[linux.git] / fs / cifs / inode.c

/*
 *   fs/cifs/inode.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2008
 *   Author(s): Steve French ([email protected])
 *
 *   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/pagemap.h>
#include <asm/div64.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"


static void cifs_set_ops(struct inode *inode, const bool is_dfs_referral)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);

	switch (inode->i_mode & S_IFMT) {
	case S_IFREG:
		inode->i_op = &cifs_file_inode_ops;
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
				inode->i_fop = &cifs_file_direct_nobrl_ops;
			else
				inode->i_fop = &cifs_file_direct_ops;
		} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
			inode->i_fop = &cifs_file_nobrl_ops;
		else { /* not direct, send byte range locks */
			inode->i_fop = &cifs_file_ops;
		}


		/* check if server can support readpages */
		if (cifs_sb->tcon->ses->server->maxBuf <
				PAGE_CACHE_SIZE + MAX_CIFS_HDR_SIZE)
			inode->i_data.a_ops = &cifs_addr_ops_smallbuf;
		else
			inode->i_data.a_ops = &cifs_addr_ops;
		break;
	case S_IFDIR:
#ifdef CONFIG_CIFS_DFS_UPCALL
		if (is_dfs_referral) {
			inode->i_op = &cifs_dfs_referral_inode_operations;
		} else {
#else /* NO DFS support, treat as a directory */
		{
#endif
			inode->i_op = &cifs_dir_inode_ops;
			inode->i_fop = &cifs_dir_ops;
		}
		break;
	case S_IFLNK:
		inode->i_op = &cifs_symlink_inode_ops;
		break;
	default:
		init_special_inode(inode, inode->i_mode, inode->i_rdev);
		break;
	}
}

/* check inode attributes against fattr. If they don't match, tag the
 * inode for cache invalidation
 */
static void
cifs_revalidate_cache(struct inode *inode, struct cifs_fattr *fattr)
{
	struct cifsInodeInfo *cifs_i = CIFS_I(inode);

	cFYI(1, ("%s: revalidating inode %llu", __func__, cifs_i->uniqueid));

	if (inode->i_state & I_NEW) {
		cFYI(1, ("%s: inode %llu is new", __func__, cifs_i->uniqueid));
		return;
	}

	/* don't bother with revalidation if we have an oplock */
	if (cifs_i->clientCanCacheRead) {
		cFYI(1, ("%s: inode %llu is oplocked", __func__,
			 cifs_i->uniqueid));
		return;
	}

	 /* revalidate if mtime or size have changed */
	if (timespec_equal(&inode->i_mtime, &fattr->cf_mtime) &&
	    cifs_i->server_eof == fattr->cf_eof) {
		cFYI(1, ("%s: inode %llu is unchanged", __func__,
			 cifs_i->uniqueid));
		return;
	}

	cFYI(1, ("%s: invalidating inode %llu mapping", __func__,
		 cifs_i->uniqueid));
	cifs_i->invalid_mapping = true;
}

/* populate an inode with info from a cifs_fattr struct */
void
cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr)
{
	struct cifsInodeInfo *cifs_i = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	unsigned long oldtime = cifs_i->time;

	cifs_revalidate_cache(inode, fattr);

	inode->i_atime = fattr->cf_atime;
	inode->i_mtime = fattr->cf_mtime;
	inode->i_ctime = fattr->cf_ctime;
	inode->i_rdev = fattr->cf_rdev;
	inode->i_nlink = fattr->cf_nlink;
	inode->i_uid = fattr->cf_uid;
	inode->i_gid = fattr->cf_gid;

	/* if dynperm is set, don't clobber existing mode */
	if (inode->i_state & I_NEW ||
	    !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM))
		inode->i_mode = fattr->cf_mode;

	cifs_i->cifsAttrs = fattr->cf_cifsattrs;
	cifs_i->uniqueid = fattr->cf_uniqueid;

	if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
		cifs_i->time = 0;
	else
		cifs_i->time = jiffies;

	cFYI(1, ("inode 0x%p old_time=%ld new_time=%ld", inode,
		 oldtime, cifs_i->time));

	cifs_i->delete_pending = fattr->cf_flags & CIFS_FATTR_DELETE_PENDING;

	cifs_i->server_eof = fattr->cf_eof;
	/*
	 * Can't safely change the file size here if the client is writing to
	 * it due to potential races.
	 */
	spin_lock(&inode->i_lock);
	if (is_size_safe_to_change(cifs_i, fattr->cf_eof)) {
		i_size_write(inode, fattr->cf_eof);

		/*
		 * i_blocks is not related to (i_size / i_blksize),
		 * but instead 512 byte (2**9) size is required for
		 * calculating num blocks.
		 */
		inode->i_blocks = (512 - 1 + fattr->cf_bytes) >> 9;
	}
	spin_unlock(&inode->i_lock);

	cifs_set_ops(inode, fattr->cf_flags & CIFS_FATTR_DFS_REFERRAL);
}

/* Fill a cifs_fattr struct with info from FILE_UNIX_BASIC_INFO. */
void
cifs_unix_basic_to_fattr(struct cifs_fattr *fattr, FILE_UNIX_BASIC_INFO *info,
			 struct cifs_sb_info *cifs_sb)
{
	memset(fattr, 0, sizeof(*fattr));
	fattr->cf_uniqueid = le64_to_cpu(info->UniqueId);
	fattr->cf_bytes = le64_to_cpu(info->NumOfBytes);
	fattr->cf_eof = le64_to_cpu(info->EndOfFile);

	fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
	fattr->cf_mtime = cifs_NTtimeToUnix(info->LastModificationTime);
	fattr->cf_ctime = cifs_NTtimeToUnix(info->LastStatusChange);
	fattr->cf_mode = le64_to_cpu(info->Permissions);

	/*
	 * Since we set the inode type below we need to mask off
	 * to avoid strange results if bits set above.
	 */
	fattr->cf_mode &= ~S_IFMT;
	switch (le32_to_cpu(info->Type)) {
	case UNIX_FILE:
		fattr->cf_mode |= S_IFREG;
		fattr->cf_dtype = DT_REG;
		break;
	case UNIX_SYMLINK:
		fattr->cf_mode |= S_IFLNK;
		fattr->cf_dtype = DT_LNK;
		break;
	case UNIX_DIR:
		fattr->cf_mode |= S_IFDIR;
		fattr->cf_dtype = DT_DIR;
		break;
	case UNIX_CHARDEV:
		fattr->cf_mode |= S_IFCHR;
		fattr->cf_dtype = DT_CHR;
		fattr->cf_rdev = MKDEV(le64_to_cpu(info->DevMajor),
				       le64_to_cpu(info->DevMinor) & MINORMASK);
		break;
	case UNIX_BLOCKDEV:
		fattr->cf_mode |= S_IFBLK;
		fattr->cf_dtype = DT_BLK;
		fattr->cf_rdev = MKDEV(le64_to_cpu(info->DevMajor),
				       le64_to_cpu(info->DevMinor) & MINORMASK);
		break;
	case UNIX_FIFO:
		fattr->cf_mode |= S_IFIFO;
		fattr->cf_dtype = DT_FIFO;
		break;
	case UNIX_SOCKET:
		fattr->cf_mode |= S_IFSOCK;
		fattr->cf_dtype = DT_SOCK;
		break;
	default:
		/* safest to call it a file if we do not know */
		fattr->cf_mode |= S_IFREG;
		fattr->cf_dtype = DT_REG;
		cFYI(1, ("unknown type %d", le32_to_cpu(info->Type)));
		break;
	}

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
		fattr->cf_uid = cifs_sb->mnt_uid;
	else
		fattr->cf_uid = le64_to_cpu(info->Uid);

