4 files changed, 46 insertions, 4 deletions
diff --git a/libmount/src/context.c b/libmount/src/context.c
index a9cb4ef26c..28cce65e83 100644
--- a/libmount/src/context.c
+++ b/libmount/src/context.c
@@ -506,13 +506,45 @@ int mnt_context_disable_canonicalize(struct libmnt_context *cxt, int disable)
  * mnt_context_is_nocanonicalize:
  * @cxt: mount context
  *
- * Returns: 1 if no-canonicalize mode is enabled or 0.
+ * Returns: 1 if no-canonicalize mode (on [u]mount command line) is enabled or 0.
  */
 int mnt_context_is_nocanonicalize(struct libmnt_context *cxt)
 {
 	return cxt->flags & MNT_FL_NOCANONICALIZE ? 1 : 0;
 }
 
+
+/*
+ * Returns 1 if "x-mount.nocanonicalize[=<type>]" userspace mount option is
+ * specified. The optional arguments 'type' should be "source" or "target".
+ */
+int mnt_context_is_xnocanonicalize(
+			struct libmnt_context *cxt,
+			const char *type)
+{
+	struct libmnt_optlist *ol;
+	struct libmnt_opt *opt;
+	const char *arg;
+
+	assert(cxt);
+	assert(type);
+
+	if (mnt_context_is_nocanonicalize(cxt))
+		return 1;
+
+	ol = mnt_context_get_optlist(cxt);
+	if (!ol)
+		return 0;
+	opt = mnt_optlist_get_named(ol,	"X-mount.nocanonicalize",
+			cxt->map_userspace);
+	if (!opt)
+		return 0;
+	arg = mnt_opt_get_value(opt);
+	if (!arg)
+		return 1;
+	return strcmp(arg, type) == 0;
+}
+
 /**
  * mnt_context_enable_lazy:
  * @cxt: mount context
@@ -1884,7 +1916,8 @@ int mnt_context_prepare_srcpath(struct libmnt_context *cxt)
 
 		rc = path ? mnt_fs_set_source(cxt->fs, path) : -MNT_ERR_NOSOURCE;
 
-	} else if (cache && !mnt_fs_is_pseudofs(cxt->fs)) {
+	} else if (cache && !mnt_fs_is_pseudofs(cxt->fs)
+			 && !mnt_context_is_xnocanonicalize(cxt, "source")) {
 		/*
 		 * Source is PATH (canonicalize)
 		 */
diff --git a/libmount/src/context_mount.c b/libmount/src/context_mount.c
index e42c8705e2..599370782f 100644
--- a/libmount/src/context_mount.c
+++ b/libmount/src/context_mount.c
@@ -726,7 +726,7 @@ static int prepare_target(struct libmnt_context *cxt)
 		return -MNT_ERR_NAMESPACE;
 
 	/* canonicalize the path */
-	if (rc == 0) {
+	if (rc == 0 && !mnt_context_is_xnocanonicalize(cxt, "target")) {
 		struct libmnt_cache *cache = mnt_context_get_cache(cxt);
 
 		if (cache) {
diff --git a/libmount/src/mountP.h b/libmount/src/mountP.h
index ed5f2ec29f..2c1f62a8ff 100644
--- a/libmount/src/mountP.h
+++ b/libmount/src/mountP.h
@@ -654,6 +654,8 @@ extern int mnt_context_apply_fs(struct libmnt_context *cxt, struct libmnt_fs *fs
 
 extern struct libmnt_optlist *mnt_context_get_optlist(struct libmnt_context *cxt);
 
+extern int mnt_context_is_xnocanonicalize(struct libmnt_context *cxt, const char *type);
+
 /* tab_update.c */
 extern int mnt_update_emit_event(struct libmnt_update *upd);
 extern int mnt_update_set_filename(struct libmnt_update *upd, const char *filename);
diff --git a/sys-utils/mount.8.adoc b/sys-utils/mount.8.adoc
index 4c9bef6f4f..28a84a86c2 100644
--- a/sys-utils/mount.8.adoc
+++ b/sys-utils/mount.8.adoc
@@ -319,7 +319,7 @@ Note that it is a bad practice to use *mount -a* for _fstab_ checking. The recom
 Remount a subtree somewhere else (so that its contents are available in both places). See above, under *Bind mount operation*.
 
 *-c*, *--no-canonicalize*::
-Don't canonicalize paths. The *mount* command canonicalizes all paths (from the command line or _fstab_) by default. This option can be used together with the *-f* flag for already canonicalized absolute paths. The option is designed for mount helpers which call *mount -i*. It is strongly recommended to not use this command-line option for normal mount operations.
+Do not canonicalize any paths or tags during the mount process. The *mount* command automatically canonicalizes all paths (from the command line or _fstab_). This option can be used in conjunction with the *-f* flag for paths that are already canonicalized. This option is intended for mount helpers that call *mount -i*. It is highly recommended to not use this command-line option for regular mount operations. See also the X-mount.nocanonicalize mount options.
 +
 Note that *mount* does not pass this option to the **/sbin/mount.**__type__ helpers.
 
@@ -714,6 +714,13 @@ ____
 *X-mount.mkdir*[=_mode_]::
 Allow to make a target directory (mountpoint) if it does not exist yet. The optional argument _mode_ specifies the filesystem access mode used for *mkdir*(2) in octal notation. The default mode is 0755. This functionality is supported only for root users or when *mount* is executed without suid permissions. The option is also supported as *x-mount.mkdir*, but this notation is deprecated since v2.30. See also *--mkdir* command line option.
 
+*X-mount.nocanonicalize*[=_type_]::
+Allows disabling of canonicalization for mount source and target paths. By default, the `mount` command resolves all paths to their absolute paths without symlinks. However, this behavior may not be desired in certain situations, such as when bind-mounting over a symlink. The optional argument _type_ can be either "source" or "target" (mountpoint). If no _type_ is specified, then canonicalization is disabled for both types. This mount option does not affect the conversion of source tags (e.g. LABEL= or UUID=) and fstab processing.
++
+The command line option *--no-canonicalize* overrides this mount option and affects all path and tag conversions in all situations.
++
+Note that *mount*(8) still sanitizes and canonicalizes the source and target paths specified on the command line by non-root users, regardless of the X-mount.nocanonicalize setting.
+
 **X-mount.subdir=**__directory__::
 Allow mounting sub-directory from a filesystem instead of the root directory. For now, this feature is implemented by temporary filesystem root directory mount in unshared namespace and then bind the sub-directory to the final mount point and umount the root of the filesystem. The sub-directory mount shows up atomically for the rest of the system although it is implemented by multiple *mount*(2) syscalls.
 +