From: Michael Tremer <michael.tremer@ipfire.org>
Date: Mon, 12 Dec 2022 18:06:26 +0000 (+0000)
Subject: mount: Fix bind-mounting read-only shares
X-Git-Tag: 0.9.29~424
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=976fbbc8f15bd9a18f6ddc0e05e4619244208eed;p=pakfire.git

mount: Fix bind-mounting read-only shares

Fixes: #12968
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/libpakfire/mount.c b/src/libpakfire/mount.c
index c00bc658f..72ba4ac57 100644
--- a/src/libpakfire/mount.c
+++ b/src/libpakfire/mount.c
@@ -421,6 +421,18 @@ int pakfire_bind(struct pakfire* pakfire, const char* src, const char* dst, int
 			return 1;
 	}
 
+	// The Linux kernel seems to be quite funny when trying to bind-mount something
+	// as read-only and requires us to mount the source first, and then remount it
+	// again using MS_RDONLY.
+	if (flags & MS_RDONLY) {
+		r = pakfire_mount(pakfire, src, mountpoint, NULL, MS_BIND|MS_REC, NULL);
+		if (r)
+			return r;
+
+		// Add the remount flag
+		flags |= MS_REMOUNT;
+	}
+
 	// Perform mount
-	return pakfire_mount(pakfire, src, mountpoint, NULL, flags|MS_REC|MS_BIND, NULL);
+	return pakfire_mount(pakfire, src, mountpoint, NULL, flags|MS_BIND|MS_REC, NULL);
 }