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mirror of git://sourceware.org/git/lvm2.git synced 2024-12-22 17:35:59 +03:00
lvm2/lib/device/online.c
David Teigland 0887896847 vgremove: remove online files in run dir
These files are automatically cleared on reboot given
that /run is tmpfs, and that remains the primary way
of clearing online files.

But, if there's extreme use of vgcreate+pvscan+vgremove
between reboots, then removing online files in vgremove
will limit the number of unused online files using space
in /run.
2022-09-14 14:19:29 -05:00

563 lines
14 KiB
C

/*
* Copyright (C) 2021 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "base/memory/zalloc.h"
#include "lib/misc/lib.h"
#include "lib/commands/toolcontext.h"
#include "lib/device/device.h"
#include "lib/device/online.h"
#include "lib/metadata/metadata.h"
#include <dirent.h>
/*
* file contains:
* <major>:<minor>\n
* vg:<vgname>\n
* dev:<devname>\n\0
*
* It's possible that vg and dev may not exist.
*/
static int _copy_pvid_file_field(const char *field, char *buf, int bufsize, char *out, int outsize)
{
char *p;
int i = 0;
if (!(p = strstr(buf, field)))
return 0;
p += strlen(field);
while (1) {
if (*p == '\n')
break;
if (*p == '\0')
break;
if (p >= (buf + bufsize))
return 0;
if (i >= outsize-1)
return 0;
out[i] = *p;
i++;
p++;
}
return i ? 1 : 0;
}
#define MAX_PVID_FILE_SIZE 512
int online_pvid_file_read(char *path, int *major, int *minor, char *vgname, char *devname)
{
char buf[MAX_PVID_FILE_SIZE] = { 0 };
int fd, rv;
fd = open(path, O_RDONLY);
if (fd < 0) {
log_warn("Failed to open %s", path);
return 0;
}
rv = read(fd, buf, sizeof(buf) - 1);
if (close(fd))
log_sys_debug("close", path);
if (!rv || rv < 0) {
log_warn("No info in %s", path);
return 0;
}
buf[rv] = 0; /* \0 terminated buffer */
if (sscanf(buf, "%d:%d", major, minor) != 2) {
log_warn("No device numbers in %s", path);
return 0;
}
if (vgname) {
if (!strstr(buf, "vg:")) {
log_debug("No vgname in %s", path);
vgname[0] = '\0';
goto copy_dev;
}
if (!_copy_pvid_file_field("vg:", buf, MAX_PVID_FILE_SIZE, vgname, NAME_LEN)) {
log_warn("Ignoring invalid vg field in %s", path);
vgname[0] = '\0';
goto copy_dev;
}
if (!validate_name(vgname)) {
log_warn("Ignoring invalid vgname in %s (%s)", path, vgname);
vgname[0] = '\0';
goto copy_dev;
}
}
copy_dev:
if (devname) {
if (!strstr(buf, "dev:")) {
log_debug("No devname in %s", path);
devname[0] = '\0';
goto out;
}
if (!_copy_pvid_file_field("dev:", buf, MAX_PVID_FILE_SIZE, devname, NAME_LEN)) {
log_warn("Ignoring invalid devname field in %s", path);
devname[0] = '\0';
goto out;
}
if (strncmp(devname, "/dev/", 5)) {
log_warn("Ignoring invalid devname in %s (%s)", path, devname);
devname[0] = '\0';
goto out;
}
}
out:
return 1;
}
void free_po_list(struct dm_list *list)
{
struct pv_online *po, *po2;
dm_list_iterate_items_safe(po, po2, list) {
dm_list_del(&po->list);
free(po);
}
}
int get_pvs_online(struct dm_list *pvs_online, const char *vgname)
{
char path[PATH_MAX];
char file_vgname[NAME_LEN];
char file_devname[NAME_LEN];
DIR *dir;
struct dirent *de;
struct pv_online *po;
int file_major = 0, file_minor = 0;
if (!(dir = opendir(PVS_ONLINE_DIR)))
return 0;
while ((de = readdir(dir))) {
if (de->d_name[0] == '.')
