, happen
 * when a volserver takes control of a volume (offlining it, moving it, etc.).
 *
 * Every file in that volume will need to be reevaluated.
 */
static void afs_break_volume_callback(struct afs_server *server,
				      struct afs_volume *volume)
	__releases(RCU)
{ … }

/*
 * allow the fileserver to explicitly break one callback
 * - happens when
 *   - the backing file is changed
 *   - a lock is released
 */
static void afs_break_one_callback(struct afs_server *server,
				   struct afs_volume *volume,
				   struct afs_fid *fid)
{ … }

static void afs_break_some_callbacks(struct afs_server *server,
				     struct afs_callback_break *cbb,
				     size_t *_count)
{ … }

/*
 * allow the fileserver to break callback promises
 */
void afs_break_callbacks(struct afs_server *server, size_t count,
			 struct afs_callback_break *callbacks)
{ … }