path: root/criu/files.c

#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#include <linux/limits.h>
#include <linux/major.h>

#include <sys/types.h>
#include <sys/prctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <stdlib.h>

#include "types.h"
#include "files.h"
#include "file-ids.h"
#include "files-reg.h"
#include "file-lock.h"
#include "image.h"
#include "common/list.h"
#include "rst-malloc.h"
#include "util-caps.h"
#include "common/lock.h"
#include "sockets.h"
#include "pstree.h"
#include "tty.h"
#include "pipes.h"
#include "fifo.h"
#include "eventfd.h"
#include "eventpoll.h"
#include "fsnotify.h"
#include "sk-packet.h"
#include "mount.h"
#include "signalfd.h"
#include "memfd.h"
#include "namespaces.h"
#include "tun.h"
#include "timerfd.h"
#include "imgset.h"
#include "fs-magic.h"
#include "fdinfo.h"
#include "cr_options.h"
#include "autofs.h"
#include "parasite.h"
#include "parasite-syscall.h"
#include "string.h"
#include "kerndat.h"
#include "fdstore.h"
#include "bpfmap.h"

#include "protobuf.h"
#include "util.h"
#include "images/fs.pb-c.h"
#include "images/ext-file.pb-c.h"

#include "plugin.h"

#define FDESC_HASH_SIZE 64
static struct hlist_head file_desc_hash[FDESC_HASH_SIZE];
/* file_desc's, which fle is not owned by a process, that is able to open them */
static LIST_HEAD(fake_master_head);

static u32 max_file_desc_id = 0;

static void init_fdesc_hash(void)
{
	int i;

	for (i = 0; i < FDESC_HASH_SIZE; i++)
		INIT_HLIST_HEAD(&file_desc_hash[i]);
}

void file_desc_init(struct file_desc *d, u32 id, struct file_desc_ops *ops)
{
	INIT_LIST_HEAD(&d->fd_info_head);
	INIT_LIST_HEAD(&d->fake_master_list);
	INIT_HLIST_NODE(&d->hash);

	d->id = id;
	d->ops = ops;
}

int file_desc_add(struct file_desc *d, u32 id, struct file_desc_ops *ops)
{
	file_desc_init(d, id, ops);
	hlist_add_head(&d->hash, &file_desc_hash[id % FDESC_HASH_SIZE]);

	if (id > max_file_desc_id)
		max_file_desc_id = id;

	return 0; /* this is to make tail-calls in collect_one_foo look nice */
}

struct file_desc *find_file_desc_raw(int type, u32 id)
{
	struct file_desc *d;
	struct hlist_head *chain;

	chain = &file_desc_hash[id % FDESC_HASH_SIZE];
	hlist_for_each_entry(d, chain, hash)
		if ((d->id == id) && (d->ops->type == type || type == FD_TYPES__UND))
			/*
			 * Warning -- old CRIU might generate matching IDs
			 * for different file types! So any code that uses
			 * FD_TYPES__UND for fdesc search MUST make sure it's
			 * dealing with the merged files images where all
			 * descs are forced to have different IDs.
			 */
			return d;

	return NULL;
}

static inline struct file_desc *find_file_desc(FdinfoEntry *fe)
{
	return find_file_desc_raw(fe->type, fe->id);
}

u32 find_unused_file_desc_id(void)
{
	return max_file_desc_id + 1;
}

struct fdinfo_list_entry *find_used_fd(struct pstree_item *task, int fd)
{
	struct list_head *head;
	struct fdinfo_list_entry *fle;

	head = &rsti(task)->fds;
	list_for_each_entry_reverse(fle, head, ps_list) {
		if (fle->fe->fd == fd)
			return fle;
		/* List is ordered, so let's stop */
		if (fle->fe->fd < fd)
			break;
	}
	return NULL;
}

static void collect_task_fd(struct fdinfo_list_entry *new_fle, struct rst_info *ri)
{
	struct fdinfo_list_entry *fle;

	/*
	 * fles in fds list are ordered by fd. Fds are restored from img files
	 * in ascending order, so it is faster to insert them from the end of
	 * the list.
	 */
	list_for_each_entry_reverse(fle, &ri->fds, ps_list) {
		if (fle->fe->fd < new_fle->fe->fd)
			break;
	}

	list_add(&new_fle->ps_list, &fle->ps_list);
}

unsigned int find_unused_fd(struct pstree_item *task, int hint_fd)
{
	struct list_head *head;
	struct fdinfo_list_entry *fle;
	int fd = 0, prev_fd;

	if ((hint_fd >= 0) && (!find_used_fd(task, hint_fd))) {
		fd = hint_fd;
		goto out;
	}

	prev_fd = service_fd_min_fd(task) - 1;
	head = &rsti(task)->fds;

	list_for_each_entry_reverse(fle, head, ps_list) {
		fd = fle->fe->fd;
		if (prev_fd > fd) {
			fd++;
			goto out;
		}
		prev_fd = fd - 1;
	}
	BUG();
out:
	return fd;
}

int find_unused_fd_pid(pid_t pid)
{
	struct pstree_item *task;

	task = pstree_item_by_virt(pid);
	if (!task) {
		pr_err("Invalid pid:%d\n", pid);
		return -1;
	}
	return find_unused_fd(task, -1);
}

int set_fds_event(pid_t virt)
{
	struct pstree_item *item;
	bool is_set;

	item = pstree_item_by_virt(virt);
	BUG_ON(!item);

	is_set = !!test_and_set_bit_le(FDS_EVENT_BIT, &item->task_st_le_bits);

	if (!is_set)
		futex_wake(&item->task_st);
	return 0;
}

void clear_fds_event(void)
{
	clear_bit_le(FDS_EVENT_BIT, &current->task_st_le_bits);
}

void wait_fds_event(void)
{
	futex_t *f = &current->task_st;
	int value;

	value = htole32(FDS_EVENT);
	futex_wait_if_cond(f, value, &);
	clear_fds_event();
}

struct fdinfo_list_entry *try_file_master(struct file_desc *d)
{
	if (list_empty(&d->fd_info_head))
		return NULL;

	return list_first_entry(&d->fd_info_head, struct fdinfo_list_entry, desc_list);
}

struct fdinfo_list_entry *file_master(struct file_desc *d)
{
	struct fdinfo_list_entry *fle;

	fle = try_file_master(d);
	if (!fle) {
		pr_err("Empty list on file desc id %#x(%d)\n", d->id, d->ops ? d->ops->type : -1);
		BUG();
	}

	return fle;
}

void show_saved_files(void)
{
	int i;
	struct file_desc *fd;

	pr_info("File descs:\n");
	for (i = 0; i < FDESC_HASH_SIZE; i++)
		hlist_for_each_entry(fd, &file_desc_hash[i], hash) {
			struct fdinfo_list_entry *le;

			pr_info(" `- type %d ID %#x\n", fd->ops->type, fd->id);
			list_for_each_entry(le, &fd->fd_info_head, desc_list)
				pr_info("   `- FD %d pid %d\n", le->fe->fd, le->pid);
		}
}

