Introduce io_uring dump/restore support

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

criu/Makefile.crtools

@@ -31,6 +31,7 @@ obj-y			+= fsnotify.o
 obj-y			+= image-desc.o
 obj-y			+= image.o
 obj-y			+= img-streamer.o
+obj-y			+= io_uring.o
 obj-y			+= ipc_ns.o
 obj-y			+= irmap.o
 obj-y			+= kcmp-ids.o

criu/cr-dump.c

@@ -85,6 +85,9 @@
 #include "pidfd-store.h"
 #include "apparmor.h"
 #include "asm/dump.h"
+#include "io_uring.h"
+
+#include "compel/plugins/std/syscall-codes.h"
 
 /*
  * Architectures can overwrite this function to restore register sets that
@@ -191,10 +194,11 @@ struct cr_imgset *glob_imgset;
 
 static int collect_fds(pid_t pid, struct parasite_drain_fd **dfds)
 {
+	char buf[PATH_MAX] = {};
 	struct dirent *de;
-	DIR *fd_dir;
+	int n, pidfd = -1;
 	int size = 0;
-	int n;
+	DIR *fd_dir;
 
 	pr_info("\n");
 	pr_info("Collecting fds (pid: %d)\n", pid);
@@ -204,6 +208,59 @@ static int collect_fds(pid_t pid, struct parasite_drain_fd **dfds)
 	if (!fd_dir)
 		return -1;
 
+	/* Before collecting fds, we need to bring io_uring to steady state,
+	 * since it can install fds into task's fdtable, and if we do it later,
+	 * during actual io_uring dump, we will miss dumping these files.
+	 */
+	while ((de = readdir(fd_dir))) {
+		if (dir_dots(de))
+			continue;
+
+		n = dirfd(fd_dir);
+		if (n == -1) {
+			close(pidfd);
+			return -1;
+		}
+
+		n = readlinkat(n, de->d_name, buf, sizeof(buf));
+		if (n == -1) {
+			close(pidfd);
+			return -1;
+		}
+
+		if (is_io_uring_link(buf)) {
+			if (!kdat.has_pidfd_open) {
+				pr_err("pidfd_open system call not supported\n");
+				return -ENOTSUP;
+			}
+
+			if (!kdat.has_pidfd_getfd) {
+				pr_err("pidfd_getfd system call not supported\n");
+				return -ENOTSUP;
+			}
+
+			if (pidfd == -1) {
+				pidfd = syscall(SYS_pidfd_open, pid, 0);
+				if (pidfd < 0) {
+					pr_err("Failed to open pidfd for pid %d\n", pid);
+					return pidfd;
+				}
+			}
+
+			if (io_uring_synchronize_fd(syscall(SYS_pidfd_getfd, pidfd, atoi(de->d_name), 0))) {
+				pr_err("Failed to synchronize io_uring fd %d for pid %d\n", atoi(de->d_name), pid);
+				close(pidfd);
+				return -1;
+			}
+		}
+	}
+
+	if (pidfd >= 0)
+		close(pidfd);
+
+	/* Collect fds now */
+	rewinddir(fd_dir);
+
 	n = 0;
 	while ((de = readdir(fd_dir))) {
 		if (dir_dots(de))
@@ -489,6 +546,8 @@ static int dump_task_mm(pid_t pid, const struct proc_pid_stat *stat, const struc
 			ret = check_sysvipc_map_dump(pid, vma);
 		else if (vma_entry_is(vma, VMA_AREA_SOCKET))
 			ret = dump_socket_map(vma_area);
+		else if (vma_entry_is(vma, VMA_AREA_IO_URING))
+			ret = dump_io_uring_map(vma_area);
 		else
 			ret = 0;
 		if (ret)

criu/cr-restore.c

@@ -29,6 +29,7 @@
 #include "servicefd.h"
 #include "image.h"
 #include "img-streamer.h"
+#include "io_uring.h"
 #include "util.h"
 #include "util-pie.h"
 #include "criu-log.h"
@@ -277,7 +278,7 @@ static struct collect_image_info *cinfos_files[] = {
 	&unix_sk_cinfo,	      &fifo_cinfo,     &pipe_cinfo,    &nsfile_cinfo,	    &packet_sk_cinfo,
 	&netlink_sk_cinfo,    &eventfd_cinfo,  &epoll_cinfo,   &epoll_tfd_cinfo,    &signalfd_cinfo,
 	&tunfile_cinfo,	      &timerfd_cinfo,  &inotify_cinfo, &inotify_mark_cinfo, &fanotify_cinfo,
-	&fanotify_mark_cinfo, &ext_file_cinfo, &memfd_cinfo,
+	&fanotify_mark_cinfo, &ext_file_cinfo, &memfd_cinfo,   &io_uring_cinfo,
 };
 
