/*
   *   fs/cifs/misc.c
   *
   *   Copyright (C) International Business Machines  Corp., 2002,2008
   *   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/slab.h>
  #include <linux/ctype.h>
  #include <linux/mempool.h>
  #include "cifspdu.h"
  #include "cifsglob.h"
  #include "cifsproto.h"
  #include "cifs_debug.h"
  #include "smberr.h"
  #include "nterr.h"
  #include "cifs_unicode.h"
  #ifdef CONFIG_CIFS_SMB2
  #include "smb2pdu.h"
  #endif
  
  extern mempool_t *cifs_sm_req_poolp;
  extern mempool_t *cifs_req_poolp;
  
  /* The xid serves as a useful identifier for each incoming vfs request,
     in a similar way to the mid which is useful to track each sent smb,
     and CurrentXid can also provide a running counter (although it
     will eventually wrap past zero) of the total vfs operations handled
     since the cifs fs was mounted */
  
  unsigned int
  _get_xid(void)
  {
  	unsigned int xid;
  
  	spin_lock(&GlobalMid_Lock);
  	GlobalTotalActiveXid++;
  
  	/* keep high water mark for number of simultaneous ops in filesystem */
  	if (GlobalTotalActiveXid > GlobalMaxActiveXid)
  		GlobalMaxActiveXid = GlobalTotalActiveXid;
  	if (GlobalTotalActiveXid > 65000)
  		cifs_dbg(FYI, "warning: more than 65000 requests active
  ");
  	xid = GlobalCurrentXid++;
  	spin_unlock(&GlobalMid_Lock);
  	return xid;
  }
  
  void
  _free_xid(unsigned int xid)
  {
  	spin_lock(&GlobalMid_Lock);
  	/* if (GlobalTotalActiveXid == 0)
  		BUG(); */
  	GlobalTotalActiveXid--;
  	spin_unlock(&GlobalMid_Lock);
  }
  
  struct cifs_ses *
  sesInfoAlloc(void)
  {
  	struct cifs_ses *ret_buf;
  
  	ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
  	if (ret_buf) {
  		atomic_inc(&sesInfoAllocCount);
  		ret_buf->status = CifsNew;
  		++ret_buf->ses_count;
  		INIT_LIST_HEAD(&ret_buf->smb_ses_list);
  		INIT_LIST_HEAD(&ret_buf->tcon_list);
  		mutex_init(&ret_buf->session_mutex);
  	}
  	return ret_buf;
  }
  
  void
  sesInfoFree(struct cifs_ses *buf_to_free)
  {
  	if (buf_to_free == NULL) {
  		cifs_dbg(FYI, "Null buffer passed to sesInfoFree
  ");
  		return;
  	}
  
  	atomic_dec(&sesInfoAllocCount);
  	kfree(buf_to_free->serverOS);
  	kfree(buf_to_free->serverDomain);
  	kfree(buf_to_free->serverNOS);
  	if (buf_to_free->password) {
  		memset(buf_to_free->password, 0, strlen(buf_to_free->password));
  		kfree(buf_to_free->password);
  	}
  	kfree(buf_to_free->user_name);
  	kfree(buf_to_free->domainName);
  	kfree(buf_to_free->auth_key.response);
  	kfree(buf_to_free);
  }
  
  struct cifs_tcon *
  tconInfoAlloc(void)
  {
  	struct cifs_tcon *ret_buf;
  	ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
  	if (ret_buf) {
  		atomic_inc(&tconInfoAllocCount);
  		ret_buf->tidStatus = CifsNew;
  		++ret_buf->tc_count;
  		INIT_LIST_HEAD(&ret_buf->openFileList);
  		INIT_LIST_HEAD(&ret_buf->tcon_list);
  #ifdef CONFIG_CIFS_STATS
  		spin_lock_init(&ret_buf->stat_lock);
  #endif
  	}
  	return ret_buf;
  }
  
  void
  tconInfoFree(struct cifs_tcon *buf_to_free)
  {
  	if (buf_to_free == NULL) {
  		cifs_dbg(FYI, "Null buffer passed to tconInfoFree
  ");
  		return;
  	}
  	atomic_dec(&tconInfoAllocCount);
  	kfree(buf_to_free->nativeFileSystem);
  	if (buf_to_free->password) {
  		memset(buf_to_free->password, 0, strlen(buf_to_free->password));
  		kfree(buf_to_free->password);
  	}
  	kfree(buf_to_free);
  }
  
  struct smb_hdr *
  cifs_buf_get(void)
  {
  	struct smb_hdr *ret_buf = NULL;
  	size_t buf_size = sizeof(struct smb_hdr);
  
