create parent paths of target mounts as needed
Currently if you want to bind mount a single subdir, you have to make
sure to create the full parent directory chain. For example, if you
want /var/lib/timezone/ but not the rest of /var, you have to do:
-k none,/var,tmpfs
-k none,/var/lib,tmpfs
-b /var/lib/timezone/
For every additional subdir, you need to add another -k option just to
do an [effective] mkdir with a tmpfs mount.
The current -k/-b behavior is to run mkdir if the target doesn't already
exist, but only for the final target. Lets extend it to also create any
missing parent paths, so now only the base path needs to be writable:
-k none,/var,tmpfs
-b /var/lib/timezone/
Bug: None
Test: `minijail0 --profile minimalistic-mountns -k none,/var,tmpfs -b /var/lib/timezone /bin/date` works
Change-Id: I7f36bcb445ce40ed66a9403a4ee1c1fe3f9e5ea8
diff --git a/minijail0.1 b/minijail0.1
index e713fed..7c535e0 100644
--- a/minijail0.1
+++ b/minijail0.1
@@ -17,7 +17,7 @@
The \fIsrc\fR path must be an absolute path.
If \fIdest\fR is not specified, it will default to \fIsrc\fR.
If the destination does not exist, it will be created as a file or directory
-based on the \fIsrc\fR type.
+based on the \fIsrc\fR type (including missing parent directories).
.TP
\fB-c <caps>\fR
Restrict capabilities to \fIcaps\fR. When used in conjunction with \fB-u\fR and
@@ -81,7 +81,8 @@
If the mount is not a pseudo filesystem (e.g. proc or sysfs), \fIsrc\fR path
must be an absolute path (e.g. \fI/dev/sda1\fR and not \fIsda1\fR).
-If the destination does not exist, it will be created as a directory.
+If the destination does not exist, it will be created as a directory (including
+missing parent directories).
.TP
\fB-K\fR
Don't mark all existing mounts as MS_PRIVATE.