xref: /kernel/linux/linux-6.6/fs/smb/client/inode.c

// SPDX-License-Identifier: LGPL-2.1
/*
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2010
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 */
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/freezer.h>
#include <linux/sched/signal.h>
#include <linux/wait_bit.h>
#include <linux/fiemap.h>
#include <asm/div64.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "smb2proto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifs_unicode.h"
#include "fscache.h"
#include "fs_context.h"
#include "cifs_ioctl.h"
#include "cached_dir.h"

static void cifs_set_ops(struct inode *inode)
{
	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_STRICT_IO) {
			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
				inode->i_fop = &cifs_file_strict_nobrl_ops;
			else
				inode->i_fop = &cifs_file_strict_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 readahead */
		if (cifs_sb_master_tcon(cifs_sb)->ses->server->max_read <
				PAGE_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:
		if (IS_AUTOMOUNT(inode)) {
			inode->i_op = &cifs_namespace_inode_operations;
		} else {
			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 cifs_fscache_inode_coherency_data cd;
	struct cifsInodeInfo *cifs_i = CIFS_I(inode);
	struct timespec64 mtime;

	cifs_dbg(FYI, "%s: revalidating inode %llu\n",
		 __func__, cifs_i->uniqueid);

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

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

	 /* revalidate if mtime or size have changed */
	fattr->cf_mtime = timestamp_truncate(fattr->cf_mtime, inode);
	mtime = inode_get_mtime(inode);
	if (timespec64_equal(&mtime, &fattr->cf_mtime) &&
	    cifs_i->server_eof == fattr->cf_eof) {
		cifs_dbg(FYI, "%s: inode %llu is unchanged\n",
			 __func__, cifs_i->uniqueid);
		return;
	}

	cifs_dbg(FYI, "%s: invalidating inode %llu mapping\n",
		 __func__, cifs_i->uniqueid);
	set_bit(CIFS_INO_INVALID_MAPPING, &cifs_i->flags);
	/* Invalidate fscache cookie */
	cifs_fscache_fill_coherency(&cifs_i->netfs.inode, &cd);
	fscache_invalidate(cifs_inode_cookie(inode), &cd, i_size_read(inode), 0);
}

/*
 * copy nlink to the inode, unless it wasn't provided.  Provide
 * sane values if we don't have an existing one and none was provided
 */
static void
cifs_nlink_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr)
{
	/*
	 * if we're in a situation where we can't trust what we
	 * got from the server (readdir, some non-unix cases)
	 * fake reasonable values
	 */
	if (fattr->cf_flags & CIFS_FATTR_UNKNOWN_NLINK) {
		/* only provide fake values on a new inode */
		if (inode->i_state & I_NEW) {
			if (fattr->cf_cifsattrs & ATTR_DIRECTORY)
				set_nlink(inode, 2);
			else
				set_nlink(inode, 1);
		}
		return;
	}

	/* we trust the server, so update it */
	set_nlink(inode, fattr->cf_nlink);
}

/* populate an inode with info from a cifs_fattr struct */
int
cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr,
		    bool from_readdir)
{
	struct cifsInodeInfo *cifs_i = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);

	if (!(inode->i_state & I_NEW) &&
	    unlikely(inode_wrong_type(inode, fattr->cf_mode))) {
		CIFS_I(inode)->time = 0; /* force reval */
		return -ESTALE;
	}

	cifs_revalidate_cache(inode, fattr);

	spin_lock(&inode->i_lock);
	fattr->cf_mtime = timestamp_truncate(fattr->cf_mtime, inode);
	fattr->cf_atime = timestamp_truncate(fattr->cf_atime, inode);
	fattr->cf_ctime = timestamp_truncate(fattr->cf_ctime, inode);
	/* we do not want atime to be less than mtime, it broke some apps */
	if (timespec64_compare(&fattr->cf_atime, &fattr->cf_mtime) < 0)
		inode_set_atime_to_ts(inode, fattr->cf_mtime);
	else
		inode_set_atime_to_ts(inode, fattr->cf_atime);
	inode_set_mtime_to_ts(inode, fattr->cf_mtime);
	inode_set_ctime_to_ts(inode, fattr->cf_ctime);
	inode->i_rdev = fattr->cf_rdev;
	cifs_nlink_fattr_to_inode(inode, fattr);
	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->reparse_tag = fattr->cf_cifstag;

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

	if (fattr->cf_flags & CIFS_FATTR_DELETE_PENDING)
		set_bit(CIFS_INO_DELETE_PENDING, &cifs_i->flags);
	else
		clear_bit(CIFS_INO_DELETE_PENDING, &cifs_i->flags);

	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.
	 */
	if (is_size_safe_to_change(cifs_i, fattr->cf_eof, from_readdir)) {
		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;
	}

	if (S_ISLNK(fattr->cf_mode) && fattr->cf_symlink_target) {
		kfree(cifs_i->symlink_target);
		cifs_i->symlink_target = fattr->cf_symlink_target;
		fattr->cf_symlink_target = NULL;
	}
	spin_unlock(&inode->i_lock);

	if (fattr->cf_flags & CIFS_FATTR_JUNCTION)
		inode->i_flags |= S_AUTOMOUNT;
	if (inode->i_state & I_NEW)
		cifs_set_ops(inode);
	return 0;
}

void
cifs_fill_uniqueid(struct super_block *sb, struct cifs_fattr *fattr)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
		return;

	fattr->cf_uniqueid = iunique(sb, ROOT_I);
}

/* 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);
	/* old POSIX extensions don't get create time */

	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;
		cifs_dbg(FYI, "unknown type %d\n", le32_to_cpu(info->Type));
		break;
	}

	fattr->cf_uid = cifs_sb->ctx->linux_uid;
	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)) {
		u64 id = le64_to_cpu(info->Uid);
		if (id < ((uid_t)-1)) {
			kuid_t uid = make_kuid(&init_user_ns, id);
			if (uid_valid(uid))
				fattr->cf_uid = uid;
		}
	}

	fattr->cf_gid = cifs_sb->ctx->linux_gid;
	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)) {
		u64 id = le64_to_cpu(info->Gid);
		if (id < ((gid_t)-1)) {
			kgid_t gid = make_kgid(&init_user_ns, id);
			if (gid_valid(gid))
				fattr->cf_gid = 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 or reparse mount point).
 */
static void cifs_create_junction_fattr(struct cifs_fattr *fattr,
				       struct super_block *sb)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);

	cifs_dbg(FYI, "%s: creating fake fattr\n", __func__);

	memset(fattr, 0, sizeof(*fattr));
	fattr->cf_mode = S_IFDIR | S_IXUGO | S_IRWXU;
	fattr->cf_uid = cifs_sb->ctx->linux_uid;
	fattr->cf_gid = cifs_sb->ctx->linux_gid;
	ktime_get_coarse_real_ts64(&fattr->cf_mtime);
	fattr->cf_atime = fattr->cf_ctime = fattr->cf_mtime;
	fattr->cf_nlink = 2;
	fattr->cf_flags = CIFS_FATTR_JUNCTION;
}

/* Update inode with final fattr data */
static int update_inode_info(struct super_block *sb,
			     struct cifs_fattr *fattr,
			     struct inode **inode)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	int rc = 0;

	if (!*inode) {
		*inode = cifs_iget(sb, fattr);
		if (!*inode)
			rc = -ENOMEM;
		return rc;
	}
	/* We already have inode, update it.
	 *
	 * If file type or uniqueid is different, return error.
	 */
	if (unlikely((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) &&
		     CIFS_I(*inode)->uniqueid != fattr->cf_uniqueid)) {
		CIFS_I(*inode)->time = 0; /* force reval */
		return -ESTALE;
	}
	return cifs_fattr_to_inode(*inode, fattr, false);
}

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
static int
cifs_get_file_info_unix(struct file *filp)
{
	int rc;
	unsigned int xid;
	FILE_UNIX_BASIC_INFO find_data;
	struct cifs_fattr fattr = {};
	struct inode *inode = file_inode(filp);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsFileInfo *cfile = filp->private_data;
	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);

	xid = get_xid();

	if (cfile->symlink_target) {
		fattr.cf_symlink_target = kstrdup(cfile->symlink_target, GFP_KERNEL);
		if (!fattr.cf_symlink_target) {
			rc = -ENOMEM;
			goto cifs_gfiunix_out;
		}
	}

	rc = CIFSSMBUnixQFileInfo(xid, tcon, cfile->fid.netfid, &find_data);
	if (!rc) {
		cifs_unix_basic_to_fattr(&fattr, &find_data, cifs_sb);
	} else if (rc == -EREMOTE) {
		cifs_create_junction_fattr(&fattr, inode->i_sb);
		rc = 0;
	} else
		goto cifs_gfiunix_out;

	rc = cifs_fattr_to_inode(inode, &fattr, false);

cifs_gfiunix_out:
	free_xid(xid);
	return rc;
}

static int cifs_get_unix_fattr(const unsigned char *full_path,
			       struct super_block *sb,
			       struct cifs_fattr *fattr,
			       struct inode **pinode,
			       const unsigned int xid)
{
	struct TCP_Server_Info *server;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	FILE_UNIX_BASIC_INFO find_data;
	struct cifs_tcon *tcon;
	struct tcon_link *tlink;
	int rc, tmprc;

	cifs_dbg(FYI, "Getting info on %s\n", full_path);

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);
	server = tcon->ses->server;

	/* 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_remap(cifs_sb));
	cifs_dbg(FYI, "%s: query path info: rc = %d\n", __func__, rc);
	cifs_put_tlink(tlink);

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

	if (!*pinode)
		cifs_fill_uniqueid(sb, fattr);

