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|
// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "bbpos.h"
#include "alloc_background.h"
#include "backpointers.h"
#include "btree_cache.h"
#include "btree_update.h"
#include "btree_write_buffer.h"
#include "error.h"
#include <linux/mm.h>
static bool extent_matches_bp(struct bch_fs *c,
enum btree_id btree_id, unsigned level,
struct bkey_s_c k,
struct bpos bucket,
struct bch_backpointer bp)
{
struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
const union bch_extent_entry *entry;
struct extent_ptr_decoded p;
bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
struct bpos bucket2;
struct bch_backpointer bp2;
if (p.ptr.cached)
continue;
bch2_extent_ptr_to_bp(c, btree_id, level, k, p,
&bucket2, &bp2);
if (bpos_eq(bucket, bucket2) &&
!memcmp(&bp, &bp2, sizeof(bp)))
return true;
}
return false;
}
int bch2_backpointer_invalid(const struct bch_fs *c, struct bkey_s_c k,
enum bkey_invalid_flags flags,
struct printbuf *err)
{
struct bkey_s_c_backpointer bp = bkey_s_c_to_backpointer(k);
struct bpos bucket = bp_pos_to_bucket(c, bp.k->p);
if (!bpos_eq(bp.k->p, bucket_pos_to_bp(c, bucket, bp.v->bucket_offset))) {
prt_str(err, "backpointer at wrong pos");
return -BCH_ERR_invalid_bkey;
}
return 0;
}
void bch2_backpointer_to_text(struct printbuf *out, const struct bch_backpointer *bp)
{
prt_printf(out, "btree=%s l=%u offset=%llu:%u len=%u pos=",
bch2_btree_ids[bp->btree_id],
bp->level,
(u64) (bp->bucket_offset >> MAX_EXTENT_COMPRESS_RATIO_SHIFT),
(u32) bp->bucket_offset & ~(~0U << MAX_EXTENT_COMPRESS_RATIO_SHIFT),
bp->bucket_len);
bch2_bpos_to_text(out, bp->pos);
}
void bch2_backpointer_k_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
{
prt_str(out, "bucket=");
bch2_bpos_to_text(out, bp_pos_to_bucket(c, k.k->p));
prt_str(out, " ");
bch2_backpointer_to_text(out, bkey_s_c_to_backpointer(k).v);
}
void bch2_backpointer_swab(struct bkey_s k)
{
struct bkey_s_backpointer bp = bkey_s_to_backpointer(k);
bp.v->bucket_offset = swab32(bp.v->bucket_offset);
bp.v->bucket_len = swab32(bp.v->bucket_len);
bch2_bpos_swab(&bp.v->pos);
}
static noinline int backpointer_mod_err(struct btree_trans *trans,
struct bch_backpointer bp,
struct bkey_s_c bp_k,
struct bkey_s_c orig_k,
bool insert)
{
struct bch_fs *c = trans->c;
struct printbuf buf = PRINTBUF;
if (insert) {
prt_printf(&buf, "existing backpointer found when inserting ");
bch2_backpointer_to_text(&buf, &bp);
prt_newline(&buf);
printbuf_indent_add(&buf, 2);
prt_printf(&buf, "found ");
bch2_bkey_val_to_text(&buf, c, bp_k);
prt_newline(&buf);
prt_printf(&buf, "for ");
bch2_bkey_val_to_text(&buf, c, orig_k);
bch_err(c, "%s", buf.buf);
} else if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_extents_to_backpointers) {
prt_printf(&buf, "backpointer not found when deleting");
prt_newline(&buf);
printbuf_indent_add(&buf, 2);
prt_printf(&buf, "searching for ");
bch2_backpointer_to_text(&buf, &bp);
