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[netbsd-mini2440.git] / external / gpl2 / lvm2 / dist / lib / format1 / import-extents.c

/*      $NetBSD$        */

/*
 * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
 * Copyright (C) 2004-2007 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 "metadata.h"
#include "disk-rep.h"
#include "lv_alloc.h"
#include "display.h"
#include "segtype.h"

/*
 * After much thought I have decided it is easier,
 * and probably no less efficient, to convert the
 * pe->le map to a full le->pe map, and then
 * process this to get the segments form that
 * we're after.  Any code which goes directly from
 * the pe->le map to segments would be gladly
 * accepted, if it is less complicated than this
 * file.
 */
struct pe_specifier {
        struct physical_volume *pv;
        uint32_t pe;
};

struct lv_map {
        struct logical_volume *lv;
        uint32_t stripes;
        uint32_t stripe_size;
        struct pe_specifier *map;
};

static struct dm_hash_table *_create_lv_maps(struct dm_pool *mem,
                                          struct volume_group *vg)
{
        struct dm_hash_table *maps = dm_hash_create(32);
        struct lv_list *ll;
        struct lv_map *lvm;

        if (!maps) {
                log_error("Unable to create hash table for holding "
                          "extent maps.");
                return NULL;
        }

        dm_list_iterate_items(ll, &vg->lvs) {
                if (ll->lv->status & SNAPSHOT)
                        continue;

                if (!(lvm = dm_pool_alloc(mem, sizeof(*lvm))))
                        goto_bad;

                lvm->lv = ll->lv;
                if (!(lvm->map = dm_pool_zalloc(mem, sizeof(*lvm->map)
                                             * ll->lv->le_count)))
                        goto_bad;

                if (!dm_hash_insert(maps, ll->lv->name, lvm))
                        goto_bad;
        }

        return maps;

      bad:
        dm_hash_destroy(maps);
        return NULL;
}

static int _fill_lv_array(struct lv_map **lvs,
                          struct dm_hash_table *maps, struct disk_list *dl)
{
        struct lvd_list *ll;
        struct lv_map *lvm;

        memset(lvs, 0, sizeof(*lvs) * MAX_LV);

        dm_list_iterate_items(ll, &dl->lvds) {
                if (!(lvm = dm_hash_lookup(maps, strrchr((char *)ll->lvd.lv_name, '/')
                                        + 1))) {
                        log_error("Physical volume (%s) contains an "
                                  "unknown logical volume (%s).",
                                dev_name(dl->dev), ll->lvd.lv_name);
                        return 0;
                }

                lvm->stripes = ll->lvd.lv_stripes;
                lvm->stripe_size = ll->lvd.lv_stripesize;

                lvs[ll->lvd.lv_number] = lvm;
        }

        return 1;
}

static int _fill_maps(struct dm_hash_table *maps, struct volume_group *vg,
                      struct dm_list *pvds)
{
        struct disk_list *dl;
        struct physical_volume *pv;
        struct lv_map *lvms[MAX_LV], *lvm;
        struct pe_disk *e;
        uint32_t i, lv_num, le;

        dm_list_iterate_items(dl, pvds) {
                pv = find_pv(vg, dl->dev);
                e = dl->extents;

                /* build an array of lv's for this pv */
                if (!_fill_lv_array(lvms, maps, dl))
                        return_0;

                for (i = 0; i < dl->pvd.pe_total; i++) {
                        lv_num = e[i].lv_num;

                        if (lv_num == UNMAPPED_EXTENT)
                                continue;

                        else {
                                lv_num--;
                                lvm = lvms[lv_num];

                                if (!lvm) {
                                        log_error("Invalid LV in extent map "
                                                  "(PV %s, PE %" PRIu32
                                                  ", LV %" PRIu32
                                                  ", LE %" PRIu32 ")",
                                                  dev_name(pv->dev), i,
                                                  lv_num, e[i].le_num);
                                        return 0;
                                }

                                le = e[i].le_num;

                                if (le >= lvm->lv->le_count) {
                                        log_error("logical extent number "
                                                  "out of bounds");
                                        return 0;
                                }

                                if (lvm->map[le].pv) {
                                        log_error("logical extent (%u) "
                                                  "already mapped.", le);
                                        return 0;
                                }

                                lvm->map[le].pv = pv;
                                lvm->map[le].pe = i;
                        }
                }
        }

        return 1;
}

static int _check_single_map(struct lv_map *lvm)
{
        uint32_t i;

        for (i = 0; i < lvm->lv->le_count; i++) {
                if (!lvm->map[i].pv) {
                        log_error("Logical volume (%s) contains an incomplete "
                                  "mapping table.", lvm->lv->name);
                        return 0;
                }
        }

        return 1;
}

static int _check_maps_are_complete(struct dm_hash_table *maps)
{
        struct dm_hash_node *n;
        struct lv_map *lvm;

        for (n = dm_hash_get_first(maps); n; n = dm_hash_get_next(maps, n)) {
                lvm = (struct lv_map *) dm_hash_get_data(maps, n);

                if (!_check_single_map(lvm))
                        return_0;
        }
        return 1;
}

static uint32_t _area_length(struct lv_map *lvm, uint32_t le)
{
        uint32_t len = 0;

