root/fs/smb/server/vfs.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
 *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
 */

#include <crypto/sha2.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/filelock.h>
#include <linux/uaccess.h>
#include <linux/backing-dev.h>
#include <linux/writeback.h>
#include <linux/xattr.h>
#include <linux/falloc.h>
#include <linux/fsnotify.h>
#include <linux/dcache.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/sched/xacct.h>
#include <linux/crc32c.h>
#include <linux/namei.h>
#include <linux/splice.h>

#include "glob.h"
#include "oplock.h"
#include "connection.h"
#include "vfs.h"
#include "vfs_cache.h"
#include "smbacl.h"
#include "ndr.h"
#include "auth.h"
#include "misc.h"
#include "stats.h"

#include "smb_common.h"
#include "mgmt/share_config.h"
#include "mgmt/tree_connect.h"
#include "mgmt/user_session.h"
#include "mgmt/user_config.h"

static void ksmbd_vfs_inherit_owner(struct ksmbd_work *work,
                                    struct inode *parent_inode,
                                    struct inode *inode)
{
        if (!test_share_config_flag(work->tcon->share_conf,
                                    KSMBD_SHARE_FLAG_INHERIT_OWNER))
                return;

        i_uid_write(inode, i_uid_read(parent_inode));
}

static int ksmbd_vfs_path_lookup(struct ksmbd_share_config *share_conf,
                                 char *pathname, unsigned int flags,
                                 struct path *path, bool for_remove)
{
        struct qstr last;
        const struct path *root_share_path = &share_conf->vfs_path;
        int err, type;
        struct dentry *d;

        if (pathname[0] == '\0') {
                pathname = share_conf->path;
                root_share_path = NULL;
        } else {
                flags |= LOOKUP_BENEATH;
        }

        CLASS(filename_kernel, filename)(pathname);
        err = vfs_path_parent_lookup(filename, flags,
                                     path, &last, &type,
                                     root_share_path);
        if (err)
                return err;

        if (unlikely(type != LAST_NORM)) {
                path_put(path);
                return -ENOENT;
        }

        if (for_remove) {
                err = mnt_want_write(path->mnt);
                if (err) {
                        path_put(path);
                        return -ENOENT;
                }

                d = start_removing_noperm(path->dentry, &last);

                if (!IS_ERR(d)) {
                        dput(path->dentry);
                        path->dentry = d;
                        return 0;
                }
                mnt_drop_write(path->mnt);
                path_put(path);
                return -ENOENT;
        }

        d = lookup_noperm_unlocked(&last, path->dentry);
        if (!IS_ERR(d) && d_is_negative(d)) {
                dput(d);
                d = ERR_PTR(-ENOENT);
        }
        if (IS_ERR(d)) {
                path_put(path);
                return -ENOENT;
        }
        dput(path->dentry);
        path->dentry = d;

        if (test_share_config_flag(share_conf, KSMBD_SHARE_FLAG_CROSSMNT)) {
                err = follow_down(path, 0);
                if (err < 0) {
                        path_put(path);
                        return -ENOENT;
                }
        }
        return 0;
}

void ksmbd_vfs_query_maximal_access(struct mnt_idmap *idmap,
                                   struct dentry *dentry, __le32 *daccess)
{
        *daccess = cpu_to_le32(FILE_READ_ATTRIBUTES | READ_CONTROL);

        if (!inode_permission(idmap, d_inode(dentry), MAY_OPEN | MAY_WRITE))
                *daccess |= cpu_to_le32(WRITE_DAC | WRITE_OWNER | SYNCHRONIZE |
                                FILE_WRITE_DATA | FILE_APPEND_DATA |
                                FILE_WRITE_EA | FILE_WRITE_ATTRIBUTES |
                                FILE_DELETE_CHILD);

        if (!inode_permission(idmap, d_inode(dentry), MAY_OPEN | MAY_READ))
                *daccess |= FILE_READ_DATA_LE | FILE_READ_EA_LE;

        if (!inode_permission(idmap, d_inode(dentry), MAY_OPEN | MAY_EXEC))
                *daccess |= FILE_EXECUTE_LE;

        if (!inode_permission(idmap, d_inode(dentry->d_parent), MAY_EXEC | MAY_WRITE))
                *daccess |= FILE_DELETE_LE;
}

/**
 * ksmbd_vfs_create() - vfs helper for smb create file
 * @work:       work
 * @name:       file name that is relative to share
 * @mode:       file create mode
 *
 * Return:      0 on success, otherwise error
 */
int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode)
{
        struct path path;
        struct dentry *dentry;
        int err;

        dentry = ksmbd_vfs_kern_path_create(work, name,
                                            LOOKUP_NO_SYMLINKS, &path);
        if (IS_ERR(dentry)) {
                err = PTR_ERR(dentry);
                if (err != -ENOENT)
                        pr_err("path create failed for %s, err %d\n",
                               name, err);
                return err;
        }

        mode |= S_IFREG;
        err = vfs_create(mnt_idmap(path.mnt), dentry, mode, NULL);
        if (!err) {
                ksmbd_vfs_inherit_owner(work, d_inode(path.dentry),
                                        d_inode(dentry));
        } else {
                pr_err("File(%s): creation failed (err:%d)\n", name, err);
        }

        end_creating_path(&path, dentry);
        return err;
}

/**
 * ksmbd_vfs_mkdir() - vfs helper for smb create directory
 * @work:       work
 * @name:       directory name that is relative to share
 * @mode:       directory create mode
 *
 * Return:      0 on success, otherwise error
 */
int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode)
{
        struct mnt_idmap *idmap;
        struct path path;
        struct dentry *dentry, *d;
        int err = 0;

        dentry = ksmbd_vfs_kern_path_create(work, name,
                                            LOOKUP_NO_SYMLINKS | LOOKUP_DIRECTORY,
                                            &path);
        if (IS_ERR(dentry)) {
                err = PTR_ERR(dentry);
                if (err != -EEXIST)
                        ksmbd_debug(VFS, "path create failed for %s, err %d\n",
                                    name, err);
                return err;
        }

        idmap = mnt_idmap(path.mnt);
        mode |= S_IFDIR;
        d = dentry;
        dentry = vfs_mkdir(idmap, d_inode(path.dentry), dentry, mode, NULL);
        if (IS_ERR(dentry))
                err = PTR_ERR(dentry);
        else if (d_is_negative(dentry))
                err = -ENOENT;
        if (!err && dentry != d)
                ksmbd_vfs_inherit_owner(work, d_inode(path.dentry), d_inode(dentry));

        end_creating_path(&path, dentry);
        if (err)
                pr_err("mkdir(%s): creation failed (err:%d)\n", name, err);
        return err;
}

static ssize_t ksmbd_vfs_getcasexattr(struct mnt_idmap *idmap,
                                      struct dentry *dentry, char *attr_name,
                                      int attr_name_len, char **attr_value)
{
        char *name, *xattr_list = NULL;
        ssize_t value_len = -ENOENT, xattr_list_len;

        xattr_list_len = ksmbd_vfs_listxattr(dentry, &xattr_list);
        if (xattr_list_len <= 0)
                goto out;

        for (name = xattr_list; name - xattr_list < xattr_list_len;
                        name += strlen(name) + 1) {
                ksmbd_debug(VFS, "%s, len %zd\n", name, strlen(name));
                if (strncasecmp(attr_name, name, attr_name_len))
                        continue;

                value_len = ksmbd_vfs_getxattr(idmap,
                                               dentry,
                                               name,
                                               attr_value);
                if (value_len < 0)
                        pr_err("failed to get xattr in file\n");
                break;
        }

