mirror of
git://sourceware.org/git/lvm2.git
synced 2024-12-22 17:35:59 +03:00
239 lines
6.4 KiB
C
239 lines
6.4 KiB
C
/*
|
|
* Copyright (C) 2007-2015 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 "dmeventd_lvm.h"
|
|
#include "libdevmapper-event.h"
|
|
|
|
#include <sys/wait.h>
|
|
#include <stdarg.h>
|
|
|
|
/* 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
|
|
|
|
#define UMOUNT_COMMAND "/bin/umount"
|
|
|
|
struct dso_state {
|
|
struct dm_pool *mem;
|
|
int percent_check;
|
|
uint64_t known_size;
|
|
char cmd_lvextend[512];
|
|
};
|
|
|
|
DM_EVENT_LOG_FN("snap")
|
|
|
|
static int _run(const char *cmd, ...)
|
|
{
|
|
va_list ap;
|
|
int argc = 1; /* for argv[0], i.e. cmd */
|
|
int i = 0;
|
|
const char **argv;
|
|
pid_t pid = fork();
|
|
int status;
|
|
|
|
if (pid == 0) { /* child */
|
|
va_start(ap, cmd);
|
|
while (va_arg(ap, const char *))
|
|
++ argc;
|
|
va_end(ap);
|
|
|
|
/* + 1 for the terminating NULL */
|
|
argv = alloca(sizeof(const char *) * (argc + 1));
|
|
|
|
argv[0] = cmd;
|
|
va_start(ap, cmd);
|
|
while ((argv[++i] = va_arg(ap, const char *)));
|
|
va_end(ap);
|
|
|
|
execvp(cmd, (char **)argv);
|
|
log_sys_error("exec", cmd);
|
|
exit(127);
|
|
}
|
|
|
|
if (pid > 0) { /* parent */
|
|
if (waitpid(pid, &status, 0) != pid)
|
|
return 0; /* waitpid failed */
|
|
if (!WIFEXITED(status) || WEXITSTATUS(status))
|
|
return 0; /* the child failed */
|
|
}
|
|
|
|
if (pid < 0)
|
|
return 0; /* fork failed */
|
|
|
|
return 1; /* all good */
|
|
}
|
|
|
|
static int _extend(const char *cmd)
|
|
{
|
|
log_debug("Extending snapshot via %s.", cmd);
|
|
return dmeventd_lvm2_run_with_lock(cmd);
|
|
}
|
|
|
|
static void _umount(const char *device, int major, int minor)
|
|
{
|
|
FILE *mounts;
|
|
char buffer[4096];
|
|
char *words[3];
|
|
struct stat st;
|
|
const char procmounts[] = "/proc/mounts";
|
|
|
|
if (!(mounts = fopen(procmounts, "r"))) {
|
|
log_sys_error("fopen", procmounts);
|
|
log_error("Not umounting %s.", device);
|
|
return;
|
|
}
|
|
|
|
while (!feof(mounts)) {
|
|
/* read a line of /proc/mounts */
|
|
if (!fgets(buffer, sizeof(buffer), mounts))
|
|
break; /* eof, likely */
|
|
|
|
/* words[0] is the mount point and words[1] is the device path */
|
|
if (dm_split_words(buffer, 3, 0, words) < 2)
|
|
continue;
|
|
|
|
/* find the major/minor of the device */
|
|
if (stat(words[0], &st))
|
|
continue; /* can't stat, skip this one */
|
|
|
|
if (S_ISBLK(st.st_mode) &&
|
|
major(st.st_rdev) == major &&
|
|
minor(st.st_rdev) == minor) {
|
|
log_error("Unmounting invalid snapshot %s from %s.", device, words[1]);
|
|
if (!_run(UMOUNT_COMMAND, "-fl", words[1], NULL))
|
|
log_error("Failed to umount snapshot %s from %s: %s.",
|
|
device, words[1], strerror(errno));
|
|
}
|
|
}
|
|
|
|
if (fclose(mounts))
|
|
log_sys_error("close", procmounts);
|
|
}
|
|
|
|
void process_event(struct dm_task *dmt,
|
|
enum dm_event_mask event __attribute__((unused)),
|
|
void **user)
|
|
{
|
|
struct dso_state *state = *user;
|
|
void *next = NULL;
|
|
uint64_t start, length;
