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lvm2/lib/cache/lvmcache.c
David Teigland 17f5572bc9 Remove independent metadata areas 
in which metadata is stored in files on the local fs
instead of on PVs.
2018-06-13 12:25:19 -05:00

2341 lines
64 KiB
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/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2011 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/cache/lvmcache.h"
#include "lib/commands/toolcontext.h"
#include "lib/device/dev-cache.h"
#include "lib/locking/locking.h"
#include "lib/metadata/metadata.h"
#include "lib/mm/memlock.h"
#include "lib/datastruct/str_list.h"
#include "lib/format_text/format-text.h"
#include "lib/config/config.h"
#include "lib/cache/lvmetad.h"
#include "daemons/lvmetad/lvmetad-client.h"
/* One per device */
struct lvmcache_info {
struct dm_list list; /* Join VG members together */
struct dm_list mdas; /* list head for metadata areas */
struct dm_list das; /* list head for data areas */
struct dm_list bas; /* list head for bootloader areas */
struct lvmcache_vginfo *vginfo; /* NULL == unknown */
struct label *label;
const struct format_type *fmt;
struct device *dev;
uint64_t device_size; /* Bytes */
uint32_t ext_version; /* Extension version */
uint32_t ext_flags; /* Extension flags */
uint32_t status;
};
/* One per VG */
struct lvmcache_vginfo {
struct dm_list list; /* Join these vginfos together */
struct dm_list infos; /* List head for lvmcache_infos */
const struct format_type *fmt;
char *vgname; /* "" == orphan */
uint32_t status;
char vgid[ID_LEN + 1];
char _padding[7];
struct lvmcache_vginfo *next; /* Another VG with same name? */
char *creation_host;
char *system_id;
char *lock_type;
uint32_t mda_checksum;
size_t mda_size;
int seqno;
int scan_summary_mismatch; /* vgsummary from devs had mismatching seqno or checksum */
};
static struct dm_hash_table *_pvid_hash = NULL;
static struct dm_hash_table *_vgid_hash = NULL;
static struct dm_hash_table *_vgname_hash = NULL;
static DM_LIST_INIT(_vginfos);
static DM_LIST_INIT(_found_duplicate_devs);
static DM_LIST_INIT(_unused_duplicate_devs);
static int _scanning_in_progress = 0;
static int _has_scanned = 0;
static int _vgs_locked = 0;
static int _found_duplicate_pvs = 0; /* If we never see a duplicate PV we can skip checking for them later. */
int lvmcache_init(struct cmd_context *cmd)
{
/*
* FIXME add a proper lvmcache_locking_reset() that
* resets the cache so no previous locks are locked
*/
_vgs_locked = 0;
dm_list_init(&_vginfos);
dm_list_init(&_found_duplicate_devs);
dm_list_init(&_unused_duplicate_devs);
if (!(_vgname_hash = dm_hash_create(128)))
return 0;
if (!(_vgid_hash = dm_hash_create(128)))
return 0;
if (!(_pvid_hash = dm_hash_create(128)))
return 0;
return 1;
}
void lvmcache_seed_infos_from_lvmetad(struct cmd_context *cmd)
{
if (!lvmetad_used() || _has_scanned)
return;
dev_cache_scan();
if (!lvmetad_pv_list_to_lvmcache(cmd)) {
stack;
return;
}
_has_scanned = 1;
}
void lvmcache_lock_vgname(const char *vgname, int read_only __attribute__((unused)))
{
if (strcmp(vgname, VG_GLOBAL))
_vgs_locked++;
}
void lvmcache_unlock_vgname(const char *vgname)
{
/* FIXME Do this per-VG */
if (strcmp(vgname, VG_GLOBAL) && !--_vgs_locked) {
dev_size_seqno_inc(); /* invalidate all cached dev sizes */
}
}
int lvmcache_vgs_locked(void)
{
return _vgs_locked;
}
/*
* When lvmcache sees a duplicate PV, this is set.
* process_each_pv() can avoid searching for duplicates
* by checking this and seeing that no duplicate PVs exist.
*
*
* found_duplicate_pvs tells the process_each_pv code
* to search the devices list for duplicates, so that
* devices can be processed together with their
* duplicates (while processing the VG, rather than
* reporting pv->dev under the VG, and its duplicate
* outside the VG context.)
*/
int lvmcache_found_duplicate_pvs(void)
{
return _found_duplicate_pvs;
}
int lvmcache_get_unused_duplicate_devs(struct cmd_context *cmd, struct dm_list *head)
{
struct device_list *devl, *devl2;
dm_list_iterate_items(devl, &_unused_duplicate_devs) {
if (!(devl2 = dm_pool_alloc(cmd->mem, sizeof(*devl2)))) {
log_error("device_list element allocation failed");
return 0;
}
devl2->dev = devl->dev;
dm_list_add(head, &devl2->list);
}
return 1;
}
void lvmcache_remove_unchosen_duplicate(struct device *dev)
{
struct device_list *devl;
dm_list_iterate_items(devl, &_unused_duplicate_devs) {
if (devl->dev == dev) {
dm_list_del(&devl->list);
return;
}
}
}
static void _destroy_duplicate_device_list(struct dm_list *head)
{
struct device_list *devl, *devl2;
dm_list_iterate_items_safe(devl, devl2, head) {
dm_list_del(&devl->list);
free(devl);
}
dm_list_init(head);
}
static void _vginfo_attach_info(struct lvmcache_vginfo *vginfo,
struct lvmcache_info *info)
{
if (!vginfo)
return;
info->vginfo = vginfo;
dm_list_add(&vginfo->infos, &info->list);
}
static void _vginfo_detach_info(struct lvmcache_info *info)
{
if (!dm_list_empty(&info->list)) {
dm_list_del(&info->list);
dm_list_init(&info->list);
}
info->vginfo = NULL;
}
/* If vgid supplied, require a match. */
struct lvmcache_vginfo *lvmcache_vginfo_from_vgname(const char *vgname, const char *vgid)
{
struct lvmcache_vginfo *vginfo;
if (!vgname)
return lvmcache_vginfo_from_vgid(vgid);
if (!_vgname_hash) {
log_debug_cache(INTERNAL_ERROR "Internal lvmcache is no yet initialized.");
return NULL;
}
if (!(vginfo = dm_hash_lookup(_vgname_hash, vgname))) {
log_debug_cache("lvmcache has no info for vgname \"%s\"%s" FMTVGID ".",
vgname, (vgid) ? " with VGID " : "", (vgid) ? : "");
return NULL;
}
if (vgid)
do
if (!strncmp(vgid, vginfo->vgid, ID_LEN))
return vginfo;
while ((vginfo = vginfo->next));
if (!vginfo)
log_debug_cache("lvmcache has not found vgname \"%s\"%s" FMTVGID ".",
vgname, (vgid) ? " with VGID " : "", (vgid) ? : "");
return vginfo;
}
const struct format_type *lvmcache_fmt_from_vgname(struct cmd_context *cmd,
const char *vgname, const char *vgid,
unsigned revalidate_labels)
{
struct lvmcache_vginfo *vginfo;
struct lvmcache_info *info;
struct dm_list *devh, *tmp;
struct dm_list devs;
struct device_list *devl;
struct volume_group *vg;
const struct format_type *fmt;
char vgid_found[ID_LEN + 1] __attribute__((aligned(8)));
if (!(vginfo = lvmcache_vginfo_from_vgname(vgname, vgid))) {
if (!lvmetad_used())
return NULL; /* too bad */
/* If we don't have the info but we have lvmetad, we can ask
* there before failing. */
if ((vg = lvmetad_vg_lookup(cmd, vgname, vgid))) {
fmt = vg->fid->fmt;
release_vg(vg);
return fmt;
}
return NULL;
}
/*
* If this function is called repeatedly, only the first one needs to revalidate.
*/
if (!revalidate_labels)
goto out;
/*
* This function is normally called before reading metadata so
* we check cached labels here. Unfortunately vginfo is volatile.
*/
dm_list_init(&devs);
dm_list_iterate_items(info, &vginfo->infos) {
if (!(devl = malloc(sizeof(*devl)))) {
log_error("device_list element allocation failed");
return NULL;
}
devl->dev = info->dev;
dm_list_add(&devs, &devl->list);
}
memcpy(vgid_found, vginfo->vgid, sizeof(vgid_found));
dm_list_iterate_safe(devh, tmp, &devs) {
devl = dm_list_item(devh, struct device_list);
label_read(devl->dev);
dm_list_del(&devl->list);
free(devl);
}
/* If vginfo changed, caller needs to rescan */
if (!(vginfo = lvmcache_vginfo_from_vgname(vgname, vgid_found)) ||
strncmp(vginfo->vgid, vgid_found, ID_LEN))
return NULL;
out:
return vginfo->fmt;
}
struct lvmcache_vginfo *lvmcache_vginfo_from_vgid(const char *vgid)
{
struct lvmcache_vginfo *vginfo;
char id[ID_LEN + 1] __attribute__((aligned(8)));
if (!_vgid_hash || !vgid) {
log_debug_cache(INTERNAL_ERROR "Internal cache cannot lookup vgid.");
return NULL;
}
/* vgid not necessarily NULL-terminated */
(void) dm_strncpy(id, vgid, sizeof(id));
if (!(vginfo = dm_hash_lookup(_vgid_hash, id))) {
log_debug_cache("lvmcache has no info for vgid \"%s\"", id);
return NULL;
}
return vginfo;
}
const char *lvmcache_vgname_from_vgid(struct dm_pool *mem, const char *vgid)
{
struct lvmcache_vginfo *vginfo;
const char *vgname = NULL;
if ((vginfo = lvmcache_vginfo_from_vgid(vgid)))
vgname = vginfo->vgname;
if (mem && vgname)
return dm_pool_strdup(mem, vgname);
return vgname;
}
const char *lvmcache_vgid_from_vgname(struct cmd_context *cmd, const char *vgname)
{
struct lvmcache_vginfo *vginfo;
if (!(vginfo = dm_hash_lookup(_vgname_hash, vgname)))
return_NULL;
if (!vginfo->next)
return dm_pool_strdup(cmd->mem, vginfo->vgid);
/*
* There are multiple VGs with this name to choose from.
