Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 999 insertions, 0 deletions

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
new file mode 100644
index 000000000..c7e162c93
--- /dev/null
+++ b/fs/cifs/dir.c
@@ -0,0 +1,999 @@
+/*
+ *   fs/cifs/dir.c
+ *
+ *   vfs operations that deal with dentries
+ *
+ *   Copyright (C) International Business Machines  Corp., 2002,2009
+ *   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 <linux/mount.h>
+#include <linux/file.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"
+
+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 {
+		cifs_set_time(direntry, jiffies);
+		direntry = direntry->d_parent;
+	} while (!IS_ROOT(direntry));
+}
+
+char *
+cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
+			struct cifs_tcon *tcon, int add_treename)
+{
+	int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0;
+	int dfsplen;
+	char *full_path = NULL;
+
+	/* if no prefix path, simply set path to the root of share to "" */
+	if (pplen == 0) {
+		full_path = kzalloc(1, GFP_KERNEL);
+		return full_path;
+	}
+
+	if (add_treename)
+		dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
+	else
+		dfsplen = 0;
+
+	full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
+	if (full_path == NULL)
+		return full_path;
+
+	if (dfsplen)
+		strncpy(full_path, tcon->treeName, dfsplen);
+	full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
+	strncpy(full_path + dfsplen + 1, vol->prepath, pplen);
+	convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
+	full_path[dfsplen + pplen] = 0; /* add trailing null */
+	return full_path;
+}
+
+/* Note: caller must free return buffer */
+char *
+build_path_from_dentry(struct dentry *direntry)
+{
+	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
+	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+	bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
+
+	return build_path_from_dentry_optional_prefix(direntry,
+						      prefix);
+}
+
+char *
+build_path_from_dentry_optional_prefix(struct dentry *direntry, bool prefix)
+{
+	struct dentry *temp;
+	int namelen;
+	int dfsplen;
+	int pplen = 0;
+	char *full_path;
+	char dirsep;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
+	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+	unsigned seq;
+
+	dirsep = CIFS_DIR_SEP(cifs_sb);
+	if (prefix)
+		dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
+	else
+		dfsplen = 0;
+
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
+		pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
+
+cifs_bp_rename_retry:
+	namelen = dfsplen + pplen;
+	seq = read_seqbegin(&rename_lock);
+	rcu_read_lock();
+	for (temp = direntry; !IS_ROOT(temp);) {
+		namelen += (1 + temp->d_name.len);
+		temp = temp->d_parent;
+		if (temp == NULL) {
+			cifs_dbg(VFS, "corrupt dentry\n");
+			rcu_read_unlock();
+			return NULL;
+		}
+	}
+	rcu_read_unlock();
+
+	full_path = kmalloc(namelen+1, GFP_KERNEL);
+	if (full_path == NULL)
+		return full_path;
+	full_path[namelen] = 0;	/* trailing null */
+	rcu_read_lock();
+	for (temp = direntry; !IS_ROOT(temp);) {
+		spin_lock(&temp->d_lock);
+		namelen -= 1 + temp->d_name.len;
+		if (namelen < 0) {
+			spin_unlock(&temp->d_lock);
+			break;
+		} else {
+			full_path[namelen] = dirsep;
+			strncpy(full_path + namelen + 1, temp->d_name.name,
+				temp->d_name.len);
+			cifs_dbg(FYI, "name: %s\n", full_path + namelen);
+		}
+		spin_unlock(&temp->d_lock);
+		temp = temp->d_parent;
+		if (temp == NULL) {
+			cifs_dbg(VFS, "corrupt dentry\n");
+			rcu_read_unlock();
+			kfree(full_path);
+			return NULL;
+		}
+	}
+	rcu_read_unlock();
+	if (namelen != dfsplen + pplen || read_seqretry(&rename_lock, seq)) {
+		cifs_dbg(FYI, "did not end path lookup where expected. namelen=%ddfsplen=%d\n",
+			 namelen, dfsplen);
+		/* 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 (pplen) {
+		int i;
+
+		cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
+		memcpy(full_path+dfsplen+1, cifs_sb->prepath, pplen-1);
+		full_path[dfsplen] = dirsep;
+		for (i = 0; i < pplen-1; i++)
+			if (full_path[dfsplen+1+i] == '/')
+				full_path[dfsplen+1+i] = CIFS_DIR_SEP(cifs_sb);
+	}
+
+	if (dfsplen) {
+		strncpy(full_path, 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] = '/';
+			}
+		}
+	}
+	return full_path;
+}
+
+/*
+ * Don't allow path components longer than the server max.