prt_newline(&buf);
prt_printf(&buf, "got ");
bch2_bkey_val_to_text(&buf, c, bp_k);
prt_newline(&buf);
prt_printf(&buf, "for ");
bch2_bkey_val_to_text(&buf, c, orig_k);
bch_err(c, "%s", buf.buf);
}
printbuf_exit(&buf);
if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_extents_to_backpointers) {
bch2_inconsistent_error(c);
return -EIO;
} else {
return 0;
}
}
int bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans *trans,
struct bpos bucket,
struct bch_backpointer bp,
struct bkey_s_c orig_k,
bool insert)
{
struct bch_fs *c = trans->c;
struct bkey_i_backpointer *bp_k;
struct btree_iter bp_iter;
struct bkey_s_c k;
int ret;
bp_k = bch2_trans_kmalloc_nomemzero(trans, sizeof(struct bkey_i_backpointer));
ret = PTR_ERR_OR_ZERO(bp_k);
if (ret)
return ret;
bkey_backpointer_init(&bp_k->k_i);
bp_k->k.p = bucket_pos_to_bp(c, bucket, bp.bucket_offset);
bp_k->v = bp;
if (!insert) {
bp_k->k.type = KEY_TYPE_deleted;
set_bkey_val_u64s(&bp_k->k, 0);
}
k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers,
bp_k->k.p,
BTREE_ITER_INTENT|
BTREE_ITER_SLOTS|
BTREE_ITER_WITH_UPDATES);
ret = bkey_err(k);
if (ret)
goto err;
if (insert
? k.k->type
: (k.k->type != KEY_TYPE_backpointer ||
memcmp(bkey_s_c_to_backpointer(k).v, &bp, sizeof(bp)))) {
ret = backpointer_mod_err(trans, bp, k, orig_k, insert);
if (ret)
goto err;
}
ret = bch2_trans_update(trans, &bp_iter, &bp_k->k_i, 0);
err:
bch2_trans_iter_exit(trans, &bp_iter);
return ret;
}
/*
* Find the next backpointer >= *bp_offset:
*/
int bch2_get_next_backpointer(struct btree_trans *trans,
struct bpos bucket, int gen,
struct bpos *bp_pos,
struct bch_backpointer *bp,
unsigned iter_flags)
{
struct bch_fs *c = trans->c;
struct bpos bp_end_pos = bucket_pos_to_bp(c, bpos_nosnap_successor(bucket), 0);
struct btree_iter alloc_iter = { NULL }, bp_iter = { NULL };
struct bkey_s_c k;
int ret = 0;
if (bpos_ge(*bp_pos, bp_end_pos))
goto done;
if (gen >= 0) {
k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc,
bucket, BTREE_ITER_CACHED|iter_flags);
ret = bkey_err(k);
if (ret)
goto out;
if (k.k->type != KEY_TYPE_alloc_v4 ||
bkey_s_c_to_alloc_v4(k).v->gen != gen)
goto done;
}
*bp_pos = bpos_max(*bp_pos, bucket_pos_to_bp(c, bucket, 0));
for_each_btree_key_norestart(trans, bp_iter, BTREE_ID_backpointers,
*bp_pos, iter_flags, k, ret) {
if (bpos_ge(k.k->p, bp_end_pos))
break;
*bp_pos = k.k->p;
*bp = *bkey_s_c_to_backpointer(k).v;
goto out;
}
done:
*bp_pos = SPOS_MAX;
out:
bch2_trans_iter_exit(trans, &bp_iter);
bch2_trans_iter_exit(trans, &alloc_iter);
return ret;
}
static void backpointer_not_found(struct btree_trans *trans,
struct bpos bp_pos,
struct bch_backpointer bp,
struct bkey_s_c k,
const char *thing_it_points_to)
{
struct bch_fs *c = trans->c;
struct printbuf buf = PRINTBUF;
struct bpos bucket = bp_pos_to_bucket(c, bp_pos);
if (likely(!bch2_backpointers_no_use_write_buffer))
return;
prt_printf(&buf, "backpointer doesn't match %s it points to:\n ",
thing_it_points_to);
