C++ NFS_CLIENT函数代码示例

static int nfsio_commit(struct ploop_io *io, u64 * verf)
{
	struct inode *inode = io->files.inode;
	struct nfs_commit_data *creq;
	struct nfsio_comp comp;
	int err;

	nfsio_comp_init(&comp);
	comp.verf = verf;

	creq = cbio_init(io, &comp);
	if (unlikely(creq == NULL))
		return -ENOMEM;

	atomic_inc(&comp.count);

	err = nfs_initiate_commit(NFS_CLIENT(inode), creq, creq->mds_ops, 0);
	if (err) {
		comp.error = err;
		if (atomic_dec_and_test(&comp.count))
			complete(&comp.comp);
	}

	if (atomic_dec_and_test(&comp.count))
		complete(&comp.comp);

	wait_for_completion(&comp.comp);

	if (err)
		nfsio_cbio_release(creq);

	return comp.error;
}

static int
nfs3_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
			struct iattr *sattr)
{
	struct inode *inode = dentry->d_inode;
	struct nfs3_sattrargs	arg = {
		.fh		= NFS_FH(inode),
		.sattr		= sattr,
	};
	struct rpc_message msg = {
		.rpc_proc	= &nfs3_procedures[NFS3PROC_SETATTR],
		.rpc_argp	= &arg,
		.rpc_resp	= fattr,
	};
	int	status;

	dprintk("NFS call  setattr\n");
	if (sattr->ia_valid & ATTR_FILE)
		msg.rpc_cred = nfs_file_cred(sattr->ia_file);
	nfs_fattr_init(fattr);
	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
	if (status == 0)
		nfs_setattr_update_inode(inode, sattr);
	dprintk("NFS reply setattr: %d\n", status);
	return status;
}

static int
nfs_proc_remove(struct inode *dir, struct qstr *name)
{
	struct nfs_removeargs arg = {
		.fh = NFS_FH(dir),
		.name.len = name->len,
		.name.name = name->name,
	};
	struct rpc_message msg = {
		.rpc_proc = &nfs_procedures[NFSPROC_REMOVE],
		.rpc_argp = &arg,
	};
	int			status;

	dprintk("NFS call  remove %s\n", name->name);
	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
	nfs_mark_for_revalidate(dir);

	dprintk("NFS reply remove: %d\n", status);
	return status;
}

static void
nfs_proc_unlink_setup(struct rpc_message *msg, struct inode *dir)
{
	msg->rpc_proc = &nfs_procedures[NFSPROC_REMOVE];
}

static void nfs_proc_unlink_rpc_prepare(struct rpc_task *task, struct nfs_unlinkdata *data)
{
	rpc_call_start(task);
}

static int
nfs_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
		 struct iattr *sattr)
{
	struct inode *inode = dentry->d_inode;
	struct nfs_sattrargs	arg = { 
		.fh	= NFS_FH(inode),
		.sattr	= sattr
	};
	struct rpc_message msg = {
		.rpc_proc	= &nfs_procedures[NFSPROC_SETATTR],
		.rpc_argp	= &arg,
		.rpc_resp	= fattr,
	};
	int	status;

	/* Mask out the non-modebit related stuff from attr->ia_mode */
	sattr->ia_mode &= S_IALLUGO;

	dprintk("NFS call  setattr\n");
	nfs_fattr_init(fattr);
	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
	if (status == 0)
		nfs_setattr_update_inode(inode, sattr);
	dprintk("NFS reply setattr: %d\n", status);
	return status;
}

static int
nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
		int flags, struct nfs_open_context *ctx)
{
	struct nfs_createdata *data;
	struct rpc_message msg = {
		.rpc_proc	= &nfs_procedures[NFSPROC_CREATE],
	};
	int status = -ENOMEM;

	dprintk("NFS call  create %s\n", dentry->d_name.name);
	data = nfs_alloc_createdata(dir, dentry, sattr);
	if (data == NULL)
		goto out;
	msg.rpc_argp = &data->arg;
	msg.rpc_resp = &data->res;
	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
	nfs_mark_for_revalidate(dir);
	if (status == 0)
		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
	nfs_free_createdata(data);
out:
	dprintk("NFS reply create: %d\n", status);
	return status;
}

int
nfs_permission(struct inode *inode, int mask)
{
	int			error = vfs_permission(inode, mask);

	if (!NFS_PROTO(inode)->access)
		goto out;

	if (error == -EROFS)
		goto out;