+ * Don't allow the separator character in a path component.
+ * The VFS will not allow "/", but "\" is allowed by posix.
+ */
+static int
+check_name(struct dentry *direntry, struct cifs_tcon *tcon)
+{
+	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
+	int i;
+
+	if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
+		     direntry->d_name.len >
+		     le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
+		return -ENAMETOOLONG;
+
+	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
+		for (i = 0; i < direntry->d_name.len; i++) {
+			if (direntry->d_name.name[i] == '\\') {
+				cifs_dbg(FYI, "Invalid file name\n");
+				return -EINVAL;
+			}
+		}
+	}
+	return 0;
+}
+
+
+/* Inode operations in similar order to how they appear in Linux file fs.h */
+
+static int
+cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
+	       struct tcon_link *tlink, unsigned oflags, umode_t mode,
+	       __u32 *oplock, struct cifs_fid *fid)
+{
+	int rc = -ENOENT;
+	int create_options = CREATE_NOT_DIR;
+	int desired_access;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+	struct cifs_tcon *tcon = tlink_tcon(tlink);
+	char *full_path = NULL;
+	FILE_ALL_INFO *buf = NULL;
+	struct inode *newinode = NULL;
+	int disposition;
+	struct TCP_Server_Info *server = tcon->ses->server;
+	struct cifs_open_parms oparms;
+
+	*oplock = 0;
+	if (tcon->ses->server->oplocks)
+		*oplock = REQ_OPLOCK;
+
+	full_path = build_path_from_dentry(direntry);
+	if (full_path == NULL) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
+	    (CIFS_UNIX_POSIX_PATH_OPS_CAP &
+			le64_to_cpu(tcon->fsUnixInfo.Capability))) {
+		rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
+				     oflags, oplock, &fid->netfid, xid);
+		switch (rc) {
+		case 0:
+			if (newinode == NULL) {
+				/* query inode info */
+				goto cifs_create_get_file_info;
+			}
+
+			if (S_ISDIR(newinode->i_mode)) {
+				CIFSSMBClose(xid, tcon, fid->netfid);
+				iput(newinode);
+				rc = -EISDIR;
+				goto out;
+			}
+
+			if (!S_ISREG(newinode->i_mode)) {
+				/*
+				 * The server may allow us to open things like
+				 * FIFOs, but the client isn't set up to deal
+				 * with that. If it's not a regular file, just
+				 * close it and proceed as if it were a normal
+				 * lookup.
+				 */
+				CIFSSMBClose(xid, tcon, fid->netfid);
+				goto cifs_create_get_file_info;
+			}
+			/* success, no need to query */
+			goto cifs_create_set_dentry;
+
+		case -ENOENT:
+			goto cifs_create_get_file_info;
+
+		case -EIO:
+		case -EINVAL:
+			/*
+			 * EIO could indicate that (posix open) operation is not
+			 * supported, despite what server claimed in capability
+			 * negotiation.
+			 *
+			 * POSIX open in samba versions 3.3.1 and earlier could
+			 * incorrectly fail with invalid parameter.
+			 */
+			tcon->broken_posix_open = true;
+			break;
+
+		case -EREMOTE:
+		case -EOPNOTSUPP:
+			/*
+			 * EREMOTE indicates DFS junction, which is not handled
+			 * in posix open.  If either that or op not supported
+			 * returned, follow the normal lookup.
