mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
ee1235a9a0
Pass the object size in to fscache_acquire_cookie() and fscache_write_page() rather than the netfs providing a callback by which it can be received. This makes it easier to update the size of the object when a new page is written that extends the object. The current object size is also passed by fscache to the check_aux function, obviating the need to store it in the aux data. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Anna Schumaker <anna.schumaker@netapp.com> Tested-by: Steve Dickson <steved@redhat.com>
102 lines
3.1 KiB
C
102 lines
3.1 KiB
C
/* Filesystem index definition
|
|
*
|
|
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#define FSCACHE_DEBUG_LEVEL CACHE
|
|
#include <linux/module.h>
|
|
#include "internal.h"
|
|
|
|
static
|
|
enum fscache_checkaux fscache_fsdef_netfs_check_aux(void *cookie_netfs_data,
|
|
const void *data,
|
|
uint16_t datalen,
|
|
loff_t object_size);
|
|
|
|
/*
|
|
* The root index is owned by FS-Cache itself.
|
|
*
|
|
* When a netfs requests caching facilities, FS-Cache will, if one doesn't
|
|
* already exist, create an entry in the root index with the key being the name
|
|
* of the netfs ("AFS" for example), and the auxiliary data holding the index
|
|
* structure version supplied by the netfs:
|
|
*
|
|
* FSDEF
|
|
* |
|
|
* +-----------+
|
|
* | |
|
|
* NFS AFS
|
|
* [v=1] [v=1]
|
|
*
|
|
* If an entry with the appropriate name does already exist, the version is
|
|
* compared. If the version is different, the entire subtree from that entry
|
|
* will be discarded and a new entry created.
|
|
*
|
|
* The new entry will be an index, and a cookie referring to it will be passed
|
|
* to the netfs. This is then the root handle by which the netfs accesses the
|
|
* cache. It can create whatever objects it likes in that index, including
|
|
* further indices.
|
|
*/
|
|
static struct fscache_cookie_def fscache_fsdef_index_def = {
|
|
.name = ".FS-Cache",
|
|
.type = FSCACHE_COOKIE_TYPE_INDEX,
|
|
};
|
|
|
|
struct fscache_cookie fscache_fsdef_index = {
|
|
.usage = ATOMIC_INIT(1),
|
|
.n_active = ATOMIC_INIT(1),
|
|
.lock = __SPIN_LOCK_UNLOCKED(fscache_fsdef_index.lock),
|
|
.backing_objects = HLIST_HEAD_INIT,
|
|
.def = &fscache_fsdef_index_def,
|
|
.flags = 1 << FSCACHE_COOKIE_ENABLED,
|
|
.type = FSCACHE_COOKIE_TYPE_INDEX,
|
|
};
|
|
EXPORT_SYMBOL(fscache_fsdef_index);
|
|
|
|
/*
|
|
* Definition of an entry in the root index. Each entry is an index, keyed to
|
|
* a specific netfs and only applicable to a particular version of the index
|
|
* structure used by that netfs.
|
|
*/
|
|
struct fscache_cookie_def fscache_fsdef_netfs_def = {
|
|
.name = "FSDEF.netfs",
|
|
.type = FSCACHE_COOKIE_TYPE_INDEX,
|
|
.check_aux = fscache_fsdef_netfs_check_aux,
|
|
};
|
|
|
|
/*
|
|
* check that the index structure version number stored in the auxiliary data
|
|
* matches the one the netfs gave us
|
|
*/
|
|
static enum fscache_checkaux fscache_fsdef_netfs_check_aux(
|
|
void *cookie_netfs_data,
|
|
const void *data,
|
|
uint16_t datalen,
|
|
loff_t object_size)
|
|
{
|
|
struct fscache_netfs *netfs = cookie_netfs_data;
|
|
uint32_t version;
|
|
|
|
_enter("{%s},,%hu", netfs->name, datalen);
|
|
|
|
if (datalen != sizeof(version)) {
|
|
_leave(" = OBSOLETE [dl=%d v=%zu]", datalen, sizeof(version));
|
|
return FSCACHE_CHECKAUX_OBSOLETE;
|
|
}
|
|
|
|
memcpy(&version, data, sizeof(version));
|
|
if (version != netfs->version) {
|
|
_leave(" = OBSOLETE [ver=%x net=%x]", version, netfs->version);
|
|
return FSCACHE_CHECKAUX_OBSOLETE;
|
|
}
|
|
|
|
_leave(" = OKAY");
|
|
return FSCACHE_CHECKAUX_OKAY;
|
|
}
|