prt_printf(&buf, "bucket: ");
bch2_bpos_to_text(&buf, bucket);
prt_printf(&buf, "\n ");
prt_printf(&buf, "backpointer pos: ");
bch2_bpos_to_text(&buf, bp_pos);
prt_printf(&buf, "\n ");
bch2_backpointer_to_text(&buf, &bp);
prt_printf(&buf, "\n ");
bch2_bkey_val_to_text(&buf, c, k);
if (c->curr_recovery_pass >= BCH_RECOVERY_PASS_check_extents_to_backpointers)
bch_err_ratelimited(c, "%s", buf.buf);
else
bch2_trans_inconsistent(trans, "%s", buf.buf);
printbuf_exit(&buf);
}
struct bkey_s_c bch2_backpointer_get_key(struct btree_trans *trans,
struct btree_iter *iter,
struct bpos bp_pos,
struct bch_backpointer bp,
unsigned iter_flags)
{
struct bch_fs *c = trans->c;
struct btree_root *r = bch2_btree_id_root(c, bp.btree_id);
struct bpos bucket = bp_pos_to_bucket(c, bp_pos);
struct bkey_s_c k;
bch2_trans_node_iter_init(trans, iter,
bp.btree_id,
bp.pos,
0,
min(bp.level, r->level),
iter_flags);
k = bch2_btree_iter_peek_slot(iter);
if (bkey_err(k)) {
bch2_trans_iter_exit(trans, iter);
return k;
}
if (bp.level == r->level + 1)
k = bkey_i_to_s_c(&r->key);
if (k.k && extent_matches_bp(c, bp.btree_id, bp.level, k, bucket, bp))
return k;
bch2_trans_iter_exit(trans, iter);
if (unlikely(bch2_backpointers_no_use_write_buffer)) {
if (bp.level) {
struct btree *b;
/*
* If a backpointer for a btree node wasn't found, it may be
* because it was overwritten by a new btree node that hasn't
* been written out yet - backpointer_get_node() checks for
* this:
*/
b = bch2_backpointer_get_node(trans, iter, bp_pos, bp);
if (!IS_ERR_OR_NULL(b))
return bkey_i_to_s_c(&b->key);
bch2_trans_iter_exit(trans, iter);
if (IS_ERR(b))
return bkey_s_c_err(PTR_ERR(b));
return bkey_s_c_null;
}
backpointer_not_found(trans, bp_pos, bp, k, "extent");
}
return bkey_s_c_null;
}
struct btree *bch2_backpointer_get_node(struct btree_trans *trans,
struct btree_iter *iter,
struct bpos bp_pos,
struct bch_backpointer bp)
{
struct bch_fs *c = trans->c;
struct bpos bucket = bp_pos_to_bucket(c, bp_pos);
struct btree *b;
BUG_ON(!bp.level);
bch2_trans_node_iter_init(trans, iter,
bp.btree_id,
bp.pos,
0,
bp.level - 1,
0);
b = bch2_btree_iter_peek_node(iter);
if (IS_ERR(b))
goto err;
if (b && extent_matches_bp(c, bp.btree_id, bp.level,
bkey_i_to_s_c(&b->key),
bucket, bp))
return b;
if (b && btree_node_will_make_reachable(b)) {
b = ERR_PTR(-BCH_ERR_backpointer_to_overwritten_btree_node);
} else {
backpointer_not_found(trans, bp_pos, bp,
bkey_i_to_s_c(&b->key), "btree node");
b = NULL;
}
err:
bch2_trans_iter_exit(trans, iter);
return b;
}
static int bch2_check_btree_backpointer(struct btree_trans *trans, struct btree_iter *bp_iter,
struct bkey_s_c k)
{
struct bch_fs *c = trans->c;
struct btree_iter alloc_iter = { NULL };
struct bch_dev *ca;
struct bkey_s_c alloc_k;
struct printbuf buf = PRINTBUF;
int ret = 0;
if (fsck_err_on(!bch2_dev_exists2(c, k.k->p.inode), c,
"backpointer for mising device:\n%s",
(bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
