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-rw-r--r--fs/afs/vnode.c395
1 files changed, 395 insertions, 0 deletions
diff --git a/fs/afs/vnode.c b/fs/afs/vnode.c
new file mode 100644
index 0000000..9867fef
--- /dev/null
+++ b/fs/afs/vnode.c
@@ -0,0 +1,395 @@
+/* vnode.c: AFS vnode management
+ *
+ * Copyright (C) 2002 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 <linux/pagemap.h>
+#include "volume.h"
+#include "cell.h"
+#include "cmservice.h"
+#include "fsclient.h"
+#include "vlclient.h"
+#include "vnode.h"
+#include "internal.h"
+
+static void afs_vnode_cb_timed_out(struct afs_timer *timer);
+
+struct afs_timer_ops afs_vnode_cb_timed_out_ops = {
+ .timed_out = afs_vnode_cb_timed_out,
+};
+
+#ifdef AFS_CACHING_SUPPORT
+static cachefs_match_val_t afs_vnode_cache_match(void *target,
+ const void *entry);
+static void afs_vnode_cache_update(void *source, void *entry);
+
+struct cachefs_index_def afs_vnode_cache_index_def = {
+ .name = "vnode",
+ .data_size = sizeof(struct afs_cache_vnode),
+ .keys[0] = { CACHEFS_INDEX_KEYS_BIN, 4 },
+ .match = afs_vnode_cache_match,
+ .update = afs_vnode_cache_update,
+};
+#endif
+
+/*****************************************************************************/
+/*
+ * handle a callback timing out
+ * TODO: retain a ref to vnode struct for an outstanding callback timeout
+ */
+static void afs_vnode_cb_timed_out(struct afs_timer *timer)
+{
+ struct afs_server *oldserver;
+ struct afs_vnode *vnode;
+
+ vnode = list_entry(timer, struct afs_vnode, cb_timeout);
+
+ _enter("%p", vnode);
+
+ /* set the changed flag in the vnode and release the server */
+ spin_lock(&vnode->lock);
+
+ oldserver = xchg(&vnode->cb_server, NULL);
+ if (oldserver) {
+ vnode->flags |= AFS_VNODE_CHANGED;
+
+ spin_lock(&afs_cb_hash_lock);
+ list_del_init(&vnode->cb_hash_link);
+ spin_unlock(&afs_cb_hash_lock);
+
+ spin_lock(&oldserver->cb_lock);
+ list_del_init(&vnode->cb_link);
+ spin_unlock(&oldserver->cb_lock);
+ }
+
+ spin_unlock(&vnode->lock);
+
+ afs_put_server(oldserver);
+
+ _leave("");
+} /* end afs_vnode_cb_timed_out() */
+
+/*****************************************************************************/
+/*
+ * 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);
+
+ vnode->flags &= ~AFS_VNODE_CHANGED;
+
+ if (ret == 0) {
+ /* adjust the callback timeout appropriately */
+ afs_kafstimod_add_timer(&vnode->cb_timeout,
+ vnode->cb_expiry * HZ);
+
+ spin_lock(&afs_cb_hash_lock);
+ list_del(&vnode->cb_hash_link);
+ list_add_tail(&vnode->cb_hash_link,
+ &afs_cb_hash(server, &vnode->fid));
+ spin_unlock(&afs_cb_hash_lock);
+
+ /* swap ref to old callback server with that for new callback
+ * server */
+ oldserver = xchg(&vnode->cb_server, server);
+ if (oldserver != server) {
+ if (oldserver) {
+ spin_lock(&oldserver->cb_lock);
+ list_del_init(&vnode->cb_link);
+ spin_unlock(&oldserver->cb_lock);
+ }
+
+ afs_get_server(server);
+ spin_lock(&server->cb_lock);
+ list_add_tail(&vnode->cb_link, &server->cb_promises);
+ spin_unlock(&server->cb_lock);
+ }
+ else {
+ /* same server */
+ oldserver = NULL;
+ }
+ }
+ else if (ret == -ENOENT) {
+ /* the file was deleted - clear the callback timeout */
+ oldserver = xchg(&vnode->cb_server, NULL);
+ afs_kafstimod_del_timer(&vnode->cb_timeout);
+
+ _debug("got NOENT from server - marking file deleted");
+ vnode->flags |= AFS_VNODE_DELETED;
+ }
+
+ vnode->update_cnt--;
+
+ spin_unlock(&vnode->lock);
+
+ wake_up_all(&vnode->update_waitq);
+
+ afs_put_server(oldserver);
+
+ _leave("");
+
+} /* end afs_vnode_finalise_status_update() */
+
+/*****************************************************************************/
+/*
+ * 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 (!(vnode->flags & AFS_VNODE_CHANGED) && vnode->cb_server) {
+ _leave(" [unchanged]");
+ return 0;
+ }
+
+ if (vnode->flags & AFS_VNODE_DELETED) {
+ _leave(" [deleted]");
+ return -ENOENT;
+ }
+
+ spin_lock(&vnode->lock);
+
+ if (!(vnode->flags & AFS_VNODE_CHANGED)) {
+ spin_unlock(&vnode->lock);
+ _leave(" [unchanged]");
+ return 0;
+ }
+
+ if (vnode->update_cnt > 0) {
