1 files changed, 372 insertions, 0 deletions
diff --git a/lib/metadata/integrity_manip.c b/lib/metadata/integrity_manip.c
new file mode 100644
index 000000000..c3dde2555
--- /dev/null
+++ b/lib/metadata/integrity_manip.c
@@ -0,0 +1,372 @@
+/*
+ * Copyright (C) 2014-2015 Red Hat, Inc. All rights reserved.
+ *
+ * This file is part of LVM2.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU Lesser General Public License v.2.1.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "lib/misc/lib.h"
+#include "lib/metadata/metadata.h"
+#include "lib/locking/locking.h"
+#include "lib/misc/lvm-string.h"
+#include "lib/commands/toolcontext.h"
+#include "lib/display/display.h"
+#include "lib/metadata/segtype.h"
+#include "lib/activate/activate.h"
+#include "lib/config/defaults.h"
+#include "lib/activate/dev_manager.h"
+
+#define DEFAULT_TAG_SIZE 4 /* bytes */
+#define DEFAULT_MODE 'B'
+#define DEFAULT_INTERNAL_HASH "crc32c"
+
+#define ONE_MB_IN_BYTES 1048576
+
+/*
+ * Every 500M of data needs 4M of metadata.
+ * (From trial and error testing.)
+ */
+static uint64_t _lv_size_bytes_to_integrity_meta_bytes(uint64_t lv_size_bytes)
+{
+	return ((lv_size_bytes / (500 * ONE_MB_IN_BYTES)) + 1) * (4 * ONE_MB_IN_BYTES);
+}
+
+/*
+ * The user wants external metadata, but did not specify an existing
+ * LV to hold metadata, so create an LV for metadata.  Save it in
+ * lp->integrity_meta_lv and it will be passed to lv_add_integrity().
+ */
+int lv_create_integrity_metadata(struct cmd_context *cmd,
+				struct volume_group *vg,
+				struct lvcreate_params *lp)
+{
+	char metaname[NAME_LEN];
+	uint64_t lv_size_bytes, meta_bytes, meta_sectors;
+	struct logical_volume *lv;
+	struct lvcreate_params lp_meta = {
+		.activate = CHANGE_AN,
+		.alloc = ALLOC_INHERIT,
+		.major = -1,
+		.minor = -1,
+		.permission = LVM_READ | LVM_WRITE,
+		.pvh = &vg->pvs,
+		.read_ahead = DM_READ_AHEAD_NONE,
+		.stripes = 1,
+		.vg_name = vg->name,
+		.zero = 0,
+		.wipe_signatures = 0,
+		.suppress_zero_warn = 1,
+	};
+
+	if (dm_snprintf(metaname, NAME_LEN, "%s_imeta", lp->lv_name) < 0) {
+		log_error("Failed to create metadata LV name.");
+		return 0;
+	}
+
+	if (!(lp_meta.lv_name = strdup(metaname)))
+		return_0;
+
+	lp_meta.pvh = lp->pvh;
+
+	lv_size_bytes = lp->extents * vg->extent_size * 512;
+	meta_bytes = _lv_size_bytes_to_integrity_meta_bytes(lv_size_bytes);
+	meta_sectors = meta_bytes / 512;
+	lp_meta.extents = meta_sectors / vg->extent_size;
+
+	log_print("Creating integrity metadata LV %s with size %s.",
+		  metaname, display_size(cmd, meta_sectors));
+
+	dm_list_init(&lp_meta.tags);
+
+	if (!(lp_meta.segtype = get_segtype_from_string(vg->cmd, SEG_TYPE_NAME_STRIPED)))
+		return_0;
+
+	if (!(lv = lv_create_single(vg, &lp_meta))) {
+		log_error("Failed to create integrity metadata LV");
+		return 0;
+	}
+
+	lp->integrity_meta_lv = lv;
+	return 1;
+}
+
+static int _get_provided_data_sectors(struct logical_volume *lv, uint64_t *provided_data_sectors)
+{
+	struct lv_with_info_and_seg_status status;
+	uint64_t data_sectors, extra_sectors;
+
+	memset(&status, 0, sizeof(status));
