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/*
* Copyright (C) 2007-2010 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 "lvm2cmd.h"
#include "errors.h"
#include "libdevmapper-event.h"
#include "dmeventd_lvm.h"
#include "lvm-string.h"
#include <syslog.h> /* FIXME Replace syslog with multilog */
/* FIXME Missing openlog? */
/* First warning when snapshot is 80% full. */
#define WARNING_THRESH 80
/* Run a check every 5%. */
#define CHECK_STEP 5
/* Do not bother checking snapshots less than 50% full. */
#define CHECK_MINIMUM 50
struct snap_status {
int invalid;
int used;
int max;
};
/* FIXME possibly reconcile this with target_percent when we gain
access to regular LVM library here. */
static void _parse_snapshot_params(char *params, struct snap_status *status)
{
char *p;
/*
* xx/xx -- fractions used/max
* Invalid -- snapshot invalidated
* Unknown -- status unknown
*/
status->used = status->max = 0;
if (!strncmp(params, "Invalid", 7)) {
status->invalid = 1;
return;
}
/*
* When we return without setting non-zero max, the parent is
* responsible for reporting errors.
*/
if (!strncmp(params, "Unknown", 7))
return;
if (!(p = strstr(params, "/")))
return;
*p = '\0';
p++;
status->used = atoi(params);
status->max = atoi(p);
}
static int _extend(const char *device)
{
char *vg = NULL, *lv = NULL, *layer = NULL;
char cmd_str[1024];
int r = 0;
if (!dm_split_lvm_name(dmeventd_lvm2_pool(), device, &vg, &lv, &layer)) {
syslog(LOG_ERR, "Unable to determine VG name from %s.", device);
return 0;
}
if (sizeof(cmd_str) <= snprintf(cmd_str, sizeof(cmd_str),
"lvextend --use-policies %s/%s", vg, lv)) {
syslog(LOG_ERR, "Unable to form LVM command: Device name too long.");
return 0;
}
r = dmeventd_lvm2_run(cmd_str);
syslog(LOG_INFO, "Extension of snapshot %s/%s %s.", vg, lv,
(r == ECMD_PROCESSED) ? "finished successfully" : "failed");
return r == ECMD_PROCESSED;
}
void process_event(struct dm_task *dmt,
enum dm_event_mask event __attribute__((unused)),
void **private)
{
void *next = NULL;
uint64_t start, length;
char *target_type = NULL;
char *params;
struct snap_status status = { 0 };
const char *device = dm_task_get_name(dmt);
int percent, *percent_check = (int*)private;
/* No longer monitoring, waiting for remove */
if (!*percent_check)
return;
dmeventd_lvm2_lock();
dm_get_next_target(dmt, next, &start, &length, &target_type, ¶ms);
if (!target_type)
goto out;
_parse_snapshot_params(params, &status);
/*
* If the snapshot has been invalidated or we failed to parse
* the status string. Report the full status string to syslog.
*/
if (status.invalid || !status.max) {
syslog(LOG_ERR, "Snapshot %s changed state to: %s\n", device, params);
*percent_check = 0;
goto out;
}
percent = 100 * status.used / status.max;
if (percent >= *percent_check) {
/* Usage has raised more than CHECK_STEP since the last
time. Run actions. */
*percent_check = (percent / CHECK_STEP) * CHECK_STEP + CHECK_STEP;
if (percent >= WARNING_THRESH) /* Print a warning to syslog. */
syslog(LOG_WARNING, "Snapshot %s is now %i%% full.\n", device, percent);
/* Try to extend the snapshot, in accord with user-set policies */
if (!_extend(device))
syslog(LOG_ERR, "Failed to extend snapshot %s.", device);
}
out:
dmeventd_lvm2_unlock();
}
int register_device(const char *device,
const char *uuid __attribute__((unused)),
int major __attribute__((unused)),
int minor __attribute__((unused)),
void **private)
{
int *percent_check = (int*)private;
int r = dmeventd_lvm2_init();
*percent_check = CHECK_MINIMUM;
syslog(LOG_INFO, "Monitoring snapshot %s\n", device);
return r;
}
int unregister_device(const char *device,
const char *uuid __attribute__((unused)),
int major __attribute__((unused)),
int minor __attribute__((unused)),
void **unused __attribute__((unused)))
{
syslog(LOG_INFO, "No longer monitoring snapshot %s\n",
device);
dmeventd_lvm2_exit();
return 1;
}
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