fs/cifs/dir.c - linux/kernel/git/davem/net - Git at Google

 /*
  *   fs/cifs/dir.c
  *
  *   vfs operations that deal with dentries
  *
  *   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/fs.h>
 #include <linux/stat.h>
 #include <linux/slab.h>
 #include <linux/namei.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
 #include "cifsglob.h"
 #include "cifsproto.h"
 #include "cifs_debug.h"
 #include "cifs_fs_sb.h"

 static void
 renew_parental_timestamps(struct dentry *direntry)
 {
 	/* BB check if there is a way to get the kernel to do this or if we
 	   really need this */
 	do {
 		direntry->d_time = jiffies;
 		direntry = direntry->d_parent;
 	} while (!IS_ROOT(direntry));
 }

 /* Note: caller must free return buffer */
 char *
 build_path_from_dentry(struct dentry *direntry)
 {
 	struct dentry *temp;
 	int namelen;
 	int pplen;
 	int dfsplen;
 	char *full_path;
 	char dirsep;
 	struct cifs_sb_info *cifs_sb;

 	if (direntry == NULL)
 		return NULL;  /* not much we can do if dentry is freed and
 		we need to reopen the file after it was closed implicitly
 		when the server crashed */

 	cifs_sb = CIFS_SB(direntry->d_sb);
 	dirsep = CIFS_DIR_SEP(cifs_sb);
 	pplen = cifs_sb->prepathlen;
 	if (cifs_sb->tcon && (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS))
 		dfsplen = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE + 1);
 	else
 		dfsplen = 0;
 cifs_bp_rename_retry:
 	namelen = pplen + dfsplen;
 	for (temp = direntry; !IS_ROOT(temp);) {
 		namelen += (1 + temp->d_name.len);
 		temp = temp->d_parent;
 		if (temp == NULL) {
 			cERROR(1, ("corrupt dentry"));
 			return NULL;
 		}
 	}

 	full_path = kmalloc(namelen+1, GFP_KERNEL);
 	if (full_path == NULL)
 		return full_path;
 	full_path[namelen] = 0;	/* trailing null */
 	for (temp = direntry; !IS_ROOT(temp);) {
 		namelen -= 1 + temp->d_name.len;
 		if (namelen < 0) {
 			break;
 		} else {
 			full_path[namelen] = dirsep;
 			strncpy(full_path + namelen + 1, temp->d_name.name,
 				temp->d_name.len);
 			cFYI(0, ("name: %s", full_path + namelen));
 		}
 		temp = temp->d_parent;
 		if (temp == NULL) {
 			cERROR(1, ("corrupt dentry"));
 			kfree(full_path);
 			return NULL;
 		}
 	}
 	if (namelen != pplen + dfsplen) {
 		cERROR(1,
 		       ("did not end path lookup where expected namelen is %d",
 			namelen));
 		/* presumably this is only possible if racing with a rename
 		of one of the parent directories  (we can not lock the dentries
 		above us to prevent this, but retrying should be harmless) */
 		kfree(full_path);
 		goto cifs_bp_rename_retry;
 	}
 	/* DIR_SEP already set for byte  0 / vs \ but not for
 	   subsequent slashes in prepath which currently must
 	   be entered the right way - not sure if there is an alternative
 	   since the '\' is a valid posix character so we can not switch
 	   those safely to '/' if any are found in the middle of the prepath */
 	/* BB test paths to Windows with '/' in the midst of prepath */

 	if (dfsplen) {
 		strncpy(full_path, cifs_sb->tcon->treeName, dfsplen);
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
 			int i;
 			for (i = 0; i < dfsplen; i++) {
 				if (full_path[i] == '\\')
 					full_path[i] = '/';
 			}
 		}
 	}
 	strncpy(full_path + dfsplen, CIFS_SB(direntry->d_sb)->prepath, pplen);
 	return full_path;
 }

 /* Inode operations in similar order to how they appear in Linux file fs.h */

 int
 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 		struct nameidata *nd)
 {
 	int rc = -ENOENT;
 	int xid;
 	int create_options = CREATE_NOT_DIR;
 	int oplock = 0;
 	int desiredAccess = GENERIC_READ | GENERIC_WRITE;
 	__u16 fileHandle;
 	struct cifs_sb_info *cifs_sb;
 	struct cifsTconInfo *pTcon;
 	char *full_path = NULL;
 	FILE_ALL_INFO *buf = NULL;
 	struct inode *newinode = NULL;
 	struct cifsFileInfo *pCifsFile = NULL;
 	struct cifsInodeInfo *pCifsInode;
 	int disposition = FILE_OVERWRITE_IF;
 	bool write_only = false;

 	xid = GetXid();

 	cifs_sb = CIFS_SB(inode->i_sb);
 	pTcon = cifs_sb->tcon;

 	full_path = build_path_from_dentry(direntry);
 	if (full_path == NULL) {
 		FreeXid(xid);
 		return -ENOMEM;
 	}

 	if (nd && (nd->flags & LOOKUP_OPEN)) {
 		int oflags = nd->intent.open.flags;

 		desiredAccess = 0;
 		if (oflags & FMODE_READ)
 			desiredAccess |= GENERIC_READ;
 		if (oflags & FMODE_WRITE) {
 			desiredAccess |= GENERIC_WRITE;
 			if (!(oflags & FMODE_READ))
 				write_only = true;
 		}

 		if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 			disposition = FILE_CREATE;
 		else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 			disposition = FILE_OVERWRITE_IF;
 		else if ((oflags & O_CREAT) == O_CREAT)
 			disposition = FILE_OPEN_IF;
 		else
 			cFYI(1, ("Create flag not set in create function"));
 	}

 	/* BB add processing to set equivalent of mode - e.g. via CreateX with
 	   ACLs */
 	if (oplockEnabled)
 		oplock = REQ_OPLOCK;

 	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 	if (buf == NULL) {
 		kfree(full_path);
 		FreeXid(xid);
 		return -ENOMEM;
 	}

 	mode &= ~current->fs->umask;

 	/*
 	 * if we're not using unix extensions, see if we need to set
 	 * ATTR_READONLY on the create call
 	 */
 	if (!pTcon->unix_ext && (mode & S_IWUGO) == 0)
 		create_options |= CREATE_OPTION_READONLY;

 	if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
 		rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 			 desiredAccess, create_options,
 			 &fileHandle, &oplock, buf, cifs_sb->local_nls,
 			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 	else
 		rc = -EIO; /* no NT SMB support fall into legacy open below */

 	if (rc == -EIO) {
 		/* old server, retry the open legacy style */
 		rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
 			desiredAccess, create_options,
 			&fileHandle, &oplock, buf, cifs_sb->local_nls,
 			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 	}
 	if (rc) {
 		cFYI(1, ("cifs_create returned 0x%x", rc));
 	} else {
 		/* If Open reported that we actually created a file
 		then we now have to set the mode if possible */
 		if ((pTcon->unix_ext) && (oplock & CIFS_CREATE_ACTION)) {
 			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 				CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 					(__u64)current->fsuid,
 					(__u64)current->fsgid,
 					0 /* dev */,
 					cifs_sb->local_nls,
 					cifs_sb->mnt_cifs_flags &
 						CIFS_MOUNT_MAP_SPECIAL_CHR);
 			} else {
 				CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 					(__u64)-1,
 					(__u64)-1,
 					0 /* dev */,
 					cifs_sb->local_nls,
 					cifs_sb->mnt_cifs_flags &
 						CIFS_MOUNT_MAP_SPECIAL_CHR);
 			}
 		} else {
 			/* BB implement mode setting via Windows security
 			   descriptors e.g. */
 			/* CIFSSMBWinSetPerms(xid,pTcon,path,mode,-1,-1,nls);*/

 			/* Could set r/o dos attribute if mode & 0222 == 0 */
 		}

 		/* server might mask mode so we have to query for it */
 		if (pTcon->unix_ext)
 			rc = cifs_get_inode_info_unix(&newinode, full_path,
 						 inode->i_sb, xid);
 		else {
 			rc = cifs_get_inode_info(&newinode, full_path,
 						 buf, inode->i_sb, xid,
 						 &fileHandle);
 			if (newinode) {
 				newinode->i_mode = mode;
 				if ((oplock & CIFS_CREATE_ACTION) &&
 				    (cifs_sb->mnt_cifs_flags &
 				     CIFS_MOUNT_SET_UID)) {
 					newinode->i_uid = current->fsuid;
 					newinode->i_gid = current->fsgid;
 				}
 			}
 		}

 		if (rc != 0) {
 			cFYI(1,
 			     ("Create worked but get_inode_info failed rc = %d",
 			      rc));
 		} else {
 			if (pTcon->nocase)
 				direntry->d_op = &cifs_ci_dentry_ops;
 			else
 				direntry->d_op = &cifs_dentry_ops;
 			d_instantiate(direntry, newinode);
 		}
 		if ((nd == NULL /* nfsd case - nfs srv does not set nd */) ||
 			(!(nd->flags & LOOKUP_OPEN))) {
 			/* mknod case - do not leave file open */
 			CIFSSMBClose(xid, pTcon, fileHandle);
 		} else if (newinode) {
 			pCifsFile =
 			   kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);

 			if (pCifsFile == NULL)
 				goto cifs_create_out;
 			pCifsFile->netfid = fileHandle;
 			pCifsFile->pid = current->tgid;
 			pCifsFile->pInode = newinode;
 			pCifsFile->invalidHandle = false;
 			pCifsFile->closePend     = false;
 			init_MUTEX(&pCifsFile->fh_sem);
 			mutex_init(&pCifsFile->lock_mutex);
 			INIT_LIST_HEAD(&pCifsFile->llist);
 			atomic_set(&pCifsFile->wrtPending, 0);