	/* check for Minshall+French symlinks */
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) {
		tmprc = check_mf_symlink(xid, tcon, cifs_sb, fattr, full_path);
		cifs_dbg(FYI, "check_mf_symlink: %d\n", tmprc);
	}

	if (S_ISLNK(fattr->cf_mode) && !fattr->cf_symlink_target) {
		if (!server->ops->query_symlink)
			return -EOPNOTSUPP;
		rc = server->ops->query_symlink(xid, tcon,
						cifs_sb, full_path,
						&fattr->cf_symlink_target);
		cifs_dbg(FYI, "%s: query_symlink: %d\n", __func__, rc);
	}
	return rc;
}

int cifs_get_inode_info_unix(struct inode **pinode,
			     const unsigned char *full_path,
			     struct super_block *sb, unsigned int xid)
{
	struct cifs_fattr fattr = {};
	int rc;

	rc = cifs_get_unix_fattr(full_path, sb, &fattr, pinode, xid);
	if (rc)
		goto out;

	rc = update_inode_info(sb, &fattr, pinode);
out:
	kfree(fattr.cf_symlink_target);
	return rc;
}
#else
static inline int cifs_get_unix_fattr(const unsigned char *full_path,
				      struct super_block *sb,
				      struct cifs_fattr *fattr,
				      struct inode **pinode,
				      const unsigned int xid)
{
	return -EOPNOTSUPP;
}

int cifs_get_inode_info_unix(struct inode **pinode,
			     const unsigned char *full_path,
			     struct super_block *sb, unsigned int xid)
{
	return -EOPNOTSUPP;
}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

static int
cifs_sfu_type(struct cifs_fattr *fattr, const char *path,
	      struct cifs_sb_info *cifs_sb, unsigned int xid)
{
	int rc;
	__u32 oplock;
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	struct cifs_fid fid;
	struct cifs_open_parms oparms;
	struct cifs_io_parms io_parms = {0};
	char buf[24];
	unsigned int bytes_read;
	char *pbuf;
	int buf_type = CIFS_NO_BUFFER;

	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? */
	}

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);

	oparms = (struct cifs_open_parms) {
		.tcon = tcon,
		.cifs_sb = cifs_sb,
		.desired_access = GENERIC_READ,
		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
		.disposition = FILE_OPEN,
		.path = path,
		.fid = &fid,
	};

	if (tcon->ses->server->oplocks)
		oplock = REQ_OPLOCK;
	else
		oplock = 0;
	rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL);
	if (rc) {
		cifs_dbg(FYI, "check sfu type of %s, open rc = %d\n", path, rc);
		cifs_put_tlink(tlink);
		return rc;
	}

	/* Read header */
	io_parms.netfid = fid.netfid;
	io_parms.pid = current->tgid;
	io_parms.tcon = tcon;
	io_parms.offset = 0;
	io_parms.length = 24;

	rc = tcon->ses->server->ops->sync_read(xid, &fid, &io_parms,
					&bytes_read, &pbuf, &buf_type);
	if ((rc == 0) && (bytes_read >= 8)) {
		if (memcmp("IntxBLK", pbuf, 8) == 0) {
			cifs_dbg(FYI, "Block device\n");
			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) {
			cifs_dbg(FYI, "Char device\n");
			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) {
			cifs_dbg(FYI, "Symlink\n");
			fattr->cf_mode |= S_IFLNK;
			fattr->cf_dtype = DT_LNK;
		} else if (memcmp("LnxFIFO", pbuf, 8) == 0) {
			cifs_dbg(FYI, "FIFO\n");
			fattr->cf_mode |= S_IFIFO;
			fattr->cf_dtype = DT_FIFO;
		} 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 */
	}

	tcon->ses->server->ops->close(xid, tcon, &fid);
	cifs_put_tlink(tlink);
	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, unsigned int xid)
{
#ifdef CONFIG_CIFS_XATTR
	ssize_t rc;
	char ea_value[4];
	__u32 mode;
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);

	if (tcon->ses->server->ops->query_all_EAs == NULL) {
		cifs_put_tlink(tlink);
		return -EOPNOTSUPP;
	}

	rc = tcon->ses->server->ops->query_all_EAs(xid, tcon, path,
			"SETFILEBITS", ea_value, 4 /* size of buf */,
			cifs_sb);
	cifs_put_tlink(tlink);
	if (rc < 0)
		return (int)rc;
	else if (rc > 3) {
		mode = le32_to_cpu(*((__le32 *)ea_value));
		fattr->cf_mode &= ~SFBITS_MASK;
		cifs_dbg(FYI, "special bits 0%o org mode 0%o\n",
			 mode, fattr->cf_mode);
		fattr->cf_mode = (mode & SFBITS_MASK) | fattr->cf_mode;
		cifs_dbg(FYI, "special mode bits 0%o\n", mode);
	}

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

/* Fill a cifs_fattr struct with info from POSIX info struct */
static void smb311_posix_info_to_fattr(struct cifs_fattr *fattr,
				       struct cifs_open_info_data *data,
				       struct cifs_sid *owner,
				       struct cifs_sid *group,
				       struct super_block *sb)
{
	struct smb311_posix_qinfo *info = &data->posix_fi;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);

	memset(fattr, 0, sizeof(*fattr));

	/* no fattr->flags to set */
	fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
	fattr->cf_uniqueid = le64_to_cpu(info->Inode);

	if (info->LastAccessTime)
		fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
	else
		ktime_get_coarse_real_ts64(&fattr->cf_atime);

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

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

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

	fattr->cf_nlink = le32_to_cpu(info->HardLinks);
	fattr->cf_mode = (umode_t) le32_to_cpu(info->Mode);
	/* The srv fs device id is overridden on network mount so setting rdev isn't needed here */
	/* fattr->cf_rdev = le32_to_cpu(info->DeviceId); */

	if (data->symlink) {
		fattr->cf_mode |= S_IFLNK;
		fattr->cf_dtype = DT_LNK;
		fattr->cf_symlink_target = data->symlink_target;
		data->symlink_target = NULL;
	} else if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
		fattr->cf_mode |= S_IFDIR;
		fattr->cf_dtype = DT_DIR;
	} else { /* file */
		fattr->cf_mode |= S_IFREG;
		fattr->cf_dtype = DT_REG;
	}
	/* else if reparse point ... TODO: add support for FIFO and blk dev; special file types */

	sid_to_id(cifs_sb, owner, fattr, SIDOWNER);
	sid_to_id(cifs_sb, group, fattr, SIDGROUP);

	cifs_dbg(FYI, "POSIX query info: mode 0x%x uniqueid 0x%llx nlink %d\n",
		fattr->cf_mode, fattr->cf_uniqueid, fattr->cf_nlink);
}

static inline dev_t nfs_mkdev(struct reparse_posix_data *buf)
{
	u64 v = le64_to_cpu(*(__le64 *)buf->DataBuffer);

	return MKDEV(v >> 32, v & 0xffffffff);
}

bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb,
				 struct cifs_fattr *fattr,
				 struct cifs_open_info_data *data)
{
	struct reparse_posix_data *buf = data->reparse.posix;
	u32 tag = data->reparse.tag;

	if (tag == IO_REPARSE_TAG_NFS && buf) {
		switch (le64_to_cpu(buf->InodeType)) {
		case NFS_SPECFILE_CHR:
			fattr->cf_mode |= S_IFCHR | cifs_sb->ctx->file_mode;
			fattr->cf_dtype = DT_CHR;
			fattr->cf_rdev = nfs_mkdev(buf);
			break;
		case NFS_SPECFILE_BLK:
			fattr->cf_mode |= S_IFBLK | cifs_sb->ctx->file_mode;
			fattr->cf_dtype = DT_BLK;
			fattr->cf_rdev = nfs_mkdev(buf);
			break;
		case NFS_SPECFILE_FIFO:
			fattr->cf_mode |= S_IFIFO | cifs_sb->ctx->file_mode;
			fattr->cf_dtype = DT_FIFO;
			break;
		case NFS_SPECFILE_SOCK:
			fattr->cf_mode |= S_IFSOCK | cifs_sb->ctx->file_mode;
			fattr->cf_dtype = DT_SOCK;
			break;
		case NFS_SPECFILE_LNK:
			fattr->cf_mode = S_IFLNK | cifs_sb->ctx->file_mode;
			fattr->cf_dtype = DT_LNK;
			break;
		default:
			WARN_ON_ONCE(1);
			return false;
		}
		return true;
	}

	switch (tag) {
	case IO_REPARSE_TAG_LX_SYMLINK:
		fattr->cf_mode |= S_IFLNK | cifs_sb->ctx->file_mode;
		fattr->cf_dtype = DT_LNK;
		break;
	case IO_REPARSE_TAG_LX_FIFO:
		fattr->cf_mode |= S_IFIFO | cifs_sb->ctx->file_mode;
		fattr->cf_dtype = DT_FIFO;
		break;
	case IO_REPARSE_TAG_AF_UNIX:
		fattr->cf_mode |= S_IFSOCK | cifs_sb->ctx->file_mode;
		fattr->cf_dtype = DT_SOCK;
		break;
	case IO_REPARSE_TAG_LX_CHR:
		fattr->cf_mode |= S_IFCHR | cifs_sb->ctx->file_mode;
		fattr->cf_dtype = DT_CHR;
		break;
	case IO_REPARSE_TAG_LX_BLK:
		fattr->cf_mode |= S_IFBLK | cifs_sb->ctx->file_mode;
		fattr->cf_dtype = DT_BLK;
		break;
	case 0: /* SMB1 symlink */
	case IO_REPARSE_TAG_SYMLINK:
	case IO_REPARSE_TAG_NFS:
		fattr->cf_mode = S_IFLNK | cifs_sb->ctx->file_mode;
		fattr->cf_dtype = DT_LNK;
		break;
	default:
		return false;
	}
	return true;
}

static void cifs_open_info_to_fattr(struct cifs_fattr *fattr,
				    struct cifs_open_info_data *data,
				    struct super_block *sb)
{
	struct smb2_file_all_info *info = &data->fi;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);

	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
		ktime_get_coarse_real_ts64(&fattr->cf_atime);

