linux-stable/fs/bcachefs/ec.c
Kent Overstreet d97de0d017 bcachefs: Make bkey_fsck_err() a wrapper around fsck_err()
bkey_fsck_err() was added as an interface that looks like fsck_err(),
but previously all it did was ensure that the appropriate error counter
was incremented in the superblock.

This is a cleanup and bugfix patch that converts it to a wrapper around
fsck_err(). This is needed to fix an issue with the upgrade path to
disk_accounting_v3, where the "silent fix" error list now includes
bkey_fsck errors; fsck_err() handles this in a unified way, and since we
need to change printing of bkey fsck errors from the caller to the inner
bkey_fsck_err() calls, this ends up being a pretty big change.

Als,, rename .invalid() methods to .validate(), for clarity, while we're
changing the function signature anyways (to drop the printbuf argument).

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-08-13 23:00:50 -04:00

2332 lines
57 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* erasure coding */
#include "bcachefs.h"
#include "alloc_background.h"
#include "alloc_foreground.h"
#include "backpointers.h"
#include "bkey_buf.h"
#include "bset.h"
#include "btree_gc.h"
#include "btree_update.h"
#include "btree_write_buffer.h"
#include "buckets.h"
#include "checksum.h"
#include "disk_accounting.h"
#include "disk_groups.h"
#include "ec.h"
#include "error.h"
#include "io_read.h"
#include "keylist.h"
#include "recovery.h"
#include "replicas.h"
#include "super-io.h"
#include "util.h"
#include <linux/sort.h>
#ifdef __KERNEL__
#include <linux/raid/pq.h>
#include <linux/raid/xor.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;
struct ec_stripe_buf *buf;
size_t idx;
struct bio bio;
};
/* Stripes btree keys: */
int bch2_stripe_validate(struct bch_fs *c, struct bkey_s_c k,
enum bch_validate_flags flags)
{
const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
int ret = 0;
bkey_fsck_err_on(bkey_eq(k.k->p, POS_MIN) ||
bpos_gt(k.k->p, POS(0, U32_MAX)),
c, stripe_pos_bad,
"stripe at bad pos");
bkey_fsck_err_on(bkey_val_u64s(k.k) < stripe_val_u64s(s),
c, stripe_val_size_bad,
"incorrect value size (%zu < %u)",
bkey_val_u64s(k.k), stripe_val_u64s(s));
ret = bch2_bkey_ptrs_validate(c, k, flags);
fsck_err:
return ret;
}
void bch2_stripe_to_text(struct printbuf *out, struct bch_fs *c,
struct bkey_s_c k)
{
const struct bch_stripe *sp = bkey_s_c_to_stripe(k).v;
struct bch_stripe s = {};
memcpy(&s, sp, min(sizeof(s), bkey_val_bytes(k.k)));
unsigned nr_data = s.nr_blocks - s.nr_redundant;
prt_printf(out, "algo %u sectors %u blocks %u:%u csum ",
s.algorithm,
le16_to_cpu(s.sectors),
nr_data,
s.nr_redundant);
bch2_prt_csum_type(out, s.csum_type);
prt_printf(out, " gran %u", 1U << s.csum_granularity_bits);
for (unsigned i = 0; i < s.nr_blocks; i++) {
const struct bch_extent_ptr *ptr = sp->ptrs + i;
if ((void *) ptr >= bkey_val_end(k))
break;
bch2_extent_ptr_to_text(out, c, ptr);
if (s.csum_type < BCH_CSUM_NR &&
i < nr_data &&
stripe_blockcount_offset(&s, i) < bkey_val_bytes(k.k))
prt_printf(out, "#%u", stripe_blockcount_get(sp, i));
}
}
/* Triggers: */
static int __mark_stripe_bucket(struct btree_trans *trans,
struct bch_dev *ca,
struct bkey_s_c_stripe s,
unsigned ptr_idx, bool deleting,
struct bpos bucket,
struct bch_alloc_v4 *a,
enum btree_iter_update_trigger_flags flags)
{
const struct bch_extent_ptr *ptr = s.v->ptrs + ptr_idx;
unsigned nr_data = s.v->nr_blocks - s.v->nr_redundant;
bool parity = ptr_idx >= nr_data;
enum bch_data_type data_type = parity ? BCH_DATA_parity : BCH_DATA_stripe;
s64 sectors = parity ? le16_to_cpu(s.v->sectors) : 0;
struct printbuf buf = PRINTBUF;
int ret = 0;
struct bch_fs *c = trans->c;
if (deleting)
sectors = -sectors;
if (!deleting) {
if (bch2_trans_inconsistent_on(a->stripe ||
a->stripe_redundancy, trans,
"bucket %llu:%llu gen %u data type %s dirty_sectors %u: multiple stripes using same bucket (%u, %llu)\n%s",
bucket.inode, bucket.offset, a->gen,
bch2_data_type_str(a->data_type),
a->dirty_sectors,
a->stripe, s.k->p.offset,
(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
ret = -EIO;
goto err;
}
if (bch2_trans_inconsistent_on(parity && bch2_bucket_sectors_total(*a), trans,
"bucket %llu:%llu gen %u data type %s dirty_sectors %u cached_sectors %u: data already in parity bucket\n%s",
bucket.inode, bucket.offset, a->gen,
bch2_data_type_str(a->data_type),
a->dirty_sectors,
a->cached_sectors,
(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
ret = -EIO;
goto err;
}
} else {
if (bch2_trans_inconsistent_on(a->stripe != s.k->p.offset ||
a->stripe_redundancy != s.v->nr_redundant, trans,
"bucket %llu:%llu gen %u: not marked as stripe when deleting stripe (got %u)\n%s",
bucket.inode, bucket.offset, a->gen,
a->stripe,
(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
ret = -EIO;
goto err;
}
if (bch2_trans_inconsistent_on(a->data_type != data_type, trans,
"bucket %llu:%llu gen %u data type %s: wrong data type when stripe, should be %s\n%s",
bucket.inode, bucket.offset, a->gen,
bch2_data_type_str(a->data_type),
bch2_data_type_str(data_type),
(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
ret = -EIO;
goto err;
}
if (bch2_trans_inconsistent_on(parity &&
(a->dirty_sectors != -sectors ||
a->cached_sectors), trans,
"bucket %llu:%llu gen %u dirty_sectors %u cached_sectors %u: wrong sectors when deleting parity block of stripe\n%s",
bucket.inode, bucket.offset, a->gen,
a->dirty_sectors,
a->cached_sectors,
(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
ret = -EIO;
goto err;
}
}
if (sectors) {
ret = bch2_bucket_ref_update(trans, ca, s.s_c, ptr, sectors, data_type,
a->gen, a->data_type, &a->dirty_sectors);
if (ret)
goto err;
}
if (!deleting) {
a->stripe = s.k->p.offset;
a->stripe_redundancy = s.v->nr_redundant;
} else {
a->stripe = 0;
a->stripe_redundancy = 0;
}
alloc_data_type_set(a, data_type);
err:
printbuf_exit(&buf);
return ret;
}
static int mark_stripe_bucket(struct btree_trans *trans,
struct bkey_s_c_stripe s,
unsigned ptr_idx, bool deleting,
enum btree_iter_update_trigger_flags flags)
{
struct bch_fs *c = trans->c;
const struct bch_extent_ptr *ptr = s.v->ptrs + ptr_idx;
struct printbuf buf = PRINTBUF;
int ret = 0;
struct bch_dev *ca = bch2_dev_tryget(c, ptr->dev);
if (unlikely(!ca)) {
if (!(flags & BTREE_TRIGGER_overwrite))
ret = -EIO;
goto err;
}
struct bpos bucket = PTR_BUCKET_POS(ca, ptr);
if (flags & BTREE_TRIGGER_transactional) {
struct bkey_i_alloc_v4 *a =
bch2_trans_start_alloc_update(trans, bucket, 0);
ret = PTR_ERR_OR_ZERO(a) ?:
__mark_stripe_bucket(trans, ca, s, ptr_idx, deleting, bucket, &a->v, flags);
}
if (flags & BTREE_TRIGGER_gc) {
percpu_down_read(&c->mark_lock);
struct bucket *g = gc_bucket(ca, bucket.offset);
if (bch2_fs_inconsistent_on(!g, c, "reference to invalid bucket on device %u\n %s",
ptr->dev,
(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
ret = -EIO;
goto err_unlock;
}
bucket_lock(g);
struct bch_alloc_v4 old = bucket_m_to_alloc(*g), new = old;
ret = __mark_stripe_bucket(trans, ca, s, ptr_idx, deleting, bucket, &new, flags);
alloc_to_bucket(g, new);
bucket_unlock(g);
err_unlock:
percpu_up_read(&c->mark_lock);
if (!ret)
ret = bch2_alloc_key_to_dev_counters(trans, ca, &old, &new, flags);
}
err:
bch2_dev_put(ca);
printbuf_exit(&buf);
return ret;
}
static int mark_stripe_buckets(struct btree_trans *trans,
struct bkey_s_c old, struct bkey_s_c new,
enum btree_iter_update_trigger_flags flags)
