libmount: revert X-* and x-* meaning

Let's hope this is last change necessary to cleanup x-* usage:

  x-*  persistent option, stored in utab, available for umount, etc.
  X-*  fstab comment only

mount(8) supports x-mount.mkdir= as well as newly recommended X-mount.mkdir=

Advantages:

 * less invasive
 * does not require exception for x-systemd
 * does not require rename x-initrd to X-initrd

The systemd and dracut users will get the new (=fixed) functionality without a
change in fstab configuration. This is the primary goal.

Disadvantages:

 * not 100% compatible libmount behavior, x-* options have not been
   previously stored in utab. The API is the same, options will be still
   available, but on x-* libmount will write to /run/mount/utab. For now
   it seems only systemd uses x-*, and they like this behavior, so...

Addresses: https://github.com/systemd/systemd/pull/4515
Signed-off-by: Karel Zak <kzak@redhat.com>

3 files changed, 11 insertions, 13 deletions

diff --git a/libmount/src/context.c b/libmount/src/context.c
index 87ccccfc6..44282c07b 100644
--- a/libmount/src/context.c
+++ b/libmount/src/context.c
@@ -1531,7 +1531,7 @@ int mnt_context_prepare_srcpath(struct libmnt_context *cxt)
 	return 0;
 }
 
-/* create a mountpoint if x-mount.mkdir[=<mode>] specified */
+/* create a mountpoint if X-mount.mkdir[=<mode>] specified */
 static int mkdir_target(const char *tgt, struct libmnt_fs *fs)
 {
 	char *mstr = NULL;
@@ -1543,8 +1543,12 @@ static int mkdir_target(const char *tgt, struct libmnt_fs *fs)
 	assert(tgt);
 	assert(fs);
 
-	if (mnt_optstr_get_option(fs->user_optstr, "x-mount.mkdir", &mstr, &mstr_sz) != 0)
+	if (mnt_optstr_get_option(fs->user_optstr, "X-mount.mkdir", &mstr, &mstr_sz) != 0 &&
+	    mnt_optstr_get_option(fs->user_optstr, "x-mount.mkdir", &mstr, &mstr_sz) != 0)   	/* obsolete */
 		return 0;
+
+	DBG(CXT, ul_debug("mkdir %s (%s) wanted", tgt, mstr));
+
 	if (mnt_stat_mountpoint(tgt, &st) == 0)
 		return 0;
 
@@ -1591,7 +1595,8 @@ int mnt_context_prepare_target(struct libmnt_context *cxt)
 	/* mkdir target */
 	if (cxt->action == MNT_ACT_MOUNT
 	    && !mnt_context_is_restricted(cxt)
-	    && cxt->user_mountflags & MNT_MS_XCOMMENT) {
+	    && (cxt->user_mountflags & MNT_MS_XCOMMENT ||
+		cxt->user_mountflags & MNT_MS_XFSTABCOMM)) {
 
 		rc = mkdir_target(tgt, cxt->fs);
 		if (rc)
diff --git a/libmount/src/libmount.h.in b/libmount/src/libmount.h.in
index cbd4f000e..f191a52fe 100644
--- a/libmount/src/libmount.h.in
+++ b/libmount/src/libmount.h.in
@@ -774,7 +774,7 @@ extern int mnt_context_set_syscall_status(struct libmnt_context *cxt, int status
 #define MNT_MS_OFFSET   (1 << 14)
 #define MNT_MS_SIZELIMIT (1 << 15)
 #define MNT_MS_ENCRYPTION (1 << 16)
-#define MNT_MS_XPERSIST (1 << 17)
+#define MNT_MS_XFSTABCOMM (1 << 17)
 
 /*
  * mount(2) MS_* masks (MNT_MAP_LINUX map)
diff --git a/libmount/src/optmap.c b/libmount/src/optmap.c
index 114eb994e..0aa285f93 100644
--- a/libmount/src/optmap.c
+++ b/libmount/src/optmap.c
@@ -160,15 +160,8 @@ static const struct libmnt_optmap userspace_opts_map[] =
 
    { "comment=", MNT_MS_COMMENT, MNT_NOHLPS | MNT_NOMTAB },/* fstab comment only */
 
-   /*
-    * systemd assumes that x-systemd options namespace is available for umount,
-    * let's use the options as X-*
-    */
-#ifdef HAVE_SYSTEMD
-   { "x-systemd", MNT_MS_XPERSIST, MNT_NOHLPS | MNT_PREFIX },		 /* like X-* */
-#endif
-   { "X-",      MNT_MS_XPERSIST, MNT_NOHLPS | MNT_PREFIX },              /* X- persistent comments (utab) */
-   { "x-",      MNT_MS_XCOMMENT, MNT_NOHLPS | MNT_NOMTAB | MNT_PREFIX }, /* x- fstab only comments */
+   { "x-",      MNT_MS_XCOMMENT,   MNT_NOHLPS | MNT_PREFIX },              /* persistent comments (utab) */
+   { "X-",      MNT_MS_XFSTABCOMM, MNT_NOHLPS | MNT_NOMTAB | MNT_PREFIX }, /* fstab only comments */
 
    { "loop[=]", MNT_MS_LOOP, MNT_NOHLPS },                             /* use the loop device */
    { "offset=", MNT_MS_OFFSET, MNT_NOHLPS | MNT_NOMTAB },		   /* loop device offset */