Esempio n. 1
0
static int dbg_check_name(const struct ubifs_info *c,
			  const struct ubifs_dent_node *dent,
			  const struct fscrypt_name *nm)
{
	if (!dbg_is_chk_gen(c))
		return 0;
	if (le16_to_cpu(dent->nlen) != fname_len(nm))
		return -EINVAL;
	if (memcmp(dent->name, fname_name(nm), fname_len(nm)))
		return -EINVAL;
	return 0;
}
Esempio n. 2
0
int handle_client(int csockfd, int timeout) {
    uint64_t fsize;
    ssize_t namelen;
    char buf[BUF_SZ];
    char path[DIRLEN + FNAME_LENGTH + 1];
    char *filename = path + DIRLEN;
    ssize_t nbytes;
    bool delete_file;

    /* reading filesize */
    nbytes = read_tout(csockfd, &fsize, sizeof(fsize), timeout, 0, false);
    if (nbytes != sizeof(fsize)) {
        log("Filesize reading error\n");
        return -1;
    }
    fsize = le64toh(fsize);

    if (fsize > ((uint64_t)1 << 62)) {
        log("Filesize is too big\n");
        send_code(csockfd, CODE_BAD_FILELEN, timeout);
        return -1;
    }

    if (send_code(csockfd, CODE_ACK, timeout))
        return -1;
    log("Filesize %llu accepted\n", fsize);

    /* reading filename */
    //memset(path, 0, sizeof(path));
    memcpy(path, DIRNAME, DIRLEN);

    nbytes = read_tout(csockfd, buf, sizeof(buf), timeout, MSG_PEEK, false);
    if (nbytes > 0) {
        namelen = fname_len(buf, nbytes);
        if (namelen <= 0 || namelen > FNAME_LENGTH) {
            log("Bad filename length\n");
            send_code(csockfd, CODE_BAD_FILELEN, timeout);
            return -1;
        }
        /* There is no lseek() for socket, so .. */
        read_tout(csockfd, filename, namelen + 1, 0, 0, true);
    } else {
        log("Filename reading error");
        send_code(csockfd, CODE_ERR_UNKNOWN, timeout);
        return -1;
    }

    if (!check_fname(filename)) {
        log("Bad filename (check_fname)!\n");
        send_code(csockfd, CODE_BAD_FILENAME, timeout);
        return -1;
    }

    if (access(path, F_OK) != -1) {
        send_code(csockfd, CODE_FILE_EXISTS, timeout);
        return -1;
    }
    int fd = open(path, O_CREAT | O_WRONLY, 0600);
    if (fd == -1) {
        perror("open()");
        if (errno == ENAMETOOLONG)
            send_code(csockfd, CODE_BAD_FILELEN, timeout);
        else
            send_code(csockfd, CODE_ERR_UNKNOWN, timeout);
        return -1;
    }

    if (send_code(csockfd, CODE_ACK, timeout))
        return -1;
    log("Filename `%s` accepted and file exchange started\n", filename);

    /* reading file */
    nbytes = 0;
    delete_file = false;

    do {
        fsize -= (uint64_t) nbytes;
        nbytes = read_tout(csockfd, buf, sizeof(buf), timeout, 0, false);
        if (nbytes > 0) {
            if (write(fd, buf, min(nbytes, fsize)) == -1) {
                perror("write()");
                send_code(csockfd, CODE_ERR_TRANSFER, timeout);
                delete_file = true;
                break;
            }
        }
    } while (nbytes > 0 && nbytes < fsize);

    if (nbytes < 0) {
        log("Error while transfer\n");
        send_code(csockfd, CODE_ERR_TRANSFER, timeout);
        delete_file = true;
    }

    close(fd);

    if (delete_file) {
        log("Deleting file\n");
        unlink(path);
        return -1;
    }

    if (send_code(csockfd, CODE_ACK, timeout))
        log("Warning: send_code was unsuccessful, but file recieved ok");
    log("File `%s` recieved ok!\n", path);

    return 0;
}
Esempio n. 3
0
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 = d_inode(old_dentry);
	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) };
	struct fscrypt_name nm;

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

	dbg_gen("dent '%pd' to ino %lu (nlink %d) in dir ino %lu",
		dentry, inode->i_ino,
		inode->i_nlink, dir->i_ino);
	ubifs_assert(inode_is_locked(dir));
	ubifs_assert(inode_is_locked(inode));

	if (ubifs_crypt_is_encrypted(dir) &&
	    !fscrypt_has_permitted_context(dir, inode))
		return -EPERM;

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		return err;

	err = dbg_check_synced_i_size(c, inode);
	if (err)
		goto out_fname;

	err = ubifs_budget_space(c, &req);
	if (err)
		goto out_fname;

	lock_2_inodes(dir, inode);

