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lvm2/lib/format_text/format-text.c
David Teigland aecf542126 metadata: prevent writing beyond metadata area 
lvm uses a bcache block size of 128K.  A bcache block
at the end of the metadata area will overlap the PEs
from which LVs are allocated.  How much depends on
alignments.  When lvm reads and writes one of these
bcache blocks to update VG metadata, it can also be
reading and writing PEs that belong to an LV.

If these overlapping PEs are being written to by the
LV user (e.g. filesystem) at the same time that lvm
is modifying VG metadata in the overlapping bcache
block, then the user's updates to the PEs can be lost.

This patch is a quick hack to prevent lvm from writing
past the end of the metadata area.
2018-10-29 16:53:17 -05:00

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/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2012 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 "lib/misc/lib.h"
#include "lib/format_text/format-text.h"
#include "import-export.h"
#include "lib/device/device.h"
#include "lib/misc/lvm-file.h"
#include "lib/config/config.h"
#include "lib/display/display.h"
#include "lib/commands/toolcontext.h"
#include "lib/misc/lvm-string.h"
#include "lib/uuid/uuid.h"
#include "layout.h"
#include "lib/misc/crc.h"
#include "lib/mm/xlate.h"
#include "lib/label/label.h"
#include "lib/cache/lvmcache.h"
#include <unistd.h>
#include <limits.h>
#include <dirent.h>
#include <ctype.h>
static struct format_instance *_text_create_text_instance(const struct format_type *fmt,
const struct format_instance_ctx *fic);
struct text_fid_context {
char *raw_metadata_buf;
uint32_t raw_metadata_buf_size;
};
int rlocn_is_ignored(const struct raw_locn *rlocn)
{
return (rlocn->flags & RAW_LOCN_IGNORED ? 1 : 0);
}
void rlocn_set_ignored(struct raw_locn *rlocn, unsigned mda_ignored)
{
if (mda_ignored)
rlocn->flags |= RAW_LOCN_IGNORED;
else
rlocn->flags &= ~RAW_LOCN_IGNORED;
}
/*
* NOTE: Currently there can be only one vg per text file.
*/
/*
* Only used by vgcreate.
*/
static int _text_vg_setup(struct format_instance *fid,
struct volume_group *vg)
{
if (!vg_check_new_extent_size(vg->fid->fmt, vg->extent_size))
return_0;
return 1;
}
static uint64_t _mda_free_sectors_raw(struct metadata_area *mda)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
return mdac->free_sectors;
}
static uint64_t _mda_total_sectors_raw(struct metadata_area *mda)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
return mdac->area.size >> SECTOR_SHIFT;
}
/*
* Check if metadata area belongs to vg
*/
static int _mda_in_vg_raw(struct format_instance *fid __attribute__((unused)),
struct volume_group *vg, struct metadata_area *mda)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
struct pv_list *pvl;
dm_list_iterate_items(pvl, &vg->pvs)
if (pvl->pv->dev == mdac->area.dev)
return 1;
return 0;
}
static unsigned _mda_locns_match_raw(struct metadata_area *mda1,
struct metadata_area *mda2)
{
struct mda_context *mda1c = (struct mda_context *) mda1->metadata_locn;
struct mda_context *mda2c = (struct mda_context *) mda2->metadata_locn;
if ((mda1c->area.dev == mda2c->area.dev) &&
(mda1c->area.start == mda2c->area.start) &&
(mda1c->area.size == mda2c->area.size))
return 1;
return 0;
}
static struct device *_mda_get_device_raw(struct metadata_area *mda)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
return mdac->area.dev;
}
/*
* For circular region between region_start and region_start + region_size,
* back up one SECTOR_SIZE from 'region_ptr' and return the value.
* This allows reverse traversal through text metadata area to find old
* metadata.
*
* Parameters:
* region_start: start of the region (bytes)
* region_size: size of the region (bytes)
* region_ptr: pointer within the region (bytes)
* NOTE: region_start <= region_ptr <= region_start + region_size
*/
static uint64_t _get_prev_sector_circular(uint64_t region_start,
uint64_t region_size,
uint64_t region_ptr)
{
if (region_ptr >= region_start + SECTOR_SIZE)
return region_ptr - SECTOR_SIZE;
return (region_start + region_size - SECTOR_SIZE);
}
/*
* Analyze a metadata area for old metadata records in the circular buffer.
* This function just looks through and makes a first pass at the data in
* the sectors for particular things.
* FIXME: do something with each metadata area (try to extract vg, write
* raw data to file, etc)
*/
static int _pv_analyze_mda_raw (const struct format_type * fmt,
struct metadata_area *mda)
{
struct mda_header *mdah;
struct raw_locn *rlocn;
uint64_t area_start;
uint64_t area_size;
uint64_t prev_sector, prev_sector2;
uint64_t latest_mrec_offset;
uint64_t offset;
uint64_t offset2;
size_t size;
size_t size2;
char *buf=NULL;
struct device_area *area;
struct mda_context *mdac;
int r=0;
mdac = (struct mda_context *) mda->metadata_locn;
log_print("Found text metadata area: offset=" FMTu64 ", size="
FMTu64, mdac->area.start, mdac->area.size);
area = &mdac->area;
if (!(mdah = raw_read_mda_header(fmt, area, mda_is_primary(mda))))
goto_out;
rlocn = mdah->raw_locns;
/*
* The device area includes the metadata header as well as the
* records, so remove the metadata header from the start and size
*/
area_start = area->start + MDA_HEADER_SIZE;
area_size = area->size - MDA_HEADER_SIZE;
latest_mrec_offset = rlocn->offset + area->start;
/*
* Start searching at rlocn (point of live metadata) and go
* backwards.
*/
prev_sector = _get_prev_sector_circular(area_start, area_size,
latest_mrec_offset);
offset = prev_sector;
size = SECTOR_SIZE;
offset2 = size2 = 0;
while (prev_sector != latest_mrec_offset) {
prev_sector2 = prev_sector;
prev_sector = _get_prev_sector_circular(area_start, area_size,
prev_sector);
if (prev_sector > prev_sector2)
goto_out;
/*
* FIXME: for some reason, the whole metadata region from
* area->start to area->start+area->size is not used.
* Only ~32KB seems to contain valid metadata records
* (LVM2 format - format_text). As a result, I end up with
* "dm_config_maybe_section" returning true when there's no valid
* metadata in a sector (sectors with all nulls).
*/
if (!(buf = malloc(size + size2)))
goto_out;
if (!dev_read_bytes(area->dev, offset, size, buf)) {
log_error("Failed to read dev %s offset %llu size %llu",
dev_name(area->dev),
(unsigned long long)offset,
(unsigned long long)size);
goto out;
}
if (size2) {
if (!dev_read_bytes(area->dev, offset2, size2, buf + size)) {
log_error("Failed to read dev %s offset %llu size %llu",
dev_name(area->dev),
(unsigned long long)offset2,
(unsigned long long)size2);
goto out;
}
}
/*
* FIXME: We could add more sophisticated metadata detection
*/
if (dm_config_maybe_section(buf, size + size2)) {
/* FIXME: Validate region, pull out timestamp?, etc */
/* FIXME: Do something with this region */
log_verbose ("Found LVM2 metadata record at "
"offset=" FMTu64 ", size=" FMTsize_t ", "
"offset2=" FMTu64 " size2=" FMTsize_t,
offset, size, offset2, size2);
offset = prev_sector;
size = SECTOR_SIZE;
offset2 = size2 = 0;
} else {
/*
* Not a complete metadata record, assume we have
* metadata and just increase the size and offset.
* Start the second region if the previous sector is
* wrapping around towards the end of the disk.
*/
if (prev_sector > offset) {
offset2 = prev_sector;
size2 += SECTOR_SIZE;
} else {
offset = prev_sector;
size += SECTOR_SIZE;
}
}
free(buf);
buf = NULL;
}
r = 1;
out:
free(buf);
return r;
}
static int _text_lv_setup(struct format_instance *fid __attribute__((unused)),
struct logical_volume *lv)
{
/******** FIXME Any LV size restriction?
uint64_t max_size = UINT_MAX;
if (lv->size > max_size) {
char *dummy = display_size(max_size);
log_error("logical volumes cannot be larger than %s", dummy);
free(dummy);
return 0;
}
*/
if (!*lv->lvid.s && !lvid_create(&lv->lvid, &lv->vg->id)) {
log_error("Random lvid creation failed for %s/%s.",
lv->vg->name, lv->name);
return 0;
}
return 1;
}
static void _xlate_mdah(struct mda_header *mdah)
{
struct raw_locn *rl;
mdah->version = xlate32(mdah->version);
mdah->start = xlate64(mdah->start);
mdah->size = xlate64(mdah->size);
rl = &mdah->raw_locns[0];
while (rl->offset) {
rl->checksum = xlate32(rl->checksum);
rl->offset = xlate64(rl->offset);
rl->size = xlate64(rl->size);
rl++;
}
}
static int _raw_read_mda_header(struct mda_header *mdah, struct device_area *dev_area, int primary_mda)
{
log_debug_metadata("Reading mda header sector from %s at %llu",
dev_name(dev_area->dev), (unsigned long long)dev_area->start);
if (!dev_read_bytes(dev_area->dev, dev_area->start, MDA_HEADER_SIZE, mdah)) {
log_error("Failed to read metadata area header on %s at %llu",
dev_name(dev_area->dev), (unsigned long long)dev_area->start);
return 0;
}
if (mdah->checksum_xl != xlate32(calc_crc(INITIAL_CRC, (uint8_t *)mdah->magic,
MDA_HEADER_SIZE -
sizeof(mdah->checksum_xl)))) {
log_error("Incorrect checksum in metadata area header on %s at %llu",
dev_name(dev_area->dev), (unsigned long long)dev_area->start);
return 0;
}
_xlate_mdah(mdah);
if (strncmp((char *)mdah->magic, FMTT_MAGIC, sizeof(mdah->magic))) {
log_error("Wrong magic number in metadata area header on %s at %llu",
dev_name(dev_area->dev), (unsigned long long)dev_area->start);
return 0;
}
if (mdah->version != FMTT_VERSION) {
log_error("Incompatible version %u metadata area header on %s at %llu",
mdah->version,
dev_name(dev_area->dev), (unsigned long long)dev_area->start);
return 0;
}
if (mdah->start != dev_area->start) {
log_error("Incorrect start sector %llu in metadata area header on %s at %llu",
(unsigned long long)mdah->start,
dev_name(dev_area->dev), (unsigned long long)dev_area->start);
return 0;
}
return 1;
}
struct mda_header *raw_read_mda_header(const struct format_type *fmt,
struct device_area *dev_area, int primary_mda)
{
struct mda_header *mdah;
if (!(mdah = dm_pool_alloc(fmt->cmd->mem, MDA_HEADER_SIZE))) {
log_error("struct mda_header allocation failed");
return NULL;
}
if (!_raw_read_mda_header(mdah, dev_area, primary_mda)) {
dm_pool_free(fmt->cmd->mem, mdah);
return NULL;
}
return mdah;
}
static int _raw_write_mda_header(const struct format_type *fmt,
struct device *dev, int primary_mda,
uint64_t start_byte, struct mda_header *mdah)
{
strncpy((char *)mdah->magic, FMTT_MAGIC, sizeof(mdah->magic));
mdah->version = FMTT_VERSION;
mdah->start = start_byte;
_xlate_mdah(mdah);
mdah->checksum_xl = xlate32(calc_crc(INITIAL_CRC, (uint8_t *)mdah->magic,
MDA_HEADER_SIZE -
sizeof(mdah->checksum_xl)));
dev_set_last_byte(dev, start_byte + MDA_HEADER_SIZE);
if (!dev_write_bytes(dev, start_byte, MDA_HEADER_SIZE, mdah)) {
dev_unset_last_byte(dev);
log_error("Failed to write mda header to %s fd %d", dev_name(dev), dev->bcache_fd);
return 0;
}
dev_unset_last_byte(dev);
return 1;
}
/*
* FIXME: unify this with read_metadata_location() which is used
* in the label scanning path.