* Return an error because we don't know which VG is intended.
*/
return NULL;
}
/*
* If valid_only is set, data will only be returned if the cached data is
* known still to be valid.
*
* When the device being worked with is known, pass that dev as the second arg.
* This ensures that when duplicates exist, the wrong dev isn't used.
*/
struct lvmcache_info *lvmcache_info_from_pvid(const char *pvid, struct device *dev, int valid_only)
{
struct lvmcache_info *info;
char id[ID_LEN + 1] __attribute__((aligned(8)));
if (!_pvid_hash || !pvid)
return NULL;
(void) dm_strncpy(id, pvid, sizeof(id));
if (!(info = dm_hash_lookup(_pvid_hash, id)))
return NULL;
/*
* When handling duplicate PVs, more than one device can have this pvid.
*/
if (dev && info->dev && (info->dev != dev)) {
log_debug_cache("Ignoring lvmcache info for dev %s because dev %s was requested for PVID %s.",
dev_name(info->dev), dev_name(dev), id);
return NULL;
}
return info;
}
const struct format_type *lvmcache_fmt_from_info(struct lvmcache_info *info)
{
return info->fmt;
}
const char *lvmcache_vgname_from_info(struct lvmcache_info *info)
{
if (info->vginfo)
return info->vginfo->vgname;
return NULL;
}
/*
* Check if any PVs in vg->pvs have the same PVID as any
* entries in _unused_duplicate_devices.
*/
int vg_has_duplicate_pvs(struct volume_group *vg)
{
struct pv_list *pvl;
struct device_list *devl;
dm_list_iterate_items(pvl, &vg->pvs) {
dm_list_iterate_items(devl, &_unused_duplicate_devs) {
if (id_equal(&pvl->pv->id, (const struct id *)devl->dev->pvid))
return 1;
}
}
return 0;
}
static int _dev_in_device_list(struct device *dev, struct dm_list *head)
{
struct device_list *devl;
dm_list_iterate_items(devl, head) {
if (devl->dev == dev)
return 1;
}
return 0;
}
int lvmcache_dev_is_unchosen_duplicate(struct device *dev)
{
return _dev_in_device_list(dev, &_unused_duplicate_devs);
}
/*
* Treat some duplicate devs as if they were filtered out by filters.
* The actual filters are evaluated too early, before a complete
* picture of all PVs is available, to eliminate these duplicates.
*
* By removing some duplicates from unused_duplicate_devs here, we remove
* the restrictions that are placed on using duplicate devs or VGs with
* duplicate devs.
*
* In cases where we know that two duplicates refer to the same underlying
* storage, and we know which dev path to use, it's best for us to just
* use that one preferred device path and ignore the others. It is the cases
* where we are unsure whether dups refer to the same underlying storage where
* we need to keep the unused duplicate referenced in the
* unused_duplicate_devs list, and restrict what we allow done with it.
*
* In the case of md components, we usually filter these out in filter-md,
* but in the special case of md superblocks <= 1.0 where the superblock
* is at the end of the device, filter-md doesn't always eliminate them
* first, so we eliminate them here.
*
* There may other kinds of duplicates that we want to eliminate at
* this point (using the knowledge from the scan) that we couldn't
* eliminate in the filters prior to the scan.
*/
static void _filter_duplicate_devs(struct cmd_context *cmd)
{
struct dev_types *dt = cmd->dev_types;
struct lvmcache_info *info;
struct device_list *devl, *devl2;
dm_list_iterate_items_safe(devl, devl2, &_unused_duplicate_devs) {
if (!(info = lvmcache_info_from_pvid(devl->dev->pvid, NULL, 0)))
continue;
if (MAJOR(info->dev->dev) == dt->md_major) {
log_debug_devs("Ignoring md component duplicate %s", dev_name(devl->dev));
dm_list_del(&devl->list);
free(devl);
}
}
if (dm_list_empty(&_unused_duplicate_devs))
_found_duplicate_pvs = 0;
}
static void _warn_duplicate_devs(struct cmd_context *cmd)
{
char uuid[64] __attribute__((aligned(8)));
struct lvmcache_info *info;
struct device_list *devl, *devl2;
dm_list_iterate_items_safe(devl, devl2, &_unused_duplicate_devs) {
if (!id_write_format((const struct id *)devl->dev->pvid, uuid, sizeof(uuid)))
stack;
log_warn("WARNING: Not using device %s for PV %s.", dev_name(devl->dev), uuid);
}
dm_list_iterate_items_safe(devl, devl2, &_unused_duplicate_devs) {
/* info for the preferred device that we're actually using */
if (!(info = lvmcache_info_from_pvid(devl->dev->pvid, NULL, 0)))
continue;
if (!id_write_format((const struct id *)info->dev->pvid, uuid, sizeof(uuid)))
stack;
log_warn("WARNING: PV %s prefers device %s because %s.",
uuid, dev_name(info->dev), info->dev->duplicate_prefer_reason);
}
}
/*
* Compare _found_duplicate_devs entries with the corresponding duplicate dev
* in lvmcache. There may be multiple duplicates in _found_duplicate_devs for
* a given pvid. If a dev from _found_duplicate_devs is preferred over the dev
* in lvmcache, then drop the dev in lvmcache and rescan the preferred dev to
* add it to lvmcache.
*
* _found_duplicate_devs: duplicate devs found during initial scan.
* These are compared to lvmcache devs to see if any are preferred.
*
* _unused_duplicate_devs: duplicate devs not chosen to be used.
* These are _found_duplicate_devs entries that were not chosen,
* or unpreferred lvmcache devs that were dropped.
*
* del_cache_devs: devices to drop from lvmcache
* add_cache_devs: devices to scan to add to lvmcache
*/
static void _choose_preferred_devs(struct cmd_context *cmd,
struct dm_list *del_cache_devs,
struct dm_list *add_cache_devs)
{
const char *reason;
struct dm_list altdevs;
struct dm_list new_unused;
struct dev_types *dt = cmd->dev_types;
struct device_list *devl, *devl_safe, *alt, *del;
struct lvmcache_info *info;
struct device *dev1, *dev2;
uint32_t dev1_major, dev1_minor, dev2_major, dev2_minor;
uint64_t info_size, dev1_size, dev2_size;
int in_subsys1, in_subsys2;
int is_dm1, is_dm2;
int has_fs1, has_fs2;
int has_lv1, has_lv2;
int same_size1, same_size2;
int prev_unchosen1, prev_unchosen2;
int change;
dm_list_init(&new_unused);
/*
* Create a list of all alternate devs for the same pvid: altdevs.
*/
next:
dm_list_init(&altdevs);
alt = NULL;
dm_list_iterate_items_safe(devl, devl_safe, &_found_duplicate_devs) {
if (!alt) {
dm_list_move(&altdevs, &devl->list);
alt = devl;
} else {
if (!strcmp(alt->dev->pvid, devl->dev->pvid))
dm_list_move(&altdevs, &devl->list);
}
}
if (!alt) {
_destroy_duplicate_device_list(&_unused_duplicate_devs);
dm_list_splice(&_unused_duplicate_devs, &new_unused);
return;
}
/*
* Find the device for the pvid that's currently in lvmcache.
*/
if (!(info = lvmcache_info_from_pvid(alt->dev->pvid, NULL, 0))) {
/* This shouldn't happen */
log_warn("WARNING: PV %s on duplicate device %s not found in cache.",
alt->dev->pvid, dev_name(alt->dev));
goto next;
}
/*
* Compare devices for the given pvid to find one that's preferred.
* "dev1" is the currently preferred device, starting with the device
* currently in lvmcache.
*/
dev1 = info->dev;
dm_list_iterate_items(devl, &altdevs) {
dev2 = devl->dev;
if (dev1 == dev2) {
/* This shouldn't happen */
log_warn("Same duplicate device repeated %s", dev_name(dev1));
continue;
}
prev_unchosen1 = _dev_in_device_list(dev1, &_unused_duplicate_devs);
prev_unchosen2 = _dev_in_device_list(dev2, &_unused_duplicate_devs);
if (!prev_unchosen1 && !prev_unchosen2) {
/*
* The cmd list saves the unchosen preference across
* lvmcache_destroy. Sometimes a single command will
* fill lvmcache, destroy it, and refill it, and we
* want the same duplicate preference to be preserved
* in each instance of lvmcache for a single command.