	/* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */
	if (inode->i_nlink == 0)
		ubifs_delete_orphan(c, inode->i_ino);

	inc_nlink(inode);
	ihold(inode);
	inode->i_ctime = 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, &nm, inode, 0, 0);
	if (err)
		goto out_cancel;
	unlock_2_inodes(dir, inode);

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

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	drop_nlink(inode);
	if (inode->i_nlink == 0)
		ubifs_add_orphan(c, inode->i_ino);
	unlock_2_inodes(dir, inode);
	ubifs_release_budget(c, &req);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
	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 = d_inode(dentry);
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	int err, sz_change, budgeted = 1;
	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
	unsigned int saved_nlink = inode->i_nlink;
	struct fscrypt_name nm;

	/*
	 * 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 '%pd' from ino %lu (nlink %d) in dir ino %lu",
		dentry, inode->i_ino,
		inode->i_nlink, dir->i_ino);

	if (ubifs_crypt_is_encrypted(dir)) {
		err = fscrypt_get_encryption_info(dir);
		if (err && err != -ENOKEY)
			return err;
	}

	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
	if (err)
		return err;

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

	ubifs_assert(inode_is_locked(dir));
	ubifs_assert(inode_is_locked(inode));
	err = dbg_check_synced_i_size(c, inode);
	if (err)
		goto out_fname;

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

	lock_2_inodes(dir, inode);
	inode->i_ctime = 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, &nm, 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->bi.nospace = c->bi.nospace_rp = 0;
		smp_wmb();
	}
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	set_nlink(inode, saved_nlink);
	unlock_2_inodes(dir, inode);
	if (budgeted)
		ubifs_release_budget(c, &req);
out_fname:
	fscrypt_free_filename(&nm);
	return err;
}

/**
 * check_dir_empty - check if a directory is empty or not.
 * @dir: VFS inode object of the directory to check
 *
 * This function checks if directory @dir is empty. Returns zero if the
 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
 * in case of of errors.
 */
int ubifs_check_dir_empty(struct inode *dir)
{
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct fscrypt_name nm = { 0 };
	struct ubifs_dent_node *dent;
	union ubifs_key key;
	int err;

	lowest_dent_key(c, &key, dir->i_ino);
	dent = ubifs_tnc_next_ent(c, &key, &nm);
	if (IS_ERR(dent)) {
		err = PTR_ERR(dent);
		if (err == -ENOENT)
			err = 0;
	} else {
		kfree(dent);
		err = -ENOTEMPTY;
	}
	return err;
}

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

	/*
	 * Budget request settings: deletion direntry, deletion inode and
	 * changing the parent inode. If budgeting fails, go ahead anyway
	 * because we have extra space reserved for deletions.
	 */

	dbg_gen("directory '%pd', ino %lu in dir ino %lu", dentry,
		inode->i_ino, dir->i_ino);
	ubifs_assert(inode_is_locked(dir));
	ubifs_assert(inode_is_locked(inode));
	err = ubifs_check_dir_empty(d_inode(dentry));
	if (err)
		return err;

	if (ubifs_crypt_is_encrypted(dir)) {
		err = fscrypt_get_encryption_info(dir);
		if (err && err != -ENOKEY)
			return err;
	}

	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
	if (err)
		return err;

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

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

	lock_2_inodes(dir, inode);
	inode->i_ctime = current_time(dir);
	clear_nlink(inode);
	drop_nlink(dir);
	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, &nm, 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->bi.nospace = c->bi.nospace_rp = 0;
		smp_wmb();
	}
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size += sz_change;
	dir_ui->ui_size = dir->i_size;
	inc_nlink(dir);
	set_nlink(inode, 2);
	unlock_2_inodes(dir, inode);
	if (budgeted)
		ubifs_release_budget(c, &req);
out_fname:
	fscrypt_free_filename(&nm);
	return err;
}

static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct inode *inode;
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	int err, sz_change;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
	struct fscrypt_name nm;

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

	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
		dentry, mode, dir->i_ino);

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

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		goto out_budg;

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

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

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	mutex_lock(&dir_ui->ui_mutex);
	insert_inode_hash(inode);
	inc_nlink(inode);
	inc_nlink(dir);
	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, &nm, inode, 0, 0);
	if (err) {
		ubifs_err(c, "cannot create directory, error %d", err);
		goto out_cancel;
	}
	mutex_unlock(&dir_ui->ui_mutex);

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

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	drop_nlink(dir);
	mutex_unlock(&dir_ui->ui_mutex);
out_inode:
	make_bad_inode(inode);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
out_budg:
	ubifs_release_budget(c, &req);
	return err;
}

static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
		       umode_t mode, dev_t rdev)
{
	struct inode *inode;
	struct ubifs_inode *ui;
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	union ubifs_dev_desc *dev = NULL;
	int sz_change;
	int err, devlen = 0;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
					.dirtied_ino = 1 };
	struct fscrypt_name nm;