*/
static struct raw_locn *_read_metadata_location_vg(struct device_area *dev_area,
struct mda_header *mdah, int primary_mda,
const char *vgname,
int *precommitted)
{
size_t len;
char vgnamebuf[NAME_LEN + 2] __attribute__((aligned(8)));
struct raw_locn *rlocn, *rlocn_precommitted;
struct lvmcache_info *info;
struct lvmcache_vgsummary vgsummary_orphan = {
.vgname = FMT_TEXT_ORPHAN_VG_NAME,
};
int rlocn_was_ignored;
memcpy(&vgsummary_orphan.vgid, FMT_TEXT_ORPHAN_VG_NAME, sizeof(FMT_TEXT_ORPHAN_VG_NAME));
rlocn = mdah->raw_locns; /* Slot 0 */
rlocn_precommitted = rlocn + 1; /* Slot 1 */
rlocn_was_ignored = rlocn_is_ignored(rlocn);
/* Should we use precommitted metadata? */
if (*precommitted && rlocn_precommitted->size &&
(rlocn_precommitted->offset != rlocn->offset)) {
rlocn = rlocn_precommitted;
log_debug_metadata("VG %s metadata check %s mda %llu slot1 offset %llu size %llu",
vgname ?: "",
dev_name(dev_area->dev),
(unsigned long long)dev_area->start,
(unsigned long long)rlocn->offset,
(unsigned long long)rlocn->size);
} else {
*precommitted = 0;
log_debug_metadata("VG %s metadata check %s mda %llu slot0 offset %llu size %llu",
vgname ?: "",
dev_name(dev_area->dev),
(unsigned long long)dev_area->start,
(unsigned long long)rlocn->offset,
(unsigned long long)rlocn->size);
}
/* Do not check non-existent metadata. */
if (!rlocn->offset && !rlocn->size)
return NULL;
/*
* Don't try to check existing metadata
* if given vgname is an empty string.
*/
if (!*vgname)
return rlocn;
/*
* If live rlocn has ignored flag, data will be out-of-date so skip further checks.
*/
if (rlocn_was_ignored)
return rlocn;
/*
* Verify that the VG metadata pointed to by the rlocn
* begins with a valid vgname.
*/
memset(vgnamebuf, 0, sizeof(vgnamebuf));
if (!dev_read_bytes(dev_area->dev, dev_area->start + rlocn->offset, NAME_LEN, vgnamebuf))
goto fail;
if (!strncmp(vgnamebuf, vgname, len = strlen(vgname)) &&
(isspace(vgnamebuf[len]) || vgnamebuf[len] == '{'))
return rlocn;
fail:
log_error("Metadata on %s at %llu has wrong VG name \"%s\" expected %s.",
dev_name(dev_area->dev),
(unsigned long long)(dev_area->start + rlocn->offset),
vgnamebuf, vgname);
if ((info = lvmcache_info_from_pvid(dev_area->dev->pvid, dev_area->dev, 0)) &&
!lvmcache_update_vgname_and_id(info, &vgsummary_orphan))
stack;
return NULL;
}
/*
* Determine offset for new metadata
*
* FIXME: The rounding can have a negative effect: when the current metadata
* text size is just below the max, a command to remove something, that
* *reduces* the text metadata size, can still be rejected for being too large,
* even though it's smaller than the current size. In this case, the user
* would need to find something in the VG to remove that uses more text space
* to compensate for the increase due to rounding.
*/
static uint64_t _next_rlocn_offset(struct raw_locn *rlocn_old, uint64_t old_last, struct mda_header *mdah, uint64_t mdac_area_start, uint64_t alignment)
{
uint64_t next_start;
uint64_t new_start;
uint64_t adjust;
/*
* No metadata has been written yet, begin at MDA_HEADER_SIZE offset
* from the start of the area.
*/
if (!rlocn_old)
return MDA_HEADER_SIZE;
/*
* If new start would be less than alignment bytes from the end of the
* metadata area, then start at beginning.
*/
if (mdah->size - old_last < alignment) {
log_debug_metadata("new metadata offset adjusted from %llu to beginning %u",
(unsigned long long)(old_last + 1), MDA_HEADER_SIZE);
return MDA_HEADER_SIZE;
}
/*
* New metadata begins after the old, rounded up to alignment.
*/
next_start = old_last + 1;
adjust = alignment - (next_start % alignment);
new_start = next_start + adjust;
log_debug_metadata("new metadata offset adjusted from %llu to %llu (+%llu) for alignment %llu",
(unsigned long long)next_start,
(unsigned long long)new_start,
(unsigned long long)adjust,
(unsigned long long)alignment);
/*
* If new_start is beyond the end of the metadata area or within
* alignment bytes of the end, then start at the beginning.
*/
if (new_start > mdah->size - alignment) {
log_debug_metadata("new metadata offset adjusted from %llu to beginning %u",
(unsigned long long)new_start, MDA_HEADER_SIZE);
return MDA_HEADER_SIZE;
}
return new_start;
}
static struct volume_group *_vg_read_raw_area(struct format_instance *fid,
const char *vgname,
struct device_area *area,
struct cached_vg_fmtdata **vg_fmtdata,
unsigned *use_previous_vg,
int precommitted,
int primary_mda)
{
struct volume_group *vg = NULL;
struct raw_locn *rlocn;
struct mda_header *mdah;
time_t when;
char *desc;
uint32_t wrap = 0;
if (!(mdah = raw_read_mda_header(fid->fmt, area, primary_mda))) {
log_error("Failed to read vg %s from %s", vgname, dev_name(area->dev));
goto_out;
}
if (!(rlocn = _read_metadata_location_vg(area, mdah, primary_mda, vgname, &precommitted))) {
log_debug_metadata("VG %s not found on %s", vgname, dev_name(area->dev));
goto out;
}
if (rlocn->offset + rlocn->size > mdah->size)
wrap = (uint32_t) ((rlocn->offset + rlocn->size) - mdah->size);
vg = text_read_metadata(fid, NULL, vg_fmtdata, use_previous_vg, area->dev, primary_mda,
(off_t) (area->start + rlocn->offset),
(uint32_t) (rlocn->size - wrap),
(off_t) (area->start + MDA_HEADER_SIZE),
wrap,
calc_crc,
rlocn->checksum,
&when, &desc);
if (!vg) {
/* FIXME: detect and handle errors, and distinguish from the optimization
that skips parsing the metadata which also returns NULL. */
}
log_debug_metadata("Found metadata on %s at %llu size %llu for VG %s",
dev_name(area->dev),
(unsigned long long)(area->start + rlocn->offset),
(unsigned long long)rlocn->size,
vgname);
if (vg && precommitted)
vg->status |= PRECOMMITTED;
out:
return vg;
}
static struct volume_group *_vg_read_raw(struct format_instance *fid,
const char *vgname,
struct metadata_area *mda,
struct cached_vg_fmtdata **vg_fmtdata,
unsigned *use_previous_vg)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
struct volume_group *vg;
vg = _vg_read_raw_area(fid, vgname, &mdac->area, vg_fmtdata, use_previous_vg, 0, mda_is_primary(mda));
return vg;
}
static struct volume_group *_vg_read_precommit_raw(struct format_instance *fid,
const char *vgname,
struct metadata_area *mda,
struct cached_vg_fmtdata **vg_fmtdata,
unsigned *use_previous_vg)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
struct volume_group *vg;
vg = _vg_read_raw_area(fid, vgname, &mdac->area, vg_fmtdata, use_previous_vg, 1, mda_is_primary(mda));
return vg;
}
/*
* VG metadata updates:
*
* [mda_header] [raw_locn_0] [raw_locn_1] [text metadata circular buffer]
*
* raw_locn.offset points into the metadata circular buffer to the
* start of metadata.
*
* When vg_read wants to read metadata from disk, it looks at the
* raw_locn_0 offset and reads the text metadata from that location
* in the circular buffer.
*
* Two full copies of the text metadata always exist in the circular
* buffer. When new metadata needs to be written, the following
* process is followed:
*
* - vg_write is called and writes the new text metadata into the
* circular buffer after the end of the current copy. vg_write saves
* an in-memory raw_locn struct (mdac->rlocn) pointing to the new
* metadata in the buffer. No raw_locn structs are written to disk.
*
* - vg_precommit is called and writes the in-memory raw_locn struct that
* was saved by vg_write into raw_locn_1 (slot 1, the "precommit" slot.)
* raw_locn_0 still points to the old metadata, and raw_locn_1 points
* to the new metadata.
*
* - vg_commit is called and writes the new raw_locn struct into raw_locn_0
* (slot 0, the "committed" slot).
*/
/*
* Writes new text metadata into the circular metadata buffer following the
* current (old) text metadata that's already in the metadata buffer.
*
* vg_write does *not* write new raw_locn fields pointing to the new metadata.
* The new raw_locn fields for the new metadata are saved in mdac->rlocn and
* are written later by both vg_precommit and vg_commit. vg_precommit will
* write the new raw_locn into slot 1 and vg_commit will write the new raw_locn
* into slot 0.
