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super1: encourage data alignment on 1Meg boundary 

For 1.1 and 1.2 metadata where data_offset is not zero,
it is important to align the data_offset to underlying
block size.

We don't currently have access to the particular device
in avail_size so just try to force to a 1Meg boundary.

Also default 1.x metadata to 1.2 as documented.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2010-03-03 15:22:56 +11:00
parent d1d3482b56
commit a380e2751e
1 changed files with 40 additions and 12 deletions
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52
super1.c
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@ -994,6 +994,8 @@ static unsigned long choose_bm_space(unsigned long devsize)
{
/* if the device is bigger than 8Gig, save 64k for bitmap usage,
* if bigger than 200Gig, save 128k
* NOTE: result must be multiple of 4K else bad things happen
* on 4K-sector devices.
*/
if (devsize < 64*2) return 0;
if (devsize - 64*2 >= 200*1024*1024*2)
@ -1011,6 +1013,7 @@ static int write_init_super1(struct supertype *st)
int rfd;
int rv = 0;
int bm_space;
unsigned long long reserved;
struct devinfo *di;
unsigned long long dsize, array_size;
long long sb_offset;
@ -1088,16 +1091,23 @@ static int write_init_super1(struct supertype *st)
sb_offset &= ~(4*2-1);
sb->super_offset = __cpu_to_le64(sb_offset);
sb->data_offset = __cpu_to_le64(0);
if (sb_offset - bm_space < array_size)
bm_space = sb_offset - array_size;
if (sb_offset - bm_space < array_size)
bm_space = sb_offset - array_size;
sb->data_size = __cpu_to_le64(sb_offset - bm_space);
break;
case 1:
sb->super_offset = __cpu_to_le64(0);
if (4*2 + bm_space + __le64_to_cpu(sb->size) > dsize)
bm_space = dsize - __le64_to_cpu(sb->size) -4*2;
sb->data_offset = __cpu_to_le64(bm_space + 4*2);
sb->data_size = __cpu_to_le64(dsize - bm_space - 4*2);
reserved = bm_space + 4*2;
/* Try for multiple of 1Meg so it is nicely aligned */
#define ONE_MEG (2*1024)
reserved = ((reserved + ONE_MEG-1)/ONE_MEG) * ONE_MEG;
if (reserved + __le64_to_cpu(sb->size) > dsize)
reserved = dsize - __le64_to_cpu(sb->size);
/* force 4K alignment */
reserved &= ~7ULL;
sb->data_offset = __cpu_to_le64(reserved);
sb->data_size = __cpu_to_le64(dsize - reserved);
break;
case 2:
sb_offset = 4*2;
@ -1106,9 +1116,18 @@ static int write_init_super1(struct supertype *st)
> dsize)
bm_space = dsize - __le64_to_cpu(sb->size)
- 4*2 - 4*2;
sb->data_offset = __cpu_to_le64(4*2 + 4*2 + bm_space);
sb->data_size = __cpu_to_le64(dsize - 4*2 - 4*2
- bm_space );
reserved = bm_space + 4*2 + 4*2;
/* Try for multiple of 1Meg so it is nicely aligned */
#define ONE_MEG (2*1024)
reserved = ((reserved + ONE_MEG-1)/ONE_MEG) * ONE_MEG;
if (reserved + __le64_to_cpu(sb->size) > dsize)
reserved = dsize - __le64_to_cpu(sb->size);
/* force 4K alignment */
reserved &= ~7ULL;
sb->data_offset = __cpu_to_le64(reserved);
sb->data_size = __cpu_to_le64(dsize - reserved);
break;
default:
return -EINVAL;
@ -1400,10 +1419,19 @@ static __u64 avail_size1(struct supertype *st, __u64 devsize)
}
#endif
if (st->minor_version < 0)
/* not specified, so time to set default */
st->minor_version = 2;
if (super == NULL && st->minor_version > 0) {
/* haven't committed to a size yet, so allow some
* slack for alignment of data_offset.
* We haven't access to device details so allow
* 1 Meg if bigger than 1Gig
*/
if (devsize > 1024*1024*2)
devsize -= 1024*2;
}
switch(st->minor_version) {
case -1: /* no specified. Now time to set default */
st->minor_version = 0;
/* FALL THROUGH */
case 0:
/* at end */
return ((devsize - 8*2 ) & ~(4*2-1));