cifs: fix noserverino handling when unix extensions are enabled
[safe/jmp/linux-2.6] / fs / cifs / dir.c
index 2f02c52..391816b 100644 (file)
@@ -3,7 +3,7 @@
  *
  *   vfs operations that deal with dentries
  *
- *   Copyright (C) International Business Machines  Corp., 2002,2008
+ *   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
@@ -24,6 +24,7 @@
 #include <linux/stat.h>
 #include <linux/slab.h>
 #include <linux/namei.h>
+#include <linux/mount.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
 #include "cifsglob.h"
@@ -72,7 +73,7 @@ cifs_bp_rename_retry:
                namelen += (1 + temp->d_name.len);
                temp = temp->d_parent;
                if (temp == NULL) {
-                       cERROR(1, ("corrupt dentry"));
+                       cERROR(1, "corrupt dentry");
                        return NULL;
                }
        }
@@ -89,19 +90,18 @@ cifs_bp_rename_retry:
                        full_path[namelen] = dirsep;
                        strncpy(full_path + namelen + 1, temp->d_name.name,
                                temp->d_name.len);
-                       cFYI(0, ("name: %s", full_path + namelen));
+                       cFYI(0, "name: %s", full_path + namelen);
                }
                temp = temp->d_parent;
                if (temp == NULL) {
-                       cERROR(1, ("corrupt dentry"));
+                       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));
+               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) */
@@ -129,6 +129,164 @@ cifs_bp_rename_retry:
        return full_path;
 }
 
+/*
+ * When called with struct file pointer set to NULL, there is no way we could
+ * update file->private_data, but getting it stuck on openFileList provides a
+ * way to access it from cifs_fill_filedata and thereby set file->private_data
+ * from cifs_open.
+ */
+struct cifsFileInfo *
+cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle,
+                 struct file *file, struct vfsmount *mnt, unsigned int oflags)
+{
+       int oplock = 0;
+       struct cifsFileInfo *pCifsFile;
+       struct cifsInodeInfo *pCifsInode;
+       struct cifs_sb_info *cifs_sb = CIFS_SB(mnt->mnt_sb);
+
+       pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
+       if (pCifsFile == NULL)
+               return pCifsFile;
+
+       if (oplockEnabled)
+               oplock = REQ_OPLOCK;
+
+       pCifsFile->netfid = fileHandle;
+       pCifsFile->pid = current->tgid;
+       pCifsFile->pInode = igrab(newinode);
+       pCifsFile->mnt = mnt;
+       pCifsFile->pfile = file;
+       pCifsFile->invalidHandle = false;
+       pCifsFile->closePend = false;
+       mutex_init(&pCifsFile->fh_mutex);
+       mutex_init(&pCifsFile->lock_mutex);
+       INIT_LIST_HEAD(&pCifsFile->llist);
+       atomic_set(&pCifsFile->count, 1);
+       slow_work_init(&pCifsFile->oplock_break, &cifs_oplock_break_ops);
+
+       write_lock(&GlobalSMBSeslock);
+       list_add(&pCifsFile->tlist, &cifs_sb->tcon->openFileList);
+       pCifsInode = CIFS_I(newinode);
+       if (pCifsInode) {
+               /* if readable file instance put first in list*/
+               if (oflags & FMODE_READ)
+                       list_add(&pCifsFile->flist, &pCifsInode->openFileList);
+               else
+                       list_add_tail(&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);
+
+       return pCifsFile;
+}
+
+int cifs_posix_open(char *full_path, struct inode **pinode,
+                       struct vfsmount *mnt, struct super_block *sb,
+                       int mode, int oflags,
+                       __u32 *poplock, __u16 *pnetfid, int xid)
+{
+       int rc;
+       FILE_UNIX_BASIC_INFO *presp_data;
+       __u32 posix_flags = 0;
+       struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+       struct cifs_fattr fattr;
+
+       cFYI(1, "posix open %s", full_path);
+
+       presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
+       if (presp_data == NULL)
+               return -ENOMEM;
+
+/* So far cifs posix extensions can only map the following flags.
+   There are other valid fmode oflags such as FMODE_LSEEK, FMODE_PREAD, but
+   so far we do not seem to need them, and we can treat them as local only */
+       if ((oflags & (FMODE_READ | FMODE_WRITE)) ==
+               (FMODE_READ | FMODE_WRITE))
+               posix_flags = SMB_O_RDWR;
+       else if (oflags & FMODE_READ)
+               posix_flags = SMB_O_RDONLY;
+       else if (oflags & FMODE_WRITE)
+               posix_flags = SMB_O_WRONLY;
+       if (oflags & O_CREAT)
+               posix_flags |= SMB_O_CREAT;
+       if (oflags & O_EXCL)
+               posix_flags |= SMB_O_EXCL;
+       if (oflags & O_TRUNC)
+               posix_flags |= SMB_O_TRUNC;
+       /* be safe and imply O_SYNC for O_DSYNC */
+       if (oflags & O_DSYNC)
+               posix_flags |= SMB_O_SYNC;
+       if (oflags & O_DIRECTORY)
+               posix_flags |= SMB_O_DIRECTORY;
+       if (oflags & O_NOFOLLOW)
+               posix_flags |= SMB_O_NOFOLLOW;
+       if (oflags & O_DIRECT)
+               posix_flags |= SMB_O_DIRECT;
+
+       mode &= ~current_umask();
+       rc = CIFSPOSIXCreate(xid, cifs_sb->tcon, posix_flags, mode,
+                       pnetfid, presp_data, poplock, full_path,
+                       cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
+                                       CIFS_MOUNT_MAP_SPECIAL_CHR);
+       if (rc)
+               goto posix_open_ret;
+
+       if (presp_data->Type == cpu_to_le32(-1))
+               goto posix_open_ret; /* open ok, caller does qpathinfo */
+
+       if (!pinode)
+               goto posix_open_ret; /* caller does not need info */
+
+       cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
+
+       /* get new inode and set it up */
+       if (*pinode == NULL) {
+               cifs_fill_uniqueid(sb, &fattr);
+               *pinode = cifs_iget(sb, &fattr);
+               if (!*pinode) {
+                       rc = -ENOMEM;
+                       goto posix_open_ret;
+               }
+       } else {
+               cifs_fattr_to_inode(*pinode, &fattr);
+       }
+
+       /*
+        * cifs_fill_filedata() takes care of setting cifsFileInfo pointer to
+        * file->private_data.
+        */
+       if (mnt) {
+               struct cifsFileInfo *pfile_info;
+
+               pfile_info = cifs_new_fileinfo(*pinode, *pnetfid, NULL, mnt,
+                                              oflags);
+               if (pfile_info == NULL)
+                       rc = -ENOMEM;
+       }
+
+posix_open_ret:
+       kfree(presp_data);
+       return rc;
+}
+
+static void setup_cifs_dentry(struct cifsTconInfo *tcon,
+                             struct dentry *direntry,
+                             struct inode *newinode)
+{
+       if (tcon->nocase)
+               direntry->d_op = &cifs_ci_dentry_ops;
+       else
+               direntry->d_op = &cifs_dentry_ops;
+       d_instantiate(direntry, newinode);
+}
+
 /* Inode operations in similar order to how they appear in Linux file fs.h */
 