+ /* someone else started a fetch */
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ add_wait_queue(&vnode->update_waitq, &myself);
+
+ /* wait for the status to be updated */
+ for (;;) {
+ if (!(vnode->flags & AFS_VNODE_CHANGED))
+ break;
+ if (vnode->flags & AFS_VNODE_DELETED)
+ break;
+
+ /* 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 vnode->flags & AFS_VNODE_DELETED ? -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 */
+ ret = afs_volume_pick_fileserver(vnode->volume, &server);
+ if (ret<0)
+ return ret;
+
+ _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
+
+ ret = afs_rxfs_fetch_file_status(server, vnode, NULL);
+
+ } while (!afs_volume_release_fileserver(vnode->volume, server, ret));
+
+ /* adjust the flags */
+ afs_vnode_finalise_status_update(vnode, server, ret);
+
+ _leave(" = %d", ret);
+ return ret;
+} /* end afs_vnode_fetch_status() */
+
+/*****************************************************************************/
+/*
+ * fetch file data from the volume
+ * - TODO implement caching and server failover
+ */
+int afs_vnode_fetch_data(struct afs_vnode *vnode,
+ struct afs_rxfs_fetch_descriptor *desc)
+{
+ 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 */
+ ret = afs_volume_pick_fileserver(vnode->volume, &server);
+ if (ret < 0)
+ return ret;
+
+ _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
+
+ ret = afs_rxfs_fetch_file_data(server, vnode, desc, NULL);
+
+ } while (!afs_volume_release_fileserver(vnode->volume, server, ret));
+
+ /* adjust the flags */
+ afs_vnode_finalise_status_update(vnode, server, ret);
+
+ _leave(" = %d", ret);
+ return ret;
+
+} /* end afs_vnode_fetch_data() */
+
+/*****************************************************************************/
+/*
+ * break any outstanding callback on a vnode
+ * - only relevent to server that issued it
+ */
+int afs_vnode_give_up_callback(struct afs_vnode *vnode)
+{
+ 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);
+
+ spin_lock(&afs_cb_hash_lock);
+ list_del_init(&vnode->cb_hash_link);
+ spin_unlock(&afs_cb_hash_lock);
+
+ /* set the changed flag in the vnode and release the server */
+ spin_lock(&vnode->lock);
+
+ afs_kafstimod_del_timer(&vnode->cb_timeout);
+
+ server = xchg(&vnode->cb_server, NULL);
+ if (server) {
+ vnode->flags |= AFS_VNODE_CHANGED;
+
+ spin_lock(&server->cb_lock);
+ list_del_init(&vnode->cb_link);
+ spin_unlock(&server->cb_lock);
+ }
+
+ spin_unlock(&vnode->lock);
+
+ ret = 0;
+ if (server) {
+ ret = afs_rxfs_give_up_callback(server, vnode);
+ afs_put_server(server);
+ }
+
+ _leave(" = %d", ret);
+ return ret;
+} /* end afs_vnode_give_up_callback() */
+
+/*****************************************************************************/
+/*
+ * match a vnode record stored in the cache
+ */
+#ifdef AFS_CACHING_SUPPORT
+static cachefs_match_val_t afs_vnode_cache_match(void *target,
+ const void *entry)
+{
+ const struct afs_cache_vnode *cvnode = entry;
+ struct afs_vnode *vnode = target;
+
+ _enter("{%x,%x,%Lx},{%x,%x,%Lx}",
+ vnode->fid.vnode,
+ vnode->fid.unique,
+ vnode->status.version,
+ cvnode->vnode_id,
+ cvnode->vnode_unique,
+ cvnode->data_version);
+
+ if (vnode->fid.vnode != cvnode->vnode_id) {
+ _leave(" = FAILED");
+ return CACHEFS_MATCH_FAILED;
+ }
+
+ if (vnode->fid.unique != cvnode->vnode_unique ||
+ vnode->status.version != cvnode->data_version) {
+ _leave(" = DELETE");
+ return CACHEFS_MATCH_SUCCESS_DELETE;
+ }
+
+ _leave(" = SUCCESS");
+ return CACHEFS_MATCH_SUCCESS;
+} /* end afs_vnode_cache_match() */
+#endif
+
+/*****************************************************************************/
+/*
+ * update a vnode record stored in the cache
+ */
+#ifdef AFS_CACHING_SUPPORT
+static void afs_vnode_cache_update(void *source, void *entry)
+{
+ struct afs_cache_vnode *cvnode = entry;
+ struct afs_vnode *vnode = source;
+
+ _enter("");
+
+ cvnode->vnode_id = vnode->fid.vnode;
+ cvnode->vnode_unique = vnode->fid.unique;
+ cvnode->data_version = vnode->status.version;
+
+} /* end afs_vnode_cache_update() */
+#endif
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