{
const struct bch_stripe *old_s = old.k->type == KEY_TYPE_stripe
? bkey_s_c_to_stripe(old).v : NULL;
const struct bch_stripe *new_s = new.k->type == KEY_TYPE_stripe
? bkey_s_c_to_stripe(new).v : NULL;
BUG_ON(old_s && new_s && old_s->nr_blocks != new_s->nr_blocks);
unsigned nr_blocks = new_s ? new_s->nr_blocks : old_s->nr_blocks;
for (unsigned i = 0; i < nr_blocks; i++) {
if (new_s && old_s &&
!memcmp(&new_s->ptrs[i],
&old_s->ptrs[i],
sizeof(new_s->ptrs[i])))
continue;
if (new_s) {
int ret = mark_stripe_bucket(trans,
bkey_s_c_to_stripe(new), i, false, flags);
if (ret)
return ret;
}
if (old_s) {
int ret = mark_stripe_bucket(trans,
bkey_s_c_to_stripe(old), i, true, flags);
if (ret)
return ret;
}
}
return 0;
}
int bch2_trigger_stripe(struct btree_trans *trans,
enum btree_id btree, unsigned level,
struct bkey_s_c old, struct bkey_s _new,
enum btree_iter_update_trigger_flags flags)
{
struct bkey_s_c new = _new.s_c;
struct bch_fs *c = trans->c;
u64 idx = new.k->p.offset;
const struct bch_stripe *old_s = old.k->type == KEY_TYPE_stripe
? bkey_s_c_to_stripe(old).v : NULL;
const struct bch_stripe *new_s = new.k->type == KEY_TYPE_stripe
? bkey_s_c_to_stripe(new).v : NULL;
if (unlikely(flags & BTREE_TRIGGER_check_repair))
return bch2_check_fix_ptrs(trans, btree, level, _new.s_c, flags);
BUG_ON(new_s && old_s &&
(new_s->nr_blocks != old_s->nr_blocks ||
new_s->nr_redundant != old_s->nr_redundant));
if (flags & (BTREE_TRIGGER_transactional|BTREE_TRIGGER_gc)) {
/*
* If the pointers aren't changing, we don't need to do anything:
*/
if (new_s && old_s &&
new_s->nr_blocks == old_s->nr_blocks &&
new_s->nr_redundant == old_s->nr_redundant &&
!memcmp(old_s->ptrs, new_s->ptrs,
new_s->nr_blocks * sizeof(struct bch_extent_ptr)))
return 0;
struct gc_stripe *gc = NULL;
if (flags & BTREE_TRIGGER_gc) {
gc = genradix_ptr_alloc(&c->gc_stripes, idx, GFP_KERNEL);
if (!gc) {
bch_err(c, "error allocating memory for gc_stripes, idx %llu", idx);
return -BCH_ERR_ENOMEM_mark_stripe;
}
/*
* This will be wrong when we bring back runtime gc: we should
* be unmarking the old key and then marking the new key
*
* Also: when we bring back runtime gc, locking
*/
gc->alive = true;
gc->sectors = le16_to_cpu(new_s->sectors);
gc->nr_blocks = new_s->nr_blocks;
gc->nr_redundant = new_s->nr_redundant;
for (unsigned i = 0; i < new_s->nr_blocks; i++)
gc->ptrs[i] = new_s->ptrs[i];
/*
* gc recalculates this field from stripe ptr
* references:
*/
memset(gc->block_sectors, 0, sizeof(gc->block_sectors));
}
if (new_s) {
s64 sectors = (u64) le16_to_cpu(new_s->sectors) * new_s->nr_redundant;
struct disk_accounting_pos acc = {
.type = BCH_DISK_ACCOUNTING_replicas,
};
bch2_bkey_to_replicas(&acc.replicas, new);
int ret = bch2_disk_accounting_mod(trans, &acc, &sectors, 1, gc);
if (ret)
return ret;
if (gc)
memcpy(&gc->r.e, &acc.replicas, replicas_entry_bytes(&acc.replicas));
}
if (old_s) {
s64 sectors = -((s64) le16_to_cpu(old_s->sectors)) * old_s->nr_redundant;
struct disk_accounting_pos acc = {
.type = BCH_DISK_ACCOUNTING_replicas,
};
bch2_bkey_to_replicas(&acc.replicas, old);
int ret = bch2_disk_accounting_mod(trans, &acc, &sectors, 1, gc);
if (ret)
return ret;
}
int ret = mark_stripe_buckets(trans, old, new, flags);
if (ret)
return ret;
}
if (flags & BTREE_TRIGGER_atomic) {
struct stripe *m = genradix_ptr(&c->stripes, idx);
if (!m) {
struct printbuf buf1 = PRINTBUF;
struct printbuf buf2 = PRINTBUF;
bch2_bkey_val_to_text(&buf1, c, old);
bch2_bkey_val_to_text(&buf2, c, new);
bch_err_ratelimited(c, "error marking nonexistent stripe %llu while marking\n"
"old %s\n"
"new %s", idx, buf1.buf, buf2.buf);
printbuf_exit(&buf2);
printbuf_exit(&buf1);
bch2_inconsistent_error(c);
return -1;
}
if (!new_s) {
bch2_stripes_heap_del(c, m, idx);
memset(m, 0, sizeof(*m));
} else {
m->sectors = le16_to_cpu(new_s->sectors);
m->algorithm = new_s->algorithm;
m->nr_blocks = new_s->nr_blocks;
m->nr_redundant = new_s->nr_redundant;
m->blocks_nonempty = 0;
for (unsigned i = 0; i < new_s->nr_blocks; i++)
m->blocks_nonempty += !!stripe_blockcount_get(new_s, i);
if (!old_s)
bch2_stripes_heap_insert(c, m, idx);
else
bch2_stripes_heap_update(c, m, idx);
}
}
return 0;
}
/* returns blocknr in stripe that we matched: */
static const struct bch_extent_ptr *bkey_matches_stripe(struct bch_stripe *s,
struct bkey_s_c k, unsigned *block)
{
struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
unsigned i, nr_data = s->nr_blocks - s->nr_redundant;
bkey_for_each_ptr(ptrs, ptr)
for (i = 0; i < nr_data; i++)
if (__bch2_ptr_matches_stripe(&s->ptrs[i], ptr,
le16_to_cpu(s->sectors))) {
*block = i;
return ptr;
}
return NULL;
}
static bool extent_has_stripe_ptr(struct bkey_s_c k, u64 idx)
{
switch (k.k->type) {
case KEY_TYPE_extent: {
struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
const union bch_extent_entry *entry;
extent_for_each_entry(e, entry)
if (extent_entry_type(entry) ==
BCH_EXTENT_ENTRY_stripe_ptr &&
entry->stripe_ptr.idx == idx)
return true;
break;
}
}
return false;
}
/* Stripe bufs: */
static void ec_stripe_buf_exit(struct ec_stripe_buf *buf)
{
if (buf->key.k.type == KEY_TYPE_stripe) {
struct bkey_i_stripe *s = bkey_i_to_stripe(&buf->key);
unsigned i;
for (i = 0; i < s->v.nr_blocks; i++) {
kvfree(buf->data[i]);
buf->data[i] = NULL;
}
}
}
/* XXX: this is a non-mempoolified memory allocation: */
static int ec_stripe_buf_init(struct ec_stripe_buf *buf,
unsigned offset, unsigned size)
{
struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
unsigned csum_granularity = 1U << v->csum_granularity_bits;
unsigned end = offset + size;
unsigned i;
BUG_ON(end > le16_to_cpu(v->sectors));
offset = round_down(offset, csum_granularity);
end = min_t(unsigned, le16_to_cpu(v->sectors),
round_up(end, csum_granularity));
buf->offset = offset;
buf->size = end - offset;
memset(buf->valid, 0xFF, sizeof(buf->valid));
for (i = 0; i < v->nr_blocks; i++) {
buf->data[i] = kvmalloc(buf->size << 9, GFP_KERNEL);
if (!buf->data[i])
goto err;
}
return 0;
err:
ec_stripe_buf_exit(buf);
return -BCH_ERR_ENOMEM_stripe_buf;
}
/* Checksumming: */
static struct bch_csum ec_block_checksum(struct ec_stripe_buf *buf,
unsigned block, unsigned offset)
{
struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
unsigned csum_granularity = 1 << v->csum_granularity_bits;
unsigned end = buf->offset + buf->size;
unsigned len = min(csum_granularity, end - offset);
BUG_ON(offset >= end);
BUG_ON(offset < buf->offset);
BUG_ON(offset & (csum_granularity - 1));
BUG_ON(offset + len != le16_to_cpu(v->sectors) &&
(len & (csum_granularity - 1)));
return bch2_checksum(NULL, v->csum_type,
null_nonce(),
buf->data[block] + ((offset - buf->offset) << 9),
len << 9);
}
static void ec_generate_checksums(struct ec_stripe_buf *buf)
{
struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
unsigned i, j, csums_per_device = stripe_csums_per_device(v);
if (!v->csum_type)
return;
BUG_ON(buf->offset);
BUG_ON(buf->size != le16_to_cpu(v->sectors));
for (i = 0; i < v->nr_blocks; i++)
for (j = 0; j < csums_per_device; j++)
stripe_csum_set(v, i, j,
ec_block_checksum(buf, i, j << v->csum_granularity_bits));
}
static void ec_validate_checksums(struct bch_fs *c, struct ec_stripe_buf *buf)
{
struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
unsigned csum_granularity = 1 << v->csum_granularity_bits;
unsigned i;
if (!v->csum_type)
return;
for (i = 0; i < v->nr_blocks; i++) {