+			 */
+			break;
+
+		default:
+			goto out;
+		}
+		/*
+		 * fallthrough to retry, using older open call, this is case
+		 * where server does not support this SMB level, and falsely
+		 * claims capability (also get here for DFS case which should be
+		 * rare for path not covered on files)
+		 */
+	}
+
+	desired_access = 0;
+	if (OPEN_FMODE(oflags) & FMODE_READ)
+		desired_access |= GENERIC_READ; /* is this too little? */
+	if (OPEN_FMODE(oflags) & FMODE_WRITE)
+		desired_access |= GENERIC_WRITE;
+
+	disposition = FILE_OVERWRITE_IF;
+	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
+		cifs_dbg(FYI, "Create flag not set in create function\n");
+
+	/*
+	 * BB add processing to set equivalent of mode - e.g. via CreateX with
+	 * ACLs
+	 */
+
+	if (!server->ops->open) {
+		rc = -ENOSYS;
+		goto out;
+	}
+
+	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
+	if (buf == NULL) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * if we're not using unix extensions, see if we need to set
+	 * ATTR_READONLY on the create call
+	 */
+	if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
+		create_options |= CREATE_OPTION_READONLY;
+
+	if (backup_cred(cifs_sb))
+		create_options |= CREATE_OPEN_BACKUP_INTENT;
+
+	oparms.tcon = tcon;
+	oparms.cifs_sb = cifs_sb;
+	oparms.desired_access = desired_access;
+	oparms.create_options = create_options;
+	oparms.disposition = disposition;
+	oparms.path = full_path;
+	oparms.fid = fid;
+	oparms.reconnect = false;
+	oparms.mode = mode;
+	rc = server->ops->open(xid, &oparms, oplock, buf);
+	if (rc) {
+		cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
+		goto out;
+	}
+
+	/*
+	 * If Open reported that we actually created a file then we now have to
+	 * set the mode if possible.
+	 */
+	if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
+		struct cifs_unix_set_info_args args = {
+				.mode	= mode,
+				.ctime	= NO_CHANGE_64,
+				.atime	= NO_CHANGE_64,
+				.mtime	= NO_CHANGE_64,
+				.device	= 0,
+		};
+
+		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
+			args.uid = current_fsuid();
+			if (inode->i_mode & S_ISGID)
+				args.gid = inode->i_gid;
+			else
+				args.gid = current_fsgid();
+		} else {
+			args.uid = INVALID_UID; /* no change */
+			args.gid = INVALID_GID; /* no change */
+		}
+		CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
+				       current->tgid);
+	} else {
+		/*
+		 * BB implement mode setting via Windows security
+		 * descriptors e.g.
+		 */
+		/* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
+
+		/* Could set r/o dos attribute if mode & 0222 == 0 */
+	}
+
+cifs_create_get_file_info:
+	/* server might mask mode so we have to query for it */
+	if (tcon->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, fid);
+		if (newinode) {
+			if (server->ops->set_lease_key)
+				server->ops->set_lease_key(newinode, fid);
+			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
+				newinode->i_mode = mode;
+			if ((*oplock & CIFS_CREATE_ACTION) &&
+			    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) {
+				newinode->i_uid = current_fsuid();
+				if (inode->i_mode & S_ISGID)
+					newinode->i_gid = inode->i_gid;
+				else
+					newinode->i_gid = current_fsgid();
+			}
+		}
+	}
+
+cifs_create_set_dentry:
+	if (rc != 0) {
+		cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
+			 rc);
+		goto out_err;
+	}
+
+	if (S_ISDIR(newinode->i_mode)) {
+		rc = -EISDIR;
+		goto out_err;
+	}
+
+	d_drop(direntry);
+	d_add(direntry, newinode);
+
+out:
+	kfree(buf);
+	kfree(full_path);
+	return rc;
+
+out_err:
+	if (server->ops->close)
+		server->ops->close(xid, tcon, fid);
+	if (newinode)
+		iput(newinode);
+	goto out;
+}
+
+int
+cifs_atomic_open(struct inode *inode, struct dentry *direntry,
+		 struct file *file, unsigned oflags, umode_t mode)
+{
+	int rc;
+	unsigned int xid;
+	struct tcon_link *tlink;
+	struct cifs_tcon *tcon;
+	struct TCP_Server_Info *server;
+	struct cifs_fid fid;
+	struct cifs_pending_open open;
+	__u32 oplock;
+	struct cifsFileInfo *file_info;
+
+	/*
+	 * Posix open is only called (at lookup time) for file create now. For
+	 * opens (rather than creates), because we do not know if it is a file
+	 * or directory yet, and current Samba no longer allows us to do posix
+	 * open on dirs, we could end up wasting an open call on what turns out
+	 * to be a dir. For file opens, we wait to call posix open till
+	 * cifs_open.  It could be added to atomic_open in the future but the
+	 * performance tradeoff of the extra network request when EISDIR or
+	 * EACCES is returned would have to be weighed against the 50% reduction
+	 * in network traffic in the other paths.
+	 */
+	if (!(oflags & O_CREAT)) {
+		struct dentry *res;
+
+		/*
+		 * Check for hashed negative dentry. We have already revalidated
+		 * the dentry and it is fine. No need to perform another lookup.
