/*
   *   fs/cifs/ioctl.c
   *
   *   vfs operations that deal with io control
   *
   *   Copyright (C) International Business Machines  Corp., 2005,2013
   *   Author(s): Steve French (sfrench@us.ibm.com)
   *
   *   This library is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU Lesser General Public License as published
   *   by the Free Software Foundation; either version 2.1 of the License, or
   *   (at your option) any later version.
   *
   *   This library is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   *   the GNU Lesser General Public License for more details.
   *
   *   You should have received a copy of the GNU Lesser General Public License
   *   along with this library; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
  #include <linux/fs.h>
  #include <linux/file.h>
  #include <linux/mount.h>
  #include <linux/mm.h>
  #include <linux/pagemap.h>
  #include "cifspdu.h"
  #include "cifsglob.h"
  #include "cifsproto.h"
  #include "cifs_debug.h"
  #include "cifsfs.h"
  
  #define CIFS_IOCTL_MAGIC	0xCF
  #define CIFS_IOC_COPYCHUNK_FILE	_IOW(CIFS_IOCTL_MAGIC, 3, int)
  
  static long cifs_ioctl_clone(unsigned int xid, struct file *dst_file,
  			unsigned long srcfd, u64 off, u64 len, u64 destoff)
  {
  	int rc;
  	struct cifsFileInfo *smb_file_target = dst_file->private_data;
  	struct inode *target_inode = file_inode(dst_file);
  	struct cifs_tcon *target_tcon;
  	struct fd src_file;
  	struct cifsFileInfo *smb_file_src;
  	struct inode *src_inode;
  	struct cifs_tcon *src_tcon;
  
  	cifs_dbg(FYI, "ioctl clone range
  ");
  	/* the destination must be opened for writing */
  	if (!(dst_file->f_mode & FMODE_WRITE)) {
  		cifs_dbg(FYI, "file target not open for write
  ");
  		return -EINVAL;
  	}
  
  	/* check if target volume is readonly and take reference */
  	rc = mnt_want_write_file(dst_file);
  	if (rc) {
  		cifs_dbg(FYI, "mnt_want_write failed with rc %d
  ", rc);
  		return rc;
  	}
  
  	src_file = fdget(srcfd);
  	if (!src_file.file) {
  		rc = -EBADF;
  		goto out_drop_write;
  	}
  
  	if ((!src_file.file->private_data) || (!dst_file->private_data)) {
  		rc = -EBADF;
  		cifs_dbg(VFS, "missing cifsFileInfo on copy range src file
  ");
  		goto out_fput;
  	}
  
  	rc = -EXDEV;
  	smb_file_target = dst_file->private_data;
  	smb_file_src = src_file.file->private_data;
  	src_tcon = tlink_tcon(smb_file_src->tlink);
  	target_tcon = tlink_tcon(smb_file_target->tlink);
  
  	/* check if source and target are on same tree connection */
  	if (src_tcon != target_tcon) {
  		cifs_dbg(VFS, "file copy src and target on different volume
  ");
  		goto out_fput;
  	}
  
  	src_inode = src_file.file->f_dentry->d_inode;
  
  	/*
  	 * Note: cifs case is easier than btrfs since server responsible for
  	 * checks for proper open modes and file type and if it wants
  	 * server could even support copy of range where source = target
  	 */
  
  	/* so we do not deadlock racing two ioctls on same files */
  	if (target_inode < src_inode) {
  		mutex_lock_nested(&target_inode->i_mutex, I_MUTEX_PARENT);
  		mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_CHILD);
  	} else {
  		mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_PARENT);
  		mutex_lock_nested(&target_inode->i_mutex, I_MUTEX_CHILD);
  	}
  
  	/* determine range to clone */
  	rc = -EINVAL;
  	if (off + len > src_inode->i_size || off + len < off)
  		goto out_unlock;
  	if (len == 0)
  		len = src_inode->i_size - off;
  
  	cifs_dbg(FYI, "about to flush pages
  ");
  	/* should we flush first and last page first */
  	truncate_inode_pages_range(&target_inode->i_data, destoff,
  				   PAGE_CACHE_ALIGN(destoff + len)-1);
  
  	if (target_tcon->ses->server->ops->clone_range)
  		rc = target_tcon->ses->server->ops->clone_range(xid,
  			smb_file_src, smb_file_target, off, len, destoff);
  
