From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 29 Sep 2017 12:19:22 +0000 (+0200)
Subject: dissect: automatically mark partitions read-only that have a read-only file system
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=6c78120a2db66990f872fa03dd14dd77d452e57d;p=elogind.git

dissect: automatically mark partitions read-only that have a read-only file system

Specifically, squashfs and iso9660 are always read-only, hence make sure
we never even think about mounting them writable.
---

diff --git a/src/basic/mount-util.c b/src/basic/mount-util.c
index adf60c7ee..d8850bf83 100644
--- a/src/basic/mount-util.c
+++ b/src/basic/mount-util.c
@@ -578,6 +578,19 @@ bool fstype_is_api_vfs(const char *fstype) {
         return nulstr_contains(table, fstype);
 }
 
+bool fstype_is_ro(const char *fstype) {
+
+        /* All Linux file systems that are necessarily read-only */
+
+        static const char table[] =
+                "DM_verity_hash\0"
+                "iso9660\0"
+                "squashfs\0"
+                ;
+
+        return nulstr_contains(table, fstype);
+}
+
 int repeat_unmount(const char *path, int flags) {
         bool done = false;
 
diff --git a/src/basic/mount-util.h b/src/basic/mount-util.h
index 571a0eb50..3b026c1b5 100644
--- a/src/basic/mount-util.h
+++ b/src/basic/mount-util.h
@@ -49,6 +49,7 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, endmntent);
 bool fstype_is_network(const char *fstype);
 #endif // 0
 bool fstype_is_api_vfs(const char *fstype);
+bool fstype_is_ro(const char *fsype);
 
 union file_handle_union {
         struct file_handle handle;