1 /* AFS vnode management
3 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
20 static noinline bool dump_tree_aux(struct rb_node *node, struct rb_node *parent,
23 struct afs_vnode *vnode;
30 bad = dump_tree_aux(node->rb_left, node, depth + 2, '/');
32 vnode = rb_entry(node, struct afs_vnode, cb_promise);
33 kdebug("%c %*.*s%c%p {%d}",
34 rb_is_red(node) ? 'R' : 'B',
36 vnode, vnode->cb_expires_at);
37 if (rb_parent(node) != parent) {
38 printk("BAD: %p != %p\n", rb_parent(node), parent);
43 bad |= dump_tree_aux(node->rb_right, node, depth + 2, '\\');
48 static noinline void dump_tree(const char *name, struct afs_server *server)
51 if (dump_tree_aux(server->cb_promises.rb_node, NULL, 0, '-'))
57 * insert a vnode into the backing server's vnode tree
59 static void afs_install_vnode(struct afs_vnode *vnode,
60 struct afs_server *server)
62 struct afs_server *old_server = vnode->server;
63 struct afs_vnode *xvnode;
64 struct rb_node *parent, **p;
66 _enter("%p,%p", vnode, server);
69 spin_lock(&old_server->fs_lock);
70 rb_erase(&vnode->server_rb, &old_server->fs_vnodes);
71 spin_unlock(&old_server->fs_lock);
74 afs_get_server(server);
75 vnode->server = server;
76 afs_put_server(old_server);
78 /* insert into the server's vnode tree in FID order */
79 spin_lock(&server->fs_lock);
82 p = &server->fs_vnodes.rb_node;
85 xvnode = rb_entry(parent, struct afs_vnode, server_rb);
86 if (vnode->fid.vid < xvnode->fid.vid)
88 else if (vnode->fid.vid > xvnode->fid.vid)
90 else if (vnode->fid.vnode < xvnode->fid.vnode)
92 else if (vnode->fid.vnode > xvnode->fid.vnode)
94 else if (vnode->fid.unique < xvnode->fid.unique)
96 else if (vnode->fid.unique > xvnode->fid.unique)
99 BUG(); /* can't happen unless afs_iget() malfunctions */
102 rb_link_node(&vnode->server_rb, parent, p);
103 rb_insert_color(&vnode->server_rb, &server->fs_vnodes);
105 spin_unlock(&server->fs_lock);
110 * insert a vnode into the promising server's update/expiration tree
111 * - caller must hold vnode->lock
113 static void afs_vnode_note_promise(struct afs_vnode *vnode,
114 struct afs_server *server)
116 struct afs_server *old_server;
117 struct afs_vnode *xvnode;
118 struct rb_node *parent, **p;
120 _enter("%p,%p", vnode, server);
122 ASSERT(server != NULL);
124 old_server = vnode->server;
125 if (vnode->cb_promised) {
126 if (server == old_server &&
127 vnode->cb_expires == vnode->cb_expires_at) {
128 _leave(" [no change]");
132 spin_lock(&old_server->cb_lock);
133 if (vnode->cb_promised) {
135 rb_erase(&vnode->cb_promise, &old_server->cb_promises);
136 vnode->cb_promised = false;
138 spin_unlock(&old_server->cb_lock);
141 if (vnode->server != server)
142 afs_install_vnode(vnode, server);
144 vnode->cb_expires_at = vnode->cb_expires;
145 _debug("PROMISE on %p {%lu}",
146 vnode, (unsigned long) vnode->cb_expires_at);
148 /* abuse an RB-tree to hold the expiration order (we may have multiple
149 * items with the same expiration time) */
150 spin_lock(&server->cb_lock);
153 p = &server->cb_promises.rb_node;
156 xvnode = rb_entry(parent, struct afs_vnode, cb_promise);
157 if (vnode->cb_expires_at < xvnode->cb_expires_at)
163 rb_link_node(&vnode->cb_promise, parent, p);
164 rb_insert_color(&vnode->cb_promise, &server->cb_promises);
165 vnode->cb_promised = true;
167 spin_unlock(&server->cb_lock);
172 * handle remote file deletion by discarding the callback promise
174 static void afs_vnode_deleted_remotely(struct afs_vnode *vnode)
176 struct afs_server *server;
178 set_bit(AFS_VNODE_DELETED, &vnode->flags);
180 server = vnode->server;
181 if (vnode->cb_promised) {
182 spin_lock(&server->cb_lock);
183 if (vnode->cb_promised) {
184 rb_erase(&vnode->cb_promise, &server->cb_promises);
185 vnode->cb_promised = false;
187 spin_unlock(&server->cb_lock);
190 afs_put_server(server);
194 * finish off updating the recorded status of a file
195 * - starts callback expiry timer
196 * - adds to server's callback list
198 static void afs_vnode_finalise_status_update(struct afs_vnode *vnode,
