/**
 * anon_inode_getfd - creates a new file instance by hooking it up to an
 *                    anonymous inode, and a dentry that describe the "class"
 *                    of the file
 *
 * @name:    [in]    name of the "class" of the new file
 * @fops:    [in]    file operations for the new file
 * @priv:    [in]    private data for the new file (will be file's private_data)
 * @flags:   [in]    flags
 *
 * Creates a new file by hooking it on a single inode. This is useful for files
 * that do not need to have a full-fledged inode in order to operate correctly.
 * All the files created with anon_inode_getfd() will share a single inode,
 * hence saving memory and avoiding code duplication for the file/inode/dentry
 * setup.  Returns new descriptor or -error.
 */
int anon_inode_getfd(const char *name, const struct file_operations *fops,
		     void *priv, int flags)
{
	struct qstr this;
	struct dentry *dentry;
	struct file *file;
	int error, fd;

	if (IS_ERR(anon_inode_inode))
		return -ENODEV;

	if (fops->owner && !try_module_get(fops->owner))
		return -ENOENT;

	error = get_unused_fd_flags(flags);
	if (error < 0)
		goto err_module;
	fd = error;

	/*
	 * Link the inode to a directory entry by creating a unique name
	 * using the inode sequence number.
	 */
	error = -ENOMEM;
	this.name = name;
	this.len = strlen(name);
	this.hash = 0;
	dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this);
	if (!dentry)
		goto err_put_unused_fd;

	/*
	 * We know the anon_inode inode count is always greater than zero,
	 * so we can avoid doing an igrab() and we can use an open-coded
	 * atomic_inc().
	 */
	atomic_inc(&anon_inode_inode->i_count);

	dentry->d_op = &anon_inodefs_dentry_operations;
	/* Do not publish this dentry inside the global dentry hash table */
	dentry->d_flags &= ~DCACHE_UNHASHED;
	d_instantiate(dentry, anon_inode_inode);

	error = -ENFILE;
	file = alloc_file(anon_inode_mnt, dentry,
			  FMODE_READ | FMODE_WRITE, fops);
	if (!file)
		goto err_dput;
	file->f_mapping = anon_inode_inode->i_mapping;

	file->f_pos = 0;
	file->f_flags = O_RDWR | (flags & O_NONBLOCK);
	file->f_version = 0;
	file->private_data = priv;

	fd_install(fd, file);

	return fd;

err_dput:
	dput(dentry);
err_put_unused_fd:
	put_unused_fd(fd);
err_module:
	module_put(fops->owner);
	return error;
}

//.........这里部分代码省略.........
        goto out_parent;

    err = 0;
    sb = dentry->d_sb;
    a->bdst = au_dbstart(dentry);
    a->h_path.dentry = au_h_dptr(dentry, a->bdst);
    a->h_path.mnt = au_sbr_mnt(sb, a->bdst);
    a->bsrc = au_ibstart(inode);
    h_src_dentry = au_h_d_alias(src_dentry, a->bsrc);
    if (!h_src_dentry) {
        a->bsrc = au_dbstart(src_dentry);
        h_src_dentry = au_h_d_alias(src_dentry, a->bsrc);
        AuDebugOn(!h_src_dentry);
    } else if (IS_ERR(h_src_dentry))
        goto out_parent;

    if (au_opt_test(au_mntflags(sb), PLINK)) {
        if (a->bdst < a->bsrc
                /* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */)
            err = au_cpup_or_link(src_dentry, a);
        else
            err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
                             &a->h_path);
        dput(h_src_dentry);
    } else {
        /*
         * copyup src_dentry to the branch we process,
         * and then link(2) to it.
         */
        dput(h_src_dentry);
        if (a->bdst < a->bsrc
                /* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */) {
            au_unpin(&a->pin);
            di_write_unlock(a->parent);
            err = au_cpup_before_link(src_dentry, a);
            di_write_lock_parent(a->parent);
            if (!err)
                err = au_pin(&a->pin, dentry, a->bdst,
                             au_opt_udba(sb),
                             AuPin_DI_LOCKED | AuPin_MNT_WRITE);
            if (unlikely(err))
                goto out_wh;
        }
        if (!err) {
            h_src_dentry = au_h_dptr(src_dentry, a->bdst);
            err = -ENOENT;
            if (h_src_dentry && h_src_dentry->d_inode)
                err = vfsub_link(h_src_dentry,
                                 au_pinned_h_dir(&a->pin),
                                 &a->h_path);
        }
    }
    if (unlikely(err))
        goto out_unpin;

    if (wh_dentry) {
        a->h_path.dentry = wh_dentry;
        err = au_wh_unlink_dentry(au_pinned_h_dir(&a->pin), &a->h_path,
                                  dentry);
        if (unlikely(err))
            goto out_revert;
    }

