Commit 92e1c29a authored by Kent Overstreet's avatar Kent Overstreet
Browse files

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: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent ef05bdf5

fs/bcachefs/backpointers.c

+24 −44
Original line number Diff line number Diff line
@@ -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 ");
@@ -565,23 +555,10 @@ 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);

		ret = bch2_btree_write_buffer_maybe_flush(trans, orig_k, &s->last_flushed);

		if (ret)

			goto err;



			bch2_bkey_buf_copy(&s->last_flushed, c, tmp.k);

			ret = -BCH_ERR_transaction_restart_write_buffer_flush;

			goto out;

		}



		goto check_existing_bp;

	}

out:
@@ -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;
@@ -925,21 +901,19 @@ 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;

	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,

		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:

	bch2_trans_iter_exit(trans, &iter);
@@ -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;



	bch2_bkey_buf_init(&last_flushed);

	bkey_init(&last_flushed.k->k);



	return for_each_btree_key_commit(trans, iter, BTREE_ID_backpointers,

	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)

fs/bcachefs/bkey.h

+7 −0
Original line number Diff line number Diff line
@@ -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 *);

fs/bcachefs/btree_write_buffer.c

+37 −0
Original line number Diff line number Diff line 
// 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);

fs/bcachefs/btree_write_buffer.h

+3 −0
Original line number Diff line number Diff line
@@ -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;