*/
static int _vg_write_raw(struct format_instance *fid, struct volume_group *vg,
struct metadata_area *mda)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
struct text_fid_context *fidtc = (struct text_fid_context *) fid->private;
struct raw_locn *rlocn_old;
struct raw_locn *rlocn_new;
struct mda_header *mdah;
struct pv_list *pvl;
uint64_t old_start = 0, old_last = 0, old_size = 0, old_wrap = 0;
uint64_t new_start = 0, new_last = 0, new_size = 0, new_wrap = 0;
uint64_t max_size;
char *new_buf = NULL;
int overlap;
int found = 0;
int r = 0;
/* Ignore any mda on a PV outside the VG. vgsplit relies on this */
dm_list_iterate_items(pvl, &vg->pvs) {
if (pvl->pv->dev == mdac->area.dev) {
found = 1;
break;
}
}
if (!found)
return 1;
if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area, mda_is_primary(mda))))
goto_out;
/*
* Create a text metadata representation of struct vg in buffer.
* This buffer is written to disk below. This function is called
* to write metadata to each device/mda in the VG. The first time
* the metadata text is saved in raw_metadata_buf and subsequent
* mdas use that.
*/
if (fidtc->raw_metadata_buf) {
new_buf = fidtc->raw_metadata_buf;
new_size = fidtc->raw_metadata_buf_size;
} else {
new_size = text_vg_export_raw(vg, "", &new_buf);
fidtc->raw_metadata_buf = new_buf;
fidtc->raw_metadata_buf_size = new_size;
}
if (!new_size || !new_buf) {
log_error("VG %s metadata writing failed", vg->name);
goto out;
}
/*
* The max size of a single copy of text metadata.
*
* The space available for all text metadata is the size of the
* metadata area (mdah->size) minus the sector used for the header.
* Two copies of the text metadata must fit in this space, so it is
* divided in two. This result is then reduced by 512 because any
* single copy of metadata is rounded to begin on a sector boundary.
*/
max_size = ((mdah->size - MDA_HEADER_SIZE) / 2) - 512;
if (new_size > max_size) {
log_error("VG %s metadata on %s (%llu bytes) exceeds maximum metadata size (%llu bytes)",
vg->name,
dev_name(mdac->area.dev),
(unsigned long long)new_size,
(unsigned long long)max_size);
goto out;
}
/*
* rlocn_old is the current, committed, raw_locn data in slot0 on disk.
*
* rlocn_new (mdac->rlocn) is the new, in-memory, raw_locn data for the
* new metadata. It is in-memory only, not yet written to disk.
*
* rlocn_new is not written to disk by vg_write. vg_write only writes
* the new text metadata into the circular buffer, it does not update any
* raw_locn slot to point to that new metadata. vg_write saves raw_locn
* values for the new metadata in memory at mdac->rlocn so that
* vg_precommit and vg_commit can find it later and write it to disk.
*
* rlocn/raw_locn values, old_start, old_last, old_size, new_start,
* new_last, new_size, are all in bytes.
*
* The start and last values are the first and last bytes that hold
* the metadata inclusively, e.g.
* metadata_v1 start = 512, last = 611, size = 100
* metadata_v2 start = 612, last = 711, size = 100
*
* {old,new}_{start,last} values are all offset values from the
* beginning of the metadata area mdac->area.start. At the beginning
* of the metadata area (area.start), the first 512 bytes
* (MDA_HEADER_SIZE) is reserved for the mda_header/raw_locn structs,
* after which the circular buffer of text metadata begins.
* So, the when the text metadata wraps around, it starts again at
* area.start + MDA_HEADER_SIZE.
*/
rlocn_old = &mdah->raw_locns[0]; /* slot0, committed metadata */
if (rlocn_is_ignored(rlocn_old))
rlocn_old = NULL;
else if (!rlocn_old->offset && !rlocn_old->size)
rlocn_old = NULL;
else {
old_start = rlocn_old->offset;
old_size = rlocn_old->size;
if (rlocn_old->offset + rlocn_old->size > mdah->size) {
old_wrap = (old_start + old_size) - mdah->size;
old_last = old_wrap + MDA_HEADER_SIZE - 1;
} else {
old_wrap = 0;
old_last = old_start + old_size - 1;
}
}
/*
* _next_rlocn_offset returns the new offset to use for the new
* metadata. It is set to follow the end of the old metadata, plus
* some adjustment to start the new metadata on a 512 byte alignment.
* If the new metadata would start beyond the end of the metadata area,
* or would start less than 512 bytes before the end of the metadata
* area, then the new start is set back at the beginning
* (metadata begins MDA_HEADER_SIZE after start of metadata area).
*/
new_start = _next_rlocn_offset(rlocn_old, old_last, mdah, mdac->area.start, MDA_ORIGINAL_ALIGNMENT);
if (new_start + new_size > mdah->size) {
new_wrap = (new_start + new_size) - mdah->size;
new_last = new_wrap + MDA_HEADER_SIZE - 1;
} else {
new_wrap = 0;
new_last = new_start + new_size - 1;
}
/*
* Save the new metadata location in memory for vg_precommit and
* vg_commit. The new location is not written to disk here.
*/
rlocn_new = &mdac->rlocn;
rlocn_new->offset = new_start;
rlocn_new->size = new_size;
log_debug_metadata("VG %s metadata offsets: old start %llu last %llu size %llu wrap %llu",
vg->name,
(unsigned long long)old_start,
(unsigned long long)old_last,
(unsigned long long)old_size,
(unsigned long long)old_wrap);
log_debug_metadata("VG %s metadata offsets: new start %llu last %llu size %llu wrap %llu",
vg->name,
(unsigned long long)new_start,
(unsigned long long)new_last,
(unsigned long long)new_size,
(unsigned long long)new_wrap);
/*
* If the new copy of the metadata would overlap the old copy of the
* metadata, it means that the circular metadata buffer is full.
*
* Given the max_size restriction above, two copies of metadata should
* never overlap, so these overlap checks should not be technically
* necessary, and a failure should not occur here. It's left as a
* sanity check. For some unknown time, lvm did not enforce a
* max_size, but rather detected the too-large failure by checking for
* overlap between old and new.
*/
if (new_wrap && old_wrap) {
/* old and new can't both wrap without overlapping */
overlap = 1;
} else if (!new_wrap && !old_wrap &&
(new_start > old_last) && (new_last > new_start)) {
/* new metadata is located entirely after the old metadata */
overlap = 0;
} else if (!new_wrap && !old_wrap &&
(new_start < old_start) && (new_last < old_start)) {
/* new metadata is located entirely before the old metadata */
overlap = 0;
} else if (old_wrap && !new_wrap &&
(old_last < new_start) && (new_start < new_last) && (new_last < old_start)) {
/* when old wraps and the new doesn't, then no overlap is:
old_last followed by new_start followed by new_last
followed by old_start */
overlap = 0;
} else if (new_wrap && !old_wrap &&
(new_last < old_start) && (old_start < old_last) && (old_last < new_start)) {
/* when new wraps and the old doesn't, then no overlap is:
new_last followed by old_start followed by old_last
followed by new_start. */
overlap = 0;
} else {
overlap = 1;
}
if (overlap) {
log_error("VG %s metadata on %s (%llu bytes) too large for circular buffer (%llu bytes with %llu used)",
vg->name,
dev_name(mdac->area.dev),
(unsigned long long)new_size,
(unsigned long long)(mdah->size - MDA_HEADER_SIZE),
(unsigned long long)old_size);
goto out;
}
log_debug_metadata("VG %s metadata write to %s at %llu len %llu (wrap %llu)",
vg->name, dev_name(mdac->area.dev),
(unsigned long long)(mdac->area.start + rlocn_new->offset),
(unsigned long long)(rlocn_new->size - new_wrap),
(unsigned long long)new_wrap);
dev_set_last_byte(mdac->area.dev, mdac->area.start + mdah->size);
if (!dev_write_bytes(mdac->area.dev, mdac->area.start + rlocn_new->offset,
(size_t) (rlocn_new->size - new_wrap), new_buf)) {
log_error("Failed to write metadata to %s fd %d", dev_name(mdac->area.dev), mdac->area.dev->bcache_fd);
dev_unset_last_byte(mdac->area.dev);
goto out;
}
if (new_wrap) {
log_debug_metadata("VG %s metadata write to %s at %llu len %llu (wrapped)",
vg->name, dev_name(mdac->area.dev),
(unsigned long long)(mdac->area.start + MDA_HEADER_SIZE),
(unsigned long long)new_wrap);
if (!dev_write_bytes(mdac->area.dev, mdac->area.start + MDA_HEADER_SIZE,
(size_t) new_wrap, new_buf + rlocn_new->size - new_wrap)) {
log_error("Failed to write metadata wrap to %s fd %d", dev_name(mdac->area.dev), mdac->area.dev->bcache_fd);
dev_unset_last_byte(mdac->area.dev);
goto out;
}
}
dev_unset_last_byte(mdac->area.dev);
rlocn_new->checksum = calc_crc(INITIAL_CRC,
(uint8_t *)new_buf,
(uint32_t)(rlocn_new->size - new_wrap));
if (new_wrap)
rlocn_new->checksum = calc_crc(rlocn_new->checksum,
(uint8_t *)new_buf + rlocn_new->size - new_wrap,
(uint32_t)new_wrap);
r = 1;
out:
if (!r) {
free(fidtc->raw_metadata_buf);
fidtc->raw_metadata_buf = NULL;
fidtc->raw_metadata_buf_size = 0;
}
return r;
}
/*
* Writes new raw_locn to disk that was saved by vg_write_raw (in mdac->rlocn).
* The new raw_locn points to the new metadata that was written by vg_write_raw.
*
* After vg_write writes the new text metadata into the circular buffer,
* vg_precommit writes the new raw_locn (pointing to the new metadata)
* into slot1 (raw_locns[1]). Then vg_commit writes the same raw_locn
* values again, but into slot0 (raw_locns[0]). slot0 is the committed
* slot, and once slot0 is written, subsequent vg_reads will see the new
* metadata.
*/
static int _vg_commit_raw_rlocn(struct format_instance *fid,
struct volume_group *vg,
struct metadata_area *mda,
int precommit)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
struct text_fid_context *fidtc = (struct text_fid_context *) fid->private;
struct mda_header *mdab;
struct raw_locn *rlocn_slot0;
struct raw_locn *rlocn_slot1;
struct raw_locn *rlocn_new;
struct pv_list *pvl;
int r = 0;
int found = 0;
/* Ignore any mda on a PV outside the VG. vgsplit relies on this */
dm_list_iterate_items(pvl, &vg->pvs) {
if (pvl->pv->dev == mdac->area.dev) {
found = 1;
break;
}
}
if (!found)
return 1;
/*
* Data is read into the mdab buffer, the mdab buffer is then modified
* with new raw_locn values, then the mdab buffer is written. Note
* this is different than _vg_write_raw, where data is read into the
* mdah buffer, but the mdah buffer is not modified and mdac->rlocn is
* modified.