    dir->i_version++;
    if (au_ibstart(dir) == au_dbstart(dentry))
        au_cpup_attr_timesizes(dir);
    inc_nlink(inode);
    inode->i_ctime = dir->i_ctime;
    d_instantiate(dentry, au_igrab(inode));
    if (d_unhashed(a->h_path.dentry))
        /* some filesystem calls d_drop() */
        d_drop(dentry);
    goto out_unpin; /* success */

out_revert:
    rerr = vfsub_unlink(au_pinned_h_dir(&a->pin), &a->h_path, /*force*/0);
    if (unlikely(rerr)) {
        AuIOErr("%.*s reverting failed(%d, %d)\n",
                AuDLNPair(dentry), err, rerr);
        err = -EIO;
    }
    au_dtime_revert(&dt);
out_unpin:
    au_unpin(&a->pin);
out_wh:
    dput(wh_dentry);
out_parent:
    di_write_unlock(a->parent);
    dput(a->src_parent);
out_unlock:
    if (unlikely(err)) {
        au_update_dbstart(dentry);
        d_drop(dentry);
    }
    aufs_read_and_write_unlock2(dentry, src_dentry);
out_kfree:
    kfree(a);
out:
    return err;
}

/*
 * Code shared between mknod, mkdir, symlink and link
 */
static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
			    struct inode *dir, struct dentry *entry,
			    umode_t mode)
{
	struct fuse_entry_out outarg;
	struct inode *inode;
	int err;
	struct fuse_forget_link *forget;

	forget = fuse_alloc_forget();
	if (!forget) {
		fuse_put_request(fc, req);
		return -ENOMEM;
	}

	memset(&outarg, 0, sizeof(outarg));
	req->in.h.nodeid = get_node_id(dir);
	req->out.numargs = 1;
	if (fc->minor < 9)
		req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
	else
		req->out.args[0].size = sizeof(outarg);
	req->out.args[0].value = &outarg;
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err)
		goto out_put_forget_req;

	err = -EIO;
	if (invalid_nodeid(outarg.nodeid))
		goto out_put_forget_req;

	if ((outarg.attr.mode ^ mode) & S_IFMT)
		goto out_put_forget_req;

	inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
			  &outarg.attr, entry_attr_timeout(&outarg), 0);
	if (!inode) {
		fuse_queue_forget(fc, forget, outarg.nodeid, 1);
		return -ENOMEM;
	}
	kfree(forget);

	if (S_ISDIR(inode->i_mode)) {
		struct dentry *alias;
		mutex_lock(&fc->inst_mutex);
		alias = d_find_alias(inode);
		if (alias) {
			/* New directory must have moved since mkdir */
			mutex_unlock(&fc->inst_mutex);
			dput(alias);
			iput(inode);
			return -EBUSY;
		}
		d_instantiate(entry, inode);
		mutex_unlock(&fc->inst_mutex);
	} else
		d_instantiate(entry, inode);

	fuse_change_entry_timeout(entry, &outarg);
	fuse_invalidate_attr(dir);
	return 0;

 out_put_forget_req:
	kfree(forget);
	return err;
}

static int afs_symlink(struct inode *dir, struct dentry *dentry,
		       const char *content)
{
	struct afs_file_status status;
	struct afs_server *server;
	struct afs_vnode *dvnode, *vnode;
	struct afs_fid fid;
	struct inode *inode;
	struct key *key;
	int ret;

	dvnode = AFS_FS_I(dir);

	_enter("{%x:%u},{%s},%s",
	       dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name,
	       content);

	ret = -ENAMETOOLONG;
	if (dentry->d_name.len >= AFSNAMEMAX)
		goto error;

	ret = -EINVAL;
	if (strlen(content) >= AFSPATHMAX)
		goto error;

	key = afs_request_key(dvnode->volume->cell);
	if (IS_ERR(key)) {
		ret = PTR_ERR(key);
		goto error;
	}

	ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
				&fid, &status, &server);
	if (ret < 0)
		goto create_error;

	inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
	if (IS_ERR(inode)) {
		/* ENOMEM at a really inconvenient time - just abandon the new
		 * directory on the server */
		ret = PTR_ERR(inode);
		goto iget_error;
	}

	/* apply the status report we've got for the new vnode */
	vnode = AFS_FS_I(inode);
	spin_lock(&vnode->lock);
	vnode->update_cnt++;
	spin_unlock(&vnode->lock);
	afs_vnode_finalise_status_update(vnode, server);
	afs_put_server(server);

	d_instantiate(dentry, inode);
	if (d_unhashed(dentry)) {
		_debug("not hashed");
		d_rehash(dentry);
	}
	key_put(key);
	_leave(" = 0");
	return 0;

iget_error:
	afs_put_server(server);
create_error:
	key_put(key);
error:
	d_drop(dentry);
	_leave(" = %d", ret);
	return ret;
}