 			/* set the following in open now
 				pCifsFile->pfile = file; */
 			write_lock(&GlobalSMBSeslock);
 			list_add(&pCifsFile->tlist, &pTcon->openFileList);
 			pCifsInode = CIFS_I(newinode);
 			if (pCifsInode) {
 				/* if readable file instance put first in list*/
 				if (write_only) {
 					list_add_tail(&pCifsFile->flist,
 						&pCifsInode->openFileList);
 				} else {
 					list_add(&pCifsFile->flist,
 						&pCifsInode->openFileList);
 				}
 				if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 					pCifsInode->clientCanCacheAll = true;
 					pCifsInode->clientCanCacheRead = true;
 					cFYI(1, ("Exclusive Oplock inode %p",
 						newinode));
 				} else if ((oplock & 0xF) == OPLOCK_READ)
 					pCifsInode->clientCanCacheRead = true;
 			}
 			write_unlock(&GlobalSMBSeslock);
 		}
 	}
 cifs_create_out:
 	kfree(buf);
 	kfree(full_path);
 	FreeXid(xid);
 	return rc;
 }

 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
 		dev_t device_number)
 {
 	int rc = -EPERM;
 	int xid;
 	struct cifs_sb_info *cifs_sb;
 	struct cifsTconInfo *pTcon;
 	char *full_path = NULL;
 	struct inode *newinode = NULL;

 	if (!old_valid_dev(device_number))
 		return -EINVAL;

 	xid = GetXid();

 	cifs_sb = CIFS_SB(inode->i_sb);
 	pTcon = cifs_sb->tcon;

 	full_path = build_path_from_dentry(direntry);
 	if (full_path == NULL)
 		rc = -ENOMEM;
 	else if (pTcon->unix_ext) {
 		mode &= ~current->fs->umask;
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 			rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 				mode, (__u64)current->fsuid,
 				(__u64)current->fsgid,
 				device_number, cifs_sb->local_nls,
 				cifs_sb->mnt_cifs_flags &
 					CIFS_MOUNT_MAP_SPECIAL_CHR);
 		} else {
 			rc = CIFSSMBUnixSetPerms(xid, pTcon,
 				full_path, mode, (__u64)-1, (__u64)-1,
 				device_number, cifs_sb->local_nls,
 				cifs_sb->mnt_cifs_flags &
 					CIFS_MOUNT_MAP_SPECIAL_CHR);
 		}

 		if (!rc) {
 			rc = cifs_get_inode_info_unix(&newinode, full_path,
 						inode->i_sb, xid);
 			if (pTcon->nocase)
 				direntry->d_op = &cifs_ci_dentry_ops;
 			else
 				direntry->d_op = &cifs_dentry_ops;
 			if (rc == 0)
 				d_instantiate(direntry, newinode);
 		}
 	} else {
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
 			int oplock = 0;
 			u16 fileHandle;
 			FILE_ALL_INFO *buf;

 			cFYI(1, ("sfu compat create special file"));

 			buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 			if (buf == NULL) {
 				kfree(full_path);
 				FreeXid(xid);
 				return -ENOMEM;
 			}

 			rc = CIFSSMBOpen(xid, pTcon, full_path,
 					 FILE_CREATE, /* fail if exists */
 					 GENERIC_WRITE /* BB would
 					  WRITE_OWNER | WRITE_DAC be better? */,
 					 /* Create a file and set the
 					    file attribute to SYSTEM */
 					 CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
 					 &fileHandle, &oplock, buf,
 					 cifs_sb->local_nls,
 					 cifs_sb->mnt_cifs_flags &
 					    CIFS_MOUNT_MAP_SPECIAL_CHR);

 			/* BB FIXME - add handling for backlevel servers
 			   which need legacy open and check for all
 			   calls to SMBOpen for fallback to SMBLeagcyOpen */
 			if (!rc) {
 				/* BB Do not bother to decode buf since no
 				   local inode yet to put timestamps in,
 				   but we can reuse it safely */
 				unsigned int bytes_written;
 				struct win_dev *pdev;
 				pdev = (struct win_dev *)buf;
 				if (S_ISCHR(mode)) {
 					memcpy(pdev->type, "IntxCHR", 8);
 					pdev->major =
 					      cpu_to_le64(MAJOR(device_number));
 					pdev->minor =
 					      cpu_to_le64(MINOR(device_number));
 					rc = CIFSSMBWrite(xid, pTcon,
 						fileHandle,
 						sizeof(struct win_dev),
 						0, &bytes_written, (char *)pdev,
 						NULL, 0);
 				} else if (S_ISBLK(mode)) {
 					memcpy(pdev->type, "IntxBLK", 8);
 					pdev->major =
 					      cpu_to_le64(MAJOR(device_number));
 					pdev->minor =
 					      cpu_to_le64(MINOR(device_number));
 					rc = CIFSSMBWrite(xid, pTcon,
 						fileHandle,
 						sizeof(struct win_dev),
 						0, &bytes_written, (char *)pdev,
 						NULL, 0);
 				} /* else if(S_ISFIFO */
 				CIFSSMBClose(xid, pTcon, fileHandle);
 				d_drop(direntry);
 			}
 			kfree(buf);
 			/* add code here to set EAs */
 		}
 	}

