From 92e1c29ae803f85d2f50b4450becb258acae4311 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Sat, 29 Jun 2024 18:32:01 -0400
Subject: [PATCH] bcachefs: bch2_btree_write_buffer_maybe_flush()
Add a new helper for checking references to write buffer btrees, where
we need a flush before we definitively know we have an inconsistency.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
fs/bcachefs/backpointers.c | 68 +++++++++++---------------------
fs/bcachefs/bkey.h | 7 ++++
fs/bcachefs/btree_write_buffer.c | 37 +++++++++++++++++
fs/bcachefs/btree_write_buffer.h | 3 ++
4 files changed, 71 insertions(+), 44 deletions(-)
diff --git a/fs/bcachefs/backpointers.c b/fs/bcachefs/backpointers.c
index 4321f9fb73bd9..e8037b5d8332e 100644
--- a/fs/bcachefs/backpointers.c
+++ b/fs/bcachefs/backpointers.c
@@ -434,13 +434,6 @@ int bch2_check_btree_backpointers(struct bch_fs *c)
return ret;
}
-static inline bool bkey_and_val_eq(struct bkey_s_c l, struct bkey_s_c r)
-{
- return bpos_eq(l.k->p, r.k->p) &&
- bkey_bytes(l.k) == bkey_bytes(r.k) &&
- !memcmp(l.v, r.v, bkey_val_bytes(l.k));
-}
-
struct extents_to_bp_state {
struct bpos bucket_start;
struct bpos bucket_end;
@@ -536,11 +529,8 @@ static int check_bp_exists(struct btree_trans *trans,
struct btree_iter other_extent_iter = {};
struct printbuf buf = PRINTBUF;
struct bkey_s_c bp_k;
- struct bkey_buf tmp;
int ret = 0;
- bch2_bkey_buf_init(&tmp);
-
struct bch_dev *ca = bch2_dev_bucket_tryget(c, bucket);
if (!ca) {
prt_str(&buf, "extent for nonexistent device:bucket ");
@@ -565,22 +555,9 @@ static int check_bp_exists(struct btree_trans *trans,
if (bp_k.k->type != KEY_TYPE_backpointer ||
memcmp(bkey_s_c_to_backpointer(bp_k).v, &bp, sizeof(bp))) {
- bch2_bkey_buf_reassemble(&tmp, c, orig_k);
-
- if (!bkey_and_val_eq(orig_k, bkey_i_to_s_c(s->last_flushed.k))) {
- if (bp.level) {
- bch2_trans_unlock(trans);
- bch2_btree_interior_updates_flush(c);
- }
-
- ret = bch2_btree_write_buffer_flush_sync(trans);
- if (ret)
- goto err;
-
- bch2_bkey_buf_copy(&s->last_flushed, c, tmp.k);
- ret = -BCH_ERR_transaction_restart_write_buffer_flush;
- goto out;
- }
+ ret = bch2_btree_write_buffer_maybe_flush(trans, orig_k, &s->last_flushed);
+ if (ret)
+ goto err;
goto check_existing_bp;
}
@@ -589,7 +566,6 @@ static int check_bp_exists(struct btree_trans *trans,
fsck_err:
bch2_trans_iter_exit(trans, &other_extent_iter);
bch2_trans_iter_exit(trans, &bp_iter);
- bch2_bkey_buf_exit(&tmp, c);
bch2_dev_put(ca);
printbuf_exit(&buf);
return ret;
@@ -905,7 +881,7 @@ 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 bkey_buf *last_flushed)
{
struct bch_fs *c = trans->c;
struct btree_iter iter;
@@ -925,20 +901,18 @@ static int check_one_backpointer(struct btree_trans *trans,
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 (!k.k) {
+ ret = bch2_btree_write_buffer_maybe_flush(trans, bp.s_c, last_flushed);
+ if (ret)
+ goto out;
- if (fsck_err_on(!k.k, c,
- backpointer_to_missing_ptr,
- "backpointer for missing %s\n %s",
- bp.v->level ? "btree node" : "extent",
- (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;
+ if (fsck_err(c, backpointer_to_missing_ptr,
+ "backpointer for missing %s\n %s",
+ bp.v->level ? "btree node" : "extent",
+ (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:
@@ -951,14 +925,20 @@ static int bch2_check_backpointers_to_extents_pass(struct btree_trans *trans,
struct bbpos start,
struct bbpos end)
{
- struct bpos last_flushed_pos = SPOS_MAX;
+ struct bkey_buf last_flushed;