unsigned offset = buf->offset;
unsigned end = buf->offset + buf->size;
if (!test_bit(i, buf->valid))
continue;
while (offset < end) {
unsigned j = offset >> v->csum_granularity_bits;
unsigned len = min(csum_granularity, end - offset);
struct bch_csum want = stripe_csum_get(v, i, j);
struct bch_csum got = ec_block_checksum(buf, i, offset);
if (bch2_crc_cmp(want, got)) {
struct bch_dev *ca = bch2_dev_tryget(c, v->ptrs[i].dev);
if (ca) {
struct printbuf err = PRINTBUF;
prt_str(&err, "stripe ");
bch2_csum_err_msg(&err, v->csum_type, want, got);
prt_printf(&err, " for %ps at %u of\n ", (void *) _RET_IP_, i);
bch2_bkey_val_to_text(&err, c, bkey_i_to_s_c(&buf->key));
bch_err_ratelimited(ca, "%s", err.buf);
printbuf_exit(&err);
bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
}
clear_bit(i, buf->valid);
break;
}
offset += len;
}
}
}
/* Erasure coding: */
static void ec_generate_ec(struct ec_stripe_buf *buf)
{
struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
unsigned nr_data = v->nr_blocks - v->nr_redundant;
unsigned bytes = le16_to_cpu(v->sectors) << 9;
raid_gen(nr_data, v->nr_redundant, bytes, buf->data);
}
static unsigned ec_nr_failed(struct ec_stripe_buf *buf)
{
struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
return v->nr_blocks - bitmap_weight(buf->valid, v->nr_blocks);
}
static int ec_do_recov(struct bch_fs *c, struct ec_stripe_buf *buf)
{
struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
unsigned i, failed[BCH_BKEY_PTRS_MAX], nr_failed = 0;
unsigned nr_data = v->nr_blocks - v->nr_redundant;
unsigned bytes = buf->size << 9;
if (ec_nr_failed(buf) > v->nr_redundant) {
bch_err_ratelimited(c,
"error doing reconstruct read: unable to read enough blocks");
return -1;
}
for (i = 0; i < nr_data; i++)
if (!test_bit(i, buf->valid))
failed[nr_failed++] = i;
raid_rec(nr_failed, failed, nr_data, v->nr_redundant, bytes, buf->data);
return 0;
}
/* IO: */
static void ec_block_endio(struct bio *bio)
{
struct ec_bio *ec_bio = container_of(bio, struct ec_bio, bio);
struct bch_stripe *v = &bkey_i_to_stripe(&ec_bio->buf->key)->v;
struct bch_extent_ptr *ptr = &v->ptrs[ec_bio->idx];
struct bch_dev *ca = ec_bio->ca;
struct closure *cl = bio->bi_private;
if (bch2_dev_io_err_on(bio->bi_status, ca,
bio_data_dir(bio)
? BCH_MEMBER_ERROR_write
: BCH_MEMBER_ERROR_read,
"erasure coding %s error: %s",
bio_data_dir(bio) ? "write" : "read",
bch2_blk_status_to_str(bio->bi_status)))
clear_bit(ec_bio->idx, ec_bio->buf->valid);
int stale = dev_ptr_stale(ca, ptr);
if (stale) {
bch_err_ratelimited(ca->fs,
"error %s stripe: stale/invalid pointer (%i) after io",
bio_data_dir(bio) == READ ? "reading from" : "writing to",
stale);
clear_bit(ec_bio->idx, ec_bio->buf->valid);
}
bio_put(&ec_bio->bio);
percpu_ref_put(&ca->io_ref);
closure_put(cl);
}
static void ec_block_io(struct bch_fs *c, struct ec_stripe_buf *buf,
blk_opf_t opf, unsigned idx, struct closure *cl)
{
struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
unsigned offset = 0, bytes = buf->size << 9;
struct bch_extent_ptr *ptr = &v->ptrs[idx];
enum bch_data_type data_type = idx < v->nr_blocks - v->nr_redundant
? BCH_DATA_user
: BCH_DATA_parity;
int rw = op_is_write(opf);
struct bch_dev *ca = bch2_dev_get_ioref(c, ptr->dev, rw);
if (!ca) {
clear_bit(idx, buf->valid);
return;
}
int stale = dev_ptr_stale(ca, ptr);
if (stale) {
bch_err_ratelimited(c,
"error %s stripe: stale pointer (%i)",
rw == READ ? "reading from" : "writing to",
stale);
clear_bit(idx, buf->valid);
return;
}
this_cpu_add(ca->io_done->sectors[rw][data_type], buf->size);
while (offset < bytes) {
unsigned nr_iovecs = min_t(size_t, BIO_MAX_VECS,
DIV_ROUND_UP(bytes, PAGE_SIZE));
unsigned b = min_t(size_t, bytes - offset,
nr_iovecs << PAGE_SHIFT);
struct ec_bio *ec_bio;
ec_bio = container_of(bio_alloc_bioset(ca->disk_sb.bdev,
nr_iovecs,
opf,
GFP_KERNEL,
&c->ec_bioset),
struct ec_bio, bio);
ec_bio->ca = ca;
ec_bio->buf = buf;
ec_bio->idx = idx;
ec_bio->bio.bi_iter.bi_sector = ptr->offset + buf->offset + (offset >> 9);
ec_bio->bio.bi_end_io = ec_block_endio;
ec_bio->bio.bi_private = cl;
bch2_bio_map(&ec_bio->bio, buf->data[idx] + offset, b);
closure_get(cl);
percpu_ref_get(&ca->io_ref);
submit_bio(&ec_bio->bio);
offset += b;
}
percpu_ref_put(&ca->io_ref);
}
static int get_stripe_key_trans(struct btree_trans *trans, u64 idx,
struct ec_stripe_buf *stripe)
{
struct btree_iter iter;
struct bkey_s_c k;
int ret;
k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes,
POS(0, idx), BTREE_ITER_slots);
ret = bkey_err(k);
if (ret)
goto err;
if (k.k->type != KEY_TYPE_stripe) {
ret = -ENOENT;
goto err;
}
bkey_reassemble(&stripe->key, k);
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
/* recovery read path: */
int bch2_ec_read_extent(struct btree_trans *trans, struct bch_read_bio *rbio)
{
struct bch_fs *c = trans->c;
struct ec_stripe_buf *buf;
struct closure cl;
struct bch_stripe *v;
unsigned i, offset;
int ret = 0;
closure_init_stack(&cl);
BUG_ON(!rbio->pick.has_ec);
buf = kzalloc(sizeof(*buf), GFP_NOFS);
if (!buf)
return -BCH_ERR_ENOMEM_ec_read_extent;
ret = lockrestart_do(trans, get_stripe_key_trans(trans, rbio->pick.ec.idx, buf));
if (ret) {
bch_err_ratelimited(c,
"error doing reconstruct read: error %i looking up stripe", ret);
kfree(buf);
return -EIO;
}
v = &bkey_i_to_stripe(&buf->key)->v;
if (!bch2_ptr_matches_stripe(v, rbio->pick)) {
bch_err_ratelimited(c,
"error doing reconstruct read: pointer doesn't match stripe");
ret = -EIO;
goto err;
}
offset = rbio->bio.bi_iter.bi_sector - v->ptrs[rbio->pick.ec.block].offset;
if (offset + bio_sectors(&rbio->bio) > le16_to_cpu(v->sectors)) {
bch_err_ratelimited(c,
"error doing reconstruct read: read is bigger than stripe");
ret = -EIO;
goto err;
}
ret = ec_stripe_buf_init(buf, offset, bio_sectors(&rbio->bio));
if (ret)
goto err;
for (i = 0; i < v->nr_blocks; i++)
ec_block_io(c, buf, REQ_OP_READ, i, &cl);
closure_sync(&cl);
if (ec_nr_failed(buf) > v->nr_redundant) {
bch_err_ratelimited(c,
"error doing reconstruct read: unable to read enough blocks");
ret = -EIO;
goto err;
}
ec_validate_checksums(c, buf);
ret = ec_do_recov(c, buf);
if (ret)
goto err;
memcpy_to_bio(&rbio->bio, rbio->bio.bi_iter,
buf->data[rbio->pick.ec.block] + ((offset - buf->offset) << 9));
err:
ec_stripe_buf_exit(buf);
kfree(buf);
return ret;
}
/* stripe bucket accounting: */
static int __ec_stripe_mem_alloc(struct bch_fs *c, size_t idx, gfp_t gfp)
{
ec_stripes_heap n, *h = &c->ec_stripes_heap;
if (idx >= h->size) {
if (!init_heap(&n, max(1024UL, roundup_pow_of_two(idx + 1)), gfp))
return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
mutex_lock(&c->ec_stripes_heap_lock);
if (n.size > h->size) {
memcpy(n.data, h->data, h->nr * sizeof(h->data[0]));
n.nr = h->nr;
swap(*h, n);
}
mutex_unlock(&c->ec_stripes_heap_lock);
free_heap(&n);
}
if (!genradix_ptr_alloc(&c->stripes, idx, gfp))
return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
if (c->gc_pos.phase != GC_PHASE_not_running &&
!genradix_ptr_alloc(&c->gc_stripes, idx, gfp))
return -BCH_ERR_ENOMEM_ec_stripe_mem_alloc;
return 0;
}
static int ec_stripe_mem_alloc(struct btree_trans *trans,
struct btree_iter *iter)
{
return allocate_dropping_locks_errcode(trans,
__ec_stripe_mem_alloc(trans->c, iter->pos.offset, _gfp));
}
/*
* Hash table of open stripes:
* Stripes that are being created or modified are kept in a hash table, so that
* stripe deletion can skip them.
