x86/amd-iommu: Add per IOMMU reference counting

[linux/fpc-iii.git] / fs / cifs / inode.c

/*
 *   fs/cifs/inode.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2008
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/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;
        }
}

/* 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;

        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;

        /*
         * 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 = CIFSSMBQueryEA(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 EACESS
 * but will return the EACESS 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;
}

int cifs_revalidate(struct dentry *direntry)
{
        int xid;
        int rc = 0, wbrc = 0;
        char *full_path;
        struct cifs_sb_info *cifs_sb;
        struct cifsInodeInfo *cifsInode;
        loff_t local_size;
        struct timespec local_mtime;
        bool invalidate_inode = false;

        if (direntry->d_inode == NULL)
                return -ENOENT;

        cifsInode = CIFS_I(direntry->d_inode);

        if (cifsInode == NULL)
                return -ENOENT;

        /* no sense revalidating inode info on file that no one can write */
        if (CIFS_I(direntry->d_inode)->clientCanCacheRead)
                return rc;

        xid = GetXid();

        cifs_sb = CIFS_SB(direntry->d_sb);

        /* can not safely grab the rename sem here if rename calls revalidate
           since that would deadlock */
        full_path = build_path_from_dentry(direntry);
        if (full_path == NULL) {
                rc = -ENOMEM;
                FreeXid(xid);
                return rc;
        }
        cFYI(1, ("Revalidate: %s inode 0x%p count %d dentry: 0x%p d_time %ld "
                 "jiffies %ld", full_path, direntry->d_inode,
                 direntry->d_inode->i_count.counter, direntry,
                 direntry->d_time, jiffies));

        if (cifsInode->time == 0) {
                /* was set to zero previously to force revalidate */
        } else if (time_before(jiffies, cifsInode->time + HZ) &&
                   lookupCacheEnabled) {
                if ((S_ISREG(direntry->d_inode->i_mode) == 0) ||
                    (direntry->d_inode->i_nlink == 1)) {
                        kfree(full_path);
                        FreeXid(xid);
                        return rc;
                } else {
                        cFYI(1, ("Have to revalidate file due to hardlinks"));
                }
        }

        /* save mtime and size */
        local_mtime = direntry->d_inode->i_mtime;
        local_size = direntry->d_inode->i_size;

        if (cifs_sb->tcon->unix_ext) {
                rc = cifs_get_inode_info_unix(&direntry->d_inode, full_path,
                                              direntry->d_sb, xid);
                if (rc) {
                        cFYI(1, ("error on getting revalidate info %d", rc));
/*                      if (rc != -ENOENT)
                                rc = 0; */      /* BB should we cache info on
                                                   certain errors? */
                }
        } else {
                rc = cifs_get_inode_info(&direntry->d_inode, full_path, NULL,
                                         direntry->d_sb, xid, NULL);
                if (rc) {
                        cFYI(1, ("error on getting revalidate info %d", rc));
/*                      if (rc != -ENOENT)
                                rc = 0; */      /* BB should we cache info on
                                                   certain errors? */
                }
        }
        /* should we remap certain errors, access denied?, to zero */

        /* if not oplocked, we invalidate inode pages if mtime or file size
           had changed on server */

        if (timespec_equal(&local_mtime, &direntry->d_inode->i_mtime) &&
            (local_size == direntry->d_inode->i_size)) {
                cFYI(1, ("cifs_revalidate - inode unchanged"));
        } else {
                /* file may have changed on server */
                if (cifsInode->clientCanCacheRead) {
                        /* no need to invalidate inode pages since we were the
                           only ones who could have modified the file and the
                           server copy is staler than ours */
                } else {
                        invalidate_inode = true;
                }
        }

        /* can not grab this sem since kernel filesys locking documentation
           indicates i_mutex may be taken by the kernel on lookup and rename
           which could deadlock if we grab the i_mutex here as well */
/*      mutex_lock(&direntry->d_inode->i_mutex);*/
        /* need to write out dirty pages here  */
        if (direntry->d_inode->i_mapping) {
                /* do we need to lock inode until after invalidate completes
                   below? */
                wbrc = filemap_fdatawrite(direntry->d_inode->i_mapping);
                if (wbrc)
                        CIFS_I(direntry->d_inode)->write_behind_rc = wbrc;
        }
        if (invalidate_inode) {
        /* shrink_dcache not necessary now that cifs dentry ops
        are exported for negative dentries */
/*              if (S_ISDIR(direntry->d_inode->i_mode))
                        shrink_dcache_parent(direntry); */
                if (S_ISREG(direntry->d_inode->i_mode)) {
                        if (direntry->d_inode->i_mapping) {
                                wbrc = filemap_fdatawait(direntry->d_inode->i_mapping);
                                if (wbrc)
                                        CIFS_I(direntry->d_inode)->write_behind_rc = wbrc;
                        }
                        /* may eventually have to do this for open files too */
                        if (list_empty(&(cifsInode->openFileList))) {
                                /* changed on server - flush read ahead pages */
                                cFYI(1, ("Invalidating read ahead data on "
                                         "closed file"));
                                invalidate_remote_inode(direntry->d_inode);
                        }
                }
        }
/*      mutex_unlock(&direntry->d_inode->i_mutex); */

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

int cifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
        struct kstat *stat)
{
        int err = cifs_revalidate(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);
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