+		 */
+		if (!d_in_lookup(direntry))
+			return -ENOENT;
+
+		res = cifs_lookup(inode, direntry, 0);
+		if (IS_ERR(res))
+			return PTR_ERR(res);
+
+		return finish_no_open(file, res);
+	}
+
+	xid = get_xid();
+
+	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
+		 inode, direntry, direntry);
+
+	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
+	if (IS_ERR(tlink)) {
+		rc = PTR_ERR(tlink);
+		goto out_free_xid;
+	}
+
+	tcon = tlink_tcon(tlink);
+
+	rc = check_name(direntry, tcon);
+	if (rc)
+		goto out;
+
+	server = tcon->ses->server;
+
+	if (server->ops->new_lease_key)
+		server->ops->new_lease_key(&fid);
+
+	cifs_add_pending_open(&fid, tlink, &open);
+
+	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
+			    &oplock, &fid);
+
+	if (rc) {
+		cifs_del_pending_open(&open);
+		goto out;
+	}
+
+	if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
+		file->f_mode |= FMODE_CREATED;
+
+	rc = finish_open(file, direntry, generic_file_open);
+	if (rc) {
+		if (server->ops->close)
+			server->ops->close(xid, tcon, &fid);
+		cifs_del_pending_open(&open);
+		goto out;
+	}
+
+	if (file->f_flags & O_DIRECT &&
+	    CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
+		if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
+			file->f_op = &cifs_file_direct_nobrl_ops;
+		else
+			file->f_op = &cifs_file_direct_ops;
+		}
+
+	file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
+	if (file_info == NULL) {
+		if (server->ops->close)
+			server->ops->close(xid, tcon, &fid);
+		cifs_del_pending_open(&open);
+		rc = -ENOMEM;
+	}
+
+out:
+	cifs_put_tlink(tlink);
+out_free_xid:
+	free_xid(xid);
+	return rc;
+}
+
+int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
+		bool excl)
+{
+	int rc;
+	unsigned int xid = get_xid();
+	/*
+	 * BB below access is probably too much for mknod to request
+	 *    but we have to do query and setpathinfo so requesting
+	 *    less could fail (unless we want to request getatr and setatr
+	 *    permissions (only).  At least for POSIX we do not have to
+	 *    request so much.
+	 */
+	unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
+	struct tcon_link *tlink;
+	struct cifs_tcon *tcon;
+	struct TCP_Server_Info *server;
+	struct cifs_fid fid;
+	__u32 oplock;
+
+	cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
+		 inode, direntry, direntry);
+
+	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
+	rc = PTR_ERR(tlink);
+	if (IS_ERR(tlink))
+		goto out_free_xid;
+
+	tcon = tlink_tcon(tlink);
+	server = tcon->ses->server;
+
+	if (server->ops->new_lease_key)
+		server->ops->new_lease_key(&fid);
+
+	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
+			    &oplock, &fid);
+	if (!rc && server->ops->close)
+		server->ops->close(xid, tcon, &fid);
+
+	cifs_put_tlink(tlink);
+out_free_xid:
+	free_xid(xid);
+	return rc;
+}
+
+int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
+		dev_t device_number)
+{
+	int rc = -EPERM;
+	unsigned int xid;
+	int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
+	struct cifs_sb_info *cifs_sb;
+	struct tcon_link *tlink;
+	struct cifs_tcon *tcon;
+	struct cifs_io_parms io_parms;
+	char *full_path = NULL;
+	struct inode *newinode = NULL;
+	__u32 oplock = 0;
+	struct cifs_fid fid;
+	struct cifs_open_parms oparms;
+	FILE_ALL_INFO *buf = NULL;
+	unsigned int bytes_written;
+	struct win_dev *pdev;
+	struct kvec iov[2];
+
+	if (!old_valid_dev(device_number))
+		return -EINVAL;
+
+	cifs_sb = CIFS_SB(inode->i_sb);
+	tlink = cifs_sb_tlink(cifs_sb);
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+
+	tcon = tlink_tcon(tlink);
+
+	xid = get_xid();
+
+	full_path = build_path_from_dentry(direntry);
+	if (full_path == NULL) {
+		rc = -ENOMEM;
+		goto mknod_out;
+	}
+
+	if (tcon->unix_ext) {
+		struct cifs_unix_set_info_args args = {
+			.mode	= mode & ~current_umask(),
+			.ctime	= NO_CHANGE_64,
+			.atime	= NO_CHANGE_64,
+			.mtime	= NO_CHANGE_64,
+			.device	= device_number,
+		};
+		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
+			args.uid = current_fsuid();
+			args.gid = current_fsgid();
+		} else {
+			args.uid = INVALID_UID; /* no change */
+			args.gid = INVALID_GID; /* no change */
+		}
+		rc = CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
+					    cifs_sb->local_nls,
+					    cifs_remap(cifs_sb));
+		if (rc)
+			goto mknod_out;
+
+		rc = cifs_get_inode_info_unix(&newinode, full_path,
+						inode->i_sb, xid);
+
+		if (rc == 0)
+			d_instantiate(direntry, newinode);