 	kfree(full_path);
 	FreeXid(xid);
 	return rc;
 }


 struct dentry *
 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 	    struct nameidata *nd)
 {
 	int xid;
 	int rc = 0; /* to get around spurious gcc warning, set to zero here */
 	struct cifs_sb_info *cifs_sb;
 	struct cifsTconInfo *pTcon;
 	struct inode *newInode = NULL;
 	char *full_path = NULL;

 	xid = GetXid();

 	cFYI(1, (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 	      parent_dir_inode, direntry->d_name.name, direntry));

 	/* check whether path exists */

 	cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 	pTcon = cifs_sb->tcon;

 	/*
 	 * Don't allow the separator character in a path component.
 	 * The VFS will not allow "/", but "\" is allowed by posix.
 	 */
 	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
 		int i;
 		for (i = 0; i < direntry->d_name.len; i++)
 			if (direntry->d_name.name[i] == '\\') {
 				cFYI(1, ("Invalid file name"));
 				FreeXid(xid);
 				return ERR_PTR(-EINVAL);
 			}
 	}

 	/* can not grab the rename sem here since it would
 	deadlock in the cases (beginning of sys_rename itself)
 	in which we already have the sb rename sem */
 	full_path = build_path_from_dentry(direntry);
 	if (full_path == NULL) {
 		FreeXid(xid);
 		return ERR_PTR(-ENOMEM);
 	}

 	if (direntry->d_inode != NULL) {
 		cFYI(1, (" non-NULL inode in lookup"));
 	} else {
 		cFYI(1, (" NULL inode in lookup"));
 	}
 	cFYI(1,
 	     (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));

 	if (pTcon->unix_ext)
 		rc = cifs_get_inode_info_unix(&newInode, full_path,
 					      parent_dir_inode->i_sb, xid);
 	else
 		rc = cifs_get_inode_info(&newInode, full_path, NULL,
 					 parent_dir_inode->i_sb, xid, NULL);

 	if ((rc == 0) && (newInode != NULL)) {
 		if (pTcon->nocase)
 			direntry->d_op = &cifs_ci_dentry_ops;
 		else
 			direntry->d_op = &cifs_dentry_ops;
 		d_add(direntry, newInode);

 		/* since paths are not looked up by component - the parent
 		   directories are presumed to be good here */
 		renew_parental_timestamps(direntry);

 	} else if (rc == -ENOENT) {
 		rc = 0;
 		direntry->d_time = jiffies;
 		if (pTcon->nocase)
 			direntry->d_op = &cifs_ci_dentry_ops;
 		else
 			direntry->d_op = &cifs_dentry_ops;
 		d_add(direntry, NULL);
 	/*	if it was once a directory (but how can we tell?) we could do
 		shrink_dcache_parent(direntry); */
 	} else if (rc != -EACCES) {
 		cERROR(1, ("Unexpected lookup error %d", rc));
 		/* We special case check for Access Denied - since that
 		is a common return code */
 	}

 	kfree(full_path);
 	FreeXid(xid);
 	return ERR_PTR(rc);
 }

 static int
 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 {
 	int isValid = 1;

 	if (direntry->d_inode) {
 		if (cifs_revalidate(direntry))
 			return 0;
 	} else {
 		cFYI(1, ("neg dentry 0x%p name = %s",
 			 direntry, direntry->d_name.name));
 		if (time_after(jiffies, direntry->d_time + HZ) ||
 			!lookupCacheEnabled) {
 			d_drop(direntry);
 			isValid = 0;
 		}
 	}

 	return isValid;
 }

 /* static int cifs_d_delete(struct dentry *direntry)
 {
 	int rc = 0;

 	cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));

 	return rc;
 }     */

 struct dentry_operations cifs_dentry_ops = {
 	.d_revalidate = cifs_d_revalidate,
 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
 };

 static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
 {
 	struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
 	unsigned long hash;
 	int i;

 	hash = init_name_hash();
 	for (i = 0; i < q->len; i++)
 		hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
 					 hash);
 	q->hash = end_name_hash(hash);

 	return 0;
 }

 static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
 			   struct qstr *b)
 {
 	struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;