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

	dbg_gen("dent '%pd' in dir ino %lu", dentry, dir->i_ino);

	if (S_ISBLK(mode) || S_ISCHR(mode)) {
		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
		if (!dev)
			return -ENOMEM;
		devlen = ubifs_encode_dev(dev, rdev);
	}

	req.new_ino_d = ALIGN(devlen, 8);
	err = ubifs_budget_space(c, &req);
	if (err) {
		kfree(dev);
		return err;
	}

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err) {
		kfree(dev);
		goto out_budg;
	}

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

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

	init_special_inode(inode, inode->i_mode, rdev);
	inode->i_size = ubifs_inode(inode)->ui_size = devlen;
	ui = ubifs_inode(inode);
	ui->data = dev;
	ui->data_len = devlen;

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	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, &nm, 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);
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	mutex_unlock(&dir_ui->ui_mutex);
out_inode:
	make_bad_inode(inode);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
out_budg:
	ubifs_release_budget(c, &req);
	return err;
}

static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
			 const char *symname)
{
	struct inode *inode;
	struct ubifs_inode *ui;
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	int err, len = strlen(symname);
	int sz_change = CALC_DENT_SIZE(len);
	struct fscrypt_str disk_link = FSTR_INIT((char *)symname, len + 1);
	struct fscrypt_symlink_data *sd = NULL;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
					.new_ino_d = ALIGN(len, 8),
					.dirtied_ino = 1 };
	struct fscrypt_name nm;

	if (ubifs_crypt_is_encrypted(dir)) {
		err = fscrypt_get_encryption_info(dir);
		if (err)
			goto out_budg;

		if (!fscrypt_has_encryption_key(dir)) {
			err = -EPERM;
			goto out_budg;
		}

		disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
				sizeof(struct fscrypt_symlink_data));
	}

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

	dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry,
		symname, dir->i_ino);

	if (disk_link.len > UBIFS_MAX_INO_DATA)
		return -ENAMETOOLONG;

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

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		goto out_budg;

	inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_fname;
	}

	ui = ubifs_inode(inode);
	ui->data = kmalloc(disk_link.len, GFP_NOFS);
	if (!ui->data) {
		err = -ENOMEM;
		goto out_inode;
	}

	if (ubifs_crypt_is_encrypted(dir)) {
		struct qstr istr = QSTR_INIT(symname, len);
		struct fscrypt_str ostr;

		sd = kzalloc(disk_link.len, GFP_NOFS);
		if (!sd) {
			err = -ENOMEM;
			goto out_inode;
		}

		ostr.name = sd->encrypted_path;
		ostr.len = disk_link.len;

		err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
		if (err) {
			kfree(sd);
			goto out_inode;
		}

		sd->len = cpu_to_le16(ostr.len);
		disk_link.name = (char *)sd;
	} else {
		inode->i_link = ui->data;
	}

	memcpy(ui->data, disk_link.name, disk_link.len);
	((char *)ui->data)[disk_link.len - 1] = '\0';

	/*
	 * The terminating zero byte is not written to the flash media and it
	 * is put just to make later in-memory string processing simpler. Thus,
	 * data length is @len, not @len + %1.
	 */
	ui->data_len = disk_link.len - 1;
	inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1;

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	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, &nm, 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);
	fscrypt_free_filename(&nm);
	return 0;

out_cancel:
	dir->i_size -= sz_change;
	dir_ui->ui_size = dir->i_size;
	mutex_unlock(&dir_ui->ui_mutex);
out_inode:
	make_bad_inode(inode);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
out_budg:
	ubifs_release_budget(c, &req);
	return err;
}

/**
 * lock_4_inodes - a wrapper for locking three UBIFS inodes.
 * @inode1: first inode
 * @inode2: second inode
 * @inode3: third inode
 * @inode4: fouth inode
 *
 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
 * @inode2 whereas @inode3 and @inode4 may be %NULL.
 *
 * We do not implement any tricks to guarantee strict lock ordering, because
 * VFS has already done it for us on the @i_mutex. So this is just a simple
 * wrapper function.
 */
static void lock_4_inodes(struct inode *inode1, struct inode *inode2,
			  struct inode *inode3, struct inode *inode4)
{
	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
	if (inode2 != inode1)
		mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
	if (inode3)
		mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
	if (inode4)
		mutex_lock_nested(&ubifs_inode(inode4)->ui_mutex, WB_MUTEX_4);
}