continue;
if (strlen(de->d_name) != ID_LEN)
continue;
memset(path, 0, sizeof(path));
snprintf(path, sizeof(path), "%s/%s", PVS_ONLINE_DIR, de->d_name);
file_major = 0;
file_minor = 0;
memset(file_vgname, 0, sizeof(file_vgname));
memset(file_devname, 0, sizeof(file_devname));
if (!online_pvid_file_read(path, &file_major, &file_minor, file_vgname, file_devname))
continue;
if (vgname && strcmp(file_vgname, vgname))
continue;
if (!(po = zalloc(sizeof(*po))))
continue;
memcpy(po->pvid, de->d_name, ID_LEN);
if (file_major || file_minor)
po->devno = MKDEV(file_major, file_minor);
if (file_vgname[0])
strncpy(po->vgname, file_vgname, NAME_LEN);
if (file_devname[0])
strncpy(po->devname, file_devname, NAME_LEN);
log_debug("Found PV online %s for VG %s %s", path, vgname, file_devname);
dm_list_add(pvs_online, &po->list);
}
if (closedir(dir))
log_sys_debug("closedir", PVS_ONLINE_DIR);
log_debug("Found PVs online %d for %s", dm_list_size(pvs_online), vgname ?: "all");
return 1;
}
/*
* When a PV goes offline, remove the vg online file for that VG
* (even if other PVs for the VG are still online). This means
* that the vg will be activated again when it becomes complete.
*/
void online_vg_file_remove(const char *vgname)
{
char path[PATH_MAX];
if (dm_snprintf(path, sizeof(path), "%s/%s", VGS_ONLINE_DIR, vgname) < 0) {
log_error("Path %s/%s is too long.", VGS_ONLINE_DIR, vgname);
return;
}
log_debug("Unlink vg online: %s", path);
if (unlink(path) && (errno != ENOENT))
log_sys_debug("unlink", path);
}
int online_vg_file_create(struct cmd_context *cmd, const char *vgname)
{
char path[PATH_MAX];
int fd;
if (dm_snprintf(path, sizeof(path), "%s/%s", VGS_ONLINE_DIR, vgname) < 0) {
log_error_pvscan(cmd, "Path %s/%s is too long.", VGS_ONLINE_DIR, vgname);
return 0;
}
log_debug("Create vg online: %s", path);
fd = open(path, O_CREAT | O_EXCL | O_TRUNC | O_RDWR, S_IRUSR | S_IWUSR);
if (fd < 0) {
log_debug("Failed to create %s: %d", path, errno);
return 0;
}
/* We don't care about syncing, these files are not even persistent. */
if (close(fd))
log_sys_debug("close", path);
return 1;
}
int online_pvid_file_create(struct cmd_context *cmd, struct device *dev, const char *vgname)
{
char path[PATH_MAX];
char buf[MAX_PVID_FILE_SIZE] = { 0 };
char file_vgname[NAME_LEN];
char file_devname[NAME_LEN];
char devname[NAME_LEN];
int devnamelen;
int file_major = 0, file_minor = 0;
int major, minor;
int fd;
int rv;
int len;
int len1 = 0;
int len2 = 0;
int len3 = 0;
major = (int)MAJOR(dev->dev);
minor = (int)MINOR(dev->dev);
if (dm_snprintf(path, sizeof(path), "%s/%s", PVS_ONLINE_DIR, dev->pvid) < 0) {
log_error_pvscan(cmd, "Path %s/%s is too long.", PVS_ONLINE_DIR, dev->pvid);
return 0;
}
if ((len1 = dm_snprintf(buf, sizeof(buf), "%d:%d\n", major, minor)) < 0) {
log_error_pvscan(cmd, "Cannot create online file path for %s %d:%d.", dev_name(dev), major, minor);
return 0;
}
if (vgname) {
if ((len2 = dm_snprintf(buf + len1, sizeof(buf) - len1, "vg:%s\n", vgname)) < 0) {
log_print("Incomplete online file for %s %d:%d vg %s.", dev_name(dev), major, minor, vgname);
/* can still continue without vgname */
len2 = 0;
}
}
devnamelen = dm_snprintf(devname, sizeof(devname), "%s", dev_name(dev));
if ((devnamelen > 5) && (devnamelen < NAME_LEN-1)) {
if ((len3 = dm_snprintf(buf + len1 + len2, sizeof(buf) - len1 - len2, "dev:%s\n", devname)) < 0) {
log_print("Incomplete devname in online file for %s.", dev_name(dev));
/* can continue without devname */
len3 = 0;
}
}
len = len1 + len2 + len3;
log_debug("Create pv online: %s %d:%d %s", path, major, minor, dev_name(dev));
fd = open(path, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR);
if (fd < 0) {
if (errno == EEXIST)
goto check_duplicate;
log_error_pvscan(cmd, "Failed to create online file for %s path %s error %d", dev_name(dev), path, errno);
return 0;
}
while (len > 0) {
rv = write(fd, buf, len);
if (rv < 0) {
/* file exists so it still works in part */
log_warn("Cannot write online file for %s to %s error %d",
dev_name(dev), path, errno);
if (close(fd))
log_sys_debug("close", path);
return 1;
}
len -= rv;
}
/* We don't care about syncing, these files are not even persistent. */
if (close(fd))
log_sys_debug("close", path);
return 1;
check_duplicate:
/*
* If a PVID online file already exists for this PVID, check if the
* file contains a different device number, and if so we may have a
* duplicate PV.