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
		fattr->cf_gid = cifs_sb->mnt_gid;
	else
		fattr->cf_gid = le64_to_cpu(info->Gid);

	fattr->cf_nlink = le64_to_cpu(info->Nlinks);
}

/*
 * Fill a cifs_fattr struct with fake inode info.
 *
 * Needed to setup cifs_fattr data for the directory which is the
 * junction to the new submount (ie to setup the fake directory
 * which represents a DFS referral).
 */
static void
cifs_create_dfs_fattr(struct cifs_fattr *fattr, struct super_block *sb)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);

	cFYI(1, ("creating fake fattr for DFS referral"));

	memset(fattr, 0, sizeof(*fattr));
	fattr->cf_mode = S_IFDIR | S_IXUGO | S_IRWXU;
	fattr->cf_uid = cifs_sb->mnt_uid;
	fattr->cf_gid = cifs_sb->mnt_gid;
	fattr->cf_atime = CURRENT_TIME;
	fattr->cf_ctime = CURRENT_TIME;
	fattr->cf_mtime = CURRENT_TIME;
	fattr->cf_nlink = 2;
	fattr->cf_flags |= CIFS_FATTR_DFS_REFERRAL;
}

int cifs_get_inode_info_unix(struct inode **pinode,
			     const unsigned char *full_path,
			     struct super_block *sb, int xid)
{
	int rc;
	FILE_UNIX_BASIC_INFO find_data;
	struct cifs_fattr fattr;
	struct cifsTconInfo *tcon;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);

	tcon = cifs_sb->tcon;
	cFYI(1, ("Getting info on %s", full_path));

	/* could have done a find first instead but this returns more info */
	rc = CIFSSMBUnixQPathInfo(xid, tcon, full_path, &find_data,
				  cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);

	if (!rc) {
		cifs_unix_basic_to_fattr(&fattr, &find_data, cifs_sb);
	} else if (rc == -EREMOTE) {
		cifs_create_dfs_fattr(&fattr, sb);
		rc = 0;
	} else {
		return rc;
	}

	if (*pinode == NULL) {
		/* get new inode */
		*pinode = cifs_iget(sb, &fattr);
		if (!*pinode)
			rc = -ENOMEM;
	} else {
		/* we already have inode, update it */
		cifs_fattr_to_inode(*pinode, &fattr);
	}

	return rc;
}

static int
cifs_sfu_type(struct cifs_fattr *fattr, const unsigned char *path,
	      struct cifs_sb_info *cifs_sb, int xid)
{
	int rc;
	int oplock = 0;
	__u16 netfid;
	struct cifsTconInfo *pTcon = cifs_sb->tcon;
	char buf[24];
	unsigned int bytes_read;
	char *pbuf;

	pbuf = buf;

	fattr->cf_mode &= ~S_IFMT;

	if (fattr->cf_eof == 0) {
		fattr->cf_mode |= S_IFIFO;
		fattr->cf_dtype = DT_FIFO;
		return 0;
	} else if (fattr->cf_eof < 8) {
		fattr->cf_mode |= S_IFREG;
		fattr->cf_dtype = DT_REG;
		return -EINVAL;	 /* EOPNOTSUPP? */
	}

	rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ,
			 CREATE_NOT_DIR, &netfid, &oplock, NULL,
			 cifs_sb->local_nls,
			 cifs_sb->mnt_cifs_flags &
				CIFS_MOUNT_MAP_SPECIAL_CHR);
	if (rc == 0) {
		int buf_type = CIFS_NO_BUFFER;
			/* Read header */
		rc = CIFSSMBRead(xid, pTcon, netfid,
				 24 /* length */, 0 /* offset */,
				 &bytes_read, &pbuf, &buf_type);
		if ((rc == 0) && (bytes_read >= 8)) {
			if (memcmp("IntxBLK", pbuf, 8) == 0) {
				cFYI(1, ("Block device"));
				fattr->cf_mode |= S_IFBLK;
				fattr->cf_dtype = DT_BLK;
				if (bytes_read == 24) {
					/* we have enough to decode dev num */
					__u64 mjr; /* major */
					__u64 mnr; /* minor */
					mjr = le64_to_cpu(*(__le64 *)(pbuf+8));
					mnr = le64_to_cpu(*(__le64 *)(pbuf+16));
					fattr->cf_rdev = MKDEV(mjr, mnr);
				}
			} else if (memcmp("IntxCHR", pbuf, 8) == 0) {
				cFYI(1, ("Char device"));
				fattr->cf_mode |= S_IFCHR;
				fattr->cf_dtype = DT_CHR;
				if (bytes_read == 24) {
					/* we have enough to decode dev num */
					__u64 mjr; /* major */
					__u64 mnr; /* minor */
					mjr = le64_to_cpu(*(__le64 *)(pbuf+8));
					mnr = le64_to_cpu(*(__le64 *)(pbuf+16));
					fattr->cf_rdev = MKDEV(mjr, mnr);
				}
			} else if (memcmp("IntxLNK", pbuf, 7) == 0) {
				cFYI(1, ("Symlink"));
				fattr->cf_mode |= S_IFLNK;
				fattr->cf_dtype = DT_LNK;
			} else {
				fattr->cf_mode |= S_IFREG; /* file? */
				fattr->cf_dtype = DT_REG;
				rc = -EOPNOTSUPP;
			}
		} else {
			fattr->cf_mode |= S_IFREG; /* then it is a file */
			fattr->cf_dtype = DT_REG;
			rc = -EOPNOTSUPP; /* or some unknown SFU type */
		}
		CIFSSMBClose(xid, pTcon, netfid);
	}
	return rc;
}

#define SFBITS_MASK (S_ISVTX | S_ISGID | S_ISUID)  /* SETFILEBITS valid bits */

/*
 * Fetch mode bits as provided by SFU.
 *
 * FIXME: Doesn't this clobber the type bit we got from cifs_sfu_type ?
 */
static int cifs_sfu_mode(struct cifs_fattr *fattr, const unsigned char *path,
			 struct cifs_sb_info *cifs_sb, int xid)
{
#ifdef CONFIG_CIFS_XATTR
	ssize_t rc;
	char ea_value[4];
	__u32 mode;

	rc = CIFSSMBQAllEAs(xid, cifs_sb->tcon, path, "SETFILEBITS",
			    ea_value, 4 /* size of buf */, cifs_sb->local_nls,
			    cifs_sb->mnt_cifs_flags &
				CIFS_MOUNT_MAP_SPECIAL_CHR);
	if (rc < 0)
		return (int)rc;
	else if (rc > 3) {
		mode = le32_to_cpu(*((__le32 *)ea_value));
		fattr->cf_mode &= ~SFBITS_MASK;
		cFYI(1, ("special bits 0%o org mode 0%o", mode,
			 fattr->cf_mode));
		fattr->cf_mode = (mode & SFBITS_MASK) | fattr->cf_mode;
		cFYI(1, ("special mode bits 0%o", mode));
	}

	return 0;
#else
	return -EOPNOTSUPP;
#endif
}

/* Fill a cifs_fattr struct with info from FILE_ALL_INFO */
static void
cifs_all_info_to_fattr(struct cifs_fattr *fattr, FILE_ALL_INFO *info,
		       struct cifs_sb_info *cifs_sb, bool adjust_tz)
{
	memset(fattr, 0, sizeof(*fattr));
	fattr->cf_cifsattrs = le32_to_cpu(info->Attributes);
	if (info->DeletePending)
		fattr->cf_flags |= CIFS_FATTR_DELETE_PENDING;

	if (info->LastAccessTime)
		fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
	else
		fattr->cf_atime = CURRENT_TIME;

	fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
	fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);

	if (adjust_tz) {
		fattr->cf_ctime.tv_sec += cifs_sb->tcon->ses->server->timeAdj;
		fattr->cf_mtime.tv_sec += cifs_sb->tcon->ses->server->timeAdj;
	}

	fattr->cf_eof = le64_to_cpu(info->EndOfFile);
	fattr->cf_bytes = le64_to_cpu(info->AllocationSize);

	if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
		fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
		fattr->cf_dtype = DT_DIR;
	} else {
		fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
		fattr->cf_dtype = DT_REG;

