1 files changed, 270 insertions, 0 deletions
diff --git a/lib/snapshot/snapshot.c b/lib/snapshot/snapshot.c
new file mode 100644
index 0000000..1a98d7e
--- /dev/null
+++ b/lib/snapshot/snapshot.c
@@ -0,0 +1,270 @@
+/*
+ * Copyright (C) 2003-2004 Sistina Software, Inc. All rights reserved.
+ * Copyright (C) 2004-2008 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "lib.h"
+#include "toolcontext.h"
+#include "metadata.h"
+#include "segtype.h"
+#include "text_export.h"
+#include "config.h"
+#include "activate.h"
+#include "str_list.h"
+#include "defaults.h"
+
+static const char *_snap_name(const struct lv_segment *seg)
+{
+	return seg->segtype->name;
+}
+
+static const char *_snap_target_name(const struct lv_segment *seg)
+{
+	if (seg->status & MERGING)
+		return "snapshot-merge";
+
+	return _snap_name(seg);
+}
+
+static int _snap_text_import(struct lv_segment *seg, const struct config_node *sn,
+			struct dm_hash_table *pv_hash __attribute__((unused)))
+{
+	uint32_t chunk_size;
+	const char *org_name, *cow_name;
+	struct logical_volume *org, *cow;
+	int old_suppress, merge = 0;
+
+	if (!get_config_uint32(sn, "chunk_size", &chunk_size)) {
+		log_error("Couldn't read chunk size for snapshot.");
+		return 0;
+	}
+
+	old_suppress = log_suppress(1);
+
+	if ((cow_name = find_config_str(sn, "merging_store", NULL))) {
+		if (find_config_str(sn, "cow_store", NULL)) {
+			log_suppress(old_suppress);
+			log_error("Both snapshot cow and merging storage were specified.");
+			return 0;
+		}
+		merge = 1;
+	}
+	else if (!(cow_name = find_config_str(sn, "cow_store", NULL))) {
+		log_suppress(old_suppress);
+		log_error("Snapshot cow storage not specified.");
+		return 0;
+	}
+
+	if (!(org_name = find_config_str(sn, "origin", NULL))) {
+		log_suppress(old_suppress);
+		log_error("Snapshot origin not specified.");
+		return 0;
+	}
+
+	log_suppress(old_suppress);
+
+	if (!(cow = find_lv(seg->lv->vg, cow_name))) {
+		log_error("Unknown logical volume specified for "
+			  "snapshot cow store.");
+		return 0;
+	}
+
+	if (!(org = find_lv(seg->lv->vg, org_name))) {
+		log_error("Unknown logical volume specified for "
+			  "snapshot origin.");
+		return 0;
+	}
+
+	init_snapshot_seg(seg, org, cow, chunk_size, merge);
+
+	return 1;
+}
+
+static int _snap_text_export(const struct lv_segment *seg, struct formatter *f)
+{
+	outf(f, "chunk_size = %u", seg->chunk_size);
+	outf(f, "origin = \"%s\"", seg->origin->name);
+	if (!(seg->status & MERGING))
+		outf(f, "cow_store = \"%s\"", seg->cow->name);
+	else
+		outf(f, "merging_store = \"%s\"", seg->cow->name);
+
+	return 1;
+}
+
+static int _snap_target_status_compatible(const char *type)
+{
+	return (strcmp(type, "snapshot-merge") == 0);
+}
+
+#ifdef DEVMAPPER_SUPPORT
+static int _snap_target_percent(void **target_state __attribute__((unused)),
+				percent_t *percent,
+				struct dm_pool *mem __attribute__((unused)),
+				struct cmd_context *cmd __attribute__((unused)),
+				struct lv_segment *seg __attribute__((unused)),
+				char *params, uint64_t *total_numerator,
+				uint64_t *total_denominator)
+{
+	uint64_t total_sectors, sectors_allocated, metadata_sectors;
+	int r;
+
+	/*
+	 * snapshot target's percent format:
+	 * <= 1.7.0: <sectors_allocated>/<total_sectors>
+	 * >= 1.8.0: <sectors_allocated>/<total_sectors> <metadata_sectors>
+	 */
+	r = sscanf(params, "%" PRIu64 "/%" PRIu64 " %" PRIu64,
+		   &sectors_allocated, &total_sectors, &metadata_sectors);
+	if (r == 2 || r == 3) {
+		*total_numerator += sectors_allocated;
+		*total_denominator += total_sectors;
+		if (r == 3 && sectors_allocated == metadata_sectors)
+			*percent = PERCENT_0;
+		else if (sectors_allocated == total_sectors)
