From: Karel Zak <kzak@redhat.com>
Date: Thu, 22 Sep 2022 09:05:53 +0000 (+0200)
Subject: libmount: support VFS flags attributes clear
X-Git-Tag: v2.39-rc1~253
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ddebca17498f485c70bcba2f3f5dcec4a27aa99d;p=thirdparty%2Futil-linux.git

libmount: support VFS flags attributes clear

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libmount/src/hook_mount.c b/libmount/src/hook_mount.c
index d4be4d7370..abfd00ebf7 100644
--- a/libmount/src/hook_mount.c
+++ b/libmount/src/hook_mount.c
@@ -137,7 +137,7 @@ static int hook_set_vfsflags(struct libmnt_context *cxt,
 	struct libmnt_optlist *ol;
 	struct mount_attr attr = { .attr_clr = 0 };
 	unsigned int callflags = AT_EMPTY_PATH;
-	uint64_t mask = 0;
+	uint64_t set = 0, clr = 0;
 	int rc;
 
 	api = get_sysapi(cxt, hs);
@@ -148,15 +148,17 @@ static int hook_set_vfsflags(struct libmnt_context *cxt,
 	if (!ol)
 		return -ENOMEM;
 
-	rc = mnt_optlist_get_attrs(ol, &mask);
+	rc = mnt_optlist_get_attrs(ol, &set, &clr);
 	if (rc)
 		return rc;
 
 	if (mnt_optlist_is_recursive(ol))
 		callflags |= AT_RECURSIVE;
 
-	DBG(HOOK, ul_debugobj(hs, "mount_setattr(set=0x%" PRIx64")", mask));
-	attr.attr_set = mask;
+	DBG(HOOK, ul_debugobj(hs,
+			"mount_setattr(set=0x%08" PRIx64" clr=0x%08" PRIx64")", set, clr));
+	attr.attr_set = set;
+	attr.attr_clr = clr;
 
 	rc = mount_setattr(api->fd_tree, "", callflags, &attr, sizeof(attr));
 	set_syscall_status(cxt, "move_setattr", rc == 0);
@@ -287,7 +289,7 @@ static int hook_prepare(struct libmnt_context *cxt,
 {
 	struct libmnt_optlist *ol;
 	unsigned long flags = 0;
-	uint64_t attrs = 0;
+	uint64_t set = 0, clr = 0;
 	int rc = 0;
 
 	assert(cxt);
@@ -304,7 +306,7 @@ static int hook_prepare(struct libmnt_context *cxt,
 
 	/* MOUNT_ATTR_* flags for mount_setattr() */
 	if (!rc)
-		rc = mnt_optlist_get_attrs(ol, &attrs);
+		rc = mnt_optlist_get_attrs(ol, &set, &clr);
 
 	/* open_tree() or fsopen() */
 	if (!rc)
@@ -322,7 +324,7 @@ static int hook_prepare(struct libmnt_context *cxt,
 					hook_reconfigure_mount);
 
 	/* call mount_setattr() */
-	if (!rc && attrs != 0)
+	if (!rc && (set != 0 || clr != 0))
 		rc = mnt_context_append_hook(cxt, hs, MNT_STAGE_MOUNT, NULL,
 					hook_set_vfsflags);
 
diff --git a/libmount/src/mountP.h b/libmount/src/mountP.h
index 54b12f42ae..8304d3af0e 100644
--- a/libmount/src/mountP.h
+++ b/libmount/src/mountP.h
@@ -530,7 +530,7 @@ enum {
 
 extern int mnt_optlist_get_flags(struct libmnt_optlist *ls, unsigned long *flags,
                           const struct libmnt_optmap *map, unsigned int what);
-extern int mnt_optlist_get_attrs(struct libmnt_optlist *ls, uint64_t *attrs);
+extern int mnt_optlist_get_attrs(struct libmnt_optlist *ls, uint64_t *set, uint64_t *clr);
 extern int mnt_optlist_get_optstr(struct libmnt_optlist *ol, const char **optstr,
                         const struct libmnt_optmap *map, unsigned int what);
 extern int mnt_optlist_strdup_optstr(struct libmnt_optlist *ls, char **optstr,
diff --git a/libmount/src/optlist.c b/libmount/src/optlist.c
index 6531d5b46e..939473dc56 100644
--- a/libmount/src/optlist.c
+++ b/libmount/src/optlist.c
@@ -746,39 +746,65 @@ int mnt_optlist_get_flags(struct libmnt_optlist *ls, unsigned long *flags,
 	return 0;
 }
 
