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mirror of git://sourceware.org/git/lvm2.git synced 2024-12-22 17:35:59 +03:00
lvm2/lib/cache/lvmcache.c

607 lines
13 KiB
C

/*
* Copyright (C) 2001-2004 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 "lvmcache.h"
#include "hash.h"
#include "toolcontext.h"
#include "dev-cache.h"
#include "metadata.h"
#include "filter.h"
#include "memlock.h"
#include "str_list.h"
static struct hash_table *_pvid_hash = NULL;
static struct hash_table *_vgid_hash = NULL;
static struct hash_table *_vgname_hash = NULL;
static struct hash_table *_lock_hash = NULL;
static struct list _vginfos;
static int _has_scanned = 0;
static int _vgs_locked = 0;
int lvmcache_init(void)
{
list_init(&_vginfos);
if (!(_vgname_hash = hash_create(128)))
return 0;
if (!(_vgid_hash = hash_create(128)))
return 0;
if (!(_pvid_hash = hash_create(128)))
return 0;
if (!(_lock_hash = hash_create(128)))
return 0;
return 1;
}
void lvmcache_lock_vgname(const char *vgname, int read_only)
{
if (!_lock_hash && !lvmcache_init()) {
log_error("Internal cache initialisation failed");
return;
}
if (!hash_insert(_lock_hash, vgname, (void *) 1))
log_error("Cache locking failure for %s", vgname);
_vgs_locked++;
}
static int _vgname_is_locked(const char *vgname) __attribute__ ((unused));
static int _vgname_is_locked(const char *vgname)
{
if (!_lock_hash)
return 0;
return hash_lookup(_lock_hash, vgname) ? 1 : 0;
}
void lvmcache_unlock_vgname(const char *vgname)
{
/* FIXME: Clear all CACHE_LOCKED flags in this vg */
hash_remove(_lock_hash, vgname);
/* FIXME Do this per-VG */
if (!--_vgs_locked)
dev_close_all();
}
int vgs_locked(void)
{
return _vgs_locked;
}
struct lvmcache_vginfo *vginfo_from_vgname(const char *vgname)
{
struct lvmcache_vginfo *vginfo;
if (!_vgname_hash)
return NULL;
if (!(vginfo = hash_lookup(_vgname_hash, vgname)))
return NULL;
return vginfo;
}
const struct format_type *fmt_from_vgname(const char *vgname)
{
struct lvmcache_vginfo *vginfo;
struct label *label;
struct list *ih, *devh, *tmp;
struct list devs;
struct device_list *devl;
if (!(vginfo = vginfo_from_vgname(vgname)))
return NULL;
/* This function is normally called before reading metadata so
* we check cached labels here. Unfortunately vginfo is volatile. */
list_init(&devs);
list_iterate(ih, &vginfo->infos) {
devl = malloc(sizeof(*devl));
devl->dev = list_item(ih, struct lvmcache_info)->dev;
list_add(&devs, &devl->list);
}
list_iterate_safe(devh, tmp, &devs) {
devl = list_item(devh, struct device_list);
label_read(devl->dev, &label);
list_del(&devl->list);
free(devl);
}
return vginfo->fmt;
}
struct lvmcache_vginfo *vginfo_from_vgid(const char *vgid)
{
struct lvmcache_vginfo *vginfo;
char id[ID_LEN + 1];
if (!_vgid_hash || !vgid)
return NULL;
/* vgid not necessarily NULL-terminated */
strncpy(&id[0], vgid, ID_LEN);
id[ID_LEN] = '\0';
if (!(vginfo = hash_lookup(_vgid_hash, id)))
return NULL;
return vginfo;
}
struct lvmcache_info *info_from_pvid(const char *pvid)
{
struct lvmcache_info *info;
char id[ID_LEN + 1];
if (!_pvid_hash || !pvid)
return NULL;
strncpy(&id[0], pvid, ID_LEN);
id[ID_LEN] = '\0';