 int
@@ -138,41 +296,79 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
        int rc = -ENOENT;
        int xid;
        int create_options = CREATE_NOT_DIR;
-       int oplock = 0;
+       __u32 oplock = 0;
+       int oflags;
+       bool posix_create = false;
+       /*
+        * 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.
+        */
        int desiredAccess = GENERIC_READ | GENERIC_WRITE;
        __u16 fileHandle;
        struct cifs_sb_info *cifs_sb;
-       struct cifsTconInfo *pTcon;
+       struct cifsTconInfo *tcon;
        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;
+       tcon = cifs_sb->tcon;
 
        full_path = build_path_from_dentry(direntry);
        if (full_path == NULL) {
+               rc = -ENOMEM;
                FreeXid(xid);
-               return -ENOMEM;
+               return rc;
        }
 
-       if (nd && (nd->flags & LOOKUP_OPEN)) {
-               int oflags = nd->intent.open.flags;
+       if (oplockEnabled)
+               oplock = REQ_OPLOCK;
+
+       if (nd && (nd->flags & LOOKUP_OPEN))
+               oflags = nd->intent.open.flags;
+       else
+               oflags = FMODE_READ | SMB_O_CREAT;
+
+       if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
+           (CIFS_UNIX_POSIX_PATH_OPS_CAP &
+                       le64_to_cpu(tcon->fsUnixInfo.Capability))) {
+               rc = cifs_posix_open(full_path, &newinode,
+                       nd ? nd->path.mnt : NULL,
+                       inode->i_sb, mode, oflags, &oplock, &fileHandle, xid);
+               /* EIO could indicate that (posix open) operation is not
+                  supported, despite what server claimed in capability
+                  negotation.  EREMOTE indicates DFS junction, which is not
+                  handled in posix open */
+
+               if (rc == 0) {
+                       posix_create = true;
+                       if (newinode == NULL) /* query inode info */
+                               goto cifs_create_get_file_info;
+                       else /* success, no need to query */
+                               goto cifs_create_set_dentry;
+               } else if ((rc != -EIO) && (rc != -EREMOTE) &&
+                        (rc != -EOPNOTSUPP) && (rc != -EINVAL))
+                       goto cifs_create_out;
+               /* else 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) */
+       }
 