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

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

	fattr->cf_eof = le64_to_cpu(info->EndOfFile);
	fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
	fattr->cf_createtime = le64_to_cpu(info->CreationTime);
	fattr->cf_nlink = le32_to_cpu(info->NumberOfLinks);

	if (cifs_open_data_reparse(data) &&
	    cifs_reparse_point_to_fattr(cifs_sb, fattr, data))
		goto out_reparse;

	if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
		fattr->cf_mode = S_IFDIR | cifs_sb->ctx->dir_mode;
		fattr->cf_dtype = DT_DIR;
		/*
		 * Server can return wrong NumberOfLinks value for directories
		 * when Unix extensions are disabled - fake it.
		 */
		if (!tcon->unix_ext)
			fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
	} else {
		fattr->cf_mode = S_IFREG | cifs_sb->ctx->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);

		/*
		 * Don't accept zero nlink from non-unix servers unless
		 * delete is pending.  Instead mark it as unknown.
		 */
		if ((fattr->cf_nlink < 1) && !tcon->unix_ext &&
		    !info->DeletePending) {
			cifs_dbg(VFS, "bogus file nlink value %u\n",
				 fattr->cf_nlink);
			fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
		}
	}

out_reparse:
	if (S_ISLNK(fattr->cf_mode)) {
		if (likely(data->symlink_target))
			fattr->cf_eof = strnlen(data->symlink_target, PATH_MAX);
		fattr->cf_symlink_target = data->symlink_target;
		data->symlink_target = NULL;
	}

	fattr->cf_uid = cifs_sb->ctx->linux_uid;
	fattr->cf_gid = cifs_sb->ctx->linux_gid;
}

static int
cifs_get_file_info(struct file *filp)
{
	int rc;
	unsigned int xid;
	struct cifs_open_info_data data = {};
	struct cifs_fattr fattr;
	struct inode *inode = file_inode(filp);
	struct cifsFileInfo *cfile = filp->private_data;
	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
	struct TCP_Server_Info *server = tcon->ses->server;

	if (!server->ops->query_file_info)
		return -ENOSYS;

	xid = get_xid();
	rc = server->ops->query_file_info(xid, tcon, cfile, &data);
	switch (rc) {
	case 0:
		/* TODO: add support to query reparse tag */
		data.adjust_tz = false;
		if (data.symlink_target) {
			data.symlink = true;
			data.reparse.tag = IO_REPARSE_TAG_SYMLINK;
		}
		cifs_open_info_to_fattr(&fattr, &data, inode->i_sb);
		break;
	case -EREMOTE:
		cifs_create_junction_fattr(&fattr, inode->i_sb);
		rc = 0;
		break;
	case -EOPNOTSUPP:
	case -EINVAL:
		/*
		 * FIXME: legacy server -- fall back to path-based call?
		 * for now, just skip revalidating and mark inode for
		 * immediate reval.
		 */
		rc = 0;
		CIFS_I(inode)->time = 0;
		goto cgfi_exit;
	default:
		goto cgfi_exit;
	}

	/*
	 * don't bother with SFU junk here -- just mark inode as needing
	 * revalidation.
	 */
	fattr.cf_uniqueid = CIFS_I(inode)->uniqueid;
	fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
	/* if filetype is different, return error */
	rc = cifs_fattr_to_inode(inode, &fattr, false);
cgfi_exit:
	cifs_free_open_info(&data);
	free_xid(xid);
	return rc;
}

/* Simple function to return a 64 bit hash of string.  Rarely called */
static __u64 simple_hashstr(const char *str)
{
	const __u64 hash_mult =  1125899906842597ULL; /* a big enough prime */
	__u64 hash = 0;

	while (*str)
		hash = (hash + (__u64) *str++) * hash_mult;

	return hash;
}

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
/**
 * cifs_backup_query_path_info - SMB1 fallback code to get ino
 *
 * Fallback code to get file metadata when we don't have access to
 * full_path (EACCES) and have backup creds.
 *
 * @xid:	transaction id used to identify original request in logs
 * @tcon:	information about the server share we have mounted
 * @sb:	the superblock stores info such as disk space available
 * @full_path:	name of the file we are getting the metadata for
 * @resp_buf:	will be set to cifs resp buf and needs to be freed with
 * 		cifs_buf_release() when done with @data
 * @data:	will be set to search info result buffer
 */
static int
cifs_backup_query_path_info(int xid,
			    struct cifs_tcon *tcon,
			    struct super_block *sb,
			    const char *full_path,
			    void **resp_buf,
			    FILE_ALL_INFO **data)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifs_search_info info = {0};
	u16 flags;
	int rc;

	*resp_buf = NULL;
	info.endOfSearch = false;
	if (tcon->unix_ext)
		info.info_level = SMB_FIND_FILE_UNIX;
	else if ((tcon->ses->capabilities &
		  tcon->ses->server->vals->cap_nt_find) == 0)
		info.info_level = SMB_FIND_FILE_INFO_STANDARD;
	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
		info.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
	else /* no srvino useful for fallback to some netapp */
		info.info_level = SMB_FIND_FILE_DIRECTORY_INFO;

	flags = CIFS_SEARCH_CLOSE_ALWAYS |
		CIFS_SEARCH_CLOSE_AT_END |
		CIFS_SEARCH_BACKUP_SEARCH;

	rc = CIFSFindFirst(xid, tcon, full_path,
			   cifs_sb, NULL, flags, &info, false);
	if (rc)
		return rc;

	*resp_buf = (void *)info.ntwrk_buf_start;
	*data = (FILE_ALL_INFO *)info.srch_entries_start;
	return 0;
}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

static void cifs_set_fattr_ino(int xid, struct cifs_tcon *tcon, struct super_block *sb,
			       struct inode **inode, const char *full_path,
			       struct cifs_open_info_data *data, struct cifs_fattr *fattr)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct TCP_Server_Info *server = tcon->ses->server;
	int rc;

	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
		if (*inode)
			fattr->cf_uniqueid = CIFS_I(*inode)->uniqueid;
		else
			fattr->cf_uniqueid = iunique(sb, ROOT_I);
		return;
	}

	/*
	 * If we have an inode pass a NULL tcon to ensure we don't
	 * make a round trip to the server. This only works for SMB2+.
	 */
	rc = server->ops->get_srv_inum(xid, *inode ? NULL : tcon, cifs_sb, full_path,
				       &fattr->cf_uniqueid, data);
	if (rc) {
		/*
		 * If that fails reuse existing ino or generate one
		 * and disable server ones
		 */
		if (*inode)
			fattr->cf_uniqueid = CIFS_I(*inode)->uniqueid;
		else {
			fattr->cf_uniqueid = iunique(sb, ROOT_I);
			cifs_autodisable_serverino(cifs_sb);
		}
		return;
	}

	/* If no errors, check for zero root inode (invalid) */
	if (fattr->cf_uniqueid == 0 && strlen(full_path) == 0) {
		cifs_dbg(FYI, "Invalid (0) inodenum\n");
		if (*inode) {
			/* reuse */
			fattr->cf_uniqueid = CIFS_I(*inode)->uniqueid;
		} else {
			/* make an ino by hashing the UNC */
			fattr->cf_flags |= CIFS_FATTR_FAKE_ROOT_INO;
			fattr->cf_uniqueid = simple_hashstr(tcon->tree_name);
		}
	}
}

static inline bool is_inode_cache_good(struct inode *ino)
{
	return ino && CIFS_CACHE_READ(CIFS_I(ino)) && CIFS_I(ino)->time != 0;
}

static int reparse_info_to_fattr(struct cifs_open_info_data *data,
				 struct super_block *sb,
				 const unsigned int xid,
				 struct cifs_tcon *tcon,
				 const char *full_path,
				 struct cifs_fattr *fattr)
{
	struct TCP_Server_Info *server = tcon->ses->server;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct kvec rsp_iov, *iov = NULL;
	int rsp_buftype = CIFS_NO_BUFFER;
	u32 tag = data->reparse.tag;
	int rc = 0;

	if (!tag && server->ops->query_reparse_point) {
		rc = server->ops->query_reparse_point(xid, tcon, cifs_sb,
						      full_path, &tag,
						      &rsp_iov, &rsp_buftype);
		if (!rc)
			iov = &rsp_iov;
	}

	rc = -EOPNOTSUPP;
	switch ((data->reparse.tag = tag)) {
	case 0: /* SMB1 symlink */
		if (server->ops->query_symlink) {
			rc = server->ops->query_symlink(xid, tcon,
							cifs_sb, full_path,
							&data->symlink_target);
		}
		break;
	case IO_REPARSE_TAG_MOUNT_POINT:
		cifs_create_junction_fattr(fattr, sb);
		rc = 0;
		goto out;
	default:
		if (data->symlink_target) {
			rc = 0;
		} else if (server->ops->parse_reparse_point) {
			rc = server->ops->parse_reparse_point(cifs_sb,
							      iov, data);
		}
		break;
	}

	cifs_open_info_to_fattr(fattr, data, sb);
out:
	fattr->cf_cifstag = data->reparse.tag;
	free_rsp_buf(rsp_buftype, rsp_iov.iov_base);
	return rc;
}

static int cifs_get_fattr(struct cifs_open_info_data *data,
			  struct super_block *sb, int xid,
			  const struct cifs_fid *fid,
			  struct cifs_fattr *fattr,
			  struct inode **inode,
			  const char *full_path)
{
	struct cifs_open_info_data tmp_data = {};
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;
	struct tcon_link *tlink;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	void *smb1_backup_rsp_buf = NULL;
	int rc = 0;
	int tmprc = 0;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);
	server = tcon->ses->server;

	/*
	 * 1. Fetch file metadata if not provided (data)
	 */

	if (!data) {
		rc = server->ops->query_path_info(xid, tcon, cifs_sb,
						  full_path, &tmp_data);
		data = &tmp_data;
	}

