libmount: convert /dev/root from mountinfo to the device name

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libmount/src/tab_parse.c b/libmount/src/tab_parse.c
index 2cae750dc2336ae7f363129f7ce8a775bf7a3c50..ad88320640acbcf9de8b40ea21f96a611cc26f6c 100644 (file)
--- a/libmount/src/tab_parse.c
+++ b/libmount/src/tab_parse.c
@@ -452,6 +452,43 @@ done:
        return tid;
 }
 
+static int kernel_fs_postparse(struct libmnt_table *tb,
+                              struct libmnt_fs *fs, pid_t *tid,
+                              const char *filename)
+{
+       int rc = 0;
+       const char *src = mnt_fs_get_srcpath(fs);
+
+       /* This is filesystem description from /proc, so we're in some process
+        * namespace. Let's remember the process PID.
+        */
+       if (filename && *tid == -1)
+               *tid = path_to_tid(filename);
+
+       fs->tid = *tid;
+
+       /*
+        * Convert obscure /dev/root to something more usable
+        */
+       if (src && strcmp(src, "/dev/root") == 0) {
+               char *spec = mnt_get_kernel_cmdline_option("root=");
+               char *real = NULL;
+
+               DBG(TAB, mnt_debug_h(tb, "root FS: %s", spec));
+               if (spec)
+                       real = mnt_resolve_spec(spec, tb->cache);
+               if (real) {
+                       DBG(TAB, mnt_debug_h(tb, "canonical root FS: %s", real));
+                       rc = mnt_fs_set_source(fs, real);
+                       if (!tb->cache)
+                               free(real);
+               }
+               free(spec);
+       }
+
+       return rc;
+}
+
 /**
  * mnt_table_parse_stream:
  * @tb: tab pointer
@@ -494,11 +531,9 @@ int mnt_table_parse_stream(struct libmnt_table *tb, FILE *f, const char *filenam
                if (!rc) {
                        rc = mnt_table_add_fs(tb, fs);
                        fs->flags |= flags;
-                       if (tb->fmt == MNT_FMT_MOUNTINFO && filename) {
-                               if (tid == -1)
-                                       tid = path_to_tid(filename);
-                               fs->tid = tid;
-                       }
+
+                       if (rc == 0 && tb->fmt == MNT_FMT_MOUNTINFO)
+                               rc = kernel_fs_postparse(tb, fs, &tid, filename);
                }
                if (rc) {
                        mnt_free_fs(fs);