*/
prev_unchosen1 = _dev_in_device_list(dev1, &cmd->unused_duplicate_devs);
prev_unchosen2 = _dev_in_device_list(dev2, &cmd->unused_duplicate_devs);
}
dev1_major = MAJOR(dev1->dev);
dev1_minor = MINOR(dev1->dev);
dev2_major = MAJOR(dev2->dev);
dev2_minor = MINOR(dev2->dev);
if (!dev_get_size(dev1, &dev1_size))
dev1_size = 0;
if (!dev_get_size(dev2, &dev2_size))
dev2_size = 0;
has_lv1 = (dev1->flags & DEV_USED_FOR_LV) ? 1 : 0;
has_lv2 = (dev2->flags & DEV_USED_FOR_LV) ? 1 : 0;
in_subsys1 = dev_subsystem_part_major(dt, dev1);
in_subsys2 = dev_subsystem_part_major(dt, dev2);
is_dm1 = dm_is_dm_major(dev1_major);
is_dm2 = dm_is_dm_major(dev2_major);
has_fs1 = dm_device_has_mounted_fs(dev1_major, dev1_minor);
has_fs2 = dm_device_has_mounted_fs(dev2_major, dev2_minor);
info_size = info->device_size >> SECTOR_SHIFT;
same_size1 = (dev1_size == info_size);
same_size2 = (dev2_size == info_size);
log_debug_cache("PV %s compare duplicates: %s %u:%u. %s %u:%u.",
devl->dev->pvid,
dev_name(dev1), dev1_major, dev1_minor,
dev_name(dev2), dev2_major, dev2_minor);
log_debug_cache("PV %s: wants size %llu. %s is %llu. %s is %llu.",
devl->dev->pvid,
(unsigned long long)info_size,
dev_name(dev1), (unsigned long long)dev1_size,
dev_name(dev2), (unsigned long long)dev2_size);
log_debug_cache("PV %s: %s was prev %s. %s was prev %s.",
devl->dev->pvid,
dev_name(dev1), prev_unchosen1 ? "not chosen" : "<none>",
dev_name(dev2), prev_unchosen2 ? "not chosen" : "<none>");
log_debug_cache("PV %s: %s %s subsystem. %s %s subsystem.",
devl->dev->pvid,
dev_name(dev1), in_subsys1 ? "is in" : "is not in",
dev_name(dev2), in_subsys2 ? "is in" : "is not in");
log_debug_cache("PV %s: %s %s dm. %s %s dm.",
devl->dev->pvid,
dev_name(dev1), is_dm1 ? "is" : "is not",
dev_name(dev2), is_dm2 ? "is" : "is not");
log_debug_cache("PV %s: %s %s mounted fs. %s %s mounted fs.",
devl->dev->pvid,
dev_name(dev1), has_fs1 ? "has" : "has no",
dev_name(dev2), has_fs2 ? "has" : "has no");
log_debug_cache("PV %s: %s %s LV. %s %s LV.",
devl->dev->pvid,
dev_name(dev1), has_lv1 ? "is used for" : "is not used for",
dev_name(dev2), has_lv2 ? "is used for" : "is not used for");
change = 0;
if (prev_unchosen1 && !prev_unchosen2) {
/* change to 2 (NB when unchosen is set we unprefer) */
change = 1;
reason = "of previous preference";
} else if (prev_unchosen2 && !prev_unchosen1) {
/* keep 1 (NB when unchosen is set we unprefer) */
reason = "of previous preference";
} else if (has_lv1 && !has_lv2) {
/* keep 1 */
reason = "device is used by LV";
} else if (has_lv2 && !has_lv1) {
/* change to 2 */
change = 1;
reason = "device is used by LV";
} else if (same_size1 && !same_size2) {
/* keep 1 */
reason = "device size is correct";
} else if (same_size2 && !same_size1) {
/* change to 2 */
change = 1;
reason = "device size is correct";
} else if (has_fs1 && !has_fs2) {
/* keep 1 */
reason = "device has fs mounted";
} else if (has_fs2 && !has_fs1) {
/* change to 2 */
change = 1;
reason = "device has fs mounted";
} else if (is_dm1 && !is_dm2) {
/* keep 1 */
reason = "device is in dm subsystem";
} else if (is_dm2 && !is_dm1) {
/* change to 2 */
change = 1;
reason = "device is in dm subsystem";
} else if (in_subsys1 && !in_subsys2) {
/* keep 1 */
reason = "device is in subsystem";
} else if (in_subsys2 && !in_subsys1) {
/* change to 2 */
change = 1;
reason = "device is in subsystem";
} else {
reason = "device was seen first";
}
if (change) {
dev1 = dev2;
alt = devl;
}
dev1->duplicate_prefer_reason = reason;
}
if (dev1 != info->dev) {
log_debug_cache("PV %s: switching to device %s instead of device %s.",
dev1->pvid, dev_name(dev1), dev_name(info->dev));
/*
* Move the preferred device from altdevs to add_cache_devs.
* Create a del_cache_devs entry for the current lvmcache
* device to drop.
*/
dm_list_move(add_cache_devs, &alt->list);
if ((del = zalloc(sizeof(*del)))) {
del->dev = info->dev;
dm_list_add(del_cache_devs, &del->list);
}
} else {
log_debug_cache("PV %s: keeping current device %s.", dev1->pvid, dev_name(info->dev));
}
/*
* alt devs not chosen are moved to _unused_duplicate_devs.
* del_cache_devs being dropped are moved to _unused_duplicate_devs
* after being dropped. So, _unused_duplicate_devs represents all
* duplicates not being used in lvmcache.
*/
dm_list_splice(&new_unused, &altdevs);
goto next;
}
/*
* The initial label_scan at the start of the command is done without
* holding VG locks. Then for each VG identified during the label_scan,
* vg_read(vgname) is called while holding the VG lock. The labels
* and metadata on this VG's devices could have changed between the
* initial unlocked label_scan and the current vg_read(). So, we reread
* the labels/metadata for each device in the VG now that we hold the
* lock, and use this for processing the VG.
*
* A label scan is ultimately creating associations between devices
* and VGs so that when vg_read wants to get VG metadata, it knows
* which devices to read.
*
* It's possible that a VG is being modified during the first label
* scan, causing the scan to see inconsistent metadata on different
* devs in the VG. It's possible that those modifications are
* adding/removing devs from the VG, in which case the device/VG
* associations in lvmcache after the scan are not correct.
* NB. It's even possible the VG was removed completely between
* label scan and here, in which case we'd not find the VG in
* lvmcache after this rescan.
*
* A scan will also create in incorrect/incomplete picture of a VG
* when devices have no metadata areas. The scan does not use
* VG metadata to figure out that a dev with no metadata belongs
* to a particular VG, so a device with no mdas will not be linked
* to that VG after a scan.
*/
int lvmcache_label_rescan_vg(struct cmd_context *cmd, const char *vgname, const char *vgid)
{
struct dm_list devs;
struct device_list *devl, *devl2;
struct lvmcache_vginfo *vginfo;
struct lvmcache_info *info;
if (lvmetad_used())
return 1;
dm_list_init(&devs);
if (!(vginfo = lvmcache_vginfo_from_vgname(vgname, vgid)))
return_0;
dm_list_iterate_items(info, &vginfo->infos) {
if (!(devl = malloc(sizeof(*devl)))) {
log_error("device_list element allocation failed");
return 0;
}
devl->dev = info->dev;
dm_list_add(&devs, &devl->list);
}
/* Delete info for each dev, deleting the last info will delete vginfo. */
dm_list_iterate_items(devl, &devs)
lvmcache_del_dev(devl->dev);
/* Dropping the last info struct is supposed to drop vginfo. */
if ((vginfo = lvmcache_vginfo_from_vgname(vgname, vgid)))
log_warn("VG info not dropped before rescan of %s", vgname);
/* FIXME: should we also rescan unused_duplicate_devs for devs
being rescanned here and then repeat resolving the duplicates? */
label_scan_devs(cmd, cmd->filter, &devs);
dm_list_iterate_items_safe(devl, devl2, &devs) {
dm_list_del(&devl->list);
free(devl);
}
if (!(vginfo = lvmcache_vginfo_from_vgname(vgname, vgid))) {
log_warn("VG info not found after rescan of %s", vgname);
return 0;
}
return 1;
}
/*
* Uses label_scan to populate lvmcache with 'vginfo' struct for each VG
* and associated 'info' structs for those VGs. Only VG summary information
* is used to assemble the vginfo/info during the scan, so the resulting
* representation of VG/PV state is incomplete and even incorrect.
