Merge pull request #24646 from yuwata/udev-node-symlink_atomic

udev: introduce symlink_atomic_full() and use it

src/basic/fs-util.c

@@ -406,13 +406,7 @@ int symlink_idempotent(const char *from, const char *to, bool make_relative) {
         assert(to);
 
         if (make_relative) {
-                _cleanup_free_ char *parent = NULL;
-
-                r = path_extract_directory(to, &parent);
-                if (r < 0)
-                        return r;
-
-                r = path_make_relative(parent, from, &relpath);
+                r = path_make_relative_parent(to, from, &relpath);
                 if (r < 0)
                         return r;
 
@@ -438,13 +432,21 @@ int symlink_idempotent(const char *from, const char *to, bool make_relative) {
         return 0;
 }
 
-int symlink_atomic(const char *from, const char *to) {
-        _cleanup_free_ char *t = NULL;
+int symlink_atomic_full(const char *from, const char *to, bool make_relative) {
+        _cleanup_free_ char *relpath = NULL, *t = NULL;
         int r;
 
         assert(from);
         assert(to);
 
+        if (make_relative) {
+                r = path_make_relative_parent(to, from, &relpath);
+                if (r < 0)
+                        return r;
+
+                from = relpath;
+        }
+
         r = tempfn_random(to, NULL, &t);
         if (r < 0)
                 return r;

src/basic/fs-util.h

@@ -58,7 +58,10 @@ static inline int touch(const char *path) {
 
 int symlink_idempotent(const char *from, const char *to, bool make_relative);
 
-int symlink_atomic(const char *from, const char *to);
+int symlink_atomic_full(const char *from, const char *to, bool make_relative);
+static inline int symlink_atomic(const char *from, const char *to) {
+        return symlink_atomic_full(from, to, false);
+}
 int mknod_atomic(const char *path, mode_t mode, dev_t dev);
 int mkfifo_atomic(const char *path, mode_t mode);
 int mkfifoat_atomic(int dir_fd, const char *path, mode_t mode);

src/shared/label.c

@@ -61,7 +61,7 @@ int symlink_label(const char *old_path, const char *new_path) {
         return mac_smack_fix(new_path, 0);
 }
 
-int symlink_atomic_label(const char *from, const char *to) {
+int symlink_atomic_full_label(const char *from, const char *to, bool make_relative) {
         int r;
 
         assert(from);
@@ -71,7 +71,7 @@ int symlink_atomic_label(const char *from, const char *to) {
         if (r < 0)
                 return r;
 
-        r = symlink_atomic(from, to);
+        r = symlink_atomic_full(from, to, make_relative);
         mac_selinux_create_file_clear();
 
         if (r < 0)

src/shared/label.h

@@ -17,7 +17,10 @@ static inline int label_fix(const char *path, LabelFixFlags flags) {
 }
 
 int symlink_label(const char *old_path, const char *new_path);
-int symlink_atomic_label(const char *from, const char *to);
+int symlink_atomic_full_label(const char *from, const char *to, bool make_relative);
+static inline int symlink_atomic_label(const char *from, const char *to) {
+        return symlink_atomic_full_label(from, to, false);
+}
 int mknod_label(const char *pathname, mode_t mode, dev_t dev);
 
 int btrfs_subvol_make_label(const char *path);

src/udev/udev-node.c

@@ -14,6 +14,7 @@
 #include "format-util.h"
 #include "fs-util.h"
 #include "hexdecoct.h"
+#include "label.h"
 #include "mkdir-label.h"
 #include "parse-util.h"
 #include "path-util.h"
@@ -69,8 +70,6 @@ int udev_node_cleanup(void) {
 }
 
 static int node_symlink(sd_device *dev, const char *devnode, const char *slink) {
-        _cleanup_free_ char *target = NULL;
-        const char *id, *slink_tmp;
         struct stat st;
         int r;
 
@@ -91,34 +90,16 @@ static int node_symlink(sd_device *dev, const char *devnode, const char *slink)
         } else if (errno != ENOENT)
                 return log_device_debug_errno(dev, errno, "Failed to lstat() '%s': %m", slink);
 
+        r = mkdir_parents_label(slink, 0755);
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to create parent directory of '%s': %m", slink);
+
         /* use relative link */
-        r = path_make_relative_parent(slink, devnode, &target);
+        r = symlink_atomic_full_label(devnode, slink, /* make_relative = */ true);
         if (r < 0)
-                return log_device_debug_errno(dev, r, "Failed to get relative path from '%s' to '%s': %m", slink, devnode);
-
-        r = device_get_device_id(dev, &id);
-        if (r < 0)
-                return log_device_debug_errno(dev, r, "Failed to get device id: %m");
-
-        slink_tmp = strjoina(slink, ".tmp-", id);
-        (void) unlink(slink_tmp);
-
-        r = mkdir_parents_label(slink_tmp, 0755);
-        if (r < 0)
-                return log_device_debug_errno(dev, r, "Failed to create parent directory of '%s': %m", slink_tmp);
-
-        mac_selinux_create_file_prepare(slink_tmp, S_IFLNK);
-        r = RET_NERRNO(symlink(target, slink_tmp));
-        mac_selinux_create_file_clear();
-        if (r < 0)
-                return log_device_debug_errno(dev, r, "Failed to create symlink '%s' to '%s': %m", slink_tmp, target);
-
-        if (rename(slink_tmp, slink) < 0) {
-                r = log_device_debug_errno(dev, errno, "Failed to rename '%s' to '%s': %m", slink_tmp, slink);
-                (void) unlink(slink_tmp);
-                return r;
-        }
+                return log_device_debug_errno(dev, r, "Failed to create symlink '%s' to '%s': %m", slink, devnode);
 
+        log_device_debug(dev, "Successfully created symlink '%s' to '%s'", slink, devnode);
         return 0;
 }