/* lvm.c - module to read Logical Volumes. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2006,2007 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/dl.h>
#include <grub/disk.h>
#include <grub/mm.h>
#include <grub/err.h>
#include <grub/misc.h>
#include <grub/lvm.h>
static struct grub_lvm_vg *vg_list;
static int lv_count;
/* Go the string STR and return the number after STR. *P will point
at the number. */
static int
grub_lvm_getvalue (char **p, char *str)
{
*p = grub_strstr (*p, str) + grub_strlen (str);
return grub_strtoul (*p, NULL, 10);
}
static int
grub_lvm_iterate (int (*hook) (const char *name))
{
struct grub_lvm_vg *vg;
for (vg = vg_list; vg; vg = vg->next)
{
struct grub_lvm_lv *lv;
for (lv = vg->lvs; lv; lv = lv->next)
if (hook (lv->name))
return 1;
}
return 0;
}
static grub_err_t
grub_lvm_open (const char *name, grub_disk_t disk)
{
struct grub_lvm_vg *vg;
struct grub_lvm_lv *lv = NULL;
for (vg = vg_list; vg; vg = vg->next)
{
for (lv = vg->lvs; lv; lv = lv->next)
if (! grub_strcmp (lv->name, name))
break;
if (lv)
break;
}
if (! lv)
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "Unknown device");
disk->has_partitions = 0;
disk->id = lv->number;
disk->data = lv;
disk->total_sectors = lv->size;
return 0;
}
static void
grub_lvm_close (grub_disk_t disk __attribute ((unused)))
{
return;
}
static grub_err_t
grub_lvm_read (grub_disk_t disk, grub_disk_addr_t sector,
grub_size_t size, char *buf)
{
grub_err_t err = 0;
struct grub_lvm_lv *lv = disk->data;
struct grub_lvm_vg *vg = lv->vg;
struct grub_lvm_segment *seg = lv->segments;
struct grub_lvm_pv *pv;
grub_uint64_t offset;
grub_uint64_t extent;
unsigned int i;
extent = grub_divmod64 (sector, vg->extent_size, NULL);
/* Find the right segment. */
for (i = 0; i < lv->segment_count; i++)
{
if ((seg->start_extent <= extent)
&& ((seg->start_extent + seg->extent_count) > extent))
{
break;
}
seg++;
}
if (seg->stripe_count == 1)
{
/* This segment is linear, so that's easy. We just need to find
out the offset in the physical volume and read SIZE bytes
from that. */
struct grub_lvm_stripe *stripe = seg->stripes;
grub_uint64_t seg_offset; /* Offset of the segment in PV device. */
pv = stripe->pv;
seg_offset = ((grub_uint64_t) stripe->start
* (grub_uint64_t) vg->extent_size) + pv->start;
offset = sector - ((grub_uint64_t) seg->start_extent
* (grub_uint64_t) vg->extent_size) + seg_offset;
}
else
{
/* This is a striped segment. We have to find the right PV
similar to RAID0. */
struct grub_lvm_stripe *stripe = seg->stripes;
grub_uint32_t a, b;
grub_uint64_t seg_offset; /* Offset of the segment in PV device. */
unsigned int stripenr;
offset = sector - ((grub_uint64_t) seg->start_extent
* (grub_uint64_t) vg->extent_size);
a = grub_divmod64 (offset, seg->stripe_size, NULL);
grub_divmod64 (a, seg->stripe_count, &stripenr);
a = grub_divmod64 (offset, seg->stripe_size * seg->stripe_count, NULL);
grub_divmod64 (offset, seg->stripe_size, &b);
offset = a * seg->stripe_size + b;
stripe += stripenr;
pv = stripe->pv;
seg_offset = ((grub_uint64_t) stripe->start
* (grub_uint64_t) vg->extent_size) + pv->start;
offset += seg_offset;
}
/* Check whether we actually know the physical volume we want to
read from. */
if (pv->disk)
err = grub_disk_read (pv->disk, offset, 0,
size << GRUB_DISK_SECTOR_BITS, buf);
else