* Specifically, PVs with no MDAs are considered orphans and placed in the
* orphan vginfo by lvmcache_label_scan. This is corrected during the
* processing phase as each vg_read() uses VG metadata for each VG to correct
* the lvmcache state, i.e. it moves no-MDA PVs from the orphan vginfo onto
* the correct vginfo. Once vg_read() is finished for all VGs, all of the
* incorrectly placed PVs should have been moved from the orphan vginfo
* onto their correct vginfo's, and the orphan vginfo should (in theory)
* represent only real orphan PVs. (Note: if lvmcache_label_scan is run
* after vg_read udpates to lvmcache state, then the lvmcache will be
* incorrect again, so do not run lvmcache_label_scan during the
* processing phase.)
*
* TODO: in this label scan phase, don't stash no-MDA PVs into the
* orphan VG. We know that's a fiction, and it can have harmful/damaging
* results. Instead, put them into a temporary list where they can be
* pulled from later when vg_read uses metadata to resolve which VG
* they actually belong to.
*/
int lvmcache_label_scan(struct cmd_context *cmd)
{
struct dm_list del_cache_devs;
struct dm_list add_cache_devs;
struct lvmcache_info *info;
struct lvmcache_vginfo *vginfo;
struct device_list *devl;
int vginfo_count = 0;
int r = 0;
if (lvmetad_used()) {
if (!label_scan_setup_bcache())
return 0;
return 1;
}
log_debug_cache("Finding VG info");
/* Avoid recursion when a PVID can't be found! */
if (_scanning_in_progress)
return 0;
_scanning_in_progress = 1;
/* FIXME: can this happen? */
if (!cmd->full_filter) {
log_error("label scan is missing full filter");
goto out;
}
if (!refresh_filters(cmd))
log_error("Scan failed to refresh device filter.");
/*
* Duplicates found during this label scan are added to _found_duplicate_devs().
*/
_destroy_duplicate_device_list(&_found_duplicate_devs);
/*
* Do the actual scanning. This populates lvmcache
* with infos/vginfos based on reading headers from
* each device, and a vg summary from each mda.
*
* Note that this will *skip* scanning a device if
* an info struct already exists in lvmcache for
* the device.
*/
label_scan(cmd);
/*
* _choose_preferred_devs() returns:
*
* . del_cache_devs: a list of devs currently in lvmcache that should
* be removed from lvmcache because they will be replaced with
* alternative devs for the same PV.
*
* . add_cache_devs: a list of devs that are preferred over devs in
* lvmcache for the same PV. These devices should be rescanned to
* populate lvmcache from them.
*
* First remove lvmcache info for the devs to be dropped, then rescan
* the devs that are preferred to add them to lvmcache.
*
* Keep a complete list of all devs that are unused by moving the
* del_cache_devs onto _unused_duplicate_devs.
*/
if (!dm_list_empty(&_found_duplicate_devs)) {
dm_list_init(&del_cache_devs);
dm_list_init(&add_cache_devs);
log_debug_cache("Resolving duplicate devices");
_choose_preferred_devs(cmd, &del_cache_devs, &add_cache_devs);
dm_list_iterate_items(devl, &del_cache_devs) {
log_debug_cache("Drop duplicate device %s in lvmcache", dev_name(devl->dev));
if ((info = lvmcache_info_from_pvid(devl->dev->pvid, NULL, 0)))
lvmcache_del(info);
}
dm_list_iterate_items(devl, &add_cache_devs) {
log_debug_cache("Rescan preferred device %s for lvmcache", dev_name(devl->dev));
label_read(devl->dev);
}
dm_list_splice(&_unused_duplicate_devs, &del_cache_devs);
/*
* This may remove some entries from the unused_duplicates list for
* devs that we know are the same underlying dev.
*/
_filter_duplicate_devs(cmd);
/*
* Warn about remaining duplicates that may actually be separate copies of
* the same device.
*/
_warn_duplicate_devs(cmd);
if (!_found_duplicate_pvs && lvmetad_used()) {
log_warn("WARNING: Disabling lvmetad cache which does not support duplicate PVs.");
lvmetad_set_disabled(cmd, LVMETAD_DISABLE_REASON_DUPLICATES);
}
}
r = 1;
out:
_scanning_in_progress = 0;
dm_list_iterate_items(vginfo, &_vginfos) {
if (is_orphan_vg(vginfo->vgname))
continue;
vginfo_count++;
}
log_debug_cache("Found VG info for %d VGs", vginfo_count);
return r;
}
/*
* When not using lvmetad, lvmcache_label_scan() detects duplicates in
* the basic label_scan(), then filters out some dups, and chooses
* preferred duplicates to use.
*
* When using lvmetad, pvscan --cache does not use lvmcache_label_scan(),
* only label_scan() which detects the duplicates. This function is used
* after pvscan's label_scan() to filter out some dups, print any warnings,
* and disable lvmetad if any dups are left.
*/
void lvmcache_pvscan_duplicate_check(struct cmd_context *cmd)
{
struct device_list *devl;
/* Check if label_scan() detected any dups. */
if (!_found_duplicate_pvs)
return;
/*
* Once all the dups are identified, they are moved from the
* "found" list to the "unused" list to sort out.
*/
dm_list_splice(&_unused_duplicate_devs, &_found_duplicate_devs);
/*
* Remove items from the dups list that we know are the same
* underlying dev, e.g. md components, that we want to just ignore.
*/
_filter_duplicate_devs(cmd);
/*
* If no more dups after ignoring some, then we can use lvmetad.
*/
if (!_found_duplicate_pvs)
return;
/* Duplicates are found where we would have to pick one, so disable lvmetad. */
dm_list_iterate_items(devl, &_unused_duplicate_devs)
log_warn("WARNING: found device with duplicate %s", dev_name(devl->dev));
log_warn("WARNING: Disabling lvmetad cache which does not support duplicate PVs.");
lvmetad_set_disabled(cmd, LVMETAD_DISABLE_REASON_DUPLICATES);
lvmetad_make_unused(cmd);
}
int lvmcache_get_vgnameids(struct cmd_context *cmd, int include_internal,
struct dm_list *vgnameids)
{
struct vgnameid_list *vgnl;
struct lvmcache_vginfo *vginfo;
dm_list_iterate_items(vginfo, &_vginfos) {
if (!include_internal && is_orphan_vg(vginfo->vgname))
continue;
if (!(vgnl = dm_pool_alloc(cmd->mem, sizeof(*vgnl)))) {
log_error("vgnameid_list allocation failed.");
return 0;
}
vgnl->vgid = dm_pool_strdup(cmd->mem, vginfo->vgid);
vgnl->vg_name = dm_pool_strdup(cmd->mem, vginfo->vgname);
if (!vgnl->vgid || !vgnl->vg_name) {
log_error("vgnameid_list member allocation failed.");
return 0;
}
dm_list_add(vgnameids, &vgnl->list);
}
return 1;
}
struct dm_list *lvmcache_get_pvids(struct cmd_context *cmd, const char *vgname,
const char *vgid)
{
struct dm_list *pvids;
struct lvmcache_vginfo *vginfo;
struct lvmcache_info *info;
if (!(pvids = str_list_create(cmd->mem))) {
log_error("pvids list allocation failed");
return NULL;
}
if (!(vginfo = lvmcache_vginfo_from_vgname(vgname, vgid)))
return pvids;
dm_list_iterate_items(info, &vginfo->infos) {
if (!str_list_add(cmd->mem, pvids,
dm_pool_strdup(cmd->mem, info->dev->pvid))) {
log_error("strlist allocation failed");
return NULL;
}
}
return pvids;
}
int lvmcache_get_vg_devs(struct cmd_context *cmd,
struct lvmcache_vginfo *vginfo,
struct dm_list *devs)
{
struct lvmcache_info *info;
struct device_list *devl;
dm_list_iterate_items(info, &vginfo->infos) {
if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl))))
return_0;
devl->dev = info->dev;
dm_list_add(devs, &devl->list);
}
return 1;
}
static struct device *_device_from_pvid(const struct id *pvid, uint64_t *label_sector)