  #ifdef CONFIG_CIFS_SMB2
  	/*
  	 * SMB2 header is bigger than CIFS one - no problems to clean some
  	 * more bytes for CIFS.
  	 */
  	buf_size = sizeof(struct smb2_hdr);
  #endif
  	/*
  	 * We could use negotiated size instead of max_msgsize -
  	 * but it may be more efficient to always alloc same size
  	 * albeit slightly larger than necessary and maxbuffersize
  	 * defaults to this and can not be bigger.
  	 */
  	ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
  
  	/* clear the first few header bytes */
  	/* for most paths, more is cleared in header_assemble */
  	if (ret_buf) {
  		memset(ret_buf, 0, buf_size + 3);
  		atomic_inc(&bufAllocCount);
  #ifdef CONFIG_CIFS_STATS2
  		atomic_inc(&totBufAllocCount);
  #endif /* CONFIG_CIFS_STATS2 */
  	}
  
  	return ret_buf;
  }
  
  void
  cifs_buf_release(void *buf_to_free)
  {
  	if (buf_to_free == NULL) {
  		/* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release
  ");*/
  		return;
  	}
  	mempool_free(buf_to_free, cifs_req_poolp);
  
  	atomic_dec(&bufAllocCount);
  	return;
  }
  
  struct smb_hdr *
  cifs_small_buf_get(void)
  {
  	struct smb_hdr *ret_buf = NULL;
  
  /* We could use negotiated size instead of max_msgsize -
     but it may be more efficient to always alloc same size
     albeit slightly larger than necessary and maxbuffersize
     defaults to this and can not be bigger */
  	ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
  	if (ret_buf) {
  	/* No need to clear memory here, cleared in header assemble */
  	/*	memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
  		atomic_inc(&smBufAllocCount);
  #ifdef CONFIG_CIFS_STATS2
  		atomic_inc(&totSmBufAllocCount);
  #endif /* CONFIG_CIFS_STATS2 */
  
  	}
  	return ret_buf;
  }
  
  void
  cifs_small_buf_release(void *buf_to_free)
  {
  
  	if (buf_to_free == NULL) {
  		cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release
  ");
  		return;
  	}
  	mempool_free(buf_to_free, cifs_sm_req_poolp);
  
  	atomic_dec(&smBufAllocCount);
  	return;
  }
  
  /* NB: MID can not be set if treeCon not passed in, in that
     case it is responsbility of caller to set the mid */
  void
  header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
  		const struct cifs_tcon *treeCon, int word_count
  		/* length of fixed section (word count) in two byte units  */)
  {
  	char *temp = (char *) buffer;
  
  	memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
  
  	buffer->smb_buf_length = cpu_to_be32(
  	    (2 * word_count) + sizeof(struct smb_hdr) -
  	    4 /*  RFC 1001 length field does not count */  +
  	    2 /* for bcc field itself */) ;
  
  	buffer->Protocol[0] = 0xFF;
  	buffer->Protocol[1] = 'S';
  	buffer->Protocol[2] = 'M';
  	buffer->Protocol[3] = 'B';
  	buffer->Command = smb_command;
  	buffer->Flags = 0x00;	/* case sensitive */
  	buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
  	buffer->Pid = cpu_to_le16((__u16)current->tgid);
  	buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
  	if (treeCon) {
  		buffer->Tid = treeCon->tid;
  		if (treeCon->ses) {
  			if (treeCon->ses->capabilities & CAP_UNICODE)
  				buffer->Flags2 |= SMBFLG2_UNICODE;
  			if (treeCon->ses->capabilities & CAP_STATUS32)
  				buffer->Flags2 |= SMBFLG2_ERR_STATUS;
  