/*
 * Workaround for the OverlayFS bug present before Kernel 4.2
 *
 * This is here only to support the Linux Kernel between versions
 * 3.18 and 4.2. After that, this workaround is not needed anymore,
 * but it will work properly on both a kernel with and without the bug.
 *
 * When a process has a file open in an OverlayFS directory,
 * the information in /proc/<pid>/fd/<fd> and /proc/<pid>/fdinfo/<fd>
 * is wrong. We can't even rely on stat()-ing /proc/<pid>/fd/<fd> since
 * this will show us the wrong filesystem type.
 *
 * So we grab that information from the mountinfo table instead. This is done
 * every time fill_fdlink is called. See lookup_overlayfs for more details.
 *
 */
static int fixup_overlayfs(struct fd_parms *p, struct fd_link *link)
{
	struct mount_info *m;

	if (!link)
		return 0;

	m = lookup_overlayfs(link->name, p->stat.st_dev, p->stat.st_ino, p->mnt_id);
	if (IS_ERR(m))
		return -1;

	if (!m)
		return 0;

	p->mnt_id = m->mnt_id;

	/*
	 * If the bug is present, the file path from /proc/<pid>/fd
	 * does not include the mountpoint, so we prepend it ourselves.
	 */
	if (strcmp("./", m->ns_mountpoint) != 0) {
		char buf[PATH_MAX];
		int n;

		strlcpy(buf, link->name, PATH_MAX);
		n = snprintf(link->name, PATH_MAX, "%s/%s", m->ns_mountpoint, buf + 2);
		if (n >= PATH_MAX) {
			pr_err("Not enough space to replace %s\n", buf);
			return -1;
		}
	}
	return 0;
}

/*
 * The gen_id thing is used to optimize the comparison of shared files.
 * If two files have different gen_ids, then they are different for sure.
 * If it matches, we don't know it and have to call sys_kcmp().
 *
 * The kcmp-ids.c engine does this trick, see comments in it for more info.
 */

uint32_t make_gen_id(uint32_t st_dev, uint32_t st_ino, uint64_t pos)
{
	uint32_t pos_hi = pos >> 32;
	uint32_t pos_low = pos & 0xffffffff;

	return st_dev ^ st_ino ^ pos_hi ^ pos_low;
}

int do_dump_gen_file(struct fd_parms *p, int lfd, const struct fdtype_ops *ops, FdinfoEntry *e)
{
	int ret = -1;

	e->type = ops->type;
	e->id = make_gen_id((uint32_t)p->stat.st_dev, (uint32_t)p->stat.st_ino, (uint64_t)p->pos);
	e->fd = p->fd;
	e->flags = p->fd_flags;

	ret = fd_id_generate(p->pid, e, p);
	if (ret == 1) /* new ID generated */
		ret = ops->dump(lfd, e->id, p);
	else
		/* Remove locks generated by the fd before going to the next */
		discard_dup_locks_tail(p->pid, e->fd);

	return ret;
}

int fill_fdlink(int lfd, const struct fd_parms *p, struct fd_link *link)
{
	int len;

	link->name[0] = '.';

	len = read_fd_link(lfd, &link->name[1], sizeof(link->name) - 1);
	if (len < 0) {
		pr_err("Can't read link for pid %d fd %d\n", p->pid, p->fd);
		return -1;
	}

	link->len = len + 1;

	if (opts.overlayfs)
		if (fixup_overlayfs((struct fd_parms *)p, link) < 0)
			return -1;
	return 0;
}

static int fill_fd_params(struct pid *owner_pid, int fd, int lfd, struct fd_opts *opts, struct fd_parms *p)
{
	int ret;
	struct statfs fsbuf;
	struct fdinfo_common fdinfo = { .mnt_id = -1, .owner = owner_pid->ns[0].virt };

	if (fstat(lfd, &p->stat) < 0) {
		pr_perror("Can't stat fd %d", lfd);
		return -1;
	}

	if (fstatfs(lfd, &fsbuf) < 0) {
		pr_perror("Can't statfs fd %d", lfd);
		return -1;
	}

	if (parse_fdinfo_pid(owner_pid->real, fd, FD_TYPES__UND, &fdinfo))
		return -1;

	p->fs_type = fsbuf.f_type;
	p->fd = fd;
	p->pos = fdinfo.pos;
	/*
	 * The kernel artificially adds the O_CLOEXEC flag on the file pointer
	 * flags by looking at the flags on the file descriptor (see kernel
	 * code fs/proc/fd.c). FD_CLOEXEC is a file descriptor property, which
	 * is saved in fd_flags.
	 */
	p->flags = fdinfo.flags & ~O_CLOEXEC;
	p->mnt_id = fdinfo.mnt_id;
	p->pid = owner_pid->real;
	p->fd_flags = opts->flags;

	fown_entry__init(&p->fown);

	pr_info("%d fdinfo %d: pos: %#16" PRIx64 " flags: %16o/%#x\n", owner_pid->real, fd, p->pos, p->flags,
		(int)p->fd_flags);

	if (p->flags & O_PATH)
		ret = 0;
	else
		ret = fcntl(lfd, F_GETSIG, 0);
	if (ret < 0) {
		pr_perror("Can't get owner signum on %d", lfd);
		return -1;
	}
	p->fown.signum = ret;

	if (opts->fown.pid == 0)
		return 0;

	p->fown.pid = opts->fown.pid;
	p->fown.pid_type = opts->fown.pid_type;
	p->fown.uid = opts->fown.uid;
	p->fown.euid = opts->fown.euid;

	return 0;
}

static const struct fdtype_ops *get_misc_dev_ops(int minor)
{
	switch (minor) {
	case TUN_MINOR:
		return &tunfile_dump_ops;
	case AUTOFS_MINOR:
		return &regfile_dump_ops;
	};

	return NULL;
}

static const struct fdtype_ops *get_mem_dev_ops(struct fd_parms *p, int minor)
{
	const struct fdtype_ops *ops = NULL;

