Remove O_SYNC from device open and use fsync().

This speed up wipe operation considerably.

lib/internal.h

@@ -104,6 +104,7 @@ int device_is_rotational(struct device *device);
 size_t device_alignment(struct device *device);
 int device_direct_io(const struct device *device);
 int device_fallocate(struct device *device, uint64_t size);
+void device_sync(struct device *device, int devfd);
 
 int device_open_locked(struct device *device, int flags);
 int device_read_lock(struct crypt_device *cd, struct device *device);

lib/luks1/keyencryption.c

@@ -193,8 +193,10 @@ int LUKS_encrypt_to_storage(char *src, size_t srcLength,
 
 	r = 0;
 out:
-	if (devfd >= 0)
+	if (devfd >= 0) {
+		device_sync(device, devfd);
 		close(devfd);
+	}
 	if (r)
 		log_err(ctx, _("IO error while encrypting keyslot."));
 

lib/luks1/keymanage.c

@@ -378,8 +378,10 @@ int LUKS_hdr_restore(
 	/* Be sure to reload new data */
 	r = LUKS_read_phdr(hdr, 1, 0, ctx);
 out:
-	if (devfd >= 0)
+	if (devfd >= 0) {
+		device_sync(device, devfd);
 		close(devfd);
+	}
 	crypt_safe_free(buffer);
 	return r;
 }
@@ -681,6 +683,8 @@ int LUKS_write_phdr(struct luks_phdr *hdr,
 			    &convHdr, hdr_size) < hdr_size ? -EIO : 0;
 	if (r)
 		log_err(ctx, _("Error during update of LUKS header on device %s."), device_path(device));
+
+	device_sync(device, devfd);
 	close(devfd);
 
 	/* Re-read header from disk to be sure that in-memory and on-disk data are the same. */

lib/luks2/luks2_disk_metadata.c

@@ -341,6 +341,7 @@ static int hdr_write_disk(struct device *device, struct luks2_hdr *hdr,
 				  LUKS2_HDR_BIN_LEN, offset) < (ssize_t)LUKS2_HDR_BIN_LEN)
 		r = -EIO;
 
+	device_sync(device, devfd);
 	close(devfd);
 	return r;
 }

lib/luks2/luks2_json_metadata.c

@@ -1195,8 +1195,10 @@ out:
 	crypt_memzero(&tmp_hdr, sizeof(tmp_hdr));
 	crypt_safe_free(buffer);
 
-	if (devfd >= 0)
+	if (devfd >= 0) {
+		device_sync(device, devfd);
 		close(devfd);
+	}
 
 	if (!r) {
 		LUKS2_hdr_free(hdr);

lib/luks2/luks2_keyslot_luks2.c

@@ -79,6 +79,8 @@ static int luks2_encrypt_to_storage(char *src, size_t srcLength,
 			r = -EIO;
 		else
 			r = 0;
+
+		device_sync(device, devfd);
 		close(devfd);
 	} else
 		r = -EIO;

lib/luks2/luks2_luks1_convert.c

@@ -461,6 +461,7 @@ static int move_keyslot_areas(struct crypt_device *cd, off_t offset_from,
 
 	r = 0;
 out:
+	device_sync(device, devfd);
 	close(devfd);
 	crypt_memzero(buf, buf_size);
 	free(buf);

lib/utils_device.c

@@ -229,6 +229,16 @@ static int _open_locked(struct device *device, int flags)
 	return fd;
 }
 
+/*
+ * Common wrapper for device sync.
+ * FIXME: file descriptor will be in struct later.
+ */
+void device_sync(struct device *device, int devfd)
+{
+	if (fsync(devfd) == -1)
+		log_dbg("Cannot sync device %s.", device_path(device));
+}
+
 /*
  * in non-locked mode returns always fd or -1
  *
@@ -242,7 +252,6 @@ static int device_open_internal(struct device *device, int flags)
 {
 	int devfd;
 
-	flags |= O_SYNC;
 	if (device->o_direct)
 		flags |= O_DIRECT;
 

lib/utils_wipe.c

@@ -213,7 +213,7 @@ int crypt_wipe_device(struct crypt_device *cd,
 		}
 	}
 
-	fsync(devfd);
+	device_sync(device, devfd);
 out:
 	close(devfd);
 	free(sf);

lib/verity/verity.c

@@ -201,6 +201,8 @@ int VERITY_write_sb(struct crypt_device *cd,
 	if (r)
 		log_err(cd, _("Error during update of verity header on device %s."),
 			device_path(device));
+
+	device_sync(device, devfd);
 	close(devfd);
 
 	return r;