/*
   *   fs/cifs/smb2file.c
   *
   *   Copyright (C) International Business Machines  Corp., 2002, 2011
   *   Author(s): Steve French (sfrench@us.ibm.com),
   *              Pavel Shilovsky ((pshilovsky@samba.org) 2012
   *
   *   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/stat.h>
  #include <linux/slab.h>
  #include <linux/pagemap.h>
  #include <asm/div64.h>
  #include "cifsfs.h"
  #include "cifspdu.h"
  #include "cifsglob.h"
  #include "cifsproto.h"
  #include "cifs_debug.h"
  #include "cifs_fs_sb.h"
  #include "cifs_unicode.h"
  #include "fscache.h"
  #include "smb2proto.h"
  
  int
  smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
  	       __u32 *oplock, FILE_ALL_INFO *buf)
  {
  	int rc;
  	__le16 *smb2_path;
  	struct smb2_file_all_info *smb2_data = NULL;
  	__u8 smb2_oplock[17];
  	struct cifs_fid *fid = oparms->fid;
  
  	smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
  	if (smb2_path == NULL) {
  		rc = -ENOMEM;
  		goto out;
  	}
  
  	smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
  			    GFP_KERNEL);
  	if (smb2_data == NULL) {
  		rc = -ENOMEM;
  		goto out;
  	}
  
  	oparms->desired_access |= FILE_READ_ATTRIBUTES;
  	*smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
  
  	if (oparms->tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
  		memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE);
  
  	rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data, NULL);
  	if (rc)
  		goto out;
  
  	if (buf) {
  		/* open response does not have IndexNumber field - get it */
  		rc = SMB2_get_srv_num(xid, oparms->tcon, fid->persistent_fid,
  				      fid->volatile_fid,
  				      &smb2_data->IndexNumber);
  		if (rc) {
  			/* let get_inode_info disable server inode numbers */
  			smb2_data->IndexNumber = 0;
  			rc = 0;
  		}
  		move_smb2_info_to_cifs(buf, smb2_data);
  	}
  
  	*oplock = *smb2_oplock;
  out:
  	kfree(smb2_data);
  	kfree(smb2_path);
  	return rc;
  }
  
  int
  smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
  		  const unsigned int xid)
  {
  	int rc = 0, stored_rc;
  	unsigned int max_num, num = 0, max_buf;
  	struct smb2_lock_element *buf, *cur;
  	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
  	struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
  	struct cifsLockInfo *li, *tmp;
  	__u64 length = 1 + flock->fl_end - flock->fl_start;
  	struct list_head tmp_llist;
  
  	INIT_LIST_HEAD(&tmp_llist);
  
  	/*
  	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
  	 * and check it for zero before using.
  	 */
  	max_buf = tcon->ses->server->maxBuf;
  	if (!max_buf)
  		return -EINVAL;
  
  	max_num = max_buf / sizeof(struct smb2_lock_element);
  	buf = kzalloc(max_num * sizeof(struct smb2_lock_element), GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;
  
  	cur = buf;
  
  	down_write(&cinode->lock_sem);
  	list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
  		if (flock->fl_start > li->offset ||
  		    (flock->fl_start + length) <
  		    (li->offset + li->length))
  			continue;
  		if (current->tgid != li->pid)
  			continue;
  		if (cinode->can_cache_brlcks) {
  			/*
  			 * We can cache brlock requests - simply remove a lock
  			 * from the file's list.
  			 */
  			list_del(&li->llist);
  			cifs_del_lock_waiters(li);
  			kfree(li);
  			continue;
  		}
  		cur->Length = cpu_to_le64(li->length);
  		cur->Offset = cpu_to_le64(li->offset);
  		cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
  		/*
  		 * We need to save a lock here to let us add it again to the
  		 * file's list if the unlock range request fails on the server.
  		 */
  		list_move(&li->llist, &tmp_llist);
  		if (++num == max_num) {
  			stored_rc = smb2_lockv(xid, tcon,
  					       cfile->fid.persistent_fid,
  					       cfile->fid.volatile_fid,
  					       current->tgid, num, buf);
  			if (stored_rc) {
  				/*
  				 * We failed on the unlock range request - add
  				 * all locks from the tmp list to the head of
  				 * the file's list.
  				 */
  				cifs_move_llist(&tmp_llist,
  						&cfile->llist->locks);
  				rc = stored_rc;
  			} else
  				/*
  				 * The unlock range request succeed - free the
  				 * tmp list.
  				 */
  				cifs_free_llist(&tmp_llist);
  			cur = buf;
  			num = 0;
  		} else
  			cur++;
  	}
  	if (num) {
  		stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
  				       cfile->fid.volatile_fid, current->tgid,
  				       num, buf);
  		if (stored_rc) {
  			cifs_move_llist(&tmp_llist, &cfile->llist->locks);
  			rc = stored_rc;
  		} else
  			cifs_free_llist(&tmp_llist);
  	}
  	up_write(&cinode->lock_sem);
  
  	kfree(buf);
  	return rc;
  }
  
  static int
  smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
  		       struct smb2_lock_element *buf, unsigned int max_num)
  {
  	int rc = 0, stored_rc;
  	struct cifsFileInfo *cfile = fdlocks->cfile;
  	struct cifsLockInfo *li;
  	unsigned int num = 0;
  	struct smb2_lock_element *cur = buf;
  	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
  
  	list_for_each_entry(li, &fdlocks->locks, llist) {
  		cur->Length = cpu_to_le64(li->length);
  		cur->Offset = cpu_to_le64(li->offset);
  		cur->Flags = cpu_to_le32(li->type |
  						SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
  		if (++num == max_num) {
  			stored_rc = smb2_lockv(xid, tcon,
  					       cfile->fid.persistent_fid,
  					       cfile->fid.volatile_fid,
  					       current->tgid, num, buf);
  			if (stored_rc)
  				rc = stored_rc;
  			cur = buf;
  			num = 0;
  		} else
  			cur++;
  	}
  	if (num) {
  		stored_rc = smb2_lockv(xid, tcon,
  				       cfile->fid.persistent_fid,
  				       cfile->fid.volatile_fid,
  				       current->tgid, num, buf);
  		if (stored_rc)
  			rc = stored_rc;
  	}
  
  	return rc;
  }
  
  int
  smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
  {
  	int rc = 0, stored_rc;
  	unsigned int xid;
  	unsigned int max_num, max_buf;
  	struct smb2_lock_element *buf;
  	struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
  	struct cifs_fid_locks *fdlocks;
  
  	xid = get_xid();
  
  	/*
  	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
  	 * and check it for zero before using.
  	 */
  	max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
  	if (!max_buf) {
  		free_xid(xid);
  		return -EINVAL;
  	}
  
  	max_num = max_buf / sizeof(struct smb2_lock_element);
  	buf = kzalloc(max_num * sizeof(struct smb2_lock_element), GFP_KERNEL);
  	if (!buf) {
  		free_xid(xid);
  		return -ENOMEM;
  	}
  
  	list_for_each_entry(fdlocks, &cinode->llist, llist) {
  		stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
  		if (stored_rc)
  			rc = stored_rc;
  	}
  
  	kfree(buf);
  	free_xid(xid);
  	return rc;
  }