*
* FIXME: disable autoactivation of the VG somehow?
* The VG may or may not already be activated when a dupicate appears.
* Perhaps write a new field in the pv online or vg online file?
*/
memset(file_vgname, 0, sizeof(file_vgname));
memset(file_devname, 0, sizeof(file_devname));
online_pvid_file_read(path, &file_major, &file_minor, file_vgname, file_devname);
if ((file_major == major) && (file_minor == minor)) {
log_debug("Existing online file for %d:%d", major, minor);
return 1;
}
/* Don't know how vgname might not match, but it's not good so fail. */
if ((file_major != major) || (file_minor != minor))
log_error_pvscan(cmd, "PV %s %d:%d is duplicate for PVID %s on %d:%d %s.",
dev_name(dev), major, minor, dev->pvid, file_major, file_minor, file_devname);
if (file_vgname[0] && vgname && strcmp(file_vgname, vgname))
log_error_pvscan(cmd, "PV %s has unexpected VG %s vs %s.",
dev_name(dev), vgname, file_vgname);
return 0;
}
int online_pvid_file_exists(const char *pvid)
{
char path[PATH_MAX] = { 0 };
struct stat buf;
int rv;
if (dm_snprintf(path, sizeof(path), "%s/%s", PVS_ONLINE_DIR, pvid) < 0) {
log_debug(INTERNAL_ERROR "Path %s/%s is too long.", PVS_ONLINE_DIR, pvid);
return 0;
}
log_debug("Check pv online: %s", path);
rv = stat(path, &buf);
if (!rv) {
log_debug("Check pv online %s: yes", pvid);
return 1;
}
log_debug("Check pv online %s: no", pvid);
return 0;
}
int get_pvs_lookup(struct dm_list *pvs_online, const char *vgname)
{
char lookup_path[PATH_MAX] = { 0 };
char path[PATH_MAX] = { 0 };
char line[64];
char pvid[ID_LEN + 1] __attribute__((aligned(8))) = { 0 };
char file_vgname[NAME_LEN];
char file_devname[NAME_LEN];
struct pv_online *po;
int file_major = 0, file_minor = 0;
FILE *fp;
if (dm_snprintf(lookup_path, sizeof(path), "%s/%s", PVS_LOOKUP_DIR, vgname) < 0)
return_0;
if (!(fp = fopen(lookup_path, "r")))
return_0;
while (fgets(line, sizeof(line), fp)) {
memcpy(pvid, line, ID_LEN);
if (strlen(pvid) != ID_LEN)
goto_bad;
memset(path, 0, sizeof(path));
snprintf(path, sizeof(path), "%s/%s", PVS_ONLINE_DIR, pvid);
file_major = 0;
file_minor = 0;
memset(file_vgname, 0, sizeof(file_vgname));
memset(file_devname, 0, sizeof(file_devname));
if (!online_pvid_file_read(path, &file_major, &file_minor, file_vgname, file_devname))
goto_bad;
/*
* PVs without metadata will not have a vgname in their pvid
* file, but the purpose of using the lookup file is that we
* know the PV is for this VG even without the pvid vgname
* field.