 /* These images are required to restore namespaces */

criu/files.c

@@ -49,6 +49,7 @@
 #include "kerndat.h"
 #include "fdstore.h"
 #include "bpfmap.h"
+#include "io_uring.h"
 
 #include "protobuf.h"
 #include "util.h"
@@ -536,6 +537,8 @@ static int dump_one_file(struct pid *pid, int fd, int lfd, struct fd_opts *opts,
 		else if (is_bpfmap_link(link))
 			ops = &bpfmap_dump_ops;
 #endif
+		else if (is_io_uring_link(link))
+			ops = &io_uring_dump_ops;
 		else
 			return dump_unsupp_fd(&p, lfd, "anon", link, e);
 

criu/image-desc.c

@@ -107,6 +107,8 @@ struct cr_fd_desc_tmpl imgset_template[CR_FD_MAX] = {
 	FD_ENTRY_F(BPFMAP_FILE,	"bpfmap-file", O_NOBUF),
 	FD_ENTRY_F(BPFMAP_DATA,	"bpfmap-data", O_NOBUF),
 	FD_ENTRY(APPARMOR,	"apparmor"),
+	FD_ENTRY_F(IO_URING_FILE, "io_uring-file", O_NOBUF),
+	FD_ENTRY_F(IO_URING_DATA, "io_uring-data", O_NOBUF),
 
 	[CR_FD_STATS] = {
 		.fmt	= "stats-%s",

criu/include/image-desc.h

@@ -71,6 +71,8 @@ enum {
 	CR_FD_MEMFD_INODE,
 	CR_FD_BPFMAP_FILE,
 	CR_FD_BPFMAP_DATA,
+	CR_FD_IO_URING_FILE,
+	CR_FD_IO_URING_DATA,
 	_CR_FD_GLOB_TO,
 
 	CR_FD_TMPFS_IMG,

criu/include/image.h

@@ -79,11 +79,12 @@
 #define VMA_ANON_SHARED	 (1 << 8)
 #define VMA_ANON_PRIVATE (1 << 9)
 
-#define VMA_AREA_SYSVIPC (1 << 10)
-#define VMA_AREA_SOCKET	 (1 << 11)
-#define VMA_AREA_VVAR	 (1 << 12)
-#define VMA_AREA_AIORING (1 << 13)
-#define VMA_AREA_MEMFD	 (1 << 14)
+#define VMA_AREA_SYSVIPC  (1 << 10)
+#define VMA_AREA_SOCKET	  (1 << 11)
+#define VMA_AREA_VVAR	  (1 << 12)
+#define VMA_AREA_AIORING  (1 << 13)
+#define VMA_AREA_MEMFD	  (1 << 14)
+#define VMA_AREA_IO_URING (1 << 15)
 
 #define VMA_CLOSE	  (1 << 28)
 #define VMA_NO_PROT_WRITE (1 << 29)

