/*
   * Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
   */
  #include <linux/fs.h>
  #include <linux/sunrpc/sched.h>
  #include <linux/nfs.h>
  #include <linux/nfs3.h>
  #include <linux/nfs4.h>
  #include <linux/nfs_xdr.h>
  #include <linux/nfs_fs.h>
  #include "nfs4_fs.h"
  #include "nfs42.h"
  #include "iostat.h"
  #include "pnfs.h"
  #include "internal.h"
  
  #define NFSDBG_FACILITY NFSDBG_PROC
  
  static int nfs42_set_rw_stateid(nfs4_stateid *dst, struct file *file,
  				fmode_t fmode)
  {
  	struct nfs_open_context *open;
  	struct nfs_lock_context *lock;
  	int ret;
  
  	open = get_nfs_open_context(nfs_file_open_context(file));
  	lock = nfs_get_lock_context(open);
  	if (IS_ERR(lock)) {
  		put_nfs_open_context(open);
  		return PTR_ERR(lock);
  	}
  
  	ret = nfs4_set_rw_stateid(dst, open, lock, fmode);
  
  	nfs_put_lock_context(lock);
  	put_nfs_open_context(open);
  	return ret;
  }
  
  static int _nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
  				 loff_t offset, loff_t len)
  {
  	struct inode *inode = file_inode(filep);
  	struct nfs_server *server = NFS_SERVER(inode);
  	struct nfs42_falloc_args args = {
  		.falloc_fh	= NFS_FH(inode),
  		.falloc_offset	= offset,
  		.falloc_length	= len,
  		.falloc_bitmask	= server->cache_consistency_bitmask,
  	};
  	struct nfs42_falloc_res res = {
  		.falloc_server	= server,
  	};
  	int status;
  
  	msg->rpc_argp = &args;
  	msg->rpc_resp = &res;
  
  	status = nfs42_set_rw_stateid(&args.falloc_stateid, filep, FMODE_WRITE);
  	if (status)
  		return status;
  
  	res.falloc_fattr = nfs_alloc_fattr();
  	if (!res.falloc_fattr)
  		return -ENOMEM;
  
  	status = nfs4_call_sync(server->client, server, msg,
  				&args.seq_args, &res.seq_res, 0);
  	if (status == 0)
  		status = nfs_post_op_update_inode(inode, res.falloc_fattr);
  
  	kfree(res.falloc_fattr);
  	return status;
  }
  
  static int nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
  				loff_t offset, loff_t len)
  {
  	struct nfs_server *server = NFS_SERVER(file_inode(filep));
  	struct nfs4_exception exception = { };
  	int err;
  
  	do {
  		err = _nfs42_proc_fallocate(msg, filep, offset, len);
  		if (err == -ENOTSUPP)
  			return -EOPNOTSUPP;
  		err = nfs4_handle_exception(server, err, &exception);
  	} while (exception.retry);
  
  	return err;
  }
  
  int nfs42_proc_allocate(struct file *filep, loff_t offset, loff_t len)
  {
  	struct rpc_message msg = {
  		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_ALLOCATE],
  	};
  	struct inode *inode = file_inode(filep);
  	int err;
  
  	if (!nfs_server_capable(inode, NFS_CAP_ALLOCATE))
  		return -EOPNOTSUPP;
  
  	mutex_lock(&inode->i_mutex);
  
  	err = nfs42_proc_fallocate(&msg, filep, offset, len);
  	if (err == -EOPNOTSUPP)
  		NFS_SERVER(inode)->caps &= ~NFS_CAP_ALLOCATE;
  
  	mutex_unlock(&inode->i_mutex);
  	return err;
  }
  
  int nfs42_proc_deallocate(struct file *filep, loff_t offset, loff_t len)
  {
  	struct rpc_message msg = {
  		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_DEALLOCATE],
  	};
  	struct inode *inode = file_inode(filep);
  	int err;
  
  	if (!nfs_server_capable(inode, NFS_CAP_DEALLOCATE))
  		return -EOPNOTSUPP;
  
  	nfs_wb_all(inode);
  	mutex_lock(&inode->i_mutex);
  
  	err = nfs42_proc_fallocate(&msg, filep, offset, len);
  	if (err == 0)
  		truncate_pagecache_range(inode, offset, (offset + len) -1);
  	if (err == -EOPNOTSUPP)
  		NFS_SERVER(inode)->caps &= ~NFS_CAP_DEALLOCATE;
  
  	mutex_unlock(&inode->i_mutex);
  	return err;
  }
  
  static loff_t _nfs42_proc_llseek(struct file *filep, loff_t offset, int whence)
  {
  	struct inode *inode = file_inode(filep);
  	struct nfs42_seek_args args = {
  		.sa_fh		= NFS_FH(inode),
  		.sa_offset	= offset,
  		.sa_what	= (whence == SEEK_HOLE) ?
  					NFS4_CONTENT_HOLE : NFS4_CONTENT_DATA,
  	};
  	struct nfs42_seek_res res;
  	struct rpc_message msg = {
  		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SEEK],
  		.rpc_argp = &args,
  		.rpc_resp = &res,
  	};
  	struct nfs_server *server = NFS_SERVER(inode);
  	int status;
  
  	if (!nfs_server_capable(inode, NFS_CAP_SEEK))
  		return -ENOTSUPP;
  
  	status = nfs42_set_rw_stateid(&args.sa_stateid, filep, FMODE_READ);
  	if (status)
  		return status;
  
  	nfs_wb_all(inode);
  	status = nfs4_call_sync(server->client, server, &msg,
  				&args.seq_args, &res.seq_res, 0);
  	if (status == -ENOTSUPP)
  		server->caps &= ~NFS_CAP_SEEK;
  	if (status)
  		return status;
  
  	return vfs_setpos(filep, res.sr_offset, inode->i_sb->s_maxbytes);
  }
  
  loff_t nfs42_proc_llseek(struct file *filep, loff_t offset, int whence)
  {
  	struct nfs_server *server = NFS_SERVER(file_inode(filep));
  	struct nfs4_exception exception = { };
  	loff_t err;
  
  	do {
  		err = _nfs42_proc_llseek(filep, offset, whence);
  		if (err >= 0)
  			break;
  		if (err == -ENOTSUPP)
  			return -EOPNOTSUPP;
  		err = nfs4_handle_exception(server, err, &exception);
  	} while (exception.retry);
  
  	return err;
  }
  
  
  static void
  nfs42_layoutstat_prepare(struct rpc_task *task, void *calldata)
  {
  	struct nfs42_layoutstat_data *data = calldata;
  	struct nfs_server *server = NFS_SERVER(data->args.inode);
  
  	nfs41_setup_sequence(nfs4_get_session(server), &data->args.seq_args,
  			     &data->res.seq_res, task);
  }
  
  static void
  nfs42_layoutstat_done(struct rpc_task *task, void *calldata)
  {
  	struct nfs42_layoutstat_data *data = calldata;
  
  	if (!nfs4_sequence_done(task, &data->res.seq_res))
  		return;
  
  	switch (task->tk_status) {
  	case 0:
  		break;
  	case -ENOTSUPP:
  	case -EOPNOTSUPP:
  		NFS_SERVER(data->inode)->caps &= ~NFS_CAP_LAYOUTSTATS;
  	default:
  		dprintk("%s server returns %d
  ", __func__, task->tk_status);
  	}
  }
  
  static void
  nfs42_layoutstat_release(void *calldata)
  {
  	struct nfs42_layoutstat_data *data = calldata;
  	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
  
  	if (nfss->pnfs_curr_ld->cleanup_layoutstats)
  		nfss->pnfs_curr_ld->cleanup_layoutstats(data);
  
  	pnfs_put_layout_hdr(NFS_I(data->args.inode)->layout);
  	smp_mb__before_atomic();
  	clear_bit(NFS_INO_LAYOUTSTATS, &NFS_I(data->args.inode)->flags);
  	smp_mb__after_atomic();
  	nfs_iput_and_deactive(data->inode);
  	kfree(data->args.devinfo);
  	kfree(data);
  }
  