/**
 * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename.
 * @inode1: first inode
 * @inode2: second inode
 * @inode3: third inode
 * @inode4: fouth inode
 */
static void unlock_4_inodes(struct inode *inode1, struct inode *inode2,
			    struct inode *inode3, struct inode *inode4)
{
	if (inode4)
		mutex_unlock(&ubifs_inode(inode4)->ui_mutex);
	if (inode3)
		mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
	if (inode1 != inode2)
		mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
	mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
}

static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
		     struct inode *new_dir, struct dentry *new_dentry,
		     unsigned int flags)
{
	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
	struct inode *old_inode = d_inode(old_dentry);
	struct inode *new_inode = d_inode(new_dentry);
	struct inode *whiteout = NULL;
	struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
	struct ubifs_inode *whiteout_ui = NULL;
	int err, release, sync = 0, move = (new_dir != old_dir);
	int is_dir = S_ISDIR(old_inode->i_mode);
	int unlink = !!new_inode, new_sz, old_sz;
	struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
					.dirtied_ino = 3 };
	struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
			.dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
	struct timespec time;
	unsigned int uninitialized_var(saved_nlink);
	struct fscrypt_name old_nm, new_nm;

	/*
	 * Budget request settings: deletion direntry, new direntry, removing
	 * the old inode, and changing old and new parent directory inodes.
	 *
	 * However, this operation also marks the target inode as dirty and
	 * does not write it, so we allocate budget for the target inode
	 * separately.
	 */

	dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x",
		old_dentry, old_inode->i_ino, old_dir->i_ino,
		new_dentry, new_dir->i_ino, flags);

	if (unlink)
		ubifs_assert(inode_is_locked(new_inode));

	if (old_dir != new_dir) {
		if (ubifs_crypt_is_encrypted(new_dir) &&
		    !fscrypt_has_permitted_context(new_dir, old_inode))
			return -EPERM;
	}

	if (unlink && is_dir) {
		err = ubifs_check_dir_empty(new_inode);
		if (err)
			return err;
	}

	err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_nm);
	if (err)
		return err;

	err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_nm);
	if (err) {
		fscrypt_free_filename(&old_nm);
		return err;
	}

	new_sz = CALC_DENT_SIZE(fname_len(&new_nm));
	old_sz = CALC_DENT_SIZE(fname_len(&old_nm));

	err = ubifs_budget_space(c, &req);
	if (err) {
		fscrypt_free_filename(&old_nm);
		fscrypt_free_filename(&new_nm);
		return err;
	}
	err = ubifs_budget_space(c, &ino_req);
	if (err) {
		fscrypt_free_filename(&old_nm);
		fscrypt_free_filename(&new_nm);
		ubifs_release_budget(c, &req);
		return err;
	}

	if (flags & RENAME_WHITEOUT) {
		union ubifs_dev_desc *dev = NULL;

		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
		if (!dev) {
			err = -ENOMEM;
			goto out_release;
		}

		err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout);
		if (err) {
			kfree(dev);
			goto out_release;
		}

		whiteout->i_state |= I_LINKABLE;
		whiteout_ui = ubifs_inode(whiteout);
		whiteout_ui->data = dev;
		whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
		ubifs_assert(!whiteout_ui->dirty);
	}

	lock_4_inodes(old_dir, new_dir, new_inode, whiteout);

	/*
	 * Like most other Unix systems, set the @i_ctime for inodes on a
	 * rename.
	 */
	time = current_time(old_dir);
	old_inode->i_ctime = time;

	/* We must adjust parent link count when renaming directories */
	if (is_dir) {
		if (move) {
			/*
			 * @old_dir loses a link because we are moving
			 * @old_inode to a different directory.
			 */
			drop_nlink(old_dir);
			/*
			 * @new_dir only gains a link if we are not also
			 * overwriting an existing directory.
			 */
			if (!unlink)
				inc_nlink(new_dir);
		} else {
			/*
			 * @old_inode is not moving to a different directory,
			 * but @old_dir still loses a link if we are
			 * overwriting an existing directory.
			 */
			if (unlink)
				drop_nlink(old_dir);
		}
	}

	old_dir->i_size -= old_sz;
	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
	old_dir->i_mtime = old_dir->i_ctime = time;
	new_dir->i_mtime = new_dir->i_ctime = time;

	/*
	 * And finally, if we unlinked a direntry which happened to have the
	 * same name as the moved direntry, we have to decrement @i_nlink of
	 * the unlinked inode and change its ctime.
	 */
	if (unlink) {
		/*
		 * Directories cannot have hard-links, so if this is a
		 * directory, just clear @i_nlink.
		 */
		saved_nlink = new_inode->i_nlink;
		if (is_dir)
			clear_nlink(new_inode);
		else
			drop_nlink(new_inode);
		new_inode->i_ctime = time;
	} else {
		new_dir->i_size += new_sz;
		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
	}