{
struct lvmcache_info *info;
if ((info = lvmcache_info_from_pvid((const char *) pvid, NULL, 0))) {
if (info->label && label_sector)
*label_sector = info->label->sector;
return info->dev;
}
return NULL;
}
struct device *lvmcache_device_from_pvid(struct cmd_context *cmd, const struct id *pvid, uint64_t *label_sector)
{
struct device *dev;
dev = _device_from_pvid(pvid, label_sector);
if (dev)
return dev;
log_debug_devs("No device with uuid %s.", (const char *)pvid);
return NULL;
}
int lvmcache_pvid_in_unchosen_duplicates(const char *pvid)
{
struct device_list *devl;
dm_list_iterate_items(devl, &_unused_duplicate_devs) {
if (!strncmp(devl->dev->pvid, pvid, ID_LEN))
return 1;
}
return 0;
}
static int _free_vginfo(struct lvmcache_vginfo *vginfo)
{
struct lvmcache_vginfo *primary_vginfo, *vginfo2;
int r = 1;
vginfo2 = primary_vginfo = lvmcache_vginfo_from_vgname(vginfo->vgname, NULL);
if (vginfo == primary_vginfo) {
dm_hash_remove(_vgname_hash, vginfo->vgname);
if (vginfo->next && !dm_hash_insert(_vgname_hash, vginfo->vgname,
vginfo->next)) {
log_error("_vgname_hash re-insertion for %s failed",
vginfo->vgname);
r = 0;
}
} else
while (vginfo2) {
if (vginfo2->next == vginfo) {
vginfo2->next = vginfo->next;
break;
}
vginfo2 = vginfo2->next;
}
free(vginfo->system_id);
free(vginfo->vgname);
free(vginfo->creation_host);
if (*vginfo->vgid && _vgid_hash &&
lvmcache_vginfo_from_vgid(vginfo->vgid) == vginfo)
dm_hash_remove(_vgid_hash, vginfo->vgid);
dm_list_del(&vginfo->list);
free(vginfo);
return r;
}
/*
* vginfo must be info->vginfo unless info is NULL
*/
static int _drop_vginfo(struct lvmcache_info *info, struct lvmcache_vginfo *vginfo)
{
if (info)
_vginfo_detach_info(info);
/* vginfo still referenced? */
if (!vginfo || is_orphan_vg(vginfo->vgname) ||
!dm_list_empty(&vginfo->infos))
return 1;
if (!_free_vginfo(vginfo))
return_0;
return 1;
}
void lvmcache_del(struct lvmcache_info *info)
{
if (info->dev->pvid[0] && _pvid_hash)
dm_hash_remove(_pvid_hash, info->dev->pvid);
_drop_vginfo(info, info->vginfo);
info->label->labeller->ops->destroy_label(info->label->labeller,
info->label);
label_destroy(info->label);
free(info);
}
void lvmcache_del_dev(struct device *dev)
{
struct lvmcache_info *info;
if ((info = lvmcache_info_from_pvid((const char *)dev->pvid, dev, 0)))
lvmcache_del(info);
}
/*
* vginfo must be info->vginfo unless info is NULL (orphans)
*/
static int _lvmcache_update_vgid(struct lvmcache_info *info,
struct lvmcache_vginfo *vginfo,
const char *vgid)
{
if (!vgid || !vginfo ||
!strncmp(vginfo->vgid, vgid, ID_LEN))
return 1;
if (vginfo && *vginfo->vgid)
dm_hash_remove(_vgid_hash, vginfo->vgid);
if (!vgid) {
/* FIXME: unreachable code path */
log_debug_cache("lvmcache: %s: clearing VGID", info ? dev_name(info->dev) : vginfo->vgname);
return 1;
}
(void) dm_strncpy(vginfo->vgid, vgid, sizeof(vginfo->vgid));
if (!dm_hash_insert(_vgid_hash, vginfo->vgid, vginfo)) {
log_error("_lvmcache_update: vgid hash insertion failed: %s",
vginfo->vgid);
return 0;
}
if (!is_orphan_vg(vginfo->vgname))
log_debug_cache("lvmcache %s: VG %s: set VGID to " FMTVGID ".",
(info) ? dev_name(info->dev) : "",
vginfo->vgname, vginfo->vgid);
return 1;
}
static int _insert_vginfo(struct lvmcache_vginfo *new_vginfo, const char *vgid,
uint32_t vgstatus, const char *creation_host,
struct lvmcache_vginfo *primary_vginfo)
{
struct lvmcache_vginfo *last_vginfo = primary_vginfo;
char uuid_primary[64] __attribute__((aligned(8)));
char uuid_new[64] __attribute__((aligned(8)));
int use_new = 0;
/* Pre-existing VG takes precedence. Unexported VG takes precedence. */
if (primary_vginfo) {
if (!id_write_format((const struct id *)vgid, uuid_new, sizeof(uuid_new)))
return_0;
if (!id_write_format((const struct id *)&primary_vginfo->vgid, uuid_primary,
sizeof(uuid_primary)))
return_0;
/*
* vginfo is kept for each VG with the same name.
* They are saved with the vginfo->next list.
* These checks just decide the ordering of
* that list.
*
* FIXME: it should no longer matter what order
* the vginfo's are kept in, so we can probably
* remove these comparisons and reordering entirely.
*
* If Primary not exported, new exported => keep
* Else Primary exported, new not exported => change
* Else Primary has hostname for this machine => keep
* Else Primary has no hostname, new has one => change
* Else New has hostname for this machine => change
* Else Keep primary.
*/
if (!(primary_vginfo->status & EXPORTED_VG) &&
(vgstatus & EXPORTED_VG))
log_verbose("Cache: Duplicate VG name %s: "
"Existing %s takes precedence over "
"exported %s", new_vginfo->vgname,
uuid_primary, uuid_new);
else if ((primary_vginfo->status & EXPORTED_VG) &&
!(vgstatus & EXPORTED_VG)) {
log_verbose("Cache: Duplicate VG name %s: "
"%s takes precedence over exported %s",
new_vginfo->vgname, uuid_new,
uuid_primary);
use_new = 1;
} else if (primary_vginfo->creation_host &&
!strcmp(primary_vginfo->creation_host,
primary_vginfo->fmt->cmd->hostname))
log_verbose("Cache: Duplicate VG name %s: "
"Existing %s (created here) takes precedence "
"over %s", new_vginfo->vgname, uuid_primary,
uuid_new);
else if (!primary_vginfo->creation_host && creation_host) {
log_verbose("Cache: Duplicate VG name %s: "
"%s (with creation_host) takes precedence over %s",
new_vginfo->vgname, uuid_new,
uuid_primary);
use_new = 1;
} else if (creation_host &&
!strcmp(creation_host,
primary_vginfo->fmt->cmd->hostname)) {
log_verbose("Cache: Duplicate VG name %s: "
"%s (created here) takes precedence over %s",
new_vginfo->vgname, uuid_new,
uuid_primary);
use_new = 1;
} else {
log_verbose("Cache: Duplicate VG name %s: "
"Prefer existing %s vs new %s",
new_vginfo->vgname, uuid_primary, uuid_new);
}
if (!use_new) {
while (last_vginfo->next)
last_vginfo = last_vginfo->next;
last_vginfo->next = new_vginfo;
return 1;
}
dm_hash_remove(_vgname_hash, primary_vginfo->vgname);
}
if (!dm_hash_insert(_vgname_hash, new_vginfo->vgname, new_vginfo)) {
log_error("cache_update: vg hash insertion failed: %s",
new_vginfo->vgname);
return 0;
}
if (primary_vginfo)
new_vginfo->next = primary_vginfo;
return 1;
}
static int _lvmcache_update_vgname(struct lvmcache_info *info,
const char *vgname, const char *vgid,
uint32_t vgstatus, const char *creation_host,
const struct format_type *fmt)
{
struct lvmcache_vginfo *vginfo, *primary_vginfo;
char mdabuf[32];
if (!vgname || (info && info->vginfo && !strcmp(info->vginfo->vgname, vgname)))
return 1;
/* Remove existing vginfo entry */
if (info)
_drop_vginfo(info, info->vginfo);
if (!(vginfo = lvmcache_vginfo_from_vgname(vgname, vgid))) {
/*
* Create a vginfo struct for this VG and put the vginfo
* into the hash table.
*/
if (!(vginfo = zalloc(sizeof(*vginfo)))) {
log_error("lvmcache_update_vgname: list alloc failed");
return 0;
}
if (!(vginfo->vgname = strdup(vgname))) {
free(vginfo);
log_error("cache vgname alloc failed for %s", vgname);
return 0;
}
dm_list_init(&vginfo->infos);
/*
* A different VG (different uuid) can exist with the same name.
* In this case, the two VGs will have separate vginfo structs,
* but the second will be linked onto the existing vginfo->next,
* not in the hash.
