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linux/fs/bcachefs/lru.c
Kent Overstreet 260af1562e bcachefs: Kill alloc_v4.fragmentation_lru
The fragmentation_lru field hasn't been needed since we reworked the LRU
btrees to use the btree write buffer; previously it was used to resolve
collisions, but the revised LRU btree uses the backpointer (the bucket)
as part of the key.

It should have been deleted at the time of the LRU rework; since it
wasn't, that left places for bugs to hide, in check/repair.

This fixes LRU fsck on a filesystem image helpfully provided by a user
who disappeared before I could get his name for the reported-by.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-10-04 20:25:32 -04:00

203 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "alloc_background.h"
#include "bkey_buf.h"
#include "btree_iter.h"
#include "btree_update.h"
#include "btree_write_buffer.h"
#include "error.h"
#include "lru.h"
#include "recovery.h"
/* KEY_TYPE_lru is obsolete: */
int bch2_lru_validate(struct bch_fs *c, struct bkey_s_c k,
enum bch_validate_flags flags)
{
int ret = 0;
bkey_fsck_err_on(!lru_pos_time(k.k->p),
c, lru_entry_at_time_0,
"lru entry at time=0");
fsck_err:
return ret;
}
void bch2_lru_to_text(struct printbuf *out, struct bch_fs *c,
struct bkey_s_c k)
{
const struct bch_lru *lru = bkey_s_c_to_lru(k).v;
prt_printf(out, "idx %llu", le64_to_cpu(lru->idx));
}
void bch2_lru_pos_to_text(struct printbuf *out, struct bpos lru)
{
prt_printf(out, "%llu:%llu -> %llu:%llu",
lru_pos_id(lru),
lru_pos_time(lru),
u64_to_bucket(lru.offset).inode,
u64_to_bucket(lru.offset).offset);
}
static int __bch2_lru_set(struct btree_trans *trans, u16 lru_id,
u64 dev_bucket, u64 time, bool set)
{
return time
? bch2_btree_bit_mod_buffered(trans, BTREE_ID_lru,
lru_pos(lru_id, dev_bucket, time), set)
: 0;
}
int bch2_lru_del(struct btree_trans *trans, u16 lru_id, u64 dev_bucket, u64 time)
{
return __bch2_lru_set(trans, lru_id, dev_bucket, time, KEY_TYPE_deleted);
}
int bch2_lru_set(struct btree_trans *trans, u16 lru_id, u64 dev_bucket, u64 time)
{
return __bch2_lru_set(trans, lru_id, dev_bucket, time, KEY_TYPE_set);
}
int bch2_lru_change(struct btree_trans *trans,
u16 lru_id, u64 dev_bucket,
u64 old_time, u64 new_time)
{
if (old_time == new_time)
return 0;
return bch2_lru_del(trans, lru_id, dev_bucket, old_time) ?:
bch2_lru_set(trans, lru_id, dev_bucket, new_time);
}
static const char * const bch2_lru_types[] = {
#define x(n) #n,
BCH_LRU_TYPES()
#undef x
NULL
};
int bch2_lru_check_set(struct btree_trans *trans,
u16 lru_id, u64 time,
struct bkey_s_c referring_k,
struct bkey_buf *last_flushed)
{
struct bch_fs *c = trans->c;
struct printbuf buf = PRINTBUF;
struct btree_iter lru_iter;
struct bkey_s_c lru_k =
bch2_bkey_get_iter(trans, &lru_iter, BTREE_ID_lru,
lru_pos(lru_id,
bucket_to_u64(referring_k.k->p),
time), 0);
int ret = bkey_err(lru_k);
if (ret)
return ret;
if (lru_k.k->type != KEY_TYPE_set) {
ret = bch2_btree_write_buffer_maybe_flush(trans, referring_k, last_flushed);
if (ret)
goto err;
if (fsck_err(trans, alloc_key_to_missing_lru_entry,
"missing %s lru entry\n"
" %s",
bch2_lru_types[lru_type(lru_k)],
(bch2_bkey_val_to_text(&buf, c, referring_k), buf.buf))) {
ret = bch2_lru_set(trans, lru_id, bucket_to_u64(referring_k.k->p), time);
if (ret)
goto err;
}
}
err:
fsck_err:
bch2_trans_iter_exit(trans, &lru_iter);
printbuf_exit(&buf);
return ret;
}
static int bch2_check_lru_key(struct btree_trans *trans,
struct btree_iter *lru_iter,
struct bkey_s_c lru_k,
struct bkey_buf *last_flushed)
{
struct bch_fs *c = trans->c;
struct btree_iter iter;
struct bkey_s_c k;
struct bch_alloc_v4 a_convert;
const struct bch_alloc_v4 *a;
struct printbuf buf1 = PRINTBUF;
struct printbuf buf2 = PRINTBUF;
enum bch_lru_type type = lru_type(lru_k);
struct bpos alloc_pos = u64_to_bucket(lru_k.k->p.offset);
u64 idx;
int ret;
struct bch_dev *ca = bch2_dev_bucket_tryget_noerror(c, alloc_pos);
if (fsck_err_on(!ca,
trans, lru_entry_to_invalid_bucket,
"lru key points to nonexistent device:bucket %llu:%llu",
alloc_pos.inode, alloc_pos.offset))
return bch2_btree_bit_mod_buffered(trans, BTREE_ID_lru, lru_iter->pos, false);
k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_alloc, alloc_pos, 0);
ret = bkey_err(k);
if (ret)
goto err;
a = bch2_alloc_to_v4(k, &a_convert);
switch (type) {
case BCH_LRU_read:
idx = alloc_lru_idx_read(*a);
break;
case BCH_LRU_fragmentation:
idx = alloc_lru_idx_fragmentation(*a, ca);
break;
}
if (lru_k.k->type != KEY_TYPE_set ||
lru_pos_time(lru_k.k->p) != idx) {
ret = bch2_btree_write_buffer_maybe_flush(trans, lru_k, last_flushed);
if (ret)
goto err;
if (fsck_err(trans, lru_entry_bad,
"incorrect lru entry: lru %s time %llu\n"
" %s\n"
" for %s",
bch2_lru_types[type],
lru_pos_time(lru_k.k->p),
(bch2_bkey_val_to_text(&buf1, c, lru_k), buf1.buf),
(bch2_bkey_val_to_text(&buf2, c, k), buf2.buf)))
ret = bch2_btree_bit_mod_buffered(trans, BTREE_ID_lru, lru_iter->pos, false);
}
err:
fsck_err:
bch2_trans_iter_exit(trans, &iter);
bch2_dev_put(ca);
printbuf_exit(&buf2);
printbuf_exit(&buf1);
return ret;
}
int bch2_check_lrus(struct bch_fs *c)
{
struct bkey_buf last_flushed;
bch2_bkey_buf_init(&last_flushed);
bkey_init(&last_flushed.k->k);
int ret = bch2_trans_run(c,
for_each_btree_key_commit(trans, iter,
BTREE_ID_lru, POS_MIN, BTREE_ITER_prefetch, k,
NULL, NULL, BCH_TRANS_COMMIT_no_enospc|BCH_TRANS_COMMIT_lazy_rw,
bch2_check_lru_key(trans, &iter, k, &last_flushed)));
bch2_bkey_buf_exit(&last_flushed, c);
bch_err_fn(c, ret);
return ret;
}