	/*
	 * Trust UNIX mode bits except:
	 *
	 * 1) When override capabilities may have been invoked
	 * 2) When root squashing may be involved
	 * 3) When ACLs may overturn a negative answer */
	if (!capable(CAP_DAC_OVERRIDE) && !capable(CAP_DAC_READ_SEARCH)
	    && (current->fsuid != 0) && (current->fsgid != 0)
	    && error != -EACCES)
		goto out;

	error = NFS_PROTO(inode)->access(inode, mask, 0);

	if (error == -EACCES && NFS_CLIENT(inode)->cl_droppriv &&
	    current->uid != 0 && current->gid != 0 &&
	    (current->fsuid != current->uid || current->fsgid != current->gid))
		error = NFS_PROTO(inode)->access(inode, mask, 1);

 out:
	return error;
}

static void nfs_swap_deactivate(struct file *file)
{
	struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host);

	rcu_read_lock();
	xs_swapper(rcu_dereference(clnt->cl_xprt), 0);
	rcu_read_unlock();
}

/**
 * nfs_wait_on_request - Wait for a request to complete.
 * @req: request to wait upon.
 *
 * Interruptible by signals only if mounted with intr flag.
 * The user is responsible for holding a count on the request.
 */
int
nfs_wait_on_request(struct nfs_page *req)
{
	struct inode	*inode = req->wb_context->dentry->d_inode;
        struct rpc_clnt	*clnt = NFS_CLIENT(inode);

	if (!NFS_WBACK_BUSY(req))
		return 0;
	return nfs_wait_event(clnt, req->wb_context->waitq, !NFS_WBACK_BUSY(req));
}

/*
 * In NFSv2, mknod is grafted onto the create call.
 */
static int
nfs_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
	       dev_t rdev)
{
	struct nfs_createdata *data;
	struct rpc_message msg = {
		.rpc_proc	= &nfs_procedures[NFSPROC_CREATE],
	};
	umode_t mode;
	int status = -ENOMEM;

	dprintk("NFS call  mknod %s\n", dentry->d_name.name);

	mode = sattr->ia_mode;
	if (S_ISFIFO(mode)) {
		sattr->ia_mode = (mode & ~S_IFMT) | S_IFCHR;
		sattr->ia_valid &= ~ATTR_SIZE;
	} else if (S_ISCHR(mode) || S_ISBLK(mode)) {
		sattr->ia_valid |= ATTR_SIZE;
		sattr->ia_size = new_encode_dev(rdev);/* get out your barf bag */
	}

	data = nfs_alloc_createdata(dir, dentry, sattr);
	if (data == NULL)
		goto out;
	msg.rpc_argp = &data->arg;
	msg.rpc_resp = &data->res;

	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
	nfs_mark_for_revalidate(dir);

	if (status == -EINVAL && S_ISFIFO(mode)) {
		sattr->ia_mode = mode;
		nfs_fattr_init(data->res.fattr);
		status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
	}
	if (status == 0)
		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr, NULL);
	nfs_free_createdata(data);
out:
	dprintk("NFS reply mknod: %d\n", status);
	return status;
}

static inline int
nfs_direct_write_rpc(struct file *file, struct nfs_writeargs *arg,
	struct nfs_writeverf *verf)
{
	int result;
	struct inode *inode = file->f_dentry->d_inode;
	struct nfs_fattr fattr;
        struct rpc_message msg;
        struct nfs_writeres res = { &fattr, verf, 0 };

#ifdef CONFIG_NFS_V3
	msg.rpc_proc = (NFS_PROTO(inode)->version == 3) ?
						NFS3PROC_WRITE : NFSPROC_WRITE;
#else
	msg.rpc_proc = NFSPROC_WRITE;
#endif
	msg.rpc_argp = arg;
        msg.rpc_resp = &res;

	lock_kernel();
	msg.rpc_cred = get_rpccred(nfs_file_cred(file));
	fattr.valid = 0;
        result = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
	nfs_write_attributes(inode, &fattr);
	put_rpccred(msg.rpc_cred);
	unlock_kernel();