/***** Make a directory */
int msdos_mkdir(struct inode *dir,struct dentry *dentry,int mode)
{
	struct super_block *sb = dir->i_sb;
	struct buffer_head *bh;
	struct msdos_dir_entry *de;
	struct inode *inode;
	int res,is_hid;
	char msdos_name[MSDOS_NAME];
	int ino;

	res = msdos_format_name(dentry->d_name.name,dentry->d_name.len,
				msdos_name, &MSDOS_SB(sb)->options);
	if (res < 0)
		return res;
	is_hid = (dentry->d_name.name[0]=='.') && (msdos_name[0]!='.');
	/* foo vs .foo situation */
	if (fat_scan(dir,msdos_name,&bh,&de,&ino) >= 0)
		goto out_exist;

	res = msdos_add_entry(dir, msdos_name, &bh, &de, &ino, 1, is_hid);
	if (res)
		goto out_unlock;
	inode = fat_build_inode(dir->i_sb, de, ino, &res);
	if (!inode) {
		fat_brelse(sb, bh);
		goto out_unlock;
	}
	res = 0;

	dir->i_nlink++;
	inode->i_nlink = 2; /* no need to mark them dirty */

	res = fat_new_dir(inode, dir, 0);
	if (res)
		goto mkdir_error;

	fat_brelse(sb, bh);
	d_instantiate(dentry, inode);
	res = 0;

out_unlock:
	return res;

mkdir_error:
	printk("msdos_mkdir: error=%d, attempting cleanup\n", res);
	inode->i_nlink = 0;
	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
	dir->i_nlink--;
	mark_inode_dirty(inode);
	mark_inode_dirty(dir);
	de->name[0] = DELETED_FLAG;
	fat_mark_buffer_dirty(sb, bh);
	fat_brelse(sb, bh);
	fat_detach(inode);
	iput(inode);
	goto out_unlock;

out_exist:
	fat_brelse(sb, bh);
	res = -EINVAL;
	goto out_unlock;
}

static int reiserfs_symlink(struct inode *parent_dir,
			    struct dentry *dentry, const char *symname)
{
	int retval;
	struct inode *inode;
	char *name;
	int item_len;
	struct reiserfs_transaction_handle th;
	struct reiserfs_security_handle security;
	int mode = S_IFLNK | S_IRWXUGO;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 3 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(parent_dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(parent_dir->i_sb));

	dquot_initialize(parent_dir);

	if (!(inode = new_inode(parent_dir->i_sb))) {
		return -ENOMEM;
	}
	new_inode_init(inode, parent_dir, mode);

	retval = reiserfs_security_init(parent_dir, inode, &dentry->d_name,
					&security);
	if (retval < 0) {
		drop_new_inode(inode);
		return retval;
	}
	jbegin_count += retval;

	reiserfs_write_lock(parent_dir->i_sb);
	item_len = ROUND_UP(strlen(symname));
	if (item_len > MAX_DIRECT_ITEM_LEN(parent_dir->i_sb->s_blocksize)) {
		retval = -ENAMETOOLONG;
		drop_new_inode(inode);
		goto out_failed;
	}

	name = kmalloc(item_len, GFP_NOFS);
	if (!name) {
		drop_new_inode(inode);
		retval = -ENOMEM;
		goto out_failed;
	}
	memcpy(name, symname, strlen(symname));
	padd_item(name, item_len, strlen(symname));

	retval = journal_begin(&th, parent_dir->i_sb, jbegin_count);
	if (retval) {
		drop_new_inode(inode);
		kfree(name);
		goto out_failed;
	}

	retval =
	    reiserfs_new_inode(&th, parent_dir, mode, name, strlen(symname),
			       dentry, inode, &security);
	kfree(name);
	if (retval) {		/* reiserfs_new_inode iputs for us */
		goto out_failed;
	}

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(parent_dir);

	inode->i_op = &reiserfs_symlink_inode_operations;
	inode->i_mapping->a_ops = &reiserfs_address_space_operations;

	// must be sure this inode is written with this transaction
	//
	//reiserfs_update_sd (&th, inode, READ_BLOCKS);

	retval = reiserfs_add_entry(&th, parent_dir, dentry->d_name.name,
				    dentry->d_name.len, inode, 1 /*visible */ );
	if (retval) {
		int err;
		inode->i_nlink--;
		reiserfs_update_sd(&th, inode);
		err = journal_end(&th, parent_dir->i_sb, jbegin_count);
		if (err)
			retval = err;
		unlock_new_inode(inode);
		iput(inode);
		goto out_failed;
	}

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	retval = journal_end(&th, parent_dir->i_sb, jbegin_count);
      out_failed:
	reiserfs_write_unlock(parent_dir->i_sb);
	return retval;
}

static int reiserfs_create(struct inode *dir, struct dentry *dentry, int mode,
			   struct nameidata *nd)
{
	int retval;
	struct inode *inode;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 2 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));
	struct reiserfs_transaction_handle th;
	struct reiserfs_security_handle security;

	dquot_initialize(dir);

	if (!(inode = new_inode(dir->i_sb))) {
		return -ENOMEM;
	}
	new_inode_init(inode, dir, mode);

	jbegin_count += reiserfs_cache_default_acl(dir);
	retval = reiserfs_security_init(dir, inode, &dentry->d_name, &security);
	if (retval < 0) {
		drop_new_inode(inode);
		return retval;
	}
	jbegin_count += retval;
	reiserfs_write_lock(dir->i_sb);

