From: Karel Zak Date: Tue, 14 May 2024 11:58:20 +0200 Subject: 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 --- libmount/src/optlist.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/libmount/src/optlist.c b/libmount/src/optlist.c index 476acfd..e324896 100644 --- 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;