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lvm2/lib/snapshot/snapshot.c
2006-10-18 18:01:53 +00:00

183 lines
4.4 KiB
C

/*
* Copyright (C) 2003-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004 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 General Public License v.2.
*
* You should have received a copy of the GNU 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"
static const char *_snap_name(const struct lv_segment *seg)
{
return seg->segtype->name;
}
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;
seg->lv->status |= SNAPSHOT;
if (!get_config_uint32(sn, "chunk_size", &chunk_size)) {
log_error("Couldn't read chunk size for snapshot.");
return 0;
}
log_suppress(1);
if (!(cow_name = find_config_str(sn, "cow_store", NULL))) {
log_suppress(0);
log_error("Snapshot cow storage not specified.");
return 0;
}
if (!(org_name = find_config_str(sn, "origin", NULL))) {
log_suppress(0);
log_error("Snapshot origin not specified.");
return 0;
}
log_suppress(0);
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;
}
if (!vg_add_snapshot(seg->lv->vg->fid, seg->lv->name, org, cow,
&seg->lv->lvid, seg->len, chunk_size)) {
stack;
return 0;
}
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);
outf(f, "cow_store = \"%s\"", seg->cow->name);
return 1;
}
#ifdef DEVMAPPER_SUPPORT
static int _snap_target_percent(void **target_state __attribute((unused)),
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, float *percent)
{
float percent2;
uint64_t numerator, denominator;
if (index(params, '/')) {
if (sscanf(params, "%" PRIu64 "/%" PRIu64,
&numerator, &denominator) == 2) {
*total_numerator += numerator;
*total_denominator += denominator;
}
} else if (sscanf(params, "%f", &percent2) == 1) {
*percent += percent2;
*percent /= 2;
}
return 1;
}
static int _snap_target_present(const struct lv_segment *seg __attribute((unused)))
{
static int _snap_checked = 0;
static int _snap_present = 0;
if (!_snap_checked)
_snap_present = target_present("snapshot", 1) &&
target_present("snapshot-origin", 0);
_snap_checked = 1;
return _snap_present;
}
#endif
static int _snap_modules_needed(struct dm_pool *mem,
const struct lv_segment *seg,
struct list *modules)
{
if (!str_list_add(mem, modules, "snapshot")) {
log_error("snapshot string list allocation failed");
return 0;
}
return 1;
}
static void _snap_destroy(const struct segment_type *segtype)
{
dm_free((void *)segtype);
}
static struct segtype_handler _snapshot_ops = {
.name = _snap_name,
.text_import = _snap_text_import,
.text_export = _snap_text_export,
#ifdef DEVMAPPER_SUPPORT
.target_percent = _snap_target_percent,
.target_present = _snap_target_present,
#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) {
stack;
return NULL;
}
segtype->cmd = cmd;
segtype->ops = &_snapshot_ops;
segtype->name = "snapshot";
segtype->private = NULL;
segtype->flags = SEG_SNAPSHOT;
log_very_verbose("Initialised segtype: %s", segtype->name);
return segtype;
}