From 2e4aaa1adad2d0838593b13efbf5efe79f58255c Mon Sep 17 00:00:00 2001

From: Ondrej Kozina <okozina@redhat.com>

Date: Mon, 16 Oct 2017 16:41:43 +0200

Subject: [PATCH] crypt_deactivate: fail earlier when holders detected

crypt_deactivate fails earlier without noisy dm retries

when other device holders detected. The early detection

works if:

a) other device-mapper device has a hold reference on the

   device

- or -

b) mounted fs is detected on the device

diff -rupN cryptsetup-1.7.4.old/config.h.in cryptsetup-1.7.4/config.h.in

--- cryptsetup-1.7.4.old/config.h.in	2017-03-15 10:43:26.000000000 +0100

+++ cryptsetup-1.7.4/config.h.in	2017-10-19 09:37:17.000000000 +0200

@@ -97,6 +97,14 @@

    */

 #undef HAVE_DCGETTEXT

+/* Define to 1 if you have the declaration of `dm_device_has_holders', and to

+   0 if you don't. */

+#undef HAVE_DECL_DM_DEVICE_HAS_HOLDERS

+

+/* Define to 1 if you have the declaration of `dm_device_has_mounted_fs', and

+   to 0 if you don't. */

+#undef HAVE_DECL_DM_DEVICE_HAS_MOUNTED_FS

+

 /* Define to 1 if you have the declaration of `dm_task_retry_remove', and to 0

    if you don't. */

 #undef HAVE_DECL_DM_TASK_RETRY_REMOVE

diff -rupN cryptsetup-1.7.4.old/configure cryptsetup-1.7.4/configure

--- cryptsetup-1.7.4.old/configure	2017-03-15 10:43:13.000000000 +0100

+++ cryptsetup-1.7.4/configure	2017-10-19 09:37:18.590530138 +0200

@@ -16735,6 +16735,30 @@ cat >>confdefs.h <<_ACEOF

 #define HAVE_DECL_DM_TASK_RETRY_REMOVE $ac_have_decl

 _ACEOF

+ac_fn_c_check_decl "$LINENO" "dm_device_has_mounted_fs" "ac_cv_have_decl_dm_device_has_mounted_fs" "#include <libdevmapper.h>

+"

+if test "x$ac_cv_have_decl_dm_device_has_mounted_fs" = xyes; then :

+  ac_have_decl=1

+else

+  ac_have_decl=0

+fi

+

+cat >>confdefs.h <<_ACEOF

+#define HAVE_DECL_DM_DEVICE_HAS_MOUNTED_FS $ac_have_decl

+_ACEOF

+

+ac_fn_c_check_decl "$LINENO" "dm_device_has_holders" "ac_cv_have_decl_dm_device_has_holders" "#include <libdevmapper.h>

+"

+if test "x$ac_cv_have_decl_dm_device_has_holders" = xyes; then :

+  ac_have_decl=1

+else

+  ac_have_decl=0

+fi

+

+cat >>confdefs.h <<_ACEOF

+#define HAVE_DECL_DM_DEVICE_HAS_HOLDERS $ac_have_decl

+_ACEOF

+

 ac_fn_c_check_decl "$LINENO" "DM_UDEV_DISABLE_DISK_RULES_FLAG" "ac_cv_have_decl_DM_UDEV_DISABLE_DISK_RULES_FLAG" "#include <libdevmapper.h>

 "

 if test "x$ac_cv_have_decl_DM_UDEV_DISABLE_DISK_RULES_FLAG" = xyes; then :

diff --git a/lib/libdevmapper.c b/lib/libdevmapper.c

index a0d6872..d6017b1 100644

--- a/lib/libdevmapper.c

+++ b/lib/libdevmapper.c

@@ -1181,6 +1181,13 @@ int dm_query_device(struct crypt_device *cd, const char *name,

 			dmd->uuid = strdup(tmp_uuid + DM_UUID_PREFIX_LEN);

 	}

+	dmd->holders = 0;

+#if (HAVE_DECL_DM_DEVICE_HAS_HOLDERS && HAVE_DECL_DM_DEVICE_HAS_MOUNTED_FS)

+	if (get_flags & DM_ACTIVE_HOLDERS)

+		dmd->holders = (dm_device_has_mounted_fs(dmi.major, dmi.minor) ||

+				dm_device_has_holders(dmi.major, dmi.minor));

+#endif

+

 	r = (dmi.open_count > 0);

 out:

 	if (dmt)

diff --git a/lib/setup.c b/lib/setup.c

index b2e4396..93e8079 100644

--- a/lib/setup.c

+++ b/lib/setup.c

@@ -2249,6 +2249,7 @@ int crypt_activate_by_volume_key(struct crypt_device *cd,

 int crypt_deactivate(struct crypt_device *cd, const char *name)

 {

 	struct crypt_device *fake_cd = NULL;

+	struct crypt_dm_active_device dmd = {};

 	int r;

 	if (!name)

@@ -2266,6 +2267,13 @@ int crypt_deactivate(struct crypt_device *cd, const char *name)

 	switch (crypt_status(cd, name)) {

 		case CRYPT_ACTIVE:

 		case CRYPT_BUSY:

+			r = dm_query_device(cd, name, DM_ACTIVE_HOLDERS, &dmd);

+			if (r >= 0 && dmd.holders) {

+				log_err(cd, _("Device %s is still in use.\n"), name);

+				r = -EBUSY;

+				break;

+			}

+

 			if (isTCRYPT(cd->type))

 				r = TCRYPT_deactivate(cd, name);

 			else

diff --git a/lib/utils_dm.h b/lib/utils_dm.h

index c87e9aa..cf22e12 100644

--- a/lib/utils_dm.h

+++ b/lib/utils_dm.h

@@ -48,14 +48,16 @@ uint32_t dm_flags(void);

 #define DM_ACTIVE_DEVICE	(1 << 0)

 #define DM_ACTIVE_UUID		(1 << 1)

+#define DM_ACTIVE_HOLDERS	(1 << 2)

-#define DM_ACTIVE_CRYPT_CIPHER	(1 << 2)

-#define DM_ACTIVE_CRYPT_KEYSIZE	(1 << 3)

-#define DM_ACTIVE_CRYPT_KEY	(1 << 4)

+#define DM_ACTIVE_CRYPT_CIPHER	(1 << 3)

+#define DM_ACTIVE_CRYPT_KEYSIZE	(1 << 4)

+#define DM_ACTIVE_CRYPT_KEY	(1 << 5)

+

+#define DM_ACTIVE_VERITY_ROOT_HASH	(1 << 6)

+#define DM_ACTIVE_VERITY_HASH_DEVICE	(1 << 7)

+#define DM_ACTIVE_VERITY_PARAMS		(1 << 8)

-#define DM_ACTIVE_VERITY_ROOT_HASH	(1 << 5)

-#define DM_ACTIVE_VERITY_HASH_DEVICE	(1 << 6)

-#define DM_ACTIVE_VERITY_PARAMS		(1 << 7)

 struct crypt_dm_active_device {

 	enum { DM_CRYPT = 0, DM_VERITY } target;

@@ -63,6 +65,7 @@ struct crypt_dm_active_device {

 	uint32_t flags;		/* activation flags */

 	const char *uuid;

 	struct device *data_device;

+	unsigned holders:1;

 	union {

 	struct {

 		const char *cipher;

-- 

1.8.3.1