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		drop_new_inode(inode);
		goto out_failed;
	}

	retval =
	    reiserfs_new_inode(&th, dir, mode, NULL, 0 /*i_size */ , dentry,
			       inode, &security);
	if (retval)
		goto out_failed;

	inode->i_op = &reiserfs_file_inode_operations;
	inode->i_fop = &reiserfs_file_operations;
	inode->i_mapping->a_ops = &reiserfs_address_space_operations;

	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );
	if (retval) {
		int err;
		inode->i_nlink--;
		reiserfs_update_sd(&th, inode);
		err = journal_end(&th, dir->i_sb, jbegin_count);
		if (err)
			retval = err;
		unlock_new_inode(inode);
		iput(inode);
		goto out_failed;
	}
	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	retval = journal_end(&th, dir->i_sb, jbegin_count);

      out_failed:
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}

void *ns_get_path(struct path *path, struct task_struct *task,
			const struct proc_ns_operations *ns_ops)
{
	struct vfsmount *mnt = mntget(nsfs_mnt);
	struct qstr qname = { .name = "", };
	struct dentry *dentry;
	struct inode *inode;
	struct ns_common *ns;
	unsigned long d;

again:
	ns = ns_ops->get(task);
	if (!ns) {
		mntput(mnt);
		return ERR_PTR(-ENOENT);
	}
	rcu_read_lock();
	d = atomic_long_read(&ns->stashed);
	if (!d)
		goto slow;
	dentry = (struct dentry *)d;
	if (!lockref_get_not_dead(&dentry->d_lockref))
		goto slow;
	rcu_read_unlock();
	ns_ops->put(ns);
got_it:
	path->mnt = mnt;
	path->dentry = dentry;
	return NULL;
slow:
	rcu_read_unlock();
	inode = new_inode_pseudo(mnt->mnt_sb);
	if (!inode) {
		ns_ops->put(ns);
		mntput(mnt);
		return ERR_PTR(-ENOMEM);
	}
	inode->i_ino = ns->inum;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	inode->i_flags |= S_IMMUTABLE;
	inode->i_mode = S_IFREG | S_IRUGO;
	inode->i_fop = &ns_file_operations;
	inode->i_private = ns;

	dentry = d_alloc_pseudo(mnt->mnt_sb, &qname);
	if (!dentry) {
		iput(inode);
		mntput(mnt);
		return ERR_PTR(-ENOMEM);
	}
	d_instantiate(dentry, inode);
	dentry->d_fsdata = (void *)ns_ops;
	d = atomic_long_cmpxchg(&ns->stashed, 0, (unsigned long)dentry);
	if (d) {
		d_delete(dentry);	/* make sure ->d_prune() does nothing */
		dput(dentry);
		cpu_relax();
		goto again;
	}
	goto got_it;
}

int ns_get_name(char *buf, size_t size, struct task_struct *task,
			const struct proc_ns_operations *ns_ops)
{
	struct ns_common *ns;
	int res = -ENOENT;
	ns = ns_ops->get(task);
	if (ns) {
		res = snprintf(buf, size, "%s:[%u]", ns_ops->name, ns->inum);
		ns_ops->put(ns);
	}
	return res;
}

struct file *proc_ns_fget(int fd)
{
	struct file *file;

	file = fget(fd);
	if (!file)
		return ERR_PTR(-EBADF);

	if (file->f_op != &ns_file_operations)
		goto out_invalid;

	return file;

out_invalid:
	fput(file);
	return ERR_PTR(-EINVAL);
}

static const struct super_operations nsfs_ops = {
	.statfs = simple_statfs,
	.evict_inode = nsfs_evict,
};
static struct dentry *nsfs_mount(struct file_system_type *fs_type,
			int flags, const char *dev_name, void *data)
{
//.........这里部分代码省略.........

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

	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;

	down(&inode->i_sb->s_vfs_rename_sem);
	full_path = build_path_from_dentry(direntry);
	up(&inode->i_sb->s_vfs_rename_sem);
	if (full_path == NULL) {
		FreeXid(xid);
		return -ENOMEM;
	}
	/* 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 {
		inode->i_nlink++;
		if (pTcon->ses->capabilities & CAP_UNIX)
			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);

		direntry->d_op = &cifs_dentry_ops;
		d_instantiate(direntry, newinode);
		if (direntry->d_inode)
			direntry->d_inode->i_nlink = 2;
		if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
				CIFSSMBUnixSetPerms(xid, pTcon, full_path,
						    mode,
						    (__u64)current->euid,
						    (__u64)current->egid,
						    0 /* dev_t */,
						    cifs_sb->local_nls,
						    cifs_sb->mnt_cifs_flags &
						    CIFS_MOUNT_MAP_SPECIAL_CHR);
			} else {
				CIFSSMBUnixSetPerms(xid, pTcon, full_path,
						    mode, (__u64)-1,
						    (__u64)-1, 0 /* dev_t */,
						    cifs_sb->local_nls,
						    cifs_sb->mnt_cifs_flags & 
						    CIFS_MOUNT_MAP_SPECIAL_CHR);
			}
		else {
			/* BB to be implemented via Windows secrty descriptors
			   eg CIFSSMBWinSetPerms(xid, pTcon, full_path, mode,
						 -1, -1, local_nls); */
		}
	}
	kfree(full_path);
	FreeXid(xid);
	return rc;
}