- return for_each_btree_key_commit(trans, iter, BTREE_ID_backpointers,
+ bch2_bkey_buf_init(&last_flushed);
+ bkey_init(&last_flushed.k->k);
+
+ int ret = for_each_btree_key_commit(trans, iter, BTREE_ID_backpointers,
POS_MIN, BTREE_ITER_prefetch, k,
NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
check_one_backpointer(trans, start, end,
bkey_s_c_to_backpointer(k),
- &last_flushed_pos));
+ &last_flushed));
+
+ bch2_bkey_buf_exit(&last_flushed, trans->c);
+ return ret;
}
int bch2_check_backpointers_to_extents(struct bch_fs *c)
diff --git a/fs/bcachefs/bkey.h b/fs/bcachefs/bkey.h
index fcd43915df079..936357149cf0f 100644
--- a/fs/bcachefs/bkey.h
+++ b/fs/bcachefs/bkey.h
@@ -194,6 +194,13 @@ static inline struct bpos bkey_max(struct bpos l, struct bpos r)
return bkey_gt(l, r) ? l : r;
}
+static inline bool bkey_and_val_eq(struct bkey_s_c l, struct bkey_s_c r)
+{
+ return bpos_eq(l.k->p, r.k->p) &&
+ bkey_bytes(l.k) == bkey_bytes(r.k) &&
+ !memcmp(l.v, r.v, bkey_val_bytes(l.k));
+}
+
void bch2_bpos_swab(struct bpos *);
void bch2_bkey_swab_key(const struct bkey_format *, struct bkey_packed *);
diff --git a/fs/bcachefs/btree_write_buffer.c b/fs/bcachefs/btree_write_buffer.c
index 75c8a196b3f63..d0e92d948002d 100644
--- a/fs/bcachefs/btree_write_buffer.c
+++ b/fs/bcachefs/btree_write_buffer.c
@@ -1,11 +1,13 @@
// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
+#include "bkey_buf.h"
#include "btree_locking.h"
#include "btree_update.h"
#include "btree_update_interior.h"
#include "btree_write_buffer.h"
#include "error.h"
+#include "extents.h"
#include "journal.h"
#include "journal_io.h"
#include "journal_reclaim.h"
@@ -492,6 +494,41 @@ int bch2_btree_write_buffer_tryflush(struct btree_trans *trans)
return ret;
}
+/**
+ * In check and repair code, when checking references to write buffer btrees we
+ * need to issue a flush before we have a definitive error: this issues a flush
+ * if this is a key we haven't yet checked.
+ */
+int bch2_btree_write_buffer_maybe_flush(struct btree_trans *trans,
+ struct bkey_s_c referring_k,
+ struct bkey_buf *last_flushed)
+{
+ struct bch_fs *c = trans->c;
+ struct bkey_buf tmp;
+ int ret = 0;
+
+ bch2_bkey_buf_init(&tmp);
+
+ if (!bkey_and_val_eq(referring_k, bkey_i_to_s_c(last_flushed->k))) {
+ bch2_bkey_buf_reassemble(&tmp, c, referring_k);
+
+ if (bkey_is_btree_ptr(referring_k.k)) {
+ bch2_trans_unlock(trans);
+ bch2_btree_interior_updates_flush(c);
+ }
+
+ ret = bch2_btree_write_buffer_flush_sync(trans);
+ if (ret)
+ goto err;
+
+ bch2_bkey_buf_copy(last_flushed, c, tmp.k);
+ ret = -BCH_ERR_transaction_restart_write_buffer_flush;
+ }
+err:
+ bch2_bkey_buf_exit(&tmp, c);
+ return ret;
+}
+
static void bch2_btree_write_buffer_flush_work(struct work_struct *work)
{
struct bch_fs *c = container_of(work, struct bch_fs, btree_write_buffer.flush_work);
diff --git a/fs/bcachefs/btree_write_buffer.h b/fs/bcachefs/btree_write_buffer.h
index eebcd2b15249a..dd5e64218b50f 100644
--- a/fs/bcachefs/btree_write_buffer.h
+++ b/fs/bcachefs/btree_write_buffer.h
@@ -23,6 +23,9 @@ int bch2_btree_write_buffer_flush_sync(struct btree_trans *);
int bch2_btree_write_buffer_flush_nocheck_rw(struct btree_trans *);
int bch2_btree_write_buffer_tryflush(struct btree_trans *);
+struct bkey_buf;
+int bch2_btree_write_buffer_maybe_flush(struct btree_trans *, struct bkey_s_c, struct bkey_buf *);
+
struct journal_keys_to_wb {
struct btree_write_buffer_keys *wb;
size_t room;
--
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