		/* clear write bits if ATTR_READONLY is set */
		if (fattr->cf_cifsattrs & ATTR_READONLY)
			fattr->cf_mode &= ~(S_IWUGO);
	}

	fattr->cf_nlink = le32_to_cpu(info->NumberOfLinks);

	fattr->cf_uid = cifs_sb->mnt_uid;
	fattr->cf_gid = cifs_sb->mnt_gid;
}

int cifs_get_inode_info(struct inode **pinode,
	const unsigned char *full_path, FILE_ALL_INFO *pfindData,
	struct super_block *sb, int xid, const __u16 *pfid)
{
	int rc = 0, tmprc;
	struct cifsTconInfo *pTcon;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	char *buf = NULL;
	bool adjustTZ = false;
	struct cifs_fattr fattr;

	pTcon = cifs_sb->tcon;
	cFYI(1, ("Getting info on %s", full_path));

	if ((pfindData == NULL) && (*pinode != NULL)) {
		if (CIFS_I(*pinode)->clientCanCacheRead) {
			cFYI(1, ("No need to revalidate cached inode sizes"));
			return rc;
		}
	}

	/* if file info not passed in then get it from server */
	if (pfindData == NULL) {
		buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
		if (buf == NULL)
			return -ENOMEM;
		pfindData = (FILE_ALL_INFO *)buf;

		/* could do find first instead but this returns more info */
		rc = CIFSSMBQPathInfo(xid, pTcon, full_path, pfindData,
			      0 /* not legacy */,
			      cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
				CIFS_MOUNT_MAP_SPECIAL_CHR);
		/* BB optimize code so we do not make the above call
		when server claims no NT SMB support and the above call
		failed at least once - set flag in tcon or mount */
		if ((rc == -EOPNOTSUPP) || (rc == -EINVAL)) {
			rc = SMBQueryInformation(xid, pTcon, full_path,
					pfindData, cifs_sb->local_nls,
					cifs_sb->mnt_cifs_flags &
					  CIFS_MOUNT_MAP_SPECIAL_CHR);
			adjustTZ = true;
		}
	}

	if (!rc) {
		cifs_all_info_to_fattr(&fattr, (FILE_ALL_INFO *) pfindData,
				       cifs_sb, adjustTZ);
	} else if (rc == -EREMOTE) {
		cifs_create_dfs_fattr(&fattr, sb);
		rc = 0;
	} else {
		goto cgii_exit;
	}

	/*
	 * If an inode wasn't passed in, then get the inode number
	 *
	 * Is an i_ino of zero legal? Can we use that to check if the server
	 * supports returning inode numbers?  Are there other sanity checks we
	 * can use to ensure that the server is really filling in that field?
	 *
	 * We can not use the IndexNumber field by default from Windows or
	 * Samba (in ALL_INFO buf) but we can request it explicitly. The SNIA
	 * CIFS spec claims that this value is unique within the scope of a
	 * share, and the windows docs hint that it's actually unique
	 * per-machine.
	 *
	 * There may be higher info levels that work but are there Windows
	 * server or network appliances for which IndexNumber field is not
	 * guaranteed unique?
	 */
	if (*pinode == NULL) {
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
			int rc1 = 0;

			rc1 = CIFSGetSrvInodeNumber(xid, pTcon,
					full_path, &fattr.cf_uniqueid,
					cifs_sb->local_nls,
					cifs_sb->mnt_cifs_flags &
						CIFS_MOUNT_MAP_SPECIAL_CHR);
			if (rc1 || !fattr.cf_uniqueid) {
				cFYI(1, ("GetSrvInodeNum rc %d", rc1));
				fattr.cf_uniqueid = iunique(sb, ROOT_I);
				cifs_autodisable_serverino(cifs_sb);
			}
		} else {
			fattr.cf_uniqueid = iunique(sb, ROOT_I);
		}
	} else {
		fattr.cf_uniqueid = CIFS_I(*pinode)->uniqueid;
	}

	/* query for SFU type info if supported and needed */
	if (fattr.cf_cifsattrs & ATTR_SYSTEM &&
	    cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
		tmprc = cifs_sfu_type(&fattr, full_path, cifs_sb, xid);
		if (tmprc)
			cFYI(1, ("cifs_sfu_type failed: %d", tmprc));
	}

#ifdef CONFIG_CIFS_EXPERIMENTAL
	/* fill in 0777 bits from ACL */
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
		cFYI(1, ("Getting mode bits from ACL"));
		cifs_acl_to_fattr(cifs_sb, &fattr, *pinode, full_path, pfid);
	}
#endif

	/* fill in remaining high mode bits e.g. SUID, VTX */
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL)
		cifs_sfu_mode(&fattr, full_path, cifs_sb, xid);

	if (!*pinode) {
		*pinode = cifs_iget(sb, &fattr);
		if (!*pinode)
			rc = -ENOMEM;
	} else {
		cifs_fattr_to_inode(*pinode, &fattr);
	}

cgii_exit:
	kfree(buf);
	return rc;
}

static const struct inode_operations cifs_ipc_inode_ops = {
	.lookup = cifs_lookup,
};

char *cifs_build_path_to_root(struct cifs_sb_info *cifs_sb)
{
	int pplen = cifs_sb->prepathlen;
	int dfsplen;
	char *full_path = NULL;

	/* if no prefix path, simply set path to the root of share to "" */
	if (pplen == 0) {
		full_path = kmalloc(1, GFP_KERNEL);
		if (full_path)
			full_path[0] = 0;
		return full_path;
	}

	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;

	full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
	if (full_path == NULL)
		return full_path;

	if (dfsplen) {
		strncpy(full_path, cifs_sb->tcon->treeName, dfsplen);
		/* switch slash direction in prepath depending on whether
		 * windows or posix style path names
		 */
		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->prepath, pplen);
	full_path[dfsplen + pplen] = 0; /* add trailing null */
	return full_path;
}

static int
cifs_find_inode(struct inode *inode, void *opaque)
{
	struct cifs_fattr *fattr = (struct cifs_fattr *) opaque;

	if (CIFS_I(inode)->uniqueid != fattr->cf_uniqueid)
		return 0;

	return 1;
}

static int
cifs_init_inode(struct inode *inode, void *opaque)
{
	struct cifs_fattr *fattr = (struct cifs_fattr *) opaque;

	CIFS_I(inode)->uniqueid = fattr->cf_uniqueid;
	return 0;
}

/* Given fattrs, get a corresponding inode */
struct inode *
cifs_iget(struct super_block *sb, struct cifs_fattr *fattr)
{
	unsigned long hash;
	struct inode *inode;

	cFYI(1, ("looking for uniqueid=%llu", fattr->cf_uniqueid));

	/* hash down to 32-bits on 32-bit arch */
	hash = cifs_uniqueid_to_ino_t(fattr->cf_uniqueid);

	inode = iget5_locked(sb, hash, cifs_find_inode, cifs_init_inode, fattr);

