diff options
Diffstat (limited to 'fs/afs/vnode.c')
| -rw-r--r-- | fs/afs/vnode.c | 395 |
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 |