*/
static bool __bch2_stripe_is_open(struct bch_fs *c, u64 idx)
{
unsigned hash = hash_64(idx, ilog2(ARRAY_SIZE(c->ec_stripes_new)));
struct ec_stripe_new *s;
hlist_for_each_entry(s, &c->ec_stripes_new[hash], hash)
if (s->idx == idx)
return true;
return false;
}
static bool bch2_stripe_is_open(struct bch_fs *c, u64 idx)
{
bool ret = false;
spin_lock(&c->ec_stripes_new_lock);
ret = __bch2_stripe_is_open(c, idx);
spin_unlock(&c->ec_stripes_new_lock);
return ret;
}
static bool bch2_try_open_stripe(struct bch_fs *c,
struct ec_stripe_new *s,
u64 idx)
{
bool ret;
spin_lock(&c->ec_stripes_new_lock);
ret = !__bch2_stripe_is_open(c, idx);
if (ret) {
unsigned hash = hash_64(idx, ilog2(ARRAY_SIZE(c->ec_stripes_new)));
s->idx = idx;
hlist_add_head(&s->hash, &c->ec_stripes_new[hash]);
}
spin_unlock(&c->ec_stripes_new_lock);
return ret;
}
static void bch2_stripe_close(struct bch_fs *c, struct ec_stripe_new *s)
{
BUG_ON(!s->idx);
spin_lock(&c->ec_stripes_new_lock);
hlist_del_init(&s->hash);
spin_unlock(&c->ec_stripes_new_lock);
s->idx = 0;
}
/* Heap of all existing stripes, ordered by blocks_nonempty */
static u64 stripe_idx_to_delete(struct bch_fs *c)
{
ec_stripes_heap *h = &c->ec_stripes_heap;
lockdep_assert_held(&c->ec_stripes_heap_lock);
if (h->nr &&
h->data[0].blocks_nonempty == 0 &&
!bch2_stripe_is_open(c, h->data[0].idx))
return h->data[0].idx;
return 0;
}
static inline void ec_stripes_heap_set_backpointer(ec_stripes_heap *h,
size_t i)
{
struct bch_fs *c = container_of(h, struct bch_fs, ec_stripes_heap);
genradix_ptr(&c->stripes, h->data[i].idx)->heap_idx = i;
}
static inline bool ec_stripes_heap_cmp(const void *l, const void *r, void __always_unused *args)
{
struct ec_stripe_heap_entry *_l = (struct ec_stripe_heap_entry *)l;
struct ec_stripe_heap_entry *_r = (struct ec_stripe_heap_entry *)r;
return ((_l->blocks_nonempty > _r->blocks_nonempty) <
(_l->blocks_nonempty < _r->blocks_nonempty));
}
static inline void ec_stripes_heap_swap(void *l, void *r, void *h)
{
struct ec_stripe_heap_entry *_l = (struct ec_stripe_heap_entry *)l;
struct ec_stripe_heap_entry *_r = (struct ec_stripe_heap_entry *)r;
ec_stripes_heap *_h = (ec_stripes_heap *)h;
size_t i = _l - _h->data;
size_t j = _r - _h->data;
swap(*_l, *_r);
ec_stripes_heap_set_backpointer(_h, i);
ec_stripes_heap_set_backpointer(_h, j);
}
static void heap_verify_backpointer(struct bch_fs *c, size_t idx)
{
ec_stripes_heap *h = &c->ec_stripes_heap;
struct stripe *m = genradix_ptr(&c->stripes, idx);
BUG_ON(m->heap_idx >= h->nr);
BUG_ON(h->data[m->heap_idx].idx != idx);
}
void bch2_stripes_heap_del(struct bch_fs *c,
struct stripe *m, size_t idx)
{
const struct min_heap_callbacks callbacks = {
.less = ec_stripes_heap_cmp,
.swp = ec_stripes_heap_swap,
};
mutex_lock(&c->ec_stripes_heap_lock);
heap_verify_backpointer(c, idx);
min_heap_del(&c->ec_stripes_heap, m->heap_idx, &callbacks, &c->ec_stripes_heap);
mutex_unlock(&c->ec_stripes_heap_lock);
}
void bch2_stripes_heap_insert(struct bch_fs *c,
struct stripe *m, size_t idx)
{
const struct min_heap_callbacks callbacks = {
.less = ec_stripes_heap_cmp,
.swp = ec_stripes_heap_swap,
};
mutex_lock(&c->ec_stripes_heap_lock);
BUG_ON(min_heap_full(&c->ec_stripes_heap));
genradix_ptr(&c->stripes, idx)->heap_idx = c->ec_stripes_heap.nr;
min_heap_push(&c->ec_stripes_heap, &((struct ec_stripe_heap_entry) {
.idx = idx,
.blocks_nonempty = m->blocks_nonempty,
}),
&callbacks,
&c->ec_stripes_heap);
heap_verify_backpointer(c, idx);
mutex_unlock(&c->ec_stripes_heap_lock);
}
void bch2_stripes_heap_update(struct bch_fs *c,
struct stripe *m, size_t idx)
{
const struct min_heap_callbacks callbacks = {
.less = ec_stripes_heap_cmp,
.swp = ec_stripes_heap_swap,
};
ec_stripes_heap *h = &c->ec_stripes_heap;
bool do_deletes;
size_t i;
mutex_lock(&c->ec_stripes_heap_lock);
heap_verify_backpointer(c, idx);
h->data[m->heap_idx].blocks_nonempty = m->blocks_nonempty;
i = m->heap_idx;
min_heap_sift_up(h, i, &callbacks, &c->ec_stripes_heap);
min_heap_sift_down(h, i, &callbacks, &c->ec_stripes_heap);
heap_verify_backpointer(c, idx);
do_deletes = stripe_idx_to_delete(c) != 0;
mutex_unlock(&c->ec_stripes_heap_lock);
if (do_deletes)
bch2_do_stripe_deletes(c);
}
/* stripe deletion */
static int ec_stripe_delete(struct btree_trans *trans, u64 idx)
{
struct bch_fs *c = trans->c;
struct btree_iter iter;
struct bkey_s_c k;
struct bkey_s_c_stripe s;
int ret;
k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes, POS(0, idx),
BTREE_ITER_intent);
ret = bkey_err(k);
if (ret)
goto err;
if (k.k->type != KEY_TYPE_stripe) {
bch2_fs_inconsistent(c, "attempting to delete nonexistent stripe %llu", idx);
ret = -EINVAL;
goto err;
}
s = bkey_s_c_to_stripe(k);
for (unsigned i = 0; i < s.v->nr_blocks; i++)
if (stripe_blockcount_get(s.v, i)) {
struct printbuf buf = PRINTBUF;
bch2_bkey_val_to_text(&buf, c, k);
bch2_fs_inconsistent(c, "attempting to delete nonempty stripe %s", buf.buf);
printbuf_exit(&buf);
ret = -EINVAL;
goto err;
}
ret = bch2_btree_delete_at(trans, &iter, 0);
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static void ec_stripe_delete_work(struct work_struct *work)
{
struct bch_fs *c =
container_of(work, struct bch_fs, ec_stripe_delete_work);
while (1) {
mutex_lock(&c->ec_stripes_heap_lock);
u64 idx = stripe_idx_to_delete(c);
mutex_unlock(&c->ec_stripes_heap_lock);
if (!idx)
break;
int ret = bch2_trans_do(c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
ec_stripe_delete(trans, idx));
bch_err_fn(c, ret);
if (ret)
break;
}
bch2_write_ref_put(c, BCH_WRITE_REF_stripe_delete);
}
void bch2_do_stripe_deletes(struct bch_fs *c)
{
if (bch2_write_ref_tryget(c, BCH_WRITE_REF_stripe_delete) &&
!queue_work(c->write_ref_wq, &c->ec_stripe_delete_work))
bch2_write_ref_put(c, BCH_WRITE_REF_stripe_delete);
}
/* stripe creation: */
static int ec_stripe_key_update(struct btree_trans *trans,
struct bkey_i_stripe *new,
bool create)
{
struct bch_fs *c = trans->c;
struct btree_iter iter;
struct bkey_s_c k;
int ret;
k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes,
new->k.p, BTREE_ITER_intent);
ret = bkey_err(k);
if (ret)
goto err;
if (k.k->type != (create ? KEY_TYPE_deleted : KEY_TYPE_stripe)) {
bch2_fs_inconsistent(c, "error %s stripe: got existing key type %s",
create ? "creating" : "updating",
bch2_bkey_types[k.k->type]);
ret = -EINVAL;
