1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-22 17:35:59 +03:00
lvm2/daemons/clvmd/system-lv.c
Patrick Caulfield 5c7fc7c4f7 You can now build clvmd with cman & gulm support in the same binary.
./configure --with-clvmd
wil do this by default. Or you can choose which you want with
./configure --with-clvmd=gulm    or
./configure --with-clvmd=cman

When clvmd with both included is run, it will automatically detect the cluster
manager in use.
2005-01-13 13:24:02 +00:00

372 lines
8.5 KiB
C

/*
* Copyright (C) 2002-2004 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
*/
/* Routines dealing with the System LV */
#include <pthread.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/utsname.h>
#include <syslog.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include <mntent.h>
#include "libdlm.h"
#include "log.h"
#include "list.h"
#include "locking.h"
#include "system-lv.h"
#include "clvm.h"
#include "clvmd-comms.h"
#include "clvmd.h"
#ifdef HAVE_CCS
#include "ccs.h"
#endif
#define SYSTEM_LV_FILESYSTEM "ext2"
#define SYSTEM_LV_MOUNTPOINT "/tmp/.clvmd-XXXXXX"
extern char *config_filename(void);
static char system_lv_name[PATH_MAX] = { '\0' };
static char mount_point[PATH_MAX] = { '\0' };
static int mounted = 0;
static int mounted_rw = 0;
static int lockid;
static const char *lock_name = "CLVM_SYSTEM_LV";
/* Look in /proc/mounts or (as a last resort) /etc/mtab to
see if the system-lv is mounted. If it is mounted and we
think it's not then abort because we don't have the right
lock status and we don't know what other processes are doing with it.
Returns 1 for mounted, 0 for not mounted so it matches the condition
of the "mounted" static variable above.
*/
static int is_really_mounted(void)
{
FILE *mountfile;
struct mntent *ment;
mountfile = setmntent("/proc/mounts", "r");
if (!mountfile) {
mountfile = setmntent("/etc/mtab", "r");
if (!mountfile) {
log_error("Unable to open /proc/mounts or /etc/mtab");
return -1;
}
}
/* Look for system LV name in the file */
do {
ment = getmntent(mountfile);
if (ment) {
if (strcmp(ment->mnt_fsname, system_lv_name) == 0) {
endmntent(mountfile);
return 1;
}
}
}
while (ment);
endmntent(mountfile);
return 0;
}
/* Get the system LV name from the config file */
static int find_system_lv(void)
{
if (system_lv_name[0] == '\0') {
#ifdef HAVE_CCS
int error;
ccs_node_t *ctree;
/* Read the cluster config file */
/* Open the config file */
error = open_ccs_file(&ctree, "clvm.ccs");
if (error) {
perror("reading config file");
return -1;
}
strcpy(system_lv_name, find_ccs_str(ctree,
"cluster/systemlv", '/',
"/dev/vg/system_lv"));
/* Finished with config file */
close_ccs_file(ctree);
#else
if (getenv("CLVMD_SYSTEM_LV"))
strcpy(system_lv_name, getenv("CLVMD_SYSTEM_LV"));
else
return -1;
#endif
}
/* See if it has been mounted outside our control */
if (is_really_mounted() != mounted) {
log_error
("The system LV state has been mounted/umounted outside the control of clvmd\n"
"it cannot not be used for cluster communications until this is fixed.\n");
return -1;
}
return 0;
}
/* No prizes */
int system_lv_umount(void)
{
if (!mounted)
return 0;
if (umount(mount_point) < 0) {
log_error("umount of system LV (%s) failed: %m\n",
system_lv_name);
return -1;
}
sync_unlock(lock_name, lockid);
mounted = 0;
/* Remove the mount point */
rmdir(mount_point);
return 0;
}
int system_lv_mount(int readwrite)
{
int status;
int saved_errno;
int fd;
if (find_system_lv()) {
errno = EBUSY;
return -1;
}
/* Is it already mounted suitably? */
if (mounted) {
if (!readwrite || (readwrite && mounted_rw)) {
return 0;
} else {
/* Mounted RO and we need RW */
if (system_lv_umount() < 0)
return -1;
}
}
/* Randomize the mount point */
strcpy(mount_point, SYSTEM_LV_MOUNTPOINT);
fd = mkstemp(mount_point);
if (fd < 0) {
log_error("mkstemp for system LV mount point failed: %m\n");
return -1;
}
/* Race condition here but there's no mkstemp for directories */
close(fd);
unlink(mount_point);