  			/* Uid is not converted */
  			buffer->Uid = treeCon->ses->Suid;
  			buffer->Mid = get_next_mid(treeCon->ses->server);
  		}
  		if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
  			buffer->Flags2 |= SMBFLG2_DFS;
  		if (treeCon->nocase)
  			buffer->Flags  |= SMBFLG_CASELESS;
  		if ((treeCon->ses) && (treeCon->ses->server))
  			if (treeCon->ses->server->sign)
  				buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
  	}
  
  /*  endian conversion of flags is now done just before sending */
  	buffer->WordCount = (char) word_count;
  	return;
  }
  
  static int
  check_smb_hdr(struct smb_hdr *smb)
  {
  	/* does it have the right SMB "signature" ? */
  	if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
  		cifs_dbg(VFS, "Bad protocol string signature header 0x%x
  ",
  			 *(unsigned int *)smb->Protocol);
  		return 1;
  	}
  
  	/* if it's a response then accept */
  	if (smb->Flags & SMBFLG_RESPONSE)
  		return 0;
  
  	/* only one valid case where server sends us request */
  	if (smb->Command == SMB_COM_LOCKING_ANDX)
  		return 0;
  
  	cifs_dbg(VFS, "Server sent request, not response. mid=%u
  ",
  		 get_mid(smb));
  	return 1;
  }
  
  int
  checkSMB(char *buf, unsigned int total_read)
  {
  	struct smb_hdr *smb = (struct smb_hdr *)buf;
  	__u32 rfclen = be32_to_cpu(smb->smb_buf_length);
  	__u32 clc_len;  /* calculated length */
  	cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x
  ",
  		 total_read, rfclen);
  
  	/* is this frame too small to even get to a BCC? */
  	if (total_read < 2 + sizeof(struct smb_hdr)) {
  		if ((total_read >= sizeof(struct smb_hdr) - 1)
  			    && (smb->Status.CifsError != 0)) {
  			/* it's an error return */
  			smb->WordCount = 0;
  			/* some error cases do not return wct and bcc */
  			return 0;
  		} else if ((total_read == sizeof(struct smb_hdr) + 1) &&
  				(smb->WordCount == 0)) {
  			char *tmp = (char *)smb;
  			/* Need to work around a bug in two servers here */
  			/* First, check if the part of bcc they sent was zero */
  			if (tmp[sizeof(struct smb_hdr)] == 0) {
  				/* some servers return only half of bcc
  				 * on simple responses (wct, bcc both zero)
  				 * in particular have seen this on
  				 * ulogoffX and FindClose. This leaves
  				 * one byte of bcc potentially unitialized
  				 */
  				/* zero rest of bcc */
  				tmp[sizeof(struct smb_hdr)+1] = 0;
  				return 0;
  			}
  			cifs_dbg(VFS, "rcvd invalid byte count (bcc)
  ");
  		} else {
  			cifs_dbg(VFS, "Length less than smb header size
  ");
  		}
  		return -EIO;
  	}
  
  	/* otherwise, there is enough to get to the BCC */
  	if (check_smb_hdr(smb))
  		return -EIO;
  	clc_len = smbCalcSize(smb);
  
  	if (4 + rfclen != total_read) {
  		cifs_dbg(VFS, "Length read does not match RFC1001 length %d
  ",
  			 rfclen);
  		return -EIO;
  	}
  
  	if (4 + rfclen != clc_len) {
  		__u16 mid = get_mid(smb);
  		/* check if bcc wrapped around for large read responses */
  		if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
  			/* check if lengths match mod 64K */
  			if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
  				return 0; /* bcc wrapped */
  		}
  		cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u
  ",
  			 clc_len, 4 + rfclen, mid);
  
  		if (4 + rfclen < clc_len) {
  			cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u
  ",
  				 rfclen, mid);
  			return -EIO;
  		} else if (rfclen > clc_len + 512) {
  			/*
  			 * Some servers (Windows XP in particular) send more
  			 * data than the lengths in the SMB packet would
  			 * indicate on certain calls (byte range locks and
  			 * trans2 find first calls in particular). While the
  			 * client can handle such a frame by ignoring the
  			 * trailing data, we choose limit the amount of extra
  			 * data to 512 bytes.
  			 */
  			cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u
  ",
  				 rfclen, mid);
  			return -EIO;
  		}
  	}
  	return 0;
  }
  
