linux/fs/xfs/libxfs/xfs_btree_mem.c

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2021-2024 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <[email protected]>
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_trans.h"
#include "xfs_btree.h"
#include "xfs_error.h"
#include "xfs_buf_mem.h"
#include "xfs_btree_mem.h"
#include "xfs_ag.h"
#include "xfs_buf_item.h"
#include "xfs_trace.h"

/* Set the root of an in-memory btree. */
void
xfbtree_set_root(
	struct xfs_btree_cur		*cur,
	const union xfs_btree_ptr	*ptr,
	int				inc)
{ … }

/* Initialize a pointer from the in-memory btree header. */
void
xfbtree_init_ptr_from_cur(
	struct xfs_btree_cur		*cur,
	union xfs_btree_ptr		*ptr)
{ … }

/* Duplicate an in-memory btree cursor. */
struct xfs_btree_cur *
xfbtree_dup_cursor(
	struct xfs_btree_cur		*cur)
{ … }

/* Close the btree xfile and release all resources. */
void
xfbtree_destroy(
	struct xfbtree		*xfbt)
{ … }

/* Compute the number of bytes available for records. */
static inline unsigned int
xfbtree_rec_bytes(
	struct xfs_mount		*mp,
	const struct xfs_btree_ops	*ops)
{ … }

/* Initialize an empty leaf block as the btree root. */
STATIC int
xfbtree_init_leaf_block(
	struct xfs_mount		*mp,
	struct xfbtree			*xfbt,
	const struct xfs_btree_ops	*ops)
{ … }

/*
 * Create an in-memory btree root that can be used with the given xmbuf.
 * Callers must set xfbt->owner.
 */
int
xfbtree_init(
	struct xfs_mount		*mp,
	struct xfbtree			*xfbt,
	struct xfs_buftarg		*btp,
	const struct xfs_btree_ops	*ops)
{ … }

/* Allocate a block to our in-memory btree. */
int
xfbtree_alloc_block(
	struct xfs_btree_cur		*cur,
	const union xfs_btree_ptr	*start,
	union xfs_btree_ptr		*new,
	int				*stat)
{ … }

/* Free a block from our in-memory btree. */
int
xfbtree_free_block(
	struct xfs_btree_cur	*cur,
	struct xfs_buf		*bp)
{ … }

/* Return the minimum number of records for a btree block. */
int
xfbtree_get_minrecs(
	struct xfs_btree_cur	*cur,
	int			level)
{ … }

/* Return the maximum number of records for a btree block. */
int
xfbtree_get_maxrecs(
	struct xfs_btree_cur	*cur,
	int			level)
{ … }

/* If this log item is a buffer item that came from the xfbtree, return it. */
static inline struct xfs_buf *
xfbtree_buf_match(
	struct xfbtree			*xfbt,
	const struct xfs_log_item	*lip)
{ … }

/*
 * Commit changes to the incore btree immediately by writing all dirty xfbtree
 * buffers to the backing xfile.  This detaches all xfbtree buffers from the
 * transaction, even on failure.  The buffer locks are dropped between the
 * delwri queue and submit, so the caller must synchronize btree access.
 *
 * Normally we'd let the buffers commit with the transaction and get written to
 * the xfile via the log, but online repair stages ephemeral btrees in memory
 * and uses the btree_staging functions to write new btrees to disk atomically.
 * The in-memory btree (and its backing store) are discarded at the end of the
 * repair phase, which means that xfbtree buffers cannot commit with the rest
 * of a transaction.
 *
 * In other words, online repair only needs the transaction to collect buffer
 * pointers and to avoid buffer deadlocks, not to guarantee consistency of
 * updates.
 */
int
xfbtree_trans_commit(
	struct xfbtree		*xfbt,
	struct xfs_trans	*tp)
{ … }

/*
 * Cancel changes to the incore btree by detaching all the xfbtree buffers.
 * Changes are not undone, so callers must not access the btree ever again.
 */
void
xfbtree_trans_cancel(
	struct xfbtree		*xfbt,
	struct xfs_trans	*tp)
{ … }