381 lines
9.0 KiB
C
381 lines
9.0 KiB
C
/* AFS vnode management
|
|
*
|
|
* Copyright (C) 2002, 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.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/fs.h>
|
|
#include "internal.h"
|
|
|
|
#if 0
|
|
static noinline bool dump_tree_aux(struct rb_node *node, struct rb_node *parent,
|
|
int depth, char lr)
|
|
{
|
|
struct afs_vnode *vnode;
|
|
bool bad = false;
|
|
|
|
if (!node)
|
|
return false;
|
|
|
|
if (node->rb_left)
|
|
bad = dump_tree_aux(node->rb_left, node, depth + 2, '/');
|
|
|
|
vnode = rb_entry(node, struct afs_vnode, cb_promise);
|
|
kdebug("%c %*.*s%c%p {%d}",
|
|
rb_is_red(node) ? 'R' : 'B',
|
|
depth, depth, "", lr,
|
|
vnode, vnode->cb_expires_at);
|
|
if (rb_parent(node) != parent) {
|
|
printk("BAD: %p != %p\n", rb_parent(node), parent);
|
|
bad = true;
|
|
}
|
|
|
|
if (node->rb_right)
|
|
bad |= dump_tree_aux(node->rb_right, node, depth + 2, '\\');
|
|
|
|
return bad;
|
|
}
|
|
|
|
static noinline void dump_tree(const char *name, struct afs_server *server)
|
|
{
|
|
kenter("%s", name);
|
|
if (dump_tree_aux(server->cb_promises.rb_node, NULL, 0, '-'))
|
|
BUG();
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* insert a vnode into the backing server's vnode tree
|
|
*/
|
|
static void afs_install_vnode(struct afs_vnode *vnode,
|
|
struct afs_server *server)
|
|
{
|
|
struct afs_server *old_server = vnode->server;
|
|
struct afs_vnode *xvnode;
|
|
struct rb_node *parent, **p;
|
|
|
|
_enter("%p,%p", vnode, server);
|
|
|
|
if (old_server) {
|
|
spin_lock(&old_server->fs_lock);
|
|
rb_erase(&vnode->server_rb, &old_server->fs_vnodes);
|
|
spin_unlock(&old_server->fs_lock);
|
|
}
|
|
|
|
afs_get_server(server);
|
|
vnode->server = server;
|
|
afs_put_server(old_server);
|
|
|
|
/* insert into the server's vnode tree in FID order */
|
|
spin_lock(&server->fs_lock);
|
|
|
|
parent = NULL;
|
|
p = &server->fs_vnodes.rb_node;
|
|
while (*p) {
|
|
parent = *p;
|
|
xvnode = rb_entry(parent, struct afs_vnode, server_rb);
|
|
if (vnode->fid.vid < xvnode->fid.vid)
|
|
p = &(*p)->rb_left;
|
|
else if (vnode->fid.vid > xvnode->fid.vid)
|
|
p = &(*p)->rb_right;
|
|
else if (vnode->fid.vnode < xvnode->fid.vnode)
|
|
p = &(*p)->rb_left;
|
|
else if (vnode->fid.vnode > xvnode->fid.vnode)
|
|
p = &(*p)->rb_right;
|
|
else if (vnode->fid.unique < xvnode->fid.unique)
|
|
p = &(*p)->rb_left;
|
|
else if (vnode->fid.unique > xvnode->fid.unique)
|
|
p = &(*p)->rb_right;
|
|
else
|
|
BUG(); /* can't happen unless afs_iget() malfunctions */
|
|
}
|
|
|
|
rb_link_node(&vnode->server_rb, parent, p);
|
|
rb_insert_color(&vnode->server_rb, &server->fs_vnodes);
|
|
|
|
spin_unlock(&server->fs_lock);
|
|
_leave("");
|
|
}
|
|
|
|
/*
|
|
* insert a vnode into the promising server's update/expiration tree
|
|
* - caller must hold vnode->lock
|
|
*/
|
|
static void afs_vnode_note_promise(struct afs_vnode *vnode,
|
|
struct afs_server *server)
|
|
{
|
|
struct afs_server *old_server;
|
|
struct afs_vnode *xvnode;
|
|
struct rb_node *parent, **p;
|
|
|
|
_enter("%p,%p", vnode, server);
|
|
|
|
ASSERT(server != NULL);
|
|
|
|
old_server = vnode->server;
|
|
if (vnode->cb_promised) {
|
|
if (server == old_server &&
|
|
vnode->cb_expires == vnode->cb_expires_at) {