mkdir(mount_point, 0600);
/* Make sure we have a system-lv lock */
status =
sync_lock(lock_name, (readwrite) ? LKM_EXMODE : LKM_CRMODE, 0,
&lockid);
if (status < 0)
return -1;
/* Mount it */
if (mount(system_lv_name, mount_point, SYSTEM_LV_FILESYSTEM,
MS_MGC_VAL | MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_SYNCHRONOUS
| (readwrite ? 0 : MS_RDONLY), NULL) < 0) {
/* mount(2) returns EINVAL if the volume has no FS on it. So, if we want to
write to it we try to make a filesystem in it and retry the mount */
if (errno == EINVAL && readwrite) {
char cmd[256];
log_error("Attempting mkfs on system LV device %s\n",
system_lv_name);
snprintf(cmd, sizeof(cmd), "/sbin/mkfs -t %s %s",
SYSTEM_LV_FILESYSTEM, system_lv_name);
system(cmd);
if (mount
(system_lv_name, mount_point, SYSTEM_LV_FILESYSTEM,
MS_MGC_VAL | MS_NOSUID | MS_NODEV | MS_NOEXEC |
MS_SYNCHRONOUS | (readwrite ? 0 : MS_RDONLY),
NULL) == 0)
goto mounted;
}
saved_errno = errno;
log_error("mount of system LV (%s, %s, %s) failed: %m\n",
system_lv_name, mount_point, SYSTEM_LV_FILESYSTEM);
sync_unlock(lock_name, lockid);
errno = saved_errno;
return -1;
}
mounted:
/* Set the internal flags */
mounted = 1;
mounted_rw = readwrite;
return 0;
}
/* Erase *all* files in the root directory of the system LV.
This *MUST* be called with an appropriate lock held!
The LV is left mounted RW because it is assumed that the
caller wants to write something here after clearing some space */
int system_lv_eraseall(void)
{
DIR *dir;
struct dirent *ent;
char fname[PATH_MAX];
/* Must be mounted R/W */
system_lv_mount(1);
dir = opendir(mount_point);
if (!dir)
return -1;
while ((ent = readdir(dir))) {
struct stat st;
snprintf(fname, sizeof(fname), "%s/%s", mount_point,
ent->d_name);
if (stat(fname, &st)) {
if (S_ISREG(st.st_mode))
unlink(fname);
}
}
closedir(dir);
return 0;
}
/* This is a "high-level" routine - it mounts the system LV, writes
the data into a file named after this node and then umounts the LV
again */
int system_lv_write_data(char *data, ssize_t len)
{
struct utsname nodeinfo;
char fname[PATH_MAX];
int outfile;
ssize_t thiswrite;
ssize_t written;
if (system_lv_mount(1))
return -1;
/* Build the file name we are goingto use. */
uname(&nodeinfo);
snprintf(fname, sizeof(fname), "%s/%s", mount_point, nodeinfo.nodename);
/* Open the file for output */
outfile = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0600);
if (outfile < 0) {
int saved_errno = errno;
system_lv_umount();
errno = saved_errno;
return -1;
}
written = 0;
do {
thiswrite = write(outfile, data + written, len - written);
if (thiswrite > 0)
written += thiswrite;
} while (written < len && thiswrite > 0);
close(outfile);
system_lv_umount();
return (thiswrite < 0) ? -1 : 0;
}
/* This is a "high-level" routine - it mounts the system LV, reads
the data from a named file and then umounts the LV
again */
int system_lv_read_data(char *fname_base, char *data, ssize_t *len)
{
char fname[PATH_MAX];
int outfile;
struct stat st;
ssize_t filesize;
ssize_t thisread;
ssize_t readbytes;
if (system_lv_mount(0))
return -1;
/* Build the file name we are going to use. */
snprintf(fname, sizeof(fname), "%s/%s", mount_point, fname_base);
/* Get the file size and stuff. Actually we only need the file size but
this will also check that the file exists */
if (stat(fname, &st) < 0) {
int saved_errno = errno;
log_error("stat of file %s on system LV failed: %m\n", fname);
system_lv_umount();
errno = saved_errno;
return -1;
}
filesize = st.st_size;
outfile = open(fname, O_RDONLY);
if (outfile < 0) {
int saved_errno = errno;
log_error("open of file %s on system LV failed: %m\n", fname);
system_lv_umount();
errno = saved_errno;
return -1;
}
readbytes = 0;
do {
thisread =
read(outfile, data + readbytes, filesize - readbytes);
if (thisread > 0)
readbytes += thisread;
} while (readbytes < filesize && thisread > 0);
close(outfile);
system_lv_umount();
*len = readbytes;
return (thisread < 0) ? -1 : 0;
}