	/*
	 * 2. Convert it to internal cifs metadata (fattr)
	 */

	switch (rc) {
	case 0:
		/*
		 * If the file is a reparse point, it is more complicated
		 * since we have to check if its reparse tag matches a known
		 * special file type e.g. symlink or fifo or char etc.
		 */
		if (cifs_open_data_reparse(data)) {
			rc = reparse_info_to_fattr(data, sb, xid, tcon,
						   full_path, fattr);
		} else {
			cifs_open_info_to_fattr(fattr, data, sb);
		}
		break;
	case -EREMOTE:
		/* DFS link, no metadata available on this server */
		cifs_create_junction_fattr(fattr, sb);
		rc = 0;
		break;
	case -EACCES:
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
		/*
		 * perm errors, try again with backup flags if possible
		 *
		 * For SMB2 and later the backup intent flag
		 * is already sent if needed on open and there
		 * is no path based FindFirst operation to use
		 * to retry with
		 */
		if (backup_cred(cifs_sb) && is_smb1_server(server)) {
			/* for easier reading */
			FILE_ALL_INFO *fi;
			FILE_DIRECTORY_INFO *fdi;
			SEARCH_ID_FULL_DIR_INFO *si;

			rc = cifs_backup_query_path_info(xid, tcon, sb,
							 full_path,
							 &smb1_backup_rsp_buf,
							 &fi);
			if (rc)
				goto out;

			move_cifs_info_to_smb2(&data->fi, fi);
			fdi = (FILE_DIRECTORY_INFO *)fi;
			si = (SEARCH_ID_FULL_DIR_INFO *)fi;

			cifs_dir_info_to_fattr(fattr, fdi, cifs_sb);
			fattr->cf_uniqueid = le64_to_cpu(si->UniqueId);
			/* uniqueid set, skip get inum step */
			goto handle_mnt_opt;
		} else {
			/* nothing we can do, bail out */
			goto out;
		}
#else
		goto out;
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
		break;
	default:
		cifs_dbg(FYI, "%s: unhandled err rc %d\n", __func__, rc);
		goto out;
	}

	/*
	 * 3. Get or update inode number (fattr->cf_uniqueid)
	 */

	cifs_set_fattr_ino(xid, tcon, sb, inode, full_path, data, fattr);

	/*
	 * 4. Tweak fattr based on mount options
	 */
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
handle_mnt_opt:
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
	/* 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)
			cifs_dbg(FYI, "cifs_sfu_type failed: %d\n", tmprc);
	}

	/* fill in 0777 bits from ACL */
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID) {
		rc = cifs_acl_to_fattr(cifs_sb, fattr, *inode,
				       true, full_path, fid);
		if (rc == -EREMOTE)
			rc = 0;
		if (rc) {
			cifs_dbg(FYI, "%s: Get mode from SID failed. rc=%d\n",
				 __func__, rc);
			goto out;
		}
	} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
		rc = cifs_acl_to_fattr(cifs_sb, fattr, *inode,
				       false, full_path, fid);
		if (rc == -EREMOTE)
			rc = 0;
		if (rc) {
			cifs_dbg(FYI, "%s: Getting ACL failed with error: %d\n",
				 __func__, rc);
			goto out;
		}
	}

	/* 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);

	/* check for Minshall+French symlinks */
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) {
		tmprc = check_mf_symlink(xid, tcon, cifs_sb, fattr, full_path);
		cifs_dbg(FYI, "check_mf_symlink: %d\n", tmprc);
	}

out:
	cifs_buf_release(smb1_backup_rsp_buf);
	cifs_put_tlink(tlink);
	cifs_free_open_info(&tmp_data);
	return rc;
}

int cifs_get_inode_info(struct inode **inode,
			const char *full_path,
			struct cifs_open_info_data *data,
			struct super_block *sb, int xid,
			const struct cifs_fid *fid)
{
	struct cifs_fattr fattr = {};
	int rc;

	if (is_inode_cache_good(*inode)) {
		cifs_dbg(FYI, "No need to revalidate cached inode sizes\n");
		return 0;
	}

	rc = cifs_get_fattr(data, sb, xid, fid, &fattr, inode, full_path);
	if (rc)
		goto out;

	rc = update_inode_info(sb, &fattr, inode);
out:
	kfree(fattr.cf_symlink_target);
	return rc;
}

static int smb311_posix_get_fattr(struct cifs_fattr *fattr,
				  const char *full_path,
				  struct super_block *sb,
				  const unsigned int xid)
{
	struct cifs_open_info_data data = {};
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifs_tcon *tcon;
	struct tcon_link *tlink;
	struct cifs_sid owner, group;
	int tmprc;
	int rc;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);

	/*
	 * 1. Fetch file metadata
	 */

	rc = smb311_posix_query_path_info(xid, tcon, cifs_sb,
					  full_path, &data,
					  &owner, &group);

	/*
	 * 2. Convert it to internal cifs metadata (fattr)
	 */

	switch (rc) {
	case 0:
		smb311_posix_info_to_fattr(fattr, &data, &owner, &group, sb);
		break;
	case -EREMOTE:
		/* DFS link, no metadata available on this server */
		cifs_create_junction_fattr(fattr, sb);
		rc = 0;
		break;
	case -EACCES:
		/*
		 * For SMB2 and later the backup intent flag
		 * is already sent if needed on open and there
		 * is no path based FindFirst operation to use
		 * to retry with so nothing we can do, bail out
		 */
		goto out;
	default:
		cifs_dbg(FYI, "%s: unhandled err rc %d\n", __func__, rc);
		goto out;
	}

	/*
	 * 3. Tweak fattr based on mount options
	 */
	/* check for Minshall+French symlinks */
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) {
		tmprc = check_mf_symlink(xid, tcon, cifs_sb, fattr, full_path);
		cifs_dbg(FYI, "check_mf_symlink: %d\n", tmprc);
	}

out:
	cifs_put_tlink(tlink);
	cifs_free_open_info(&data);
	return rc;
}

int smb311_posix_get_inode_info(struct inode **inode, const char *full_path,
				struct super_block *sb, const unsigned int xid)
{
	struct cifs_fattr fattr = {};
	int rc;

	if (is_inode_cache_good(*inode)) {
		cifs_dbg(FYI, "No need to revalidate cached inode sizes\n");
		return 0;
	}

	rc = smb311_posix_get_fattr(&fattr, full_path, sb, xid);
	if (rc)
		goto out;

	rc = update_inode_info(sb, &fattr, inode);
out:
	kfree(fattr.cf_symlink_target);
	return rc;
}

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

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

	/* don't match inode with different uniqueid */
	if (CIFS_I(inode)->uniqueid != fattr->cf_uniqueid)
		return 0;

	/* use createtime like an i_generation field */
	if (CIFS_I(inode)->createtime != fattr->cf_createtime)
		return 0;

	/* don't match inode of different type */
	if (inode_wrong_type(inode, fattr->cf_mode))
		return 0;

	/* if it's not a directory or has no dentries, then flag it */
	if (S_ISDIR(inode->i_mode) && !hlist_empty(&inode->i_dentry))
		fattr->cf_flags |= CIFS_FATTR_INO_COLLISION;

	return 1;
}

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

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

/*
 * walk dentry list for an inode and report whether it has aliases that
 * are hashed. We use this to determine if a directory inode can actually
 * be used.
 */
static bool
inode_has_hashed_dentries(struct inode *inode)
{
	struct dentry *dentry;

	spin_lock(&inode->i_lock);
	hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
		if (!d_unhashed(dentry) || IS_ROOT(dentry)) {
			spin_unlock(&inode->i_lock);
			return true;
		}
	}
	spin_unlock(&inode->i_lock);
	return false;
}

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

retry_iget5_locked:
	cifs_dbg(FYI, "looking for uniqueid=%llu\n", 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);
	if (inode) {
		/* was there a potentially problematic inode collision? */
		if (fattr->cf_flags & CIFS_FATTR_INO_COLLISION) {
			fattr->cf_flags &= ~CIFS_FATTR_INO_COLLISION;

			if (inode_has_hashed_dentries(inode)) {
				cifs_autodisable_serverino(CIFS_SB(sb));
				iput(inode);
				fattr->cf_uniqueid = iunique(sb, ROOT_I);
				goto retry_iget5_locked;
			}
		}

		/* can't fail - see cifs_find_inode() */
		cifs_fattr_to_inode(inode, fattr, false);
		if (sb->s_flags & SB_NOATIME)
			inode->i_flags |= S_NOATIME | S_NOCMTIME;
		if (inode->i_state & I_NEW) {
			inode->i_ino = hash;
			cifs_fscache_get_inode_cookie(inode);
			unlock_new_inode(inode);
		}
	}

	return inode;
}

/* gets root inode */
struct inode *cifs_root_iget(struct super_block *sb)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifs_fattr fattr = {};
	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
	struct inode *inode = NULL;
	unsigned int xid;
	char *path = NULL;
	int len;
	int rc;