+       if (nd && (nd->flags & LOOKUP_OPEN)) {
+               /* if the file is going to stay open, then we
+                  need to set the desired access properly */
                desiredAccess = 0;
                if (oflags & FMODE_READ)
-                       desiredAccess |= GENERIC_READ;
-               if (oflags & FMODE_WRITE) {
+                       desiredAccess |= GENERIC_READ; /* is this too little? */
+               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;
@@ -181,13 +377,11 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
                else if ((oflags & O_CREAT) == O_CREAT)
                        disposition = FILE_OPEN_IF;
                else
-                       cFYI(1, ("Create flag not set in create function"));
+                       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) {
@@ -196,17 +390,15 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
                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)
+       if (!tcon->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,
+               rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
                         desiredAccess, create_options,
                         &fileHandle, &oplock, buf, cifs_sb->local_nls,
                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
@@ -215,129 +407,92 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 
        if (rc == -EIO) {
                /* old server, retry the open legacy style */
-               rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
+               rc = SMBLegacyOpen(xid, tcon, 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)) {
-                       struct cifs_unix_set_info_args args = {
+               cFYI(1, "cifs_create returned 0x%x", rc);
+               goto cifs_create_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 = (__u64) current_fsuid();
-                               if (inode->i_mode & S_ISGID)
-                                       args.gid = (__u64) inode->i_gid;
-                               else
-                                       args.gid = (__u64) current_fsgid();
-                       } else {
-                               args.uid = NO_CHANGE_64;
-                               args.gid = NO_CHANGE_64;
-                       }
-                       CIFSSMBUnixSetInfo(xid, pTcon, full_path, &args,
-                               cifs_sb->local_nls,
-                               cifs_sb->mnt_cifs_flags &
-                                       CIFS_MOUNT_MAP_SPECIAL_CHR);
+               if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
+                       args.uid = (__u64) current_fsuid();
+                       if (inode->i_mode & S_ISGID)
+                               args.gid = (__u64) inode->i_gid;
+                       else
+                               args.gid = (__u64) current_fsgid();
                } 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 */
+                       args.uid = NO_CHANGE_64;
+                       args.gid = NO_CHANGE_64;
                }
+               CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
+                                       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,tcon,path,mode,-1,-1,nls);*/
 
-               /* 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) {
-                               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();
-                               }
-                       }
-               }
+               /* Could set r/o dos attribute if mode & 0222 == 0 */
+       }
 
-               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;
+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, &fileHandle);
+               if (newinode) {
+                       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();
                        }
-                       write_unlock(&GlobalSMBSeslock);
                }
        }
+
+cifs_create_set_dentry:
+       if (rc == 0)
+               setup_cifs_dentry(tcon, direntry, newinode);
+       else
+               cFYI(1, "Create worked, get_inode_info failed rc = %d", rc);
+
+       /* nfsd case - nfs srv does not set nd */
+       if ((nd == NULL) || (!(nd->flags & LOOKUP_OPEN))) {
+               /* mknod case - do not leave file open */
+               CIFSSMBClose(xid, tcon, fileHandle);
+       } else if (!(posix_create) && (newinode)) {
+               struct cifsFileInfo *pfile_info;
+               /*
+                * cifs_fill_filedata() takes care of setting cifsFileInfo
+                * pointer to file->private_data.
+                */
+               pfile_info = cifs_new_fileinfo(newinode, fileHandle, NULL,
+                                              nd->path.mnt, oflags);
+               if (pfile_info == NULL)
+                       rc = -ENOMEM;
+       }
 cifs_create_out:
        kfree(buf);
        kfree(full_path);
@@ -368,7 +523,7 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
                rc = -ENOMEM;
        else if (pTcon->unix_ext) {
                struct cifs_unix_set_info_args args = {
-                       .mode   = mode & ~current->fs->umask,
+                       .mode   = mode & ~current_umask(),
                        .ctime  = NO_CHANGE_64,
                        .atime  = NO_CHANGE_64,
                        .mtime  = NO_CHANGE_64,
@@ -381,10 +536,10 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
                        args.uid = NO_CHANGE_64;
                        args.gid = NO_CHANGE_64;
                }
-               rc = CIFSSMBUnixSetInfo(xid, pTcon, full_path,
-                       &args, cifs_sb->local_nls,
-                       cifs_sb->mnt_cifs_flags &
-                               CIFS_MOUNT_MAP_SPECIAL_CHR);
+               rc = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, &args,
+                                           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,
@@ -402,13 +557,14 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
                        u16 fileHandle;
                        FILE_ALL_INFO *buf;
 
-                       cFYI(1, ("sfu compat create special file"));
+                       cFYI(1, "sfu compat create special file");
 