 	if ((a->len == b->len) &&
 	    (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
 		/*
 		 * To preserve case, don't let an existing negative dentry's
 		 * case take precedence.  If a is not a negative dentry, this
 		 * should have no side effects
 		 */
 		memcpy((void *)a->name, b->name, a->len);
 		return 0;
 	}
 	return 1;
 }

 struct dentry_operations cifs_ci_dentry_ops = {
 	.d_revalidate = cifs_d_revalidate,
 	.d_hash = cifs_ci_hash,
 	.d_compare = cifs_ci_compare,
 };
	/*
	* fs/cifs/dir.c
	*
	* vfs operations that deal with dentries
	*
	* 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/fs.h>
	#include <linux/stat.h>
	#include <linux/slab.h>
	#include <linux/namei.h>
	#include "cifsfs.h"
	#include "cifspdu.h"
	#include "cifsglob.h"
	#include "cifsproto.h"
	#include "cifs_debug.h"
	#include "cifs_fs_sb.h"

	static void
	renew_parental_timestamps(struct dentry *direntry)
	{
	/* BB check if there is a way to get the kernel to do this or if we
	really need this */
	do {
	direntry->d_time = jiffies;
	direntry = direntry->d_parent;
	} while (!IS_ROOT(direntry));
	}

	/* Note: caller must free return buffer */
	char *
	build_path_from_dentry(struct dentry *direntry)
	{
	struct dentry *temp;
	int namelen;
	int pplen;
	int dfsplen;
	char *full_path;
	char dirsep;
	struct cifs_sb_info *cifs_sb;

	if (direntry == NULL)
	return NULL; /* not much we can do if dentry is freed and
	we need to reopen the file after it was closed implicitly
	when the server crashed */

	cifs_sb = CIFS_SB(direntry->d_sb);
	dirsep = CIFS_DIR_SEP(cifs_sb);
	pplen = cifs_sb->prepathlen;
	if (cifs_sb->tcon && (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS))
	dfsplen = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE + 1);
	else
	dfsplen = 0;
	cifs_bp_rename_retry:
	namelen = pplen + dfsplen;
	for (temp = direntry; !IS_ROOT(temp);) {
	namelen += (1 + temp->d_name.len);
	temp = temp->d_parent;
	if (temp == NULL) {
	cERROR(1, ("corrupt dentry"));
	return NULL;
	}
	}

	full_path = kmalloc(namelen+1, GFP_KERNEL);
	if (full_path == NULL)
	return full_path;
	full_path[namelen] = 0; /* trailing null */
	for (temp = direntry; !IS_ROOT(temp);) {
	namelen -= 1 + temp->d_name.len;
	if (namelen < 0) {
	break;
	} else {
	full_path[namelen] = dirsep;
	strncpy(full_path + namelen + 1, temp->d_name.name,
	temp->d_name.len);
	cFYI(0, ("name: %s", full_path + namelen));
	}
	temp = temp->d_parent;
	if (temp == NULL) {
	cERROR(1, ("corrupt dentry"));
	kfree(full_path);
	return NULL;
	}
	}
	if (namelen != pplen + dfsplen) {
	cERROR(1,
	("did not end path lookup where expected namelen is %d",
	namelen));
	/* presumably this is only possible if racing with a rename
	of one of the parent directories (we can not lock the dentries
	above us to prevent this, but retrying should be harmless) */
	kfree(full_path);
	goto cifs_bp_rename_retry;
	}
	/* DIR_SEP already set for byte 0 / vs \ but not for
	subsequent slashes in prepath which currently must
	be entered the right way - not sure if there is an alternative
	since the '\' is a valid posix character so we can not switch
	those safely to '/' if any are found in the middle of the prepath */
	/* BB test paths to Windows with '/' in the midst of prepath */

	if (dfsplen) {
	strncpy(full_path, cifs_sb->tcon->treeName, dfsplen);
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
	int i;
	for (i = 0; i < dfsplen; i++) {
	if (full_path[i] == '\\')
	full_path[i] = '/';
	}
	}
	}
	strncpy(full_path + dfsplen, CIFS_SB(direntry->d_sb)->prepath, pplen);
	return full_path;
	}

	/* Inode operations in similar order to how they appear in Linux file fs.h */

	int
	cifs_create(struct inode inode, struct dentry direntry, int mode,
	struct nameidata *nd)
	{
	int rc = -ENOENT;
	int xid;
	int create_options = CREATE_NOT_DIR;
	int oplock = 0;
	int desiredAccess = GENERIC_READ \| GENERIC_WRITE;
	__u16 fileHandle;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	FILE_ALL_INFO *buf = NULL;
	struct inode *newinode = NULL;
	struct cifsFileInfo *pCifsFile = NULL;
	struct cifsInodeInfo *pCifsInode;
	int disposition = FILE_OVERWRITE_IF;
	bool write_only = false;