	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
	    && cifs_sb->prepath) {
		len = strlen(cifs_sb->prepath);
		path = kzalloc(len + 2 /* leading sep + null */, GFP_KERNEL);
		if (path == NULL)
			return ERR_PTR(-ENOMEM);
		path[0] = '/';
		memcpy(path+1, cifs_sb->prepath, len);
	} else {
		path = kstrdup("", GFP_KERNEL);
		if (path == NULL)
			return ERR_PTR(-ENOMEM);
	}

	xid = get_xid();
	if (tcon->unix_ext) {
		rc = cifs_get_unix_fattr(path, sb, &fattr, &inode, xid);
		/* some servers mistakenly claim POSIX support */
		if (rc != -EOPNOTSUPP)
			goto iget_root;
		cifs_dbg(VFS, "server does not support POSIX extensions\n");
		tcon->unix_ext = false;
	}

	convert_delimiter(path, CIFS_DIR_SEP(cifs_sb));
	if (tcon->posix_extensions)
		rc = smb311_posix_get_fattr(&fattr, path, sb, xid);
	else
		rc = cifs_get_fattr(NULL, sb, xid, NULL, &fattr, &inode, path);

iget_root:
	if (!rc) {
		if (fattr.cf_flags & CIFS_FATTR_JUNCTION) {
			fattr.cf_flags &= ~CIFS_FATTR_JUNCTION;
			cifs_autodisable_serverino(cifs_sb);
		}
		inode = cifs_iget(sb, &fattr);
	}

	if (!inode) {
		inode = ERR_PTR(rc);
		goto out;
	}

	if (rc && tcon->pipe) {
		cifs_dbg(FYI, "ipc connection - fake read inode\n");
		spin_lock(&inode->i_lock);
		inode->i_mode |= S_IFDIR;
		set_nlink(inode, 2);
		inode->i_op = &cifs_ipc_inode_ops;
		inode->i_fop = &simple_dir_operations;
		inode->i_uid = cifs_sb->ctx->linux_uid;
		inode->i_gid = cifs_sb->ctx->linux_gid;
		spin_unlock(&inode->i_lock);
	} else if (rc) {
		iget_failed(inode);
		inode = ERR_PTR(rc);
	}

out:
	kfree(path);
	free_xid(xid);
	kfree(fattr.cf_symlink_target);
	return inode;
}

int
cifs_set_file_info(struct inode *inode, struct iattr *attrs, unsigned int xid,
		   const char *full_path, __u32 dosattr)
{
	bool set_time = false;
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct TCP_Server_Info *server;
	FILE_BASIC_INFO	info_buf;

	if (attrs == NULL)
		return -EINVAL;

	server = cifs_sb_master_tcon(cifs_sb)->ses->server;
	if (!server->ops->set_file_info)
		return -ENOSYS;

	info_buf.Pad = 0;

	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)) {
		cifs_dbg(FYI, "CIFS - CTIME changed\n");
		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);

	return server->ops->set_file_info(inode, full_path, &info_buf, xid);
}

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
/*
 * 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.
 */
int
cifs_rename_pending_delete(const char *full_path, struct dentry *dentry,
			   const unsigned int xid)
{
	int oplock = 0;
	int rc;
	struct cifs_fid fid;
	struct cifs_open_parms oparms;
	struct inode *inode = d_inode(dentry);
	struct cifsInodeInfo *cifsInode = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	__u32 dosattr, origattr;
	FILE_BASIC_INFO *info_buf = NULL;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);

	/*
	 * We cannot rename the file if the server doesn't support
	 * CAP_INFOLEVEL_PASSTHRU
	 */
	if (!(tcon->ses->capabilities & CAP_INFOLEVEL_PASSTHRU)) {
		rc = -EBUSY;
		goto out;
	}

	oparms = (struct cifs_open_parms) {
		.tcon = tcon,
		.cifs_sb = cifs_sb,
		.desired_access = DELETE | FILE_WRITE_ATTRIBUTES,
		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
		.disposition = FILE_OPEN,
		.path = full_path,
		.fid = &fid,
	};

	rc = CIFS_open(xid, &oparms, &oplock, NULL);
	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, fid.netfid,
					current->tgid);
		/* although we would like to mark the file hidden
 		   if that fails we will still try to rename it */
		if (!rc)
			cifsInode->cifsAttrs = dosattr;
		else
			dosattr = origattr; /* since not able to change them */
	}

	/* rename the file */
	rc = CIFSSMBRenameOpenFile(xid, tcon, fid.netfid, NULL,
				   cifs_sb->local_nls,
				   cifs_remap(cifs_sb));
	if (rc != 0) {
		rc = -EBUSY;
		goto undo_setattr;
	}

	/* try to set DELETE_ON_CLOSE */
	if (!test_bit(CIFS_INO_DELETE_PENDING, &cifsInode->flags)) {
		rc = CIFSSMBSetFileDisposition(xid, tcon, true, fid.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 = -EBUSY;
			goto undo_rename;
		}
		set_bit(CIFS_INO_DELETE_PENDING, &cifsInode->flags);
	}

out_close:
	CIFSSMBClose(xid, tcon, fid.netfid);
out:
	kfree(info_buf);
	cifs_put_tlink(tlink);
	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, fid.netfid, dentry->d_name.name,
				cifs_sb->local_nls, cifs_remap(cifs_sb));
undo_setattr:
	if (dosattr != origattr) {
		info_buf->Attributes = cpu_to_le32(origattr);
		if (!CIFSSMBSetFileInfo(xid, tcon, info_buf, fid.netfid,
					current->tgid))
			cifsInode->cifsAttrs = origattr;
	}

	goto out_close;
}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

/* copied from fs/nfs/dir.c with small changes */
static void
cifs_drop_nlink(struct inode *inode)
{
	spin_lock(&inode->i_lock);
	if (inode->i_nlink > 0)
		drop_nlink(inode);
	spin_unlock(&inode->i_lock);
}

/*
 * If d_inode(dentry) 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 EACCES
 * but will return the EACCES 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;
	unsigned int xid;
	const char *full_path;
	void *page;
	struct inode *inode = d_inode(dentry);
	struct cifsInodeInfo *cifs_inode;
	struct super_block *sb = dir->i_sb;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;
	struct iattr *attrs = NULL;
	__u32 dosattr = 0, origattr = 0;

	cifs_dbg(FYI, "cifs_unlink, dir=0x%p, dentry=0x%p\n", dir, dentry);

	if (unlikely(cifs_forced_shutdown(cifs_sb)))
		return -EIO;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);
	server = tcon->ses->server;

	xid = get_xid();
	page = alloc_dentry_path();

	if (tcon->nodelete) {
		rc = -EACCES;
		goto unlink_out;
	}

	/* 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, page);
	if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		goto unlink_out;
	}

	cifs_close_deferred_file_under_dentry(tcon, full_path);
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	if (cap_unix(tcon->ses) && (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_remap(cifs_sb));
		cifs_dbg(FYI, "posix del rc %d\n", rc);
		if ((rc == 0) || (rc == -ENOENT))
			goto psx_del_no_retry;
	}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

retry_std_delete:
	if (!server->ops->unlink) {
		rc = -ENOSYS;
		goto psx_del_no_retry;
	}

	rc = server->ops->unlink(xid, tcon, full_path, cifs_sb);

psx_del_no_retry:
	if (!rc) {
		if (inode)
			cifs_drop_nlink(inode);
	} else if (rc == -ENOENT) {
		d_drop(dentry);
	} else if (rc == -EBUSY) {
		if (server->ops->rename_pending_delete) {
			rc = server->ops->rename_pending_delete(full_path,
								dentry, xid);
			if (rc == 0)
				cifs_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_set_ctime_current(inode);
	}
	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
	cifs_inode = CIFS_I(dir);
	CIFS_I(dir)->time = 0;	/* force revalidate of dir as well */
unlink_out:
	free_dentry_path(page);
	kfree(attrs);
	free_xid(xid);
	cifs_put_tlink(tlink);
	return rc;
}

static int
cifs_mkdir_qinfo(struct inode *parent, struct dentry *dentry, umode_t mode,
		 const char *full_path, struct cifs_sb_info *cifs_sb,
		 struct cifs_tcon *tcon, const unsigned int xid)
{
	int rc = 0;
	struct inode *inode = NULL;

	if (tcon->posix_extensions)
		rc = smb311_posix_get_inode_info(&inode, full_path, parent->i_sb, xid);
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	else if (tcon->unix_ext)
		rc = cifs_get_inode_info_unix(&inode, full_path, parent->i_sb,
					      xid);
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
	else
		rc = cifs_get_inode_info(&inode, full_path, NULL, parent->i_sb,
					 xid, NULL);

	if (rc)
		return rc;

	if (!S_ISDIR(inode->i_mode)) {
		/*
		 * mkdir succeeded, but another client has managed to remove the
		 * sucker and replace it with non-directory.  Return success,
		 * but don't leave the child in dcache.
		 */
		 iput(inode);
		 d_drop(dentry);
		 return 0;
	}
	/*
	 * setting nlink not necessary except in cases where we failed to get it
	 * from the server or was set bogus. Also, since this is a brand new
	 * inode, no need to grab the i_lock before setting the i_nlink.
	 */
	if (inode->i_nlink < 2)
		set_nlink(inode, 2);
	mode &= ~current_umask();
	/* must turn on setgid bit if parent dir has it */
	if (parent->i_mode & S_ISGID)
		mode |= S_ISGID;

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	if (tcon->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 = current_fsuid();
			if (parent->i_mode & S_ISGID)
				args.gid = parent->i_gid;
			else
				args.gid = current_fsgid();
		} else {
			args.uid = INVALID_UID; /* no change */
			args.gid = INVALID_GID; /* no change */
		}
		CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
				       cifs_sb->local_nls,
				       cifs_remap(cifs_sb));
	} else {
#else
	{
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
		struct TCP_Server_Info *server = tcon->ses->server;
		if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) &&
		    (mode & S_IWUGO) == 0 && server->ops->mkdir_setinfo)
			server->ops->mkdir_setinfo(inode, full_path, cifs_sb,
						   tcon, xid);
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
			inode->i_mode = (mode | S_IFDIR);

		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
			inode->i_uid = current_fsuid();
			if (inode->i_mode & S_ISGID)
				inode->i_gid = parent->i_gid;
			else
				inode->i_gid = current_fsgid();
		}
	}
	d_instantiate(dentry, inode);
	return 0;
}

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
static int
cifs_posix_mkdir(struct inode *inode, struct dentry *dentry, umode_t mode,
		 const char *full_path, struct cifs_sb_info *cifs_sb,
		 struct cifs_tcon *tcon, const unsigned int xid)
{
	int rc = 0;
	u32 oplock = 0;
	FILE_UNIX_BASIC_INFO *info = NULL;
	struct inode *newinode = NULL;
	struct cifs_fattr fattr;

	info = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
	if (info == NULL) {
		rc = -ENOMEM;
		goto posix_mkdir_out;
	}

	mode &= ~current_umask();
	rc = CIFSPOSIXCreate(xid, tcon, SMB_O_DIRECTORY | SMB_O_CREAT, mode,
			     NULL /* netfid */, info, &oplock, full_path,
			     cifs_sb->local_nls, cifs_remap(cifs_sb));
	if (rc == -EOPNOTSUPP)
		goto posix_mkdir_out;
	else if (rc) {
		cifs_dbg(FYI, "posix mkdir returned 0x%x\n", rc);
		d_drop(dentry);
		goto posix_mkdir_out;
	}

	if (info->Type == cpu_to_le32(-1))
		/* no return info, go query for it */
		goto posix_mkdir_get_info;
	/*
	 * BB check (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID ) to see if
	 * need to set uid/gid.
	 */

	cifs_unix_basic_to_fattr(&fattr, info, cifs_sb);
	cifs_fill_uniqueid(inode->i_sb, &fattr);
	newinode = cifs_iget(inode->i_sb, &fattr);
	if (!newinode)
		goto posix_mkdir_get_info;

	d_instantiate(dentry, newinode);