  bool
  is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
  {
  	struct smb_hdr *buf = (struct smb_hdr *)buffer;
  	struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
  	struct list_head *tmp, *tmp1, *tmp2;
  	struct cifs_ses *ses;
  	struct cifs_tcon *tcon;
  	struct cifsInodeInfo *pCifsInode;
  	struct cifsFileInfo *netfile;
  
  	cifs_dbg(FYI, "Checking for oplock break or dnotify response
  ");
  	if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
  	   (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
  		struct smb_com_transaction_change_notify_rsp *pSMBr =
  			(struct smb_com_transaction_change_notify_rsp *)buf;
  		struct file_notify_information *pnotify;
  		__u32 data_offset = 0;
  		if (get_bcc(buf) > sizeof(struct file_notify_information)) {
  			data_offset = le32_to_cpu(pSMBr->DataOffset);
  
  			pnotify = (struct file_notify_information *)
  				((char *)&pSMBr->hdr.Protocol + data_offset);
  			cifs_dbg(FYI, "dnotify on %s Action: 0x%x
  ",
  				 pnotify->FileName, pnotify->Action);
  			/*   cifs_dump_mem("Rcvd notify Data: ",buf,
  				sizeof(struct smb_hdr)+60); */
  			return true;
  		}
  		if (pSMBr->hdr.Status.CifsError) {
  			cifs_dbg(FYI, "notify err 0x%d
  ",
  				 pSMBr->hdr.Status.CifsError);
  			return true;
  		}
  		return false;
  	}
  	if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
  		return false;
  	if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
  		/* no sense logging error on invalid handle on oplock
  		   break - harmless race between close request and oplock
  		   break response is expected from time to time writing out
  		   large dirty files cached on the client */
  		if ((NT_STATUS_INVALID_HANDLE) ==
  		   le32_to_cpu(pSMB->hdr.Status.CifsError)) {
  			cifs_dbg(FYI, "invalid handle on oplock break
  ");
  			return true;
  		} else if (ERRbadfid ==
  		   le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
  			return true;
  		} else {
  			return false; /* on valid oplock brk we get "request" */
  		}
  	}
  	if (pSMB->hdr.WordCount != 8)
  		return false;
  
  	cifs_dbg(FYI, "oplock type 0x%d level 0x%d
  ",
  		 pSMB->LockType, pSMB->OplockLevel);
  	if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
  		return false;
  
  	/* look up tcon based on tid & uid */
  	spin_lock(&cifs_tcp_ses_lock);
  	list_for_each(tmp, &srv->smb_ses_list) {
  		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
  		list_for_each(tmp1, &ses->tcon_list) {
  			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
  			if (tcon->tid != buf->Tid)
  				continue;
  
  			cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
  			spin_lock(&cifs_file_list_lock);
  			list_for_each(tmp2, &tcon->openFileList) {
  				netfile = list_entry(tmp2, struct cifsFileInfo,
  						     tlist);
  				if (pSMB->Fid != netfile->fid.netfid)
  					continue;
  
  				cifs_dbg(FYI, "file id match, oplock break
  ");
  				pCifsInode = CIFS_I(netfile->dentry->d_inode);
  
  				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
  					&pCifsInode->flags);
  
  				/*
  				 * Set flag if the server downgrades the oplock
  				 * to L2 else clear.
  				 */
  				if (pSMB->OplockLevel)
  					set_bit(
  					   CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
  					   &pCifsInode->flags);
  				else
  					clear_bit(
  					   CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
  					   &pCifsInode->flags);
  
  				queue_work(cifsiod_wq,
  					   &netfile->oplock_break);
  				netfile->oplock_break_cancelled = false;
  
  				spin_unlock(&cifs_file_list_lock);
  				spin_unlock(&cifs_tcp_ses_lock);
  				return true;
  			}
  			spin_unlock(&cifs_file_list_lock);
  			spin_unlock(&cifs_tcp_ses_lock);
  			cifs_dbg(FYI, "No matching file for oplock break
  ");
  			return true;
  		}
  	}
  	spin_unlock(&cifs_tcp_ses_lock);
  	cifs_dbg(FYI, "Can not process oplock break for non-existent connection
  ");
  	return true;
  }
  