|
|
char *target_type = NULL;
|
|
char *params;
|
|
struct dm_status_snapshot *status = NULL;
|
|
const char *device = dm_task_get_name(dmt);
|
|
int percent;
|
|
|
|
/* No longer monitoring, waiting for remove */
|
|
if (!state->percent_check)
|
|
return;
|
|
|
|
dm_get_next_target(dmt, next, &start, &length, &target_type, ¶ms);
|
|
if (!target_type || strcmp(target_type, "snapshot")) {
|
|
log_error("Target %s is not snapshot.", target_type);
|
|
return;
|
|
}
|
|
|
|
if (!dm_get_status_snapshot(state->mem, params, &status))
|
|
return;
|
|
|
|
if (status->invalid || status->overflow) {
|
|
struct dm_info info;
|
|
log_error("Snapshot %s is lost.", device);
|
|
if (dm_task_get_info(dmt, &info)) {
|
|
_umount(device, info.major, info.minor);
|
|
goto_out;
|
|
} /* else; too bad, but this is best-effort thing... */
|
|
}
|
|
|
|
/* Snapshot size had changed. Clear the threshold. */
|
|
if (state->known_size != status->total_sectors) {
|
|
state->percent_check = CHECK_MINIMUM;
|
|
state->known_size = status->total_sectors;
|
|
}
|
|
|
|
/*
|
|
* 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->overflow || !status->total_sectors) {
|
|
log_error("Snapshot %s changed state to: %s.", device, params);
|
|
state->percent_check = 0;
|
|
goto out;
|
|
}
|
|
|
|
percent = (int) (100 * status->used_sectors / status->total_sectors);
|
|
if (percent >= state->percent_check) {
|
|
/* Usage has raised more than CHECK_STEP since the last
|
|
time. Run actions. */
|
|
state->percent_check = (percent / CHECK_STEP) * CHECK_STEP + CHECK_STEP;
|
|
|
|
if (percent >= WARNING_THRESH) /* Print a warning to syslog. */
|
|
log_warn("WARNING: Snapshot %s is now %i%% full.", device, percent);
|
|
|
|
/* Try to extend the snapshot, in accord with user-set policies */
|
|
if (!_extend(state->cmd_lvextend))
|
|
log_error("Failed to extend snapshot %s.", device);
|
|
}
|
|
out:
|
|
dm_pool_free(state->mem, status);
|
|
}
|
|
|
|
int register_device(const char *device,
|
|
const char *uuid __attribute__((unused)),
|
|
int major __attribute__((unused)),
|
|
int minor __attribute__((unused)),
|
|
void **user)
|
|
{
|
|
struct dso_state *state;
|
|
|
|
if (!dmeventd_lvm2_init_with_pool("snapshot_state", state))
|
|
goto_bad;
|
|
|
|
if (!dmeventd_lvm2_command(state->mem, state->cmd_lvextend,
|
|
sizeof(state->cmd_lvextend),
|
|
"lvextend --use-policies", device)) {
|
|
dmeventd_lvm2_exit_with_pool(state);
|
|
goto_bad;
|
|
}
|
|
|
|
state->percent_check = CHECK_MINIMUM;
|
|
*user = state;
|
|
|
|
log_info("Monitoring snapshot %s.", device);
|
|
|
|
return 1;
|
|
bad:
|
|
log_error("Failed to monitor snapshot %s.", device);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int unregister_device(const char *device,
|
|
const char *uuid __attribute__((unused)),
|
|
int major __attribute__((unused)),
|
|
int minor __attribute__((unused)),
|
|
void **user)
|
|
{
|
|
struct dso_state *state = *user;
|
|
|
|
dmeventd_lvm2_exit_with_pool(state);
|
|
log_info("No longer monitoring snapshot %s.", device);
|
|
|
|
return 1;
|
|
}
|