	/* we have fattrs in hand, update the inode */
	if (inode) {
		cifs_fattr_to_inode(inode, fattr);
		if (sb->s_flags & MS_NOATIME)
			inode->i_flags |= S_NOATIME | S_NOCMTIME;
		if (inode->i_state & I_NEW) {
			inode->i_ino = hash;
			unlock_new_inode(inode);
		}
	}

	return inode;
}

/* gets root inode */
struct inode *cifs_root_iget(struct super_block *sb, unsigned long ino)
{
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct inode *inode = NULL;
	long rc;
	char *full_path;

	cifs_sb = CIFS_SB(sb);
	full_path = cifs_build_path_to_root(cifs_sb);
	if (full_path == NULL)
		return ERR_PTR(-ENOMEM);

	xid = GetXid();
	if (cifs_sb->tcon->unix_ext)
		rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid);
	else
		rc = cifs_get_inode_info(&inode, full_path, NULL, sb,
						xid, NULL);

	if (!inode)
		return ERR_PTR(-ENOMEM);

	if (rc && cifs_sb->tcon->ipc) {
		cFYI(1, ("ipc connection - fake read inode"));
		inode->i_mode |= S_IFDIR;
		inode->i_nlink = 2;
		inode->i_op = &cifs_ipc_inode_ops;
		inode->i_fop = &simple_dir_operations;
		inode->i_uid = cifs_sb->mnt_uid;
		inode->i_gid = cifs_sb->mnt_gid;
	} else if (rc) {
		kfree(full_path);
		_FreeXid(xid);
		iget_failed(inode);
		return ERR_PTR(rc);
	}


	kfree(full_path);
	/* can not call macro FreeXid here since in a void func
	 * TODO: This is no longer true
	 */
	_FreeXid(xid);
	return inode;
}

static int
cifs_set_file_info(struct inode *inode, struct iattr *attrs, int xid,
		    char *full_path, __u32 dosattr)
{
	int rc;
	int oplock = 0;
	__u16 netfid;
	__u32 netpid;
	bool set_time = false;
	struct cifsFileInfo *open_file;
	struct cifsInodeInfo *cifsInode = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsTconInfo *pTcon = cifs_sb->tcon;
	FILE_BASIC_INFO	info_buf;

	if (attrs == NULL)
		return -EINVAL;

	if (attrs->ia_valid & ATTR_ATIME) {
		set_time = true;
		info_buf.LastAccessTime =
			cpu_to_le64(cifs_UnixTimeToNT(attrs->ia_atime));
	} else
		info_buf.LastAccessTime = 0;

	if (attrs->ia_valid & ATTR_MTIME) {
		set_time = true;
		info_buf.LastWriteTime =
		    cpu_to_le64(cifs_UnixTimeToNT(attrs->ia_mtime));
	} else
		info_buf.LastWriteTime = 0;

	/*
	 * Samba throws this field away, but windows may actually use it.
	 * Do not set ctime unless other time stamps are changed explicitly
	 * (i.e. by utimes()) since we would then have a mix of client and
	 * server times.
	 */
	if (set_time && (attrs->ia_valid & ATTR_CTIME)) {
		cFYI(1, ("CIFS - CTIME changed"));
		info_buf.ChangeTime =
		    cpu_to_le64(cifs_UnixTimeToNT(attrs->ia_ctime));
	} else
		info_buf.ChangeTime = 0;

	info_buf.CreationTime = 0;	/* don't change */
	info_buf.Attributes = cpu_to_le32(dosattr);

	/*
	 * If the file is already open for write, just use that fileid
	 */
	open_file = find_writable_file(cifsInode);
	if (open_file) {
		netfid = open_file->netfid;
		netpid = open_file->pid;
		goto set_via_filehandle;
	}

	/*
	 * NT4 apparently returns success on this call, but it doesn't
	 * really work.
	 */
	if (!(pTcon->ses->flags & CIFS_SES_NT4)) {
		rc = CIFSSMBSetPathInfo(xid, pTcon, full_path,
				     &info_buf, cifs_sb->local_nls,
				     cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
		if (rc == 0) {
			cifsInode->cifsAttrs = dosattr;
			goto out;
		} else if (rc != -EOPNOTSUPP && rc != -EINVAL)
			goto out;
	}

	cFYI(1, ("calling SetFileInfo since SetPathInfo for "
		 "times not supported by this server"));
	rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN,
			 SYNCHRONIZE | FILE_WRITE_ATTRIBUTES,
			 CREATE_NOT_DIR, &netfid, &oplock,
			 NULL, cifs_sb->local_nls,
			 cifs_sb->mnt_cifs_flags &
				CIFS_MOUNT_MAP_SPECIAL_CHR);

	if (rc != 0) {
		if (rc == -EIO)
			rc = -EINVAL;
		goto out;
	}

	netpid = current->tgid;

set_via_filehandle:
	rc = CIFSSMBSetFileInfo(xid, pTcon, &info_buf, netfid, netpid);
	if (!rc)
		cifsInode->cifsAttrs = dosattr;

	if (open_file == NULL)
		CIFSSMBClose(xid, pTcon, netfid);
	else
		cifsFileInfo_put(open_file);
out:
	return rc;
}

/*
 * open the given file (if it isn't already), set the DELETE_ON_CLOSE bit
 * and rename it to a random name that hopefully won't conflict with
 * anything else.
 */
static int
cifs_rename_pending_delete(char *full_path, struct dentry *dentry, int xid)
{
	int oplock = 0;
	int rc;
	__u16 netfid;
	struct inode *inode = dentry->d_inode;
	struct cifsInodeInfo *cifsInode = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsTconInfo *tcon = cifs_sb->tcon;
	__u32 dosattr, origattr;
	FILE_BASIC_INFO *info_buf = NULL;

	rc = CIFSSMBOpen(xid, tcon, full_path, FILE_OPEN,
			 DELETE|FILE_WRITE_ATTRIBUTES, CREATE_NOT_DIR,
			 &netfid, &oplock, NULL, cifs_sb->local_nls,
			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
	if (rc != 0)
		goto out;

	origattr = cifsInode->cifsAttrs;
	if (origattr == 0)
		origattr |= ATTR_NORMAL;

	dosattr = origattr & ~ATTR_READONLY;
	if (dosattr == 0)
		dosattr |= ATTR_NORMAL;
	dosattr |= ATTR_HIDDEN;

	/* set ATTR_HIDDEN and clear ATTR_READONLY, but only if needed */
	if (dosattr != origattr) {
		info_buf = kzalloc(sizeof(*info_buf), GFP_KERNEL);
		if (info_buf == NULL) {
			rc = -ENOMEM;
			goto out_close;
		}
		info_buf->Attributes = cpu_to_le32(dosattr);
		rc = CIFSSMBSetFileInfo(xid, tcon, info_buf, netfid,
					current->tgid);
		/* although we would like to mark the file hidden
 		   if that fails we will still try to rename it */
		if (rc != 0)
			cifsInode->cifsAttrs = dosattr;
		else
			dosattr = origattr; /* since not able to change them */
	}

	/* rename the file */
	rc = CIFSSMBRenameOpenFile(xid, tcon, netfid, NULL, cifs_sb->local_nls,
				   cifs_sb->mnt_cifs_flags &
					    CIFS_MOUNT_MAP_SPECIAL_CHR);
	if (rc != 0) {
		rc = -ETXTBSY;
		goto undo_setattr;
	}

	/* try to set DELETE_ON_CLOSE */
	if (!cifsInode->delete_pending) {
		rc = CIFSSMBSetFileDisposition(xid, tcon, true, netfid,
					       current->tgid);
		/*
		 * some samba versions return -ENOENT when we try to set the
		 * file disposition here. Likely a samba bug, but work around
		 * it for now. This means that some cifsXXX files may hang
		 * around after they shouldn't.
		 *
		 * BB: remove this hack after more servers have the fix
		 */
		if (rc == -ENOENT)
			rc = 0;
		else if (rc != 0) {
			rc = -ETXTBSY;
			goto undo_rename;
		}
		cifsInode->delete_pending = true;
	}

out_close:
	CIFSSMBClose(xid, tcon, netfid);
out:
	kfree(info_buf);
	return rc;