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	full_path = build_path_from_dentry(direntry);
	if (full_path == NULL) {
	FreeXid(xid);
	return -ENOMEM;
	}

	if (nd && (nd->flags & LOOKUP_OPEN)) {
	int oflags = nd->intent.open.flags;

	desiredAccess = 0;
	if (oflags & FMODE_READ)
	desiredAccess \|= GENERIC_READ;
	if (oflags & FMODE_WRITE) {
	desiredAccess \|= GENERIC_WRITE;
	if (!(oflags & FMODE_READ))
	write_only = true;
	}

	if ((oflags & (O_CREAT \| O_EXCL)) == (O_CREAT \| O_EXCL))
	disposition = FILE_CREATE;
	else if ((oflags & (O_CREAT \| O_TRUNC)) == (O_CREAT \| O_TRUNC))
	disposition = FILE_OVERWRITE_IF;
	else if ((oflags & O_CREAT) == O_CREAT)
	disposition = FILE_OPEN_IF;
	else
	cFYI(1, ("Create flag not set in create function"));
	}

	/* BB add processing to set equivalent of mode - e.g. via CreateX with
	ACLs */
	if (oplockEnabled)
	oplock = REQ_OPLOCK;

	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
	if (buf == NULL) {
	kfree(full_path);
	FreeXid(xid);
	return -ENOMEM;
	}

	mode &= ~current->fs->umask;

	/*
	* if we're not using unix extensions, see if we need to set
	* ATTR_READONLY on the create call
	*/
	if (!pTcon->unix_ext && (mode & S_IWUGO) == 0)
	create_options \|= CREATE_OPTION_READONLY;

	if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
	rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
	desiredAccess, create_options,
	&fileHandle, &oplock, buf, cifs_sb->local_nls,
	cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
	else
	rc = -EIO; /* no NT SMB support fall into legacy open below */

	if (rc == -EIO) {
	/* old server, retry the open legacy style */
	rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
	desiredAccess, create_options,
	&fileHandle, &oplock, buf, cifs_sb->local_nls,
	cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
	}
	if (rc) {
	cFYI(1, ("cifs_create returned 0x%x", rc));
	} else {
	/* If Open reported that we actually created a file
	then we now have to set the mode if possible */
	if ((pTcon->unix_ext) && (oplock & CIFS_CREATE_ACTION)) {
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
	CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
	(__u64)current->fsuid,
	(__u64)current->fsgid,
	0 /* dev */,
	cifs_sb->local_nls,
	cifs_sb->mnt_cifs_flags &
	CIFS_MOUNT_MAP_SPECIAL_CHR);
	} else {
	CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
	(__u64)-1,
	(__u64)-1,
	0 /* dev */,
	cifs_sb->local_nls,
	cifs_sb->mnt_cifs_flags &
	CIFS_MOUNT_MAP_SPECIAL_CHR);
	}
	} else {
	/* BB implement mode setting via Windows security
	descriptors e.g. */
	/* CIFSSMBWinSetPerms(xid,pTcon,path,mode,-1,-1,nls);*/

	/* Could set r/o dos attribute if mode & 0222 == 0 */
	}

	/* server might mask mode so we have to query for it */
	if (pTcon->unix_ext)
	rc = cifs_get_inode_info_unix(&newinode, full_path,
	inode->i_sb, xid);
	else {
	rc = cifs_get_inode_info(&newinode, full_path,
	buf, inode->i_sb, xid,
	&fileHandle);
	if (newinode) {
	newinode->i_mode = mode;
	if ((oplock & CIFS_CREATE_ACTION) &&
	(cifs_sb->mnt_cifs_flags &
	CIFS_MOUNT_SET_UID)) {
	newinode->i_uid = current->fsuid;
	newinode->i_gid = current->fsgid;
	}
	}
	}

	if (rc != 0) {
	cFYI(1,
	("Create worked but get_inode_info failed rc = %d",
	rc));
	} else {
	if (pTcon->nocase)
	direntry->d_op = &cifs_ci_dentry_ops;
	else
	direntry->d_op = &cifs_dentry_ops;
	d_instantiate(direntry, newinode);
	}
	if ((nd == NULL /* nfsd case - nfs srv does not set nd */) \|\|
	(!(nd->flags & LOOKUP_OPEN))) {
	/* mknod case - do not leave file open */
	CIFSSMBClose(xid, pTcon, fileHandle);
	} else if (newinode) {
	pCifsFile =
	kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);

	if (pCifsFile == NULL)
	goto cifs_create_out;
	pCifsFile->netfid = fileHandle;
	pCifsFile->pid = current->tgid;
	pCifsFile->pInode = newinode;
	pCifsFile->invalidHandle = false;
	pCifsFile->closePend = false;
	init_MUTEX(&pCifsFile->fh_sem);
	mutex_init(&pCifsFile->lock_mutex);
	INIT_LIST_HEAD(&pCifsFile->llist);
	atomic_set(&pCifsFile->wrtPending, 0);