out:
        kvfree(xattr_list);
        return value_len;
}

static int ksmbd_vfs_stream_read(struct ksmbd_file *fp, char *buf, loff_t *pos,
                                 size_t count)
{
        ssize_t v_len;
        char *stream_buf = NULL;

        ksmbd_debug(VFS, "read stream data pos : %llu, count : %zd\n",
                    *pos, count);

        v_len = ksmbd_vfs_getcasexattr(file_mnt_idmap(fp->filp),
                                       fp->filp->f_path.dentry,
                                       fp->stream.name,
                                       fp->stream.size,
                                       &stream_buf);
        if ((int)v_len <= 0)
                return (int)v_len;

        if (v_len <= *pos) {
                count = -EINVAL;
                goto free_buf;
        }

        if (v_len - *pos < count)
                count = v_len - *pos;
        fp->stream.pos = v_len;

        memcpy(buf, &stream_buf[*pos], count);

free_buf:
        kvfree(stream_buf);
        return count;
}

/**
 * check_lock_range() - vfs helper for smb byte range file locking
 * @filp:       the file to apply the lock to
 * @start:      lock start byte offset
 * @end:        lock end byte offset
 * @type:       byte range type read/write
 *
 * Return:      0 on success, otherwise error
 */
static int check_lock_range(struct file *filp, loff_t start, loff_t end,
                            unsigned char type)
{
        struct file_lock *flock;
        struct file_lock_context *ctx = locks_inode_context(file_inode(filp));
        int error = 0;

        if (start == end)
                return 0;

        if (!ctx || list_empty_careful(&ctx->flc_posix))
                return 0;

        spin_lock(&ctx->flc_lock);
        for_each_file_lock(flock, &ctx->flc_posix) {
                /* check conflict locks */
                if (flock->fl_end >= start && end >= flock->fl_start) {
                        if (lock_is_read(flock)) {
                                if (type == WRITE) {
                                        pr_err("not allow write by shared lock\n");
                                        error = 1;
                                        goto out;
                                }
                        } else if (lock_is_write(flock)) {
                                /* check owner in lock */
                                if (flock->c.flc_file != filp) {
                                        error = 1;
                                        pr_err("not allow rw access by exclusive lock from other opens\n");
                                        goto out;
                                }
                        }
                }
        }
out:
        spin_unlock(&ctx->flc_lock);
        return error;
}

/**
 * ksmbd_vfs_read() - vfs helper for smb file read
 * @work:       smb work
 * @fp:         ksmbd file pointer
 * @count:      read byte count
 * @pos:        file pos
 * @rbuf:       read data buffer
 *
 * Return:      number of read bytes on success, otherwise error
 */
int ksmbd_vfs_read(struct ksmbd_work *work, struct ksmbd_file *fp, size_t count,
                   loff_t *pos, char *rbuf)
{
        struct file *filp = fp->filp;
        ssize_t nbytes = 0;
        struct inode *inode = file_inode(filp);

        if (S_ISDIR(inode->i_mode))
                return -EISDIR;

        if (unlikely(count == 0))
                return 0;

        if (work->conn->connection_type) {
                if (!(fp->daccess & (FILE_READ_DATA_LE | FILE_EXECUTE_LE))) {
                        pr_err("no right to read(%pD)\n", fp->filp);
                        return -EACCES;
                }
        }

        if (ksmbd_stream_fd(fp))
                return ksmbd_vfs_stream_read(fp, rbuf, pos, count);

        if (!work->tcon->posix_extensions) {
                int ret;

                ret = check_lock_range(filp, *pos, *pos + count - 1, READ);
                if (ret) {
                        pr_err("unable to read due to lock\n");
                        return -EAGAIN;
                }
        }

        nbytes = kernel_read(filp, rbuf, count, pos);
        if (nbytes < 0) {
                pr_err("smb read failed, err = %zd\n", nbytes);
                return nbytes;
        }

        filp->f_pos = *pos;
        ksmbd_counter_add(KSMBD_COUNTER_READ_BYTES, (s64)nbytes);
        return nbytes;
}

static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos,
                                  size_t count)
{
        char *stream_buf = NULL, *wbuf;
        struct mnt_idmap *idmap = file_mnt_idmap(fp->filp);
        size_t size;
        ssize_t v_len;
        int err = 0;

        ksmbd_debug(VFS, "write stream data pos : %llu, count : %zd\n",
                    *pos, count);

        if (*pos >= XATTR_SIZE_MAX) {
                pr_err("stream write position %lld is out of bounds\n", *pos);
                return -EINVAL;
        }

        size = *pos + count;
        if (size > XATTR_SIZE_MAX) {
                size = XATTR_SIZE_MAX;
                count = XATTR_SIZE_MAX - *pos;
        }

        v_len = ksmbd_vfs_getcasexattr(idmap,
                                       fp->filp->f_path.dentry,
                                       fp->stream.name,
                                       fp->stream.size,
                                       &stream_buf);
        if (v_len < 0) {
                pr_err("not found stream in xattr : %zd\n", v_len);
                err = v_len;
                goto out;
        }

        if (v_len < size) {
                wbuf = kvzalloc(size, KSMBD_DEFAULT_GFP);
                if (!wbuf) {
                        err = -ENOMEM;
                        goto out;
                }

                if (v_len > 0)
                        memcpy(wbuf, stream_buf, v_len);
                kvfree(stream_buf);
                stream_buf = wbuf;
        }

        memcpy(&stream_buf[*pos], buf, count);

        err = ksmbd_vfs_setxattr(idmap,
                                 &fp->filp->f_path,
                                 fp->stream.name,
                                 (void *)stream_buf,
                                 size,
                                 0,
                                 true);
        if (err < 0)
                goto out;
        else
                fp->stream.pos = size;
        err = 0;
out:
        kvfree(stream_buf);
        return err;
}

/**
 * ksmbd_vfs_write() - vfs helper for smb file write
 * @work:       work
 * @fp:         ksmbd file pointer
 * @buf:        buf containing data for writing
 * @count:      read byte count
 * @pos:        file pos
 * @sync:       fsync after write
 * @written:    number of bytes written
 *
 * Return:      0 on success, otherwise error
 */
int ksmbd_vfs_write(struct ksmbd_work *work, struct ksmbd_file *fp,
                    char *buf, size_t count, loff_t *pos, bool sync,
                    ssize_t *written)
{
        struct file *filp;
        loff_t  offset = *pos;
        int err = 0;

        if (work->conn->connection_type) {
                if (!(fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE)) ||
                    S_ISDIR(file_inode(fp->filp)->i_mode)) {
                        pr_err("no right to write(%pD)\n", fp->filp);
                        err = -EACCES;
                        goto out;
                }
        }

        filp = fp->filp;

        if (ksmbd_stream_fd(fp)) {
                err = ksmbd_vfs_stream_write(fp, buf, pos, count);
                if (!err)
                        *written = count;
                goto out;
        }

        if (!work->tcon->posix_extensions) {
                err = check_lock_range(filp, *pos, *pos + count - 1, WRITE);
                if (err) {
                        pr_err("unable to write due to lock\n");
                        err = -EAGAIN;
                        goto out;
                }
        }

        /* Reserve lease break for parent dir at closing time */
        fp->reserve_lease_break = true;