	/*
	 * If /dev/kmsg is opened in write-only mode the file position
	 * should not be set up upon restore, kernel doesn't allow that.
	 */
	if (minor == 11 && (p->flags & O_ACCMODE) == O_WRONLY && p->pos == 0)
		p->pos = -1ULL;

	ops = &regfile_dump_ops;

	return ops;
}

static int dump_chrdev(struct fd_parms *p, int lfd, FdinfoEntry *e)
{
	struct fd_link *link_old = p->link;
	int maj = major(p->stat.st_rdev);
	const struct fdtype_ops *ops;
	struct fd_link link;
	int err;

	switch (maj) {
	case MEM_MAJOR:
		ops = get_mem_dev_ops(p, minor(p->stat.st_rdev));
		break;
	case MISC_MAJOR:
		ops = get_misc_dev_ops(minor(p->stat.st_rdev));
		if (ops)
			break;
		/* fallthrough */
	default: {
		char more[32];

		if (is_tty(p->stat.st_rdev, p->stat.st_dev)) {
			if (fill_fdlink(lfd, p, &link))
				return -1;
			p->link = &link;
			ops = &tty_dump_ops;
			break;
		}

		sprintf(more, "%d:%d", maj, minor(p->stat.st_rdev));
		err = dump_unsupp_fd(p, lfd, "chr", more, e);
		p->link = link_old;
		return err;
	}
	}

	err = do_dump_gen_file(p, lfd, ops, e);
	p->link = link_old;
	return err;
}

static int dump_one_file(struct pid *pid, int fd, int lfd, struct fd_opts *opts, struct parasite_ctl *ctl,
			 FdinfoEntry *e, struct parasite_drain_fd *dfds)
{
	struct fd_parms p = FD_PARMS_INIT;
	const struct fdtype_ops *ops;
	struct fd_link link;

	if (fill_fd_params(pid, fd, lfd, opts, &p) < 0) {
		pr_err("Can't get stat on %d\n", fd);
		return -1;
	}

	if (note_file_lock(pid, fd, lfd, &p))
		return -1;

	/* Lease can be set only on regular file */
	if (S_ISREG(p.stat.st_mode)) {
		int ret = correct_file_leases_type(pid, fd, lfd);

		if (ret < 0)
			return ret;
	}

	p.fd_ctl = ctl; /* Some dump_opts require this to talk to parasite */
	p.dfds = dfds;	/* epoll needs to verify if target fd exist */

	if (S_ISSOCK(p.stat.st_mode))
		return dump_socket(&p, lfd, e);

	if (S_ISCHR(p.stat.st_mode))
		return dump_chrdev(&p, lfd, e);

	if (p.fs_type == ANON_INODE_FS_MAGIC) {
		char link[32];

		if (read_fd_link(lfd, link, sizeof(link)) < 0)
			return -1;

		if (is_eventfd_link(link))
			ops = &eventfd_dump_ops;
		else if (is_eventpoll_link(link))
			ops = &eventpoll_dump_ops;
		else if (is_inotify_link(link))
			ops = &inotify_dump_ops;
		else if (is_fanotify_link(link))
			ops = &fanotify_dump_ops;
		else if (is_signalfd_link(link))
			ops = &signalfd_dump_ops;
		else if (is_timerfd_link(link))
			ops = &timerfd_dump_ops;
#ifdef CONFIG_HAS_LIBBPF
		else if (is_bpfmap_link(link))
			ops = &bpfmap_dump_ops;
#endif
		else
			return dump_unsupp_fd(&p, lfd, "anon", link, e);

		return do_dump_gen_file(&p, lfd, ops, e);
	}

	if (S_ISREG(p.stat.st_mode) || S_ISDIR(p.stat.st_mode) || S_ISLNK(p.stat.st_mode)) {
		if (fill_fdlink(lfd, &p, &link))
			return -1;

		p.link = &link;

		/* TODO: Dump for hugetlb fd when memfd hugetlb is not supported */
		if (is_memfd(p.stat.st_dev) || (kdat.has_memfd_hugetlb && is_hugetlb_dev(p.stat.st_dev, NULL)))
			ops = &memfd_dump_ops;
		else if (link.name[1] == '/')
			ops = &regfile_dump_ops;
		else if (check_ns_proc(&link))
			ops = &nsfile_dump_ops;
		else
			return dump_unsupp_fd(&p, lfd, "reg", link.name + 1, e);

		return do_dump_gen_file(&p, lfd, ops, e);
	}

	if (S_ISFIFO(p.stat.st_mode)) {
		if (p.fs_type == PIPEFS_MAGIC)
			ops = &pipe_dump_ops;
		else
			ops = &fifo_dump_ops;

		return do_dump_gen_file(&p, lfd, ops, e);
	}

	/*
	 * For debug purpose -- at least show the link
	 * file pointing to when reporting unsupported file.
	 * On error simply empty string here.
	 */
	if (fill_fdlink(lfd, &p, &link))
		memzero(&link, sizeof(link));

	return dump_unsupp_fd(&p, lfd, "unknown", link.name + 1, e);
}

int dump_my_file(int lfd, u32 *id, int *type)
{
	struct pid me = {};
	struct fd_opts fdo = {};
	FdinfoEntry e = FDINFO_ENTRY__INIT;

	me.real = getpid();
	me.ns[0].virt = -1; /* FIXME */

	if (dump_one_file(&me, lfd, lfd, &fdo, NULL, &e, NULL))
		return -1;

	*id = e.id;
	*type = e.type;
	return 0;
}

int dump_task_files_seized(struct parasite_ctl *ctl, struct pstree_item *item, struct parasite_drain_fd *dfds)
{
	int *lfds = NULL;
	struct cr_img *img = NULL;
	struct fd_opts *opts = NULL;
	int i, ret = -1;
	int off, nr_fds = min((int)PARASITE_MAX_FDS, dfds->nr_fds);

	pr_info("\n");
	pr_info("Dumping opened files (pid: %d)\n", item->pid->real);
	pr_info("----------------------------------------\n");

	lfds = xmalloc(nr_fds * sizeof(int));
	if (!lfds)
		goto err;

	opts = xmalloc(nr_fds * sizeof(struct fd_opts));
	if (!opts)
		goto err;

	img = open_image(CR_FD_FDINFO, O_DUMP, item->ids->files_id);
	if (!img)
		goto err;

	ret = 0; /* Don't fail if nr_fds == 0 */
	for (off = 0; ret == 0 && off < dfds->nr_fds; off += nr_fds) {
		if (nr_fds + off > dfds->nr_fds)
			nr_fds = dfds->nr_fds - off;

		ret = parasite_drain_fds_seized(ctl, dfds, nr_fds, off, lfds, opts);
		if (ret)
			goto err;

		for (i = 0; i < nr_fds; i++) {
			FdinfoEntry e = FDINFO_ENTRY__INIT;

			ret = dump_one_file(item->pid, dfds->fds[i + off], lfds[i], opts + i, ctl, &e, dfds);
			if (ret)
				break;