goto err;
}
if (k.k->type == KEY_TYPE_stripe) {
const struct bch_stripe *old = bkey_s_c_to_stripe(k).v;
unsigned i;
if (old->nr_blocks != new->v.nr_blocks) {
bch_err(c, "error updating stripe: nr_blocks does not match");
ret = -EINVAL;
goto err;
}
for (i = 0; i < new->v.nr_blocks; i++) {
unsigned v = stripe_blockcount_get(old, i);
BUG_ON(v &&
(old->ptrs[i].dev != new->v.ptrs[i].dev ||
old->ptrs[i].gen != new->v.ptrs[i].gen ||
old->ptrs[i].offset != new->v.ptrs[i].offset));
stripe_blockcount_set(&new->v, i, v);
}
}
ret = bch2_trans_update(trans, &iter, &new->k_i, 0);
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static int ec_stripe_update_extent(struct btree_trans *trans,
struct bch_dev *ca,
struct bpos bucket, u8 gen,
struct ec_stripe_buf *s,
struct bpos *bp_pos)
{
struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
struct bch_fs *c = trans->c;
struct bch_backpointer bp;
struct btree_iter iter;
struct bkey_s_c k;
const struct bch_extent_ptr *ptr_c;
struct bch_extent_ptr *ec_ptr = NULL;
struct bch_extent_stripe_ptr stripe_ptr;
struct bkey_i *n;
int ret, dev, block;
ret = bch2_get_next_backpointer(trans, ca, bucket, gen,
bp_pos, &bp, BTREE_ITER_cached);
if (ret)
return ret;
if (bpos_eq(*bp_pos, SPOS_MAX))
return 0;
if (bp.level) {
struct printbuf buf = PRINTBUF;
struct btree_iter node_iter;
struct btree *b;
b = bch2_backpointer_get_node(trans, &node_iter, *bp_pos, bp);
bch2_trans_iter_exit(trans, &node_iter);
if (!b)
return 0;
prt_printf(&buf, "found btree node in erasure coded bucket: b=%px\n", b);
bch2_backpointer_to_text(&buf, &bp);
bch2_fs_inconsistent(c, "%s", buf.buf);
printbuf_exit(&buf);
return -EIO;
}
k = bch2_backpointer_get_key(trans, &iter, *bp_pos, bp, BTREE_ITER_intent);
ret = bkey_err(k);
if (ret)
return ret;
if (!k.k) {
/*
* extent no longer exists - we could flush the btree
* write buffer and retry to verify, but no need:
*/
return 0;
}
if (extent_has_stripe_ptr(k, s->key.k.p.offset))
goto out;
ptr_c = bkey_matches_stripe(v, k, &block);
/*
* It doesn't generally make sense to erasure code cached ptrs:
* XXX: should we be incrementing a counter?
*/
if (!ptr_c || ptr_c->cached)
goto out;
dev = v->ptrs[block].dev;
n = bch2_trans_kmalloc(trans, bkey_bytes(k.k) + sizeof(stripe_ptr));
ret = PTR_ERR_OR_ZERO(n);
if (ret)
goto out;
bkey_reassemble(n, k);
bch2_bkey_drop_ptrs(bkey_i_to_s(n), ptr, ptr->dev != dev);
ec_ptr = bch2_bkey_has_device(bkey_i_to_s(n), dev);
BUG_ON(!ec_ptr);
stripe_ptr = (struct bch_extent_stripe_ptr) {
.type = 1 << BCH_EXTENT_ENTRY_stripe_ptr,
.block = block,
.redundancy = v->nr_redundant,
.idx = s->key.k.p.offset,
};
__extent_entry_insert(n,
(union bch_extent_entry *) ec_ptr,
(union bch_extent_entry *) &stripe_ptr);
ret = bch2_trans_update(trans, &iter, n, 0);
out:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static int ec_stripe_update_bucket(struct btree_trans *trans, struct ec_stripe_buf *s,
unsigned block)
{
struct bch_fs *c = trans->c;
struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
struct bch_extent_ptr ptr = v->ptrs[block];
struct bpos bp_pos = POS_MIN;
int ret = 0;
struct bch_dev *ca = bch2_dev_tryget(c, ptr.dev);
if (!ca)
return -EIO;
struct bpos bucket_pos = PTR_BUCKET_POS(ca, &ptr);
while (1) {
ret = commit_do(trans, NULL, NULL,
BCH_TRANS_COMMIT_no_check_rw|
BCH_TRANS_COMMIT_no_enospc,
ec_stripe_update_extent(trans, ca, bucket_pos, ptr.gen, s, &bp_pos));
if (ret)
break;
if (bkey_eq(bp_pos, POS_MAX))
break;
bp_pos = bpos_nosnap_successor(bp_pos);
}
bch2_dev_put(ca);
return ret;
}
static int ec_stripe_update_extents(struct bch_fs *c, struct ec_stripe_buf *s)
{
struct btree_trans *trans = bch2_trans_get(c);
struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
unsigned i, nr_data = v->nr_blocks - v->nr_redundant;
int ret = 0;
ret = bch2_btree_write_buffer_flush_sync(trans);
if (ret)
goto err;
for (i = 0; i < nr_data; i++) {
ret = ec_stripe_update_bucket(trans, s, i);
if (ret)
break;
}
err:
bch2_trans_put(trans);
return ret;
}
static void zero_out_rest_of_ec_bucket(struct bch_fs *c,
struct ec_stripe_new *s,
unsigned block,
struct open_bucket *ob)
{
struct bch_dev *ca = bch2_dev_get_ioref(c, ob->dev, WRITE);
if (!ca) {
s->err = -BCH_ERR_erofs_no_writes;
return;
}
unsigned offset = ca->mi.bucket_size - ob->sectors_free;
memset(s->new_stripe.data[block] + (offset << 9),
0,
ob->sectors_free << 9);
int ret = blkdev_issue_zeroout(ca->disk_sb.bdev,
ob->bucket * ca->mi.bucket_size + offset,
ob->sectors_free,
GFP_KERNEL, 0);
percpu_ref_put(&ca->io_ref);
if (ret)
s->err = ret;
}
void bch2_ec_stripe_new_free(struct bch_fs *c, struct ec_stripe_new *s)
{
if (s->idx)
bch2_stripe_close(c, s);
kfree(s);
}
/*
* data buckets of new stripe all written: create the stripe
*/
static void ec_stripe_create(struct ec_stripe_new *s)
{
struct bch_fs *c = s->c;
struct open_bucket *ob;
struct bch_stripe *v = &bkey_i_to_stripe(&s->new_stripe.key)->v;
unsigned i, nr_data = v->nr_blocks - v->nr_redundant;
int ret;
BUG_ON(s->h->s == s);
closure_sync(&s->iodone);
if (!s->err) {
for (i = 0; i < nr_data; i++)
if (s->blocks[i]) {
ob = c->open_buckets + s->blocks[i];
if (ob->sectors_free)
zero_out_rest_of_ec_bucket(c, s, i, ob);
}
}
if (s->err) {
if (!bch2_err_matches(s->err, EROFS))
bch_err(c, "error creating stripe: error writing data buckets");
goto err;
}
if (s->have_existing_stripe) {
ec_validate_checksums(c, &s->existing_stripe);
if (ec_do_recov(c, &s->existing_stripe)) {
bch_err(c, "error creating stripe: error reading existing stripe");
goto err;
}
for (i = 0; i < nr_data; i++)
if (stripe_blockcount_get(&bkey_i_to_stripe(&s->existing_stripe.key)->v, i))
swap(s->new_stripe.data[i],
s->existing_stripe.data[i]);
ec_stripe_buf_exit(&s->existing_stripe);
}
BUG_ON(!s->allocated);
BUG_ON(!s->idx);
ec_generate_ec(&s->new_stripe);
ec_generate_checksums(&s->new_stripe);
/* write p/q: */
for (i = nr_data; i < v->nr_blocks; i++)
ec_block_io(c, &s->new_stripe, REQ_OP_WRITE, i, &s->iodone);
closure_sync(&s->iodone);
if (ec_nr_failed(&s->new_stripe)) {
bch_err(c, "error creating stripe: error writing redundancy buckets");
goto err;
}
ret = bch2_trans_do(c, &s->res, NULL,
BCH_TRANS_COMMIT_no_check_rw|
BCH_TRANS_COMMIT_no_enospc,
ec_stripe_key_update(trans,
bkey_i_to_stripe(&s->new_stripe.key),
!s->have_existing_stripe));