#ifdef CONFIG_CIFS_DEBUG2
	cifs_dbg(FYI, "instantiated dentry %p %pd to inode %p\n",
		 dentry, dentry, newinode);

	if (newinode->i_nlink != 2)
		cifs_dbg(FYI, "unexpected number of links %d\n",
			 newinode->i_nlink);
#endif

posix_mkdir_out:
	kfree(info);
	return rc;
posix_mkdir_get_info:
	rc = cifs_mkdir_qinfo(inode, dentry, mode, full_path, cifs_sb, tcon,
			      xid);
	goto posix_mkdir_out;
}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

int cifs_mkdir(struct mnt_idmap *idmap, struct inode *inode,
	       struct dentry *direntry, umode_t mode)
{
	int rc = 0;
	unsigned int xid;
	struct cifs_sb_info *cifs_sb;
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;
	const char *full_path;
	void *page;

	cifs_dbg(FYI, "In cifs_mkdir, mode = %04ho inode = 0x%p\n",
		 mode, inode);

	cifs_sb = CIFS_SB(inode->i_sb);
	if (unlikely(cifs_forced_shutdown(cifs_sb)))
		return -EIO;
	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);

	xid = get_xid();

	page = alloc_dentry_path();
	full_path = build_path_from_dentry(direntry, page);
	if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		goto mkdir_out;
	}

	server = tcon->ses->server;

	if ((server->ops->posix_mkdir) && (tcon->posix_extensions)) {
		rc = server->ops->posix_mkdir(xid, inode, mode, tcon, full_path,
					      cifs_sb);
		d_drop(direntry); /* for time being always refresh inode info */
		goto mkdir_out;
	}

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	if (cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP &
				le64_to_cpu(tcon->fsUnixInfo.Capability))) {
		rc = cifs_posix_mkdir(inode, direntry, mode, full_path, cifs_sb,
				      tcon, xid);
		if (rc != -EOPNOTSUPP)
			goto mkdir_out;
	}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

	if (!server->ops->mkdir) {
		rc = -ENOSYS;
		goto mkdir_out;
	}

	/* BB add setting the equivalent of mode via CreateX w/ACLs */
	rc = server->ops->mkdir(xid, inode, mode, tcon, full_path, cifs_sb);
	if (rc) {
		cifs_dbg(FYI, "cifs_mkdir returned 0x%x\n", rc);
		d_drop(direntry);
		goto mkdir_out;
	}

	/* TODO: skip this for smb2/smb3 */
	rc = cifs_mkdir_qinfo(inode, direntry, mode, full_path, cifs_sb, tcon,
			      xid);
mkdir_out:
	/*
	 * Force revalidate to get parent dir info when needed since cached
	 * attributes are invalid now.
	 */
	CIFS_I(inode)->time = 0;
	free_dentry_path(page);
	free_xid(xid);
	cifs_put_tlink(tlink);
	return rc;
}

int cifs_rmdir(struct inode *inode, struct dentry *direntry)
{
	int rc = 0;
	unsigned int xid;
	struct cifs_sb_info *cifs_sb;
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;
	const char *full_path;
	void *page = alloc_dentry_path();
	struct cifsInodeInfo *cifsInode;

	cifs_dbg(FYI, "cifs_rmdir, inode = 0x%p\n", inode);

	xid = get_xid();

	full_path = build_path_from_dentry(direntry, page);
	if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		goto rmdir_exit;
	}

	cifs_sb = CIFS_SB(inode->i_sb);
	if (unlikely(cifs_forced_shutdown(cifs_sb))) {
		rc = -EIO;
		goto rmdir_exit;
	}

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink)) {
		rc = PTR_ERR(tlink);
		goto rmdir_exit;
	}
	tcon = tlink_tcon(tlink);
	server = tcon->ses->server;

	if (!server->ops->rmdir) {
		rc = -ENOSYS;
		cifs_put_tlink(tlink);
		goto rmdir_exit;
	}

	if (tcon->nodelete) {
		rc = -EACCES;
		cifs_put_tlink(tlink);
		goto rmdir_exit;
	}

	rc = server->ops->rmdir(xid, tcon, full_path, cifs_sb);
	cifs_put_tlink(tlink);

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

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

	cifsInode = CIFS_I(inode);
	/*
	 * Force revalidate to get parent dir info when needed since cached
	 * attributes are invalid now.
	 */
	cifsInode->time = 0;

	inode_set_ctime_current(d_inode(direntry));
	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));

rmdir_exit:
	free_dentry_path(page);
	free_xid(xid);
	return rc;
}

static int
cifs_do_rename(const unsigned int xid, struct dentry *from_dentry,
	       const char *from_path, struct dentry *to_dentry,
	       const char *to_path)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(from_dentry->d_sb);
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	struct cifs_fid fid;
	struct cifs_open_parms oparms;
	int oplock;
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
	int rc;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);
	server = tcon->ses->server;

	if (!server->ops->rename)
		return -ENOSYS;

	/* try path-based rename first */
	rc = server->ops->rename(xid, tcon, from_dentry,
				 from_path, to_path, cifs_sb);

	/*
	 * 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 != -EBUSY)
		goto do_rename_exit;

	/* Don't fall back to using SMB on SMB 2+ mount */
	if (server->vals->protocol_id != 0)
		goto do_rename_exit;

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	/* open-file renames don't work across directories */
	if (to_dentry->d_parent != from_dentry->d_parent)
		goto do_rename_exit;

	oparms = (struct cifs_open_parms) {
		.tcon = tcon,
		.cifs_sb = cifs_sb,
		/* open the file to be renamed -- we need DELETE perms */
		.desired_access = DELETE,
		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
		.disposition = FILE_OPEN,
		.path = from_path,
		.fid = &fid,
	};

	rc = CIFS_open(xid, &oparms, &oplock, NULL);
	if (rc == 0) {
		rc = CIFSSMBRenameOpenFile(xid, tcon, fid.netfid,
				(const char *) to_dentry->d_name.name,
				cifs_sb->local_nls, cifs_remap(cifs_sb));
		CIFSSMBClose(xid, tcon, fid.netfid);
	}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
do_rename_exit:
	if (rc == 0)
		d_move(from_dentry, to_dentry);
	cifs_put_tlink(tlink);
	return rc;
}

int
cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
	     struct dentry *source_dentry, struct inode *target_dir,
	     struct dentry *target_dentry, unsigned int flags)
{
	const char *from_name, *to_name;
	void *page1, *page2;
	struct cifs_sb_info *cifs_sb;
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	unsigned int xid;
	int rc, tmprc;
	int retry_count = 0;
	FILE_UNIX_BASIC_INFO *info_buf_source = NULL;
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	FILE_UNIX_BASIC_INFO *info_buf_target;
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

	if (flags & ~RENAME_NOREPLACE)
		return -EINVAL;

	cifs_sb = CIFS_SB(source_dir->i_sb);
	if (unlikely(cifs_forced_shutdown(cifs_sb)))
		return -EIO;

	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);
	tcon = tlink_tcon(tlink);

	page1 = alloc_dentry_path();
	page2 = alloc_dentry_path();
	xid = get_xid();

	from_name = build_path_from_dentry(source_dentry, page1);
	if (IS_ERR(from_name)) {
		rc = PTR_ERR(from_name);
		goto cifs_rename_exit;
	}

	to_name = build_path_from_dentry(target_dentry, page2);
	if (IS_ERR(to_name)) {
		rc = PTR_ERR(to_name);
		goto cifs_rename_exit;
	}

	cifs_close_deferred_file_under_dentry(tcon, from_name);
	if (d_inode(target_dentry) != NULL)
		cifs_close_deferred_file_under_dentry(tcon, to_name);

	rc = cifs_do_rename(xid, source_dentry, from_name, target_dentry,
			    to_name);

	if (rc == -EACCES) {
		while (retry_count < 3) {
			cifs_close_all_deferred_files(tcon);
			rc = cifs_do_rename(xid, source_dentry, from_name, target_dentry,
					    to_name);
			if (rc != -EACCES)
				break;
			retry_count++;
		}
	}

	/*
	 * No-replace is the natural behavior for CIFS, so skip unlink hacks.
	 */
	if (flags & RENAME_NOREPLACE)
		goto cifs_rename_exit;

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	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_array(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, from_name,
					     info_buf_source,
					     cifs_sb->local_nls,
					     cifs_remap(cifs_sb));
		if (tmprc != 0)
			goto unlink_target;

		tmprc = CIFSSMBUnixQPathInfo(xid, tcon, to_name,
					     info_buf_target,
					     cifs_sb->local_nls,
					     cifs_remap(cifs_sb));

		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:
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

	/* Try unlinking the target dentry if it's not negative */
	if (d_really_is_positive(target_dentry) && (rc == -EACCES || rc == -EEXIST)) {
		if (d_is_dir(target_dentry))
			tmprc = cifs_rmdir(target_dir, target_dentry);
		else
			tmprc = cifs_unlink(target_dir, target_dentry);
		if (tmprc)
			goto cifs_rename_exit;
		rc = cifs_do_rename(xid, source_dentry, from_name,
				    target_dentry, to_name);
	}