*/
primary_vginfo = lvmcache_vginfo_from_vgname(vgname, NULL);
if (!_insert_vginfo(vginfo, vgid, vgstatus, creation_host, primary_vginfo)) {
free(vginfo->vgname);
free(vginfo);
return 0;
}
/* Ensure orphans appear last on list_iterate */
if (is_orphan_vg(vgname))
dm_list_add(&_vginfos, &vginfo->list);
else
dm_list_add_h(&_vginfos, &vginfo->list);
}
if (info)
_vginfo_attach_info(vginfo, info);
else if (!_lvmcache_update_vgid(NULL, vginfo, vgid)) /* Orphans */
return_0;
/* FIXME Check consistency of list! */
vginfo->fmt = fmt;
if (info) {
if (info->mdas.n)
sprintf(mdabuf, " with %u mda(s)", dm_list_size(&info->mdas));
else
mdabuf[0] = '\0';
log_debug_cache("lvmcache %s: now in VG %s%s%s%s%s.",
dev_name(info->dev),
vgname, vginfo->vgid[0] ? " (" : "",
vginfo->vgid[0] ? vginfo->vgid : "",
vginfo->vgid[0] ? ")" : "", mdabuf);
} else
log_debug_cache("lvmcache: Initialised VG %s.", vgname);
return 1;
}
static int _lvmcache_update_vgstatus(struct lvmcache_info *info, uint32_t vgstatus,
const char *creation_host, const char *lock_type,
const char *system_id)
{
if (!info || !info->vginfo)
return 1;
if ((info->vginfo->status & EXPORTED_VG) != (vgstatus & EXPORTED_VG))
log_debug_cache("lvmcache %s: VG %s %s exported.",
dev_name(info->dev), info->vginfo->vgname,
vgstatus & EXPORTED_VG ? "now" : "no longer");
info->vginfo->status = vgstatus;
if (!creation_host)
goto set_lock_type;
if (info->vginfo->creation_host && !strcmp(creation_host,
info->vginfo->creation_host))
goto set_lock_type;
free(info->vginfo->creation_host);
if (!(info->vginfo->creation_host = strdup(creation_host))) {
log_error("cache creation host alloc failed for %s.",
creation_host);
return 0;
}
log_debug_cache("lvmcache %s: VG %s: set creation host to %s.",
dev_name(info->dev), info->vginfo->vgname, creation_host);
set_lock_type:
if (!lock_type)
goto set_system_id;
if (info->vginfo->lock_type && !strcmp(lock_type, info->vginfo->lock_type))
goto set_system_id;
free(info->vginfo->lock_type);
if (!(info->vginfo->lock_type = strdup(lock_type))) {
log_error("cache lock_type alloc failed for %s", lock_type);
return 0;
}
log_debug_cache("lvmcache %s: VG %s: set lock_type to %s.",
dev_name(info->dev), info->vginfo->vgname, lock_type);
set_system_id:
if (!system_id)
goto out;
if (info->vginfo->system_id && !strcmp(system_id, info->vginfo->system_id))
goto out;
free(info->vginfo->system_id);
if (!(info->vginfo->system_id = strdup(system_id))) {
log_error("cache system_id alloc failed for %s", system_id);
return 0;
}
log_debug_cache("lvmcache %s: VG %s: set system_id to %s.",
dev_name(info->dev), info->vginfo->vgname, system_id);
out:
return 1;
}
int lvmcache_add_orphan_vginfo(const char *vgname, struct format_type *fmt)
{
return _lvmcache_update_vgname(NULL, vgname, vgname, 0, "", fmt);
}
/*
* FIXME: get rid of other callers of this function which call it
* in odd cases to "fix up" some bit of lvmcache state. Make those
* callers fix up what they need to directly, and leave this function
* with one purpose and caller.
*/
int lvmcache_update_vgname_and_id(struct lvmcache_info *info, struct lvmcache_vgsummary *vgsummary)
{
const char *vgname = vgsummary->vgname;
const char *vgid = (char *)&vgsummary->vgid;
struct lvmcache_vginfo *vginfo;
if (!vgname && !info->vginfo) {
log_error(INTERNAL_ERROR "NULL vgname handed to cache");
/* FIXME Remove this */
vgname = info->fmt->orphan_vg_name;
vgid = vgname;
}
/* If PV without mdas is already in a real VG, don't make it orphan */
if (is_orphan_vg(vgname) && info->vginfo &&
mdas_empty_or_ignored(&info->mdas) &&
!is_orphan_vg(info->vginfo->vgname) && critical_section())
return 1;
/*
* Creates a new vginfo struct for this vgname/vgid if none exists,
* and attaches the info struct for the dev to the vginfo.
* Puts the vginfo into the vgname hash table.
*/
if (!_lvmcache_update_vgname(info, vgname, vgid, vgsummary->vgstatus, vgsummary->creation_host, info->fmt)) {
log_error("Failed to update VG %s info in lvmcache.", vgname);
return 0;
}
/*
* Puts the vginfo into the vgid hash table.
*/
if (!_lvmcache_update_vgid(info, info->vginfo, vgid)) {
log_error("Failed to update VG %s info in lvmcache.", vgname);
return 0;
}
/*
* FIXME: identify which case this is and why this is needed, then
* change that so it doesn't use this function and we can remove
* this special case.
* (I think this distinguishes the scan path, where these things
* are set from the vg_read path where lvmcache_update_vg() is
* called which calls this function without seqno/mda_size/mda_checksum.)
*/
if (!vgsummary->seqno && !vgsummary->mda_size && !vgsummary->mda_checksum)
return 1;
if (!(vginfo = info->vginfo))
return 1;
if (!vginfo->seqno) {
vginfo->seqno = vgsummary->seqno;
log_debug_cache("lvmcache %s: VG %s: set seqno to %d",
dev_name(info->dev), vginfo->vgname, vginfo->seqno);
} else if (vgsummary->seqno != vginfo->seqno) {
log_warn("Scan of VG %s from %s found metadata seqno %d vs previous %d.",
vgname, dev_name(info->dev), vgsummary->seqno, vginfo->seqno);
vginfo->scan_summary_mismatch = 1;
/* If we don't return success, this dev info will be removed from lvmcache,
and then we won't be able to rescan it or repair it. */
return 1;
}
if (!vginfo->mda_size) {
vginfo->mda_checksum = vgsummary->mda_checksum;
vginfo->mda_size = vgsummary->mda_size;
log_debug_cache("lvmcache %s: VG %s: set mda_checksum to %x mda_size to %zu",
dev_name(info->dev), vginfo->vgname,
vginfo->mda_checksum, vginfo->mda_size);
} else if ((vginfo->mda_size != vgsummary->mda_size) || (vginfo->mda_checksum != vgsummary->mda_checksum)) {
log_warn("Scan of VG %s from %s found mda_checksum %x mda_size %zu vs previous %x %zu",
vgname, dev_name(info->dev), vgsummary->mda_checksum, vgsummary->mda_size,
vginfo->mda_checksum, vginfo->mda_size);
vginfo->scan_summary_mismatch = 1;
/* If we don't return success, this dev info will be removed from lvmcache,
and then we won't be able to rescan it or repair it. */
return 1;
}
/*
* If a dev has an unmatching checksum, ignore the other
* info from it, keeping the info we already saved.
*/
if (!_lvmcache_update_vgstatus(info, vgsummary->vgstatus, vgsummary->creation_host,
vgsummary->lock_type, vgsummary->system_id)) {
log_error("Failed to update VG %s info in lvmcache.", vgname);
return 0;
}
return 1;
}
int lvmcache_update_vg(struct volume_group *vg, unsigned precommitted)
{
struct pv_list *pvl;
struct lvmcache_info *info;
char pvid_s[ID_LEN + 1] __attribute__((aligned(8)));
struct lvmcache_vgsummary vgsummary = {
.vgname = vg->name,
.vgstatus = vg->status,
.vgid = vg->id,
.system_id = vg->system_id,
.lock_type = vg->lock_type
};
dm_list_iterate_items(pvl, &vg->pvs) {
(void) dm_strncpy(pvid_s, (char *) &pvl->pv->id, sizeof(pvid_s));
/* FIXME Could pvl->pv->dev->pvid ever be different? */
if ((info = lvmcache_info_from_pvid(pvid_s, pvl->pv->dev, 0)) &&
!lvmcache_update_vgname_and_id(info, &vgsummary))
return_0;
}
return 1;
}
/*
* We can see multiple different devices with the
* same pvid, i.e. duplicates.
*
* There may be different reasons for seeing two
* devices with the same pvid:
* - multipath showing two paths to the same thing
* - one device copied to another, e.g. with dd,
* also referred to as cloned devices.
* - a "subsystem" taking a device and creating
* another device of its own that represents the
* underlying device it is using, e.g. using dm
* to create an identity mapping of a PV.
*
* Given duplicate devices, we have to choose one
* of them to be the "preferred" dev, i.e. the one
* that will be referenced in lvmcache, by pv->dev.
* We can keep the existing dev, that's currently
* used in lvmcache, or we can replace the existing
* dev with the new duplicate.
*
* Regardless of which device is preferred, we need
* to print messages explaining which devices were
* found so that a user can sort out for themselves
* what has happened if the preferred device is not
* the one they are interested in.
*
* If a user wants to use the non-preferred device,
* they will need to filter out the device that
* lvm is preferring.
*
* The dev_subsystem calls check if the major number
* of the dev is part of a subsystem like DM/MD/DRBD.
* A dev that's part of a subsystem is preferred over a
* duplicate of that dev that is not part of a
* subsystem.
*
* FIXME: there may be other reasons to prefer one
* device over another:
*
* . are there other use/open counts we could check
* beyond the holders?
*
* . check if either is bad/usable and prefer
* the good one?
*
* . prefer the one with smaller minor number?
* Might avoid disturbing things due to a new
* transient duplicate?
*/
static struct lvmcache_info * _create_info(struct labeller *labeller, struct device *dev)
{
struct lvmcache_info *info;
struct label *label;
if (!(label = label_create(labeller)))
return_NULL;
if (!(info = zalloc(sizeof(*info)))) {
log_error("lvmcache_info allocation failed");
label_destroy(label);
return NULL;
}
info->dev = dev;
info->fmt = labeller->fmt;
label->info = info;
info->label = label;
dm_list_init(&info->list);
lvmcache_del_mdas(info);
lvmcache_del_das(info);
lvmcache_del_bas(info);
return info;
}
struct lvmcache_info *lvmcache_add(struct labeller *labeller,
const char *pvid, struct device *dev,
const char *vgname, const char *vgid, uint32_t vgstatus)
{
char pvid_s[ID_LEN + 1] __attribute__((aligned(8)));
char uuid[64] __attribute__((aligned(8)));
struct lvmcache_vgsummary vgsummary = { 0 };
struct lvmcache_info *info;
struct lvmcache_info *info_lookup;
struct device_list *devl;
int created = 0;
(void) dm_strncpy(pvid_s, pvid, sizeof(pvid_s));
if (!id_write_format((const struct id *)&pvid_s, uuid, sizeof(uuid)))
stack;
/*
* Find existing info struct in _pvid_hash or create a new one.