199 struct afs_server *server,
202 struct afs_server *oldserver = NULL;
204 _enter("%p,%p,%d", vnode, server, ret);
206 spin_lock(&vnode->lock);
208 clear_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
212 afs_vnode_note_promise(vnode, server);
215 /* the file was deleted on the server */
216 _debug("got NOENT from server - marking file deleted");
217 afs_vnode_deleted_remotely(vnode);
225 spin_unlock(&vnode->lock);
227 wake_up_all(&vnode->update_waitq);
229 afs_put_server(oldserver);
235 * fetch file status from the volume
236 * - don't issue a fetch if:
237 * - the changed bit is not set and there's a valid callback
238 * - there are any outstanding ops that will fetch the status
239 * - TODO implement local caching
241 int afs_vnode_fetch_status(struct afs_vnode *vnode,
242 struct afs_vnode *auth_vnode, struct key *key)
244 struct afs_server *server;
245 unsigned long acl_order;
248 DECLARE_WAITQUEUE(myself, current);
250 _enter("%s,{%u,%u,%u}",
251 vnode->volume->vlocation->vldb.name,
252 vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
254 if (!test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
255 vnode->cb_promised) {
256 _leave(" [unchanged]");
260 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
261 _leave(" [deleted]");
267 acl_order = auth_vnode->acl_order;
269 spin_lock(&vnode->lock);
271 if (!test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
272 vnode->cb_promised) {
273 spin_unlock(&vnode->lock);
274 _leave(" [unchanged]");
278 if (vnode->update_cnt > 0) {
279 /* someone else started a fetch */
280 set_current_state(TASK_UNINTERRUPTIBLE);
281 ASSERT(myself.func != NULL);
282 add_wait_queue(&vnode->update_waitq, &myself);
284 /* wait for the status to be updated */
286 if (!test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
288 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
291 /* check to see if it got updated and invalidated all
292 * before we saw it */
293 if (vnode->update_cnt == 0) {
294 remove_wait_queue(&vnode->update_waitq,
296 set_current_state(TASK_RUNNING);
300 spin_unlock(&vnode->lock);
303 set_current_state(TASK_UNINTERRUPTIBLE);
305 spin_lock(&vnode->lock);
308 remove_wait_queue(&vnode->update_waitq, &myself);
309 spin_unlock(&vnode->lock);
310 set_current_state(TASK_RUNNING);
312 return test_bit(AFS_VNODE_DELETED, &vnode->flags) ?
317 /* okay... we're going to have to initiate the op */
320 spin_unlock(&vnode->lock);
322 /* merge AFS status fetches and clear outstanding callback on this
325 /* pick a server to query */
326 server = afs_volume_pick_fileserver(vnode);
328 return PTR_ERR(server);
330 _debug("USING SERVER: %p{%08x}",
331 server, ntohl(server->addr.s_addr));
333 ret = afs_fs_fetch_file_status(server, key, vnode, NULL,
336 } while (!afs_volume_release_fileserver(vnode, server, ret));
338 /* adjust the flags */
339 if (ret == 0 && auth_vnode)
340 afs_cache_permit(vnode, key, acl_order);
341 afs_vnode_finalise_status_update(vnode, server, ret);
343 _leave(" = %d", ret);
348 * fetch file data from the volume
349 * - TODO implement caching and server failover
351 int afs_vnode_fetch_data(struct afs_vnode *vnode, struct key *key,
352 off_t offset, size_t length, struct page *page)
354 struct afs_server *server;
357 _enter("%s{%u,%u,%u},%x,,,",
358 vnode->volume->vlocation->vldb.name,
364 /* this op will fetch the status */
365 spin_lock(&vnode->lock);
367 spin_unlock(&vnode->lock);
369 /* merge in AFS status fetches and clear outstanding callback on this
372 /* pick a server to query */
373 server = afs_volume_pick_fileserver(vnode);
375 return PTR_ERR(server);
377 _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
379 ret = afs_fs_fetch_data(server, key, vnode, offset, length,
380 page, NULL, &afs_sync_call);
382 } while (!afs_volume_release_fileserver(vnode, server, ret));
384 /* adjust the flags */
385 afs_vnode_finalise_status_update(vnode, server, ret);
387 _leave(" = %d", ret);