*/
if (vgname && file_vgname[0] && strcmp(file_vgname, vgname)) {
/* Should never happen */
log_error("Incorrect VG lookup file %s PVID %s %s.", vgname, pvid, file_vgname);
goto_bad;
}
if (!(po = zalloc(sizeof(*po))))
goto_bad;
memcpy(po->pvid, pvid, ID_LEN);
if (file_major || file_minor)
po->devno = MKDEV(file_major, file_minor);
if (file_vgname[0])
strncpy(po->vgname, file_vgname, NAME_LEN-1);
if (file_devname[0])
strncpy(po->devname, file_devname, NAME_LEN-1);
log_debug("Found PV online lookup %s for VG %s on %s", path, vgname, file_devname);
dm_list_add(pvs_online, &po->list);
}
log_debug("Found PVs online lookup %d for %s", dm_list_size(pvs_online), vgname);
fclose(fp);
return 1;
bad:
free_po_list(pvs_online);
fclose(fp);
return 0;
}
void online_dir_setup(struct cmd_context *cmd)
{
struct stat st;
int rv;
if (!stat(DEFAULT_RUN_DIR, &st))
goto do_pvs;
log_debug("Creating run_dir.");
dm_prepare_selinux_context(DEFAULT_RUN_DIR, S_IFDIR);
rv = mkdir(DEFAULT_RUN_DIR, 0755);
dm_prepare_selinux_context(NULL, 0);
if ((rv < 0) && stat(DEFAULT_RUN_DIR, &st))
log_error_pvscan(cmd, "Failed to create %s %d", DEFAULT_RUN_DIR, errno);
do_pvs:
if (!stat(PVS_ONLINE_DIR, &st))
goto do_vgs;
log_debug("Creating pvs_online_dir.");
dm_prepare_selinux_context(PVS_ONLINE_DIR, S_IFDIR);
rv = mkdir(PVS_ONLINE_DIR, 0755);
dm_prepare_selinux_context(NULL, 0);
if ((rv < 0) && stat(PVS_ONLINE_DIR, &st))
log_error_pvscan(cmd, "Failed to create %s %d", PVS_ONLINE_DIR, errno);
do_vgs:
if (!stat(VGS_ONLINE_DIR, &st))
goto do_lookup;
log_debug("Creating vgs_online_dir.");
dm_prepare_selinux_context(VGS_ONLINE_DIR, S_IFDIR);
rv = mkdir(VGS_ONLINE_DIR, 0755);
dm_prepare_selinux_context(NULL, 0);
if ((rv < 0) && stat(VGS_ONLINE_DIR, &st))
log_error_pvscan(cmd, "Failed to create %s %d", VGS_ONLINE_DIR, errno);
do_lookup:
if (!stat(PVS_LOOKUP_DIR, &st))
return;
log_debug("Creating pvs_lookup_dir.");
dm_prepare_selinux_context(PVS_LOOKUP_DIR, S_IFDIR);
rv = mkdir(PVS_LOOKUP_DIR, 0755);
dm_prepare_selinux_context(NULL, 0);
if ((rv < 0) && stat(PVS_LOOKUP_DIR, &st))
log_error_pvscan(cmd, "Failed to create %s %d", PVS_LOOKUP_DIR, errno);
}
void online_lookup_file_remove(const char *vgname)
{
char path[PATH_MAX];
if (dm_snprintf(path, sizeof(path), "%s/%s", PVS_LOOKUP_DIR, vgname) < 0) {
log_error("Path %s/%s is too long.", PVS_LOOKUP_DIR, vgname);
return;
}
log_debug("Unlink pvs_lookup: %s", path);
if (unlink(path) && (errno != ENOENT))
log_sys_debug("unlink", path);
}
static int _online_pvid_file_remove(char *pvid)
{
char path[PATH_MAX];
if (dm_snprintf(path, sizeof(path), "%s/%s", PVS_ONLINE_DIR, pvid) < 0)
return_0;
if (!unlink(path))
return 1;
return 0;
}
/*
* Reboot automatically clearing tmpfs on /run is the main method of removing
* online files. It's important to note that removing the online files for a
* VG is not a technical requirement for anything and could easily be skipped
* if it had any downside. It's only done to clean up the space used in /run
* by the online files, e.g. if there happens to be an extreme amount of
* vgcreate/pvscan/vgremove between reboots that are leaving a large number of
* useless online files consuming tmpfs space.
*/
void online_vgremove(struct volume_group *vg)
{
char pvid[ID_LEN + 1] __attribute__((aligned(8))) = { 0 };
struct pv_list *pvl;
/*
* online files may not exist for the vg if there has been no
* pvscans or autoactivation.
*/
online_vg_file_remove(vg->name);
online_lookup_file_remove(vg->name);
dm_list_iterate_items(pvl, &vg->pvs) {
memcpy(pvid, &pvl->pv->id.uuid, ID_LEN);
_online_pvid_file_remove(pvid);
}
}