  	/* force revalidate of size and timestamps of target file now
  	   that target is updated on the server */
  	CIFS_I(target_inode)->time = 0;
  out_unlock:
  	/* although unlocking in the reverse order from locking is not
  	   strictly necessary here it is a little cleaner to be consistent */
  	if (target_inode < src_inode) {
  		mutex_unlock(&src_inode->i_mutex);
  		mutex_unlock(&target_inode->i_mutex);
  	} else {
  		mutex_unlock(&target_inode->i_mutex);
  		mutex_unlock(&src_inode->i_mutex);
  	}
  out_fput:
  	fdput(src_file);
  out_drop_write:
  	mnt_drop_write_file(dst_file);
  	return rc;
  }
  
  long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
  {
  	struct inode *inode = file_inode(filep);
  	int rc = -ENOTTY; /* strange error - but the precedent */
  	unsigned int xid;
  	struct cifs_sb_info *cifs_sb;
  	struct cifsFileInfo *pSMBFile = filep->private_data;
  	struct cifs_tcon *tcon;
  	__u64	ExtAttrBits = 0;
  	__u64   caps;
  
  	xid = get_xid();
  
  	cifs_dbg(FYI, "ioctl file %p  cmd %u  arg %lu
  ", filep, command, arg);
  
  	cifs_sb = CIFS_SB(inode->i_sb);
  
  	switch (command) {
  		case FS_IOC_GETFLAGS:
  			if (pSMBFile == NULL)
  				break;
  			tcon = tlink_tcon(pSMBFile->tlink);
  			caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
  #ifdef CONFIG_CIFS_POSIX
  			if (CIFS_UNIX_EXTATTR_CAP & caps) {
  				__u64	ExtAttrMask = 0;
  				rc = CIFSGetExtAttr(xid, tcon,
  						    pSMBFile->fid.netfid,
  						    &ExtAttrBits, &ExtAttrMask);
  				if (rc == 0)
  					rc = put_user(ExtAttrBits &
  						FS_FL_USER_VISIBLE,
  						(int __user *)arg);
  				if (rc != EOPNOTSUPP)
  					break;
  			}
  #endif /* CONFIG_CIFS_POSIX */
  			rc = 0;
  			if (CIFS_I(inode)->cifsAttrs & ATTR_COMPRESSED) {
  				/* add in the compressed bit */
  				ExtAttrBits = FS_COMPR_FL;
  				rc = put_user(ExtAttrBits & FS_FL_USER_VISIBLE,
  					      (int __user *)arg);
  			}
  			break;
  		case FS_IOC_SETFLAGS:
  			if (pSMBFile == NULL)
  				break;
  			tcon = tlink_tcon(pSMBFile->tlink);
  			caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
  
  			if (get_user(ExtAttrBits, (int __user *)arg)) {
  				rc = -EFAULT;
  				break;
  			}
  
  			/*
  			 * if (CIFS_UNIX_EXTATTR_CAP & caps)
  			 *	rc = CIFSSetExtAttr(xid, tcon,
  			 *		       pSMBFile->fid.netfid,
  			 *		       extAttrBits,
  			 *		       &ExtAttrMask);
  			 * if (rc != EOPNOTSUPP)
  			 *	break;
  			 */
  
  			/* Currently only flag we can set is compressed flag */
  			if ((ExtAttrBits & FS_COMPR_FL) == 0)
  				break;
  
  			/* Try to set compress flag */
  			if (tcon->ses->server->ops->set_compression) {
  				rc = tcon->ses->server->ops->set_compression(
  							xid, tcon, pSMBFile);
  				cifs_dbg(FYI, "set compress flag rc %d
  ", rc);
  			}
  			break;
  		case CIFS_IOC_COPYCHUNK_FILE:
  			rc = cifs_ioctl_clone(xid, filep, arg, 0, 0, 0);
  			break;
  		default:
  			cifs_dbg(FYI, "unsupported ioctl
  ");
  			break;
  	}
  
  	free_xid(xid);
  	return rc;
  }