if (!(info = hash_lookup(_pvid_hash, id)))
return NULL;
return info;
}
static void _rescan_entry(struct lvmcache_info *info)
{
struct label *label;
if (info->status & CACHE_INVALID)
label_read(info->dev, &label);
}
static int _scan_invalid(void)
{
hash_iter(_pvid_hash, (iterate_fn) _rescan_entry);
return 1;
}
int lvmcache_label_scan(struct cmd_context *cmd, int full_scan)
{
struct label *label;
struct dev_iter *iter;
struct device *dev;
struct list *fmth;
struct format_type *fmt;
static int _scanning_in_progress = 0;
int r = 0;
/* Avoid recursion when a PVID can't be found! */
if (_scanning_in_progress)
return 0;
_scanning_in_progress = 1;
if (!_vgname_hash && !lvmcache_init()) {
log_error("Internal cache initialisation failed");
goto out;
}
if (_has_scanned && !full_scan) {
r = _scan_invalid();
goto out;
}
if (!(iter = dev_iter_create(cmd->filter, (full_scan == 2) ? 1: 0))) {
log_error("dev_iter creation failed");
goto out;
}
while ((dev = dev_iter_get(iter)))
label_read(dev, &label);
dev_iter_destroy(iter);
_has_scanned = 1;
/* Perform any format-specific scanning e.g. text files */
list_iterate(fmth, &cmd->formats) {
fmt = list_item(fmth, struct format_type);
if (fmt->ops->scan && !fmt->ops->scan(fmt))
goto out;
}
r = 1;
out:
_scanning_in_progress = 0;
return r;
}
struct list *lvmcache_get_vgnames(struct cmd_context *cmd, int full_scan)
{
struct list *vgnames;
struct lvmcache_vginfo *vgi;
lvmcache_label_scan(cmd, full_scan);
if (!(vgnames = str_list_create(cmd->mem))) {
log_error("vgnames list allocation failed");
return NULL;
}
list_iterate_items(vgi, &_vginfos) {
if (!str_list_add(cmd->mem, vgnames,
pool_strdup(cmd->mem, vgi->vgname))) {
log_error("strlist allocation failed");
return NULL;
}
}
return vgnames;
}
struct device *device_from_pvid(struct cmd_context *cmd, struct id *pvid)
{
struct label *label;
struct lvmcache_info *info;
/* Already cached ? */
if ((info = info_from_pvid((char *) pvid))) {
if (label_read(info->dev, &label)) {
info = (struct lvmcache_info *) label->info;
if (id_equal(pvid, (struct id *) &info->dev->pvid))
return info->dev;
}
}
lvmcache_label_scan(cmd, 0);
/* Try again */
if ((info = info_from_pvid((char *) pvid))) {
if (label_read(info->dev, &label)) {
info = (struct lvmcache_info *) label->info;
if (id_equal(pvid, (struct id *) &info->dev->pvid))
return info->dev;
}
}
if (memlock())
return NULL;
lvmcache_label_scan(cmd, 2);
/* Try again */
if ((info = info_from_pvid((char *) pvid))) {
if (label_read(info->dev, &label)) {
info = (struct lvmcache_info *) label->info;
if (id_equal(pvid, (struct id *) &info->dev->pvid))
return info->dev;
}
}
return NULL;
}
static void _drop_vginfo(struct lvmcache_info *info)
{
if (!list_empty(&info->list)) {
list_del(&info->list);
list_init(&info->list);
}
if (info->vginfo && list_empty(&info->vginfo->infos)) {
hash_remove(_vgname_hash, info->vginfo->vgname);
if (info->vginfo->vgname)
dbg_free(info->vginfo->vgname);
if (*info->vginfo->vgid)
hash_remove(_vgid_hash, info->vginfo->vgid);
list_del(&info->vginfo->list);
dbg_free(info->vginfo);
}
info->vginfo = NULL;
}
/* Unused
void lvmcache_del(struct lvmcache_info *info)
{