	/*
	 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
	 * is dirty, because this will be done later on at the end of
	 * 'ubifs_rename()'.
	 */
	if (IS_SYNC(old_inode)) {
		sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
		if (unlink && IS_SYNC(new_inode))
			sync = 1;
	}

	if (whiteout) {
		struct ubifs_budget_req wht_req = { .dirtied_ino = 1,
				.dirtied_ino_d = \
				ALIGN(ubifs_inode(whiteout)->data_len, 8) };

		err = ubifs_budget_space(c, &wht_req);
		if (err) {
			kfree(whiteout_ui->data);
			whiteout_ui->data_len = 0;
			iput(whiteout);
			goto out_release;
		}

		inc_nlink(whiteout);
		mark_inode_dirty(whiteout);
		whiteout->i_state &= ~I_LINKABLE;
		iput(whiteout);
	}

	err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir,
			       new_inode, &new_nm, whiteout, sync);
	if (err)
		goto out_cancel;

	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
	ubifs_release_budget(c, &req);

	mutex_lock(&old_inode_ui->ui_mutex);
	release = old_inode_ui->dirty;
	mark_inode_dirty_sync(old_inode);
	mutex_unlock(&old_inode_ui->ui_mutex);

	if (release)
		ubifs_release_budget(c, &ino_req);
	if (IS_SYNC(old_inode))
		err = old_inode->i_sb->s_op->write_inode(old_inode, NULL);

	fscrypt_free_filename(&old_nm);
	fscrypt_free_filename(&new_nm);
	return err;

out_cancel:
	if (unlink) {
		set_nlink(new_inode, saved_nlink);
	} else {
		new_dir->i_size -= new_sz;
		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
	}
	old_dir->i_size += old_sz;
	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
	if (is_dir) {
		if (move) {
			inc_nlink(old_dir);
			if (!unlink)
				drop_nlink(new_dir);
		} else {
			if (unlink)
				inc_nlink(old_dir);
		}
	}
	if (whiteout) {
		drop_nlink(whiteout);
		iput(whiteout);
	}
	unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
out_release:
	ubifs_release_budget(c, &ino_req);
	ubifs_release_budget(c, &req);
	fscrypt_free_filename(&old_nm);
	fscrypt_free_filename(&new_nm);
	return err;
}

static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir, struct dentry *new_dentry)
{
	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
	struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
				.dirtied_ino = 2 };
	int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
	struct inode *fst_inode = d_inode(old_dentry);
	struct inode *snd_inode = d_inode(new_dentry);
	struct timespec time;
	int err;
	struct fscrypt_name fst_nm, snd_nm;

	ubifs_assert(fst_inode && snd_inode);

	if ((ubifs_crypt_is_encrypted(old_dir) ||
	    ubifs_crypt_is_encrypted(new_dir)) &&
	    (old_dir != new_dir) &&
	    (!fscrypt_has_permitted_context(new_dir, fst_inode) ||
	     !fscrypt_has_permitted_context(old_dir, snd_inode)))
		return -EPERM;

	err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &fst_nm);
	if (err)
		return err;

	err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &snd_nm);
	if (err) {
		fscrypt_free_filename(&fst_nm);
		return err;
	}

	lock_4_inodes(old_dir, new_dir, NULL, NULL);

	time = current_time(old_dir);
	fst_inode->i_ctime = time;
	snd_inode->i_ctime = time;
	old_dir->i_mtime = old_dir->i_ctime = time;
	new_dir->i_mtime = new_dir->i_ctime = time;

	if (old_dir != new_dir) {
		if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
			inc_nlink(new_dir);
			drop_nlink(old_dir);
		}
		else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
			drop_nlink(new_dir);
			inc_nlink(old_dir);
		}
	}

	err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir,
				snd_inode, &snd_nm, sync);

	unlock_4_inodes(old_dir, new_dir, NULL, NULL);
	ubifs_release_budget(c, &req);

	fscrypt_free_filename(&fst_nm);
	fscrypt_free_filename(&snd_nm);
	return err;
}

static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir, struct dentry *new_dentry,
			unsigned int flags)
{
	if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
		return -EINVAL;

	ubifs_assert(inode_is_locked(old_dir));
	ubifs_assert(inode_is_locked(new_dir));

	if (flags & RENAME_EXCHANGE)
		return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);

	return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
}

int ubifs_getattr(const struct path *path, struct kstat *stat,
		  u32 request_mask, unsigned int flags)
{
	loff_t size;
	struct inode *inode = d_inode(path->dentry);
	struct ubifs_inode *ui = ubifs_inode(inode);

	mutex_lock(&ui->ui_mutex);