//.........这里部分代码省略.........
			goto err_out;

		err = f2fs_fname_crypto_alloc_buffer(inode, len, &disk_link);
		if (err)
			goto err_out;

		err = f2fs_fname_usr_to_disk(inode, &istr, &disk_link);
		if (err < 0)
			goto err_out;

		p_len = encrypted_symlink_data_len(disk_link.len) + 1;

		if (p_len > dir->i_sb->s_blocksize) {
			err = -ENAMETOOLONG;
			goto err_out;
		}

		sd = kzalloc(p_len, GFP_NOFS);
		if (!sd) {
			err = -ENOMEM;
			goto err_out;
		}
		memcpy(sd->encrypted_path, disk_link.name, disk_link.len);
		sd->len = cpu_to_le16(disk_link.len);
		p_str = (char *)sd;
	} else {
		p_len = len + 1;
		p_str = (char *)symname;
	}

	err = page_symlink(inode, p_str, p_len);

err_out:
	d_instantiate(dentry, inode);
	unlock_new_inode(inode);

	/*
	 * Let's flush symlink data in order to avoid broken symlink as much as
	 * possible. Nevertheless, fsyncing is the best way, but there is no
	 * way to get a file descriptor in order to flush that.
	 *
	 * Note that, it needs to do dir->fsync to make this recoverable.
	 * If the symlink path is stored into inline_data, there is no
	 * performance regression.
	 */
	if (!err)
		filemap_write_and_wait_range(inode->i_mapping, 0, p_len - 1);

	if (IS_DIRSYNC(dir))
		f2fs_sync_fs(sbi->sb, 1);

	kfree(sd);
	f2fs_fname_crypto_free_buffer(&disk_link);
	return err;
out:
	handle_failed_inode(inode);
	return err;
}

static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
	struct inode *inode;
	int err;

	f2fs_balance_fs(sbi);

static int reiserfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
			  dev_t rdev)
{
	int retval;
	struct inode *inode;
	struct reiserfs_transaction_handle th;
	struct reiserfs_security_handle security;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 3 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));

	if (!new_valid_dev(rdev))
		return -EINVAL;

	dquot_initialize(dir);

	if (!(inode = new_inode(dir->i_sb))) {
		return -ENOMEM;
	}
	new_inode_init(inode, dir, mode);

	jbegin_count += reiserfs_cache_default_acl(dir);
	retval = reiserfs_security_init(dir, inode, &dentry->d_name, &security);
	if (retval < 0) {
		drop_new_inode(inode);
		return retval;
	}
	jbegin_count += retval;
	reiserfs_write_lock(dir->i_sb);

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		drop_new_inode(inode);
		goto out_failed;
	}

	retval =
	    reiserfs_new_inode(&th, dir, mode, NULL, 0 /*i_size */ , dentry,
			       inode, &security);
	if (retval) {
		goto out_failed;
	}

	inode->i_op = &reiserfs_special_inode_operations;
	init_special_inode(inode, inode->i_mode, rdev);

	//FIXME: needed for block and char devices only
	reiserfs_update_sd(&th, inode);

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );
	if (retval) {
		int err;
		inode->i_nlink--;
		reiserfs_update_sd(&th, inode);
		err = journal_end(&th, dir->i_sb, jbegin_count);
		if (err)
			retval = err;
		unlock_new_inode(inode);
		iput(inode);
		goto out_failed;
	}

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	retval = journal_end(&th, dir->i_sb, jbegin_count);

      out_failed:
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}

//.........这里部分代码省略.........
	/*
	 * 1 - inode item
	 * 2 - refs
	 * 1 - root item
	 * 2 - dir items
	 */
	trans = btrfs_start_transaction(root, 6);
	if (IS_ERR(trans))
		return PTR_ERR(trans);

	leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
				      0, objectid, NULL, 0, 0, 0);
	if (IS_ERR(leaf)) {
		ret = PTR_ERR(leaf);
		goto fail;
	}

	memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
	btrfs_set_header_bytenr(leaf, leaf->start);
	btrfs_set_header_generation(leaf, trans->transid);
	btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
	btrfs_set_header_owner(leaf, objectid);

	write_extent_buffer(leaf, root->fs_info->fsid,
			    (unsigned long)btrfs_header_fsid(leaf),
			    BTRFS_FSID_SIZE);
	write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
			    (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
			    BTRFS_UUID_SIZE);
	btrfs_mark_buffer_dirty(leaf);

