From 3062a9ba91333953829a8db994f82cc18b5b2955 Mon Sep 17 00:00:00 2001
From: Luca Boccassi <luca.boccassi@microsoft.com>
Date: Wed, 15 Jul 2020 15:35:19 +0100
Subject: [PATCH] libcrypsetup: add CRYPT_DEACTIVATE_DEFERRED_CANCEL for
 crypt_deactivate_by_name

Allows to cancel a previously set deferred deactivation flag
for a specific device.

[mbroz: slight changes]
---
 lib/libcryptsetup.h |  2 ++
 lib/libdevmapper.c  |  5 +++++
 lib/setup.c         | 12 +++++++++++-
 lib/utils_dm.h      |  1 +
 4 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/lib/libcryptsetup.h b/lib/libcryptsetup.h
index 6dd9da41..5886ee07 100644
--- a/lib/libcryptsetup.h
+++ b/lib/libcryptsetup.h
@@ -1351,6 +1351,8 @@ int crypt_activate_by_keyring(struct crypt_device *cd,
 #define CRYPT_DEACTIVATE_DEFERRED (1 << 0)
 /** force deactivation - if the device is busy, it is replaced by error device */
 #define CRYPT_DEACTIVATE_FORCE    (1 << 1)
+/** if set, remove lazy deactivation */
+#define CRYPT_DEACTIVATE_DEFERRED_CANCEL (1 << 2)
 
 /**
  * Deactivate crypt device. This function tries to remove active device-mapper
diff --git a/lib/libdevmapper.c b/lib/libdevmapper.c
index 8f8c94b5..8560d1e5 100644
--- a/lib/libdevmapper.c
+++ b/lib/libdevmapper.c
@@ -2942,6 +2942,11 @@ out:
 	return r;
 }
 
+int dm_cancel_deferred_removal(const char *name)
+{
+	return _dm_message(name, "@cancel_deferred_remove") ? 0 : -ENOTSUP;
+}
+
 const char *dm_get_dir(void)
 {
 	return dm_dir();
diff --git a/lib/setup.c b/lib/setup.c
index 2631fd73..389ae724 100644
--- a/lib/setup.c
+++ b/lib/setup.c
@@ -4474,6 +4474,9 @@ int crypt_deactivate_by_name(struct crypt_device *cd, const char *name, uint32_t
 	if (!name)
 		return -EINVAL;
 
+	if ((flags & CRYPT_DEACTIVATE_DEFERRED) && (flags & CRYPT_DEACTIVATE_DEFERRED_CANCEL))
+		return -EINVAL;
+
 	log_dbg(cd, "Deactivating volume %s.", name);
 
 	if (!cd) {
@@ -4484,12 +4487,19 @@ int crypt_deactivate_by_name(struct crypt_device *cd, const char *name, uint32_t
 	}
 
 	/* skip holders detection and early abort when some flags raised */
-	if (flags & (CRYPT_DEACTIVATE_FORCE | CRYPT_DEACTIVATE_DEFERRED))
+	if (flags & (CRYPT_DEACTIVATE_FORCE | CRYPT_DEACTIVATE_DEFERRED | CRYPT_DEACTIVATE_DEFERRED_CANCEL))
 		get_flags &= ~DM_ACTIVE_HOLDERS;
 
 	switch (crypt_status(cd, name)) {
 		case CRYPT_ACTIVE:
 		case CRYPT_BUSY:
+			if (flags & CRYPT_DEACTIVATE_DEFERRED_CANCEL) {
+				r = dm_cancel_deferred_removal(name);
+				if (r < 0)
+					log_err(cd, _("Could not cancel deferred remove from device %s."), name);
+				break;
+			}
+
 			r = dm_query_device(cd, name, get_flags, &dmd);
 			if (r >= 0) {
 				if (dmd.holders) {
diff --git a/lib/utils_dm.h b/lib/utils_dm.h
index 0cd543b0..ef48c0e0 100644
--- a/lib/utils_dm.h
+++ b/lib/utils_dm.h
@@ -220,6 +220,7 @@ int dm_resume_and_reinstate_key(struct crypt_device *cd, const char *name,
 				const struct volume_key *vk);
 int dm_error_device(struct crypt_device *cd, const char *name);
 int dm_clear_device(struct crypt_device *cd, const char *name);
+int dm_cancel_deferred_removal(const char *name);
 
 const char *dm_get_dir(void);