+		goto mknod_out;
+	}
+
+	if (!S_ISCHR(mode) && !S_ISBLK(mode))
+		goto mknod_out;
+
+	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
+		goto mknod_out;
+
+
+	cifs_dbg(FYI, "sfu compat create special file\n");
+
+	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
+	if (buf == NULL) {
+		rc = -ENOMEM;
+		goto mknod_out;
+	}
+
+	if (backup_cred(cifs_sb))
+		create_options |= CREATE_OPEN_BACKUP_INTENT;
+
+	oparms.tcon = tcon;
+	oparms.cifs_sb = cifs_sb;
+	oparms.desired_access = GENERIC_WRITE;
+	oparms.create_options = create_options;
+	oparms.disposition = FILE_CREATE;
+	oparms.path = full_path;
+	oparms.fid = &fid;
+	oparms.reconnect = false;
+
+	if (tcon->ses->server->oplocks)
+		oplock = REQ_OPLOCK;
+	else
+		oplock = 0;
+	rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, buf);
+	if (rc)
+		goto mknod_out;
+
+	/*
+	 * BB Do not bother to decode buf since no local inode yet to put
+	 * timestamps in, but we can reuse it safely.
+	 */
+
+	pdev = (struct win_dev *)buf;
+	io_parms.pid = current->tgid;
+	io_parms.tcon = tcon;
+	io_parms.offset = 0;
+	io_parms.length = sizeof(struct win_dev);
+	iov[1].iov_base = buf;
+	iov[1].iov_len = sizeof(struct win_dev);
+	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 = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
+							&bytes_written, iov, 1);
+	} 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 = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
+							&bytes_written, iov, 1);
+	}
+	tcon->ses->server->ops->close(xid, tcon, &fid);
+	d_drop(direntry);
+
+	/* FIXME: add code here to set EAs */
+
+mknod_out:
+	kfree(full_path);
+	kfree(buf);
+	free_xid(xid);
+	cifs_put_tlink(tlink);
+	return rc;
+}
+
+struct dentry *
+cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
+	    unsigned int flags)
+{
+	unsigned int xid;
+	int rc = 0; /* to get around spurious gcc warning, set to zero here */
+	struct cifs_sb_info *cifs_sb;
+	struct tcon_link *tlink;
+	struct cifs_tcon *pTcon;
+	struct inode *newInode = NULL;
+	char *full_path = NULL;
+
+	xid = get_xid();
+
+	cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
+		 parent_dir_inode, direntry, direntry);
+
+	/* check whether path exists */
+
+	cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
+	tlink = cifs_sb_tlink(cifs_sb);
+	if (IS_ERR(tlink)) {
+		free_xid(xid);
+		return ERR_CAST(tlink);
+	}
+	pTcon = tlink_tcon(tlink);
+
+	rc = check_name(direntry, pTcon);
+	if (unlikely(rc)) {
+		cifs_put_tlink(tlink);
+		free_xid(xid);
+		return ERR_PTR(rc);
+	}
+
+	/* 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) {
+		cifs_put_tlink(tlink);
+		free_xid(xid);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	if (d_really_is_positive(direntry)) {
+		cifs_dbg(FYI, "non-NULL inode in lookup\n");
+	} else {
+		cifs_dbg(FYI, "NULL inode in lookup\n");
+	}
+	cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
+		 full_path, d_inode(direntry));
+
+	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) {
+		/* 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) {
+		cifs_set_time(direntry, jiffies);
+		newInode = NULL;
+	} else {
+		if (rc != -EACCES) {
+			cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
+			/* We special case check for Access Denied - since that
+			is a common return code */
+		}
+		newInode = ERR_PTR(rc);
+	}
+	kfree(full_path);
+	cifs_put_tlink(tlink);
+	free_xid(xid);
+	return d_splice_alias(newInode, direntry);
+}
+
+static int
+cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
+{
+	struct inode *inode;
+	int rc;
+
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	if (d_really_is_positive(direntry)) {
+		inode = d_inode(direntry);
+		if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
+			CIFS_I(inode)->time = 0; /* force reval */
+
+		rc = cifs_revalidate_dentry(direntry);
+		if (rc) {
+			cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
+			switch (rc) {
+			case -ENOENT:
+			case -ESTALE:
+				/*
+				 * Those errors mean the dentry is invalid
+				 * (file was deleted or recreated)
+				 */
+				return 0;
+			default:
+				/*
+				 * Otherwise some unexpected error happened
+				 * report it as-is to VFS layer
+				 */
+				return rc;
+			}
+		}
+		else {
+			/*
+			 * If the inode wasn't known to be a dfs entry when
+			 * the dentry was instantiated, such as when created
+			 * via ->readdir(), it needs to be set now since the
+			 * attributes will have been updated by
+			 * cifs_revalidate_dentry().