        do
                len++;
        while ((lvm->map[le + len].pv == lvm->map[le].pv) &&
                 (lvm->map[le].pv &&
                  lvm->map[le + len].pe == lvm->map[le].pe + len));

        return len;
}

static int _read_linear(struct cmd_context *cmd, struct lv_map *lvm)
{
        uint32_t le = 0, len;
        struct lv_segment *seg;
        struct segment_type *segtype;

        if (!(segtype = get_segtype_from_string(cmd, "striped")))
                return_0;

        while (le < lvm->lv->le_count) {
                len = _area_length(lvm, le);

                if (!(seg = alloc_lv_segment(cmd->mem, segtype, lvm->lv, le,
                                             len, 0, 0, NULL, 1, len, 0, 0, 0))) {
                        log_error("Failed to allocate linear segment.");
                        return 0;
                }

                if (!set_lv_segment_area_pv(seg, 0, lvm->map[le].pv,
                                            lvm->map[le].pe))
                        return_0;

                dm_list_add(&lvm->lv->segments, &seg->list);

                le += seg->len;
        }

        return 1;
}

static int _check_stripe(struct lv_map *lvm, uint32_t area_count,
                         uint32_t area_len, uint32_t base_le,
                         uint32_t total_area_len)
{
        uint32_t st;

        /*
         * Is the next physical extent in every stripe adjacent to the last?
         */
        for (st = 0; st < area_count; st++)
                if ((lvm->map[base_le + st * total_area_len + area_len].pv !=
                     lvm->map[base_le + st * total_area_len].pv) ||
                    (lvm->map[base_le + st * total_area_len].pv &&
                     lvm->map[base_le + st * total_area_len + area_len].pe !=
                     lvm->map[base_le + st * total_area_len].pe + area_len))
                        return 0;

        return 1;
}

static int _read_stripes(struct cmd_context *cmd, struct lv_map *lvm)
{
        uint32_t st, first_area_le = 0, total_area_len;
        uint32_t area_len;
        struct lv_segment *seg;
        struct segment_type *segtype;

        /*
         * Work out overall striped length
         */
        if (lvm->lv->le_count % lvm->stripes) {
                log_error("Number of stripes (%u) incompatible "
                          "with logical extent count (%u) for %s",
                          lvm->stripes, lvm->lv->le_count, lvm->lv->name);
        }

        total_area_len = lvm->lv->le_count / lvm->stripes;

        if (!(segtype = get_segtype_from_string(cmd, "striped")))
                return_0;

        while (first_area_le < total_area_len) {
                area_len = 1;

                /*
                 * Find how many extents are contiguous in all stripes
                 * and so can form part of this segment
                 */
                while (_check_stripe(lvm, lvm->stripes,
                                     area_len, first_area_le, total_area_len))
                        area_len++;

                if (!(seg = alloc_lv_segment(cmd->mem, segtype, lvm->lv,
                                             lvm->stripes * first_area_le,
                                             lvm->stripes * area_len,
                                             0, lvm->stripe_size, NULL,
                                             lvm->stripes,
                                             area_len, 0, 0, 0))) {
                        log_error("Failed to allocate striped segment.");
                        return 0;
                }

                /*
                 * Set up start positions of each stripe in this segment
                 */
                for (st = 0; st < seg->area_count; st++)
                        if (!set_lv_segment_area_pv(seg, st,
                              lvm->map[first_area_le + st * total_area_len].pv,
                              lvm->map[first_area_le + st * total_area_len].pe))
                                return_0;

                dm_list_add(&lvm->lv->segments, &seg->list);

                first_area_le += area_len;
        }

        return 1;
}

static int _build_segments(struct cmd_context *cmd, struct lv_map *lvm)
{
        return (lvm->stripes > 1 ? _read_stripes(cmd, lvm) :
                _read_linear(cmd, lvm));
}

static int _build_all_segments(struct cmd_context *cmd, struct dm_hash_table *maps)
{
        struct dm_hash_node *n;
        struct lv_map *lvm;

        for (n = dm_hash_get_first(maps); n; n = dm_hash_get_next(maps, n)) {
                lvm = (struct lv_map *) dm_hash_get_data(maps, n);
                if (!_build_segments(cmd, lvm))
                        return_0;
        }

        return 1;
}

int import_extents(struct cmd_context *cmd, struct volume_group *vg,
                   struct dm_list *pvds)
{
        int r = 0;
        struct dm_pool *scratch = dm_pool_create("lvm1 import_extents", 10 * 1024);
        struct dm_hash_table *maps;

        if (!scratch)
                return_0;

        if (!(maps = _create_lv_maps(scratch, vg))) {
                log_error("Couldn't allocate logical volume maps.");
                goto out;
        }

        if (!_fill_maps(maps, vg, pvds)) {
                log_error("Couldn't fill logical volume maps.");
                goto out;
        }

        if (!_check_maps_are_complete(maps) && !(vg->status & PARTIAL_VG))
                goto_out;

        if (!_build_all_segments(cmd, maps)) {
                log_error("Couldn't build extent segments.");
                goto out;
        }
        r = 1;

      out:
        if (maps)
                dm_hash_destroy(maps);
        dm_pool_destroy(scratch);
        return r;
}