+			*percent = PERCENT_100;
+		else
+			*percent = make_percent(*total_numerator, *total_denominator);
+	} else if (!strcmp(params, "Invalid") ||
+		   !strcmp(params, "Merge failed"))
+		*percent = PERCENT_INVALID;
+	else
+		return 0;
+
+	return 1;
+}
+
+static int _snap_target_present(struct cmd_context *cmd,
+				const struct lv_segment *seg,
+				unsigned *attributes __attribute__((unused)))
+{
+	static int _snap_checked = 0;
+	static int _snap_merge_checked = 0;
+	static int _snap_present = 0;
+	static int _snap_merge_present = 0;
+
+	if (!_snap_checked) {
+		_snap_present = target_present(cmd, "snapshot", 1) &&
+		    target_present(cmd, "snapshot-origin", 0);
+		_snap_checked = 1;
+	}
+
+	if (!_snap_merge_checked && seg && (seg->status & MERGING)) {
+		_snap_merge_present = target_present(cmd, "snapshot-merge", 0);
+		_snap_merge_checked = 1;
+		return _snap_present && _snap_merge_present;
+	}
+
+	return _snap_present;
+}
+
+#ifdef DMEVENTD
+
+static const char *_get_snapshot_dso_path(struct cmd_context *cmd)
+{
+	return get_monitor_dso_path(cmd, find_config_tree_str(cmd, "dmeventd/snapshot_library",
+							      DEFAULT_DMEVENTD_SNAPSHOT_LIB));
+}
+
+/* FIXME Cache this */
+static int _target_registered(struct lv_segment *seg, int *pending)
+{
+	return target_registered_with_dmeventd(seg->lv->vg->cmd, _get_snapshot_dso_path(seg->lv->vg->cmd),
+					       seg->cow, pending);
+}
+
+/* FIXME This gets run while suspended and performs banned operations. */
+static int _target_set_events(struct lv_segment *seg, int evmask, int set)
+{
+	/* FIXME Make timeout (10) configurable */
+	return target_register_events(seg->lv->vg->cmd, _get_snapshot_dso_path(seg->lv->vg->cmd),
+				      seg->cow, evmask, set, 10);
+}
+
+static int _target_register_events(struct lv_segment *seg,
+				   int events)
+{
+	return _target_set_events(seg, events, 1);
+}
+
+static int _target_unregister_events(struct lv_segment *seg,
+				     int events)
+{
+	return _target_set_events(seg, events, 0);
+}
+
+#endif /* DMEVENTD */
+#endif
+
+static int _snap_modules_needed(struct dm_pool *mem,
+				const struct lv_segment *seg __attribute__((unused)),
+				struct dm_list *modules)
+{
+	if (!str_list_add(mem, modules, "snapshot")) {
+		log_error("snapshot string list allocation failed");
+		return 0;
+	}
+
+	return 1;
+}
+
+static void _snap_destroy(struct segment_type *segtype)
+{
+	dm_free(segtype);
+}
+
+static struct segtype_handler _snapshot_ops = {
+	.name = _snap_name,
+	.target_name = _snap_target_name,
+	.text_import = _snap_text_import,
+	.text_export = _snap_text_export,
+	.target_status_compatible = _snap_target_status_compatible,
+#ifdef DEVMAPPER_SUPPORT
+	.target_percent = _snap_target_percent,
+	.target_present = _snap_target_present,
+#ifdef DMEVENTD
+	.target_monitored = _target_registered,
+	.target_monitor_events = _target_register_events,
+	.target_unmonitor_events = _target_unregister_events,
+#endif
+#endif
+	.modules_needed = _snap_modules_needed,
+	.destroy = _snap_destroy,
+};
+
+#ifdef SNAPSHOT_INTERNAL
+struct segment_type *init_snapshot_segtype(struct cmd_context *cmd)
+#else				/* Shared */
+struct segment_type *init_segtype(struct cmd_context *cmd);
+struct segment_type *init_segtype(struct cmd_context *cmd)
+#endif
+{
+	struct segment_type *segtype = dm_malloc(sizeof(*segtype));
+
+	if (!segtype)
+		return_NULL;
+
+	segtype->cmd = cmd;
+	segtype->ops = &_snapshot_ops;
+	segtype->name = "snapshot";
+	segtype->private = NULL;
+	segtype->flags = SEG_SNAPSHOT;
+
+#ifdef DMEVENTD
+	if (_get_snapshot_dso_path(cmd))
+		segtype->flags |= SEG_MONITORED;
+#endif
+	log_very_verbose("Initialised segtype: %s", segtype->name);
+
+	return segtype;
+}