#include "fdiskP.h"
/*
* Alignment according to logical granulity (usually 1MiB)
*/
static int lba_is_aligned(struct fdisk_context *cxt, sector_t lba)
{
unsigned long granularity = max(cxt->phy_sector_size, cxt->min_io_size);
uintmax_t offset;
if (cxt->grain > granularity)
granularity = cxt->grain;
offset = (lba * cxt->sector_size) & (granularity - 1);
return !((granularity + cxt->alignment_offset - offset) & (granularity - 1));
}
/*
* Alignment according to physical device topology (usually minimal i/o size)
*/
static int lba_is_phy_aligned(struct fdisk_context *cxt, sector_t lba)
{
unsigned long granularity = max(cxt->phy_sector_size, cxt->min_io_size);
uintmax_t offset = (lba * cxt->sector_size) & (granularity - 1);
return !((granularity + cxt->alignment_offset - offset) & (granularity - 1));
}
/*
* Align @lba in @direction FDISK_ALIGN_{UP,DOWN,NEAREST}
*/
sector_t fdisk_align_lba(struct fdisk_context *cxt, sector_t lba, int direction)
{
sector_t res;
if (lba_is_aligned(cxt, lba))
res = lba;
else {
sector_t sects_in_phy = cxt->grain / cxt->sector_size;
if (lba < cxt->first_lba)
res = cxt->first_lba;
else if (direction == FDISK_ALIGN_UP)
res = ((lba + sects_in_phy) / sects_in_phy) * sects_in_phy;
else if (direction == FDISK_ALIGN_DOWN)
res = (lba / sects_in_phy) * sects_in_phy;
else /* FDISK_ALIGN_NEAREST */
res = ((lba + sects_in_phy / 2) / sects_in_phy) * sects_in_phy;
if (cxt->alignment_offset && !lba_is_aligned(cxt, res) &&
res > cxt->alignment_offset / cxt->sector_size) {
/*
* apply alignment_offset
*
* On disk with alignment compensation physical blocks starts
* at LBA < 0 (usually LBA -1). It means we have to move LBA
* according the offset to be on the physical boundary.
*/
/* fprintf(stderr, "LBA: %llu apply alignment_offset\n", res); */
res -= (max(cxt->phy_sector_size, cxt->min_io_size) -
cxt->alignment_offset) / cxt->sector_size;
if (direction == FDISK_ALIGN_UP && res < lba)
res += sects_in_phy;
}
}
return res;
}
/*
* Align @lba, the result has to be between @start and @stop
*/
sector_t fdisk_align_lba_in_range(struct fdisk_context *cxt,
sector_t lba, sector_t start, sector_t stop)
{
start = fdisk_align_lba(cxt, start, FDISK_ALIGN_UP);
stop = fdisk_align_lba(cxt, stop, FDISK_ALIGN_DOWN);
lba = fdisk_align_lba(cxt, lba, FDISK_ALIGN_NEAREST);
if (lba < start)
return start;
else if (lba > stop)
return stop;
return lba;
}
/*
* Print warning if the partition @lba (start of the @partition) is not
* aligned to physical sector boundary.
*/
void fdisk_warn_alignment(struct fdisk_context *cxt, sector_t lba, int partition)
{
if (!lba_is_phy_aligned(cxt, lba))
printf(_("Partition %i does not start on physical sector boundary.\n"),
partition + 1);
}
