marko10_000
/
btrfs-progs
forked from Mirrors/btrfs-progs
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

btrfs-progs: raid56: Allow raid6 to recover data and P 

Copied from kernel lib/raid6/recov.c.

Minor modifications includes:
- Rename from raid6_datap_recov_intx() to raid5_recov_datap()
- Rename parameter from faila to dest1

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
master
Qu Wenruo 2017-05-25 14:21:49 +08:00 committed by David Sterba
parent 9604ce49d6
commit 008bbd8842
2 changed files with 44 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
kernel-lib/raid56.c
View File

@ -239,3 +239,44 @@ int raid6_recov_data2(int nr_devs, size_t stripe_len, int dest1, int dest2,
free(zero_mem2);
return ret;
}
/*
* Raid 6 recover code copied from kernel lib/raid6/recov.c
* - rename from raid6_datap_recov_intx1()
* - parameter changed from faila to dest1
*/
int raid6_recov_datap(int nr_devs, size_t stripe_len, int dest1, void **data)
{
u8 *p, *q, *dq;
const u8 *qmul; /* Q multiplier table */
char *zero_mem;
p = (u8 *)data[nr_devs - 2];
q = (u8 *)data[nr_devs - 1];
zero_mem = calloc(1, stripe_len);
if (!zero_mem)
return -ENOMEM;
/* Compute syndrome with zero for the missing data page
Use the dead data page as temporary storage for delta q */
dq = (u8 *)data[dest1];
data[dest1] = (void *)zero_mem;
data[nr_devs - 1] = dq;
raid6_gen_syndrome(nr_devs, stripe_len, data);
/* Restore pointer table */
data[dest1] = dq;
data[nr_devs - 1] = q;
/* Now, pick the proper data tables */
qmul = raid6_gfmul[raid6_gfinv[raid6_gfexp[dest1]]];
/* Now do it... */
while ( stripe_len-- ) {
*p++ ^= *dq = qmul[*q ^ *dq];
q++; dq++;
}
return 0;
}

3
kernel-lib/raid56.h
View File

@ -41,4 +41,7 @@ extern const u8 raid6_gfexi[256] __attribute__((aligned(256)));
int raid6_recov_data2(int nr_devs, size_t stripe_len, int dest1, int dest2,
void **data);
/* Recover data and P */
int raid6_recov_datap(int nr_devs, size_t stripe_len, int dest1, void **data);
#endif