#ifdef CONFIG_NFS_V3
	if (NFS_PROTO(inode)->version == 3) {
		if (result > 0) {
			if ((arg->stable == NFS_FILE_SYNC) &&
			    (verf->committed != NFS_FILE_SYNC)) {
				printk(KERN_ERR
				"%s: server didn't sync stable write request\n",
				__FUNCTION__);
				return -EIO;
			}

			if (result != arg->count) {
				printk(KERN_INFO
					"%s: short write, count=%u, result=%d\n",
					__FUNCTION__, arg->count, result);
			}
		}
		return result;
	} else {
#endif
        	verf->committed = NFS_FILE_SYNC; /* NFSv2 always syncs data */
		if (result == 0)
			return arg->count;
		return result;
#ifdef CONFIG_NFS_V3
	}
#endif
}

static int do_setlk(struct file *filp, int cmd, struct file_lock *fl)
{
	struct inode *inode = filp->f_mapping->host;
	sigset_t oldset;
	int status;

	rpc_clnt_sigmask(NFS_CLIENT(inode), &oldset);
	/*
	 * Flush all pending writes before doing anything
	 * with locks..
	 */
	status = nfs_sync_mapping(filp->f_mapping);
	if (status != 0)
		goto out;

	lock_kernel();
	/* Use local locking if mounted with "-onolock" */
	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) {
		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
		/* If we were signalled we still need to ensure that
		 * we clean up any state on the server. We therefore
		 * record the lock call as having succeeded in order to
		 * ensure that locks_remove_posix() cleans it out when
		 * the process exits.
		 */
		if (status == -EINTR || status == -ERESTARTSYS)
			do_vfs_lock(filp, fl);
	} else
		status = do_vfs_lock(filp, fl);
	unlock_kernel();
	if (status < 0)
		goto out;
	/*
	 * Make sure we clear the cache whenever we try to get the lock.
	 * This makes locking act as a cache coherency point.
	 */
	nfs_sync_mapping(filp->f_mapping);
	nfs_zap_caches(inode);
out:
	rpc_clnt_sigunmask(NFS_CLIENT(inode), &oldset);
	return status;
}

static int
nfs3_proc_lookup(struct inode *dir, struct qstr *name,
		 struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	struct nfs_fattr	dir_attr;
	struct nfs3_diropargs	arg = { NFS_FH(dir), name->name, name->len };
	struct nfs3_diropres	res = { &dir_attr, fhandle, fattr };
	int			status;

	dprintk("NFS call  lookup %s\n", name->name);
	dir_attr.valid = 0;
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(dir), NFS3PROC_LOOKUP, &arg, &res, 0);
	if (status >= 0 && !(fattr->valid & NFS_ATTR_FATTR))
		status = rpc_call(NFS_CLIENT(dir), NFS3PROC_GETATTR,
			 fhandle, fattr, 0);
	dprintk("NFS reply lookup: %d\n", status);
	nfs_refresh_inode(dir, &dir_attr);
	return status;
}

/*
 * One function for each procedure in the NFS protocol.
 */
static int
nfs3_proc_getattr(struct inode *inode, struct nfs_fattr *fattr)
{
	int	status;

	dprintk("NFS call  getattr\n");
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(inode), NFS3PROC_GETATTR,
			  NFS_FH(inode), fattr, 0);
	dprintk("NFS reply getattr\n");
	return status;
}

static int
nfs3_proc_setattr(struct inode *inode, struct nfs_fattr *fattr,
			struct iattr *sattr)
{
	struct nfs3_sattrargs	arg = { NFS_FH(inode), sattr, 0, 0 };
	int	status;

	dprintk("NFS call  setattr\n");
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(inode), NFS3PROC_SETATTR, &arg, fattr, 0);
	dprintk("NFS reply setattr\n");
	return status;
}

static int
nfs3_proc_rmdir(struct inode *dir, struct qstr *name)
{
	struct nfs_fattr	dir_attr;
	struct nfs3_diropargs	arg = { NFS_FH(dir), name->name, name->len };
	int			status;

	dprintk("NFS call  rmdir %s\n", name->name);
	dir_attr.valid = 0;
	status = rpc_call(NFS_CLIENT(dir), NFS3PROC_RMDIR, &arg, &dir_attr, 0);
	nfs_refresh_inode(dir, &dir_attr);
	dprintk("NFS reply rmdir: %d\n", status);
	return status;
}