treewide: sanitize loop_write

loop_write() didn't follow the usual systemd rules and returned status
partially in errno and required extensive checks from callers. Some of
the callers dealt with this properly, but many did not, treating
partial writes as successful. Simplify things by conforming to usual rules.

1 files changed, 5 insertions, 10 deletions

diff --git a/src/random-seed/random-seed.c b/src/random-seed/random-seed.c
index 40eaaf46d9..06c1239601 100644
--- a/src/random-seed/random-seed.c
+++ b/src/random-seed/random-seed.c
@@ -113,12 +113,9 @@ int main(int argc, char *argv[]) {
                 } else {
                         lseek(seed_fd, 0, SEEK_SET);
 
-                        k = loop_write(random_fd, buf, (size_t) k, false);
-                        if (k <= 0) {
-                                log_error("Failed to write seed to /dev/urandom: %s", r < 0 ? strerror(-r) : "short write");
-
-                                r = k == 0 ? -EIO : (int) k;
-                        }
+                        r = loop_write(random_fd, buf, (size_t) k, false);
+                        if (r < 0)
+                                log_error_errno(r, "Failed to write seed to /dev/urandom: %m");
                 }
 
         } else if (streq(argv[1], "save")) {
@@ -155,10 +152,8 @@ int main(int argc, char *argv[]) {
                 r = k == 0 ? -EIO : (int) k;
         } else {
                 r = loop_write(seed_fd, buf, (size_t) k, false);
-                if (r <= 0) {
-                        log_error("Failed to write new random seed file: %s", r < 0 ? strerror(-r) : "short write");
-                        r = r == 0 ? -EIO : r;
-                }
+                if (r < 0)
+                        log_error_errno(r, "Failed to write new random seed file: %m");
         }
 
 finish: