1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-21 13:34:40 +03:00

device: Tag I/O for each mda on a device separately in log messages.

Mark the first metadata area on each text format PV as MDA_PRIMARY.
Pass this information down to the device layer so that when
there are two metadata areas on a block device, we can easily
distinguish two independent streams of I/O.
This commit is contained in:
Alasdair G Kergon 2017-12-07 03:34:59 +00:00
parent 54154dc6f1
commit d591d04103
10 changed files with 77 additions and 55 deletions

View File

@ -494,7 +494,7 @@ int override_config_tree_from_profile(struct cmd_context *cmd,
* and function avoids parsing of mda into config tree which
* remains unmodified and should not be used.
*/
int config_file_read_fd(struct dm_config_tree *cft, struct device *dev,
int config_file_read_fd(struct dm_config_tree *cft, struct device *dev, dev_io_reason_t reason,
off_t offset, size_t size, off_t offset2, size_t size2,
checksum_fn_t checksum_fn, uint32_t checksum,
int checksum_only, int no_dup_node_check)
@ -533,7 +533,7 @@ int config_file_read_fd(struct dm_config_tree *cft, struct device *dev,
return 0;
}
if (!dev_read_circular(dev, (uint64_t) offset, size,
(uint64_t) offset2, size2, DEV_IO_MDA_CONTENT, buf)) {
(uint64_t) offset2, size2, reason, buf)) {
goto out;
}
fb = buf;
@ -601,7 +601,7 @@ int config_file_read(struct dm_config_tree *cft)
}
}
r = config_file_read_fd(cft, cf->dev, 0, (size_t) info.st_size, 0, 0,
r = config_file_read_fd(cft, cf->dev, DEV_IO_MDA_CONTENT, 0, (size_t) info.st_size, 0, 0,
(checksum_fn_t) NULL, 0, 0, 0);
if (!cf->keep_open) {

View File

@ -17,12 +17,12 @@
#define _LVM_CONFIG_H
#include "libdevmapper.h"
#include "device.h"
/* 16 bits: 3 bits for major, 4 bits for minor, 9 bits for patchlevel */
/* FIXME Max LVM version supported: 7.15.511. Extend bits when needed. */
#define vsn(major, minor, patchlevel) (major << 13 | minor << 9 | patchlevel)
struct device;
struct cmd_context;
typedef enum {
@ -239,7 +239,7 @@ config_source_t config_get_source_type(struct dm_config_tree *cft);
typedef uint32_t (*checksum_fn_t) (uint32_t initial, const uint8_t *buf, uint32_t size);
struct dm_config_tree *config_open(config_source_t source, const char *filename, int keep_open);
int config_file_read_fd(struct dm_config_tree *cft, struct device *dev,
int config_file_read_fd(struct dm_config_tree *cft, struct device *dev, dev_io_reason_t reason,
off_t offset, size_t size, off_t offset2, size_t size2,
checksum_fn_t checksum_fn, uint32_t checksum,
int skip_parse, int no_dup_node_check);

View File

@ -61,6 +61,8 @@ static const char *_reasons[] = {
"PV labels",
"VG metadata header",
"VG metadata content",
"extra VG metadata header",
"extra VG metadata content",
"LVM1 metadata",
"pool metadata",
"LV content",

View File

@ -87,6 +87,8 @@ typedef enum dev_io_reason {
DEV_IO_LABEL, /* LVM PV disk label */
DEV_IO_MDA_HEADER, /* Text format metadata area header */
DEV_IO_MDA_CONTENT, /* Text format metadata area content */
DEV_IO_MDA_EXTRA_HEADER, /* Header of any extra metadata areas on device */
DEV_IO_MDA_EXTRA_CONTENT, /* Content of any extra metadata areas on device */
DEV_IO_FMT1, /* Original LVM1 metadata format */
DEV_IO_POOL, /* Pool metadata format */
DEV_IO_LV, /* Content written to an LV */

View File

@ -190,7 +190,7 @@ static int _pv_analyze_mda_raw (const struct format_type * fmt,
if (!dev_open_readonly(area->dev))
return_0;
if (!(mdah = raw_read_mda_header(fmt, area)))
if (!(mdah = raw_read_mda_header(fmt, area, mda_is_primary(mda))))
goto_out;
rlocn = mdah->raw_locns;
@ -230,7 +230,7 @@ static int _pv_analyze_mda_raw (const struct format_type * fmt,
if (!(buf = dm_malloc(size + size2)))
goto_out;
if (!dev_read_circular(area->dev, offset, size, offset2, size2, DEV_IO_MDA_CONTENT, buf))
if (!dev_read_circular(area->dev, offset, size, offset2, size2, MDA_CONTENT_REASON(mda_is_primary(mda)), buf))
goto_out;
/*
@ -315,12 +315,12 @@ static void _xlate_mdah(struct mda_header *mdah)
}
}
static int _raw_read_mda_header(struct mda_header *mdah, struct device_area *dev_area)
static int _raw_read_mda_header(struct mda_header *mdah, struct device_area *dev_area, int primary_mda)
{
if (!dev_open_readonly(dev_area->dev))
return_0;
if (!dev_read(dev_area->dev, dev_area->start, MDA_HEADER_SIZE, DEV_IO_MDA_HEADER, mdah)) {
if (!dev_read(dev_area->dev, dev_area->start, MDA_HEADER_SIZE, MDA_HEADER_REASON(primary_mda), mdah)) {
if (!dev_close(dev_area->dev))
stack;
return_0;
@ -365,7 +365,7 @@ static int _raw_read_mda_header(struct mda_header *mdah, struct device_area *dev
}
struct mda_header *raw_read_mda_header(const struct format_type *fmt,
struct device_area *dev_area)
struct device_area *dev_area, int primary_mda)
{
struct mda_header *mdah;
@ -374,7 +374,7 @@ struct mda_header *raw_read_mda_header(const struct format_type *fmt,
return NULL;
}
if (!_raw_read_mda_header(mdah, dev_area)) {
if (!_raw_read_mda_header(mdah, dev_area, primary_mda)) {
dm_pool_free(fmt->cmd->mem, mdah);
return NULL;
}
@ -383,7 +383,7 @@ struct mda_header *raw_read_mda_header(const struct format_type *fmt,
}
static int _raw_write_mda_header(const struct format_type *fmt,
struct device *dev,
struct device *dev, int primary_mda,
uint64_t start_byte, struct mda_header *mdah)
{
strncpy((char *)mdah->magic, FMTT_MAGIC, sizeof(mdah->magic));
@ -395,14 +395,14 @@ static int _raw_write_mda_header(const struct format_type *fmt,
MDA_HEADER_SIZE -
sizeof(mdah->checksum_xl)));
if (!dev_write(dev, start_byte, MDA_HEADER_SIZE, DEV_IO_MDA_HEADER, mdah))
if (!dev_write(dev, start_byte, MDA_HEADER_SIZE, MDA_HEADER_REASON(primary_mda), mdah))
return_0;
return 1;
}
static struct raw_locn *_find_vg_rlocn(struct device_area *dev_area,
struct mda_header *mdah,
struct mda_header *mdah, int primary_mda,
const char *vgname,
int *precommitted)
{
@ -449,7 +449,7 @@ static struct raw_locn *_find_vg_rlocn(struct device_area *dev_area,
/* FIXME Loop through rlocns two-at-a-time. List null-terminated. */
/* FIXME Ignore if checksum incorrect!!! */
if (!dev_read(dev_area->dev, dev_area->start + rlocn->offset,
sizeof(vgnamebuf), DEV_IO_MDA_CONTENT, vgnamebuf))
sizeof(vgnamebuf), MDA_CONTENT_REASON(primary_mda), vgnamebuf))
goto_bad;
if (!strncmp(vgnamebuf, vgname, len = strlen(vgname)) &&
@ -497,10 +497,10 @@ static int _raw_holds_vgname(struct format_instance *fid,
if (!dev_open_readonly(dev_area->dev))
return_0;
if (!(mdah = raw_read_mda_header(fid->fmt, dev_area)))
if (!(mdah = raw_read_mda_header(fid->fmt, dev_area, 0)))
return_0;
if (_find_vg_rlocn(dev_area, mdah, vgname, &noprecommit))
if (_find_vg_rlocn(dev_area, mdah, 0, vgname, &noprecommit))
r = 1;
if (!dev_close(dev_area->dev))
@ -515,7 +515,7 @@ static struct volume_group *_vg_read_raw_area(struct format_instance *fid,
struct cached_vg_fmtdata **vg_fmtdata,
unsigned *use_previous_vg,
int precommitted,
int single_device)
int single_device, int primary_mda)
{
struct volume_group *vg = NULL;
struct raw_locn *rlocn;
@ -524,10 +524,10 @@ static struct volume_group *_vg_read_raw_area(struct format_instance *fid,
char *desc;
uint32_t wrap = 0;
if (!(mdah = raw_read_mda_header(fid->fmt, area)))
if (!(mdah = raw_read_mda_header(fid->fmt, area, primary_mda)))
goto_out;
if (!(rlocn = _find_vg_rlocn(area, mdah, vgname, &precommitted))) {
if (!(rlocn = _find_vg_rlocn(area, mdah, primary_mda, vgname, &precommitted))) {
log_debug_metadata("VG %s not found on %s", vgname, dev_name(area->dev));
goto out;
}
@ -543,6 +543,7 @@ static struct volume_group *_vg_read_raw_area(struct format_instance *fid,
/* FIXME 64-bit */
if (!(vg = text_vg_import_fd(fid, NULL, vg_fmtdata, use_previous_vg, single_device, area->dev,
primary_mda,
(off_t) (area->start + rlocn->offset),
(uint32_t) (rlocn->size - wrap),
(off_t) (area->start + MDA_HEADER_SIZE),
@ -581,7 +582,7 @@ static struct volume_group *_vg_read_raw(struct format_instance *fid,
if (!dev_open_readonly(mdac->area.dev))
return_NULL;
vg = _vg_read_raw_area(fid, vgname, &mdac->area, vg_fmtdata, use_previous_vg, 0, single_device);
vg = _vg_read_raw_area(fid, vgname, &mdac->area, vg_fmtdata, use_previous_vg, 0, single_device, mda_is_primary(mda));
if (!dev_close(mdac->area.dev))
stack;
@ -601,7 +602,7 @@ static struct volume_group *_vg_read_precommit_raw(struct format_instance *fid,
if (!dev_open_readonly(mdac->area.dev))
return_NULL;
vg = _vg_read_raw_area(fid, vgname, &mdac->area, vg_fmtdata, use_previous_vg, 1, 0);
vg = _vg_read_raw_area(fid, vgname, &mdac->area, vg_fmtdata, use_previous_vg, 1, 0, mda_is_primary(mda));
if (!dev_close(mdac->area.dev))
stack;
@ -639,10 +640,10 @@ static int _vg_write_raw(struct format_instance *fid, struct volume_group *vg,
if (!dev_open(mdac->area.dev))
return_0;
if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area)))
if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area, mda_is_primary(mda))))
goto_out;
rlocn = _find_vg_rlocn(&mdac->area, mdah, old_vg_name ? : vg->name, &noprecommit);
rlocn = _find_vg_rlocn(&mdac->area, mdah, mda_is_primary(mda), old_vg_name ? : vg->name, &noprecommit);
mdac->rlocn.offset = _next_rlocn_offset(rlocn, mdah);
if (!fidtc->raw_metadata_buf &&
@ -677,7 +678,7 @@ static int _vg_write_raw(struct format_instance *fid, struct volume_group *vg,
/* Write text out, circularly */
if (!dev_write(mdac->area.dev, mdac->area.start + mdac->rlocn.offset,
(size_t) (mdac->rlocn.size - new_wrap), DEV_IO_MDA_CONTENT,
(size_t) (mdac->rlocn.size - new_wrap), MDA_CONTENT_REASON(mda_is_primary(mda)),
fidtc->raw_metadata_buf))
goto_out;
@ -687,7 +688,7 @@ static int _vg_write_raw(struct format_instance *fid, struct volume_group *vg,
MDA_HEADER_SIZE, new_wrap);
if (!dev_write(mdac->area.dev, mdac->area.start + MDA_HEADER_SIZE,
(size_t) new_wrap, DEV_IO_MDA_CONTENT,
(size_t) new_wrap, MDA_CONTENT_REASON(mda_is_primary(mda)),
fidtc->raw_metadata_buf + mdac->rlocn.size - new_wrap))
goto_out;
}
@ -743,10 +744,10 @@ static int _vg_commit_raw_rlocn(struct format_instance *fid,
if (!found)
return 1;
if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area)))
if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area, mda_is_primary(mda))))
goto_out;
if (!(rlocn = _find_vg_rlocn(&mdac->area, mdah, old_vg_name ? : vg->name, &noprecommit))) {
if (!(rlocn = _find_vg_rlocn(&mdac->area, mdah, mda_is_primary(mda), old_vg_name ? : vg->name, &noprecommit))) {
mdah->raw_locns[0].offset = 0;
mdah->raw_locns[0].size = 0;
mdah->raw_locns[0].checksum = 0;
@ -793,7 +794,7 @@ static int _vg_commit_raw_rlocn(struct format_instance *fid,
rlocn_set_ignored(mdah->raw_locns, mda_is_ignored(mda));
if (!_raw_write_mda_header(fid->fmt, mdac->area.dev, mdac->area.start,
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");
@ -863,10 +864,10 @@ static int _vg_remove_raw(struct format_instance *fid, struct volume_group *vg,
if (!dev_open(mdac->area.dev))
return_0;
if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area)))
if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area, mda_is_primary(mda))))
goto_out;
if (!(rlocn = _find_vg_rlocn(&mdac->area, mdah, vg->name, &noprecommit))) {
if (!(rlocn = _find_vg_rlocn(&mdac->area, mdah, mda_is_primary(mda), vg->name, &noprecommit))) {
rlocn = &mdah->raw_locns[0];
mdah->raw_locns[1].offset = 0;
}
@ -876,7 +877,7 @@ static int _vg_remove_raw(struct format_instance *fid, struct volume_group *vg,
rlocn->checksum = 0;
rlocn_set_ignored(mdah->raw_locns, mda_is_ignored(mda));
if (!_raw_write_mda_header(fid->fmt, mdac->area.dev, mdac->area.start,
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");
@ -1172,7 +1173,7 @@ static int _scan_file(const struct format_type *fmt, const char *vgname)
}
int vgname_from_mda(const struct format_type *fmt,
struct mda_header *mdah, struct device_area *dev_area,
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;
@ -1204,7 +1205,7 @@ int vgname_from_mda(const struct format_type *fmt,
/* Do quick check for a vgname */
if (!dev_read(dev_area->dev, dev_area->start + rlocn->offset,
NAME_LEN, DEV_IO_MDA_CONTENT, buf))
NAME_LEN, MDA_CONTENT_REASON(primary_mda), buf))
return_0;
while (buf[len] && !isspace(buf[len]) && buf[len] != '{' &&
@ -1235,7 +1236,7 @@ int vgname_from_mda(const struct format_type *fmt,
used_cached_metadata = 1;
/* FIXME 64-bit */
if (!text_vgsummary_import(fmt, dev_area->dev,
if (!text_vgsummary_import(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),
@ -1292,14 +1293,14 @@ static int _scan_raw(const struct format_type *fmt, const char *vgname __attribu
continue;
}
if (!(mdah = raw_read_mda_header(fmt, &rl->dev_area))) {
if (!(mdah = raw_read_mda_header(fmt, &rl->dev_area, 0))) {
stack;
goto close_dev;
}
/* TODO: caching as in vgname_from_mda() (trigger this code?) */
if (vgname_from_mda(fmt, mdah, &rl->dev_area, &vgsummary, NULL)) {
vg = _vg_read_raw_area(&fid, vgsummary.vgname, &rl->dev_area, NULL, NULL, 0, 0);
if (vgname_from_mda(fmt, mdah, 0, &rl->dev_area, &vgsummary, NULL)) {
vg = _vg_read_raw_area(&fid, vgsummary.vgname, &rl->dev_area, NULL, NULL, 0, 0, 0);
if (vg)
lvmcache_update_vg(vg, 0);
}
@ -1333,7 +1334,7 @@ static int _write_single_mda(struct metadata_area *mda, void *baton)
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,
if (!_raw_write_mda_header(p->fmt, mdac->area.dev, mda_is_primary(mda),
mdac->area.start, mdah)) {
if (!dev_close(p->pv->dev))
stack;
@ -1772,7 +1773,7 @@ static int _mda_export_text_raw(struct metadata_area *mda,
struct mda_context *mdc = (struct mda_context *) mda->metadata_locn;
char mdah[MDA_HEADER_SIZE]; /* temporary */
if (!mdc || !_raw_read_mda_header((struct mda_header *)mdah, &mdc->area))
if (!mdc || !_raw_read_mda_header((struct mda_header *)mdah, &mdc->area, mda_is_primary(mda)))
return 1; /* pretend the MDA does not exist */
return config_make_nodes(cft, parent, NULL,
@ -2314,7 +2315,7 @@ static int _text_pv_add_metadata_area(const struct format_type *fmt,
/* Wipe metadata area with zeroes. */
if (!dev_set(pv->dev, mda_start,
(size_t) ((mda_size > wipe_size) ? wipe_size : mda_size),
DEV_IO_MDA_HEADER, 0)) {
MDA_HEADER_REASON(!mda_index), 0)) {
log_error("Failed to wipe new metadata area "
"at the %s of the %s",
mda_index ? "end" : "start",

View File

@ -76,7 +76,7 @@ struct volume_group *text_vg_import_fd(struct format_instance *fid,
struct cached_vg_fmtdata **vg_fmtdata,
unsigned *use_previous_vg,
int single_device,
struct device *dev,
struct device *dev, int primary_mda,
off_t offset, uint32_t size,
off_t offset2, uint32_t size2,
checksum_fn_t checksum_fn,
@ -84,7 +84,7 @@ struct volume_group *text_vg_import_fd(struct format_instance *fid,
time_t *when, char **desc);
int text_vgsummary_import(const struct format_type *fmt,
struct device *dev,
struct device *dev, dev_io_reason_t reason,
off_t offset, uint32_t size,
off_t offset2, uint32_t size2,
checksum_fn_t checksum_fn,

View File

@ -36,7 +36,7 @@ static void _init_text_import(void)
* Find out vgname on a given device.
*/
int text_vgsummary_import(const struct format_type *fmt,
struct device *dev,
struct device *dev, dev_io_reason_t reason,
off_t offset, uint32_t size,
off_t offset2, uint32_t size2,
checksum_fn_t checksum_fn,
@ -53,7 +53,7 @@ int text_vgsummary_import(const struct format_type *fmt,
return_0;
if ((!dev && !config_file_read(cft)) ||
(dev && !config_file_read_fd(cft, dev, offset, size,
(dev && !config_file_read_fd(cft, dev, reason, offset, size,
offset2, size2, checksum_fn,
vgsummary->mda_checksum,
checksum_only, 1))) {
@ -96,7 +96,7 @@ struct volume_group *text_vg_import_fd(struct format_instance *fid,
struct cached_vg_fmtdata **vg_fmtdata,
unsigned *use_previous_vg,
int single_device,
struct device *dev,
struct device *dev, int primary_mda,
off_t offset, uint32_t size,
off_t offset2, uint32_t size2,
checksum_fn_t checksum_fn,
@ -128,7 +128,7 @@ struct volume_group *text_vg_import_fd(struct format_instance *fid,
((*vg_fmtdata)->cached_mda_size == (size + size2));
if ((!dev && !config_file_read(cft)) ||
(dev && !config_file_read_fd(cft, dev, offset, size,
(dev && !config_file_read_fd(cft, dev, MDA_CONTENT_REASON(primary_mda), offset, size,
offset2, size2, checksum_fn, checksum,
skip_parse, 1)))
goto_out;
@ -170,7 +170,7 @@ struct volume_group *text_vg_import_file(struct format_instance *fid,
const char *file,
time_t *when, char **desc)
{
return text_vg_import_fd(fid, file, NULL, NULL, 0, NULL, (off_t)0, 0, (off_t)0, 0, NULL, 0,
return text_vg_import_fd(fid, file, NULL, NULL, 0, NULL, 0, (off_t)0, 0, (off_t)0, 0, NULL, 0,
when, desc);
}