if (info->dev->pvid[0] && _pvid_hash)
hash_remove(_pvid_hash, info->dev->pvid);
_drop_vginfo(info);
info->label->labeller->ops->destroy_label(info->label->labeller,
info->label);
dbg_free(info);
return;
} */
static int _lvmcache_update_pvid(struct lvmcache_info *info, const char *pvid)
{
if (!strcmp(info->dev->pvid, pvid))
return 1;
if (*info->dev->pvid) {
hash_remove(_pvid_hash, info->dev->pvid);
}
strncpy(info->dev->pvid, pvid, sizeof(info->dev->pvid));
if (!hash_insert(_pvid_hash, pvid, info)) {
log_error("_lvmcache_update: pvid insertion failed: %s", pvid);
return 0;
}
return 1;
}
static int _lvmcache_update_vgid(struct lvmcache_info *info, const char *vgid)
{
if (!vgid || !info->vginfo || !strncmp(info->vginfo->vgid, vgid,
sizeof(info->vginfo->vgid)))
return 1;
if (info->vginfo && *info->vginfo->vgid)
hash_remove(_vgid_hash, info->vginfo->vgid);
if (!vgid)
return 1;
strncpy(info->vginfo->vgid, vgid, sizeof(info->vginfo->vgid));
info->vginfo->vgid[sizeof(info->vginfo->vgid) - 1] = '\0';
if (!hash_insert(_vgid_hash, info->vginfo->vgid, info->vginfo)) {
log_error("_lvmcache_update: vgid hash insertion failed: %s",
info->vginfo->vgid);
return 0;
}
return 1;
}
int lvmcache_update_vgname(struct lvmcache_info *info, const char *vgname)
{
struct lvmcache_vginfo *vginfo;
/* If vgname is NULL and we don't already have a vgname,
* assume ORPHAN - we want every entry to have a vginfo
* attached for scanning reasons.
*/
if (!vgname && !info->vginfo)
vgname = ORPHAN;
if (!vgname || (info->vginfo && !strcmp(info->vginfo->vgname, vgname)))
return 1;
/* Remove existing vginfo entry */
_drop_vginfo(info);
/* Get existing vginfo or create new one */
if (!(vginfo = vginfo_from_vgname(vgname))) {
if (!(vginfo = dbg_malloc(sizeof(*vginfo)))) {
log_error("lvmcache_update_vgname: list alloc failed");
return 0;
}
memset(vginfo, 0, sizeof(*vginfo));
if (!(vginfo->vgname = dbg_strdup(vgname))) {
dbg_free(vginfo);
log_error("cache vgname alloc failed for %s", vgname);
return 0;
}
list_init(&vginfo->infos);
if (!hash_insert(_vgname_hash, vginfo->vgname, vginfo)) {
log_error("cache_update: vg hash insertion failed: %s",
vginfo->vgname);
dbg_free(vginfo->vgname);
dbg_free(vginfo);
return 0;
}
/* Ensure orphans appear last on list_iterate */
if (!*vgname)
list_add(&_vginfos, &vginfo->list);
else
list_add_h(&_vginfos, &vginfo->list);
}
info->vginfo = vginfo;
list_add(&vginfo->infos, &info->list);
/* FIXME Check consistency of list! */
vginfo->fmt = info->fmt;
log_debug("lvmcache: %s now %s%s", dev_name(info->dev),
*vgname ? "in VG " : "orphaned", vgname);
return 1;
}
int lvmcache_update_vg(struct volume_group *vg)
{
struct list *pvh;
struct physical_volume *pv;
struct lvmcache_info *info;
char pvid_s[ID_LEN + 1];
int vgid_updated = 0;
pvid_s[sizeof(pvid_s) - 1] = '\0';
list_iterate(pvh, &vg->pvs) {
pv = list_item(pvh, struct pv_list)->pv;
strncpy(pvid_s, (char *) &pv->id, sizeof(pvid_s) - 1);
/* FIXME Could pv->dev->pvid ever be different? */
if ((info = info_from_pvid(pvid_s))) {
lvmcache_update_vgname(info, vg->name);
if (!vgid_updated) {
_lvmcache_update_vgid(info, (char *) &vg->id);
vgid_updated = 1;
}