*/
if (!(mdab = raw_read_mda_header(fid->fmt, &mdac->area, mda_is_primary(mda))))
goto_out;
/*
* rlocn_slot0/rlocn_slot1 point into mdab which is the buffer that
* will be modified and written.
*/
rlocn_slot0 = &mdab->raw_locns[0];
rlocn_slot1 = &mdab->raw_locns[1];
if (rlocn_is_ignored(rlocn_slot0) || (!rlocn_slot0->offset && !rlocn_slot0->size)) {
rlocn_slot0->offset = 0;
rlocn_slot0->size = 0;
rlocn_slot0->checksum = 0;
rlocn_slot1->offset = 0;
rlocn_slot1->size = 0;
rlocn_slot1->checksum = 0;
}
/*
* mdac->rlocn is the in-memory copy of the new metadata's location on
* disk. mdac->rlocn was saved by vg_write after it wrote the new text
* metadata to disk. This location of the new metadata is now written
* to disk by vg_precommit and vg_commit. vg_precommit writes the new
* location into the precommit slot (slot1 / raw_locns[1]) and
* vg_commit writes the new location into committed slot (slot0 /
* raw_locns[0]).
*
* vg_revert sets the size of the im-memory mdac->rlocn to 0 and calls
* this function to clear the precommit slot.
*/
rlocn_new = &mdac->rlocn;
if (!rlocn_new->size) {
/*
* When there is no new metadata, the precommit slot is
* cleared and the committed slot is left alone. (see revert)
*/
rlocn_slot1->offset = 0;
rlocn_slot1->size = 0;
rlocn_slot1->checksum = 0;
} else if (precommit) {
/*
* vg_precommit writes the new raw_locn into slot 1,
* and keeps the existing committed raw_locn in slot 0.
*/
rlocn_slot1->offset = rlocn_new->offset;
rlocn_slot1->size = rlocn_new->size;
rlocn_slot1->checksum = rlocn_new->checksum;
} else {
/*
* vg_commit writes the new raw_locn into slot 0,
* and zeros the precommitted values in slot 1.
*/
rlocn_slot0->offset = rlocn_new->offset;
rlocn_slot0->size = rlocn_new->size;
rlocn_slot0->checksum = rlocn_new->checksum;
rlocn_slot1->offset = 0;
rlocn_slot1->size = 0;
rlocn_slot1->checksum = 0;
}
rlocn_set_ignored(rlocn_slot0, mda_is_ignored(mda));
if (mdac->rlocn.size) {
if (precommit) {
log_debug_metadata("VG %s metadata precommit seq %u on %s mda header at %llu %s",
vg->name, vg->seqno, dev_name(mdac->area.dev),
(unsigned long long)mdac->area.start,
mda_is_ignored(mda) ? "(ignored)" : "(used)");
log_debug_metadata("VG %s metadata precommit slot0 offset %llu size %llu slot1 offset %llu size %llu",
vg->name,
(unsigned long long)mdab->raw_locns[0].offset,
(unsigned long long)mdab->raw_locns[0].size,
(unsigned long long)mdab->raw_locns[1].offset,
(unsigned long long)mdab->raw_locns[1].size);
} else {
log_debug_metadata("VG %s metadata commit seq %u on %s mda header at %llu %s",
vg->name, vg->seqno, dev_name(mdac->area.dev),
(unsigned long long)mdac->area.start,
mda_is_ignored(mda) ? "(ignored)" : "(used)");
log_debug_metadata("VG %s metadata commit slot0 offset %llu size %llu slot1 offset %llu size %llu",
vg->name,
(unsigned long long)mdab->raw_locns[0].offset,
(unsigned long long)mdab->raw_locns[0].size,
(unsigned long long)mdab->raw_locns[1].offset,
(unsigned long long)mdab->raw_locns[1].size);
}
} else {
if (precommit) {
log_debug_metadata("VG %s metadata precommit empty seq %u on %s mda header at %llu %s",
vg->name, vg->seqno, dev_name(mdac->area.dev),
(unsigned long long)mdac->area.start,
mda_is_ignored(mda) ? "(ignored)" : "(used)");
log_debug_metadata("VG %s metadata precommit empty slot0 offset %llu size %llu slot1 offset %llu size %llu",
vg->name,
(unsigned long long)mdab->raw_locns[0].offset,
(unsigned long long)mdab->raw_locns[0].size,
(unsigned long long)mdab->raw_locns[1].offset,
(unsigned long long)mdab->raw_locns[1].size);
} else {
log_debug_metadata("VG %s metadata commit empty seq %u on %s mda header at %llu %s",
vg->name, vg->seqno, dev_name(mdac->area.dev),
(unsigned long long)mdac->area.start,
mda_is_ignored(mda) ? "(ignored)" : "(used)");
log_debug_metadata("VG %s metadata commit empty slot0 offset %llu size %llu slot1 offset %llu size %llu",
vg->name,
(unsigned long long)mdab->raw_locns[0].offset,
(unsigned long long)mdab->raw_locns[0].size,
(unsigned long long)mdab->raw_locns[1].offset,
(unsigned long long)mdab->raw_locns[1].size);
}
}
rlocn_set_ignored(mdab->raw_locns, mda_is_ignored(mda));
if (!_raw_write_mda_header(fid->fmt, mdac->area.dev, mda_is_primary(mda), mdac->area.start,
mdab)) {
dm_pool_free(fid->fmt->cmd->mem, mdab);
log_error("Failed to write metadata area header");
goto out;
}
r = 1;
out:
if (!precommit) {
free(fidtc->raw_metadata_buf);
fidtc->raw_metadata_buf = NULL;
}
return r;
}
static int _vg_commit_raw(struct format_instance *fid, struct volume_group *vg,
struct metadata_area *mda)
{
return _vg_commit_raw_rlocn(fid, vg, mda, 0);
}
static int _vg_precommit_raw(struct format_instance *fid,
struct volume_group *vg,
struct metadata_area *mda)
{
return _vg_commit_raw_rlocn(fid, vg, mda, 1);
}
/* Close metadata area devices */
static int _vg_revert_raw(struct format_instance *fid, struct volume_group *vg,
struct metadata_area *mda)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
struct pv_list *pvl;
int found = 0;
/* Ignore any mda on a PV outside the VG. vgsplit relies on this */
dm_list_iterate_items(pvl, &vg->pvs) {
if (pvl->pv->dev == mdac->area.dev) {
found = 1;
break;
}
}
if (!found)
return 1;
/* Wipe pre-committed metadata */
mdac->rlocn.size = 0;
return _vg_commit_raw_rlocn(fid, vg, mda, 0);
}
/*
* vg_remove clears the two raw_locn slots but leaves the circular metadata
* buffer alone.
*/
static int _vg_remove_raw(struct format_instance *fid, struct volume_group *vg,
struct metadata_area *mda)
{
struct mda_context *mdac = (struct mda_context *) mda->metadata_locn;
struct mda_header *mdah;
struct raw_locn *rlocn_slot0;
struct raw_locn *rlocn_slot1;
int r = 0;
if (!(mdah = dm_pool_alloc(fid->fmt->cmd->mem, MDA_HEADER_SIZE))) {
log_error("struct mda_header allocation failed");
return 0;
}
/*
* FIXME: what's the point of reading the mda_header and metadata,
* since we zero the rlocn fields whether we can read them or not.
* Just to print the warning?
*/
if (!_raw_read_mda_header(mdah, &mdac->area, mda_is_primary(mda)))
log_warn("WARNING: Removing metadata location on %s with bad mda header.",
dev_name(mdac->area.dev));
rlocn_slot0 = &mdah->raw_locns[0];
rlocn_slot1 = &mdah->raw_locns[1];
rlocn_slot0->offset = 0;
rlocn_slot0->size = 0;
rlocn_slot0->checksum = 0;
rlocn_set_ignored(rlocn_slot0, mda_is_ignored(mda));
rlocn_slot1->offset = 0;
rlocn_slot1->size = 0;
rlocn_slot1->checksum = 0;
if (!_raw_write_mda_header(fid->fmt, mdac->area.dev, mda_is_primary(mda), mdac->area.start,
mdah)) {
dm_pool_free(fid->fmt->cmd->mem, mdah);
log_error("Failed to write metadata area header");
goto out;
}
r = 1;
out:
return r;
}
static struct volume_group *_vg_read_file_name(struct format_instance *fid,
const char *vgname,
const char *read_path)
{
struct volume_group *vg;
time_t when;
char *desc;
if (!(vg = text_read_metadata_file(fid, read_path, &when, &desc))) {
log_error("Failed to read VG %s from %s", vgname, read_path);
return NULL;
}
/*
* Currently you can only have a single volume group per
* text file (this restriction may remain). We need to
* check that it contains the correct volume group.