	/*
	 * reset everything back to the original state. Don't bother
	 * dealing with errors here since we can't do anything about
	 * them anyway.
	 */
undo_rename:
	CIFSSMBRenameOpenFile(xid, tcon, netfid, dentry->d_name.name,
				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
					    CIFS_MOUNT_MAP_SPECIAL_CHR);
undo_setattr:
	if (dosattr != origattr) {
		info_buf->Attributes = cpu_to_le32(origattr);
		if (!CIFSSMBSetFileInfo(xid, tcon, info_buf, netfid,
					current->tgid))
			cifsInode->cifsAttrs = origattr;
	}

	goto out_close;
}


/*
 * If dentry->d_inode is null (usually meaning the cached dentry
 * is a negative dentry) then we would attempt a standard SMB delete, but
 * if that fails we can not attempt the fall back mechanisms on EACCESS
 * but will return the EACCESS to the caller. Note that the VFS does not call
 * unlink on negative dentries currently.
 */
int cifs_unlink(struct inode *dir, struct dentry *dentry)
{
	int rc = 0;
	int xid;
	char *full_path = NULL;
	struct inode *inode = dentry->d_inode;
	struct cifsInodeInfo *cifs_inode;
	struct super_block *sb = dir->i_sb;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifsTconInfo *tcon = cifs_sb->tcon;
	struct iattr *attrs = NULL;
	__u32 dosattr = 0, origattr = 0;

	cFYI(1, ("cifs_unlink, dir=0x%p, dentry=0x%p", dir, dentry));

	xid = GetXid();

	/* Unlink can be called from rename so we can not take the
	 * sb->s_vfs_rename_mutex here */
	full_path = build_path_from_dentry(dentry);
	if (full_path == NULL) {
		rc = -ENOMEM;
		FreeXid(xid);
		return rc;
	}

	if ((tcon->ses->capabilities & CAP_UNIX) &&
		(CIFS_UNIX_POSIX_PATH_OPS_CAP &
			le64_to_cpu(tcon->fsUnixInfo.Capability))) {
		rc = CIFSPOSIXDelFile(xid, tcon, full_path,
			SMB_POSIX_UNLINK_FILE_TARGET, cifs_sb->local_nls,
			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
		cFYI(1, ("posix del rc %d", rc));
		if ((rc == 0) || (rc == -ENOENT))
			goto psx_del_no_retry;
	}

retry_std_delete:
	rc = CIFSSMBDelFile(xid, tcon, full_path, cifs_sb->local_nls,
			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

psx_del_no_retry:
	if (!rc) {
		if (inode)
			drop_nlink(inode);
	} else if (rc == -ENOENT) {
		d_drop(dentry);
	} else if (rc == -ETXTBSY) {
		rc = cifs_rename_pending_delete(full_path, dentry, xid);
		if (rc == 0)
			drop_nlink(inode);
	} else if ((rc == -EACCES) && (dosattr == 0) && inode) {
		attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
		if (attrs == NULL) {
			rc = -ENOMEM;
			goto out_reval;
		}

		/* try to reset dos attributes */
		cifs_inode = CIFS_I(inode);
		origattr = cifs_inode->cifsAttrs;
		if (origattr == 0)
			origattr |= ATTR_NORMAL;
		dosattr = origattr & ~ATTR_READONLY;
		if (dosattr == 0)
			dosattr |= ATTR_NORMAL;
		dosattr |= ATTR_HIDDEN;

		rc = cifs_set_file_info(inode, attrs, xid, full_path, dosattr);
		if (rc != 0)
			goto out_reval;

		goto retry_std_delete;
	}

	/* undo the setattr if we errored out and it's needed */
	if (rc != 0 && dosattr != 0)
		cifs_set_file_info(inode, attrs, xid, full_path, origattr);

out_reval:
	if (inode) {
		cifs_inode = CIFS_I(inode);
		cifs_inode->time = 0;	/* will force revalidate to get info
					   when needed */
		inode->i_ctime = current_fs_time(sb);
	}
	dir->i_ctime = dir->i_mtime = current_fs_time(sb);
	cifs_inode = CIFS_I(dir);
	CIFS_I(dir)->time = 0;	/* force revalidate of dir as well */

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

int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
{
	int rc = 0, tmprc;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	struct inode *newinode = NULL;
	struct cifs_fattr fattr;

	cFYI(1, ("In cifs_mkdir, mode = 0x%x inode = 0x%p", mode, inode));

	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;
		FreeXid(xid);
		return rc;
	}

	if ((pTcon->ses->capabilities & CAP_UNIX) &&
		(CIFS_UNIX_POSIX_PATH_OPS_CAP &
			le64_to_cpu(pTcon->fsUnixInfo.Capability))) {
		u32 oplock = 0;
		FILE_UNIX_BASIC_INFO *pInfo =
			kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
		if (pInfo == NULL) {
			rc = -ENOMEM;
			goto mkdir_out;
		}

		mode &= ~current_umask();
		rc = CIFSPOSIXCreate(xid, pTcon, SMB_O_DIRECTORY | SMB_O_CREAT,
				mode, NULL /* netfid */, pInfo, &oplock,
				full_path, cifs_sb->local_nls,
				cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
		if (rc == -EOPNOTSUPP) {
			kfree(pInfo);
			goto mkdir_retry_old;
		} else if (rc) {
			cFYI(1, ("posix mkdir returned 0x%x", rc));
			d_drop(direntry);
		} else {
			if (pInfo->Type == cpu_to_le32(-1)) {
				/* no return info, go query for it */
				kfree(pInfo);
				goto mkdir_get_info;
			}
/*BB check (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID ) to see if need
	to set uid/gid */
			inc_nlink(inode);
			if (pTcon->nocase)
				direntry->d_op = &cifs_ci_dentry_ops;
			else
				direntry->d_op = &cifs_dentry_ops;

			cifs_unix_basic_to_fattr(&fattr, pInfo, cifs_sb);
			newinode = cifs_iget(inode->i_sb, &fattr);
			if (!newinode) {
				kfree(pInfo);
				goto mkdir_get_info;
			}

			d_instantiate(direntry, newinode);

#ifdef CONFIG_CIFS_DEBUG2
			cFYI(1, ("instantiated dentry %p %s to inode %p",
				direntry, direntry->d_name.name, newinode));

			if (newinode->i_nlink != 2)
				cFYI(1, ("unexpected number of links %d",
					newinode->i_nlink));
#endif
		}
		kfree(pInfo);
		goto mkdir_out;
	}
mkdir_retry_old:
	/* BB add setting the equivalent of mode via CreateX w/ACLs */
	rc = CIFSSMBMkDir(xid, pTcon, full_path, cifs_sb->local_nls,
			  cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
	if (rc) {
		cFYI(1, ("cifs_mkdir returned 0x%x", rc));
		d_drop(direntry);
	} else {
mkdir_get_info:
		inc_nlink(inode);
		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, NULL,
						 inode->i_sb, xid, NULL);

		if (pTcon->nocase)
			direntry->d_op = &cifs_ci_dentry_ops;
		else
			direntry->d_op = &cifs_dentry_ops;
		d_instantiate(direntry, newinode);
		 /* setting nlink not necessary except in cases where we
		  * failed to get it from the server or was set bogus */
		if ((direntry->d_inode) && (direntry->d_inode->i_nlink < 2))
				direntry->d_inode->i_nlink = 2;

