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restripe : various fixed for RAID6 2-failure recovery. 

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2009-10-12 16:57:22 +11:00
parent 487e48afab
commit cc50ccdc29
1 changed files with 40 additions and 12 deletions
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52
restripe.c
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@ -425,7 +425,7 @@ int save_stripes(int *source, unsigned long long *offsets,
raid_disks, level, layout);
if (dnum < 0) abort();
if (source[dnum] < 0 ||
lseek64(source[dnum], offsets[disk]+offset, 0) < 0 ||
lseek64(source[dnum], offsets[dnum]+offset, 0) < 0 ||
read(source[dnum], buf+disk * chunk_size, chunk_size)
!= chunk_size)
if (failed <= 2) {
@ -465,32 +465,60 @@ int save_stripes(int *source, unsigned long long *offsets,
* 'p' and 'q' get to be all zero
*/
for (i = 0; i < raid_disks; i++)
if (i == disk || i == qdisk)
bufs[i] = zero;
else
bufs[i] = (uint8_t*)buf+i*chunk_size;
bufs[i] = zero;
for (i = 0; i < data_disks; i++) {
int dnum = geo_map(i,
start/chunk_size/data_disks,
raid_disks, level, layout);
int snum;
/* i is the logical block number, so is index to 'buf'.
* dnum is physical disk number
* and thus the syndrome number.
*/
snum = dnum;
bufs[snum] = (uint8_t*)buf + chunk_size * i;
}
syndrome_disks = raid_disks;
} else {
/* for md, q is over 'data_disks' blocks,
* starting immediately after 'q'
*/
for (i = 0; i < data_disks; i++)
bufs[i] = (uint8_t*)buf + chunk_size * ((qdisk+1+i) % raid_disks);
for (i = 0; i < data_disks; i++) {
int dnum = geo_map(i,
start/chunk_size/data_disks,
raid_disks, level, layout);
int snum;
/* i is the logical block number, so is index to 'buf'.
* dnum is physical disk number
* snum is syndrome disk for which 0 is immediately after Q
*/
snum = (raid_disks + dnum - qdisk - 1) % raid_disks;
bufs[snum] = (uint8_t*)buf + chunk_size * i;
}
fdisk[0] = (qdisk + 1 + fdisk[0]) % raid_disks;
fdisk[1] = (qdisk + 1 + fdisk[1]) % raid_disks;
fdisk[0] = (raid_disks + fdisk[0] - qdisk - 1) % raid_disks;
fdisk[1] = (raid_disks + fdisk[1] - qdisk - 1) % raid_disks;
syndrome_disks = data_disks;
}
bufs[syndrome_disks] = (uint8_t*)buf + chunk_size * disk;
bufs[syndrome_disks+1] = (uint8_t*)buf + chunk_size * qdisk;
/* Place P and Q blocks at end of bufs */
bufs[syndrome_disks] = (uint8_t*)buf + chunk_size * data_disks;
bufs[syndrome_disks+1] = (uint8_t*)buf + chunk_size * (data_disks+1);
if (fblock[1] == data_disks)
/* One data failed, and parity failed */
raid6_datap_recov(syndrome_disks+2, chunk_size,
fdisk[0], bufs);
else
else {
if (fdisk[0] > fdisk[1]) {
int t = fdisk[0];
fdisk[0] = fdisk[1];
fdisk[1] = t;
}
/* Two data blocks failed, P,Q OK */
raid6_2data_recov(syndrome_disks+2, chunk_size,
fdisk[0], fdisk[1], bufs);
}
}
for (i=0; i<nwrites; i++)