			ret = pb_write_one(img, &e, PB_FDINFO);
			if (ret)
				break;
		}

		for (i = 0; i < nr_fds; i++)
			close(lfds[i]);
	}

	pr_info("----------------------------------------\n");
err:
	if (img)
		close_image(img);
	xfree(opts);
	xfree(lfds);
	return ret;
}

static int predump_one_fd(int pid, int fd)
{
	const struct fdtype_ops *ops;
	char link[PATH_MAX], t[32];
	int ret = 0;

	snprintf(t, sizeof(t), "/proc/%d/fd/%d", pid, fd);
	ret = readlink(t, link, sizeof(link));
	if (ret < 0) {
		pr_perror("Can't read link of fd %d", fd);
		return -1;
	} else if ((size_t)ret == sizeof(link)) {
		pr_err("Buffer for read link of fd %d is too small\n", fd);
		return -1;
	}
	link[ret] = 0;

	ret = 0;
	if (is_inotify_link(link))
		ops = &inotify_dump_ops;
	else if (is_fanotify_link(link))
		ops = &fanotify_dump_ops;
	else
		goto out;

	pr_debug("Pre-dumping %d's %d fd\n", pid, fd);
	ret = ops->pre_dump(pid, fd);
out:
	return ret;
}

int predump_task_files(int pid)
{
	struct dirent *de;
	DIR *fd_dir;
	int ret = -1;

	pr_info("Pre-dump fds for %d)\n", pid);

	fd_dir = opendir_proc(pid, "fd");
	if (!fd_dir)
		return -1;

	while ((de = readdir(fd_dir))) {
		if (dir_dots(de))
			continue;

		if (predump_one_fd(pid, atoi(de->d_name)))
			goto out;
	}

	ret = 0;
out:
	closedir(fd_dir);
	return ret;
}

int restore_fown(int fd, FownEntry *fown)
{
	struct f_owner_ex owner;
	uid_t uids[3];

	if (fown->signum) {
		if (fcntl(fd, F_SETSIG, fown->signum)) {
			pr_perror("Can't set signal");
			return -1;
		}
	}

	/* May be untouched */
	if (!fown->pid)
		return 0;

	if (getresuid(&uids[0], &uids[1], &uids[2])) {
		pr_perror("Can't get current UIDs");
		return -1;
	}

	if (setresuid(fown->uid, fown->euid, uids[2])) {
		pr_perror("Can't set UIDs");
		return -1;
	}

	owner.type = fown->pid_type;
	owner.pid = fown->pid;

	if (fcntl(fd, F_SETOWN_EX, &owner)) {
		pr_perror("Can't setup %d file owner pid", fd);
		return -1;
	}

	if (setresuid(uids[0], uids[1], uids[2])) {
		pr_perror("Can't revert UIDs back");
		return -1;
	}

	if (prctl(PR_SET_DUMPABLE, 1, 0))
		pr_perror("Unable to set PR_SET_DUMPABLE");

	return 0;
}

int rst_file_params(int fd, FownEntry *fown, int flags)
{
	if (set_fd_flags(fd, flags) < 0)
		return -1;
	if (restore_fown(fd, fown) < 0)
		return -1;
	return 0;
}

static struct fdinfo_list_entry *alloc_fle(int pid, FdinfoEntry *fe)
{
	struct fdinfo_list_entry *fle;

	fle = shmalloc(sizeof(*fle));
	if (!fle)
		return NULL;
	fle->pid = pid;
	fle->fe = fe;
	fle->received = 0;
	fle->fake = 0;
	fle->stage = FLE_INITIALIZED;
	fle->task = pstree_item_by_virt(pid);
	if (!fle->task) {
		pr_err("Can't find task with pid %d\n", pid);
		shfree_last(fle);
		return NULL;
	}

	return fle;
}

static void __collect_desc_fle(struct fdinfo_list_entry *new_le, struct file_desc *fdesc)
{
	struct fdinfo_list_entry *le;

	list_for_each_entry_reverse(le, &fdesc->fd_info_head, desc_list)
		if (pid_rst_prio_eq(le->pid, new_le->pid))
			break;
	list_add(&new_le->desc_list, &le->desc_list);
}

static void collect_desc_fle(struct fdinfo_list_entry *new_le, struct file_desc *fdesc, bool force_master)
{
	new_le->desc = fdesc;

	if (!force_master)
		__collect_desc_fle(new_le, fdesc);
	else {
		/* Link as first entry */
		list_add(&new_le->desc_list, &fdesc->fd_info_head);
	}
}

struct fdinfo_list_entry *collect_fd_to(int pid, FdinfoEntry *e, struct rst_info *rst_info, struct file_desc *fdesc,
					bool fake, bool force_master)
{
	struct fdinfo_list_entry *new_le;

	new_le = alloc_fle(pid, e);
	if (new_le) {
		new_le->fake = (!!fake);
		collect_desc_fle(new_le, fdesc, force_master);
		collect_task_fd(new_le, rst_info);
	}

	return new_le;
}

int collect_fd(int pid, FdinfoEntry *e, struct rst_info *rst_info, bool fake)
{
	struct file_desc *fdesc;

	pr_info("Collect fdinfo pid=%d fd=%d id=%#x\n", pid, e->fd, e->id);

	fdesc = find_file_desc(e);
	if (fdesc == NULL) {
		pr_err("No file for fd %d id %#x\n", e->fd, e->id);
		return -1;
	}

	if (!collect_fd_to(pid, e, rst_info, fdesc, fake, false))
		return -1;

	return 0;
}

FdinfoEntry *dup_fdinfo(FdinfoEntry *old, int fd, unsigned flags)
{
	FdinfoEntry *e;

	e = shmalloc(sizeof(*e));
	if (!e)
		return NULL;

	fdinfo_entry__init(e);

	e->id = old->id;
	e->type = old->type;
	e->fd = fd;
	e->flags = flags;
	return e;
}

int dup_fle(struct pstree_item *task, struct fdinfo_list_entry *ple, int fd, unsigned flags)
{
	FdinfoEntry *e;

	e = dup_fdinfo(ple->fe, fd, flags);
	if (!e)
		return -1;

	return collect_fd(vpid(task), e, rsti(task), false);
}

int prepare_fd_pid(struct pstree_item *item)
{
	int ret = 0;
	struct cr_img *img;
	pid_t pid = vpid(item);
	struct rst_info *rst_info = rsti(item);

