path-util: unify path_extract_filename/directory into path_split_prefix_filename() (#40608)

src/shared/blockdev-util.c

@@ -922,6 +922,7 @@ int blockdev_get_root(int level, dev_t *ret) {
 }
 
 int partition_node_of(const char *node, unsigned nr, char **ret) {
+        _cleanup_free_ char *fn = NULL, *dn = NULL;
         int r;
 
         assert(node);
@@ -931,18 +932,12 @@ int partition_node_of(const char *node, unsigned nr, char **ret) {
         /* Given a device node path to a block device returns the device node path to the partition block
          * device of the specified partition */
 
-        _cleanup_free_ char *fn = NULL;
-        r = path_extract_filename(node, &fn);
+        r = path_split_prefix_filename(node, &dn, &fn);
         if (r < 0)
                 return r;
         if (r == O_DIRECTORY)
                 return -EISDIR;
 
-        _cleanup_free_ char *dn = NULL;
-        r = path_extract_directory(node, &dn);
-        if (r < 0 && r != -EDESTADDRREQ) /* allow if only filename is specified */
-                return r;
-
         size_t l = strlen(fn);
         assert(l > 0); /* underflow check for the subtraction below */
 

src/shared/creds-util.c

@@ -480,14 +480,13 @@ int get_credential_host_secret(CredentialSecretFlags flags, struct iovec *ret) {
                 if (!path_is_absolute(e))
                         return -EINVAL;
 
-                r = path_extract_directory(e, &_dirname);
-                if (r < 0)
-                        return r;
-
-                r = path_extract_filename(e, &_filename);
+                r = path_split_prefix_filename(e, &_dirname, &_filename);
                 if (r < 0)
                         return r;
+                if (r == O_DIRECTORY)
+                        return -EINVAL;
 
+                /* We validate that the path is absolute above, hence dirname must be extractable. */
                 dirname = _dirname;
                 filename = _filename;
         } else {
@@ -498,7 +497,8 @@ int get_credential_host_secret(CredentialSecretFlags flags, struct iovec *ret) {
         assert(dirname);
         assert(filename);
 
-        mkdir_parents(dirname, 0755);
+        (void) mkdir_parents(dirname, 0755);
+
         dfd = open_mkdir(dirname, O_CLOEXEC, 0755);
         if (dfd < 0)
                 return log_debug_errno(dfd, "Failed to create or open directory '%s': %m", dirname);

src/shared/generator.c

@@ -109,13 +109,9 @@ int generator_add_symlink_full(
          *
          * If <instance> is specified, then <src> must be a template unit name, and we'll instantiate it. */
 
-        r = path_extract_directory(src, &dn);
-        if (r < 0 && r != -EDESTADDRREQ) /* EDESTADDRREQ → just a file name was passed */
-                return log_error_errno(r, "Failed to extract directory name from '%s': %m", src);
-
-        r = path_extract_filename(src, &fn);
+        r = path_split_prefix_filename(src, &dn, &fn);
         if (r < 0)
-                return log_error_errno(r, "Failed to extract file name from '%s': %m", src);
+                return log_error_errno(r, "Failed to split '%s' into directory prefix and filename: %m", src);
         if (r == O_DIRECTORY)
                 return log_error_errno(SYNTHETIC_ERRNO(EISDIR), "Expected path to regular file name, but got '%s', refusing.", src);
 

src/shared/snapshot-util.c

@@ -7,6 +7,7 @@
 #include "discover-image.h"
 #include "log.h"
 #include "mountpoint-util.h"
+#include "runtime-scope.h"
 #include "snapshot-util.h"
 #include "signal-util.h"
 #include "tmpfile-util.h"

src/shared/snapshot-util.h

@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include "runtime-scope.h"
+#include "shared-forward.h"
 
 /* create_ephemeral_snapshot - create a snapshot of the given directory.
  *

src/shared/unit-file.c

@@ -291,17 +291,15 @@ int unit_file_resolve_symlink(
                                          dir, dir ? "/" : "", filename);
 
         if (!dir) {
-                r = path_extract_directory(filename, &_dir);
-                if (r < 0)
-                        return r;
-                dir = _dir;
-
-                r = path_extract_filename(filename, &_filename);
+                r = path_split_prefix_filename(filename, &_dir, &_filename);
                 if (r < 0)
                         return r;
                 if (r == O_DIRECTORY)
                         return log_warning_errno(SYNTHETIC_ERRNO(EISDIR),
                                                  "Unexpected path to a directory \"%s\", refusing.", filename);
+
+                /* We validate that the path is absolute above, hence dir must be extractable. */
+                dir = ASSERT_PTR(_dir);
                 filename = _filename;
         }