        /* Do we need to break any of a levelII oplock? */
        smb_break_all_levII_oplock(work, fp, 1);

        err = kernel_write(filp, buf, count, pos);
        if (err < 0) {
                ksmbd_debug(VFS, "smb write failed, err = %d\n", err);
                goto out;
        }

        filp->f_pos = *pos;
        *written = err;
        err = 0;
        if (sync) {
                err = vfs_fsync_range(filp, offset, offset + *written, 0);
                if (err < 0)
                        pr_err("fsync failed for filename = %pD, err = %d\n",
                               fp->filp, err);
        }
        ksmbd_counter_add(KSMBD_COUNTER_WRITE_BYTES, (s64)*written);

out:
        return err;
}

/**
 * ksmbd_vfs_getattr() - vfs helper for smb getattr
 * @path:       path of dentry
 * @stat:       pointer to returned kernel stat structure
 * Return:      0 on success, otherwise error
 */
int ksmbd_vfs_getattr(const struct path *path, struct kstat *stat)
{
        int err;

        err = vfs_getattr(path, stat, STATX_BASIC_STATS | STATX_BTIME,
                        AT_STATX_SYNC_AS_STAT);
        if (err)
                pr_err("getattr failed, err %d\n", err);
        return err;
}

/**
 * ksmbd_vfs_fsync() - vfs helper for smb fsync
 * @work:       work
 * @fid:        file id of open file
 * @p_id:       persistent file id
 *
 * Return:      0 on success, otherwise error
 */
int ksmbd_vfs_fsync(struct ksmbd_work *work, u64 fid, u64 p_id)
{
        struct ksmbd_file *fp;
        int err;

        fp = ksmbd_lookup_fd_slow(work, fid, p_id);
        if (!fp) {
                pr_err("failed to get filp for fid %llu\n", fid);
                return -ENOENT;
        }
        err = vfs_fsync(fp->filp, 0);
        if (err < 0)
                pr_err("smb fsync failed, err = %d\n", err);
        ksmbd_fd_put(work, fp);
        return err;
}

/**
 * ksmbd_vfs_remove_file() - vfs helper for smb rmdir or unlink
 * @work:       work
 * @path:       path of dentry
 *
 * Return:      0 on success, otherwise error
 */
int ksmbd_vfs_remove_file(struct ksmbd_work *work, const struct path *path)
{
        struct mnt_idmap *idmap;
        struct dentry *parent = path->dentry->d_parent;
        int err;

        if (ksmbd_override_fsids(work))
                return -ENOMEM;

        if (!d_inode(path->dentry)->i_nlink) {
                err = -ENOENT;
                goto out_err;
        }

        idmap = mnt_idmap(path->mnt);
        if (S_ISDIR(d_inode(path->dentry)->i_mode)) {
                err = vfs_rmdir(idmap, d_inode(parent), path->dentry, NULL);
                if (err && err != -ENOTEMPTY)
                        ksmbd_debug(VFS, "rmdir failed, err %d\n", err);
        } else {
                err = vfs_unlink(idmap, d_inode(parent), path->dentry, NULL);
                if (err)
                        ksmbd_debug(VFS, "unlink failed, err %d\n", err);
        }

out_err:
        ksmbd_revert_fsids(work);
        return err;
}

/**
 * ksmbd_vfs_link() - vfs helper for creating smb hardlink
 * @work:       work
 * @oldname:    source file name
 * @newname:    hardlink name that is relative to share
 *
 * Return:      0 on success, otherwise error
 */
int ksmbd_vfs_link(struct ksmbd_work *work, const char *oldname,
                   const char *newname)
{
        struct path oldpath, newpath;
        struct dentry *dentry;
        int err;

        if (ksmbd_override_fsids(work))
                return -ENOMEM;

        err = kern_path(oldname, LOOKUP_NO_SYMLINKS, &oldpath);
        if (err) {
                pr_err("cannot get linux path for %s, err = %d\n",
                       oldname, err);
                goto out1;
        }

        dentry = ksmbd_vfs_kern_path_create(work, newname,
                                            LOOKUP_NO_SYMLINKS | LOOKUP_REVAL,
                                            &newpath);
        if (IS_ERR(dentry)) {
                err = PTR_ERR(dentry);
                pr_err("path create err for %s, err %d\n", newname, err);
                goto out2;
        }

        err = -EXDEV;
        if (oldpath.mnt != newpath.mnt) {
                pr_err("vfs_link failed err %d\n", err);
                goto out3;
        }

        err = vfs_link(oldpath.dentry, mnt_idmap(newpath.mnt),
                       d_inode(newpath.dentry),
                       dentry, NULL);
        if (err)
                ksmbd_debug(VFS, "vfs_link failed err %d\n", err);

out3:
        end_creating_path(&newpath, dentry);
out2:
        path_put(&oldpath);
out1:
        ksmbd_revert_fsids(work);
        return err;
}

int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_path,
                     char *newname, int flags)
{
        struct dentry *old_child = old_path->dentry;
        struct path new_path;
        struct qstr new_last;
        struct renamedata rd;
        struct ksmbd_share_config *share_conf = work->tcon->share_conf;
        struct ksmbd_file *parent_fp;
        int new_type;
        int err, lookup_flags = LOOKUP_NO_SYMLINKS;

        if (ksmbd_override_fsids(work))
                return -ENOMEM;

        CLASS(filename_kernel, to)(newname);

retry:
        err = vfs_path_parent_lookup(to, lookup_flags | LOOKUP_BENEATH,
                                     &new_path, &new_last, &new_type,
                                     &share_conf->vfs_path);
        if (err)
                goto out1;

        if (old_path->mnt != new_path.mnt) {
                err = -EXDEV;
                goto out2;
        }

        err = mnt_want_write(old_path->mnt);
        if (err)
                goto out2;

        rd.mnt_idmap            = mnt_idmap(old_path->mnt);
        rd.old_parent           = NULL;
        rd.new_parent           = new_path.dentry;
        rd.flags                = flags;
        rd.delegated_inode      = NULL;
        err = start_renaming_dentry(&rd, lookup_flags, old_child, &new_last);
        if (err)
                goto out_drop_write;

        parent_fp = ksmbd_lookup_fd_inode(old_child->d_parent);
        if (parent_fp) {
                if (parent_fp->daccess & FILE_DELETE_LE) {
                        pr_err("parent dir is opened with delete access\n");
                        err = -ESHARE;
                        ksmbd_fd_put(work, parent_fp);
                        goto out3;
                }
                ksmbd_fd_put(work, parent_fp);
        }

        if (d_is_symlink(rd.new_dentry)) {
                err = -EACCES;
                goto out3;
        }

        err = vfs_rename(&rd);
        if (err)
                ksmbd_debug(VFS, "vfs_rename failed err %d\n", err);

out3:
        end_renaming(&rd);
out_drop_write:
        mnt_drop_write(old_path->mnt);
out2:
        path_put(&new_path);

        if (retry_estale(err, lookup_flags)) {
                lookup_flags |= LOOKUP_REVAL;
                goto retry;
        }
out1:
        ksmbd_revert_fsids(work);
        return err;
}

/**
 * ksmbd_vfs_truncate() - vfs helper for smb file truncate
 * @work:       work
 * @fp:         ksmbd file pointer
 * @size:       truncate to given size
 *
 * Return:      0 on success, otherwise error
 */
int ksmbd_vfs_truncate(struct ksmbd_work *work,
                       struct ksmbd_file *fp, loff_t size)
{
        int err = 0;
        struct file *filp;

        filp = fp->filp;

