lvm2/lib/format_text/import.c

/*
 * Copyright (C) 2001 Sistina Software (UK) Limited.
 *
 * This file is released under the LGPL.
 */

#include "metadata.h"
#include "import-export.h"
#include "pool.h"
#include "log.h"
#include "uuid.h"
#include "hash.h"


typedef int (*section_fn)(struct pool *mem,
			  struct volume_group *vg, struct config_node *pvn,
			  struct config_node *vgn, struct hash_table *pv_hash);

#define _read_int32(root, path, result) \
	get_config_uint32(root, path, '/', result)

#define _read_int64(root, path, result) \
	get_config_uint64(root, path, '/', result)

static int _read_id(struct id *id, struct config_node *cn, const char *path)
{
	struct config_value *cv;

	if (!(cn = find_config_node(cn, path, '/'))) {
		log_err("Couldn't find uuid.");
		return 0;
	}

	cv = cn->v;
	if (!cv || !cv->v.str) {
		log_err("uuid must be a string.");
		return 0;
	}

	if (!id_read_format(id, cv->v.str)) {
		log_err("Invalid uuid.");
		return 0;
	}

	return 1;
}

static int _read_pv(struct pool *mem,
		    struct volume_group *vg, struct config_node *pvn,
		    struct config_node *vgn,
		    struct hash_table *pv_hash)
{
	struct physical_volume *pv;
	struct pv_list *pvl;
	struct config_node *cn;

	if (!(pvl = pool_zalloc(mem, sizeof(*pvl)))) {
		stack;
		return 0;
	}

	pv = &pvl->pv;

	if (!_read_id(&pv->id, vgn, "id")) {
		log_err("Couldn't read uuid for volume group.");
		return 0;
	}

	/*
	 * FIXME: need label/vgcache code to convert the uuid
	 * into a device.
	 */

	if (!(pv->vg_name = pool_strdup(mem, vg->name))) {
		stack;
		return 0;
	}

	if (!(cn = find_config_node(vgn, "status", '/'))) {
		log_err("Couldn't find status flags for physical volume.");
		return 0;
	}

	if (!(read_flags(&pv->status, PV_FLAGS, cn->v))) {
		log_err("Couldn't read status flags for physical volume.");
		return 0;
	}

	if (!_read_int64(pvn, "pe_start", &pv->pe_start)) {
		log_err("Couldn't read extent size for volume group.");
		return 0;
	}

	if (!_read_int32(pvn, "pe_count", &pv->pe_count)) {
		log_err("Couldn't find extent count (pe_count) for "
			"physical volume.");
		return 0;
	}

	/* adjust the volume group. */
	vg->extent_count += pv->pe_count;
	vg->free_count += pv->pe_count;

	pv->size = pv->pe_size * (uint64_t) pv->pe_count;
	pv->pe_allocated = 0;

	list_add(&vg->pvs, &pvl->list);

	/*
	 * Add the pv to the pv hash for quick lookup when we read
	 * the lv segments.
	 */
	if (!hash_insert(pv_hash, pvn->key, pv)) {
		stack;
		return 0;
	}

	return 1;
}

static void _insert_segment(struct logical_volume *lv,
			    struct stripe_segment *seg)
{
	struct list *segh;
	struct stripe_segment *comp;

	list_iterate (segh, &lv->segments) {
		comp = list_item(segh, struct stripe_segment);

		if (comp->le > seg->le) {
			list_add(&comp->list, &seg->list);
			return;
		}
	}

	list_add(&lv->segments, &seg->list);
}

static int _read_segment(struct pool *mem, struct volume_group *vg,
			 struct logical_volume *lv, struct config_node *sn,
			 struct hash_table *pv_hash)
{
	int s;
	struct stripe_segment *seg;
	struct config_node *cn;
	struct config_value *cv;

	if (!(seg = pool_zalloc(mem, sizeof(*seg)))) {
		stack;
		return 0;
	}

	if (!_read_int32(sn, "start_extent", &seg->le)) {
		log_err("Couldn't read 'start_extent' for segment '%s'.",
			sn->key);
		return 0;
	}

	if (!_read_int32(sn, "extent_count", &seg->len)) {
		log_err("Couldn't read 'extent_count' for segment '%s'.",
			sn->key);
		return 0;
	}

