util: replace close_pipe() with new safe_close_pair()

safe_close_pair() is more like safe_close(), except that it handles
pairs of fds, and doesn't make and misleading allusion, as it works
similarly well for socketpairs() as for pipe()s...

4 files changed, 16 insertions, 20 deletions

diff --git a/src/shared/logs-show.c b/src/shared/logs-show.c
index df49375724..9d14933bc1 100644
--- a/src/shared/logs-show.c
+++ b/src/shared/logs-show.c
@@ -1139,7 +1139,7 @@ int add_matches_for_user_unit(sd_journal *j, const char *unit, uid_t uid) {
 }
 
 static int get_boot_id_for_machine(const char *machine, sd_id128_t *boot_id) {
-        _cleanup_close_pipe_ int pair[2] = { -1, -1 };
+        _cleanup_close_pair_ int pair[2] = { -1, -1 };
         _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, rootfd = -1;
         pid_t pid, child;
         siginfo_t si;
diff --git a/src/shared/pager.c b/src/shared/pager.c
index 55b13d6ff6..002e3aa373 100644
--- a/src/shared/pager.c
+++ b/src/shared/pager.c
@@ -78,7 +78,7 @@ int pager_open(bool jump_to_end) {
         if (pager_pid < 0) {
                 r = -errno;
                 log_error("Failed to fork pager: %m");
-                close_pipe(fd);
+                safe_close_pair(fd);
                 return r;
         }
 
@@ -87,7 +87,7 @@ int pager_open(bool jump_to_end) {
                 const char* less_opts;
 
                 dup2(fd[0], STDIN_FILENO);
-                close_pipe(fd);
+                safe_close_pair(fd);
 
                 less_opts = getenv("SYSTEMD_LESS");
                 if (!less_opts)
@@ -131,7 +131,7 @@ int pager_open(bool jump_to_end) {
                 return -errno;
         }
 
-        close_pipe(fd);
+        safe_close_pair(fd);
         return 1;
 }
 
diff --git a/src/shared/util.c b/src/shared/util.c
index a8c4523905..dd67c22641 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -2037,22 +2037,18 @@ int default_signals(int sig, ...) {
         return r;
 }
 
-int close_pipe(int p[]) {
-        int a = 0, b = 0;
-
+void safe_close_pair(int p[]) {
         assert(p);
 
-        if (p[0] >= 0) {
-                a = close_nointr(p[0]);
-                p[0] = -1;
-        }
-
-        if (p[1] >= 0) {
-                b = close_nointr(p[1]);
-                p[1] = -1;
+        if (p[0] == p[1]) {
+                /* Special case pairs which use the same fd in both
+                 * directions... */
+                p[0] = p[1] = safe_close(p[0]);
+                return;
         }
 
-        return a < 0 ? a : b;
+        p[0] = safe_close(p[0]);
+        p[1] = safe_close(p[1]);
 }
 
 ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
diff --git a/src/shared/util.h b/src/shared/util.h
index 70c20fdcf1..90464c940b 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -150,6 +150,7 @@ bool first_word(const char *s, const char *word) _pure_;
 
 int close_nointr(int fd);
 int safe_close(int fd);
+void safe_close_pair(int p[]);
 
 void close_many(const int fds[], unsigned n_fd);
 
@@ -378,7 +379,6 @@ int ignore_signals(int sig, ...);
 int default_signals(int sig, ...);
 int sigaction_many(const struct sigaction *sa, ...);
 
-int close_pipe(int p[]);
 int fopen_temporary(const char *path, FILE **_f, char **_temp_path);
 
 ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll);
@@ -628,8 +628,8 @@ static inline void umaskp(mode_t *u) {
         umask(*u);
 }
 
-static inline void close_pipep(int (*p)[2]) {
-        close_pipe(*p);
+static inline void close_pairp(int (*p)[2]) {
+        safe_close_pair(*p);
 }
 
 DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, fclose);
@@ -645,7 +645,7 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, endmntent);
 #define _cleanup_pclose_ _cleanup_(pclosep)
 #define _cleanup_closedir_ _cleanup_(closedirp)
 #define _cleanup_endmntent_ _cleanup_(endmntentp)
-#define _cleanup_close_pipe_ _cleanup_(close_pipep)
+#define _cleanup_close_pair_ _cleanup_(close_pairp)
 
 _malloc_  _alloc_(1, 2) static inline void *malloc_multiply(size_t a, size_t b) {
         if (_unlikely_(b == 0 || a > ((size_t) -1) / b))