|
|
_leave(" [no change]");
|
|
return;
|
|
}
|
|
|
|
spin_lock(&old_server->cb_lock);
|
|
if (vnode->cb_promised) {
|
|
_debug("delete");
|
|
rb_erase(&vnode->cb_promise, &old_server->cb_promises);
|
|
vnode->cb_promised = false;
|
|
}
|
|
spin_unlock(&old_server->cb_lock);
|
|
}
|
|
|
|
if (vnode->server != server)
|
|
afs_install_vnode(vnode, server);
|
|
|
|
vnode->cb_expires_at = vnode->cb_expires;
|
|
_debug("PROMISE on %p {%lu}",
|
|
vnode, (unsigned long) vnode->cb_expires_at);
|
|
|
|
/* abuse an RB-tree to hold the expiration order (we may have multiple
|
|
* items with the same expiration time) */
|
|
spin_lock(&server->cb_lock);
|
|
|
|
parent = NULL;
|
|
p = &server->cb_promises.rb_node;
|
|
while (*p) {
|
|
parent = *p;
|
|
xvnode = rb_entry(parent, struct afs_vnode, cb_promise);
|
|
if (vnode->cb_expires_at < xvnode->cb_expires_at)
|
|
p = &(*p)->rb_left;
|
|
else
|
|
p = &(*p)->rb_right;
|
|
}
|
|
|
|
rb_link_node(&vnode->cb_promise, parent, p);
|
|
rb_insert_color(&vnode->cb_promise, &server->cb_promises);
|
|
vnode->cb_promised = true;
|
|
|
|
spin_unlock(&server->cb_lock);
|
|
_leave("");
|
|
}
|
|
|
|
/*
|
|
* handle remote file deletion by discarding the callback promise
|
|
*/
|
|
static void afs_vnode_deleted_remotely(struct afs_vnode *vnode)
|
|
{
|
|
struct afs_server *server;
|
|
|
|
set_bit(AFS_VNODE_DELETED, &vnode->flags);
|
|
|
|
server = vnode->server;
|
|
if (vnode->cb_promised) {
|
|
spin_lock(&server->cb_lock);
|
|
if (vnode->cb_promised) {
|
|
rb_erase(&vnode->cb_promise, &server->cb_promises);
|
|
vnode->cb_promised = false;
|
|
}
|
|
spin_unlock(&server->cb_lock);
|
|
}
|
|
|
|
afs_put_server(server);
|
|
}
|
|
|
|
/*
|
|
* finish off updating the recorded status of a file
|
|
* - starts callback expiry timer
|
|
* - adds to server's callback list
|
|
*/
|
|
static void afs_vnode_finalise_status_update(struct afs_vnode *vnode,
|
|
struct afs_server *server,
|
|
int ret)
|
|
{
|
|
struct afs_server *oldserver = NULL;
|
|
|
|
_enter("%p,%p,%d", vnode, server, ret);
|
|
|
|
spin_lock(&vnode->lock);
|
|
|
|
clear_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
|
|
|
|
switch (ret) {
|
|
case 0:
|
|
afs_vnode_note_promise(vnode, server);
|
|
break;
|
|
case -ENOENT:
|
|
/* the file was deleted on the server */
|
|
_debug("got NOENT from server - marking file deleted");
|
|
afs_vnode_deleted_remotely(vnode);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
vnode->update_cnt--;
|
|
|
|
spin_unlock(&vnode->lock);
|
|
|
|
wake_up_all(&vnode->update_waitq);
|
|
|
|
afs_put_server(oldserver);
|
|
|
|
_leave("");
|
|
}
|
|
|
|
/*
|
|
* fetch file status from the volume
|
|
* - don't issue a fetch if:
|
|
* - the changed bit is not set and there's a valid callback
|
|
* - there are any outstanding ops that will fetch the status
|
|
* - TODO implement local caching
|
|
*/
|
|
int afs_vnode_fetch_status(struct afs_vnode *vnode)
|
|
{
|
|
struct afs_server *server;
|
|
int ret;
|
|
|
|
DECLARE_WAITQUEUE(myself, current);
|
|
|
|
_enter("%s,{%u,%u,%u}",
|
|
vnode->volume->vlocation->vldb.name,
|
|
vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
|
|
|
|
if (!test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
|
|
vnode->cb_promised) {
|
|