err = grub_error (GRUB_ERR_UNKNOWN_DEVICE,
"Physical volume %s not found", pv->name);
return err;
}
static grub_err_t
grub_lvm_write (grub_disk_t disk __attribute ((unused)),
grub_disk_addr_t sector __attribute ((unused)),
grub_size_t size __attribute ((unused)),
const char *buf __attribute ((unused)))
{
return GRUB_ERR_NOT_IMPLEMENTED_YET;
}
static int
grub_lvm_scan_device (const char *name)
{
grub_err_t err;
grub_disk_t disk;
grub_uint64_t da_offset, da_size, mda_offset, mda_size;
char buf[GRUB_LVM_LABEL_SIZE];
char vg_id[GRUB_LVM_ID_STRLEN+1];
char pv_id[GRUB_LVM_ID_STRLEN+1];
char *metadatabuf, *p, *q, *vgname;
struct grub_lvm_label_header *lh = (struct grub_lvm_label_header *) buf;
struct grub_lvm_pv_header *pvh;
struct grub_lvm_disk_locn *dlocn;
struct grub_lvm_mda_header *mdah;
struct grub_lvm_raw_locn *rlocn;
unsigned int i, j, vgname_len;
struct grub_lvm_vg *vg;
struct grub_lvm_pv *pv;
disk = grub_disk_open (name);
if (!disk)
return 0;
/* Search for label. */
for (i = 0; i < GRUB_LVM_LABEL_SCAN_SECTORS; i++)
{
err = grub_disk_read (disk, i, 0, sizeof(buf), buf);
if (err)
goto fail;
if ((! grub_strncmp ((char *)lh->id, GRUB_LVM_LABEL_ID,
sizeof (lh->id)))
&& (! grub_strncmp ((char *)lh->type, GRUB_LVM_LVM2_LABEL,
sizeof (lh->type))))
break;
}
/* Return if we didn't find a label. */
if (i == GRUB_LVM_LABEL_SCAN_SECTORS)
goto fail;
pvh = (struct grub_lvm_pv_header *) (buf + grub_le_to_cpu32(lh->offset_xl));
for (i = 0, j = 0; i < GRUB_LVM_ID_LEN; i++)
{
pv_id[j++] = pvh->pv_uuid[i];
if ((i != 1) && (i != 29) && (i % 4 == 1))
pv_id[j++] = '-';
}
pv_id[j] = '\0';
dlocn = pvh->disk_areas_xl;
da_offset = grub_le_to_cpu64 (dlocn->offset);
da_size = grub_le_to_cpu64 (dlocn->size);
dlocn++;
/* Is it possible to have multiple data/metadata areas? I haven't
seen devices that have it. */
if (dlocn->offset)
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"We don't support multiple data areas");
goto fail;
}
dlocn++;
mda_offset = grub_le_to_cpu64 (dlocn->offset);
mda_size = grub_le_to_cpu64 (dlocn->size);
dlocn++;
if (dlocn->offset)
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"We don't support multiple metadata areas");
goto fail;
}
metadatabuf = grub_malloc (mda_size);
if (! metadatabuf)
goto fail;
err = grub_disk_read (disk, 0, mda_offset, mda_size, metadatabuf);
if (err)
goto fail2;
mdah = (struct grub_lvm_mda_header *) metadatabuf;
if ((grub_strncmp ((char *)mdah->magic, GRUB_LVM_FMTT_MAGIC,
sizeof (mdah->magic)))
|| (grub_le_to_cpu32 (mdah->version) != GRUB_LVM_FMTT_VERSION))
{
grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"Unknown metadata header");
goto fail2;
}
rlocn = mdah->raw_locns;
p = q = metadatabuf + grub_le_to_cpu64 (rlocn->offset);
while (*q != ' ')
q++;
vgname_len = q - p;
vgname = grub_malloc (vgname_len + 1);
if (!vgname)
goto fail2;
grub_memcpy (vgname, p, vgname_len);
vgname[vgname_len] = '\0';
p = grub_strstr (q, "id = \"") + sizeof ("id = \"") - 1;
grub_memcpy (vg_id, p, GRUB_LVM_ID_STRLEN);
vg_id[GRUB_LVM_ID_STRLEN] = '\0';
for (vg = vg_list; vg; vg = vg->next)
{
if (! grub_memcmp(vg_id, vg->id, GRUB_LVM_ID_STRLEN))
break;
}
if (! vg)
{
/* First time we see this volume group. We've to create the
whole volume group structure. */
vg = grub_malloc (sizeof (*vg));
if (! vg)
{
grub_free (vgname);
goto fail;