+			 */
+			if (IS_AUTOMOUNT(inode) &&
+			   !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
+				spin_lock(&direntry->d_lock);
+				direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
+				spin_unlock(&direntry->d_lock);
+			}
+
+			return 1;
+		}
+	}
+
+	/*
+	 * This may be nfsd (or something), anyway, we can't see the
+	 * intent of this. So, since this can be for creation, drop it.
+	 */
+	if (!flags)
+		return 0;
+
+	/*
+	 * Drop the negative dentry, in order to make sure to use the
+	 * case sensitive name which is specified by user if this is
+	 * for creation.
+	 */
+	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
+		return 0;
+
+	if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
+		return 0;
+
+	return 1;
+}
+
+/* static int cifs_d_delete(struct dentry *direntry)
+{
+	int rc = 0;
+
+	cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
+
+	return rc;
+}     */
+
+const struct dentry_operations cifs_dentry_ops = {
+	.d_revalidate = cifs_d_revalidate,
+	.d_automount = cifs_dfs_d_automount,
+/* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
+};
+
+static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
+{
+	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
+	unsigned long hash;
+	wchar_t c;
+	int i, charlen;
+
+	hash = init_name_hash(dentry);
+	for (i = 0; i < q->len; i += charlen) {
+		charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
+		/* error out if we can't convert the character */
+		if (unlikely(charlen < 0))
+			return charlen;
+		hash = partial_name_hash(cifs_toupper(c), hash);
+	}
+	q->hash = end_name_hash(hash);
+
+	return 0;
+}
+
+static int cifs_ci_compare(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
+	wchar_t c1, c2;
+	int i, l1, l2;
+
+	/*
+	 * We make the assumption here that uppercase characters in the local
+	 * codepage are always the same length as their lowercase counterparts.
+	 *
+	 * If that's ever not the case, then this will fail to match it.
+	 */
+	if (name->len != len)
+		return 1;
+
+	for (i = 0; i < len; i += l1) {
+		/* Convert characters in both strings to UTF-16. */
+		l1 = codepage->char2uni(&str[i], len - i, &c1);
+		l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
+
+		/*
+		 * If we can't convert either character, just declare it to
+		 * be 1 byte long and compare the original byte.
+		 */
+		if (unlikely(l1 < 0 && l2 < 0)) {
+			if (str[i] != name->name[i])
+				return 1;
+			l1 = 1;
+			continue;
+		}
+
+		/*
+		 * Here, we again ass|u|me that upper/lowercase versions of
+		 * a character are the same length in the local NLS.
+		 */
+		if (l1 != l2)
+			return 1;
+
+		/* Now compare uppercase versions of these characters */
+		if (cifs_toupper(c1) != cifs_toupper(c2))
+			return 1;
+	}
+
+	return 0;
+}
+
+const struct dentry_operations cifs_ci_dentry_ops = {
+	.d_revalidate = cifs_d_revalidate,
+	.d_hash = cifs_ci_hash,
+	.d_compare = cifs_ci_compare,
+	.d_automount = cifs_dfs_d_automount,
+};