+	status.seg_status.type = SEG_STATUS_NONE;
+
+	status.seg_status.seg = first_seg(lv);
+
+	/* FIXME: why reporter_pool? */
+	if (!(status.seg_status.mem = dm_pool_create("reporter_pool", 1024))) {
+		log_error("Failed to get mem for LV status.");
+		return 0;
+	}
+
+	if (!lv_info_with_seg_status(lv->vg->cmd, first_seg(lv), &status, 1, 1)) {
+		log_error("Failed to get device mapper status for %s", display_lvname(lv));
+		goto fail;
+	}
+
+	if (!status.info.exists) {
+		log_error("No device mapper info exists for %s", display_lvname(lv));
+		goto fail;
+	}
+
+	if (status.seg_status.type != SEG_STATUS_INTEGRITY) {
+		log_error("Invalid device mapper status type (%d) for %s",
+			  (uint32_t)status.seg_status.type, display_lvname(lv));
+		goto fail;
+	}
+
+	data_sectors = status.seg_status.integrity->provided_data_sectors;
+
+	if ((extra_sectors = (data_sectors % lv->vg->extent_size))) {
+		data_sectors -= extra_sectors;
+		log_debug("Reduce provided_data_sectors by %llu to %llu for extent alignment",
+			  (unsigned long long)extra_sectors, (unsigned long long)data_sectors);
+	}
+
+	*provided_data_sectors = data_sectors;
+
+	dm_pool_destroy(status.seg_status.mem);
+	return 1;
+
+fail:
+	dm_pool_destroy(status.seg_status.mem);
+	return 0;
+}
+
+int lv_remove_integrity(struct logical_volume *lv)
+{
+	struct lv_segment *seg = first_seg(lv);
+	struct logical_volume *origin;
+	struct logical_volume *meta_lv;
+
+	if (!seg_is_integrity(seg)) {
+		log_error("LV %s segment is not integrity.", display_lvname(lv));
+		return 0;
+	}
+
+	if (!(meta_lv = seg->integrity_meta_dev)) {
+		log_error("LV %s segment has no integrity metadata device.", display_lvname(lv));
+		return 0;
+	}
+
+	if (!(origin = seg_lv(seg, 0))) {
+		log_error("LV %s integrity segment has no origin", display_lvname(lv));
+		return 0;
+	}
+
+	if (!remove_seg_from_segs_using_this_lv(seg->integrity_meta_dev, seg))
+		return_0;
+
+	lv_set_visible(seg->integrity_meta_dev);
+
+	lv->status &= ~INTEGRITY;
+	seg->integrity_meta_dev = NULL;
+
+	if (!remove_layer_from_lv(lv, origin))
+		return_0;
+
+	if (!lv_remove(origin))
+		return_0;
+
+	if (!lv_remove(meta_lv))
+		log_warn("WARNING: failed to remove integrity metadata LV.");
+
+	return 1;
+}
+
+int lv_add_integrity(struct logical_volume *lv, const char *arg,
+		     struct logical_volume *meta_lv_created,
+		     const char *meta_name,
+		     struct integrity_settings *settings)
+{
+	struct cmd_context *cmd = lv->vg->cmd;
+	struct volume_group *vg = lv->vg;
+	struct integrity_settings *set;
+	struct logical_volume *lv_orig;
+	struct logical_volume *meta_lv = NULL;
+	const struct segment_type *segtype;
+	struct lv_segment *seg;
+	uint64_t meta_bytes, meta_sectors;
+	uint64_t lv_size_sectors;
+	int ret;
+
+	lv_size_sectors = lv->size;
+
+	if (!(segtype = get_segtype_from_string(cmd, SEG_TYPE_NAME_INTEGRITY)))
+		return_0;
+
+	/*
+	 * "lv_orig" is a new LV with new id, but with the segments from "lv".
+	 * "lv" keeps the existing name and id, but gets a new integrity segment,
+	 * in place of the segments that were moved to lv_orig.