		mode &= ~current_umask();
		/* must turn on setgid bit if parent dir has it */
		if (inode->i_mode & S_ISGID)
			mode |= S_ISGID;

		if (pTcon->unix_ext) {
			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;
			}
			CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, &args,
					       cifs_sb->local_nls,
					       cifs_sb->mnt_cifs_flags &
						CIFS_MOUNT_MAP_SPECIAL_CHR);
		} else {
			if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) &&
			    (mode & S_IWUGO) == 0) {
				FILE_BASIC_INFO pInfo;
				struct cifsInodeInfo *cifsInode;
				u32 dosattrs;

				memset(&pInfo, 0, sizeof(pInfo));
				cifsInode = CIFS_I(newinode);
				dosattrs = cifsInode->cifsAttrs|ATTR_READONLY;
				pInfo.Attributes = cpu_to_le32(dosattrs);
				tmprc = CIFSSMBSetPathInfo(xid, pTcon,
						full_path, &pInfo,
						cifs_sb->local_nls,
						cifs_sb->mnt_cifs_flags &
						CIFS_MOUNT_MAP_SPECIAL_CHR);
				if (tmprc == 0)
					cifsInode->cifsAttrs = dosattrs;
			}
			if (direntry->d_inode) {
				if (cifs_sb->mnt_cifs_flags &
				     CIFS_MOUNT_DYNPERM)
					direntry->d_inode->i_mode =
						(mode | S_IFDIR);

				if (cifs_sb->mnt_cifs_flags &
				     CIFS_MOUNT_SET_UID) {
					direntry->d_inode->i_uid =
						current_fsuid();
					if (inode->i_mode & S_ISGID)
						direntry->d_inode->i_gid =
							inode->i_gid;
					else
						direntry->d_inode->i_gid =
							current_fsgid();
				}
			}
		}
	}
mkdir_out:
	kfree(full_path);
	FreeXid(xid);
	return rc;
}

int cifs_rmdir(struct inode *inode, struct dentry *direntry)
{
	int rc = 0;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	struct cifsInodeInfo *cifsInode;

	cFYI(1, ("cifs_rmdir, inode = 0x%p", inode));

	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;
		FreeXid(xid);
		return rc;
	}

	rc = CIFSSMBRmDir(xid, pTcon, full_path, cifs_sb->local_nls,
			  cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

	if (!rc) {
		drop_nlink(inode);
		spin_lock(&direntry->d_inode->i_lock);
		i_size_write(direntry->d_inode, 0);
		clear_nlink(direntry->d_inode);
		spin_unlock(&direntry->d_inode->i_lock);
	}

	cifsInode = CIFS_I(direntry->d_inode);
	cifsInode->time = 0;	/* force revalidate to go get info when
				   needed */

	cifsInode = CIFS_I(inode);
	cifsInode->time = 0;	/* force revalidate to get parent dir info
				   since cached search results now invalid */

	direntry->d_inode->i_ctime = inode->i_ctime = inode->i_mtime =
		current_fs_time(inode->i_sb);

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

static int
cifs_do_rename(int xid, struct dentry *from_dentry, const char *fromPath,
		struct dentry *to_dentry, const char *toPath)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(from_dentry->d_sb);
	struct cifsTconInfo *pTcon = cifs_sb->tcon;
	__u16 srcfid;
	int oplock, rc;

	/* try path-based rename first */
	rc = CIFSSMBRename(xid, pTcon, fromPath, toPath, cifs_sb->local_nls,
			   cifs_sb->mnt_cifs_flags &
				CIFS_MOUNT_MAP_SPECIAL_CHR);

	/*
	 * don't bother with rename by filehandle unless file is busy and
	 * source Note that cross directory moves do not work with
	 * rename by filehandle to various Windows servers.
	 */
	if (rc == 0 || rc != -ETXTBSY)
		return rc;

	/* open the file to be renamed -- we need DELETE perms */
	rc = CIFSSMBOpen(xid, pTcon, fromPath, FILE_OPEN, DELETE,
			 CREATE_NOT_DIR, &srcfid, &oplock, NULL,
			 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
				CIFS_MOUNT_MAP_SPECIAL_CHR);

	if (rc == 0) {
		rc = CIFSSMBRenameOpenFile(xid, pTcon, srcfid,
				(const char *) to_dentry->d_name.name,
				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);

		CIFSSMBClose(xid, pTcon, srcfid);
	}

	return rc;
}

int cifs_rename(struct inode *source_dir, struct dentry *source_dentry,
	struct inode *target_dir, struct dentry *target_dentry)
{
	char *fromName = NULL;
	char *toName = NULL;
	struct cifs_sb_info *cifs_sb_source;
	struct cifs_sb_info *cifs_sb_target;
	struct cifsTconInfo *tcon;
	FILE_UNIX_BASIC_INFO *info_buf_source = NULL;
	FILE_UNIX_BASIC_INFO *info_buf_target;
	int xid, rc, tmprc;

	cifs_sb_target = CIFS_SB(target_dir->i_sb);
	cifs_sb_source = CIFS_SB(source_dir->i_sb);
	tcon = cifs_sb_source->tcon;

	xid = GetXid();

	/*
	 * BB: this might be allowed if same server, but different share.
	 * Consider adding support for this
	 */
	if (tcon != cifs_sb_target->tcon) {
		rc = -EXDEV;
		goto cifs_rename_exit;
	}

	/*
	 * we already have the rename sem so we do not need to
	 * grab it again here to protect the path integrity
	 */
	fromName = build_path_from_dentry(source_dentry);
	if (fromName == NULL) {
		rc = -ENOMEM;
		goto cifs_rename_exit;
	}

	toName = build_path_from_dentry(target_dentry);
	if (toName == NULL) {
		rc = -ENOMEM;
		goto cifs_rename_exit;
	}

	rc = cifs_do_rename(xid, source_dentry, fromName,
			    target_dentry, toName);

	if (rc == -EEXIST && tcon->unix_ext) {
		/*
		 * Are src and dst hardlinks of same inode? We can
		 * only tell with unix extensions enabled
		 */
		info_buf_source =
			kmalloc(2 * sizeof(FILE_UNIX_BASIC_INFO),
					GFP_KERNEL);
		if (info_buf_source == NULL) {
			rc = -ENOMEM;
			goto cifs_rename_exit;
		}

		info_buf_target = info_buf_source + 1;
		tmprc = CIFSSMBUnixQPathInfo(xid, tcon, fromName,
					info_buf_source,
					cifs_sb_source->local_nls,
					cifs_sb_source->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
		if (tmprc != 0)
			goto unlink_target;

		tmprc = CIFSSMBUnixQPathInfo(xid, tcon,
					toName, info_buf_target,
					cifs_sb_target->local_nls,
					/* remap based on source sb */
					cifs_sb_source->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);

		if (tmprc == 0 && (info_buf_source->UniqueId ==
				   info_buf_target->UniqueId)) {
			/* same file, POSIX says that this is a noop */
			rc = 0;
			goto cifs_rename_exit;
		}
	} /* else ... BB we could add the same check for Windows by
		     checking the UniqueId via FILE_INTERNAL_INFO */

unlink_target:
	/* Try unlinking the target dentry if it's not negative */
	if (target_dentry->d_inode && (rc == -EACCES || rc == -EEXIST)) {
		tmprc = cifs_unlink(target_dir, target_dentry);
		if (tmprc)
			goto cifs_rename_exit;

		rc = cifs_do_rename(xid, source_dentry, fromName,
				    target_dentry, toName);
	}

cifs_rename_exit:
	kfree(info_buf_source);
	kfree(fromName);
	kfree(toName);
	FreeXid(xid);
	return rc;
}

static bool
cifs_inode_needs_reval(struct inode *inode)
{
	struct cifsInodeInfo *cifs_i = CIFS_I(inode);

	if (cifs_i->clientCanCacheRead)
		return false;

	if (!lookupCacheEnabled)
		return true;

	if (cifs_i->time == 0)
		return true;