bch_err_msg(c, ret, "creating stripe key");
if (ret) {
goto err;
}
ret = ec_stripe_update_extents(c, &s->new_stripe);
bch_err_msg(c, ret, "error updating extents");
if (ret)
goto err;
err:
bch2_disk_reservation_put(c, &s->res);
for (i = 0; i < v->nr_blocks; i++)
if (s->blocks[i]) {
ob = c->open_buckets + s->blocks[i];
if (i < nr_data) {
ob->ec = NULL;
__bch2_open_bucket_put(c, ob);
} else {
bch2_open_bucket_put(c, ob);
}
}
mutex_lock(&c->ec_stripe_new_lock);
list_del(&s->list);
mutex_unlock(&c->ec_stripe_new_lock);
wake_up(&c->ec_stripe_new_wait);
ec_stripe_buf_exit(&s->existing_stripe);
ec_stripe_buf_exit(&s->new_stripe);
closure_debug_destroy(&s->iodone);
ec_stripe_new_put(c, s, STRIPE_REF_stripe);
}
static struct ec_stripe_new *get_pending_stripe(struct bch_fs *c)
{
struct ec_stripe_new *s;
mutex_lock(&c->ec_stripe_new_lock);
list_for_each_entry(s, &c->ec_stripe_new_list, list)
if (!atomic_read(&s->ref[STRIPE_REF_io]))
goto out;
s = NULL;
out:
mutex_unlock(&c->ec_stripe_new_lock);
return s;
}
static void ec_stripe_create_work(struct work_struct *work)
{
struct bch_fs *c = container_of(work,
struct bch_fs, ec_stripe_create_work);
struct ec_stripe_new *s;
while ((s = get_pending_stripe(c)))
ec_stripe_create(s);
bch2_write_ref_put(c, BCH_WRITE_REF_stripe_create);
}
void bch2_ec_do_stripe_creates(struct bch_fs *c)
{
bch2_write_ref_get(c, BCH_WRITE_REF_stripe_create);
if (!queue_work(system_long_wq, &c->ec_stripe_create_work))
bch2_write_ref_put(c, BCH_WRITE_REF_stripe_create);
}
static void ec_stripe_set_pending(struct bch_fs *c, struct ec_stripe_head *h)
{
struct ec_stripe_new *s = h->s;
BUG_ON(!s->allocated && !s->err);
h->s = NULL;
s->pending = true;
mutex_lock(&c->ec_stripe_new_lock);
list_add(&s->list, &c->ec_stripe_new_list);
mutex_unlock(&c->ec_stripe_new_lock);
ec_stripe_new_put(c, s, STRIPE_REF_io);
}
void bch2_ec_bucket_cancel(struct bch_fs *c, struct open_bucket *ob)
{
struct ec_stripe_new *s = ob->ec;
s->err = -EIO;
}
void *bch2_writepoint_ec_buf(struct bch_fs *c, struct write_point *wp)
{
struct open_bucket *ob = ec_open_bucket(c, &wp->ptrs);
if (!ob)
return NULL;
BUG_ON(!ob->ec->new_stripe.data[ob->ec_idx]);
struct bch_dev *ca = ob_dev(c, ob);
unsigned offset = ca->mi.bucket_size - ob->sectors_free;
return ob->ec->new_stripe.data[ob->ec_idx] + (offset << 9);
}
static int unsigned_cmp(const void *_l, const void *_r)
{
unsigned l = *((const unsigned *) _l);
unsigned r = *((const unsigned *) _r);
return cmp_int(l, r);
}
/* pick most common bucket size: */
static unsigned pick_blocksize(struct bch_fs *c,
struct bch_devs_mask *devs)
{
unsigned nr = 0, sizes[BCH_SB_MEMBERS_MAX];
struct {
unsigned nr, size;
} cur = { 0, 0 }, best = { 0, 0 };
for_each_member_device_rcu(c, ca, devs)
sizes[nr++] = ca->mi.bucket_size;
sort(sizes, nr, sizeof(unsigned), unsigned_cmp, NULL);
for (unsigned i = 0; i < nr; i++) {
if (sizes[i] != cur.size) {
if (cur.nr > best.nr)
best = cur;
cur.nr = 0;
cur.size = sizes[i];
}
cur.nr++;
}
if (cur.nr > best.nr)
best = cur;
return best.size;
}
static bool may_create_new_stripe(struct bch_fs *c)
{
return false;
}
static void ec_stripe_key_init(struct bch_fs *c,
struct bkey_i *k,
unsigned nr_data,
unsigned nr_parity,
unsigned stripe_size)
{
struct bkey_i_stripe *s = bkey_stripe_init(k);
unsigned u64s;
s->v.sectors = cpu_to_le16(stripe_size);
s->v.algorithm = 0;
s->v.nr_blocks = nr_data + nr_parity;
s->v.nr_redundant = nr_parity;
s->v.csum_granularity_bits = ilog2(c->opts.encoded_extent_max >> 9);
s->v.csum_type = BCH_CSUM_crc32c;
s->v.pad = 0;
while ((u64s = stripe_val_u64s(&s->v)) > BKEY_VAL_U64s_MAX) {
BUG_ON(1 << s->v.csum_granularity_bits >=
le16_to_cpu(s->v.sectors) ||
s->v.csum_granularity_bits == U8_MAX);
s->v.csum_granularity_bits++;
}
set_bkey_val_u64s(&s->k, u64s);
}
static int ec_new_stripe_alloc(struct bch_fs *c, struct ec_stripe_head *h)
{
struct ec_stripe_new *s;
lockdep_assert_held(&h->lock);
s = kzalloc(sizeof(*s), GFP_KERNEL);
if (!s)
return -BCH_ERR_ENOMEM_ec_new_stripe_alloc;
mutex_init(&s->lock);
closure_init(&s->iodone, NULL);
atomic_set(&s->ref[STRIPE_REF_stripe], 1);
atomic_set(&s->ref[STRIPE_REF_io], 1);
s->c = c;
s->h = h;
s->nr_data = min_t(unsigned, h->nr_active_devs,
BCH_BKEY_PTRS_MAX) - h->redundancy;
s->nr_parity = h->redundancy;
ec_stripe_key_init(c, &s->new_stripe.key,
s->nr_data, s->nr_parity, h->blocksize);
h->s = s;
return 0;
}
static struct ec_stripe_head *
ec_new_stripe_head_alloc(struct bch_fs *c, unsigned target,
unsigned algo, unsigned redundancy,
enum bch_watermark watermark)
{
struct ec_stripe_head *h;
h = kzalloc(sizeof(*h), GFP_KERNEL);
if (!h)
return NULL;
mutex_init(&h->lock);
BUG_ON(!mutex_trylock(&h->lock));
h->target = target;
h->algo = algo;
h->redundancy = redundancy;
h->watermark = watermark;
rcu_read_lock();
h->devs = target_rw_devs(c, BCH_DATA_user, target);
for_each_member_device_rcu(c, ca, &h->devs)
if (!ca->mi.durability)
__clear_bit(ca->dev_idx, h->devs.d);
h->blocksize = pick_blocksize(c, &h->devs);
for_each_member_device_rcu(c, ca, &h->devs)
if (ca->mi.bucket_size == h->blocksize)
h->nr_active_devs++;
rcu_read_unlock();
/*
* If we only have redundancy + 1 devices, we're better off with just
* replication:
*/
if (h->nr_active_devs < h->redundancy + 2)
bch_err(c, "insufficient devices available to create stripe (have %u, need %u) - mismatched bucket sizes?",
h->nr_active_devs, h->redundancy + 2);
list_add(&h->list, &c->ec_stripe_head_list);
return h;
}
void bch2_ec_stripe_head_put(struct bch_fs *c, struct ec_stripe_head *h)
{
if (h->s &&
h->s->allocated &&
bitmap_weight(h->s->blocks_allocated,
h->s->nr_data) == h->s->nr_data)
ec_stripe_set_pending(c, h);
mutex_unlock(&h->lock);
}
static struct ec_stripe_head *
__bch2_ec_stripe_head_get(struct btree_trans *trans,
unsigned target,
unsigned algo,
unsigned redundancy,
enum bch_watermark watermark)
{
struct bch_fs *c = trans->c;
struct ec_stripe_head *h;
int ret;
if (!redundancy)
return NULL;
ret = bch2_trans_mutex_lock(trans, &c->ec_stripe_head_lock);
if (ret)
return ERR_PTR(ret);
if (test_bit(BCH_FS_going_ro, &c->flags)) {
h = ERR_PTR(-BCH_ERR_erofs_no_writes);
goto found;
}
list_for_each_entry(h, &c->ec_stripe_head_list, list)
if (h->target == target &&
h->algo == algo &&
h->redundancy == redundancy &&
h->watermark == watermark) {
ret = bch2_trans_mutex_lock(trans, &h->lock);