ret = bch2_btree_delete_at(trans, bp_iter, 0);
goto out;
}
ca = bch_dev_bkey_exists(c, k.k->p.inode);
alloc_k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc,
bp_pos_to_bucket(c, k.k->p), 0);
ret = bkey_err(alloc_k);
if (ret)
goto out;
if (fsck_err_on(alloc_k.k->type != KEY_TYPE_alloc_v4, c,
"backpointer for nonexistent alloc key: %llu:%llu:0\n%s",
alloc_iter.pos.inode, alloc_iter.pos.offset,
(bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) {
ret = bch2_btree_delete_at(trans, bp_iter, 0);
goto out;
}
out:
fsck_err:
bch2_trans_iter_exit(trans, &alloc_iter);
printbuf_exit(&buf);
return ret;
}
/* verify that every backpointer has a corresponding alloc key */
int bch2_check_btree_backpointers(struct bch_fs *c)
{
struct btree_iter iter;
struct bkey_s_c k;
int ret;
ret = bch2_trans_run(c,
for_each_btree_key_commit(&trans, iter,
BTREE_ID_backpointers, POS_MIN, 0, k,
NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL,
bch2_check_btree_backpointer(&trans, &iter, k)));
if (ret)
bch_err_fn(c, ret);
return ret;
}
struct bpos_level {
unsigned level;
struct bpos pos;
};
static int check_bp_exists(struct btree_trans *trans,
struct bpos bucket,
struct bch_backpointer bp,
struct bkey_s_c orig_k,
struct bpos bucket_start,
struct bpos bucket_end,
struct bpos_level *last_flushed)
{
struct bch_fs *c = trans->c;
struct btree_iter bp_iter = { NULL };
struct printbuf buf = PRINTBUF;
struct bkey_s_c bp_k;
int ret;
if (bpos_lt(bucket, bucket_start) ||
bpos_gt(bucket, bucket_end))
return 0;
if (!bch2_dev_bucket_exists(c, bucket))
goto missing;
bp_k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers,
bucket_pos_to_bp(c, bucket, bp.bucket_offset),
0);
ret = bkey_err(bp_k);
if (ret)
goto err;
if (bp_k.k->type != KEY_TYPE_backpointer ||
memcmp(bkey_s_c_to_backpointer(bp_k).v, &bp, sizeof(bp))) {
if (last_flushed->level != bp.level ||
!bpos_eq(last_flushed->pos, orig_k.k->p)) {
last_flushed->level = bp.level;
last_flushed->pos = orig_k.k->p;
ret = bch2_btree_write_buffer_flush_sync(trans) ?:
-BCH_ERR_transaction_restart_write_buffer_flush;
goto out;
}
goto missing;
}
out:
err:
fsck_err:
bch2_trans_iter_exit(trans, &bp_iter);
printbuf_exit(&buf);
return ret;
missing:
prt_printf(&buf, "missing backpointer for btree=%s l=%u ",
bch2_btree_ids[bp.btree_id], bp.level);
bch2_bkey_val_to_text(&buf, c, orig_k);
prt_printf(&buf, "\nbp pos ");
bch2_bpos_to_text(&buf, bp_iter.pos);
if (c->sb.version < bcachefs_metadata_version_backpointers ||
c->opts.reconstruct_alloc ||
fsck_err(c, "%s", buf.buf))
ret = bch2_bucket_backpointer_mod(trans, bucket, bp, orig_k, true);
goto out;
}
static int check_extent_to_backpointers(struct btree_trans *trans,
struct btree_iter *iter,
struct bpos bucket_start,
struct bpos bucket_end,
struct bpos_level *last_flushed)
{
struct bch_fs *c = trans->c;
struct bkey_ptrs_c ptrs;
const union bch_extent_entry *entry;
struct extent_ptr_decoded p;
struct bkey_s_c k;
int ret;
k = bch2_btree_iter_peek_all_levels(iter);