	/* FIXME: the actimeo should be tunable */
	if (time_after_eq(jiffies, cifs_i->time + HZ))
		return true;

	return false;
}

/* check invalid_mapping flag and zap the cache if it's set */
static void
cifs_invalidate_mapping(struct inode *inode)
{
	int rc;
	struct cifsInodeInfo *cifs_i = CIFS_I(inode);

	cifs_i->invalid_mapping = false;

	/* write back any cached data */
	if (inode->i_mapping && inode->i_mapping->nrpages != 0) {
		rc = filemap_write_and_wait(inode->i_mapping);
		if (rc)
			cifs_i->write_behind_rc = rc;
	}
	invalidate_remote_inode(inode);
}

/* revalidate a dentry's inode attributes */
int cifs_revalidate_dentry(struct dentry *dentry)
{
	int xid;
	int rc = 0;
	char *full_path = NULL;
	struct inode *inode = dentry->d_inode;
	struct super_block *sb = dentry->d_sb;

	if (inode == NULL)
		return -ENOENT;

	xid = GetXid();

	if (!cifs_inode_needs_reval(inode))
		goto check_inval;

	/* can not safely grab the rename sem here if rename calls revalidate
	   since that would deadlock */
	full_path = build_path_from_dentry(dentry);
	if (full_path == NULL) {
		rc = -ENOMEM;
		goto check_inval;
	}

	cFYI(1, ("Revalidate: %s inode 0x%p count %d dentry: 0x%p d_time %ld "
		 "jiffies %ld", full_path, inode, inode->i_count.counter,
		 dentry, dentry->d_time, jiffies));

	if (CIFS_SB(sb)->tcon->unix_ext)
		rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid);
	else
		rc = cifs_get_inode_info(&inode, full_path, NULL, sb,
					 xid, NULL);

check_inval:
	if (CIFS_I(inode)->invalid_mapping)
		cifs_invalidate_mapping(inode);

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

int cifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
	struct kstat *stat)
{
	int err = cifs_revalidate_dentry(dentry);
	if (!err) {
		generic_fillattr(dentry->d_inode, stat);
		stat->blksize = CIFS_MAX_MSGSIZE;
		stat->ino = CIFS_I(dentry->d_inode)->uniqueid;
	}
	return err;
}

static int cifs_truncate_page(struct address_space *mapping, loff_t from)
{
	pgoff_t index = from >> PAGE_CACHE_SHIFT;
	unsigned offset = from & (PAGE_CACHE_SIZE - 1);
	struct page *page;
	int rc = 0;

	page = grab_cache_page(mapping, index);
	if (!page)
		return -ENOMEM;

	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
	unlock_page(page);
	page_cache_release(page);
	return rc;
}

static int cifs_vmtruncate(struct inode *inode, loff_t offset)
{
	loff_t oldsize;
	int err;

	spin_lock(&inode->i_lock);
	err = inode_newsize_ok(inode, offset);
	if (err) {
		spin_unlock(&inode->i_lock);
		goto out;
	}

	oldsize = inode->i_size;
	i_size_write(inode, offset);
	spin_unlock(&inode->i_lock);
	truncate_pagecache(inode, oldsize, offset);
	if (inode->i_op->truncate)
		inode->i_op->truncate(inode);
out:
	return err;
}

static int
cifs_set_file_size(struct inode *inode, struct iattr *attrs,
		   int xid, char *full_path)
{
	int rc;
	struct cifsFileInfo *open_file;
	struct cifsInodeInfo *cifsInode = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsTconInfo *pTcon = cifs_sb->tcon;

	/*
	 * To avoid spurious oplock breaks from server, in the case of
	 * inodes that we already have open, avoid doing path based
	 * setting of file size if we can do it by handle.
	 * This keeps our caching token (oplock) and avoids timeouts
	 * when the local oplock break takes longer to flush
	 * writebehind data than the SMB timeout for the SetPathInfo
	 * request would allow
	 */
	open_file = find_writable_file(cifsInode);
	if (open_file) {
		__u16 nfid = open_file->netfid;
		__u32 npid = open_file->pid;
		rc = CIFSSMBSetFileSize(xid, pTcon, attrs->ia_size, nfid,
					npid, false);
		cifsFileInfo_put(open_file);
		cFYI(1, ("SetFSize for attrs rc = %d", rc));
		if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
			unsigned int bytes_written;
			rc = CIFSSMBWrite(xid, pTcon, nfid, 0, attrs->ia_size,
					  &bytes_written, NULL, NULL, 1);
			cFYI(1, ("Wrt seteof rc %d", rc));
		}
	} else
		rc = -EINVAL;

	if (rc != 0) {
		/* Set file size by pathname rather than by handle
		   either because no valid, writeable file handle for
		   it was found or because there was an error setting
		   it by handle */
		rc = CIFSSMBSetEOF(xid, pTcon, full_path, attrs->ia_size,
				   false, cifs_sb->local_nls,
				   cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
		cFYI(1, ("SetEOF by path (setattrs) rc = %d", rc));
		if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
			__u16 netfid;
			int oplock = 0;

			rc = SMBLegacyOpen(xid, pTcon, full_path,
				FILE_OPEN, GENERIC_WRITE,
				CREATE_NOT_DIR, &netfid, &oplock, NULL,
				cifs_sb->local_nls,
				cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
			if (rc == 0) {
				unsigned int bytes_written;
				rc = CIFSSMBWrite(xid, pTcon, netfid, 0,
						  attrs->ia_size,
						  &bytes_written, NULL,
						  NULL, 1);
				cFYI(1, ("wrt seteof rc %d", rc));
				CIFSSMBClose(xid, pTcon, netfid);
			}
		}
	}

	if (rc == 0) {
		cifsInode->server_eof = attrs->ia_size;
		rc = cifs_vmtruncate(inode, attrs->ia_size);
		cifs_truncate_page(inode->i_mapping, inode->i_size);
	}

	return rc;
}

static int
cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
{
	int rc;
	int xid;
	char *full_path = NULL;
	struct inode *inode = direntry->d_inode;
	struct cifsInodeInfo *cifsInode = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsTconInfo *pTcon = cifs_sb->tcon;
	struct cifs_unix_set_info_args *args = NULL;
	struct cifsFileInfo *open_file;

	cFYI(1, ("setattr_unix on file %s attrs->ia_valid=0x%x",
		 direntry->d_name.name, attrs->ia_valid));

	xid = GetXid();

	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM) == 0) {
		/* check if we have permission to change attrs */
		rc = inode_change_ok(inode, attrs);
		if (rc < 0)
			goto out;
		else
			rc = 0;
	}

	full_path = build_path_from_dentry(direntry);
	if (full_path == NULL) {
		rc = -ENOMEM;
		goto out;
	}

	/*
	 * Attempt to flush data before changing attributes. We need to do
	 * this for ATTR_SIZE and ATTR_MTIME for sure, and if we change the
	 * ownership or mode then we may also need to do this. Here, we take
	 * the safe way out and just do the flush on all setattr requests. If
	 * the flush returns error, store it to report later and continue.
	 *
	 * BB: This should be smarter. Why bother flushing pages that
	 * will be truncated anyway? Also, should we error out here if
	 * the flush returns error?
	 */
	rc = filemap_write_and_wait(inode->i_mapping);
	if (rc != 0) {
		cifsInode->write_behind_rc = rc;
		rc = 0;
	}

	if (attrs->ia_valid & ATTR_SIZE) {
		rc = cifs_set_file_size(inode, attrs, xid, full_path);
		if (rc != 0)
			goto out;
	}

