open_proc: don't print error twice

open_proc* and fopen_proc* are all macros, and they print errors in case
something is wrong (and as they are macros they print correct file:line
info, too). So, there is no need to print another error message
right after calling those.

This fixes double error messages like these:

(00.047295) Error (criu/proc_parse.c:990): Can't open 18472/status on procfs: No such file or directory
(00.047298) Error (criu/proc_parse.c:992): Can't open proc status: No such file or directory

travis-ci: success for Assorted nitpicks
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/autofs.c

@@ -297,10 +297,8 @@ static int autofs_revisit_options(struct mount_info *pm)
 	}
 
 	f = fopen_proc(getpid(), "mountinfo");
-	if (!f) {
-		pr_perror("Can't open %d mountinfo", getpid());
+	if (!f)
 		goto free_str;
-	}
 
 	while (fgets(str, 1024, f)) {
 		int mnt_id = -1;

criu/cr-check.c

@@ -838,10 +838,8 @@ static int check_autofs_pipe_ino(void)
 	int ret = -ENOENT;
 
 	f = fopen_proc(PROC_SELF, "mountinfo");
-	if (!f) {
-		pr_perror("Can't open %d mountinfo", getpid());
+	if (!f)
 		return -1;
-	}
 
 	while (fgets(str, sizeof(str), f)) {
 		if (strstr(str, " autofs ")) {

criu/cr-restore.c

@@ -901,10 +901,8 @@ static inline int fork_with_pid(struct pstree_item *item)
 		int len;
 
 		ca.fd = open_proc_rw(PROC_GEN, LAST_PID_PATH);
-		if (ca.fd < 0) {
-			pr_perror("%d: Can't open %s", pid, LAST_PID_PATH);
+		if (ca.fd < 0)
 			goto err;
-		}
 
 		if (flock(ca.fd, LOCK_EX)) {
 			close(ca.fd);
@@ -1727,10 +1725,8 @@ static int restore_root_task(struct pstree_item *init)
 
 	if (root_ns_mask & CLONE_NEWNS) {
 		mnt_ns_fd = open_proc(init->pid.real, "ns/mnt");
-		if (mnt_ns_fd < 0) {
-			pr_perror("Can't open init's mntns fd");
+		if (mnt_ns_fd < 0)
 			goto out_kill;
-		}
 	}
 
 	ret = run_scripts(ACT_SETUP_NS);

criu/kerndat.c

@@ -74,10 +74,8 @@ static int parse_self_maps(unsigned long vm_start, dev_t *device)
 	char buf[1024];
 
 	maps = fopen_proc(PROC_SELF, "maps");
-	if (maps == NULL) {
-		pr_perror("Can't open self maps");
+	if (maps == NULL)
 		return -1;
-	}
 
 	while (fgets(buf, sizeof(buf), maps) != NULL) {
 		char *end, *aux;

criu/namespaces.c

@@ -225,10 +225,8 @@ int switch_ns(int pid, struct ns_desc *nd, int *rst)
 	int ret;
 
 	nsfd = open_proc(pid, "ns/%s", nd->str);
-	if (nsfd < 0) {
-		pr_perror("Can't open ns file");
+	if (nsfd < 0)
 		return -1;
-	}
 
 	ret = switch_ns_by_fd(nsfd, nd, rst);
 

criu/net.c

@@ -1152,10 +1152,8 @@ static int restore_one_macvlan(NetDeviceEntry *nde, int nlsk, int criu_nlsk)
 	extras.link = (int) (unsigned long) val;
 
 	my_netns = open_proc(PROC_SELF, "ns/net");
-	if (my_netns < 0) {
-		pr_perror("couldn't get my netns");
+	if (my_netns < 0)
 		return -1;
-	}
 