}
}
return 1;
}
struct lvmcache_info *lvmcache_add(struct labeller *labeller, const char *pvid,
struct device *dev,
const char *vgname, const char *vgid)
{
struct label *label;
struct lvmcache_info *existing, *info;
char pvid_s[ID_LEN + 1];
if (!_vgname_hash && !lvmcache_init()) {
log_error("Internal cache initialisation failed");
return NULL;
}
strncpy(pvid_s, pvid, sizeof(pvid_s));
pvid_s[sizeof(pvid_s) - 1] = '\0';
if (!(existing = info_from_pvid(pvid_s)) &&
!(existing = info_from_pvid(dev->pvid))) {
if (!(label = label_create(labeller))) {
stack;
return NULL;
}
if (!(info = dbg_malloc(sizeof(*info)))) {
log_error("lvmcache_info allocation failed");
label_destroy(label);
return NULL;
}
memset(info, 0, sizeof(*info));
label->info = info;
info->label = label;
list_init(&info->list);
info->dev = dev;
} else {
if (existing->dev != dev) {
/* Is the existing entry a duplicate pvid e.g. md ? */
if (MAJOR(existing->dev->dev) == md_major() &&
MAJOR(dev->dev) != md_major()) {
log_very_verbose("Ignoring duplicate PV %s on "
"%s - using md %s",
pvid, dev_name(dev),
dev_name(existing->dev));
return NULL;
} else if (MAJOR(existing->dev->dev) != md_major() &&
MAJOR(dev->dev) == md_major())
log_very_verbose("Duplicate PV %s on %s - "
"using md %s", pvid,
dev_name(existing->dev),
dev_name(dev));
else
log_error("Found duplicate PV %s: using %s not "
"%s", pvid, dev_name(dev),
dev_name(existing->dev));
}
info = existing;
/* Has labeller changed? */
if (info->label->labeller != labeller) {
label_destroy(info->label);
if (!(info->label = label_create(labeller))) {
/* FIXME leaves info without label! */
stack;
return NULL;
}
info->label->info = info;
}
label = info->label;
}
info->fmt = (const struct format_type *) labeller->private;
info->status |= CACHE_INVALID;
if (!_lvmcache_update_pvid(info, pvid_s)) {
if (!existing) {
dbg_free(info);
label_destroy(label);
}
return NULL;
}
if (!lvmcache_update_vgname(info, vgname)) {
if (!existing) {
hash_remove(_pvid_hash, pvid_s);
strcpy(info->dev->pvid, "");
dbg_free(info);
label_destroy(label);
}
return NULL;
}
if (!_lvmcache_update_vgid(info, vgid))
/* Non-critical */
stack;
return info;
}
static void _lvmcache_destroy_entry(struct lvmcache_info *info)
{
if (!list_empty(&info->list))
list_del(&info->list);
strcpy(info->dev->pvid, "");
label_destroy(info->label);
dbg_free(info);
}
static void _lvmcache_destroy_vgnamelist(struct lvmcache_vginfo *vginfo)
{
if (vginfo->vgname)
dbg_free(vginfo->vgname);
dbg_free(vginfo);
}
static void _lvmcache_destroy_lockname(int present)
{
/* Nothing to do */
}
void lvmcache_destroy(void)
{
log_verbose("Wiping internal VG cache");
_has_scanned = 0;
if (_vgid_hash) {
hash_destroy(_vgid_hash);
_vgid_hash = NULL;
}
if (_pvid_hash) {
hash_iter(_pvid_hash, (iterate_fn) _lvmcache_destroy_entry);
hash_destroy(_pvid_hash);
_pvid_hash = NULL;
}
if (_vgname_hash) {
hash_iter(_vgname_hash,
(iterate_fn) _lvmcache_destroy_vgnamelist);
hash_destroy(_vgname_hash);
_vgname_hash = NULL;
}
if (_lock_hash) {
hash_iter(_lock_hash, (iterate_fn) _lvmcache_destroy_lockname);
hash_destroy(_lock_hash);
_lock_hash = NULL;
}
list_init(&_vginfos);
}