  static const struct rpc_call_ops nfs42_layoutstat_ops = {
  	.rpc_call_prepare = nfs42_layoutstat_prepare,
  	.rpc_call_done = nfs42_layoutstat_done,
  	.rpc_release = nfs42_layoutstat_release,
  };
  
  int nfs42_proc_layoutstats_generic(struct nfs_server *server,
  				   struct nfs42_layoutstat_data *data)
  {
  	struct rpc_message msg = {
  		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTSTATS],
  		.rpc_argp = &data->args,
  		.rpc_resp = &data->res,
  	};
  	struct rpc_task_setup task_setup = {
  		.rpc_client = server->client,
  		.rpc_message = &msg,
  		.callback_ops = &nfs42_layoutstat_ops,
  		.callback_data = data,
  		.flags = RPC_TASK_ASYNC,
  	};
  	struct rpc_task *task;
  
  	data->inode = nfs_igrab_and_active(data->args.inode);
  	if (!data->inode) {
  		nfs42_layoutstat_release(data);
  		return -EAGAIN;
  	}
  	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 0);
  	task = rpc_run_task(&task_setup);
  	if (IS_ERR(task))
  		return PTR_ERR(task);
  	rpc_put_task(task);
  	return 0;
  }
  
  static int _nfs42_proc_clone(struct rpc_message *msg, struct file *src_f,
  			     struct file *dst_f, loff_t src_offset,
  			     loff_t dst_offset, loff_t count)
  {
  	struct inode *src_inode = file_inode(src_f);
  	struct inode *dst_inode = file_inode(dst_f);
  	struct nfs_server *server = NFS_SERVER(dst_inode);
  	struct nfs42_clone_args args = {
  		.src_fh = NFS_FH(src_inode),
  		.dst_fh = NFS_FH(dst_inode),
  		.src_offset = src_offset,
  		.dst_offset = dst_offset,
  		.count = count,
  		.dst_bitmask = server->cache_consistency_bitmask,
  	};
  	struct nfs42_clone_res res = {
  		.server	= server,
  	};
  	int status;
  
  	msg->rpc_argp = &args;
  	msg->rpc_resp = &res;
  
  	status = nfs42_set_rw_stateid(&args.src_stateid, src_f, FMODE_READ);
  	if (status)
  		return status;
  
  	status = nfs42_set_rw_stateid(&args.dst_stateid, dst_f, FMODE_WRITE);
  	if (status)
  		return status;
  
  	res.dst_fattr = nfs_alloc_fattr();
  	if (!res.dst_fattr)
  		return -ENOMEM;
  
  	status = nfs4_call_sync(server->client, server, msg,
  				&args.seq_args, &res.seq_res, 0);
  	if (status == 0)
  		status = nfs_post_op_update_inode(dst_inode, res.dst_fattr);
  
  	kfree(res.dst_fattr);
  	return status;
  }
  
  int nfs42_proc_clone(struct file *src_f, struct file *dst_f,
  		     loff_t src_offset, loff_t dst_offset, loff_t count)
  {
  	struct rpc_message msg = {
  		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLONE],
  	};
  	struct inode *inode = file_inode(src_f);
  	struct nfs_server *server = NFS_SERVER(file_inode(src_f));
  	struct nfs4_exception exception = { };
  	int err;
  
  	if (!nfs_server_capable(inode, NFS_CAP_CLONE))
  		return -EOPNOTSUPP;
  
  	do {
  		err = _nfs42_proc_clone(&msg, src_f, dst_f, src_offset,
  					dst_offset, count);
  		if (err == -ENOTSUPP || err == -EOPNOTSUPP) {
  			NFS_SERVER(inode)->caps &= ~NFS_CAP_CLONE;
  			return -EOPNOTSUPP;
  		}
  		err = nfs4_handle_exception(server, err, &exception);
  	} while (exception.retry);
  
  	return err;
  
  }