	inode_item = &root_item.inode;
	memset(inode_item, 0, sizeof(*inode_item));
	inode_item->generation = cpu_to_le64(1);
	inode_item->size = cpu_to_le64(3);
	inode_item->nlink = cpu_to_le32(1);
	inode_item->nbytes = cpu_to_le64(root->leafsize);
	inode_item->mode = cpu_to_le32(S_IFDIR | 0755);

	btrfs_set_root_bytenr(&root_item, leaf->start);
	btrfs_set_root_generation(&root_item, trans->transid);
	btrfs_set_root_level(&root_item, 0);
	btrfs_set_root_refs(&root_item, 1);
	btrfs_set_root_used(&root_item, leaf->len);
	btrfs_set_root_last_snapshot(&root_item, 0);

	memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
	root_item.drop_level = 0;

	btrfs_tree_unlock(leaf);
	free_extent_buffer(leaf);
	leaf = NULL;

	btrfs_set_root_dirid(&root_item, new_dirid);

	key.objectid = objectid;
	key.offset = 0;
	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
	ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
				&root_item);
	if (ret)
		goto fail;

	key.offset = (u64)-1;
	new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
	BUG_ON(IS_ERR(new_root));

	btrfs_record_root_in_trans(trans, new_root);

	ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
				       BTRFS_I(dir)->block_group);
	/*
	 * insert the directory item
	 */
	ret = btrfs_set_inode_index(dir, &index);
	BUG_ON(ret);

	ret = btrfs_insert_dir_item(trans, root,
				    name, namelen, dir->i_ino, &key,
				    BTRFS_FT_DIR, index);
	if (ret)
		goto fail;

	btrfs_i_size_write(dir, dir->i_size + namelen * 2);
	ret = btrfs_update_inode(trans, root, dir);
	BUG_ON(ret);

	ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
				 objectid, root->root_key.objectid,
				 dir->i_ino, index, name, namelen);

	BUG_ON(ret);

	d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
fail:
	err = btrfs_commit_transaction(trans, root);
	if (err && !ret)
		ret = err;
	return ret;
}

static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	int retval;
	struct inode *inode;
	struct reiserfs_transaction_handle th;
	struct reiserfs_security_handle security;
	int lock_depth;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 3 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));

	dquot_initialize(dir);

#ifdef DISPLACE_NEW_PACKING_LOCALITIES
	/* set flag that new packing locality created and new blocks for the content     * of that directory are not displaced yet */
	REISERFS_I(dir)->new_packing_locality = 1;
#endif
	mode = S_IFDIR | mode;
	if (!(inode = new_inode(dir->i_sb))) {
		return -ENOMEM;
	}
	new_inode_init(inode, dir, mode);

	jbegin_count += reiserfs_cache_default_acl(dir);
	retval = reiserfs_security_init(dir, inode, &dentry->d_name, &security);
	if (retval < 0) {
		drop_new_inode(inode);
		return retval;
	}
	jbegin_count += retval;
	lock_depth = reiserfs_write_lock_once(dir->i_sb);

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		drop_new_inode(inode);
		goto out_failed;
	}

	/* inc the link count now, so another writer doesn't overflow it while
	 ** we sleep later on.
	 */
	INC_DIR_INODE_NLINK(dir)

	    retval = reiserfs_new_inode(&th, dir, mode, NULL /*symlink */ ,
					old_format_only(dir->i_sb) ?
					EMPTY_DIR_SIZE_V1 : EMPTY_DIR_SIZE,
					dentry, inode, &security);
	if (retval) {
		DEC_DIR_INODE_NLINK(dir)
		goto out_failed;
	}

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	inode->i_op = &reiserfs_dir_inode_operations;
	inode->i_fop = &reiserfs_dir_operations;

	// note, _this_ add_entry will not update dir's stat data
	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );
	if (retval) {
		int err;
		inode->i_nlink = 0;
		DEC_DIR_INODE_NLINK(dir);
		reiserfs_update_sd(&th, inode);
		err = journal_end(&th, dir->i_sb, jbegin_count);
		if (err)
			retval = err;
		unlock_new_inode(inode);
		iput(inode);
		goto out_failed;
	}
	// the above add_entry did not update dir's stat data
	reiserfs_update_sd(&th, dir);

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
	retval = journal_end(&th, dir->i_sb, jbegin_count);
out_failed:
	reiserfs_write_unlock_once(dir->i_sb, lock_depth);
	return retval;
}

int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
               dev_t device_number)
{
    int rc = -EPERM;
    unsigned int xid;
    int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
    struct cifs_sb_info *cifs_sb;
    struct tcon_link *tlink;
    struct cifs_tcon *tcon;
    struct cifs_io_parms io_parms;
    char *full_path = NULL;
    struct inode *newinode = NULL;
    __u32 oplock = 0;
    struct cifs_fid fid;
    struct cifs_open_parms oparms;
    FILE_ALL_INFO *buf = NULL;
    unsigned int bytes_written;
    struct win_dev *pdev;
    struct kvec iov[2];

    if (!old_valid_dev(device_number))
        return -EINVAL;

    cifs_sb = CIFS_SB(inode->i_sb);
    tlink = cifs_sb_tlink(cifs_sb);
    if (IS_ERR(tlink))
        return PTR_ERR(tlink);

    tcon = tlink_tcon(tlink);

    xid = get_xid();