_leave(" [unchanged]");
|
|
return 0;
|
|
}
|
|
|
|
if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
|
|
_leave(" [deleted]");
|
|
return -ENOENT;
|
|
}
|
|
|
|
spin_lock(&vnode->lock);
|
|
|
|
if (!test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
|
|
vnode->cb_promised) {
|
|
spin_unlock(&vnode->lock);
|
|
_leave(" [unchanged]");
|
|
return 0;
|
|
}
|
|
|
|
if (vnode->update_cnt > 0) {
|
|
/* someone else started a fetch */
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
ASSERT(myself.func != NULL);
|
|
add_wait_queue(&vnode->update_waitq, &myself);
|
|
|
|
/* wait for the status to be updated */
|
|
for (;;) {
|
|
if (!test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
|
|
break;
|
|
if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
|
|
break;
|
|
|
|
/* check to see if it got updated and invalidated all
|
|
* before we saw it */
|
|
if (vnode->update_cnt == 0) {
|
|
remove_wait_queue(&vnode->update_waitq,
|
|
&myself);
|
|
set_current_state(TASK_RUNNING);
|
|
goto get_anyway;
|
|
}
|
|
|
|
spin_unlock(&vnode->lock);
|
|
|
|
schedule();
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
|
|
spin_lock(&vnode->lock);
|
|
}
|
|
|
|
remove_wait_queue(&vnode->update_waitq, &myself);
|
|
spin_unlock(&vnode->lock);
|
|
set_current_state(TASK_RUNNING);
|
|
|
|
return test_bit(AFS_VNODE_DELETED, &vnode->flags) ?
|
|
-ENOENT : 0;
|
|
}
|
|
|
|
get_anyway:
|
|
/* okay... we're going to have to initiate the op */
|
|
vnode->update_cnt++;
|
|
|
|
spin_unlock(&vnode->lock);
|
|
|
|
/* merge AFS status fetches and clear outstanding callback on this
|
|
* vnode */
|
|
do {
|
|
/* pick a server to query */
|
|
server = afs_volume_pick_fileserver(vnode);
|
|
if (IS_ERR(server))
|
|
return PTR_ERR(server);
|
|
|
|
_debug("USING SERVER: %p{%08x}",
|
|
server, ntohl(server->addr.s_addr));
|
|
|
|
ret = afs_fs_fetch_file_status(server, vnode, NULL,
|
|
&afs_sync_call);
|
|
|
|
} while (!afs_volume_release_fileserver(vnode, server, ret));
|
|
|
|
/* adjust the flags */
|
|
afs_vnode_finalise_status_update(vnode, server, ret);
|
|
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* fetch file data from the volume
|
|
* - TODO implement caching and server failover
|
|
*/
|
|
int afs_vnode_fetch_data(struct afs_vnode *vnode, off_t offset, size_t length,
|
|
struct page *page)
|
|
{
|
|
struct afs_server *server;
|
|
int ret;
|
|
|
|
_enter("%s,{%u,%u,%u}",
|
|
vnode->volume->vlocation->vldb.name,
|
|
vnode->fid.vid,
|
|
vnode->fid.vnode,
|
|
vnode->fid.unique);
|
|
|
|
/* this op will fetch the status */
|
|
spin_lock(&vnode->lock);
|
|
vnode->update_cnt++;
|
|
spin_unlock(&vnode->lock);
|
|
|
|
/* merge in AFS status fetches and clear outstanding callback on this
|
|
* vnode */
|
|
do {
|
|
/* pick a server to query */
|
|
server = afs_volume_pick_fileserver(vnode);
|
|
if (IS_ERR(server))
|
|
return PTR_ERR(server);
|
|
|
|
_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
|
|
|
|
ret = afs_fs_fetch_data(server, vnode, offset, length, page,
|
|
NULL, &afs_sync_call);
|
|
|
|
} while (!afs_volume_release_fileserver(vnode, server, ret));
|
|
|
|
/* adjust the flags */
|
|
afs_vnode_finalise_status_update(vnode, server, ret);
|
|
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
}
|