if (ret)
h = ERR_PTR(ret);
goto found;
}
h = ec_new_stripe_head_alloc(c, target, algo, redundancy, watermark);
found:
if (!IS_ERR_OR_NULL(h) &&
h->nr_active_devs < h->redundancy + 2) {
mutex_unlock(&h->lock);
h = NULL;
}
mutex_unlock(&c->ec_stripe_head_lock);
return h;
}
static int new_stripe_alloc_buckets(struct btree_trans *trans, struct ec_stripe_head *h,
enum bch_watermark watermark, struct closure *cl)
{
struct bch_fs *c = trans->c;
struct bch_devs_mask devs = h->devs;
struct open_bucket *ob;
struct open_buckets buckets;
struct bch_stripe *v = &bkey_i_to_stripe(&h->s->new_stripe.key)->v;
unsigned i, j, nr_have_parity = 0, nr_have_data = 0;
bool have_cache = true;
int ret = 0;
BUG_ON(v->nr_blocks != h->s->nr_data + h->s->nr_parity);
BUG_ON(v->nr_redundant != h->s->nr_parity);
/* * We bypass the sector allocator which normally does this: */
bitmap_and(devs.d, devs.d, c->rw_devs[BCH_DATA_user].d, BCH_SB_MEMBERS_MAX);
for_each_set_bit(i, h->s->blocks_gotten, v->nr_blocks) {
__clear_bit(v->ptrs[i].dev, devs.d);
if (i < h->s->nr_data)
nr_have_data++;
else
nr_have_parity++;
}
BUG_ON(nr_have_data > h->s->nr_data);
BUG_ON(nr_have_parity > h->s->nr_parity);
buckets.nr = 0;
if (nr_have_parity < h->s->nr_parity) {
ret = bch2_bucket_alloc_set_trans(trans, &buckets,
&h->parity_stripe,
&devs,
h->s->nr_parity,
&nr_have_parity,
&have_cache, 0,
BCH_DATA_parity,
watermark,
cl);
open_bucket_for_each(c, &buckets, ob, i) {
j = find_next_zero_bit(h->s->blocks_gotten,
h->s->nr_data + h->s->nr_parity,
h->s->nr_data);
BUG_ON(j >= h->s->nr_data + h->s->nr_parity);
h->s->blocks[j] = buckets.v[i];
v->ptrs[j] = bch2_ob_ptr(c, ob);
__set_bit(j, h->s->blocks_gotten);
}
if (ret)
return ret;
}
buckets.nr = 0;
if (nr_have_data < h->s->nr_data) {
ret = bch2_bucket_alloc_set_trans(trans, &buckets,
&h->block_stripe,
&devs,
h->s->nr_data,
&nr_have_data,
&have_cache, 0,
BCH_DATA_user,
watermark,
cl);
open_bucket_for_each(c, &buckets, ob, i) {
j = find_next_zero_bit(h->s->blocks_gotten,
h->s->nr_data, 0);
BUG_ON(j >= h->s->nr_data);
h->s->blocks[j] = buckets.v[i];
v->ptrs[j] = bch2_ob_ptr(c, ob);
__set_bit(j, h->s->blocks_gotten);
}
if (ret)
return ret;
}
return 0;
}
/* XXX: doesn't obey target: */
static s64 get_existing_stripe(struct bch_fs *c,
struct ec_stripe_head *head)
{
ec_stripes_heap *h = &c->ec_stripes_heap;
struct stripe *m;
size_t heap_idx;
u64 stripe_idx;
s64 ret = -1;
if (may_create_new_stripe(c))
return -1;
mutex_lock(&c->ec_stripes_heap_lock);
for (heap_idx = 0; heap_idx < h->nr; heap_idx++) {
/* No blocks worth reusing, stripe will just be deleted: */
if (!h->data[heap_idx].blocks_nonempty)
continue;
stripe_idx = h->data[heap_idx].idx;
m = genradix_ptr(&c->stripes, stripe_idx);
if (m->algorithm == head->algo &&
m->nr_redundant == head->redundancy &&
m->sectors == head->blocksize &&
m->blocks_nonempty < m->nr_blocks - m->nr_redundant &&
bch2_try_open_stripe(c, head->s, stripe_idx)) {
ret = stripe_idx;
break;
}
}
mutex_unlock(&c->ec_stripes_heap_lock);
return ret;
}
static int __bch2_ec_stripe_head_reuse(struct btree_trans *trans, struct ec_stripe_head *h)
{
struct bch_fs *c = trans->c;
struct bch_stripe *new_v = &bkey_i_to_stripe(&h->s->new_stripe.key)->v;
struct bch_stripe *existing_v;
unsigned i;
s64 idx;
int ret;
/*
* If we can't allocate a new stripe, and there's no stripes with empty
* blocks for us to reuse, that means we have to wait on copygc:
*/
idx = get_existing_stripe(c, h);
if (idx < 0)
return -BCH_ERR_stripe_alloc_blocked;
ret = get_stripe_key_trans(trans, idx, &h->s->existing_stripe);
bch2_fs_fatal_err_on(ret && !bch2_err_matches(ret, BCH_ERR_transaction_restart), c,
"reading stripe key: %s", bch2_err_str(ret));
if (ret) {
bch2_stripe_close(c, h->s);
return ret;
}
existing_v = &bkey_i_to_stripe(&h->s->existing_stripe.key)->v;
BUG_ON(existing_v->nr_redundant != h->s->nr_parity);
h->s->nr_data = existing_v->nr_blocks -
existing_v->nr_redundant;
ret = ec_stripe_buf_init(&h->s->existing_stripe, 0, h->blocksize);
if (ret) {
bch2_stripe_close(c, h->s);
return ret;
}
BUG_ON(h->s->existing_stripe.size != h->blocksize);
BUG_ON(h->s->existing_stripe.size != le16_to_cpu(existing_v->sectors));
/*
* Free buckets we initially allocated - they might conflict with
* blocks from the stripe we're reusing:
*/
for_each_set_bit(i, h->s->blocks_gotten, new_v->nr_blocks) {
bch2_open_bucket_put(c, c->open_buckets + h->s->blocks[i]);
h->s->blocks[i] = 0;
}
memset(h->s->blocks_gotten, 0, sizeof(h->s->blocks_gotten));
memset(h->s->blocks_allocated, 0, sizeof(h->s->blocks_allocated));
for (i = 0; i < existing_v->nr_blocks; i++) {
if (stripe_blockcount_get(existing_v, i)) {
__set_bit(i, h->s->blocks_gotten);
__set_bit(i, h->s->blocks_allocated);
}
ec_block_io(c, &h->s->existing_stripe, READ, i, &h->s->iodone);
}
bkey_copy(&h->s->new_stripe.key, &h->s->existing_stripe.key);
h->s->have_existing_stripe = true;
return 0;
}
static int __bch2_ec_stripe_head_reserve(struct btree_trans *trans, struct ec_stripe_head *h)
{
struct bch_fs *c = trans->c;
struct btree_iter iter;
struct bkey_s_c k;
struct bpos min_pos = POS(0, 1);
struct bpos start_pos = bpos_max(min_pos, POS(0, c->ec_stripe_hint));
int ret;
if (!h->s->res.sectors) {
ret = bch2_disk_reservation_get(c, &h->s->res,
h->blocksize,
h->s->nr_parity,
BCH_DISK_RESERVATION_NOFAIL);
if (ret)
return ret;
}
for_each_btree_key_norestart(trans, iter, BTREE_ID_stripes, start_pos,
BTREE_ITER_slots|BTREE_ITER_intent, k, ret) {
if (bkey_gt(k.k->p, POS(0, U32_MAX))) {
if (start_pos.offset) {
start_pos = min_pos;
bch2_btree_iter_set_pos(&iter, start_pos);
continue;
}
ret = -BCH_ERR_ENOSPC_stripe_create;
break;
}
if (bkey_deleted(k.k) &&
bch2_try_open_stripe(c, h->s, k.k->p.offset))
break;
}
c->ec_stripe_hint = iter.pos.offset;
if (ret)
goto err;
ret = ec_stripe_mem_alloc(trans, &iter);
if (ret) {
bch2_stripe_close(c, h->s);
goto err;
}
h->s->new_stripe.key.k.p = iter.pos;
out:
bch2_trans_iter_exit(trans, &iter);
return ret;
err:
bch2_disk_reservation_put(c, &h->s->res);
goto out;
}
struct ec_stripe_head *bch2_ec_stripe_head_get(struct btree_trans *trans,
unsigned target,
unsigned algo,
unsigned redundancy,
enum bch_watermark watermark,
struct closure *cl)
{
struct bch_fs *c = trans->c;
struct ec_stripe_head *h;
bool waiting = false;
int ret;
