Merge pull request #7740 from yuwata/fix-7676

 sd-device: support the case that /sys is a symlink

1 files changed, 25 insertions, 12 deletions

diff --git a/src/libsystemd/sd-device/sd-device.c b/src/libsystemd/sd-device/sd-device.c
index a96d7445ce..1297dfa911 100644
--- a/src/libsystemd/sd-device/sd-device.c
+++ b/src/libsystemd/sd-device/sd-device.c
@@ -166,25 +166,38 @@ int device_set_syspath(sd_device *device, const char *_syspath, bool verify) {
         }
 
         if (verify) {
-                r = readlink_and_canonicalize(_syspath, NULL, &syspath);
+                r = chase_symlinks(_syspath, NULL, 0, &syspath);
                 if (r == -ENOENT)
                         /* the device does not exist (any more?) */
                         return -ENODEV;
-                else if (r == -EINVAL) {
-                        /* not a symlink */
-                        syspath = canonicalize_file_name(_syspath);
-                        if (!syspath) {
-                                if (errno == ENOENT)
-                                        /* the device does not exist (any more?) */
-                                        return -ENODEV;
-
-                                return log_debug_errno(errno, "sd-device: could not canonicalize '%s': %m", _syspath);
-                        }
-                } else if (r < 0) {
+                else if (r < 0) {
                         log_debug_errno(r, "sd-device: could not get target of '%s': %m", _syspath);
                         return r;
                 }
 
+                if (!path_startswith(syspath, "/sys")) {
+                        _cleanup_free_ char *real_sys = NULL, *new_syspath = NULL;
+                        char *p;
+
+                        /* /sys is a symlink to somewhere sysfs is mounted on? In that case, we convert the path to real sysfs to "/sys". */
+                        r = chase_symlinks("/sys", NULL, 0, &real_sys);
+                        if (r < 0)
+                                return log_debug_errno(r, "sd-device: could not chase symlink /sys: %m");
+
+                        p = path_startswith(syspath, real_sys);
+                        if (!p) {
+                                log_debug("sd-device: canonicalized path '%s' does not starts with sysfs mount point '%s'", syspath, real_sys);
+                                return -ENODEV;
+                        }
+
+                        new_syspath = strjoin("/sys/", p);
+                        if (!new_syspath)
+                                return log_oom();
+
+                        free_and_replace(syspath, new_syspath);
+                        path_kill_slashes(syspath);
+                }
+
                 if (path_startswith(syspath,  "/sys/devices/")) {
                         char *path;