	INIT_LIST_HEAD(&rst_info->fds);

	if (item->ids == NULL) /* zombie */
		return 0;

	if (rsti(item)->fdt && rsti(item)->fdt->pid != vpid(item))
		return 0;

	img = open_image(CR_FD_FDINFO, O_RSTR, item->ids->files_id);
	if (!img)
		return -1;

	while (1) {
		FdinfoEntry *e;

		ret = pb_read_one_eof(img, &e, PB_FDINFO);
		if (ret <= 0)
			break;

		if (e->fd >= kdat.sysctl_nr_open) {
			ret = -1;
			pr_err("Too big FD number to restore %d\n", e->fd);
			break;
		}

		ret = collect_fd(pid, e, rst_info, false);
		if (ret < 0) {
			fdinfo_entry__free_unpacked(e, NULL);
			break;
		}
	}

	close_image(img);
	return ret;
}

#define SETFL_MASK (O_APPEND | O_ASYNC | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME)
int set_fd_flags(int fd, int flags)
{
	int ret;

	ret = fcntl(fd, F_GETFL, 0);
	if (ret < 0)
		goto err;

	flags = (SETFL_MASK & flags) | (ret & ~SETFL_MASK);

	ret = fcntl(fd, F_SETFL, flags);
	if (ret < 0)
		goto err;

	/* Let's check, that now actual flags contains those we need */
	ret = fcntl(fd, F_GETFL, 0);
	if (ret < 0)
		goto err;

	if (ret != flags) {
		pr_err("fcntl call on fd %d (flags %#o) succeeded, "
		       "but some flags were dropped: %#o\n",
		       fd, flags, ret);
		return -1;
	}
	return 0;

err:
	pr_perror("fcntl call on fd %d (flags %x) failed", fd, flags);
	return -1;
}

struct fd_open_state {
	char *name;
	int (*cb)(int, struct fdinfo_list_entry *);
};

static int receive_fd(struct fdinfo_list_entry *fle);

static void transport_name_gen(struct sockaddr_un *addr, int *len, int pid)
{
	addr->sun_family = AF_UNIX;
	snprintf(addr->sun_path, UNIX_PATH_MAX, "x/crtools-fd-%d-%" PRIx64, pid, criu_run_id);
	*len = SUN_LEN(addr);
	*addr->sun_path = '\0';
}

static bool task_fle(struct pstree_item *task, struct fdinfo_list_entry *fle)
{
	struct fdinfo_list_entry *tmp;

	list_for_each_entry(tmp, &rsti(task)->fds, ps_list)
		if (fle == tmp)
			return true;
	return false;
}

static int plant_fd(struct fdinfo_list_entry *fle, int fd)
{
	BUG_ON(fle->received);
	fle->received = 1;
	return reopen_fd_as(fle->fe->fd, fd);
}

static int recv_fd_from_peer(struct fdinfo_list_entry *fle)
{
	struct fdinfo_list_entry *tmp;
	int fd, ret, tsock;

	if (fle->received)
		return 0;

	tsock = get_service_fd(TRANSPORT_FD_OFF);
	do {
		ret = __recv_fds(tsock, &fd, 1, (void *)&tmp, sizeof(struct fdinfo_list_entry *), MSG_DONTWAIT);
		if (ret == -EAGAIN || ret == -EWOULDBLOCK)
			return 1;
		else if (ret)
			return -1;

		pr_info("Further fle=%p, pid=%d\n", tmp, fle->pid);
		if (!task_fle(current, tmp)) {
			pr_err("Unexpected fle %p, pid=%d\n", tmp, vpid(current));
			return -1;
		}
		if (plant_fd(tmp, fd))
			return -1;
	} while (tmp != fle);

	return 0;
}

static int send_fd_to_peer(int fd, struct fdinfo_list_entry *fle)
{
	struct sockaddr_un saddr;
	int len, sock, ret;

	sock = get_service_fd(TRANSPORT_FD_OFF);

	transport_name_gen(&saddr, &len, fle->pid);
	pr_info("\t\tSend fd %d to %s\n", fd, saddr.sun_path + 1);
	ret = send_fds(sock, &saddr, len, &fd, 1, (void *)&fle, sizeof(struct fdinfo_list_entry *));
	if (ret < 0)
		return -1;
	return set_fds_event(fle->pid);
}

/*
 * Helpers to scatter file_desc across users for those files, that
 * create two descriptors from a single system call at once (e.g.
 * ... or better i.e. -- pipes, socketpairs and ttys)
 */
int recv_desc_from_peer(struct file_desc *d, int *fd)
{
	struct fdinfo_list_entry *fle;

	fle = file_master(d);
	*fd = fle->fe->fd;
	return recv_fd_from_peer(fle);
}

int send_desc_to_peer(int fd, struct file_desc *d)
{
	return send_fd_to_peer(fd, file_master(d));
}

static int send_fd_to_self(int fd, struct fdinfo_list_entry *fle)
{
	int dfd = fle->fe->fd;

	if (fd == dfd)
		return 0;

	BUG_ON(dfd == get_service_fd(TRANSPORT_FD_OFF));

	pr_info("\t\t\tGoing to dup %d into %d\n", fd, dfd);
	if (dup2(fd, dfd) != dfd) {
		pr_perror("Can't dup local fd %d -> %d", fd, dfd);
		return -1;
	}

	if (fcntl(dfd, F_SETFD, fle->fe->flags) == -1) {
		pr_perror("Unable to set file descriptor flags");
		return -1;
	}

	fle->received = 1;

	return 0;
}

static int serve_out_fd(int pid, int fd, struct file_desc *d)
{
	int ret;
	struct fdinfo_list_entry *fle;

	pr_info("\t\tCreate fd for %d\n", fd);

	list_for_each_entry(fle, &d->fd_info_head, desc_list) {
		if (pid == fle->pid)
			ret = send_fd_to_self(fd, fle);
		else
			ret = send_fd_to_peer(fd, fle);

		if (ret) {
			pr_err("Can't sent fd %d to %d\n", fd, fle->pid);
			goto out;
		}
	}

	ret = 0;
out:
	return ret;
}

int setup_and_serve_out(struct fdinfo_list_entry *fle, int new_fd)
{
	struct file_desc *d = fle->desc;
	pid_t pid = fle->pid;

	if (reopen_fd_as(fle->fe->fd, new_fd))
		return -1;

	if (fcntl(fle->fe->fd, F_SETFD, fle->fe->flags) == -1) {
		pr_perror("Unable to set file descriptor flags");
		return -1;
	}

	BUG_ON(fle->stage != FLE_INITIALIZED);
	fle->stage = FLE_OPEN;

	if (serve_out_fd(pid, fle->fe->fd, d))
		return -1;
	return 0;
}

static int open_fd(struct fdinfo_list_entry *fle)
{
	struct file_desc *d = fle->desc;
	struct fdinfo_list_entry *fle_m;
	int new_fd = -1, ret;

	fle_m = file_master(d);
	if (fle != fle_m) {
		BUG_ON(fle->stage != FLE_INITIALIZED);
		ret = receive_fd(fle);
		if (ret != 0)
			return ret;
		goto out;
	}