                        buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
                        if (buf == NULL) {
                                kfree(full_path);
+                               rc = -ENOMEM;
                                FreeXid(xid);
-                               return -ENOMEM;
+                               return rc;
                        }
 
                        rc = CIFSSMBOpen(xid, pTcon, full_path,
@@ -469,22 +625,25 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
        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 */
+       __u32 oplock = 0;
+       __u16 fileHandle = 0;
+       bool posix_open = false;
        struct cifs_sb_info *cifs_sb;
        struct cifsTconInfo *pTcon;
        struct inode *newInode = NULL;
        char *full_path = NULL;
+       struct file *filp;
 
        xid = GetXid();
 
-       cFYI(1, (" parent inode = 0x%p name is: %s and dentry = 0x%p",
-             parent_dir_inode, direntry->d_name.name, direntry));
+       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 */
 
@@ -499,12 +658,21 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
                int i;
                for (i = 0; i < direntry->d_name.len; i++)
                        if (direntry->d_name.name[i] == '\\') {
-                               cFYI(1, ("Invalid file name"));
+                               cFYI(1, "Invalid file name");
                                FreeXid(xid);
                                return ERR_PTR(-EINVAL);
                        }
        }
 
+       /*
+        * O_EXCL: optimize away the lookup, but don't hash the dentry. Let
+        * the VFS handle the create.
+        */
+       if (nd && (nd->flags & LOOKUP_EXCL)) {
+               d_instantiate(direntry, NULL);
+               return NULL;
+       }
+
        /* 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 */
@@ -515,19 +683,49 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
        }
 
        if (direntry->d_inode != NULL) {
-               cFYI(1, (" non-NULL inode in lookup"));
+               cFYI(1, "non-NULL inode in lookup");
        } else {
-               cFYI(1, (" NULL inode in lookup"));
+               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
+       cFYI(1, "Full path: %s inode = 0x%p", full_path, direntry->d_inode);
+
+       /* 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 here (lookup) 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 (pTcon->unix_ext) {
+               if (nd && !(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY)) &&
+                    (nd->flags & LOOKUP_OPEN) && !pTcon->broken_posix_open &&
+                    (nd->intent.open.flags & O_CREAT)) {
+                       rc = cifs_posix_open(full_path, &newInode, nd->path.mnt,
+                                       parent_dir_inode->i_sb,
+                                       nd->intent.open.create_mode,
+                                       nd->intent.open.flags, &oplock,
+                                       &fileHandle, xid);
+                       /*
+                        * The check below works around a bug in POSIX
+                        * open in samba versions 3.3.1 and earlier where
+                        * open could incorrectly fail with invalid parameter.
+                        * If either that or op not supported returned, follow
+                        * the normal lookup.
+                        */
+                       if ((rc == 0) || (rc == -ENOENT))
+                               posix_open = true;
+                       else if ((rc == -EINVAL) || (rc != -EOPNOTSUPP))
+                               pTcon->broken_posix_open = true;
+               }
+               if (!posix_open)
+                       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);
+                               parent_dir_inode->i_sb, xid, NULL);
 
        if ((rc == 0) && (newInode != NULL)) {
                if (pTcon->nocase)
@@ -535,7 +733,8 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
                else
                        direntry->d_op = &cifs_dentry_ops;
                d_add(direntry, newInode);
-
+               if (posix_open)
+                       filp = lookup_instantiate_filp(nd, direntry, NULL);
                /* since paths are not looked up by component - the parent
                   directories are presumed to be good here */
                renew_parental_timestamps(direntry);
@@ -551,7 +750,7 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
        /*      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));
+               cERROR(1, "Unexpected lookup error %d", rc);
                /* We special case check for Access Denied - since that
                is a common return code */
        }
@@ -567,11 +766,11 @@ cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
        int isValid = 1;
 
        if (direntry->d_inode) {
-               if (cifs_revalidate(direntry))
+               if (cifs_revalidate_dentry(direntry))
                        return 0;
        } else {
-               cFYI(1, ("neg dentry 0x%p name = %s",
-                        direntry, direntry->d_name.name));
+               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);
@@ -586,12 +785,12 @@ cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 {
        int rc = 0;
 
-       cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
+       cFYI(1, "In cifs d_delete, name = %s", direntry->d_name.name);
 
        return rc;
 }     */
 
-struct dentry_operations cifs_dentry_ops = {
+const struct dentry_operations cifs_dentry_ops = {
        .d_revalidate = cifs_d_revalidate,
 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
 };
@@ -629,7 +828,7 @@ static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
        return 1;
 }
 
-struct dentry_operations cifs_ci_dentry_ops = {
+const struct dentry_operations cifs_ci_dentry_ops = {
        .d_revalidate = cifs_d_revalidate,
        .d_hash = cifs_ci_hash,
        .d_compare = cifs_ci_compare,