        /* Do we need to break any of a levelII oplock? */
        smb_break_all_levII_oplock(work, fp, 1);

        if (!work->tcon->posix_extensions) {
                struct inode *inode = file_inode(filp);

                if (size < inode->i_size) {
                        err = check_lock_range(filp, size,
                                               inode->i_size - 1, WRITE);
                } else if (size > inode->i_size) {
                        err = check_lock_range(filp, inode->i_size,
                                               size - 1, WRITE);
                }

                if (err) {
                        pr_err("failed due to lock\n");
                        return -EAGAIN;
                }
        }

        err = vfs_truncate(&filp->f_path, size);
        if (err)
                pr_err("truncate failed, err %d\n", err);
        return err;
}

/**
 * ksmbd_vfs_listxattr() - vfs helper for smb list extended attributes
 * @dentry:     dentry of file for listing xattrs
 * @list:       destination buffer
 *
 * Return:      xattr list length on success, otherwise error
 */
ssize_t ksmbd_vfs_listxattr(struct dentry *dentry, char **list)
{
        ssize_t size;
        char *vlist = NULL;

        size = vfs_listxattr(dentry, NULL, 0);
        if (size <= 0)
                return size;

        vlist = kvzalloc(size, KSMBD_DEFAULT_GFP);
        if (!vlist)
                return -ENOMEM;

        *list = vlist;
        size = vfs_listxattr(dentry, vlist, size);
        if (size < 0) {
                ksmbd_debug(VFS, "listxattr failed\n");
                kvfree(vlist);
                *list = NULL;
        }

        return size;
}

static ssize_t ksmbd_vfs_xattr_len(struct mnt_idmap *idmap,
                                   struct dentry *dentry, char *xattr_name)
{
        return vfs_getxattr(idmap, dentry, xattr_name, NULL, 0);
}

/**
 * ksmbd_vfs_getxattr() - vfs helper for smb get extended attributes value
 * @idmap:      idmap
 * @dentry:     dentry of file for getting xattrs
 * @xattr_name: name of xattr name to query
 * @xattr_buf:  destination buffer xattr value
 *
 * Return:      read xattr value length on success, otherwise error
 */
ssize_t ksmbd_vfs_getxattr(struct mnt_idmap *idmap,
                           struct dentry *dentry,
                           char *xattr_name, char **xattr_buf)
{
        ssize_t xattr_len;
        char *buf;

        *xattr_buf = NULL;
        xattr_len = ksmbd_vfs_xattr_len(idmap, dentry, xattr_name);
        if (xattr_len < 0)
                return xattr_len;

        buf = kmalloc(xattr_len + 1, KSMBD_DEFAULT_GFP);
        if (!buf)
                return -ENOMEM;

        xattr_len = vfs_getxattr(idmap, dentry, xattr_name,
                                 (void *)buf, xattr_len);
        if (xattr_len > 0)
                *xattr_buf = buf;
        else
                kfree(buf);
        return xattr_len;
}

/**
 * ksmbd_vfs_setxattr() - vfs helper for smb set extended attributes value
 * @idmap:      idmap of the relevant mount
 * @path:       path of dentry to set XATTR at
 * @attr_name:  xattr name for setxattr
 * @attr_value: xattr value to set
 * @attr_size:  size of xattr value
 * @flags:      destination buffer length
 * @get_write:  get write access to a mount
 *
 * Return:      0 on success, otherwise error
 */
int ksmbd_vfs_setxattr(struct mnt_idmap *idmap,
                       const struct path *path, const char *attr_name,
                       void *attr_value, size_t attr_size, int flags,
                       bool get_write)
{
        int err;

        if (get_write == true) {
                err = mnt_want_write(path->mnt);
                if (err)
                        return err;
        }

        err = vfs_setxattr(idmap,
                           path->dentry,
                           attr_name,
                           attr_value,
                           attr_size,
                           flags);
        if (err)
                ksmbd_debug(VFS, "setxattr failed, err %d\n", err);
        if (get_write == true)
                mnt_drop_write(path->mnt);
        return err;
}

/**
 * ksmbd_vfs_set_fadvise() - convert smb IO caching options to linux options
 * @filp:       file pointer for IO
 * @option:     smb IO options
 */
void ksmbd_vfs_set_fadvise(struct file *filp, __le32 option)
{
        struct address_space *mapping;

        mapping = filp->f_mapping;

        if (!option || !mapping)
                return;

        if (option & FILE_WRITE_THROUGH_LE) {
                filp->f_flags |= O_SYNC;
        } else if (option & FILE_SEQUENTIAL_ONLY_LE) {
                filp->f_ra.ra_pages = inode_to_bdi(mapping->host)->ra_pages * 2;
                spin_lock(&filp->f_lock);
                filp->f_mode &= ~FMODE_RANDOM;
                spin_unlock(&filp->f_lock);
        } else if (option & FILE_RANDOM_ACCESS_LE) {
                spin_lock(&filp->f_lock);
                filp->f_mode |= FMODE_RANDOM;
                spin_unlock(&filp->f_lock);
        }
}

int ksmbd_vfs_zero_data(struct ksmbd_work *work, struct ksmbd_file *fp,
                        loff_t off, loff_t len)
{
        smb_break_all_levII_oplock(work, fp, 1);
        if (fp->f_ci->m_fattr & FILE_ATTRIBUTE_SPARSE_FILE_LE)
                return vfs_fallocate(fp->filp,
                                     FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
                                     off, len);

        return vfs_fallocate(fp->filp,
                             FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE,
                             off, len);
}

int ksmbd_vfs_fqar_lseek(struct ksmbd_file *fp, loff_t start, loff_t length,
                         struct file_allocated_range_buffer *ranges,
                         unsigned int in_count, unsigned int *out_count)
{
        struct file *f = fp->filp;
        struct inode *inode = file_inode(fp->filp);
        loff_t maxbytes = (u64)inode->i_sb->s_maxbytes, end;
        loff_t extent_start, extent_end;
        int ret = 0;

        if (start > maxbytes)
                return -EFBIG;

        if (!in_count)
                return 0;

        /*
         * Shrink request scope to what the fs can actually handle.
         */
        if (length > maxbytes || (maxbytes - length) < start)
                length = maxbytes - start;

        if (start + length > inode->i_size)
                length = inode->i_size - start;

        *out_count = 0;
        end = start + length;
        while (start < end && *out_count < in_count) {
                extent_start = vfs_llseek(f, start, SEEK_DATA);
                if (extent_start < 0) {
                        if (extent_start != -ENXIO)
                                ret = (int)extent_start;
                        break;
                }

                if (extent_start >= end)
                        break;

                extent_end = vfs_llseek(f, extent_start, SEEK_HOLE);
                if (extent_end < 0) {
                        if (extent_end != -ENXIO)
                                ret = (int)extent_end;
                        break;
                } else if (extent_start >= extent_end) {
                        break;
                }

                ranges[*out_count].file_offset = cpu_to_le64(extent_start);
                ranges[(*out_count)++].length =
                        cpu_to_le64(min(extent_end, end) - extent_start);

                start = extent_end;
        }

        return ret;
}

int ksmbd_vfs_remove_xattr(struct mnt_idmap *idmap,
                           const struct path *path, char *attr_name,
                           bool get_write)
{
        int err;

        if (get_write == true) {
                err = mnt_want_write(path->mnt);
                if (err)
                        return err;
        }

        err = vfs_removexattr(idmap, path->dentry, attr_name);

        if (get_write == true)
                mnt_drop_write(path->mnt);

        return err;
}

int ksmbd_vfs_unlink(struct file *filp)
{
        int err = 0;
        struct dentry *dir, *dentry = filp->f_path.dentry;
        struct mnt_idmap *idmap = file_mnt_idmap(filp);