	/* set the following in open now
	pCifsFile->pfile = file; */
	write_lock(&GlobalSMBSeslock);
	list_add(&pCifsFile->tlist, &pTcon->openFileList);
	pCifsInode = CIFS_I(newinode);
	if (pCifsInode) {
	/* if readable file instance put first in list*/
	if (write_only) {
	list_add_tail(&pCifsFile->flist,
	&pCifsInode->openFileList);
	} else {
	list_add(&pCifsFile->flist,
	&pCifsInode->openFileList);
	}
	if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
	pCifsInode->clientCanCacheAll = true;
	pCifsInode->clientCanCacheRead = true;
	cFYI(1, ("Exclusive Oplock inode %p",
	newinode));
	} else if ((oplock & 0xF) == OPLOCK_READ)
	pCifsInode->clientCanCacheRead = true;
	}
	write_unlock(&GlobalSMBSeslock);
	}
	}
	cifs_create_out:
	kfree(buf);
	kfree(full_path);
	FreeXid(xid);
	return rc;
	}

	int cifs_mknod(struct inode inode, struct dentry direntry, int mode,
	dev_t device_number)
	{
	int rc = -EPERM;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	struct inode *newinode = NULL;

	if (!old_valid_dev(device_number))
	return -EINVAL;

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	full_path = build_path_from_dentry(direntry);
	if (full_path == NULL)
	rc = -ENOMEM;
	else if (pTcon->unix_ext) {
	mode &= ~current->fs->umask;
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
	rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
	mode, (__u64)current->fsuid,
	(__u64)current->fsgid,
	device_number, cifs_sb->local_nls,
	cifs_sb->mnt_cifs_flags &
	CIFS_MOUNT_MAP_SPECIAL_CHR);
	} else {
	rc = CIFSSMBUnixSetPerms(xid, pTcon,
	full_path, mode, (__u64)-1, (__u64)-1,
	device_number, cifs_sb->local_nls,
	cifs_sb->mnt_cifs_flags &
	CIFS_MOUNT_MAP_SPECIAL_CHR);
	}

	if (!rc) {
	rc = cifs_get_inode_info_unix(&newinode, full_path,
	inode->i_sb, xid);
	if (pTcon->nocase)
	direntry->d_op = &cifs_ci_dentry_ops;
	else
	direntry->d_op = &cifs_dentry_ops;
	if (rc == 0)
	d_instantiate(direntry, newinode);
	}
	} else {
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
	int oplock = 0;
	u16 fileHandle;
	FILE_ALL_INFO *buf;

	cFYI(1, ("sfu compat create special file"));

	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
	if (buf == NULL) {
	kfree(full_path);
	FreeXid(xid);
	return -ENOMEM;
	}

	rc = CIFSSMBOpen(xid, pTcon, full_path,
	FILE_CREATE, /* fail if exists */
	GENERIC_WRITE /* BB would
	WRITE_OWNER \| WRITE_DAC be better? */,
	/* Create a file and set the
	file attribute to SYSTEM */
	CREATE_NOT_DIR \| CREATE_OPTION_SPECIAL,
	&fileHandle, &oplock, buf,
	cifs_sb->local_nls,
	cifs_sb->mnt_cifs_flags &
	CIFS_MOUNT_MAP_SPECIAL_CHR);

	/* BB FIXME - add handling for backlevel servers
	which need legacy open and check for all
	calls to SMBOpen for fallback to SMBLeagcyOpen */
	if (!rc) {
	/* BB Do not bother to decode buf since no
	local inode yet to put timestamps in,
	but we can reuse it safely */
	unsigned int bytes_written;
	struct win_dev *pdev;
	pdev = (struct win_dev *)buf;
	if (S_ISCHR(mode)) {
	memcpy(pdev->type, "IntxCHR", 8);
	pdev->major =
	cpu_to_le64(MAJOR(device_number));
	pdev->minor =
	cpu_to_le64(MINOR(device_number));
	rc = CIFSSMBWrite(xid, pTcon,
	fileHandle,
	sizeof(struct win_dev),
	0, &bytes_written, (char *)pdev,
	NULL, 0);
	} else if (S_ISBLK(mode)) {
	memcpy(pdev->type, "IntxBLK", 8);
	pdev->major =
	cpu_to_le64(MAJOR(device_number));
	pdev->minor =
	cpu_to_le64(MINOR(device_number));
	rc = CIFSSMBWrite(xid, pTcon,
	fileHandle,
	sizeof(struct win_dev),
	0, &bytes_written, (char *)pdev,
	NULL, 0);
	} /* else if(S_ISFIFO */
	CIFSSMBClose(xid, pTcon, fileHandle);
	d_drop(direntry);
	}
	kfree(buf);
	/* add code here to set EAs */
	}
	}

	kfree(full_path);
	FreeXid(xid);
	return rc;
	}


	struct dentry *
	cifs_lookup(struct inode parent_dir_inode, struct dentry direntry,
	struct nameidata *nd)
	{
	int xid;
	int rc = 0; /* to get around spurious gcc warning, set to zero here */
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct inode *newInode = NULL;
	char *full_path = NULL;

	xid = GetXid();

	cFYI(1, (" parent inode = 0x%p name is: %s and dentry = 0x%p",
	parent_dir_inode, direntry->d_name.name, direntry));