	/* force revalidate to go get info when needed */
	CIFS_I(source_dir)->time = CIFS_I(target_dir)->time = 0;

cifs_rename_exit:
	kfree(info_buf_source);
	free_dentry_path(page2);
	free_dentry_path(page1);
	free_xid(xid);
	cifs_put_tlink(tlink);
	return rc;
}

static bool
cifs_dentry_needs_reval(struct dentry *dentry)
{
	struct inode *inode = d_inode(dentry);
	struct cifsInodeInfo *cifs_i = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
	struct cached_fid *cfid = NULL;

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

	if (CIFS_CACHE_READ(cifs_i))
		return false;

	if (!lookupCacheEnabled)
		return true;

	if (!open_cached_dir_by_dentry(tcon, dentry->d_parent, &cfid)) {
		spin_lock(&cfid->fid_lock);
		if (cfid->time && cifs_i->time > cfid->time) {
			spin_unlock(&cfid->fid_lock);
			close_cached_dir(cfid);
			return false;
		}
		spin_unlock(&cfid->fid_lock);
		close_cached_dir(cfid);
	}
	/*
	 * depending on inode type, check if attribute caching disabled for
	 * files or directories
	 */
	if (S_ISDIR(inode->i_mode)) {
		if (!cifs_sb->ctx->acdirmax)
			return true;
		if (!time_in_range(jiffies, cifs_i->time,
				   cifs_i->time + cifs_sb->ctx->acdirmax))
			return true;
	} else { /* file */
		if (!cifs_sb->ctx->acregmax)
			return true;
		if (!time_in_range(jiffies, cifs_i->time,
				   cifs_i->time + cifs_sb->ctx->acregmax))
			return true;
	}

	/* hardlinked files w/ noserverino get "special" treatment */
	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) &&
	    S_ISREG(inode->i_mode) && inode->i_nlink != 1)
		return true;

	return false;
}

/*
 * Zap the cache. Called when invalid_mapping flag is set.
 */
int
cifs_invalidate_mapping(struct inode *inode)
{
	int rc = 0;

	if (inode->i_mapping && inode->i_mapping->nrpages != 0) {
		rc = invalidate_inode_pages2(inode->i_mapping);
		if (rc)
			cifs_dbg(VFS, "%s: invalidate inode %p failed with rc %d\n",
				 __func__, inode, rc);
	}

	return rc;
}

/**
 * cifs_wait_bit_killable - helper for functions that are sleeping on bit locks
 *
 * @key:	currently unused
 * @mode:	the task state to sleep in
 */
static int
cifs_wait_bit_killable(struct wait_bit_key *key, int mode)
{
	schedule();
	if (signal_pending_state(mode, current))
		return -ERESTARTSYS;
	return 0;
}

int
cifs_revalidate_mapping(struct inode *inode)
{
	int rc;
	unsigned long *flags = &CIFS_I(inode)->flags;
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);

	/* swapfiles are not supposed to be shared */
	if (IS_SWAPFILE(inode))
		return 0;

	rc = wait_on_bit_lock_action(flags, CIFS_INO_LOCK, cifs_wait_bit_killable,
				     TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
	if (rc)
		return rc;

	if (test_and_clear_bit(CIFS_INO_INVALID_MAPPING, flags)) {
		/* for cache=singleclient, do not invalidate */
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RW_CACHE)
			goto skip_invalidate;

		rc = cifs_invalidate_mapping(inode);
		if (rc)
			set_bit(CIFS_INO_INVALID_MAPPING, flags);
	}

skip_invalidate:
	clear_bit_unlock(CIFS_INO_LOCK, flags);
	smp_mb__after_atomic();
	wake_up_bit(flags, CIFS_INO_LOCK);

	return rc;
}

int
cifs_zap_mapping(struct inode *inode)
{
	set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(inode)->flags);
	return cifs_revalidate_mapping(inode);
}

int cifs_revalidate_file_attr(struct file *filp)
{
	int rc = 0;
	struct dentry *dentry = file_dentry(filp);
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	struct cifsFileInfo *cfile = (struct cifsFileInfo *) filp->private_data;
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

	if (!cifs_dentry_needs_reval(dentry))
		return rc;

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	if (tlink_tcon(cfile->tlink)->unix_ext)
		rc = cifs_get_file_info_unix(filp);
	else
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
		rc = cifs_get_file_info(filp);

	return rc;
}

int cifs_revalidate_dentry_attr(struct dentry *dentry)
{
	unsigned int xid;
	int rc = 0;
	struct inode *inode = d_inode(dentry);
	struct super_block *sb = dentry->d_sb;
	const char *full_path;
	void *page;
	int count = 0;

	if (inode == NULL)
		return -ENOENT;

	if (!cifs_dentry_needs_reval(dentry))
		return rc;

	xid = get_xid();

	page = alloc_dentry_path();
	full_path = build_path_from_dentry(dentry, page);
	if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		goto out;
	}

	cifs_dbg(FYI, "Update attributes: %s inode 0x%p count %d dentry: 0x%p d_time %ld jiffies %ld\n",
		 full_path, inode, inode->i_count.counter,
		 dentry, cifs_get_time(dentry), jiffies);

again:
	if (cifs_sb_master_tcon(CIFS_SB(sb))->posix_extensions)
		rc = smb311_posix_get_inode_info(&inode, full_path, sb, xid);
	else if (cifs_sb_master_tcon(CIFS_SB(sb))->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 (rc == -EAGAIN && count++ < 10)
		goto again;
out:
	free_dentry_path(page);
	free_xid(xid);

	return rc;
}

int cifs_revalidate_file(struct file *filp)
{
	int rc;
	struct inode *inode = file_inode(filp);

	rc = cifs_revalidate_file_attr(filp);
	if (rc)
		return rc;

	return cifs_revalidate_mapping(inode);
}

/* revalidate a dentry's inode attributes */
int cifs_revalidate_dentry(struct dentry *dentry)
{
	int rc;
	struct inode *inode = d_inode(dentry);

	rc = cifs_revalidate_dentry_attr(dentry);
	if (rc)
		return rc;

	return cifs_revalidate_mapping(inode);
}

int cifs_getattr(struct mnt_idmap *idmap, const struct path *path,
		 struct kstat *stat, u32 request_mask, unsigned int flags)
{
	struct dentry *dentry = path->dentry;
	struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb);
	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
	struct inode *inode = d_inode(dentry);
	int rc;

	if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
		return -EIO;

	/*
	 * We need to be sure that all dirty pages are written and the server
	 * has actual ctime, mtime and file length.
	 */
	if ((request_mask & (STATX_CTIME | STATX_MTIME | STATX_SIZE | STATX_BLOCKS)) &&
	    !CIFS_CACHE_READ(CIFS_I(inode)) &&
	    inode->i_mapping && inode->i_mapping->nrpages != 0) {
		rc = filemap_fdatawait(inode->i_mapping);
		if (rc) {
			mapping_set_error(inode->i_mapping, rc);
			return rc;
		}
	}

	if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_FORCE_SYNC)
		CIFS_I(inode)->time = 0; /* force revalidate */

	/*
	 * If the caller doesn't require syncing, only sync if
	 * necessary (e.g. due to earlier truncate or setattr
	 * invalidating the cached metadata)
	 */
	if (((flags & AT_STATX_SYNC_TYPE) != AT_STATX_DONT_SYNC) ||
	    (CIFS_I(inode)->time == 0)) {
		rc = cifs_revalidate_dentry_attr(dentry);
		if (rc)
			return rc;
	}

	generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
	stat->blksize = cifs_sb->ctx->bsize;
	stat->ino = CIFS_I(inode)->uniqueid;

	/* old CIFS Unix Extensions doesn't return create time */
	if (CIFS_I(inode)->createtime) {
		stat->result_mask |= STATX_BTIME;
		stat->btime =
		      cifs_NTtimeToUnix(cpu_to_le64(CIFS_I(inode)->createtime));
	}

	stat->attributes_mask |= (STATX_ATTR_COMPRESSED | STATX_ATTR_ENCRYPTED);
	if (CIFS_I(inode)->cifsAttrs & FILE_ATTRIBUTE_COMPRESSED)
		stat->attributes |= STATX_ATTR_COMPRESSED;
	if (CIFS_I(inode)->cifsAttrs & FILE_ATTRIBUTE_ENCRYPTED)
		stat->attributes |= STATX_ATTR_ENCRYPTED;

	/*
	 * If on a multiuser mount without unix extensions or cifsacl being
	 * enabled, and the admin hasn't overridden them, set the ownership
	 * to the fsuid/fsgid of the current process.
	 */
	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER) &&
	    !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) &&
	    !tcon->unix_ext) {
		if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID))
			stat->uid = current_fsuid();
		if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID))
			stat->gid = current_fsgid();
	}
	return 0;
}

int cifs_fiemap(struct inode *inode, struct fiemap_extent_info *fei, u64 start,
		u64 len)
{
	struct cifsInodeInfo *cifs_i = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_i->netfs.inode.i_sb);
	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
	struct TCP_Server_Info *server = tcon->ses->server;
	struct cifsFileInfo *cfile;
	int rc;

	if (unlikely(cifs_forced_shutdown(cifs_sb)))
		return -EIO;

	/*
	 * We need to be sure that all dirty pages are written as they
	 * might fill holes on the server.
	 */
	if (!CIFS_CACHE_READ(CIFS_I(inode)) && inode->i_mapping &&
	    inode->i_mapping->nrpages != 0) {
		rc = filemap_fdatawait(inode->i_mapping);
		if (rc) {
			mapping_set_error(inode->i_mapping, rc);
			return rc;
		}
	}

	cfile = find_readable_file(cifs_i, false);
	if (cfile == NULL)
		return -EINVAL;

	if (server->ops->fiemap) {
		rc = server->ops->fiemap(tcon, cfile, fei, start, len);
		cifsFileInfo_put(cfile);
		return rc;
	}

	cifsFileInfo_put(cfile);
	return -EOPNOTSUPP;
}

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

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

	zero_user_segment(page, offset, PAGE_SIZE);
	unlock_page(page);
	put_page(page);
	return rc;
}

void cifs_setsize(struct inode *inode, loff_t offset)
{
	struct cifsInodeInfo *cifs_i = CIFS_I(inode);

	spin_lock(&inode->i_lock);
	i_size_write(inode, offset);
	spin_unlock(&inode->i_lock);