}
vg->name = vgname;
grub_memcpy (vg->id, vg_id, GRUB_LVM_ID_STRLEN+1);
vg->extent_size = grub_lvm_getvalue (&p, "extent_size = ");
vg->lvs = NULL;
vg->pvs = NULL;
vg->next = vg_list;
vg_list = vg;
p = grub_strstr (p, "physical_volumes {")
+ sizeof ("physical_volumes {") - 1;
/* Add all the pvs to the volume group. */
while (1)
{
int s;
while (grub_isspace (*p))
p++;
if (*p == '}')
break;
pv = grub_malloc (sizeof (*pv));
q = p;
while (*q != ' ')
q++;
s = q - p;
pv->name = grub_malloc (s + 1);
grub_memcpy (pv->name, p, s);
pv->name[s] = '\0';
p = grub_strstr (p, "id = \"") + sizeof("id = \"") - 1;
grub_memcpy (pv->id, p, GRUB_LVM_ID_STRLEN);
pv->id[GRUB_LVM_ID_STRLEN] = '\0';
pv->start = grub_lvm_getvalue (&p, "pe_start = ");
pv->disk = NULL;
pv->next = vg->pvs;
vg->pvs = pv;
p = grub_strchr (p, '}') + 1;
}
p = grub_strstr (p, "logical_volumes");
p += 18;
/* And add all the lvs to the volume group. */
while (1)
{
int s;
struct grub_lvm_lv *lv;
struct grub_lvm_segment *seg;
while (grub_isspace (*p))
p++;
if (*p == '}')
break;
lv = grub_malloc (sizeof (*lv));
q = p;
while (*q != ' ')
q++;
s = q - p;
lv->name = grub_malloc (vgname_len + 1 + s + 1);
grub_memcpy (lv->name, vgname, vgname_len);
lv->name[vgname_len] = '-';
grub_memcpy (lv->name + vgname_len + 1, p, s);
lv->name[vgname_len + 1 + s] = '\0';
lv->size = 0;
lv->segment_count = grub_lvm_getvalue (&p, "segment_count = ");
lv->segments = grub_malloc (sizeof (*seg) * lv->segment_count);
seg = lv->segments;
for (i = 0; i < lv->segment_count; i++)
{
struct grub_lvm_stripe *stripe;
p = grub_strstr (p, "segment");
seg->start_extent = grub_lvm_getvalue (&p, "start_extent = ");
seg->extent_count = grub_lvm_getvalue (&p, "extent_count = ");
seg->stripe_count = grub_lvm_getvalue (&p, "stripe_count = ");
lv->size += seg->extent_count * vg->extent_size;
if (seg->stripe_count != 1)
seg->stripe_size = grub_lvm_getvalue (&p, "stripe_size = ");
seg->stripes = grub_malloc (sizeof (*stripe)
* seg->stripe_count);
stripe = seg->stripes;
p = grub_strstr (p, "stripes = [")
+ sizeof("stripes = [") - 1;
for (j = 0; j < seg->stripe_count; j++)
{
char pvname[10];
q = p = grub_strchr (p, '"') + 1;
while (*q != '"')
q++;
s = q - p;
grub_memcpy (pvname, p, s);
pvname[s] = '\0';
for (pv = vg->pvs; pv; pv = pv->next)
{
if (! grub_strcmp (pvname, pv->name))
{
stripe->pv = pv;
break;
}
}
p = grub_strchr (p, ',') + 1;
stripe->start = grub_strtoul (p, NULL, 10);
stripe++;
}
seg++;
}
lv->number = lv_count++;
lv->vg = vg;
lv->next = vg->lvs;
vg->lvs = lv;
p = grub_strchr (p, '}') + 3;
}
}
else
{
grub_free (vgname);
}
/* Match the device we are currently reading from with the right
PV. */
for (pv = vg->pvs; pv; pv = pv->next)
{
if (! grub_memcmp (pv->id, pv_id, GRUB_LVM_ID_STRLEN))
{
pv->disk = grub_disk_open (name);
break;
}
}
fail2:
grub_free (metadatabuf);
fail:
grub_disk_close (disk);
return 0;
}
static struct grub_disk_dev grub_lvm_dev =
{
.name = "lvm",
.id = GRUB_DISK_DEVICE_LVM_ID,
.iterate = grub_lvm_iterate,
.open = grub_lvm_open,
.close = grub_lvm_close,
.read = grub_lvm_read,
.write = grub_lvm_write,
.next = 0
};
GRUB_MOD_INIT(lvm)
{
grub_device_iterate (&grub_lvm_scan_device);
grub_disk_dev_register (&grub_lvm_dev);
}
GRUB_MOD_FINI(lvm)
{
grub_disk_dev_unregister (&grub_lvm_dev);
/* FIXME: free the lvm list. */
}