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

    if (tcon->unix_ext) {
        struct cifs_unix_set_info_args args = {
            .mode	= mode & ~current_umask(),
            .ctime	= NO_CHANGE_64,
            .atime	= NO_CHANGE_64,
            .mtime	= NO_CHANGE_64,
            .device	= device_number,
        };
        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
            args.uid = current_fsuid();
            args.gid = current_fsgid();
        } else {
            args.uid = INVALID_UID; /* no change */
            args.gid = INVALID_GID; /* no change */
        }
        rc = CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
                                    cifs_sb->local_nls,
                                    cifs_remap(cifs_sb));
        if (rc)
            goto mknod_out;

        rc = cifs_get_inode_info_unix(&newinode, full_path,
                                      inode->i_sb, xid);

        if (rc == 0)
            d_instantiate(direntry, newinode);
        goto mknod_out;
    }

    if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
        goto mknod_out;


    cifs_dbg(FYI, "sfu compat create special file\n");

    buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
    if (buf == NULL) {
        kfree(full_path);
        rc = -ENOMEM;
        free_xid(xid);
        return rc;
    }

    if (backup_cred(cifs_sb))
        create_options |= CREATE_OPEN_BACKUP_INTENT;

    oparms.tcon = tcon;
    oparms.cifs_sb = cifs_sb;
    oparms.desired_access = GENERIC_WRITE;
    oparms.create_options = create_options;
    oparms.disposition = FILE_CREATE;
    oparms.path = full_path;
    oparms.fid = &fid;
    oparms.reconnect = false;

    if (tcon->ses->server->oplocks)
        oplock = REQ_OPLOCK;
    else
        oplock = 0;
    rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, buf);
    if (rc)
        goto mknod_out;
//.........这里部分代码省略.........

static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode,
			struct nameidata *nd)
{
	struct inode *inode;
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
					.dirtied_ino = 1 };
	struct ubifs_inode *dir_ui = ubifs_inode(dir);

	/*
	 * Budget request settings: new inode, new direntry, changing the
	 * parent directory inode.
	 */

	dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
		dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);

	err = ubifs_budget_space(c, &req);
	if (err)
		return err;

	inode = ubifs_new_inode(c, dir, mode);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_budg;
	}

	mutex_lock(&dir_ui->ui_mutex);
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
	if (err)
		goto out_cancel;
	mutex_unlock(&dir_ui->ui_mutex);

	ubifs_release_budget(c, &req);
	insert_inode_hash(inode);
	d_instantiate(dentry, inode);
	return 0;

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	mutex_unlock(&dir_ui->ui_mutex);
	make_bad_inode(inode);
	iput(inode);
out_budg:
	ubifs_release_budget(c, &req);
	ubifs_err("cannot create regular file, error %d", err);
	return err;
}

/**
 * vfs_dent_type - get VFS directory entry type.
 * @type: UBIFS directory entry type
 *
 * This function converts UBIFS directory entry type into VFS directory entry
 * type.
 */
static unsigned int vfs_dent_type(uint8_t type)
{
	switch (type) {
	case UBIFS_ITYPE_REG:
		return DT_REG;
	case UBIFS_ITYPE_DIR:
		return DT_DIR;
	case UBIFS_ITYPE_LNK:
		return DT_LNK;
	case UBIFS_ITYPE_BLK:
		return DT_BLK;
	case UBIFS_ITYPE_CHR:
		return DT_CHR;
	case UBIFS_ITYPE_FIFO:
		return DT_FIFO;
	case UBIFS_ITYPE_SOCK:
		return DT_SOCK;
	default:
		BUG();
	}
	return 0;
}

/*
 * The classical Unix view for directory is that it is a linear array of
 * (name, inode number) entries. Linux/VFS assumes this model as well.
 * Particularly, 'readdir()' call wants us to return a directory entry offset
 * which later may be used to continue 'readdir()'ing the directory or to
 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
 * model because directory entries are identified by keys, which may collide.
 *
 * UBIFS uses directory entry hash value for directory offsets, so
 * 'seekdir()'/'telldir()' may not always work because of possible key
 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
 * properly by means of saving full directory entry name in the private field
 * of the file description object.
 *
 * This means that UBIFS cannot support NFS which requires full
 * 'seekdir()'/'telldir()' support.
//.........这里部分代码省略.........