	if (ui->flags & UBIFS_APPEND_FL)
		stat->attributes |= STATX_ATTR_APPEND;
	if (ui->flags & UBIFS_COMPR_FL)
		stat->attributes |= STATX_ATTR_COMPRESSED;
	if (ui->flags & UBIFS_CRYPT_FL)
		stat->attributes |= STATX_ATTR_ENCRYPTED;
	if (ui->flags & UBIFS_IMMUTABLE_FL)
		stat->attributes |= STATX_ATTR_IMMUTABLE;

	stat->attributes_mask |= (STATX_ATTR_APPEND |
				STATX_ATTR_COMPRESSED |
				STATX_ATTR_ENCRYPTED |
				STATX_ATTR_IMMUTABLE);

	generic_fillattr(inode, stat);
	stat->blksize = UBIFS_BLOCK_SIZE;
	stat->size = ui->ui_size;

	/*
	 * Unfortunately, the 'stat()' system call was designed for block
	 * device based file systems, and it is not appropriate for UBIFS,
	 * because UBIFS does not have notion of "block". For example, it is
	 * difficult to tell how many block a directory takes - it actually
	 * takes less than 300 bytes, but we have to round it to block size,
	 * which introduces large mistake. This makes utilities like 'du' to
	 * report completely senseless numbers. This is the reason why UBIFS
	 * goes the same way as JFFS2 - it reports zero blocks for everything
	 * but regular files, which makes more sense than reporting completely
	 * wrong sizes.
	 */
	if (S_ISREG(inode->i_mode)) {
		size = ui->xattr_size;
		size += stat->size;
		size = ALIGN(size, UBIFS_BLOCK_SIZE);
		/*
		 * Note, user-space expects 512-byte blocks count irrespectively
		 * of what was reported in @stat->size.
		 */
		stat->blocks = size >> 9;
	} else
		stat->blocks = 0;
	mutex_unlock(&ui->ui_mutex);
	return 0;
}

static int ubifs_dir_open(struct inode *dir, struct file *file)
{
	if (ubifs_crypt_is_encrypted(dir))
		return fscrypt_get_encryption_info(dir) ? -EACCES : 0;

	return 0;
}

const struct inode_operations ubifs_dir_inode_operations = {
	.lookup      = ubifs_lookup,
	.create      = ubifs_create,
	.link        = ubifs_link,
	.symlink     = ubifs_symlink,
	.unlink      = ubifs_unlink,
	.mkdir       = ubifs_mkdir,
	.rmdir       = ubifs_rmdir,
	.mknod       = ubifs_mknod,
	.rename      = ubifs_rename,
	.setattr     = ubifs_setattr,
	.getattr     = ubifs_getattr,
	.listxattr   = ubifs_listxattr,
#ifdef CONFIG_UBIFS_ATIME_SUPPORT
	.update_time = ubifs_update_time,
#endif
	.tmpfile     = ubifs_tmpfile,
};

const struct file_operations ubifs_dir_operations = {
	.llseek         = generic_file_llseek,
	.release        = ubifs_dir_release,
	.read           = generic_read_dir,
	.iterate_shared = ubifs_readdir,
	.fsync          = ubifs_fsync,
	.unlocked_ioctl = ubifs_ioctl,
	.open		= ubifs_dir_open,
#ifdef CONFIG_COMPAT
	.compat_ioctl   = ubifs_compat_ioctl,
#endif
};
Esempio n. 4
0
static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
			bool excl)
{
	struct inode *inode;
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
					.dirtied_ino = 1 };
	struct ubifs_inode *dir_ui = ubifs_inode(dir);
	struct fscrypt_name nm;
	int err, sz_change;

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

	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
		dentry, mode, dir->i_ino);

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

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		goto out_budg;

	sz_change = CALC_DENT_SIZE(fname_len(&nm));

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

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	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, &nm, inode, 0, 0);
	if (err)
		goto out_cancel;
	mutex_unlock(&dir_ui->ui_mutex);

	ubifs_release_budget(c, &req);
	fscrypt_free_filename(&nm);
	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);
out_inode:
	make_bad_inode(inode);
	iput(inode);
out_fname:
	fscrypt_free_filename(&nm);
out_budg:
	ubifs_release_budget(c, &req);
	ubifs_err(c, "cannot create regular file, error %d", err);
	return err;
}

static int do_tmpfile(struct inode *dir, struct dentry *dentry,
		      umode_t mode, struct inode **whiteout)
{
	struct inode *inode;
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1};
	struct ubifs_budget_req ino_req = { .dirtied_ino = 1 };
	struct ubifs_inode *ui, *dir_ui = ubifs_inode(dir);
	int err, instantiated = 0;
	struct fscrypt_name nm;

	/*
	 * Budget request settings: new dirty inode, new direntry,
	 * budget for dirtied inode will be released via writeback.
	 */

	dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
		dentry, mode, dir->i_ino);

	err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
	if (err)
		return err;

	err = ubifs_budget_space(c, &req);
	if (err) {
		fscrypt_free_filename(&nm);
		return err;
	}

	err = ubifs_budget_space(c, &ino_req);
	if (err) {
		ubifs_release_budget(c, &req);
		fscrypt_free_filename(&nm);
		return err;
	}

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

	if (whiteout) {
		init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
		ubifs_assert(inode->i_op == &ubifs_file_inode_operations);
	}

	err = ubifs_init_security(dir, inode, &dentry->d_name);
	if (err)
		goto out_inode;

	mutex_lock(&ui->ui_mutex);
	insert_inode_hash(inode);

	if (whiteout) {
		mark_inode_dirty(inode);
		drop_nlink(inode);
		*whiteout = inode;
	} else {
		d_tmpfile(dentry, inode);
	}
	ubifs_assert(ui->dirty);

	instantiated = 1;
	mutex_unlock(&ui->ui_mutex);

	mutex_lock(&dir_ui->ui_mutex);
	err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
	if (err)
		goto out_cancel;
	mutex_unlock(&dir_ui->ui_mutex);

	ubifs_release_budget(c, &req);

	return 0;

out_cancel:
	mutex_unlock(&dir_ui->ui_mutex);
out_inode:
	make_bad_inode(inode);
	if (!instantiated)
		iput(inode);
out_budg:
	ubifs_release_budget(c, &req);
	if (!instantiated)
		ubifs_release_budget(c, &ino_req);
	fscrypt_free_filename(&nm);
	ubifs_err(c, "cannot create temporary file, error %d", err);
	return err;
}

static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry,
			 umode_t mode)
{
	return do_tmpfile(dir, dentry, mode, NULL);
}

/**
 * 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.
 */
static int ubifs_readdir(struct file *file, struct dir_context *ctx)
{
	int fstr_real_len = 0, err = 0;
	struct fscrypt_name nm;
	struct fscrypt_str fstr = {0};
	union ubifs_key key;
	struct ubifs_dent_node *dent;
	struct inode *dir = file_inode(file);
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	bool encrypted = ubifs_crypt_is_encrypted(dir);

	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos);

	if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2)
		/*
		 * The directory was seek'ed to a senseless position or there
		 * are no more entries.
		 */
		return 0;

	if (encrypted) {
		err = fscrypt_get_encryption_info(dir);
		if (err && err != -ENOKEY)
			return err;

		err = fscrypt_fname_alloc_buffer(dir, UBIFS_MAX_NLEN, &fstr);
		if (err)
			return err;

		fstr_real_len = fstr.len;
	}

	if (file->f_version == 0) {
		/*
		 * The file was seek'ed, which means that @file->private_data
		 * is now invalid. This may also be just the first
		 * 'ubifs_readdir()' invocation, in which case
		 * @file->private_data is NULL, and the below code is
		 * basically a no-op.
		 */
		kfree(file->private_data);
		file->private_data = NULL;
	}

	/*
	 * 'generic_file_llseek()' unconditionally sets @file->f_version to
	 * zero, and we use this for detecting whether the file was seek'ed.
	 */
	file->f_version = 1;

	/* File positions 0 and 1 correspond to "." and ".." */
	if (ctx->pos < 2) {
		ubifs_assert(!file->private_data);
		if (!dir_emit_dots(file, ctx)) {
			if (encrypted)
				fscrypt_fname_free_buffer(&fstr);
			return 0;
		}

		/* Find the first entry in TNC and save it */
		lowest_dent_key(c, &key, dir->i_ino);
		fname_len(&nm) = 0;
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}

		ctx->pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
	}

	dent = file->private_data;
	if (!dent) {
		/*
		 * The directory was seek'ed to and is now readdir'ed.
		 * Find the entry corresponding to @ctx->pos or the closest one.
		 */
		dent_key_init_hash(c, &key, dir->i_ino, ctx->pos);
		fname_len(&nm) = 0;
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}
		ctx->pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
	}

	while (1) {
		dbg_gen("ino %llu, new f_pos %#x",
			(unsigned long long)le64_to_cpu(dent->inum),
			key_hash_flash(c, &dent->key));
		ubifs_assert(le64_to_cpu(dent->ch.sqnum) >
			     ubifs_inode(dir)->creat_sqnum);

		fname_len(&nm) = le16_to_cpu(dent->nlen);
		fname_name(&nm) = dent->name;

		if (encrypted) {
			fstr.len = fstr_real_len;

			err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c,
							&dent->key),
							le32_to_cpu(dent->cookie),
							&nm.disk_name, &fstr);
			if (err)
				goto out;
		} else {
			fstr.len = fname_len(&nm);
			fstr.name = fname_name(&nm);
		}

		if (!dir_emit(ctx, fstr.name, fstr.len,
			       le64_to_cpu(dent->inum),
			       vfs_dent_type(dent->type))) {
			if (encrypted)
				fscrypt_fname_free_buffer(&fstr);
			return 0;
		}