-/*
- * Like mnt_optlist_get_flags() for VFS flags, but converts classic MS_* flags to
- * new MOUNT_ATTR_*
- */
-int mnt_optlist_get_attrs(struct libmnt_optlist *ls, uint64_t *attrs)
-{
 #ifdef UL_HAVE_MOUNT_API
-	int rc;
-	unsigned long flags = 0;
-
-	assert(ls);
-	assert(ls->linux_map);
-
-	rc = mnt_optlist_get_flags(ls, &flags, ls->linux_map, 0);
-	if (rc)
-		return rc;
+static inline uint64_t flags_to_attrs(unsigned long flags)
+{
+	uint64_t attrs = 0;
 
 	if (flags & MS_RDONLY)
-		*attrs |= MOUNT_ATTR_RDONLY;
+		attrs |= MOUNT_ATTR_RDONLY;
 	if (flags & MS_NOSUID)
-		*attrs |= MOUNT_ATTR_NOSUID;
+		attrs |= MOUNT_ATTR_NOSUID;
 	if (flags & MS_NOEXEC)
-		*attrs |= MOUNT_ATTR_NOEXEC;
+		attrs |= MOUNT_ATTR_NOEXEC;
 	if (flags & MS_NODIRATIME)
-		*attrs |= MOUNT_ATTR_NODIRATIME;
+		attrs |= MOUNT_ATTR_NODIRATIME;
 	if (flags & MS_RELATIME)
-		*attrs |= MOUNT_ATTR_RELATIME;
+		attrs |= MOUNT_ATTR_RELATIME;
 	if (flags & MS_NOATIME)
-		*attrs |= MOUNT_ATTR_NOATIME;
+		attrs |= MOUNT_ATTR_NOATIME;
 	if (flags & MS_STRICTATIME)
-		*attrs |= MOUNT_ATTR_STRICTATIME;
+		attrs |= MOUNT_ATTR_STRICTATIME;
 	if (flags & MS_NOSYMFOLLOW)
-		*attrs |= MOUNT_ATTR_NOSYMFOLLOW;
+		attrs |= MOUNT_ATTR_NOSYMFOLLOW;
+
+	return attrs;
+}
+#endif
+
+/*
+ * Like mnt_optlist_get_flags() for VFS flags, but converts classic MS_* flags to
+ * new MOUNT_ATTR_*
+ */
+int mnt_optlist_get_attrs(struct libmnt_optlist *ls, uint64_t *set, uint64_t *clr)
+{
+#ifdef UL_HAVE_MOUNT_API
+	struct libmnt_iter itr;
+	struct libmnt_opt *opt;
+
+	if (!ls || !ls->linux_map || !set || !clr)
+		return -EINVAL;
+
+	mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+
+	while (mnt_optlist_next_opt(ls, &itr, &opt) == 0) {
+		if (ls->linux_map != opt->map)
+			continue;
+		if (!opt->ent || !opt->ent->id)
+			continue;
+		if (!is_wanted_opt(opt, ls->linux_map, MNT_OL_FLTR_DFLT))
+			continue;
+
+		if (opt->ent->mask & MNT_INVERT)
+			*clr |= flags_to_attrs( opt->ent->id );
+		else
+			*set |= flags_to_attrs( opt->ent->id );
+	}
+
+	DBG(OPTLIST, ul_debugobj(ls, "return attrs set=0x%08" PRIx64
+				      ", clr=0x08%" PRIx64, *set, *clr));
+	return 0;
+
 #endif
 	return 0;
 }