/**
 * securityfs_create_file - create a file in the securityfs filesystem
 *
 * @name: a pointer to a string containing the name of the file to create.
 * @mode: the permission that the file should have
 * @parent: a pointer to the parent dentry for this file.  This should be a
 *          directory dentry if set.  If this parameter is %NULL, then the
 *          file will be created in the root of the securityfs filesystem.
 * @data: a pointer to something that the caller will want to get to later
 *        on.  The inode.i_private pointer will point to this value on
 *        the open() call.
 * @fops: a pointer to a struct file_operations that should be used for
 *        this file.
 *
 * This is the basic "create a file" function for securityfs.  It allows for a
 * wide range of flexibility in creating a file, or a directory (if you
 * want to create a directory, the securityfs_create_dir() function is
 * recommended to be used instead).
 *
 * This function returns a pointer to a dentry if it succeeds.  This
 * pointer must be passed to the securityfs_remove() function when the file is
 * to be removed (no automatic cleanup happens if your module is unloaded,
 * you are responsible here).  If an error occurs, the function will return
 * the error value (via ERR_PTR).
 *
 * If securityfs is not enabled in the kernel, the value %-ENODEV is
 * returned.
 */
struct dentry *securityfs_create_file(const char *name, umode_t mode,
				   struct dentry *parent, void *data,
				   const struct file_operations *fops)
{
	struct dentry *dentry;
	int is_dir = S_ISDIR(mode);
	struct inode *dir, *inode;
	int error;

	if (!is_dir) {
		BUG_ON(!fops);
		mode = (mode & S_IALLUGO) | S_IFREG;
	}

	pr_debug("securityfs: creating file '%s'\n",name);

	error = simple_pin_fs(&fs_type, &mount, &mount_count);
	if (error)
		return ERR_PTR(error);

	if (!parent)
		parent = mount->mnt_root;

	dir = d_inode(parent);

	inode_lock(dir);
	dentry = lookup_one_len(name, parent, strlen(name));
	if (IS_ERR(dentry))
		goto out;

	if (d_really_is_positive(dentry)) {
		error = -EEXIST;
		goto out1;
	}

	inode = new_inode(dir->i_sb);
	if (!inode) {
		error = -ENOMEM;
		goto out1;
	}

	inode->i_ino = get_next_ino();
	inode->i_mode = mode;
	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
	inode->i_private = data;
	if (is_dir) {
		inode->i_op = &simple_dir_inode_operations;
		inode->i_fop = &simple_dir_operations;
		inc_nlink(inode);
		inc_nlink(dir);
	} else {
		inode->i_fop = fops;
	}
	d_instantiate(dentry, inode);
	dget(dentry);
	inode_unlock(dir);
	return dentry;

out1:
	dput(dentry);
	dentry = ERR_PTR(error);
out:
	inode_unlock(dir);
	simple_release_fs(&mount, &mount_count);
	return dentry;
}

static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
		      struct dentry *dentry)
{
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct inode *inode = old_dentry->d_inode;
	struct ubifs_inode *ui = ubifs_inode(inode);
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
	struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
				.dirtied_ino_d = ALIGN(ui->data_len, 8) };

	/*
	 * Budget request settings: new direntry, changing the target inode,
	 * changing the parent inode.
	 */

	dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
		dentry->d_name.len, dentry->d_name.name, inode->i_ino,
		inode->i_nlink, dir->i_ino);
	err = dbg_check_synced_i_size(inode);
	if (err)
		return err;

	err = ubifs_budget_space(c, &req);
	if (err)
		return err;

	lock_2_inodes(dir, inode);
	inc_nlink(inode);
	atomic_inc(&inode->i_count);
	inode->i_ctime = ubifs_current_time(inode);
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
	if (err)
		goto out_cancel;
	unlock_2_inodes(dir, inode);

	ubifs_release_budget(c, &req);
	d_instantiate(dentry, inode);
	return 0;

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	drop_nlink(inode);
	unlock_2_inodes(dir, inode);
	ubifs_release_budget(c, &req);
	iput(inode);
	return err;
}

static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct inode *inode = dentry->d_inode;
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
	int err, budgeted = 1;
	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };

	/*
	 * Budget request settings: deletion direntry, deletion inode (+1 for
	 * @dirtied_ino), changing the parent directory inode. If budgeting
	 * fails, go ahead anyway because we have extra space reserved for
	 * deletions.
	 */

	dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
		dentry->d_name.len, dentry->d_name.name, inode->i_ino,
		inode->i_nlink, dir->i_ino);
	err = dbg_check_synced_i_size(inode);
	if (err)
		return err;

	err = ubifs_budget_space(c, &req);
	if (err) {
		if (err != -ENOSPC)
			return err;
		budgeted = 0;
	}

	lock_2_inodes(dir, inode);
	inode->i_ctime = ubifs_current_time(dir);
	drop_nlink(inode);
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	dir->i_mtime = dir->i_ctime = inode->i_ctime;
	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
	if (err)
		goto out_cancel;
	unlock_2_inodes(dir, inode);

	if (budgeted)
		ubifs_release_budget(c, &req);
	else {
		/* We've deleted something - clean the "no space" flags */
		c->nospace = c->nospace_rp = 0;
		smp_wmb();
//.........这里部分代码省略.........