On Sat, Jan 24, 2015 at 11:23 PM, Wesley W. Terpstra <wesley@xxxxxxxxxxx> wrote:
>> First, it is obviously the last test in super_1_load that is rejecting
>> the array. The superblock reports more sectors than are calculated, so
>> the check
>> if (sectors < le64_to_cpu(sb->data_size)) {
>> fails.
>
> Thus, an alternative explanation could be that the the sb->data_size
> was not updated after the reshape completed.
I can confirm that this was the problem.
I manually modified my super block using the attached quick hack.
Thereafter I was able to reassemble the array and fsck everything
successfully.
I will try and see if I can reproduce the problem tomorrow. It's a
pretty nasty bug to have a reshape complete and render your array
unassemblable.
#include <string.h>
#include <stdint.h>
#include <inttypes.h>
#include <stdio.h>
int main() {
char buf[512];
uint64_t data_offset, data_size, reshape_position;
uint32_t checksum;
fread(buf, sizeof(buf), 1, stdin);
/* Assumes little-endian */
memcpy(&reshape_position, buf+0x68, 8);
memcpy(&data_offset, buf+0x80, 8);
memcpy(&data_size, buf+0x88, 8);
memcpy(&checksum, buf+0xD8, 4);
fprintf(stderr, "data_offset: %"PRIu64"\n", data_offset);
fprintf(stderr, "data_size: %"PRIu64"\n", data_size);
fprintf(stderr, "reshape: %"PRIu64"\n", reshape_position);
fprintf(stderr, "checksum: %x\n", checksum);
/* Assumes no overflow */
checksum += (5842894848 - data_size);
data_size = 5842894848;
memcpy(buf+0x88, &data_size, 8);
memcpy(buf+0xD8, &checksum, 4);
fwrite(buf, sizeof(buf), 1, stdout);
return 0;
}