View File

@ -81,7 +81,7 @@ struct mda_header {
} __attribute__ ((packed));
struct mda_header *raw_read_mda_header(const struct format_type *fmt,
struct device_area *dev_area);
struct device_area *dev_area, int primary_mda);
struct mda_lists {
struct dm_list dirs;
@ -103,7 +103,7 @@ struct mda_context {
#define LVM2_LABEL "LVM2 001"
#define MDA_SIZE_MIN (8 * (unsigned) lvm_getpagesize())
int vgname_from_mda(const struct format_type *fmt, struct mda_header *mdah,
int vgname_from_mda(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);

View File

@ -245,9 +245,9 @@ int add_mda(const struct format_type *fmt, struct dm_pool *mem, struct dm_list *
struct device *dev, uint64_t start, uint64_t size, unsigned ignored)
{
/* FIXME List size restricted by pv_header SECTOR_SIZE */
struct metadata_area *mdal;
struct metadata_area *mdal, *mda;
struct mda_lists *mda_lists = (struct mda_lists *) fmt->private;
struct mda_context *mdac;
struct mda_context *mdac, *mdac2;
if (!mem) {
if (!(mdal = dm_malloc(sizeof(struct metadata_area)))) {
@ -274,13 +274,23 @@ int add_mda(const struct format_type *fmt, struct dm_pool *mem, struct dm_list *
mdal->ops = mda_lists->raw_ops;
mdal->metadata_locn = mdac;
mdal->status = 0;
mdac->area.dev = dev;
mdac->area.start = start;
mdac->area.size = size;
mdac->free_sectors = UINT64_C(0);
memset(&mdac->rlocn, 0, sizeof(mdac->rlocn));
/* Set MDA_PRIMARY only if this is the first metadata area on this device. */
mdal->status = MDA_PRIMARY;
dm_list_iterate_items(mda, mdas) {
mdac2 = mda->metadata_locn;
if (mdac2->area.dev == dev) {
mdal->status = 0;
break;
}
}
mda_set_ignored(mdal, ignored);
dm_list_add(mdas, &mdal->list);
@ -334,7 +344,7 @@ static int _update_mda(struct metadata_area *mda, void *baton)
return 1;
}
if (!(mdah = raw_read_mda_header(fmt, &mdac->area))) {
if (!(mdah = raw_read_mda_header(fmt, &mdac->area, mda_is_primary(mda)))) {
stack;
goto close_dev;
}
@ -350,7 +360,7 @@ static int _update_mda(struct metadata_area *mda, void *baton)
return 1;
}
if (vgname_from_mda(fmt, mdah, &mdac->area, &vgsummary,
if (vgname_from_mda(fmt, mdah, mda_is_primary(mda), &mdac->area, &vgsummary,
&mdac->free_sectors) &&
!lvmcache_update_vgname_and_id(p->info, &vgsummary)) {
if (!dev_close(mdac->area.dev))

View File

@ -162,6 +162,13 @@ struct metadata_area_ops {
#define MDA_INCONSISTENT 0x00000002
#define MDA_FAILED 0x00000004
/* The primary metadata area on a device if the format supports more than one. */
#define MDA_PRIMARY 0x00000008
#define mda_is_primary(mda) (((mda->status) & MDA_PRIMARY) ? 1 : 0)
#define MDA_CONTENT_REASON(primary_mda) ((primary_mda) ? DEV_IO_MDA_CONTENT : DEV_IO_MDA_EXTRA_CONTENT)
#define MDA_HEADER_REASON(primary_mda) ((primary_mda) ? DEV_IO_MDA_HEADER : DEV_IO_MDA_EXTRA_HEADER)
struct metadata_area {
struct dm_list list;
struct metadata_area_ops *ops;