text: /* 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/fs.h>
  #include <linux/sched.h>
  #include "internal.h"
  
  
  /*
   * 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;
  
  	_enter("{%p}", vnode->server);
  
  	set_bit(AFS_VNODE_DELETED, &vnode->flags);
  
  	server = vnode->server;
  	if (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);
  		}
  
  		spin_lock(&server->fs_lock);
  		rb_erase(&vnode->server_rb, &server->fs_vnodes);
  		spin_unlock(&server->fs_lock);
  
  		vnode->server = NULL;
  		afs_put_server(server);
  	} else {
  		ASSERT(!vnode->cb_promised);
  	}
  
  	_leave("");
  }
  
  /*
   * finish off updating the recorded status of a file after a successful
   * operation completion
   * - starts callback expiry timer
   * - adds to server's callback list
   */
  void afs_vnode_finalise_status_update(struct afs_vnode *vnode,
  				      struct afs_server *server)
  {
  	struct afs_server *oldserver = NULL;
  
  	_enter("%p,%p", vnode, server);
  
  	spin_lock(&vnode->lock);
  	clear_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
  	afs_vnode_note_promise(vnode, server);
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  
  	wake_up_all(&vnode->update_waitq);
  	afs_put_server(oldserver);
  	_leave("");
  }
  
  /*
   * finish off updating the recorded status of a file after an operation failed
   */
  static void afs_vnode_status_update_failed(struct afs_vnode *vnode, int ret)
  {
  	_enter("{%x:%u},%d", vnode->fid.vid, vnode->fid.vnode, ret);
  
  	spin_lock(&vnode->lock);
  
  	clear_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
  
  	if (ret == -ENOENT) {
  		/* the file was deleted on the server */
  		_debug("got NOENT from server - marking file deleted");
  		afs_vnode_deleted_remotely(vnode);
  	}
  
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  
  	wake_up_all(&vnode->update_waitq);
  	_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_vnode *auth_vnode, struct key *key)
  {
  	struct afs_server *server;
  	unsigned long acl_order;
  	int ret;
  
  	DECLARE_WAITQUEUE(myself, current);
  
  	_enter("%s,{%x:%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;
  	}
  
  	acl_order = 0;
  	if (auth_vnode)
  		acl_order = auth_vnode->acl_order;
  
  	spin_lock(&vnode->lock);
  
  	if (!test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
  	    vnode->cb_promised) {
  		spin_unlock(&vnode->lock);
  		_leave(" [unchanged]");
  		return 0;
  	}
  
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  
  	if (vnode->update_cnt > 0) {
  		/* someone else started a fetch */
  		_debug("wait on fetch %d", vnode->update_cnt);
  
  		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))
  			goto no_server;
  
  		_debug("USING SERVER: %p{%08x}",
  		       server, ntohl(server->addr.s_addr));
  
  		ret = afs_fs_fetch_file_status(server, key, vnode, NULL,
  					       &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0) {
  		_debug("adjust");
  		if (auth_vnode)
  			afs_cache_permit(vnode, key, acl_order);
  		afs_vnode_finalise_status_update(vnode, server);
  		afs_put_server(server);
  	} else {
  		_debug("failed [%d]", ret);
  		afs_vnode_status_update_failed(vnode, ret);
  	}
  
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  
  	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
  	return ret;
  
  no_server:
  	spin_lock(&vnode->lock);
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
  	return PTR_ERR(server);
  }
  
  /*
   * fetch file data from the volume
   * - TODO implement caching
   */
  int afs_vnode_fetch_data(struct afs_vnode *vnode, struct key *key,
  			 off_t offset, size_t length, struct page *page)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x,,,",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key));
  
  	/* 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))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_fetch_data(server, key, vnode, offset, length,
  					page, &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0) {
  		afs_vnode_finalise_status_update(vnode, server);
  		afs_put_server(server);
  	} else {
  		afs_vnode_status_update_failed(vnode, ret);
  	}
  
  	_leave(" = %d", ret);
  	return ret;
  
  no_server:
  	spin_lock(&vnode->lock);
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  	return PTR_ERR(server);
  }
  
  /*
   * make a file or a directory
   */
  int afs_vnode_create(struct afs_vnode *vnode, struct key *key,
  		     const char *name, umode_t mode, struct afs_fid *newfid,
  		     struct afs_file_status *newstatus,
  		     struct afs_callback *newcb, struct afs_server **_server)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x,%s,,",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key),
  	       name);
  
  	/* this op will fetch the status on the directory we're creating in */
  	spin_lock(&vnode->lock);
  	vnode->update_cnt++;
  	spin_unlock(&vnode->lock);
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(vnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_create(server, key, vnode, name, mode, newfid,
  				    newstatus, newcb, &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0) {
  		afs_vnode_finalise_status_update(vnode, server);
  		*_server = server;
  	} else {
  		afs_vnode_status_update_failed(vnode, ret);
  		*_server = NULL;
  	}
  
  	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
  	return ret;
  
  no_server:
  	spin_lock(&vnode->lock);
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
  	return PTR_ERR(server);
  }
  
