[CRIU] [PATCH 16/28] rst: migrate cwd update

[Kinsbursky Stanislav]

From: Stanislav Kinsbursky <skinsbursky at openvz.org>

Migrate cwd using reg files engine.

Signed-off-by: Stanislav Kinsbursky <skinsbursky at openvz.org>
---
 cr-dump.c       |   10 ++++++++--
 files.c         |   33 +++++++++++++++++++++------------
 include/image.h |    1 -
 3 files changed, 29 insertions(+), 15 deletions(-)
-------------- next part --------------
diff --git a/cr-dump.c b/cr-dump.c
index 6e6a5ec..179f49a 100644
--- a/cr-dump.c
+++ b/cr-dump.c
@@ -97,6 +97,12 @@ static int dump_one_reg_file(struct file_entry *p, pid_t pid,
 	int len;
 	int ret = -1;
 	struct fd_entry *fde = &e.fde;
+	struct stat fd_stat;
+
+	if (fstat(lfd, &fd_stat) < 0) {
+		pr_perror("Can't get stat on %d", lfd);
+		return -1;
+	}
 
 	snprintf(fd_str, sizeof(fd_str), "/proc/self/fd/%d", lfd);
 	len = readlink(fd_str, big_buffer, sizeof(big_buffer) - 1);
@@ -120,6 +126,7 @@ static int dump_one_reg_file(struct file_entry *p, pid_t pid,
 		u8 new;
 		long id;
 
+		p->id = MAKE_FD_GENID(fd_stat.st_dev, fd_stat.st_ino, p->pos);
 		id = file_collect(pid, target_fd, p, &new);
 		if (id < 0)
 			return id;
@@ -174,7 +181,7 @@ static int dump_task_special_files(pid_t pid, const struct cr_fdset *cr_fdset)
 	fd = open_proc(pid, "cwd");
 	if (fd < 0)
 		return -1;
-	ret = dump_one_reg_file(&fe, FD_PID_INVALID, fd, 0, cr_fdset, 1);
+	ret = dump_one_reg_file(&fe, pid, fd, 0, cr_fdset, 1);
 	if (ret)
 		return ret;
 
@@ -357,7 +364,6 @@ static int dump_one_fd(pid_t pid, int pid_fd_dir, const char *d_name,
 	    S_ISDIR(fd_stat.st_mode) ||
 	    (S_ISCHR(fd_stat.st_mode) && major(fd_stat.st_rdev) == MEM_MAJOR)) {
 
-		p.id = MAKE_FD_GENID(fd_stat.st_dev, fd_stat.st_ino, p.pos);
 		p.type = FDINFO_REG;
 
 		return dump_one_reg_file(&p, pid, lfd, target_fd, cr_fdset, 1);
diff --git a/files.c b/files.c
index 6bdc518..b4cc0c3 100644
--- a/files.c
+++ b/files.c
@@ -196,21 +196,26 @@ static int open_fe_fd(struct fdinfo_entry *fe, int fd)
 	return tmp;
 }
 
-static int restore_cwd(struct fdinfo_entry *fe, int fd)
+static int restore_cwd(int id)
 {
-	char path[PATH_MAX];
+	struct file_info *fi;
+	char *path;
 	int ret;
 
-	if (get_file_path(path, fe, fd))
+	fi = file_search(FDINFO_CWD, id);
+	if (fi == NULL) {
+		pr_err("Failed to find cwd with id %d\n", id);
 		return -1;
+	}
+
+	path = (char *)fi->rfe->name;
 
-	pr_info("Restore CWD %s\n", path);
+	pr_info("\t%d: Restore CWD %s\n", fi->pid, path);
 	ret = chdir(path);
 	if (ret < 0) {
 		pr_perror("Can't change dir %s", path);
 		return -1;
 	}
-
 	return 0;
 }
 
@@ -368,9 +373,6 @@ static int open_fd_transport(int pid, struct file_info *fi, struct fd_entry *fde
 	if (fi->pid == pid)
 		return 0;
 
-	if (fde->type != FDINFO_REG)
-		return 0;
-
 	pr_info("\t%d: Create transport for fd %d type %d id %ld\n", pid,
 			fde->fd, fde->type, fde->id);
 
@@ -412,6 +414,9 @@ static int open_fdinfo(int pid, struct fd_entry *fde, int *fdinfo_fd, int state)
 	if (move_img_fd(fdinfo_fd, fde->fd))
 		return -1;
 
+	pr_info("\t%d: Got fd for %d type %d id %ld\n", pid,
+			fde->fd, fde->type, fde->id);
+
 	BUG_ON(fde->type != FDINFO_REG);
 
 	fi = file_search(fde->type, fde->id);
@@ -446,8 +451,6 @@ static int open_special_fdinfo(int pid, struct fdinfo_entry *fe,
 
 	if (fe->fde.type == FDINFO_MAP)
 		return open_fmap(pid, fe, fdinfo_fd);
-	if (fe->fde.type == FDINFO_CWD)
-		return restore_cwd(fe, fdinfo_fd);
 	if (fe->fde.type == FDINFO_EXE)
 		return restore_exe_early(fe, fdinfo_fd);
 
@@ -458,7 +461,7 @@ static int open_special_fdinfo(int pid, struct fdinfo_entry *fe,
 
 int prepare_fds(int pid)
 {
-	int ret, err = -1, fdinfo_fd, state;
+	int ret, err = -1, fdinfo_fd, state, cwd_id = 0;
 	off_t offset, magic_offset;
 	struct fdinfo_entry fe;
 
@@ -485,6 +488,11 @@ int prepare_fds(int pid)
 				goto err;
 			}
 
+			if (fe.fde.type == FDINFO_CWD) {
+				cwd_id = fe.fde.id;
+				continue;
+			}
+
 			if (fd_is_special(&fe.fde)) {
 				if (open_special_fdinfo(pid, &fe, fdinfo_fd, state))
 					goto err;
@@ -499,7 +507,8 @@ int prepare_fds(int pid)
 			lseek(fdinfo_fd, offset + fe.len, SEEK_SET);
 		}
 	}
-	err = 0;
+	BUG_ON(cwd_id == 0);
+	err = restore_cwd(cwd_id);
 err:
 	close(fdinfo_fd);
 	return err;
diff --git a/include/image.h b/include/image.h
index 62cf603..685fe06 100644
--- a/include/image.h
+++ b/include/image.h
@@ -71,7 +71,6 @@ struct fdinfo_entry {
 
 #define fd_is_special(fde)		\
 	(((fde)->type == FDINFO_MAP) ||	\
-	 ((fde)->type == FDINFO_CWD) ||	\
 	 ((fde)->type == FDINFO_EXE))
 
 struct pstree_entry {