libmount: always store rw/ro flags to mtab

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

diff --git a/shlibs/mount/src/optstr.c b/shlibs/mount/src/optstr.c
index 626711c48775d5ba4cc7b16536d063edd4b207c7..84ce048964763b47e9945ae368aadca2e265c498 100644 (file)
--- a/shlibs/mount/src/optstr.c
+++ b/shlibs/mount/src/optstr.c
@@ -248,7 +248,7 @@ int mnt_optstr_prepend_option(char **optstr, const char *name, const char *value
        *optstr = NULL;
 
        rc = mnt_optstr_append_option(optstr, name, value);
-       if (!rc && tmp)
+       if (!rc && tmp && *tmp)
                rc = mnt_optstr_append_option(optstr, tmp, NULL);
        if (!rc) {
                free(tmp);
@@ -629,22 +629,59 @@ int mnt_optstr_apply_flags(char **optstr, unsigned long flags,
        next = *optstr;
        fl = flags;
 
-       /* scan @optstr and remove options that are missing in the @flags */
-       while(!mnt_optstr_next_option(&next, &name, &namesz, &val, &valsz)) {
-               const struct mnt_optmap *ent;
-
-               if (mnt_optmap_get_entry(maps, 1, name, namesz, &ent)) {
+       /*
+        * There is convetion that 'rw/ro' flags is always at the begin of
+        * the string (athough the 'rw' is unnecessary).
+        */
+       if (map == mnt_get_builtin_optmap(MNT_LINUX_MAP)) {
+               const char *o = (fl & MS_RDONLY) ? "ro" : "rw";
+
+               if (next &&
+                   (!strncmp(next, "rw", 2) || !strncmp(next, "ro", 2)) &&
+                   (*(next + 2) == '\0' || *(next + 2) == ',')) {
+
+                       /* already set, be paranoid and fix it */
+                       memcpy(next, o, 2);
+               } else {
+                       rc = mnt_optstr_prepend_option(optstr, o, NULL);
+                       if (rc)
+                               goto err;
+                       next = *optstr;         /* because realloc() */
+               }
+               fl &= ~MS_RDONLY;
+               next += 2;
+               if (*next == ',')
+                       next++;
+       }
 
-                       /* remove unwanted option */
-                       if ((ent->mask & MNT_INVERT) || !(fl & ent->id)) {
-                               char *end = val ? val + valsz : name + namesz;
-                               next = name;
-                               rc = mnt_optstr_remove_option_at(optstr, name, end);
-                               if (rc)
-                                       goto err;
+       if (next && *next) {
+               /*
+                * scan @optstr and remove options that are missing in
+                * the @flags
+                */
+               while(!mnt_optstr_next_option(&next, &name, &namesz,
+                                                       &val, &valsz)) {
+                       const struct mnt_optmap *ent;
+
+                       if (mnt_optmap_get_entry(maps, 1, name, namesz, &ent)) {
+                               /*
+                                * remove unwanted option (rw/ro is already set)
+                                */
+                               if (ent->id == MS_RDONLY ||
+                                   (ent->mask & MNT_INVERT) ||
+                                   !(fl & ent->id)) {
+
+                                       char *end = val ? val + valsz :
+                                                         name + namesz;
+                                       next = name;
+                                       rc = mnt_optstr_remove_option_at(
+                                                       optstr, name, end);
+                                       if (rc)
+                                               goto err;
+                               }
+                               if (!(ent->mask & MNT_INVERT))
+                                       fl &= ~ent->id;
                        }
-                       if (!(ent->mask & MNT_INVERT))
-                               fl &= ~ent->id;
                }
        }