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bcachefs: shim for userspace raid library

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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet
2018-11-23 02:06:18 -05:00
committed by Kent Overstreet
parent 4e65431c85
commit de5bb710f9
1 changed files with 73 additions and 54 deletions
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127
fs/bcachefs/ec.c
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@@ -16,9 +16,79 @@
#include "super-io.h"
#include "util.h"
#include <linux/sort.h>
#ifdef __KERNEL__
#include <linux/raid/pq.h>
#include <linux/raid/xor.h>
#include <linux/sort.h>
static void raid5_recov(unsigned disks, unsigned failed_idx,
size_t size, void **data)
{
unsigned i = 2, nr;
BUG_ON(failed_idx >= disks);
swap(data[0], data[failed_idx]);
memcpy(data[0], data[1], size);
while (i < disks) {
nr = min_t(unsigned, disks - i, MAX_XOR_BLOCKS);
xor_blocks(nr, size, data[0], data + i);
i += nr;
}
swap(data[0], data[failed_idx]);
}
static void raid_gen(int nd, int np, size_t size, void **v)
{
if (np >= 1)
raid5_recov(nd + np, nd, size, v);
if (np >= 2)
raid6_call.gen_syndrome(nd + np, size, v);
BUG_ON(np > 2);
}
static void raid_rec(int nr, int *ir, int nd, int np, size_t size, void **v)
{
switch (nr) {
case 0:
break;
case 1:
if (ir[0] < nd + 1)
raid5_recov(nd + 1, ir[0], size, v);
else
raid6_call.gen_syndrome(nd + np, size, v);
break;
case 2:
if (ir[1] < nd) {
/* data+data failure. */
raid6_2data_recov(nd + np, size, ir[0], ir[1], v);
} else if (ir[0] < nd) {
/* data + p/q failure */
if (ir[1] == nd) /* data + p failure */
raid6_datap_recov(nd + np, size, ir[0], v);
else { /* data + q failure */
raid5_recov(nd + 1, ir[0], size, v);
raid6_call.gen_syndrome(nd + np, size, v);
}
} else {
raid_gen(nd, np, size, v);
}
break;
default:
BUG();
}
}
#else
#include <raid/raid.h>
#endif
struct ec_bio {
struct bch_dev *ca;
@@ -251,41 +321,13 @@ static void ec_validate_checksums(struct bch_fs *c, struct ec_stripe_buf *buf)
/* Erasure coding: */
static void raid5_recov(unsigned disks, unsigned bytes,
unsigned failed, void **data)
{
unsigned i = 2, nr;
BUG_ON(failed >= disks);
swap(data[0], data[failed]);
memcpy(data[0], data[1], bytes);
while (i < disks) {
nr = min_t(unsigned, disks - i, MAX_XOR_BLOCKS);
xor_blocks(nr, bytes, data[0], data + i);
i += nr;
}
swap(data[0], data[failed]);
}
static void ec_generate_ec(struct ec_stripe_buf *buf)
{
struct bch_stripe *v = &buf->key.v;
unsigned nr_data = v->nr_blocks - v->nr_redundant;
unsigned bytes = le16_to_cpu(v->sectors) << 9;
switch (v->nr_redundant) {
case 2:
raid6_call.gen_syndrome(v->nr_blocks, bytes, buf->data);
fallthrough;
case 1:
raid5_recov(v->nr_blocks, bytes, nr_data, buf->data);
break;
default:
BUG();
}
raid_gen(nr_data, v->nr_redundant, bytes, buf->data);
}
static unsigned __ec_nr_failed(struct ec_stripe_buf *buf, unsigned nr)
@@ -315,30 +357,7 @@ static int ec_do_recov(struct bch_fs *c, struct ec_stripe_buf *buf)
if (!test_bit(i, buf->valid))
failed[nr_failed++] = i;
switch (nr_failed) {
case 0:
break;
case 1:
if (test_bit(nr_data, buf->valid))
raid5_recov(nr_data + 1, bytes, failed[0], buf->data);
else
raid6_datap_recov(v->nr_blocks, bytes, failed[0], buf->data);
break;
case 2:
/* data+data failure. */
raid6_2data_recov(v->nr_blocks, bytes, failed[0], failed[1], buf->data);
break;
default:
BUG();
}
for (i = nr_data; i < v->nr_blocks; i++)
if (!test_bit(i, buf->valid)) {
ec_generate_ec(buf);
break;
}
raid_rec(nr_failed, failed, nr_data, v->nr_redundant, bytes, buf->data);
return 0;
}