        err = mnt_want_write(filp->f_path.mnt);
        if (err)
                return err;

        dir = dget_parent(dentry);
        dentry = start_removing_dentry(dir, dentry);
        err = PTR_ERR(dentry);
        if (IS_ERR(dentry))
                goto out;

        if (S_ISDIR(d_inode(dentry)->i_mode))
                err = vfs_rmdir(idmap, d_inode(dir), dentry, NULL);
        else
                err = vfs_unlink(idmap, d_inode(dir), dentry, NULL);

        end_removing(dentry);
        if (err)
                ksmbd_debug(VFS, "failed to delete, err %d\n", err);
out:
        dput(dir);
        mnt_drop_write(filp->f_path.mnt);

        return err;
}

static bool __dir_empty(struct dir_context *ctx, const char *name, int namlen,
                       loff_t offset, u64 ino, unsigned int d_type)
{
        struct ksmbd_readdir_data *buf;

        buf = container_of(ctx, struct ksmbd_readdir_data, ctx);
        if (!name_is_dot_dotdot(name, namlen))
                buf->dirent_count++;

        return !buf->dirent_count;
}

/**
 * ksmbd_vfs_empty_dir() - check for empty directory
 * @fp: ksmbd file pointer
 *
 * Return:      true if directory empty, otherwise false
 */
int ksmbd_vfs_empty_dir(struct ksmbd_file *fp)
{
        int err;
        struct ksmbd_readdir_data readdir_data;

        memset(&readdir_data, 0, sizeof(struct ksmbd_readdir_data));

        set_ctx_actor(&readdir_data.ctx, __dir_empty);
        readdir_data.dirent_count = 0;

        err = iterate_dir(fp->filp, &readdir_data.ctx);
        if (readdir_data.dirent_count)
                err = -ENOTEMPTY;
        else
                err = 0;
        return err;
}

static bool __caseless_lookup(struct dir_context *ctx, const char *name,
                             int namlen, loff_t offset, u64 ino,
                             unsigned int d_type)
{
        struct ksmbd_readdir_data *buf;
        int cmp = -EINVAL;

        buf = container_of(ctx, struct ksmbd_readdir_data, ctx);

        if (buf->used != namlen)
                return true;
        if (IS_ENABLED(CONFIG_UNICODE) && buf->um) {
                const struct qstr q_buf = {.name = buf->private,
                                           .len = buf->used};
                const struct qstr q_name = {.name = name,
                                            .len = namlen};

                cmp = utf8_strncasecmp(buf->um, &q_buf, &q_name);
        }
        if (cmp < 0)
                cmp = strncasecmp((char *)buf->private, name, namlen);
        if (!cmp) {
                memcpy((char *)buf->private, name, buf->used);
                buf->dirent_count = 1;
                return false;
        }
        return true;
}

/**
 * ksmbd_vfs_lookup_in_dir() - lookup a file in a directory
 * @dir:        path info
 * @name:       filename to lookup
 * @namelen:    filename length
 * @um:         &struct unicode_map to use
 *
 * Return:      0 on success, otherwise error
 */
static int ksmbd_vfs_lookup_in_dir(const struct path *dir, char *name,
                                   size_t namelen, struct unicode_map *um)
{
        int ret;
        struct file *dfilp;
        int flags = O_RDONLY | O_LARGEFILE;
        struct ksmbd_readdir_data readdir_data = {
                .ctx.actor      = __caseless_lookup,
                .private        = name,
                .used           = namelen,
                .dirent_count   = 0,
                .um             = um,
        };

        dfilp = dentry_open(dir, flags, current_cred());
        if (IS_ERR(dfilp))
                return PTR_ERR(dfilp);

        ret = iterate_dir(dfilp, &readdir_data.ctx);
        if (readdir_data.dirent_count > 0)
                ret = 0;
        fput(dfilp);
        return ret;
}

static
int __ksmbd_vfs_kern_path(struct ksmbd_work *work, char *filepath,
                          unsigned int flags,
                          struct path *path, bool caseless, bool for_remove)
{
        struct ksmbd_share_config *share_conf = work->tcon->share_conf;
        struct path parent_path;
        size_t path_len, remain_len;
        int err;

retry:
        err = ksmbd_vfs_path_lookup(share_conf, filepath, flags, path, for_remove);
        if (!err || !caseless)
                return err;

        path_len = strlen(filepath);
        remain_len = path_len;

        parent_path = share_conf->vfs_path;
        path_get(&parent_path);

        while (d_can_lookup(parent_path.dentry)) {
                char *filename = filepath + path_len - remain_len;
                char *next = strchrnul(filename, '/');
                size_t filename_len = next - filename;
                bool is_last = !next[0];

                if (filename_len == 0)
                        break;

                err = ksmbd_vfs_lookup_in_dir(&parent_path, filename,
                                              filename_len,
                                              work->conn->um);
                path_put(&parent_path);
                if (err)
                        goto out;
                if (is_last) {
                        caseless = false;
                        goto retry;
                }
                next[0] = '\0';

                err = vfs_path_lookup(share_conf->vfs_path.dentry,
                                      share_conf->vfs_path.mnt,
                                      filepath,
                                      flags,
                                      &parent_path);
                next[0] = '/';
                if (err)
                        goto out;

                remain_len -= filename_len + 1;
        }

        err = -EINVAL;
        path_put(&parent_path);
out:
        return err;
}

/**
 * ksmbd_vfs_kern_path() - lookup a file and get path info
 * @work:               work
 * @filepath:           file path that is relative to share
 * @flags:              lookup flags
 * @path:               if lookup succeed, return path info
 * @caseless:   caseless filename lookup
 *
 * Perform the lookup, possibly crossing over any mount point.
 * On return no locks will be held and write-access to filesystem
 * won't have been checked.
 * Return:      0 if file was found, otherwise error
 */
int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *filepath,
                        unsigned int flags,
                        struct path *path, bool caseless)
{
        return __ksmbd_vfs_kern_path(work, filepath, flags, path,
                                     caseless, false);
}

/**
 * ksmbd_vfs_kern_path_start_removing() - lookup a file and get path info prior to removal
 * @work:               work
 * @filepath:           file path that is relative to share
 * @flags:              lookup flags
 * @path:               if lookup succeed, return path info
 * @caseless:   caseless filename lookup
 *
 * Perform the lookup, but don't cross over any mount point.
 * On return the parent of path->dentry will be locked and write-access to
 * filesystem will have been gained.
 * Return:      0 on if file was found, otherwise error
 */
int ksmbd_vfs_kern_path_start_removing(struct ksmbd_work *work, char *filepath,
                                       unsigned int flags,
                                       struct path *path, bool caseless)
{
        return __ksmbd_vfs_kern_path(work, filepath, flags, path,
                                     caseless, true);
}

void ksmbd_vfs_kern_path_end_removing(const struct path *path)
{
        end_removing(path->dentry);
        mnt_drop_write(path->mnt);
        mntput(path->mnt);
}

struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work,
                                          const char *name,
                                          unsigned int flags,
                                          struct path *path)
{
        char *abs_name;
        struct dentry *dent;

        abs_name = convert_to_unix_name(work->tcon->share_conf, name);
        if (!abs_name)
                return ERR_PTR(-ENOMEM);

        dent = start_creating_path(AT_FDCWD, abs_name, path, flags);
        kfree(abs_name);
        return dent;
}