  void
  dump_smb(void *buf, int smb_buf_length)
  {
  	int i, j;
  	char debug_line[17];
  	unsigned char *buffer = buf;
  
  	if (traceSMB == 0)
  		return;
  
  	for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
  		if (i % 8 == 0) {
  			/* have reached the beginning of line */
  			printk(KERN_DEBUG "| ");
  			j = 0;
  		}
  		printk("%0#4x ", buffer[i]);
  		debug_line[2 * j] = ' ';
  		if (isprint(buffer[i]))
  			debug_line[1 + (2 * j)] = buffer[i];
  		else
  			debug_line[1 + (2 * j)] = '_';
  
  		if (i % 8 == 7) {
  			/* reached end of line, time to print ascii */
  			debug_line[16] = 0;
  			printk(" | %s
  ", debug_line);
  		}
  	}
  	for (; j < 8; j++) {
  		printk("     ");
  		debug_line[2 * j] = ' ';
  		debug_line[1 + (2 * j)] = ' ';
  	}
  	printk(" | %s
  ", debug_line);
  	return;
  }
  
  void
  cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
  {
  	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
  		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
  		cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s. This server doesn't seem to support them properly. Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.
  ",
  			 cifs_sb_master_tcon(cifs_sb)->treeName);
  	}
  }
  
  void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
  {
  	oplock &= 0xF;
  
  	if (oplock == OPLOCK_EXCLUSIVE) {
  		cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
  		cifs_dbg(FYI, "Exclusive Oplock granted on inode %p
  ",
  			 &cinode->vfs_inode);
  	} else if (oplock == OPLOCK_READ) {
  		cinode->oplock = CIFS_CACHE_READ_FLG;
  		cifs_dbg(FYI, "Level II Oplock granted on inode %p
  ",
  			 &cinode->vfs_inode);
  	} else
  		cinode->oplock = 0;
  }
  
  static int
  cifs_oplock_break_wait(void *unused)
  {
  	schedule();
  	return signal_pending(current) ? -ERESTARTSYS : 0;
  }
  
  /*
   * We wait for oplock breaks to be processed before we attempt to perform
   * writes.
   */
  int cifs_get_writer(struct cifsInodeInfo *cinode)
  {
  	int rc;
  
  start:
  	rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
  				   cifs_oplock_break_wait, TASK_KILLABLE);
  	if (rc)
  		return rc;
  
  	spin_lock(&cinode->writers_lock);
  	if (!cinode->writers)
  		set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
  	cinode->writers++;
  	/* Check to see if we have started servicing an oplock break */
  	if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
  		cinode->writers--;
  		if (cinode->writers == 0) {
  			clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
  			wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
  		}
  		spin_unlock(&cinode->writers_lock);
  		goto start;
  	}
  	spin_unlock(&cinode->writers_lock);
  	return 0;
  }
  
  void cifs_put_writer(struct cifsInodeInfo *cinode)
  {
  	spin_lock(&cinode->writers_lock);
  	cinode->writers--;
  	if (cinode->writers == 0) {
  		clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
  		wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
  	}
  	spin_unlock(&cinode->writers_lock);
  }
  
  void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
  {
  	clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
  	wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
  }
  
  bool
  backup_cred(struct cifs_sb_info *cifs_sb)
  {
  	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
  		if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
  			return true;
  	}
  	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
  		if (in_group_p(cifs_sb->mnt_backupgid))
  			return true;
  	}
  
  	return false;
  }
  
  void
  cifs_del_pending_open(struct cifs_pending_open *open)
  {
  	spin_lock(&cifs_file_list_lock);
  	list_del(&open->olist);
  	spin_unlock(&cifs_file_list_lock);
  }
  
  void
  cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
  			     struct cifs_pending_open *open)
  {
  #ifdef CONFIG_CIFS_SMB2
  	memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
  #endif
  	open->oplock = CIFS_OPLOCK_NO_CHANGE;
  	open->tlink = tlink;
  	fid->pending_open = open;
  	list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
  }
  
  void
  cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
  		      struct cifs_pending_open *open)
  {
  	spin_lock(&cifs_file_list_lock);
  	cifs_add_pending_open_locked(fid, tlink, open);
  	spin_unlock(&cifs_file_list_lock);
  }