	/*
	 * Open method returns the following values:
	 * 0  -- restore is successfully finished;
	 * 1  -- restore is in process or can't be started
	 *       yet, because of it depends on another fles,
	 *       so the method should be called once again;
	 * -1 -- restore failed.
	 * In case of 0 and 1 return values, new_fd may
	 * be not negative. In this case it contains newly
	 * opened file descriptor, which may be served out.
	 * For every fle, new_fd is populated only once.
	 * See setup_and_serve_out() BUG_ON for the details.
	 */
	ret = d->ops->open(d, &new_fd);
	if (ret != -1 && new_fd >= 0) {
		if (setup_and_serve_out(fle, new_fd) < 0)
			return -1;
	}
out:
	if (ret == 0)
		fle->stage = FLE_RESTORED;
	return ret;
}

static int receive_fd(struct fdinfo_list_entry *fle)
{
	int ret;

	pr_info("\tReceive fd for %d\n", fle->fe->fd);

	ret = recv_fd_from_peer(fle);
	if (ret != 0) {
		if (ret != 1)
			pr_err("Can't get fd=%d, pid=%d\n", fle->fe->fd, fle->pid);
		return ret;
	}

	if (fcntl(fle->fe->fd, F_SETFD, fle->fe->flags) == -1) {
		pr_perror("Unable to set file descriptor flags");
		return -1;
	}

	return 0;
}

static void close_fdinfos(struct list_head *list)
{
	struct fdinfo_list_entry *fle;

	list_for_each_entry(fle, list, ps_list)
		close(fle->fe->fd);
}

static int open_fdinfos(struct pstree_item *me)
{
	struct list_head *list = &rsti(me)->fds;
	struct fdinfo_list_entry *fle, *tmp;
	LIST_HEAD(completed);
	LIST_HEAD(fake);
	bool progress, again;
	int st, ret = 0;

	do {
		progress = again = false;
		clear_fds_event();

		list_for_each_entry_safe(fle, tmp, list, ps_list) {
			st = fle->stage;
			BUG_ON(st == FLE_RESTORED);
			ret = open_fd(fle);
			if (ret == -1) {
				pr_err("Unable to open fd=%d id=%#x\n", fle->fe->fd, fle->fe->id);
				goto splice;
			}
			if (st != fle->stage || ret == 0)
				progress = true;
			if (ret == 0) {
				/*
				 * We delete restored items from fds list,
				 * so open() methods may base on this feature
				 * and reduce number of fles in their checks.
				 */
				list_del(&fle->ps_list);
				if (!fle->fake)
					list_add(&fle->ps_list, &completed);
				else
					list_add(&fle->ps_list, &fake);
			}
			if (ret == 1)
				again = true;
		}
		if (!progress && again)
			wait_fds_event();
	} while (again || progress);

	BUG_ON(!list_empty(list));
	/*
	 * Fake fles may be used for restore other
	 * file types, so their closing is delayed.
	 */
	close_fdinfos(&fake);
splice:
	list_splice(&fake, list);
	list_splice(&completed, list);

	return ret;
}

int close_old_fds(void)
{
	DIR *dir;
	struct dirent *de;
	int fd, ret;

	/**
	 * Close previous /proc/self/ service fd, as we don't want to reuse it
	 * from a different task. Also there can be some junk fd in it's place
	 * after we've moved our service fds (e.g. from other task of parents
	 * shared fdtable), we need to close it before opendir_proc() below.
	 */
	__close_service_fd(PROC_SELF_FD_OFF);

	dir = opendir_proc(PROC_SELF, "fd");
	if (dir == NULL)
		return -1;

	while ((de = readdir(dir))) {
		if (dir_dots(de))
			continue;

		ret = sscanf(de->d_name, "%d", &fd);
		if (ret != 1) {
			pr_err("Can't parse %s\n", de->d_name);
			closedir(dir);
			close_pid_proc();
			return -1;
		}

		if ((!is_any_service_fd(fd)) && (dirfd(dir) != fd))
			close_safe(&fd);
	}

	closedir(dir);
	close_pid_proc();

	return 0;
}

int prepare_fds(struct pstree_item *me)
{
	u32 ret = 0;

	pr_info("Opening fdinfo-s\n");

	/*
	 * This must be done after forking to allow child
	 * to get the cgroup fd so it can move into the
	 * correct /tasks file if it is in a different cgroup
	 * set than its parent
	 */
	sfds_protected = false;
	close_service_fd(CGROUP_YARD);
	sfds_protected = true;

	if (rsti(me)->fdt) {
		struct fdt *fdt = rsti(me)->fdt;

		/*
		 * Wait all tasks, who share a current fd table.
		 * We should be sure, that nobody use any file
		 * descriptor while fdtable is being restored.
		 */
		futex_inc_and_wake(&fdt->fdt_lock);
		futex_wait_while_lt(&fdt->fdt_lock, fdt->nr);

		if (fdt->pid != vpid(me)) {
			pr_info("File descriptor table is shared with %d\n", fdt->pid);
			futex_wait_until(&fdt->fdt_lock, fdt->nr + 1);
			goto out;
		}
	}

	BUG_ON(current->pid->state == TASK_HELPER);
	ret = open_fdinfos(me);

	if (rsti(me)->fdt)
		futex_inc_and_wake(&rsti(me)->fdt->fdt_lock);
out:
	return ret;
}

static int fchroot(int fd)
{
	/*
	 * There's no such thing in syscalls. We can emulate
	 * it using fchdir()
	 */

	if (fchdir(fd) < 0) {
		pr_perror("Can't chdir to proc");
		return -1;
	}

	pr_debug("Going to chroot into /proc/self/fd/%d\n", fd);
	return chroot(".");
}

static int need_chroot(int saved_root)
{
	struct stat saved_root_stat, cur_root_stat;
	int psd;

	if (fstat(saved_root, &saved_root_stat) == -1) {
		pr_perror("Failed to stat saved root dir");
		return -1;
	}

	psd = open_pid_proc(PROC_SELF);
	if (psd < 0) {
		pr_perror("Failed to open PROC_SELF");
		return -1;
	}

	if (fstatat(psd, "root", &cur_root_stat, 0) == -1) {
		pr_perror("Failed to stat current root dir");
		return -1;
	}

	return saved_root_stat.st_ino != cur_root_stat.st_ino || saved_root_stat.st_dev != cur_root_stat.st_dev;
}

int restore_fs(struct pstree_item *me)
{
	int dd_root = -1, dd_cwd = -1, ret, err = -1;
	struct rst_info *ri = rsti(me);
	bool do_chroot = true;