int ksmbd_vfs_remove_acl_xattrs(struct mnt_idmap *idmap,
                                const struct path *path)
{
        char *name, *xattr_list = NULL;
        ssize_t xattr_list_len;
        int err = 0;

        xattr_list_len = ksmbd_vfs_listxattr(path->dentry, &xattr_list);
        if (xattr_list_len < 0) {
                goto out;
        } else if (!xattr_list_len) {
                ksmbd_debug(SMB, "empty xattr in the file\n");
                goto out;
        }

        err = mnt_want_write(path->mnt);
        if (err)
                goto out;

        for (name = xattr_list; name - xattr_list < xattr_list_len;
             name += strlen(name) + 1) {
                ksmbd_debug(SMB, "%s, len %zd\n", name, strlen(name));

                if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS,
                             sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1) ||
                    !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT,
                             sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1)) {
                        err = vfs_remove_acl(idmap, path->dentry, name);
                        if (err)
                                ksmbd_debug(SMB,
                                            "remove acl xattr failed : %s\n", name);
                }
        }
        mnt_drop_write(path->mnt);

out:
        kvfree(xattr_list);
        return err;
}

int ksmbd_vfs_remove_sd_xattrs(struct mnt_idmap *idmap, const struct path *path)
{
        char *name, *xattr_list = NULL;
        ssize_t xattr_list_len;
        int err = 0;

        xattr_list_len = ksmbd_vfs_listxattr(path->dentry, &xattr_list);
        if (xattr_list_len < 0) {
                goto out;
        } else if (!xattr_list_len) {
                ksmbd_debug(SMB, "empty xattr in the file\n");
                goto out;
        }

        for (name = xattr_list; name - xattr_list < xattr_list_len;
                        name += strlen(name) + 1) {
                ksmbd_debug(SMB, "%s, len %zd\n", name, strlen(name));

                if (!strncmp(name, XATTR_NAME_SD, XATTR_NAME_SD_LEN)) {
                        err = ksmbd_vfs_remove_xattr(idmap, path, name, true);
                        if (err)
                                ksmbd_debug(SMB, "remove xattr failed : %s\n", name);
                }
        }
out:
        kvfree(xattr_list);
        return err;
}

static struct xattr_smb_acl *ksmbd_vfs_make_xattr_posix_acl(struct mnt_idmap *idmap,
                                                            struct inode *inode,
                                                            int acl_type)
{
        struct xattr_smb_acl *smb_acl = NULL;
        struct posix_acl *posix_acls;
        struct posix_acl_entry *pa_entry;
        struct xattr_acl_entry *xa_entry;
        int i;

        if (!IS_ENABLED(CONFIG_FS_POSIX_ACL))
                return NULL;

        posix_acls = get_inode_acl(inode, acl_type);
        if (IS_ERR_OR_NULL(posix_acls))
                return NULL;

        smb_acl = kzalloc(sizeof(struct xattr_smb_acl) +
                          sizeof(struct xattr_acl_entry) * posix_acls->a_count,
                          KSMBD_DEFAULT_GFP);
        if (!smb_acl)
                goto out;

        smb_acl->count = posix_acls->a_count;
        pa_entry = posix_acls->a_entries;
        xa_entry = smb_acl->entries;
        for (i = 0; i < posix_acls->a_count; i++, pa_entry++, xa_entry++) {
                switch (pa_entry->e_tag) {
                case ACL_USER:
                        xa_entry->type = SMB_ACL_USER;
                        xa_entry->uid = posix_acl_uid_translate(idmap, pa_entry);
                        break;
                case ACL_USER_OBJ:
                        xa_entry->type = SMB_ACL_USER_OBJ;
                        break;
                case ACL_GROUP:
                        xa_entry->type = SMB_ACL_GROUP;
                        xa_entry->gid = posix_acl_gid_translate(idmap, pa_entry);
                        break;
                case ACL_GROUP_OBJ:
                        xa_entry->type = SMB_ACL_GROUP_OBJ;
                        break;
                case ACL_OTHER:
                        xa_entry->type = SMB_ACL_OTHER;
                        break;
                case ACL_MASK:
                        xa_entry->type = SMB_ACL_MASK;
                        break;
                default:
                        pr_err("unknown type : 0x%x\n", pa_entry->e_tag);
                        goto out;
                }

                if (pa_entry->e_perm & ACL_READ)
                        xa_entry->perm |= SMB_ACL_READ;
                if (pa_entry->e_perm & ACL_WRITE)
                        xa_entry->perm |= SMB_ACL_WRITE;
                if (pa_entry->e_perm & ACL_EXECUTE)
                        xa_entry->perm |= SMB_ACL_EXECUTE;
        }
out:
        posix_acl_release(posix_acls);
        return smb_acl;
}

int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
                           struct mnt_idmap *idmap,
                           const struct path *path,
                           struct smb_ntsd *pntsd, int len,
                           bool get_write)
{
        int rc;
        struct ndr sd_ndr = {0}, acl_ndr = {0};
        struct xattr_ntacl acl = {0};
        struct xattr_smb_acl *smb_acl, *def_smb_acl = NULL;
        struct dentry *dentry = path->dentry;
        struct inode *inode = d_inode(dentry);

        acl.version = 4;
        acl.hash_type = XATTR_SD_HASH_TYPE_SHA256;
        acl.current_time = ksmbd_UnixTimeToNT(current_time(inode));

        memcpy(acl.desc, "posix_acl", 9);
        acl.desc_len = 10;

        pntsd->osidoffset =
                cpu_to_le32(le32_to_cpu(pntsd->osidoffset) + NDR_NTSD_OFFSETOF);
        pntsd->gsidoffset =
                cpu_to_le32(le32_to_cpu(pntsd->gsidoffset) + NDR_NTSD_OFFSETOF);
        pntsd->dacloffset =
                cpu_to_le32(le32_to_cpu(pntsd->dacloffset) + NDR_NTSD_OFFSETOF);

        acl.sd_buf = (char *)pntsd;
        acl.sd_size = len;

        sha256(acl.sd_buf, acl.sd_size, acl.hash);

        smb_acl = ksmbd_vfs_make_xattr_posix_acl(idmap, inode,
                                                 ACL_TYPE_ACCESS);
        if (S_ISDIR(inode->i_mode))
                def_smb_acl = ksmbd_vfs_make_xattr_posix_acl(idmap, inode,
                                                             ACL_TYPE_DEFAULT);

        rc = ndr_encode_posix_acl(&acl_ndr, idmap, inode,
                                  smb_acl, def_smb_acl);
        if (rc) {
                pr_err("failed to encode ndr to posix acl\n");
                goto out;
        }

        sha256(acl_ndr.data, acl_ndr.offset, acl.posix_acl_hash);

        rc = ndr_encode_v4_ntacl(&sd_ndr, &acl);
        if (rc) {
                pr_err("failed to encode ndr to posix acl\n");
                goto out;
        }

        rc = ksmbd_vfs_setxattr(idmap, path,
                                XATTR_NAME_SD, sd_ndr.data,
                                sd_ndr.offset, 0, get_write);
        if (rc < 0)
                pr_err("Failed to store XATTR ntacl :%d\n", rc);

        kfree(sd_ndr.data);
out:
        kfree(acl_ndr.data);
        kfree(smb_acl);
        kfree(def_smb_acl);
        return rc;
}

int ksmbd_vfs_get_sd_xattr(struct ksmbd_conn *conn,
                           struct mnt_idmap *idmap,
                           struct dentry *dentry,
                           struct smb_ntsd **pntsd)
{
        int rc;
        struct ndr n;
        struct inode *inode = d_inode(dentry);
        struct ndr acl_ndr = {0};
        struct xattr_ntacl acl;
        struct xattr_smb_acl *smb_acl = NULL, *def_smb_acl = NULL;
        __u8 cmp_hash[XATTR_SD_HASH_SIZE] = {0};