	/* Cached inode must be refreshed on truncate */
	cifs_i->time = 0;
	truncate_pagecache(inode, offset);
}

static int
cifs_set_file_size(struct inode *inode, struct iattr *attrs,
		   unsigned int xid, const 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 tcon_link *tlink = NULL;
	struct cifs_tcon *tcon = NULL;
	struct TCP_Server_Info *server;

	/*
	 * 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, FIND_WR_FSUID_ONLY);
	if (open_file) {
		tcon = tlink_tcon(open_file->tlink);
		server = tcon->ses->server;
		if (server->ops->set_file_size)
			rc = server->ops->set_file_size(xid, tcon, open_file,
							attrs->ia_size, false);
		else
			rc = -ENOSYS;
		cifsFileInfo_put(open_file);
		cifs_dbg(FYI, "SetFSize for attrs rc = %d\n", rc);
	} else
		rc = -EINVAL;

	if (!rc)
		goto set_size_out;

	if (tcon == NULL) {
		tlink = cifs_sb_tlink(cifs_sb);
		if (IS_ERR(tlink))
			return PTR_ERR(tlink);
		tcon = tlink_tcon(tlink);
		server = tcon->ses->server;
	}

	/*
	 * 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.
	 */
	if (server->ops->set_path_size)
		rc = server->ops->set_path_size(xid, tcon, full_path,
						attrs->ia_size, cifs_sb, false);
	else
		rc = -ENOSYS;
	cifs_dbg(FYI, "SetEOF by path (setattrs) rc = %d\n", rc);

	if (tlink)
		cifs_put_tlink(tlink);

set_size_out:
	if (rc == 0) {
		cifsInode->server_eof = attrs->ia_size;
		cifs_setsize(inode, attrs->ia_size);
		/*
		 * i_blocks is not related to (i_size / i_blksize), but instead
		 * 512 byte (2**9) size is required for calculating num blocks.
		 * Until we can query the server for actual allocation size,
		 * this is best estimate we have for blocks allocated for a file
		 * Number of blocks must be rounded up so size 1 is not 0 blocks
		 */
		inode->i_blocks = (512 - 1 + attrs->ia_size) >> 9;

		/*
		 * The man page of truncate says if the size changed,
		 * then the st_ctime and st_mtime fields for the file
		 * are updated.
		 */
		attrs->ia_ctime = attrs->ia_mtime = current_time(inode);
		attrs->ia_valid |= ATTR_CTIME | ATTR_MTIME;

		cifs_truncate_page(inode->i_mapping, inode->i_size);
	}

	return rc;
}

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
static int
cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
{
	int rc;
	unsigned int xid;
	const char *full_path;
	void *page = alloc_dentry_path();
	struct inode *inode = d_inode(direntry);
	struct cifsInodeInfo *cifsInode = CIFS_I(inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct tcon_link *tlink;
	struct cifs_tcon *pTcon;
	struct cifs_unix_set_info_args *args = NULL;
	struct cifsFileInfo *open_file;

	cifs_dbg(FYI, "setattr_unix on file %pd attrs->ia_valid=0x%x\n",
		 direntry, attrs->ia_valid);

	xid = get_xid();

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM)
		attrs->ia_valid |= ATTR_FORCE;

	rc = setattr_prepare(&nop_mnt_idmap, direntry, attrs);
	if (rc < 0)
		goto out;

	full_path = build_path_from_dentry(direntry, page);
	if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		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 (is_interrupt_error(rc)) {
		rc = -ERESTARTSYS;
		goto out;
	}

	mapping_set_error(inode->i_mapping, 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 = INVALID_UID; /* no change */

	if (attrs->ia_valid & ATTR_GID)
		args->gid = attrs->ia_gid;
	else
		args->gid = INVALID_GID; /* no change */

	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, FIND_WR_FSUID_ONLY);
	if (open_file) {
		u16 nfid = open_file->fid.netfid;
		u32 npid = open_file->pid;
		pTcon = tlink_tcon(open_file->tlink);
		rc = CIFSSMBUnixSetFileInfo(xid, pTcon, args, nfid, npid);
		cifsFileInfo_put(open_file);
	} else {
		tlink = cifs_sb_tlink(cifs_sb);
		if (IS_ERR(tlink)) {
			rc = PTR_ERR(tlink);
			goto out;
		}
		pTcon = tlink_tcon(tlink);
		rc = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, args,
				    cifs_sb->local_nls,
				    cifs_remap(cifs_sb));
		cifs_put_tlink(tlink);
	}

	if (rc)
		goto out;

	if ((attrs->ia_valid & ATTR_SIZE) &&
	    attrs->ia_size != i_size_read(inode)) {
		truncate_setsize(inode, attrs->ia_size);
		fscache_resize_cookie(cifs_inode_cookie(inode), attrs->ia_size);
	}

	setattr_copy(&nop_mnt_idmap, inode, attrs);
	mark_inode_dirty(inode);

	/* 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 (attrs->ia_valid & (ATTR_MTIME | ATTR_CTIME))
		cifsInode->time = 0;
out:
	kfree(args);
	free_dentry_path(page);
	free_xid(xid);
	return rc;
}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

static int
cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
{
	unsigned int xid;
	kuid_t uid = INVALID_UID;
	kgid_t gid = INVALID_GID;
	struct inode *inode = d_inode(direntry);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsInodeInfo *cifsInode = CIFS_I(inode);
	struct cifsFileInfo *wfile;
	struct cifs_tcon *tcon;
	const char *full_path;
	void *page = alloc_dentry_path();
	int rc = -EACCES;
	__u32 dosattr = 0;
	__u64 mode = NO_CHANGE_64;

	xid = get_xid();

	cifs_dbg(FYI, "setattr on file %pd attrs->ia_valid 0x%x\n",
		 direntry, attrs->ia_valid);

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM)
		attrs->ia_valid |= ATTR_FORCE;

	rc = setattr_prepare(&nop_mnt_idmap, direntry, attrs);
	if (rc < 0)
		goto cifs_setattr_exit;

	full_path = build_path_from_dentry(direntry, page);
	if (IS_ERR(full_path)) {
		rc = PTR_ERR(full_path);
		goto cifs_setattr_exit;
	}

	/*
	 * Attempt to flush data before changing attributes. We need to do
	 * this for ATTR_SIZE and ATTR_MTIME.  If the flush of the data
	 * 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? Do we need to check for ATTR_MTIME_SET flag?
	 */
	if (attrs->ia_valid & (ATTR_MTIME | ATTR_SIZE | ATTR_CTIME)) {
		rc = filemap_write_and_wait(inode->i_mapping);
		if (is_interrupt_error(rc)) {
			rc = -ERESTARTSYS;
			goto cifs_setattr_exit;
		}
		mapping_set_error(inode->i_mapping, rc);
	}

	rc = 0;

	if ((attrs->ia_valid & ATTR_MTIME) &&
	    !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
		rc = cifs_get_writable_file(cifsInode, FIND_WR_ANY, &wfile);
		if (!rc) {
			tcon = tlink_tcon(wfile->tlink);
			rc = tcon->ses->server->ops->flush(xid, tcon, &wfile->fid);
			cifsFileInfo_put(wfile);
			if (rc)
				goto cifs_setattr_exit;
		} else if (rc != -EBADF)
			goto cifs_setattr_exit;
		else
			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;
	}

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

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

	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
	    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID)) {
		if (uid_valid(uid) || gid_valid(gid)) {
			mode = NO_CHANGE_64;
			rc = id_mode_to_cifs_acl(inode, full_path, &mode,
							uid, gid);
			if (rc) {
				cifs_dbg(FYI, "%s: Setting id failed with error: %d\n",
					 __func__, rc);
				goto cifs_setattr_exit;
			}
		}
	} else
	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) {
		mode = attrs->ia_mode;
		rc = 0;
		if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
		    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID)) {
			rc = id_mode_to_cifs_acl(inode, full_path, &mode,
						INVALID_UID, INVALID_GID);
			if (rc) {
				cifs_dbg(FYI, "%s: Setting ACL failed with error: %d\n",
					 __func__, rc);
				goto cifs_setattr_exit;
			}

			/*
			 * In case of CIFS_MOUNT_CIFS_ACL, we cannot support all modes.
			 * Pick up the actual mode bits that were set.
			 */
			if (mode != attrs->ia_mode)
				attrs->ia_mode = mode;
		} else
		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->ctx->dir_mode;
				else
					attrs->ia_mode |=
						cifs_sb->ctx->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)
		goto cifs_setattr_exit;

	if ((attrs->ia_valid & ATTR_SIZE) &&
	    attrs->ia_size != i_size_read(inode)) {
		truncate_setsize(inode, attrs->ia_size);
		fscache_resize_cookie(cifs_inode_cookie(inode), attrs->ia_size);
	}

	setattr_copy(&nop_mnt_idmap, inode, attrs);
	mark_inode_dirty(inode);

cifs_setattr_exit:
	free_xid(xid);
	free_dentry_path(page);
	return rc;
}

int
cifs_setattr(struct mnt_idmap *idmap, struct dentry *direntry,
	     struct iattr *attrs)
{
	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
	int rc, retries = 0;
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
	struct cifs_tcon *pTcon = cifs_sb_master_tcon(cifs_sb);
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

	if (unlikely(cifs_forced_shutdown(cifs_sb)))
		return -EIO;

	do {
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
		if (pTcon->unix_ext)
			rc = cifs_setattr_unix(direntry, attrs);
		else
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
			rc = cifs_setattr_nounix(direntry, attrs);
		retries++;
	} while (is_retryable_error(rc) && retries < 2);

	/* BB: add cifs_setattr_legacy for really old servers */
	return rc;
}