	/*
	 * First -- open both descriptors. We will not
	 * be able to open the cwd one after we chroot.
	 */

	dd_root = open_reg_fd(ri->root);
	if (dd_root < 0) {
		pr_err("Can't open root\n");
		goto out;
	}

	dd_cwd = open_reg_fd(ri->cwd);
	if (dd_cwd < 0) {
		pr_err("Can't open cwd\n");
		goto out;
	}

	/*
	 * In unprivileged mode chroot() may fail if we don't have
	 * sufficient privileges, therefore only do it if the process
	 * is actually chrooted.
	 */
	if (opts.unprivileged)
		do_chroot = need_chroot(dd_root);

	/*
	 * Now do chroot/chdir. Chroot goes first as it calls chdir into
	 * dd_root so we'd need to fix chdir after it anyway.
	 */
	if (do_chroot) {
		ret = fchroot(dd_root);
		if (ret < 0) {
			pr_perror("Can't change root");
			goto out;
		}
	}

	ret = fchdir(dd_cwd);
	if (ret < 0) {
		pr_perror("Can't change cwd");
		goto out;
	}

	if (ri->has_umask) {
		pr_info("Restoring umask to %o\n", ri->umask);
		umask(ri->umask);
	}

	err = 0;
out:
	if (dd_cwd >= 0)
		close(dd_cwd);
	if (dd_root >= 0)
		close(dd_root);

	return err;
}

int prepare_fs_pid(struct pstree_item *item)
{
	pid_t pid = vpid(item);
	struct rst_info *ri = rsti(item);
	struct cr_img *img;
	FsEntry *fe;
	int ret = -1;

	img = open_image(CR_FD_FS, O_RSTR, pid);
	if (!img)
		goto out;

	ret = pb_read_one_eof(img, &fe, PB_FS);
	close_image(img);
	if (ret <= 0)
		goto out;

	ri->cwd = collect_special_file(fe->cwd_id);
	if (!ri->cwd) {
		pr_err("Can't find task cwd file\n");
		goto out_f;
	}

	ri->root = collect_special_file(fe->root_id);
	if (!ri->root) {
		pr_err("Can't find task root file\n");
		goto out_f;
	}

	ri->has_umask = fe->has_umask;
	ri->umask = fe->umask;

	ret = 0;
out_f:
	fs_entry__free_unpacked(fe, NULL);
out:
	return ret;
}

int shared_fdt_prepare(struct pstree_item *item)
{
	struct pstree_item *parent = item->parent;
	struct fdt *fdt;

	if (!rsti(parent)->fdt) {
		fdt = shmalloc(sizeof(*rsti(item)->fdt));
		if (fdt == NULL)
			return -1;

		rsti(parent)->fdt = fdt;

		futex_init(&fdt->fdt_lock);
		fdt->nr = 1;
		fdt->pid = vpid(parent);
	} else
		fdt = rsti(parent)->fdt;

	rsti(item)->fdt = fdt;
	rsti(item)->service_fd_id = fdt->nr;
	fdt->nr++;

	return 0;
}

/*
 * Inherit fd support.
 *
 * There are cases where a process's file descriptor cannot be restored
 * from the checkpointed image.  For example, a pipe file descriptor with
 * one end in the checkpointed process and the other end in a separate
 * process (that was not part of the checkpointed process tree) cannot be
 * restored because after checkpoint the pipe would be broken and removed.
 *
 * There are also cases where the user wants to use a new file during
 * restore instead of the original file in the checkpointed image.  For
 * example, the user wants to change the log file of a process from
 * /path/to/oldlog to /path/to/newlog.
 *
 * In these cases, criu's caller should set up a new file descriptor to be
 * inherited by the restored process and specify it with the --inherit-fd
 * command line option.  The argument of --inherit-fd has the format
 * fd[%d]:%s, where %d tells criu which of its own file descriptor to use
 * for restoring file identified by %s.
 *
 * As a debugging aid, if the argument has the format debug[%d]:%s, it tells
 * criu to write out the string after colon to the file descriptor %d.  This
 * can be used to leave a "restore marker" in the output stream of the process.
 *
 * It's important to note that inherit fd support breaks applications
 * that depend on the state of the file descriptor being inherited.  So,
 * consider inherit fd only for specific use cases that you know for sure
 * won't break the application.
 *
 * For examples please visit http://criu.org/Category:HOWTO.
 */

struct inherit_fd {
	struct list_head inh_list;
	char *inh_id; /* file identifier */
	int inh_fd;   /* criu's descriptor to inherit */
	int inh_fd_id;
};

int inh_fd_max = -1;

int inherit_fd_parse(char *optarg)
{
	char *cp = NULL;
	int n = -1;
	int fd = -1;
	int dbg = 0;

	/*
	 * Parse the argument.
	 */
	if (!strncmp(optarg, "fd", 2))
		cp = &optarg[2];
	else if (!strncmp(optarg, "debug", 5)) {
		cp = &optarg[5];
		dbg = 1;
	}
	if (cp) {
		n = sscanf(cp, "[%d]:", &fd);
		cp = strchr(optarg, ':');
	}
	if (n != 1 || fd < 0 || !cp || !cp[1]) {
		pr_err("Invalid inherit fd argument: %s\n", optarg);
		return -1;
	}

	/*
	 * If the argument is a debug string, write it to fd.
	 * Otherwise, add it to the inherit fd list.
	 */
	cp++;
	if (dbg) {
		n = strlen(cp);
		if (write(fd, cp, n) != n) {
			pr_err("Can't write debug message %s to inherit fd %d\n", cp, fd);
			return -1;
		}
		return 0;
	}

	return inherit_fd_add(fd, cp);
}

int inherit_fd_add(int fd, char *key)
{
	struct inherit_fd *inh;
	struct stat sbuf;

	if (fstat(fd, &sbuf) == -1) {
		pr_perror("Can't fstat inherit fd %d", fd);
		return -1;
	}

	inh = xmalloc(sizeof *inh);
	if (inh == NULL)
		return -1;

	if (fd > inh_fd_max)
		inh_fd_max = fd;

	inh->inh_id = xstrdup(key);
	if (inh->inh_id == NULL) {
		xfree(inh);
		return -1;
	}

	inh->inh_fd = fd;
	list_add_tail(&inh->inh_list, &opts.inherit_fds);
	return 0;
}