ret = bkey_err(k);
if (ret)
return ret;
if (!k.k)
return 0;
ptrs = bch2_bkey_ptrs_c(k);
bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
struct bpos bucket_pos;
struct bch_backpointer bp;
if (p.ptr.cached)
continue;
bch2_extent_ptr_to_bp(c, iter->btree_id, iter->path->level,
k, p, &bucket_pos, &bp);
ret = check_bp_exists(trans, bucket_pos, bp, k,
bucket_start, bucket_end,
last_flushed);
if (ret)
return ret;
}
return 0;
}
static int check_btree_root_to_backpointers(struct btree_trans *trans,
enum btree_id btree_id,
struct bpos bucket_start,
struct bpos bucket_end,
struct bpos_level *last_flushed)
{
struct bch_fs *c = trans->c;
struct btree_root *r = bch2_btree_id_root(c, btree_id);
struct btree_iter iter;
struct btree *b;
struct bkey_s_c k;
struct bkey_ptrs_c ptrs;
struct extent_ptr_decoded p;
const union bch_extent_entry *entry;
int ret;
bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0, r->level, 0);
b = bch2_btree_iter_peek_node(&iter);
ret = PTR_ERR_OR_ZERO(b);
if (ret)
goto err;
BUG_ON(b != btree_node_root(c, b));
k = bkey_i_to_s_c(&b->key);
ptrs = bch2_bkey_ptrs_c(k);
bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
struct bpos bucket_pos;
struct bch_backpointer bp;
if (p.ptr.cached)
continue;
bch2_extent_ptr_to_bp(c, iter.btree_id, b->c.level + 1,
k, p, &bucket_pos, &bp);
ret = check_bp_exists(trans, bucket_pos, bp, k,
bucket_start, bucket_end,
last_flushed);
if (ret)
goto err;
}
err:
bch2_trans_iter_exit(trans, &iter);
return ret;
}
static inline struct bbpos bp_to_bbpos(struct bch_backpointer bp)
{
return (struct bbpos) {
.btree = bp.btree_id,
.pos = bp.pos,
};
}
static size_t btree_nodes_fit_in_ram(struct bch_fs *c)
{
struct sysinfo i;
u64 mem_bytes;
si_meminfo(&i);
mem_bytes = i.totalram * i.mem_unit;
return div_u64(mem_bytes >> 1, btree_bytes(c));
}
static int bch2_get_btree_in_memory_pos(struct btree_trans *trans,
unsigned btree_leaf_mask,
unsigned btree_interior_mask,
struct bbpos start, struct bbpos *end)
{
struct btree_iter iter;
struct bkey_s_c k;
size_t btree_nodes = btree_nodes_fit_in_ram(trans->c);
enum btree_id btree;
int ret = 0;
for (btree = start.btree; btree < BTREE_ID_NR && !ret; btree++) {
unsigned depth = ((1U << btree) & btree_leaf_mask) ? 1 : 2;
if (!((1U << btree) & btree_leaf_mask) &&
!((1U << btree) & btree_interior_mask))
continue;
bch2_trans_node_iter_init(trans, &iter, btree,
btree == start.btree ? start.pos : POS_MIN,
0, depth, 0);
/*
* for_each_btree_key_contineu() doesn't check the return value
* from bch2_btree_iter_advance(), which is needed when
* iterating over interior nodes where we'll see keys at
* SPOS_MAX:
*/
do {
k = __bch2_btree_iter_peek_and_restart(trans, &iter, 0);
ret = bkey_err(k);
if (!k.k || ret)
break;
--btree_nodes;
if (!btree_nodes) {
*end = BBPOS(btree, k.k->p);
bch2_trans_iter_exit(trans, &iter);
return 0;
}
} while (bch2_btree_iter_advance(&iter));
bch2_trans_iter_exit(trans, &iter);
}
*end = BBPOS_MAX;