criu/include/io_uring.h

@@ -0,0 +1,108 @@
+#ifndef __CR_IO_URING_H__
+#define __CR_IO_URING_H__
+
+#include <linux/capability.h>
+
+#include "files.h"
+#include "io_uring.pb-c.h"
+
+/* Definitions */
+struct __io_uring_restriction {
+	__u16 opcode;
+	union {
+		__u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
+		__u8 sqe_op;	  /* IORING_RESTRICTION_SQE_OP */
+		__u8 sqe_flags;	  /* IORING_RESTRICTION_SQE_FLAGS_* */
+	};
+	__u8 resv;
+	__u32 resv2[3];
+};
+
+#ifndef IORING_SETUP_IOPOLL
+#define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
+#endif
+#ifndef IORING_SETUP_SQPOLL
+#define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
+#endif
+#ifndef IORING_SETUP_SQ_AFF
+#define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
+#endif
+#ifndef IORING_SETUP_CQSIZE
+#define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */
+#endif
+#ifndef IORING_SETUP_ATTACH_WQ
+#define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */
+#endif
+#ifndef IORING_SETUP_R_DISABLED
+#define IORING_SETUP_R_DISABLED (1U << 6) /* start with ring disabled */
+#endif
+
+#ifndef IORING_OFF_SQ_RING
+#define IORING_OFF_SQ_RING 0ULL
+#endif
+#ifndef IORING_OFF_CQ_RING
+#define IORING_OFF_CQ_RING 0x8000000ULL
+#endif
+#ifndef IORING_OFF_SQES
+#define IORING_OFF_SQES 0x10000000ULL
+#endif
+
+#ifndef IOSQE_IO_DRAIN
+#define IOSQE_IO_DRAIN (1U << 1)
+#endif
+
+#define __IORING_RESTRICTION_REGISTER_OP	0
+#define __IORING_RESTRICTION_SQE_OP		1
+#define __IORING_RESTRICTION_SQE_FLAGS_ALLOWED	2
+#define __IORING_RESTRICTION_SQE_FLAGS_REQUIRED 3
+#define __IORING_REGISTER_PERSONALITY		9
+#define __IORING_REGISTER_RESTRICTIONS		11
+#define __IORING_REGISTER_ENABLE_RINGS		12
+
+struct io_uring_file_info {
+	IoUringFileEntry *iofe;
+	struct file_desc d;
+};
+
+struct io_uring_data_info {
+	IoUringDataEntry *iode;
+};
+
+struct io_uring_group_desc {
+	struct list_head list;
+	gid_t group;
+	char group_name[32];
+};
+
+struct io_uring_personality_desc {
+	int id;
+	uid_t uid;
+	uid_t euid;
+	uid_t suid;
+	uid_t fsuid;
+	gid_t gid;
+	gid_t egid;
+	gid_t sgid;
+	gid_t fsgid;
+	u32 cap_eff[CR_CAP_SIZE];
+	size_t nr_groups;
+	struct list_head group_list;
+};
+
+struct io_uring_ctx;
+
+extern struct collect_image_info io_uring_cinfo;
+extern struct collect_image_info io_uring_data_cinfo;
+extern const struct fdtype_ops io_uring_dump_ops;
+
+int is_io_uring_link(char *link);
+int io_uring_synchronize_fd(int fd);
+int collect_io_uring_map(struct vma_area *vma);
+int dump_io_uring_map(struct vma_area *vma);
+int add_one_io_uring_mapping(uint64_t offset, ino_t inode);
+
+int io_uring_push_buf(struct io_uring_ctx *ctx, unsigned int idx, long long unsigned int address, unsigned int len);
+int io_uring_push_personality(struct io_uring_ctx *ctx, struct io_uring_personality_desc *desc);
+IoUringFileEntry *io_uring_get_iofe(struct io_uring_ctx *ctx);
+
+#endif /* __CR_IO_URING_H__ */

criu/include/magic.h

@@ -100,6 +100,8 @@
 #define BPFMAP_FILE_MAGIC    0x57506142 /* Alapayevsk */
 #define BPFMAP_DATA_MAGIC    0x64324033 /* Arkhangelsk */
 #define APPARMOR_MAGIC	     0x59423047 /* Nikolskoye */
+#define IO_URING_FILE_MAGIC  0x55403656 /* Butyn */
+#define IO_URING_DATA_MAGIC  0x54194822 /* Ulyanovsk */
 
 #define IFADDR_MAGIC	RAW_IMAGE_MAGIC
 #define ROUTE_MAGIC	RAW_IMAGE_MAGIC

criu/include/protobuf-desc.h

@@ -70,6 +70,8 @@ enum {
 	PB_BPFMAP_FILE,
 	PB_BPFMAP_DATA,
 	PB_APPARMOR,
+	PB_IO_URING_FILE,
+	PB_IO_URING_DATA,
 
 	/* PB_AUTOGEN_STOP */
 

criu/include/vma.h

@@ -35,7 +35,10 @@ struct vma_area {
 
 	union {
 		struct /* for dump */ {
-			int vm_socket_id;
+			union {
+				int vm_socket_id;
+				int io_uring_id;
+			};
 
 			char *aufs_rpath; /* path from aufs root */
 			char *aufs_fpath; /* full path from global root */