libmount: Fix atime remount for new API

All atime settings are mutually exclusive, and the attr_set mask for
the mount_setattr() syscall cannot contain multiple MOUNT_ATTR_ atime
related options.

Unfortunately, during a remount, the list of options is composed of
both old and new options. In this case, libmount sets more atime
options to the mask. The correct behavior is to use the last atime
related option from the list.

Fixes: https://github.com/util-linux/util-linux/issues/3032
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libmount/src/optlist.c b/libmount/src/optlist.c
index 476acfd656f14b0103b87c380438f605be403517..e324896273b99b203494ebf415571c059fc6d138 100644 (file)
--- a/libmount/src/optlist.c
+++ b/libmount/src/optlist.c
@@ -837,6 +837,7 @@ int mnt_optlist_get_attrs(struct libmnt_optlist *ls, uint64_t *set, uint64_t *cl
        struct libmnt_iter itr;
        struct libmnt_opt *opt;
        uint64_t remount_reset = 0;
+       uint64_t atime_set = 0;
 
        if (!ls || !ls->linux_map || !set || !clr)
                return -EINVAL;
@@ -879,29 +880,37 @@ int mnt_optlist_get_attrs(struct libmnt_optlist *ls, uint64_t *set, uint64_t *cl
                        remount_reset &= ~x;
 
                if (opt->ent->mask & MNT_INVERT) {
-                       DBG(OPTLIST, ul_debugobj(ls, " clr: %s", opt->ent->name));
-                       /*
-                        * All atime settings are mutually exclusive so *clr must
-                        * have MOUNT_ATTR__ATIME set.
-                        *
-                        * See the function fs/namespace.c:build_mount_kattr()
-                        * in the linux kernel source.
-                        */
+                       DBG(OPTLIST, ul_debugobj(ls, " clr: %s 0x%08" PRIx64,
+                                               opt->ent->name, x));
+
                        if (x == MOUNT_ATTR_RELATIME || x == MOUNT_ATTR_NOATIME ||
                            x == MOUNT_ATTR_STRICTATIME)
                                *clr |= MOUNT_ATTR__ATIME;
                        else
                                *clr |= x;
                } else {
-                       DBG(OPTLIST, ul_debugobj(ls, " set: %s", opt->ent->name));
-                       *set |= x;
-
                        if (x == MOUNT_ATTR_RELATIME || x == MOUNT_ATTR_NOATIME ||
-                           x == MOUNT_ATTR_STRICTATIME)
+                           x == MOUNT_ATTR_STRICTATIME) {
+                               /* All atime settings are mutually exclusive,
+                                * the last option wins and MOUNT_ATTR__ATIME
+                                * is required in clr mask.
+                                */
+                               DBG(OPTLIST, ul_debugobj(ls, " atime: %s 0x%08" PRIx64,
+                                                       opt->ent->name, x));
                                *clr |= MOUNT_ATTR__ATIME;
+                               atime_set = x;
+                       } else {
+                               DBG(OPTLIST, ul_debugobj(ls, " set: %s 0x%08" PRIx64,
+                                                       opt->ent->name, x));
+                               *set |= x;
+                       }
                }
        }
 
+       if (atime_set) {
+               DBG(OPTLIST, ul_debugobj(ls, " set atime 0x%08" PRIx64, atime_set));
+               *set |= atime_set;
+       }
        if (remount_reset)
                *clr |= remount_reset;