1 files changed, 17 insertions, 14 deletions
diff --git a/shared/systemd/src/basic/fd-util.c b/shared/systemd/src/basic/fd-util.c
index ea2c1612..a401663e 100644
--- a/shared/systemd/src/basic/fd-util.c
+++ b/shared/systemd/src/basic/fd-util.c
@@ -23,9 +23,10 @@
 #include "path-util.h"
 #include "process-util.h"
 #include "socket-util.h"
+#include "stat-util.h"
 #include "stdio-util.h"
-#include "util.h"
 #include "tmpfile-util.h"
+#include "util.h"
 
 /* The maximum number of iterations in the loop to close descriptors in the fallback case
  * when /proc/self/fd/ is inaccessible. */
@@ -104,13 +105,16 @@ int fclose_nointr(FILE *f) {
 
         /* Same as close_nointr(), but for fclose() */
 
+        errno = 0; /* Extra safety: if the FILE* object is not encapsulating an fd, it might not set errno
+                    * correctly. Let's hence initialize it to zero first, so that we aren't confused by any
+                    * prior errno here */
         if (fclose(f) == 0)
                 return 0;
 
         if (errno == EINTR)
                 return 0;
 
-        return -errno;
+        return errno_or_else(EIO);
 }
 
 FILE* safe_fclose(FILE *f) {
@@ -146,11 +150,7 @@ int fd_nonblock(int fd, bool nonblock) {
         if (flags < 0)
                 return -errno;
 
-        if (nonblock)
-                nflags = flags | O_NONBLOCK;
-        else
-                nflags = flags & ~O_NONBLOCK;
-
+        nflags = UPDATE_FLAG(flags, O_NONBLOCK, nonblock);
         if (nflags == flags)
                 return 0;
 
@@ -169,11 +169,7 @@ int fd_cloexec(int fd, bool cloexec) {
         if (flags < 0)
                 return -errno;
 
-        if (cloexec)
-                nflags = flags | FD_CLOEXEC;
-        else
-                nflags = flags & ~FD_CLOEXEC;
-
+        nflags = UPDATE_FLAG(flags, FD_CLOEXEC, cloexec);
         if (nflags == flags)
                 return 0;
 
@@ -954,8 +950,15 @@ int fd_reopen(int fd, int flags) {
 
         xsprintf(procfs_path, "/proc/self/fd/%i", fd);
         new_fd = open(procfs_path, flags);
-        if (new_fd < 0)
-                return -errno;
+        if (new_fd < 0) {
+                if (errno != ENOENT)
+                        return -errno;
+
+                if (proc_mounted() == 0)
+                        return -ENOSYS; /* if we have no /proc/, the concept is not implementable */
+
+                return -ENOENT;
+        }
 
         return new_fd;
 }