  /*
   * remove a file or directory
   */
  int afs_vnode_remove(struct afs_vnode *vnode, struct key *key, const char *name,
  		     bool isdir)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x,%s",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key),
  	       name);
  
  	/* this op will fetch the status on the directory we're removing from */
  	spin_lock(&vnode->lock);
  	vnode->update_cnt++;
  	spin_unlock(&vnode->lock);
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(vnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_remove(server, key, vnode, name, isdir,
  				    &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0) {
  		afs_vnode_finalise_status_update(vnode, server);
  		afs_put_server(server);
  	} else {
  		afs_vnode_status_update_failed(vnode, ret);
  	}
  
  	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
  	return ret;
  
  no_server:
  	spin_lock(&vnode->lock);
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
  	return PTR_ERR(server);
  }
  
  /*
   * create a hard link
   */
  int afs_vnode_link(struct afs_vnode *dvnode, struct afs_vnode *vnode,
  			  struct key *key, const char *name)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%s{%x:%u.%u},%x,%s",
  	       dvnode->volume->vlocation->vldb.name,
  	       dvnode->fid.vid,
  	       dvnode->fid.vnode,
  	       dvnode->fid.unique,
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key),
  	       name);
  
  	/* this op will fetch the status on the directory we're removing from */
  	spin_lock(&vnode->lock);
  	vnode->update_cnt++;
  	spin_unlock(&vnode->lock);
  	spin_lock(&dvnode->lock);
  	dvnode->update_cnt++;
  	spin_unlock(&dvnode->lock);
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(dvnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_link(server, key, dvnode, vnode, name,
  				  &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(dvnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0) {
  		afs_vnode_finalise_status_update(vnode, server);
  		afs_vnode_finalise_status_update(dvnode, server);
  		afs_put_server(server);
  	} else {
  		afs_vnode_status_update_failed(vnode, ret);
  		afs_vnode_status_update_failed(dvnode, ret);
  	}
  
  	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
  	return ret;
  
  no_server:
  	spin_lock(&vnode->lock);
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  	spin_lock(&dvnode->lock);
  	dvnode->update_cnt--;
  	ASSERTCMP(dvnode->update_cnt, >=, 0);
  	spin_unlock(&dvnode->lock);
  	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
  	return PTR_ERR(server);
  }
  
  /*
   * create a symbolic link
   */
  int afs_vnode_symlink(struct afs_vnode *vnode, struct key *key,
  		      const char *name, const char *content,
  		      struct afs_fid *newfid,
  		      struct afs_file_status *newstatus,
  		      struct afs_server **_server)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x,%s,%s,,,",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key),
  	       name, content);
  
  	/* this op will fetch the status on the directory we're creating in */
  	spin_lock(&vnode->lock);
  	vnode->update_cnt++;
  	spin_unlock(&vnode->lock);
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(vnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_symlink(server, key, vnode, name, content,
  				     newfid, newstatus, &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0) {
  		afs_vnode_finalise_status_update(vnode, server);
  		*_server = server;
  	} else {
  		afs_vnode_status_update_failed(vnode, ret);
  		*_server = NULL;
  	}
  
  	_leave(" = %d [cnt %d]", ret, vnode->update_cnt);
  	return ret;
  
  no_server:
  	spin_lock(&vnode->lock);
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  	_leave(" = %ld [cnt %d]", PTR_ERR(server), vnode->update_cnt);
  	return PTR_ERR(server);
  }
  
  /*
   * rename a file
   */
  int afs_vnode_rename(struct afs_vnode *orig_dvnode,
  		     struct afs_vnode *new_dvnode,
  		     struct key *key,
  		     const char *orig_name,
  		     const char *new_name)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%s{%u,%u,%u},%x,%s,%s",
  	       orig_dvnode->volume->vlocation->vldb.name,
  	       orig_dvnode->fid.vid,
  	       orig_dvnode->fid.vnode,
  	       orig_dvnode->fid.unique,
  	       new_dvnode->volume->vlocation->vldb.name,
  	       new_dvnode->fid.vid,
  	       new_dvnode->fid.vnode,
  	       new_dvnode->fid.unique,
  	       key_serial(key),
  	       orig_name,
  	       new_name);
  
  	/* this op will fetch the status on both the directories we're dealing
  	 * with */
  	spin_lock(&orig_dvnode->lock);
  	orig_dvnode->update_cnt++;
  	spin_unlock(&orig_dvnode->lock);
  	if (new_dvnode != orig_dvnode) {
  		spin_lock(&new_dvnode->lock);
  		new_dvnode->update_cnt++;
  		spin_unlock(&new_dvnode->lock);
  	}
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(orig_dvnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_rename(server, key, orig_dvnode, orig_name,
  				    new_dvnode, new_name, &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(orig_dvnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0) {
  		afs_vnode_finalise_status_update(orig_dvnode, server);
  		if (new_dvnode != orig_dvnode)
  			afs_vnode_finalise_status_update(new_dvnode, server);
  		afs_put_server(server);
  	} else {
  		afs_vnode_status_update_failed(orig_dvnode, ret);
  		if (new_dvnode != orig_dvnode)
  			afs_vnode_status_update_failed(new_dvnode, ret);
  	}
  
