1 files changed, 395 insertions, 0 deletions

diff --git a/fs/afs/vnode.c b/fs/afs/vnode.c
new file mode 100644
index 000000000000..9867fef3261d
--- /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