return ret;
}
static int bch2_check_extents_to_backpointers_pass(struct btree_trans *trans,
struct bpos bucket_start,
struct bpos bucket_end)
{
struct bch_fs *c = trans->c;
struct btree_iter iter;
enum btree_id btree_id;
struct bpos_level last_flushed = { UINT_MAX };
int ret = 0;
for (btree_id = 0; btree_id < btree_id_nr_alive(c); btree_id++) {
unsigned depth = btree_type_has_ptrs(btree_id) ? 0 : 1;
bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0,
depth,
BTREE_ITER_ALL_LEVELS|
BTREE_ITER_PREFETCH);
do {
ret = commit_do(trans, NULL, NULL,
BTREE_INSERT_LAZY_RW|
BTREE_INSERT_NOFAIL,
check_extent_to_backpointers(trans, &iter,
bucket_start, bucket_end,
&last_flushed));
if (ret)
break;
} while (!bch2_btree_iter_advance(&iter));
bch2_trans_iter_exit(trans, &iter);
if (ret)
break;
ret = commit_do(trans, NULL, NULL,
BTREE_INSERT_LAZY_RW|
BTREE_INSERT_NOFAIL,
check_btree_root_to_backpointers(trans, btree_id,
bucket_start, bucket_end,
&last_flushed));
if (ret)
break;
}
return ret;
}
static struct bpos bucket_pos_to_bp_safe(const struct bch_fs *c,
struct bpos bucket)
{
return bch2_dev_exists2(c, bucket.inode)
? bucket_pos_to_bp(c, bucket, 0)
: bucket;
}
static int bch2_get_alloc_in_memory_pos(struct btree_trans *trans,
struct bpos start, struct bpos *end)
{
struct btree_iter alloc_iter;
struct btree_iter bp_iter;
struct bkey_s_c alloc_k, bp_k;
size_t btree_nodes = btree_nodes_fit_in_ram(trans->c);
bool alloc_end = false, bp_end = false;
int ret = 0;
bch2_trans_node_iter_init(trans, &alloc_iter, BTREE_ID_alloc,
start, 0, 1, 0);
bch2_trans_node_iter_init(trans, &bp_iter, BTREE_ID_backpointers,
bucket_pos_to_bp_safe(trans->c, start), 0, 1, 0);
while (1) {
alloc_k = !alloc_end
? __bch2_btree_iter_peek_and_restart(trans, &alloc_iter, 0)
: bkey_s_c_null;
bp_k = !bp_end
? __bch2_btree_iter_peek_and_restart(trans, &bp_iter, 0)
: bkey_s_c_null;
ret = bkey_err(alloc_k) ?: bkey_err(bp_k);
if ((!alloc_k.k && !bp_k.k) || ret) {
*end = SPOS_MAX;
break;
}
--btree_nodes;
if (!btree_nodes) {
*end = alloc_k.k->p;
break;
}
if (bpos_lt(alloc_iter.pos, SPOS_MAX) &&
bpos_lt(bucket_pos_to_bp_safe(trans->c, alloc_iter.pos), bp_iter.pos)) {
if (!bch2_btree_iter_advance(&alloc_iter))
alloc_end = true;
} else {
if (!bch2_btree_iter_advance(&bp_iter))
bp_end = true;
}
}
bch2_trans_iter_exit(trans, &bp_iter);
bch2_trans_iter_exit(trans, &alloc_iter);
return ret;
}
int bch2_check_extents_to_backpointers(struct bch_fs *c)
{
struct btree_trans trans;
struct bpos start = POS_MIN, end;
int ret;
bch2_trans_init(&trans, c, 0, 0);
while (1) {
ret = bch2_get_alloc_in_memory_pos(&trans, start, &end);
if (ret)
break;
if (bpos_eq(start, POS_MIN) && !bpos_eq(end, SPOS_MAX))
bch_verbose(c, "%s(): alloc info does not fit in ram, running in multiple passes with %zu nodes per pass",
__func__, btree_nodes_fit_in_ram(c));
if (!bpos_eq(start, POS_MIN) || !bpos_eq(end, SPOS_MAX)) {
struct printbuf buf = PRINTBUF;
prt_str(&buf, "check_extents_to_backpointers(): ");