        rc = ksmbd_vfs_getxattr(idmap, dentry, XATTR_NAME_SD, &n.data);
        if (rc <= 0)
                return rc;

        n.length = rc;
        rc = ndr_decode_v4_ntacl(&n, &acl);
        if (rc)
                goto free_n_data;

        smb_acl = ksmbd_vfs_make_xattr_posix_acl(idmap, inode,
                                                 ACL_TYPE_ACCESS);
        if (S_ISDIR(inode->i_mode))
                def_smb_acl = ksmbd_vfs_make_xattr_posix_acl(idmap, inode,
                                                             ACL_TYPE_DEFAULT);

        rc = ndr_encode_posix_acl(&acl_ndr, idmap, inode, smb_acl,
                                  def_smb_acl);
        if (rc) {
                pr_err("failed to encode ndr to posix acl\n");
                goto out_free;
        }

        sha256(acl_ndr.data, acl_ndr.offset, cmp_hash);

        if (memcmp(cmp_hash, acl.posix_acl_hash, XATTR_SD_HASH_SIZE)) {
                pr_err("hash value diff\n");
                rc = -EINVAL;
                goto out_free;
        }

        *pntsd = acl.sd_buf;
        if (acl.sd_size < sizeof(struct smb_ntsd)) {
                pr_err("sd size is invalid\n");
                goto out_free;
        }

        (*pntsd)->osidoffset = cpu_to_le32(le32_to_cpu((*pntsd)->osidoffset) -
                                           NDR_NTSD_OFFSETOF);
        (*pntsd)->gsidoffset = cpu_to_le32(le32_to_cpu((*pntsd)->gsidoffset) -
                                           NDR_NTSD_OFFSETOF);
        (*pntsd)->dacloffset = cpu_to_le32(le32_to_cpu((*pntsd)->dacloffset) -
                                           NDR_NTSD_OFFSETOF);

        rc = acl.sd_size;
out_free:
        kfree(acl_ndr.data);
        kfree(smb_acl);
        kfree(def_smb_acl);
        if (rc < 0) {
                kfree(acl.sd_buf);
                *pntsd = NULL;
        }

free_n_data:
        kfree(n.data);
        return rc;
}

int ksmbd_vfs_set_dos_attrib_xattr(struct mnt_idmap *idmap,
                                   const struct path *path,
                                   struct xattr_dos_attrib *da,
                                   bool get_write)
{
        struct ndr n;
        int err;

        err = ndr_encode_dos_attr(&n, da);
        if (err)
                return err;

        err = ksmbd_vfs_setxattr(idmap, path, XATTR_NAME_DOS_ATTRIBUTE,
                                 (void *)n.data, n.offset, 0, get_write);
        if (err)
                ksmbd_debug(SMB, "failed to store dos attribute in xattr\n");
        kfree(n.data);

        return err;
}

int ksmbd_vfs_get_dos_attrib_xattr(struct mnt_idmap *idmap,
                                   struct dentry *dentry,
                                   struct xattr_dos_attrib *da)
{
        struct ndr n;
        int err;

        err = ksmbd_vfs_getxattr(idmap, dentry, XATTR_NAME_DOS_ATTRIBUTE,
                                 (char **)&n.data);
        if (err > 0) {
                n.length = err;
                if (ndr_decode_dos_attr(&n, da))
                        err = -EINVAL;
                kfree(n.data);
        } else {
                ksmbd_debug(SMB, "failed to load dos attribute in xattr\n");
        }

        return err;
}

/**
 * ksmbd_vfs_init_kstat() - convert unix stat information to smb stat format
 * @p:          destination buffer
 * @ksmbd_kstat:      ksmbd kstat wrapper
 *
 * Returns: pointer to the converted &struct file_directory_info
 */
void *ksmbd_vfs_init_kstat(char **p, struct ksmbd_kstat *ksmbd_kstat)
{
        FILE_DIRECTORY_INFO *info = (FILE_DIRECTORY_INFO *)(*p);
        struct kstat *kstat = ksmbd_kstat->kstat;
        u64 time;

        info->FileIndex = 0;
        info->CreationTime = cpu_to_le64(ksmbd_kstat->create_time);
        time = ksmbd_UnixTimeToNT(kstat->atime);
        info->LastAccessTime = cpu_to_le64(time);
        time = ksmbd_UnixTimeToNT(kstat->mtime);
        info->LastWriteTime = cpu_to_le64(time);
        time = ksmbd_UnixTimeToNT(kstat->ctime);
        info->ChangeTime = cpu_to_le64(time);

        if (ksmbd_kstat->file_attributes & FILE_ATTRIBUTE_DIRECTORY_LE) {
                info->EndOfFile = 0;
                info->AllocationSize = 0;
        } else {
                info->EndOfFile = cpu_to_le64(kstat->size);
                info->AllocationSize = cpu_to_le64(kstat->blocks << 9);
        }
        info->ExtFileAttributes = ksmbd_kstat->file_attributes;

        return info;
}

int ksmbd_vfs_fill_dentry_attrs(struct ksmbd_work *work,
                                struct mnt_idmap *idmap,
                                struct dentry *dentry,
                                struct ksmbd_kstat *ksmbd_kstat)
{
        struct ksmbd_share_config *share_conf = work->tcon->share_conf;
        u64 time;
        int rc;
        struct path path = {
                .mnt = share_conf->vfs_path.mnt,
                .dentry = dentry,
        };

        rc = vfs_getattr(&path, ksmbd_kstat->kstat,
                         STATX_BASIC_STATS | STATX_BTIME,
                         AT_STATX_SYNC_AS_STAT);
        if (rc)
                return rc;

        time = ksmbd_UnixTimeToNT(ksmbd_kstat->kstat->ctime);
        ksmbd_kstat->create_time = time;

        /*
         * set default value for the case that store dos attributes is not yes
         * or that acl is disable in server's filesystem and the config is yes.
         */
        if (S_ISDIR(ksmbd_kstat->kstat->mode))
                ksmbd_kstat->file_attributes = FILE_ATTRIBUTE_DIRECTORY_LE;
        else
                ksmbd_kstat->file_attributes = FILE_ATTRIBUTE_ARCHIVE_LE;

        if (test_share_config_flag(work->tcon->share_conf,
                                   KSMBD_SHARE_FLAG_STORE_DOS_ATTRS)) {
                struct xattr_dos_attrib da;

                rc = ksmbd_vfs_get_dos_attrib_xattr(idmap, dentry, &da);
                if (rc > 0) {
                        ksmbd_kstat->file_attributes = cpu_to_le32(da.attr);
                        ksmbd_kstat->create_time = da.create_time;
                } else {
                        ksmbd_debug(VFS, "fail to load dos attribute.\n");
                }
        }

        return 0;
}

ssize_t ksmbd_vfs_casexattr_len(struct mnt_idmap *idmap,
                                struct dentry *dentry, char *attr_name,
                                int attr_name_len)
{
        char *name, *xattr_list = NULL;
        ssize_t value_len = -ENOENT, xattr_list_len;

        xattr_list_len = ksmbd_vfs_listxattr(dentry, &xattr_list);
        if (xattr_list_len <= 0)
                goto out;

        for (name = xattr_list; name - xattr_list < xattr_list_len;
                        name += strlen(name) + 1) {
                ksmbd_debug(VFS, "%s, len %zd\n", name, strlen(name));
                if (strncasecmp(attr_name, name, attr_name_len))
                        continue;

                value_len = ksmbd_vfs_xattr_len(idmap, dentry, name);
                break;
        }

out:
        kvfree(xattr_list);
        return value_len;
}

int ksmbd_vfs_xattr_stream_name(char *stream_name, char **xattr_stream_name,
                                size_t *xattr_stream_name_size, int s_type)
{
        char *type, *buf;

        if (s_type == DIR_STREAM)
                type = ":$INDEX_ALLOCATION";
        else
                type = ":$DATA";

        buf = kasprintf(KSMBD_DEFAULT_GFP, "%s%s%s",
                        XATTR_NAME_STREAM, stream_name, type);
        if (!buf)
                return -ENOMEM;