*/
if (vgname && strcmp(vgname, vg->name)) {
fid->ref_count++; /* Preserve FID after vg release */
release_vg(vg);
log_error("'%s' does not contain volume group '%s'.",
read_path, vgname);
return NULL;
}
log_debug_metadata("Read volume group %s from %s", vg->name, read_path);
return vg;
}
static struct volume_group *_vg_read_file(struct format_instance *fid,
const char *vgname,
struct metadata_area *mda,
struct cached_vg_fmtdata **vg_fmtdata,
unsigned *use_previous_vg __attribute__((unused)))
{
struct text_context *tc = (struct text_context *) mda->metadata_locn;
return _vg_read_file_name(fid, vgname, tc->path_live);
}
static struct volume_group *_vg_read_precommit_file(struct format_instance *fid,
const char *vgname,
struct metadata_area *mda,
struct cached_vg_fmtdata **vg_fmtdata,
unsigned *use_previous_vg __attribute__((unused)))
{
struct text_context *tc = (struct text_context *) mda->metadata_locn;
struct volume_group *vg;
if ((vg = _vg_read_file_name(fid, vgname, tc->path_edit)))
vg->status |= PRECOMMITTED;
else
vg = _vg_read_file_name(fid, vgname, tc->path_live);
return vg;
}
static int _vg_write_file(struct format_instance *fid __attribute__((unused)),
struct volume_group *vg, struct metadata_area *mda)
{
struct text_context *tc = (struct text_context *) mda->metadata_locn;
FILE *fp;
int fd;
char *slash;
char temp_file[PATH_MAX], temp_dir[PATH_MAX];
slash = strrchr(tc->path_edit, '/');
if (slash == 0)
strcpy(temp_dir, ".");
else if (slash - tc->path_edit < PATH_MAX) {
(void) dm_strncpy(temp_dir, tc->path_edit,
(size_t) (slash - tc->path_edit + 1));
} else {
log_error("Text format failed to determine directory.");
return 0;
}
if (!create_temp_name(temp_dir, temp_file, sizeof(temp_file), &fd,
&vg->cmd->rand_seed)) {
log_error("Couldn't create temporary text file name.");
return 0;
}
if (!(fp = fdopen(fd, "w"))) {
log_sys_error("fdopen", temp_file);
if (close(fd))
log_sys_error("fclose", temp_file);
return 0;
}
log_debug_metadata("Writing %s metadata to %s", vg->name, temp_file);
if (!text_vg_export_file(vg, tc->desc, fp)) {
log_error("Failed to write metadata to %s.", temp_file);
if (fclose(fp))
log_sys_error("fclose", temp_file);
return 0;
}
if (fsync(fd) && (errno != EROFS) && (errno != EINVAL)) {
log_sys_error("fsync", tc->path_edit);
if (fclose(fp))
log_sys_error("fclose", tc->path_edit);
return 0;
}
if (lvm_fclose(fp, tc->path_edit))
return_0;
log_debug_metadata("Renaming %s to %s", temp_file, tc->path_edit);
if (rename(temp_file, tc->path_edit)) {
log_error("%s: rename to %s failed: %s", temp_file,
tc->path_edit, strerror(errno));
return 0;
}
return 1;
}
static int _vg_commit_file_backup(struct format_instance *fid __attribute__((unused)),
struct volume_group *vg,
struct metadata_area *mda)
{
struct text_context *tc = (struct text_context *) mda->metadata_locn;
if (test_mode()) {
log_verbose("Test mode: Skipping committing %s metadata (%u)",
vg->name, vg->seqno);
if (unlink(tc->path_edit)) {
log_debug_metadata("Unlinking %s", tc->path_edit);
log_sys_error("unlink", tc->path_edit);
return 0;
}
} else {
log_debug_metadata("Committing file %s metadata (%u)", vg->name, vg->seqno);
log_debug_metadata("Renaming %s to %s", tc->path_edit, tc->path_live);
if (rename(tc->path_edit, tc->path_live)) {
log_error("%s: rename to %s failed: %s", tc->path_edit,
tc->path_live, strerror(errno));
return 0;
}
}
sync_dir(tc->path_edit);
return 1;
}
static int _vg_commit_file(struct format_instance *fid, struct volume_group *vg,
struct metadata_area *mda)
{
struct text_context *tc = (struct text_context *) mda->metadata_locn;
const char *slash;
char new_name[PATH_MAX];
size_t len;
if (!_vg_commit_file_backup(fid, vg, mda))
return 0;
/* vgrename? */
if ((slash = strrchr(tc->path_live, '/')))
slash = slash + 1;
else
slash = tc->path_live;
if (strcmp(slash, vg->name)) {
len = slash - tc->path_live;
if ((len + strlen(vg->name)) > (sizeof(new_name) - 1)) {
log_error("Renaming path %s is too long for VG %s.",
tc->path_live, vg->name);
return 0;
}
strncpy(new_name, tc->path_live, len);
strcpy(new_name + len, vg->name);
log_debug_metadata("Renaming %s to %s", tc->path_live, new_name);
if (test_mode())
log_verbose("Test mode: Skipping rename");
else {
if (rename(tc->path_live, new_name)) {
log_error("%s: rename to %s failed: %s",
tc->path_live, new_name,
strerror(errno));
sync_dir(new_name);
return 0;
}
}
}
return 1;
}
static int _vg_remove_file(struct format_instance *fid __attribute__((unused)),
struct volume_group *vg __attribute__((unused)),
struct metadata_area *mda)
{
struct text_context *tc = (struct text_context *) mda->metadata_locn;
if (path_exists(tc->path_edit) && unlink(tc->path_edit)) {
log_sys_error("unlink", tc->path_edit);
return 0;
}
if (path_exists(tc->path_live) && unlink(tc->path_live)) {
log_sys_error("unlink", tc->path_live);
return 0;
}
sync_dir(tc->path_live);
return 1;
}
int read_metadata_location_summary(const struct format_type *fmt,
struct mda_header *mdah, int primary_mda, struct device_area *dev_area,
struct lvmcache_vgsummary *vgsummary, uint64_t *mda_free_sectors)
{
struct raw_locn *rlocn;
uint32_t wrap = 0;
unsigned int len = 0;
char namebuf[NAME_LEN + 1] __attribute__((aligned(8)));
uint64_t max_size;
if (!mdah) {
log_error(INTERNAL_ERROR "read_metadata_location_summary called with NULL pointer for mda_header");
return 0;
}
/*
* For the case where the metadata area is unused, half is available.
*/
if (mda_free_sectors) {
max_size = ((mdah->size - MDA_HEADER_SIZE) / 2) - 512;
*mda_free_sectors = max_size >> SECTOR_SHIFT;
}
rlocn = mdah->raw_locns; /* slot0, committed metadata */
/*
* If no valid offset, do not try to search for vgname
*/
if (!rlocn->offset) {
log_debug_metadata("Metadata location on %s at %llu has offset 0.",
dev_name(dev_area->dev),
(unsigned long long)(dev_area->start + rlocn->offset));
vgsummary->zero_offset = 1;
return 0;
}
memset(namebuf, 0, sizeof(namebuf));
if (!dev_read_bytes(dev_area->dev, dev_area->start + rlocn->offset, NAME_LEN, namebuf))
stack;
while (namebuf[len] && !isspace(namebuf[len]) && namebuf[len] != '{' &&
len < (NAME_LEN - 1))
len++;
namebuf[len] = '\0';
/*
* Check that the text metadata in the circular buffer begins with a
* valid vg name.
*/
if (!validate_name(namebuf)) {
log_error("Metadata location on %s at %llu begins with invalid VG name.",
dev_name(dev_area->dev),
(unsigned long long)(dev_area->start + rlocn->offset));
return 0;
}
/*
* When the current metadata wraps around the end of the metadata area
* (so some is located at the end and some is located at the
* beginning), then "wrap" is the number of bytes that was written back
* at the beginning. The end of this wrapped metadata is located at an
* offset of wrap+MDA_HEADER_SIZE from area.start.
*/
if (rlocn->offset + rlocn->size > mdah->size)
wrap = (uint32_t) ((rlocn->offset + rlocn->size) - mdah->size);
/*
* Did we see this metadata before?
* Look in lvmcache to see if there is vg info matching
* the checksum/size that we see in the mda_header (rlocn)
* on this device. If so, then vgsummary->name is is set
* and controls if the "checksum_only" flag passed to
* text_read_metadata_summary() is 1 or 0.
*
* If checksum_only = 1, then text_read_metadata_summary()
* will read the metadata from this device, and run the
* checksum function on it. If the calculated checksum
* of the metadata matches the checksum in the mda_header,
* which also matches the checksum saved in vginfo from
* another device, then it skips parsing the metadata into
* a config tree, which saves considerable cpu time.
*
* (NB. there can be different VGs with different metadata
* and checksums, but with the same name.)
*
* FIXME: handle the case where mda_header checksum is bad
* but metadata checksum is good.
*/
/*
* If the checksum we compute of the metadata differs from
* the checksum from mda_header that we save here, then we
* ignore the device. FIXME: we need to classify a device
* with errors like this as defective.
*
* If the checksum from mda_header and computed from metadata
* does not match the checksum saved in lvmcache from a prev
* device, then we do not skip parsing/saving metadata from
* this dev. It's parsed, fields saved in vgsummary, which
* is passed into lvmcache (update_vgname_and_id), and
* there we'll see a checksum mismatch.
*/
vgsummary->mda_checksum = rlocn->checksum;
vgsummary->mda_size = rlocn->size;
lvmcache_lookup_mda(vgsummary);
if (!text_read_metadata_summary(fmt, dev_area->dev, MDA_CONTENT_REASON(primary_mda),
(off_t) (dev_area->start + rlocn->offset),
(uint32_t) (rlocn->size - wrap),
(off_t) (dev_area->start + MDA_HEADER_SIZE),
wrap, calc_crc, vgsummary->vgname ? 1 : 0,
vgsummary)) {
log_error("Metadata location on %s at %llu has invalid summary for VG.",
dev_name(dev_area->dev),
(unsigned long long)(dev_area->start + rlocn->offset));
return 0;
}
/* Ignore this entry if the characters aren't permissible */
if (!validate_name(vgsummary->vgname)) {
log_error("Metadata location on %s at %llu has invalid VG name.",
dev_name(dev_area->dev),
(unsigned long long)(dev_area->start + rlocn->offset));
return 0;
}
log_debug_metadata("Found metadata summary on %s at %llu size %llu for VG %s",
dev_name(dev_area->dev),
(unsigned long long)(dev_area->start + rlocn->offset),
(unsigned long long)rlocn->size,
vgsummary->vgname);
if (mda_free_sectors) {
/*
* Report remaining space given that a single copy of metadata
* can be as large as half the total metadata space, minus 512
* because each copy is rounded to begin on a sector boundary.