	if (!_read_int32(sn, "stripes", &seg->stripes)) {
		log_err("Couldn't read 'stripes' for segment '%s'.",
			sn->key);
		return 0;
	}

	if (seg->stripes == 0) {
		log_err("Zero stripes is *not* allowed for segment '%s'.",
			sn->key);
		return 0;
	}

	if ((seg->stripes != 1) &&
	    !_read_int32(sn, "stripe_size", &seg->stripe_size)) {
		log_err("Couldn't read 'stripe_size' for segment '%s'.",
			sn->key);
		return 0;
	}

	if (!(cn = find_config_node(sn, "areas", '/'))) {
		log_err("Couldn't find 'areas' array for segment '%s'.",
			sn->key);
		return 0;
	}

	/*
	 * Read the stripes from the 'areas' array.
	 * FIXME: we could move this to a separate function.
	 */
	for (cv = cn->v, s = 0; cv && s < seg->stripes; s++, cv = cv->next) {

		/* first we read the pv */
		const char *bad = "Badly formed areas array for segment '%s'.";
		struct physical_volume *pv;
		uint32_t allocated;

		if (cv->type != CFG_STRING) {
			log_err(bad, sn->key);
			return 0;
		}

		if (!(pv = hash_lookup(pv_hash, cv->v.str))) {
			log_err("Couldn't find physical volume (%s) for "
				"segment '%s'.",
				cn->v->v.str ? cn->v->v.str : "NULL", sn->key);
				return 0;
		}

		seg->area[s].pv = pv;

		if (!(cv = cv->next)) {
			log_err(bad, sn->key);
			return 0;
		}

		if (cv->type != CFG_INT) {
			log_err(bad, sn->key);
			return 0;
		}

		seg->area[s].pe = cv->v.i;

		/*
		 * Adjust the extent counts in the pv and vg.
		 */
		allocated = seg->len / seg->stripes;
		pv->pe_allocated += allocated;
		vg->free_count -= allocated;
	}

	/*
	 * Check we read the correct number of stripes.
	 */
	if (cv || (s < seg->stripes)) {
		log_err("Incorrect number of stripes in 'area' array "
			"for segment '%s'.", sn->key);
		return 0;
	}

	/*
	 * Insert into correct part of segment list.
	 */
	_insert_segment(lv, seg);
	return 1;
}

static int _read_segments(struct pool *mem, struct volume_group *vg,
			  struct logical_volume *lv, struct config_node *lvn,
			  struct hash_table *pv_hash)
{
	struct config_node *sn;
	int count = 0, seg_count;

	for (sn = lvn->child; sn; sn = sn->sib) {

		/*
		 * All sub-sections are assumed to be segments.
		 */
		if (sn->v) {
			if (!_read_segment(mem, vg, lv, sn, pv_hash)) {
				stack;
				return 0;
			}

			count++;
		}
	}

	if (!_read_int32(lvn, "segment_count", &seg_count)) {
		log_err("Couldn't read segment count for logical volume.");
		return 0;
	}

	if (seg_count != count) {
		log_err("segment_count and actual number of segments "
			"disagree.");
		return 0;
	}

	/*
	 * Check there are no gaps or overlaps in the lv.
	 */
	if (!lv_check_segments(lv)) {
		stack;
		return 0;
	}

	/*
	 * Merge segments in case someones been editing things by hand.
	 */
	if (!lv_merge_segments(lv)) {
		stack;
		return 0;
	}

	return 1;
}

static int _read_lv(struct pool *mem,
		    struct volume_group *vg, struct config_node *lvn,
		    struct config_node *vgn, struct hash_table *pv_hash)
{
	struct logical_volume *lv;
	struct lv_list *lvl;
	struct config_node *cn;

	if (!(lvl = pool_zalloc(mem, sizeof(*lvl)))) {
		stack;
		return 0;
	}

	lv = &lvl->lv;

	if (!(lv->name = pool_strdup(mem, lvn->key))) {
		stack;
		return 0;
	}

	lv->vg = vg;

	if (!(cn = find_config_node(lvn, "status", '/'))) {
		log_err("Couldn't find status flags for logical volume.");
		return 0;
	}