h = __bch2_ec_stripe_head_get(trans, target, algo, redundancy, watermark);
if (IS_ERR_OR_NULL(h))
return h;
if (!h->s) {
ret = ec_new_stripe_alloc(c, h);
if (ret) {
bch_err(c, "failed to allocate new stripe");
goto err;
}
}
if (h->s->allocated)
goto allocated;
if (h->s->have_existing_stripe)
goto alloc_existing;
/* First, try to allocate a full stripe: */
ret = new_stripe_alloc_buckets(trans, h, BCH_WATERMARK_stripe, NULL) ?:
__bch2_ec_stripe_head_reserve(trans, h);
if (!ret)
goto allocate_buf;
if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
bch2_err_matches(ret, ENOMEM))
goto err;
/*
* Not enough buckets available for a full stripe: we must reuse an
* existing stripe:
*/
while (1) {
ret = __bch2_ec_stripe_head_reuse(trans, h);
if (!ret)
break;
if (waiting || !cl || ret != -BCH_ERR_stripe_alloc_blocked)
goto err;
if (watermark == BCH_WATERMARK_copygc) {
ret = new_stripe_alloc_buckets(trans, h, watermark, NULL) ?:
__bch2_ec_stripe_head_reserve(trans, h);
if (ret)
goto err;
goto allocate_buf;
}
/* XXX freelist_wait? */
closure_wait(&c->freelist_wait, cl);
waiting = true;
}
if (waiting)
closure_wake_up(&c->freelist_wait);
alloc_existing:
/*
* Retry allocating buckets, with the watermark for this
* particular write:
*/
ret = new_stripe_alloc_buckets(trans, h, watermark, cl);
if (ret)
goto err;
allocate_buf:
ret = ec_stripe_buf_init(&h->s->new_stripe, 0, h->blocksize);
if (ret)
goto err;
h->s->allocated = true;
allocated:
BUG_ON(!h->s->idx);
BUG_ON(!h->s->new_stripe.data[0]);
BUG_ON(trans->restarted);
return h;
err:
bch2_ec_stripe_head_put(c, h);
return ERR_PTR(ret);
}
static void __bch2_ec_stop(struct bch_fs *c, struct bch_dev *ca)
{
struct ec_stripe_head *h;
struct open_bucket *ob;
unsigned i;
mutex_lock(&c->ec_stripe_head_lock);
list_for_each_entry(h, &c->ec_stripe_head_list, list) {
mutex_lock(&h->lock);
if (!h->s)
goto unlock;
if (!ca)
goto found;
for (i = 0; i < bkey_i_to_stripe(&h->s->new_stripe.key)->v.nr_blocks; i++) {
if (!h->s->blocks[i])
continue;
ob = c->open_buckets + h->s->blocks[i];
if (ob->dev == ca->dev_idx)
goto found;
}
goto unlock;
found:
h->s->err = -BCH_ERR_erofs_no_writes;
ec_stripe_set_pending(c, h);
unlock:
mutex_unlock(&h->lock);
}
mutex_unlock(&c->ec_stripe_head_lock);
}
void bch2_ec_stop_dev(struct bch_fs *c, struct bch_dev *ca)
{
__bch2_ec_stop(c, ca);
}
void bch2_fs_ec_stop(struct bch_fs *c)
{
__bch2_ec_stop(c, NULL);
}
static bool bch2_fs_ec_flush_done(struct bch_fs *c)
{
bool ret;
mutex_lock(&c->ec_stripe_new_lock);
ret = list_empty(&c->ec_stripe_new_list);
mutex_unlock(&c->ec_stripe_new_lock);
return ret;
}
void bch2_fs_ec_flush(struct bch_fs *c)
{
wait_event(c->ec_stripe_new_wait, bch2_fs_ec_flush_done(c));
}
int bch2_stripes_read(struct bch_fs *c)
{
int ret = bch2_trans_run(c,
for_each_btree_key(trans, iter, BTREE_ID_stripes, POS_MIN,
BTREE_ITER_prefetch, k, ({
if (k.k->type != KEY_TYPE_stripe)
continue;
ret = __ec_stripe_mem_alloc(c, k.k->p.offset, GFP_KERNEL);
if (ret)
break;
const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
struct stripe *m = genradix_ptr(&c->stripes, k.k->p.offset);
m->sectors = le16_to_cpu(s->sectors);
m->algorithm = s->algorithm;
m->nr_blocks = s->nr_blocks;
m->nr_redundant = s->nr_redundant;
m->blocks_nonempty = 0;
for (unsigned i = 0; i < s->nr_blocks; i++)
m->blocks_nonempty += !!stripe_blockcount_get(s, i);
bch2_stripes_heap_insert(c, m, k.k->p.offset);
0;
})));
bch_err_fn(c, ret);
return ret;
}
void bch2_stripes_heap_to_text(struct printbuf *out, struct bch_fs *c)
{
ec_stripes_heap *h = &c->ec_stripes_heap;
struct stripe *m;
size_t i;
mutex_lock(&c->ec_stripes_heap_lock);
for (i = 0; i < min_t(size_t, h->nr, 50); i++) {
m = genradix_ptr(&c->stripes, h->data[i].idx);
prt_printf(out, "%zu %u/%u+%u", h->data[i].idx,
h->data[i].blocks_nonempty,
m->nr_blocks - m->nr_redundant,
m->nr_redundant);
if (bch2_stripe_is_open(c, h->data[i].idx))
prt_str(out, " open");
prt_newline(out);
}
mutex_unlock(&c->ec_stripes_heap_lock);
}
static void bch2_new_stripe_to_text(struct printbuf *out, struct bch_fs *c,
struct ec_stripe_new *s)
{
prt_printf(out, "\tidx %llu blocks %u+%u allocated %u ref %u %u %s obs",
s->idx, s->nr_data, s->nr_parity,
bitmap_weight(s->blocks_allocated, s->nr_data),
atomic_read(&s->ref[STRIPE_REF_io]),
atomic_read(&s->ref[STRIPE_REF_stripe]),
bch2_watermarks[s->h->watermark]);
struct bch_stripe *v = &bkey_i_to_stripe(&s->new_stripe.key)->v;
unsigned i;
for_each_set_bit(i, s->blocks_gotten, v->nr_blocks)
prt_printf(out, " %u", s->blocks[i]);
prt_newline(out);
}
void bch2_new_stripes_to_text(struct printbuf *out, struct bch_fs *c)
{
struct ec_stripe_head *h;
struct ec_stripe_new *s;
mutex_lock(&c->ec_stripe_head_lock);
list_for_each_entry(h, &c->ec_stripe_head_list, list) {
prt_printf(out, "target %u algo %u redundancy %u %s:\n",
h->target, h->algo, h->redundancy,
bch2_watermarks[h->watermark]);
if (h->s)
bch2_new_stripe_to_text(out, c, h->s);
}
mutex_unlock(&c->ec_stripe_head_lock);
prt_printf(out, "in flight:\n");
mutex_lock(&c->ec_stripe_new_lock);
list_for_each_entry(s, &c->ec_stripe_new_list, list)
bch2_new_stripe_to_text(out, c, s);
mutex_unlock(&c->ec_stripe_new_lock);
}
void bch2_fs_ec_exit(struct bch_fs *c)
{
struct ec_stripe_head *h;
unsigned i;
while (1) {
mutex_lock(&c->ec_stripe_head_lock);
h = list_first_entry_or_null(&c->ec_stripe_head_list,
struct ec_stripe_head, list);
if (h)
list_del(&h->list);
mutex_unlock(&c->ec_stripe_head_lock);
if (!h)
break;
if (h->s) {
for (i = 0; i < bkey_i_to_stripe(&h->s->new_stripe.key)->v.nr_blocks; i++)
BUG_ON(h->s->blocks[i]);
kfree(h->s);
}
kfree(h);
}
BUG_ON(!list_empty(&c->ec_stripe_new_list));
free_heap(&c->ec_stripes_heap);
genradix_free(&c->stripes);
bioset_exit(&c->ec_bioset);
}
void bch2_fs_ec_init_early(struct bch_fs *c)
{
spin_lock_init(&c->ec_stripes_new_lock);
mutex_init(&c->ec_stripes_heap_lock);
INIT_LIST_HEAD(&c->ec_stripe_head_list);
mutex_init(&c->ec_stripe_head_lock);
INIT_LIST_HEAD(&c->ec_stripe_new_list);
mutex_init(&c->ec_stripe_new_lock);
init_waitqueue_head(&c->ec_stripe_new_wait);
INIT_WORK(&c->ec_stripe_create_work, ec_stripe_create_work);
INIT_WORK(&c->ec_stripe_delete_work, ec_stripe_delete_work);
}
int bch2_fs_ec_init(struct bch_fs *c)
{
return bioset_init(&c->ec_bioset, 1, offsetof(struct ec_bio, bio),
BIOSET_NEED_BVECS);
}