  	_leave(" = %d [cnt %d]", ret, orig_dvnode->update_cnt);
  	return ret;
  
  no_server:
  	spin_lock(&orig_dvnode->lock);
  	orig_dvnode->update_cnt--;
  	ASSERTCMP(orig_dvnode->update_cnt, >=, 0);
  	spin_unlock(&orig_dvnode->lock);
  	if (new_dvnode != orig_dvnode) {
  		spin_lock(&new_dvnode->lock);
  		new_dvnode->update_cnt--;
  		ASSERTCMP(new_dvnode->update_cnt, >=, 0);
  		spin_unlock(&new_dvnode->lock);
  	}
  	_leave(" = %ld [cnt %d]", PTR_ERR(server), orig_dvnode->update_cnt);
  	return PTR_ERR(server);
  }
  
  /*
   * write to a file
   */
  int afs_vnode_store_data(struct afs_writeback *wb, pgoff_t first, pgoff_t last,
  			 unsigned offset, unsigned to)
  {
  	struct afs_server *server;
  	struct afs_vnode *vnode = wb->vnode;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x,%lx,%lx,%x,%x",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(wb->key),
  	       first, last, offset, to);
  
  	/* this op will fetch the status */
  	spin_lock(&vnode->lock);
  	vnode->update_cnt++;
  	spin_unlock(&vnode->lock);
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(vnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_store_data(server, wb, first, last, offset, to,
  					&afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0) {
  		afs_vnode_finalise_status_update(vnode, server);
  		afs_put_server(server);
  	} else {
  		afs_vnode_status_update_failed(vnode, ret);
  	}
  
  	_leave(" = %d", ret);
  	return ret;
  
  no_server:
  	spin_lock(&vnode->lock);
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  	return PTR_ERR(server);
  }
  
  /*
   * set the attributes on a file
   */
  int afs_vnode_setattr(struct afs_vnode *vnode, struct key *key,
  		      struct iattr *attr)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key));
  
  	/* this op will fetch the status */
  	spin_lock(&vnode->lock);
  	vnode->update_cnt++;
  	spin_unlock(&vnode->lock);
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(vnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_setattr(server, key, vnode, attr, &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0) {
  		afs_vnode_finalise_status_update(vnode, server);
  		afs_put_server(server);
  	} else {
  		afs_vnode_status_update_failed(vnode, ret);
  	}
  
  	_leave(" = %d", ret);
  	return ret;
  
  no_server:
  	spin_lock(&vnode->lock);
  	vnode->update_cnt--;
  	ASSERTCMP(vnode->update_cnt, >=, 0);
  	spin_unlock(&vnode->lock);
  	return PTR_ERR(server);
  }
  
  /*
   * get the status of a volume
   */
  int afs_vnode_get_volume_status(struct afs_vnode *vnode, struct key *key,
  				struct afs_volume_status *vs)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x,",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key));
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(vnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_get_volume_status(server, key, vnode, vs, &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0)
  		afs_put_server(server);
  
  	_leave(" = %d", ret);
  	return ret;
  
  no_server:
  	return PTR_ERR(server);
  }
  
  /*
   * get a lock on a file
   */
  int afs_vnode_set_lock(struct afs_vnode *vnode, struct key *key,
  		       afs_lock_type_t type)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x,%u",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key), type);
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(vnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_set_lock(server, key, vnode, type, &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0)
  		afs_put_server(server);
  
  	_leave(" = %d", ret);
  	return ret;
  
  no_server:
  	return PTR_ERR(server);
  }
  
  /*
   * extend a lock on a file
   */
  int afs_vnode_extend_lock(struct afs_vnode *vnode, struct key *key)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key));
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(vnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_extend_lock(server, key, vnode, &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0)
  		afs_put_server(server);
  
  	_leave(" = %d", ret);
  	return ret;
  
  no_server:
  	return PTR_ERR(server);
  }
  
  /*
   * release a lock on a file
   */
  int afs_vnode_release_lock(struct afs_vnode *vnode, struct key *key)
  {
  	struct afs_server *server;
  	int ret;
  
  	_enter("%s{%x:%u.%u},%x",
  	       vnode->volume->vlocation->vldb.name,
  	       vnode->fid.vid,
  	       vnode->fid.vnode,
  	       vnode->fid.unique,
  	       key_serial(key));
  
  	do {
  		/* pick a server to query */
  		server = afs_volume_pick_fileserver(vnode);
  		if (IS_ERR(server))
  			goto no_server;
  
  		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
  
  		ret = afs_fs_release_lock(server, key, vnode, &afs_sync_call);
  
  	} while (!afs_volume_release_fileserver(vnode, server, ret));
  
  	/* adjust the flags */
  	if (ret == 0)
  		afs_put_server(server);
  
  	_leave(" = %d", ret);
  	return ret;
  
  no_server:
  	return PTR_ERR(server);
  }
  