        *xattr_stream_name = buf;
        *xattr_stream_name_size = strlen(buf) + 1;

        return 0;
}

int ksmbd_vfs_copy_file_ranges(struct ksmbd_work *work,
                               struct ksmbd_file *src_fp,
                               struct ksmbd_file *dst_fp,
                               struct srv_copychunk *chunks,
                               unsigned int chunk_count,
                               unsigned int *chunk_count_written,
                               unsigned int *chunk_size_written,
                               loff_t *total_size_written)
{
        unsigned int i;
        loff_t src_off, dst_off, src_file_size;
        size_t len;
        int ret;

        *chunk_count_written = 0;
        *chunk_size_written = 0;
        *total_size_written = 0;

        if (!(src_fp->daccess & (FILE_READ_DATA_LE | FILE_EXECUTE_LE))) {
                pr_err("no right to read(%pD)\n", src_fp->filp);
                return -EACCES;
        }
        if (!(dst_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE))) {
                pr_err("no right to write(%pD)\n", dst_fp->filp);
                return -EACCES;
        }

        if (ksmbd_stream_fd(src_fp) || ksmbd_stream_fd(dst_fp))
                return -EBADF;

        smb_break_all_levII_oplock(work, dst_fp, 1);

        if (!work->tcon->posix_extensions) {
                for (i = 0; i < chunk_count; i++) {
                        src_off = le64_to_cpu(chunks[i].SourceOffset);
                        dst_off = le64_to_cpu(chunks[i].TargetOffset);
                        len = le32_to_cpu(chunks[i].Length);

                        if (check_lock_range(src_fp->filp, src_off,
                                             src_off + len - 1, READ))
                                return -EAGAIN;
                        if (check_lock_range(dst_fp->filp, dst_off,
                                             dst_off + len - 1, WRITE))
                                return -EAGAIN;
                }
        }

        src_file_size = i_size_read(file_inode(src_fp->filp));

        for (i = 0; i < chunk_count; i++) {
                src_off = le64_to_cpu(chunks[i].SourceOffset);
                dst_off = le64_to_cpu(chunks[i].TargetOffset);
                len = le32_to_cpu(chunks[i].Length);

                if (src_off + len > src_file_size)
                        return -E2BIG;

                /*
                 * vfs_copy_file_range does not allow overlapped copying
                 * within the same file.
                 */
                if (file_inode(src_fp->filp) == file_inode(dst_fp->filp) &&
                                dst_off + len > src_off &&
                                dst_off < src_off + len)
                        ret = do_splice_direct(src_fp->filp, &src_off,
                                        dst_fp->filp, &dst_off,
                                        min_t(size_t, len, MAX_RW_COUNT), 0);
                else
                        ret = vfs_copy_file_range(src_fp->filp, src_off,
                                        dst_fp->filp, dst_off, len, 0);
                if (ret == -EOPNOTSUPP || ret == -EXDEV)
                        ret = vfs_copy_file_range(src_fp->filp, src_off,
                                                  dst_fp->filp, dst_off, len,
                                                  COPY_FILE_SPLICE);
                if (ret < 0)
                        return ret;

                *chunk_count_written += 1;
                *total_size_written += ret;
        }
        return 0;
}

void ksmbd_vfs_posix_lock_wait(struct file_lock *flock)
{
        wait_event(flock->c.flc_wait, !flock->c.flc_blocker);
}

void ksmbd_vfs_posix_lock_unblock(struct file_lock *flock)
{
        locks_delete_block(flock);
}

int ksmbd_vfs_set_init_posix_acl(struct mnt_idmap *idmap,
                                 const struct path *path)
{
        struct posix_acl_state acl_state;
        struct posix_acl *acls;
        struct dentry *dentry = path->dentry;
        struct inode *inode = d_inode(dentry);
        int rc;

        if (!IS_ENABLED(CONFIG_FS_POSIX_ACL))
                return -EOPNOTSUPP;

        ksmbd_debug(SMB, "Set posix acls\n");
        rc = init_acl_state(&acl_state, 1);
        if (rc)
                return rc;

        /* Set default owner group */
        acl_state.owner.allow = (inode->i_mode & 0700) >> 6;
        acl_state.group.allow = (inode->i_mode & 0070) >> 3;
        acl_state.other.allow = inode->i_mode & 0007;
        acl_state.users->aces[acl_state.users->n].uid = inode->i_uid;
        acl_state.users->aces[acl_state.users->n++].perms.allow =
                acl_state.owner.allow;
        acl_state.groups->aces[acl_state.groups->n].gid = inode->i_gid;
        acl_state.groups->aces[acl_state.groups->n++].perms.allow =
                acl_state.group.allow;
        acl_state.mask.allow = 0x07;

        acls = posix_acl_alloc(6, KSMBD_DEFAULT_GFP);
        if (!acls) {
                free_acl_state(&acl_state);
                return -ENOMEM;
        }
        posix_state_to_acl(&acl_state, acls->a_entries);

        rc = set_posix_acl(idmap, dentry, ACL_TYPE_ACCESS, acls);
        if (rc < 0)
                ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
                            rc);
        else if (S_ISDIR(inode->i_mode)) {
                posix_state_to_acl(&acl_state, acls->a_entries);
                rc = set_posix_acl(idmap, dentry, ACL_TYPE_DEFAULT, acls);
                if (rc < 0)
                        ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
                                    rc);
        }

        free_acl_state(&acl_state);
        posix_acl_release(acls);
        return rc;
}

int ksmbd_vfs_inherit_posix_acl(struct mnt_idmap *idmap,
                                const struct path *path, struct inode *parent_inode)
{
        struct posix_acl *acls;
        struct posix_acl_entry *pace;
        struct dentry *dentry = path->dentry;
        struct inode *inode = d_inode(dentry);
        int rc, i;

        if (!IS_ENABLED(CONFIG_FS_POSIX_ACL))
                return -EOPNOTSUPP;

        acls = get_inode_acl(parent_inode, ACL_TYPE_DEFAULT);
        if (IS_ERR_OR_NULL(acls))
                return -ENOENT;
        pace = acls->a_entries;

        for (i = 0; i < acls->a_count; i++, pace++) {
                if (pace->e_tag == ACL_MASK) {
                        pace->e_perm = 0x07;
                        break;
                }
        }

        rc = set_posix_acl(idmap, dentry, ACL_TYPE_ACCESS, acls);
        if (rc < 0)
                ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
                            rc);
        if (S_ISDIR(inode->i_mode)) {
                rc = set_posix_acl(idmap, dentry, ACL_TYPE_DEFAULT,
                                   acls);
                if (rc < 0)
                        ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
                                    rc);
        }

        posix_acl_release(acls);
        return rc;
}