	/* check whether path exists */

	cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
	pTcon = cifs_sb->tcon;

	/*
	* Don't allow the separator character in a path component.
	* The VFS will not allow "/", but "\" is allowed by posix.
	*/
	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
	int i;
	for (i = 0; i < direntry->d_name.len; i++)
	if (direntry->d_name.name[i] == '\\') {
	cFYI(1, ("Invalid file name"));
	FreeXid(xid);
	return ERR_PTR(-EINVAL);
	}
	}

	/* can not grab the rename sem here since it would
	deadlock in the cases (beginning of sys_rename itself)
	in which we already have the sb rename sem */
	full_path = build_path_from_dentry(direntry);
	if (full_path == NULL) {
	FreeXid(xid);
	return ERR_PTR(-ENOMEM);
	}

	if (direntry->d_inode != NULL) {
	cFYI(1, (" non-NULL inode in lookup"));
	} else {
	cFYI(1, (" NULL inode in lookup"));
	}
	cFYI(1,
	(" Full path: %s inode = 0x%p", full_path, direntry->d_inode));

	if (pTcon->unix_ext)
	rc = cifs_get_inode_info_unix(&newInode, full_path,
	parent_dir_inode->i_sb, xid);
	else
	rc = cifs_get_inode_info(&newInode, full_path, NULL,
	parent_dir_inode->i_sb, xid, NULL);

	if ((rc == 0) && (newInode != NULL)) {
	if (pTcon->nocase)
	direntry->d_op = &cifs_ci_dentry_ops;
	else
	direntry->d_op = &cifs_dentry_ops;
	d_add(direntry, newInode);

	/* since paths are not looked up by component - the parent
	directories are presumed to be good here */
	renew_parental_timestamps(direntry);

	} else if (rc == -ENOENT) {
	rc = 0;
	direntry->d_time = jiffies;
	if (pTcon->nocase)
	direntry->d_op = &cifs_ci_dentry_ops;
	else
	direntry->d_op = &cifs_dentry_ops;
	d_add(direntry, NULL);
	/* if it was once a directory (but how can we tell?) we could do
	shrink_dcache_parent(direntry); */
	} else if (rc != -EACCES) {
	cERROR(1, ("Unexpected lookup error %d", rc));
	/* We special case check for Access Denied - since that
	is a common return code */
	}

	kfree(full_path);
	FreeXid(xid);
	return ERR_PTR(rc);
	}

	static int
	cifs_d_revalidate(struct dentry direntry, struct nameidata nd)
	{
	int isValid = 1;

	if (direntry->d_inode) {
	if (cifs_revalidate(direntry))
	return 0;
	} else {
	cFYI(1, ("neg dentry 0x%p name = %s",
	direntry, direntry->d_name.name));
	if (time_after(jiffies, direntry->d_time + HZ) \|\|
	!lookupCacheEnabled) {
	d_drop(direntry);
	isValid = 0;
	}
	}

	return isValid;
	}

	/* static int cifs_d_delete(struct dentry *direntry)
	{
	int rc = 0;

	cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));

	return rc;
	} */

	struct dentry_operations cifs_dentry_ops = {
	.d_revalidate = cifs_d_revalidate,
	/* d_delete: cifs_d_delete, / / not needed except for debugging */
	};

	static int cifs_ci_hash(struct dentry dentry, struct qstr q)
	{
	struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
	unsigned long hash;
	int i;

	hash = init_name_hash();
	for (i = 0; i < q->len; i++)
	hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
	hash);
	q->hash = end_name_hash(hash);

	return 0;
	}

	static int cifs_ci_compare(struct dentry dentry, struct qstr a,
	struct qstr *b)
	{
	struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;

	if ((a->len == b->len) &&
	(nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
	/*
	* To preserve case, don't let an existing negative dentry's
	* case take precedence. If a is not a negative dentry, this
	* should have no side effects
	*/
	memcpy((void *)a->name, b->name, a->len);
	return 0;
	}
	return 1;
	}

	struct dentry_operations cifs_ci_dentry_ops = {
	.d_revalidate = cifs_d_revalidate,
	.d_hash = cifs_ci_hash,
	.d_compare = cifs_ci_compare,
	};