From 81694f8c60dffb7851f941e69a1b79bc573ace53 Mon Sep 17 00:00:00 2001 From: Petr Uzel Date: Fri, 21 May 2010 15:19:31 +0200 Subject: [PATCH] mount: detect when kernel silently adds MS_RDONLY flag Linux kernel can silently add MS_RDONLY flag when mounting file system that does not have write support. Check this to avoid 'ro' in /proc/mounts and 'rw' in mtab. [kzak@redhat.com: - don't check for 'ro' for MS_MOVE and MS_PROPAGATION] Reported-by: James Foris Signed-off-by: Petr Uzel Signed-off-by: Karel Zak --- mount/mount.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) Index: util-linux-ng-2.17.2/mount/mount.c =================================================================== --- util-linux-ng-2.17.2.orig/mount/mount.c 2010-05-28 15:22:47.000000000 +0200 +++ util-linux-ng-2.17.2/mount/mount.c 2010-05-28 15:23:03.000000000 +0200 @@ -1388,6 +1388,18 @@ mount_retry: flags &= ~MS_RDONLY; } + /* Kernel can silently add MS_RDONLY flag when mounting file system that + * does not have write support. Check this to avoid 'ro' in /proc/mounts + * and 'rw' in mtab. + */ + if (!fake && mnt5_res == 0 && + !(flags & MS_RDONLY) && !(flags & MS_PROPAGATION) && !(flags & MS_MOVE) && + is_readonly(node)) { + + printf(_("mount: warning: %s seems to be mounted read-only.\n"), node); + flags |= MS_RDONLY; + } + if (fake || mnt5_res == 0) { /* Mount succeeded, report this (if verbose) and write mtab entry. */