+	 */
+
+	if (!(lv_orig = insert_layer_for_lv(cmd, lv, INTEGRITY, "_iorig")))
+		return_0;
+
+	seg = first_seg(lv);
+	seg->segtype = segtype;
+
+	lv->status |= INTEGRITY;
+
+	memcpy(&seg->integrity_settings, settings, sizeof(struct integrity_settings));
+	set = &seg->integrity_settings;
+
+	if (!set->mode[0])
+		set->mode[0] = DEFAULT_MODE;
+
+	if (!set->tag_size)
+		set->tag_size = DEFAULT_TAG_SIZE;
+
+	if (!set->internal_hash)
+	       	set->internal_hash = DEFAULT_INTERNAL_HASH;
+
+	/*
+	 * --integrity <arg> is y|external|internal
+	 */
+
+	if (!arg)
+		arg = "external";
+
+	if (!strcmp(arg, "none")) {
+		log_error("Invalid --integrity arg for lvcreate.");
+		return 0;
+	}
+
+	if (!strcmp(arg, "internal") && meta_name) {
+		log_error("Internal integrity cannot be used with integritymetadata option.");
+		return 0;
+	}
+
+	if (meta_lv_created)
+		meta_lv = meta_lv_created;
+	else if (meta_name) {
+		if (!(meta_lv = find_lv(vg, meta_name))) {
+			log_error("LV %s not found.", meta_name);
+			return_0;
+		}
+
+		meta_bytes = _lv_size_bytes_to_integrity_meta_bytes(lv->size * 512);
+		meta_sectors = meta_bytes / 512;
+
+		if (meta_lv->size < meta_sectors) {
+			log_error("Integrity metadata needs %s, metadata LV is only %s.",
+				 display_size(cmd, meta_sectors), display_size(cmd, meta_lv->size));
+			return 0;
+		}
+	}
+
+	/*
+	 * When not using a meta_dev, dm-integrity needs to tell us what the
+	 * usable size of the LV is, which is the dev size minus the integrity
+	 * overhead.  To find that, we need to do a special, temporary activation
+	 * of the new LV, specifying a dm dev size of 1, then check the dm dev
+	 * status field provided_data_sectors, which is the actual size of the
+	 * LV.  We need to include provided_data_sectors in the metadata for the
+	 * new LV, and use this as the dm dev size for normal LV activation.
+	 *
+	 * When using a meta_dev, the dm dev size is the size of the data
+	 * device.  The necessary size of the meta_dev for the given data
+	 * device needs to be estimated.
+	 */
+
+	if (meta_lv) {
+		struct wipe_params wipe;
+
+		if (!sync_local_dev_names(cmd)) {
+			log_error("Failed to sync local devices.");
+			return 0;
+		}
+
+		log_verbose("Zeroing LV for integrity metadata");
+
+		if (!lv_is_active(meta_lv)) {
+			if (!activate_lv(cmd, meta_lv)) {
+				log_error("Failed to activate LV %s to zero", display_lvname(meta_lv));
+				return 0;
+			}
+		}
+
+		memset(&wipe, 0, sizeof(wipe));
+		wipe.do_zero = 1;
+		wipe.zero_sectors = 8;
+
+		if (!wipe_lv(meta_lv, wipe)) {
+			log_error("Failed to zero LV for integrity metadata %s", display_lvname(meta_lv));
+			return 0;
+		}
+
+		if (!deactivate_lv(cmd, meta_lv)) {
+			log_error("Failed to deactivate LV %s after zero", display_lvname(meta_lv));
+			return 0;
+		}
+
+		seg->integrity_data_sectors = lv_size_sectors;
+		seg->integrity_meta_dev = meta_lv;
+		lv_set_hidden(meta_lv);
+		/* TODO: give meta_lv a suffix? e.g. _imeta */
+		ret = 1;
+	} else {
+		/* dm-integrity wants temp/fake size of 1 to report usable size */
+		seg->integrity_data_sectors = 1;
+
+		lv->status |= LV_TEMPORARY;
+		lv->status |= LV_NOSCAN;
+		lv->status |= LV_UNCOMMITTED;
+
+		log_debug("Activating temporary integrity LV to get data sectors.");
+
+		if (!activate_lv(cmd, lv)) {
+			log_error("Failed to activate temporary integrity.");
+			ret = 0;
+			goto out;
+		}
+
+		if (!_get_provided_data_sectors(lv, &seg->integrity_data_sectors)) {
+			log_error("Failed to get data sectors from dm-integrity");
+			ret = 0;
+		} else {
+			log_debug("Found integrity provided_data_sectors %llu", (unsigned long long)seg->integrity_data_sectors);
+			ret = 1;
+		}
+
+		if (!seg->integrity_data_sectors) {
+			log_error("LV size too small to include metadata.");
+			ret = 0;
+		}
+
+		lv->status |= LV_UNCOMMITTED;
+
+		if (!deactivate_lv(cmd, lv)) {
+			log_error("Failed to deactivate temporary integrity.");
+			ret = 0;
+		}
+
+		lv->status &= ~LV_UNCOMMITTED;
+		lv->status &= ~LV_NOSCAN;
+		lv->status &= ~LV_TEMPORARY;
+	}
+
+	log_debug("Write VG with integrity added to LV");
+
+	if (!vg_write(vg) || !vg_commit(vg))
+		ret = 0;
+ out:
+	return ret;
+}
+
+