 	{
 		struct newlink_req req;

criu/proc_parse.c

@@ -423,10 +423,8 @@ int parse_self_maps_lite(struct vm_area_list *vms)
 	vm_area_list_init(vms);
 
 	maps = fopen_proc(PROC_SELF, "maps");
-	if (maps == NULL) {
-		pr_perror("Can't open self maps");
+	if (maps == NULL)
 		return -1;
-	}
 
 	while (fgets(buf, BUF_SIZE, maps) != NULL) {
 		struct vma_area *vma;
@@ -988,10 +986,8 @@ int parse_pid_status(pid_t pid, struct proc_status_creds *cr)
 	bool parsed_seccomp = false;
 
 	f.fd = open_proc(pid, "status");
-	if (f.fd < 0) {
-		pr_perror("Can't open proc status");
+	if (f.fd < 0)
 		return -1;
-	}
 
 	cr->sigpnd = 0;
 	cr->shdpnd = 0;
@@ -1414,10 +1410,8 @@ struct mount_info *parse_mountinfo(pid_t pid, struct ns_id *nsid, bool for_dump)
 	FILE *f;
 
 	f = fopen_proc(pid, "mountinfo");
-	if (!f) {
-		pr_perror("Can't open %d mountinfo", pid);
+	if (!f)
 		return NULL;
-	}
 
 	while (fgets(buf, BUF_SIZE, f)) {
 		struct mount_info *new;
@@ -1626,10 +1620,8 @@ static int parse_fdinfo_pid_s(int pid, int fd, int type,
 	int ret, exit_code = -1;;
 
 	f.fd = open_proc(pid, "fdinfo/%d", fd);
-	if (f.fd < 0) {
-		pr_perror("Can't open fdinfo/%d to parse", fd);
+	if (f.fd < 0)
 		return -1;
-	}
 
 	if (bfdopenr(&f))
 		return -1;
@@ -2029,10 +2021,8 @@ int parse_file_locks(void)
 		return 0;
 
 	fl_locks = fopen_proc(PROC_GEN, "locks");
-	if (!fl_locks) {
-		pr_perror("Can't open file locks file!");
+	if (!fl_locks)
 		return -1;
-	}
 
 	while (fgets(buf, BUF_SIZE, fl_locks)) {
 		is_blocked = strstr(buf, "->") != NULL;
@@ -2117,10 +2107,8 @@ int parse_posix_timers(pid_t pid, struct proc_posix_timers_stat *args)
 	args->timer_n = 0;
 
 	f.fd = open_proc(pid, "timers");
-	if (f.fd < 0) {
-		pr_perror("Can't open posix timers file!");
+	if (f.fd < 0)
 		return -1;
-	}
 
 	if (bfdopenr(&f))
 		return -1;
@@ -2323,10 +2311,8 @@ int parse_task_cgroup(int pid, struct parasite_dump_cgroup_args *args, struct li
 	struct cg_ctl *intern, *ext;
 
 	f = fopen_proc(pid, "cgroup");
-	if (!f) {
-		pr_perror("couldn't open task cgroup file");
+	if (!f)
 		return -1;
-	}
 
 	ret = parse_cgroup_file(f, retl, n);
 	fclose(f);

criu/seize.c

@@ -273,7 +273,7 @@ static int log_unfrozen_stacks(char *root)
 
 		stack = open_proc(pid, "stack");
 		if (stack < 0) {
-			pr_perror("couldn't log %d's stack", pid);
+			pr_err("`- couldn't log %d's stack\n", pid);
 			fclose(f);
 			return -1;
 		}

criu/shmem.c

@@ -448,9 +448,6 @@ static int shmem_wait_and_open(int pid, struct shmem_info *si, VmaEntry *vi)
 
 	pr_info("Opening shmem [%s] \n", path);
 	ret = open_proc_rw(si->pid, "fd/%d", si->fd);
-	if (ret < 0)
-		pr_perror("     %d: Can't stat shmem at %s",
-				si->pid, path);
 	futex_inc_and_wake(&si->lock);
 	if (ret < 0)
 		return -1;

criu/vdso.c

@@ -223,10 +223,8 @@ static int vdso_fill_self_symtable(struct vdso_symtable *s)
 	*s = (struct vdso_symtable)VDSO_SYMTABLE_INIT;
 
 	maps = fopen_proc(PROC_SELF, "maps");
-	if (!maps) {
-		pr_perror("Can't open self-vma");
+	if (!maps)
 		return -1;
-	}
 
 	while (fgets(buf, sizeof(buf), maps)) {
 		unsigned long start, end;