*/
max_size = ((mdah->size - MDA_HEADER_SIZE) / 2) - 512;
if (rlocn->size >= max_size)
*mda_free_sectors = UINT64_C(0);
else
*mda_free_sectors = (max_size - rlocn->size) >> SECTOR_SHIFT;
}
return 1;
}
struct _write_single_mda_baton {
const struct format_type *fmt;
struct physical_volume *pv;
};
static int _write_single_mda(struct metadata_area *mda, void *baton)
{
struct _write_single_mda_baton *p = baton;
struct mda_context *mdac;
char buf[MDA_HEADER_SIZE] __attribute__((aligned(8))) = { 0 };
struct mda_header *mdah = (struct mda_header *) buf;
mdac = mda->metadata_locn;
mdah->size = mdac->area.size;
rlocn_set_ignored(mdah->raw_locns, mda_is_ignored(mda));
if (!_raw_write_mda_header(p->fmt, mdac->area.dev, mda_is_primary(mda),
mdac->area.start, mdah)) {
return_0;
}
return 1;
}
static int _set_ext_flags(struct physical_volume *pv, struct lvmcache_info *info)
{
uint32_t ext_flags = lvmcache_ext_flags(info);
if (is_orphan(pv))
ext_flags &= ~PV_EXT_USED;
else
ext_flags |= PV_EXT_USED;
lvmcache_set_ext_version(info, PV_HEADER_EXTENSION_VSN);
lvmcache_set_ext_flags(info, ext_flags);
return 1;
}
/* Only for orphans - FIXME That's not true any more */
static int _text_pv_write(const struct format_type *fmt, struct physical_volume *pv)
{
struct format_instance *fid = pv->fid;
const char *pvid = (const char *) (*pv->old_id.uuid ? &pv->old_id : &pv->id);
struct label *label;
struct lvmcache_info *info;
struct mda_context *mdac;
struct metadata_area *mda;
struct _write_single_mda_baton baton;
unsigned mda_index;
/* Add a new cache entry with PV info or update existing one. */
if (!(info = lvmcache_add(fmt->labeller, (const char *) &pv->id,
pv->dev, pv->vg_name,
is_orphan_vg(pv->vg_name) ? pv->vg_name : pv->vg ? (const char *) &pv->vg->id : NULL, 0)))
return_0;
label = lvmcache_get_label(info);
label->sector = pv->label_sector;
label->dev = pv->dev;
lvmcache_update_pv(info, pv, fmt);
/* Flush all cached metadata areas, we will reenter new/modified ones. */
lvmcache_del_mdas(info);
/*
* Add all new or modified metadata areas for this PV stored in
* its format instance. If this PV is not part of a VG yet,
* pv->fid will be used. Otherwise pv->vg->fid will be used.
* The fid_get_mda_indexed fn can handle that transparently,
* just pass the right format_instance in.
*/
for (mda_index = 0; mda_index < FMT_TEXT_MAX_MDAS_PER_PV; mda_index++) {
if (!(mda = fid_get_mda_indexed(fid, pvid, ID_LEN, mda_index)))
continue;
mdac = (struct mda_context *) mda->metadata_locn;
log_debug_metadata("Creating metadata area on %s at sector "
FMTu64 " size " FMTu64 " sectors",
dev_name(mdac->area.dev),
mdac->area.start >> SECTOR_SHIFT,
mdac->area.size >> SECTOR_SHIFT);
// if fmt is not the same as info->fmt we are in trouble
if (!lvmcache_add_mda(info, mdac->area.dev,
mdac->area.start, mdac->area.size,
mda_is_ignored(mda)))
return_0;
}
if (!lvmcache_update_bas(info, pv))
return_0;
/*
* FIXME: Allow writing zero offset/size data area to disk.
* This requires defining a special value since we can't
* write offset/size that is 0/0 - this is already reserved
* as a delimiter in data/metadata area area list in PV header
* (needs exploring compatibility with older lvm2).
*/
/*
* We can't actually write pe_start = 0 (a data area offset)
* in PV header now. We need to replace this value here. This can
* happen with vgcfgrestore with redefined pe_start or
* pvcreate --restorefile. However, we can can have this value in
* metadata which will override the value in the PV header.
*/
if (!lvmcache_update_das(info, pv))
return_0;
baton.pv = pv;
baton.fmt = fmt;
if (!lvmcache_foreach_mda(info, _write_single_mda, &baton))
return_0;
if (!_set_ext_flags(pv, info))
return_0;
if (!label_write(pv->dev, label)) {
stack;
return 0;
}
/*
* FIXME: We should probably use the format instance's metadata
* areas for label_write and only if it's successful,
* update the cache afterwards?
*/
return 1;
}
static int _text_pv_needs_rewrite(const struct format_type *fmt, struct physical_volume *pv,
int *needs_rewrite)
{
struct lvmcache_info *info;
uint32_t ext_vsn;
*needs_rewrite = 0;
if (!pv->is_labelled)
return 1;
if (!(info = lvmcache_info_from_pvid((const char *)&pv->id, pv->dev, 0))) {
log_error("Failed to find cached info for PV %s.", pv_dev_name(pv));
return 0;
}
ext_vsn = lvmcache_ext_version(info);
if (ext_vsn < PV_HEADER_EXTENSION_VSN)
*needs_rewrite = 1;
return 1;
}
/*
* Copy constructor for a metadata_locn.
*/
static void *_metadata_locn_copy_raw(struct dm_pool *mem, void *metadata_locn)
{
struct mda_context *mdac, *mdac_new;
mdac = (struct mda_context *) metadata_locn;
if (!(mdac_new = dm_pool_alloc(mem, sizeof(*mdac_new)))) {
log_error("mda_context allocation failed");
return NULL;
}
memcpy(mdac_new, mdac, sizeof(*mdac));
return mdac_new;
}
/*
* Return a string description of the metadata location.
*/
static const char *_metadata_locn_name_raw(void *metadata_locn)
{
struct mda_context *mdac = (struct mda_context *) metadata_locn;
return dev_name(mdac->area.dev);
}
static uint64_t _metadata_locn_offset_raw(void *metadata_locn)
{
struct mda_context *mdac = (struct mda_context *) metadata_locn;
return mdac->area.start;
}
static int _text_pv_initialise(const struct format_type *fmt,
struct pv_create_args *pva,
struct physical_volume *pv)
{
unsigned long data_alignment = pva->data_alignment;
unsigned long data_alignment_offset = pva->data_alignment_offset;
unsigned long adjustment, final_alignment = 0;
if (!data_alignment)
data_alignment = find_config_tree_int(pv->fmt->cmd, devices_data_alignment_CFG, NULL) * 2;
if (set_pe_align(pv, data_alignment) != data_alignment &&
data_alignment) {
log_error("%s: invalid data alignment of "
"%lu sectors (requested %lu sectors)",
pv_dev_name(pv), pv->pe_align, data_alignment);
return 0;
}
if (set_pe_align_offset(pv, data_alignment_offset) != data_alignment_offset &&
data_alignment_offset) {
log_error("%s: invalid data alignment offset of "
"%lu sectors (requested %lu sectors)",
pv_dev_name(pv), pv->pe_align_offset, data_alignment_offset);
return 0;
}
if (pv->pe_align < pv->pe_align_offset) {
log_error("%s: pe_align (%lu sectors) must not be less "
"than pe_align_offset (%lu sectors)",
pv_dev_name(pv), pv->pe_align, pv->pe_align_offset);
return 0;
}
final_alignment = pv->pe_align + pv->pe_align_offset;
if (pv->size < final_alignment) {
log_error("%s: Data alignment must not exceed device size.",
pv_dev_name(pv));
return 0;
}
if (pv->size < final_alignment + pva->ba_size) {
log_error("%s: Bootloader area with data-aligned start must "
"not exceed device size.", pv_dev_name(pv));
return 0;
}
if (pva->pe_start == PV_PE_START_CALC) {
/*
* Calculate new PE start and bootloader area start value.
* Make sure both are properly aligned!
* If PE start can't be aligned because BA is taking
* the whole space, make PE start equal to the PV size
* which effectively disables DA - it will have zero size.
* This needs to be done as we can't have a PV without any DA.
* But we still want to support a PV with BA only!
*/
if (pva->ba_size) {
pv->ba_start = final_alignment;
pv->ba_size = pva->ba_size;
if ((adjustment = pva->ba_size % pv->pe_align))
pv->ba_size += pv->pe_align - adjustment;
if (pv->size < pv->ba_start + pv->ba_size)
pv->ba_size = pv->size - pv->ba_start;
pv->pe_start = pv->ba_start + pv->ba_size;
} else
pv->pe_start = final_alignment;
} else {
/*
* Try to keep the value of PE start set to a firm value if
* requested. This is useful when restoring existing PE start
* value (e.g. backups). Also, if creating a BA, try to place
* it in between the final alignment and existing PE start
* if possible.
*/
pv->pe_start = pva->pe_start;
if (pva->ba_size) {
if ((pva->ba_start && pva->ba_start + pva->ba_size > pva->pe_start) ||
(pva->pe_start <= final_alignment) ||
(pva->pe_start - final_alignment < pva->ba_size)) {
log_error("%s: Bootloader area would overlap "
"data area.", pv_dev_name(pv));
return 0;
}
pv->ba_start = pva->ba_start ? : final_alignment;
pv->ba_size = pva->ba_size;
}
}
if (pva->extent_size)
pv->pe_size = pva->extent_size;
if (pva->extent_count)
pv->pe_count = pva->extent_count;
if ((pv->pe_start + pv->pe_count * (uint64_t)pv->pe_size - 1) > pv->size) {
log_error("Physical extents end beyond end of device %s.",
pv_dev_name(pv));
return 0;
}
if (pva->label_sector != -1)
pv->label_sector = pva->label_sector;
return 1;
}
static void _text_destroy_instance(struct format_instance *fid)
{
if (--fid->ref_count <= 1) {
if (fid->metadata_areas_index)
dm_hash_destroy(fid->metadata_areas_index);
dm_pool_destroy(fid->mem);
}
}
static void _text_destroy(struct format_type *fmt)
{
if (fmt->orphan_vg)
free_orphan_vg(fmt->orphan_vg);
if (fmt->private)
free(fmt->private);
free(fmt);
}
static struct metadata_area_ops _metadata_text_file_ops = {
.vg_read = _vg_read_file,
.vg_read_precommit = _vg_read_precommit_file,
.vg_write = _vg_write_file,
.vg_remove = _vg_remove_file,
.vg_commit = _vg_commit_file
};
static struct metadata_area_ops _metadata_text_file_backup_ops = {
.vg_read = _vg_read_file,
.vg_write = _vg_write_file,
.vg_remove = _vg_remove_file,
.vg_commit = _vg_commit_file_backup
};
static struct metadata_area_ops _metadata_text_raw_ops = {
.vg_read = _vg_read_raw,
.vg_read_precommit = _vg_read_precommit_raw,
.vg_write = _vg_write_raw,
.vg_remove = _vg_remove_raw,
.vg_precommit = _vg_precommit_raw,
.vg_commit = _vg_commit_raw,
.vg_revert = _vg_revert_raw,
.mda_metadata_locn_copy = _metadata_locn_copy_raw,
.mda_metadata_locn_name = _metadata_locn_name_raw,
.mda_metadata_locn_offset = _metadata_locn_offset_raw,
.mda_free_sectors = _mda_free_sectors_raw,
.mda_total_sectors = _mda_total_sectors_raw,
.mda_in_vg = _mda_in_vg_raw,
.pv_analyze_mda = _pv_analyze_mda_raw,
.mda_locns_match = _mda_locns_match_raw,
.mda_get_device = _mda_get_device_raw,
};
static int _text_pv_setup(const struct format_type *fmt,
struct physical_volume *pv,
struct volume_group *vg)
{
struct format_instance *fid = pv->fid;
const char *pvid = (const char *) (*pv->old_id.uuid ? &pv->old_id : &pv->id);
struct lvmcache_info *info;
unsigned mda_index;
struct metadata_area *pv_mda, *pv_mda_copy;
struct mda_context *pv_mdac;
uint64_t pe_count;
uint64_t size_reduction = 0;
/* If PV has its own format instance, add mdas from pv->fid to vg->fid. */
if (pv->fid != vg->fid) {
for (mda_index = 0; mda_index < FMT_TEXT_MAX_MDAS_PER_PV; mda_index++) {
if (!(pv_mda = fid_get_mda_indexed(fid, pvid, ID_LEN, mda_index)))
continue;
/* Be sure it's not already in VG's format instance! */
if (!fid_get_mda_indexed(vg->fid, pvid, ID_LEN, mda_index)) {
if (!(pv_mda_copy = mda_copy(vg->fid->mem, pv_mda)))
return_0;
fid_add_mda(vg->fid, pv_mda_copy, pvid, ID_LEN, mda_index);
}
}
}
/*
* Otherwise, if the PV is already a part of the VG (pv->fid == vg->fid),
* reread PV mda information from the cache and add it to vg->fid.