		/* Switch to the next entry */
		key_read(c, &dent->key, &key);
		dent = ubifs_tnc_next_ent(c, &key, &nm);
		if (IS_ERR(dent)) {
			err = PTR_ERR(dent);
			goto out;
		}

		kfree(file->private_data);
		ctx->pos = key_hash_flash(c, &dent->key);
		file->private_data = dent;
		cond_resched();
	}

out:
	kfree(file->private_data);
	file->private_data = NULL;

	if (encrypted)
		fscrypt_fname_free_buffer(&fstr);

	if (err != -ENOENT)
		ubifs_err(c, "cannot find next direntry, error %d", err);
	else
		/*
		 * -ENOENT is a non-fatal error in this context, the TNC uses
		 * it to indicate that the cursor moved past the current directory
		 * and readdir() has to stop.
		 */
		err = 0;


	/* 2 is a special value indicating that there are no more direntries */
	ctx->pos = 2;
	return err;
}

/* Free saved readdir() state when the directory is closed */
static int ubifs_dir_release(struct inode *dir, struct file *file)
{
	kfree(file->private_data);
	file->private_data = NULL;
	return 0;
}

/**
 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
 * @inode1: first inode
 * @inode2: second inode
 *
 * We do not implement any tricks to guarantee strict lock ordering, because
 * VFS has already done it for us on the @i_mutex. So this is just a simple
 * wrapper function.
 */
static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
{
	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
	mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
}
Esempio n. 5
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static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
				   unsigned int flags)
{
	int err;
	union ubifs_key key;
	struct inode *inode = NULL;
	struct ubifs_dent_node *dent;
	struct ubifs_info *c = dir->i_sb->s_fs_info;
	struct fscrypt_name nm;

	dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino);

	if (ubifs_crypt_is_encrypted(dir)) {
		err = fscrypt_get_encryption_info(dir);

		/*
		 * DCACHE_ENCRYPTED_WITH_KEY is set if the dentry is
		 * created while the directory was encrypted and we
		 * have access to the key.
		 */
		if (fscrypt_has_encryption_key(dir))
			fscrypt_set_encrypted_dentry(dentry);
		fscrypt_set_d_op(dentry);
		if (err && err != -ENOKEY)
			return ERR_PTR(err);
	}

	err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
	if (err)
		return ERR_PTR(err);

	if (fname_len(&nm) > UBIFS_MAX_NLEN) {
		err = -ENAMETOOLONG;
		goto out_fname;
	}

	dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
	if (!dent) {
		err = -ENOMEM;
		goto out_fname;
	}

	if (nm.hash) {
		ubifs_assert(fname_len(&nm) == 0);
		ubifs_assert(fname_name(&nm) == NULL);
		dent_key_init_hash(c, &key, dir->i_ino, nm.hash);
		err = ubifs_tnc_lookup_dh(c, &key, dent, nm.minor_hash);
	} else {
		dent_key_init(c, &key, dir->i_ino, &nm);
		err = ubifs_tnc_lookup_nm(c, &key, dent, &nm);
	}

	if (err) {
		if (err == -ENOENT) {
			dbg_gen("not found");
			goto done;
		}
		goto out_dent;
	}

	if (dbg_check_name(c, dent, &nm)) {
		err = -EINVAL;
		goto out_dent;
	}

	inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
	if (IS_ERR(inode)) {
		/*
		 * This should not happen. Probably the file-system needs
		 * checking.
		 */
		err = PTR_ERR(inode);
		ubifs_err(c, "dead directory entry '%pd', error %d",
			  dentry, err);
		ubifs_ro_mode(c, err);
		goto out_dent;
	}

	if (ubifs_crypt_is_encrypted(dir) &&
	    (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
	    !fscrypt_has_permitted_context(dir, inode)) {
		ubifs_warn(c, "Inconsistent encryption contexts: %lu/%lu",
			   dir->i_ino, inode->i_ino);
		err = -EPERM;
		goto out_inode;
	}

done:
	kfree(dent);
	fscrypt_free_filename(&nm);
	/*
	 * Note, d_splice_alias() would be required instead if we supported
	 * NFS.
	 */
	d_add(dentry, inode);
	return NULL;

out_inode:
	iput(inode);
out_dent:
	kfree(dent);
out_fname:
	fscrypt_free_filename(&nm);
	return ERR_PTR(err);
}