*
* Don't pass the known "dev" as an arg here. The mismatching
* devs for the duplicate case is checked below.
*/
info = lvmcache_info_from_pvid(pvid_s, NULL, 0);
if (!info)
info = lvmcache_info_from_pvid(dev->pvid, NULL, 0);
if (!info) {
info = _create_info(labeller, dev);
created = 1;
}
if (!info)
return_NULL;
/*
* If an existing info struct was found, check if any values are new.
*/
if (!created) {
if (info->dev != dev) {
log_debug_cache("PV %s on %s was already found on %s.",
uuid, dev_name(dev), dev_name(info->dev));
strncpy(dev->pvid, pvid_s, sizeof(dev->pvid));
/*
* Keep the existing PV/dev in lvmcache, and save the
* new duplicate in the list of duplicates. After
* scanning is complete, compare the duplicate devs
* with those in lvmcache to check if one of the
* duplicates is preferred and if so switch lvmcache to
* use it.
*/
if (!(devl = zalloc(sizeof(*devl))))
return_NULL;
devl->dev = dev;
dm_list_add(&_found_duplicate_devs, &devl->list);
_found_duplicate_pvs = 1;
return NULL;
}
if (info->dev->pvid[0] && pvid[0] && strcmp(pvid_s, info->dev->pvid)) {
/* This happens when running pvcreate on an existing PV. */
log_verbose("Changing pvid on dev %s from %s to %s",
dev_name(info->dev), info->dev->pvid, pvid_s);
}
if (info->label->labeller != labeller) {
log_verbose("Changing labeller on dev %s from %s to %s",
dev_name(info->dev),
info->label->labeller->fmt->name,
labeller->fmt->name);
label_destroy(info->label);
if (!(info->label = label_create(labeller)))
return_NULL;
info->label->info = info;
}
}
/*
* Add or update the _pvid_hash mapping, pvid to info.
*/
info_lookup = dm_hash_lookup(_pvid_hash, pvid_s);
if ((info_lookup == info) && !strcmp(info->dev->pvid, pvid_s))
goto update_vginfo;
if (info->dev->pvid[0])
dm_hash_remove(_pvid_hash, info->dev->pvid);
strncpy(info->dev->pvid, pvid_s, sizeof(info->dev->pvid));
if (!dm_hash_insert(_pvid_hash, pvid_s, info)) {
log_error("Adding pvid to hash failed %s", pvid_s);
return NULL;
}
update_vginfo:
vgsummary.vgstatus = vgstatus;
vgsummary.vgname = vgname;
if (vgid)
strncpy((char *)&vgsummary.vgid, vgid, sizeof(vgsummary.vgid));
if (!lvmcache_update_vgname_and_id(info, &vgsummary)) {
if (created) {
dm_hash_remove(_pvid_hash, pvid_s);
strcpy(info->dev->pvid, "");
free(info->label);
free(info);
}
return NULL;
}
return info;
}
static void _lvmcache_destroy_entry(struct lvmcache_info *info)
{
_vginfo_detach_info(info);
info->dev->pvid[0] = 0;
label_destroy(info->label);
free(info);
}
static void _lvmcache_destroy_vgnamelist(struct lvmcache_vginfo *vginfo)
{
struct lvmcache_vginfo *next;
do {
next = vginfo->next;
if (!_free_vginfo(vginfo))
stack;
} while ((vginfo = next));
}
void lvmcache_destroy(struct cmd_context *cmd, int retain_orphans, int reset)
{
log_debug_cache("Dropping VG info");
_has_scanned = 0;
if (_vgid_hash) {
dm_hash_destroy(_vgid_hash);
_vgid_hash = NULL;
}
if (_pvid_hash) {
dm_hash_iter(_pvid_hash, (dm_hash_iterate_fn) _lvmcache_destroy_entry);
dm_hash_destroy(_pvid_hash);
_pvid_hash = NULL;
}
if (_vgname_hash) {
dm_hash_iter(_vgname_hash,
(dm_hash_iterate_fn) _lvmcache_destroy_vgnamelist);
dm_hash_destroy(_vgname_hash);
_vgname_hash = NULL;
}
if (!dm_list_empty(&_vginfos))
log_error(INTERNAL_ERROR "_vginfos list should be empty");
dm_list_init(&_vginfos);
/*
* Copy the current _unused_duplicate_devs into a cmd list before
* destroying _unused_duplicate_devs.
*
* One command can init/populate/destroy lvmcache multiple times. Each
* time it will encounter duplicates and choose the preferrred devs.
* We want the same preferred devices to be chosen each time, so save
* the unpreferred devs here so that _choose_preferred_devs can use
* this to make the same choice each time.
*/
dm_list_init(&cmd->unused_duplicate_devs);
lvmcache_get_unused_duplicate_devs(cmd, &cmd->unused_duplicate_devs);
_destroy_duplicate_device_list(&_unused_duplicate_devs);
_destroy_duplicate_device_list(&_found_duplicate_devs); /* should be empty anyway */
_found_duplicate_pvs = 0;
if (retain_orphans) {
struct format_type *fmt;
lvmcache_init(cmd);
dm_list_iterate_items(fmt, &cmd->formats) {
if (!lvmcache_add_orphan_vginfo(fmt->orphan_vg_name, fmt))
stack;
}
}
}
int lvmcache_fid_add_mdas(struct lvmcache_info *info, struct format_instance *fid,
const char *id, int id_len)
{
return fid_add_mdas(fid, &info->mdas, id, id_len);
}
int lvmcache_fid_add_mdas_pv(struct lvmcache_info *info, struct format_instance *fid)
{
return lvmcache_fid_add_mdas(info, fid, info->dev->pvid, ID_LEN);
}
int lvmcache_fid_add_mdas_vg(struct lvmcache_vginfo *vginfo, struct format_instance *fid)
{
struct lvmcache_info *info;
dm_list_iterate_items(info, &vginfo->infos) {
if (!lvmcache_fid_add_mdas_pv(info, fid))
return_0;
}
return 1;
}
int lvmcache_populate_pv_fields(struct lvmcache_info *info,
struct volume_group *vg,
struct physical_volume *pv)
{
struct data_area_list *da;
if (!info->label) {
log_error("No cached label for orphan PV %s", pv_dev_name(pv));
return 0;
}
pv->label_sector = info->label->sector;
pv->dev = info->dev;
pv->fmt = info->fmt;
pv->size = info->device_size >> SECTOR_SHIFT;
pv->vg_name = FMT_TEXT_ORPHAN_VG_NAME;
memcpy(&pv->id, &info->dev->pvid, sizeof(pv->id));
if (!pv->size) {
log_error("PV %s size is zero.", dev_name(info->dev));
return 0;
}
/* Currently only support exactly one data area */
if (dm_list_size(&info->das) != 1) {
log_error("Must be exactly one data area (found %d) on PV %s",
dm_list_size(&info->das), dev_name(info->dev));
return 0;
}
/* Currently only support one bootloader area at most */
if (dm_list_size(&info->bas) > 1) {
log_error("Must be at most one bootloader area (found %d) on PV %s",
dm_list_size(&info->bas), dev_name(info->dev));
return 0;
}
dm_list_iterate_items(da, &info->das)
pv->pe_start = da->disk_locn.offset >> SECTOR_SHIFT;
dm_list_iterate_items(da, &info->bas) {
pv->ba_start = da->disk_locn.offset >> SECTOR_SHIFT;
pv->ba_size = da->disk_locn.size >> SECTOR_SHIFT;
}
return 1;
}
int lvmcache_check_format(struct lvmcache_info *info, const struct format_type *fmt)
{
if (info->fmt != fmt) {
log_error("PV %s is a different format (seqno %s)",
dev_name(info->dev), info->fmt->name);
return 0;
}
return 1;
}
void lvmcache_del_mdas(struct lvmcache_info *info)
{
if (info->mdas.n)
del_mdas(&info->mdas);
dm_list_init(&info->mdas);
}
void lvmcache_del_das(struct lvmcache_info *info)
{
if (info->das.n)
del_das(&info->das);
dm_list_init(&info->das);
}
void lvmcache_del_bas(struct lvmcache_info *info)
{
if (info->bas.n)
del_bas(&info->bas);
dm_list_init(&info->bas);
}
int lvmcache_add_mda(struct lvmcache_info *info, struct device *dev,
uint64_t start, uint64_t size, unsigned ignored)
{
return add_mda(info->fmt, NULL, &info->mdas, dev, start, size, ignored);
}
int lvmcache_add_da(struct lvmcache_info *info, uint64_t start, uint64_t size)
{
return add_da(NULL, &info->das, start, size);
}
int lvmcache_add_ba(struct lvmcache_info *info, uint64_t start, uint64_t size)
{
return add_ba(NULL, &info->bas, start, size);
}
void lvmcache_update_pv(struct lvmcache_info *info, struct physical_volume *pv,