/*
 * Log the inherit fd list.  Called for diagnostics purposes
 * after the log file is initialized.
 */
void inherit_fd_log(void)
{
	struct inherit_fd *inh;

	list_for_each_entry(inh, &opts.inherit_fds, inh_list) {
		pr_info("File %s will be restored from inherit fd %d\n", inh->inh_id, inh->inh_fd);
	}
}

int inherit_fd_move_to_fdstore(void)
{
	struct inherit_fd *inh;

	list_for_each_entry(inh, &opts.inherit_fds, inh_list) {
		inh->inh_fd_id = fdstore_add(inh->inh_fd);
		if (inh->inh_fd_id < 0)
			return -1;
		close_safe(&inh->inh_fd);
	}

	return 0;
}

/*
 * Look up the inherit fd list by a file identifier.
 */
int inherit_fd_lookup_id(char *id)
{
	int ret;
	struct inherit_fd *inh;

	ret = -1;
	list_for_each_entry(inh, &opts.inherit_fds, inh_list) {
		if (!strcmp(inh->inh_id, id)) {
			ret = fdstore_get(inh->inh_fd_id);
			pr_debug("Found id %s (fd %d) in inherit fd list\n", id, ret);
			break;
		}
	}
	return ret;
}

bool inherited_fd(struct file_desc *d, int *fd_p)
{
	char buf[PATH_MAX], *id_str;
	int i_fd;

	if (!d->ops->name)
		return false;

	id_str = d->ops->name(d, buf, sizeof(buf));
	i_fd = inherit_fd_lookup_id(id_str);
	if (i_fd < 0)
		return false;

	if (fd_p == NULL)
		return true;

	*fd_p = i_fd;
	pr_info("File %s will be restored from fd %d dumped "
		"from inherit fd %d\n",
		id_str, *fd_p, i_fd);
	return true;
}

int open_transport_socket(void)
{
	pid_t pid = vpid(current);
	struct sockaddr_un saddr;
	int sock, slen, ret = -1;

	sock = socket(PF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0);
	if (sock < 0) {
		pr_perror("Can't create socket");
		goto out;
	}

	transport_name_gen(&saddr, &slen, pid);
	if (bind(sock, (struct sockaddr *)&saddr, slen) < 0) {
		pr_perror("Can't bind transport socket %s", saddr.sun_path + 1);
		close(sock);
		goto out;
	}

	if (install_service_fd(TRANSPORT_FD_OFF, sock) < 0)
		goto out;
	ret = 0;
out:
	return ret;
}

static int collect_one_file_entry(FileEntry *fe, u_int32_t id, ProtobufCMessage *base, struct collect_image_info *cinfo)
{
	if (fe->id != id) {
		pr_err("ID mismatch %u != %u\n", fe->id, id);
		return -1;
	}

	return collect_entry(base, cinfo);
}

static int collect_one_file(void *o, ProtobufCMessage *base, struct cr_img *i)
{
	int ret = 0;
	FileEntry *fe;

	fe = pb_msg(base, FileEntry);
	switch (fe->type) {
	default:
		pr_err("Unknown file type %d\n", fe->type);
		return -1;
	case FD_TYPES__REG:
		ret = collect_one_file_entry(fe, fe->reg->id, &fe->reg->base, &reg_file_cinfo);
		break;
	case FD_TYPES__INETSK:
		ret = collect_one_file_entry(fe, fe->isk->id, &fe->isk->base, &inet_sk_cinfo);
		break;
	case FD_TYPES__NS:
		ret = collect_one_file_entry(fe, fe->nsf->id, &fe->nsf->base, &nsfile_cinfo);
		break;
	case FD_TYPES__PACKETSK:
		ret = collect_one_file_entry(fe, fe->psk->id, &fe->psk->base, &packet_sk_cinfo);
		break;
	case FD_TYPES__NETLINKSK:
		ret = collect_one_file_entry(fe, fe->nlsk->id, &fe->nlsk->base, &netlink_sk_cinfo);
		break;
	case FD_TYPES__EVENTFD:
		ret = collect_one_file_entry(fe, fe->efd->id, &fe->efd->base, &eventfd_cinfo);
		break;
	case FD_TYPES__EVENTPOLL:
		ret = collect_one_file_entry(fe, fe->epfd->id, &fe->epfd->base, &epoll_cinfo);
		break;
	case FD_TYPES__SIGNALFD:
		ret = collect_one_file_entry(fe, fe->sgfd->id, &fe->sgfd->base, &signalfd_cinfo);
		break;
	case FD_TYPES__TUNF:
		ret = collect_one_file_entry(fe, fe->tunf->id, &fe->tunf->base, &tunfile_cinfo);
		break;
	case FD_TYPES__TIMERFD:
		ret = collect_one_file_entry(fe, fe->tfd->id, &fe->tfd->base, &timerfd_cinfo);
		break;
	case FD_TYPES__INOTIFY:
		ret = collect_one_file_entry(fe, fe->ify->id, &fe->ify->base, &inotify_cinfo);
		break;
	case FD_TYPES__FANOTIFY:
		ret = collect_one_file_entry(fe, fe->ffy->id, &fe->ffy->base, &fanotify_cinfo);
		break;
	case FD_TYPES__EXT:
		ret = collect_one_file_entry(fe, fe->ext->id, &fe->ext->base, &ext_file_cinfo);
		break;
	case FD_TYPES__UNIXSK:
		ret = collect_one_file_entry(fe, fe->usk->id, &fe->usk->base, &unix_sk_cinfo);
		break;
	case FD_TYPES__FIFO:
		ret = collect_one_file_entry(fe, fe->fifo->id, &fe->fifo->base, &fifo_cinfo);
		break;
	case FD_TYPES__PIPE:
		ret = collect_one_file_entry(fe, fe->pipe->id, &fe->pipe->base, &pipe_cinfo);
		break;
	case FD_TYPES__TTY:
		ret = collect_one_file_entry(fe, fe->tty->id, &fe->tty->base, &tty_cinfo);
		break;
	case FD_TYPES__MEMFD:
		ret = collect_one_file_entry(fe, fe->memfd->id, &fe->memfd->base, &memfd_cinfo);
		break;
#ifdef CONFIG_HAS_LIBBPF
	case FD_TYPES__BPFMAP:
		ret = collect_one_file_entry(fe, fe->bpf->id, &fe->bpf->base, &bpfmap_cinfo);
		break;
#endif
	}

	return ret;
}

struct collect_image_info files_cinfo = {
	.fd_type = CR_FD_FILES,
	.pb_type = PB_FILE,
	.priv_size = 0,
	.collect = collect_one_file,
	.flags = COLLECT_NOFREE,
};

int prepare_files(void)
{
	init_fdesc_hash();
	init_sk_info_hash();
	return collect_image(&files_cinfo);
}