bch2_bpos_to_text(&buf, start);
prt_str(&buf, "-");
bch2_bpos_to_text(&buf, end);
bch_verbose(c, "%s", buf.buf);
printbuf_exit(&buf);
}
ret = bch2_check_extents_to_backpointers_pass(&trans, start, end);
if (ret || bpos_eq(end, SPOS_MAX))
break;
start = bpos_successor(end);
}
bch2_trans_exit(&trans);
if (ret)
bch_err_fn(c, ret);
return ret;
}
static int check_one_backpointer(struct btree_trans *trans,
struct bbpos start,
struct bbpos end,
struct bkey_s_c_backpointer bp,
struct bpos *last_flushed_pos)
{
struct bch_fs *c = trans->c;
struct btree_iter iter;
struct bbpos pos = bp_to_bbpos(*bp.v);
struct bkey_s_c k;
struct printbuf buf = PRINTBUF;
int ret;
if (bbpos_cmp(pos, start) < 0 ||
bbpos_cmp(pos, end) > 0)
return 0;
k = bch2_backpointer_get_key(trans, &iter, bp.k->p, *bp.v, 0);
ret = bkey_err(k);
if (ret == -BCH_ERR_backpointer_to_overwritten_btree_node)
return 0;
if (ret)
return ret;
if (!k.k && !bpos_eq(*last_flushed_pos, bp.k->p)) {
*last_flushed_pos = bp.k->p;
ret = bch2_btree_write_buffer_flush_sync(trans) ?:
-BCH_ERR_transaction_restart_write_buffer_flush;
goto out;
}
if (fsck_err_on(!k.k, c,
"backpointer for missing extent\n %s",
(bch2_bkey_val_to_text(&buf, c, bp.s_c), buf.buf))) {
ret = bch2_btree_delete_at_buffered(trans, BTREE_ID_backpointers, bp.k->p);
goto out;
}
out:
fsck_err:
bch2_trans_iter_exit(trans, &iter);
printbuf_exit(&buf);
return ret;
}
static int bch2_check_backpointers_to_extents_pass(struct btree_trans *trans,
struct bbpos start,
struct bbpos end)
{
struct btree_iter iter;
struct bkey_s_c k;
struct bpos last_flushed_pos = SPOS_MAX;
return for_each_btree_key_commit(trans, iter, BTREE_ID_backpointers,
POS_MIN, BTREE_ITER_PREFETCH, k,
NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL,
check_one_backpointer(trans, start, end,
bkey_s_c_to_backpointer(k),
&last_flushed_pos));
}
int bch2_check_backpointers_to_extents(struct bch_fs *c)
{
struct btree_trans trans;
struct bbpos start = (struct bbpos) { .btree = 0, .pos = POS_MIN, }, end;
int ret;
bch2_trans_init(&trans, c, 0, 0);
while (1) {
ret = bch2_get_btree_in_memory_pos(&trans,
(1U << BTREE_ID_extents)|
(1U << BTREE_ID_reflink),
~0,
start, &end);
if (ret)
break;
if (!bbpos_cmp(start, BBPOS_MIN) &&
bbpos_cmp(end, BBPOS_MAX))
bch_verbose(c, "%s(): extents do not fit in ram, running in multiple passes with %zu nodes per pass",
__func__, btree_nodes_fit_in_ram(c));
if (bbpos_cmp(start, BBPOS_MIN) ||
bbpos_cmp(end, BBPOS_MAX)) {
struct printbuf buf = PRINTBUF;
prt_str(&buf, "check_backpointers_to_extents(): ");
bch2_bbpos_to_text(&buf, start);
prt_str(&buf, "-");
bch2_bbpos_to_text(&buf, end);
bch_verbose(c, "%s", buf.buf);
printbuf_exit(&buf);
}
ret = bch2_check_backpointers_to_extents_pass(&trans, start, end);
if (ret || !bbpos_cmp(end, BBPOS_MAX))
break;
start = bbpos_successor(end);
}
bch2_trans_exit(&trans);
if (ret)
bch_err_fn(c, ret);
return ret;
}
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