*/
else {
if (!pv->dev ||
!(info = lvmcache_info_from_pvid(pv->dev->pvid, pv->dev, 0))) {
log_error("PV %s missing from cache", pv_dev_name(pv));
return 0;
}
if (!lvmcache_check_format(info, fmt))
return_0;
if (!lvmcache_fid_add_mdas_pv(info, fid))
return_0;
}
/* If there's the 2nd mda, we need to reduce
* usable size for further pe_count calculation! */
if ((pv_mda = fid_get_mda_indexed(fid, pvid, ID_LEN, 1)) &&
(pv_mdac = pv_mda->metadata_locn))
size_reduction = pv_mdac->area.size >> SECTOR_SHIFT;
/* From now on, VG format instance will be used. */
pv_set_fid(pv, vg->fid);
/* FIXME Cope with genuine pe_count 0 */
/* If missing, estimate pv->size from file-based metadata */
if (!pv->size && pv->pe_count)
pv->size = pv->pe_count * (uint64_t) vg->extent_size +
pv->pe_start + size_reduction;
/* Recalculate number of extents that will fit */
if (!pv->pe_count && vg->extent_size) {
pe_count = (pv->size - pv->pe_start - size_reduction) /
vg->extent_size;
if (pe_count > UINT32_MAX) {
log_error("PV %s too large for extent size %s.",
pv_dev_name(pv),
display_size(vg->cmd, (uint64_t) vg->extent_size));
return 0;
}
pv->pe_count = (uint32_t) pe_count;
}
return 1;
}
static void *_create_text_context(struct dm_pool *mem, struct text_context *tc)
{
struct text_context *new_tc;
const char *path;
char *tmp;
if (!tc)
return NULL;
path = tc->path_live;
if ((tmp = strstr(path, ".tmp")) && (tmp == path + strlen(path) - 4)) {
log_error("%s: Volume group filename may not end in .tmp",
path);
return NULL;
}
if (!(new_tc = dm_pool_alloc(mem, sizeof(*new_tc))))
return_NULL;
if (!(new_tc->path_live = dm_pool_strdup(mem, path)))
goto_bad;
/* If path_edit not defined, create one from path_live with .tmp suffix. */
if (!tc->path_edit) {
if (!(tmp = dm_pool_alloc(mem, strlen(path) + 5)))
goto_bad;
sprintf(tmp, "%s.tmp", path);
new_tc->path_edit = tmp;
}
else if (!(new_tc->path_edit = dm_pool_strdup(mem, tc->path_edit)))
goto_bad;
if (!(new_tc->desc = tc->desc ? dm_pool_strdup(mem, tc->desc)
: dm_pool_strdup(mem, "")))
goto_bad;
return (void *) new_tc;
bad:
dm_pool_free(mem, new_tc);
log_error("Couldn't allocate text format context object.");
return NULL;
}
static int _create_vg_text_instance(struct format_instance *fid,
const struct format_instance_ctx *fic)
{
uint32_t type = fic->type;
struct text_fid_context *fidtc;
struct metadata_area *mda;
struct lvmcache_vginfo *vginfo;
const char *vg_name, *vg_id;
if (!(fidtc = (struct text_fid_context *)
dm_pool_zalloc(fid->mem, sizeof(*fidtc)))) {
log_error("Couldn't allocate text_fid_context.");
return 0;
}
fid->private = (void *) fidtc;
if (type & FMT_INSTANCE_PRIVATE_MDAS) {
if (!(mda = dm_pool_zalloc(fid->mem, sizeof(*mda))))
return_0;
mda->ops = &_metadata_text_file_backup_ops;
mda->metadata_locn = _create_text_context(fid->mem, fic->context.private);
mda->status = 0;
fid->metadata_areas_index = NULL;
fid_add_mda(fid, mda, NULL, 0, 0);
} else {
vg_name = fic->context.vg_ref.vg_name;
vg_id = fic->context.vg_ref.vg_id;
if (!(fid->metadata_areas_index = dm_hash_create(128))) {
log_error("Couldn't create metadata index for format "
"instance of VG %s.", vg_name);
return 0;
}
if (type & FMT_INSTANCE_MDAS) {
if (!(vginfo = lvmcache_vginfo_from_vgname(vg_name, vg_id)))
goto_out;
if (!lvmcache_fid_add_mdas_vg(vginfo, fid))
goto_out;
}
}
out:
return 1;
}
static int _add_metadata_area_to_pv(struct physical_volume *pv,
unsigned mda_index,
uint64_t mda_start,
uint64_t mda_size,
unsigned mda_ignored)
{
struct metadata_area *mda;
struct mda_context *mdac;
struct mda_lists *mda_lists = (struct mda_lists *) pv->fmt->private;
if (mda_index >= FMT_TEXT_MAX_MDAS_PER_PV) {
log_error(INTERNAL_ERROR "can't add metadata area with "
"index %u to PV %s. Metadata "
"layout not supported by %s format.",
mda_index, dev_name(pv->dev),
pv->fmt->name);
}
if (!(mda = dm_pool_zalloc(pv->fid->mem, sizeof(struct metadata_area)))) {
log_error("struct metadata_area allocation failed");
return 0;
}
if (!(mdac = dm_pool_zalloc(pv->fid->mem, sizeof(struct mda_context)))) {
log_error("struct mda_context allocation failed");
free(mda);
return 0;
}
mda->ops = mda_lists->raw_ops;
mda->metadata_locn = mdac;
mda->status = 0;
mdac->area.dev = pv->dev;
mdac->area.start = mda_start;
mdac->area.size = mda_size;
mdac->free_sectors = UINT64_C(0);
memset(&mdac->rlocn, 0, sizeof(mdac->rlocn));
mda_set_ignored(mda, mda_ignored);
fid_add_mda(pv->fid, mda, (char *) &pv->id, ID_LEN, mda_index);
return 1;
}
static int _text_pv_remove_metadata_area(const struct format_type *fmt,
struct physical_volume *pv,
unsigned mda_index);
static int _text_pv_add_metadata_area(const struct format_type *fmt,
struct physical_volume *pv,
int pe_start_locked,
unsigned mda_index,
uint64_t mda_size,
unsigned mda_ignored)
{
struct format_instance *fid = pv->fid;
const char *pvid = (const char *) (*pv->old_id.uuid ? &pv->old_id : &pv->id);
uint64_t ba_size, pe_start, first_unallocated;
uint64_t alignment, alignment_offset;
uint64_t disk_size;
uint64_t mda_start;
uint64_t adjustment, limit, tmp_mda_size;
uint64_t wipe_size = 8 << SECTOR_SHIFT;
uint64_t zero_len;
size_t page_size = lvm_getpagesize();
struct metadata_area *mda;
struct mda_context *mdac;
const char *limit_name;
int limit_applied = 0;
if (mda_index >= FMT_TEXT_MAX_MDAS_PER_PV) {
log_error(INTERNAL_ERROR "invalid index of value %u used "
"while trying to add metadata area on PV %s. "
"Metadata layout not supported by %s format.",
mda_index, pv_dev_name(pv), fmt->name);
return 0;
}
pe_start = pv->pe_start << SECTOR_SHIFT;
ba_size = pv->ba_size << SECTOR_SHIFT;
alignment = pv->pe_align << SECTOR_SHIFT;
alignment_offset = pv->pe_align_offset << SECTOR_SHIFT;
disk_size = pv->size << SECTOR_SHIFT;
mda_size = mda_size << SECTOR_SHIFT;
if (fid_get_mda_indexed(fid, pvid, ID_LEN, mda_index)) {
if (!_text_pv_remove_metadata_area(fmt, pv, mda_index)) {
log_error(INTERNAL_ERROR "metadata area with index %u already "
"exists on PV %s and removal failed.",
mda_index, pv_dev_name(pv));
return 0;
}
}
/* First metadata area at the start of the device. */
if (mda_index == 0) {
/*
* Try to fit MDA0 end within given pe_start limit if its value
* is locked. If it's not locked, count with any existing MDA1.
* If there's no MDA1, just use disk size as the limit.
*/
if (pe_start_locked) {
limit = pe_start;
limit_name = "pe_start";
}
else if ((mda = fid_get_mda_indexed(fid, pvid, ID_LEN, 1)) &&
(mdac = mda->metadata_locn)) {
limit = mdac->area.start;
limit_name = "MDA1 start";
}
else {
limit = disk_size;
limit_name = "disk size";
}
/* Adjust limits for bootloader area if present. */
if (ba_size) {
limit -= ba_size;
limit_name = "ba_start";
}
if (limit > disk_size)
goto bad;
mda_start = LABEL_SCAN_SIZE;
/* Align MDA0 start with page size if possible. */
if (limit - mda_start >= MDA_SIZE_MIN) {
if ((adjustment = mda_start % page_size))
mda_start += (page_size - adjustment);
}
/* Align MDA0 end position with given alignment if possible. */
if (alignment &&
(adjustment = (mda_start + mda_size) % alignment)) {
tmp_mda_size = mda_size + alignment - adjustment;
if (mda_start + tmp_mda_size <= limit)
mda_size = tmp_mda_size;
}
/* Align MDA0 end position with given alignment offset if possible. */
if (alignment && alignment_offset &&
(((mda_start + mda_size) % alignment) == 0)) {
tmp_mda_size = mda_size + alignment_offset;
if (mda_start + tmp_mda_size <= limit)
mda_size = tmp_mda_size;
}
if (mda_start + mda_size > limit) {
/*
* Try to decrease the MDA0 size with twice the
* alignment and then align with given alignment.