const struct format_type *fmt)
{
info->device_size = pv->size << SECTOR_SHIFT;
info->fmt = fmt;
}
int lvmcache_update_das(struct lvmcache_info *info, struct physical_volume *pv)
{
struct data_area_list *da;
if (info->das.n) {
if (!pv->pe_start)
dm_list_iterate_items(da, &info->das)
pv->pe_start = da->disk_locn.offset >> SECTOR_SHIFT;
del_das(&info->das);
} else
dm_list_init(&info->das);
if (!add_da(NULL, &info->das, pv->pe_start << SECTOR_SHIFT, 0 /*pv->size << SECTOR_SHIFT*/))
return_0;
return 1;
}
int lvmcache_update_bas(struct lvmcache_info *info, struct physical_volume *pv)
{
struct data_area_list *ba;
if (info->bas.n) {
if (!pv->ba_start && !pv->ba_size)
dm_list_iterate_items(ba, &info->bas) {
pv->ba_start = ba->disk_locn.offset >> SECTOR_SHIFT;
pv->ba_size = ba->disk_locn.size >> SECTOR_SHIFT;
}
del_das(&info->bas);
} else
dm_list_init(&info->bas);
if (!add_ba(NULL, &info->bas, pv->ba_start << SECTOR_SHIFT, pv->ba_size << SECTOR_SHIFT))
return_0;
return 1;
}
int lvmcache_foreach_pv(struct lvmcache_vginfo *vginfo,
int (*fun)(struct lvmcache_info *, void *),
void *baton)
{
struct lvmcache_info *info;
dm_list_iterate_items(info, &vginfo->infos) {
if (!fun(info, baton))
return_0;
}
return 1;
}
int lvmcache_foreach_mda(struct lvmcache_info *info,
int (*fun)(struct metadata_area *, void *),
void *baton)
{
struct metadata_area *mda;
dm_list_iterate_items(mda, &info->mdas) {
if (!fun(mda, baton))
return_0;
}
return 1;
}
unsigned lvmcache_mda_count(struct lvmcache_info *info)
{
return dm_list_size(&info->mdas);
}
int lvmcache_foreach_da(struct lvmcache_info *info,
int (*fun)(struct disk_locn *, void *),
void *baton)
{
struct data_area_list *da;
dm_list_iterate_items(da, &info->das) {
if (!fun(&da->disk_locn, baton))
return_0;
}
return 1;
}
int lvmcache_foreach_ba(struct lvmcache_info *info,
int (*fun)(struct disk_locn *, void *),
void *baton)
{
struct data_area_list *ba;
dm_list_iterate_items(ba, &info->bas) {
if (!fun(&ba->disk_locn, baton))
return_0;
}
return 1;
}
struct label *lvmcache_get_dev_label(struct device *dev)
{
struct lvmcache_info *info;
if ((info = lvmcache_info_from_pvid(dev->pvid, NULL, 0))) {
/* dev would be different for a duplicate */
if (info->dev == dev)
return info->label;
}
return NULL;
}
int lvmcache_has_dev_info(struct device *dev)
{
if (lvmcache_info_from_pvid(dev->pvid, NULL, 0))
return 1;
return 0;
}
/*
* The lifetime of the label returned is tied to the lifetime of the
* lvmcache_info which is the same as lvmcache itself.
*/
struct label *lvmcache_get_label(struct lvmcache_info *info) {
return info->label;
}
uint64_t lvmcache_device_size(struct lvmcache_info *info) {
return info->device_size;
}
void lvmcache_set_device_size(struct lvmcache_info *info, uint64_t size) {
info->device_size = size;
}
struct device *lvmcache_device(struct lvmcache_info *info) {
return info->dev;
}
void lvmcache_set_ext_version(struct lvmcache_info *info, uint32_t version)
{
info->ext_version = version;
}
uint32_t lvmcache_ext_version(struct lvmcache_info *info) {
return info->ext_version;
}
void lvmcache_set_ext_flags(struct lvmcache_info *info, uint32_t flags) {
info->ext_flags = flags;
}
uint32_t lvmcache_ext_flags(struct lvmcache_info *info) {
return info->ext_flags;
}
int lvmcache_is_orphan(struct lvmcache_info *info) {
if (!info->vginfo)
return 1; /* FIXME? */
return is_orphan_vg(info->vginfo->vgname);
}
int lvmcache_vgid_is_cached(const char *vgid) {
struct lvmcache_vginfo *vginfo;
if (lvmetad_used())
return 1;
vginfo = lvmcache_vginfo_from_vgid(vgid);
if (!vginfo || !vginfo->vgname)
return 0;
if (is_orphan_vg(vginfo->vgname))
return 0;
return 1;
}
uint64_t lvmcache_smallest_mda_size(struct lvmcache_info *info)
{
if (!info)
return UINT64_C(0);
return find_min_mda_size(&info->mdas);
}
const struct format_type *lvmcache_fmt(struct lvmcache_info *info) {
return info->fmt;
}
int lvmcache_lookup_mda(struct lvmcache_vgsummary *vgsummary)
{
struct lvmcache_vginfo *vginfo;
if (!vgsummary->mda_size)
return 0;
/* FIXME Index the checksums */
dm_list_iterate_items(vginfo, &_vginfos) {
if (vgsummary->mda_checksum == vginfo->mda_checksum &&
vgsummary->mda_size == vginfo->mda_size &&
!is_orphan_vg(vginfo->vgname)) {
vgsummary->vgname = vginfo->vgname;
vgsummary->creation_host = vginfo->creation_host;
vgsummary->vgstatus = vginfo->status;
vgsummary->seqno = vginfo->seqno;
/* vginfo->vgid has 1 extra byte then vgsummary->vgid */
memcpy(&vgsummary->vgid, vginfo->vgid, sizeof(vgsummary->vgid));
return 1;
}
}
return 0;
}
int lvmcache_contains_lock_type_sanlock(struct cmd_context *cmd)
{
struct lvmcache_vginfo *vginfo;
dm_list_iterate_items(vginfo, &_vginfos) {
if (vginfo->lock_type && !strcmp(vginfo->lock_type, "sanlock"))
return 1;
}
return 0;
}
void lvmcache_get_max_name_lengths(struct cmd_context *cmd,
unsigned *pv_max_name_len,
unsigned *vg_max_name_len)
{
struct lvmcache_vginfo *vginfo;
struct lvmcache_info *info;
unsigned len;
*vg_max_name_len = 0;
*pv_max_name_len = 0;
dm_list_iterate_items(vginfo, &_vginfos) {
len = strlen(vginfo->vgname);
if (*vg_max_name_len < len)
*vg_max_name_len = len;
dm_list_iterate_items(info, &vginfo->infos) {
len = strlen(dev_name(info->dev));
if (*pv_max_name_len < len)
*pv_max_name_len = len;
}
}
}
int lvmcache_vg_is_foreign(struct cmd_context *cmd, const char *vgname, const char *vgid)
{
struct lvmcache_vginfo *vginfo;
int ret = 0;
if (lvmetad_used())
return lvmetad_vg_is_foreign(cmd, vgname, vgid);
if ((vginfo = lvmcache_vginfo_from_vgid(vgid)))
ret = !is_system_id_allowed(cmd, vginfo->system_id);
return ret;
}
/*
* Example of reading four devs in sequence from the same VG:
*
* dev1:
* lvmcache: creates vginfo with initial values
*
* dev2: all checksums match.
* mda_header checksum matches vginfo from dev1
* metadata checksum matches vginfo from dev1
* metadata is not parsed, and the vgsummary values copied
* from lvmcache from dev1 and passed back to lvmcache for dev2.
* lvmcache: attach info for dev2 to existing vginfo
*
* dev3: mda_header and metadata have unmatching checksums.
* mda_header checksum matches vginfo from dev1
* metadata checksum doesn't match vginfo from dev1
* produces read error in config.c
* lvmcache: info for dev3 is deleted, FIXME: use a defective state
*
* dev4: mda_header and metadata have matching checksums, but
* does not match checksum in lvmcache from prev dev.
* mda_header checksum doesn't match vginfo from dev1
* lvmcache_lookup_mda returns 0, no vgname, no checksum_only
* lvmcache: update_vgname_and_id sees checksum from dev4 does not
* match vginfo from dev1, so vginfo->scan_summary_mismatch is set.
* attach info for dev4 to existing vginfo
*
* dev5: config parsing error.
* lvmcache: info for dev5 is deleted, FIXME: use a defective state
*/
int lvmcache_scan_mismatch(struct cmd_context *cmd, const char *vgname, const char *vgid)
{
struct lvmcache_vginfo *vginfo;
if (!vgname || !vgid)
return 1;
if ((vginfo = lvmcache_vginfo_from_vgid(vgid)))
return vginfo->scan_summary_mismatch;
return 1;
}
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