	if (!(read_flags(&lv->status, LV_FLAGS, cn->v))) {
		log_err("Couldn't read status flags for logical volume.");
		return 0;
	}

	if (!_read_int32(lvn, "read_ahead", &lv->read_ahead)) {
		log_err("Couldn't read 'read_ahead' value for "
			"logical volume.");
		return 0;
	}

	list_init(&lv->segments);
	if (!_read_segments(mem, vg, lv, lvn, pv_hash)) {
		stack;
		return 0;
	}

	list_add(&vg->lvs, &lvl->list);

	return 1;
}

static int _read_sections(const char *section, section_fn fn,
			  struct pool *mem,
			  struct volume_group *vg, struct config_node *vgn,
			  struct hash_table *pv_hash)
{
	struct config_node *n;

	if (!(n = find_config_node(vgn, section, '/'))) {
		log_err("Couldn't find section '%s'.", section);
		return 0;
	}

	for (n = n->child; n; n = n->sib) {
		if (!fn(mem, vg, vgn, n, pv_hash)) {
			stack;
			return 0;
		}
	}

	return 1;
}

static struct volume_group *_read_vg(struct pool *mem, struct config_file *cf)
{
	struct config_node *vgn = cf->root, *cn;
	struct volume_group *vg;
	struct hash_table *pv_hash = NULL;

	if (!vgn) {
		log_err("Couldn't not find volume group.");
		return NULL;
	}

	if (!(vgn = find_config_node(cf->root, "volume_group", '/'))) {
		log_err("Couldn't find volume_group section.");
		return NULL;
	}

	if (!(vg = pool_zalloc(mem, sizeof(*vg)))) {
		stack;
		return NULL;
	}

	if (!_read_id(&vg->id, vgn, "id")) {
		log_err("Couldn't read uuid for volume group.");
		goto bad;
	}

	if (!(vg->name = pool_strdup(mem, vgn->key))) {
		stack;
		goto bad;
	}

	if (!(cn = find_config_node(vgn, "status", '/'))) {
		log_err("Couldn't find status flags for volume group.");
		goto bad;
	}

	if (!(read_flags(&vg->status, VG_FLAGS, cn->v))) {
		log_err("Couldn't read status flags for volume group.");
		goto bad;
	}

	if (!_read_int32(vgn, "extent_size", &vg->extent_size)) {
		log_err("Couldn't read extent size for volume group.");
		goto bad;
	}

	/*
	 * 'extent_count' and 'free_count' get filled in
	 * implicitly when reading in the pv's and lv's.
	 */

	if (!_read_int32(vgn, "max_lv", &vg->max_lv)) {
		log_err("Couldn't read 'max_lv' for volume group.");
		goto bad;
	}

	if (!_read_int32(vgn, "max_pv", &vg->max_pv)) {
		log_err("Couldn't read 'max_pv' for volume group.");
		goto bad;
	}

	/*
	 * The pv hash memoises the pv section names -> pv
	 * structures.
	 */
	if (!(pv_hash = hash_create(32))) {
		log_err("Couldn't create hash table.");
		goto bad;
	}

	list_init(&vg->pvs);
	if (!_read_sections("physical_volumes", _read_pv, mem, vg,
			    vgn, pv_hash)) {
		log_err("Couldn't read all physical volumes for volume "
			"group.");
		goto bad;
	}

	list_init(&vg->lvs);
	if (!_read_sections("logical_volumes", _read_lv, mem, vg,
			    vgn, pv_hash)) {
		log_err("Couldn't read all logical volumes for volume "
			"group.");
		goto bad;
	}

	hash_destroy(pv_hash);

	/*
	 * Finished.
	 */
	return vg;

 bad:
	if (pv_hash)
		hash_destroy(pv_hash);

	pool_free(mem, vg);
	return NULL;
}

struct volume_group *text_vg_import(struct cmd_context *cmd,
				    const char *file)
{
	struct volume_group *vg = NULL;
	struct config_file *cf;

	if (!(cf = create_config_file())) {
		stack;
		goto out;
	}

	if (!read_config(cf, file)) {
		log_err("Couldn't read volume group file.");
		goto out;
	}

	if (!(vg = _read_vg(cmd->mem, cf)))
		stack;

 out:
	destroy_config_file(cf);
	return vg;
}