* If pe_start is locked, skip this type of
* alignment since it would be useless.
* Check first whether we can apply that!
*/
if (!pe_start_locked && alignment &&
((limit - mda_start) > alignment * 2)) {
mda_size = limit - mda_start - alignment * 2;
if ((adjustment = (mda_start + mda_size) % alignment))
mda_size += (alignment - adjustment);
/* Still too much? Then there's nothing else to do. */
if (mda_start + mda_size > limit)
goto bad;
}
/* Otherwise, give up and take any usable space. */
else
mda_size = limit - mda_start;
limit_applied = 1;
}
/*
* If PV's pe_start is not locked, update pe_start value with the
* start of the area that follows the MDA0 we've just calculated.
*/
if (!pe_start_locked) {
if (ba_size) {
pv->ba_start = (mda_start + mda_size) >> SECTOR_SHIFT;
pv->pe_start = pv->ba_start + pv->ba_size;
} else
pv->pe_start = (mda_start + mda_size) >> SECTOR_SHIFT;
}
}
/* Second metadata area at the end of the device. */
else {
/*
* Try to fit MDA1 start within given pe_end or pe_start limit
* if defined or locked. If pe_start is not defined yet, count
* with any existing MDA0. If MDA0 does not exist, just use
* LABEL_SCAN_SIZE.
*
* The first_unallocated here is the first unallocated byte
* beyond existing pe_end if there is any preallocated data area
* reserved already so we can take that as lower limit for our MDA1
* start calculation. If data area is not reserved yet, we set
* first_unallocated to 0, meaning this is not our limiting factor
* and we will look at other limiting factors if they exist.
* Of course, if we have preallocated data area, we also must
* have pe_start assigned too (simply, data area needs its start
* and end specification).
*/
first_unallocated = pv->pe_count ? (pv->pe_start + pv->pe_count *
(uint64_t)pv->pe_size) << SECTOR_SHIFT
: 0;
if (pe_start || pe_start_locked) {
limit = first_unallocated ? first_unallocated : pe_start;
limit_name = first_unallocated ? "pe_end" : "pe_start";
} else {
if ((mda = fid_get_mda_indexed(fid, pvid, ID_LEN, 0)) &&
(mdac = mda->metadata_locn)) {
limit = mdac->area.start + mdac->area.size;
limit_name = "MDA0 end";
}
else {
limit = LABEL_SCAN_SIZE;
limit_name = "label scan size";
}
/* Adjust limits for bootloader area if present. */
if (ba_size) {
limit += ba_size;
limit_name = "ba_end";
}
}
if (limit >= disk_size)
goto bad;
if (mda_size > disk_size) {
mda_size = disk_size - limit;
limit_applied = 1;
}
mda_start = disk_size - mda_size;
/* If MDA1 size is too big, just take any usable space. */
if (disk_size - mda_size < limit) {
mda_size = disk_size - limit;
mda_start = disk_size - mda_size;
limit_applied = 1;
}
/* Otherwise, try to align MDA1 start if possible. */
else if (alignment &&
(adjustment = mda_start % alignment)) {
tmp_mda_size = mda_size + adjustment;
if (tmp_mda_size < disk_size &&
disk_size - tmp_mda_size >= limit) {
mda_size = tmp_mda_size;
mda_start = disk_size - mda_size;
}
}
}
if (limit_applied)
log_very_verbose("Using limited metadata area size on %s "
"with value " FMTu64 " (limited by %s of "
FMTu64 ").", pv_dev_name(pv),
mda_size, limit_name, limit);
if (mda_size) {
if (mda_size < MDA_SIZE_MIN) {
log_error("Metadata area size too small: " FMTu64 " bytes. "
"It must be at least %u bytes.", mda_size, MDA_SIZE_MIN);
goto bad;
}
/* Wipe metadata area with zeroes. */
zero_len = (mda_size > wipe_size) ? wipe_size : mda_size;
if (!dev_write_zeros(pv->dev, mda_start, zero_len)) {
log_error("Failed to wipe new metadata area on %s at %llu len %llu",
pv_dev_name(pv),
(unsigned long long)mda_start,
(unsigned long long)zero_len);
return 0;
}
/* Finally, add new metadata area to PV's format instance. */
if (!_add_metadata_area_to_pv(pv, mda_index, mda_start,
mda_size, mda_ignored))
return_0;
}
return 1;
bad:
log_error("Not enough space available for metadata area "
"with index %u on PV %s.", mda_index, pv_dev_name(pv));
return 0;
}
static int _remove_metadata_area_from_pv(struct physical_volume *pv,
unsigned mda_index)
{
if (mda_index >= FMT_TEXT_MAX_MDAS_PER_PV) {
log_error(INTERNAL_ERROR "can't remove metadata area with "
"index %u from PV %s. Metadata "
"layou not supported by %s format.",
mda_index, dev_name(pv->dev),
pv->fmt->name);
return 0;
}
return fid_remove_mda(pv->fid, NULL, (const char *) &pv->id,
ID_LEN, mda_index);
}
static int _text_pv_remove_metadata_area(const struct format_type *fmt,
struct physical_volume *pv,
unsigned mda_index)
{
return _remove_metadata_area_from_pv(pv, mda_index);
}
static int _text_pv_resize(const struct format_type *fmt,
struct physical_volume *pv,
struct volume_group *vg,
uint64_t size)
{
struct format_instance *fid = pv->fid;
const char *pvid = (const char *) (*pv->old_id.uuid ? &pv->old_id : &pv->id);
struct metadata_area *mda;
struct mda_context *mdac;
uint64_t size_reduction;
uint64_t mda_size;
unsigned mda_ignored;
/*
* First, set the new size and update the cache and reset pe_count.
* (pe_count must be reset otherwise it would be considered as
* a limiting factor while moving the mda!)
*/
pv->size = size;
pv->pe_count = 0;
/* If there's an mda at the end, move it to a new position. */
if ((mda = fid_get_mda_indexed(fid, pvid, ID_LEN, 1)) &&
(mdac = mda->metadata_locn)) {
/* FIXME: Maybe MDA0 size would be better? */
mda_size = mdac->area.size >> SECTOR_SHIFT;
mda_ignored = mda_is_ignored(mda);
if (!_text_pv_remove_metadata_area(fmt, pv, 1) ||
!_text_pv_add_metadata_area(fmt, pv, 1, 1, mda_size,
mda_ignored)) {
log_error("Failed to move metadata area with index 1 "
"while resizing PV %s.", pv_dev_name(pv));
return 0;
}
}
/* If there's a VG, reduce size by counting in pe_start and metadata areas. */
if (vg && !is_orphan_vg(vg->name)) {
size_reduction = pv_pe_start(pv);
if ((mda = fid_get_mda_indexed(fid, pvid, ID_LEN, 1)) &&
(mdac = mda->metadata_locn))
size_reduction += mdac->area.size >> SECTOR_SHIFT;
pv->size -= size_reduction;
}
return 1;
}
static struct format_instance *_text_create_text_instance(const struct format_type *fmt,
const struct format_instance_ctx *fic)
{
struct format_instance *fid;
if (!(fid = alloc_fid(fmt, fic)))
return_NULL;
if (!_create_vg_text_instance(fid, fic)) {
dm_pool_destroy(fid->mem);
return_NULL;
}
return fid;
}
static struct format_handler _text_handler = {
.pv_initialise = _text_pv_initialise,
.pv_setup = _text_pv_setup,
.pv_add_metadata_area = _text_pv_add_metadata_area,
.pv_remove_metadata_area = _text_pv_remove_metadata_area,
.pv_resize = _text_pv_resize,
.pv_write = _text_pv_write,
.pv_needs_rewrite = _text_pv_needs_rewrite,
.vg_setup = _text_vg_setup,
.lv_setup = _text_lv_setup,
.create_instance = _text_create_text_instance,
.destroy_instance = _text_destroy_instance,
.destroy = _text_destroy
};
struct format_type *create_text_format(struct cmd_context *cmd)
{
struct format_instance_ctx fic;
struct format_instance *fid;
struct format_type *fmt;
struct mda_lists *mda_lists;
if (!(fmt = malloc(sizeof(*fmt)))) {
log_error("Failed to allocate text format type structure.");
return NULL;
}
fmt->cmd = cmd;
fmt->ops = &_text_handler;
fmt->name = FMT_TEXT_NAME;
fmt->alias = FMT_TEXT_ALIAS;
fmt->orphan_vg_name = ORPHAN_VG_NAME(FMT_TEXT_NAME);
fmt->features = FMT_SEGMENTS | FMT_TAGS | FMT_PRECOMMIT |
FMT_UNLIMITED_VOLS | FMT_RESIZE_PV |
FMT_UNLIMITED_STRIPESIZE | FMT_CONFIG_PROFILE |
FMT_NON_POWER2_EXTENTS | FMT_PV_FLAGS;
if (!(mda_lists = malloc(sizeof(struct mda_lists)))) {
log_error("Failed to allocate dir_list");
free(fmt);
return NULL;
}
mda_lists->file_ops = &_metadata_text_file_ops;
mda_lists->raw_ops = &_metadata_text_raw_ops;
fmt->private = (void *) mda_lists;
dm_list_init(&fmt->mda_ops);
dm_list_add(&fmt->mda_ops, &_metadata_text_raw_ops.list);
if (!(fmt->labeller = text_labeller_create(fmt))) {
log_error("Couldn't create text label handler.");
goto bad;
}
if (!(label_register_handler(fmt->labeller))) {
log_error("Couldn't register text label handler.");
fmt->labeller->ops->destroy(fmt->labeller);
goto bad;
}
if (!(fmt->orphan_vg = alloc_vg("text_orphan", cmd, fmt->orphan_vg_name)))
goto_bad;
fic.type = FMT_INSTANCE_AUX_MDAS;
fic.context.vg_ref.vg_name = fmt->orphan_vg_name;
fic.context.vg_ref.vg_id = NULL;
if (!(fid = _text_create_text_instance(fmt, &fic)))
goto_bad;
vg_set_fid(fmt->orphan_vg, fid);
log_very_verbose("Initialised format: %s", fmt->name);
return fmt;
bad:
_text_destroy(fmt);
return NULL;
}
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