	/* skip mode change if it's just for clearing setuid/setgid */
	if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
		attrs->ia_valid &= ~ATTR_MODE;

	args = kmalloc(sizeof(*args), GFP_KERNEL);
	if (args == NULL) {
		rc = -ENOMEM;
		goto out;
	}

	/* set up the struct */
	if (attrs->ia_valid & ATTR_MODE)
		args->mode = attrs->ia_mode;
	else
		args->mode = NO_CHANGE_64;

	if (attrs->ia_valid & ATTR_UID)
		args->uid = attrs->ia_uid;
	else
		args->uid = NO_CHANGE_64;

	if (attrs->ia_valid & ATTR_GID)
		args->gid = attrs->ia_gid;
	else
		args->gid = NO_CHANGE_64;

	if (attrs->ia_valid & ATTR_ATIME)
		args->atime = cifs_UnixTimeToNT(attrs->ia_atime);
	else
		args->atime = NO_CHANGE_64;

	if (attrs->ia_valid & ATTR_MTIME)
		args->mtime = cifs_UnixTimeToNT(attrs->ia_mtime);
	else
		args->mtime = NO_CHANGE_64;

	if (attrs->ia_valid & ATTR_CTIME)
		args->ctime = cifs_UnixTimeToNT(attrs->ia_ctime);
	else
		args->ctime = NO_CHANGE_64;

	args->device = 0;
	open_file = find_writable_file(cifsInode);
	if (open_file) {
		u16 nfid = open_file->netfid;
		u32 npid = open_file->pid;
		rc = CIFSSMBUnixSetFileInfo(xid, pTcon, args, nfid, npid);
		cifsFileInfo_put(open_file);
	} else {
		rc = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, args,
				    cifs_sb->local_nls,
				    cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
	}

	if (!rc) {
		rc = inode_setattr(inode, attrs);

		/* force revalidate when any of these times are set since some
		   of the fs types (eg ext3, fat) do not have fine enough
		   time granularity to match protocol, and we do not have a
		   a way (yet) to query the server fs's time granularity (and
		   whether it rounds times down).
		*/
		if (!rc && (attrs->ia_valid & (ATTR_MTIME | ATTR_CTIME)))
			cifsInode->time = 0;
	}
out:
	kfree(args);
	kfree(full_path);
	FreeXid(xid);
	return rc;
}

static int
cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
{
	int xid;
	struct inode *inode = direntry->d_inode;
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsInodeInfo *cifsInode = CIFS_I(inode);
	char *full_path = NULL;
	int rc = -EACCES;
	__u32 dosattr = 0;
	__u64 mode = NO_CHANGE_64;

	xid = GetXid();

	cFYI(1, ("setattr on file %s attrs->iavalid 0x%x",
		 direntry->d_name.name, attrs->ia_valid));

	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM) == 0) {
		/* check if we have permission to change attrs */
		rc = inode_change_ok(inode, attrs);
		if (rc < 0) {
			FreeXid(xid);
			return rc;
		} else
			rc = 0;
	}

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

	/*
	 * Attempt to flush data before changing attributes. We need to do
	 * this for ATTR_SIZE and ATTR_MTIME for sure, and if we change the
	 * ownership or mode then we may also need to do this. Here, we take
	 * the safe way out and just do the flush on all setattr requests. If
	 * the flush returns error, store it to report later and continue.
	 *
	 * BB: This should be smarter. Why bother flushing pages that
	 * will be truncated anyway? Also, should we error out here if
	 * the flush returns error?
	 */
	rc = filemap_write_and_wait(inode->i_mapping);
	if (rc != 0) {
		cifsInode->write_behind_rc = rc;
		rc = 0;
	}

	if (attrs->ia_valid & ATTR_SIZE) {
		rc = cifs_set_file_size(inode, attrs, xid, full_path);
		if (rc != 0)
			goto cifs_setattr_exit;
	}

	/*
	 * Without unix extensions we can't send ownership changes to the
	 * server, so silently ignore them. This is consistent with how
	 * local DOS/Windows filesystems behave (VFAT, NTFS, etc). With
	 * CIFSACL support + proper Windows to Unix idmapping, we may be
	 * able to support this in the future.
	 */
	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID))
		attrs->ia_valid &= ~(ATTR_UID | ATTR_GID);

	/* skip mode change if it's just for clearing setuid/setgid */
	if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
		attrs->ia_valid &= ~ATTR_MODE;

	if (attrs->ia_valid & ATTR_MODE) {
		cFYI(1, ("Mode changed to 0%o", attrs->ia_mode));
		mode = attrs->ia_mode;
	}

	if (attrs->ia_valid & ATTR_MODE) {
		rc = 0;
#ifdef CONFIG_CIFS_EXPERIMENTAL
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
			rc = mode_to_acl(inode, full_path, mode);
		else
#endif
		if (((mode & S_IWUGO) == 0) &&
		    (cifsInode->cifsAttrs & ATTR_READONLY) == 0) {

			dosattr = cifsInode->cifsAttrs | ATTR_READONLY;

			/* fix up mode if we're not using dynperm */
			if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM) == 0)
				attrs->ia_mode = inode->i_mode & ~S_IWUGO;
		} else if ((mode & S_IWUGO) &&
			   (cifsInode->cifsAttrs & ATTR_READONLY)) {

			dosattr = cifsInode->cifsAttrs & ~ATTR_READONLY;
			/* Attributes of 0 are ignored */
			if (dosattr == 0)
				dosattr |= ATTR_NORMAL;

			/* reset local inode permissions to normal */
			if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)) {
				attrs->ia_mode &= ~(S_IALLUGO);
				if (S_ISDIR(inode->i_mode))
					attrs->ia_mode |=
						cifs_sb->mnt_dir_mode;
				else
					attrs->ia_mode |=
						cifs_sb->mnt_file_mode;
			}
		} else if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)) {
			/* ignore mode change - ATTR_READONLY hasn't changed */
			attrs->ia_valid &= ~ATTR_MODE;
		}
	}

	if (attrs->ia_valid & (ATTR_MTIME|ATTR_ATIME|ATTR_CTIME) ||
	    ((attrs->ia_valid & ATTR_MODE) && dosattr)) {
		rc = cifs_set_file_info(inode, attrs, xid, full_path, dosattr);
		/* BB: check for rc = -EOPNOTSUPP and switch to legacy mode */

		/* Even if error on time set, no sense failing the call if
		the server would set the time to a reasonable value anyway,
		and this check ensures that we are not being called from
		sys_utimes in which case we ought to fail the call back to
		the user when the server rejects the call */
		if ((rc) && (attrs->ia_valid &
				(ATTR_MODE | ATTR_GID | ATTR_UID | ATTR_SIZE)))
			rc = 0;
	}

	/* do not need local check to inode_check_ok since the server does
	   that */
	if (!rc)
		rc = inode_setattr(inode, attrs);
cifs_setattr_exit:
	kfree(full_path);
	FreeXid(xid);
	return rc;
}

int
cifs_setattr(struct dentry *direntry, struct iattr *attrs)
{
	struct inode *inode = direntry->d_inode;
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsTconInfo *pTcon = cifs_sb->tcon;

	if (pTcon->unix_ext)
		return cifs_setattr_unix(direntry, attrs);

	return cifs_setattr_nounix(direntry, attrs);

	/* BB: add cifs_setattr_legacy for really old servers */
}

#if 0
void cifs_delete_inode(struct inode *inode)
{
	cFYI(1, ("In cifs_delete_inode, inode = 0x%p", inode));
	/* may have to add back in if and when safe distributed caching of
	   directories added e.g. via FindNotify */
}
#endif